Merge pull request #1110 from Ryan-CW-Code/perf_gc

perf: gc might try to populate the lookahead buffer each time

.gitattributes

@@ -0,0 +1,4 @@
+# GitHub really wants to mark littlefs as a python project, telling it to
+# reclassify our test .toml files as C code (which they are 95% of anyways)
+# remedies this
+*.toml linguist-language=c

.github/workflows/post-release.yml

@@ -0,0 +1,31 @@
+name: post-release
+on:
+  release:
+    branches: [master]
+    types: [released]
+
+defaults:
+  run:
+    shell: bash -euv -o pipefail {0}
+
+jobs:
+  post-release:
+    runs-on: ubuntu-latest
+    steps:
+      # trigger post-release in dependency repo, this indirection allows the
+      # dependency repo to be updated often without affecting this repo. At
+      # the time of this comment, the dependency repo is responsible for
+      # creating PRs for other dependent repos post-release.
+      - name: trigger-post-release
+        continue-on-error: true
+        run: |
+          curl -sS -X POST -H "authorization: token ${{secrets.BOT_TOKEN}}" \
+            "$GITHUB_API_URL/repos/${{secrets.POST_RELEASE_REPO}}/dispatches" \
+            -d "$(jq -n '{
+              event_type: "post-release",
+              client_payload: {
+                repo: env.GITHUB_REPOSITORY,
+                version: "${{github.event.release.tag_name}}",
+              },
+            }' | tee /dev/stderr)"
+

.github/workflows/release.yml

@@ -0,0 +1,263 @@
+name: release
+on:
+  workflow_run:
+    workflows: [test]
+    branches: [master]
+    types: [completed]
+
+defaults:
+  run:
+    shell: bash -euv -o pipefail {0}
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+
+    # need to manually check for a couple things
+    # - tests passed?
+    # - we are the most recent commit on master?
+    if: ${{github.event.workflow_run.conclusion == 'success' &&
+      github.event.workflow_run.head_sha == github.sha}}
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{github.event.workflow_run.head_sha}}
+          # need workflow access since we push branches
+          # containing workflows
+          token: ${{secrets.BOT_TOKEN}}
+          # need all tags
+          fetch-depth: 0
+
+      # try to get results from tests
+      - uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          run-id: ${{github.event.workflow_run.id}}
+          pattern: '{sizes,sizes-*}'
+          merge-multiple: true
+          path: sizes
+      - uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          run-id: ${{github.event.workflow_run.id}}
+          pattern: '{cov,cov-*}'
+          merge-multiple: true
+          path: cov
+      - uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          run-id: ${{github.event.workflow_run.id}}
+          pattern: '{bench,bench-*}'
+          merge-multiple: true
+          path: bench
+
+      - name: find-version
+        run: |
+          # rip version from lfs.h
+          LFS_VERSION="$(grep -o '^#define LFS_VERSION .*$' lfs.h \
+            | awk '{print $3}')"
+          LFS_VERSION_MAJOR="$((0xffff & ($LFS_VERSION >> 16)))"
+          LFS_VERSION_MINOR="$((0xffff & ($LFS_VERSION >>  0)))"
+
+          # find a new patch version based on what we find in our tags
+          LFS_VERSION_PATCH="$( \
+            ( git describe --tags --abbrev=0 \
+                --match="v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.*" \
+              || echo 'v0.0.-1' ) \
+            | awk -F '.' '{print $3+1}')"
+
+          # found new version
+          LFS_VERSION="v$LFS_VERSION_MAJOR`
+            `.$LFS_VERSION_MINOR`
+            `.$LFS_VERSION_PATCH"
+          echo "LFS_VERSION=$LFS_VERSION"
+          echo "LFS_VERSION=$LFS_VERSION" >> $GITHUB_ENV
+          echo "LFS_VERSION_MAJOR=$LFS_VERSION_MAJOR" >> $GITHUB_ENV
+          echo "LFS_VERSION_MINOR=$LFS_VERSION_MINOR" >> $GITHUB_ENV
+          echo "LFS_VERSION_PATCH=$LFS_VERSION_PATCH" >> $GITHUB_ENV
+
+      # try to find previous version?
+      - name: find-prev-version
+        continue-on-error: true
+        run: |
+          LFS_PREV_VERSION="$( \
+            git describe --tags --abbrev=0 --match 'v*' \
+            || true)"
+          echo "LFS_PREV_VERSION=$LFS_PREV_VERSION"
+          echo "LFS_PREV_VERSION=$LFS_PREV_VERSION" >> $GITHUB_ENV
+
+      # try to find results from tests
+      - name: create-table
+        run: |
+          # previous results to compare against?
+          [ -n "$LFS_PREV_VERSION" ] && curl -sS \
+            "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/status/$LFS_PREV_VERSION`
+              `?per_page=100" \
+            | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]' \
+            >> prev-status.json \
+            || true
+
+          # build table for GitHub
+          declare -A table
+
+          # sizes table
+          i=0
+          j=0
+          for c in "" readonly threadsafe multiversion migrate error-asserts
+          do
+            # per-config results
+            c_or_default=${c:-default}
+            c_camel=${c_or_default^}
+            table[$i,$j]=$c_camel
+            ((j+=1))
+
+            for s in code stack structs
+            do
+              f=sizes/thumb${c:+-$c}.$s.csv
+              [ -e $f ] && table[$i,$j]=$( \
+                export PREV="$(jq -re '
+                    select(.context == "'"sizes (thumb${c:+, $c}) / $s"'").description
+                    | capture("(?<prev>[0-9∞]+)").prev' \
+                  prev-status.json || echo 0)"
+                ./scripts/summary.py $f --max=stack_limit -Y \
+                  | awk '
+                    NR==2 {$1=0; printf "%s B",$NF}
+                    NR==2 && ENVIRON["PREV"]+0 != 0 {
+                      printf " (%+.1f%%)",100*($NF-ENVIRON["PREV"])/ENVIRON["PREV"]
+                    }' \
+                  | sed -e 's/ /\&nbsp;/g')
+              ((j+=1))
+            done
+            ((j=0, i+=1))
+          done
+
+          # coverage table
+          i=0
+          j=4
+          for s in lines branches
+          do
+            table[$i,$j]=${s^}
+            ((j+=1))
+
+            f=cov/cov.csv
+            [ -e $f ] && table[$i,$j]=$( \
+              export PREV="$(jq -re '
+                  select(.context == "'"cov / $s"'").description
+                  | capture("(?<prev_a>[0-9]+)/(?<prev_b>[0-9]+)")
+                  | 100*((.prev_a|tonumber) / (.prev_b|tonumber))' \
+                prev-status.json || echo 0)"
+              ./scripts/cov.py -u $f -f$s -Y \
+                | awk -F '[ /%]+' -v s=$s '
+                  NR==2 {$1=0; printf "%d/%d %s",$2,$3,s}
+                  NR==2 && ENVIRON["PREV"]+0 != 0 {
+                    printf " (%+.1f%%)",$4-ENVIRON["PREV"]
+                  }' \
+                | sed -e 's/ /\&nbsp;/g')
+            ((j=4, i+=1))
+          done
+
+          # benchmark table
+          i=3
+          j=4
+          for s in readed proged erased
+          do
+            table[$i,$j]=${s^}
+            ((j+=1))
+
+            f=bench/bench.csv
+            [ -e $f ] && table[$i,$j]=$( \
+              export PREV="$(jq -re '
+                  select(.context == "'"bench / $s"'").description
+                  | capture("(?<prev>[0-9]+)").prev' \
+                prev-status.json || echo 0)"
+              ./scripts/summary.py $f -f$s=bench_$s -Y \
+                | awk '
+                  NR==2 {$1=0; printf "%s B",$NF}
+                  NR==2 && ENVIRON["PREV"]+0 != 0 {
+                    printf " (%+.1f%%)",100*($NF-ENVIRON["PREV"])/ENVIRON["PREV"]
+                  }' \
+                | sed -e 's/ /\&nbsp;/g')
+            ((j=4, i+=1))
+          done
+
+          # build the actual table
+          echo "|   | Code | Stack | Structs |   | Coverage |" >> table.txt
+          echo "|:--|-----:|------:|--------:|:--|---------:|" >> table.txt
+          for ((i=0; i<6; i++))
+          do
+            echo -n "|" >> table.txt
+            for ((j=0; j<6; j++))
+            do
+              echo -n " " >> table.txt
+              [[ i -eq 2 && j -eq 5 ]] && echo -n "**Benchmarks**" >> table.txt
+              echo -n "${table[$i,$j]:-}" >> table.txt
+              echo -n " |" >> table.txt
+            done
+            echo >> table.txt
+          done
+
+          cat table.txt
+
+      # find changes from history
+      - name: create-changes
+        run: |
+          [ -n "$LFS_PREV_VERSION" ] || exit 0
+          # use explicit link to github commit so that release notes can
+          # be copied elsewhere
+          git log "$LFS_PREV_VERSION.." \
+            --grep='^Merge' --invert-grep \
+            --format="format:[\`%h\`](`
+              `https://github.com/$GITHUB_REPOSITORY/commit/%h) %s" \
+            > changes.txt
+          echo "CHANGES:"
+          cat changes.txt
+
+      # create and update major branches (vN and vN-prefix)
+      - name: create-major-branches
+        run: |
+          # create major branch
+          git branch "v$LFS_VERSION_MAJOR" HEAD
+
+          # create major prefix branch
+          git config user.name ${{secrets.BOT_USER}}
+          git config user.email ${{secrets.BOT_EMAIL}}
+          git fetch "https://github.com/$GITHUB_REPOSITORY.git" \
+            "v$LFS_VERSION_MAJOR-prefix" || true
+          ./scripts/changeprefix.py --git "lfs" "lfs$LFS_VERSION_MAJOR"
+          git branch "v$LFS_VERSION_MAJOR-prefix" $( \
+            git commit-tree $(git write-tree) \
+              $(git rev-parse --verify -q FETCH_HEAD | sed -e 's/^/-p /') \
+              -p HEAD \
+              -m "Generated v$LFS_VERSION_MAJOR prefixes")
+          git reset --hard
+
+          # push!
+          git push --atomic origin \
+            "v$LFS_VERSION_MAJOR" \
+            "v$LFS_VERSION_MAJOR-prefix"
+
+      # build release notes
+      - name: create-release
+        run: |
+          # create release and patch version tag (vN.N.N)
+          # only draft if not a patch release
+          touch release.txt
+          [ -e table.txt ] && cat table.txt >> release.txt
+          echo >> release.txt
+          [ -e changes.txt ] && cat changes.txt >> release.txt
+          cat release.txt
+
+          curl -sS -X POST -H "authorization: token ${{secrets.BOT_TOKEN}}" \
+            "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/releases" \
+            -d "$(jq -n --rawfile release release.txt '{
+              tag_name: env.LFS_VERSION,
+              name: env.LFS_VERSION | rtrimstr(".0"),
+              target_commitish: "${{github.event.workflow_run.head_sha}}",
+              draft: env.LFS_VERSION | endswith(".0"),
+              body: $release,
+            }' | tee /dev/stderr)"
+

.github/workflows/status.yml

@@ -0,0 +1,102 @@
+name: status
+on:
+  workflow_run:
+    workflows: [test]
+    types: [completed]
+
+defaults:
+  run:
+    shell: bash -euv -o pipefail {0}
+
+jobs:
+  # forward custom statuses
+  status:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          run-id: ${{github.event.workflow_run.id}}
+          pattern: '{status,status-*}'
+          merge-multiple: true
+          path: status
+      - name: update-status
+        continue-on-error: true
+        run: |
+          ls status
+          for s in $(shopt -s nullglob ; echo status/*.json)
+          do
+            # parse requested status
+            export STATE="$(jq -er '.state' $s)"
+            export CONTEXT="$(jq -er '.context' $s)"
+            export DESCRIPTION="$(jq -er '.description' $s)"
+            # help lookup URL for job/steps because GitHub makes
+            # it VERY HARD to link to specific jobs
+            export TARGET_URL="$(
+              jq -er '.target_url // empty' $s || (
+                export TARGET_JOB="$(jq -er '.target_job' $s)"
+                export TARGET_STEP="$(jq -er '.target_step // ""' $s)"
+                curl -sS -H "authorization: token ${{secrets.BOT_TOKEN}}" \
+                  "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/actions/runs/`
+                    `${{github.event.workflow_run.id}}/jobs" \
+                  | jq -er '.jobs[]
+                    | select(.name == env.TARGET_JOB)
+                    | .html_url
+                      + "?check_suite_focus=true"
+                      + ((.steps[]
+                        | select(.name == env.TARGET_STEP)
+                        | "#step:\(.number):0") // "")'))"
+            # update status
+            curl -sS -X POST -H "authorization: token ${{secrets.BOT_TOKEN}}" \
+              "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/statuses/`
+                `${{github.event.workflow_run.head_sha}}" \
+              -d "$(jq -n '{
+                state: env.STATE,
+                context: env.CONTEXT,
+                description: env.DESCRIPTION,
+                target_url: env.TARGET_URL,
+              }' | tee /dev/stderr)"
+          done
+
+  # forward custom pr-comments
+  comment:
+    runs-on: ubuntu-latest
+
+    # only run on success (we don't want garbage comments!)
+    if: ${{github.event.workflow_run.conclusion == 'success'}}
+
+    steps:
+      # generated comment?
+      - uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          run-id: ${{github.event.workflow_run.id}}
+          pattern: '{comment,comment-*}'
+          merge-multiple: true
+          path: comment
+      - name: update-comment
+        continue-on-error: true
+        run: |
+          ls comment
+          for s in $(shopt -s nullglob ; echo comment/*.json)
+          do
+            export NUMBER="$(jq -er '.number' $s)"
+            export BODY="$(jq -er '.body' $s)"
+
+            # check that the comment was from the most recent commit on the
+            # pull request
+            [ "$(curl -sS -H "authorization: token ${{secrets.BOT_TOKEN}}" \
+                "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/pulls/$NUMBER" \
+                | jq -er '.head.sha')" \
+              == ${{github.event.workflow_run.head_sha}} ] || continue
+
+            # update comment
+            curl -sS -X POST -H "authorization: token ${{secrets.BOT_TOKEN}}" \
+              "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/`
+                `$NUMBER/comments" \
+              -d "$(jq -n '{
+                body: env.BODY,
+              }' | tee /dev/stderr)"
+          done

.github/workflows/test.yml

@@ -0,0 +1,907 @@
+name: test
+on: [push, pull_request]
+
+defaults:
+  run:
+    shell: bash -euv -o pipefail {0}
+
+env:
+  CFLAGS: -Werror
+  MAKEFLAGS: -j
+  TESTFLAGS: -k
+  BENCHFLAGS:
+
+jobs:
+  # run tests
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        arch: [x86_64, thumb, mips, powerpc]
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+
+      # cross-compile with ARM Thumb (32-bit, little-endian)
+      - name: install-thumb
+        if: ${{matrix.arch == 'thumb'}}
+        run: |
+          sudo apt-get install -qq \
+            gcc-arm-linux-gnueabi \
+            libc6-dev-armel-cross \
+            qemu-user
+          echo "CC=arm-linux-gnueabi-gcc -mthumb --static" >> $GITHUB_ENV
+          echo "EXEC=qemu-arm" >> $GITHUB_ENV
+          arm-linux-gnueabi-gcc --version
+          qemu-arm -version
+      # cross-compile with MIPS (32-bit, big-endian)
+      - name: install-mips
+        if: ${{matrix.arch == 'mips'}}
+        run: |
+          sudo apt-get install -qq \
+            gcc-mips-linux-gnu \
+            libc6-dev-mips-cross \
+            qemu-user
+          echo "CC=mips-linux-gnu-gcc --static" >> $GITHUB_ENV
+          echo "EXEC=qemu-mips" >> $GITHUB_ENV
+          mips-linux-gnu-gcc --version
+          qemu-mips -version
+      # cross-compile with PowerPC (32-bit, big-endian)
+      - name: install-powerpc
+        if: ${{matrix.arch == 'powerpc'}}
+        run: |
+          sudo apt-get install -qq \
+            gcc-powerpc-linux-gnu \
+            libc6-dev-powerpc-cross \
+            qemu-user
+          echo "CC=powerpc-linux-gnu-gcc --static" >> $GITHUB_ENV
+          echo "EXEC=qemu-ppc" >> $GITHUB_ENV
+          powerpc-linux-gnu-gcc --version
+          qemu-ppc -version
+
+      # does littlefs compile?
+      - name: test-build
+        run: |
+          make clean
+          make build
+
+      # make sure example can at least compile
+      - name: test-example
+        run: |
+          make clean
+          sed -n '/``` c/,/```/{/```/d; p}' README.md > test.c
+          CFLAGS="$CFLAGS \
+            -Duser_provided_block_device_read=NULL \
+            -Duser_provided_block_device_prog=NULL \
+            -Duser_provided_block_device_erase=NULL \
+            -Duser_provided_block_device_sync=NULL \
+            -include stdio.h" \
+            make all
+          rm test.c
+
+      # run the tests!
+      - name: test
+        run: |
+          make clean
+          make test
+
+      # collect coverage info
+      #
+      # Note the goal is to maximize coverage in the small, easy-to-run
+      # tests, so we intentionally exclude more aggressive powerloss testing
+      # from coverage results
+      - name: cov
+        if: ${{matrix.arch == 'x86_64'}}
+        run: |
+          make lfs.cov.csv
+          ./scripts/cov.py -u lfs.cov.csv
+          mkdir -p cov
+          cp lfs.cov.csv cov/cov.csv
+
+      # find compile-time measurements
+      - name: sizes
+        run: |
+          make clean
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_ASSERT \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.structs.csv
+          ./scripts/structs.py -u lfs.structs.csv
+          ./scripts/summary.py lfs.code.csv lfs.data.csv lfs.stack.csv \
+            -bfunction \
+            -fcode=code_size \
+            -fdata=data_size \
+            -fstack=stack_limit --max=stack_limit
+          mkdir -p sizes
+          cp lfs.code.csv sizes/${{matrix.arch}}.code.csv
+          cp lfs.data.csv sizes/${{matrix.arch}}.data.csv
+          cp lfs.stack.csv sizes/${{matrix.arch}}.stack.csv
+          cp lfs.structs.csv sizes/${{matrix.arch}}.structs.csv
+      - name: sizes-readonly
+        run: |
+          make clean
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_ASSERT \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR \
+            -DLFS_READONLY" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.structs.csv
+          ./scripts/structs.py -u lfs.structs.csv
+          ./scripts/summary.py lfs.code.csv lfs.data.csv lfs.stack.csv \
+            -bfunction \
+            -fcode=code_size \
+            -fdata=data_size \
+            -fstack=stack_limit --max=stack_limit
+          mkdir -p sizes
+          cp lfs.code.csv sizes/${{matrix.arch}}-readonly.code.csv
+          cp lfs.data.csv sizes/${{matrix.arch}}-readonly.data.csv
+          cp lfs.stack.csv sizes/${{matrix.arch}}-readonly.stack.csv
+          cp lfs.structs.csv sizes/${{matrix.arch}}-readonly.structs.csv
+      - name: sizes-threadsafe
+        run: |
+          make clean
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_ASSERT \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR \
+            -DLFS_THREADSAFE" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.structs.csv
+          ./scripts/structs.py -u lfs.structs.csv
+          ./scripts/summary.py lfs.code.csv lfs.data.csv lfs.stack.csv \
+            -bfunction \
+            -fcode=code_size \
+            -fdata=data_size \
+            -fstack=stack_limit --max=stack_limit
+          mkdir -p sizes
+          cp lfs.code.csv sizes/${{matrix.arch}}-threadsafe.code.csv
+          cp lfs.data.csv sizes/${{matrix.arch}}-threadsafe.data.csv
+          cp lfs.stack.csv sizes/${{matrix.arch}}-threadsafe.stack.csv
+          cp lfs.structs.csv sizes/${{matrix.arch}}-threadsafe.structs.csv
+      - name: sizes-multiversion
+        run: |
+          make clean
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_ASSERT \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR \
+            -DLFS_MULTIVERSION" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.structs.csv
+          ./scripts/structs.py -u lfs.structs.csv
+          ./scripts/summary.py lfs.code.csv lfs.data.csv lfs.stack.csv \
+            -bfunction \
+            -fcode=code_size \
+            -fdata=data_size \
+            -fstack=stack_limit --max=stack_limit
+          mkdir -p sizes
+          cp lfs.code.csv sizes/${{matrix.arch}}-multiversion.code.csv
+          cp lfs.data.csv sizes/${{matrix.arch}}-multiversion.data.csv
+          cp lfs.stack.csv sizes/${{matrix.arch}}-multiversion.stack.csv
+          cp lfs.structs.csv sizes/${{matrix.arch}}-multiversion.structs.csv
+      - name: sizes-migrate
+        run: |
+          make clean
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_ASSERT \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR \
+            -DLFS_MIGRATE" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.structs.csv
+          ./scripts/structs.py -u lfs.structs.csv
+          ./scripts/summary.py lfs.code.csv lfs.data.csv lfs.stack.csv \
+            -bfunction \
+            -fcode=code_size \
+            -fdata=data_size \
+            -fstack=stack_limit --max=stack_limit
+          mkdir -p sizes
+          cp lfs.code.csv sizes/${{matrix.arch}}-migrate.code.csv
+          cp lfs.data.csv sizes/${{matrix.arch}}-migrate.data.csv
+          cp lfs.stack.csv sizes/${{matrix.arch}}-migrate.stack.csv
+          cp lfs.structs.csv sizes/${{matrix.arch}}-migrate.structs.csv
+      - name: sizes-error-asserts
+        run: |
+          make clean
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR \
+            -D'LFS_ASSERT(test)=do {if(!(test)) {return -1;}} while(0)'" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.structs.csv
+          ./scripts/structs.py -u lfs.structs.csv
+          ./scripts/summary.py lfs.code.csv lfs.data.csv lfs.stack.csv \
+            -bfunction \
+            -fcode=code_size \
+            -fdata=data_size \
+            -fstack=stack_limit --max=stack_limit
+          mkdir -p sizes
+          cp lfs.code.csv sizes/${{matrix.arch}}-error-asserts.code.csv
+          cp lfs.data.csv sizes/${{matrix.arch}}-error-asserts.data.csv
+          cp lfs.stack.csv sizes/${{matrix.arch}}-error-asserts.stack.csv
+          cp lfs.structs.csv sizes/${{matrix.arch}}-error-asserts.structs.csv
+
+      # create size statuses
+      - name: upload-sizes
+        uses: actions/upload-artifact@v4
+        with:
+          name: sizes-${{matrix.arch}}
+          path: sizes
+      - name: status-sizes
+        run: |
+          mkdir -p status
+          for f in $(shopt -s nullglob ; echo sizes/*.csv)
+          do
+            # skip .data.csv as it should always be zero
+            [[ $f == *.data.csv ]] && continue
+            export STEP="sizes$(echo $f \
+              | sed -n 's/[^-.]*-\([^.]*\)\..*csv/-\1/p')"
+            export CONTEXT="sizes (${{matrix.arch}}$(echo $f \
+              | sed -n 's/[^-.]*-\([^.]*\)\..*csv/, \1/p')) / $(echo $f \
+              | sed -n 's/[^.]*\.\(.*\)\.csv/\1/p')"
+            export PREV="$(curl -sS \
+              "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/status/master`
+                `?per_page=100" \
+              | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]
+                | select(.context == env.CONTEXT).description
+                | capture("(?<prev>[0-9∞]+)").prev' \
+              || echo 0)"
+            export DESCRIPTION="$(./scripts/summary.py $f --max=stack_limit -Y \
+              | awk '
+                NR==2 {$1=0; printf "%s B",$NF}
+                NR==2 && ENVIRON["PREV"]+0 != 0 {
+                  printf " (%+.1f%%)",100*($NF-ENVIRON["PREV"])/ENVIRON["PREV"]
+                }')"
+            jq -n '{
+              state: "success",
+              context: env.CONTEXT,
+              description: env.DESCRIPTION,
+              target_job: "${{github.job}} (${{matrix.arch}})",
+              target_step: env.STEP,
+            }' | tee status/$(basename $f .csv).json
+          done
+      - name: upload-status-sizes
+        uses: actions/upload-artifact@v4
+        with:
+          name: status-sizes-${{matrix.arch}}
+          path: status
+          retention-days: 1
+
+      # create cov statuses
+      - name: upload-cov
+        if: ${{matrix.arch == 'x86_64'}}
+        uses: actions/upload-artifact@v4
+        with:
+          name: cov
+          path: cov
+      - name: status-cov
+        if: ${{matrix.arch == 'x86_64'}}
+        run: |
+          mkdir -p status
+          f=cov/cov.csv
+          for s in lines branches
+          do
+            export STEP="cov"
+            export CONTEXT="cov / $s"
+            export PREV="$(curl -sS \
+              "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/status/master`
+                `?per_page=100" \
+              | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]
+                | select(.context == env.CONTEXT).description
+                | capture("(?<prev_a>[0-9]+)/(?<prev_b>[0-9]+)")
+                | 100*((.prev_a|tonumber) / (.prev_b|tonumber))' \
+              || echo 0)"
+            export DESCRIPTION="$(./scripts/cov.py -u $f -f$s -Y \
+              | awk -F '[ /%]+' -v s=$s '
+                NR==2 {$1=0; printf "%d/%d %s",$2,$3,s}
+                NR==2 && ENVIRON["PREV"]+0 != 0 {
+                  printf " (%+.1f%%)",$4-ENVIRON["PREV"]
+                }')"
+            jq -n '{
+              state: "success",
+              context: env.CONTEXT,
+              description: env.DESCRIPTION,
+              target_job: "${{github.job}} (${{matrix.arch}})",
+              target_step: env.STEP,
+            }' | tee status/$(basename $f .csv)-$s.json
+          done
+      - name: upload-status-cov
+        if: ${{matrix.arch == 'x86_64'}}
+        uses: actions/upload-artifact@v4
+        with:
+          name: status-cov
+          path: status
+          retention-days: 1
+
+  # run as many exhaustive tests as fits in GitHub's time limits
+  #
+  # this grows exponentially, so it doesn't turn out to be that many
+  test-pls:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        pls: [1, 2]
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      - name: test-pls
+        if: ${{matrix.pls <= 1}}
+        run: |
+          TESTFLAGS="$TESTFLAGS -P${{matrix.pls}}" make test
+      # >=2pls takes multiple days to run fully, so we can only
+      # run a subset of tests, these are the most important
+      - name: test-limited-pls
+        if: ${{matrix.pls > 1}}
+        run: |
+          TESTFLAGS="$TESTFLAGS -P${{matrix.pls}} test_dirs test_relocations" \
+            make test
+
+  # run with LFS_NO_INTRINSICS to make sure that works
+  test-no-intrinsics:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      - name: test-no-intrinsics
+        run: |
+          CFLAGS="$CFLAGS -DLFS_NO_INTRINSICS" make test
+
+  test-shrink:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      - name: test-no-intrinsics
+        run: |
+          CFLAGS="$CFLAGS -DLFS_SHRINKNONRELOCATING" make test
+
+  # run with all trace options enabled to at least make sure these
+  # all compile
+  test-yes-trace:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      - name: test-yes-trace
+        run: |
+          CFLAGS="$CFLAGS \
+            -DLFS_YES_TRACE \
+            -DLFS_RAMBD_YES_TRACE \
+            -DLFS_FILEBD_YES_TRACE \
+            -DLFS_RAMBD_YES_TRACE" \
+            make test
+
+  # run LFS_MULTIVERSION tests
+  test-multiversion:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      - name: test-multiversion
+        run: |
+          CFLAGS="$CFLAGS -DLFS_MULTIVERSION" make test
+
+  # run tests on the older version lfs2.0
+  test-lfs2_0:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      - name: test-lfs2_0
+        run: |
+          CFLAGS="$CFLAGS -DLFS_MULTIVERSION" \
+          TESTFLAGS="$TESTFLAGS -DDISK_VERSION=0x00020000" \
+            make test
+
+  # run under Valgrind to check for memory errors
+  test-valgrind:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip valgrind
+          pip3 install toml
+          gcc --version
+          python3 --version
+          valgrind --version
+      # Valgrind takes a while with diminishing value, so only test
+      # on one geometry
+      - name: test-valgrind
+        run: |
+          TESTFLAGS="$TESTFLAGS --valgrind --context=1024 -Gdefault -Pnone" \
+            make test
+
+  # compile/run with Clang, mostly to check for Clang-specific warnings
+  test-clang:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get install -qq clang python3 python3-pip
+          pip3 install toml
+          clang --version
+          python3 --version
+      - name: test-clang
+        run: |
+          CC=clang \
+            make test
+
+  # run benchmarks
+  #
+  # note there's no real benefit to running these on multiple archs
+  bench:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip valgrind
+          pip3 install toml
+          gcc --version
+          python3 --version
+          valgrind --version
+      - name: bench
+        run: |
+          make bench
+
+          # find bench results
+          make lfs.bench.csv
+          ./scripts/summary.py lfs.bench.csv \
+            -bsuite \
+            -freaded=bench_readed \
+            -fproged=bench_proged \
+            -ferased=bench_erased
+          mkdir -p bench
+          cp lfs.bench.csv bench/bench.csv
+
+          # find perfbd results
+          make lfs.perfbd.csv
+          ./scripts/perfbd.py -u lfs.perfbd.csv
+          mkdir -p bench
+          cp lfs.perfbd.csv bench/perfbd.csv
+
+      # create bench statuses
+      - name: upload-bench
+        uses: actions/upload-artifact@v4
+        with:
+          name: bench
+          path: bench
+      - name: status-bench
+        run: |
+          mkdir -p status
+          f=bench/bench.csv
+          for s in readed proged erased
+          do
+            export STEP="bench"
+            export CONTEXT="bench / $s"
+            export PREV="$(curl -sS \
+              "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/status/master`
+                `?per_page=100" \
+              | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]
+                | select(.context == env.CONTEXT).description
+                | capture("(?<prev>[0-9]+)").prev' \
+              || echo 0)"
+            export DESCRIPTION="$(./scripts/summary.py $f -f$s=bench_$s -Y \
+              | awk '
+                NR==2 {$1=0; printf "%s B",$NF}
+                NR==2 && ENVIRON["PREV"]+0 != 0 {
+                  printf " (%+.1f%%)",100*($NF-ENVIRON["PREV"])/ENVIRON["PREV"]
+                }')"
+            jq -n '{
+              state: "success",
+              context: env.CONTEXT,
+              description: env.DESCRIPTION,
+              target_job: "${{github.job}}",
+              target_step: env.STEP,
+            }' | tee status/$(basename $f .csv)-$s.json
+          done
+      - name: upload-status-bench
+        uses: actions/upload-artifact@v4
+        with:
+          name: status-bench
+          path: status
+          retention-days: 1
+
+  # run compatibility tests using the current master as the previous version
+  test-compat:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        if: ${{github.event_name == 'pull_request'}}
+      # checkout the current pr target into lfsp
+      - uses: actions/checkout@v4
+        if: ${{github.event_name == 'pull_request'}}
+        with:
+          ref: ${{github.event.pull_request.base.ref}}
+          path: lfsp
+      - name: install
+        if: ${{github.event_name == 'pull_request'}}
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      # adjust prefix of lfsp
+      - name: changeprefix
+        if: ${{github.event_name == 'pull_request'}}
+        run: |
+          ./scripts/changeprefix.py lfs lfsp lfsp/*.h lfsp/*.c
+      - name: test-compat
+        if: ${{github.event_name == 'pull_request'}}
+        run: |
+          TESTS=tests/test_compat.toml \
+            SRC="$(find . lfsp -name '*.c' -maxdepth 1 \
+                -and -not -name '*.t.*' \
+                -and -not -name '*.b.*')" \
+            CFLAGS="-DLFSP=lfsp/lfsp.h" \
+            make test
+
+  # self-host with littlefs-fuse for a fuzz-like test
+  fuse:
+    runs-on: ubuntu-latest
+    if: ${{!endsWith(github.ref, '-prefix')}}
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip libfuse-dev
+          sudo pip3 install toml
+          gcc --version
+          python3 --version
+          fusermount -V
+      - uses: actions/checkout@v4
+        with:
+          repository: littlefs-project/littlefs-fuse
+          ref: v2
+          path: littlefs-fuse
+      - name: setup
+        run: |
+          # copy our new version into littlefs-fuse
+          rm -rf littlefs-fuse/littlefs/*
+          cp -r $(git ls-tree --name-only HEAD) littlefs-fuse/littlefs
+
+          # setup disk for littlefs-fuse
+          mkdir mount
+          LOOP=$(sudo losetup -f)
+          sudo chmod a+rw $LOOP
+          dd if=/dev/zero bs=512 count=128K of=disk
+          losetup $LOOP disk
+          echo "LOOP=$LOOP" >> $GITHUB_ENV
+      - name: test
+        run: |
+          # self-host test
+          make -C littlefs-fuse
+
+          littlefs-fuse/lfs --format $LOOP
+          littlefs-fuse/lfs $LOOP mount
+
+          ls mount
+          mkdir mount/littlefs
+          cp -r $(git ls-tree --name-only HEAD) mount/littlefs
+          cd mount/littlefs
+          stat .
+          ls -flh
+          make -B test-runner
+          make -B test
+
+  # test migration using littlefs-fuse
+  migrate:
+    runs-on: ubuntu-latest
+    if: ${{!endsWith(github.ref, '-prefix')}}
+    steps:
+      - uses: actions/checkout@v4
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get update -qq
+          sudo apt-get install -qq gcc python3 python3-pip libfuse-dev
+          sudo pip3 install toml
+          gcc --version
+          python3 --version
+          fusermount -V
+      - uses: actions/checkout@v4
+        with:
+          repository: littlefs-project/littlefs-fuse
+          ref: v2
+          path: v2
+      - uses: actions/checkout@v4
+        with:
+          repository: littlefs-project/littlefs-fuse
+          ref: v1
+          path: v1
+      - name: setup
+        run: |
+          # copy our new version into littlefs-fuse
+          rm -rf v2/littlefs/*
+          cp -r $(git ls-tree --name-only HEAD) v2/littlefs
+
+          # setup disk for littlefs-fuse
+          mkdir mount
+          LOOP=$(sudo losetup -f)
+          sudo chmod a+rw $LOOP
+          dd if=/dev/zero bs=512 count=128K of=disk
+          losetup $LOOP disk
+          echo "LOOP=$LOOP" >> $GITHUB_ENV
+      - name: test
+        run: |
+          # compile v1 and v2
+          make -C v1
+          make -C v2
+
+          # run self-host test with v1
+          v1/lfs --format $LOOP
+          v1/lfs $LOOP mount
+
+          ls mount
+          mkdir mount/littlefs
+          cp -r $(git ls-tree --name-only HEAD) mount/littlefs
+          cd mount/littlefs
+          stat .
+          ls -flh
+          make -B test-runner
+          make -B test
+
+          # attempt to migrate
+          cd ../..
+          fusermount -u mount
+
+          v2/lfs --migrate $LOOP
+          v2/lfs $LOOP mount
+
+          # run self-host test with v2 right where we left off
+          ls mount
+          cd mount/littlefs
+          stat .
+          ls -flh
+          make -B test-runner
+          make -B test
+
+  # status related tasks that run after tests
+  status:
+    runs-on: ubuntu-latest
+    needs: [test, bench]
+    steps:
+      - uses: actions/checkout@v4
+        if: ${{github.event_name == 'pull_request'}}
+      - name: install
+        if: ${{github.event_name == 'pull_request'}}
+        run: |
+          # need a few things
+          sudo apt-get install -qq gcc python3 python3-pip
+          pip3 install toml
+          gcc --version
+          python3 --version
+      - uses: actions/download-artifact@v4
+        if: ${{github.event_name == 'pull_request'}}
+        continue-on-error: true
+        with:
+          pattern: '{sizes,sizes-*}'
+          merge-multiple: true
+          path: sizes
+      - uses: actions/download-artifact@v4
+        if: ${{github.event_name == 'pull_request'}}
+        continue-on-error: true
+        with:
+          pattern: '{cov,cov-*}'
+          merge-multiple: true
+          path: cov
+      - uses: actions/download-artifact@v4
+        if: ${{github.event_name == 'pull_request'}}
+        continue-on-error: true
+        with:
+          pattern: '{bench,bench-*}'
+          merge-multiple: true
+          path: bench
+
+      # try to find results from tests
+      - name: create-table
+        if: ${{github.event_name == 'pull_request'}}
+        run: |
+          # compare against pull-request target
+          curl -sS \
+            "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/status/`
+              `${{github.event.pull_request.base.ref}}`
+              `?per_page=100" \
+            | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]' \
+            >> prev-status.json \
+            || true
+
+          # build table for GitHub
+          declare -A table
+
+          # sizes table
+          i=0
+          j=0
+          for c in "" readonly threadsafe multiversion migrate error-asserts
+          do
+            # per-config results
+            c_or_default=${c:-default}
+            c_camel=${c_or_default^}
+            table[$i,$j]=$c_camel
+            ((j+=1))
+
+            for s in code stack structs
+            do
+              f=sizes/thumb${c:+-$c}.$s.csv
+              [ -e $f ] && table[$i,$j]=$( \
+                export PREV="$(jq -re '
+                    select(.context == "'"sizes (thumb${c:+, $c}) / $s"'").description
+                    | capture("(?<prev>[0-9∞]+)").prev' \
+                  prev-status.json || echo 0)"
+                ./scripts/summary.py $f --max=stack_limit -Y \
+                  | awk '
+                    NR==2 {$1=0; printf "%s B",$NF}
+                    NR==2 && ENVIRON["PREV"]+0 != 0 {
+                      printf " (%+.1f%%)",100*($NF-ENVIRON["PREV"])/ENVIRON["PREV"]
+                    }' \
+                  | sed -e 's/ /\&nbsp;/g')
+              ((j+=1))
+            done
+            ((j=0, i+=1))
+          done
+
+          # coverage table
+          i=0
+          j=4
+          for s in lines branches
+          do
+            table[$i,$j]=${s^}
+            ((j+=1))
+
+            f=cov/cov.csv
+            [ -e $f ] && table[$i,$j]=$( \
+              export PREV="$(jq -re '
+                  select(.context == "'"cov / $s"'").description
+                  | capture("(?<prev_a>[0-9]+)/(?<prev_b>[0-9]+)")
+                  | 100*((.prev_a|tonumber) / (.prev_b|tonumber))' \
+                prev-status.json || echo 0)"
+              ./scripts/cov.py -u $f -f$s -Y \
+                | awk -F '[ /%]+' -v s=$s '
+                  NR==2 {$1=0; printf "%d/%d %s",$2,$3,s}
+                  NR==2 && ENVIRON["PREV"]+0 != 0 {
+                    printf " (%+.1f%%)",$4-ENVIRON["PREV"]
+                  }' \
+                | sed -e 's/ /\&nbsp;/g')
+            ((j=4, i+=1))
+          done
+
+          # benchmark table
+          i=3
+          j=4
+          for s in readed proged erased
+          do
+            table[$i,$j]=${s^}
+            ((j+=1))
+
+            f=bench/bench.csv
+            [ -e $f ] && table[$i,$j]=$( \
+              export PREV="$(jq -re '
+                  select(.context == "'"bench / $s"'").description
+                  | capture("(?<prev>[0-9]+)").prev' \
+                prev-status.json || echo 0)"
+              ./scripts/summary.py $f -f$s=bench_$s -Y \
+                | awk '
+                  NR==2 {$1=0; printf "%s B",$NF}
+                  NR==2 && ENVIRON["PREV"]+0 != 0 {
+                    printf " (%+.1f%%)",100*($NF-ENVIRON["PREV"])/ENVIRON["PREV"]
+                  }' \
+                | sed -e 's/ /\&nbsp;/g')
+            ((j=4, i+=1))
+          done
+
+          # build the actual table
+          echo "|   | Code | Stack | Structs |   | Coverage |" >> table.txt
+          echo "|:--|-----:|------:|--------:|:--|---------:|" >> table.txt
+          for ((i=0; i<6; i++))
+          do
+            echo -n "|" >> table.txt
+            for ((j=0; j<6; j++))
+            do
+              echo -n " " >> table.txt
+              [[ i -eq 2 && j -eq 5 ]] && echo -n "**Benchmarks**" >> table.txt
+              echo -n "${table[$i,$j]:-}" >> table.txt
+              echo -n " |" >> table.txt
+            done
+            echo >> table.txt
+          done
+
+          cat table.txt
+
+      # create a bot comment for successful runs on pull requests
+      - name: create-comment
+        if: ${{github.event_name == 'pull_request'}}
+        run: |
+          touch comment.txt
+          echo "<details>" >> comment.txt
+          echo "<summary>" >> comment.txt
+          echo "Tests passed ✓, `
+            `Code: $(awk 'NR==3 {print $4}' table.txt || true), `
+            `Stack: $(awk 'NR==3 {print $6}' table.txt || true), `
+            `Structs: $(awk 'NR==3 {print $8}' table.txt || true)" \
+            >> comment.txt
+          echo "</summary>" >> comment.txt
+          echo >> comment.txt
+          [ -e table.txt ] && cat table.txt >> comment.txt
+          echo >> comment.txt
+          echo "</details>" >> comment.txt
+          cat comment.txt
+
+          mkdir -p comment
+          jq -n --rawfile comment comment.txt '{
+            number: ${{github.event.number}},
+            body: $comment,
+          }' | tee comment/comment.json
+      - name: upload-comment
+        uses: actions/upload-artifact@v4
+        with:
+          name: comment
+          path: comment
+          retention-days: 1
+    

.gitignore

@@ -2,11 +2,33 @@
 *.o
 *.d
 *.a
+*.ci
+*.csv
+*.t.*
+*.b.*
+*.gcno
+*.gcda
+*.perf
+lfs
+liblfs.a
 
 # Testing things
-blocks/
-lfs
-test.c
-tests/*.toml.*
-scripts/__pycache__
+runners/test_runner
+runners/bench_runner
+lfs.code.csv
+lfs.data.csv
+lfs.stack.csv
+lfs.structs.csv
+lfs.cov.csv
+lfs.perf.csv
+lfs.perfbd.csv
+lfs.test.csv
+lfs.bench.csv
+
+# Misc
+tags
 .gdb_history
+scripts/__pycache__
+
+# Historical, probably should remove at some point
+tests/*.toml.*

.travis.yml

@@ -1,429 +0,0 @@
-# environment variables
-env:
-  global:
-    - CFLAGS=-Werror
-    - MAKEFLAGS=-j
-
-# cache installation dirs
-cache:
-  pip: true
-  directories:
-    - $HOME/.cache/apt
-
-# common installation
-_: &install-common
-  # need toml, also pip3 isn't installed by default?
-  - sudo apt-get install python3 python3-pip
-  - sudo pip3 install toml
-  # setup a ram-backed disk to speed up reentrant tests
-  - mkdir disks
-  - sudo mount -t tmpfs -o size=100m tmpfs disks
-  - export TFLAGS="$TFLAGS --disk=disks/disk"
-
-# test cases
-_: &test-example
-  # make sure example can at least compile
-  - sed -n '/``` c/,/```/{/```/d; p}' README.md > test.c &&
-    make all CFLAGS+="
-        -Duser_provided_block_device_read=NULL
-        -Duser_provided_block_device_prog=NULL
-        -Duser_provided_block_device_erase=NULL
-        -Duser_provided_block_device_sync=NULL
-        -include stdio.h"
-# default tests
-_: &test-default
-  # normal+reentrant tests
-  - make test TFLAGS+="-nrk"
-# common real-life geometries
-_: &test-nor
-  # NOR flash: read/prog = 1 block = 4KiB
-  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=1 -DLFS_BLOCK_SIZE=4096"
-_: &test-emmc
-  # eMMC: read/prog = 512 block = 512
-  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=512 -DLFS_BLOCK_SIZE=512"
-_: &test-nand
-  # NAND flash: read/prog = 4KiB block = 32KiB
-  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=4096 -DLFS_BLOCK_SIZE=\(32*1024\)"
-# other extreme geometries that are useful for testing various corner cases
-_: &test-no-intrinsics
-  - make test TFLAGS+="-nrk -DLFS_NO_INTRINSICS"
-_: &test-no-inline
-  - make test TFLAGS+="-nrk -DLFS_INLINE_MAX=0"
-_: &test-byte-writes
-  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=1 -DLFS_CACHE_SIZE=1"
-_: &test-block-cycles
-  - make test TFLAGS+="-nrk -DLFS_BLOCK_CYCLES=1"
-_: &test-odd-block-count
-  - make test TFLAGS+="-nrk -DLFS_BLOCK_COUNT=1023 -DLFS_LOOKAHEAD_SIZE=256"
-_: &test-odd-block-size
-  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=11 -DLFS_BLOCK_SIZE=704"
-
-# report size 
-_: &report-size
-  # compile and find the code size with the smallest configuration
-  - make -j1 clean size
-        OBJ="$(ls lfs*.c | sed 's/\.c/\.o/' | tr '\n' ' ')"
-        CFLAGS+="-DLFS_NO_ASSERT -DLFS_NO_DEBUG -DLFS_NO_WARN -DLFS_NO_ERROR"
-        | tee sizes
-  # update status if we succeeded, compare with master if possible
-  - |
-    if [ "$TRAVIS_TEST_RESULT" -eq 0 ]
-    then
-        CURR=$(tail -n1 sizes | awk '{print $1}')
-        PREV=$(curl -u "$GEKY_BOT_STATUSES" https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/master \
-            | jq -re "select(.sha != \"$TRAVIS_COMMIT\")
-                | .statuses[] | select(.context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\").description
-                | capture(\"code size is (?<size>[0-9]+)\").size" \
-            || echo 0)
-  
-        STATUS="Passed, code size is ${CURR}B"
-        if [ "$PREV" -ne 0 ]
-        then
-            STATUS="$STATUS ($(python -c "print '%+.2f' % (100*($CURR-$PREV)/$PREV.0)")%)"
-        fi
-    fi
-
-# stage control
-stages:
-  - name: test
-  - name: deploy
-    if: branch = master AND type = push
-
-# job control
-jobs:
-  # native testing
-  - &x86
-    stage: test
-    env:
-      - NAME=littlefs-x86
-    install: *install-common
-    script: [*test-example, *report-size]
-  - {<<: *x86, script: [*test-default,          *report-size]}
-  - {<<: *x86, script: [*test-nor,              *report-size]}
-  - {<<: *x86, script: [*test-emmc,             *report-size]}
-  - {<<: *x86, script: [*test-nand,             *report-size]}
-  - {<<: *x86, script: [*test-no-intrinsics,    *report-size]}
-  - {<<: *x86, script: [*test-no-inline,        *report-size]}
-  - {<<: *x86, script: [*test-byte-writes,      *report-size]}
-  - {<<: *x86, script: [*test-block-cycles,     *report-size]}
-  - {<<: *x86, script: [*test-odd-block-count,  *report-size]}
-  - {<<: *x86, script: [*test-odd-block-size,   *report-size]}
-
-  # cross-compile with ARM (thumb mode)
-  - &arm
-    stage: test
-    env:
-      - NAME=littlefs-arm
-      - CC="arm-linux-gnueabi-gcc --static -mthumb"
-      - TFLAGS="$TFLAGS --exec=qemu-arm"
-    install:
-      - *install-common
-      - sudo apt-get install
-            gcc-arm-linux-gnueabi
-            libc6-dev-armel-cross
-            qemu-user
-      - arm-linux-gnueabi-gcc --version
-      - qemu-arm -version
-    script: [*test-example, *report-size]
-  - {<<: *arm, script: [*test-default,          *report-size]}
-  - {<<: *arm, script: [*test-nor,              *report-size]}
-  - {<<: *arm, script: [*test-emmc,             *report-size]}
-  - {<<: *arm, script: [*test-nand,             *report-size]}
-  - {<<: *arm, script: [*test-no-intrinsics,    *report-size]}
-  - {<<: *arm, script: [*test-no-inline,        *report-size]}
-  # it just takes way to long to run byte-level writes in qemu,
-  # note this is still tested in the native tests
-  #- {<<: *arm, script: [*test-byte-writes,      *report-size]}
-  - {<<: *arm, script: [*test-block-cycles,     *report-size]}
-  - {<<: *arm, script: [*test-odd-block-count,  *report-size]}
-  - {<<: *arm, script: [*test-odd-block-size,   *report-size]}
-
-  # cross-compile with MIPS
-  - &mips
-    stage: test
-    env:
-      - NAME=littlefs-mips
-      - CC="mips-linux-gnu-gcc --static"
-      - TFLAGS="$TFLAGS --exec=qemu-mips"
-    install:
-      - *install-common
-      - sudo apt-get install
-            gcc-mips-linux-gnu
-            libc6-dev-mips-cross
-            qemu-user
-      - mips-linux-gnu-gcc --version
-      - qemu-mips -version
-    script: [*test-example, *report-size]
-  - {<<: *mips, script: [*test-default,          *report-size]}
-  - {<<: *mips, script: [*test-nor,              *report-size]}
-  - {<<: *mips, script: [*test-emmc,             *report-size]}
-  - {<<: *mips, script: [*test-nand,             *report-size]}
-  - {<<: *mips, script: [*test-no-intrinsics,    *report-size]}
-  - {<<: *mips, script: [*test-no-inline,        *report-size]}
-  # it just takes way to long to run byte-level writes in qemu,
-  # note this is still tested in the native tests
-  #- {<<: *mips, script: [*test-byte-writes,      *report-size]}
-  - {<<: *mips, script: [*test-block-cycles,     *report-size]}
-  - {<<: *mips, script: [*test-odd-block-count,  *report-size]}
-  - {<<: *mips, script: [*test-odd-block-size,   *report-size]}
-
-  # cross-compile with PowerPC
-  - &powerpc
-    stage: test
-    env:
-      - NAME=littlefs-powerpc
-      - CC="powerpc-linux-gnu-gcc --static"
-      - TFLAGS="$TFLAGS --exec=qemu-ppc"
-    install:
-      - *install-common
-      - sudo apt-get install
-            gcc-powerpc-linux-gnu
-            libc6-dev-powerpc-cross
-            qemu-user
-      - powerpc-linux-gnu-gcc --version
-      - qemu-ppc -version
-    script: [*test-example, *report-size]
-  - {<<: *powerpc, script: [*test-default,          *report-size]}
-  - {<<: *powerpc, script: [*test-nor,              *report-size]}
-  - {<<: *powerpc, script: [*test-emmc,             *report-size]}
-  - {<<: *powerpc, script: [*test-nand,             *report-size]}
-  - {<<: *powerpc, script: [*test-no-intrinsics,    *report-size]}
-  - {<<: *powerpc, script: [*test-no-inline,        *report-size]}
-  # it just takes way to long to run byte-level writes in qemu,
-  # note this is still tested in the native tests
-  #- {<<: *powerpc, script: [*test-byte-writes,      *report-size]}
-  - {<<: *powerpc, script: [*test-block-cycles,     *report-size]}
-  - {<<: *powerpc, script: [*test-odd-block-count,  *report-size]}
-  - {<<: *powerpc, script: [*test-odd-block-size,   *report-size]}
-
-  # test under valgrind, checking for memory errors
-  - &valgrind
-    stage: test
-    env:
-      - NAME=littlefs-valgrind
-    install:
-      - *install-common
-      - sudo apt-get install valgrind
-      - valgrind --version
-    script:
-      - make test TFLAGS+="-k --valgrind"
-
-  # self-host with littlefs-fuse for fuzz test
-  - stage: test
-    env:
-      - NAME=littlefs-fuse
-    if: branch !~ -prefix$
-    install:
-      - *install-common
-      - sudo apt-get install libfuse-dev
-      - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2
-      - fusermount -V
-      - gcc --version
-
-      # setup disk for littlefs-fuse
-      - rm -rf littlefs-fuse/littlefs/*
-      - cp -r $(git ls-tree --name-only HEAD) littlefs-fuse/littlefs
-
-      - mkdir mount
-      - sudo chmod a+rw /dev/loop0
-      - dd if=/dev/zero bs=512 count=128K of=disk
-      - losetup /dev/loop0 disk
-    script:
-      # self-host test
-      - make -C littlefs-fuse
-
-      - littlefs-fuse/lfs --format /dev/loop0
-      - littlefs-fuse/lfs /dev/loop0 mount
-
-      - ls mount
-      - mkdir mount/littlefs
-      - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
-      - cd mount/littlefs
-      - stat .
-      - ls -flh
-      - make -B test
-
-  # test migration using littlefs-fuse
-  - stage: test
-    env:
-      - NAME=littlefs-migration
-    if: branch !~ -prefix$
-    install:
-      - *install-common
-      - sudo apt-get install libfuse-dev
-      - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2 v2
-      - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v1 v1
-      - fusermount -V
-      - gcc --version
-
-      # setup disk for littlefs-fuse
-      - rm -rf v2/littlefs/*
-      - cp -r $(git ls-tree --name-only HEAD) v2/littlefs
-
-      - mkdir mount
-      - sudo chmod a+rw /dev/loop0
-      - dd if=/dev/zero bs=512 count=128K of=disk
-      - losetup /dev/loop0 disk
-    script:
-      # compile v1 and v2
-      - make -C v1
-      - make -C v2
-
-      # run self-host test with v1
-      - v1/lfs --format /dev/loop0
-      - v1/lfs /dev/loop0 mount
-
-      - ls mount
-      - mkdir mount/littlefs
-      - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
-      - cd mount/littlefs
-      - stat .
-      - ls -flh
-      - make -B test
-
-      # attempt to migrate
-      - cd ../..
-      - fusermount -u mount
-
-      - v2/lfs --migrate /dev/loop0
-      - v2/lfs /dev/loop0 mount
-
-      # run self-host test with v2 right where we left off
-      - ls mount
-      - cd mount/littlefs
-      - stat .
-      - ls -flh
-      - make -B test
-
-  # automatically create releases
-  - stage: deploy
-    env:
-      - NAME=deploy
-    script:
-      - |
-        bash << 'SCRIPT'
-        set -ev
-        # Find version defined in lfs.h
-        LFS_VERSION=$(grep -ox '#define LFS_VERSION .*' lfs.h | cut -d ' ' -f3)
-        LFS_VERSION_MAJOR=$((0xffff & ($LFS_VERSION >> 16)))
-        LFS_VERSION_MINOR=$((0xffff & ($LFS_VERSION >>  0)))
-        # Grab latests patch from repo tags, default to 0, needs finagling
-        # to get past github's pagination api
-        PREV_URL=https://api.github.com/repos/$TRAVIS_REPO_SLUG/git/refs/tags/v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.
-        PREV_URL=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" -I \
-            | sed -n '/^Link/{s/.*<\(.*\)>; rel="last"/\1/;p;q0};$q1' \
-            || echo $PREV_URL)
-        LFS_VERSION_PATCH=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" \
-            | jq 'map(.ref | match("\\bv.*\\..*\\.(.*)$";"g")
-                .captures[].string | tonumber) | max + 1' \
-            || echo 0)
-        # We have our new version
-        LFS_VERSION="v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.$LFS_VERSION_PATCH"
-        echo "VERSION $LFS_VERSION"
-        # Check that we're the most recent commit
-        CURRENT_COMMIT=$(curl -f -u "$GEKY_BOT_RELEASES" \
-            https://api.github.com/repos/$TRAVIS_REPO_SLUG/commits/master \
-            | jq -re '.sha')
-        [ "$TRAVIS_COMMIT" == "$CURRENT_COMMIT" ] || exit 0
-        # Create major branch
-        git branch v$LFS_VERSION_MAJOR HEAD
-        # Create major prefix branch
-        git config user.name "geky bot"
-        git config user.email "bot@geky.net"
-        git fetch https://github.com/$TRAVIS_REPO_SLUG.git \
-            --depth=50 v$LFS_VERSION_MAJOR-prefix || true
-        ./scripts/prefix.py lfs$LFS_VERSION_MAJOR
-        git branch v$LFS_VERSION_MAJOR-prefix $( \
-            git commit-tree $(git write-tree) \
-                $(git rev-parse --verify -q FETCH_HEAD | sed -e 's/^/-p /') \
-                -p HEAD \
-                -m "Generated v$LFS_VERSION_MAJOR prefixes")
-        git reset --hard
-        # Update major version branches (vN and vN-prefix)
-        git push --atomic https://$GEKY_BOT_RELEASES@github.com/$TRAVIS_REPO_SLUG.git \
-            v$LFS_VERSION_MAJOR \
-            v$LFS_VERSION_MAJOR-prefix
-        # Build release notes
-        PREV=$(git tag --sort=-v:refname -l "v*" | head -1)
-        if [ ! -z "$PREV" ]
-        then
-            echo "PREV $PREV"
-            CHANGES=$(git log --oneline $PREV.. --grep='^Merge' --invert-grep)
-            printf "CHANGES\n%s\n\n" "$CHANGES"
-        fi
-        case ${GEKY_BOT_DRAFT:-minor} in
-            true)  DRAFT=true ;;
-            minor) DRAFT=$(jq -R 'endswith(".0")' <<< "$LFS_VERSION") ;;
-            false) DRAFT=false ;;
-        esac
-        # Create the release and patch version tag (vN.N.N)
-        curl -f -u "$GEKY_BOT_RELEASES" -X POST \
-            https://api.github.com/repos/$TRAVIS_REPO_SLUG/releases \
-            -d "{
-                \"tag_name\": \"$LFS_VERSION\",
-                \"name\": \"${LFS_VERSION%.0}\",
-                \"target_commitish\": \"$TRAVIS_COMMIT\",
-                \"draft\": $DRAFT,
-                \"body\": $(jq -sR '.' <<< "$CHANGES")
-            }" #"
-        SCRIPT
-
-# manage statuses
-before_install:
-  - |
-    # don't clobber other (not us) failures
-    if ! curl https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-        | jq -e ".statuses[] | select(
-            .context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\" and
-            .state == \"failure\" and
-            (.target_url | endswith(\"$TRAVIS_JOB_NUMBER\") | not))"
-    then
-        curl -u "$GEKY_BOT_STATUSES" -X POST \
-            https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-            -d "{
-                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
-                \"state\": \"pending\",
-                \"description\": \"${STATUS:-In progress}\",
-                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
-            }"
-    fi
-
-after_failure:
-  - |
-    # don't clobber other (not us) failures
-    if ! curl https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-        | jq -e ".statuses[] | select(
-            .context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\" and
-            .state == \"failure\" and
-            (.target_url | endswith(\"$TRAVIS_JOB_NUMBER\") | not))"
-    then
-        curl -u "$GEKY_BOT_STATUSES" -X POST \
-            https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-            -d "{
-                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
-                \"state\": \"failure\",
-                \"description\": \"${STATUS:-Failed}\",
-                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
-            }"
-    fi
-
-after_success:
-  - |
-    # don't clobber other (not us) failures
-    # only update if we were last job to mark in progress,
-    # this isn't perfect but is probably good enough
-    if ! curl https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-        | jq -e ".statuses[] | select(
-            .context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\" and
-            (.state == \"failure\" or .state == \"pending\") and
-            (.target_url | endswith(\"$TRAVIS_JOB_NUMBER\") | not))"
-    then
-        curl -u "$GEKY_BOT_STATUSES" -X POST \
-            https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-            -d "{
-                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
-                \"state\": \"success\",
-                \"description\": \"${STATUS:-Passed}\",
-                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
-            }"
-    fi

DESIGN.md

@@ -59,7 +59,7 @@ This leaves us with three major requirements for an embedded filesystem.
    RAM to temporarily store filesystem metadata.
 
    For ROM, this means we need to keep our design simple and reuse code paths
-   were possible. For RAM we have a stronger requirement, all RAM usage is
+   where possible. For RAM we have a stronger requirement, all RAM usage is
    bounded. This means RAM usage does not grow as the filesystem changes in
    size or number of files. This creates a unique challenge as even presumably
    simple operations, such as traversing the filesystem, become surprisingly
@@ -626,7 +626,7 @@ log₂_n_ pointers that skip to different preceding elements of the
 skip-list.
 
 The name comes from heavy use of the [CTZ instruction][wikipedia-ctz], which
-lets us calculate the power-of-two factors efficiently. For a give block _n_,
+lets us calculate the power-of-two factors efficiently. For a given block _n_,
 that block contains ctz(_n_)+1 pointers.
 
 ```

LICENSE.md

@@ -1,3 +1,4 @@
+Copyright (c) 2022, The littlefs authors.  
 Copyright (c) 2017, Arm Limited. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,

Makefile

@@ -1,69 +1,595 @@
-TARGET = lfs.a
+# overrideable build dir, default is in-place
+BUILDDIR ?= .
+# overridable target/src/tools/flags/etc
 ifneq ($(wildcard test.c main.c),)
-override TARGET = lfs
+TARGET ?= $(BUILDDIR)/lfs
+else
+TARGET ?= $(BUILDDIR)/liblfs.a
 endif
 
-CC ?= gcc
-AR ?= ar
-SIZE ?= size
 
-SRC += $(wildcard *.c bd/*.c)
-OBJ := $(SRC:.c=.o)
-DEP := $(SRC:.c=.d)
-ASM := $(SRC:.c=.s)
+CC       ?= gcc
+AR       ?= ar
+SIZE     ?= size
+CTAGS    ?= ctags
+NM       ?= nm
+OBJDUMP  ?= objdump
+VALGRIND ?= valgrind
+GDB		 ?= gdb
+PERF	 ?= perf
+
+# guess clang or gcc (clang sometimes masquerades as gcc because of
+# course it does)
+ifneq ($(shell $(CC) --version | grep clang),)
+NO_GCC = 1
+endif
+
+SRC  ?= $(filter-out $(wildcard *.t.* *.b.*),$(wildcard *.c))
+OBJ  := $(SRC:%.c=$(BUILDDIR)/%.o)
+DEP  := $(SRC:%.c=$(BUILDDIR)/%.d)
+ASM  := $(SRC:%.c=$(BUILDDIR)/%.s)
+CI   := $(SRC:%.c=$(BUILDDIR)/%.ci)
+GCDA := $(SRC:%.c=$(BUILDDIR)/%.t.gcda)
+
+TESTS ?= $(wildcard tests/*.toml)
+TEST_SRC ?= $(SRC) \
+		$(filter-out $(wildcard bd/*.t.* bd/*.b.*),$(wildcard bd/*.c)) \
+		runners/test_runner.c
+TEST_RUNNER ?= $(BUILDDIR)/runners/test_runner
+TEST_A     := $(TESTS:%.toml=$(BUILDDIR)/%.t.a.c) \
+		$(TEST_SRC:%.c=$(BUILDDIR)/%.t.a.c)
+TEST_C     := $(TEST_A:%.t.a.c=%.t.c)
+TEST_OBJ   := $(TEST_C:%.t.c=%.t.o)
+TEST_DEP   := $(TEST_C:%.t.c=%.t.d)
+TEST_CI	   := $(TEST_C:%.t.c=%.t.ci)
+TEST_GCNO  := $(TEST_C:%.t.c=%.t.gcno)
+TEST_GCDA  := $(TEST_C:%.t.c=%.t.gcda)
+TEST_PERF  := $(TEST_RUNNER:%=%.perf)
+TEST_TRACE := $(TEST_RUNNER:%=%.trace)
+TEST_CSV   := $(TEST_RUNNER:%=%.csv)
+
+BENCHES ?= $(wildcard benches/*.toml)
+BENCH_SRC ?= $(SRC) \
+		$(filter-out $(wildcard bd/*.t.* bd/*.b.*),$(wildcard bd/*.c)) \
+		runners/bench_runner.c
+BENCH_RUNNER ?= $(BUILDDIR)/runners/bench_runner
+BENCH_A     := $(BENCHES:%.toml=$(BUILDDIR)/%.b.a.c) \
+		$(BENCH_SRC:%.c=$(BUILDDIR)/%.b.a.c)
+BENCH_C     := $(BENCH_A:%.b.a.c=%.b.c)
+BENCH_OBJ   := $(BENCH_C:%.b.c=%.b.o)
+BENCH_DEP   := $(BENCH_C:%.b.c=%.b.d)
+BENCH_CI    := $(BENCH_C:%.b.c=%.b.ci)
+BENCH_GCNO  := $(BENCH_C:%.b.c=%.b.gcno)
+BENCH_GCDA  := $(BENCH_C:%.b.c=%.b.gcda)
+BENCH_PERF  := $(BENCH_RUNNER:%=%.perf)
+BENCH_TRACE := $(BENCH_RUNNER:%=%.trace)
+BENCH_CSV   := $(BENCH_RUNNER:%=%.csv)
+
+CFLAGS += -g3
+CFLAGS += -I.
+CFLAGS += -std=c99 -Wall -Wextra -pedantic
+CFLAGS += -Wmissing-prototypes
+ifndef NO_GCC
+CFLAGS += -fcallgraph-info=su
+CFLAGS += -ftrack-macro-expansion=0
+endif
 
 ifdef DEBUG
-override CFLAGS += -O0 -g3
+CFLAGS += -O0
 else
-override CFLAGS += -Os
-endif
-ifdef WORD
-override CFLAGS += -m$(WORD)
+CFLAGS += -Os
 endif
 ifdef TRACE
-override CFLAGS += -DLFS_YES_TRACE
+CFLAGS += -DLFS_YES_TRACE
+endif
+ifdef YES_COV
+CFLAGS += --coverage
+endif
+ifdef YES_PERF
+CFLAGS += -fno-omit-frame-pointer
+endif
+ifdef YES_PERFBD
+CFLAGS += -fno-omit-frame-pointer
 endif
-override CFLAGS += -I.
-override CFLAGS += -std=c99 -Wall -pedantic
-override CFLAGS += -Wextra -Wshadow -Wjump-misses-init -Wundef
-# Remove missing-field-initializers because of GCC bug
-override CFLAGS += -Wno-missing-field-initializers
 
 ifdef VERBOSE
-override TFLAGS += -v
+CODEFLAGS    += -v
+DATAFLAGS    += -v
+STACKFLAGS   += -v
+STRUCTSFLAGS += -v
+COVFLAGS     += -v
+PERFFLAGS    += -v
+PERFBDFLAGS  += -v
+endif
+# forward -j flag
+PERFFLAGS   += $(filter -j%,$(MAKEFLAGS))
+PERFBDFLAGS += $(filter -j%,$(MAKEFLAGS))
+ifneq ($(NM),nm)
+CODEFLAGS += --nm-path="$(NM)"
+DATAFLAGS += --nm-path="$(NM)"
+endif
+ifneq ($(OBJDUMP),objdump)
+CODEFLAGS    += --objdump-path="$(OBJDUMP)"
+DATAFLAGS    += --objdump-path="$(OBJDUMP)"
+STRUCTSFLAGS += --objdump-path="$(OBJDUMP)"
+PERFFLAGS    += --objdump-path="$(OBJDUMP)"
+PERFBDFLAGS  += --objdump-path="$(OBJDUMP)"
+endif
+ifneq ($(PERF),perf)
+PERFFLAGS += --perf-path="$(PERF)"
+endif
+
+TESTFLAGS  += -b
+BENCHFLAGS += -b
+# forward -j flag
+TESTFLAGS  += $(filter -j%,$(MAKEFLAGS))
+BENCHFLAGS += $(filter -j%,$(MAKEFLAGS))
+ifdef YES_PERF
+TESTFLAGS  += -p $(TEST_PERF)
+BENCHFLAGS += -p $(BENCH_PERF)
+endif
+ifdef YES_PERFBD
+TESTFLAGS += -t $(TEST_TRACE) --trace-backtrace --trace-freq=100
+endif
+ifndef NO_PERFBD
+BENCHFLAGS += -t $(BENCH_TRACE) --trace-backtrace --trace-freq=100
+endif
+ifdef YES_TESTMARKS
+TESTFLAGS += -o $(TEST_CSV)
+endif
+ifndef NO_BENCHMARKS
+BENCHFLAGS += -o $(BENCH_CSV)
+endif
+ifdef VERBOSE
+TESTFLAGS   += -v
+TESTCFLAGS  += -v
+BENCHFLAGS  += -v
+BENCHCFLAGS += -v
+endif
+ifdef EXEC
+TESTFLAGS  += --exec="$(EXEC)"
+BENCHFLAGS += --exec="$(EXEC)"
+endif
+ifneq ($(GDB),gdb)
+TESTFLAGS  += --gdb-path="$(GDB)"
+BENCHFLAGS += --gdb-path="$(GDB)"
+endif
+ifneq ($(VALGRIND),valgrind)
+TESTFLAGS  += --valgrind-path="$(VALGRIND)"
+BENCHFLAGS += --valgrind-path="$(VALGRIND)"
+endif
+ifneq ($(PERF),perf)
+TESTFLAGS  += --perf-path="$(PERF)"
+BENCHFLAGS += --perf-path="$(PERF)"
+endif
+
+# this is a bit of a hack, but we want to make sure the BUILDDIR
+# directory structure is correct before we run any commands
+ifneq ($(BUILDDIR),.)
+$(if $(findstring n,$(MAKEFLAGS)),, $(shell mkdir -p \
+	$(addprefix $(BUILDDIR)/,$(dir \
+		$(SRC) \
+		$(TESTS) \
+		$(TEST_SRC) \
+		$(BENCHES) \
+		$(BENCH_SRC)))))
 endif
 
 
-all: $(TARGET)
+# commands
 
+## Build littlefs
+.PHONY: all build
+all build: $(TARGET)
+
+## Build assembly files
+.PHONY: asm
 asm: $(ASM)
 
+## Find the total size
+.PHONY: size
 size: $(OBJ)
 	$(SIZE) -t $^
 
-test:
-	./scripts/test.py $(TFLAGS)
-.SECONDEXPANSION:
-test%: tests/test$$(firstword $$(subst \#, ,%)).toml
-	./scripts/test.py $@ $(TFLAGS)
+## Generate a ctags file
+.PHONY: tags
+tags:
+	$(CTAGS) --totals --c-types=+p $(shell find -H -name '*.h') $(SRC)
 
+## Show this help text
+.PHONY: help
+help:
+	@$(strip awk '/^## / { \
+			sub(/^## /,""); \
+			getline rule; \
+			while (rule ~ /^(#|\.PHONY|ifdef|ifndef)/) getline rule; \
+			gsub(/:.*/, "", rule); \
+			printf " "" %-25s %s\n", rule, $$0 \
+		}' $(MAKEFILE_LIST))
+
+## Find the per-function code size
+.PHONY: code
+code: CODEFLAGS+=-S
+code: $(OBJ) $(BUILDDIR)/lfs.code.csv
+	./scripts/code.py $(OBJ) $(CODEFLAGS)
+
+## Compare per-function code size
+.PHONY: code-diff
+code-diff: $(OBJ)
+	./scripts/code.py $^ $(CODEFLAGS) -d $(BUILDDIR)/lfs.code.csv
+
+## Find the per-function data size
+.PHONY: data
+data: DATAFLAGS+=-S
+data: $(OBJ) $(BUILDDIR)/lfs.data.csv
+	./scripts/data.py $(OBJ) $(DATAFLAGS)
+
+## Compare per-function data size
+.PHONY: data-diff
+data-diff: $(OBJ)
+	./scripts/data.py $^ $(DATAFLAGS) -d $(BUILDDIR)/lfs.data.csv
+
+## Find the per-function stack usage
+.PHONY: stack
+stack: STACKFLAGS+=-S
+stack: $(CI) $(BUILDDIR)/lfs.stack.csv
+	./scripts/stack.py $(CI) $(STACKFLAGS)
+
+## Compare per-function stack usage
+.PHONY: stack-diff
+stack-diff: $(CI)
+	./scripts/stack.py $^ $(STACKFLAGS) -d $(BUILDDIR)/lfs.stack.csv
+
+## Find function sizes
+.PHONY: funcs
+funcs: SUMMARYFLAGS+=-S
+funcs: \
+		$(BUILDDIR)/lfs.code.csv \
+		$(BUILDDIR)/lfs.data.csv \
+		$(BUILDDIR)/lfs.stack.csv
+	$(strip ./scripts/summary.py $^ \
+		-bfunction \
+		-fcode=code_size \
+		-fdata=data_size \
+		-fstack=stack_limit --max=stack \
+		$(SUMMARYFLAGS))
+
+## Compare function sizes
+.PHONY: funcs-diff
+funcs-diff: SHELL=/bin/bash
+funcs-diff: $(OBJ) $(CI)
+	$(strip ./scripts/summary.py \
+		<(./scripts/code.py $(OBJ) -q $(CODEFLAGS) -o-) \
+		<(./scripts/data.py $(OBJ) -q $(DATAFLAGS) -o-) \
+		<(./scripts/stack.py $(CI) -q $(STACKFLAGS) -o-) \
+		-bfunction \
+		-fcode=code_size \
+		-fdata=data_size \
+		-fstack=stack_limit --max=stack \
+		$(SUMMARYFLAGS) -d <(./scripts/summary.py \
+			$(BUILDDIR)/lfs.code.csv \
+			$(BUILDDIR)/lfs.data.csv \
+			$(BUILDDIR)/lfs.stack.csv \
+			-q $(SUMMARYFLAGS) -o-))
+
+## Find struct sizes
+.PHONY: structs
+structs: STRUCTSFLAGS+=-S
+structs: $(OBJ) $(BUILDDIR)/lfs.structs.csv
+	./scripts/structs.py $(OBJ) $(STRUCTSFLAGS)
+
+## Compare struct sizes
+.PHONY: structs-diff
+structs-diff: $(OBJ)
+	./scripts/structs.py $^ $(STRUCTSFLAGS) -d $(BUILDDIR)/lfs.structs.csv
+
+## Find the line/branch coverage after a test run
+.PHONY: cov
+cov: COVFLAGS+=-s
+cov: $(GCDA) $(BUILDDIR)/lfs.cov.csv
+	$(strip ./scripts/cov.py $(GCDA) \
+		$(patsubst %,-F%,$(SRC)) \
+		$(COVFLAGS))
+
+## Compare line/branch coverage
+.PHONY: cov-diff
+cov-diff: $(GCDA)
+	$(strip ./scripts/cov.py $^ \
+		$(patsubst %,-F%,$(SRC)) \
+		$(COVFLAGS) -d $(BUILDDIR)/lfs.cov.csv)
+
+## Find the perf results after bench run with YES_PERF
+.PHONY: perf
+perf: PERFFLAGS+=-S
+perf: $(BENCH_PERF) $(BUILDDIR)/lfs.perf.csv
+	$(strip ./scripts/perf.py $(BENCH_PERF) \
+		$(patsubst %,-F%,$(SRC)) \
+		$(PERFFLAGS))
+
+## Compare perf results
+.PHONY: perf-diff
+perf-diff: $(BENCH_PERF)
+	$(strip ./scripts/perf.py $^ \
+		$(patsubst %,-F%,$(SRC)) \
+		$(PERFFLAGS) -d $(BUILDDIR)/lfs.perf.csv)
+
+## Find the perfbd results after a bench run
+.PHONY: perfbd
+perfbd: PERFBDFLAGS+=-S
+perfbd: $(BENCH_TRACE) $(BUILDDIR)/lfs.perfbd.csv
+	$(strip ./scripts/perfbd.py $(BENCH_RUNNER) $(BENCH_TRACE) \
+		$(patsubst %,-F%,$(SRC)) \
+		$(PERFBDFLAGS))
+
+## Compare perfbd results
+.PHONY: perfbd-diff
+perfbd-diff: $(BENCH_TRACE)
+	$(strip ./scripts/perfbd.py $(BENCH_RUNNER) $^ \
+		$(patsubst %,-F%,$(SRC)) \
+		$(PERFBDFLAGS) -d $(BUILDDIR)/lfs.perfbd.csv)
+
+## Find a summary of compile-time sizes
+.PHONY: summary sizes
+summary sizes: \
+		$(BUILDDIR)/lfs.code.csv \
+		$(BUILDDIR)/lfs.data.csv \
+		$(BUILDDIR)/lfs.stack.csv \
+		$(BUILDDIR)/lfs.structs.csv
+	$(strip ./scripts/summary.py $^ \
+		-fcode=code_size \
+		-fdata=data_size \
+		-fstack=stack_limit --max=stack \
+		-fstructs=struct_size \
+		-Y $(SUMMARYFLAGS))
+
+## Compare compile-time sizes
+.PHONY: summary-diff sizes-diff
+summary-diff sizes-diff: SHELL=/bin/bash
+summary-diff sizes-diff: $(OBJ) $(CI)
+	$(strip ./scripts/summary.py \
+		<(./scripts/code.py $(OBJ) -q $(CODEFLAGS) -o-) \
+		<(./scripts/data.py $(OBJ) -q $(DATAFLAGS) -o-) \
+		<(./scripts/stack.py $(CI) -q $(STACKFLAGS) -o-) \
+		<(./scripts/structs.py $(OBJ) -q $(STRUCTSFLAGS) -o-) \
+		-fcode=code_size \
+		-fdata=data_size \
+		-fstack=stack_limit --max=stack \
+		-fstructs=struct_size \
+		-Y $(SUMMARYFLAGS) -d <(./scripts/summary.py \
+			$(BUILDDIR)/lfs.code.csv \
+			$(BUILDDIR)/lfs.data.csv \
+			$(BUILDDIR)/lfs.stack.csv \
+			$(BUILDDIR)/lfs.structs.csv \
+			-q $(SUMMARYFLAGS) -o-))
+
+## Build the test-runner
+.PHONY: test-runner build-test
+test-runner build-test: CFLAGS+=-Wno-missing-prototypes
+ifndef NO_COV
+test-runner build-test: CFLAGS+=--coverage
+endif
+ifdef YES_PERF
+test-runner build-test: CFLAGS+=-fno-omit-frame-pointer
+endif
+ifdef YES_PERFBD
+test-runner build-test: CFLAGS+=-fno-omit-frame-pointer
+endif
+# note we remove some binary dependent files during compilation,
+# otherwise it's way to easy to end up with outdated results
+test-runner build-test: $(TEST_RUNNER)
+ifndef NO_COV
+	rm -f $(TEST_GCDA)
+endif
+ifdef YES_PERF
+	rm -f $(TEST_PERF)
+endif
+ifdef YES_PERFBD
+	rm -f $(TEST_TRACE)
+endif
+
+## Run the tests, -j enables parallel tests
+.PHONY: test
+test: test-runner
+	./scripts/test.py $(TEST_RUNNER) $(TESTFLAGS)
+
+## List the tests
+.PHONY: test-list
+test-list: test-runner
+	./scripts/test.py $(TEST_RUNNER) $(TESTFLAGS) -l
+
+## Summarize the testmarks
+.PHONY: testmarks
+testmarks: SUMMARYFLAGS+=-spassed
+testmarks: $(TEST_CSV) $(BUILDDIR)/lfs.test.csv
+	$(strip ./scripts/summary.py $(TEST_CSV) \
+		-bsuite \
+		-fpassed=test_passed \
+		$(SUMMARYFLAGS))
+
+## Compare testmarks against a previous run
+.PHONY: testmarks-diff
+testmarks-diff: $(TEST_CSV)
+	$(strip ./scripts/summary.py $^ \
+		-bsuite \
+		-fpassed=test_passed \
+		$(SUMMARYFLAGS) -d $(BUILDDIR)/lfs.test.csv)
+
+## Build the bench-runner
+.PHONY: bench-runner build-bench
+bench-runner build-bench: CFLAGS+=-Wno-missing-prototypes
+ifdef YES_COV
+bench-runner build-bench: CFLAGS+=--coverage
+endif
+ifdef YES_PERF
+bench-runner build-bench: CFLAGS+=-fno-omit-frame-pointer
+endif
+ifndef NO_PERFBD
+bench-runner build-bench: CFLAGS+=-fno-omit-frame-pointer
+endif
+# note we remove some binary dependent files during compilation,
+# otherwise it's way to easy to end up with outdated results
+bench-runner build-bench: $(BENCH_RUNNER)
+ifdef YES_COV 
+	rm -f $(BENCH_GCDA)
+endif
+ifdef YES_PERF
+	rm -f $(BENCH_PERF)
+endif
+ifndef NO_PERFBD
+	rm -f $(BENCH_TRACE)
+endif
+
+## Run the benchmarks, -j enables parallel benchmarks
+.PHONY: bench
+bench: bench-runner
+	./scripts/bench.py $(BENCH_RUNNER) $(BENCHFLAGS)
+
+## List the benchmarks
+.PHONY: bench-list
+bench-list: bench-runner
+	./scripts/bench.py $(BENCH_RUNNER) $(BENCHFLAGS) -l
+
+## Summarize the benchmarks
+.PHONY: benchmarks
+benchmarks: SUMMARYFLAGS+=-Serased -Sproged -Sreaded
+benchmarks: $(BENCH_CSV) $(BUILDDIR)/lfs.bench.csv
+	$(strip ./scripts/summary.py $(BENCH_CSV) \
+		-bsuite \
+		-freaded=bench_readed \
+		-fproged=bench_proged \
+		-ferased=bench_erased \
+		$(SUMMARYFLAGS))
+
+## Compare benchmarks against a previous run
+.PHONY: benchmarks-diff
+benchmarks-diff: $(BENCH_CSV)
+	$(strip ./scripts/summary.py $^ \
+		-bsuite \
+		-freaded=bench_readed \
+		-fproged=bench_proged \
+		-ferased=bench_erased \
+		$(SUMMARYFLAGS) -d $(BUILDDIR)/lfs.bench.csv)
+
+
+
+# rules
 -include $(DEP)
+-include $(TEST_DEP)
+-include $(BENCH_DEP)
+.SUFFIXES:
+.SECONDARY:
 
-lfs: $(OBJ)
+$(BUILDDIR)/lfs: $(OBJ)
 	$(CC) $(CFLAGS) $^ $(LFLAGS) -o $@
 
-%.a: $(OBJ)
+$(BUILDDIR)/liblfs.a: $(OBJ)
 	$(AR) rcs $@ $^
 
-%.o: %.c
-	$(CC) -c -MMD $(CFLAGS) $< -o $@
+$(BUILDDIR)/lfs.code.csv: $(OBJ)
+	./scripts/code.py $^ -q $(CODEFLAGS) -o $@
 
-%.s: %.c
+$(BUILDDIR)/lfs.data.csv: $(OBJ)
+	./scripts/data.py $^ -q $(DATAFLAGS) -o $@
+
+$(BUILDDIR)/lfs.stack.csv: $(CI)
+	./scripts/stack.py $^ -q $(STACKFLAGS) -o $@
+
+$(BUILDDIR)/lfs.structs.csv: $(OBJ)
+	./scripts/structs.py $^ -q $(STRUCTSFLAGS) -o $@
+
+$(BUILDDIR)/lfs.cov.csv: $(GCDA)
+	$(strip ./scripts/cov.py $^ \
+		$(patsubst %,-F%,$(SRC)) \
+		-q $(COVFLAGS) -o $@)
+
+$(BUILDDIR)/lfs.perf.csv: $(BENCH_PERF)
+	$(strip ./scripts/perf.py $^ \
+		$(patsubst %,-F%,$(SRC)) \
+		-q $(PERFFLAGS) -o $@)
+
+$(BUILDDIR)/lfs.perfbd.csv: $(BENCH_TRACE)
+	$(strip ./scripts/perfbd.py $(BENCH_RUNNER) $^ \
+		$(patsubst %,-F%,$(SRC)) \
+		-q $(PERFBDFLAGS) -o $@)
+
+$(BUILDDIR)/lfs.test.csv: $(TEST_CSV)
+	cp $^ $@
+
+$(BUILDDIR)/lfs.bench.csv: $(BENCH_CSV)
+	cp $^ $@
+
+$(BUILDDIR)/runners/test_runner: $(TEST_OBJ)
+	$(CC) $(CFLAGS) $^ $(LFLAGS) -o $@
+
+$(BUILDDIR)/runners/bench_runner: $(BENCH_OBJ)
+	$(CC) $(CFLAGS) $^ $(LFLAGS) -o $@
+
+# our main build rule generates .o, .d, and .ci files, the latter
+# used for stack analysis
+$(BUILDDIR)/%.o $(BUILDDIR)/%.ci: %.c
+	$(CC) -c -MMD $(CFLAGS) $< -o $(BUILDDIR)/$*.o
+
+$(BUILDDIR)/%.o $(BUILDDIR)/%.ci: $(BUILDDIR)/%.c
+	$(CC) -c -MMD $(CFLAGS) $< -o $(BUILDDIR)/$*.o
+
+$(BUILDDIR)/%.s: %.c
 	$(CC) -S $(CFLAGS) $< -o $@
 
+$(BUILDDIR)/%.c: %.a.c
+	./scripts/prettyasserts.py -p LFS_ASSERT $< -o $@
+
+$(BUILDDIR)/%.c: $(BUILDDIR)/%.a.c
+	./scripts/prettyasserts.py -p LFS_ASSERT $< -o $@
+
+$(BUILDDIR)/%.t.a.c: %.toml
+	./scripts/test.py -c $< $(TESTCFLAGS) -o $@
+
+$(BUILDDIR)/%.t.a.c: %.c $(TESTS)
+	./scripts/test.py -c $(TESTS) -s $< $(TESTCFLAGS) -o $@
+
+$(BUILDDIR)/%.b.a.c: %.toml
+	./scripts/bench.py -c $< $(BENCHCFLAGS) -o $@
+
+$(BUILDDIR)/%.b.a.c: %.c $(BENCHES)
+	./scripts/bench.py -c $(BENCHES) -s $< $(BENCHCFLAGS) -o $@
+
+## Clean everything
+.PHONY: clean
 clean:
-	rm -f $(TARGET)
+	rm -f $(BUILDDIR)/lfs
+	rm -f $(BUILDDIR)/liblfs.a
+	rm -f $(BUILDDIR)/lfs.code.csv
+	rm -f $(BUILDDIR)/lfs.data.csv
+	rm -f $(BUILDDIR)/lfs.stack.csv
+	rm -f $(BUILDDIR)/lfs.structs.csv
+	rm -f $(BUILDDIR)/lfs.cov.csv
+	rm -f $(BUILDDIR)/lfs.perf.csv
+	rm -f $(BUILDDIR)/lfs.perfbd.csv
+	rm -f $(BUILDDIR)/lfs.test.csv
+	rm -f $(BUILDDIR)/lfs.bench.csv
 	rm -f $(OBJ)
 	rm -f $(DEP)
 	rm -f $(ASM)
-	rm -f tests/*.toml.*
+	rm -f $(CI)
+	rm -f $(TEST_RUNNER)
+	rm -f $(TEST_A)
+	rm -f $(TEST_C)
+	rm -f $(TEST_OBJ)
+	rm -f $(TEST_DEP)
+	rm -f $(TEST_CI)
+	rm -f $(TEST_GCNO)
+	rm -f $(TEST_GCDA)
+	rm -f $(TEST_PERF)
+	rm -f $(TEST_TRACE)
+	rm -f $(TEST_CSV)
+	rm -f $(BENCH_RUNNER)
+	rm -f $(BENCH_A)
+	rm -f $(BENCH_C)
+	rm -f $(BENCH_OBJ)
+	rm -f $(BENCH_DEP)
+	rm -f $(BENCH_CI)
+	rm -f $(BENCH_GCNO)
+	rm -f $(BENCH_GCDA)
+	rm -f $(BENCH_PERF)
+	rm -f $(BENCH_TRACE)
+	rm -f $(BENCH_CSV)

README.md

@@ -192,13 +192,54 @@ More details on how littlefs works can be found in [DESIGN.md](DESIGN.md) and
 ## Testing
 
 The littlefs comes with a test suite designed to run on a PC using the
-[emulated block device](emubd/lfs_emubd.h) found in the emubd directory.
+[emulated block device](bd/lfs_testbd.h) found in the `bd` directory.
 The tests assume a Linux environment and can be started with make:
 
 ``` bash
 make test
 ```
 
+Tests are implemented in C in the .toml files found in the `tests` directory.
+When developing a feature or fixing a bug, it is frequently useful to run a
+single test case or suite of tests:
+
+``` bash
+./scripts/test.py -l runners/test_runner  # list available test suites
+./scripts/test.py -L runners/test_runner test_dirs  # list available test cases
+./scripts/test.py runners/test_runner test_dirs  # run a specific test suite
+```
+
+If an assert fails in a test, test.py will try to print information about the
+failure:
+
+``` bash
+tests/test_dirs.toml:1:failure: test_dirs_root:1g12gg2 (PROG_SIZE=16, ERASE_SIZE=512) failed
+tests/test_dirs.toml:5:assert: assert failed with 0, expected eq 42
+    lfs_mount(&lfs, cfg) => 42;
+```
+
+This includes the test id, which can be passed to test.py to run only that
+specific test permutation:
+
+``` bash
+./scripts/test.py runners/test_runner test_dirs_root:1g12gg2  # run a specific test permutation
+./scripts/test.py runners/test_runner test_dirs_root:1g12gg2 --gdb  # drop into gdb on failure
+```
+
+Some other flags that may be useful:
+
+```bash
+./scripts/test.py runners/test_runner -b -j  # run tests in parallel
+./scripts/test.py runners/test_runner -v -O-  # redirect stdout to stdout
+./scripts/test.py runners/test_runner -ddisk  # capture resulting disk image
+```
+
+See `-h/--help` for a full list of available flags:
+
+``` bash
+./scripts/test.py --help
+```
+
 ## License
 
 The littlefs is provided under the [BSD-3-Clause] license. See
@@ -221,9 +262,41 @@ License Identifiers that are here available: http://spdx.org/licenses/
 - [littlefs-js] - A javascript wrapper for littlefs. I'm not sure why you would
   want this, but it is handy for demos.  You can see it in action
   [here][littlefs-js-demo].
+  
+- [littlefs-python] - A Python wrapper for littlefs. The project allows you
+  to create images of the filesystem on your PC. Check if littlefs will fit
+  your needs, create images for a later download to the target memory or
+  inspect the content of a binary image of the target memory.
+  
+- [littlefs2-rust] - A Rust wrapper for littlefs. This project allows you
+  to use littlefs in a Rust-friendly API, reaping the benefits of Rust's memory
+  safety and other guarantees.
 
-- [mklfs] - A command line tool built by the [Lua RTOS] guys for making
-  littlefs images from a host PC. Supports Windows, Mac OS, and Linux.
+- [nim-littlefs] - A Nim wrapper and API for littlefs. Includes a fuse
+  implementation based on [littlefs-fuse]
+
+- [chamelon] - A pure-OCaml implementation of (most of) littlefs, designed for
+  use with the MirageOS library operating system project. It is interoperable
+  with the reference implementation, with some caveats.
+
+- [littlefs-disk-img-viewer] - A memory-efficient web application for viewing
+  littlefs disk images in your web browser.
+
+- [mklfs] - A command line tool for creating littlefs images. Used in the Lua
+  RTOS ecosystem.
+
+- [mklittlefs] - A command line tool for creating littlefs images. Used in the
+  ESP8266 and RP2040 ecosystem.
+
+- [pico-littlefs-usb] - An interface for littlefs that emulates a FAT12
+  filesystem over USB. Allows mounting littlefs on a host PC without additional
+  drivers.
+
+- [ramcrc32bd] - An example block device using littlefs's 32-bit CRC for
+  error-correction.
+
+- [ramrsbd] - An example block device using Reed-Solomon codes for
+  error-correction.
 
 - [Mbed OS] - The easiest way to get started with littlefs is to jump into Mbed
   which already has block device drivers for most forms of embedded storage.
@@ -238,15 +311,27 @@ License Identifiers that are here available: http://spdx.org/licenses/
   MCUs. It offers static wear-leveling and power-resilience with only a fixed
   _O(|address|)_ pointer structure stored on each block and in RAM.
 
+- [ChaN's FatFs] - A lightweight reimplementation of the infamous FAT filesystem
+  for microcontroller-scale devices. Due to limitations of FAT it can't provide
+  power-loss resilience, but it does allow easy interop with PCs.
 
 [BSD-3-Clause]: https://spdx.org/licenses/BSD-3-Clause.html
 [littlefs-fuse]: https://github.com/geky/littlefs-fuse
 [FUSE]: https://github.com/libfuse/libfuse
 [littlefs-js]: https://github.com/geky/littlefs-js
 [littlefs-js-demo]:http://littlefs.geky.net/demo.html
+[littlefs-python]: https://pypi.org/project/littlefs-python/
+[littlefs2-rust]: https://crates.io/crates/littlefs2
+[nim-littlefs]: https://github.com/Graveflo/nim-littlefs
+[chamelon]: https://github.com/yomimono/chamelon
+[littlefs-disk-img-viewer]: https://github.com/tniessen/littlefs-disk-img-viewer
 [mklfs]: https://github.com/whitecatboard/Lua-RTOS-ESP32/tree/master/components/mklfs/src
-[Lua RTOS]: https://github.com/whitecatboard/Lua-RTOS-ESP32
+[mklittlefs]: https://github.com/earlephilhower/mklittlefs
+[pico-littlefs-usb]: https://github.com/oyama/pico-littlefs-usb
+[ramcrc32bd]: https://github.com/geky/ramcrc32bd
+[ramrsbd]: https://github.com/geky/ramrsbd
 [Mbed OS]: https://github.com/armmbed/mbed-os
-[LittleFileSystem]: https://os.mbed.com/docs/mbed-os/v5.12/apis/littlefilesystem.html
+[LittleFileSystem]: https://os.mbed.com/docs/mbed-os/latest/apis/littlefilesystem.html
 [SPIFFS]: https://github.com/pellepl/spiffs
 [Dhara]: https://github.com/dlbeer/dhara
+[ChaN's FatFs]: http://elm-chan.org/fsw/ff/00index_e.html

SPEC.md

@@ -1,10 +1,10 @@
 ## littlefs technical specification
 
-This is the technical specification of the little filesystem. This document
-covers the technical details of how the littlefs is stored on disk for
-introspection and tooling. This document assumes you are familiar with the
-design of the littlefs, for more info on how littlefs works check
-out [DESIGN.md](DESIGN.md).
+This is the technical specification of the little filesystem with on-disk
+version lfs2.1. This document covers the technical details of how the littlefs
+is stored on disk for introspection and tooling. This document assumes you are
+familiar with the design of the littlefs, for more info on how littlefs works
+check out [DESIGN.md](DESIGN.md).
 
 ```
    | | |     .---._____
@@ -133,12 +133,6 @@ tags XORed together, starting with `0xffffffff`.
 '-------------------'                    '-------------------'
 ```
 
-One last thing to note before we get into the details around tag encoding. Each
-tag contains a valid bit used to indicate if the tag and containing commit is
-valid. This valid bit is the first bit found in the tag and the commit and can
-be used to tell if we've attempted to write to the remaining space in the
-block.
-
 Here's a more complete example of metadata block containing 4 entries:
 
 ```
@@ -191,6 +185,53 @@ Here's a more complete example of metadata block containing 4 entries:
                                              '---- most recent D
 ```
 
+Two things to note before we get into the details around tag encoding:
+
+1. Each tag contains a valid bit used to indicate if the tag and containing
+   commit is valid. After XORing, this bit should always be zero.
+
+   At the end of each commit, the valid bit of the previous tag is XORed
+   with the lowest bit in the type field of the CRC tag. This allows
+   the CRC tag to force the next commit to fail the valid bit test if it
+   has not yet been written to.
+
+2. The valid bit alone is not enough info to know if the next commit has been
+   erased. We don't know the order bits will be programmed in a program block,
+   so it's possible that the next commit had an attempted program that left the
+   valid bit unchanged.
+
+   To ensure we only ever program erased bytes, each commit can contain an
+   optional forward-CRC (FCRC). An FCRC contains a checksum of some amount of
+   bytes in the next commit at the time it was erased.
+
+   ```
+   .-------------------. \      \
+   |  revision count   | |      |
+   |-------------------| |      |
+   |     metadata      | |      |
+   |                   | +---.  +-- current commit
+   |                   | |   |  |
+   |-------------------| |   |  |
+   |       FCRC       ---|-. |  |
+   |-------------------| / | |  |
+   |        CRC       -----|-'  /
+   |-------------------|   |
+   |      padding      |   |        padding (does't need CRC)
+   |                   |   |
+   |-------------------| \ |    \
+   |      erased?      | +-'    |
+   |         |         | |      +-- next commit
+   |         v         | /      |
+   |                   |        /
+   |                   |
+   '-------------------'
+   ```
+
+   If the FCRC is missing or the checksum does not match, we must assume a
+   commit was attempted but failed due to power-loss.
+
+   Note that end-of-block commits do not need an FCRC.
+
 ## Metadata tags
 
 So in littlefs, 32-bit tags describe every type of metadata. And this means
@@ -233,19 +274,19 @@ Metadata tag fields:
    into a 3-bit abstract type and an 8-bit chunk field. Note that the value
    `0x000` is invalid and not assigned a type.
 
-3. **Type1 (3-bits)** - Abstract type of the tag. Groups the tags into
-   8 categories that facilitate bitmasked lookups.
+    1. **Type1 (3-bits)** - Abstract type of the tag. Groups the tags into
+       8 categories that facilitate bitmasked lookups.
 
-4. **Chunk (8-bits)** - Chunk field used for various purposes by the different
-   abstract types.  type1+chunk+id form a unique identifier for each tag in the
-   metadata block.
+    2. **Chunk (8-bits)** - Chunk field used for various purposes by the different
+       abstract types.  type1+chunk+id form a unique identifier for each tag in the
+       metadata block.
 
-5. **Id (10-bits)** - File id associated with the tag. Each file in a metadata
+3. **Id (10-bits)** - File id associated with the tag. Each file in a metadata
    block gets a unique id which is used to associate tags with that file. The
    special value `0x3ff` is used for any tags that are not associated with a
    file, such as directory and global metadata.
 
-6. **Length (10-bits)** - Length of the data in bytes. The special value
+4. **Length (10-bits)** - Length of the data in bytes. The special value
    `0x3ff` indicates that this tag has been deleted.
 
 ## Metadata types
@@ -400,9 +441,10 @@ Superblock fields:
 
 7. **Attr max (32-bits)** - Maximum size of file attributes in bytes.
 
-The superblock must always be the first entry (id 0) in a metadata pair as well
-as be the first entry written to the block. This means that the superblock
-entry can be read from a device using offsets alone.
+The superblock must always be the first entry (id 0) in the metadata pair, and
+the name tag must always be the first tag in the metadata pair. This makes it
+so that the magic string "littlefs" will always reside at offset=8 in a valid
+littlefs superblock.
 
 ---
 #### `0x2xx` LFS_TYPE_STRUCT
@@ -785,3 +827,41 @@ CRC fields:
    are made about the contents.
 
 ---
+#### `0x5ff` LFS_TYPE_FCRC
+
+Added in lfs2.1, the optional FCRC tag contains a checksum of some amount of
+bytes in the next commit at the time it was erased. This allows us to ensure
+that we only ever program erased bytes, even if a previous commit failed due
+to power-loss.
+
+When programming a commit, the FCRC size must be at least as large as the
+program block size. However, the program block is not saved on disk, and can
+change between mounts, so the FCRC size on disk may be different than the
+current program block size.
+
+If the FCRC is missing or the checksum does not match, we must assume a
+commit was attempted but failed due to power-loss.
+
+Layout of the FCRC tag:
+
+```
+        tag                          data
+[--      32      --][--      32      --|--      32      --]
+[1|- 11 -| 10 | 10 ][--      32      --|--      32      --]
+ ^    ^     ^    ^            ^- fcrc size       ^- fcrc
+ |    |     |    '- size (8)
+ |    |     '------ id (0x3ff)
+ |    '------------ type (0x5ff)
+ '----------------- valid bit
+```
+
+FCRC fields:
+
+1. **FCRC size (32-bits)** - Number of bytes after this commit's CRC tag's
+   padding to include in the FCRC.
+
+2. **FCRC (32-bits)** - CRC of the bytes after this commit's CRC tag's padding
+   when erased. Like the CRC tag, this uses a CRC-32 with a polynomial of
+   `0x04c11db7` initialized with `0xffffffff`.
+
+---

bd/lfs_emubd.c

@@ -0,0 +1,739 @@
+/*
+ * Emulating block device, wraps filebd and rambd while providing a bunch
+ * of hooks for testing littlefs in various conditions.
+ *
+ * Copyright (c) 2022, The littlefs authors.
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 199309L
+#endif
+
+#include "bd/lfs_emubd.h"
+
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <time.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+
+// access to lazily-allocated/copy-on-write blocks
+//
+// Note we can only modify a block if we have exclusive access to it (rc == 1)
+//
+
+static lfs_emubd_block_t *lfs_emubd_incblock(lfs_emubd_block_t *block) {
+    if (block) {
+        block->rc += 1;
+    }
+    return block;
+}
+
+static void lfs_emubd_decblock(lfs_emubd_block_t *block) {
+    if (block) {
+        block->rc -= 1;
+        if (block->rc == 0) {
+            free(block);
+        }
+    }
+}
+
+static lfs_emubd_block_t *lfs_emubd_mutblock(
+        const struct lfs_config *cfg,
+        lfs_emubd_block_t **block) {
+    lfs_emubd_t *bd = cfg->context;
+    lfs_emubd_block_t *block_ = *block;
+    if (block_ && block_->rc == 1) {
+        // rc == 1? can modify
+        return block_;
+
+    } else if (block_) {
+        // rc > 1? need to create a copy
+        lfs_emubd_block_t *nblock = malloc(
+                sizeof(lfs_emubd_block_t) + bd->cfg->erase_size);
+        if (!nblock) {
+            return NULL;
+        }
+
+        memcpy(nblock, block_,
+                sizeof(lfs_emubd_block_t) + bd->cfg->erase_size);
+        nblock->rc = 1;
+
+        lfs_emubd_decblock(block_);
+        *block = nblock;
+        return nblock;
+
+    } else {
+        // no block? need to allocate
+        lfs_emubd_block_t *nblock = malloc(
+                sizeof(lfs_emubd_block_t) + bd->cfg->erase_size);
+        if (!nblock) {
+            return NULL;
+        }
+
+        nblock->rc = 1;
+        nblock->wear = 0;
+
+        // zero for consistency
+        memset(nblock->data,
+                (bd->cfg->erase_value != -1) ? bd->cfg->erase_value : 0,
+                bd->cfg->erase_size);
+
+        *block = nblock;
+        return nblock;
+    }
+}
+
+
+// emubd create/destroy
+
+int lfs_emubd_create(const struct lfs_config *cfg,
+        const struct lfs_emubd_config *bdcfg) {
+    LFS_EMUBD_TRACE("lfs_emubd_create(%p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p}, "
+                "%p {.read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".erase_size=%"PRIu32", .erase_count=%"PRIu32", "
+                ".erase_value=%"PRId32", .erase_cycles=%"PRIu32", "
+                ".badblock_behavior=%"PRIu8", .power_cycles=%"PRIu32", "
+                ".powerloss_behavior=%"PRIu8", .powerloss_cb=%p, "
+                ".powerloss_data=%p, .track_branches=%d})",
+            (void*)cfg, cfg->context,
+            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
+            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
+            (void*)bdcfg,
+            bdcfg->read_size, bdcfg->prog_size, bdcfg->erase_size,
+            bdcfg->erase_count, bdcfg->erase_value, bdcfg->erase_cycles,
+            bdcfg->badblock_behavior, bdcfg->power_cycles,
+            bdcfg->powerloss_behavior, (void*)(uintptr_t)bdcfg->powerloss_cb,
+            bdcfg->powerloss_data, bdcfg->track_branches);
+    lfs_emubd_t *bd = cfg->context;
+    bd->cfg = bdcfg;
+
+    // allocate our block array, all blocks start as uninitialized
+    bd->blocks = malloc(bd->cfg->erase_count * sizeof(lfs_emubd_block_t*));
+    if (!bd->blocks) {
+        LFS_EMUBD_TRACE("lfs_emubd_create -> %d", LFS_ERR_NOMEM);
+        return LFS_ERR_NOMEM;
+    }
+    memset(bd->blocks, 0, bd->cfg->erase_count * sizeof(lfs_emubd_block_t*));
+
+    // setup testing things
+    bd->readed = 0;
+    bd->proged = 0;
+    bd->erased = 0;
+    bd->power_cycles = bd->cfg->power_cycles;
+    bd->ooo_block = -1;
+    bd->ooo_data = NULL;
+    bd->disk = NULL;
+
+    if (bd->cfg->disk_path) {
+        bd->disk = malloc(sizeof(lfs_emubd_disk_t));
+        if (!bd->disk) {
+            LFS_EMUBD_TRACE("lfs_emubd_create -> %d", LFS_ERR_NOMEM);
+            return LFS_ERR_NOMEM;
+        }
+        bd->disk->rc = 1;
+        bd->disk->scratch = NULL;
+
+        #ifdef _WIN32
+        bd->disk->fd = open(bd->cfg->disk_path,
+                O_RDWR | O_CREAT | O_BINARY, 0666);
+        #else
+        bd->disk->fd = open(bd->cfg->disk_path,
+                O_RDWR | O_CREAT, 0666);
+        #endif
+        if (bd->disk->fd < 0) {
+            int err = -errno;
+            LFS_EMUBD_TRACE("lfs_emubd_create -> %d", err);
+            return err;
+        }
+
+        // if we're emulating erase values, we can keep a block around in
+        // memory of just the erase state to speed up emulated erases
+        if (bd->cfg->erase_value != -1) {
+            bd->disk->scratch = malloc(bd->cfg->erase_size);
+            if (!bd->disk->scratch) {
+                LFS_EMUBD_TRACE("lfs_emubd_create -> %d", LFS_ERR_NOMEM);
+                return LFS_ERR_NOMEM;
+            }
+            memset(bd->disk->scratch,
+                    bd->cfg->erase_value,
+                    bd->cfg->erase_size);
+
+            // go ahead and erase all of the disk, otherwise the file will not
+            // match our internal representation
+            for (size_t i = 0; i < bd->cfg->erase_count; i++) {
+                ssize_t res = write(bd->disk->fd,
+                        bd->disk->scratch,
+                        bd->cfg->erase_size);
+                if (res < 0) {
+                    int err = -errno;
+                    LFS_EMUBD_TRACE("lfs_emubd_create -> %d", err);
+                    return err;
+                }
+            }
+        }
+    }
+
+    LFS_EMUBD_TRACE("lfs_emubd_create -> %d", 0);
+    return 0;
+}
+
+int lfs_emubd_destroy(const struct lfs_config *cfg) {
+    LFS_EMUBD_TRACE("lfs_emubd_destroy(%p)", (void*)cfg);
+    lfs_emubd_t *bd = cfg->context;
+
+    // decrement reference counts
+    for (lfs_block_t i = 0; i < bd->cfg->erase_count; i++) {
+        lfs_emubd_decblock(bd->blocks[i]);
+    }
+    free(bd->blocks);
+
+    // clean up other resources 
+    lfs_emubd_decblock(bd->ooo_data);
+    if (bd->disk) {
+        bd->disk->rc -= 1;
+        if (bd->disk->rc == 0) {
+            close(bd->disk->fd);
+            free(bd->disk->scratch);
+            free(bd->disk);
+        }
+    }
+
+    LFS_EMUBD_TRACE("lfs_emubd_destroy -> %d", 0);
+    return 0;
+}
+
+
+// powerloss hook
+static int lfs_emubd_powerloss(const struct lfs_config *cfg) {
+    lfs_emubd_t *bd = cfg->context;
+
+    // emulate out-of-order writes?
+    lfs_emubd_block_t *ooo_data = NULL;
+    if (bd->cfg->powerloss_behavior == LFS_EMUBD_POWERLOSS_OOO
+            && bd->ooo_block != -1) {
+        // since writes between syncs are allowed to be out-of-order, it
+        // shouldn't hurt to restore the first write on powerloss, right?
+        ooo_data = bd->blocks[bd->ooo_block];
+        bd->blocks[bd->ooo_block] = lfs_emubd_incblock(bd->ooo_data);
+
+        // mirror to disk file?
+        if (bd->disk
+                && (bd->blocks[bd->ooo_block]
+                    || bd->cfg->erase_value != -1)) {
+            off_t res1 = lseek(bd->disk->fd,
+                    (off_t)bd->ooo_block*bd->cfg->erase_size,
+                    SEEK_SET);
+            if (res1 < 0) {
+                return -errno;
+            }
+
+            ssize_t res2 = write(bd->disk->fd,
+                    (bd->blocks[bd->ooo_block])
+                        ? bd->blocks[bd->ooo_block]->data
+                        : bd->disk->scratch,
+                    bd->cfg->erase_size);
+            if (res2 < 0) {
+                return -errno;
+            }
+        }
+    }
+
+    // simulate power loss
+    bd->cfg->powerloss_cb(bd->cfg->powerloss_data);
+
+    // if we continue, undo out-of-order write emulation
+    if (bd->cfg->powerloss_behavior == LFS_EMUBD_POWERLOSS_OOO
+            && bd->ooo_block != -1) {
+        lfs_emubd_decblock(bd->blocks[bd->ooo_block]);
+        bd->blocks[bd->ooo_block] = ooo_data;
+
+        // mirror to disk file?
+        if (bd->disk
+                && (bd->blocks[bd->ooo_block]
+                    || bd->cfg->erase_value != -1)) {
+            off_t res1 = lseek(bd->disk->fd,
+                    (off_t)bd->ooo_block*bd->cfg->erase_size,
+                    SEEK_SET);
+            if (res1 < 0) {
+                return -errno;
+            }
+
+            ssize_t res2 = write(bd->disk->fd,
+                    (bd->blocks[bd->ooo_block])
+                        ? bd->blocks[bd->ooo_block]->data
+                        : bd->disk->scratch,
+                    bd->cfg->erase_size);
+            if (res2 < 0) {
+                return -errno;
+            }
+        }
+    }
+
+    return 0;
+}
+
+
+// block device API
+
+int lfs_emubd_read(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, void *buffer, lfs_size_t size) {
+    LFS_EMUBD_TRACE("lfs_emubd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+            (void*)cfg, block, off, buffer, size);
+    lfs_emubd_t *bd = cfg->context;
+
+    // check if read is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
+
+    // get the block
+    const lfs_emubd_block_t *b = bd->blocks[block];
+    if (b) {
+        // block bad?
+        if (bd->cfg->erase_cycles && b->wear >= bd->cfg->erase_cycles &&
+                bd->cfg->badblock_behavior == LFS_EMUBD_BADBLOCK_READERROR) {
+            LFS_EMUBD_TRACE("lfs_emubd_read -> %d", LFS_ERR_CORRUPT);
+            return LFS_ERR_CORRUPT;
+        }
+
+        // read data
+        memcpy(buffer, &b->data[off], size);
+    } else {
+        // zero for consistency
+        memset(buffer,
+                (bd->cfg->erase_value != -1) ? bd->cfg->erase_value : 0,
+                size);
+    }   
+
+    // track reads
+    bd->readed += size;
+    if (bd->cfg->read_sleep) {
+        int err = nanosleep(&(struct timespec){
+                .tv_sec=bd->cfg->read_sleep/1000000000,
+                .tv_nsec=bd->cfg->read_sleep%1000000000},
+            NULL);
+        if (err) {
+            err = -errno;
+            LFS_EMUBD_TRACE("lfs_emubd_read -> %d", err);
+            return err;
+        }
+    }
+
+    LFS_EMUBD_TRACE("lfs_emubd_read -> %d", 0);
+    return 0;
+}
+
+int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, const void *buffer, lfs_size_t size) {
+    LFS_EMUBD_TRACE("lfs_emubd_prog(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+            (void*)cfg, block, off, buffer, size);
+    lfs_emubd_t *bd = cfg->context;
+
+    // check if write is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
+
+    // get the block
+    lfs_emubd_block_t *b = lfs_emubd_mutblock(cfg, &bd->blocks[block]);
+    if (!b) {
+        LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", LFS_ERR_NOMEM);
+        return LFS_ERR_NOMEM;
+    }
+
+    // block bad?
+    if (bd->cfg->erase_cycles && b->wear >= bd->cfg->erase_cycles) {
+        if (bd->cfg->badblock_behavior ==
+                LFS_EMUBD_BADBLOCK_PROGERROR) {
+            LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", LFS_ERR_CORRUPT);
+            return LFS_ERR_CORRUPT;
+        } else if (bd->cfg->badblock_behavior ==
+                LFS_EMUBD_BADBLOCK_PROGNOOP ||
+                bd->cfg->badblock_behavior ==
+                LFS_EMUBD_BADBLOCK_ERASENOOP) {
+            LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", 0);
+            return 0;
+        }
+    }
+
+    // were we erased properly?
+    if (bd->cfg->erase_value != -1) {
+        for (lfs_off_t i = 0; i < size; i++) {
+            LFS_ASSERT(b->data[off+i] == bd->cfg->erase_value);
+        }
+    }
+
+    // prog data
+    memcpy(&b->data[off], buffer, size);
+
+    // mirror to disk file?
+    if (bd->disk) {
+        off_t res1 = lseek(bd->disk->fd,
+                (off_t)block*bd->cfg->erase_size + (off_t)off,
+                SEEK_SET);
+        if (res1 < 0) {
+            int err = -errno;
+            LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", err);
+            return err;
+        }
+
+        ssize_t res2 = write(bd->disk->fd, buffer, size);
+        if (res2 < 0) {
+            int err = -errno;
+            LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", err);
+            return err;
+        }
+    }
+
+    // track progs
+    bd->proged += size;
+    if (bd->cfg->prog_sleep) {
+        int err = nanosleep(&(struct timespec){
+                .tv_sec=bd->cfg->prog_sleep/1000000000,
+                .tv_nsec=bd->cfg->prog_sleep%1000000000},
+            NULL);
+        if (err) {
+            err = -errno;
+            LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", err);
+            return err;
+        }
+    }
+
+    // lose power?
+    if (bd->power_cycles > 0) {
+        bd->power_cycles -= 1;
+        if (bd->power_cycles == 0) {
+            int err = lfs_emubd_powerloss(cfg);
+            if (err) {
+                LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", err);
+                return err;
+            }
+        }
+    }
+
+    LFS_EMUBD_TRACE("lfs_emubd_prog -> %d", 0);
+    return 0;
+}
+
+int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block) {
+    LFS_EMUBD_TRACE("lfs_emubd_erase(%p, 0x%"PRIx32" (%"PRIu32"))",
+            (void*)cfg, block, ((lfs_emubd_t*)cfg->context)->cfg->erase_size);
+    lfs_emubd_t *bd = cfg->context;
+
+    // check if erase is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+
+    // emulate out-of-order writes? save first write
+    if (bd->cfg->powerloss_behavior == LFS_EMUBD_POWERLOSS_OOO
+            && bd->ooo_block == -1) {
+        bd->ooo_block = block;
+        bd->ooo_data = lfs_emubd_incblock(bd->blocks[block]);
+    }
+
+    // get the block
+    lfs_emubd_block_t *b = lfs_emubd_mutblock(cfg, &bd->blocks[block]);
+    if (!b) {
+        LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", LFS_ERR_NOMEM);
+        return LFS_ERR_NOMEM;
+    }
+
+    // block bad?
+    if (bd->cfg->erase_cycles) {
+        if (b->wear >= bd->cfg->erase_cycles) {
+            if (bd->cfg->badblock_behavior ==
+                    LFS_EMUBD_BADBLOCK_ERASEERROR) {
+                LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", LFS_ERR_CORRUPT);
+                return LFS_ERR_CORRUPT;
+            } else if (bd->cfg->badblock_behavior ==
+                    LFS_EMUBD_BADBLOCK_ERASENOOP) {
+                LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", 0);
+                return 0;
+            }
+        } else {
+            // mark wear
+            b->wear += 1;
+        }
+    }
+
+    // emulate an erase value?
+    if (bd->cfg->erase_value != -1) {
+        memset(b->data, bd->cfg->erase_value, bd->cfg->erase_size);
+
+        // mirror to disk file?
+        if (bd->disk) {
+            off_t res1 = lseek(bd->disk->fd,
+                    (off_t)block*bd->cfg->erase_size,
+                    SEEK_SET);
+            if (res1 < 0) {
+                int err = -errno;
+                LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", err);
+                return err;
+            }
+
+            ssize_t res2 = write(bd->disk->fd,
+                    bd->disk->scratch,
+                    bd->cfg->erase_size);
+            if (res2 < 0) {
+                int err = -errno;
+                LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", err);
+                return err;
+            }
+        }
+    }
+
+    // track erases
+    bd->erased += bd->cfg->erase_size;
+    if (bd->cfg->erase_sleep) {
+        int err = nanosleep(&(struct timespec){
+                .tv_sec=bd->cfg->erase_sleep/1000000000,
+                .tv_nsec=bd->cfg->erase_sleep%1000000000},
+            NULL);
+        if (err) {
+            err = -errno;
+            LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", err);
+            return err;
+        }
+    }
+
+    // lose power?
+    if (bd->power_cycles > 0) {
+        bd->power_cycles -= 1;
+        if (bd->power_cycles == 0) {
+            int err = lfs_emubd_powerloss(cfg);
+            if (err) {
+                LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", err);
+                return err;
+            }
+        }
+    }
+
+    LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", 0);
+    return 0;
+}
+
+int lfs_emubd_sync(const struct lfs_config *cfg) {
+    LFS_EMUBD_TRACE("lfs_emubd_sync(%p)", (void*)cfg);
+    lfs_emubd_t *bd = cfg->context;
+
+    // emulate out-of-order writes? reset first write, writes
+    // cannot be out-of-order across sync
+    if (bd->cfg->powerloss_behavior == LFS_EMUBD_POWERLOSS_OOO) {
+        lfs_emubd_decblock(bd->ooo_data);
+        bd->ooo_block = -1;
+        bd->ooo_data = NULL;
+    }
+
+    LFS_EMUBD_TRACE("lfs_emubd_sync -> %d", 0);
+    return 0;
+}
+
+
+/// Additional extended API for driving test features ///
+
+static int lfs_emubd_crc_(const struct lfs_config *cfg,
+        lfs_block_t block, uint32_t *crc) {
+    lfs_emubd_t *bd = cfg->context;
+
+    // check if crc is valid
+    LFS_ASSERT(block < cfg->block_count);
+
+    // crc the block
+    uint32_t crc_ = 0xffffffff;
+    const lfs_emubd_block_t *b = bd->blocks[block];
+    if (b) {
+        crc_ = lfs_crc(crc_, b->data, cfg->block_size);
+    } else {
+        uint8_t erase_value = (bd->cfg->erase_value != -1)
+                ? bd->cfg->erase_value
+                : 0;
+        for (lfs_size_t i = 0; i < cfg->block_size; i++) {
+            crc_ = lfs_crc(crc_, &erase_value, 1);
+        }
+    }
+    *crc = 0xffffffff ^ crc_;
+
+    return 0;
+}
+
+int lfs_emubd_crc(const struct lfs_config *cfg,
+        lfs_block_t block, uint32_t *crc) {
+    LFS_EMUBD_TRACE("lfs_emubd_crc(%p, %"PRIu32", %p)",
+            (void*)cfg, block, crc);
+    int err = lfs_emubd_crc_(cfg, block, crc);
+    LFS_EMUBD_TRACE("lfs_emubd_crc -> %d", err);
+    return err;
+}
+
+int lfs_emubd_bdcrc(const struct lfs_config *cfg, uint32_t *crc) {
+    LFS_EMUBD_TRACE("lfs_emubd_bdcrc(%p, %p)", (void*)cfg, crc);
+
+    uint32_t crc_ = 0xffffffff;
+    for (lfs_block_t i = 0; i < cfg->block_count; i++) {
+        uint32_t i_crc;
+        int err = lfs_emubd_crc_(cfg, i, &i_crc);
+        if (err) {
+            LFS_EMUBD_TRACE("lfs_emubd_bdcrc -> %d", err);
+            return err;
+        }
+
+        crc_ = lfs_crc(crc_, &i_crc, sizeof(uint32_t));
+    }
+    *crc = 0xffffffff ^ crc_;
+
+    LFS_EMUBD_TRACE("lfs_emubd_bdcrc -> %d", 0);
+    return 0;
+}
+
+lfs_emubd_sio_t lfs_emubd_readed(const struct lfs_config *cfg) {
+    LFS_EMUBD_TRACE("lfs_emubd_readed(%p)", (void*)cfg);
+    lfs_emubd_t *bd = cfg->context;
+    LFS_EMUBD_TRACE("lfs_emubd_readed -> %"PRIu64, bd->readed);
+    return bd->readed;
+}
+
+lfs_emubd_sio_t lfs_emubd_proged(const struct lfs_config *cfg) {
+    LFS_EMUBD_TRACE("lfs_emubd_proged(%p)", (void*)cfg);
+    lfs_emubd_t *bd = cfg->context;
+    LFS_EMUBD_TRACE("lfs_emubd_proged -> %"PRIu64, bd->proged);
+    return bd->proged;
+}
+
+lfs_emubd_sio_t lfs_emubd_erased(const struct lfs_config *cfg) {
+    LFS_EMUBD_TRACE("lfs_emubd_erased(%p)", (void*)cfg);
+    lfs_emubd_t *bd = cfg->context;
+    LFS_EMUBD_TRACE("lfs_emubd_erased -> %"PRIu64, bd->erased);
+    return bd->erased;
+}
+
+int lfs_emubd_setreaded(const struct lfs_config *cfg, lfs_emubd_io_t readed) {
+    LFS_EMUBD_TRACE("lfs_emubd_setreaded(%p, %"PRIu64")", (void*)cfg, readed);
+    lfs_emubd_t *bd = cfg->context;
+    bd->readed = readed;
+    LFS_EMUBD_TRACE("lfs_emubd_setreaded -> %d", 0);
+    return 0;
+}
+
+int lfs_emubd_setproged(const struct lfs_config *cfg, lfs_emubd_io_t proged) {
+    LFS_EMUBD_TRACE("lfs_emubd_setproged(%p, %"PRIu64")", (void*)cfg, proged);
+    lfs_emubd_t *bd = cfg->context;
+    bd->proged = proged;
+    LFS_EMUBD_TRACE("lfs_emubd_setproged -> %d", 0);
+    return 0;
+}
+
+int lfs_emubd_seterased(const struct lfs_config *cfg, lfs_emubd_io_t erased) {
+    LFS_EMUBD_TRACE("lfs_emubd_seterased(%p, %"PRIu64")", (void*)cfg, erased);
+    lfs_emubd_t *bd = cfg->context;
+    bd->erased = erased;
+    LFS_EMUBD_TRACE("lfs_emubd_seterased -> %d", 0);
+    return 0;
+}
+
+lfs_emubd_swear_t lfs_emubd_wear(const struct lfs_config *cfg,
+        lfs_block_t block) {
+    LFS_EMUBD_TRACE("lfs_emubd_wear(%p, %"PRIu32")", (void*)cfg, block);
+    lfs_emubd_t *bd = cfg->context;
+
+    // check if block is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+
+    // get the wear
+    lfs_emubd_wear_t wear;
+    const lfs_emubd_block_t *b = bd->blocks[block];
+    if (b) {
+        wear = b->wear;
+    } else {
+        wear = 0;
+    }
+
+    LFS_EMUBD_TRACE("lfs_emubd_wear -> %"PRIi32, wear);
+    return wear;
+}
+
+int lfs_emubd_setwear(const struct lfs_config *cfg,
+        lfs_block_t block, lfs_emubd_wear_t wear) {
+    LFS_EMUBD_TRACE("lfs_emubd_setwear(%p, %"PRIu32", %"PRIi32")",
+            (void*)cfg, block, wear);
+    lfs_emubd_t *bd = cfg->context;
+
+    // check if block is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+
+    // set the wear
+    lfs_emubd_block_t *b = lfs_emubd_mutblock(cfg, &bd->blocks[block]);
+    if (!b) {
+        LFS_EMUBD_TRACE("lfs_emubd_setwear -> %d", LFS_ERR_NOMEM);
+        return LFS_ERR_NOMEM;
+    }
+    b->wear = wear;
+
+    LFS_EMUBD_TRACE("lfs_emubd_setwear -> %d", 0);
+    return 0;
+}
+
+lfs_emubd_spowercycles_t lfs_emubd_powercycles(
+        const struct lfs_config *cfg) {
+    LFS_EMUBD_TRACE("lfs_emubd_powercycles(%p)", (void*)cfg);
+    lfs_emubd_t *bd = cfg->context;
+
+    LFS_EMUBD_TRACE("lfs_emubd_powercycles -> %"PRIi32, bd->power_cycles);
+    return bd->power_cycles;
+}
+
+int lfs_emubd_setpowercycles(const struct lfs_config *cfg,
+        lfs_emubd_powercycles_t power_cycles) {
+    LFS_EMUBD_TRACE("lfs_emubd_setpowercycles(%p, %"PRIi32")",
+            (void*)cfg, power_cycles);
+    lfs_emubd_t *bd = cfg->context;
+
+    bd->power_cycles = power_cycles;
+
+    LFS_EMUBD_TRACE("lfs_emubd_powercycles -> %d", 0);
+    return 0;
+}
+
+int lfs_emubd_copy(const struct lfs_config *cfg, lfs_emubd_t *copy) {
+    LFS_EMUBD_TRACE("lfs_emubd_copy(%p, %p)", (void*)cfg, (void*)copy);
+    lfs_emubd_t *bd = cfg->context;
+
+    // lazily copy over our block array
+    copy->blocks = malloc(bd->cfg->erase_count * sizeof(lfs_emubd_block_t*));
+    if (!copy->blocks) {
+        LFS_EMUBD_TRACE("lfs_emubd_copy -> %d", LFS_ERR_NOMEM);
+        return LFS_ERR_NOMEM;
+    }
+
+    for (size_t i = 0; i < bd->cfg->erase_count; i++) {
+        copy->blocks[i] = lfs_emubd_incblock(bd->blocks[i]);
+    }
+
+    // other state
+    copy->readed = bd->readed;
+    copy->proged = bd->proged;
+    copy->erased = bd->erased;
+    copy->power_cycles = bd->power_cycles;
+    copy->ooo_block = bd->ooo_block;
+    copy->ooo_data = lfs_emubd_incblock(bd->ooo_data);
+    copy->disk = bd->disk;
+    if (copy->disk) {
+        copy->disk->rc += 1;
+    }
+    copy->cfg = bd->cfg;
+
+    LFS_EMUBD_TRACE("lfs_emubd_copy -> %d", 0);
+    return 0;
+}
+

bd/lfs_emubd.h

@@ -0,0 +1,244 @@
+/*
+ * Emulating block device, wraps filebd and rambd while providing a bunch
+ * of hooks for testing littlefs in various conditions.
+ *
+ * Copyright (c) 2022, The littlefs authors.
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef LFS_EMUBD_H
+#define LFS_EMUBD_H
+
+#include "lfs.h"
+#include "lfs_util.h"
+#include "bd/lfs_rambd.h"
+#include "bd/lfs_filebd.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+
+// Block device specific tracing
+#ifndef LFS_EMUBD_TRACE
+#ifdef LFS_EMUBD_YES_TRACE
+#define LFS_EMUBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_EMUBD_TRACE(...)
+#endif
+#endif
+
+// Mode determining how "bad-blocks" behave during testing. This simulates
+// some real-world circumstances such as progs not sticking (prog-noop),
+// a readonly disk (erase-noop), and ECC failures (read-error).
+//
+// Not that read-noop is not allowed. Read _must_ return a consistent (but
+// may be arbitrary) value on every read.
+typedef enum lfs_emubd_badblock_behavior {
+    LFS_EMUBD_BADBLOCK_PROGERROR  = 0, // Error on prog
+    LFS_EMUBD_BADBLOCK_ERASEERROR = 1, // Error on erase
+    LFS_EMUBD_BADBLOCK_READERROR  = 2, // Error on read
+    LFS_EMUBD_BADBLOCK_PROGNOOP   = 3, // Prog does nothing silently
+    LFS_EMUBD_BADBLOCK_ERASENOOP  = 4, // Erase does nothing silently
+} lfs_emubd_badblock_behavior_t;
+
+// Mode determining how power-loss behaves during testing. For now this
+// only supports a noop behavior, leaving the data on-disk untouched.
+typedef enum lfs_emubd_powerloss_behavior {
+    LFS_EMUBD_POWERLOSS_NOOP = 0, // Progs are atomic
+    LFS_EMUBD_POWERLOSS_OOO  = 1, // Blocks are written out-of-order
+} lfs_emubd_powerloss_behavior_t;
+
+// Type for measuring read/program/erase operations
+typedef uint64_t lfs_emubd_io_t;
+typedef int64_t lfs_emubd_sio_t;
+
+// Type for measuring wear
+typedef uint32_t lfs_emubd_wear_t;
+typedef int32_t lfs_emubd_swear_t;
+
+// Type for tracking power-cycles
+typedef uint32_t lfs_emubd_powercycles_t;
+typedef int32_t lfs_emubd_spowercycles_t;
+
+// Type for delays in nanoseconds
+typedef uint64_t lfs_emubd_sleep_t;
+typedef int64_t lfs_emubd_ssleep_t;
+
+// emubd config, this is required for testing
+struct lfs_emubd_config {
+    // Minimum size of a read operation in bytes.
+    lfs_size_t read_size;
+
+    // Minimum size of a program operation in bytes.
+    lfs_size_t prog_size;
+
+    // Size of an erase operation in bytes.
+    lfs_size_t erase_size;
+
+    // Number of erase blocks on the device.
+    lfs_size_t erase_count;
+
+    // 8-bit erase value to use for simulating erases. -1 does not simulate
+    // erases, which can speed up testing by avoiding the extra block-device
+    // operations to store the erase value.
+    int32_t erase_value;
+
+    // Number of erase cycles before a block becomes "bad". The exact behavior
+    // of bad blocks is controlled by badblock_behavior.
+    uint32_t erase_cycles;
+
+    // The mode determining how bad-blocks fail
+    lfs_emubd_badblock_behavior_t badblock_behavior;
+
+    // Number of write operations (erase/prog) before triggering a power-loss.
+    // power_cycles=0 disables this. The exact behavior of power-loss is
+    // controlled by a combination of powerloss_behavior and powerloss_cb.
+    lfs_emubd_powercycles_t power_cycles;
+
+    // The mode determining how power-loss affects disk
+    lfs_emubd_powerloss_behavior_t powerloss_behavior;
+
+    // Function to call to emulate power-loss. The exact behavior of power-loss
+    // is up to the runner to provide.
+    void (*powerloss_cb)(void*);
+
+    // Data for power-loss callback
+    void *powerloss_data;
+
+    // True to track when power-loss could have occured. Note this involves 
+    // heavy memory usage!
+    bool track_branches;
+
+    // Path to file to use as a mirror of the disk. This provides a way to view
+    // the current state of the block device.
+    const char *disk_path;
+
+    // Artificial delay in nanoseconds, there is no purpose for this other
+    // than slowing down the simulation.
+    lfs_emubd_sleep_t read_sleep;
+
+    // Artificial delay in nanoseconds, there is no purpose for this other
+    // than slowing down the simulation.
+    lfs_emubd_sleep_t prog_sleep;
+
+    // Artificial delay in nanoseconds, there is no purpose for this other
+    // than slowing down the simulation.
+    lfs_emubd_sleep_t erase_sleep;
+};
+
+// A reference counted block
+typedef struct lfs_emubd_block {
+    uint32_t rc;
+    lfs_emubd_wear_t wear;
+
+    uint8_t data[];
+} lfs_emubd_block_t;
+
+// Disk mirror
+typedef struct lfs_emubd_disk {
+    uint32_t rc;
+    int fd;
+    uint8_t *scratch;
+} lfs_emubd_disk_t;
+
+// emubd state
+typedef struct lfs_emubd {
+    // array of copy-on-write blocks
+    lfs_emubd_block_t **blocks;
+
+    // some other test state
+    lfs_emubd_io_t readed;
+    lfs_emubd_io_t proged;
+    lfs_emubd_io_t erased;
+    lfs_emubd_powercycles_t power_cycles;
+    lfs_ssize_t ooo_block;
+    lfs_emubd_block_t *ooo_data;
+    lfs_emubd_disk_t *disk;
+
+    const struct lfs_emubd_config *cfg;
+} lfs_emubd_t;
+
+
+/// Block device API ///
+
+// Create an emulating block device using the geometry in lfs_config
+int lfs_emubd_create(const struct lfs_config *cfg,
+        const struct lfs_emubd_config *bdcfg);
+
+// Clean up memory associated with block device
+int lfs_emubd_destroy(const struct lfs_config *cfg);
+
+// Read a block
+int lfs_emubd_read(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, void *buffer, lfs_size_t size);
+
+// Program a block
+//
+// The block must have previously been erased.
+int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, const void *buffer, lfs_size_t size);
+
+// Erase a block
+//
+// A block must be erased before being programmed. The
+// state of an erased block is undefined.
+int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block);
+
+// Sync the block device
+int lfs_emubd_sync(const struct lfs_config *cfg);
+
+
+/// Additional extended API for driving test features ///
+
+// A CRC of a block for debugging purposes
+int lfs_emubd_crc(const struct lfs_config *cfg,
+        lfs_block_t block, uint32_t *crc);
+
+// A CRC of the entire block device for debugging purposes
+int lfs_emubd_bdcrc(const struct lfs_config *cfg, uint32_t *crc);
+
+// Get total amount of bytes read
+lfs_emubd_sio_t lfs_emubd_readed(const struct lfs_config *cfg);
+
+// Get total amount of bytes programmed
+lfs_emubd_sio_t lfs_emubd_proged(const struct lfs_config *cfg);
+
+// Get total amount of bytes erased
+lfs_emubd_sio_t lfs_emubd_erased(const struct lfs_config *cfg);
+
+// Manually set amount of bytes read
+int lfs_emubd_setreaded(const struct lfs_config *cfg, lfs_emubd_io_t readed);
+
+// Manually set amount of bytes programmed
+int lfs_emubd_setproged(const struct lfs_config *cfg, lfs_emubd_io_t proged);
+
+// Manually set amount of bytes erased
+int lfs_emubd_seterased(const struct lfs_config *cfg, lfs_emubd_io_t erased);
+
+// Get simulated wear on a given block
+lfs_emubd_swear_t lfs_emubd_wear(const struct lfs_config *cfg,
+        lfs_block_t block);
+
+// Manually set simulated wear on a given block
+int lfs_emubd_setwear(const struct lfs_config *cfg,
+        lfs_block_t block, lfs_emubd_wear_t wear);
+
+// Get the remaining power-cycles
+lfs_emubd_spowercycles_t lfs_emubd_powercycles(
+        const struct lfs_config *cfg);
+
+// Manually set the remaining power-cycles
+int lfs_emubd_setpowercycles(const struct lfs_config *cfg,
+        lfs_emubd_powercycles_t power_cycles);
+
+// Create a copy-on-write copy of the state of this block device
+int lfs_emubd_copy(const struct lfs_config *cfg, lfs_emubd_t *copy);
+
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

bd/lfs_filebd.c

@@ -1,6 +1,7 @@
 /*
  * Block device emulated in a file
  *
+ * Copyright (c) 2022, The littlefs authors.
  * Copyright (c) 2017, Arm Limited. All rights reserved.
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -10,51 +11,44 @@
 #include <unistd.h>
 #include <errno.h>
 
-int lfs_filebd_createcfg(const struct lfs_config *cfg, const char *path,
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+int lfs_filebd_create(const struct lfs_config *cfg, const char *path,
         const struct lfs_filebd_config *bdcfg) {
-    LFS_FILEBD_TRACE("lfs_filebd_createcfg(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
+    LFS_FILEBD_TRACE("lfs_filebd_create(%p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p}, "
                 "\"%s\", "
-                "%p {.erase_value=%"PRId32"})",
+                "%p {.read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".erase_size=%"PRIu32", .erase_count=%"PRIu32"})",
             (void*)cfg, cfg->context,
             (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
             (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
-            path, (void*)bdcfg, bdcfg->erase_value);
+            path,
+            (void*)bdcfg,
+            bdcfg->read_size, bdcfg->prog_size, bdcfg->erase_size,
+            bdcfg->erase_count);
     lfs_filebd_t *bd = cfg->context;
     bd->cfg = bdcfg;
 
     // open file
+    #ifdef _WIN32
+    bd->fd = open(path, O_RDWR | O_CREAT | O_BINARY, 0666);
+    #else
     bd->fd = open(path, O_RDWR | O_CREAT, 0666);
+    #endif
+
     if (bd->fd < 0) {
         int err = -errno;
-        LFS_FILEBD_TRACE("lfs_filebd_createcfg -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_create -> %d", err);
         return err;
     }
 
-    LFS_FILEBD_TRACE("lfs_filebd_createcfg -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_create -> %d", 0);
     return 0;
 }
 
-int lfs_filebd_create(const struct lfs_config *cfg, const char *path) {
-    LFS_FILEBD_TRACE("lfs_filebd_create(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "\"%s\")",
-            (void*)cfg, cfg->context,
-            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
-            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
-            path);
-    static const struct lfs_filebd_config defaults = {.erase_value=-1};
-    int err = lfs_filebd_createcfg(cfg, path, &defaults);
-    LFS_FILEBD_TRACE("lfs_filebd_create -> %d", err);
-    return err;
-}
-
 int lfs_filebd_destroy(const struct lfs_config *cfg) {
     LFS_FILEBD_TRACE("lfs_filebd_destroy(%p)", (void*)cfg);
     lfs_filebd_t *bd = cfg->context;
@@ -76,18 +70,17 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
     lfs_filebd_t *bd = cfg->context;
 
     // check if read is valid
-    LFS_ASSERT(off  % cfg->read_size == 0);
-    LFS_ASSERT(size % cfg->read_size == 0);
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
-    // zero for reproducability (in case file is truncated)
-    if (bd->cfg->erase_value != -1) {
-        memset(buffer, bd->cfg->erase_value, size);
-    }
+    // zero for reproducibility (in case file is truncated)
+    memset(buffer, 0, size);
 
     // read
     off_t res1 = lseek(bd->fd,
-            (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
         LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
@@ -107,41 +100,20 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
 
 int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_FILEBD_TRACE("lfs_filebd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_FILEBD_TRACE("lfs_filebd_prog(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_filebd_t *bd = cfg->context;
 
     // check if write is valid
-    LFS_ASSERT(off  % cfg->prog_size == 0);
-    LFS_ASSERT(size % cfg->prog_size == 0);
-    LFS_ASSERT(block < cfg->block_count);
-
-    // check that data was erased? only needed for testing
-    if (bd->cfg->erase_value != -1) {
-        off_t res1 = lseek(bd->fd,
-                (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
-        if (res1 < 0) {
-            int err = -errno;
-            LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
-            return err;
-        }
-
-        for (lfs_off_t i = 0; i < size; i++) {
-            uint8_t c;
-            ssize_t res2 = read(bd->fd, &c, 1);
-            if (res2 < 0) {
-                int err = -errno;
-                LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
-                return err;
-            }
-
-            LFS_ASSERT(c == bd->cfg->erase_value);
-        }
-    }
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // program data
     off_t res1 = lseek(bd->fd,
-            (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
         LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
@@ -160,30 +132,15 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
 }
 
 int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_FILEBD_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_FILEBD_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32" (%"PRIu32"))",
+            (void*)cfg, block, ((lfs_filebd_t*)cfg->context)->cfg->erase_size);
     lfs_filebd_t *bd = cfg->context;
 
     // check if erase is valid
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
-    // erase, only needed for testing
-    if (bd->cfg->erase_value != -1) {
-        off_t res1 = lseek(bd->fd, (off_t)block*cfg->block_size, SEEK_SET);
-        if (res1 < 0) {
-            int err = -errno;
-            LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
-            return err;
-        }
-
-        for (lfs_off_t i = 0; i < cfg->block_size; i++) {
-            ssize_t res2 = write(bd->fd, &(uint8_t){bd->cfg->erase_value}, 1);
-            if (res2 < 0) {
-                int err = -errno;
-                LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
-                return err;
-            }
-        }
-    }
+    // erase is a noop
+    (void)block;
 
     LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", 0);
     return 0;
@@ -191,9 +148,14 @@ int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
 
 int lfs_filebd_sync(const struct lfs_config *cfg) {
     LFS_FILEBD_TRACE("lfs_filebd_sync(%p)", (void*)cfg);
+
     // file sync
     lfs_filebd_t *bd = cfg->context;
+    #ifdef _WIN32
+    int err = FlushFileBuffers((HANDLE) _get_osfhandle(bd->fd)) ? 0 : -1;
+    #else
     int err = fsync(bd->fd);
+    #endif
     if (err) {
         err = -errno;
         LFS_FILEBD_TRACE("lfs_filebd_sync -> %d", 0);

bd/lfs_filebd.h

@@ -1,6 +1,7 @@
 /*
  * Block device emulated in a file
  *
+ * Copyright (c) 2022, The littlefs authors.
  * Copyright (c) 2017, Arm Limited. All rights reserved.
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,18 +18,27 @@ extern "C"
 
 
 // Block device specific tracing
+#ifndef LFS_FILEBD_TRACE
 #ifdef LFS_FILEBD_YES_TRACE
 #define LFS_FILEBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
 #else
 #define LFS_FILEBD_TRACE(...)
 #endif
+#endif
 
-// filebd config (optional)
+// filebd config
 struct lfs_filebd_config {
-    // 8-bit erase value to use for simulating erases. -1 does not simulate
-    // erases, which can speed up testing by avoiding all the extra block-device
-    // operations to store the erase value.
-    int32_t erase_value;
+    // Minimum size of a read operation in bytes.
+    lfs_size_t read_size;
+
+    // Minimum size of a program operation in bytes.
+    lfs_size_t prog_size;
+
+    // Size of an erase operation in bytes.
+    lfs_size_t erase_size;
+
+    // Number of erase blocks on the device.
+    lfs_size_t erase_count;
 };
 
 // filebd state
@@ -38,9 +48,8 @@ typedef struct lfs_filebd {
 } lfs_filebd_t;
 
 
-// Create a file block device using the geometry in lfs_config
-int lfs_filebd_create(const struct lfs_config *cfg, const char *path);
-int lfs_filebd_createcfg(const struct lfs_config *cfg, const char *path,
+// Create a file block device
+int lfs_filebd_create(const struct lfs_config *cfg, const char *path,
         const struct lfs_filebd_config *bdcfg);
 
 // Clean up memory associated with block device

bd/lfs_rambd.c

@@ -1,23 +1,25 @@
 /*
  * Block device emulated in RAM
  *
+ * Copyright (c) 2022, The littlefs authors.
  * Copyright (c) 2017, Arm Limited. All rights reserved.
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #include "bd/lfs_rambd.h"
 
-int lfs_rambd_createcfg(const struct lfs_config *cfg,
+int lfs_rambd_create(const struct lfs_config *cfg,
         const struct lfs_rambd_config *bdcfg) {
-    LFS_RAMBD_TRACE("lfs_rambd_createcfg(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "%p {.erase_value=%"PRId32", .buffer=%p})",
+    LFS_RAMBD_TRACE("lfs_rambd_create(%p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p}, "
+                "%p {.read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".erase_size=%"PRIu32", .erase_count=%"PRIu32", "
+                ".buffer=%p})",
             (void*)cfg, cfg->context,
             (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
             (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
-            (void*)bdcfg, bdcfg->erase_value, bdcfg->buffer);
+            (void*)bdcfg,
+            bdcfg->read_size, bdcfg->prog_size, bdcfg->erase_size,
+            bdcfg->erase_count, bdcfg->buffer);
     lfs_rambd_t *bd = cfg->context;
     bd->cfg = bdcfg;
 
@@ -25,38 +27,20 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
     if (bd->cfg->buffer) {
         bd->buffer = bd->cfg->buffer;
     } else {
-        bd->buffer = lfs_malloc(cfg->block_size * cfg->block_count);
+        bd->buffer = lfs_malloc(bd->cfg->erase_size * bd->cfg->erase_count);
         if (!bd->buffer) {
-            LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
+            LFS_RAMBD_TRACE("lfs_rambd_create -> %d", LFS_ERR_NOMEM);
             return LFS_ERR_NOMEM;
         }
     }
 
-    // zero for reproducability?
-    if (bd->cfg->erase_value != -1) {
-        memset(bd->buffer, bd->cfg->erase_value,
-                cfg->block_size * cfg->block_count);
-    }
+    // zero for reproducibility
+    memset(bd->buffer, 0, bd->cfg->erase_size * bd->cfg->erase_count);
 
-    LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_create -> %d", 0);
     return 0;
 }
 
-int lfs_rambd_create(const struct lfs_config *cfg) {
-    LFS_RAMBD_TRACE("lfs_rambd_create(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"})",
-            (void*)cfg, cfg->context,
-            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
-            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count);
-    static const struct lfs_rambd_config defaults = {.erase_value=-1};
-    int err = lfs_rambd_createcfg(cfg, &defaults);
-    LFS_RAMBD_TRACE("lfs_rambd_create -> %d", err);
-    return err;
-}
-
 int lfs_rambd_destroy(const struct lfs_config *cfg) {
     LFS_RAMBD_TRACE("lfs_rambd_destroy(%p)", (void*)cfg);
     // clean up memory
@@ -76,12 +60,13 @@ int lfs_rambd_read(const struct lfs_config *cfg, lfs_block_t block,
     lfs_rambd_t *bd = cfg->context;
 
     // check if read is valid
-    LFS_ASSERT(off  % cfg->read_size == 0);
-    LFS_ASSERT(size % cfg->read_size == 0);
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // read data
-    memcpy(buffer, &bd->buffer[block*cfg->block_size + off], size);
+    memcpy(buffer, &bd->buffer[block*bd->cfg->erase_size + off], size);
 
     LFS_RAMBD_TRACE("lfs_rambd_read -> %d", 0);
     return 0;
@@ -95,37 +80,28 @@ int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
     lfs_rambd_t *bd = cfg->context;
 
     // check if write is valid
-    LFS_ASSERT(off  % cfg->prog_size == 0);
-    LFS_ASSERT(size % cfg->prog_size == 0);
-    LFS_ASSERT(block < cfg->block_count);
-
-    // check that data was erased? only needed for testing
-    if (bd->cfg->erase_value != -1) {
-        for (lfs_off_t i = 0; i < size; i++) {
-            LFS_ASSERT(bd->buffer[block*cfg->block_size + off + i] ==
-                    bd->cfg->erase_value);
-        }
-    }
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // program data
-    memcpy(&bd->buffer[block*cfg->block_size + off], buffer, size);
+    memcpy(&bd->buffer[block*bd->cfg->erase_size + off], buffer, size);
 
     LFS_RAMBD_TRACE("lfs_rambd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_RAMBD_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_RAMBD_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32" (%"PRIu32"))",
+            (void*)cfg, block, ((lfs_rambd_t*)cfg->context)->cfg->erase_size);
     lfs_rambd_t *bd = cfg->context;
 
     // check if erase is valid
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
-    // erase, only needed for testing
-    if (bd->cfg->erase_value != -1) {
-        memset(&bd->buffer[block*cfg->block_size],
-                bd->cfg->erase_value, cfg->block_size);
-    }
+    // erase is a noop
+    (void)block;
 
     LFS_RAMBD_TRACE("lfs_rambd_erase -> %d", 0);
     return 0;
@@ -133,8 +109,10 @@ int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
 
 int lfs_rambd_sync(const struct lfs_config *cfg) {
     LFS_RAMBD_TRACE("lfs_rambd_sync(%p)", (void*)cfg);
-    // sync does nothing because we aren't backed by anything real
+
+    // sync is a noop
     (void)cfg;
+
     LFS_RAMBD_TRACE("lfs_rambd_sync -> %d", 0);
     return 0;
 }

bd/lfs_rambd.h

@@ -1,6 +1,7 @@
 /*
  * Block device emulated in RAM
  *
+ * Copyright (c) 2022, The littlefs authors.
  * Copyright (c) 2017, Arm Limited. All rights reserved.
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,17 +18,27 @@ extern "C"
 
 
 // Block device specific tracing
+#ifndef LFS_RAMBD_TRACE
 #ifdef LFS_RAMBD_YES_TRACE
 #define LFS_RAMBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
 #else
 #define LFS_RAMBD_TRACE(...)
 #endif
+#endif
 
-// rambd config (optional)
+// rambd config
 struct lfs_rambd_config {
-    // 8-bit erase value to simulate erasing with. -1 indicates no erase
-    // occurs, which is still a valid block device
-    int32_t erase_value;
+    // Minimum size of a read operation in bytes.
+    lfs_size_t read_size;
+
+    // Minimum size of a program operation in bytes.
+    lfs_size_t prog_size;
+
+    // Size of an erase operation in bytes.
+    lfs_size_t erase_size;
+
+    // Number of erase blocks on the device.
+    lfs_size_t erase_count;
 
     // Optional statically allocated buffer for the block device.
     void *buffer;
@@ -40,9 +51,8 @@ typedef struct lfs_rambd {
 } lfs_rambd_t;
 
 
-// Create a RAM block device using the geometry in lfs_config
-int lfs_rambd_create(const struct lfs_config *cfg);
-int lfs_rambd_createcfg(const struct lfs_config *cfg,
+// Create a RAM block device
+int lfs_rambd_create(const struct lfs_config *cfg,
         const struct lfs_rambd_config *bdcfg);
 
 // Clean up memory associated with block device

bd/lfs_testbd.c

@@ -1,302 +0,0 @@
-/*
- * Testing block device, wraps filebd and rambd while providing a bunch
- * of hooks for testing littlefs in various conditions.
- *
- * Copyright (c) 2017, Arm Limited. All rights reserved.
- * SPDX-License-Identifier: BSD-3-Clause
- */
-#include "bd/lfs_testbd.h"
-
-#include <stdlib.h>
-
-
-int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
-        const struct lfs_testbd_config *bdcfg) {
-    LFS_TESTBD_TRACE("lfs_testbd_createcfg(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "\"%s\", "
-                "%p {.erase_value=%"PRId32", .erase_cycles=%"PRIu32", "
-                ".badblock_behavior=%"PRIu8", .power_cycles=%"PRIu32", "
-                ".buffer=%p, .wear_buffer=%p})",
-            (void*)cfg, cfg->context,
-            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
-            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
-            path, (void*)bdcfg, bdcfg->erase_value, bdcfg->erase_cycles,
-            bdcfg->badblock_behavior, bdcfg->power_cycles,
-            bdcfg->buffer, bdcfg->wear_buffer);
-    lfs_testbd_t *bd = cfg->context;
-    bd->cfg = bdcfg;
-
-    // setup testing things
-    bd->persist = path;
-    bd->power_cycles = bd->cfg->power_cycles;
-
-    if (bd->cfg->erase_cycles) {
-        if (bd->cfg->wear_buffer) {
-            bd->wear = bd->cfg->wear_buffer;
-        } else {
-            bd->wear = lfs_malloc(sizeof(lfs_testbd_wear_t)*cfg->block_count);
-            if (!bd->wear) {
-                LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", LFS_ERR_NOMEM);
-                return LFS_ERR_NOMEM;
-            }
-        }
-
-        memset(bd->wear, 0, sizeof(lfs_testbd_wear_t) * cfg->block_count);
-    }
-
-    // create underlying block device
-    if (bd->persist) {
-        bd->u.file.cfg = (struct lfs_filebd_config){
-            .erase_value = bd->cfg->erase_value,
-        };
-        int err = lfs_filebd_createcfg(cfg, path, &bd->u.file.cfg);
-        LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
-        return err;
-    } else {
-        bd->u.ram.cfg = (struct lfs_rambd_config){
-            .erase_value = bd->cfg->erase_value,
-            .buffer = bd->cfg->buffer,
-        };
-        int err = lfs_rambd_createcfg(cfg, &bd->u.ram.cfg);
-        LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
-        return err;
-    }
-}
-
-int lfs_testbd_create(const struct lfs_config *cfg, const char *path) {
-    LFS_TESTBD_TRACE("lfs_testbd_create(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "\"%s\")",
-            (void*)cfg, cfg->context,
-            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
-            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
-            path);
-    static const struct lfs_testbd_config defaults = {.erase_value=-1};
-    int err = lfs_testbd_createcfg(cfg, path, &defaults);
-    LFS_TESTBD_TRACE("lfs_testbd_create -> %d", err);
-    return err;
-}
-
-int lfs_testbd_destroy(const struct lfs_config *cfg) {
-    LFS_TESTBD_TRACE("lfs_testbd_destroy(%p)", (void*)cfg);
-    lfs_testbd_t *bd = cfg->context;
-    if (bd->cfg->erase_cycles && !bd->cfg->wear_buffer) {
-        lfs_free(bd->wear);
-    }
-
-    if (bd->persist) {
-        int err = lfs_filebd_destroy(cfg);
-        LFS_TESTBD_TRACE("lfs_testbd_destroy -> %d", err);
-        return err;
-    } else {
-        int err = lfs_rambd_destroy(cfg);
-        LFS_TESTBD_TRACE("lfs_testbd_destroy -> %d", err);
-        return err;
-    }
-}
-
-/// Internal mapping to block devices ///
-static int lfs_testbd_rawread(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, void *buffer, lfs_size_t size) {
-    lfs_testbd_t *bd = cfg->context;
-    if (bd->persist) {
-        return lfs_filebd_read(cfg, block, off, buffer, size);
-    } else {
-        return lfs_rambd_read(cfg, block, off, buffer, size);
-    }
-}
-
-static int lfs_testbd_rawprog(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, const void *buffer, lfs_size_t size) {
-    lfs_testbd_t *bd = cfg->context;
-    if (bd->persist) {
-        return lfs_filebd_prog(cfg, block, off, buffer, size);
-    } else {
-        return lfs_rambd_prog(cfg, block, off, buffer, size);
-    }
-}
-
-static int lfs_testbd_rawerase(const struct lfs_config *cfg,
-        lfs_block_t block) {
-    lfs_testbd_t *bd = cfg->context;
-    if (bd->persist) {
-        return lfs_filebd_erase(cfg, block);
-    } else {
-        return lfs_rambd_erase(cfg, block);
-    }
-}
-
-static int lfs_testbd_rawsync(const struct lfs_config *cfg) {
-    lfs_testbd_t *bd = cfg->context;
-    if (bd->persist) {
-        return lfs_filebd_sync(cfg);
-    } else {
-        return lfs_rambd_sync(cfg);
-    }
-}
-
-/// block device API ///
-int lfs_testbd_read(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, void *buffer, lfs_size_t size) {
-    LFS_TESTBD_TRACE("lfs_testbd_read(%p, "
-                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
-            (void*)cfg, block, off, buffer, size);
-    lfs_testbd_t *bd = cfg->context;
-
-    // check if read is valid
-    LFS_ASSERT(off  % cfg->read_size == 0);
-    LFS_ASSERT(size % cfg->read_size == 0);
-    LFS_ASSERT(block < cfg->block_count);
-
-    // block bad?
-    if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles &&
-            bd->cfg->badblock_behavior == LFS_TESTBD_BADBLOCK_READERROR) {
-        LFS_TESTBD_TRACE("lfs_testbd_read -> %d", LFS_ERR_CORRUPT);
-        return LFS_ERR_CORRUPT;
-    }
-
-    // read
-    int err = lfs_testbd_rawread(cfg, block, off, buffer, size);
-    LFS_TESTBD_TRACE("lfs_testbd_read -> %d", err);
-    return err;
-}
-
-int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_TESTBD_TRACE("lfs_testbd_prog(%p, "
-                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
-            (void*)cfg, block, off, buffer, size);
-    lfs_testbd_t *bd = cfg->context;
-
-    // check if write is valid
-    LFS_ASSERT(off  % cfg->prog_size == 0);
-    LFS_ASSERT(size % cfg->prog_size == 0);
-    LFS_ASSERT(block < cfg->block_count);
-
-    // block bad?
-    if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles) {
-        if (bd->cfg->badblock_behavior ==
-                LFS_TESTBD_BADBLOCK_PROGERROR) {
-            LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", LFS_ERR_CORRUPT);
-            return LFS_ERR_CORRUPT;
-        } else if (bd->cfg->badblock_behavior ==
-                LFS_TESTBD_BADBLOCK_PROGNOOP ||
-                bd->cfg->badblock_behavior ==
-                LFS_TESTBD_BADBLOCK_ERASENOOP) {
-            LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
-            return 0;
-        }
-    }
-
-    // prog
-    int err = lfs_testbd_rawprog(cfg, block, off, buffer, size);
-    if (err) {
-        LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", err);
-        return err;
-    }
-
-    // lose power?
-    if (bd->power_cycles > 0) {
-        bd->power_cycles -= 1;
-        if (bd->power_cycles == 0) {
-            // sync to make sure we persist the last changes
-            assert(lfs_testbd_rawsync(cfg) == 0);
-            // simulate power loss
-            exit(33);
-        }
-    }
-
-    LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
-    return 0;
-}
-
-int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_TESTBD_TRACE("lfs_testbd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
-    lfs_testbd_t *bd = cfg->context;
-
-    // check if erase is valid
-    LFS_ASSERT(block < cfg->block_count);
-
-    // block bad?
-    if (bd->cfg->erase_cycles) {
-        if (bd->wear[block] >= bd->cfg->erase_cycles) {
-            if (bd->cfg->badblock_behavior ==
-                    LFS_TESTBD_BADBLOCK_ERASEERROR) {
-                LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", LFS_ERR_CORRUPT);
-                return LFS_ERR_CORRUPT;
-            } else if (bd->cfg->badblock_behavior ==
-                    LFS_TESTBD_BADBLOCK_ERASENOOP) {
-                LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", 0);
-                return 0;
-            }
-        } else {
-            // mark wear
-            bd->wear[block] += 1;
-        }
-    }
-
-    // erase
-    int err = lfs_testbd_rawerase(cfg, block);
-    if (err) {
-        LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", err);
-        return err;
-    }
-
-    // lose power?
-    if (bd->power_cycles > 0) {
-        bd->power_cycles -= 1;
-        if (bd->power_cycles == 0) {
-            // sync to make sure we persist the last changes
-            assert(lfs_testbd_rawsync(cfg) == 0);
-            // simulate power loss
-            exit(33);
-        }
-    }
-
-    LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
-    return 0;
-}
-
-int lfs_testbd_sync(const struct lfs_config *cfg) {
-    LFS_TESTBD_TRACE("lfs_testbd_sync(%p)", (void*)cfg);
-    int err = lfs_testbd_rawsync(cfg);
-    LFS_TESTBD_TRACE("lfs_testbd_sync -> %d", err);
-    return err;
-}
-
-
-/// simulated wear operations ///
-lfs_testbd_swear_t lfs_testbd_getwear(const struct lfs_config *cfg,
-        lfs_block_t block) {
-    LFS_TESTBD_TRACE("lfs_testbd_getwear(%p, %"PRIu32")", (void*)cfg, block);
-    lfs_testbd_t *bd = cfg->context;
-
-    // check if block is valid
-    LFS_ASSERT(bd->cfg->erase_cycles);
-    LFS_ASSERT(block < cfg->block_count);
-
-    LFS_TESTBD_TRACE("lfs_testbd_getwear -> %"PRIu32, bd->wear[block]);
-    return bd->wear[block];
-}
-
-int lfs_testbd_setwear(const struct lfs_config *cfg,
-        lfs_block_t block, lfs_testbd_wear_t wear) {
-    LFS_TESTBD_TRACE("lfs_testbd_setwear(%p, %"PRIu32")", (void*)cfg, block);
-    lfs_testbd_t *bd = cfg->context;
-
-    // check if block is valid
-    LFS_ASSERT(bd->cfg->erase_cycles);
-    LFS_ASSERT(block < cfg->block_count);
-
-    bd->wear[block] = wear;
-
-    LFS_TESTBD_TRACE("lfs_testbd_setwear -> %d", 0);
-    return 0;
-}

bd/lfs_testbd.h

@@ -1,141 +0,0 @@
-/*
- * Testing block device, wraps filebd and rambd while providing a bunch
- * of hooks for testing littlefs in various conditions.
- *
- * Copyright (c) 2017, Arm Limited. All rights reserved.
- * SPDX-License-Identifier: BSD-3-Clause
- */
-#ifndef LFS_TESTBD_H
-#define LFS_TESTBD_H
-
-#include "lfs.h"
-#include "lfs_util.h"
-#include "bd/lfs_rambd.h"
-#include "bd/lfs_filebd.h"
-
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-
-
-// Block device specific tracing
-#ifdef LFS_TESTBD_YES_TRACE
-#define LFS_TESTBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
-#else
-#define LFS_TESTBD_TRACE(...)
-#endif
-
-// Mode determining how "bad blocks" behave during testing. This simulates
-// some real-world circumstances such as progs not sticking (prog-noop),
-// a readonly disk (erase-noop), and ECC failures (read-error).
-//
-// Not that read-noop is not allowed. Read _must_ return a consistent (but
-// may be arbitrary) value on every read.
-enum lfs_testbd_badblock_behavior {
-    LFS_TESTBD_BADBLOCK_PROGERROR,
-    LFS_TESTBD_BADBLOCK_ERASEERROR,
-    LFS_TESTBD_BADBLOCK_READERROR,
-    LFS_TESTBD_BADBLOCK_PROGNOOP,
-    LFS_TESTBD_BADBLOCK_ERASENOOP,
-};
-
-// Type for measuring wear
-typedef uint32_t lfs_testbd_wear_t;
-typedef int32_t  lfs_testbd_swear_t;
-
-// testbd config, this is required for testing
-struct lfs_testbd_config {
-    // 8-bit erase value to use for simulating erases. -1 does not simulate
-    // erases, which can speed up testing by avoiding all the extra block-device
-    // operations to store the erase value.
-    int32_t erase_value;
-
-    // Number of erase cycles before a block becomes "bad". The exact behavior
-    // of bad blocks is controlled by the badblock_mode.
-    uint32_t erase_cycles;
-
-    // The mode determining how bad blocks fail
-    uint8_t badblock_behavior;
-
-    // Number of write operations (erase/prog) before forcefully killing
-    // the program with exit. Simulates power-loss. 0 disables.
-    uint32_t power_cycles;
-
-    // Optional buffer for RAM block device.
-    void *buffer;
-
-    // Optional buffer for wear
-    void *wear_buffer;
-};
-
-// testbd state
-typedef struct lfs_testbd {
-    union {
-        struct {
-            lfs_filebd_t bd;
-            struct lfs_filebd_config cfg;
-        } file;
-        struct {
-            lfs_rambd_t bd;
-            struct lfs_rambd_config cfg;
-        } ram;
-    } u;
-
-    bool persist;
-    uint32_t power_cycles;
-    lfs_testbd_wear_t *wear;
-
-    const struct lfs_testbd_config *cfg;
-} lfs_testbd_t;
-
-
-/// Block device API ///
-
-// Create a test block device using the geometry in lfs_config
-//
-// Note that filebd is used if a path is provided, if path is NULL
-// testbd will use rambd which can be much faster.
-int lfs_testbd_create(const struct lfs_config *cfg, const char *path);
-int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
-        const struct lfs_testbd_config *bdcfg);
-
-// Clean up memory associated with block device
-int lfs_testbd_destroy(const struct lfs_config *cfg);
-
-// Read a block
-int lfs_testbd_read(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, void *buffer, lfs_size_t size);
-
-// Program a block
-//
-// The block must have previously been erased.
-int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, const void *buffer, lfs_size_t size);
-
-// Erase a block
-//
-// A block must be erased before being programmed. The
-// state of an erased block is undefined.
-int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block);
-
-// Sync the block device
-int lfs_testbd_sync(const struct lfs_config *cfg);
-
-
-/// Additional extended API for driving test features ///
-
-// Get simulated wear on a given block
-lfs_testbd_swear_t lfs_testbd_getwear(const struct lfs_config *cfg,
-        lfs_block_t block);
-
-// Manually set simulated wear on a given block
-int lfs_testbd_setwear(const struct lfs_config *cfg,
-        lfs_block_t block, lfs_testbd_wear_t wear);
-
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
-#endif

benches/bench_dir.toml

@@ -0,0 +1,270 @@
+[cases.bench_dir_open]
+# 0 = in-order
+# 1 = reversed-order
+# 2 = random-order
+defines.ORDER = [0, 1, 2]
+defines.N = 1024
+defines.FILE_SIZE = 8
+defines.CHUNK_SIZE = 8
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    // first create the files
+    char name[256];
+    uint8_t buffer[CHUNK_SIZE];
+    for (lfs_size_t i = 0; i < N; i++) {
+        sprintf(name, "file%08x", i);
+        lfs_file_t file;
+        lfs_file_open(&lfs, &file, name,
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+
+        uint32_t file_prng = i;
+        for (lfs_size_t j = 0; j < FILE_SIZE; j += CHUNK_SIZE) {
+            for (lfs_size_t k = 0; k < CHUNK_SIZE; k++) {
+                buffer[k] = BENCH_PRNG(&file_prng);
+            }
+            lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+        }
+
+        lfs_file_close(&lfs, &file) => 0;
+    }
+
+    // then read the files
+    BENCH_START();
+    uint32_t prng = 42;
+    for (lfs_size_t i = 0; i < N; i++) {
+        lfs_off_t i_
+            = (ORDER == 0) ? i
+            : (ORDER == 1) ? (N-1-i)
+            : BENCH_PRNG(&prng) % N;
+        sprintf(name, "file%08x", i_);
+        lfs_file_t file;
+        lfs_file_open(&lfs, &file, name, LFS_O_RDONLY) => 0;
+
+        uint32_t file_prng = i_;
+        for (lfs_size_t j = 0; j < FILE_SIZE; j += CHUNK_SIZE) {
+            lfs_file_read(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+            for (lfs_size_t k = 0; k < CHUNK_SIZE; k++) {
+                assert(buffer[k] == BENCH_PRNG(&file_prng));
+            }
+        }
+
+        lfs_file_close(&lfs, &file) => 0;
+    }
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.bench_dir_creat]
+# 0 = in-order
+# 1 = reversed-order
+# 2 = random-order
+defines.ORDER = [0, 1, 2]
+defines.N = 1024
+defines.FILE_SIZE = 8
+defines.CHUNK_SIZE = 8
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    BENCH_START();
+    uint32_t prng = 42;
+    char name[256];
+    uint8_t buffer[CHUNK_SIZE];
+    for (lfs_size_t i = 0; i < N; i++) {
+        lfs_off_t i_
+            = (ORDER == 0) ? i
+            : (ORDER == 1) ? (N-1-i)
+            : BENCH_PRNG(&prng) % N;
+        sprintf(name, "file%08x", i_);
+        lfs_file_t file;
+        lfs_file_open(&lfs, &file, name,
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
+
+        uint32_t file_prng = i_;
+        for (lfs_size_t j = 0; j < FILE_SIZE; j += CHUNK_SIZE) {
+            for (lfs_size_t k = 0; k < CHUNK_SIZE; k++) {
+                buffer[k] = BENCH_PRNG(&file_prng);
+            }
+            lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+        }
+
+        lfs_file_close(&lfs, &file) => 0;
+    }
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.bench_dir_remove]
+# 0 = in-order
+# 1 = reversed-order
+# 2 = random-order
+defines.ORDER = [0, 1, 2]
+defines.N = 1024
+defines.FILE_SIZE = 8
+defines.CHUNK_SIZE = 8
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    // first create the files
+    char name[256];
+    uint8_t buffer[CHUNK_SIZE];
+    for (lfs_size_t i = 0; i < N; i++) {
+        sprintf(name, "file%08x", i);
+        lfs_file_t file;
+        lfs_file_open(&lfs, &file, name,
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+
+        uint32_t file_prng = i;
+        for (lfs_size_t j = 0; j < FILE_SIZE; j += CHUNK_SIZE) {
+            for (lfs_size_t k = 0; k < CHUNK_SIZE; k++) {
+                buffer[k] = BENCH_PRNG(&file_prng);
+            }
+            lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+        }
+
+        lfs_file_close(&lfs, &file) => 0;
+    }
+
+    // then remove the files
+    BENCH_START();
+    uint32_t prng = 42;
+    for (lfs_size_t i = 0; i < N; i++) {
+        lfs_off_t i_
+            = (ORDER == 0) ? i
+            : (ORDER == 1) ? (N-1-i)
+            : BENCH_PRNG(&prng) % N;
+        sprintf(name, "file%08x", i_);
+        int err = lfs_remove(&lfs, name);
+        assert(!err || err == LFS_ERR_NOENT);
+    }
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.bench_dir_read]
+defines.N = 1024
+defines.FILE_SIZE = 8
+defines.CHUNK_SIZE = 8
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    // first create the files
+    char name[256];
+    uint8_t buffer[CHUNK_SIZE];
+    for (lfs_size_t i = 0; i < N; i++) {
+        sprintf(name, "file%08x", i);
+        lfs_file_t file;
+        lfs_file_open(&lfs, &file, name,
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+
+        uint32_t file_prng = i;
+        for (lfs_size_t j = 0; j < FILE_SIZE; j += CHUNK_SIZE) {
+            for (lfs_size_t k = 0; k < CHUNK_SIZE; k++) {
+                buffer[k] = BENCH_PRNG(&file_prng);
+            }
+            lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+        }
+
+        lfs_file_close(&lfs, &file) => 0;
+    }
+
+    // then read the directory
+    BENCH_START();
+    lfs_dir_t dir;
+    lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, ".") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, "..") == 0);
+    for (int i = 0; i < N; i++) {
+        sprintf(name, "file%08x", i);
+        lfs_dir_read(&lfs, &dir, &info) => 1;
+        assert(info.type == LFS_TYPE_REG);
+        assert(strcmp(info.name, name) == 0);
+    }
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+    lfs_dir_close(&lfs, &dir) => 0;
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.bench_dir_mkdir]
+# 0 = in-order
+# 1 = reversed-order
+# 2 = random-order
+defines.ORDER = [0, 1, 2]
+defines.N = 8
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    BENCH_START();
+    uint32_t prng = 42;
+    char name[256];
+    for (lfs_size_t i = 0; i < N; i++) {
+        lfs_off_t i_
+            = (ORDER == 0) ? i
+            : (ORDER == 1) ? (N-1-i)
+            : BENCH_PRNG(&prng) % N;
+        printf("hm %d\n", i);
+        sprintf(name, "dir%08x", i_);
+        int err = lfs_mkdir(&lfs, name);
+        assert(!err || err == LFS_ERR_EXIST);
+    }
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.bench_dir_rmdir]
+# 0 = in-order
+# 1 = reversed-order
+# 2 = random-order
+defines.ORDER = [0, 1, 2]
+defines.N = 8
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    // first create the dirs
+    char name[256];
+    for (lfs_size_t i = 0; i < N; i++) {
+        sprintf(name, "dir%08x", i);
+        lfs_mkdir(&lfs, name) => 0;
+    }
+
+    // then remove the dirs
+    BENCH_START();
+    uint32_t prng = 42;
+    for (lfs_size_t i = 0; i < N; i++) {
+        lfs_off_t i_
+            = (ORDER == 0) ? i
+            : (ORDER == 1) ? (N-1-i)
+            : BENCH_PRNG(&prng) % N;
+        sprintf(name, "dir%08x", i_);
+        int err = lfs_remove(&lfs, name);
+        assert(!err || err == LFS_ERR_NOENT);
+    }
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+

benches/bench_file.toml

@@ -0,0 +1,95 @@
+[cases.bench_file_read]
+# 0 = in-order
+# 1 = reversed-order
+# 2 = random-order
+defines.ORDER = [0, 1, 2]
+defines.SIZE = '128*1024'
+defines.CHUNK_SIZE = 64
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_size_t chunks = (SIZE+CHUNK_SIZE-1)/CHUNK_SIZE;
+
+    // first write the file
+    lfs_file_t file;
+    uint8_t buffer[CHUNK_SIZE];
+    lfs_file_open(&lfs, &file, "file",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+    for (lfs_size_t i = 0; i < chunks; i++) {
+        uint32_t chunk_prng = i;
+        for (lfs_size_t j = 0; j < CHUNK_SIZE; j++) {
+            buffer[j] = BENCH_PRNG(&chunk_prng);
+        }
+
+        lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+    }
+    lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+    lfs_file_close(&lfs, &file) => 0;
+
+    // then read the file
+    BENCH_START();
+    lfs_file_open(&lfs, &file, "file", LFS_O_RDONLY) => 0;
+
+    uint32_t prng = 42;
+    for (lfs_size_t i = 0; i < chunks; i++) {
+        lfs_off_t i_
+            = (ORDER == 0) ? i
+            : (ORDER == 1) ? (chunks-1-i)
+            : BENCH_PRNG(&prng) % chunks;
+        lfs_file_seek(&lfs, &file, i_*CHUNK_SIZE, LFS_SEEK_SET)
+                => i_*CHUNK_SIZE;
+        lfs_file_read(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+
+        uint32_t chunk_prng = i_;
+        for (lfs_size_t j = 0; j < CHUNK_SIZE; j++) {
+            assert(buffer[j] == BENCH_PRNG(&chunk_prng));
+        }
+    }
+
+    lfs_file_close(&lfs, &file) => 0;
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.bench_file_write]
+# 0 = in-order
+# 1 = reversed-order
+# 2 = random-order
+defines.ORDER = [0, 1, 2]
+defines.SIZE = '128*1024'
+defines.CHUNK_SIZE = 64
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_size_t chunks = (SIZE+CHUNK_SIZE-1)/CHUNK_SIZE;
+
+    BENCH_START();
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "file",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+
+    uint8_t buffer[CHUNK_SIZE];
+    uint32_t prng = 42;
+    for (lfs_size_t i = 0; i < chunks; i++) {
+        lfs_off_t i_
+            = (ORDER == 0) ? i
+            : (ORDER == 1) ? (chunks-1-i)
+            : BENCH_PRNG(&prng) % chunks;
+        uint32_t chunk_prng = i_;
+        for (lfs_size_t j = 0; j < CHUNK_SIZE; j++) {
+            buffer[j] = BENCH_PRNG(&chunk_prng);
+        }
+
+        lfs_file_seek(&lfs, &file, i_*CHUNK_SIZE, LFS_SEEK_SET)
+                => i_*CHUNK_SIZE;
+        lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+    }
+
+    lfs_file_close(&lfs, &file) => 0;
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''

benches/bench_superblock.toml

@@ -0,0 +1,56 @@
+[cases.bench_superblocks_found]
+# support benchmarking with files
+defines.N = [0, 1024]
+defines.FILE_SIZE = 8
+defines.CHUNK_SIZE = 8
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    // create files?
+    lfs_mount(&lfs, cfg) => 0;
+    char name[256];
+    uint8_t buffer[CHUNK_SIZE];
+    for (lfs_size_t i = 0; i < N; i++) {
+        sprintf(name, "file%08x", i);
+        lfs_file_t file;
+        lfs_file_open(&lfs, &file, name,
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+
+        for (lfs_size_t j = 0; j < FILE_SIZE; j += CHUNK_SIZE) {
+            for (lfs_size_t k = 0; k < CHUNK_SIZE; k++) {
+                buffer[k] = i+j+k;
+            }
+            lfs_file_write(&lfs, &file, buffer, CHUNK_SIZE) => CHUNK_SIZE;
+        }
+
+        lfs_file_close(&lfs, &file) => 0;
+    }
+    lfs_unmount(&lfs) => 0;
+
+    BENCH_START();
+    lfs_mount(&lfs, cfg) => 0;
+    BENCH_STOP();
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.bench_superblocks_missing]
+code = '''
+    lfs_t lfs;
+
+    BENCH_START();
+    int err = lfs_mount(&lfs, cfg);
+    assert(err != 0);
+    BENCH_STOP();
+'''
+
+[cases.bench_superblocks_format]
+code = '''
+    lfs_t lfs;
+
+    BENCH_START();
+    lfs_format(&lfs, cfg) => 0;
+    BENCH_STOP();
+'''
+

lfs.h

@@ -1,14 +1,14 @@
 /*
  * The little filesystem
  *
+ * Copyright (c) 2022, The littlefs authors.
  * Copyright (c) 2017, Arm Limited. All rights reserved.
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #ifndef LFS_H
 #define LFS_H
 
-#include <stdint.h>
-#include <stdbool.h>
+#include "lfs_util.h"
 
 #ifdef __cplusplus
 extern "C"
@@ -21,14 +21,14 @@ extern "C"
 // Software library version
 // Major (top-nibble), incremented on backwards incompatible changes
 // Minor (bottom-nibble), incremented on feature additions
-#define LFS_VERSION 0x00020002
+#define LFS_VERSION 0x0002000b
 #define LFS_VERSION_MAJOR (0xffff & (LFS_VERSION >> 16))
 #define LFS_VERSION_MINOR (0xffff & (LFS_VERSION >>  0))
 
 // Version of On-disk data structures
 // Major (top-nibble), incremented on backwards incompatible changes
 // Minor (bottom-nibble), incremented on feature additions
-#define LFS_DISK_VERSION 0x00020000
+#define LFS_DISK_VERSION 0x00020001
 #define LFS_DISK_VERSION_MAJOR (0xffff & (LFS_DISK_VERSION >> 16))
 #define LFS_DISK_VERSION_MINOR (0xffff & (LFS_DISK_VERSION >>  0))
 
@@ -52,16 +52,15 @@ typedef uint32_t lfs_block_t;
 #endif
 
 // Maximum size of a file in bytes, may be redefined to limit to support other
-// drivers. Limited on disk to <= 4294967296. However, above 2147483647 the
-// functions lfs_file_seek, lfs_file_size, and lfs_file_tell will return
-// incorrect values due to using signed integers. Stored in superblock and
-// must be respected by other littlefs drivers.
+// drivers. Limited on disk to <= 2147483647. Stored in superblock and must be
+// respected by other littlefs drivers.
 #ifndef LFS_FILE_MAX
 #define LFS_FILE_MAX 2147483647
 #endif
 
 // Maximum size of custom attributes in bytes, may be redefined, but there is
-// no real benefit to using a smaller LFS_ATTR_MAX. Limited to <= 1022.
+// no real benefit to using a smaller LFS_ATTR_MAX. Limited to <= 1022. Stored
+// in superblock and must be respected by other littlefs drivers.
 #ifndef LFS_ATTR_MAX
 #define LFS_ATTR_MAX 1022
 #endif
@@ -112,6 +111,8 @@ enum lfs_type {
     LFS_TYPE_SOFTTAIL       = 0x600,
     LFS_TYPE_HARDTAIL       = 0x601,
     LFS_TYPE_MOVESTATE      = 0x7ff,
+    LFS_TYPE_CCRC           = 0x500,
+    LFS_TYPE_FCRC           = 0x5ff,
 
     // internal chip sources
     LFS_FROM_NOOP           = 0x000,
@@ -123,20 +124,25 @@ enum lfs_type {
 enum lfs_open_flags {
     // open flags
     LFS_O_RDONLY = 1,         // Open a file as read only
+#ifndef LFS_READONLY
     LFS_O_WRONLY = 2,         // Open a file as write only
     LFS_O_RDWR   = 3,         // Open a file as read and write
     LFS_O_CREAT  = 0x0100,    // Create a file if it does not exist
     LFS_O_EXCL   = 0x0200,    // Fail if a file already exists
     LFS_O_TRUNC  = 0x0400,    // Truncate the existing file to zero size
     LFS_O_APPEND = 0x0800,    // Move to end of file on every write
+#endif
 
     // internally used flags
+#ifndef LFS_READONLY
     LFS_F_DIRTY   = 0x010000, // File does not match storage
     LFS_F_WRITING = 0x020000, // File has been written since last flush
+#endif
     LFS_F_READING = 0x040000, // File has been read since last flush
-    LFS_F_ERRED   = 0x080000, // An error occured during write
+#ifndef LFS_READONLY
+    LFS_F_ERRED   = 0x080000, // An error occurred during write
+#endif
     LFS_F_INLINE  = 0x100000, // Currently inlined in directory entry
-    LFS_F_OPENED  = 0x200000, // File has been opened
 };
 
 // File seek flags
@@ -153,45 +159,56 @@ struct lfs_config {
     // information to the block device operations
     void *context;
 
-    // Read a region in a block. Negative error codes are propogated
+    // Read a region in a block. Negative error codes are propagated
     // to the user.
     int (*read)(const struct lfs_config *c, lfs_block_t block,
             lfs_off_t off, void *buffer, lfs_size_t size);
 
     // Program a region in a block. The block must have previously
-    // been erased. Negative error codes are propogated to the user.
+    // been erased. Negative error codes are propagated to the user.
     // May return LFS_ERR_CORRUPT if the block should be considered bad.
     int (*prog)(const struct lfs_config *c, lfs_block_t block,
             lfs_off_t off, const void *buffer, lfs_size_t size);
 
     // Erase a block. A block must be erased before being programmed.
     // The state of an erased block is undefined. Negative error codes
-    // are propogated to the user.
+    // are propagated to the user.
     // May return LFS_ERR_CORRUPT if the block should be considered bad.
     int (*erase)(const struct lfs_config *c, lfs_block_t block);
 
     // Sync the state of the underlying block device. Negative error codes
-    // are propogated to the user.
+    // are propagated to the user.
     int (*sync)(const struct lfs_config *c);
 
-    // Minimum size of a block read. All read operations will be a
+#ifdef LFS_THREADSAFE
+    // Lock the underlying block device. Negative error codes
+    // are propagated to the user.
+    int (*lock)(const struct lfs_config *c);
+
+    // Unlock the underlying block device. Negative error codes
+    // are propagated to the user.
+    int (*unlock)(const struct lfs_config *c);
+#endif
+
+    // Minimum size of a block read in bytes. All read operations will be a
     // multiple of this value.
     lfs_size_t read_size;
 
-    // Minimum size of a block program. All program operations will be a
-    // multiple of this value.
+    // Minimum size of a block program in bytes. All program operations will be
+    // a multiple of this value.
     lfs_size_t prog_size;
 
-    // Size of an erasable block. This does not impact ram consumption and
-    // may be larger than the physical erase size. However, non-inlined files
-    // take up at minimum one block. Must be a multiple of the read
-    // and program sizes.
+    // Size of an erasable block in bytes. This does not impact ram consumption
+    // and may be larger than the physical erase size. However, non-inlined
+    // files take up at minimum one block. Must be a multiple of the read and
+    // program sizes.
     lfs_size_t block_size;
 
-    // Number of erasable blocks on the device.
+    // Number of erasable blocks on the device. Defaults to block_count stored
+    // on disk when zero.
     lfs_size_t block_count;
 
-    // Number of erase cycles before littlefs evicts metadata logs and moves 
+    // Number of erase cycles before littlefs evicts metadata logs and moves
     // the metadata to another block. Suggested values are in the
     // range 100-1000, with large values having better performance at the cost
     // of less consistent wear distribution.
@@ -199,19 +216,30 @@ struct lfs_config {
     // Set to -1 to disable block-level wear-leveling.
     int32_t block_cycles;
 
-    // Size of block caches. Each cache buffers a portion of a block in RAM.
-    // The littlefs needs a read cache, a program cache, and one additional
+    // Size of block caches in bytes. Each cache buffers a portion of a block in
+    // RAM. The littlefs needs a read cache, a program cache, and one additional
     // cache per file. Larger caches can improve performance by storing more
-    // data and reducing the number of disk accesses. Must be a multiple of
-    // the read and program sizes, and a factor of the block size.
+    // data and reducing the number of disk accesses. Must be a multiple of the
+    // read and program sizes, and a factor of the block size.
     lfs_size_t cache_size;
 
     // Size of the lookahead buffer in bytes. A larger lookahead buffer
     // increases the number of blocks found during an allocation pass. The
     // lookahead buffer is stored as a compact bitmap, so each byte of RAM
-    // can track 8 blocks. Must be a multiple of 8.
+    // can track 8 blocks.
     lfs_size_t lookahead_size;
 
+    // Threshold for metadata compaction during lfs_fs_gc in bytes. Metadata
+    // pairs that exceed this threshold will be compacted during lfs_fs_gc.
+    // Defaults to ~88% block_size when zero, though the default may change
+    // in the future.
+    //
+    // Note this only affects lfs_fs_gc. Normal compactions still only occur
+    // when full.
+    //
+    // Set to -1 to disable metadata compaction during lfs_fs_gc.
+    lfs_size_t compact_thresh;
+
     // Optional statically allocated read buffer. Must be cache_size.
     // By default lfs_malloc is used to allocate this buffer.
     void *read_buffer;
@@ -220,26 +248,48 @@ struct lfs_config {
     // By default lfs_malloc is used to allocate this buffer.
     void *prog_buffer;
 
-    // Optional statically allocated lookahead buffer. Must be lookahead_size
-    // and aligned to a 32-bit boundary. By default lfs_malloc is used to
-    // allocate this buffer.
+    // Optional statically allocated lookahead buffer. Must be lookahead_size.
+    // By default lfs_malloc is used to allocate this buffer.
     void *lookahead_buffer;
 
     // Optional upper limit on length of file names in bytes. No downside for
     // larger names except the size of the info struct which is controlled by
-    // the LFS_NAME_MAX define. Defaults to LFS_NAME_MAX when zero. Stored in
-    // superblock and must be respected by other littlefs drivers.
+    // the LFS_NAME_MAX define. Defaults to LFS_NAME_MAX or name_max stored on
+    // disk when zero.
     lfs_size_t name_max;
 
     // Optional upper limit on files in bytes. No downside for larger files
-    // but must be <= LFS_FILE_MAX. Defaults to LFS_FILE_MAX when zero. Stored
-    // in superblock and must be respected by other littlefs drivers.
+    // but must be <= LFS_FILE_MAX. Defaults to LFS_FILE_MAX or file_max stored
+    // on disk when zero.
     lfs_size_t file_max;
 
     // Optional upper limit on custom attributes in bytes. No downside for
     // larger attributes size but must be <= LFS_ATTR_MAX. Defaults to
-    // LFS_ATTR_MAX when zero.
+    // LFS_ATTR_MAX or attr_max stored on disk when zero.
     lfs_size_t attr_max;
+
+    // Optional upper limit on total space given to metadata pairs in bytes. On
+    // devices with large blocks (e.g. 128kB) setting this to a low size (2-8kB)
+    // can help bound the metadata compaction time. Must be <= block_size.
+    // Defaults to block_size when zero.
+    lfs_size_t metadata_max;
+
+    // Optional upper limit on inlined files in bytes. Inlined files live in
+    // metadata and decrease storage requirements, but may be limited to
+    // improve metadata-related performance. Must be <= cache_size, <=
+    // attr_max, and <= block_size/8. Defaults to the largest possible
+    // inline_max when zero.
+    //
+    // Set to -1 to disable inlined files.
+    lfs_size_t inline_max;
+
+#ifdef LFS_MULTIVERSION
+    // On-disk version to use when writing in the form of 16-bit major version
+    // + 16-bit minor version. This limiting metadata to what is supported by
+    // older minor versions. Note that some features will be lost. Defaults to 
+    // to the most recent minor version when zero.
+    uint32_t disk_version;
+#endif
 };
 
 // File info structure
@@ -257,6 +307,27 @@ struct lfs_info {
     char name[LFS_NAME_MAX+1];
 };
 
+// Filesystem info structure
+struct lfs_fsinfo {
+    // On-disk version.
+    uint32_t disk_version;
+
+    // Size of a logical block in bytes.
+    lfs_size_t block_size;
+
+    // Number of logical blocks in filesystem.
+    lfs_size_t block_count;
+
+    // Upper limit on the length of file names in bytes.
+    lfs_size_t name_max;
+
+    // Upper limit on the size of files in bytes.
+    lfs_size_t file_max;
+
+    // Upper limit on the size of custom attributes in bytes.
+    lfs_size_t attr_max;
+};
+
 // Custom attribute structure, used to describe custom attributes
 // committed atomically during file writes.
 struct lfs_attr {
@@ -378,18 +449,20 @@ typedef struct lfs {
     lfs_gstate_t gdisk;
     lfs_gstate_t gdelta;
 
-    struct lfs_free {
-        lfs_block_t off;
+    struct lfs_lookahead {
+        lfs_block_t start;
         lfs_block_t size;
-        lfs_block_t i;
-        lfs_block_t ack;
-        uint32_t *buffer;
-    } free;
+        lfs_block_t next;
+        lfs_block_t ckpoint;
+        uint8_t *buffer;
+    } lookahead;
 
     const struct lfs_config *cfg;
+    lfs_size_t block_count;
     lfs_size_t name_max;
     lfs_size_t file_max;
     lfs_size_t attr_max;
+    lfs_size_t inline_max;
 
 #ifdef LFS_MIGRATE
     struct lfs1 *lfs1;
@@ -399,6 +472,7 @@ typedef struct lfs {
 
 /// Filesystem functions ///
 
+#ifndef LFS_READONLY
 // Format a block device with the littlefs
 //
 // Requires a littlefs object and config struct. This clobbers the littlefs
@@ -407,6 +481,7 @@ typedef struct lfs {
 //
 // Returns a negative error code on failure.
 int lfs_format(lfs_t *lfs, const struct lfs_config *config);
+#endif
 
 // Mounts a littlefs
 //
@@ -426,12 +501,15 @@ int lfs_unmount(lfs_t *lfs);
 
 /// General operations ///
 
+#ifndef LFS_READONLY
 // Removes a file or directory
 //
 // If removing a directory, the directory must be empty.
 // Returns a negative error code on failure.
 int lfs_remove(lfs_t *lfs, const char *path);
+#endif
 
+#ifndef LFS_READONLY
 // Rename or move a file or directory
 //
 // If the destination exists, it must match the source in type.
@@ -439,6 +517,7 @@ int lfs_remove(lfs_t *lfs, const char *path);
 //
 // Returns a negative error code on failure.
 int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath);
+#endif
 
 // Find info about a file or directory
 //
@@ -457,10 +536,11 @@ int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
 // Returns the size of the attribute, or a negative error code on failure.
 // Note, the returned size is the size of the attribute on disk, irrespective
 // of the size of the buffer. This can be used to dynamically allocate a buffer
-// or check for existance.
+// or check for existence.
 lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
         uint8_t type, void *buffer, lfs_size_t size);
 
+#ifndef LFS_READONLY
 // Set custom attributes
 //
 // Custom attributes are uniquely identified by an 8-bit type and limited
@@ -470,17 +550,21 @@ lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
 // Returns a negative error code on failure.
 int lfs_setattr(lfs_t *lfs, const char *path,
         uint8_t type, const void *buffer, lfs_size_t size);
+#endif
 
+#ifndef LFS_READONLY
 // Removes a custom attribute
 //
 // If an attribute is not found, nothing happens.
 //
 // Returns a negative error code on failure.
 int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
+#endif
 
 
 /// File operations ///
 
+#ifndef LFS_NO_MALLOC
 // Open a file
 //
 // The mode that the file is opened in is determined by the flags, which
@@ -490,14 +574,18 @@ int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
 int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags);
 
+// if LFS_NO_MALLOC is defined, lfs_file_open() will fail with LFS_ERR_NOMEM
+// thus use lfs_file_opencfg() with config.buffer set.
+#endif
+
 // Open a file with extra configuration
 //
 // The mode that the file is opened in is determined by the flags, which
 // are values from the enum lfs_open_flags that are bitwise-ored together.
 //
 // The config struct provides additional config options per file as described
-// above. The config struct must be allocated while the file is open, and the
-// config struct must be zeroed for defaults and backwards compatibility.
+// above. The config struct must remain allocated while the file is open, and
+// the config struct must be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
 int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
@@ -525,6 +613,7 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file);
 lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
         void *buffer, lfs_size_t size);
 
+#ifndef LFS_READONLY
 // Write data to file
 //
 // Takes a buffer and size indicating the data to write. The file will not
@@ -533,6 +622,7 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
 // Returns the number of bytes written, or a negative error code on failure.
 lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
         const void *buffer, lfs_size_t size);
+#endif
 
 // Change the position of the file
 //
@@ -541,10 +631,12 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
 lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
         lfs_soff_t off, int whence);
 
+#ifndef LFS_READONLY
 // Truncates the size of the file to the specified size
 //
 // Returns a negative error code on failure.
 int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size);
+#endif
 
 // Return the position of the file
 //
@@ -567,10 +659,12 @@ lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file);
 
 /// Directory operations ///
 
+#ifndef LFS_READONLY
 // Create a directory
 //
 // Returns a negative error code on failure.
 int lfs_mkdir(lfs_t *lfs, const char *path);
+#endif
 
 // Open a directory
 //
@@ -615,6 +709,12 @@ int lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir);
 
 /// Filesystem-level filesystem operations
 
+// Find on-disk info about the filesystem
+//
+// Fills out the fsinfo structure based on the filesystem found on-disk.
+// Returns a negative error code on failure.
+int lfs_fs_stat(lfs_t *lfs, struct lfs_fsinfo *fsinfo);
+
 // Finds the current size of the filesystem
 //
 // Note: Result is best effort. If files share COW structures, the returned
@@ -632,6 +732,51 @@ lfs_ssize_t lfs_fs_size(lfs_t *lfs);
 // Returns a negative error code on failure.
 int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 
+#ifndef LFS_READONLY
+// Attempt to make the filesystem consistent and ready for writing
+//
+// Calling this function is not required, consistency will be implicitly
+// enforced on the first operation that writes to the filesystem, but this
+// function allows the work to be performed earlier and without other
+// filesystem changes.
+//
+// Returns a negative error code on failure.
+int lfs_fs_mkconsistent(lfs_t *lfs);
+#endif
+
+#ifndef LFS_READONLY
+// Attempt any janitorial work
+//
+// This currently:
+// 1. Calls mkconsistent if not already consistent
+// 2. Compacts metadata > compact_thresh
+// 3. Populates the block allocator
+//
+// Though additional janitorial work may be added in the future.
+//
+// Calling this function is not required, but may allow the offloading of
+// expensive janitorial work to a less time-critical code path.
+//
+// Returns a negative error code on failure. Accomplishing nothing is not
+// an error.
+int lfs_fs_gc(lfs_t *lfs);
+#endif
+
+#ifndef LFS_READONLY
+// Grows the filesystem to a new size, updating the superblock with the new
+// block count.
+//
+// If LFS_SHRINKNONRELOCATING is defined, this function will also accept
+// block_counts smaller than the current configuration, after checking
+// that none of the blocks that are being removed are in use.
+// Note that littlefs's pseudorandom block allocation means that
+// this is very unlikely to work in the general case.
+//
+// Returns a negative error code on failure.
+int lfs_fs_grow(lfs_t *lfs, lfs_size_t block_count);
+#endif
+
+#ifndef LFS_READONLY
 #ifdef LFS_MIGRATE
 // Attempts to migrate a previous version of littlefs
 //
@@ -646,6 +791,7 @@ int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 // Returns a negative error code on failure.
 int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
 #endif
+#endif
 
 
 #ifdef __cplusplus

lfs_util.c

@@ -1,6 +1,7 @@
 /*
  * lfs util functions
  *
+ * Copyright (c) 2022, The littlefs authors.
  * Copyright (c) 2017, Arm Limited. All rights reserved.
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -10,6 +11,8 @@
 #ifndef LFS_CONFIG
 
 
+// If user provides their own CRC impl we don't need this
+#ifndef LFS_CRC
 // Software CRC implementation with small lookup table
 uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) {
     static const uint32_t rtable[16] = {
@@ -28,6 +31,7 @@ uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) {
 
     return crc;
 }
+#endif
 
 
 #endif

lfs_util.h

@@ -1,12 +1,16 @@
 /*
  * lfs utility functions
  *
+ * Copyright (c) 2022, The littlefs authors.
  * Copyright (c) 2017, Arm Limited. All rights reserved.
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #ifndef LFS_UTIL_H
 #define LFS_UTIL_H
 
+#define LFS_STRINGIZE(x) LFS_STRINGIZE2(x)
+#define LFS_STRINGIZE2(x) #x
+
 // Users can override lfs_util.h with their own configuration by defining
 // LFS_CONFIG as a header file to include (-DLFS_CONFIG=lfs_config.h).
 //
@@ -14,11 +18,26 @@
 // provided by the config file. To start, I would suggest copying lfs_util.h
 // and modifying as needed.
 #ifdef LFS_CONFIG
-#define LFS_STRINGIZE(x) LFS_STRINGIZE2(x)
-#define LFS_STRINGIZE2(x) #x
 #include LFS_STRINGIZE(LFS_CONFIG)
 #else
 
+// Alternatively, users can provide a header file which defines
+// macros and other things consumed by littlefs.
+//
+// For example, provide my_defines.h, which contains
+// something like:
+//
+// #include <stddef.h>
+// extern void *my_malloc(size_t sz);
+// #define LFS_MALLOC(sz) my_malloc(sz)
+//
+// And build littlefs with the header by defining LFS_DEFINES.
+// (-DLFS_DEFINES=my_defines.h)
+
+#ifdef LFS_DEFINES
+#include LFS_STRINGIZE(LFS_DEFINES)
+#endif
+
 // System includes
 #include <stdint.h>
 #include <stdbool.h>
@@ -49,6 +68,7 @@ extern "C"
 // code footprint
 
 // Logging functions
+#ifndef LFS_TRACE
 #ifdef LFS_YES_TRACE
 #define LFS_TRACE_(fmt, ...) \
     printf("%s:%d:trace: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -56,7 +76,9 @@ extern "C"
 #else
 #define LFS_TRACE(...)
 #endif
+#endif
 
+#ifndef LFS_DEBUG
 #ifndef LFS_NO_DEBUG
 #define LFS_DEBUG_(fmt, ...) \
     printf("%s:%d:debug: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -64,7 +86,9 @@ extern "C"
 #else
 #define LFS_DEBUG(...)
 #endif
+#endif
 
+#ifndef LFS_WARN
 #ifndef LFS_NO_WARN
 #define LFS_WARN_(fmt, ...) \
     printf("%s:%d:warn: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -72,7 +96,9 @@ extern "C"
 #else
 #define LFS_WARN(...)
 #endif
+#endif
 
+#ifndef LFS_ERROR
 #ifndef LFS_NO_ERROR
 #define LFS_ERROR_(fmt, ...) \
     printf("%s:%d:error: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -80,13 +106,16 @@ extern "C"
 #else
 #define LFS_ERROR(...)
 #endif
+#endif
 
 // Runtime assertions
+#ifndef LFS_ASSERT
 #ifndef LFS_NO_ASSERT
 #define LFS_ASSERT(test) assert(test)
 #else
 #define LFS_ASSERT(test)
 #endif
+#endif
 
 
 // Builtin functions, these may be replaced by more efficient
@@ -156,10 +185,9 @@ static inline int lfs_scmp(uint32_t a, uint32_t b) {
 
 // Convert between 32-bit little-endian and native order
 static inline uint32_t lfs_fromle32(uint32_t a) {
-#if !defined(LFS_NO_INTRINSICS) && ( \
-    (defined(  BYTE_ORDER  ) && defined(  ORDER_LITTLE_ENDIAN  ) &&   BYTE_ORDER   ==   ORDER_LITTLE_ENDIAN  ) || \
+#if (defined(  BYTE_ORDER  ) && defined(  ORDER_LITTLE_ENDIAN  ) &&   BYTE_ORDER   ==   ORDER_LITTLE_ENDIAN  ) || \
     (defined(__BYTE_ORDER  ) && defined(__ORDER_LITTLE_ENDIAN  ) && __BYTE_ORDER   == __ORDER_LITTLE_ENDIAN  ) || \
-    (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+    (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
     return a;
 #elif !defined(LFS_NO_INTRINSICS) && ( \
     (defined(  BYTE_ORDER  ) && defined(  ORDER_BIG_ENDIAN  ) &&   BYTE_ORDER   ==   ORDER_BIG_ENDIAN  ) || \
@@ -167,10 +195,10 @@ static inline uint32_t lfs_fromle32(uint32_t a) {
     (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
     return __builtin_bswap32(a);
 #else
-    return (((uint8_t*)&a)[0] <<  0) |
-           (((uint8_t*)&a)[1] <<  8) |
-           (((uint8_t*)&a)[2] << 16) |
-           (((uint8_t*)&a)[3] << 24);
+    return ((uint32_t)((uint8_t*)&a)[0] <<  0) |
+           ((uint32_t)((uint8_t*)&a)[1] <<  8) |
+           ((uint32_t)((uint8_t*)&a)[2] << 16) |
+           ((uint32_t)((uint8_t*)&a)[3] << 24);
 #endif
 }
 
@@ -185,16 +213,15 @@ static inline uint32_t lfs_frombe32(uint32_t a) {
     (defined(__BYTE_ORDER  ) && defined(__ORDER_LITTLE_ENDIAN  ) && __BYTE_ORDER   == __ORDER_LITTLE_ENDIAN  ) || \
     (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
     return __builtin_bswap32(a);
-#elif !defined(LFS_NO_INTRINSICS) && ( \
-    (defined(  BYTE_ORDER  ) && defined(  ORDER_BIG_ENDIAN  ) &&   BYTE_ORDER   ==   ORDER_BIG_ENDIAN  ) || \
+#elif (defined(  BYTE_ORDER  ) && defined(  ORDER_BIG_ENDIAN  ) &&   BYTE_ORDER   ==   ORDER_BIG_ENDIAN  ) || \
     (defined(__BYTE_ORDER  ) && defined(__ORDER_BIG_ENDIAN  ) && __BYTE_ORDER   == __ORDER_BIG_ENDIAN  ) || \
-    (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
+    (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
     return a;
 #else
-    return (((uint8_t*)&a)[0] << 24) |
-           (((uint8_t*)&a)[1] << 16) |
-           (((uint8_t*)&a)[2] <<  8) |
-           (((uint8_t*)&a)[3] <<  0);
+    return ((uint32_t)((uint8_t*)&a)[0] << 24) |
+           ((uint32_t)((uint8_t*)&a)[1] << 16) |
+           ((uint32_t)((uint8_t*)&a)[2] <<  8) |
+           ((uint32_t)((uint8_t*)&a)[3] <<  0);
 #endif
 }
 
@@ -203,12 +230,22 @@ static inline uint32_t lfs_tobe32(uint32_t a) {
 }
 
 // Calculate CRC-32 with polynomial = 0x04c11db7
+#ifdef LFS_CRC
+static inline uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) {
+    return LFS_CRC(crc, buffer, size);
+}
+#else
 uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size);
+#endif
 
 // Allocate memory, only used if buffers are not provided to littlefs
-// Note, memory must be 64-bit aligned
+//
+// littlefs current has no alignment requirements, as it only allocates
+// byte-level buffers.
 static inline void *lfs_malloc(size_t size) {
-#ifndef LFS_NO_MALLOC
+#if defined(LFS_MALLOC)
+    return LFS_MALLOC(size);
+#elif !defined(LFS_NO_MALLOC)
     return malloc(size);
 #else
     (void)size;
@@ -218,7 +255,9 @@ static inline void *lfs_malloc(size_t size) {
 
 // Deallocate memory, only used if buffers are not provided to littlefs
 static inline void lfs_free(void *p) {
-#ifndef LFS_NO_MALLOC
+#if defined(LFS_FREE)
+    LFS_FREE(p);
+#elif !defined(LFS_NO_MALLOC)
     free(p);
 #else
     (void)p;

runners/bench_runner.h

@@ -0,0 +1,146 @@
+/*
+ * Runner for littlefs benchmarks
+ *
+ * Copyright (c) 2022, The littlefs authors.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef BENCH_RUNNER_H
+#define BENCH_RUNNER_H
+
+
+// override LFS_TRACE
+void bench_trace(const char *fmt, ...);
+
+#define LFS_TRACE_(fmt, ...) \
+    bench_trace("%s:%d:trace: " fmt "%s\n", \
+        __FILE__, \
+        __LINE__, \
+        __VA_ARGS__)
+#define LFS_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
+#define LFS_EMUBD_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
+
+// provide BENCH_START/BENCH_STOP macros
+void bench_start(void);
+void bench_stop(void);
+
+#define BENCH_START() bench_start()
+#define BENCH_STOP() bench_stop()
+
+
+// note these are indirectly included in any generated files
+#include "bd/lfs_emubd.h"
+#include <stdio.h>
+
+// give source a chance to define feature macros
+#undef _FEATURES_H
+#undef _STDIO_H
+
+
+// generated bench configurations
+struct lfs_config;
+
+enum bench_flags {
+    BENCH_REENTRANT = 0x1,
+};
+typedef uint8_t bench_flags_t;
+
+typedef struct bench_define {
+    intmax_t (*cb)(void *data);
+    void *data;
+} bench_define_t;
+
+struct bench_case {
+    const char *name;
+    const char *path;
+    bench_flags_t flags;
+    size_t permutations;
+
+    const bench_define_t *defines;
+
+    bool (*filter)(void);
+    void (*run)(struct lfs_config *cfg);
+};
+
+struct bench_suite {
+    const char *name;
+    const char *path;
+    bench_flags_t flags;
+
+    const char *const *define_names;
+    size_t define_count;
+
+    const struct bench_case *cases;
+    size_t case_count;
+};
+
+
+// deterministic prng for pseudo-randomness in benches
+uint32_t bench_prng(uint32_t *state);
+
+#define BENCH_PRNG(state) bench_prng(state)
+
+
+// access generated bench defines
+intmax_t bench_define(size_t define);
+
+#define BENCH_DEFINE(i) bench_define(i)
+
+// a few preconfigured defines that control how benches run
+ 
+#define READ_SIZE_i          0
+#define PROG_SIZE_i          1
+#define ERASE_SIZE_i         2
+#define ERASE_COUNT_i        3
+#define BLOCK_SIZE_i         4
+#define BLOCK_COUNT_i        5
+#define CACHE_SIZE_i         6
+#define LOOKAHEAD_SIZE_i     7
+#define COMPACT_THRESH_i     8
+#define METADATA_MAX_i       9
+#define INLINE_MAX_i         10
+#define BLOCK_CYCLES_i       11
+#define ERASE_VALUE_i        12
+#define ERASE_CYCLES_i       13
+#define BADBLOCK_BEHAVIOR_i  14
+#define POWERLOSS_BEHAVIOR_i 15
+
+#define READ_SIZE           bench_define(READ_SIZE_i)
+#define PROG_SIZE           bench_define(PROG_SIZE_i)
+#define ERASE_SIZE          bench_define(ERASE_SIZE_i)
+#define ERASE_COUNT         bench_define(ERASE_COUNT_i)
+#define BLOCK_SIZE          bench_define(BLOCK_SIZE_i)
+#define BLOCK_COUNT         bench_define(BLOCK_COUNT_i)
+#define CACHE_SIZE          bench_define(CACHE_SIZE_i)
+#define LOOKAHEAD_SIZE      bench_define(LOOKAHEAD_SIZE_i)
+#define COMPACT_THRESH      bench_define(COMPACT_THRESH_i)
+#define METADATA_MAX        bench_define(METADATA_MAX_i)
+#define INLINE_MAX          bench_define(INLINE_MAX_i)
+#define BLOCK_CYCLES        bench_define(BLOCK_CYCLES_i)
+#define ERASE_VALUE         bench_define(ERASE_VALUE_i)
+#define ERASE_CYCLES        bench_define(ERASE_CYCLES_i)
+#define BADBLOCK_BEHAVIOR   bench_define(BADBLOCK_BEHAVIOR_i)
+#define POWERLOSS_BEHAVIOR  bench_define(POWERLOSS_BEHAVIOR_i)
+
+#define BENCH_IMPLICIT_DEFINES \
+    BENCH_DEF(READ_SIZE,          PROG_SIZE) \
+    BENCH_DEF(PROG_SIZE,          ERASE_SIZE) \
+    BENCH_DEF(ERASE_SIZE,         0) \
+    BENCH_DEF(ERASE_COUNT,        (1024*1024)/BLOCK_SIZE) \
+    BENCH_DEF(BLOCK_SIZE,         ERASE_SIZE) \
+    BENCH_DEF(BLOCK_COUNT,        ERASE_COUNT/lfs_max(BLOCK_SIZE/ERASE_SIZE,1))\
+    BENCH_DEF(CACHE_SIZE,         lfs_max(64,lfs_max(READ_SIZE,PROG_SIZE))) \
+    BENCH_DEF(LOOKAHEAD_SIZE,     16) \
+    BENCH_DEF(COMPACT_THRESH,     0) \
+    BENCH_DEF(METADATA_MAX,       0) \
+    BENCH_DEF(INLINE_MAX,         0) \
+    BENCH_DEF(BLOCK_CYCLES,       -1) \
+    BENCH_DEF(ERASE_VALUE,        0xff) \
+    BENCH_DEF(ERASE_CYCLES,       0) \
+    BENCH_DEF(BADBLOCK_BEHAVIOR,  LFS_EMUBD_BADBLOCK_PROGERROR) \
+    BENCH_DEF(POWERLOSS_BEHAVIOR, LFS_EMUBD_POWERLOSS_NOOP)
+
+#define BENCH_GEOMETRY_DEFINE_COUNT 4
+#define BENCH_IMPLICIT_DEFINE_COUNT 16
+
+
+#endif

runners/test_runner.h

@@ -0,0 +1,142 @@
+/*
+ * Runner for littlefs tests
+ *
+ * Copyright (c) 2022, The littlefs authors.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef TEST_RUNNER_H
+#define TEST_RUNNER_H
+
+
+// override LFS_TRACE
+void test_trace(const char *fmt, ...);
+
+#define LFS_TRACE_(fmt, ...) \
+    test_trace("%s:%d:trace: " fmt "%s\n", \
+        __FILE__, \
+        __LINE__, \
+        __VA_ARGS__)
+#define LFS_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
+#define LFS_EMUBD_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
+
+
+// note these are indirectly included in any generated files
+#include "bd/lfs_emubd.h"
+#include <stdio.h>
+
+// give source a chance to define feature macros
+#undef _FEATURES_H
+#undef _STDIO_H
+
+
+// generated test configurations
+struct lfs_config;
+
+enum test_flags {
+    TEST_REENTRANT = 0x1,
+};
+typedef uint8_t test_flags_t;
+
+typedef struct test_define {
+    intmax_t (*cb)(void *data);
+    void *data;
+} test_define_t;
+
+struct test_case {
+    const char *name;
+    const char *path;
+    test_flags_t flags;
+    size_t permutations;
+
+    const test_define_t *defines;
+
+    bool (*filter)(void);
+    void (*run)(struct lfs_config *cfg);
+};
+
+struct test_suite {
+    const char *name;
+    const char *path;
+    test_flags_t flags;
+
+    const char *const *define_names;
+    size_t define_count;
+
+    const struct test_case *cases;
+    size_t case_count;
+};
+
+
+// deterministic prng for pseudo-randomness in testes
+uint32_t test_prng(uint32_t *state);
+
+#define TEST_PRNG(state) test_prng(state)
+
+
+// access generated test defines
+intmax_t test_define(size_t define);
+
+#define TEST_DEFINE(i) test_define(i)
+
+// a few preconfigured defines that control how tests run
+ 
+#define READ_SIZE_i          0
+#define PROG_SIZE_i          1
+#define ERASE_SIZE_i         2
+#define ERASE_COUNT_i        3
+#define BLOCK_SIZE_i         4
+#define BLOCK_COUNT_i        5
+#define CACHE_SIZE_i         6
+#define LOOKAHEAD_SIZE_i     7
+#define COMPACT_THRESH_i     8
+#define METADATA_MAX_i       9
+#define INLINE_MAX_i         10
+#define BLOCK_CYCLES_i       11
+#define ERASE_VALUE_i        12
+#define ERASE_CYCLES_i       13
+#define BADBLOCK_BEHAVIOR_i  14
+#define POWERLOSS_BEHAVIOR_i 15
+#define DISK_VERSION_i       16
+
+#define READ_SIZE           TEST_DEFINE(READ_SIZE_i)
+#define PROG_SIZE           TEST_DEFINE(PROG_SIZE_i)
+#define ERASE_SIZE          TEST_DEFINE(ERASE_SIZE_i)
+#define ERASE_COUNT         TEST_DEFINE(ERASE_COUNT_i)
+#define BLOCK_SIZE          TEST_DEFINE(BLOCK_SIZE_i)
+#define BLOCK_COUNT         TEST_DEFINE(BLOCK_COUNT_i)
+#define CACHE_SIZE          TEST_DEFINE(CACHE_SIZE_i)
+#define LOOKAHEAD_SIZE      TEST_DEFINE(LOOKAHEAD_SIZE_i)
+#define COMPACT_THRESH      TEST_DEFINE(COMPACT_THRESH_i)
+#define METADATA_MAX        TEST_DEFINE(METADATA_MAX_i)
+#define INLINE_MAX          TEST_DEFINE(INLINE_MAX_i)
+#define BLOCK_CYCLES        TEST_DEFINE(BLOCK_CYCLES_i)
+#define ERASE_VALUE         TEST_DEFINE(ERASE_VALUE_i)
+#define ERASE_CYCLES        TEST_DEFINE(ERASE_CYCLES_i)
+#define BADBLOCK_BEHAVIOR   TEST_DEFINE(BADBLOCK_BEHAVIOR_i)
+#define POWERLOSS_BEHAVIOR  TEST_DEFINE(POWERLOSS_BEHAVIOR_i)
+#define DISK_VERSION        TEST_DEFINE(DISK_VERSION_i)
+
+#define TEST_IMPLICIT_DEFINES \
+    TEST_DEF(READ_SIZE,          PROG_SIZE) \
+    TEST_DEF(PROG_SIZE,          ERASE_SIZE) \
+    TEST_DEF(ERASE_SIZE,         0) \
+    TEST_DEF(ERASE_COUNT,        (1024*1024)/ERASE_SIZE) \
+    TEST_DEF(BLOCK_SIZE,         ERASE_SIZE) \
+    TEST_DEF(BLOCK_COUNT,        ERASE_COUNT/lfs_max(BLOCK_SIZE/ERASE_SIZE,1)) \
+    TEST_DEF(CACHE_SIZE,         lfs_max(64,lfs_max(READ_SIZE,PROG_SIZE))) \
+    TEST_DEF(LOOKAHEAD_SIZE,     16) \
+    TEST_DEF(COMPACT_THRESH,     0) \
+    TEST_DEF(METADATA_MAX,       0) \
+    TEST_DEF(INLINE_MAX,         0) \
+    TEST_DEF(BLOCK_CYCLES,       -1) \
+    TEST_DEF(ERASE_VALUE,        0xff) \
+    TEST_DEF(ERASE_CYCLES,       0) \
+    TEST_DEF(BADBLOCK_BEHAVIOR,  LFS_EMUBD_BADBLOCK_PROGERROR) \
+    TEST_DEF(POWERLOSS_BEHAVIOR, LFS_EMUBD_POWERLOSS_NOOP) \
+    TEST_DEF(DISK_VERSION,       0)
+
+#define TEST_GEOMETRY_DEFINE_COUNT 4
+#define TEST_IMPLICIT_DEFINE_COUNT 17
+
+
+#endif

scripts/changeprefix.py

@@ -0,0 +1,181 @@
+#!/usr/bin/env python3
+#
+# Change prefixes in files/filenames. Useful for creating different versions
+# of a codebase that don't conflict at compile time.
+#
+# Example:
+# $ ./scripts/changeprefix.py lfs lfs3
+#
+# Copyright (c) 2022, The littlefs authors.
+# Copyright (c) 2019, Arm Limited. All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import glob
+import itertools
+import os
+import os.path
+import re
+import shlex
+import shutil
+import subprocess
+import tempfile
+
+GIT_PATH = ['git']
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def changeprefix(from_prefix, to_prefix, line):
+    line, count1 = re.subn(
+        '\\b'+from_prefix,
+        to_prefix,
+        line)
+    line, count2 = re.subn(
+        '\\b'+from_prefix.upper(),
+        to_prefix.upper(),
+        line)
+    line, count3 = re.subn(
+        '\\B-D'+from_prefix.upper(),
+        '-D'+to_prefix.upper(),
+        line)
+    return line, count1+count2+count3
+
+def changefile(from_prefix, to_prefix, from_path, to_path, *,
+        no_replacements=False):
+    # rename any prefixes in file
+    count = 0
+
+    # create a temporary file to avoid overwriting ourself
+    if from_path == to_path and to_path != '-':
+        to_path_temp = tempfile.NamedTemporaryFile('w', delete=False)
+        to_path = to_path_temp.name
+    else:
+        to_path_temp = None
+
+    with openio(from_path) as from_f:
+        with openio(to_path, 'w') as to_f:
+            for line in from_f:
+                if not no_replacements:
+                    line, n = changeprefix(from_prefix, to_prefix, line)
+                    count += n
+                to_f.write(line)
+
+    if from_path != '-' and to_path != '-':
+        shutil.copystat(from_path, to_path)
+
+    if to_path_temp:
+        shutil.move(to_path, from_path)
+    elif from_path != '-':
+        os.remove(from_path)
+
+    # Summary
+    print('%s: %d replacements' % (
+        '%s -> %s' % (from_path, to_path) if not to_path_temp else from_path,
+        count))
+
+def main(from_prefix, to_prefix, paths=[], *,
+        verbose=False,
+        output=None,
+        no_replacements=False,
+        no_renames=False,
+        git=False,
+        no_stage=False,
+        git_path=GIT_PATH):
+    if not paths:
+        if git:
+            cmd = git_path + ['ls-tree', '-r', '--name-only', 'HEAD']
+            if verbose:
+                print(' '.join(shlex.quote(c) for c in cmd))
+            paths = subprocess.check_output(cmd, encoding='utf8').split()
+        else:
+            print('no paths?', file=sys.stderr)
+            sys.exit(1)
+        
+    for from_path in paths:
+        # rename filename?
+        if output:
+            to_path = output
+        elif no_renames:
+            to_path = from_path
+        else:
+            to_path = os.path.join(
+                os.path.dirname(from_path),
+                changeprefix(from_prefix, to_prefix,
+                    os.path.basename(from_path))[0])
+
+        # rename contents
+        changefile(from_prefix, to_prefix, from_path, to_path,
+            no_replacements=no_replacements)
+
+        # stage?
+        if git and not no_stage:
+            if from_path != to_path:
+                cmd = git_path + ['rm', '-q', from_path]
+                if verbose:
+                    print(' '.join(shlex.quote(c) for c in cmd))
+                subprocess.check_call(cmd)
+            cmd = git_path + ['add', to_path]
+            if verbose:
+                print(' '.join(shlex.quote(c) for c in cmd))
+            subprocess.check_call(cmd)
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Change prefixes in files/filenames. Useful for creating "
+            "different versions of a codebase that don't conflict at compile "
+            "time.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'from_prefix',
+        help="Prefix to replace.")
+    parser.add_argument(
+        'to_prefix',
+        help="Prefix to replace with.")
+    parser.add_argument(
+        'paths',
+        nargs='*',
+        help="Files to operate on.")
+    parser.add_argument(
+        '-v', '--verbose',
+        action='store_true',
+        help="Output commands that run behind the scenes.")
+    parser.add_argument(
+        '-o', '--output',
+        help="Output file.")
+    parser.add_argument(
+        '-N', '--no-replacements',
+        action='store_true',
+        help="Don't change prefixes in files")
+    parser.add_argument(
+        '-R', '--no-renames',
+        action='store_true',
+        help="Don't rename files")
+    parser.add_argument(
+        '--git',
+        action='store_true',
+        help="Use git to find/update files.")
+    parser.add_argument(
+        '--no-stage',
+        action='store_true',
+        help="Don't stage changes with git.")
+    parser.add_argument(
+        '--git-path',
+        type=lambda x: x.split(),
+        default=GIT_PATH,
+        help="Path to git executable, may include flags. "
+            "Defaults to %r." % GIT_PATH)
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/code.py

@@ -0,0 +1,707 @@
+#!/usr/bin/env python3
+#
+# Script to find code size at the function level. Basically just a big wrapper
+# around nm with some extra conveniences for comparing builds. Heavily inspired
+# by Linux's Bloat-O-Meter.
+#
+# Example:
+# ./scripts/code.py lfs.o lfs_util.o -Ssize
+#
+# Copyright (c) 2022, The littlefs authors.
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import csv
+import difflib
+import itertools as it
+import math as m
+import os
+import re
+import shlex
+import subprocess as sp
+
+
+NM_PATH = ['nm']
+NM_TYPES = 'tTrRdD'
+OBJDUMP_PATH = ['objdump']
+
+
+# integer fields
+class Int(co.namedtuple('Int', 'x')):
+    __slots__ = ()
+    def __new__(cls, x=0):
+        if isinstance(x, Int):
+            return x
+        if isinstance(x, str):
+            try:
+                x = int(x, 0)
+            except ValueError:
+                # also accept +-∞ and +-inf
+                if re.match('^\s*\+?\s*(?:∞|inf)\s*$', x):
+                    x = m.inf
+                elif re.match('^\s*-\s*(?:∞|inf)\s*$', x):
+                    x = -m.inf
+                else:
+                    raise
+        assert isinstance(x, int) or m.isinf(x), x
+        return super().__new__(cls, x)
+
+    def __str__(self):
+        if self.x == m.inf:
+            return '∞'
+        elif self.x == -m.inf:
+            return '-∞'
+        else:
+            return str(self.x)
+
+    def __int__(self):
+        assert not m.isinf(self.x)
+        return self.x
+
+    def __float__(self):
+        return float(self.x)
+
+    none = '%7s' % '-'
+    def table(self):
+        return '%7s' % (self,)
+
+    diff_none = '%7s' % '-'
+    diff_table = table
+
+    def diff_diff(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        diff = new - old
+        if diff == +m.inf:
+            return '%7s' % '+∞'
+        elif diff == -m.inf:
+            return '%7s' % '-∞'
+        else:
+            return '%+7d' % diff
+
+    def ratio(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        if m.isinf(new) and m.isinf(old):
+            return 0.0
+        elif m.isinf(new):
+            return +m.inf
+        elif m.isinf(old):
+            return -m.inf
+        elif not old and not new:
+            return 0.0
+        elif not old:
+            return 1.0
+        else:
+            return (new-old) / old
+
+    def __add__(self, other):
+        return self.__class__(self.x + other.x)
+
+    def __sub__(self, other):
+        return self.__class__(self.x - other.x)
+
+    def __mul__(self, other):
+        return self.__class__(self.x * other.x)
+
+# code size results
+class CodeResult(co.namedtuple('CodeResult', [
+        'file', 'function',
+        'size'])):
+    _by = ['file', 'function']
+    _fields = ['size']
+    _sort = ['size']
+    _types = {'size': Int}
+
+    __slots__ = ()
+    def __new__(cls, file='', function='', size=0):
+        return super().__new__(cls, file, function,
+            Int(size))
+
+    def __add__(self, other):
+        return CodeResult(self.file, self.function,
+            self.size + other.size)
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def collect(obj_paths, *,
+        nm_path=NM_PATH,
+        nm_types=NM_TYPES,
+        objdump_path=OBJDUMP_PATH,
+        sources=None,
+        everything=False,
+        **args):
+    size_pattern = re.compile(
+        '^(?P<size>[0-9a-fA-F]+)' +
+        ' (?P<type>[%s])' % re.escape(nm_types) +
+        ' (?P<func>.+?)$')
+    line_pattern = re.compile(
+        '^\s+(?P<no>[0-9]+)'
+            '(?:\s+(?P<dir>[0-9]+))?'
+            '\s+.*'
+            '\s+(?P<path>[^\s]+)$')
+    info_pattern = re.compile(
+        '^(?:.*(?P<tag>DW_TAG_[a-z_]+).*'
+            '|.*DW_AT_name.*:\s*(?P<name>[^:\s]+)\s*'
+            '|.*DW_AT_decl_file.*:\s*(?P<file>[0-9]+)\s*)$')
+
+    results = []
+    for path in obj_paths:
+        # guess the source, if we have debug-info we'll replace this later
+        file = re.sub('(\.o)?$', '.c', path, 1)
+
+        # find symbol sizes
+        results_ = []
+        # note nm-path may contain extra args
+        cmd = nm_path + ['--size-sort', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            m = size_pattern.match(line)
+            if m:
+                func = m.group('func')
+                # discard internal functions
+                if not everything and func.startswith('__'):
+                    continue
+                results_.append(CodeResult(
+                    file, func,
+                    int(m.group('size'), 16)))
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            sys.exit(-1)
+
+
+        # try to figure out the source file if we have debug-info
+        dirs = {}
+        files = {}
+        # note objdump-path may contain extra args
+        cmd = objdump_path + ['--dwarf=rawline', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            # note that files contain references to dirs, which we
+            # dereference as soon as we see them as each file table follows a
+            # dir table
+            m = line_pattern.match(line)
+            if m:
+                if not m.group('dir'):
+                    # found a directory entry
+                    dirs[int(m.group('no'))] = m.group('path')
+                else:
+                    # found a file entry
+                    dir = int(m.group('dir'))
+                    if dir in dirs:
+                        files[int(m.group('no'))] = os.path.join(
+                            dirs[dir],
+                            m.group('path'))
+                    else:
+                        files[int(m.group('no'))] = m.group('path')
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            # do nothing on error, we don't need objdump to work, source files
+            # may just be inaccurate
+            pass
+
+        defs = {}
+        is_func = False
+        f_name = None
+        f_file = None
+        # note objdump-path may contain extra args
+        cmd = objdump_path + ['--dwarf=info', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            # state machine here to find definitions
+            m = info_pattern.match(line)
+            if m:
+                if m.group('tag'):
+                    if is_func:
+                        defs[f_name] = files.get(f_file, '?')
+                    is_func = (m.group('tag') == 'DW_TAG_subprogram')
+                elif m.group('name'):
+                    f_name = m.group('name')
+                elif m.group('file'):
+                    f_file = int(m.group('file'))
+        if is_func:
+            defs[f_name] = files.get(f_file, '?')
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            # do nothing on error, we don't need objdump to work, source files
+            # may just be inaccurate
+            pass
+
+        for r in results_:
+            # find best matching debug symbol, this may be slightly different
+            # due to optimizations
+            if defs:
+                # exact match? avoid difflib if we can for speed
+                if r.function in defs:
+                    file = defs[r.function]
+                else:
+                    _, file = max(
+                        defs.items(),
+                        key=lambda d: difflib.SequenceMatcher(None,
+                            d[0],
+                            r.function, False).ratio())
+            else:
+                file = r.file
+
+            # ignore filtered sources
+            if sources is not None:
+                if not any(
+                        os.path.abspath(file) == os.path.abspath(s)
+                        for s in sources):
+                    continue
+            else:
+                # default to only cwd
+                if not everything and not os.path.commonpath([
+                        os.getcwd(),
+                        os.path.abspath(file)]) == os.getcwd():
+                    continue
+
+            # simplify path
+            if os.path.commonpath([
+                    os.getcwd(),
+                    os.path.abspath(file)]) == os.getcwd():
+                file = os.path.relpath(file)
+            else:
+                file = os.path.abspath(file)
+
+            results.append(r._replace(file=file))
+
+    return results
+
+
+def fold(Result, results, *,
+        by=None,
+        defines=None,
+        **_):
+    if by is None:
+        by = Result._by
+
+    for k in it.chain(by or [], (k for k, _ in defines or [])):
+        if k not in Result._by and k not in Result._fields:
+            print("error: could not find field %r?" % k)
+            sys.exit(-1)
+
+    # filter by matching defines
+    if defines is not None:
+        results_ = []
+        for r in results:
+            if all(getattr(r, k) in vs for k, vs in defines):
+                results_.append(r)
+        results = results_
+
+    # organize results into conflicts
+    folding = co.OrderedDict()
+    for r in results:
+        name = tuple(getattr(r, k) for k in by)
+        if name not in folding:
+            folding[name] = []
+        folding[name].append(r)
+
+    # merge conflicts
+    folded = []
+    for name, rs in folding.items():
+        folded.append(sum(rs[1:], start=rs[0]))
+
+    return folded
+
+def table(Result, results, diff_results=None, *,
+        by=None,
+        fields=None,
+        sort=None,
+        summary=False,
+        all=False,
+        percent=False,
+        **_):
+    all_, all = all, __builtins__.all
+
+    if by is None:
+        by = Result._by
+    if fields is None:
+        fields = Result._fields
+    types = Result._types
+
+    # fold again
+    results = fold(Result, results, by=by)
+    if diff_results is not None:
+        diff_results = fold(Result, diff_results, by=by)
+
+    # organize by name
+    table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in results}
+    diff_table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in diff_results or []}
+    names = list(table.keys() | diff_table.keys())
+
+    # sort again, now with diff info, note that python's sort is stable
+    names.sort()
+    if diff_results is not None:
+        names.sort(key=lambda n: tuple(
+            types[k].ratio(
+                getattr(table.get(n), k, None),
+                getattr(diff_table.get(n), k, None))
+            for k in fields),
+            reverse=True)
+    if sort:
+        for k, reverse in reversed(sort):
+            names.sort(
+                key=lambda n: tuple(
+                    (getattr(table[n], k),)
+                    if getattr(table.get(n), k, None) is not None else ()
+                    for k in ([k] if k else [
+                        k for k in Result._sort if k in fields])),
+                reverse=reverse ^ (not k or k in Result._fields))
+
+
+    # build up our lines
+    lines = []
+
+    # header
+    header = []
+    header.append('%s%s' % (
+        ','.join(by),
+        ' (%d added, %d removed)' % (
+            sum(1 for n in table if n not in diff_table),
+            sum(1 for n in diff_table if n not in table))
+            if diff_results is not None and not percent else '')
+        if not summary else '')
+    if diff_results is None:
+        for k in fields:
+            header.append(k)
+    elif percent:
+        for k in fields:
+            header.append(k)
+    else:
+        for k in fields:
+            header.append('o'+k)
+        for k in fields:
+            header.append('n'+k)
+        for k in fields:
+            header.append('d'+k)
+    header.append('')
+    lines.append(header)
+
+    def table_entry(name, r, diff_r=None, ratios=[]):
+        entry = []
+        entry.append(name)
+        if diff_results is None:
+            for k in fields:
+                entry.append(getattr(r, k).table()
+                    if getattr(r, k, None) is not None
+                    else types[k].none)
+        elif percent:
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+        else:
+            for k in fields:
+                entry.append(getattr(diff_r, k).diff_table()
+                    if getattr(diff_r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(types[k].diff_diff(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None)))
+        if diff_results is None:
+            entry.append('')
+        elif percent:
+            entry.append(' (%s)' % ', '.join(
+                '+∞%' if t == +m.inf
+                else '-∞%' if t == -m.inf
+                else '%+.1f%%' % (100*t)
+                for t in ratios))
+        else:
+            entry.append(' (%s)' % ', '.join(
+                    '+∞%' if t == +m.inf
+                    else '-∞%' if t == -m.inf
+                    else '%+.1f%%' % (100*t)
+                    for t in ratios
+                    if t)
+                if any(ratios) else '')
+        return entry
+
+    # entries
+    if not summary:
+        for name in names:
+            r = table.get(name)
+            if diff_results is None:
+                diff_r = None
+                ratios = None
+            else:
+                diff_r = diff_table.get(name)
+                ratios = [
+                    types[k].ratio(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None))
+                    for k in fields]
+                if not all_ and not any(ratios):
+                    continue
+            lines.append(table_entry(name, r, diff_r, ratios))
+
+    # total
+    r = next(iter(fold(Result, results, by=[])), None)
+    if diff_results is None:
+        diff_r = None
+        ratios = None
+    else:
+        diff_r = next(iter(fold(Result, diff_results, by=[])), None)
+        ratios = [
+            types[k].ratio(
+                getattr(r, k, None),
+                getattr(diff_r, k, None))
+            for k in fields]
+    lines.append(table_entry('TOTAL', r, diff_r, ratios))
+
+    # find the best widths, note that column 0 contains the names and column -1
+    # the ratios, so those are handled a bit differently
+    widths = [
+        ((max(it.chain([w], (len(l[i]) for l in lines)))+1+4-1)//4)*4-1
+        for w, i in zip(
+            it.chain([23], it.repeat(7)),
+            range(len(lines[0])-1))]
+
+    # print our table
+    for line in lines:
+        print('%-*s  %s%s' % (
+            widths[0], line[0],
+            ' '.join('%*s' % (w, x)
+                for w, x in zip(widths[1:], line[1:-1])),
+            line[-1]))
+
+
+def main(obj_paths, *,
+        by=None,
+        fields=None,
+        defines=None,
+        sort=None,
+        **args):
+    # find sizes
+    if not args.get('use', None):
+        results = collect(obj_paths, **args)
+    else:
+        results = []
+        with openio(args['use']) as f:
+            reader = csv.DictReader(f, restval='')
+            for r in reader:
+                if not any('code_'+k in r and r['code_'+k].strip()
+                        for k in CodeResult._fields):
+                    continue
+                try:
+                    results.append(CodeResult(
+                        **{k: r[k] for k in CodeResult._by
+                            if k in r and r[k].strip()},
+                        **{k: r['code_'+k] for k in CodeResult._fields
+                            if 'code_'+k in r and r['code_'+k].strip()}))
+                except TypeError:
+                    pass
+
+    # fold
+    results = fold(CodeResult, results, by=by, defines=defines)
+
+    # sort, note that python's sort is stable
+    results.sort()
+    if sort:
+        for k, reverse in reversed(sort):
+            results.sort(
+                key=lambda r: tuple(
+                    (getattr(r, k),) if getattr(r, k) is not None else ()
+                    for k in ([k] if k else CodeResult._sort)),
+                reverse=reverse ^ (not k or k in CodeResult._fields))
+
+    # write results to CSV
+    if args.get('output'):
+        with openio(args['output'], 'w') as f:
+            writer = csv.DictWriter(f,
+                (by if by is not None else CodeResult._by)
+                + ['code_'+k for k in (
+                    fields if fields is not None else CodeResult._fields)])
+            writer.writeheader()
+            for r in results:
+                writer.writerow(
+                    {k: getattr(r, k) for k in (
+                        by if by is not None else CodeResult._by)}
+                    | {'code_'+k: getattr(r, k) for k in (
+                        fields if fields is not None else CodeResult._fields)})
+
+    # find previous results?
+    if args.get('diff'):
+        diff_results = []
+        try:
+            with openio(args['diff']) as f:
+                reader = csv.DictReader(f, restval='')
+                for r in reader:
+                    if not any('code_'+k in r and r['code_'+k].strip()
+                            for k in CodeResult._fields):
+                        continue
+                    try:
+                        diff_results.append(CodeResult(
+                            **{k: r[k] for k in CodeResult._by
+                                if k in r and r[k].strip()},
+                            **{k: r['code_'+k] for k in CodeResult._fields
+                                if 'code_'+k in r and r['code_'+k].strip()}))
+                    except TypeError:
+                        pass
+        except FileNotFoundError:
+            pass
+
+        # fold
+        diff_results = fold(CodeResult, diff_results, by=by, defines=defines)
+
+    # print table
+    if not args.get('quiet'):
+        table(CodeResult, results,
+            diff_results if args.get('diff') else None,
+            by=by if by is not None else ['function'],
+            fields=fields,
+            sort=sort,
+            **args)
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Find code size at the function level.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'obj_paths',
+        nargs='*',
+        help="Input *.o files.")
+    parser.add_argument(
+        '-v', '--verbose',
+        action='store_true',
+        help="Output commands that run behind the scenes.")
+    parser.add_argument(
+        '-q', '--quiet',
+        action='store_true',
+        help="Don't show anything, useful with -o.")
+    parser.add_argument(
+        '-o', '--output',
+        help="Specify CSV file to store results.")
+    parser.add_argument(
+        '-u', '--use',
+        help="Don't parse anything, use this CSV file.")
+    parser.add_argument(
+        '-d', '--diff',
+        help="Specify CSV file to diff against.")
+    parser.add_argument(
+        '-a', '--all',
+        action='store_true',
+        help="Show all, not just the ones that changed.")
+    parser.add_argument(
+        '-p', '--percent',
+        action='store_true',
+        help="Only show percentage change, not a full diff.")
+    parser.add_argument(
+        '-b', '--by',
+        action='append',
+        choices=CodeResult._by,
+        help="Group by this field.")
+    parser.add_argument(
+        '-f', '--field',
+        dest='fields',
+        action='append',
+        choices=CodeResult._fields,
+        help="Show this field.")
+    parser.add_argument(
+        '-D', '--define',
+        dest='defines',
+        action='append',
+        type=lambda x: (lambda k,v: (k, set(v.split(','))))(*x.split('=', 1)),
+        help="Only include results where this field is this value.")
+    class AppendSort(argparse.Action):
+        def __call__(self, parser, namespace, value, option):
+            if namespace.sort is None:
+                namespace.sort = []
+            namespace.sort.append((value, True if option == '-S' else False))
+    parser.add_argument(
+        '-s', '--sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field.")
+    parser.add_argument(
+        '-S', '--reverse-sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field, but backwards.")
+    parser.add_argument(
+        '-Y', '--summary',
+        action='store_true',
+        help="Only show the total.")
+    parser.add_argument(
+        '-F', '--source',
+        dest='sources',
+        action='append',
+        help="Only consider definitions in this file. Defaults to anything "
+            "in the current directory.")
+    parser.add_argument(
+        '--everything',
+        action='store_true',
+        help="Include builtin and libc specific symbols.")
+    parser.add_argument(
+        '--nm-types',
+        default=NM_TYPES,
+        help="Type of symbols to report, this uses the same single-character "
+            "type-names emitted by nm. Defaults to %r." % NM_TYPES)
+    parser.add_argument(
+        '--nm-path',
+        type=lambda x: x.split(),
+        default=NM_PATH,
+        help="Path to the nm executable, may include flags. "
+            "Defaults to %r." % NM_PATH)
+    parser.add_argument(
+        '--objdump-path',
+        type=lambda x: x.split(),
+        default=OBJDUMP_PATH,
+        help="Path to the objdump executable, may include flags. "
+            "Defaults to %r." % OBJDUMP_PATH)
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/cov.py

@@ -0,0 +1,828 @@
+#!/usr/bin/env python3
+#
+# Script to find coverage info after running tests.
+#
+# Example:
+# ./scripts/cov.py \
+#     lfs.t.a.gcda lfs_util.t.a.gcda \
+#     -Flfs.c -Flfs_util.c -slines
+#
+# Copyright (c) 2022, The littlefs authors.
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import csv
+import itertools as it
+import json
+import math as m
+import os
+import re
+import shlex
+import subprocess as sp
+
+# TODO use explode_asserts to avoid counting assert branches?
+# TODO use dwarf=info to find functions for inline functions?
+
+GCOV_PATH = ['gcov']
+
+
+# integer fields
+class Int(co.namedtuple('Int', 'x')):
+    __slots__ = ()
+    def __new__(cls, x=0):
+        if isinstance(x, Int):
+            return x
+        if isinstance(x, str):
+            try:
+                x = int(x, 0)
+            except ValueError:
+                # also accept +-∞ and +-inf
+                if re.match('^\s*\+?\s*(?:∞|inf)\s*$', x):
+                    x = m.inf
+                elif re.match('^\s*-\s*(?:∞|inf)\s*$', x):
+                    x = -m.inf
+                else:
+                    raise
+        assert isinstance(x, int) or m.isinf(x), x
+        return super().__new__(cls, x)
+
+    def __str__(self):
+        if self.x == m.inf:
+            return '∞'
+        elif self.x == -m.inf:
+            return '-∞'
+        else:
+            return str(self.x)
+
+    def __int__(self):
+        assert not m.isinf(self.x)
+        return self.x
+
+    def __float__(self):
+        return float(self.x)
+
+    none = '%7s' % '-'
+    def table(self):
+        return '%7s' % (self,)
+
+    diff_none = '%7s' % '-'
+    diff_table = table
+
+    def diff_diff(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        diff = new - old
+        if diff == +m.inf:
+            return '%7s' % '+∞'
+        elif diff == -m.inf:
+            return '%7s' % '-∞'
+        else:
+            return '%+7d' % diff
+
+    def ratio(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        if m.isinf(new) and m.isinf(old):
+            return 0.0
+        elif m.isinf(new):
+            return +m.inf
+        elif m.isinf(old):
+            return -m.inf
+        elif not old and not new:
+            return 0.0
+        elif not old:
+            return 1.0
+        else:
+            return (new-old) / old
+
+    def __add__(self, other):
+        return self.__class__(self.x + other.x)
+
+    def __sub__(self, other):
+        return self.__class__(self.x - other.x)
+
+    def __mul__(self, other):
+        return self.__class__(self.x * other.x)
+
+# fractional fields, a/b
+class Frac(co.namedtuple('Frac', 'a,b')):
+    __slots__ = ()
+    def __new__(cls, a=0, b=None):
+        if isinstance(a, Frac) and b is None:
+            return a
+        if isinstance(a, str) and b is None:
+            a, b = a.split('/', 1)
+        if b is None:
+            b = a
+        return super().__new__(cls, Int(a), Int(b))
+
+    def __str__(self):
+        return '%s/%s' % (self.a, self.b)
+
+    def __float__(self):
+        return float(self.a)
+
+    none = '%11s %7s' % ('-', '-')
+    def table(self):
+        t = self.a.x/self.b.x if self.b.x else 1.0
+        return '%11s %7s' % (
+            self,
+            '∞%' if t == +m.inf
+            else '-∞%' if t == -m.inf
+            else '%.1f%%' % (100*t))
+
+    diff_none = '%11s' % '-'
+    def diff_table(self):
+        return '%11s' % (self,)
+
+    def diff_diff(self, other):
+        new_a, new_b = self if self else (Int(0), Int(0))
+        old_a, old_b = other if other else (Int(0), Int(0))
+        return '%11s' % ('%s/%s' % (
+            new_a.diff_diff(old_a).strip(),
+            new_b.diff_diff(old_b).strip()))
+
+    def ratio(self, other):
+        new_a, new_b = self if self else (Int(0), Int(0))
+        old_a, old_b = other if other else (Int(0), Int(0))
+        new = new_a.x/new_b.x if new_b.x else 1.0
+        old = old_a.x/old_b.x if old_b.x else 1.0
+        return new - old
+
+    def __add__(self, other):
+        return self.__class__(self.a + other.a, self.b + other.b)
+
+    def __sub__(self, other):
+        return self.__class__(self.a - other.a, self.b - other.b)
+
+    def __mul__(self, other):
+        return self.__class__(self.a * other.a, self.b + other.b)
+
+    def __lt__(self, other):
+        self_t = self.a.x/self.b.x if self.b.x else 1.0
+        other_t = other.a.x/other.b.x if other.b.x else 1.0
+        return (self_t, self.a.x) < (other_t, other.a.x)
+
+    def __gt__(self, other):
+        return self.__class__.__lt__(other, self)
+
+    def __le__(self, other):
+        return not self.__gt__(other)
+
+    def __ge__(self, other):
+        return not self.__lt__(other)
+
+# coverage results
+class CovResult(co.namedtuple('CovResult', [
+        'file', 'function', 'line',
+        'calls', 'hits', 'funcs', 'lines', 'branches'])):
+    _by = ['file', 'function', 'line']
+    _fields = ['calls', 'hits', 'funcs', 'lines', 'branches']
+    _sort = ['funcs', 'lines', 'branches', 'hits', 'calls']
+    _types = {
+        'calls': Int, 'hits': Int,
+        'funcs': Frac, 'lines': Frac, 'branches': Frac}
+
+    __slots__ = ()
+    def __new__(cls, file='', function='', line=0,
+            calls=0, hits=0, funcs=0, lines=0, branches=0):
+        return super().__new__(cls, file, function, int(Int(line)),
+            Int(calls), Int(hits), Frac(funcs), Frac(lines), Frac(branches))
+
+    def __add__(self, other):
+        return CovResult(self.file, self.function, self.line,
+            max(self.calls, other.calls),
+            max(self.hits, other.hits),
+            self.funcs + other.funcs,
+            self.lines + other.lines,
+            self.branches + other.branches)
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def collect(gcda_paths, *,
+        gcov_path=GCOV_PATH,
+        sources=None,
+        everything=False,
+        **args):
+    results = []
+    for path in gcda_paths:
+        # get coverage info through gcov's json output
+        # note, gcov-path may contain extra args
+        cmd = GCOV_PATH + ['-b', '-t', '--json-format', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        data = json.load(proc.stdout)
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            sys.exit(-1)
+
+        # collect line/branch coverage
+        for file in data['files']:
+            # ignore filtered sources
+            if sources is not None:
+                if not any(
+                        os.path.abspath(file['file']) == os.path.abspath(s)
+                        for s in sources):
+                    continue
+            else:
+                # default to only cwd
+                if not everything and not os.path.commonpath([
+                        os.getcwd(),
+                        os.path.abspath(file['file'])]) == os.getcwd():
+                    continue
+
+            # simplify path
+            if os.path.commonpath([
+                    os.getcwd(),
+                    os.path.abspath(file['file'])]) == os.getcwd():
+                file_name = os.path.relpath(file['file'])
+            else:
+                file_name = os.path.abspath(file['file'])
+
+            for func in file['functions']:
+                func_name = func.get('name', '(inlined)')
+                # discard internal functions (this includes injected test cases)
+                if not everything:
+                    if func_name.startswith('__'):
+                        continue
+
+                # go ahead and add functions, later folding will merge this if
+                # there are other hits on this line
+                results.append(CovResult(
+                    file_name, func_name, func['start_line'],
+                    func['execution_count'], 0,
+                    Frac(1 if func['execution_count'] > 0 else 0, 1),
+                    0,
+                    0))
+
+            for line in file['lines']:
+                func_name = line.get('function_name', '(inlined)')
+                # discard internal function (this includes injected test cases)
+                if not everything:
+                    if func_name.startswith('__'):
+                        continue
+
+                # go ahead and add lines, later folding will merge this if
+                # there are other hits on this line
+                results.append(CovResult(
+                    file_name, func_name, line['line_number'],
+                    0, line['count'],
+                    0,
+                    Frac(1 if line['count'] > 0 else 0, 1),
+                    Frac(
+                        sum(1 if branch['count'] > 0 else 0
+                            for branch in line['branches']),
+                        len(line['branches']))))
+
+    return results
+
+
+def fold(Result, results, *,
+        by=None,
+        defines=None,
+        **_):
+    if by is None:
+        by = Result._by
+
+    for k in it.chain(by or [], (k for k, _ in defines or [])):
+        if k not in Result._by and k not in Result._fields:
+            print("error: could not find field %r?" % k)
+            sys.exit(-1)
+
+    # filter by matching defines
+    if defines is not None:
+        results_ = []
+        for r in results:
+            if all(getattr(r, k) in vs for k, vs in defines):
+                results_.append(r)
+        results = results_
+
+    # organize results into conflicts
+    folding = co.OrderedDict()
+    for r in results:
+        name = tuple(getattr(r, k) for k in by)
+        if name not in folding:
+            folding[name] = []
+        folding[name].append(r)
+
+    # merge conflicts
+    folded = []
+    for name, rs in folding.items():
+        folded.append(sum(rs[1:], start=rs[0]))
+
+    return folded
+
+def table(Result, results, diff_results=None, *,
+        by=None,
+        fields=None,
+        sort=None,
+        summary=False,
+        all=False,
+        percent=False,
+        **_):
+    all_, all = all, __builtins__.all
+
+    if by is None:
+        by = Result._by
+    if fields is None:
+        fields = Result._fields
+    types = Result._types
+
+    # fold again
+    results = fold(Result, results, by=by)
+    if diff_results is not None:
+        diff_results = fold(Result, diff_results, by=by)
+
+    # organize by name
+    table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in results}
+    diff_table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in diff_results or []}
+    names = list(table.keys() | diff_table.keys())
+
+    # sort again, now with diff info, note that python's sort is stable
+    names.sort()
+    if diff_results is not None:
+        names.sort(key=lambda n: tuple(
+            types[k].ratio(
+                getattr(table.get(n), k, None),
+                getattr(diff_table.get(n), k, None))
+            for k in fields),
+            reverse=True)
+    if sort:
+        for k, reverse in reversed(sort):
+            names.sort(
+                key=lambda n: tuple(
+                    (getattr(table[n], k),)
+                    if getattr(table.get(n), k, None) is not None else ()
+                    for k in ([k] if k else [
+                        k for k in Result._sort if k in fields])),
+                reverse=reverse ^ (not k or k in Result._fields))
+
+
+    # build up our lines
+    lines = []
+
+    # header
+    header = []
+    header.append('%s%s' % (
+        ','.join(by),
+        ' (%d added, %d removed)' % (
+            sum(1 for n in table if n not in diff_table),
+            sum(1 for n in diff_table if n not in table))
+            if diff_results is not None and not percent else '')
+        if not summary else '')
+    if diff_results is None:
+        for k in fields:
+            header.append(k)
+    elif percent:
+        for k in fields:
+            header.append(k)
+    else:
+        for k in fields:
+            header.append('o'+k)
+        for k in fields:
+            header.append('n'+k)
+        for k in fields:
+            header.append('d'+k)
+    header.append('')
+    lines.append(header)
+
+    def table_entry(name, r, diff_r=None, ratios=[]):
+        entry = []
+        entry.append(name)
+        if diff_results is None:
+            for k in fields:
+                entry.append(getattr(r, k).table()
+                    if getattr(r, k, None) is not None
+                    else types[k].none)
+        elif percent:
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+        else:
+            for k in fields:
+                entry.append(getattr(diff_r, k).diff_table()
+                    if getattr(diff_r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(types[k].diff_diff(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None)))
+        if diff_results is None:
+            entry.append('')
+        elif percent:
+            entry.append(' (%s)' % ', '.join(
+                '+∞%' if t == +m.inf
+                else '-∞%' if t == -m.inf
+                else '%+.1f%%' % (100*t)
+                for t in ratios))
+        else:
+            entry.append(' (%s)' % ', '.join(
+                    '+∞%' if t == +m.inf
+                    else '-∞%' if t == -m.inf
+                    else '%+.1f%%' % (100*t)
+                    for t in ratios
+                    if t)
+                if any(ratios) else '')
+        return entry
+
+    # entries
+    if not summary:
+        for name in names:
+            r = table.get(name)
+            if diff_results is None:
+                diff_r = None
+                ratios = None
+            else:
+                diff_r = diff_table.get(name)
+                ratios = [
+                    types[k].ratio(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None))
+                    for k in fields]
+                if not all_ and not any(ratios):
+                    continue
+            lines.append(table_entry(name, r, diff_r, ratios))
+
+    # total
+    r = next(iter(fold(Result, results, by=[])), None)
+    if diff_results is None:
+        diff_r = None
+        ratios = None
+    else:
+        diff_r = next(iter(fold(Result, diff_results, by=[])), None)
+        ratios = [
+            types[k].ratio(
+                getattr(r, k, None),
+                getattr(diff_r, k, None))
+            for k in fields]
+    lines.append(table_entry('TOTAL', r, diff_r, ratios))
+
+    # find the best widths, note that column 0 contains the names and column -1
+    # the ratios, so those are handled a bit differently
+    widths = [
+        ((max(it.chain([w], (len(l[i]) for l in lines)))+1+4-1)//4)*4-1
+        for w, i in zip(
+            it.chain([23], it.repeat(7)),
+            range(len(lines[0])-1))]
+
+    # print our table
+    for line in lines:
+        print('%-*s  %s%s' % (
+            widths[0], line[0],
+            ' '.join('%*s' % (w, x)
+                for w, x in zip(widths[1:], line[1:-1])),
+            line[-1]))
+
+
+def annotate(Result, results, *,
+        annotate=False,
+        lines=False,
+        branches=False,
+        **args):
+    # if neither branches/lines specified, color both
+    if annotate and not lines and not branches:
+        lines, branches = True, True
+
+    for path in co.OrderedDict.fromkeys(r.file for r in results).keys():
+        # flatten to line info
+        results = fold(Result, results, by=['file', 'line'])
+        table = {r.line: r for r in results if r.file == path}
+
+        # calculate spans to show
+        if not annotate:
+            spans = []
+            last = None
+            func = None
+            for line, r in sorted(table.items()):
+                if ((lines and int(r.hits) == 0)
+                        or (branches and r.branches.a < r.branches.b)):
+                    if last is not None and line - last.stop <= args['context']:
+                        last = range(
+                            last.start,
+                            line+1+args['context'])
+                    else:
+                        if last is not None:
+                            spans.append((last, func))
+                        last = range(
+                            line-args['context'],
+                            line+1+args['context'])
+                        func = r.function
+            if last is not None:
+                spans.append((last, func))
+
+        with open(path) as f:
+            skipped = False
+            for i, line in enumerate(f):
+                # skip lines not in spans?
+                if not annotate and not any(i+1 in s for s, _ in spans):
+                    skipped = True
+                    continue
+
+                if skipped:
+                    skipped = False
+                    print('%s@@ %s:%d: %s @@%s' % (
+                        '\x1b[36m' if args['color'] else '',
+                        path,
+                        i+1,
+                        next(iter(f for _, f in spans)),
+                        '\x1b[m' if args['color'] else ''))
+
+                # build line
+                if line.endswith('\n'):
+                    line = line[:-1]
+
+                if i+1 in table:
+                    r = table[i+1]
+                    line = '%-*s // %s hits%s' % (
+                        args['width'],
+                        line,
+                        r.hits,
+                        ', %s branches' % (r.branches,)
+                            if int(r.branches.b) else '')
+
+                    if args['color']:
+                        if lines and int(r.hits) == 0:
+                            line = '\x1b[1;31m%s\x1b[m' % line
+                        elif branches and r.branches.a < r.branches.b:
+                            line = '\x1b[35m%s\x1b[m' % line
+
+                print(line)
+
+
+def main(gcda_paths, *,
+        by=None,
+        fields=None,
+        defines=None,
+        sort=None,
+        hits=False,
+        **args):
+    # figure out what color should be
+    if args.get('color') == 'auto':
+        args['color'] = sys.stdout.isatty()
+    elif args.get('color') == 'always':
+        args['color'] = True
+    else:
+        args['color'] = False
+
+    # find sizes
+    if not args.get('use', None):
+        results = collect(gcda_paths, **args)
+    else:
+        results = []
+        with openio(args['use']) as f:
+            reader = csv.DictReader(f, restval='')
+            for r in reader:
+                if not any('cov_'+k in r and r['cov_'+k].strip()
+                        for k in CovResult._fields):
+                    continue
+                try:
+                    results.append(CovResult(
+                        **{k: r[k] for k in CovResult._by
+                            if k in r and r[k].strip()},
+                        **{k: r['cov_'+k]
+                            for k in CovResult._fields
+                            if 'cov_'+k in r
+                                and r['cov_'+k].strip()}))
+                except TypeError:
+                    pass
+
+    # fold
+    results = fold(CovResult, results, by=by, defines=defines)
+
+    # sort, note that python's sort is stable
+    results.sort()
+    if sort:
+        for k, reverse in reversed(sort):
+            results.sort(
+                key=lambda r: tuple(
+                    (getattr(r, k),) if getattr(r, k) is not None else ()
+                    for k in ([k] if k else CovResult._sort)),
+                reverse=reverse ^ (not k or k in CovResult._fields))
+
+    # write results to CSV
+    if args.get('output'):
+        with openio(args['output'], 'w') as f:
+            writer = csv.DictWriter(f,
+                (by if by is not None else CovResult._by)
+                + ['cov_'+k for k in (
+                    fields if fields is not None else CovResult._fields)])
+            writer.writeheader()
+            for r in results:
+                writer.writerow(
+                    {k: getattr(r, k) for k in (
+                        by if by is not None else CovResult._by)}
+                    | {'cov_'+k: getattr(r, k) for k in (
+                        fields if fields is not None else CovResult._fields)})
+
+    # find previous results?
+    if args.get('diff'):
+        diff_results = []
+        try:
+            with openio(args['diff']) as f:
+                reader = csv.DictReader(f, restval='')
+                for r in reader:
+                    if not any('cov_'+k in r and r['cov_'+k].strip()
+                            for k in CovResult._fields):
+                        continue
+                    try:
+                        diff_results.append(CovResult(
+                            **{k: r[k] for k in CovResult._by
+                                if k in r and r[k].strip()},
+                            **{k: r['cov_'+k]
+                                for k in CovResult._fields
+                                if 'cov_'+k in r
+                                    and r['cov_'+k].strip()}))
+                    except TypeError:
+                        pass
+        except FileNotFoundError:
+            pass
+
+        # fold
+        diff_results = fold(CovResult, diff_results,
+            by=by, defines=defines)
+
+    # print table
+    if not args.get('quiet'):
+        if (args.get('annotate')
+                or args.get('lines')
+                or args.get('branches')):
+            # annotate sources
+            annotate(CovResult, results, **args)
+        else:
+            # print table
+            table(CovResult, results,
+                diff_results if args.get('diff') else None,
+                by=by if by is not None else ['function'],
+                fields=fields if fields is not None
+                    else ['lines', 'branches'] if not hits
+                    else ['calls', 'hits'],
+                sort=sort,
+                **args)
+
+    # catch lack of coverage
+    if args.get('error_on_lines') and any(
+            r.lines.a < r.lines.b for r in results):
+        sys.exit(2)
+    elif args.get('error_on_branches') and any(
+            r.branches.a < r.branches.b for r in results):
+        sys.exit(3)
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Find coverage info after running tests.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'gcda_paths',
+        nargs='*',
+        help="Input *.gcda files.")
+    parser.add_argument(
+        '-v', '--verbose',
+        action='store_true',
+        help="Output commands that run behind the scenes.")
+    parser.add_argument(
+        '-q', '--quiet',
+        action='store_true',
+        help="Don't show anything, useful with -o.")
+    parser.add_argument(
+        '-o', '--output',
+        help="Specify CSV file to store results.")
+    parser.add_argument(
+        '-u', '--use',
+        help="Don't parse anything, use this CSV file.")
+    parser.add_argument(
+        '-d', '--diff',
+        help="Specify CSV file to diff against.")
+    parser.add_argument(
+        '-a', '--all',
+        action='store_true',
+        help="Show all, not just the ones that changed.")
+    parser.add_argument(
+        '-p', '--percent',
+        action='store_true',
+        help="Only show percentage change, not a full diff.")
+    parser.add_argument(
+        '-b', '--by',
+        action='append',
+        choices=CovResult._by,
+        help="Group by this field.")
+    parser.add_argument(
+        '-f', '--field',
+        dest='fields',
+        action='append',
+        choices=CovResult._fields,
+        help="Show this field.")
+    parser.add_argument(
+        '-D', '--define',
+        dest='defines',
+        action='append',
+        type=lambda x: (lambda k,v: (k, set(v.split(','))))(*x.split('=', 1)),
+        help="Only include results where this field is this value.")
+    class AppendSort(argparse.Action):
+        def __call__(self, parser, namespace, value, option):
+            if namespace.sort is None:
+                namespace.sort = []
+            namespace.sort.append((value, True if option == '-S' else False))
+    parser.add_argument(
+        '-s', '--sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field.")
+    parser.add_argument(
+        '-S', '--reverse-sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field, but backwards.")
+    parser.add_argument(
+        '-Y', '--summary',
+        action='store_true',
+        help="Only show the total.")
+    parser.add_argument(
+        '-F', '--source',
+        dest='sources',
+        action='append',
+        help="Only consider definitions in this file. Defaults to anything "
+            "in the current directory.")
+    parser.add_argument(
+        '--everything',
+        action='store_true',
+        help="Include builtin and libc specific symbols.")
+    parser.add_argument(
+        '--hits',
+        action='store_true',
+        help="Show total hits instead of coverage.")
+    parser.add_argument(
+        '-A', '--annotate',
+        action='store_true',
+        help="Show source files annotated with coverage info.")
+    parser.add_argument(
+        '-L', '--lines',
+        action='store_true',
+        help="Show uncovered lines.")
+    parser.add_argument(
+        '-B', '--branches',
+        action='store_true',
+        help="Show uncovered branches.")
+    parser.add_argument(
+        '-c', '--context',
+        type=lambda x: int(x, 0),
+        default=3,
+        help="Show n additional lines of context. Defaults to 3.")
+    parser.add_argument(
+        '-W', '--width',
+        type=lambda x: int(x, 0),
+        default=80,
+        help="Assume source is styled with this many columns. Defaults to 80.")
+    parser.add_argument(
+        '--color',
+        choices=['never', 'always', 'auto'],
+        default='auto',
+        help="When to use terminal colors. Defaults to 'auto'.")
+    parser.add_argument(
+        '-e', '--error-on-lines',
+        action='store_true',
+        help="Error if any lines are not covered.")
+    parser.add_argument(
+        '-E', '--error-on-branches',
+        action='store_true',
+        help="Error if any branches are not covered.")
+    parser.add_argument(
+        '--gcov-path',
+        default=GCOV_PATH,
+        type=lambda x: x.split(),
+        help="Path to the gcov executable, may include paths. "
+            "Defaults to %r." % GCOV_PATH)
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/data.py

@@ -0,0 +1,704 @@
+#!/usr/bin/env python3
+#
+# Script to find data size at the function level. Basically just a big wrapper
+# around nm with some extra conveniences for comparing builds. Heavily inspired
+# by Linux's Bloat-O-Meter.
+#
+# Example:
+# ./scripts/data.py lfs.o lfs_util.o -Ssize
+#
+# Copyright (c) 2022, The littlefs authors.
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import csv
+import difflib
+import itertools as it
+import math as m
+import os
+import re
+import shlex
+import subprocess as sp
+
+
+NM_PATH = ['nm']
+NM_TYPES = 'dDbB'
+OBJDUMP_PATH = ['objdump']
+
+
+# integer fields
+class Int(co.namedtuple('Int', 'x')):
+    __slots__ = ()
+    def __new__(cls, x=0):
+        if isinstance(x, Int):
+            return x
+        if isinstance(x, str):
+            try:
+                x = int(x, 0)
+            except ValueError:
+                # also accept +-∞ and +-inf
+                if re.match('^\s*\+?\s*(?:∞|inf)\s*$', x):
+                    x = m.inf
+                elif re.match('^\s*-\s*(?:∞|inf)\s*$', x):
+                    x = -m.inf
+                else:
+                    raise
+        assert isinstance(x, int) or m.isinf(x), x
+        return super().__new__(cls, x)
+
+    def __str__(self):
+        if self.x == m.inf:
+            return '∞'
+        elif self.x == -m.inf:
+            return '-∞'
+        else:
+            return str(self.x)
+
+    def __int__(self):
+        assert not m.isinf(self.x)
+        return self.x
+
+    def __float__(self):
+        return float(self.x)
+
+    none = '%7s' % '-'
+    def table(self):
+        return '%7s' % (self,)
+
+    diff_none = '%7s' % '-'
+    diff_table = table
+
+    def diff_diff(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        diff = new - old
+        if diff == +m.inf:
+            return '%7s' % '+∞'
+        elif diff == -m.inf:
+            return '%7s' % '-∞'
+        else:
+            return '%+7d' % diff
+
+    def ratio(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        if m.isinf(new) and m.isinf(old):
+            return 0.0
+        elif m.isinf(new):
+            return +m.inf
+        elif m.isinf(old):
+            return -m.inf
+        elif not old and not new:
+            return 0.0
+        elif not old:
+            return 1.0
+        else:
+            return (new-old) / old
+
+    def __add__(self, other):
+        return self.__class__(self.x + other.x)
+
+    def __sub__(self, other):
+        return self.__class__(self.x - other.x)
+
+    def __mul__(self, other):
+        return self.__class__(self.x * other.x)
+
+# data size results
+class DataResult(co.namedtuple('DataResult', [
+        'file', 'function',
+        'size'])):
+    _by = ['file', 'function']
+    _fields = ['size']
+    _sort = ['size']
+    _types = {'size': Int}
+
+    __slots__ = ()
+    def __new__(cls, file='', function='', size=0):
+        return super().__new__(cls, file, function,
+            Int(size))
+
+    def __add__(self, other):
+        return DataResult(self.file, self.function,
+            self.size + other.size)
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def collect(obj_paths, *,
+        nm_path=NM_PATH,
+        nm_types=NM_TYPES,
+        objdump_path=OBJDUMP_PATH,
+        sources=None,
+        everything=False,
+        **args):
+    size_pattern = re.compile(
+        '^(?P<size>[0-9a-fA-F]+)' +
+        ' (?P<type>[%s])' % re.escape(nm_types) +
+        ' (?P<func>.+?)$')
+    line_pattern = re.compile(
+        '^\s+(?P<no>[0-9]+)'
+            '(?:\s+(?P<dir>[0-9]+))?'
+            '\s+.*'
+            '\s+(?P<path>[^\s]+)$')
+    info_pattern = re.compile(
+        '^(?:.*(?P<tag>DW_TAG_[a-z_]+).*'
+            '|.*DW_AT_name.*:\s*(?P<name>[^:\s]+)\s*'
+            '|.*DW_AT_decl_file.*:\s*(?P<file>[0-9]+)\s*)$')
+
+    results = []
+    for path in obj_paths:
+        # guess the source, if we have debug-info we'll replace this later
+        file = re.sub('(\.o)?$', '.c', path, 1)
+
+        # find symbol sizes
+        results_ = []
+        # note nm-path may contain extra args
+        cmd = nm_path + ['--size-sort', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            m = size_pattern.match(line)
+            if m:
+                func = m.group('func')
+                # discard internal functions
+                if not everything and func.startswith('__'):
+                    continue
+                results_.append(DataResult(
+                    file, func,
+                    int(m.group('size'), 16)))
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            sys.exit(-1)
+
+
+        # try to figure out the source file if we have debug-info
+        dirs = {}
+        files = {}
+        # note objdump-path may contain extra args
+        cmd = objdump_path + ['--dwarf=rawline', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            # note that files contain references to dirs, which we
+            # dereference as soon as we see them as each file table follows a
+            # dir table
+            m = line_pattern.match(line)
+            if m:
+                if not m.group('dir'):
+                    # found a directory entry
+                    dirs[int(m.group('no'))] = m.group('path')
+                else:
+                    # found a file entry
+                    dir = int(m.group('dir'))
+                    if dir in dirs:
+                        files[int(m.group('no'))] = os.path.join(
+                            dirs[dir],
+                            m.group('path'))
+                    else:
+                        files[int(m.group('no'))] = m.group('path')
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            # do nothing on error, we don't need objdump to work, source files
+            # may just be inaccurate
+            pass
+
+        defs = {}
+        is_func = False
+        f_name = None
+        f_file = None
+        # note objdump-path may contain extra args
+        cmd = objdump_path + ['--dwarf=info', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            # state machine here to find definitions
+            m = info_pattern.match(line)
+            if m:
+                if m.group('tag'):
+                    if is_func:
+                        defs[f_name] = files.get(f_file, '?')
+                    is_func = (m.group('tag') == 'DW_TAG_subprogram')
+                elif m.group('name'):
+                    f_name = m.group('name')
+                elif m.group('file'):
+                    f_file = int(m.group('file'))
+        if is_func:
+            defs[f_name] = files.get(f_file, '?')
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            # do nothing on error, we don't need objdump to work, source files
+            # may just be inaccurate
+            pass
+
+        for r in results_:
+            # find best matching debug symbol, this may be slightly different
+            # due to optimizations
+            if defs:
+                # exact match? avoid difflib if we can for speed
+                if r.function in defs:
+                    file = defs[r.function]
+                else:
+                    _, file = max(
+                        defs.items(),
+                        key=lambda d: difflib.SequenceMatcher(None,
+                            d[0],
+                            r.function, False).ratio())
+            else:
+                file = r.file
+
+            # ignore filtered sources
+            if sources is not None:
+                if not any(
+                        os.path.abspath(file) == os.path.abspath(s)
+                        for s in sources):
+                    continue
+            else:
+                # default to only cwd
+                if not everything and not os.path.commonpath([
+                        os.getcwd(),
+                        os.path.abspath(file)]) == os.getcwd():
+                    continue
+
+            # simplify path
+            if os.path.commonpath([
+                    os.getcwd(),
+                    os.path.abspath(file)]) == os.getcwd():
+                file = os.path.relpath(file)
+            else:
+                file = os.path.abspath(file)
+
+            results.append(r._replace(file=file))
+
+    return results
+
+
+def fold(Result, results, *,
+        by=None,
+        defines=None,
+        **_):
+    if by is None:
+        by = Result._by
+
+    for k in it.chain(by or [], (k for k, _ in defines or [])):
+        if k not in Result._by and k not in Result._fields:
+            print("error: could not find field %r?" % k)
+            sys.exit(-1)
+
+    # filter by matching defines
+    if defines is not None:
+        results_ = []
+        for r in results:
+            if all(getattr(r, k) in vs for k, vs in defines):
+                results_.append(r)
+        results = results_
+
+    # organize results into conflicts
+    folding = co.OrderedDict()
+    for r in results:
+        name = tuple(getattr(r, k) for k in by)
+        if name not in folding:
+            folding[name] = []
+        folding[name].append(r)
+
+    # merge conflicts
+    folded = []
+    for name, rs in folding.items():
+        folded.append(sum(rs[1:], start=rs[0]))
+
+    return folded
+
+def table(Result, results, diff_results=None, *,
+        by=None,
+        fields=None,
+        sort=None,
+        summary=False,
+        all=False,
+        percent=False,
+        **_):
+    all_, all = all, __builtins__.all
+
+    if by is None:
+        by = Result._by
+    if fields is None:
+        fields = Result._fields
+    types = Result._types
+
+    # fold again
+    results = fold(Result, results, by=by)
+    if diff_results is not None:
+        diff_results = fold(Result, diff_results, by=by)
+
+    # organize by name
+    table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in results}
+    diff_table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in diff_results or []}
+    names = list(table.keys() | diff_table.keys())
+
+    # sort again, now with diff info, note that python's sort is stable
+    names.sort()
+    if diff_results is not None:
+        names.sort(key=lambda n: tuple(
+            types[k].ratio(
+                getattr(table.get(n), k, None),
+                getattr(diff_table.get(n), k, None))
+            for k in fields),
+            reverse=True)
+    if sort:
+        for k, reverse in reversed(sort):
+            names.sort(
+                key=lambda n: tuple(
+                    (getattr(table[n], k),)
+                    if getattr(table.get(n), k, None) is not None else ()
+                    for k in ([k] if k else [
+                        k for k in Result._sort if k in fields])),
+                reverse=reverse ^ (not k or k in Result._fields))
+
+
+    # build up our lines
+    lines = []
+
+    # header
+    header = []
+    header.append('%s%s' % (
+        ','.join(by),
+        ' (%d added, %d removed)' % (
+            sum(1 for n in table if n not in diff_table),
+            sum(1 for n in diff_table if n not in table))
+            if diff_results is not None and not percent else '')
+        if not summary else '')
+    if diff_results is None:
+        for k in fields:
+            header.append(k)
+    elif percent:
+        for k in fields:
+            header.append(k)
+    else:
+        for k in fields:
+            header.append('o'+k)
+        for k in fields:
+            header.append('n'+k)
+        for k in fields:
+            header.append('d'+k)
+    header.append('')
+    lines.append(header)
+
+    def table_entry(name, r, diff_r=None, ratios=[]):
+        entry = []
+        entry.append(name)
+        if diff_results is None:
+            for k in fields:
+                entry.append(getattr(r, k).table()
+                    if getattr(r, k, None) is not None
+                    else types[k].none)
+        elif percent:
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+        else:
+            for k in fields:
+                entry.append(getattr(diff_r, k).diff_table()
+                    if getattr(diff_r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(types[k].diff_diff(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None)))
+        if diff_results is None:
+            entry.append('')
+        elif percent:
+            entry.append(' (%s)' % ', '.join(
+                '+∞%' if t == +m.inf
+                else '-∞%' if t == -m.inf
+                else '%+.1f%%' % (100*t)
+                for t in ratios))
+        else:
+            entry.append(' (%s)' % ', '.join(
+                    '+∞%' if t == +m.inf
+                    else '-∞%' if t == -m.inf
+                    else '%+.1f%%' % (100*t)
+                    for t in ratios
+                    if t)
+                if any(ratios) else '')
+        return entry
+
+    # entries
+    if not summary:
+        for name in names:
+            r = table.get(name)
+            if diff_results is None:
+                diff_r = None
+                ratios = None
+            else:
+                diff_r = diff_table.get(name)
+                ratios = [
+                    types[k].ratio(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None))
+                    for k in fields]
+                if not all_ and not any(ratios):
+                    continue
+            lines.append(table_entry(name, r, diff_r, ratios))
+
+    # total
+    r = next(iter(fold(Result, results, by=[])), None)
+    if diff_results is None:
+        diff_r = None
+        ratios = None
+    else:
+        diff_r = next(iter(fold(Result, diff_results, by=[])), None)
+        ratios = [
+            types[k].ratio(
+                getattr(r, k, None),
+                getattr(diff_r, k, None))
+            for k in fields]
+    lines.append(table_entry('TOTAL', r, diff_r, ratios))
+
+    # find the best widths, note that column 0 contains the names and column -1
+    # the ratios, so those are handled a bit differently
+    widths = [
+        ((max(it.chain([w], (len(l[i]) for l in lines)))+1+4-1)//4)*4-1
+        for w, i in zip(
+            it.chain([23], it.repeat(7)),
+            range(len(lines[0])-1))]
+
+    # print our table
+    for line in lines:
+        print('%-*s  %s%s' % (
+            widths[0], line[0],
+            ' '.join('%*s' % (w, x)
+                for w, x in zip(widths[1:], line[1:-1])),
+            line[-1]))
+
+
+def main(obj_paths, *,
+        by=None,
+        fields=None,
+        defines=None,
+        sort=None,
+        **args):
+    # find sizes
+    if not args.get('use', None):
+        results = collect(obj_paths, **args)
+    else:
+        results = []
+        with openio(args['use']) as f:
+            reader = csv.DictReader(f, restval='')
+            for r in reader:
+                try:
+                    results.append(DataResult(
+                        **{k: r[k] for k in DataResult._by
+                            if k in r and r[k].strip()},
+                        **{k: r['data_'+k] for k in DataResult._fields
+                            if 'data_'+k in r and r['data_'+k].strip()}))
+                except TypeError:
+                    pass
+
+    # fold
+    results = fold(DataResult, results, by=by, defines=defines)
+
+    # sort, note that python's sort is stable
+    results.sort()
+    if sort:
+        for k, reverse in reversed(sort):
+            results.sort(
+                key=lambda r: tuple(
+                    (getattr(r, k),) if getattr(r, k) is not None else ()
+                    for k in ([k] if k else DataResult._sort)),
+                reverse=reverse ^ (not k or k in DataResult._fields))
+
+    # write results to CSV
+    if args.get('output'):
+        with openio(args['output'], 'w') as f:
+            writer = csv.DictWriter(f,
+                (by if by is not None else DataResult._by)
+                + ['data_'+k for k in (
+                    fields if fields is not None else DataResult._fields)])
+            writer.writeheader()
+            for r in results:
+                writer.writerow(
+                    {k: getattr(r, k) for k in (
+                        by if by is not None else DataResult._by)}
+                    | {'data_'+k: getattr(r, k) for k in (
+                        fields if fields is not None else DataResult._fields)})
+
+    # find previous results?
+    if args.get('diff'):
+        diff_results = []
+        try:
+            with openio(args['diff']) as f:
+                reader = csv.DictReader(f, restval='')
+                for r in reader:
+                    if not any('data_'+k in r and r['data_'+k].strip()
+                            for k in DataResult._fields):
+                        continue
+                    try:
+                        diff_results.append(DataResult(
+                            **{k: r[k] for k in DataResult._by
+                                if k in r and r[k].strip()},
+                            **{k: r['data_'+k] for k in DataResult._fields
+                                if 'data_'+k in r and r['data_'+k].strip()}))
+                    except TypeError:
+                        pass
+        except FileNotFoundError:
+            pass
+
+        # fold
+        diff_results = fold(DataResult, diff_results, by=by, defines=defines)
+
+    # print table
+    if not args.get('quiet'):
+        table(DataResult, results,
+            diff_results if args.get('diff') else None,
+            by=by if by is not None else ['function'],
+            fields=fields,
+            sort=sort,
+            **args)
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Find data size at the function level.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'obj_paths',
+        nargs='*',
+        help="Input *.o files.")
+    parser.add_argument(
+        '-v', '--verbose',
+        action='store_true',
+        help="Output commands that run behind the scenes.")
+    parser.add_argument(
+        '-q', '--quiet',
+        action='store_true',
+        help="Don't show anything, useful with -o.")
+    parser.add_argument(
+        '-o', '--output',
+        help="Specify CSV file to store results.")
+    parser.add_argument(
+        '-u', '--use',
+        help="Don't parse anything, use this CSV file.")
+    parser.add_argument(
+        '-d', '--diff',
+        help="Specify CSV file to diff against.")
+    parser.add_argument(
+        '-a', '--all',
+        action='store_true',
+        help="Show all, not just the ones that changed.")
+    parser.add_argument(
+        '-p', '--percent',
+        action='store_true',
+        help="Only show percentage change, not a full diff.")
+    parser.add_argument(
+        '-b', '--by',
+        action='append',
+        choices=DataResult._by,
+        help="Group by this field.")
+    parser.add_argument(
+        '-f', '--field',
+        dest='fields',
+        action='append',
+        choices=DataResult._fields,
+        help="Show this field.")
+    parser.add_argument(
+        '-D', '--define',
+        dest='defines',
+        action='append',
+        type=lambda x: (lambda k,v: (k, set(v.split(','))))(*x.split('=', 1)),
+        help="Only include results where this field is this value.")
+    class AppendSort(argparse.Action):
+        def __call__(self, parser, namespace, value, option):
+            if namespace.sort is None:
+                namespace.sort = []
+            namespace.sort.append((value, True if option == '-S' else False))
+    parser.add_argument(
+        '-s', '--sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field.")
+    parser.add_argument(
+        '-S', '--reverse-sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field, but backwards.")
+    parser.add_argument(
+        '-Y', '--summary',
+        action='store_true',
+        help="Only show the total.")
+    parser.add_argument(
+        '-F', '--source',
+        dest='sources',
+        action='append',
+        help="Only consider definitions in this file. Defaults to anything "
+            "in the current directory.")
+    parser.add_argument(
+        '--everything',
+        action='store_true',
+        help="Include builtin and libc specific symbols.")
+    parser.add_argument(
+        '--nm-types',
+        default=NM_TYPES,
+        help="Type of symbols to report, this uses the same single-character "
+            "type-names emitted by nm. Defaults to %r." % NM_TYPES)
+    parser.add_argument(
+        '--nm-path',
+        type=lambda x: x.split(),
+        default=NM_PATH,
+        help="Path to the nm executable, may include flags. "
+            "Defaults to %r." % NM_PATH)
+    parser.add_argument(
+        '--objdump-path',
+        type=lambda x: x.split(),
+        default=OBJDUMP_PATH,
+        help="Path to the objdump executable, may include flags. "
+            "Defaults to %r." % OBJDUMP_PATH)
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/explode_asserts.py

@@ -1,383 +0,0 @@
-#!/usr/bin/env python3
-
-import re
-import sys
-
-PATTERN = ['LFS_ASSERT', 'assert']
-PREFIX = 'LFS'
-MAXWIDTH = 16
-
-ASSERT = "__{PREFIX}_ASSERT_{TYPE}_{COMP}"
-FAIL = """
-__attribute__((unused))
-static void __{prefix}_assert_fail_{type}(
-        const char *file, int line, const char *comp,
-        {ctype} lh, size_t lsize,
-        {ctype} rh, size_t rsize) {{
-    printf("%s:%d:assert: assert failed with ", file, line);
-    __{prefix}_assert_print_{type}(lh, lsize);
-    printf(", expected %s ", comp);
-    __{prefix}_assert_print_{type}(rh, rsize);
-    printf("\\n");
-    fflush(NULL);
-    raise(SIGABRT);
-}}
-"""
-
-COMP = {
-    '==': 'eq',
-    '!=': 'ne',
-    '<=': 'le',
-    '>=': 'ge',
-    '<':  'lt',
-    '>':  'gt',
-}
-
-TYPE = {
-    'int': {
-        'ctype': 'intmax_t',
-        'fail': FAIL,
-        'print': """
-        __attribute__((unused))
-        static void __{prefix}_assert_print_{type}({ctype} v, size_t size) {{
-            (void)size;
-            printf("%"PRIiMAX, v);
-        }}
-        """,
-        'assert': """
-        #define __{PREFIX}_ASSERT_{TYPE}_{COMP}(file, line, lh, rh)
-        do {{
-            __typeof__(lh) _lh = lh;
-            __typeof__(lh) _rh = (__typeof__(lh))rh;
-            if (!(_lh {op} _rh)) {{
-                __{prefix}_assert_fail_{type}(file, line, "{comp}",
-                        (intmax_t)_lh, 0, (intmax_t)_rh, 0);
-            }}
-        }} while (0)
-        """
-    },
-    'bool': {
-        'ctype': 'bool',
-        'fail': FAIL,
-        'print': """
-        __attribute__((unused))
-        static void __{prefix}_assert_print_{type}({ctype} v, size_t size) {{
-            (void)size;
-            printf("%s", v ? "true" : "false");
-        }}
-        """,
-        'assert': """
-        #define __{PREFIX}_ASSERT_{TYPE}_{COMP}(file, line, lh, rh)
-        do {{
-            bool _lh = !!(lh);
-            bool _rh = !!(rh);
-            if (!(_lh {op} _rh)) {{
-                __{prefix}_assert_fail_{type}(file, line, "{comp}",
-                        _lh, 0, _rh, 0);
-            }}
-        }} while (0)
-        """
-    },
-    'mem': {
-        'ctype': 'const void *',
-        'fail': FAIL,
-        'print': """
-        __attribute__((unused))
-        static void __{prefix}_assert_print_{type}({ctype} v, size_t size) {{
-            const uint8_t *s = v;
-            printf("\\\"");
-            for (size_t i = 0; i < size && i < {maxwidth}; i++) {{
-                if (s[i] >= ' ' && s[i] <= '~') {{
-                    printf("%c", s[i]);
-                }} else {{
-                    printf("\\\\x%02x", s[i]);
-                }}
-            }}
-            if (size > {maxwidth}) {{
-                printf("...");
-            }}
-            printf("\\\"");
-        }}
-        """,
-        'assert': """
-        #define __{PREFIX}_ASSERT_{TYPE}_{COMP}(file, line, lh, rh, size)
-        do {{
-            const void *_lh = lh;
-            const void *_rh = rh;
-            if (!(memcmp(_lh, _rh, size) {op} 0)) {{
-                __{prefix}_assert_fail_{type}(file, line, "{comp}",
-                        _lh, size, _rh, size);
-            }}
-        }} while (0)
-        """
-    },
-    'str': {
-        'ctype': 'const char *',
-        'fail': FAIL,
-        'print': """
-        __attribute__((unused))
-        static void __{prefix}_assert_print_{type}({ctype} v, size_t size) {{
-            __{prefix}_assert_print_mem(v, size);
-        }}
-        """,
-        'assert': """
-        #define __{PREFIX}_ASSERT_{TYPE}_{COMP}(file, line, lh, rh)
-        do {{
-            const char *_lh = lh;
-            const char *_rh = rh;
-            if (!(strcmp(_lh, _rh) {op} 0)) {{
-                __{prefix}_assert_fail_{type}(file, line, "{comp}",
-                        _lh, strlen(_lh), _rh, strlen(_rh));
-            }}
-        }} while (0)
-        """
-    }
-}
-
-def mkdecls(outf, maxwidth=16):
-    outf.write("#include <stdio.h>\n")
-    outf.write("#include <stdbool.h>\n")
-    outf.write("#include <stdint.h>\n")
-    outf.write("#include <inttypes.h>\n")
-    outf.write("#include <signal.h>\n")
-
-    for type, desc in sorted(TYPE.items()):
-        format = {
-            'type': type.lower(), 'TYPE': type.upper(),
-            'ctype': desc['ctype'],
-            'prefix': PREFIX.lower(), 'PREFIX': PREFIX.upper(),
-            'maxwidth': maxwidth,
-        }
-        outf.write(re.sub('\s+', ' ',
-            desc['print'].strip().format(**format))+'\n')
-        outf.write(re.sub('\s+', ' ',
-            desc['fail'].strip().format(**format))+'\n')
-
-        for op, comp in sorted(COMP.items()):
-            format.update({
-                'comp': comp.lower(), 'COMP': comp.upper(),
-                'op': op,
-            })
-            outf.write(re.sub('\s+', ' ',
-                desc['assert'].strip().format(**format))+'\n')
-
-def mkassert(type, comp, lh, rh, size=None):
-    format = {
-        'type': type.lower(), 'TYPE': type.upper(),
-        'comp': comp.lower(), 'COMP': comp.upper(),
-        'prefix': PREFIX.lower(), 'PREFIX': PREFIX.upper(),
-        'lh': lh.strip(' '),
-        'rh': rh.strip(' '),
-        'size': size,
-    }
-    if size:
-        return ((ASSERT + '(__FILE__, __LINE__, {lh}, {rh}, {size})')
-            .format(**format))
-    else:
-        return ((ASSERT + '(__FILE__, __LINE__, {lh}, {rh})')
-            .format(**format))
-
-
-# simple recursive descent parser
-LEX = {
-    'ws':       [r'(?:\s|\n|#.*?\n|//.*?\n|/\*.*?\*/)+'],
-    'assert':   PATTERN,
-    'string':   [r'"(?:\\.|[^"])*"', r"'(?:\\.|[^'])\'"],
-    'arrow':    ['=>'],
-    'paren':    ['\(', '\)'],
-    'op':       ['strcmp', 'memcmp', '->'],
-    'comp':     ['==', '!=', '<=', '>=', '<', '>'],
-    'logic':    ['\&\&', '\|\|'],
-    'sep':      [':', ';', '\{', '\}', ','],
-}
-
-class ParseFailure(Exception):
-    def __init__(self, expected, found):
-        self.expected = expected
-        self.found = found
-
-    def __str__(self):
-        return "expected %r, found %s..." % (
-            self.expected, repr(self.found)[:70])
-
-class Parse:
-    def __init__(self, inf, lexemes):
-        p = '|'.join('(?P<%s>%s)' % (n, '|'.join(l))
-            for n, l in lexemes.items())
-        p = re.compile(p, re.DOTALL)
-        data = inf.read()
-        tokens = []
-        while True:
-            m = p.search(data)
-            if m:
-                if m.start() > 0:
-                    tokens.append((None, data[:m.start()]))
-                tokens.append((m.lastgroup, m.group()))
-                data = data[m.end():]
-            else:
-                tokens.append((None, data))
-                break
-        self.tokens = tokens
-        self.off = 0
-
-    def lookahead(self, *pattern):
-        if self.off < len(self.tokens):
-            token = self.tokens[self.off]
-            if token[0] in pattern or token[1] in pattern:
-                self.m = token[1]
-                return self.m
-        self.m = None
-        return self.m
-
-    def accept(self, *patterns):
-        m = self.lookahead(*patterns)
-        if m is not None:
-            self.off += 1
-        return m
-
-    def expect(self, *patterns):
-        m = self.accept(*patterns)
-        if not m:
-            raise ParseFailure(patterns, self.tokens[self.off:])
-        return m
-
-    def push(self):
-        return self.off
-
-    def pop(self, state):
-        self.off = state
-
-def passert(p):
-    def pastr(p):
-        p.expect('assert') ; p.accept('ws') ; p.expect('(') ; p.accept('ws')
-        p.expect('strcmp') ; p.accept('ws') ; p.expect('(') ; p.accept('ws')
-        lh = pexpr(p) ; p.accept('ws')
-        p.expect(',') ; p.accept('ws')
-        rh = pexpr(p) ; p.accept('ws')
-        p.expect(')') ; p.accept('ws')
-        comp = p.expect('comp') ; p.accept('ws')
-        p.expect('0') ; p.accept('ws')
-        p.expect(')')
-        return mkassert('str', COMP[comp], lh, rh)
-
-    def pamem(p):
-        p.expect('assert') ; p.accept('ws') ; p.expect('(') ; p.accept('ws')
-        p.expect('memcmp') ; p.accept('ws') ; p.expect('(') ; p.accept('ws')
-        lh = pexpr(p) ; p.accept('ws')
-        p.expect(',') ; p.accept('ws')
-        rh = pexpr(p) ; p.accept('ws')
-        p.expect(',') ; p.accept('ws')
-        size = pexpr(p) ; p.accept('ws')
-        p.expect(')') ; p.accept('ws')
-        comp = p.expect('comp') ; p.accept('ws')
-        p.expect('0') ; p.accept('ws')
-        p.expect(')')
-        return mkassert('mem', COMP[comp], lh, rh, size)
-
-    def paint(p):
-        p.expect('assert') ; p.accept('ws') ; p.expect('(') ; p.accept('ws')
-        lh = pexpr(p) ; p.accept('ws')
-        comp = p.expect('comp') ; p.accept('ws')
-        rh = pexpr(p) ; p.accept('ws')
-        p.expect(')')
-        return mkassert('int', COMP[comp], lh, rh)
-
-    def pabool(p):
-        p.expect('assert') ; p.accept('ws') ; p.expect('(') ; p.accept('ws')
-        lh = pexprs(p) ; p.accept('ws')
-        p.expect(')')
-        return mkassert('bool', 'eq', lh, 'true')
-
-    def pa(p):
-        return p.expect('assert')
-
-    state = p.push()
-    lastf = None
-    for pa in [pastr, pamem, paint, pabool, pa]:
-        try:
-            return pa(p)
-        except ParseFailure as f:
-            p.pop(state)
-            lastf = f
-    else:
-        raise lastf
-
-def pexpr(p):
-    res = []
-    while True:
-        if p.accept('('):
-            res.append(p.m)
-            while True:
-                res.append(pexprs(p))
-                if p.accept('sep'):
-                    res.append(p.m)
-                else:
-                    break
-            res.append(p.expect(')'))
-        elif p.lookahead('assert'):
-            res.append(passert(p))
-        elif p.accept('assert', 'ws', 'string', 'op', None):
-            res.append(p.m)
-        else:
-            return ''.join(res)
-
-def pexprs(p):
-    res = []
-    while True:
-        res.append(pexpr(p))
-        if p.accept('comp', 'logic', ','):
-            res.append(p.m)
-        else:
-            return ''.join(res)
-
-def pstmt(p):
-    ws = p.accept('ws') or ''
-    lh = pexprs(p)
-    if p.accept('=>'):
-        rh = pexprs(p)
-        return ws + mkassert('int', 'eq', lh, rh)
-    else:
-        return ws + lh
-
-
-def main(args):
-    inf = open(args.input, 'r') if args.input else sys.stdin
-    outf = open(args.output, 'w') if args.output else sys.stdout
-
-    lexemes = LEX.copy()
-    if args.pattern:
-        lexemes['assert'] = args.pattern
-    p = Parse(inf, lexemes)
-
-    # write extra verbose asserts
-    mkdecls(outf, maxwidth=args.maxwidth)
-    if args.input:
-        outf.write("#line %d \"%s\"\n" % (1, args.input))
-
-    # parse and write out stmt at a time
-    try:
-        while True:
-            outf.write(pstmt(p))
-            if p.accept('sep'):
-                outf.write(p.m)
-            else:
-                break
-    except ParseFailure as f:
-        pass
-
-    for i in range(p.off, len(p.tokens)):
-        outf.write(p.tokens[i][1])
-
-if __name__ == "__main__":
-    import argparse
-    parser = argparse.ArgumentParser(
-        description="Cpp step that increases assert verbosity")
-    parser.add_argument('input', nargs='?',
-        help="Input C file after cpp.")
-    parser.add_argument('-o', '--output', required=True,
-        help="Output C file.")
-    parser.add_argument('-p', '--pattern', action='append',
-        help="Patterns to search for starting an assert statement.")
-    parser.add_argument('--maxwidth', default=MAXWIDTH, type=int,
-        help="Maximum number of characters to display for strcmp and memcmp.")
-    main(parser.parse_args())

scripts/prefix.py

@@ -1,61 +0,0 @@
-#!/usr/bin/env python2
-
-# This script replaces prefixes of files, and symbols in that file.
-# Useful for creating different versions of the codebase that don't
-# conflict at compile time.
-#
-# example:
-# $ ./scripts/prefix.py lfs2
-
-import os
-import os.path
-import re
-import glob
-import itertools
-import tempfile
-import shutil
-import subprocess
-
-DEFAULT_PREFIX = "lfs"
-
-def subn(from_prefix, to_prefix, name):
-    name, count1 = re.subn('\\b'+from_prefix, to_prefix, name)
-    name, count2 = re.subn('\\b'+from_prefix.upper(), to_prefix.upper(), name)
-    name, count3 = re.subn('\\B-D'+from_prefix.upper(),
-            '-D'+to_prefix.upper(), name)
-    return name, count1+count2+count3
-
-def main(from_prefix, to_prefix=None, files=None):
-    if not to_prefix:
-        from_prefix, to_prefix = DEFAULT_PREFIX, from_prefix
-
-    if not files:
-        files = subprocess.check_output([
-                'git', 'ls-tree', '-r', '--name-only', 'HEAD']).split()
-
-    for oldname in files:
-        # Rename any matching file names
-        newname, namecount = subn(from_prefix, to_prefix, oldname)
-        if namecount:
-            subprocess.check_call(['git', 'mv', oldname, newname])
-
-        # Rename any prefixes in file
-        count = 0
-        with open(newname+'~', 'w') as tempf:
-            with open(newname) as newf:
-                for line in newf:
-                    line, n = subn(from_prefix, to_prefix, line)
-                    count += n
-                    tempf.write(line)
-        shutil.copystat(newname, newname+'~')
-        os.rename(newname+'~', newname)
-        subprocess.check_call(['git', 'add', newname])
-
-        # Summary
-        print '%s: %d replacements' % (
-                '%s -> %s' % (oldname, newname) if namecount else oldname,
-                count)
-
-if __name__ == "__main__":
-    import sys
-    sys.exit(main(*sys.argv[1:]))

scripts/prettyasserts.py

@@ -0,0 +1,478 @@
+#!/usr/bin/env python3
+#
+# Preprocessor that makes asserts easier to debug.
+#
+# Example:
+# ./scripts/prettyasserts.py -p LFS_ASSERT lfs.c -o lfs.a.c
+#
+# Copyright (c) 2022, The littlefs authors.
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import re
+import sys
+
+# NOTE the use of macros here helps keep a consistent stack depth which
+# tools may rely on.
+#
+# If compilation errors are noisy consider using -ftrack-macro-expansion=0.
+#
+
+LIMIT = 16
+
+CMP = {
+    '==': 'eq',
+    '!=': 'ne',
+    '<=': 'le',
+    '>=': 'ge',
+    '<':  'lt',
+    '>':  'gt',
+}
+
+LEXEMES = {
+    'ws':       [r'(?:\s|\n|#.*?\n|//.*?\n|/\*.*?\*/)+'],
+    'assert':   ['assert'],
+    'arrow':    ['=>'],
+    'string':   [r'"(?:\\.|[^"])*"', r"'(?:\\.|[^'])\'"],
+    'paren':    [r'\(', r'\)'],
+    'cmp':      CMP.keys(),
+    'logic':    [r'\&\&', r'\|\|'],
+    'sep':      [':', ';', r'\{', r'\}', ','],
+    'op':       ['->'], # specifically ops that conflict with cmp
+}
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def write_header(f, limit=LIMIT):
+    f.writeln("// Generated by %s:" % sys.argv[0])
+    f.writeln("//")
+    f.writeln("// %s" % ' '.join(sys.argv))
+    f.writeln("//")
+    f.writeln()
+
+    f.writeln("#include <stdbool.h>")
+    f.writeln("#include <stdint.h>")
+    f.writeln("#include <inttypes.h>")
+    f.writeln("#include <stdio.h>")
+    f.writeln("#include <string.h>")
+    f.writeln("#include <signal.h>")
+    # give source a chance to define feature macros
+    f.writeln("#undef _FEATURES_H")
+    f.writeln()
+
+    # write print macros
+    f.writeln("__attribute__((unused))")
+    f.writeln("static void __pretty_assert_print_bool(")
+    f.writeln("        const void *v, size_t size) {")
+    f.writeln("    (void)size;")
+    f.writeln("    printf(\"%s\", *(const bool*)v ? \"true\" : \"false\");")
+    f.writeln("}")
+    f.writeln()
+    f.writeln("__attribute__((unused))")
+    f.writeln("static void __pretty_assert_print_int(")
+    f.writeln("        const void *v, size_t size) {")
+    f.writeln("    (void)size;")
+    f.writeln("    printf(\"%\"PRIiMAX, *(const intmax_t*)v);")
+    f.writeln("}")
+    f.writeln()
+    f.writeln("__attribute__((unused))")
+    f.writeln("static void __pretty_assert_print_ptr(")
+    f.writeln("        const void *v, size_t size) {")
+    f.writeln("    (void)size;")
+    f.writeln("    printf(\"%p\", v);")
+    f.writeln("}")
+    f.writeln()
+    f.writeln("__attribute__((unused))")
+    f.writeln("static void __pretty_assert_print_mem(")
+    f.writeln("        const void *v, size_t size) {")
+    f.writeln("    const uint8_t *v_ = v;")
+    f.writeln("    printf(\"\\\"\");")
+    f.writeln("    for (size_t i = 0; i < size && i < %d; i++) {" % limit)
+    f.writeln("        if (v_[i] >= ' ' && v_[i] <= '~') {")
+    f.writeln("            printf(\"%c\", v_[i]);")
+    f.writeln("        } else {")
+    f.writeln("            printf(\"\\\\x%02x\", v_[i]);")
+    f.writeln("        }")
+    f.writeln("    }")
+    f.writeln("    if (size > %d) {" % limit)
+    f.writeln("        printf(\"...\");")
+    f.writeln("    }")
+    f.writeln("    printf(\"\\\"\");")
+    f.writeln("}")
+    f.writeln()
+    f.writeln("__attribute__((unused))")
+    f.writeln("static void __pretty_assert_print_str(")
+    f.writeln("        const void *v, size_t size) {")
+    f.writeln("    __pretty_assert_print_mem(v, size);")
+    f.writeln("}")
+    f.writeln()
+    f.writeln("__attribute__((unused, noinline))")
+    f.writeln("static void __pretty_assert_fail(")
+    f.writeln("        const char *file, int line,")
+    f.writeln("        void (*type_print_cb)(const void*, size_t),")
+    f.writeln("        const char *cmp,")
+    f.writeln("        const void *lh, size_t lsize,")
+    f.writeln("        const void *rh, size_t rsize) {")
+    f.writeln("    printf(\"%s:%d:assert: assert failed with \", file, line);")
+    f.writeln("    type_print_cb(lh, lsize);")
+    f.writeln("    printf(\", expected %s \", cmp);")
+    f.writeln("    type_print_cb(rh, rsize);")
+    f.writeln("    printf(\"\\n\");")
+    f.writeln("    fflush(NULL);")
+    f.writeln("    raise(SIGABRT);")
+    f.writeln("}")
+    f.writeln()
+
+    # write assert macros
+    for op, cmp in sorted(CMP.items()):
+        f.writeln("#define __PRETTY_ASSERT_BOOL_%s(lh, rh) do { \\"
+            % cmp.upper())
+        f.writeln("    bool _lh = !!(lh); \\")
+        f.writeln("    bool _rh = !!(rh); \\")
+        f.writeln("    if (!(_lh %s _rh)) { \\" % op)
+        f.writeln("        __pretty_assert_fail( \\")
+        f.writeln("                __FILE__, __LINE__, \\")
+        f.writeln("                __pretty_assert_print_bool, \"%s\", \\"
+            % cmp)
+        f.writeln("                &_lh, 0, \\")
+        f.writeln("                &_rh, 0); \\")
+        f.writeln("    } \\")
+        f.writeln("} while (0)")
+    for op, cmp in sorted(CMP.items()):
+        f.writeln("#define __PRETTY_ASSERT_INT_%s(lh, rh) do { \\"
+            % cmp.upper())
+        f.writeln("    __typeof__(lh) _lh = lh; \\")
+        f.writeln("    __typeof__(lh) _rh = rh; \\")
+        f.writeln("    if (!(_lh %s _rh)) { \\" % op)
+        f.writeln("        __pretty_assert_fail( \\")
+        f.writeln("                __FILE__, __LINE__, \\")
+        f.writeln("                __pretty_assert_print_int, \"%s\", \\"
+            % cmp)
+        f.writeln("                &(intmax_t){_lh}, 0, \\")
+        f.writeln("                &(intmax_t){_rh}, 0); \\")
+        f.writeln("    } \\")
+        f.writeln("} while (0)")
+    for op, cmp in sorted(CMP.items()):
+        f.writeln("#define __PRETTY_ASSERT_MEM_%s(lh, rh, size) do { \\"
+            % cmp.upper())
+        f.writeln("    const void *_lh = lh; \\")
+        f.writeln("    const void *_rh = rh; \\")
+        f.writeln("    if (!(memcmp(_lh, _rh, size) %s 0)) { \\" % op)
+        f.writeln("        __pretty_assert_fail( \\")
+        f.writeln("                __FILE__, __LINE__, \\")
+        f.writeln("                __pretty_assert_print_mem, \"%s\", \\"
+            % cmp)
+        f.writeln("                _lh, size, \\")
+        f.writeln("                _rh, size); \\")
+        f.writeln("    } \\")
+        f.writeln("} while (0)")
+    for op, cmp in sorted(CMP.items()):
+        f.writeln("#define __PRETTY_ASSERT_STR_%s(lh, rh) do { \\"
+            % cmp.upper())
+        f.writeln("    const char *_lh = lh; \\")
+        f.writeln("    const char *_rh = rh; \\")
+        f.writeln("    if (!(strcmp(_lh, _rh) %s 0)) { \\" % op)
+        f.writeln("        __pretty_assert_fail( \\")
+        f.writeln("                __FILE__, __LINE__, \\")
+        f.writeln("                __pretty_assert_print_str, \"%s\", \\"
+            % cmp)
+        f.writeln("                _lh, strlen(_lh), \\")
+        f.writeln("                _rh, strlen(_rh)); \\")
+        f.writeln("    } \\")
+        f.writeln("} while (0)")
+    for op, cmp in sorted(CMP.items()):
+        # Only EQ and NE are supported when compared to NULL.
+        if cmp not in ['eq', 'ne']:
+            continue
+        f.writeln("#define __PRETTY_ASSERT_PTR_%s(lh, rh) do { \\"
+            % cmp.upper())
+        f.writeln("    const void *_lh = (const void*)(uintptr_t)lh; \\")
+        f.writeln("    const void *_rh = (const void*)(uintptr_t)rh; \\")
+        f.writeln("    if (!(_lh %s _rh)) { \\" % op)
+        f.writeln("        __pretty_assert_fail( \\")
+        f.writeln("                __FILE__, __LINE__, \\")
+        f.writeln("                __pretty_assert_print_ptr, \"%s\", \\"
+            % cmp)
+        f.writeln("                (const void*){_lh}, 0, \\")
+        f.writeln("                (const void*){_rh}, 0); \\")
+        f.writeln("    } \\")
+        f.writeln("} while (0)")
+    f.writeln()
+    f.writeln()
+
+def mkassert(type, cmp, lh, rh, size=None):
+    if size is not None:
+        return ("__PRETTY_ASSERT_%s_%s(%s, %s, %s)"
+            % (type.upper(), cmp.upper(), lh, rh, size))
+    else:
+        return ("__PRETTY_ASSERT_%s_%s(%s, %s)"
+            % (type.upper(), cmp.upper(), lh, rh))
+
+
+# simple recursive descent parser
+class ParseFailure(Exception):
+    def __init__(self, expected, found):
+        self.expected = expected
+        self.found = found
+
+    def __str__(self):
+        return "expected %r, found %s..." % (
+            self.expected, repr(self.found)[:70])
+
+class Parser:
+    def __init__(self, in_f, lexemes=LEXEMES):
+        p = '|'.join('(?P<%s>%s)' % (n, '|'.join(l))
+            for n, l in lexemes.items())
+        p = re.compile(p, re.DOTALL)
+        data = in_f.read()
+        tokens = []
+        line = 1
+        col = 0
+        while True:
+            m = p.search(data)
+            if m:
+                if m.start() > 0:
+                    tokens.append((None, data[:m.start()], line, col))
+                tokens.append((m.lastgroup, m.group(), line, col))
+                data = data[m.end():]
+            else:
+                tokens.append((None, data, line, col))
+                break
+        self.tokens = tokens
+        self.off = 0
+
+    def lookahead(self, *pattern):
+        if self.off < len(self.tokens):
+            token = self.tokens[self.off]
+            if token[0] in pattern or token[1] in pattern:
+                self.m = token[1]
+                return self.m
+        self.m = None
+        return self.m
+
+    def accept(self, *patterns):
+        m = self.lookahead(*patterns)
+        if m is not None:
+            self.off += 1
+        return m
+
+    def expect(self, *patterns):
+        m = self.accept(*patterns)
+        if not m:
+            raise ParseFailure(patterns, self.tokens[self.off:])
+        return m
+
+    def push(self):
+        return self.off
+
+    def pop(self, state):
+        self.off = state
+
+def p_assert(p):
+    state = p.push()
+
+    # assert(memcmp(a,b,size) cmp 0)?
+    try:
+        p.expect('assert') ; p.accept('ws')
+        p.expect('(') ; p.accept('ws')
+        p.expect('memcmp') ; p.accept('ws')
+        p.expect('(') ; p.accept('ws')
+        lh = p_expr(p) ; p.accept('ws')
+        p.expect(',') ; p.accept('ws')
+        rh = p_expr(p) ; p.accept('ws')
+        p.expect(',') ; p.accept('ws')
+        size = p_expr(p) ; p.accept('ws')
+        p.expect(')') ; p.accept('ws')
+        cmp = p.expect('cmp') ; p.accept('ws')
+        p.expect('0') ; p.accept('ws')
+        p.expect(')')
+        return mkassert('mem', CMP[cmp], lh, rh, size)
+    except ParseFailure:
+        p.pop(state)
+
+    # assert(strcmp(a,b) cmp 0)?
+    try:
+        p.expect('assert') ; p.accept('ws')
+        p.expect('(') ; p.accept('ws')
+        p.expect('strcmp') ; p.accept('ws')
+        p.expect('(') ; p.accept('ws')
+        lh = p_expr(p) ; p.accept('ws')
+        p.expect(',') ; p.accept('ws')
+        rh = p_expr(p) ; p.accept('ws')
+        p.expect(')') ; p.accept('ws')
+        cmp = p.expect('cmp') ; p.accept('ws')
+        p.expect('0') ; p.accept('ws')
+        p.expect(')')
+        return mkassert('str', CMP[cmp], lh, rh)
+    except ParseFailure:
+        p.pop(state)
+
+    # assert(a cmp b)?
+    try:
+        p.expect('assert') ; p.accept('ws')
+        p.expect('(') ; p.accept('ws')
+        lh = p_expr(p) ; p.accept('ws')
+        cmp = p.expect('cmp') ; p.accept('ws')
+        rh = p_expr(p) ; p.accept('ws')
+        p.expect(')')
+        if rh == 'NULL' or lh == 'NULL':
+            return mkassert('ptr', CMP[cmp], lh, rh)
+        return mkassert('int', CMP[cmp], lh, rh)
+    except ParseFailure:
+        p.pop(state)
+
+    # assert(a)?
+    p.expect('assert') ; p.accept('ws')
+    p.expect('(') ; p.accept('ws')
+    lh = p_exprs(p) ; p.accept('ws')
+    p.expect(')')
+    return mkassert('bool', 'eq', lh, 'true')
+
+def p_expr(p):
+    res = []
+    while True:
+        if p.accept('('):
+            res.append(p.m)
+            while True:
+                res.append(p_exprs(p))
+                if p.accept('sep'):
+                    res.append(p.m)
+                else:
+                    break
+            res.append(p.expect(')'))
+        elif p.lookahead('assert'):
+            state = p.push()
+            try:
+                res.append(p_assert(p))
+            except ParseFailure:
+                p.pop(state)
+                res.append(p.expect('assert'))
+        elif p.accept('string', 'op', 'ws', None):
+            res.append(p.m)
+        else:
+            return ''.join(res)
+
+def p_exprs(p):
+    res = []
+    while True:
+        res.append(p_expr(p))
+        if p.accept('cmp', 'logic', ','):
+            res.append(p.m)
+        else:
+            return ''.join(res)
+
+def p_stmt(p):
+    ws = p.accept('ws') or ''
+
+    # memcmp(lh,rh,size) => 0?
+    if p.lookahead('memcmp'):
+        state = p.push()
+        try:
+            p.expect('memcmp') ; p.accept('ws')
+            p.expect('(') ; p.accept('ws')
+            lh = p_expr(p) ; p.accept('ws')
+            p.expect(',') ; p.accept('ws')
+            rh = p_expr(p) ; p.accept('ws')
+            p.expect(',') ; p.accept('ws')
+            size = p_expr(p) ; p.accept('ws')
+            p.expect(')') ; p.accept('ws')
+            p.expect('=>') ; p.accept('ws')
+            p.expect('0') ; p.accept('ws')
+            return ws + mkassert('mem', 'eq', lh, rh, size)
+        except ParseFailure:
+            p.pop(state)
+
+    # strcmp(lh,rh) => 0?
+    if p.lookahead('strcmp'):
+        state = p.push()
+        try:
+            p.expect('strcmp') ; p.accept('ws') ; p.expect('(') ; p.accept('ws')
+            lh = p_expr(p) ; p.accept('ws')
+            p.expect(',') ; p.accept('ws')
+            rh = p_expr(p) ; p.accept('ws')
+            p.expect(')') ; p.accept('ws')
+            p.expect('=>') ; p.accept('ws')
+            p.expect('0') ; p.accept('ws')
+            return ws + mkassert('str', 'eq', lh, rh)
+        except ParseFailure:
+            p.pop(state)
+
+    # lh => rh?
+    lh = p_exprs(p)
+    if p.accept('=>'):
+        rh = p_exprs(p)
+        return ws + mkassert('int', 'eq', lh, rh)
+    else:
+        return ws + lh
+
+def main(input=None, output=None, pattern=[], limit=LIMIT):
+    with openio(input or '-', 'r') as in_f:
+        # create parser
+        lexemes = LEXEMES.copy()
+        lexemes['assert'] += pattern
+        p = Parser(in_f, lexemes)
+
+        with openio(output or '-', 'w') as f:
+            def writeln(s=''):
+                f.write(s)
+                f.write('\n')
+            f.writeln = writeln
+
+            # write extra verbose asserts
+            write_header(f, limit=limit)
+            if input is not None:
+                f.writeln("#line %d \"%s\"" % (1, input))
+
+            # parse and write out stmt at a time
+            try:
+                while True:
+                    f.write(p_stmt(p))
+                    if p.accept('sep'):
+                        f.write(p.m)
+                    else:
+                        break
+            except ParseFailure as e:
+                print('warning: %s' % e)
+                pass
+
+            for i in range(p.off, len(p.tokens)):
+                f.write(p.tokens[i][1])
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Preprocessor that makes asserts easier to debug.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'input',
+        help="Input C file.")
+    parser.add_argument(
+        '-o', '--output',
+        required=True,
+        help="Output C file.")
+    parser.add_argument(
+        '-p', '--pattern',
+        action='append',
+        help="Regex patterns to search for starting an assert statement. This"
+            " implicitly includes \"assert\" and \"=>\".")
+    parser.add_argument(
+        '-l', '--limit',
+        type=lambda x: int(x, 0),
+        default=LIMIT,
+        help="Maximum number of characters to display in strcmp and memcmp. "
+            "Defaults to %r." % LIMIT)
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/readmdir.py

@@ -24,6 +24,8 @@ TAG_TYPES = {
     'gstate':       (0x700, 0x700),
     'movestate':    (0x7ff, 0x7ff),
     'crc':          (0x700, 0x500),
+    'ccrc':         (0x780, 0x500),
+    'fcrc':         (0x7ff, 0x5ff),
 }
 
 class Tag:
@@ -99,7 +101,16 @@ class Tag:
         return struct.unpack('b', struct.pack('B', self.chunk))[0]
 
     def is_(self, type):
-        return (self.type & TAG_TYPES[type][0]) == TAG_TYPES[type][1]
+        try:
+            if ' ' in type:
+                type1, type3 = type.split()
+                return (self.is_(type1) and
+                    (self.type & ~TAG_TYPES[type1][0]) == int(type3, 0))
+
+            return self.type == int(type, 0)
+
+        except (ValueError, KeyError):
+            return (self.type & TAG_TYPES[type][0]) == TAG_TYPES[type][1]
 
     def mkmask(self):
         return Tag(
@@ -109,14 +120,20 @@ class Tag:
 
     def chid(self, nid):
         ntag = Tag(self.type, nid, self.size)
-        if hasattr(self, 'off'):  ntag.off  = self.off
-        if hasattr(self, 'data'): ntag.data = self.data
-        if hasattr(self, 'crc'):  ntag.crc  = self.crc
+        if hasattr(self, 'off'):    ntag.off    = self.off
+        if hasattr(self, 'data'):   ntag.data   = self.data
+        if hasattr(self, 'ccrc'):   ntag.crc    = self.crc
+        if hasattr(self, 'erased'): ntag.erased = self.erased
         return ntag
 
     def typerepr(self):
-        if self.is_('crc') and getattr(self, 'crc', 0xffffffff) != 0xffffffff:
-            return 'crc (bad)'
+        if (self.is_('ccrc')
+                and getattr(self, 'ccrc', 0xffffffff) != 0xffffffff):
+            crc_status = ' (bad)'
+        elif self.is_('fcrc') and getattr(self, 'erased', False):
+            crc_status = ' (era)'
+        else:
+            crc_status = ''
 
         reverse_types = {v: k for k, v in TAG_TYPES.items()}
         for prefix in range(12):
@@ -124,12 +141,12 @@ class Tag:
             if (mask, self.type & mask) in reverse_types:
                 type = reverse_types[mask, self.type & mask]
                 if prefix > 0:
-                    return '%s %#0*x' % (
-                        type, prefix//4, self.type & ((1 << prefix)-1))
+                    return '%s %#x%s' % (
+                        type, self.type & ((1 << prefix)-1), crc_status)
                 else:
-                    return type
+                    return '%s%s' % (type, crc_status)
         else:
-            return '%02x' % self.type
+            return '%02x%s' % (self.type, crc_status)
 
     def idrepr(self):
         return repr(self.id) if self.id != 0x3ff else '.'
@@ -172,6 +189,8 @@ class MetadataPair:
 
         self.rev, = struct.unpack('<I', block[0:4])
         crc = binascii.crc32(block[0:4])
+        fcrctag = None
+        fcrcdata = None
 
         # parse tags
         corrupt = False
@@ -182,11 +201,11 @@ class MetadataPair:
         while len(block) - off >= 4:
             ntag, = struct.unpack('>I', block[off:off+4])
 
-            tag = Tag(int(tag) ^ ntag)
+            tag = Tag((int(tag) ^ ntag) & 0x7fffffff)
             tag.off = off + 4
             tag.data = block[off+4:off+tag.dsize]
-            if tag.is_('crc'):
-                crc = binascii.crc32(block[off:off+4+4], crc)
+            if tag.is_('ccrc'):
+                crc = binascii.crc32(block[off:off+2*4], crc)
             else:
                 crc = binascii.crc32(block[off:off+tag.dsize], crc)
             tag.crc = crc
@@ -194,16 +213,29 @@ class MetadataPair:
 
             self.all_.append(tag)
 
-            if tag.is_('crc'):
+            if tag.is_('fcrc') and len(tag.data) == 8:
+                fcrctag = tag
+                fcrcdata = struct.unpack('<II', tag.data)
+            elif tag.is_('ccrc'):
                 # is valid commit?
                 if crc != 0xffffffff:
                     corrupt = True
                 if not corrupt:
                     self.log = self.all_.copy()
+                    # end of commit?
+                    if fcrcdata:
+                        fcrcsize, fcrc = fcrcdata
+                        fcrc_ = 0xffffffff ^ binascii.crc32(
+                            block[off:off+fcrcsize])
+                        if fcrc_ == fcrc:
+                            fcrctag.erased = True
+                            corrupt = True
 
                 # reset tag parsing
                 crc = 0
                 tag = Tag(int(tag) ^ ((tag.type & 1) << 31))
+                fcrctag = None
+                fcrcdata = None
 
         # find active ids
         self.ids = list(it.takewhile(
@@ -280,7 +312,7 @@ class MetadataPair:
         f.write('\n')
 
         for tag in tags:
-            f.write("%08x: %08x  %-13s %4s %4s" % (
+            f.write("%08x: %08x  %-14s %3s %4s" % (
                 tag.off, tag,
                 tag.typerepr(), tag.idrepr(), tag.sizerepr()))
             if truncate:

scripts/readtree.py

@@ -106,7 +106,7 @@ def main(args):
             struct.unpack('<HH', superblock[1].data[0:4].ljust(4, b'\xff'))))
     print("%-47s%s" % ("littlefs v%s.%s" % version,
         "data (truncated, if it fits)"
-        if not any([args.no_truncate, args.tags, args.log, args.all]) else ""))
+        if not any([args.no_truncate, args.log, args.all]) else ""))
 
     # print gstate
     print("gstate 0x%s" % ''.join('%02x' % c for c in gstate))

scripts/stack.py

@@ -0,0 +1,735 @@
+#!/usr/bin/env python3
+#
+# Script to find stack usage at the function level. Will detect recursion and
+# report as infinite stack usage.
+#
+# Example:
+# ./scripts/stack.py lfs.ci lfs_util.ci -Slimit
+#
+# Copyright (c) 2022, The littlefs authors.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import csv
+import itertools as it
+import math as m
+import os
+import re
+
+
+
+# integer fields
+class Int(co.namedtuple('Int', 'x')):
+    __slots__ = ()
+    def __new__(cls, x=0):
+        if isinstance(x, Int):
+            return x
+        if isinstance(x, str):
+            try:
+                x = int(x, 0)
+            except ValueError:
+                # also accept +-∞ and +-inf
+                if re.match('^\s*\+?\s*(?:∞|inf)\s*$', x):
+                    x = m.inf
+                elif re.match('^\s*-\s*(?:∞|inf)\s*$', x):
+                    x = -m.inf
+                else:
+                    raise
+        assert isinstance(x, int) or m.isinf(x), x
+        return super().__new__(cls, x)
+
+    def __str__(self):
+        if self.x == m.inf:
+            return '∞'
+        elif self.x == -m.inf:
+            return '-∞'
+        else:
+            return str(self.x)
+
+    def __int__(self):
+        assert not m.isinf(self.x)
+        return self.x
+
+    def __float__(self):
+        return float(self.x)
+
+    none = '%7s' % '-'
+    def table(self):
+        return '%7s' % (self,)
+
+    diff_none = '%7s' % '-'
+    diff_table = table
+
+    def diff_diff(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        diff = new - old
+        if diff == +m.inf:
+            return '%7s' % '+∞'
+        elif diff == -m.inf:
+            return '%7s' % '-∞'
+        else:
+            return '%+7d' % diff
+
+    def ratio(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        if m.isinf(new) and m.isinf(old):
+            return 0.0
+        elif m.isinf(new):
+            return +m.inf
+        elif m.isinf(old):
+            return -m.inf
+        elif not old and not new:
+            return 0.0
+        elif not old:
+            return 1.0
+        else:
+            return (new-old) / old
+
+    def __add__(self, other):
+        return self.__class__(self.x + other.x)
+
+    def __sub__(self, other):
+        return self.__class__(self.x - other.x)
+
+    def __mul__(self, other):
+        return self.__class__(self.x * other.x)
+
+# size results
+class StackResult(co.namedtuple('StackResult', [
+        'file', 'function', 'frame', 'limit', 'children'])):
+    _by = ['file', 'function']
+    _fields = ['frame', 'limit']
+    _sort = ['limit', 'frame']
+    _types = {'frame': Int, 'limit': Int}
+
+    __slots__ = ()
+    def __new__(cls, file='', function='',
+            frame=0, limit=0, children=set()):
+        return super().__new__(cls, file, function,
+            Int(frame), Int(limit),
+            children)
+
+    def __add__(self, other):
+        return StackResult(self.file, self.function,
+            self.frame + other.frame,
+            max(self.limit, other.limit),
+            self.children | other.children)
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def collect(ci_paths, *,
+        sources=None,
+        everything=False,
+        **args):
+    # parse the vcg format
+    k_pattern = re.compile('([a-z]+)\s*:', re.DOTALL)
+    v_pattern = re.compile('(?:"(.*?)"|([a-z]+))', re.DOTALL)
+    def parse_vcg(rest):
+        def parse_vcg(rest):
+            node = []
+            while True:
+                rest = rest.lstrip()
+                m_ = k_pattern.match(rest)
+                if not m_:
+                    return (node, rest)
+                k, rest = m_.group(1), rest[m_.end(0):]
+
+                rest = rest.lstrip()
+                if rest.startswith('{'):
+                    v, rest = parse_vcg(rest[1:])
+                    assert rest[0] == '}', "unexpected %r" % rest[0:1]
+                    rest = rest[1:]
+                    node.append((k, v))
+                else:
+                    m_ = v_pattern.match(rest)
+                    assert m_, "unexpected %r" % rest[0:1]
+                    v, rest = m_.group(1) or m_.group(2), rest[m_.end(0):]
+                    node.append((k, v))
+
+        node, rest = parse_vcg(rest)
+        assert rest == '', "unexpected %r" % rest[0:1]
+        return node
+
+    # collect into functions
+    callgraph = co.defaultdict(lambda: (None, None, 0, set()))
+    f_pattern = re.compile(
+        r'([^\\]*)\\n([^:]*)[^\\]*\\n([0-9]+) bytes \((.*)\)')
+    for path in ci_paths:
+        with open(path) as f:
+            vcg = parse_vcg(f.read())
+        for k, graph in vcg:
+            if k != 'graph':
+                continue
+            for k, info in graph:
+                if k == 'node':
+                    info = dict(info)
+                    m_ = f_pattern.match(info['label'])
+                    if m_:
+                        function, file, size, type = m_.groups()
+                        if (not args.get('quiet')
+                                and 'static' not in type
+                                and 'bounded' not in type):
+                            print("warning: "
+                                "found non-static stack for %s (%s, %s)" % (
+                                function, type, size))
+                        _, _, _, targets = callgraph[info['title']]
+                        callgraph[info['title']] = (
+                            file, function, int(size), targets)
+                elif k == 'edge':
+                    info = dict(info)
+                    _, _, _, targets = callgraph[info['sourcename']]
+                    targets.add(info['targetname'])
+                else:
+                    continue
+
+    callgraph_ = co.defaultdict(lambda: (None, None, 0, set()))
+    for source, (s_file, s_function, frame, targets) in callgraph.items():
+        # discard internal functions
+        if not everything and s_function.startswith('__'):
+            continue
+        # ignore filtered sources
+        if sources is not None:
+            if not any(
+                    os.path.abspath(s_file) == os.path.abspath(s)
+                    for s in sources):
+                continue
+        else:
+            # default to only cwd
+            if not everything and not os.path.commonpath([
+                    os.getcwd(),
+                    os.path.abspath(s_file)]) == os.getcwd():
+                continue
+
+        # smiplify path
+        if os.path.commonpath([
+                os.getcwd(),
+                os.path.abspath(s_file)]) == os.getcwd():
+            s_file = os.path.relpath(s_file)
+        else:
+            s_file = os.path.abspath(s_file)
+
+        callgraph_[source] = (s_file, s_function, frame, targets)
+    callgraph = callgraph_
+
+    if not everything:
+        callgraph_ = co.defaultdict(lambda: (None, None, 0, set()))
+        for source, (s_file, s_function, frame, targets) in callgraph.items():
+            # discard filtered sources
+            if sources is not None and not any(
+                    os.path.abspath(s_file) == os.path.abspath(s)
+                    for s in sources):
+                continue
+            # discard internal functions
+            if s_function.startswith('__'):
+                continue
+            callgraph_[source] = (s_file, s_function, frame, targets)
+        callgraph = callgraph_
+
+    # find maximum stack size recursively, this requires also detecting cycles
+    # (in case of recursion)
+    def find_limit(source, seen=None):
+        seen = seen or set()
+        if source not in callgraph:
+            return 0
+        _, _, frame, targets = callgraph[source]
+
+        limit = 0
+        for target in targets:
+            if target in seen:
+                # found a cycle
+                return m.inf
+            limit_ = find_limit(target, seen | {target})
+            limit = max(limit, limit_)
+
+        return frame + limit
+
+    def find_children(targets):
+        children = set()
+        for target in targets:
+            if target in callgraph:
+                t_file, t_function, _, _ = callgraph[target]
+                children.add((t_file, t_function))
+        return children
+
+    # build results
+    results = []
+    for source, (s_file, s_function, frame, targets) in callgraph.items():
+        limit = find_limit(source)
+        children = find_children(targets)
+        results.append(StackResult(s_file, s_function, frame, limit, children))
+
+    return results
+
+
+def fold(Result, results, *,
+        by=None,
+        defines=None,
+        **_):
+    if by is None:
+        by = Result._by
+
+    for k in it.chain(by or [], (k for k, _ in defines or [])):
+        if k not in Result._by and k not in Result._fields:
+            print("error: could not find field %r?" % k)
+            sys.exit(-1)
+
+    # filter by matching defines
+    if defines is not None:
+        results_ = []
+        for r in results:
+            if all(getattr(r, k) in vs for k, vs in defines):
+                results_.append(r)
+        results = results_
+
+    # organize results into conflicts
+    folding = co.OrderedDict()
+    for r in results:
+        name = tuple(getattr(r, k) for k in by)
+        if name not in folding:
+            folding[name] = []
+        folding[name].append(r)
+
+    # merge conflicts
+    folded = []
+    for name, rs in folding.items():
+        folded.append(sum(rs[1:], start=rs[0]))
+
+    return folded
+
+def table(Result, results, diff_results=None, *,
+        by=None,
+        fields=None,
+        sort=None,
+        summary=False,
+        all=False,
+        percent=False,
+        tree=False,
+        depth=1,
+        **_):
+    all_, all = all, __builtins__.all
+
+    if by is None:
+        by = Result._by
+    if fields is None:
+        fields = Result._fields
+    types = Result._types
+
+    # fold again
+    results = fold(Result, results, by=by)
+    if diff_results is not None:
+        diff_results = fold(Result, diff_results, by=by)
+
+    # organize by name
+    table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in results}
+    diff_table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in diff_results or []}
+    names = list(table.keys() | diff_table.keys())
+
+    # sort again, now with diff info, note that python's sort is stable
+    names.sort()
+    if diff_results is not None:
+        names.sort(key=lambda n: tuple(
+            types[k].ratio(
+                getattr(table.get(n), k, None),
+                getattr(diff_table.get(n), k, None))
+            for k in fields),
+            reverse=True)
+    if sort:
+        for k, reverse in reversed(sort):
+            names.sort(
+                key=lambda n: tuple(
+                    (getattr(table[n], k),)
+                    if getattr(table.get(n), k, None) is not None else ()
+                    for k in ([k] if k else [
+                        k for k in Result._sort if k in fields])),
+                reverse=reverse ^ (not k or k in Result._fields))
+
+
+    # build up our lines
+    lines = []
+
+    # header
+    header = []
+    header.append('%s%s' % (
+        ','.join(by),
+        ' (%d added, %d removed)' % (
+            sum(1 for n in table if n not in diff_table),
+            sum(1 for n in diff_table if n not in table))
+            if diff_results is not None and not percent else '')
+        if not summary else '')
+    if diff_results is None:
+        for k in fields:
+            header.append(k)
+    elif percent:
+        for k in fields:
+            header.append(k)
+    else:
+        for k in fields:
+            header.append('o'+k)
+        for k in fields:
+            header.append('n'+k)
+        for k in fields:
+            header.append('d'+k)
+    header.append('')
+    lines.append(header)
+
+    def table_entry(name, r, diff_r=None, ratios=[]):
+        entry = []
+        entry.append(name)
+        if diff_results is None:
+            for k in fields:
+                entry.append(getattr(r, k).table()
+                    if getattr(r, k, None) is not None
+                    else types[k].none)
+        elif percent:
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+        else:
+            for k in fields:
+                entry.append(getattr(diff_r, k).diff_table()
+                    if getattr(diff_r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(types[k].diff_diff(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None)))
+        if diff_results is None:
+            entry.append('')
+        elif percent:
+            entry.append(' (%s)' % ', '.join(
+                '+∞%' if t == +m.inf
+                else '-∞%' if t == -m.inf
+                else '%+.1f%%' % (100*t)
+                for t in ratios))
+        else:
+            entry.append(' (%s)' % ', '.join(
+                    '+∞%' if t == +m.inf
+                    else '-∞%' if t == -m.inf
+                    else '%+.1f%%' % (100*t)
+                    for t in ratios
+                    if t)
+                if any(ratios) else '')
+        return entry
+
+    # entries
+    if not summary:
+        for name in names:
+            r = table.get(name)
+            if diff_results is None:
+                diff_r = None
+                ratios = None
+            else:
+                diff_r = diff_table.get(name)
+                ratios = [
+                    types[k].ratio(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None))
+                    for k in fields]
+                if not all_ and not any(ratios):
+                    continue
+            lines.append(table_entry(name, r, diff_r, ratios))
+
+    # total
+    r = next(iter(fold(Result, results, by=[])), None)
+    if diff_results is None:
+        diff_r = None
+        ratios = None
+    else:
+        diff_r = next(iter(fold(Result, diff_results, by=[])), None)
+        ratios = [
+            types[k].ratio(
+                getattr(r, k, None),
+                getattr(diff_r, k, None))
+            for k in fields]
+    lines.append(table_entry('TOTAL', r, diff_r, ratios))
+
+    # find the best widths, note that column 0 contains the names and column -1
+    # the ratios, so those are handled a bit differently
+    widths = [
+        ((max(it.chain([w], (len(l[i]) for l in lines)))+1+4-1)//4)*4-1
+        for w, i in zip(
+            it.chain([23], it.repeat(7)),
+            range(len(lines[0])-1))]
+
+    # adjust the name width based on the expected call depth, though
+    # note this doesn't really work with unbounded recursion
+    if not summary and not m.isinf(depth):
+        widths[0] += 4*(depth-1)
+
+    # print the tree recursively
+    if not tree:
+        print('%-*s  %s%s' % (
+            widths[0], lines[0][0],
+            ' '.join('%*s' % (w, x)
+                for w, x in zip(widths[1:], lines[0][1:-1])),
+            lines[0][-1]))
+
+    if not summary:
+        line_table = {n: l for n, l in zip(names, lines[1:-1])}
+
+        def recurse(names_, depth_, prefixes=('', '', '', '')):
+            for i, name in enumerate(names_):
+                if name not in line_table:
+                    continue
+                line = line_table[name]
+                is_last = (i == len(names_)-1)
+
+                print('%s%-*s ' % (
+                    prefixes[0+is_last],
+                    widths[0] - (
+                        len(prefixes[0+is_last])
+                        if not m.isinf(depth) else 0),
+                    line[0]),
+                    end='')
+                if not tree:
+                    print(' %s%s' % (
+                        ' '.join('%*s' % (w, x)
+                            for w, x in zip(widths[1:], line[1:-1])),
+                        line[-1]),
+                        end='')
+                print() 
+
+                # recurse?
+                if name in table and depth_ > 1:
+                    children = {
+                        ','.join(str(getattr(Result(*c), k) or '') for k in by)
+                        for c in table[name].children}
+                    recurse(
+                        # note we're maintaining sort order
+                        [n for n in names if n in children],
+                        depth_-1,
+                        (prefixes[2+is_last] + "|-> ",
+                         prefixes[2+is_last] + "'-> ",
+                         prefixes[2+is_last] + "|   ",
+                         prefixes[2+is_last] + "    "))
+
+        recurse(names, depth)
+
+    if not tree:
+        print('%-*s  %s%s' % (
+            widths[0], lines[-1][0],
+            ' '.join('%*s' % (w, x)
+                for w, x in zip(widths[1:], lines[-1][1:-1])),
+            lines[-1][-1]))
+
+
+def main(ci_paths,
+        by=None,
+        fields=None,
+        defines=None,
+        sort=None,
+        **args):
+    # it doesn't really make sense to not have a depth with tree,
+    # so assume depth=inf if tree by default
+    if args.get('depth') is None:
+        args['depth'] = m.inf if args['tree'] else 1
+    elif args.get('depth') == 0:
+        args['depth'] = m.inf
+
+    # find sizes
+    if not args.get('use', None):
+        results = collect(ci_paths, **args)
+    else:
+        results = []
+        with openio(args['use']) as f:
+            reader = csv.DictReader(f, restval='')
+            for r in reader:
+                if not any('stack_'+k in r and r['stack_'+k].strip()
+                        for k in StackResult._fields):
+                    continue
+                try:
+                    results.append(StackResult(
+                        **{k: r[k] for k in StackResult._by
+                            if k in r and r[k].strip()},
+                        **{k: r['stack_'+k] for k in StackResult._fields
+                            if 'stack_'+k in r and r['stack_'+k].strip()}))
+                except TypeError:
+                    pass
+
+    # fold
+    results = fold(StackResult, results, by=by, defines=defines)
+
+    # sort, note that python's sort is stable
+    results.sort()
+    if sort:
+        for k, reverse in reversed(sort):
+            results.sort(
+                key=lambda r: tuple(
+                    (getattr(r, k),) if getattr(r, k) is not None else ()
+                    for k in ([k] if k else StackResult._sort)),
+                reverse=reverse ^ (not k or k in StackResult._fields))
+
+    # write results to CSV
+    if args.get('output'):
+        with openio(args['output'], 'w') as f:
+            writer = csv.DictWriter(f,
+                (by if by is not None else StackResult._by)
+                + ['stack_'+k for k in (
+                    fields if fields is not None else StackResult._fields)])
+            writer.writeheader()
+            for r in results:
+                writer.writerow(
+                    {k: getattr(r, k) for k in (
+                        by if by is not None else StackResult._by)}
+                    | {'stack_'+k: getattr(r, k) for k in (
+                        fields if fields is not None else StackResult._fields)})
+
+    # find previous results?
+    if args.get('diff'):
+        diff_results = []
+        try:
+            with openio(args['diff']) as f:
+                reader = csv.DictReader(f, restval='')
+                for r in reader:
+                    if not any('stack_'+k in r and r['stack_'+k].strip()
+                            for k in StackResult._fields):
+                        continue
+                    try:
+                        diff_results.append(StackResult(
+                            **{k: r[k] for k in StackResult._by
+                                if k in r and r[k].strip()},
+                            **{k: r['stack_'+k] for k in StackResult._fields
+                                if 'stack_'+k in r and r['stack_'+k].strip()}))
+                    except TypeError:
+                        raise
+        except FileNotFoundError:
+            pass
+
+        # fold
+        diff_results = fold(StackResult, diff_results, by=by, defines=defines)
+
+    # print table
+    if not args.get('quiet'):
+        table(StackResult, results,
+            diff_results if args.get('diff') else None,
+            by=by if by is not None else ['function'],
+            fields=fields,
+            sort=sort,
+            **args)
+
+    # error on recursion
+    if args.get('error_on_recursion') and any(
+            m.isinf(float(r.limit)) for r in results):
+        sys.exit(2)
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Find stack usage at the function level.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'ci_paths',
+        nargs='*',
+        help="Input *.ci files.")
+    parser.add_argument(
+        '-v', '--verbose',
+        action='store_true',
+        help="Output commands that run behind the scenes.")
+    parser.add_argument(
+        '-q', '--quiet',
+        action='store_true',
+        help="Don't show anything, useful with -o.")
+    parser.add_argument(
+        '-o', '--output',
+        help="Specify CSV file to store results.")
+    parser.add_argument(
+        '-u', '--use',
+        help="Don't parse anything, use this CSV file.")
+    parser.add_argument(
+        '-d', '--diff',
+        help="Specify CSV file to diff against.")
+    parser.add_argument(
+        '-a', '--all',
+        action='store_true',
+        help="Show all, not just the ones that changed.")
+    parser.add_argument(
+        '-p', '--percent',
+        action='store_true',
+        help="Only show percentage change, not a full diff.")
+    parser.add_argument(
+        '-b', '--by',
+        action='append',
+        choices=StackResult._by,
+        help="Group by this field.")
+    parser.add_argument(
+        '-f', '--field',
+        dest='fields',
+        action='append',
+        choices=StackResult._fields,
+        help="Show this field.")
+    parser.add_argument(
+        '-D', '--define',
+        dest='defines',
+        action='append',
+        type=lambda x: (lambda k,v: (k, set(v.split(','))))(*x.split('=', 1)),
+        help="Only include results where this field is this value.")
+    class AppendSort(argparse.Action):
+        def __call__(self, parser, namespace, value, option):
+            if namespace.sort is None:
+                namespace.sort = []
+            namespace.sort.append((value, True if option == '-S' else False))
+    parser.add_argument(
+        '-s', '--sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field.")
+    parser.add_argument(
+        '-S', '--reverse-sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field, but backwards.")
+    parser.add_argument(
+        '-Y', '--summary',
+        action='store_true',
+        help="Only show the total.")
+    parser.add_argument(
+        '-F', '--source',
+        dest='sources',
+        action='append',
+        help="Only consider definitions in this file. Defaults to anything "
+            "in the current directory.")
+    parser.add_argument(
+        '--everything',
+        action='store_true',
+        help="Include builtin and libc specific symbols.")
+    parser.add_argument(
+        '--tree',
+        action='store_true',
+        help="Only show the function call tree.")
+    parser.add_argument(
+        '-Z', '--depth',
+        nargs='?',
+        type=lambda x: int(x, 0),
+        const=0,
+        help="Depth of function calls to show. 0 shows all calls but may not "
+            "terminate!")
+    parser.add_argument(
+        '-e', '--error-on-recursion',
+        action='store_true',
+        help="Error if any functions are recursive.")
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/structs.py

@@ -0,0 +1,652 @@
+#!/usr/bin/env python3
+#
+# Script to find struct sizes.
+#
+# Example:
+# ./scripts/structs.py lfs.o lfs_util.o -Ssize
+#
+# Copyright (c) 2022, The littlefs authors.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import csv
+import difflib
+import itertools as it
+import math as m
+import os
+import re
+import shlex
+import subprocess as sp
+
+
+OBJDUMP_PATH = ['objdump']
+
+
+
+# integer fields
+class Int(co.namedtuple('Int', 'x')):
+    __slots__ = ()
+    def __new__(cls, x=0):
+        if isinstance(x, Int):
+            return x
+        if isinstance(x, str):
+            try:
+                x = int(x, 0)
+            except ValueError:
+                # also accept +-∞ and +-inf
+                if re.match('^\s*\+?\s*(?:∞|inf)\s*$', x):
+                    x = m.inf
+                elif re.match('^\s*-\s*(?:∞|inf)\s*$', x):
+                    x = -m.inf
+                else:
+                    raise
+        assert isinstance(x, int) or m.isinf(x), x
+        return super().__new__(cls, x)
+
+    def __str__(self):
+        if self.x == m.inf:
+            return '∞'
+        elif self.x == -m.inf:
+            return '-∞'
+        else:
+            return str(self.x)
+
+    def __int__(self):
+        assert not m.isinf(self.x)
+        return self.x
+
+    def __float__(self):
+        return float(self.x)
+
+    none = '%7s' % '-'
+    def table(self):
+        return '%7s' % (self,)
+
+    diff_none = '%7s' % '-'
+    diff_table = table
+
+    def diff_diff(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        diff = new - old
+        if diff == +m.inf:
+            return '%7s' % '+∞'
+        elif diff == -m.inf:
+            return '%7s' % '-∞'
+        else:
+            return '%+7d' % diff
+
+    def ratio(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        if m.isinf(new) and m.isinf(old):
+            return 0.0
+        elif m.isinf(new):
+            return +m.inf
+        elif m.isinf(old):
+            return -m.inf
+        elif not old and not new:
+            return 0.0
+        elif not old:
+            return 1.0
+        else:
+            return (new-old) / old
+
+    def __add__(self, other):
+        return self.__class__(self.x + other.x)
+
+    def __sub__(self, other):
+        return self.__class__(self.x - other.x)
+
+    def __mul__(self, other):
+        return self.__class__(self.x * other.x)
+
+# struct size results
+class StructResult(co.namedtuple('StructResult', ['file', 'struct', 'size'])):
+    _by = ['file', 'struct']
+    _fields = ['size']
+    _sort = ['size']
+    _types = {'size': Int}
+
+    __slots__ = ()
+    def __new__(cls, file='', struct='', size=0):
+        return super().__new__(cls, file, struct,
+            Int(size))
+
+    def __add__(self, other):
+        return StructResult(self.file, self.struct,
+            self.size + other.size)
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def collect(obj_paths, *,
+        objdump_path=OBJDUMP_PATH,
+        sources=None,
+        everything=False,
+        internal=False,
+        **args):
+    line_pattern = re.compile(
+        '^\s+(?P<no>[0-9]+)'
+            '(?:\s+(?P<dir>[0-9]+))?'
+            '\s+.*'
+            '\s+(?P<path>[^\s]+)$')
+    info_pattern = re.compile(
+        '^(?:.*(?P<tag>DW_TAG_[a-z_]+).*'
+            '|.*DW_AT_name.*:\s*(?P<name>[^:\s]+)\s*'
+            '|.*DW_AT_decl_file.*:\s*(?P<file>[0-9]+)\s*'
+            '|.*DW_AT_byte_size.*:\s*(?P<size>[0-9]+)\s*)$')
+
+    results = []
+    for path in obj_paths:
+        # find files, we want to filter by structs in .h files
+        dirs = {}
+        files = {}
+        # note objdump-path may contain extra args
+        cmd = objdump_path + ['--dwarf=rawline', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            # note that files contain references to dirs, which we
+            # dereference as soon as we see them as each file table follows a
+            # dir table
+            m = line_pattern.match(line)
+            if m:
+                if not m.group('dir'):
+                    # found a directory entry
+                    dirs[int(m.group('no'))] = m.group('path')
+                else:
+                    # found a file entry
+                    dir = int(m.group('dir'))
+                    if dir in dirs:
+                        files[int(m.group('no'))] = os.path.join(
+                            dirs[dir],
+                            m.group('path'))
+                    else:
+                        files[int(m.group('no'))] = m.group('path')
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            sys.exit(-1)
+
+        # collect structs as we parse dwarf info
+        results_ = []
+        is_struct = False
+        s_name = None
+        s_file = None
+        s_size = None
+        # note objdump-path may contain extra args
+        cmd = objdump_path + ['--dwarf=info', path]
+        if args.get('verbose'):
+            print(' '.join(shlex.quote(c) for c in cmd))
+        proc = sp.Popen(cmd,
+            stdout=sp.PIPE,
+            stderr=sp.PIPE if not args.get('verbose') else None,
+            universal_newlines=True,
+            errors='replace',
+            close_fds=False)
+        for line in proc.stdout:
+            # state machine here to find structs
+            m = info_pattern.match(line)
+            if m:
+                if m.group('tag'):
+                    if is_struct:
+                        file = files.get(s_file, '?')
+                        results_.append(StructResult(file, s_name, s_size))
+                    is_struct = (m.group('tag') == 'DW_TAG_structure_type')
+                elif m.group('name'):
+                    s_name = m.group('name')
+                elif m.group('file'):
+                    s_file = int(m.group('file'))
+                elif m.group('size'):
+                    s_size = int(m.group('size'))
+        if is_struct:
+            file = files.get(s_file, '?')
+            results_.append(StructResult(file, s_name, s_size))
+        proc.wait()
+        if proc.returncode != 0:
+            if not args.get('verbose'):
+                for line in proc.stderr:
+                    sys.stdout.write(line)
+            sys.exit(-1)
+
+        for r in results_:
+            # ignore filtered sources
+            if sources is not None:
+                if not any(
+                        os.path.abspath(r.file) == os.path.abspath(s)
+                        for s in sources):
+                    continue
+            else:
+                # default to only cwd
+                if not everything and not os.path.commonpath([
+                        os.getcwd(),
+                        os.path.abspath(r.file)]) == os.getcwd():
+                    continue
+
+                # limit to .h files unless --internal
+                if not internal and not r.file.endswith('.h'):
+                    continue
+
+            # simplify path
+            if os.path.commonpath([
+                    os.getcwd(),
+                    os.path.abspath(r.file)]) == os.getcwd():
+                file = os.path.relpath(r.file)
+            else:
+                file = os.path.abspath(r.file)
+
+            results.append(r._replace(file=file))
+
+    return results
+
+
+def fold(Result, results, *,
+        by=None,
+        defines=None,
+        **_):
+    if by is None:
+        by = Result._by
+
+    for k in it.chain(by or [], (k for k, _ in defines or [])):
+        if k not in Result._by and k not in Result._fields:
+            print("error: could not find field %r?" % k)
+            sys.exit(-1)
+
+    # filter by matching defines
+    if defines is not None:
+        results_ = []
+        for r in results:
+            if all(getattr(r, k) in vs for k, vs in defines):
+                results_.append(r)
+        results = results_
+
+    # organize results into conflicts
+    folding = co.OrderedDict()
+    for r in results:
+        name = tuple(getattr(r, k) for k in by)
+        if name not in folding:
+            folding[name] = []
+        folding[name].append(r)
+
+    # merge conflicts
+    folded = []
+    for name, rs in folding.items():
+        folded.append(sum(rs[1:], start=rs[0]))
+
+    return folded
+
+def table(Result, results, diff_results=None, *,
+        by=None,
+        fields=None,
+        sort=None,
+        summary=False,
+        all=False,
+        percent=False,
+        **_):
+    all_, all = all, __builtins__.all
+
+    if by is None:
+        by = Result._by
+    if fields is None:
+        fields = Result._fields
+    types = Result._types
+
+    # fold again
+    results = fold(Result, results, by=by)
+    if diff_results is not None:
+        diff_results = fold(Result, diff_results, by=by)
+
+    # organize by name
+    table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in results}
+    diff_table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in diff_results or []}
+    names = list(table.keys() | diff_table.keys())
+
+    # sort again, now with diff info, note that python's sort is stable
+    names.sort()
+    if diff_results is not None:
+        names.sort(key=lambda n: tuple(
+            types[k].ratio(
+                getattr(table.get(n), k, None),
+                getattr(diff_table.get(n), k, None))
+            for k in fields),
+            reverse=True)
+    if sort:
+        for k, reverse in reversed(sort):
+            names.sort(
+                key=lambda n: tuple(
+                    (getattr(table[n], k),)
+                    if getattr(table.get(n), k, None) is not None else ()
+                    for k in ([k] if k else [
+                        k for k in Result._sort if k in fields])),
+                reverse=reverse ^ (not k or k in Result._fields))
+
+
+    # build up our lines
+    lines = []
+
+    # header
+    header = []
+    header.append('%s%s' % (
+        ','.join(by),
+        ' (%d added, %d removed)' % (
+            sum(1 for n in table if n not in diff_table),
+            sum(1 for n in diff_table if n not in table))
+            if diff_results is not None and not percent else '')
+        if not summary else '')
+    if diff_results is None:
+        for k in fields:
+            header.append(k)
+    elif percent:
+        for k in fields:
+            header.append(k)
+    else:
+        for k in fields:
+            header.append('o'+k)
+        for k in fields:
+            header.append('n'+k)
+        for k in fields:
+            header.append('d'+k)
+    header.append('')
+    lines.append(header)
+
+    def table_entry(name, r, diff_r=None, ratios=[]):
+        entry = []
+        entry.append(name)
+        if diff_results is None:
+            for k in fields:
+                entry.append(getattr(r, k).table()
+                    if getattr(r, k, None) is not None
+                    else types[k].none)
+        elif percent:
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+        else:
+            for k in fields:
+                entry.append(getattr(diff_r, k).diff_table()
+                    if getattr(diff_r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(types[k].diff_diff(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None)))
+        if diff_results is None:
+            entry.append('')
+        elif percent:
+            entry.append(' (%s)' % ', '.join(
+                '+∞%' if t == +m.inf
+                else '-∞%' if t == -m.inf
+                else '%+.1f%%' % (100*t)
+                for t in ratios))
+        else:
+            entry.append(' (%s)' % ', '.join(
+                    '+∞%' if t == +m.inf
+                    else '-∞%' if t == -m.inf
+                    else '%+.1f%%' % (100*t)
+                    for t in ratios
+                    if t)
+                if any(ratios) else '')
+        return entry
+
+    # entries
+    if not summary:
+        for name in names:
+            r = table.get(name)
+            if diff_results is None:
+                diff_r = None
+                ratios = None
+            else:
+                diff_r = diff_table.get(name)
+                ratios = [
+                    types[k].ratio(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None))
+                    for k in fields]
+                if not all_ and not any(ratios):
+                    continue
+            lines.append(table_entry(name, r, diff_r, ratios))
+
+    # total
+    r = next(iter(fold(Result, results, by=[])), None)
+    if diff_results is None:
+        diff_r = None
+        ratios = None
+    else:
+        diff_r = next(iter(fold(Result, diff_results, by=[])), None)
+        ratios = [
+            types[k].ratio(
+                getattr(r, k, None),
+                getattr(diff_r, k, None))
+            for k in fields]
+    lines.append(table_entry('TOTAL', r, diff_r, ratios))
+
+    # find the best widths, note that column 0 contains the names and column -1
+    # the ratios, so those are handled a bit differently
+    widths = [
+        ((max(it.chain([w], (len(l[i]) for l in lines)))+1+4-1)//4)*4-1
+        for w, i in zip(
+            it.chain([23], it.repeat(7)),
+            range(len(lines[0])-1))]
+
+    # print our table
+    for line in lines:
+        print('%-*s  %s%s' % (
+            widths[0], line[0],
+            ' '.join('%*s' % (w, x)
+                for w, x in zip(widths[1:], line[1:-1])),
+            line[-1]))
+
+
+def main(obj_paths, *,
+        by=None,
+        fields=None,
+        defines=None,
+        sort=None,
+        **args):
+    # find sizes
+    if not args.get('use', None):
+        results = collect(obj_paths, **args)
+    else:
+        results = []
+        with openio(args['use']) as f:
+            reader = csv.DictReader(f, restval='')
+            for r in reader:
+                if not any('struct_'+k in r and r['struct_'+k].strip()
+                        for k in StructResult._fields):
+                    continue
+                try:
+                    results.append(StructResult(
+                        **{k: r[k] for k in StructResult._by
+                            if k in r and r[k].strip()},
+                        **{k: r['struct_'+k]
+                            for k in StructResult._fields
+                            if 'struct_'+k in r
+                                and r['struct_'+k].strip()}))
+                except TypeError:
+                    pass
+
+    # fold
+    results = fold(StructResult, results, by=by, defines=defines)
+
+    # sort, note that python's sort is stable
+    results.sort()
+    if sort:
+        for k, reverse in reversed(sort):
+            results.sort(
+                key=lambda r: tuple(
+                    (getattr(r, k),) if getattr(r, k) is not None else ()
+                    for k in ([k] if k else StructResult._sort)),
+                reverse=reverse ^ (not k or k in StructResult._fields))
+
+    # write results to CSV
+    if args.get('output'):
+        with openio(args['output'], 'w') as f:
+            writer = csv.DictWriter(f,
+                (by if by is not None else StructResult._by)
+                + ['struct_'+k for k in (
+                    fields if fields is not None else StructResult._fields)])
+            writer.writeheader()
+            for r in results:
+                writer.writerow(
+                    {k: getattr(r, k) for k in (
+                        by if by is not None else StructResult._by)}
+                    | {'struct_'+k: getattr(r, k) for k in (
+                        fields if fields is not None else StructResult._fields)})
+
+    # find previous results?
+    if args.get('diff'):
+        diff_results = []
+        try:
+            with openio(args['diff']) as f:
+                reader = csv.DictReader(f, restval='')
+                for r in reader:
+                    if not any('struct_'+k in r and r['struct_'+k].strip()
+                            for k in StructResult._fields):
+                        continue
+                    try:
+                        diff_results.append(StructResult(
+                            **{k: r[k] for k in StructResult._by
+                                if k in r and r[k].strip()},
+                            **{k: r['struct_'+k]
+                                for k in StructResult._fields
+                                if 'struct_'+k in r
+                                    and r['struct_'+k].strip()}))
+                    except TypeError:
+                        pass
+        except FileNotFoundError:
+            pass
+
+        # fold
+        diff_results = fold(StructResult, diff_results, by=by, defines=defines)
+
+    # print table
+    if not args.get('quiet'):
+        table(StructResult, results,
+            diff_results if args.get('diff') else None,
+            by=by if by is not None else ['struct'],
+            fields=fields,
+            sort=sort,
+            **args)
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Find struct sizes.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'obj_paths',
+        nargs='*',
+        help="Input *.o files.")
+    parser.add_argument(
+        '-v', '--verbose',
+        action='store_true',
+        help="Output commands that run behind the scenes.")
+    parser.add_argument(
+        '-q', '--quiet',
+        action='store_true',
+        help="Don't show anything, useful with -o.")
+    parser.add_argument(
+        '-o', '--output',
+        help="Specify CSV file to store results.")
+    parser.add_argument(
+        '-u', '--use',
+        help="Don't parse anything, use this CSV file.")
+    parser.add_argument(
+        '-d', '--diff',
+        help="Specify CSV file to diff against.")
+    parser.add_argument(
+        '-a', '--all',
+        action='store_true',
+        help="Show all, not just the ones that changed.")
+    parser.add_argument(
+        '-p', '--percent',
+        action='store_true',
+        help="Only show percentage change, not a full diff.")
+    parser.add_argument(
+        '-b', '--by',
+        action='append',
+        choices=StructResult._by,
+        help="Group by this field.")
+    parser.add_argument(
+        '-f', '--field',
+        dest='fields',
+        action='append',
+        choices=StructResult._fields,
+        help="Show this field.")
+    parser.add_argument(
+        '-D', '--define',
+        dest='defines',
+        action='append',
+        type=lambda x: (lambda k,v: (k, set(v.split(','))))(*x.split('=', 1)),
+        help="Only include results where this field is this value.")
+    class AppendSort(argparse.Action):
+        def __call__(self, parser, namespace, value, option):
+            if namespace.sort is None:
+                namespace.sort = []
+            namespace.sort.append((value, True if option == '-S' else False))
+    parser.add_argument(
+        '-s', '--sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field.")
+    parser.add_argument(
+        '-S', '--reverse-sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field, but backwards.")
+    parser.add_argument(
+        '-Y', '--summary',
+        action='store_true',
+        help="Only show the total.")
+    parser.add_argument(
+        '-F', '--source',
+        dest='sources',
+        action='append',
+        help="Only consider definitions in this file. Defaults to anything "
+            "in the current directory.")
+    parser.add_argument(
+        '--everything',
+        action='store_true',
+        help="Include builtin and libc specific symbols.")
+    parser.add_argument(
+        '--internal',
+        action='store_true',
+        help="Also show structs in .c files.")
+    parser.add_argument(
+        '--objdump-path',
+        type=lambda x: x.split(),
+        default=OBJDUMP_PATH,
+        help="Path to the objdump executable, may include flags. "
+            "Defaults to %r." % OBJDUMP_PATH)
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/summary.py

@@ -0,0 +1,829 @@
+#!/usr/bin/env python3
+#
+# Script to summarize the outputs of other scripts. Operates on CSV files.
+#
+# Example:
+# ./scripts/code.py lfs.o lfs_util.o -q -o lfs.code.csv
+# ./scripts/data.py lfs.o lfs_util.o -q -o lfs.data.csv
+# ./scripts/summary.py lfs.code.csv lfs.data.csv -q -o lfs.csv
+# ./scripts/summary.py -Y lfs.csv -f code=code_size,data=data_size
+#
+# Copyright (c) 2022, The littlefs authors.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import csv
+import functools as ft
+import itertools as it
+import math as m
+import os
+import re
+
+
+# supported merge operations
+#
+# this is a terrible way to express these
+#
+OPS = {
+    'sum':     lambda xs: sum(xs[1:], start=xs[0]),
+    'prod':    lambda xs: m.prod(xs[1:], start=xs[0]),
+    'min':     min,
+    'max':     max,
+    'mean':    lambda xs: Float(sum(float(x) for x in xs) / len(xs)),
+    'stddev':  lambda xs: (
+        lambda mean: Float(
+            m.sqrt(sum((float(x) - mean)**2 for x in xs) / len(xs)))
+        )(sum(float(x) for x in xs) / len(xs)),
+    'gmean':   lambda xs: Float(m.prod(float(x) for x in xs)**(1/len(xs))),
+    'gstddev': lambda xs: (
+        lambda gmean: Float(
+            m.exp(m.sqrt(sum(m.log(float(x)/gmean)**2 for x in xs) / len(xs)))
+            if gmean else m.inf)
+        )(m.prod(float(x) for x in xs)**(1/len(xs))),
+}
+
+
+# integer fields
+class Int(co.namedtuple('Int', 'x')):
+    __slots__ = ()
+    def __new__(cls, x=0):
+        if isinstance(x, Int):
+            return x
+        if isinstance(x, str):
+            try:
+                x = int(x, 0)
+            except ValueError:
+                # also accept +-∞ and +-inf
+                if re.match('^\s*\+?\s*(?:∞|inf)\s*$', x):
+                    x = m.inf
+                elif re.match('^\s*-\s*(?:∞|inf)\s*$', x):
+                    x = -m.inf
+                else:
+                    raise
+        assert isinstance(x, int) or m.isinf(x), x
+        return super().__new__(cls, x)
+
+    def __str__(self):
+        if self.x == m.inf:
+            return '∞'
+        elif self.x == -m.inf:
+            return '-∞'
+        else:
+            return str(self.x)
+
+    def __int__(self):
+        assert not m.isinf(self.x)
+        return self.x
+
+    def __float__(self):
+        return float(self.x)
+
+    none = '%7s' % '-'
+    def table(self):
+        return '%7s' % (self,)
+
+    diff_none = '%7s' % '-'
+    diff_table = table
+
+    def diff_diff(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        diff = new - old
+        if diff == +m.inf:
+            return '%7s' % '+∞'
+        elif diff == -m.inf:
+            return '%7s' % '-∞'
+        else:
+            return '%+7d' % diff
+
+    def ratio(self, other):
+        new = self.x if self else 0
+        old = other.x if other else 0
+        if m.isinf(new) and m.isinf(old):
+            return 0.0
+        elif m.isinf(new):
+            return +m.inf
+        elif m.isinf(old):
+            return -m.inf
+        elif not old and not new:
+            return 0.0
+        elif not old:
+            return 1.0
+        else:
+            return (new-old) / old
+
+    def __add__(self, other):
+        return self.__class__(self.x + other.x)
+
+    def __sub__(self, other):
+        return self.__class__(self.x - other.x)
+
+    def __mul__(self, other):
+        return self.__class__(self.x * other.x)
+
+# float fields
+class Float(co.namedtuple('Float', 'x')):
+    __slots__ = ()
+    def __new__(cls, x=0.0):
+        if isinstance(x, Float):
+            return x
+        if isinstance(x, str):
+            try:
+                x = float(x)
+            except ValueError:
+                # also accept +-∞ and +-inf
+                if re.match('^\s*\+?\s*(?:∞|inf)\s*$', x):
+                    x = m.inf
+                elif re.match('^\s*-\s*(?:∞|inf)\s*$', x):
+                    x = -m.inf
+                else:
+                    raise
+        assert isinstance(x, float), x
+        return super().__new__(cls, x)
+
+    def __str__(self):
+        if self.x == m.inf:
+            return '∞'
+        elif self.x == -m.inf:
+            return '-∞'
+        else:
+            return '%.1f' % self.x
+
+    def __float__(self):
+        return float(self.x)
+
+    none = Int.none
+    table = Int.table
+    diff_none = Int.diff_none
+    diff_table = Int.diff_table
+    diff_diff = Int.diff_diff
+    ratio = Int.ratio
+    __add__ = Int.__add__
+    __sub__ = Int.__sub__
+    __mul__ = Int.__mul__
+
+# fractional fields, a/b
+class Frac(co.namedtuple('Frac', 'a,b')):
+    __slots__ = ()
+    def __new__(cls, a=0, b=None):
+        if isinstance(a, Frac) and b is None:
+            return a
+        if isinstance(a, str) and b is None:
+            a, b = a.split('/', 1)
+        if b is None:
+            b = a
+        return super().__new__(cls, Int(a), Int(b))
+
+    def __str__(self):
+        return '%s/%s' % (self.a, self.b)
+
+    def __float__(self):
+        return float(self.a)
+
+    none = '%11s %7s' % ('-', '-')
+    def table(self):
+        t = self.a.x/self.b.x if self.b.x else 1.0
+        return '%11s %7s' % (
+            self,
+            '∞%' if t == +m.inf
+            else '-∞%' if t == -m.inf
+            else '%.1f%%' % (100*t))
+
+    diff_none = '%11s' % '-'
+    def diff_table(self):
+        return '%11s' % (self,)
+
+    def diff_diff(self, other):
+        new_a, new_b = self if self else (Int(0), Int(0))
+        old_a, old_b = other if other else (Int(0), Int(0))
+        return '%11s' % ('%s/%s' % (
+            new_a.diff_diff(old_a).strip(),
+            new_b.diff_diff(old_b).strip()))
+
+    def ratio(self, other):
+        new_a, new_b = self if self else (Int(0), Int(0))
+        old_a, old_b = other if other else (Int(0), Int(0))
+        new = new_a.x/new_b.x if new_b.x else 1.0
+        old = old_a.x/old_b.x if old_b.x else 1.0
+        return new - old
+
+    def __add__(self, other):
+        return self.__class__(self.a + other.a, self.b + other.b)
+
+    def __sub__(self, other):
+        return self.__class__(self.a - other.a, self.b - other.b)
+
+    def __mul__(self, other):
+        return self.__class__(self.a * other.a, self.b + other.b)
+
+    def __lt__(self, other):
+        self_t = self.a.x/self.b.x if self.b.x else 1.0
+        other_t = other.a.x/other.b.x if other.b.x else 1.0
+        return (self_t, self.a.x) < (other_t, other.a.x)
+
+    def __gt__(self, other):
+        return self.__class__.__lt__(other, self)
+
+    def __le__(self, other):
+        return not self.__gt__(other)
+
+    def __ge__(self, other):
+        return not self.__lt__(other)
+
+# available types
+TYPES = co.OrderedDict([
+    ('int',   Int),
+    ('float', Float),
+    ('frac',  Frac)
+])
+
+
+def infer(results, *,
+        by=None,
+        fields=None,
+        types={},
+        ops={},
+        renames=[],
+        **_):
+    # if fields not specified, try to guess from data
+    if fields is None:
+        fields = co.OrderedDict()
+        for r in results:
+            for k, v in r.items():
+                if (by is None or k not in by) and v.strip():
+                    types_ = []
+                    for t in fields.get(k, TYPES.values()):
+                        try:
+                            t(v)
+                            types_.append(t)
+                        except ValueError:
+                            pass
+                    fields[k] = types_
+        fields = list(k for k, v in fields.items() if v)
+
+    # deduplicate fields
+    fields = list(co.OrderedDict.fromkeys(fields).keys())
+
+    # if by not specified, guess it's anything not in fields and not a
+    # source of a rename
+    if by is None:
+        by = co.OrderedDict()
+        for r in results:
+            # also ignore None keys, these are introduced by csv.DictReader
+            # when header + row mismatch
+            by.update((k, True) for k in r.keys()
+                if k is not None
+                    and k not in fields
+                    and not any(k == old_k for _, old_k in renames))
+        by = list(by.keys())
+
+    # deduplicate fields
+    by = list(co.OrderedDict.fromkeys(by).keys())
+
+    # find best type for all fields
+    types_ = {}
+    for k in fields:
+        if k in types:
+            types_[k] = types[k]
+        else:
+            for t in TYPES.values():
+                for r in results:
+                    if k in r and r[k].strip():
+                        try:
+                            t(r[k])
+                        except ValueError:
+                            break
+                else:
+                    types_[k] = t
+                    break
+            else:
+                print("error: no type matches field %r?" % k)
+                sys.exit(-1)
+    types = types_
+
+    # does folding change the type?
+    types_ = {}
+    for k, t in types.items():
+        types_[k] = ops.get(k, OPS['sum'])([t()]).__class__
+
+
+    # create result class
+    def __new__(cls, **r):
+        return cls.__mro__[1].__new__(cls,
+            **{k: r.get(k, '') for k in by},
+            **{k: r[k] if k in r and isinstance(r[k], list)
+                else [types[k](r[k])] if k in r
+                else []
+                for k in fields})
+
+    def __add__(self, other):
+        return self.__class__(
+            **{k: getattr(self, k) for k in by},
+            **{k: object.__getattribute__(self, k)
+                + object.__getattribute__(other, k)
+                for k in fields})
+
+    def __getattribute__(self, k):
+        if k in fields:
+            if object.__getattribute__(self, k):
+                return ops.get(k, OPS['sum'])(object.__getattribute__(self, k))
+            else:
+                return None
+        return object.__getattribute__(self, k)
+
+    return type('Result', (co.namedtuple('Result', by + fields),), {
+        '__slots__': (),
+        '__new__': __new__,
+        '__add__': __add__,
+        '__getattribute__': __getattribute__,
+        '_by': by,
+        '_fields': fields,
+        '_sort': fields,
+        '_types': types_,
+    })
+
+
+def fold(Result, results, *,
+        by=None,
+        defines=None,
+        **_):
+    if by is None:
+        by = Result._by
+
+    for k in it.chain(by or [], (k for k, _ in defines or [])):
+        if k not in Result._by and k not in Result._fields:
+            print("error: could not find field %r?" % k)
+            sys.exit(-1)
+
+    # filter by matching defines
+    if defines is not None:
+        results_ = []
+        for r in results:
+            if all(getattr(r, k) in vs for k, vs in defines):
+                results_.append(r)
+        results = results_
+
+    # organize results into conflicts
+    folding = co.OrderedDict()
+    for r in results:
+        name = tuple(getattr(r, k) for k in by)
+        if name not in folding:
+            folding[name] = []
+        folding[name].append(r)
+
+    # merge conflicts
+    folded = []
+    for name, rs in folding.items():
+        folded.append(sum(rs[1:], start=rs[0]))
+
+    return folded
+
+def table(Result, results, diff_results=None, *,
+        by=None,
+        fields=None,
+        sort=None,
+        summary=False,
+        all=False,
+        percent=False,
+        **_):
+    all_, all = all, __builtins__.all
+
+    if by is None:
+        by = Result._by
+    if fields is None:
+        fields = Result._fields
+    types = Result._types
+
+    # fold again
+    results = fold(Result, results, by=by)
+    if diff_results is not None:
+        diff_results = fold(Result, diff_results, by=by)
+
+    # organize by name
+    table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in results}
+    diff_table = {
+        ','.join(str(getattr(r, k) or '') for k in by): r
+        for r in diff_results or []}
+    names = list(table.keys() | diff_table.keys())
+
+    # sort again, now with diff info, note that python's sort is stable
+    names.sort()
+    if diff_results is not None:
+        names.sort(key=lambda n: tuple(
+            types[k].ratio(
+                getattr(table.get(n), k, None),
+                getattr(diff_table.get(n), k, None))
+            for k in fields),
+            reverse=True)
+    if sort:
+        for k, reverse in reversed(sort):
+            names.sort(
+                key=lambda n: tuple(
+                    (getattr(table[n], k),)
+                    if getattr(table.get(n), k, None) is not None else ()
+                    for k in ([k] if k else [
+                        k for k in Result._sort if k in fields])),
+                reverse=reverse ^ (not k or k in Result._fields))
+
+
+    # build up our lines
+    lines = []
+
+    # header
+    header = []
+    header.append('%s%s' % (
+        ','.join(by),
+        ' (%d added, %d removed)' % (
+            sum(1 for n in table if n not in diff_table),
+            sum(1 for n in diff_table if n not in table))
+            if diff_results is not None and not percent else '')
+        if not summary else '')
+    if diff_results is None:
+        for k in fields:
+            header.append(k)
+    elif percent:
+        for k in fields:
+            header.append(k)
+    else:
+        for k in fields:
+            header.append('o'+k)
+        for k in fields:
+            header.append('n'+k)
+        for k in fields:
+            header.append('d'+k)
+    header.append('')
+    lines.append(header)
+
+    def table_entry(name, r, diff_r=None, ratios=[]):
+        entry = []
+        entry.append(name)
+        if diff_results is None:
+            for k in fields:
+                entry.append(getattr(r, k).table()
+                    if getattr(r, k, None) is not None
+                    else types[k].none)
+        elif percent:
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+        else:
+            for k in fields:
+                entry.append(getattr(diff_r, k).diff_table()
+                    if getattr(diff_r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(getattr(r, k).diff_table()
+                    if getattr(r, k, None) is not None
+                    else types[k].diff_none)
+            for k in fields:
+                entry.append(types[k].diff_diff(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None)))
+        if diff_results is None:
+            entry.append('')
+        elif percent:
+            entry.append(' (%s)' % ', '.join(
+                '+∞%' if t == +m.inf
+                else '-∞%' if t == -m.inf
+                else '%+.1f%%' % (100*t)
+                for t in ratios))
+        else:
+            entry.append(' (%s)' % ', '.join(
+                    '+∞%' if t == +m.inf
+                    else '-∞%' if t == -m.inf
+                    else '%+.1f%%' % (100*t)
+                    for t in ratios
+                    if t)
+                if any(ratios) else '')
+        return entry
+
+    # entries
+    if not summary:
+        for name in names:
+            r = table.get(name)
+            if diff_results is None:
+                diff_r = None
+                ratios = None
+            else:
+                diff_r = diff_table.get(name)
+                ratios = [
+                    types[k].ratio(
+                        getattr(r, k, None),
+                        getattr(diff_r, k, None))
+                    for k in fields]
+                if not all_ and not any(ratios):
+                    continue
+            lines.append(table_entry(name, r, diff_r, ratios))
+
+    # total
+    r = next(iter(fold(Result, results, by=[])), None)
+    if diff_results is None:
+        diff_r = None
+        ratios = None
+    else:
+        diff_r = next(iter(fold(Result, diff_results, by=[])), None)
+        ratios = [
+            types[k].ratio(
+                getattr(r, k, None),
+                getattr(diff_r, k, None))
+            for k in fields]
+    lines.append(table_entry('TOTAL', r, diff_r, ratios))
+
+    # find the best widths, note that column 0 contains the names and column -1
+    # the ratios, so those are handled a bit differently
+    widths = [
+        ((max(it.chain([w], (len(l[i]) for l in lines)))+1+4-1)//4)*4-1
+        for w, i in zip(
+            it.chain([23], it.repeat(7)),
+            range(len(lines[0])-1))]
+
+    # print our table
+    for line in lines:
+        print('%-*s  %s%s' % (
+            widths[0], line[0],
+            ' '.join('%*s' % (w, x)
+                for w, x in zip(widths[1:], line[1:-1])),
+            line[-1]))
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def main(csv_paths, *,
+        by=None,
+        fields=None,
+        defines=None,
+        sort=None,
+        **args):
+    # separate out renames
+    renames = list(it.chain.from_iterable(
+        ((k, v) for v in vs)
+        for k, vs in it.chain(by or [], fields or [])))
+    if by is not None:
+        by = [k for k, _ in by]
+    if fields is not None:
+        fields = [k for k, _ in fields]
+
+    # figure out types
+    types = {}
+    for t in TYPES.keys():
+        for k in args.get(t, []):
+            if k in types:
+                print("error: conflicting type for field %r?" % k)
+                sys.exit(-1)
+            types[k] = TYPES[t]
+    # rename types?
+    if renames:
+        types_ = {}
+        for new_k, old_k in renames:
+            if old_k in types:
+                types_[new_k] = types[old_k]
+        types.update(types_)
+
+    # figure out merge operations
+    ops = {}
+    for o in OPS.keys():
+        for k in args.get(o, []):
+            if k in ops:
+                print("error: conflicting op for field %r?" % k)
+                sys.exit(-1)
+            ops[k] = OPS[o]
+    # rename ops?
+    if renames:
+        ops_ = {}
+        for new_k, old_k in renames:
+            if old_k in ops:
+                ops_[new_k] = ops[old_k]
+        ops.update(ops_)
+
+    # find CSV files
+    results = []
+    for path in csv_paths:
+        try:
+            with openio(path) as f:
+                reader = csv.DictReader(f, restval='')
+                for r in reader:
+                    # rename fields?
+                    if renames:
+                        # make a copy so renames can overlap
+                        r_ = {}
+                        for new_k, old_k in renames:
+                            if old_k in r:
+                                r_[new_k] = r[old_k]
+                        r.update(r_)
+
+                    results.append(r)
+        except FileNotFoundError:
+            pass
+
+    # homogenize
+    Result = infer(results,
+        by=by,
+        fields=fields,
+        types=types,
+        ops=ops,
+        renames=renames)
+    results_ = []
+    for r in results:
+        if not any(k in r and r[k].strip()
+                for k in Result._fields):
+            continue
+        try:
+            results_.append(Result(**{
+                k: r[k] for k in Result._by + Result._fields
+                if k in r and r[k].strip()}))
+        except TypeError:
+            pass
+    results = results_
+
+    # fold
+    results = fold(Result, results, by=by, defines=defines)
+
+    # sort, note that python's sort is stable
+    results.sort()
+    if sort:
+        for k, reverse in reversed(sort):
+            results.sort(
+                key=lambda r: tuple(
+                    (getattr(r, k),) if getattr(r, k) is not None else ()
+                    for k in ([k] if k else Result._sort)),
+                reverse=reverse ^ (not k or k in Result._fields))
+
+    # write results to CSV
+    if args.get('output'):
+        with openio(args['output'], 'w') as f:
+            writer = csv.DictWriter(f, Result._by + Result._fields)
+            writer.writeheader()
+            for r in results:
+                # note we need to go through getattr to resolve lazy fields
+                writer.writerow({
+                    k: getattr(r, k) for k in Result._by + Result._fields})
+
+    # find previous results?
+    if args.get('diff'):
+        diff_results = []
+        try:
+            with openio(args['diff']) as f:
+                reader = csv.DictReader(f, restval='')
+                for r in reader:
+                    # rename fields?
+                    if renames:
+                        # make a copy so renames can overlap
+                        r_ = {}
+                        for new_k, old_k in renames:
+                            if old_k in r:
+                                r_[new_k] = r[old_k]
+                        r.update(r_)
+
+                    if not any(k in r and r[k].strip()
+                            for k in Result._fields):
+                        continue
+                    try:
+                        diff_results.append(Result(**{
+                            k: r[k] for k in Result._by + Result._fields
+                            if k in r and r[k].strip()}))
+                    except TypeError:
+                        pass
+        except FileNotFoundError:
+            pass
+
+        # fold
+        diff_results = fold(Result, diff_results, by=by, defines=defines)
+
+    # print table
+    if not args.get('quiet'):
+        table(Result, results,
+            diff_results if args.get('diff') else None,
+            by=by,
+            fields=fields,
+            sort=sort,
+            **args)
+
+
+if __name__ == "__main__":
+    import argparse
+    import sys
+    parser = argparse.ArgumentParser(
+        description="Summarize measurements in CSV files.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'csv_paths',
+        nargs='*',
+        help="Input *.csv files.")
+    parser.add_argument(
+        '-q', '--quiet',
+        action='store_true',
+        help="Don't show anything, useful with -o.")
+    parser.add_argument(
+        '-o', '--output',
+        help="Specify CSV file to store results.")
+    parser.add_argument(
+        '-d', '--diff',
+        help="Specify CSV file to diff against.")
+    parser.add_argument(
+        '-a', '--all',
+        action='store_true',
+        help="Show all, not just the ones that changed.")
+    parser.add_argument(
+        '-p', '--percent',
+        action='store_true',
+        help="Only show percentage change, not a full diff.")
+    parser.add_argument(
+        '-b', '--by',
+        action='append',
+        type=lambda x: (
+            lambda k,v=None: (k, v.split(',') if v is not None else ())
+            )(*x.split('=', 1)),
+        help="Group by this field. Can rename fields with new_name=old_name.")
+    parser.add_argument(
+        '-f', '--field',
+        dest='fields',
+        action='append',
+        type=lambda x: (
+            lambda k,v=None: (k, v.split(',') if v is not None else ())
+            )(*x.split('=', 1)),
+        help="Show this field. Can rename fields with new_name=old_name.")
+    parser.add_argument(
+        '-D', '--define',
+        dest='defines',
+        action='append',
+        type=lambda x: (lambda k,v: (k, set(v.split(','))))(*x.split('=', 1)),
+        help="Only include results where this field is this value. May include "
+            "comma-separated options.")
+    class AppendSort(argparse.Action):
+        def __call__(self, parser, namespace, value, option):
+            if namespace.sort is None:
+                namespace.sort = []
+            namespace.sort.append((value, True if option == '-S' else False))
+    parser.add_argument(
+        '-s', '--sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field.")
+    parser.add_argument(
+        '-S', '--reverse-sort',
+        nargs='?',
+        action=AppendSort,
+        help="Sort by this field, but backwards.")
+    parser.add_argument(
+        '-Y', '--summary',
+        action='store_true',
+        help="Only show the total.")
+    parser.add_argument(
+        '--int',
+        action='append',
+        help="Treat these fields as ints.")
+    parser.add_argument(
+        '--float',
+        action='append',
+        help="Treat these fields as floats.")
+    parser.add_argument(
+        '--frac',
+        action='append',
+        help="Treat these fields as fractions.")
+    parser.add_argument(
+        '--sum',
+        action='append',
+        help="Add these fields (the default).")
+    parser.add_argument(
+        '--prod',
+        action='append',
+        help="Multiply these fields.")
+    parser.add_argument(
+        '--min',
+        action='append',
+        help="Take the minimum of these fields.")
+    parser.add_argument(
+        '--max',
+        action='append',
+        help="Take the maximum of these fields.")
+    parser.add_argument(
+        '--mean',
+        action='append',
+        help="Average these fields.")
+    parser.add_argument(
+        '--stddev',
+        action='append',
+        help="Find the standard deviation of these fields.")
+    parser.add_argument(
+        '--gmean',
+        action='append',
+        help="Find the geometric mean of these fields.")
+    parser.add_argument(
+        '--gstddev',
+        action='append',
+        help="Find the geometric standard deviation of these fields.")
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/tailpipe.py

@@ -0,0 +1,177 @@
+#!/usr/bin/env python3
+#
+# Efficiently displays the last n lines of a file/pipe.
+#
+# Example:
+# ./scripts/tailpipe.py trace -n5
+#
+# Copyright (c) 2022, The littlefs authors.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import io
+import os
+import select
+import shutil
+import sys
+import threading as th
+import time
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+class LinesIO:
+    def __init__(self, maxlen=None):
+        self.maxlen = maxlen
+        self.lines = co.deque(maxlen=maxlen)
+        self.tail = io.StringIO()
+
+        # trigger automatic sizing
+        if maxlen == 0:
+            self.resize(0)
+
+    def write(self, s):
+        # note using split here ensures the trailing string has no newline
+        lines = s.split('\n')
+
+        if len(lines) > 1 and self.tail.getvalue():
+            self.tail.write(lines[0])
+            lines[0] = self.tail.getvalue()
+            self.tail = io.StringIO()
+
+        self.lines.extend(lines[:-1])
+
+        if lines[-1]:
+            self.tail.write(lines[-1])
+
+    def resize(self, maxlen):
+        self.maxlen = maxlen
+        if maxlen == 0:
+            maxlen = shutil.get_terminal_size((80, 5))[1]
+        if maxlen != self.lines.maxlen:
+            self.lines = co.deque(self.lines, maxlen=maxlen)
+
+    canvas_lines = 1
+    def draw(self):
+        # did terminal size change?
+        if self.maxlen == 0:
+            self.resize(0)
+
+        # first thing first, give ourself a canvas
+        while LinesIO.canvas_lines < len(self.lines):
+            sys.stdout.write('\n')
+            LinesIO.canvas_lines += 1
+
+        # clear the bottom of the canvas if we shrink
+        shrink = LinesIO.canvas_lines - len(self.lines)
+        if shrink > 0:
+            for i in range(shrink):
+                sys.stdout.write('\r')
+                if shrink-1-i > 0:
+                    sys.stdout.write('\x1b[%dA' % (shrink-1-i))
+                sys.stdout.write('\x1b[K')
+                if shrink-1-i > 0:
+                    sys.stdout.write('\x1b[%dB' % (shrink-1-i))
+            sys.stdout.write('\x1b[%dA' % shrink)
+            LinesIO.canvas_lines = len(self.lines)
+
+        for i, line in enumerate(self.lines):
+            # move cursor, clear line, disable/reenable line wrapping
+            sys.stdout.write('\r')
+            if len(self.lines)-1-i > 0:
+                sys.stdout.write('\x1b[%dA' % (len(self.lines)-1-i))
+            sys.stdout.write('\x1b[K')
+            sys.stdout.write('\x1b[?7l')
+            sys.stdout.write(line)
+            sys.stdout.write('\x1b[?7h')
+            if len(self.lines)-1-i > 0:
+                sys.stdout.write('\x1b[%dB' % (len(self.lines)-1-i))
+        sys.stdout.flush()
+
+
+def main(path='-', *, lines=5, cat=False, sleep=None, keep_open=False):
+    if cat:
+        ring = sys.stdout
+    else:
+        ring = LinesIO(lines)
+
+    # if sleep print in background thread to avoid getting stuck in a read call
+    event = th.Event()
+    lock = th.Lock()
+    if not cat:
+        done = False
+        def background():
+            while not done:
+                event.wait()
+                event.clear()
+                with lock:
+                    ring.draw()
+                time.sleep(sleep or 0.01)
+        th.Thread(target=background, daemon=True).start()
+
+    try:
+        while True:
+            with openio(path) as f:
+                for line in f:
+                    with lock:
+                        ring.write(line)
+                        event.set()
+
+            if not keep_open:
+                break
+            # don't just flood open calls
+            time.sleep(sleep or 0.1)
+    except FileNotFoundError as e:
+        print("error: file not found %r" % path)
+        sys.exit(-1)
+    except KeyboardInterrupt:
+        pass
+
+    if not cat:
+        done = True
+        lock.acquire() # avoids https://bugs.python.org/issue42717
+        sys.stdout.write('\n')
+
+
+if __name__ == "__main__":
+    import sys
+    import argparse
+    parser = argparse.ArgumentParser(
+        description="Efficiently displays the last n lines of a file/pipe.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'path',
+        nargs='?',
+        help="Path to read from.")
+    parser.add_argument(
+        '-n', '--lines',
+        nargs='?',
+        type=lambda x: int(x, 0),
+        const=0,
+        help="Show this many lines of history. 0 uses the terminal height. "
+            "Defaults to 5.")
+    parser.add_argument(
+        '-z', '--cat',
+        action='store_true',
+        help="Pipe directly to stdout.")
+    parser.add_argument(
+        '-s', '--sleep',
+        type=float,
+        help="Seconds to sleep between reads. Defaults to 0.01.")
+    parser.add_argument(
+        '-k', '--keep-open',
+        action='store_true',
+        help="Reopen the pipe on EOF, useful when multiple "
+            "processes are writing.")
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/teepipe.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+#
+# tee, but for pipes
+#
+# Example:
+# ./scripts/tee.py in_pipe out_pipe1 out_pipe2
+#
+# Copyright (c) 2022, The littlefs authors.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import os
+import io
+import time
+import sys
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def main(in_path, out_paths, *, keep_open=False):
+    out_pipes = [openio(p, 'wb', 0) for p in out_paths]
+    try:
+        with openio(in_path, 'rb', 0) as f:
+            while True:
+                buf = f.read(io.DEFAULT_BUFFER_SIZE)
+                if not buf:
+                    if not keep_open:
+                        break
+                    # don't just flood reads
+                    time.sleep(0.1)
+                    continue
+
+                for p in out_pipes:
+                    try:
+                        p.write(buf)
+                    except BrokenPipeError:
+                        pass
+    except FileNotFoundError as e:
+        print("error: file not found %r" % in_path)
+        sys.exit(-1)
+    except KeyboardInterrupt:
+        pass
+
+
+if __name__ == "__main__":
+    import sys
+    import argparse
+    parser = argparse.ArgumentParser(
+        description="tee, but for pipes.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'in_path',
+        help="Path to read from.")
+    parser.add_argument(
+        'out_paths',
+        nargs='+',
+        help="Path to write to.")
+    parser.add_argument(
+        '-k', '--keep-open',
+        action='store_true',
+        help="Reopen the pipe on EOF, useful when multiple "
+            "processes are writing.")
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))

scripts/watch.py

@@ -0,0 +1,265 @@
+#!/usr/bin/env python3
+#
+# Traditional watch command, but with higher resolution updates and a bit
+# different options/output format
+#
+# Example:
+# ./scripts/watch.py -s0.1 date
+#
+# Copyright (c) 2022, The littlefs authors.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import collections as co
+import errno
+import fcntl
+import io
+import os
+import pty
+import re
+import shutil
+import struct
+import subprocess as sp
+import sys
+import termios
+import time
+
+try:
+    import inotify_simple
+except ModuleNotFoundError:
+    inotify_simple = None
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def inotifywait(paths):
+    # wait for interesting events
+    inotify = inotify_simple.INotify()
+    flags = (inotify_simple.flags.ATTRIB
+        | inotify_simple.flags.CREATE
+        | inotify_simple.flags.DELETE
+        | inotify_simple.flags.DELETE_SELF
+        | inotify_simple.flags.MODIFY
+        | inotify_simple.flags.MOVED_FROM
+        | inotify_simple.flags.MOVED_TO
+        | inotify_simple.flags.MOVE_SELF)
+
+    # recurse into directories
+    for path in paths:
+        if os.path.isdir(path):
+            for dir, _, files in os.walk(path):
+                inotify.add_watch(dir, flags)
+                for f in files:
+                    inotify.add_watch(os.path.join(dir, f), flags)
+        else:
+            inotify.add_watch(path, flags)
+
+    # wait for event
+    inotify.read()
+
+class LinesIO:
+    def __init__(self, maxlen=None):
+        self.maxlen = maxlen
+        self.lines = co.deque(maxlen=maxlen)
+        self.tail = io.StringIO()
+
+        # trigger automatic sizing
+        if maxlen == 0:
+            self.resize(0)
+
+    def write(self, s):
+        # note using split here ensures the trailing string has no newline
+        lines = s.split('\n')
+
+        if len(lines) > 1 and self.tail.getvalue():
+            self.tail.write(lines[0])
+            lines[0] = self.tail.getvalue()
+            self.tail = io.StringIO()
+
+        self.lines.extend(lines[:-1])
+
+        if lines[-1]:
+            self.tail.write(lines[-1])
+
+    def resize(self, maxlen):
+        self.maxlen = maxlen
+        if maxlen == 0:
+            maxlen = shutil.get_terminal_size((80, 5))[1]
+        if maxlen != self.lines.maxlen:
+            self.lines = co.deque(self.lines, maxlen=maxlen)
+
+    canvas_lines = 1
+    def draw(self):
+        # did terminal size change?
+        if self.maxlen == 0:
+            self.resize(0)
+
+        # first thing first, give ourself a canvas
+        while LinesIO.canvas_lines < len(self.lines):
+            sys.stdout.write('\n')
+            LinesIO.canvas_lines += 1
+
+        # clear the bottom of the canvas if we shrink
+        shrink = LinesIO.canvas_lines - len(self.lines)
+        if shrink > 0:
+            for i in range(shrink):
+                sys.stdout.write('\r')
+                if shrink-1-i > 0:
+                    sys.stdout.write('\x1b[%dA' % (shrink-1-i))
+                sys.stdout.write('\x1b[K')
+                if shrink-1-i > 0:
+                    sys.stdout.write('\x1b[%dB' % (shrink-1-i))
+            sys.stdout.write('\x1b[%dA' % shrink)
+            LinesIO.canvas_lines = len(self.lines)
+
+        for i, line in enumerate(self.lines):
+            # move cursor, clear line, disable/reenable line wrapping
+            sys.stdout.write('\r')
+            if len(self.lines)-1-i > 0:
+                sys.stdout.write('\x1b[%dA' % (len(self.lines)-1-i))
+            sys.stdout.write('\x1b[K')
+            sys.stdout.write('\x1b[?7l')
+            sys.stdout.write(line)
+            sys.stdout.write('\x1b[?7h')
+            if len(self.lines)-1-i > 0:
+                sys.stdout.write('\x1b[%dB' % (len(self.lines)-1-i))
+        sys.stdout.flush()
+
+
+def main(command, *,
+        lines=0,
+        cat=False,
+        sleep=None,
+        keep_open=False,
+        keep_open_paths=None,
+        exit_on_error=False):
+    returncode = 0
+    try:
+        while True:
+            # reset ring each run
+            if cat:
+                ring = sys.stdout
+            else:
+                ring = LinesIO(lines)
+
+            try:
+                # run the command under a pseudoterminal 
+                mpty, spty = pty.openpty()
+
+                # forward terminal size
+                w, h = shutil.get_terminal_size((80, 5))
+                if lines:
+                    h = lines
+                fcntl.ioctl(spty, termios.TIOCSWINSZ,
+                    struct.pack('HHHH', h, w, 0, 0))
+
+                proc = sp.Popen(command,
+                    stdout=spty,
+                    stderr=spty,
+                    close_fds=False)
+                os.close(spty)
+                mpty = os.fdopen(mpty, 'r', 1)
+
+                while True:
+                    try:
+                        line = mpty.readline()
+                    except OSError as e:
+                        if e.errno != errno.EIO:
+                            raise
+                        break
+                    if not line:
+                        break
+
+                    ring.write(line)
+                    if not cat:
+                        ring.draw()
+
+                mpty.close()
+                proc.wait()
+                if exit_on_error and proc.returncode != 0:
+                    returncode = proc.returncode
+                    break
+            except OSError as e:
+                if e.errno != errno.ETXTBSY:
+                    raise
+                pass
+
+            # try to inotifywait
+            if keep_open and inotify_simple is not None:
+                if keep_open_paths:
+                    paths = set(keep_paths)
+                else:
+                    # guess inotify paths from command
+                    paths = set()
+                    for p in command:
+                        for p in {
+                                p,
+                                re.sub('^-.', '', p),
+                                re.sub('^--[^=]+=', '', p)}:
+                            if p and os.path.exists(p):
+                                paths.add(p)
+                ptime = time.time()
+                inotifywait(paths)
+                # sleep for a minimum amount of time, this helps issues around
+                # rapidly updating files
+                time.sleep(max(0, (sleep or 0.1) - (time.time()-ptime)))
+            else:
+                time.sleep(sleep or 0.1)
+    except KeyboardInterrupt:
+        pass
+
+    if not cat:
+        sys.stdout.write('\n')
+    sys.exit(returncode)
+
+
+if __name__ == "__main__":
+    import sys
+    import argparse
+    parser = argparse.ArgumentParser(
+        description="Traditional watch command, but with higher resolution "
+            "updates and a bit different options/output format.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'command',
+        nargs=argparse.REMAINDER,
+        help="Command to run.")
+    parser.add_argument(
+        '-n', '--lines',
+        nargs='?',
+        type=lambda x: int(x, 0),
+        const=0,
+        help="Show this many lines of history. 0 uses the terminal height. "
+            "Defaults to 0.")
+    parser.add_argument(
+        '-z', '--cat',
+        action='store_true',
+        help="Pipe directly to stdout.")
+    parser.add_argument(
+        '-s', '--sleep',
+        type=float,
+        help="Seconds to sleep between runs. Defaults to 0.1.")
+    parser.add_argument(
+        '-k', '--keep-open',
+        action='store_true',
+        help="Try to use inotify to wait for changes.")
+    parser.add_argument(
+        '-K', '--keep-open-path',
+        dest='keep_open_paths',
+        action='append',
+        help="Use this path for inotify. Defaults to guessing.")
+    parser.add_argument(
+        '-e', '--exit-on-error',
+        action='store_true',
+        help="Exit on error.")
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_args()).items()
+        if v is not None}))

tests/test_alloc.toml

@@ -1,27 +1,40 @@
 # allocator tests
 # note for these to work there are a number constraints on the device geometry
-if = 'LFS_BLOCK_CYCLES == -1'
+if = 'BLOCK_CYCLES == -1'
 
-[[case]] # parallel allocation test
-define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
+# parallel allocation test
+[cases.test_alloc_parallel]
+defines.FILES = 3
+defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
+defines.GC = [false, true]
+defines.COMPACT_THRESH = ['-1', '0', 'BLOCK_SIZE/2']
+defines.INFER_BC = [false, true]
 code = '''
-    const char *names[FILES] = {"bacon", "eggs", "pancakes"};
+    const char *names[] = {"bacon", "eggs", "pancakes"};
     lfs_file_t files[FILES];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    struct lfs_config cfg_ = *cfg;
+    if (INFER_BC) {
+        cfg_.block_count = 0;
+    }
+    lfs_mount(&lfs, &cfg_) => 0;
     lfs_mkdir(&lfs, "breakfast") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg_) => 0;
     for (int n = 0; n < FILES; n++) {
+        char path[1024];
         sprintf(path, "breakfast/%s", names[n]);
         lfs_file_open(&lfs, &files[n], path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
     }
     for (int n = 0; n < FILES; n++) {
-        size = strlen(names[n]);
+        if (GC) {
+            lfs_fs_gc(&lfs) => 0;
+        }
+        size_t size = strlen(names[n]);
         for (lfs_size_t i = 0; i < SIZE; i += size) {
             lfs_file_write(&lfs, &files[n], names[n], size) => size;
         }
@@ -31,12 +44,15 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg_) => 0;
     for (int n = 0; n < FILES; n++) {
+        char path[1024];
         sprintf(path, "breakfast/%s", names[n]);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
-        size = strlen(names[n]);
+        size_t size = strlen(names[n]);
         for (lfs_size_t i = 0; i < SIZE; i += size) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &file, buffer, size) => size;
             assert(memcmp(buffer, names[n], size) == 0);
         }
@@ -45,37 +61,55 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # serial allocation test
-define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
+# serial allocation test
+[cases.test_alloc_serial]
+defines.FILES = 3
+defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
+defines.GC = [false, true]
+defines.COMPACT_THRESH = ['-1', '0', 'BLOCK_SIZE/2']
+defines.INFER_BC = [false, true]
 code = '''
-    const char *names[FILES] = {"bacon", "eggs", "pancakes"};
+    const char *names[] = {"bacon", "eggs", "pancakes"};
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    struct lfs_config cfg_ = *cfg;
+    if (INFER_BC) {
+        cfg_.block_count = 0;
+    }
+    lfs_mount(&lfs, &cfg_) => 0;
     lfs_mkdir(&lfs, "breakfast") => 0;
     lfs_unmount(&lfs) => 0;
 
     for (int n = 0; n < FILES; n++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg_) => 0;
+        char path[1024];
         sprintf(path, "breakfast/%s", names[n]);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
-        size = strlen(names[n]);
+        size_t size = strlen(names[n]);
+        uint8_t buffer[1024];
         memcpy(buffer, names[n], size);
         for (int i = 0; i < SIZE; i += size) {
+            if (GC) {
+                lfs_fs_gc(&lfs) => 0;
+            }
             lfs_file_write(&lfs, &file, buffer, size) => size;
         }
         lfs_file_close(&lfs, &file) => 0;
         lfs_unmount(&lfs) => 0;
     }
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg_) => 0;
     for (int n = 0; n < FILES; n++) {
+        char path[1024];
         sprintf(path, "breakfast/%s", names[n]);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
-        size = strlen(names[n]);
+        size_t size = strlen(names[n]);
         for (int i = 0; i < SIZE; i += size) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &file, buffer, size) => size;
             assert(memcmp(buffer, names[n], size) == 0);
         }
@@ -84,29 +118,37 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # parallel allocation reuse test
-define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
-define.CYCLES = [1, 10]
+# parallel allocation reuse test
+[cases.test_alloc_parallel_reuse]
+defines.FILES = 3
+defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
+defines.CYCLES = [1, 10]
+defines.INFER_BC = [false, true]
 code = '''
-    const char *names[FILES] = {"bacon", "eggs", "pancakes"};
+    const char *names[] = {"bacon", "eggs", "pancakes"};
     lfs_file_t files[FILES];
 
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    struct lfs_config cfg_ = *cfg;
+    if (INFER_BC) {
+        cfg_.block_count = 0;
+    }
 
     for (int c = 0; c < CYCLES; c++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg_) => 0;
         lfs_mkdir(&lfs, "breakfast") => 0;
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg_) => 0;
         for (int n = 0; n < FILES; n++) {
+            char path[1024];
             sprintf(path, "breakfast/%s", names[n]);
             lfs_file_open(&lfs, &files[n], path,
                     LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
         }
         for (int n = 0; n < FILES; n++) {
-            size = strlen(names[n]);
+            size_t size = strlen(names[n]);
             for (int i = 0; i < SIZE; i += size) {
                 lfs_file_write(&lfs, &files[n], names[n], size) => size;
             }
@@ -116,12 +158,15 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg_) => 0;
         for (int n = 0; n < FILES; n++) {
+            char path[1024];
             sprintf(path, "breakfast/%s", names[n]);
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
-            size = strlen(names[n]);
+            size_t size = strlen(names[n]);
             for (int i = 0; i < SIZE; i += size) {
+                uint8_t buffer[1024];
                 lfs_file_read(&lfs, &file, buffer, size) => size;
                 assert(memcmp(buffer, names[n], size) == 0);
             }
@@ -129,8 +174,9 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg_) => 0;
         for (int n = 0; n < FILES; n++) {
+            char path[1024];
             sprintf(path, "breakfast/%s", names[n]);
             lfs_remove(&lfs, path) => 0;
         }
@@ -139,26 +185,36 @@ code = '''
     }
 '''
 
-[[case]] # serial allocation reuse test
-define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
-define.CYCLES = [1, 10]
+# serial allocation reuse test
+[cases.test_alloc_serial_reuse]
+defines.FILES = 3
+defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
+defines.CYCLES = [1, 10]
+defines.INFER_BC = [false, true]
 code = '''
-    const char *names[FILES] = {"bacon", "eggs", "pancakes"};
+    const char *names[] = {"bacon", "eggs", "pancakes"};
 
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    struct lfs_config cfg_ = *cfg;
+    if (INFER_BC) {
+        cfg_.block_count = 0;
+    }
 
     for (int c = 0; c < CYCLES; c++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg_) => 0;
         lfs_mkdir(&lfs, "breakfast") => 0;
         lfs_unmount(&lfs) => 0;
 
         for (int n = 0; n < FILES; n++) {
-            lfs_mount(&lfs, &cfg) => 0;
+            lfs_mount(&lfs, &cfg_) => 0;
+            char path[1024];
             sprintf(path, "breakfast/%s", names[n]);
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path,
                     LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
-            size = strlen(names[n]);
+            size_t size = strlen(names[n]);
+            uint8_t buffer[1024];
             memcpy(buffer, names[n], size);
             for (int i = 0; i < SIZE; i += size) {
                 lfs_file_write(&lfs, &file, buffer, size) => size;
@@ -167,12 +223,15 @@ code = '''
             lfs_unmount(&lfs) => 0;
         }
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (int n = 0; n < FILES; n++) {
+            char path[1024];
             sprintf(path, "breakfast/%s", names[n]);
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
-            size = strlen(names[n]);
+            size_t size = strlen(names[n]);
             for (int i = 0; i < SIZE; i += size) {
+                uint8_t buffer[1024];
                 lfs_file_read(&lfs, &file, buffer, size) => size;
                 assert(memcmp(buffer, names[n], size) == 0);
             }
@@ -180,8 +239,9 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (int n = 0; n < FILES; n++) {
+            char path[1024];
             sprintf(path, "breakfast/%s", names[n]);
             lfs_remove(&lfs, path) => 0;
         }
@@ -190,12 +250,21 @@ code = '''
     }
 '''
 
-[[case]] # exhaustion test
+# exhaustion test
+[cases.test_alloc_exhaustion]
+defines.INFER_BC = [false, true]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    struct lfs_config cfg_ = *cfg;
+    if (INFER_BC) {
+        cfg_.block_count = 0;
+    }
+    lfs_mount(&lfs, &cfg_) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
-    size = strlen("exhaustion");
+    size_t size = strlen("exhaustion");
+    uint8_t buffer[1024];
     memcpy(buffer, "exhaustion", size);
     lfs_file_write(&lfs, &file, buffer, size) => size;
     lfs_file_sync(&lfs, &file) => 0;
@@ -213,10 +282,13 @@ code = '''
     }
     res => LFS_ERR_NOSPC;
 
+    // note that lfs_fs_gc should not error here
+    lfs_fs_gc(&lfs) => 0;
+
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg_) => 0;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_RDONLY);
     size = strlen("exhaustion");
     lfs_file_size(&lfs, &file) => size;
@@ -226,14 +298,23 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # exhaustion wraparound test
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-4)) / 3)'
+# exhaustion wraparound test
+[cases.test_alloc_exhaustion_wraparound]
+defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-4)) / 3)'
+defines.INFER_BC = [false, true]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    struct lfs_config cfg_ = *cfg;
+    if (INFER_BC) {
+        cfg_.block_count = 0;
+    }
+    lfs_mount(&lfs, &cfg_) => 0;
 
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "padding", LFS_O_WRONLY | LFS_O_CREAT);
-    size = strlen("buffering");
+    size_t size = strlen("buffering");
+    uint8_t buffer[1024];
     memcpy(buffer, "buffering", size);
     for (int i = 0; i < SIZE; i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
@@ -260,10 +341,13 @@ code = '''
     }
     res => LFS_ERR_NOSPC;
 
+    // note that lfs_fs_gc should not error here
+    lfs_fs_gc(&lfs) => 0;
+
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg_) => 0;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_RDONLY);
     size = strlen("exhaustion");
     lfs_file_size(&lfs, &file) => size;
@@ -274,17 +358,27 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # dir exhaustion test
+# dir exhaustion test
+[cases.test_alloc_dir_exhaustion]
+defines.INFER_BC = [false, true]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    struct lfs_config cfg_ = *cfg;
+    if (INFER_BC) {
+        cfg_.block_count = 0;
+    }
+    lfs_mount(&lfs, &cfg_) => 0;
 
     // find out max file size
     lfs_mkdir(&lfs, "exhaustiondir") => 0;
-    size = strlen("blahblahblahblah");
+    size_t size = strlen("blahblahblahblah");
+    uint8_t buffer[1024];
     memcpy(buffer, "blahblahblahblah", size);
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
     int count = 0;
+    int err;
     while (true) {
         err = lfs_file_write(&lfs, &file, buffer, size);
         if (err < 0) {
@@ -294,6 +388,8 @@ code = '''
         count += 1;
     }
     err => LFS_ERR_NOSPC;
+    // note that lfs_fs_gc should not error here
+    lfs_fs_gc(&lfs) => 0;
     lfs_file_close(&lfs, &file) => 0;
 
     lfs_remove(&lfs, "exhaustion") => 0;
@@ -323,17 +419,21 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # what if we have a bad block during an allocation scan?
+# what if we have a bad block during an allocation scan?
+[cases.test_alloc_bad_blocks]
 in = "lfs.c"
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_BADBLOCK_BEHAVIOR = 'LFS_TESTBD_BADBLOCK_READERROR'
+defines.ERASE_CYCLES = 0xffffffff
+defines.BADBLOCK_BEHAVIOR = 'LFS_EMUBD_BADBLOCK_READERROR'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     // first fill to exhaustion to find available space
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "pacman", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    uint8_t buffer[1024];
     strcpy((char*)buffer, "waka");
-    size = strlen("waka");
+    size_t size = strlen("waka");
     lfs_size_t filesize = 0;
     while (true) {
         lfs_ssize_t res = lfs_file_write(&lfs, &file, buffer, size);
@@ -345,7 +445,7 @@ code = '''
     }
     lfs_file_close(&lfs, &file) => 0;
     // now fill all but a couple of blocks of the filesystem with data
-    filesize -= 3*LFS_BLOCK_SIZE;
+    filesize -= 3*BLOCK_SIZE;
     lfs_file_open(&lfs, &file, "pacman", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     strcpy((char*)buffer, "waka");
     size = strlen("waka");
@@ -358,11 +458,11 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // remount to force an alloc scan
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // but mark the head of our file as a "bad block", this is force our
     // scan to bail early
-    lfs_testbd_setwear(&cfg, fileblock, 0xffffffff) => 0;
+    lfs_emubd_setwear(cfg, fileblock, 0xffffffff) => 0;
     lfs_file_open(&lfs, &file, "ghost", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     strcpy((char*)buffer, "chomp");
     size = strlen("chomp");
@@ -377,7 +477,7 @@ code = '''
 
     // now reverse the "bad block" and try to write the file again until we
     // run out of space
-    lfs_testbd_setwear(&cfg, fileblock, 0) => 0;
+    lfs_emubd_setwear(cfg, fileblock, 0) => 0;
     lfs_file_open(&lfs, &file, "ghost", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     strcpy((char*)buffer, "chomp");
     size = strlen("chomp");
@@ -388,12 +488,14 @@ code = '''
             break;
         }
     }
+    // note that lfs_fs_gc should not error here
+    lfs_fs_gc(&lfs) => 0;
     lfs_file_close(&lfs, &file) => 0;
 
     lfs_unmount(&lfs) => 0;
 
     // check that the disk isn't hurt
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "pacman", LFS_O_RDONLY) => 0;
     strcpy((char*)buffer, "waka");
     size = strlen("waka");
@@ -411,24 +513,29 @@ code = '''
 # on the geometry of the block device. But they are valuable. Eventually they
 # should be removed and replaced with generalized tests.
 
-[[case]] # chained dir exhaustion test
-define.LFS_BLOCK_SIZE = 512
-define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
+# chained dir exhaustion test
+[cases.test_alloc_chained_dir_exhaustion]
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // find out max file size
     lfs_mkdir(&lfs, "exhaustiondir") => 0;
     for (int i = 0; i < 10; i++) {
+        char path[1024];
         sprintf(path, "dirwithanexhaustivelylongnameforpadding%d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
-    size = strlen("blahblahblahblah");
+    size_t size = strlen("blahblahblahblah");
+    uint8_t buffer[1024];
     memcpy(buffer, "blahblahblahblah", size);
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
     int count = 0;
+    int err;
     while (true) {
         err = lfs_file_write(&lfs, &file, buffer, size);
         if (err < 0) {
@@ -443,6 +550,7 @@ code = '''
     lfs_remove(&lfs, "exhaustion") => 0;
     lfs_remove(&lfs, "exhaustiondir") => 0;
     for (int i = 0; i < 10; i++) {
+        char path[1024];
         sprintf(path, "dirwithanexhaustivelylongnameforpadding%d", i);
         lfs_remove(&lfs, path) => 0;
     }
@@ -455,6 +563,7 @@ code = '''
     lfs_file_sync(&lfs, &file) => 0;
 
     for (int i = 0; i < 10; i++) {
+        char path[1024];
         sprintf(path, "dirwithanexhaustivelylongnameforpadding%d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
@@ -482,27 +591,31 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # split dir test
-define.LFS_BLOCK_SIZE = 512
-define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
+# split dir test
+[cases.test_alloc_split_dir]
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // create one block hole for half a directory
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "bump", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    for (lfs_size_t i = 0; i < cfg.block_size; i += 2) {
+    for (lfs_size_t i = 0; i < cfg->block_size; i += 2) {
+        uint8_t buffer[1024];
         memcpy(&buffer[i], "hi", 2);
     }
-    lfs_file_write(&lfs, &file, buffer, cfg.block_size) => cfg.block_size;
+    uint8_t buffer[1024];
+    lfs_file_write(&lfs, &file, buffer, cfg->block_size) => cfg->block_size;
     lfs_file_close(&lfs, &file) => 0;
 
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
-    size = strlen("blahblahblahblah");
+    size_t size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < (cfg.block_count-4)*(cfg.block_size-8);
+            i < (cfg->block_count-4)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }
@@ -510,7 +623,7 @@ code = '''
 
     // remount to force reset of lookahead
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // open hole
     lfs_remove(&lfs, "bump") => 0;
@@ -518,30 +631,33 @@ code = '''
     lfs_mkdir(&lfs, "splitdir") => 0;
     lfs_file_open(&lfs, &file, "splitdir/bump",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    for (lfs_size_t i = 0; i < cfg.block_size; i += 2) {
+    for (lfs_size_t i = 0; i < cfg->block_size; i += 2) {
         memcpy(&buffer[i], "hi", 2);
     }
-    lfs_file_write(&lfs, &file, buffer, 2*cfg.block_size) => LFS_ERR_NOSPC;
+    lfs_file_write(&lfs, &file, buffer, 2*cfg->block_size) => LFS_ERR_NOSPC;
     lfs_file_close(&lfs, &file) => 0;
 
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # outdated lookahead test
-define.LFS_BLOCK_SIZE = 512
-define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
+# outdated lookahead test
+[cases.test_alloc_outdated_lookahead]
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // fill completely with two files
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "exhaustion1",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    size = strlen("blahblahblahblah");
+    size_t size = strlen("blahblahblahblah");
+    uint8_t buffer[1024];
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < ((cfg.block_count-2)/2)*(cfg.block_size-8);
+            i < ((cfg->block_count-2)/2)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }
@@ -552,7 +668,7 @@ code = '''
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < ((cfg.block_count-2+1)/2)*(cfg.block_size-8);
+            i < ((cfg->block_count-2+1)/2)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }
@@ -560,7 +676,7 @@ code = '''
 
     // remount to force reset of lookahead
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // rewrite one file
     lfs_file_open(&lfs, &file, "exhaustion1",
@@ -569,7 +685,7 @@ code = '''
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < ((cfg.block_count-2)/2)*(cfg.block_size-8);
+            i < ((cfg->block_count-2)/2)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }
@@ -583,7 +699,7 @@ code = '''
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < ((cfg.block_count-2+1)/2)*(cfg.block_size-8);
+            i < ((cfg->block_count-2+1)/2)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }
@@ -592,21 +708,24 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # outdated lookahead and split dir test
-define.LFS_BLOCK_SIZE = 512
-define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
+# outdated lookahead and split dir test
+[cases.test_alloc_outdated_lookahead_split_dir]
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // fill completely with two files
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "exhaustion1",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    size = strlen("blahblahblahblah");
+    size_t size = strlen("blahblahblahblah");
+    uint8_t buffer[1024];
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < ((cfg.block_count-2)/2)*(cfg.block_size-8);
+            i < ((cfg->block_count-2)/2)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }
@@ -617,7 +736,7 @@ code = '''
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < ((cfg.block_count-2+1)/2)*(cfg.block_size-8);
+            i < ((cfg->block_count-2+1)/2)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }
@@ -625,7 +744,7 @@ code = '''
 
     // remount to force reset of lookahead
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // rewrite one file with a hole of one block
     lfs_file_open(&lfs, &file, "exhaustion1",
@@ -634,7 +753,7 @@ code = '''
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
     for (lfs_size_t i = 0;
-            i < ((cfg.block_count-2)/2 - 1)*(cfg.block_size-8);
+            i < ((cfg->block_count-2)/2 - 1)*(cfg->block_size-8);
             i += size) {
         lfs_file_write(&lfs, &file, buffer, size) => size;
     }

tests/test_attrs.toml

@@ -1,14 +1,17 @@
-[[case]] # set/get attribute
+[cases.test_attrs_get_set]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    uint8_t buffer[1024];
     memset(buffer, 0, sizeof(buffer));
     lfs_setattr(&lfs, "hello", 'A', "aaaa",   4) => 0;
     lfs_setattr(&lfs, "hello", 'B', "bbbbbb", 6) => 0;
@@ -60,7 +63,7 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  9) => 9;
@@ -76,17 +79,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # set/get root attribute
+[cases.test_attrs_get_set_root]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    uint8_t buffer[1024];
     memset(buffer, 0, sizeof(buffer));
     lfs_setattr(&lfs, "/", 'A', "aaaa",   4) => 0;
     lfs_setattr(&lfs, "/", 'B', "bbbbbb", 6) => 0;
@@ -137,7 +143,7 @@ code = '''
     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  9) => 9;
@@ -153,17 +159,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # set/get file attribute
+[cases.test_attrs_get_set_file]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    uint8_t buffer[1024];
     memset(buffer, 0, sizeof(buffer));
     struct lfs_attr attrs1[] = {
         {'A', buffer,    4},
@@ -238,7 +247,7 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     struct lfs_attr attrs3[] = {
         {'A', buffer,    4},
@@ -260,20 +269,23 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # deferred file attributes
+[cases.test_attrs_deferred_file]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_setattr(&lfs, "hello/hello", 'B', "fffffffff",  9) => 0;
     lfs_setattr(&lfs, "hello/hello", 'C', "ccccc",      5) => 0;
 
+    uint8_t buffer[1024];
     memset(buffer, 0, sizeof(buffer));
     struct lfs_attr attrs1[] = {
         {'B', "gggg", 4},

tests/test_badblocks.toml

@@ -1,28 +1,30 @@
 # bad blocks with block cycles should be tested in test_relocations
-if = 'LFS_BLOCK_CYCLES == -1'
+if = '(int32_t)BLOCK_CYCLES == -1'
 
-[[case]] # single bad blocks
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_PROGERROR',
-    'LFS_TESTBD_BADBLOCK_ERASEERROR',
-    'LFS_TESTBD_BADBLOCK_READERROR',
-    'LFS_TESTBD_BADBLOCK_PROGNOOP',
-    'LFS_TESTBD_BADBLOCK_ERASENOOP',
+[cases.test_badblocks_single]
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.ERASE_CYCLES = 0xffffffff
+defines.ERASE_VALUE = [0x00, 0xff, -1]
+defines.BADBLOCK_BEHAVIOR = [
+    'LFS_EMUBD_BADBLOCK_PROGERROR',
+    'LFS_EMUBD_BADBLOCK_ERASEERROR',
+    'LFS_EMUBD_BADBLOCK_READERROR',
+    'LFS_EMUBD_BADBLOCK_PROGNOOP',
+    'LFS_EMUBD_BADBLOCK_ERASENOOP',
 ]
-define.NAMEMULT = 64
-define.FILEMULT = 1
+defines.NAMEMULT = 64
+defines.FILEMULT = 1
 code = '''
-    for (lfs_block_t badblock = 2; badblock < LFS_BLOCK_COUNT; badblock++) {
-        lfs_testbd_setwear(&cfg, badblock-1, 0) => 0;
-        lfs_testbd_setwear(&cfg, badblock, 0xffffffff) => 0;
-        
-        lfs_format(&lfs, &cfg) => 0;
+    for (lfs_block_t badblock = 2; badblock < BLOCK_COUNT; badblock++) {
+        lfs_emubd_setwear(cfg, badblock-1, 0) => 0;
+        lfs_emubd_setwear(cfg, badblock, 0xffffffff) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_t lfs;
+        lfs_format(&lfs, cfg) => 0;
+
+        lfs_mount(&lfs, cfg) => 0;
         for (int i = 1; i < 10; i++) {
+            uint8_t buffer[1024];
             for (int j = 0; j < NAMEMULT; j++) {
                 buffer[j] = '0'+i;
             }
@@ -34,10 +36,11 @@ code = '''
                 buffer[j+NAMEMULT+1] = '0'+i;
             }
             buffer[2*NAMEMULT+1] = '\0';
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, (char*)buffer,
                     LFS_O_WRONLY | LFS_O_CREAT) => 0;
             
-            size = NAMEMULT;
+            lfs_size_t size = NAMEMULT;
             for (int j = 0; j < i*FILEMULT; j++) {
                 lfs_file_write(&lfs, &file, buffer, size) => size;
             }
@@ -46,12 +49,14 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (int i = 1; i < 10; i++) {
+            uint8_t buffer[1024];
             for (int j = 0; j < NAMEMULT; j++) {
                 buffer[j] = '0'+i;
             }
             buffer[NAMEMULT] = '\0';
+            struct lfs_info info;
             lfs_stat(&lfs, (char*)buffer, &info) => 0;
             info.type => LFS_TYPE_DIR;
 
@@ -60,9 +65,10 @@ code = '''
                 buffer[j+NAMEMULT+1] = '0'+i;
             }
             buffer[2*NAMEMULT+1] = '\0';
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, (char*)buffer, LFS_O_RDONLY) => 0;
             
-            size = NAMEMULT;
+            int size = NAMEMULT;
             for (int j = 0; j < i*FILEMULT; j++) {
                 uint8_t rbuffer[1024];
                 lfs_file_read(&lfs, &file, rbuffer, size) => size;
@@ -75,28 +81,30 @@ code = '''
     }
 '''
 
-[[case]] # region corruption (causes cascading failures)
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_PROGERROR',
-    'LFS_TESTBD_BADBLOCK_ERASEERROR',
-    'LFS_TESTBD_BADBLOCK_READERROR',
-    'LFS_TESTBD_BADBLOCK_PROGNOOP',
-    'LFS_TESTBD_BADBLOCK_ERASENOOP',
+[cases.test_badblocks_region_corruption] # (causes cascading failures)
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.ERASE_CYCLES = 0xffffffff
+defines.ERASE_VALUE = [0x00, 0xff, -1]
+defines.BADBLOCK_BEHAVIOR = [
+    'LFS_EMUBD_BADBLOCK_PROGERROR',
+    'LFS_EMUBD_BADBLOCK_ERASEERROR',
+    'LFS_EMUBD_BADBLOCK_READERROR',
+    'LFS_EMUBD_BADBLOCK_PROGNOOP',
+    'LFS_EMUBD_BADBLOCK_ERASENOOP',
 ]
-define.NAMEMULT = 64
-define.FILEMULT = 1
+defines.NAMEMULT = 64
+defines.FILEMULT = 1
 code = '''
-    for (lfs_block_t i = 0; i < (LFS_BLOCK_COUNT-2)/2; i++) {
-        lfs_testbd_setwear(&cfg, i+2, 0xffffffff) => 0;
+    for (lfs_block_t i = 0; i < (BLOCK_COUNT-2)/2; i++) {
+        lfs_emubd_setwear(cfg, i+2, 0xffffffff) => 0;
     }
-    
-    lfs_format(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 1; i < 10; i++) {
+        uint8_t buffer[1024];
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
         }
@@ -108,10 +116,11 @@ code = '''
             buffer[j+NAMEMULT+1] = '0'+i;
         }
         buffer[2*NAMEMULT+1] = '\0';
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, (char*)buffer,
                 LFS_O_WRONLY | LFS_O_CREAT) => 0;
         
-        size = NAMEMULT;
+        lfs_size_t size = NAMEMULT;
         for (int j = 0; j < i*FILEMULT; j++) {
             lfs_file_write(&lfs, &file, buffer, size) => size;
         }
@@ -120,12 +129,14 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 1; i < 10; i++) {
+        uint8_t buffer[1024];
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
         }
         buffer[NAMEMULT] = '\0';
+        struct lfs_info info;
         lfs_stat(&lfs, (char*)buffer, &info) => 0;
         info.type => LFS_TYPE_DIR;
 
@@ -134,9 +145,10 @@ code = '''
             buffer[j+NAMEMULT+1] = '0'+i;
         }
         buffer[2*NAMEMULT+1] = '\0';
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, (char*)buffer, LFS_O_RDONLY) => 0;
         
-        size = NAMEMULT;
+        lfs_size_t size = NAMEMULT;
         for (int j = 0; j < i*FILEMULT; j++) {
             uint8_t rbuffer[1024];
             lfs_file_read(&lfs, &file, rbuffer, size) => size;
@@ -148,28 +160,30 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # alternating corruption (causes cascading failures)
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_PROGERROR',
-    'LFS_TESTBD_BADBLOCK_ERASEERROR',
-    'LFS_TESTBD_BADBLOCK_READERROR',
-    'LFS_TESTBD_BADBLOCK_PROGNOOP',
-    'LFS_TESTBD_BADBLOCK_ERASENOOP',
+[cases.test_badblocks_alternating_corruption] # (causes cascading failures)
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.ERASE_CYCLES = 0xffffffff
+defines.ERASE_VALUE = [0x00, 0xff, -1]
+defines.BADBLOCK_BEHAVIOR = [
+    'LFS_EMUBD_BADBLOCK_PROGERROR',
+    'LFS_EMUBD_BADBLOCK_ERASEERROR',
+    'LFS_EMUBD_BADBLOCK_READERROR',
+    'LFS_EMUBD_BADBLOCK_PROGNOOP',
+    'LFS_EMUBD_BADBLOCK_ERASENOOP',
 ]
-define.NAMEMULT = 64
-define.FILEMULT = 1
+defines.NAMEMULT = 64
+defines.FILEMULT = 1
 code = '''
-    for (lfs_block_t i = 0; i < (LFS_BLOCK_COUNT-2)/2; i++) {
-        lfs_testbd_setwear(&cfg, (2*i) + 2, 0xffffffff) => 0;
+    for (lfs_block_t i = 0; i < (BLOCK_COUNT-2)/2; i++) {
+        lfs_emubd_setwear(cfg, (2*i) + 2, 0xffffffff) => 0;
     }
-    
-    lfs_format(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 1; i < 10; i++) {
+        uint8_t buffer[1024];
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
         }
@@ -181,10 +195,11 @@ code = '''
             buffer[j+NAMEMULT+1] = '0'+i;
         }
         buffer[2*NAMEMULT+1] = '\0';
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, (char*)buffer,
                 LFS_O_WRONLY | LFS_O_CREAT) => 0;
         
-        size = NAMEMULT;
+        lfs_size_t size = NAMEMULT;
         for (int j = 0; j < i*FILEMULT; j++) {
             lfs_file_write(&lfs, &file, buffer, size) => size;
         }
@@ -193,12 +208,14 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 1; i < 10; i++) {
+        uint8_t buffer[1024];
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
         }
         buffer[NAMEMULT] = '\0';
+        struct lfs_info info;
         lfs_stat(&lfs, (char*)buffer, &info) => 0;
         info.type => LFS_TYPE_DIR;
 
@@ -207,9 +224,10 @@ code = '''
             buffer[j+NAMEMULT+1] = '0'+i;
         }
         buffer[2*NAMEMULT+1] = '\0';
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, (char*)buffer, LFS_O_RDONLY) => 0;
         
-        size = NAMEMULT;
+        lfs_size_t size = NAMEMULT;
         for (int j = 0; j < i*FILEMULT; j++) {
             uint8_t rbuffer[1024];
             lfs_file_read(&lfs, &file, rbuffer, size) => size;
@@ -222,20 +240,21 @@ code = '''
 '''
 
 # other corner cases
-[[case]] # bad superblocks (corrupt 1 or 0)
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_PROGERROR',
-    'LFS_TESTBD_BADBLOCK_ERASEERROR',
-    'LFS_TESTBD_BADBLOCK_READERROR',
-    'LFS_TESTBD_BADBLOCK_PROGNOOP',
-    'LFS_TESTBD_BADBLOCK_ERASENOOP',
+[cases.test_badblocks_superblocks] # (corrupt 1 or 0)
+defines.ERASE_CYCLES = 0xffffffff
+defines.ERASE_VALUE = [0x00, 0xff, -1]
+defines.BADBLOCK_BEHAVIOR = [
+    'LFS_EMUBD_BADBLOCK_PROGERROR',
+    'LFS_EMUBD_BADBLOCK_ERASEERROR',
+    'LFS_EMUBD_BADBLOCK_READERROR',
+    'LFS_EMUBD_BADBLOCK_PROGNOOP',
+    'LFS_EMUBD_BADBLOCK_ERASENOOP',
 ]
 code = '''
-    lfs_testbd_setwear(&cfg, 0, 0xffffffff) => 0;
-    lfs_testbd_setwear(&cfg, 1, 0xffffffff) => 0;
+    lfs_emubd_setwear(cfg, 0, 0xffffffff) => 0;
+    lfs_emubd_setwear(cfg, 1, 0xffffffff) => 0;
 
-    lfs_format(&lfs, &cfg) => LFS_ERR_NOSPC;
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => LFS_ERR_NOSPC;
+    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
 '''

tests/test_bd.toml

@@ -0,0 +1,248 @@
+# These tests don't really test littlefs at all, they are here only to make
+# sure the underlying block device is working.
+#
+# Note we use 251, a prime, in places to avoid aliasing powers of 2.
+# 
+
+[cases.test_bd_one_block]
+defines.READ = ['READ_SIZE', 'BLOCK_SIZE']
+defines.PROG = ['PROG_SIZE', 'BLOCK_SIZE']
+code = '''
+    uint8_t buffer[lfs_max(READ, PROG)];
+
+    // write data
+    cfg->erase(cfg, 0) => 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += PROG) {
+        for (lfs_off_t j = 0; j < PROG; j++) {
+            buffer[j] = (i+j) % 251;
+        }
+        cfg->prog(cfg, 0, i, buffer, PROG) => 0;
+    }
+
+    // read data
+    for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+        cfg->read(cfg, 0, i, buffer, READ) => 0;
+
+        for (lfs_off_t j = 0; j < READ; j++) {
+            LFS_ASSERT(buffer[j] == (i+j) % 251);
+        }
+    }
+'''
+
+[cases.test_bd_two_block]
+defines.READ = ['READ_SIZE', 'BLOCK_SIZE']
+defines.PROG = ['PROG_SIZE', 'BLOCK_SIZE']
+code = '''
+    uint8_t buffer[lfs_max(READ, PROG)];
+    lfs_block_t block;
+
+    // write block 0
+    block = 0;
+    cfg->erase(cfg, block) => 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += PROG) {
+        for (lfs_off_t j = 0; j < PROG; j++) {
+            buffer[j] = (block+i+j) % 251;
+        }
+        cfg->prog(cfg, block, i, buffer, PROG) => 0;
+    }
+
+    // read block 0
+    block = 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+        cfg->read(cfg, block, i, buffer, READ) => 0;
+
+        for (lfs_off_t j = 0; j < READ; j++) {
+            LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+        }
+    }
+
+    // write block 1
+    block = 1;
+    cfg->erase(cfg, block) => 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += PROG) {
+        for (lfs_off_t j = 0; j < PROG; j++) {
+            buffer[j] = (block+i+j) % 251;
+        }
+        cfg->prog(cfg, block, i, buffer, PROG) => 0;
+    }
+
+    // read block 1
+    block = 1;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+        cfg->read(cfg, block, i, buffer, READ) => 0;
+
+        for (lfs_off_t j = 0; j < READ; j++) {
+            LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+        }
+    }
+
+    // read block 0 again
+    block = 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+        cfg->read(cfg, block, i, buffer, READ) => 0;
+
+        for (lfs_off_t j = 0; j < READ; j++) {
+            LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+        }
+    }
+'''
+
+[cases.test_bd_last_block]
+defines.READ = ['READ_SIZE', 'BLOCK_SIZE']
+defines.PROG = ['PROG_SIZE', 'BLOCK_SIZE']
+code = '''
+    uint8_t buffer[lfs_max(READ, PROG)];
+    lfs_block_t block;
+
+    // write block 0
+    block = 0;
+    cfg->erase(cfg, block) => 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += PROG) {
+        for (lfs_off_t j = 0; j < PROG; j++) {
+            buffer[j] = (block+i+j) % 251;
+        }
+        cfg->prog(cfg, block, i, buffer, PROG) => 0;
+    }
+
+    // read block 0
+    block = 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+        cfg->read(cfg, block, i, buffer, READ) => 0;
+
+        for (lfs_off_t j = 0; j < READ; j++) {
+            LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+        }
+    }
+
+    // write block n-1
+    block = cfg->block_count-1;
+    cfg->erase(cfg, block) => 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += PROG) {
+        for (lfs_off_t j = 0; j < PROG; j++) {
+            buffer[j] = (block+i+j) % 251;
+        }
+        cfg->prog(cfg, block, i, buffer, PROG) => 0;
+    }
+
+    // read block n-1
+    block = cfg->block_count-1;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+        cfg->read(cfg, block, i, buffer, READ) => 0;
+
+        for (lfs_off_t j = 0; j < READ; j++) {
+            LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+        }
+    }
+
+    // read block 0 again
+    block = 0;
+    for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+        cfg->read(cfg, block, i, buffer, READ) => 0;
+
+        for (lfs_off_t j = 0; j < READ; j++) {
+            LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+        }
+    }
+'''
+
+[cases.test_bd_powers_of_two]
+defines.READ = ['READ_SIZE', 'BLOCK_SIZE']
+defines.PROG = ['PROG_SIZE', 'BLOCK_SIZE']
+code = '''
+    uint8_t buffer[lfs_max(READ, PROG)];
+
+    // write/read every power of 2
+    lfs_block_t block = 1;
+    while (block < cfg->block_count) {
+        // write
+        cfg->erase(cfg, block) => 0;
+        for (lfs_off_t i = 0; i < cfg->block_size; i += PROG) {
+            for (lfs_off_t j = 0; j < PROG; j++) {
+                buffer[j] = (block+i+j) % 251;
+            }
+            cfg->prog(cfg, block, i, buffer, PROG) => 0;
+        }
+
+        // read
+        for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+            cfg->read(cfg, block, i, buffer, READ) => 0;
+
+            for (lfs_off_t j = 0; j < READ; j++) {
+                LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+            }
+        }
+
+        block *= 2;
+    }
+
+    // read every power of 2 again
+    block = 1;
+    while (block < cfg->block_count) {
+        // read
+        for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+            cfg->read(cfg, block, i, buffer, READ) => 0;
+
+            for (lfs_off_t j = 0; j < READ; j++) {
+                LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+            }
+        }
+
+        block *= 2;
+    }
+'''
+
+[cases.test_bd_fibonacci]
+defines.READ = ['READ_SIZE', 'BLOCK_SIZE']
+defines.PROG = ['PROG_SIZE', 'BLOCK_SIZE']
+code = '''
+    uint8_t buffer[lfs_max(READ, PROG)];
+
+    // write/read every fibonacci number on our device
+    lfs_block_t block = 1;
+    lfs_block_t block_ = 1;
+    while (block < cfg->block_count) {
+        // write
+        cfg->erase(cfg, block) => 0;
+        for (lfs_off_t i = 0; i < cfg->block_size; i += PROG) {
+            for (lfs_off_t j = 0; j < PROG; j++) {
+                buffer[j] = (block+i+j) % 251;
+            }
+            cfg->prog(cfg, block, i, buffer, PROG) => 0;
+        }
+
+        // read
+        for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+            cfg->read(cfg, block, i, buffer, READ) => 0;
+
+            for (lfs_off_t j = 0; j < READ; j++) {
+                LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+            }
+        }
+
+        lfs_block_t nblock = block + block_;
+        block_ = block;
+        block = nblock;
+    }
+
+    // read every fibonacci number again
+    block = 1;
+    block_ = 1;
+    while (block < cfg->block_count) {
+        // read
+        for (lfs_off_t i = 0; i < cfg->block_size; i += READ) {
+            cfg->read(cfg, block, i, buffer, READ) => 0;
+
+            for (lfs_off_t j = 0; j < READ; j++) {
+                LFS_ASSERT(buffer[j] == (block+i+j) % 251);
+            }
+        }
+
+        lfs_block_t nblock = block + block_;
+        block_ = block;
+        block = nblock;
+    }
+'''
+
+
+
+

tests/test_dirs.toml

@@ -1,8 +1,11 @@
-[[case]] # root
+[cases.test_dirs_root]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -14,20 +17,25 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # many directory creation
-define.N = 'range(0, 100, 3)'
+[cases.test_dirs_many_creation]
+defines.N = 'range(3, 100, 3)'
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "dir%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -35,6 +43,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "dir%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -45,20 +54,25 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # many directory removal
-define.N = 'range(3, 100, 11)'
+[cases.test_dirs_many_removal]
+defines.N = 'range(3, 100, 11)'
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "removeme%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -66,6 +80,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "removeme%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -75,14 +90,15 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "removeme%03d", i);
         lfs_remove(&lfs, path) => 0;
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -95,20 +111,25 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # many directory rename
-define.N = 'range(3, 100, 11)'
+[cases.test_dirs_many_rename]
+defines.N = 'range(3, 100, 11)'
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "test%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -116,6 +137,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "test%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -125,7 +147,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
         char oldpath[128];
         char newpath[128];
@@ -135,7 +157,7 @@ code = '''
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -144,6 +166,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "tedd%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -154,29 +177,39 @@ code = '''
     lfs_unmount(&lfs);
 '''
 
-[[case]] # reentrant many directory creation/rename/removal
-define.N = [5, 11]
+[cases.test_dirs_many_reentrant]
+defines.N = [5, 11]
+if = 'BLOCK_COUNT >= 4*N'
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hi%03d", i);
         err = lfs_mkdir(&lfs, path);
         assert(err == 0 || err == LFS_ERR_EXIST);
     }
 
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hello%03d", i);
         err = lfs_remove(&lfs, path);
         assert(err == 0 || err == LFS_ERR_NOENT);
     }
 
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -184,6 +217,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hi%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -209,6 +243,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hello%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -218,6 +253,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hello%03d", i);
         lfs_remove(&lfs, path) => 0;
     }
@@ -234,22 +270,28 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # file creation
-define.N = 'range(3, 100, 11)'
+[cases.test_dirs_file_creation]
+defines.N = 'range(3, 100, 11)'
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "file%03d", i);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         lfs_file_close(&lfs, &file) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -257,6 +299,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "file%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_REG);
@@ -267,22 +310,28 @@ code = '''
     lfs_unmount(&lfs);
 '''
 
-[[case]] # file removal
-define.N = 'range(0, 100, 3)'
+[cases.test_dirs_file_removal]
+defines.N = 'range(3, 100, 11)'
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "removeme%03d", i);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         lfs_file_close(&lfs, &file) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -290,6 +339,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "removeme%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_REG);
@@ -299,14 +349,15 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "removeme%03d", i);
         lfs_remove(&lfs, path) => 0;
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -319,22 +370,28 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # file rename
-define.N = 'range(0, 100, 3)'
+[cases.test_dirs_file_rename]
+defines.N = 'range(3, 100, 11)'
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "test%03d", i);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         lfs_file_close(&lfs, &file) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -342,6 +399,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "test%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_REG);
@@ -351,7 +409,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
         char oldpath[128];
         char newpath[128];
@@ -361,7 +419,7 @@ code = '''
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -370,6 +428,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "tedd%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_REG);
@@ -380,29 +439,40 @@ code = '''
     lfs_unmount(&lfs);
 '''
 
-[[case]] # reentrant file creation/rename/removal
-define.N = [5, 25]
+[cases.test_dirs_file_reentrant]
+defines.N = [5, 25]
+if = 'N < BLOCK_COUNT/2'
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hi%03d", i);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path, LFS_O_CREAT | LFS_O_WRONLY) => 0;
         lfs_file_close(&lfs, &file) => 0;
     }
 
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hello%03d", i);
         err = lfs_remove(&lfs, path);
         assert(err == 0 || err == LFS_ERR_NOENT);
     }
 
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -410,6 +480,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hi%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_REG);
@@ -435,6 +506,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hello%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_REG);
@@ -444,6 +516,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "hello%03d", i);
         lfs_remove(&lfs, path) => 0;
     }
@@ -460,24 +533,28 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # nested directories
+[cases.test_dirs_nested]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "potato") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "burito",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "potato/baked") => 0;
     lfs_mkdir(&lfs, "potato/sweet") => 0;
     lfs_mkdir(&lfs, "potato/fried") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "potato") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
     info.type => LFS_TYPE_DIR;
@@ -498,21 +575,21 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // try removing?
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_remove(&lfs, "potato") => LFS_ERR_NOTEMPTY;
     lfs_unmount(&lfs) => 0;
 
     // try renaming?
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "potato", "coldpotato") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "coldpotato", "warmpotato") => 0;
     lfs_rename(&lfs, "warmpotato", "hotpotato") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_remove(&lfs, "potato") => LFS_ERR_NOENT;
     lfs_remove(&lfs, "coldpotato") => LFS_ERR_NOENT;
     lfs_remove(&lfs, "warmpotato") => LFS_ERR_NOENT;
@@ -520,7 +597,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // try cross-directory renaming
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "coldpotato") => 0;
     lfs_rename(&lfs, "hotpotato/baked", "coldpotato/baked") => 0;
     lfs_rename(&lfs, "coldpotato", "hotpotato") => LFS_ERR_NOTEMPTY;
@@ -536,7 +613,7 @@ code = '''
     lfs_remove(&lfs, "hotpotato") => LFS_ERR_NOTEMPTY;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "hotpotato") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -558,7 +635,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
     
     // final remove
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_remove(&lfs, "hotpotato") => LFS_ERR_NOTEMPTY;
     lfs_remove(&lfs, "hotpotato/baked") => 0;
     lfs_remove(&lfs, "hotpotato") => LFS_ERR_NOTEMPTY;
@@ -568,7 +645,7 @@ code = '''
     lfs_remove(&lfs, "hotpotato") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -584,17 +661,22 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # recursive remove
-define.N = [10, 100]
+[cases.test_dirs_recursive_remove]
+defines.N = [10, 100]
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "prickly-pear") => 0;
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "prickly-pear/cactus%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "prickly-pear") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -602,6 +684,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "cactus%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -611,7 +694,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_remove(&lfs, "prickly-pear") => LFS_ERR_NOTEMPTY;
 
     lfs_dir_open(&lfs, &dir, "prickly-pear") => 0;
@@ -622,6 +705,7 @@ code = '''
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
     for (int i = 0; i < N; i++) {
+        char path[1024];
         sprintf(path, "cactus%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(info.type == LFS_TYPE_DIR);
@@ -636,22 +720,100 @@ code = '''
     lfs_remove(&lfs, "prickly-pear") => LFS_ERR_NOENT;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_remove(&lfs, "prickly-pear") => LFS_ERR_NOENT;
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # other error cases
+[cases.test_dirs_remove_read]
+defines.N = 10
+if = 'N < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_mkdir(&lfs, "prickly-pear") => 0;
+    for (int i = 0; i < N; i++) {
+        char path[1024];
+        sprintf(path, "prickly-pear/cactus%03d", i);
+        lfs_mkdir(&lfs, path) => 0;
+    }
+    lfs_dir_t dir;
+    lfs_dir_open(&lfs, &dir, "prickly-pear") => 0;
+    struct lfs_info info;
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, ".") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, "..") == 0);
+    for (int i = 0; i < N; i++) {
+        char path[1024];
+        sprintf(path, "cactus%03d", i);
+        lfs_dir_read(&lfs, &dir, &info) => 1;
+        assert(info.type == LFS_TYPE_DIR);
+        assert(strcmp(info.name, path) == 0);
+    }
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_unmount(&lfs);
+
+    for (lfs_size_t k = 0; k < N; k++) {
+        for (lfs_size_t j = 0; j < N; j++) {
+            lfs_mount(&lfs, cfg) => 0;
+            lfs_dir_open(&lfs, &dir, "prickly-pear") => 0;
+            lfs_dir_read(&lfs, &dir, &info) => 1;
+            assert(info.type == LFS_TYPE_DIR);
+            assert(strcmp(info.name, ".") == 0);
+            lfs_dir_read(&lfs, &dir, &info) => 1;
+            assert(info.type == LFS_TYPE_DIR);
+            assert(strcmp(info.name, "..") == 0);
+            // iterate over dirs < j
+            for (unsigned i = 0; i < j; i++) {
+                char path[1024];
+                sprintf(path, "cactus%03d", i);
+                lfs_dir_read(&lfs, &dir, &info) => 1;
+                assert(info.type == LFS_TYPE_DIR);
+                assert(strcmp(info.name, path) == 0);
+            }
+
+            // remove k while iterating
+            char path[1024];
+            sprintf(path, "prickly-pear/cactus%03d", k);
+            lfs_remove(&lfs, path) => 0;
+
+            // iterate over dirs >= j
+            for (unsigned i = j; i < ((k >= j) ? N-1 : N); i++) {
+                char path[1024];
+                sprintf(path, "cactus%03d", (k >= j && i >= k) ? i+1 : i);
+                lfs_dir_read(&lfs, &dir, &info) => 1;
+                assert(info.type == LFS_TYPE_DIR);
+                assert(strcmp(info.name, path) == 0);
+            }
+            lfs_dir_read(&lfs, &dir, &info) => 0;
+            lfs_dir_close(&lfs, &dir) => 0;
+
+            // recreate k
+            sprintf(path, "prickly-pear/cactus%03d", k);
+            lfs_mkdir(&lfs, path) => 0;
+            lfs_unmount(&lfs) => 0;
+        }
+    }
+'''
+
+[cases.test_dirs_other_errors]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "potato") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "burito",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     lfs_mkdir(&lfs, "potato") => LFS_ERR_EXIST;
     lfs_mkdir(&lfs, "burito") => LFS_ERR_EXIST;
@@ -659,6 +821,7 @@ code = '''
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => LFS_ERR_EXIST;
     lfs_file_open(&lfs, &file, "potato",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => LFS_ERR_EXIST;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "tomato") => LFS_ERR_NOENT;
     lfs_dir_open(&lfs, &dir, "burito") => LFS_ERR_NOTDIR;
     lfs_file_open(&lfs, &file, "tomato", LFS_O_RDONLY) => LFS_ERR_NOENT;
@@ -668,6 +831,11 @@ code = '''
     lfs_file_open(&lfs, &file, "potato",
             LFS_O_WRONLY | LFS_O_CREAT) => LFS_ERR_ISDIR;
 
+    lfs_file_open(&lfs, &file, "tacoto", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_rename(&lfs, "tacoto", "potato") => LFS_ERR_ISDIR;
+    lfs_rename(&lfs, "potato", "tacoto") => LFS_ERR_NOTDIR;
+
     lfs_mkdir(&lfs, "/") => LFS_ERR_EXIST;
     lfs_file_open(&lfs, &file, "/",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => LFS_ERR_EXIST;
@@ -678,6 +846,7 @@ code = '''
 
     // check that errors did not corrupt directory
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, ".") == 0);
@@ -690,13 +859,17 @@ code = '''
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "potato") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_REG);
+    assert(strcmp(info.name, "tacoto") == 0);
+    assert(info.size == 0);
     lfs_dir_read(&lfs, &dir, &info) => 0;
     lfs_dir_close(&lfs, &dir) => 0;
 
     lfs_unmount(&lfs) => 0;
 
     // or on disk
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -710,26 +883,36 @@ code = '''
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "potato") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_REG);
+    assert(strcmp(info.name, "tacoto") == 0);
+    assert(info.size == 0);
     lfs_dir_read(&lfs, &dir, &info) => 0;
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # directory seek
-define.COUNT = [4, 128, 132]
+[cases.test_dirs_seek]
+defines.COUNT = [4, 128, 132]
+if = 'COUNT < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
     for (int i = 0; i < COUNT; i++) {
+        char path[1024];
         sprintf(path, "hello/kitty%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    for (int j = 2; j < COUNT; j++) {
-        lfs_mount(&lfs, &cfg) => 0;
+    // try seeking to each dir entry
+    for (int j = 0; j < COUNT; j++) {
+        lfs_mount(&lfs, cfg) => 0;
+        lfs_dir_t dir;
         lfs_dir_open(&lfs, &dir, "hello") => 0;
+        struct lfs_info info;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, ".") == 0);
         assert(info.type == LFS_TYPE_DIR);
@@ -737,24 +920,25 @@ code = '''
         assert(strcmp(info.name, "..") == 0);
         assert(info.type == LFS_TYPE_DIR);
 
-        lfs_soff_t pos;
         for (int i = 0; i < j; i++) {
+            char path[1024];
             sprintf(path, "kitty%03d", i);
             lfs_dir_read(&lfs, &dir, &info) => 1;
             assert(strcmp(info.name, path) == 0);
             assert(info.type == LFS_TYPE_DIR);
-            pos = lfs_dir_tell(&lfs, &dir);
-            assert(pos >= 0);
         }
+        lfs_soff_t pos = lfs_dir_tell(&lfs, &dir);
+        assert(pos >= 0);
 
         lfs_dir_seek(&lfs, &dir, pos) => 0;
+        char path[1024];
         sprintf(path, "kitty%03d", j);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, path) == 0);
         assert(info.type == LFS_TYPE_DIR);
 
         lfs_dir_rewind(&lfs, &dir) => 0;
-        sprintf(path, "kitty%03d", 0);
+        sprintf(path, "kitty%03u", 0);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, ".") == 0);
         assert(info.type == LFS_TYPE_DIR);
@@ -774,22 +958,73 @@ code = '''
         lfs_dir_close(&lfs, &dir) => 0;
         lfs_unmount(&lfs) => 0;
     }
+
+    // try seeking to end of dir
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    lfs_dir_open(&lfs, &dir, "hello") => 0;
+    struct lfs_info info;
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, ".") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, "..") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+
+    for (int i = 0; i < COUNT; i++) {
+        char path[1024];
+        sprintf(path, "kitty%03d", i);
+        lfs_dir_read(&lfs, &dir, &info) => 1;
+        assert(strcmp(info.name, path) == 0);
+        assert(info.type == LFS_TYPE_DIR);
+    }
+    lfs_soff_t pos = lfs_dir_tell(&lfs, &dir);
+    assert(pos >= 0);
+
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+
+    lfs_dir_seek(&lfs, &dir, pos) => 0;
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+
+    lfs_dir_rewind(&lfs, &dir) => 0;
+    char path[1024];
+    sprintf(path, "kitty%03d", 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, ".") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, "..") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, path) == 0);
+    assert(info.type == LFS_TYPE_DIR);
+
+    lfs_dir_seek(&lfs, &dir, pos) => 0;
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # root seek
-define.COUNT = [4, 128, 132]
+[cases.test_dirs_toot_seek]
+defines.COUNT = [4, 128, 132]
+if = 'COUNT < BLOCK_COUNT/2'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < COUNT; i++) {
+        char path[1024];
         sprintf(path, "hi%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    for (int j = 2; j < COUNT; j++) {
-        lfs_mount(&lfs, &cfg) => 0;
+    for (int j = 0; j < COUNT; j++) {
+        lfs_mount(&lfs, cfg) => 0;
+        lfs_dir_t dir;
         lfs_dir_open(&lfs, &dir, "/") => 0;
+        struct lfs_info info;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, ".") == 0);
         assert(info.type == LFS_TYPE_DIR);
@@ -797,24 +1032,25 @@ code = '''
         assert(strcmp(info.name, "..") == 0);
         assert(info.type == LFS_TYPE_DIR);
 
-        lfs_soff_t pos;
         for (int i = 0; i < j; i++) {
+            char path[1024];
             sprintf(path, "hi%03d", i);
             lfs_dir_read(&lfs, &dir, &info) => 1;
             assert(strcmp(info.name, path) == 0);
             assert(info.type == LFS_TYPE_DIR);
-            pos = lfs_dir_tell(&lfs, &dir);
-            assert(pos >= 0);
         }
+        lfs_soff_t pos = lfs_dir_tell(&lfs, &dir);
+        assert(pos >= 0);
 
         lfs_dir_seek(&lfs, &dir, pos) => 0;
+        char path[1024];
         sprintf(path, "hi%03d", j);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, path) == 0);
         assert(info.type == LFS_TYPE_DIR);
 
         lfs_dir_rewind(&lfs, &dir) => 0;
-        sprintf(path, "hi%03d", 0);
+        sprintf(path, "hi%03u", 0);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, ".") == 0);
         assert(info.type == LFS_TYPE_DIR);
@@ -834,5 +1070,51 @@ code = '''
         lfs_dir_close(&lfs, &dir) => 0;
         lfs_unmount(&lfs) => 0;
     }
+
+    // try seeking to end of dir
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, ".") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, "..") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+
+    for (int i = 0; i < COUNT; i++) {
+        char path[1024];
+        sprintf(path, "hi%03d", i);
+        lfs_dir_read(&lfs, &dir, &info) => 1;
+        assert(strcmp(info.name, path) == 0);
+        assert(info.type == LFS_TYPE_DIR);
+    }
+    lfs_soff_t pos = lfs_dir_tell(&lfs, &dir);
+    assert(pos >= 0);
+
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+
+    lfs_dir_seek(&lfs, &dir, pos) => 0;
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+
+    lfs_dir_rewind(&lfs, &dir) => 0;
+    char path[1024];
+    sprintf(path, "hi%03d", 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, ".") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, "..") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(strcmp(info.name, path) == 0);
+    assert(info.type == LFS_TYPE_DIR);
+
+    lfs_dir_seek(&lfs, &dir, pos) => 0;
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_unmount(&lfs) => 0;
 '''
 

tests/test_entries.toml

@@ -2,19 +2,23 @@
 # Note that these tests are intended for 512 byte inline sizes. They should
 # still pass with other inline sizes but wouldn't be testing anything.
 
-define.LFS_CACHE_SIZE = 512
-if = 'LFS_CACHE_SIZE % LFS_PROG_SIZE == 0 && LFS_CACHE_SIZE == 512'
+defines.CACHE_SIZE = 512
+if = 'CACHE_SIZE % PROG_SIZE == 0 && CACHE_SIZE == 512'
 
-[[case]] # entry grow test
+[cases.test_entries_grow]
 code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // write hi0 20
+    char path[1024];
+    lfs_size_t size;
     sprintf(path, "hi0"); size = 20;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     memset(wbuffer, 'c', size);
@@ -94,16 +98,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # entry shrink test
+[cases.test_entries_shrink]
 code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // write hi0 20
+    char path[1024];
+    lfs_size_t size;
     sprintf(path, "hi0"); size = 20;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     memset(wbuffer, 'c', size);
@@ -183,16 +191,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # entry spill test
+[cases.test_entries_spill]
 code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // write hi0 200
+    char path[1024];
+    lfs_size_t size;
     sprintf(path, "hi0"); size = 200;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     memset(wbuffer, 'c', size);
@@ -256,16 +268,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # entry push spill test
+[cases.test_entries_push_spill]
 code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // write hi0 200
+    char path[1024];
+    lfs_size_t size;
     sprintf(path, "hi0"); size = 200;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     memset(wbuffer, 'c', size);
@@ -345,16 +361,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # entry push spill two test
+[cases.test_entries_push_spill_two]
 code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // write hi0 200
+    char path[1024];
+    lfs_size_t size;
     sprintf(path, "hi0"); size = 200;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     memset(wbuffer, 'c', size);
@@ -449,16 +469,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # entry drop test
+[cases.test_entries_drop]
 code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // write hi0 200
+    char path[1024];
+    lfs_size_t size;
     sprintf(path, "hi0"); size = 200;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     memset(wbuffer, 'c', size);
@@ -491,6 +515,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
 
     lfs_remove(&lfs, "hi1") => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "hi1", &info) => LFS_ERR_NOENT;
     // read hi0 200
     sprintf(path, "hi0"); size = 200;
@@ -547,15 +572,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # create too big
+[cases.test_entries_create_too_big]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    char path[1024];
     memset(path, 'm', 200);
     path[200] = '\0';
 
-    size = 400;
+    lfs_size_t size = 400;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     uint8_t wbuffer[1024];
@@ -572,15 +600,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # resize too big
+[cases.test_entries_resize_too_big]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    char path[1024];
     memset(path, 'm', 200);
     path[200] = '\0';
 
-    size = 40;
+    lfs_size_t size = 40;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, path,
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     uint8_t wbuffer[1024];

tests/test_evil.toml

@@ -3,16 +3,17 @@
 
 # invalid pointer tests (outside of block_count)
 
-[[case]] # invalid tail-pointer test
-define.TAIL_TYPE = ['LFS_TYPE_HARDTAIL', 'LFS_TYPE_SOFTTAIL']
-define.INVALSET = [0x3, 0x1, 0x2]
+[cases.test_evil_invalid_tail_pointer]
+defines.TAIL_TYPE = ['LFS_TYPE_HARDTAIL', 'LFS_TYPE_SOFTTAIL']
+defines.INVALSET = [0x3, 0x1, 0x2]
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     // change tail-pointer to invalid pointers
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
@@ -23,25 +24,27 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
 '''
 
-[[case]] # invalid dir pointer test
-define.INVALSET = [0x3, 0x1, 0x2]
+[cases.test_evil_invalid_dir_pointer]
+defines.INVALSET = [0x3, 0x1, 0x2]
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
     // make a dir
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "dir_here") => 0;
     lfs_unmount(&lfs) => 0;
 
     // change the dir pointer to be invalid
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     // make sure id 1 == our directory
+    uint8_t buffer[1024];
     lfs_dir_get(&lfs, &mdir,
             LFS_MKTAG(0x700, 0x3ff, 0),
             LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("dir_here")), buffer)
@@ -57,14 +60,17 @@ code = '''
 
     // test that accessing our bad dir fails, note there's a number
     // of ways to access the dir, some can fail, but some don't
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "dir_here", &info) => 0;
     assert(strcmp(info.name, "dir_here") == 0);
     assert(info.type == LFS_TYPE_DIR);
 
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "dir_here") => LFS_ERR_CORRUPT;
     lfs_stat(&lfs, "dir_here/file_here", &info) => LFS_ERR_CORRUPT;
     lfs_dir_open(&lfs, &dir, "dir_here/dir_here") => LFS_ERR_CORRUPT;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "dir_here/file_here",
             LFS_O_RDONLY) => LFS_ERR_CORRUPT;
     lfs_file_open(&lfs, &file, "dir_here/file_here",
@@ -72,24 +78,27 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # invalid file pointer test
+[cases.test_evil_invalid_file_pointer]
 in = "lfs.c"
-define.SIZE = [10, 1000, 100000] # faked file size
+defines.SIZE = [10, 1000, 100000] # faked file size
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
     // make a file
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "file_here",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
     // change the file pointer to be invalid
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     // make sure id 1 == our file
+    uint8_t buffer[1024];
     lfs_dir_get(&lfs, &mdir,
             LFS_MKTAG(0x700, 0x3ff, 0),
             LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("file_here")), buffer)
@@ -103,7 +112,8 @@ code = '''
 
     // test that accessing our bad file fails, note there's a number
     // of ways to access the dir, some can fail, but some don't
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "file_here", &info) => 0;
     assert(strcmp(info.name, "file_here") == 0);
     assert(info.type == LFS_TYPE_REG);
@@ -114,20 +124,22 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
 
     // any allocs that traverse CTZ must unfortunately must fail
-    if (SIZE > 2*LFS_BLOCK_SIZE) {
+    if (SIZE > 2*BLOCK_SIZE) {
         lfs_mkdir(&lfs, "dir_here") => LFS_ERR_CORRUPT;
     }
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # invalid pointer in CTZ skip-list test
-define.SIZE = ['2*LFS_BLOCK_SIZE', '3*LFS_BLOCK_SIZE', '4*LFS_BLOCK_SIZE']
+[cases.test_evil_invalid_ctz_pointer] # invalid pointer in CTZ skip-list test
+defines.SIZE = ['2*BLOCK_SIZE', '3*BLOCK_SIZE', '4*BLOCK_SIZE']
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
     // make a file
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "file_here",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     for (int i = 0; i < SIZE; i++) {
@@ -137,10 +149,11 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
     // change pointer in CTZ skip-list to be invalid
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     // make sure id 1 == our file and get our CTZ structure
+    uint8_t buffer[4*BLOCK_SIZE];
     lfs_dir_get(&lfs, &mdir,
             LFS_MKTAG(0x700, 0x3ff, 0),
             LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("file_here")), buffer)
@@ -153,18 +166,19 @@ code = '''
                 => LFS_MKTAG(LFS_TYPE_CTZSTRUCT, 1, sizeof(struct lfs_ctz));
     lfs_ctz_fromle32(&ctz);
     // rewrite block to contain bad pointer
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, ctz.head, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+    uint8_t bbuffer[BLOCK_SIZE];
+    cfg->read(cfg, ctz.head, 0, bbuffer, BLOCK_SIZE) => 0;
     uint32_t bad = lfs_tole32(0xcccccccc);
     memcpy(&bbuffer[0], &bad, sizeof(bad));
     memcpy(&bbuffer[4], &bad, sizeof(bad));
-    cfg.erase(&cfg, ctz.head) => 0;
-    cfg.prog(&cfg, ctz.head, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+    cfg->erase(cfg, ctz.head) => 0;
+    cfg->prog(cfg, ctz.head, 0, bbuffer, BLOCK_SIZE) => 0;
     lfs_deinit(&lfs) => 0;
 
     // test that accessing our bad file fails, note there's a number
     // of ways to access the dir, some can fail, but some don't
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "file_here", &info) => 0;
     assert(strcmp(info.name, "file_here") == 0);
     assert(info.type == LFS_TYPE_REG);
@@ -175,22 +189,23 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
 
     // any allocs that traverse CTZ must unfortunately must fail
-    if (SIZE > 2*LFS_BLOCK_SIZE) {
+    if (SIZE > 2*BLOCK_SIZE) {
         lfs_mkdir(&lfs, "dir_here") => LFS_ERR_CORRUPT;
     }
     lfs_unmount(&lfs) => 0;
 '''
 
 
-[[case]] # invalid gstate pointer
-define.INVALSET = [0x3, 0x1, 0x2]
+[cases.test_evil_invalid_gstate_pointer]
+defines.INVALSET = [0x3, 0x1, 0x2]
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     // create an invalid gstate
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     lfs_fs_prepmove(&lfs, 1, (lfs_block_t [2]){
@@ -202,21 +217,22 @@ code = '''
     // test that mount fails gracefully
     // mount may not fail, but our first alloc should fail when
     // we try to fix the gstate
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "should_fail") => LFS_ERR_CORRUPT;
     lfs_unmount(&lfs) => 0;
 '''
 
 # cycle detection/recovery tests
 
-[[case]] # metadata-pair threaded-list loop test
+[cases.test_evil_mdir_loop] # metadata-pair threaded-list loop test
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     // change tail-pointer to point to ourself
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
@@ -225,20 +241,21 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
 '''
 
-[[case]] # metadata-pair threaded-list 2-length loop test
+[cases.test_evil_mdir_loop2] # metadata-pair threaded-list 2-length loop test
 in = "lfs.c"
 code = '''
     // create littlefs with child dir
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
     // find child
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_block_t pair[2];
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
@@ -255,20 +272,21 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
 '''
 
-[[case]] # metadata-pair threaded-list 1-length child loop test
+[cases.test_evil_mdir_loop_child] # metadata-pair threaded-list 1-length child loop test
 in = "lfs.c"
 code = '''
     // create littlefs with child dir
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
     // find child
-    lfs_init(&lfs, &cfg) => 0;
+    lfs_init(&lfs, cfg) => 0;
     lfs_mdir_t mdir;
     lfs_block_t pair[2];
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
@@ -284,5 +302,5 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
 '''

tests/test_exhaustion.toml

@@ -1,46 +1,50 @@
-[[case]] # test running a filesystem to exhaustion
-define.LFS_ERASE_CYCLES = 10
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_PROGERROR',
-    'LFS_TESTBD_BADBLOCK_ERASEERROR',
-    'LFS_TESTBD_BADBLOCK_READERROR',
-    'LFS_TESTBD_BADBLOCK_PROGNOOP',
-    'LFS_TESTBD_BADBLOCK_ERASENOOP',
+# test running a filesystem to exhaustion
+[cases.test_exhaustion_normal]
+defines.ERASE_CYCLES = 10
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
+defines.BADBLOCK_BEHAVIOR = [
+    'LFS_EMUBD_BADBLOCK_PROGERROR',
+    'LFS_EMUBD_BADBLOCK_ERASEERROR',
+    'LFS_EMUBD_BADBLOCK_READERROR',
+    'LFS_EMUBD_BADBLOCK_PROGNOOP',
+    'LFS_EMUBD_BADBLOCK_ERASENOOP',
 ]
-define.FILES = 10
+defines.FILES = 10
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "roadrunner") => 0;
     lfs_unmount(&lfs) => 0;
 
     uint32_t cycle = 0;
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // chose name, roughly random seed, and random 2^n size
+            char path[1024];
             sprintf(path, "roadrunner/test%d", i);
-            srand(cycle * i);
-            size = 1 << ((rand() % 10)+2);
+            uint32_t prng = cycle * i;
+            lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path,
                     LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
             for (lfs_size_t j = 0; j < size; j++) {
-                char c = 'a' + (rand() % 26);
+                char c = 'a' + (TEST_PRNG(&prng) % 26);
                 lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                 assert(res == 1 || res == LFS_ERR_NOSPC);
                 if (res == LFS_ERR_NOSPC) {
-                    err = lfs_file_close(&lfs, &file);
+                    int err = lfs_file_close(&lfs, &file);
                     assert(err == 0 || err == LFS_ERR_NOSPC);
                     lfs_unmount(&lfs) => 0;
                     goto exhausted;
                 }
             }
 
-            err = lfs_file_close(&lfs, &file);
+            int err = lfs_file_close(&lfs, &file);
             assert(err == 0 || err == LFS_ERR_NOSPC);
             if (err == LFS_ERR_NOSPC) {
                 lfs_unmount(&lfs) => 0;
@@ -50,13 +54,15 @@ code = '''
 
         for (uint32_t i = 0; i < FILES; i++) {
             // check for errors
+            char path[1024];
             sprintf(path, "roadrunner/test%d", i);
-            srand(cycle * i);
-            size = 1 << ((rand() % 10)+2);
+            uint32_t prng = cycle * i;
+            lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
             for (lfs_size_t j = 0; j < size; j++) {
-                char c = 'a' + (rand() % 26);
+                char c = 'a' + (TEST_PRNG(&prng) % 26);
                 char r;
                 lfs_file_read(&lfs, &file, &r, 1) => 1;
                 assert(r == c);
@@ -71,10 +77,12 @@ code = '''
 
 exhausted:
     // should still be readable
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (uint32_t i = 0; i < FILES; i++) {
         // check for errors
+        char path[1024];
         sprintf(path, "roadrunner/test%d", i);
+        struct lfs_info info;
         lfs_stat(&lfs, path, &info) => 0;
     }
     lfs_unmount(&lfs) => 0;
@@ -82,47 +90,51 @@ exhausted:
     LFS_WARN("completed %d cycles", cycle);
 '''
 
-[[case]] # test running a filesystem to exhaustion
-         # which also requires expanding superblocks
-define.LFS_ERASE_CYCLES = 10
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_PROGERROR',
-    'LFS_TESTBD_BADBLOCK_ERASEERROR',
-    'LFS_TESTBD_BADBLOCK_READERROR',
-    'LFS_TESTBD_BADBLOCK_PROGNOOP',
-    'LFS_TESTBD_BADBLOCK_ERASENOOP',
+# test running a filesystem to exhaustion
+# which also requires expanding superblocks
+[cases.test_exhaustion_superblocks]
+defines.ERASE_CYCLES = 10
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
+defines.BADBLOCK_BEHAVIOR = [
+    'LFS_EMUBD_BADBLOCK_PROGERROR',
+    'LFS_EMUBD_BADBLOCK_ERASEERROR',
+    'LFS_EMUBD_BADBLOCK_READERROR',
+    'LFS_EMUBD_BADBLOCK_PROGNOOP',
+    'LFS_EMUBD_BADBLOCK_ERASENOOP',
 ]
-define.FILES = 10
+defines.FILES = 10
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     uint32_t cycle = 0;
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // chose name, roughly random seed, and random 2^n size
+            char path[1024];
             sprintf(path, "test%d", i);
-            srand(cycle * i);
-            size = 1 << ((rand() % 10)+2);
+            uint32_t prng = cycle * i;
+            lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path,
                     LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
             for (lfs_size_t j = 0; j < size; j++) {
-                char c = 'a' + (rand() % 26);
+                char c = 'a' + (TEST_PRNG(&prng) % 26);
                 lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                 assert(res == 1 || res == LFS_ERR_NOSPC);
                 if (res == LFS_ERR_NOSPC) {
-                    err = lfs_file_close(&lfs, &file);
+                    int err = lfs_file_close(&lfs, &file);
                     assert(err == 0 || err == LFS_ERR_NOSPC);
                     lfs_unmount(&lfs) => 0;
                     goto exhausted;
                 }
             }
 
-            err = lfs_file_close(&lfs, &file);
+            int err = lfs_file_close(&lfs, &file);
             assert(err == 0 || err == LFS_ERR_NOSPC);
             if (err == LFS_ERR_NOSPC) {
                 lfs_unmount(&lfs) => 0;
@@ -132,13 +144,15 @@ code = '''
 
         for (uint32_t i = 0; i < FILES; i++) {
             // check for errors
+            char path[1024];
             sprintf(path, "test%d", i);
-            srand(cycle * i);
-            size = 1 << ((rand() % 10)+2);
+            uint32_t prng = cycle * i;
+            lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
             for (lfs_size_t j = 0; j < size; j++) {
-                char c = 'a' + (rand() % 26);
+                char c = 'a' + (TEST_PRNG(&prng) % 26);
                 char r;
                 lfs_file_read(&lfs, &file, &r, 1) => 1;
                 assert(r == c);
@@ -153,9 +167,11 @@ code = '''
 
 exhausted:
     // should still be readable
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (uint32_t i = 0; i < FILES; i++) {
         // check for errors
+        char path[1024];
+        struct lfs_info info;
         sprintf(path, "test%d", i);
         lfs_stat(&lfs, path, &info) => 0;
     }
@@ -169,51 +185,55 @@ exhausted:
 # into increasing the block devices lifetime. This is something we can actually
 # check for.
 
-[[case]] # wear-level test running a filesystem to exhaustion
-define.LFS_ERASE_CYCLES = 20
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
-define.FILES = 10
+# wear-level test running a filesystem to exhaustion
+[cases.test_exhuastion_wear_leveling]
+defines.ERASE_CYCLES = 20
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
+defines.FILES = 10
 code = '''
     uint32_t run_cycles[2];
-    const uint32_t run_block_count[2] = {LFS_BLOCK_COUNT/2, LFS_BLOCK_COUNT};
+    const uint32_t run_block_count[2] = {BLOCK_COUNT/2, BLOCK_COUNT};
 
     for (int run = 0; run < 2; run++) {
-        for (lfs_block_t b = 0; b < LFS_BLOCK_COUNT; b++) {
-            lfs_testbd_setwear(&cfg, b,
-                    (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
+        for (lfs_block_t b = 0; b < BLOCK_COUNT; b++) {
+            lfs_emubd_setwear(cfg, b,
+                    (b < run_block_count[run]) ? 0 : ERASE_CYCLES) => 0;
         }
 
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_t lfs;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         lfs_mkdir(&lfs, "roadrunner") => 0;
         lfs_unmount(&lfs) => 0;
 
         uint32_t cycle = 0;
         while (true) {
-            lfs_mount(&lfs, &cfg) => 0;
+            lfs_mount(&lfs, cfg) => 0;
             for (uint32_t i = 0; i < FILES; i++) {
                 // chose name, roughly random seed, and random 2^n size
+                char path[1024];
                 sprintf(path, "roadrunner/test%d", i);
-                srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
+                uint32_t prng = cycle * i;
+                lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+                lfs_file_t file;
                 lfs_file_open(&lfs, &file, path,
                         LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
                 for (lfs_size_t j = 0; j < size; j++) {
-                    char c = 'a' + (rand() % 26);
+                    char c = 'a' + (TEST_PRNG(&prng) % 26);
                     lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                     assert(res == 1 || res == LFS_ERR_NOSPC);
                     if (res == LFS_ERR_NOSPC) {
-                        err = lfs_file_close(&lfs, &file);
+                        int err = lfs_file_close(&lfs, &file);
                         assert(err == 0 || err == LFS_ERR_NOSPC);
                         lfs_unmount(&lfs) => 0;
                         goto exhausted;
                     }
                 }
 
-                err = lfs_file_close(&lfs, &file);
+                int err = lfs_file_close(&lfs, &file);
                 assert(err == 0 || err == LFS_ERR_NOSPC);
                 if (err == LFS_ERR_NOSPC) {
                     lfs_unmount(&lfs) => 0;
@@ -223,13 +243,15 @@ code = '''
 
             for (uint32_t i = 0; i < FILES; i++) {
                 // check for errors
+                char path[1024];
                 sprintf(path, "roadrunner/test%d", i);
-                srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
+                uint32_t prng = cycle * i;
+                lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+                lfs_file_t file;
                 lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
                 for (lfs_size_t j = 0; j < size; j++) {
-                    char c = 'a' + (rand() % 26);
+                    char c = 'a' + (TEST_PRNG(&prng) % 26);
                     char r;
                     lfs_file_read(&lfs, &file, &r, 1) => 1;
                     assert(r == c);
@@ -244,9 +266,11 @@ code = '''
 
 exhausted:
         // should still be readable
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // check for errors
+            char path[1024];
+            struct lfs_info info;
             sprintf(path, "roadrunner/test%d", i);
             lfs_stat(&lfs, path, &info) => 0;
         }
@@ -261,48 +285,52 @@ exhausted:
     LFS_ASSERT(run_cycles[1]*110/100 > 2*run_cycles[0]);
 '''
 
-[[case]] # wear-level test + expanding superblock
-define.LFS_ERASE_CYCLES = 20
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
-define.FILES = 10
+# wear-level test + expanding superblock
+[cases.test_exhaustion_wear_leveling_superblocks]
+defines.ERASE_CYCLES = 20
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
+defines.FILES = 10
 code = '''
     uint32_t run_cycles[2];
-    const uint32_t run_block_count[2] = {LFS_BLOCK_COUNT/2, LFS_BLOCK_COUNT};
+    const uint32_t run_block_count[2] = {BLOCK_COUNT/2, BLOCK_COUNT};
 
     for (int run = 0; run < 2; run++) {
-        for (lfs_block_t b = 0; b < LFS_BLOCK_COUNT; b++) {
-            lfs_testbd_setwear(&cfg, b,
-                    (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
+        for (lfs_block_t b = 0; b < BLOCK_COUNT; b++) {
+            lfs_emubd_setwear(cfg, b,
+                    (b < run_block_count[run]) ? 0 : ERASE_CYCLES) => 0;
         }
 
-        lfs_format(&lfs, &cfg) => 0;
+        lfs_t lfs;
+        lfs_format(&lfs, cfg) => 0;
 
         uint32_t cycle = 0;
         while (true) {
-            lfs_mount(&lfs, &cfg) => 0;
+            lfs_mount(&lfs, cfg) => 0;
             for (uint32_t i = 0; i < FILES; i++) {
                 // chose name, roughly random seed, and random 2^n size
+                char path[1024];
                 sprintf(path, "test%d", i);
-                srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
+                uint32_t prng = cycle * i;
+                lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+                lfs_file_t file;
                 lfs_file_open(&lfs, &file, path,
                         LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
                 for (lfs_size_t j = 0; j < size; j++) {
-                    char c = 'a' + (rand() % 26);
+                    char c = 'a' + (TEST_PRNG(&prng) % 26);
                     lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                     assert(res == 1 || res == LFS_ERR_NOSPC);
                     if (res == LFS_ERR_NOSPC) {
-                        err = lfs_file_close(&lfs, &file);
+                        int err = lfs_file_close(&lfs, &file);
                         assert(err == 0 || err == LFS_ERR_NOSPC);
                         lfs_unmount(&lfs) => 0;
                         goto exhausted;
                     }
                 }
 
-                err = lfs_file_close(&lfs, &file);
+                int err = lfs_file_close(&lfs, &file);
                 assert(err == 0 || err == LFS_ERR_NOSPC);
                 if (err == LFS_ERR_NOSPC) {
                     lfs_unmount(&lfs) => 0;
@@ -312,13 +340,15 @@ code = '''
 
             for (uint32_t i = 0; i < FILES; i++) {
                 // check for errors
+                char path[1024];
                 sprintf(path, "test%d", i);
-                srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
+                uint32_t prng = cycle * i;
+                lfs_size_t size = 1 << ((TEST_PRNG(&prng) % 10)+2);
 
+                lfs_file_t file;
                 lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
                 for (lfs_size_t j = 0; j < size; j++) {
-                    char c = 'a' + (rand() % 26);
+                    char c = 'a' + (TEST_PRNG(&prng) % 26);
                     char r;
                     lfs_file_read(&lfs, &file, &r, 1) => 1;
                     assert(r == c);
@@ -333,9 +363,11 @@ code = '''
 
 exhausted:
         // should still be readable
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // check for errors
+            char path[1024];
+            struct lfs_info info;
             sprintf(path, "test%d", i);
             lfs_stat(&lfs, path, &info) => 0;
         }
@@ -350,44 +382,48 @@ exhausted:
     LFS_ASSERT(run_cycles[1]*110/100 > 2*run_cycles[0]);
 '''
 
-[[case]] # test that we wear blocks roughly evenly
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
-define.LFS_BLOCK_CYCLES = [5, 4, 3, 2, 1]
-define.CYCLES = 100
-define.FILES = 10
-if = 'LFS_BLOCK_CYCLES < CYCLES/10'
+# test that we wear blocks roughly evenly
+[cases.test_exhaustion_wear_distribution]
+defines.ERASE_CYCLES = 0xffffffff
+defines.ERASE_COUNT = 256 # small bd so test runs faster
+defines.BLOCK_CYCLES = [5, 4, 3, 2, 1]
+defines.CYCLES = 100
+defines.FILES = 10
+if = 'BLOCK_CYCLES < CYCLES/10'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "roadrunner") => 0;
     lfs_unmount(&lfs) => 0;
 
     uint32_t cycle = 0;
     while (cycle < CYCLES) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // chose name, roughly random seed, and random 2^n size
+            char path[1024];
             sprintf(path, "roadrunner/test%d", i);
-            srand(cycle * i);
-            size = 1 << 4; //((rand() % 10)+2);
+            uint32_t prng = cycle * i;
+            lfs_size_t size = 1 << 4; //((TEST_PRNG(&prng) % 10)+2);
 
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path,
                     LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
             for (lfs_size_t j = 0; j < size; j++) {
-                char c = 'a' + (rand() % 26);
+                char c = 'a' + (TEST_PRNG(&prng) % 26);
                 lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                 assert(res == 1 || res == LFS_ERR_NOSPC);
                 if (res == LFS_ERR_NOSPC) {
-                    err = lfs_file_close(&lfs, &file);
+                    int err = lfs_file_close(&lfs, &file);
                     assert(err == 0 || err == LFS_ERR_NOSPC);
                     lfs_unmount(&lfs) => 0;
                     goto exhausted;
                 }
             }
 
-            err = lfs_file_close(&lfs, &file);
+            int err = lfs_file_close(&lfs, &file);
             assert(err == 0 || err == LFS_ERR_NOSPC);
             if (err == LFS_ERR_NOSPC) {
                 lfs_unmount(&lfs) => 0;
@@ -397,13 +433,15 @@ code = '''
 
         for (uint32_t i = 0; i < FILES; i++) {
             // check for errors
+            char path[1024];
             sprintf(path, "roadrunner/test%d", i);
-            srand(cycle * i);
-            size = 1 << 4; //((rand() % 10)+2);
+            uint32_t prng = cycle * i;
+            lfs_size_t size = 1 << 4; //((TEST_PRNG(&prng) % 10)+2);
 
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
             for (lfs_size_t j = 0; j < size; j++) {
-                char c = 'a' + (rand() % 26);
+                char c = 'a' + (TEST_PRNG(&prng) % 26);
                 char r;
                 lfs_file_read(&lfs, &file, &r, 1) => 1;
                 assert(r == c);
@@ -418,9 +456,11 @@ code = '''
 
 exhausted:
     // should still be readable
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (uint32_t i = 0; i < FILES; i++) {
         // check for errors
+        char path[1024];
+        struct lfs_info info;
         sprintf(path, "roadrunner/test%d", i);
         lfs_stat(&lfs, path, &info) => 0;
     }
@@ -429,12 +469,12 @@ exhausted:
     LFS_WARN("completed %d cycles", cycle);
 
     // check the wear on our block device
-    lfs_testbd_wear_t minwear = -1;
-    lfs_testbd_wear_t totalwear = 0;
-    lfs_testbd_wear_t maxwear = 0;
+    lfs_emubd_wear_t minwear = -1;
+    lfs_emubd_wear_t totalwear = 0;
+    lfs_emubd_wear_t maxwear = 0;
     // skip 0 and 1 as superblock movement is intentionally avoided
-    for (lfs_block_t b = 2; b < LFS_BLOCK_COUNT; b++) {
-        lfs_testbd_wear_t wear = lfs_testbd_getwear(&cfg, b);
+    for (lfs_block_t b = 2; b < BLOCK_COUNT; b++) {
+        lfs_emubd_wear_t wear = lfs_emubd_wear(cfg, b);
         printf("%08x: wear %d\n", b, wear);
         assert(wear >= 0);
         if (wear < minwear) {
@@ -445,17 +485,17 @@ exhausted:
         }
         totalwear += wear;
     }
-    lfs_testbd_wear_t avgwear = totalwear / LFS_BLOCK_COUNT;
+    lfs_emubd_wear_t avgwear = totalwear / BLOCK_COUNT;
     LFS_WARN("max wear: %d cycles", maxwear);
-    LFS_WARN("avg wear: %d cycles", totalwear / LFS_BLOCK_COUNT);
+    LFS_WARN("avg wear: %d cycles", totalwear / (int)BLOCK_COUNT);
     LFS_WARN("min wear: %d cycles", minwear);
 
     // find standard deviation^2
-    lfs_testbd_wear_t dev2 = 0;
-    for (lfs_block_t b = 2; b < LFS_BLOCK_COUNT; b++) {
-        lfs_testbd_wear_t wear = lfs_testbd_getwear(&cfg, b);
+    lfs_emubd_wear_t dev2 = 0;
+    for (lfs_block_t b = 2; b < BLOCK_COUNT; b++) {
+        lfs_emubd_wear_t wear = lfs_emubd_wear(cfg, b);
         assert(wear >= 0);
-        lfs_testbd_swear_t diff = wear - avgwear;
+        lfs_emubd_swear_t diff = wear - avgwear;
         dev2 += diff*diff;
     }
     dev2 /= totalwear;

tests/test_files.toml

@@ -1,17 +1,21 @@
 
-[[case]] # simple file test
+[cases.test_files_simple]
+defines.INLINE_MAX = [0, -1, 8]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "hello",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
-    size = strlen("Hello World!")+1;
+    lfs_size_t size = strlen("Hello World!")+1;
+    uint8_t buffer[1024];
     strcpy((char*)buffer, "Hello World!");
     lfs_file_write(&lfs, &file, buffer, size) => size;
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "hello", LFS_O_RDONLY) => 0;
     lfs_file_read(&lfs, &file, buffer, size) => size;
     assert(strcmp((char*)buffer, "Hello World!") == 0);
@@ -19,21 +23,25 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # larger files
-define.SIZE = [32, 8192, 262144, 0, 7, 8193]
-define.CHUNKSIZE = [31, 16, 33, 1, 1023]
+[cases.test_files_large]
+defines.SIZE = [32, 8192, 262144, 0, 7, 8193]
+defines.CHUNKSIZE = [31, 16, 33, 1, 1023]
+defines.INLINE_MAX = [0, -1, 8]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
-    srand(1);
+    uint32_t prng = 1;
+    uint8_t buffer[1024];
     for (lfs_size_t i = 0; i < SIZE; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -41,15 +49,15 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE;
-    srand(1);
+    prng = 1;
     for (lfs_size_t i = 0; i < SIZE; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -57,22 +65,26 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # rewriting files
-define.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
-define.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
-define.CHUNKSIZE = [31, 16, 1]
+[cases.test_files_rewrite]
+defines.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
+defines.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
+defines.CHUNKSIZE = [31, 16, 1]
+defines.INLINE_MAX = [0, -1, 8]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    uint8_t buffer[1024];
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
-    srand(1);
+    uint32_t prng = 1;
     for (lfs_size_t i = 0; i < SIZE1; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -80,15 +92,15 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1;
-    srand(1);
+    prng = 1;
     for (lfs_size_t i = 0; i < SIZE1; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -96,13 +108,13 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // rewrite
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_WRONLY) => 0;
-    srand(2);
+    prng = 2;
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE2-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -110,27 +122,27 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => lfs_max(SIZE1, SIZE2);
-    srand(2);
+    prng = 2;
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE2-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     if (SIZE1 > SIZE2) {
-        srand(1);
+        prng = 1;
         for (lfs_size_t b = 0; b < SIZE2; b++) {
-            rand();
+            TEST_PRNG(&prng);
         }
         for (lfs_size_t i = SIZE2; i < SIZE1; i += CHUNKSIZE) {
             lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
             lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
             for (lfs_size_t b = 0; b < chunk; b++) {
-                assert(buffer[b] == (rand() & 0xff));
+                assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
             }
         }
     }
@@ -139,22 +151,26 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # appending files
-define.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
-define.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
-define.CHUNKSIZE = [31, 16, 1]
+[cases.test_files_append]
+defines.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
+defines.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
+defines.CHUNKSIZE = [31, 16, 1]
+defines.INLINE_MAX = [0, -1, 8]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    uint8_t buffer[1024];
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
-    srand(1);
+    uint32_t prng = 1;
     for (lfs_size_t i = 0; i < SIZE1; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -162,15 +178,15 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1;
-    srand(1);
+    prng = 1;
     for (lfs_size_t i = 0; i < SIZE1; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -178,13 +194,13 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // append
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_WRONLY | LFS_O_APPEND) => 0;
-    srand(2);
+    prng = 2;
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE2-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -192,23 +208,23 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1 + SIZE2;
-    srand(1);
+    prng = 1;
     for (lfs_size_t i = 0; i < SIZE1; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
-    srand(2);
+    prng = 2;
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE2-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -216,22 +232,26 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # truncating files
-define.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
-define.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
-define.CHUNKSIZE = [31, 16, 1]
+[cases.test_files_truncate]
+defines.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
+defines.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
+defines.CHUNKSIZE = [31, 16, 1]
+defines.INLINE_MAX = [0, -1, 8]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    uint8_t buffer[1024];
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
-    srand(1);
+    uint32_t prng = 1;
     for (lfs_size_t i = 0; i < SIZE1; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -239,15 +259,15 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1;
-    srand(1);
+    prng = 1;
     for (lfs_size_t i = 0; i < SIZE1; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE1-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -255,13 +275,13 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // truncate
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_WRONLY | LFS_O_TRUNC) => 0;
-    srand(2);
+    prng = 2;
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE2-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -269,15 +289,15 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE2;
-    srand(2);
+    prng = 2;
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE2-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -285,33 +305,41 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant file writing
-define.SIZE = [32, 0, 7, 2049]
-define.CHUNKSIZE = [31, 16, 65]
+[cases.test_files_reentrant_write]
+defines.SIZE = [32, 0, 7, 2049]
+defines.CHUNKSIZE = [31, 16, 65]
+defines.INLINE_MAX = [0, -1, 8]
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
+    lfs_file_t file;
+    uint8_t buffer[1024];
     err = lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY);
     assert(err == LFS_ERR_NOENT || err == 0);
     if (err == 0) {
         // can only be 0 (new file) or full size
-        size = lfs_file_size(&lfs, &file);
+        lfs_size_t size = lfs_file_size(&lfs, &file);
         assert(size == 0 || size == SIZE);
         lfs_file_close(&lfs, &file) => 0;
     }
 
     // write
     lfs_file_open(&lfs, &file, "avacado", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    srand(1);
+    uint32_t prng = 1;
     for (lfs_size_t i = 0; i < SIZE; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
     }
@@ -320,12 +348,12 @@ code = '''
     // read
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE;
-    srand(1);
+    prng = 1;
     for (lfs_size_t i = 0; i < SIZE; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -333,35 +361,47 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant file writing with syncs
-define = [
+[cases.test_files_reentrant_write_sync]
+defines = [
     # append (O(n))
-    {MODE='LFS_O_APPEND',   SIZE=[32, 0, 7, 2049],  CHUNKSIZE=[31, 16, 65]},
+    {MODE='LFS_O_APPEND',
+        SIZE=[32, 0, 7, 2049],
+        CHUNKSIZE=[31, 16, 65],
+        INLINE_MAX=[0, -1, 8]},
     # truncate (O(n^2))
-    {MODE='LFS_O_TRUNC',    SIZE=[32, 0, 7, 200],   CHUNKSIZE=[31, 16, 65]},
+    {MODE='LFS_O_TRUNC',
+        SIZE=[32, 0, 7, 200],
+        CHUNKSIZE=[31, 16, 65],
+        INLINE_MAX=[0, -1, 8]},
     # rewrite (O(n^2))
-    {MODE=0,                SIZE=[32, 0, 7, 200],   CHUNKSIZE=[31, 16, 65]},
+    {MODE=0,
+        SIZE=[32, 0, 7, 200],
+        CHUNKSIZE=[31, 16, 65],
+        INLINE_MAX=[0, -1, 8]},
 ]
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
+    lfs_file_t file;
+    uint8_t buffer[1024];
     err = lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY);
     assert(err == LFS_ERR_NOENT || err == 0);
     if (err == 0) {
         // with syncs we could be any size, but it at least must be valid data
-        size = lfs_file_size(&lfs, &file);
+        lfs_size_t size = lfs_file_size(&lfs, &file);
         assert(size <= SIZE);
-        srand(1);
+        uint32_t prng = 1;
         for (lfs_size_t i = 0; i < size; i += CHUNKSIZE) {
             lfs_size_t chunk = lfs_min(CHUNKSIZE, size-i);
             lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
             for (lfs_size_t b = 0; b < chunk; b++) {
-                assert(buffer[b] == (rand() & 0xff));
+                assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
             }
         }
         lfs_file_close(&lfs, &file) => 0;
@@ -370,17 +410,17 @@ code = '''
     // write
     lfs_file_open(&lfs, &file, "avacado",
         LFS_O_WRONLY | LFS_O_CREAT | MODE) => 0;
-    size = lfs_file_size(&lfs, &file);
+    lfs_size_t size = lfs_file_size(&lfs, &file);
     assert(size <= SIZE);
-    srand(1);
+    uint32_t prng = 1;
     lfs_size_t skip = (MODE == LFS_O_APPEND) ? size : 0;
     for (lfs_size_t b = 0; b < skip; b++) {
-        rand();
+        TEST_PRNG(&prng);
     }
     for (lfs_size_t i = skip; i < SIZE; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE-i);
         for (lfs_size_t b = 0; b < chunk; b++) {
-            buffer[b] = rand() & 0xff;
+            buffer[b] = TEST_PRNG(&prng) & 0xff;
         }
         lfs_file_write(&lfs, &file, buffer, chunk) => chunk;
         lfs_file_sync(&lfs, &file) => 0;
@@ -390,12 +430,12 @@ code = '''
     // read
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE;
-    srand(1);
+    prng = 1;
     for (lfs_size_t i = 0; i < SIZE; i += CHUNKSIZE) {
         lfs_size_t chunk = lfs_min(CHUNKSIZE, SIZE-i);
         lfs_file_read(&lfs, &file, buffer, chunk) => chunk;
         for (lfs_size_t b = 0; b < chunk; b++) {
-            assert(buffer[b] == (rand() & 0xff));
+            assert(buffer[b] == (TEST_PRNG(&prng) & 0xff));
         }
     }
     lfs_file_read(&lfs, &file, buffer, CHUNKSIZE) => 0;
@@ -403,19 +443,22 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # many files
-define.N = 300
+[cases.test_files_many]
+defines.N = 300
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
     // create N files of 7 bytes
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        lfs_file_t file;
+        char path[1024];
         sprintf(path, "file_%03d", i);
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         char wbuffer[1024];
-        size = 7;
-        snprintf(wbuffer, size, "Hi %03d", i);
+        lfs_size_t size = 7;
+        sprintf(wbuffer, "Hi %03d", i);
         lfs_file_write(&lfs, &file, wbuffer, size) => size;
         lfs_file_close(&lfs, &file) => 0;
 
@@ -428,25 +471,28 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # many files with power cycle
-define.N = 300
+[cases.test_files_many_power_cycle]
+defines.N = 300
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
     // create N files of 7 bytes
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        lfs_file_t file;
+        char path[1024];
         sprintf(path, "file_%03d", i);
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         char wbuffer[1024];
-        size = 7;
-        snprintf(wbuffer, size, "Hi %03d", i);
+        lfs_size_t size = 7;
+        sprintf(wbuffer, "Hi %03d", i);
         lfs_file_write(&lfs, &file, wbuffer, size) => size;
         lfs_file_close(&lfs, &file) => 0;
         lfs_unmount(&lfs) => 0;
 
         char rbuffer[1024];
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
         lfs_file_read(&lfs, &file, rbuffer, size) => size;
         assert(strcmp(rbuffer, wbuffer) == 0);
@@ -455,22 +501,29 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # many files with power loss
-define.N = 300
+[cases.test_files_many_power_loss]
+defines.N = 300
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
     // create N files of 7 bytes
     for (int i = 0; i < N; i++) {
+        lfs_file_t file;
+        char path[1024];
         sprintf(path, "file_%03d", i);
         err = lfs_file_open(&lfs, &file, path, LFS_O_WRONLY | LFS_O_CREAT);
         char wbuffer[1024];
-        size = 7;
-        snprintf(wbuffer, size, "Hi %03d", i);
+        lfs_size_t size = 7;
+        sprintf(wbuffer, "Hi %03d", i);
         if ((lfs_size_t)lfs_file_size(&lfs, &file) != size) {
             lfs_file_write(&lfs, &file, wbuffer, size) => size;
         }

tests/test_interspersed.toml

@@ -1,13 +1,15 @@
 
-[[case]] # interspersed file test
-define.SIZE = [10, 100]
-define.FILES = [4, 10, 26] 
+[cases.test_interspersed_files]
+defines.SIZE = [10, 100]
+defines.FILES = [4, 10, 26] 
 code = '''
+    lfs_t lfs;
     lfs_file_t files[FILES];
     const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int j = 0; j < FILES; j++) {
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
         lfs_file_open(&lfs, &files[j], path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
@@ -23,7 +25,9 @@ code = '''
         lfs_file_close(&lfs, &files[j]);
     }
 
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
     assert(info.type == LFS_TYPE_DIR);
@@ -31,6 +35,7 @@ code = '''
     assert(strcmp(info.name, "..") == 0);
     assert(info.type == LFS_TYPE_DIR);
     for (int j = 0; j < FILES; j++) {
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, path) == 0);
@@ -41,12 +46,14 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     for (int j = 0; j < FILES; j++) {
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
         lfs_file_open(&lfs, &files[j], path, LFS_O_RDONLY) => 0;
     }
 
     for (int i = 0; i < 10; i++) {
         for (int j = 0; j < FILES; j++) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &files[j], buffer, 1) => 1;
             assert(buffer[0] == alphas[j]);
         }
@@ -59,15 +66,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # interspersed remove file test
-define.SIZE = [10, 100]
-define.FILES = [4, 10, 26]
+[cases.test_interspersed_remove_files]
+defines.SIZE = [10, 100]
+defines.FILES = [4, 10, 26]
 code = '''
+    lfs_t lfs;
     const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int j = 0; j < FILES; j++) {
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         for (int i = 0; i < SIZE; i++) {
@@ -77,18 +87,22 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "zzz", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     for (int j = 0; j < FILES; j++) {
         lfs_file_write(&lfs, &file, (const void*)"~", 1) => 1;
         lfs_file_sync(&lfs, &file) => 0;
 
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
         lfs_remove(&lfs, path) => 0;
     }
     lfs_file_close(&lfs, &file);
 
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
     assert(info.type == LFS_TYPE_DIR);
@@ -104,6 +118,7 @@ code = '''
 
     lfs_file_open(&lfs, &file, "zzz", LFS_O_RDONLY) => 0;
     for (int i = 0; i < FILES; i++) {
+        uint8_t buffer[1024];
         lfs_file_read(&lfs, &file, buffer, 1) => 1;
         assert(buffer[0] == '~');
     }
@@ -112,11 +127,12 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # remove inconveniently test
-define.SIZE = [10, 100]
+[cases.test_interspersed_remove_inconveniently]
+defines.SIZE = [10, 100]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_t files[3];
     lfs_file_open(&lfs, &files[0], "e", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_open(&lfs, &files[1], "f", LFS_O_WRONLY | LFS_O_CREAT) => 0;
@@ -140,7 +156,9 @@ code = '''
     lfs_file_close(&lfs, &files[1]);
     lfs_file_close(&lfs, &files[2]);
 
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
     assert(info.type == LFS_TYPE_DIR);
@@ -161,6 +179,7 @@ code = '''
     lfs_file_open(&lfs, &files[0], "e", LFS_O_RDONLY) => 0;
     lfs_file_open(&lfs, &files[1], "g", LFS_O_RDONLY) => 0;
     for (int i = 0; i < SIZE; i++) {
+        uint8_t buffer[1024];
         lfs_file_read(&lfs, &files[0], buffer, 1) => 1;
         assert(buffer[0] == 'e');
         lfs_file_read(&lfs, &files[1], buffer, 1) => 1;
@@ -172,21 +191,27 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant interspersed file test
-define.SIZE = [10, 100]
-define.FILES = [4, 10, 26] 
+[cases.test_interspersed_reentrant_files]
+defines.SIZE = [10, 100]
+defines.FILES = [4, 10, 26] 
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
+    lfs_t lfs;
     lfs_file_t files[FILES];
     const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
 
-    err = lfs_mount(&lfs, &cfg);
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
     for (int j = 0; j < FILES; j++) {
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
         lfs_file_open(&lfs, &files[j], path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
@@ -194,8 +219,8 @@ code = '''
 
     for (int i = 0; i < SIZE; i++) {
         for (int j = 0; j < FILES; j++) {
-            size = lfs_file_size(&lfs, &files[j]);
-            assert((int)size >= 0);
+            lfs_ssize_t size = lfs_file_size(&lfs, &files[j]);
+            assert(size >= 0);
             if ((int)size <= i) {
                 lfs_file_write(&lfs, &files[j], &alphas[j], 1) => 1;
                 lfs_file_sync(&lfs, &files[j]) => 0;
@@ -207,7 +232,9 @@ code = '''
         lfs_file_close(&lfs, &files[j]);
     }
 
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "/") => 0;
+    struct lfs_info info;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
     assert(info.type == LFS_TYPE_DIR);
@@ -215,6 +242,7 @@ code = '''
     assert(strcmp(info.name, "..") == 0);
     assert(info.type == LFS_TYPE_DIR);
     for (int j = 0; j < FILES; j++) {
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, path) == 0);
@@ -225,12 +253,14 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     for (int j = 0; j < FILES; j++) {
+        char path[1024];
         sprintf(path, "%c", alphas[j]);
         lfs_file_open(&lfs, &files[j], path, LFS_O_RDONLY) => 0;
     }
 
     for (int i = 0; i < 10; i++) {
         for (int j = 0; j < FILES; j++) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &files[j], buffer, 1) => 1;
             assert(buffer[0] == alphas[j]);
         }

tests/test_move.toml

@@ -1,11 +1,13 @@
-[[case]] # move file
+[cases.test_move_file]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
     lfs_mkdir(&lfs, "d") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_CREAT | LFS_O_WRONLY) => 0;
     lfs_file_write(&lfs, &file, "hola\n", 5) => 5;
     lfs_file_write(&lfs, &file, "bonjour\n", 8) => 8;
@@ -13,11 +15,13 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -44,6 +48,7 @@ code = '''
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "b/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "c/hello", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 5) => 5;
     memcmp(buffer, "hola\n", 5) => 0;
     lfs_file_read(&lfs, &file, buffer, 8) => 8;
@@ -55,31 +60,35 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # noop move, yes this is legal
+[cases.test_move_nop] # yes this is legal
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "hi") => 0;
     lfs_rename(&lfs, "hi", "hi") => 0;
     lfs_mkdir(&lfs, "hi/hi") => 0;
     lfs_rename(&lfs, "hi/hi", "hi/hi") => 0;
     lfs_mkdir(&lfs, "hi/hi/hi") => 0;
     lfs_rename(&lfs, "hi/hi/hi", "hi/hi/hi") => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "hi/hi/hi", &info) => 0;
     assert(strcmp(info.name, "hi") == 0);
     assert(info.type == LFS_TYPE_DIR);
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move file corrupt source
+[cases.test_move_file_corrupt_source]
 in = "lfs.c"
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
     lfs_mkdir(&lfs, "d") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_CREAT | LFS_O_WRONLY) => 0;
     lfs_file_write(&lfs, &file, "hola\n", 5) => 5;
     lfs_file_write(&lfs, &file, "bonjour\n", 8) => 8;
@@ -87,28 +96,30 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    int off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    uint8_t buffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    int off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -146,16 +157,19 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move file corrupt source and dest
+# move file corrupt source and dest
+[cases.test_move_file_corrupt_source_dest]
 in = "lfs.c"
-if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
+if = 'PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
     lfs_mkdir(&lfs, "d") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_CREAT | LFS_O_WRONLY) => 0;
     lfs_file_write(&lfs, &file, "hola\n", 5) => 5;
     lfs_file_write(&lfs, &file, "bonjour\n", 8) => 8;
@@ -163,44 +177,46 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    int off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    uint8_t buffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    int off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -238,16 +254,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move file after corrupt
+[cases.test_move_file_after_corrupt]
 in = "lfs.c"
-if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
+if = 'PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
     lfs_mkdir(&lfs, "d") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_CREAT | LFS_O_WRONLY) => 0;
     lfs_file_write(&lfs, &file, "hola\n", 5) => 5;
     lfs_file_write(&lfs, &file, "bonjour\n", 8) => 8;
@@ -255,49 +273,51 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    int off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    uint8_t buffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    int off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
     // continue move
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -335,13 +355,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # simple reentrant move file
+[cases.test_move_reentrant_file]
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
     err = lfs_mkdir(&lfs, "a");
     assert(!err || err == LFS_ERR_EXIST);
@@ -354,9 +379,10 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         // there should never exist _2_ hello files
         int count = 0;
+        struct lfs_info info;
         if (lfs_stat(&lfs, "a/hello", &info) == 0) {
             assert(strcmp(info.name, "hello") == 0);
             assert(info.type == LFS_TYPE_REG);
@@ -384,7 +410,7 @@ code = '''
         assert(count <= 1);
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         if (lfs_stat(&lfs, "a/hello", &info) == 0 && info.size > 0) {
             lfs_rename(&lfs, "a/hello", "b/hello") => 0;
         } else if (lfs_stat(&lfs, "b/hello", &info) == 0) {
@@ -397,6 +423,7 @@ code = '''
             break;
         } else {
             // create file
+            lfs_file_t file;
             lfs_file_open(&lfs, &file, "a/hello",
                     LFS_O_WRONLY | LFS_O_CREAT) => 0;
             lfs_file_write(&lfs, &file, "hola\n", 5) => 5;
@@ -407,7 +434,9 @@ code = '''
         lfs_unmount(&lfs) => 0;
     }
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -431,10 +460,12 @@ code = '''
     lfs_dir_read(&lfs, &dir, &info) => 0;
     lfs_dir_close(&lfs, &dir) => 0;
 
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "b/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "c/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "d/hello", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 5) => 5;
     memcmp(buffer, "hola\n", 5) => 0;
     lfs_file_read(&lfs, &file, buffer, 8) => 8;
@@ -445,10 +476,11 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move dir
+[cases.test_move_dir]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -459,11 +491,13 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -510,11 +544,12 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move dir corrupt source
+[cases.test_move_dir_corrupt_source]
 in = "lfs.c"
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -525,28 +560,30 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    int off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    uint8_t buffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    int off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -593,12 +630,13 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move dir corrupt source and dest
+[cases.test_move_dir_corrupt_source_dest]
 in = "lfs.c"
-if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
+if = 'PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -609,44 +647,46 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    int off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    uint8_t buffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    int off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -693,12 +733,13 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move dir after corrupt
+[cases.test_move_dir_after_corrupt]
 in = "lfs.c"
-if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
+if = 'PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -709,49 +750,51 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    int off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    uint8_t buffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    int off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
     // continue move
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -798,13 +841,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # simple reentrant move dir
+[cases.test_reentrant_dir]
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
     err = lfs_mkdir(&lfs, "a");
     assert(!err || err == LFS_ERR_EXIST);
@@ -817,9 +865,10 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         // there should never exist _2_ hi directories
         int count = 0;
+        struct lfs_info info;
         if (lfs_stat(&lfs, "a/hi", &info) == 0) {
             assert(strcmp(info.name, "hi") == 0);
             assert(info.type == LFS_TYPE_DIR);
@@ -843,7 +892,7 @@ code = '''
         assert(count <= 1);
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
         if (lfs_stat(&lfs, "a/hi", &info) == 0) {
             lfs_rename(&lfs, "a/hi", "b/hi") => 0;
         } else if (lfs_stat(&lfs, "b/hi", &info) == 0) {
@@ -868,7 +917,9 @@ code = '''
         lfs_unmount(&lfs) => 0;
     }
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -915,14 +966,16 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move state stealing
+[cases.test_move_state_stealing]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
     lfs_mkdir(&lfs, "d") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_CREAT | LFS_O_WRONLY) => 0;
     lfs_file_write(&lfs, &file, "hola\n", 5) => 5;
     lfs_file_write(&lfs, &file, "bonjour\n", 8) => 8;
@@ -930,21 +983,22 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "a/hello", "b/hello") => 0;
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "b/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_rename(&lfs, "c/hello", "d/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "b/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "c/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "d/hello", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 5) => 5;
     memcmp(buffer, "hola\n", 5) => 0;
     lfs_file_read(&lfs, &file, buffer, 8) => 8;
@@ -954,12 +1008,13 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_remove(&lfs, "b") => 0;
     lfs_remove(&lfs, "c") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "a", &info) => 0;
     lfs_stat(&lfs, "b", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "c", &info) => LFS_ERR_NOENT;
@@ -979,12 +1034,16 @@ code = '''
 '''
 
 # Other specific corner cases
-[[case]] # create + delete in same commit with neighbors
+
+# create + delete in same commit with neighbors
+[cases.test_move_create_delete_same]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // littlefs keeps files sorted, so we know the order these will be in
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "/1.move_me",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_close(&lfs, &file) => 0;
@@ -1024,6 +1083,8 @@ code = '''
     lfs_file_close(&lfs, &files[2]) => 0;
 
     // check that nothing was corrupted
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -1051,6 +1112,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     lfs_file_open(&lfs, &file, "/0.before", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 7) => 7;
     assert(strcmp((char*)buffer, "test.4") == 0);
     lfs_file_close(&lfs, &file) => 0;
@@ -1124,13 +1186,15 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-# Other specific corner cases
-[[case]] # create + delete + delete in same commit with neighbors
+# create + delete + delete in same commit with neighbors
+[cases.test_move_create_delete_delete_same]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // littlefs keeps files sorted, so we know the order these will be in
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "/1.move_me",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_close(&lfs, &file) => 0;
@@ -1175,6 +1239,8 @@ code = '''
     lfs_file_close(&lfs, &files[2]) => 0;
 
     // check that nothing was corrupted
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -1202,6 +1268,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     lfs_file_open(&lfs, &file, "/0.before", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 7) => 7;
     assert(strcmp((char*)buffer, "test.4") == 0);
     lfs_file_close(&lfs, &file) => 0;
@@ -1281,14 +1348,17 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # create + delete in different dirs with neighbors
+# create + delete in different dirs with neighbors
+[cases.test_move_create_delete_different]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     // littlefs keeps files sorted, so we know the order these will be in
     lfs_mkdir(&lfs, "/dir.1") => 0;
     lfs_mkdir(&lfs, "/dir.2") => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "/dir.1/1.move_me",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_close(&lfs, &file) => 0;
@@ -1340,6 +1410,8 @@ code = '''
     lfs_file_close(&lfs, &files[3]) => 0;
 
     // check that nothing was corrupted
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -1397,6 +1469,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     lfs_file_open(&lfs, &file, "/dir.1/0.before", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 7) => 7;
     assert(strcmp((char*)buffer, "test.5") == 0);
     lfs_file_close(&lfs, &file) => 0;
@@ -1518,17 +1591,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move fix in relocation
+# move fix in relocation
+[cases.test_move_fix_relocation]
 in = "lfs.c"
-define.RELOCATIONS = 'range(0x3+1)'
-define.LFS_ERASE_CYCLES = 0xffffffff
+defines.RELOCATIONS = 'range(4)'
+defines.ERASE_CYCLES = 0xffffffff
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     lfs_mkdir(&lfs, "/parent") => 0;
     lfs_mkdir(&lfs, "/parent/child") => 0;
 
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "/parent/1.move_me",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "move me",
@@ -1568,15 +1644,17 @@ code = '''
 
     // force specific directories to relocate
     if (RELOCATIONS & 0x1) {
+        lfs_dir_t dir;
         lfs_dir_open(&lfs, &dir, "/parent");
-        lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
-        lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[0], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[1], 0xffffffff) => 0;
         lfs_dir_close(&lfs, &dir) => 0;
     }
     if (RELOCATIONS & 0x2) {
+        lfs_dir_t dir;
         lfs_dir_open(&lfs, &dir, "/parent/child");
-        lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
-        lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[0], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[1], 0xffffffff) => 0;
         lfs_dir_close(&lfs, &dir) => 0;
     }
 
@@ -1593,6 +1671,8 @@ code = '''
     lfs_file_close(&lfs, &files[3]) => 0;
 
     // check that nothing was corrupted
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "/parent") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -1637,6 +1717,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     lfs_file_open(&lfs, &file, "/parent/0.before", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 7) => 7;
     assert(strcmp((char*)buffer, "test.5") == 0);
     lfs_file_close(&lfs, &file) => 0;
@@ -1655,18 +1736,21 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # move fix in relocation with predecessor
+# move fix in relocation with predecessor
+[cases.test_move_fix_relocation_predecessor]
 in = "lfs.c"
-define.RELOCATIONS = 'range(0x7+1)'
-define.LFS_ERASE_CYCLES = 0xffffffff
+defines.RELOCATIONS = 'range(8)'
+defines.ERASE_CYCLES = 0xffffffff
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     lfs_mkdir(&lfs, "/parent") => 0;
     lfs_mkdir(&lfs, "/parent/child") => 0;
     lfs_mkdir(&lfs, "/parent/sibling") => 0;
 
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "/parent/sibling/1.move_me",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "move me",
@@ -1706,21 +1790,24 @@ code = '''
 
     // force specific directories to relocate
     if (RELOCATIONS & 0x1) {
+        lfs_dir_t dir;
         lfs_dir_open(&lfs, &dir, "/parent");
-        lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
-        lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[0], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[1], 0xffffffff) => 0;
         lfs_dir_close(&lfs, &dir) => 0;
     }
     if (RELOCATIONS & 0x2) {
+        lfs_dir_t dir;
         lfs_dir_open(&lfs, &dir, "/parent/sibling");
-        lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
-        lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[0], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[1], 0xffffffff) => 0;
         lfs_dir_close(&lfs, &dir) => 0;
     }
     if (RELOCATIONS & 0x4) {
+        lfs_dir_t dir;
         lfs_dir_open(&lfs, &dir, "/parent/child");
-        lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
-        lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[0], 0xffffffff) => 0;
+        lfs_emubd_setwear(cfg, dir.m.pair[1], 0xffffffff) => 0;
         lfs_dir_close(&lfs, &dir) => 0;
     }
 
@@ -1739,6 +1826,8 @@ code = '''
     lfs_file_close(&lfs, &files[3]) => 0;
 
     // check that nothing was corrupted
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "/parent") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -1796,6 +1885,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
 
     lfs_file_open(&lfs, &file, "/parent/sibling/0.before", LFS_O_RDONLY) => 0;
+    uint8_t buffer[1024];
     lfs_file_read(&lfs, &file, buffer, 7) => 7;
     assert(strcmp((char*)buffer, "test.5") == 0);
     lfs_file_close(&lfs, &file) => 0;

tests/test_orphans.toml

@@ -1,9 +1,10 @@
-[[case]] # orphan test
+[cases.test_orphans_normal]
 in = "lfs.c"
-if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
+if = 'PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_mkdir(&lfs, "parent") => 0;
     lfs_mkdir(&lfs, "parent/orphan") => 0;
     lfs_mkdir(&lfs, "parent/child") => 0;
@@ -13,29 +14,31 @@ code = '''
     // corrupt the child's most recent commit, this should be the update
     // to the linked-list entry, which should orphan the orphan. Note this
     // makes a lot of assumptions about the remove operation.
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
     lfs_dir_open(&lfs, &dir, "parent/child") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs) => 0;
-    uint8_t bbuffer[LFS_BLOCK_SIZE];
-    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    int off = LFS_BLOCK_SIZE-1;
-    while (off >= 0 && bbuffer[off] == LFS_ERASE_VALUE) {
+    uint8_t buffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    int off = BLOCK_SIZE-1;
+    while (off >= 0 && buffer[off] == ERASE_VALUE) {
         off -= 1;
     }
-    memset(&bbuffer[off-3], LFS_BLOCK_SIZE, 3);
-    cfg.erase(&cfg, block) => 0;
-    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
-    cfg.sync(&cfg) => 0;
+    memset(&buffer[off-3], BLOCK_SIZE, 3);
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, buffer, BLOCK_SIZE) => 0;
+    cfg->sync(cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "parent/child", &info) => 0;
     lfs_fs_size(&lfs) => 8;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "parent/child", &info) => 0;
     lfs_fs_size(&lfs) => 8;
@@ -48,7 +51,7 @@ code = '''
     lfs_fs_size(&lfs) => 8;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "parent/child", &info) => 0;
     lfs_stat(&lfs, "parent/otherchild", &info) => 0;
@@ -56,43 +59,193 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant testing for orphans, basically just spam mkdir/remove
+# test that we only run deorphan once per power-cycle
+[cases.test_orphans_no_orphans]
+in = 'lfs.c'
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    // mark the filesystem as having orphans
+    lfs_fs_preporphans(&lfs, +1) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_dir_commit(&lfs, &mdir, NULL, 0) => 0;
+
+    // we should have orphans at this state
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    lfs_unmount(&lfs) => 0;
+
+    // mount
+    lfs_mount(&lfs, cfg) => 0;
+    // we should detect orphans
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    // force consistency
+    lfs_fs_forceconsistency(&lfs) => 0;
+    // we should no longer have orphans
+    assert(!lfs_gstate_hasorphans(&lfs.gstate));
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.test_orphans_one_orphan]
+in = 'lfs.c'
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    // create an orphan
+    lfs_mdir_t orphan;
+    lfs_alloc_ckpoint(&lfs);
+    lfs_dir_alloc(&lfs, &orphan) => 0;
+    lfs_dir_commit(&lfs, &orphan, NULL, 0) => 0;
+
+    // append our orphan and mark the filesystem as having orphans
+    lfs_fs_preporphans(&lfs, +1) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_pair_tole32(orphan.pair);
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8), orphan.pair})) => 0;
+
+    // we should have orphans at this state
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    lfs_unmount(&lfs) => 0;
+
+    // mount
+    lfs_mount(&lfs, cfg) => 0;
+    // we should detect orphans
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    // force consistency
+    lfs_fs_forceconsistency(&lfs) => 0;
+    // we should no longer have orphans
+    assert(!lfs_gstate_hasorphans(&lfs.gstate));
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+# test that we can persist gstate with lfs_fs_mkconsistent
+[cases.test_orphans_mkconsistent_no_orphans]
+in = 'lfs.c'
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    // mark the filesystem as having orphans
+    lfs_fs_preporphans(&lfs, +1) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_dir_commit(&lfs, &mdir, NULL, 0) => 0;
+
+    // we should have orphans at this state
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    lfs_unmount(&lfs) => 0;
+
+    // mount
+    lfs_mount(&lfs, cfg) => 0;
+    // we should detect orphans
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    // force consistency
+    lfs_fs_mkconsistent(&lfs) => 0;
+    // we should no longer have orphans
+    assert(!lfs_gstate_hasorphans(&lfs.gstate));
+
+    // remount
+    lfs_unmount(&lfs) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    // we should still have no orphans
+    assert(!lfs_gstate_hasorphans(&lfs.gstate));
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.test_orphans_mkconsistent_one_orphan]
+in = 'lfs.c'
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    // create an orphan
+    lfs_mdir_t orphan;
+    lfs_alloc_ckpoint(&lfs);
+    lfs_dir_alloc(&lfs, &orphan) => 0;
+    lfs_dir_commit(&lfs, &orphan, NULL, 0) => 0;
+
+    // append our orphan and mark the filesystem as having orphans
+    lfs_fs_preporphans(&lfs, +1) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_pair_tole32(orphan.pair);
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8), orphan.pair})) => 0;
+
+    // we should have orphans at this state
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    lfs_unmount(&lfs) => 0;
+
+    // mount
+    lfs_mount(&lfs, cfg) => 0;
+    // we should detect orphans
+    assert(lfs_gstate_hasorphans(&lfs.gstate));
+    // force consistency
+    lfs_fs_mkconsistent(&lfs) => 0;
+    // we should no longer have orphans
+    assert(!lfs_gstate_hasorphans(&lfs.gstate));
+
+    // remount
+    lfs_unmount(&lfs) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    // we should still have no orphans
+    assert(!lfs_gstate_hasorphans(&lfs.gstate));
+    lfs_unmount(&lfs) => 0;
+'''
+
+# reentrant testing for orphans, basically just spam mkdir/remove
+[cases.test_orphans_reentrant]
 reentrant = true
 # TODO fix this case, caused by non-DAG trees
-if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
-define = [
+# NOTE the second condition is required
+if = '!(DEPTH == 3 && CACHE_SIZE != 64) && 2*FILES < BLOCK_COUNT'
+defines = [
     {FILES=6,  DEPTH=1, CYCLES=20},
     {FILES=26, DEPTH=1, CYCLES=20},
     {FILES=3,  DEPTH=3, CYCLES=20},
 ]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
-    srand(1);
+    uint32_t prng = 1;
     const char alpha[] = "abcdefghijklmnopqrstuvwxyz";
-    for (int i = 0; i < CYCLES; i++) {
+    for (unsigned i = 0; i < CYCLES; i++) {
         // create random path
         char full_path[256];
-        for (int d = 0; d < DEPTH; d++) {
-            sprintf(&full_path[2*d], "/%c", alpha[rand() % FILES]);
+        for (unsigned d = 0; d < DEPTH; d++) {
+            sprintf(&full_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
         }
 
         // if it does not exist, we create it, else we destroy
+        struct lfs_info info;
         int res = lfs_stat(&lfs, full_path, &info);
         if (res == LFS_ERR_NOENT) {
             // create each directory in turn, ignore if dir already exists
-            for (int d = 0; d < DEPTH; d++) {
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 err = lfs_mkdir(&lfs, path);
                 assert(!err || err == LFS_ERR_EXIST);
             }
 
-            for (int d = 0; d < DEPTH; d++) {
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 lfs_stat(&lfs, path, &info) => 0;
@@ -106,6 +259,7 @@ code = '''
 
             // try to delete path in reverse order, ignore if dir is not empty
             for (int d = DEPTH-1; d >= 0; d--) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 err = lfs_remove(&lfs, path);
@@ -118,3 +272,69 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
+# non-reentrant testing for orphans, this is the same as reentrant
+# testing, but we test way more states than we could under powerloss
+[cases.test_orphans_nonreentrant]
+# TODO fix this case, caused by non-DAG trees
+# NOTE the second condition is required
+if = '!(DEPTH == 3 && CACHE_SIZE != 64) && 2*FILES < BLOCK_COUNT'
+defines = [
+    {FILES=6,   DEPTH=1, CYCLES=2000},
+    {FILES=26,  DEPTH=1, CYCLES=2000},
+    {FILES=3,   DEPTH=3, CYCLES=2000},
+]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    uint32_t prng = 1;
+    const char alpha[] = "abcdefghijklmnopqrstuvwxyz";
+    for (unsigned i = 0; i < CYCLES; i++) {
+        // create random path
+        char full_path[256];
+        for (unsigned d = 0; d < DEPTH; d++) {
+            sprintf(&full_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
+        }
+
+        // if it does not exist, we create it, else we destroy
+        struct lfs_info info;
+        int res = lfs_stat(&lfs, full_path, &info);
+        if (res == LFS_ERR_NOENT) {
+            // create each directory in turn, ignore if dir already exists
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                int err = lfs_mkdir(&lfs, path);
+                assert(!err || err == LFS_ERR_EXIST);
+            }
+
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                lfs_stat(&lfs, path, &info) => 0;
+                assert(strcmp(info.name, &path[2*d+1]) == 0);
+                assert(info.type == LFS_TYPE_DIR);
+            }
+        } else {
+            // is valid dir?
+            assert(strcmp(info.name, &full_path[2*(DEPTH-1)+1]) == 0);
+            assert(info.type == LFS_TYPE_DIR);
+
+            // try to delete path in reverse order, ignore if dir is not empty
+            for (int d = DEPTH-1; d >= 0; d--) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                int err = lfs_remove(&lfs, path);
+                assert(!err || err == LFS_ERR_NOTEMPTY);
+            }
+
+            lfs_stat(&lfs, full_path, &info) => LFS_ERR_NOENT;
+        }
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+

tests/test_powerloss.toml

@@ -0,0 +1,185 @@
+# There are already a number of tests that test general operations under
+# power-loss (see the reentrant attribute). These tests are for explicitly
+# testing specific corner cases.
+
+# only a revision count
+[cases.test_powerloss_only_rev]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_mkdir(&lfs, "notebook") => 0;
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    char buffer[256];
+    strcpy(buffer, "hello");
+    lfs_size_t size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    char rbuffer[256];
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // get pair/rev count
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    lfs_dir_open(&lfs, &dir, "notebook") => 0;
+    lfs_block_t pair[2] = {dir.m.pair[0], dir.m.pair[1]};
+    uint32_t rev = dir.m.rev;
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // write just the revision count
+    uint8_t bbuffer[BLOCK_SIZE];
+    cfg->read(cfg, pair[1], 0, bbuffer, BLOCK_SIZE) => 0;
+
+    memcpy(bbuffer, &(uint32_t){lfs_tole32(rev+1)}, sizeof(uint32_t));
+
+    cfg->erase(cfg, pair[1]) => 0;
+    cfg->prog(cfg, pair[1], 0, bbuffer, BLOCK_SIZE) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+
+    // can read?
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    // can write?
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_APPEND) => 0;
+    strcpy(buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    strcpy(buffer, "hello");
+    size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    strcpy(buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+# partial prog, may not be byte in order!
+[cases.test_powerloss_partial_prog]
+if = '''
+    PROG_SIZE < BLOCK_SIZE
+        && (DISK_VERSION == 0 || DISK_VERSION >= 0x00020001)
+'''
+defines.BYTE_OFF = ["0", "PROG_SIZE-1", "PROG_SIZE/2"]
+defines.BYTE_VALUE = [0x33, 0xcc]
+in = "lfs.c"
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_mkdir(&lfs, "notebook") => 0;
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    char buffer[256];
+    strcpy(buffer, "hello");
+    lfs_size_t size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    char rbuffer[256];
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // imitate a partial prog, value should not matter, if littlefs
+    // doesn't notice the partial prog testbd will assert
+
+    // get offset to next prog
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    lfs_dir_open(&lfs, &dir, "notebook") => 0;
+    lfs_block_t block = dir.m.pair[0];
+    lfs_off_t off = dir.m.off;
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // tweak byte
+    uint8_t bbuffer[BLOCK_SIZE];
+    cfg->read(cfg, block, 0, bbuffer, BLOCK_SIZE) => 0;
+
+    bbuffer[off + BYTE_OFF] = BYTE_VALUE;
+
+    cfg->erase(cfg, block) => 0;
+    cfg->prog(cfg, block, 0, bbuffer, BLOCK_SIZE) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+
+    // can read?
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    // can write?
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_APPEND) => 0;
+    strcpy(buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    strcpy(buffer, "hello");
+    size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    strcpy(buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_unmount(&lfs) => 0;
+'''

tests/test_relocations.toml

@@ -1,15 +1,18 @@
 # specific corner cases worth explicitly testing for
-[[case]] # dangling split dir test
-define.ITERATIONS = 20
-define.COUNT = 10
-define.LFS_BLOCK_CYCLES = [8, 1]
+[cases.test_relocations_dangling_split_dir]
+defines.ITERATIONS = 20
+defines.COUNT = 10
+defines.BLOCK_CYCLES = [8, 1]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
     // fill up filesystem so only ~16 blocks are left
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "padding", LFS_O_CREAT | LFS_O_WRONLY) => 0;
+    uint8_t buffer[512];
     memset(buffer, 0, 512);
-    while (LFS_BLOCK_COUNT - lfs_fs_size(&lfs) > 16) {
+    while (BLOCK_COUNT - lfs_fs_size(&lfs) > 16) {
         lfs_file_write(&lfs, &file, buffer, 512) => 512;
     }
     lfs_file_close(&lfs, &file) => 0;
@@ -17,18 +20,22 @@ code = '''
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
-    for (int j = 0; j < ITERATIONS; j++) {
-        for (int i = 0; i < COUNT; i++) {
+    lfs_mount(&lfs, cfg) => 0;
+    for (unsigned j = 0; j < ITERATIONS; j++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
             lfs_file_open(&lfs, &file, path, LFS_O_CREAT | LFS_O_WRONLY) => 0;
             lfs_file_close(&lfs, &file) => 0;
         }
 
+        lfs_dir_t dir;
+        struct lfs_info info;
         lfs_dir_open(&lfs, &dir, "child") => 0;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         lfs_dir_read(&lfs, &dir, &info) => 1;
-        for (int i = 0; i < COUNT; i++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "test%03d_loooooooooooooooooong_name", i);
             lfs_dir_read(&lfs, &dir, &info) => 1;
             strcmp(info.name, path) => 0;
@@ -36,46 +43,54 @@ code = '''
         lfs_dir_read(&lfs, &dir, &info) => 0;
         lfs_dir_close(&lfs, &dir) => 0;
 
-        if (j == ITERATIONS-1) {
+        if (j == (unsigned)ITERATIONS-1) {
             break;
         }
 
-        for (int i = 0; i < COUNT; i++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
             lfs_remove(&lfs, path) => 0;
         }
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_dir_t dir;
+    struct lfs_info info;
     lfs_dir_open(&lfs, &dir, "child") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     lfs_dir_read(&lfs, &dir, &info) => 1;
-    for (int i = 0; i < COUNT; i++) {
+    for (unsigned i = 0; i < COUNT; i++) {
+        char path[1024];
         sprintf(path, "test%03d_loooooooooooooooooong_name", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;
         strcmp(info.name, path) => 0;
     }
     lfs_dir_read(&lfs, &dir, &info) => 0;
     lfs_dir_close(&lfs, &dir) => 0;
-    for (int i = 0; i < COUNT; i++) {
+    for (unsigned i = 0; i < COUNT; i++) {
+        char path[1024];
         sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
         lfs_remove(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # outdated head test
-define.ITERATIONS = 20
-define.COUNT = 10
-define.LFS_BLOCK_CYCLES = [8, 1]
+[cases.test_relocations_outdated_head]
+defines.ITERATIONS = 20
+defines.COUNT = 10
+defines.BLOCK_CYCLES = [8, 1]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
     // fill up filesystem so only ~16 blocks are left
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "padding", LFS_O_CREAT | LFS_O_WRONLY) => 0;
+    uint8_t buffer[512];
     memset(buffer, 0, 512);
-    while (LFS_BLOCK_COUNT - lfs_fs_size(&lfs) > 16) {
+    while (BLOCK_COUNT - lfs_fs_size(&lfs) > 16) {
         lfs_file_write(&lfs, &file, buffer, 512) => 512;
     }
     lfs_file_close(&lfs, &file) => 0;
@@ -83,18 +98,22 @@ code = '''
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
-    for (int j = 0; j < ITERATIONS; j++) {
-        for (int i = 0; i < COUNT; i++) {
+    lfs_mount(&lfs, cfg) => 0;
+    for (unsigned j = 0; j < ITERATIONS; j++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
             lfs_file_open(&lfs, &file, path, LFS_O_CREAT | LFS_O_WRONLY) => 0;
             lfs_file_close(&lfs, &file) => 0;
         }
 
+        lfs_dir_t dir;
+        struct lfs_info info;
         lfs_dir_open(&lfs, &dir, "child") => 0;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         lfs_dir_read(&lfs, &dir, &info) => 1;
-        for (int i = 0; i < COUNT; i++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "test%03d_loooooooooooooooooong_name", i);
             lfs_dir_read(&lfs, &dir, &info) => 1;
             strcmp(info.name, path) => 0;
@@ -110,7 +129,8 @@ code = '''
         lfs_dir_rewind(&lfs, &dir) => 0;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         lfs_dir_read(&lfs, &dir, &info) => 1;
-        for (int i = 0; i < COUNT; i++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "test%03d_loooooooooooooooooong_name", i);
             lfs_dir_read(&lfs, &dir, &info) => 1;
             strcmp(info.name, path) => 0;
@@ -126,7 +146,8 @@ code = '''
         lfs_dir_rewind(&lfs, &dir) => 0;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         lfs_dir_read(&lfs, &dir, &info) => 1;
-        for (int i = 0; i < COUNT; i++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "test%03d_loooooooooooooooooong_name", i);
             lfs_dir_read(&lfs, &dir, &info) => 1;
             strcmp(info.name, path) => 0;
@@ -135,7 +156,8 @@ code = '''
         lfs_dir_read(&lfs, &dir, &info) => 0;
         lfs_dir_close(&lfs, &dir) => 0;
 
-        for (int i = 0; i < COUNT; i++) {
+        for (unsigned i = 0; i < COUNT; i++) {
+            char path[1024];
             sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
             lfs_remove(&lfs, path) => 0;
         }
@@ -143,45 +165,51 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant testing for relocations, this is the same as the
-         # orphan testing, except here we also set block_cycles so that
-         # almost every tree operation needs a relocation
+# reentrant testing for relocations, this is the same as the
+# orphan testing, except here we also set block_cycles so that
+# almost every tree operation needs a relocation
+[cases.test_relocations_reentrant]
 reentrant = true
 # TODO fix this case, caused by non-DAG trees
-if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
-define = [
-    {FILES=6,  DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
-    {FILES=26, DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
-    {FILES=3,  DEPTH=3, CYCLES=20, LFS_BLOCK_CYCLES=1},
+# NOTE the second condition is required
+if = '!(DEPTH == 3 && CACHE_SIZE != 64) && 2*FILES < BLOCK_COUNT'
+defines = [
+    {FILES=6,  DEPTH=1, CYCLES=20, BLOCK_CYCLES=1},
+    {FILES=26, DEPTH=1, CYCLES=20, BLOCK_CYCLES=1},
+    {FILES=3,  DEPTH=3, CYCLES=20, BLOCK_CYCLES=1},
 ]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
-    srand(1);
+    uint32_t prng = 1;
     const char alpha[] = "abcdefghijklmnopqrstuvwxyz";
-    for (int i = 0; i < CYCLES; i++) {
+    for (unsigned i = 0; i < CYCLES; i++) {
         // create random path
         char full_path[256];
-        for (int d = 0; d < DEPTH; d++) {
-            sprintf(&full_path[2*d], "/%c", alpha[rand() % FILES]);
+        for (unsigned d = 0; d < DEPTH; d++) {
+            sprintf(&full_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
         }
 
         // if it does not exist, we create it, else we destroy
+        struct lfs_info info;
         int res = lfs_stat(&lfs, full_path, &info);
         if (res == LFS_ERR_NOENT) {
             // create each directory in turn, ignore if dir already exists
-            for (int d = 0; d < DEPTH; d++) {
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 err = lfs_mkdir(&lfs, path);
                 assert(!err || err == LFS_ERR_EXIST);
             }
 
-            for (int d = 0; d < DEPTH; d++) {
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 lfs_stat(&lfs, path, &info) => 0;
@@ -194,7 +222,8 @@ code = '''
             assert(info.type == LFS_TYPE_DIR);
 
             // try to delete path in reverse order, ignore if dir is not empty
-            for (int d = DEPTH-1; d >= 0; d--) {
+            for (unsigned d = DEPTH-1; d+1 > 0; d--) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 err = lfs_remove(&lfs, path);
@@ -207,44 +236,50 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant testing for relocations, but now with random renames!
+# reentrant testing for relocations, but now with random renames!
+[cases.test_relocations_reentrant_renames]
 reentrant = true
 # TODO fix this case, caused by non-DAG trees
-if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
-define = [
-    {FILES=6,  DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
-    {FILES=26, DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
-    {FILES=3,  DEPTH=3, CYCLES=20, LFS_BLOCK_CYCLES=1},
+# NOTE the second condition is required
+if = '!(DEPTH == 3 && CACHE_SIZE != 64) && 2*FILES < BLOCK_COUNT'
+defines = [
+    {FILES=6,  DEPTH=1, CYCLES=20, BLOCK_CYCLES=1},
+    {FILES=26, DEPTH=1, CYCLES=20, BLOCK_CYCLES=1},
+    {FILES=3,  DEPTH=3, CYCLES=20, BLOCK_CYCLES=1},
 ]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
-    srand(1);
+    uint32_t prng = 1;
     const char alpha[] = "abcdefghijklmnopqrstuvwxyz";
-    for (int i = 0; i < CYCLES; i++) {
+    for (unsigned i = 0; i < CYCLES; i++) {
         // create random path
         char full_path[256];
-        for (int d = 0; d < DEPTH; d++) {
-            sprintf(&full_path[2*d], "/%c", alpha[rand() % FILES]);
+        for (unsigned d = 0; d < DEPTH; d++) {
+            sprintf(&full_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
         }
 
         // if it does not exist, we create it, else we destroy
+        struct lfs_info info;
         int res = lfs_stat(&lfs, full_path, &info);
         assert(!res || res == LFS_ERR_NOENT);
         if (res == LFS_ERR_NOENT) {
             // create each directory in turn, ignore if dir already exists
-            for (int d = 0; d < DEPTH; d++) {
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 err = lfs_mkdir(&lfs, path);
                 assert(!err || err == LFS_ERR_EXIST);
             }
 
-            for (int d = 0; d < DEPTH; d++) {
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
                 strcpy(path, full_path);
                 path[2*d+2] = '\0';
                 lfs_stat(&lfs, path, &info) => 0;
@@ -257,8 +292,8 @@ code = '''
 
             // create new random path
             char new_path[256];
-            for (int d = 0; d < DEPTH; d++) {
-                sprintf(&new_path[2*d], "/%c", alpha[rand() % FILES]);
+            for (unsigned d = 0; d < DEPTH; d++) {
+                sprintf(&new_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
             }
 
             // if new path does not exist, rename, otherwise destroy
@@ -266,7 +301,8 @@ code = '''
             assert(!res || res == LFS_ERR_NOENT);
             if (res == LFS_ERR_NOENT) {
                 // stop once some dir is renamed
-                for (int d = 0; d < DEPTH; d++) {
+                for (unsigned d = 0; d < DEPTH; d++) {
+                    char path[1024];
                     strcpy(&path[2*d], &full_path[2*d]);
                     path[2*d+2] = '\0';
                     strcpy(&path[128+2*d], &new_path[2*d]);
@@ -278,7 +314,8 @@ code = '''
                     }
                 }
 
-                for (int d = 0; d < DEPTH; d++) {
+                for (unsigned d = 0; d < DEPTH; d++) {
+                    char path[1024];
                     strcpy(path, new_path);
                     path[2*d+2] = '\0';
                     lfs_stat(&lfs, path, &info) => 0;
@@ -290,7 +327,8 @@ code = '''
             } else {
                 // try to delete path in reverse order,
                 // ignore if dir is not empty
-                for (int d = DEPTH-1; d >= 0; d--) {
+                for (unsigned d = DEPTH-1; d+1 > 0; d--) {
+                    char path[1024];
                     strcpy(path, full_path);
                     path[2*d+2] = '\0';
                     err = lfs_remove(&lfs, path);
@@ -303,3 +341,171 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 '''
+
+# non-reentrant testing for orphans, this is the same as reentrant
+# testing, but we test way more states than we could under powerloss
+[cases.test_relocations_nonreentrant]
+# TODO fix this case, caused by non-DAG trees
+# NOTE the second condition is required
+if = '!(DEPTH == 3 && CACHE_SIZE != 64) && 2*FILES < BLOCK_COUNT'
+defines = [
+    {FILES=6,  DEPTH=1, CYCLES=2000, BLOCK_CYCLES=1},
+    {FILES=26, DEPTH=1, CYCLES=2000, BLOCK_CYCLES=1},
+    {FILES=3,  DEPTH=3, CYCLES=2000, BLOCK_CYCLES=1},
+]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    uint32_t prng = 1;
+    const char alpha[] = "abcdefghijklmnopqrstuvwxyz";
+    for (unsigned i = 0; i < CYCLES; i++) {
+        // create random path
+        char full_path[256];
+        for (unsigned d = 0; d < DEPTH; d++) {
+            sprintf(&full_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
+        }
+
+        // if it does not exist, we create it, else we destroy
+        struct lfs_info info;
+        int res = lfs_stat(&lfs, full_path, &info);
+        if (res == LFS_ERR_NOENT) {
+            // create each directory in turn, ignore if dir already exists
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                int err = lfs_mkdir(&lfs, path);
+                assert(!err || err == LFS_ERR_EXIST);
+            }
+
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                lfs_stat(&lfs, path, &info) => 0;
+                assert(strcmp(info.name, &path[2*d+1]) == 0);
+                assert(info.type == LFS_TYPE_DIR);
+            }
+        } else {
+            // is valid dir?
+            assert(strcmp(info.name, &full_path[2*(DEPTH-1)+1]) == 0);
+            assert(info.type == LFS_TYPE_DIR);
+
+            // try to delete path in reverse order, ignore if dir is not empty
+            for (unsigned d = DEPTH-1; d+1 > 0; d--) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                int err = lfs_remove(&lfs, path);
+                assert(!err || err == LFS_ERR_NOTEMPTY);
+            }
+
+            lfs_stat(&lfs, full_path, &info) => LFS_ERR_NOENT;
+        }
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+
+# non-reentrant testing for relocations, but now with random renames!
+[cases.test_relocations_nonreentrant_renames]
+# TODO fix this case, caused by non-DAG trees
+# NOTE the second condition is required
+if = '!(DEPTH == 3 && CACHE_SIZE != 64) && 2*FILES < BLOCK_COUNT'
+defines = [
+    {FILES=6,  DEPTH=1, CYCLES=2000, BLOCK_CYCLES=1},
+    {FILES=26, DEPTH=1, CYCLES=2000, BLOCK_CYCLES=1},
+    {FILES=3,  DEPTH=3, CYCLES=2000, BLOCK_CYCLES=1},
+]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    uint32_t prng = 1;
+    const char alpha[] = "abcdefghijklmnopqrstuvwxyz";
+    for (unsigned i = 0; i < CYCLES; i++) {
+        // create random path
+        char full_path[256];
+        for (unsigned d = 0; d < DEPTH; d++) {
+            sprintf(&full_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
+        }
+
+        // if it does not exist, we create it, else we destroy
+        struct lfs_info info;
+        int res = lfs_stat(&lfs, full_path, &info);
+        assert(!res || res == LFS_ERR_NOENT);
+        if (res == LFS_ERR_NOENT) {
+            // create each directory in turn, ignore if dir already exists
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                int err = lfs_mkdir(&lfs, path);
+                assert(!err || err == LFS_ERR_EXIST);
+            }
+
+            for (unsigned d = 0; d < DEPTH; d++) {
+                char path[1024];
+                strcpy(path, full_path);
+                path[2*d+2] = '\0';
+                lfs_stat(&lfs, path, &info) => 0;
+                assert(strcmp(info.name, &path[2*d+1]) == 0);
+                assert(info.type == LFS_TYPE_DIR);
+            }
+        } else {
+            assert(strcmp(info.name, &full_path[2*(DEPTH-1)+1]) == 0);
+            assert(info.type == LFS_TYPE_DIR);
+
+            // create new random path
+            char new_path[256];
+            for (unsigned d = 0; d < DEPTH; d++) {
+                sprintf(&new_path[2*d], "/%c", alpha[TEST_PRNG(&prng) % FILES]);
+            }
+
+            // if new path does not exist, rename, otherwise destroy
+            res = lfs_stat(&lfs, new_path, &info);
+            assert(!res || res == LFS_ERR_NOENT);
+            if (res == LFS_ERR_NOENT) {
+                // stop once some dir is renamed
+                for (unsigned d = 0; d < DEPTH; d++) {
+                    char path[1024];
+                    strcpy(&path[2*d], &full_path[2*d]);
+                    path[2*d+2] = '\0';
+                    strcpy(&path[128+2*d], &new_path[2*d]);
+                    path[128+2*d+2] = '\0';
+                    int err = lfs_rename(&lfs, path, path+128);
+                    assert(!err || err == LFS_ERR_NOTEMPTY);
+                    if (!err) {
+                        strcpy(path, path+128);
+                    }
+                }
+
+                for (unsigned d = 0; d < DEPTH; d++) {
+                    char path[1024];
+                    strcpy(path, new_path);
+                    path[2*d+2] = '\0';
+                    lfs_stat(&lfs, path, &info) => 0;
+                    assert(strcmp(info.name, &path[2*d+1]) == 0);
+                    assert(info.type == LFS_TYPE_DIR);
+                }
+
+                lfs_stat(&lfs, full_path, &info) => LFS_ERR_NOENT;
+            } else {
+                // try to delete path in reverse order,
+                // ignore if dir is not empty
+                for (unsigned d = DEPTH-1; d+1 > 0; d--) {
+                    char path[1024];
+                    strcpy(path, full_path);
+                    path[2*d+2] = '\0';
+                    int err = lfs_remove(&lfs, path);
+                    assert(!err || err == LFS_ERR_NOTEMPTY);
+                }
+
+                lfs_stat(&lfs, full_path, &info) => LFS_ERR_NOENT;
+            }
+        }
+    }
+    lfs_unmount(&lfs) => 0;
+'''

tests/test_seek.toml

@@ -1,6 +1,7 @@
 
-[[case]] # simple file seek
-define = [
+# simple file seek
+[cases.test_seek_read]
+defines = [
     {COUNT=132, SKIP=4},
     {COUNT=132, SKIP=128},
     {COUNT=200, SKIP=10},
@@ -9,11 +10,14 @@ define = [
     {COUNT=4,   SKIP=2},
 ]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
-    size = strlen("kittycatcat");
+    size_t size = strlen("kittycatcat");
+    uint8_t buffer[1024];
     memcpy(buffer, "kittycatcat", size);
     for (int j = 0; j < COUNT; j++) {
         lfs_file_write(&lfs, &file, buffer, size);
@@ -21,7 +25,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDONLY) => 0;
 
     lfs_soff_t pos = -1;
@@ -68,8 +72,9 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # simple file seek and write
-define = [
+# simple file seek and write
+[cases.test_seek_write]
+defines = [
     {COUNT=132, SKIP=4},
     {COUNT=132, SKIP=128},
     {COUNT=200, SKIP=10},
@@ -78,11 +83,14 @@ define = [
     {COUNT=4,   SKIP=2},
 ]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
-    size = strlen("kittycatcat");
+    size_t size = strlen("kittycatcat");
+    uint8_t buffer[1024];
     memcpy(buffer, "kittycatcat", size);
     for (int j = 0; j < COUNT; j++) {
         lfs_file_write(&lfs, &file, buffer, size);
@@ -90,7 +98,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
 
     lfs_soff_t pos = -1;
@@ -129,15 +137,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # boundary seek and writes
-define.COUNT = 132
-define.OFFSETS = '"{512, 1020, 513, 1021, 511, 1019, 1441}"'
+# boundary seek and reads
+[cases.test_seek_boundary_read]
+defines.COUNT = 132
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
-    size = strlen("kittycatcat");
+    size_t size = strlen("kittycatcat");
+    uint8_t buffer[1024];
     memcpy(buffer, "kittycatcat", size);
     for (int j = 0; j < COUNT; j++) {
         lfs_file_write(&lfs, &file, buffer, size);
@@ -145,35 +156,182 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_open(&lfs, &file, "kitty", LFS_O_RDONLY) => 0;
 
-    size = strlen("hedgehoghog");
-    const lfs_soff_t offsets[] = OFFSETS;
+    size = strlen("kittycatcat");
+    const lfs_soff_t offsets[] = {
+        512,
+        1024-4,
+        512+1,
+        1024-4+1,
+        512-1,
+        1024-4-1,
+
+        512-strlen("kittycatcat"),
+        1024-4-strlen("kittycatcat"),
+        512-strlen("kittycatcat")+1,
+        1024-4-strlen("kittycatcat")+1,
+        512-strlen("kittycatcat")-1,
+        1024-4-strlen("kittycatcat")-1,
+
+        strlen("kittycatcat")*(COUNT-2)-1,
+    };
 
     for (unsigned i = 0; i < sizeof(offsets) / sizeof(offsets[0]); i++) {
         lfs_soff_t off = offsets[i];
-        memcpy(buffer, "hedgehoghog", size);
-        lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        // read @ offset
         lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
         lfs_file_read(&lfs, &file, buffer, size) => size;
-        memcmp(buffer, "hedgehoghog", size) => 0;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[off % strlen("kittycatcat")],
+                size) => 0;
+        // read after
+        lfs_file_seek(&lfs, &file, off+strlen("kittycatcat")+1, LFS_SEEK_SET)
+                => off+strlen("kittycatcat")+1;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[(off+1) % strlen("kittycatcat")],
+                size) => 0;
+        // read before
+        lfs_file_seek(&lfs, &file, off-strlen("kittycatcat")-1, LFS_SEEK_SET)
+                => off-strlen("kittycatcat")-1;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[(off-1) % strlen("kittycatcat")],
+                size) => 0;
 
+        // read @ 0
         lfs_file_seek(&lfs, &file, 0, LFS_SEEK_SET) => 0;
         lfs_file_read(&lfs, &file, buffer, size) => size;
         memcmp(buffer, "kittycatcat", size) => 0;
 
+        // read @ offset
+        lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[off % strlen("kittycatcat")],
+                size) => 0;
+        // read after
+        lfs_file_seek(&lfs, &file, off+strlen("kittycatcat")+1, LFS_SEEK_SET)
+                => off+strlen("kittycatcat")+1;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[(off+1) % strlen("kittycatcat")],
+                size) => 0;
+        // read before
+        lfs_file_seek(&lfs, &file, off-strlen("kittycatcat")-1, LFS_SEEK_SET)
+                => off-strlen("kittycatcat")-1;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[(off-1) % strlen("kittycatcat")],
+                size) => 0;
+
+        // sync
+        lfs_file_sync(&lfs, &file) => 0;
+
+        // read @ 0
+        lfs_file_seek(&lfs, &file, 0, LFS_SEEK_SET) => 0;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer, "kittycatcat", size) => 0;
+
+        // read @ offset
+        lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[off % strlen("kittycatcat")],
+                size) => 0;
+        // read after
+        lfs_file_seek(&lfs, &file, off+strlen("kittycatcat")+1, LFS_SEEK_SET)
+                => off+strlen("kittycatcat")+1;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[(off+1) % strlen("kittycatcat")],
+                size) => 0;
+        // read before
+        lfs_file_seek(&lfs, &file, off-strlen("kittycatcat")-1, LFS_SEEK_SET)
+                => off-strlen("kittycatcat")-1;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer,
+                &"kittycatcatkittycatcat"[(off-1) % strlen("kittycatcat")],
+                size) => 0;
+    }
+
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+# boundary seek and writes
+[cases.test_seek_boundary_write]
+defines.COUNT = 132
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "kitty",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    size_t size = strlen("kittycatcat");
+    uint8_t buffer[1024];
+    memcpy(buffer, "kittycatcat", size);
+    for (int j = 0; j < COUNT; j++) {
+        lfs_file_write(&lfs, &file, buffer, size);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
+
+    size = strlen("hedgehoghog");
+    const lfs_soff_t offsets[] = {
+        512,
+        1024-4,
+        512+1,
+        1024-4+1,
+        512-1,
+        1024-4-1,
+
+        512-strlen("kittycatcat"),
+        1024-4-strlen("kittycatcat"),
+        512-strlen("kittycatcat")+1,
+        1024-4-strlen("kittycatcat")+1,
+        512-strlen("kittycatcat")-1,
+        1024-4-strlen("kittycatcat")-1,
+
+        strlen("kittycatcat")*(COUNT-2)-1,
+    };
+
+    for (unsigned i = 0; i < sizeof(offsets) / sizeof(offsets[0]); i++) {
+        lfs_soff_t off = offsets[i];
+        // write @ offset
+        memcpy(buffer, "hedgehoghog", size);
+        lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+
+        // read @ offset
+        lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer, "hedgehoghog", size) => 0;
+
+        // read @ 0
+        lfs_file_seek(&lfs, &file, 0, LFS_SEEK_SET) => 0;
+        lfs_file_read(&lfs, &file, buffer, size) => size;
+        memcmp(buffer, "kittycatcat", size) => 0;
+
+        // read @ offset
         lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
         lfs_file_read(&lfs, &file, buffer, size) => size;
         memcmp(buffer, "hedgehoghog", size) => 0;
 
         lfs_file_sync(&lfs, &file) => 0;
 
+        // read @ 0
         lfs_file_seek(&lfs, &file, 0, LFS_SEEK_SET) => 0;
         lfs_file_read(&lfs, &file, buffer, size) => size;
         memcmp(buffer, "kittycatcat", size) => 0;
 
+        // read @ offset
         lfs_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
         lfs_file_read(&lfs, &file, buffer, size) => size;
         memcmp(buffer, "hedgehoghog", size) => 0;
@@ -183,8 +341,9 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # out of bounds seek
-define = [
+# out of bounds seek
+[cases.test_seek_out_of_bounds]
+defines = [
     {COUNT=132, SKIP=4},
     {COUNT=132, SKIP=128},
     {COUNT=200, SKIP=10},
@@ -193,18 +352,21 @@ define = [
     {COUNT=4,   SKIP=3},
 ]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
-    size = strlen("kittycatcat");
+    size_t size = strlen("kittycatcat");
+    uint8_t buffer[1024];
     memcpy(buffer, "kittycatcat", size);
     for (int j = 0; j < COUNT; j++) {
         lfs_file_write(&lfs, &file, buffer, size);
     }
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
 
     size = strlen("kittycatcat");
@@ -238,16 +400,20 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # inline write and seek
-define.SIZE = [2, 4, 128, 132]
+# inline write and seek
+[cases.test_seek_inline_write]
+defines.SIZE = [2, 4, 128, 132]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "tinykitty",
             LFS_O_RDWR | LFS_O_CREAT) => 0;
     int j = 0;
     int k = 0;
 
+    uint8_t buffer[1024];
     memcpy(buffer, "abcdefghijklmnopqrstuvwxyz", 26);
     for (unsigned i = 0; i < SIZE; i++) {
         lfs_file_write(&lfs, &file, &buffer[j++ % 26], 1) => 1;
@@ -305,16 +471,24 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # file seek and write with power-loss
+# file seek and write with power-loss
+[cases.test_seek_reentrant_write]
 # must be power-of-2 for quadratic probing to be exhaustive
-define.COUNT = [4, 64, 128]
+defines.COUNT = [4, 64, 128]
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
+    lfs_file_t file;
+    uint8_t buffer[1024];
     err = lfs_file_open(&lfs, &file, "kitty", LFS_O_RDONLY);
     assert(!err || err == LFS_ERR_NOENT);
     if (!err) {
@@ -334,14 +508,14 @@ code = '''
     if (lfs_file_size(&lfs, &file) == 0) {
         for (int j = 0; j < COUNT; j++) {
             strcpy((char*)buffer, "kittycatcat");
-            size = strlen((char*)buffer);
+            size_t size = strlen((char*)buffer);
             lfs_file_write(&lfs, &file, buffer, size) => size;
         }
     }
     lfs_file_close(&lfs, &file) => 0;
 
     strcpy((char*)buffer, "doggodogdog");
-    size = strlen((char*)buffer);
+    size_t size = strlen((char*)buffer);
 
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => COUNT*size;
@@ -378,3 +552,111 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 '''
+
+
+# test possible overflow/underflow conditions
+#
+# note these need -fsanitize=undefined to consistently detect
+# overflow/underflow conditions
+
+[cases.test_seek_filemax]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "kitty",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    uint8_t buffer[1024];
+    strcpy((char*)buffer, "kittycatcat");
+    size_t size = strlen((char*)buffer);
+    lfs_file_write(&lfs, &file, buffer, size) => size;
+
+    // seek with LFS_SEEK_SET
+    lfs_file_seek(&lfs, &file, LFS_FILE_MAX, LFS_SEEK_SET) => LFS_FILE_MAX;
+
+    // seek with LFS_SEEK_CUR
+    lfs_file_seek(&lfs, &file, 0, LFS_SEEK_CUR) => LFS_FILE_MAX;
+
+    // the file hasn't changed size, so seek end takes us back to the offset=0
+    lfs_file_seek(&lfs, &file, +10, LFS_SEEK_END) => size+10;
+
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.test_seek_underflow]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "kitty",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    uint8_t buffer[1024];
+    strcpy((char*)buffer, "kittycatcat");
+    size_t size = strlen((char*)buffer);
+    lfs_file_write(&lfs, &file, buffer, size) => size;
+
+    // underflow with LFS_SEEK_CUR, should error
+    lfs_file_seek(&lfs, &file, -(size+10), LFS_SEEK_CUR) => LFS_ERR_INVAL;
+    lfs_file_seek(&lfs, &file, -LFS_FILE_MAX, LFS_SEEK_CUR) => LFS_ERR_INVAL;
+    lfs_file_seek(&lfs, &file, -(size+LFS_FILE_MAX), LFS_SEEK_CUR)
+            => LFS_ERR_INVAL;
+
+    // underflow with LFS_SEEK_END, should error
+    lfs_file_seek(&lfs, &file, -(size+10), LFS_SEEK_END) => LFS_ERR_INVAL;
+    lfs_file_seek(&lfs, &file, -LFS_FILE_MAX, LFS_SEEK_END) => LFS_ERR_INVAL;
+    lfs_file_seek(&lfs, &file, -(size+LFS_FILE_MAX), LFS_SEEK_END)
+            => LFS_ERR_INVAL;
+
+    // file pointer should not have changed
+    lfs_file_tell(&lfs, &file) => size;
+
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.test_seek_overflow]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "kitty",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    uint8_t buffer[1024];
+    strcpy((char*)buffer, "kittycatcat");
+    size_t size = strlen((char*)buffer);
+    lfs_file_write(&lfs, &file, buffer, size) => size;
+
+    // seek to LFS_FILE_MAX
+    lfs_file_seek(&lfs, &file, LFS_FILE_MAX, LFS_SEEK_SET) => LFS_FILE_MAX;
+
+    // overflow with LFS_SEEK_CUR, should error
+    lfs_file_seek(&lfs, &file, +10, LFS_SEEK_CUR) => LFS_ERR_INVAL;
+    lfs_file_seek(&lfs, &file, +LFS_FILE_MAX, LFS_SEEK_CUR) => LFS_ERR_INVAL;
+
+    // LFS_SEEK_SET/END don't care about the current file position, but we can
+    // still overflow with a large offset
+
+    // overflow with LFS_SEEK_SET, should error
+    lfs_file_seek(&lfs, &file,
+            +((uint32_t)LFS_FILE_MAX+10),
+            LFS_SEEK_SET) => LFS_ERR_INVAL;
+    lfs_file_seek(&lfs, &file,
+            +((uint32_t)LFS_FILE_MAX+(uint32_t)LFS_FILE_MAX),
+            LFS_SEEK_SET) => LFS_ERR_INVAL;
+
+    // overflow with LFS_SEEK_END, should error
+    lfs_file_seek(&lfs, &file, +(LFS_FILE_MAX-size+10), LFS_SEEK_END)
+            => LFS_ERR_INVAL;
+    lfs_file_seek(&lfs, &file, +(LFS_FILE_MAX-size+LFS_FILE_MAX), LFS_SEEK_END)
+            => LFS_ERR_INVAL;
+
+    // file pointer should not have changed
+    lfs_file_tell(&lfs, &file) => LFS_FILE_MAX;
+
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''

tests/test_shrink.toml

@@ -0,0 +1,109 @@
+# simple shrink
+[cases.test_shrink_simple]
+defines.BLOCK_COUNT = [10, 15, 20]
+defines.AFTER_BLOCK_COUNT = [5, 10, 15, 19]
+   
+if = "AFTER_BLOCK_COUNT <= BLOCK_COUNT"
+code = '''
+#ifdef LFS_SHRINKNONRELOCATING
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_grow(&lfs, AFTER_BLOCK_COUNT) => 0;
+    lfs_unmount(&lfs);
+    if (BLOCK_COUNT != AFTER_BLOCK_COUNT) {
+        lfs_mount(&lfs, cfg) => LFS_ERR_INVAL;
+    }
+    lfs_t lfs2 = lfs;
+    struct lfs_config cfg2 = *cfg;
+    cfg2.block_count = AFTER_BLOCK_COUNT;
+    lfs2.cfg = &cfg2;
+    lfs_mount(&lfs2, &cfg2) => 0;
+    lfs_unmount(&lfs2) => 0;
+#endif
+'''
+
+# shrinking full
+[cases.test_shrink_full]
+defines.BLOCK_COUNT = [10, 15, 20]
+defines.AFTER_BLOCK_COUNT = [5, 7, 10, 12, 15, 17, 20]
+defines.FILES_COUNT = [7, 8, 9, 10]
+if = "AFTER_BLOCK_COUNT <= BLOCK_COUNT && FILES_COUNT + 2 < BLOCK_COUNT"
+code = '''
+#ifdef LFS_SHRINKNONRELOCATING
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    // create FILES_COUNT files of BLOCK_SIZE - 50 bytes (to avoid inlining)
+    lfs_mount(&lfs, cfg) => 0;
+    for (int i = 0; i < FILES_COUNT + 1; i++) {
+        lfs_file_t file;
+        char path[1024];
+        sprintf(path, "file_%03d", i);
+        lfs_file_open(&lfs, &file, path,
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+        char wbuffer[BLOCK_SIZE];
+        memset(wbuffer, 'b', BLOCK_SIZE);
+        // Ensure one block is taken per file, but that files are not inlined.
+        lfs_size_t size = BLOCK_SIZE - 0x40;
+        sprintf(wbuffer, "Hi %03d", i);
+        lfs_file_write(&lfs, &file, wbuffer, size) => size;
+        lfs_file_close(&lfs, &file) => 0;
+    }
+
+    int err = lfs_fs_grow(&lfs, AFTER_BLOCK_COUNT);
+    if (err == 0) {
+        for (int i = 0; i < FILES_COUNT + 1; i++) {
+            lfs_file_t file;
+            char path[1024];
+            sprintf(path, "file_%03d", i);
+            lfs_file_open(&lfs, &file, path,
+                    LFS_O_RDONLY ) => 0;
+            lfs_size_t size = BLOCK_SIZE - 0x40;
+            char wbuffer[size];
+            char wbuffer_ref[size];
+            // Ensure one block is taken per file, but that files are not inlined.
+            memset(wbuffer_ref, 'b', size);
+            sprintf(wbuffer_ref, "Hi %03d", i);
+            lfs_file_read(&lfs, &file, wbuffer, BLOCK_SIZE) => size;
+            lfs_file_close(&lfs, &file) => 0;
+            for (lfs_size_t j = 0; j < size; j++) {
+                wbuffer[j] => wbuffer_ref[j];
+            }
+        }
+    } else {
+        assert(err == LFS_ERR_NOTEMPTY);
+    }
+
+    lfs_unmount(&lfs) => 0;
+    if (err == 0 ) {
+        if ( AFTER_BLOCK_COUNT != BLOCK_COUNT ) {
+            lfs_mount(&lfs, cfg) => LFS_ERR_INVAL;
+        }
+
+        lfs_t lfs2 = lfs;
+        struct lfs_config cfg2 = *cfg;
+        cfg2.block_count = AFTER_BLOCK_COUNT;
+        lfs2.cfg = &cfg2;
+        lfs_mount(&lfs2, &cfg2) => 0;
+        for (int i = 0; i < FILES_COUNT + 1; i++) {
+            lfs_file_t file;
+            char path[1024];
+            sprintf(path, "file_%03d", i);
+            lfs_file_open(&lfs2, &file, path,
+                    LFS_O_RDONLY ) => 0;
+            lfs_size_t size = BLOCK_SIZE - 0x40;
+            char wbuffer[size];
+            char wbuffer_ref[size];
+            // Ensure one block is taken per file, but that files are not inlined.
+            memset(wbuffer_ref, 'b', size);
+            sprintf(wbuffer_ref, "Hi %03d", i);
+            lfs_file_read(&lfs2, &file, wbuffer, BLOCK_SIZE) => size;
+            lfs_file_close(&lfs2, &file) => 0;
+            for (lfs_size_t j = 0; j < size; j++) {
+                wbuffer[j] => wbuffer_ref[j];
+            }
+        }
+        lfs_unmount(&lfs2);
+    }
+#endif
+'''

tests/test_superblocks.toml

@@ -1,41 +1,137 @@
-[[case]] # simple formatting test
+# simple formatting test
+[cases.test_superblocks_format]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
 '''
 
-[[case]] # mount/unmount
+# mount/unmount
+[cases.test_superblocks_mount]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant format
-reentrant = true
+# make sure the magic string "littlefs" is always at offset=8
+[cases.test_superblocks_magic]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    // check our magic string
+    //
+    // note if we lose power we may not have the magic string in both blocks!
+    // but we don't lose power in this test so we can assert the magic string
+    // is present in both
+    uint8_t magic[lfs_max(16, READ_SIZE)];
+    cfg->read(cfg, 0, 0, magic, lfs_max(16, READ_SIZE)) => 0;
+    assert(memcmp(&magic[8], "littlefs", 8) == 0);
+    cfg->read(cfg, 1, 0, magic, lfs_max(16, READ_SIZE)) => 0;
+    assert(memcmp(&magic[8], "littlefs", 8) == 0);
+'''
+
+# mount/unmount from interpretting a previous superblock block_count
+[cases.test_superblocks_mount_unknown_block_count]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    memset(&lfs, 0, sizeof(lfs));
+    struct lfs_config tweaked_cfg = *cfg;
+    tweaked_cfg.block_count = 0;
+    lfs_mount(&lfs, &tweaked_cfg) => 0;
+    assert(lfs.block_count == cfg->block_count);
+    lfs_unmount(&lfs) => 0;
+'''
+
+# reentrant format
+[cases.test_superblocks_reentrant_format]
+reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
+code = '''
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # invalid mount
+# invalid mount
+[cases.test_superblocks_invalid_mount]
 code = '''
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_t lfs;
+    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
 '''
 
-[[case]] # expanding superblock
-define.LFS_BLOCK_CYCLES = [32, 33, 1]
-define.N = [10, 100, 1000]
+# test we can read superblock info through lfs_fs_stat
+[cases.test_superblocks_stat]
+if = 'DISK_VERSION == 0'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    // test we can mount and read fsinfo
+    lfs_mount(&lfs, cfg) => 0;
+
+    struct lfs_fsinfo fsinfo;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.disk_version == LFS_DISK_VERSION);
+    assert(fsinfo.name_max == LFS_NAME_MAX);
+    assert(fsinfo.file_max == LFS_FILE_MAX);
+    assert(fsinfo.attr_max == LFS_ATTR_MAX);
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[cases.test_superblocks_stat_tweaked]
+if = 'DISK_VERSION == 0'
+defines.TWEAKED_NAME_MAX = 63
+defines.TWEAKED_FILE_MAX = '(1 << 16)-1'
+defines.TWEAKED_ATTR_MAX = 512
+code = '''
+    // create filesystem with tweaked params
+    struct lfs_config tweaked_cfg = *cfg;
+    tweaked_cfg.name_max = TWEAKED_NAME_MAX;
+    tweaked_cfg.file_max = TWEAKED_FILE_MAX;
+    tweaked_cfg.attr_max = TWEAKED_ATTR_MAX;
+
+    lfs_t lfs;
+    lfs_format(&lfs, &tweaked_cfg) => 0;
+
+    // test we can mount and read these params with the original config
+    lfs_mount(&lfs, cfg) => 0;
+
+    struct lfs_fsinfo fsinfo;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.disk_version == LFS_DISK_VERSION);
+    assert(fsinfo.name_max == TWEAKED_NAME_MAX);
+    assert(fsinfo.file_max == TWEAKED_FILE_MAX);
+    assert(fsinfo.attr_max == TWEAKED_ATTR_MAX);
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+# expanding superblock
+[cases.test_superblocks_expand]
+defines.BLOCK_CYCLES = [32, 33, 1]
+defines.N = [10, 100, 1000]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, "dummy",
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         lfs_file_close(&lfs, &file) => 0;
+        struct lfs_info info;
         lfs_stat(&lfs, "dummy", &info) => 0;
         assert(strcmp(info.name, "dummy") == 0);
         assert(info.type == LFS_TYPE_REG);
@@ -44,25 +140,63 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // one last check after power-cycle
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "dummy",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     lfs_file_close(&lfs, &file) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
     assert(info.type == LFS_TYPE_REG);
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # expanding superblock with power cycle
-define.LFS_BLOCK_CYCLES = [32, 33, 1]
-define.N = [10, 100, 1000]
+# make sure the magic string "littlefs" is always at offset=8
+[cases.test_superblocks_magic_expand]
+defines.BLOCK_CYCLES = [32, 33, 1]
+defines.N = [10, 100, 1000]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     for (int i = 0; i < N; i++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_file_t file;
+        lfs_file_open(&lfs, &file, "dummy",
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+        lfs_file_close(&lfs, &file) => 0;
+        struct lfs_info info;
+        lfs_stat(&lfs, "dummy", &info) => 0;
+        assert(strcmp(info.name, "dummy") == 0);
+        assert(info.type == LFS_TYPE_REG);
+        lfs_remove(&lfs, "dummy") => 0;
+    }
+    lfs_unmount(&lfs) => 0;
+
+    // check our magic string
+    //
+    // note if we lose power we may not have the magic string in both blocks!
+    // but we don't lose power in this test so we can assert the magic string
+    // is present in both
+    uint8_t magic[lfs_max(16, READ_SIZE)];
+    cfg->read(cfg, 0, 0, magic, lfs_max(16, READ_SIZE)) => 0;
+    assert(memcmp(&magic[8], "littlefs", 8) == 0);
+    cfg->read(cfg, 1, 0, magic, lfs_max(16, READ_SIZE)) => 0;
+    assert(memcmp(&magic[8], "littlefs", 8) == 0);
+'''
+
+# expanding superblock with power cycle
+[cases.test_superblocks_expand_power_cycle]
+defines.BLOCK_CYCLES = [32, 33, 1]
+defines.N = [10, 100, 1000]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    for (int i = 0; i < N; i++) {
+        lfs_mount(&lfs, cfg) => 0;
         // remove lingering dummy?
-        err = lfs_stat(&lfs, "dummy", &info);
+        struct lfs_info info;
+        int err = lfs_stat(&lfs, "dummy", &info);
         assert(err == 0 || (err == LFS_ERR_NOENT && i == 0));
         if (!err) {
             assert(strcmp(info.name, "dummy") == 0);
@@ -70,6 +204,7 @@ code = '''
             lfs_remove(&lfs, "dummy") => 0;
         }
 
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, "dummy",
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         lfs_file_close(&lfs, &file) => 0;
@@ -80,26 +215,34 @@ code = '''
     }
 
     // one last check after power-cycle
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
     assert(info.type == LFS_TYPE_REG);
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # reentrant expanding superblock
-define.LFS_BLOCK_CYCLES = [2, 1]
-define.N = 24
+# reentrant expanding superblock
+[cases.test_superblocks_reentrant_expand]
+defines.BLOCK_CYCLES = [2, 1]
+defines.N = 24
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
 
     for (int i = 0; i < N; i++) {
         // remove lingering dummy?
+        struct lfs_info info;
         err = lfs_stat(&lfs, "dummy", &info);
         assert(err == 0 || (err == LFS_ERR_NOENT && i == 0));
         if (!err) {
@@ -108,6 +251,7 @@ code = '''
             lfs_remove(&lfs, "dummy") => 0;
         }
 
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, "dummy",
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         lfs_file_close(&lfs, &file) => 0;
@@ -119,9 +263,398 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // one last check after power-cycle
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_info info;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
     assert(info.type == LFS_TYPE_REG);
     lfs_unmount(&lfs) => 0;
 '''
+
+
+# mount with unknown block_count
+[cases.test_superblocks_unknown_blocks]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    // known block_size/block_count
+    cfg->block_size = BLOCK_SIZE;
+    cfg->block_count = BLOCK_COUNT;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_fsinfo fsinfo;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // unknown block_count
+    cfg->block_size = BLOCK_SIZE;
+    cfg->block_count = 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // do some work
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "test",
+            LFS_O_CREAT | LFS_O_EXCL | LFS_O_WRONLY) => 0;
+    lfs_file_write(&lfs, &file, "hello!", 6) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_file_open(&lfs, &file, "test", LFS_O_RDONLY) => 0;
+    uint8_t buffer[256];
+    lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    assert(memcmp(buffer, "hello!", 6) == 0);
+    lfs_unmount(&lfs) => 0;
+'''
+
+# mount with blocks fewer than the erase_count
+[cases.test_superblocks_fewer_blocks]
+defines.BLOCK_COUNT = ['ERASE_COUNT/2', 'ERASE_COUNT/4', '2']
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    // known block_size/block_count
+    cfg->block_size = BLOCK_SIZE;
+    cfg->block_count = BLOCK_COUNT;
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_fsinfo fsinfo;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // incorrect block_count
+    cfg->block_size = BLOCK_SIZE;
+    cfg->block_count = ERASE_COUNT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_INVAL;
+
+    // unknown block_count
+    cfg->block_size = BLOCK_SIZE;
+    cfg->block_count = 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // do some work
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "test",
+            LFS_O_CREAT | LFS_O_EXCL | LFS_O_WRONLY) => 0;
+    lfs_file_write(&lfs, &file, "hello!", 6) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_file_open(&lfs, &file, "test", LFS_O_RDONLY) => 0;
+    uint8_t buffer[256];
+    lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    assert(memcmp(buffer, "hello!", 6) == 0);
+    lfs_unmount(&lfs) => 0;
+'''
+
+# mount with more blocks than the erase_count
+[cases.test_superblocks_more_blocks]
+defines.FORMAT_BLOCK_COUNT = '2*ERASE_COUNT'
+in = 'lfs.c'
+code = '''
+    lfs_t lfs;
+    lfs_init(&lfs, cfg) => 0;
+    lfs.block_count = BLOCK_COUNT;
+
+    lfs_mdir_t root = {
+        .pair = {0, 0}, // make sure this goes into block 0
+        .rev = 0,
+        .off = sizeof(uint32_t),
+        .etag = 0xffffffff,
+        .count = 0,
+        .tail = {LFS_BLOCK_NULL, LFS_BLOCK_NULL},
+        .erased = false,
+        .split = false,
+    };
+
+    lfs_superblock_t superblock = {
+        .version     = LFS_DISK_VERSION,
+        .block_size  = BLOCK_SIZE,
+        .block_count = FORMAT_BLOCK_COUNT,
+        .name_max    = LFS_NAME_MAX,
+        .file_max    = LFS_FILE_MAX,
+        .attr_max    = LFS_ATTR_MAX,
+    };
+
+    lfs_superblock_tole32(&superblock);
+    lfs_dir_commit(&lfs, &root, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_CREATE, 0, 0), NULL},
+            {LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
+            {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
+                &superblock})) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // known block_size/block_count
+    cfg->block_size = BLOCK_SIZE;
+    cfg->block_count = BLOCK_COUNT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_INVAL;
+'''
+
+# mount and grow the filesystem
+[cases.test_superblocks_grow]
+defines.BLOCK_COUNT = ['ERASE_COUNT/2', 'ERASE_COUNT/4', '2']
+defines.BLOCK_COUNT_2 = 'ERASE_COUNT'
+defines.KNOWN_BLOCK_COUNT = [true, false]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    if (KNOWN_BLOCK_COUNT) {
+        cfg->block_count = BLOCK_COUNT;
+    } else {
+        cfg->block_count = 0;
+    }
+
+    // mount with block_size < erase_size
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_fsinfo fsinfo;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // same size is a noop
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_grow(&lfs, BLOCK_COUNT) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // grow to new size
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_grow(&lfs, BLOCK_COUNT_2) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    if (KNOWN_BLOCK_COUNT) {
+        cfg->block_count = BLOCK_COUNT_2;
+    } else {
+        cfg->block_count = 0;
+    }
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    // mounting with the previous size should fail
+    cfg->block_count = BLOCK_COUNT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_INVAL;
+
+    if (KNOWN_BLOCK_COUNT) {
+        cfg->block_count = BLOCK_COUNT_2;
+    } else {
+        cfg->block_count = 0;
+    }
+
+    // same size is a noop
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_grow(&lfs, BLOCK_COUNT_2) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    // do some work
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "test",
+            LFS_O_CREAT | LFS_O_EXCL | LFS_O_WRONLY) => 0;
+    lfs_file_write(&lfs, &file, "hello!", 6) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_file_open(&lfs, &file, "test", LFS_O_RDONLY) => 0;
+    uint8_t buffer[256];
+    lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    assert(memcmp(buffer, "hello!", 6) == 0);
+    lfs_unmount(&lfs) => 0;
+'''
+
+
+# mount and grow the filesystem
+[cases.test_superblocks_shrink]
+defines.BLOCK_COUNT = 'ERASE_COUNT'
+defines.BLOCK_COUNT_2 = ['ERASE_COUNT/2', 'ERASE_COUNT/4', '2']
+defines.KNOWN_BLOCK_COUNT = [true, false]
+code = '''
+#ifdef LFS_SHRINKNONRELOCATING
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+
+    if (KNOWN_BLOCK_COUNT) {
+        cfg->block_count = BLOCK_COUNT;
+    } else {
+        cfg->block_count = 0;
+    }
+
+    // mount with block_size < erase_size
+    lfs_mount(&lfs, cfg) => 0;
+    struct lfs_fsinfo fsinfo;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // same size is a noop
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_grow(&lfs, BLOCK_COUNT) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT);
+    lfs_unmount(&lfs) => 0;
+
+    // grow to new size
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_grow(&lfs, BLOCK_COUNT_2) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    if (KNOWN_BLOCK_COUNT) {
+        cfg->block_count = BLOCK_COUNT_2;
+    } else {
+        cfg->block_count = 0;
+    }
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    // mounting with the previous size should fail
+    cfg->block_count = BLOCK_COUNT;
+    lfs_mount(&lfs, cfg) => LFS_ERR_INVAL;
+
+    if (KNOWN_BLOCK_COUNT) {
+        cfg->block_count = BLOCK_COUNT_2;
+    } else {
+        cfg->block_count = 0;
+    }
+
+    // same size is a noop
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_grow(&lfs, BLOCK_COUNT_2) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_unmount(&lfs) => 0;
+
+    // do some work
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "test",
+            LFS_O_CREAT | LFS_O_EXCL | LFS_O_WRONLY) => 0;
+    lfs_file_write(&lfs, &file, "hello!", 6) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_fs_stat(&lfs, &fsinfo) => 0;
+    assert(fsinfo.block_size == BLOCK_SIZE);
+    assert(fsinfo.block_count == BLOCK_COUNT_2);
+    lfs_file_open(&lfs, &file, "test", LFS_O_RDONLY) => 0;
+    uint8_t buffer[256];
+    lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => 6;
+    lfs_file_close(&lfs, &file) => 0;
+    assert(memcmp(buffer, "hello!", 6) == 0);
+    lfs_unmount(&lfs) => 0;
+#endif
+'''
+
+# test that metadata_max does not cause problems for superblock compaction
+[cases.test_superblocks_metadata_max]
+defines.METADATA_MAX = [
+    'lfs_max(512, PROG_SIZE)',
+    'lfs_max(BLOCK_SIZE/2, PROG_SIZE)',
+    'BLOCK_SIZE'
+]
+defines.N = [10, 100, 1000]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    for (int i = 0; i < N; i++) {
+        lfs_file_t file;
+        char name[256];
+        sprintf(name, "hello%03x", i);
+        lfs_file_open(&lfs, &file, name,
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+        lfs_file_close(&lfs, &file) => 0;
+        struct lfs_info info;
+        lfs_stat(&lfs, name, &info) => 0;
+        assert(strcmp(info.name, name) == 0);
+        assert(info.type == LFS_TYPE_REG);
+    }
+    lfs_unmount(&lfs) => 0;
+'''

tests/test_truncate.toml

@@ -1,23 +1,29 @@
-[[case]] # simple truncate
-define.MEDIUMSIZE = [32, 2048]
-define.LARGESIZE = 8192
+# simple truncate
+[cases.test_truncate_simple]
+defines.MEDIUMSIZE = [31, 32, 33, 511, 512, 513, 2047, 2048, 2049]
+defines.LARGESIZE = [32, 33, 512, 513, 2048, 2049, 8192, 8193]
+if = 'MEDIUMSIZE < LARGESIZE'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "baldynoop",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
 
+    uint8_t buffer[1024];
     strcpy((char*)buffer, "hair");
-    size = strlen((char*)buffer);
+    size_t size = strlen((char*)buffer);
     for (lfs_off_t j = 0; j < LARGESIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, LARGESIZE-j))
+                => lfs_min(size, LARGESIZE-j);
     }
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
     
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "baldynoop", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
@@ -27,14 +33,15 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "baldynoop", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
     size = strlen("hair");
     for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_read(&lfs, &file, buffer, size) => size;
-        memcmp(buffer, "hair", size) => 0;
+        lfs_file_read(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
+        memcmp(buffer, "hair", lfs_min(size, MEDIUMSIZE-j)) => 0;
     }
     lfs_file_read(&lfs, &file, buffer, size) => 0;
 
@@ -42,26 +49,32 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # truncate and read
-define.MEDIUMSIZE = [32, 2048]
-define.LARGESIZE = 8192
+# truncate and read
+[cases.test_truncate_read]
+defines.MEDIUMSIZE = [31, 32, 33, 511, 512, 513, 2047, 2048, 2049]
+defines.LARGESIZE = [32, 33, 512, 513, 2048, 2049, 8192, 8193]
+if = 'MEDIUMSIZE < LARGESIZE'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "baldyread",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
 
+    uint8_t buffer[1024];
     strcpy((char*)buffer, "hair");
-    size = strlen((char*)buffer);
+    size_t size = strlen((char*)buffer);
     for (lfs_off_t j = 0; j < LARGESIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, LARGESIZE-j))
+                => lfs_min(size, LARGESIZE-j);
     }
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "baldyread", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
@@ -70,22 +83,24 @@ code = '''
 
     size = strlen("hair");
     for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_read(&lfs, &file, buffer, size) => size;
-        memcmp(buffer, "hair", size) => 0;
+        lfs_file_read(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
+        memcmp(buffer, "hair", lfs_min(size, MEDIUMSIZE-j)) => 0;
     }
     lfs_file_read(&lfs, &file, buffer, size) => 0;
 
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "baldyread", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
     size = strlen("hair");
     for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_read(&lfs, &file, buffer, size) => size;
-        memcmp(buffer, "hair", size) => 0;
+        lfs_file_read(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
+        memcmp(buffer, "hair", lfs_min(size, MEDIUMSIZE-j)) => 0;
     }
     lfs_file_read(&lfs, &file, buffer, size) => 0;
 
@@ -93,14 +108,18 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # write, truncate, and read
+# write, truncate, and read
+[cases.test_truncate_write_read]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "sequence",
             LFS_O_RDWR | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
-    size = lfs_min(lfs.cfg->cache_size, sizeof(buffer)/2);
+    uint8_t buffer[1024];
+    size_t size = lfs_min(lfs.cfg->cache_size, sizeof(buffer)/2);
     lfs_size_t qsize = size / 4;
     uint8_t *wb = buffer;
     uint8_t *rb = buffer + size;
@@ -136,7 +155,7 @@ code = '''
     lfs_file_truncate(&lfs, &file, trunc) => 0;
     lfs_file_tell(&lfs, &file) => qsize;
     lfs_file_size(&lfs, &file) => trunc;
-    
+
     /* Read should produce second quarter */
     lfs_file_read(&lfs, &file, rb, size) => trunc - qsize;
     memcmp(rb, wb + qsize, trunc - qsize) => 0;
@@ -145,50 +164,60 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # truncate and write
-define.MEDIUMSIZE = [32, 2048]
-define.LARGESIZE = 8192
+# truncate and write
+[cases.test_truncate_write]
+defines.MEDIUMSIZE = [31, 32, 33, 511, 512, 513, 2047, 2048, 2049]
+defines.LARGESIZE = [32, 33, 512, 513, 2048, 2049, 8192, 8193]
+if = 'MEDIUMSIZE < LARGESIZE'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
     lfs_file_open(&lfs, &file, "baldywrite",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
 
+    uint8_t buffer[1024];
     strcpy((char*)buffer, "hair");
-    size = strlen((char*)buffer);
+    size_t size = strlen((char*)buffer);
     for (lfs_off_t j = 0; j < LARGESIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, LARGESIZE-j))
+                => lfs_min(size, LARGESIZE-j);
     }
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "baldywrite", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
+    /* truncate */
     lfs_file_truncate(&lfs, &file, MEDIUMSIZE) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
+    /* and write */
     strcpy((char*)buffer, "bald");
     size = strlen((char*)buffer);
     for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
     }
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
     lfs_file_open(&lfs, &file, "baldywrite", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
     size = strlen("bald");
     for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_read(&lfs, &file, buffer, size) => size;
-        memcmp(buffer, "bald", size) => 0;
+        lfs_file_read(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
+        memcmp(buffer, "bald", lfs_min(size, MEDIUMSIZE-j)) => 0;
     }
     lfs_file_read(&lfs, &file, buffer, size) => 0;
 
@@ -196,30 +225,39 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # truncate write under powerloss
-define.SMALLSIZE = [4, 512]
-define.MEDIUMSIZE = [32, 1024]
-define.LARGESIZE = 2048
+# truncate write under powerloss
+[cases.test_truncate_reentrant_write]
+defines.SMALLSIZE = [4, 512]
+defines.MEDIUMSIZE = [0, 3, 4, 5, 31, 32, 33, 511, 512, 513, 1023, 1024, 1025]
+defines.LARGESIZE = 2048
 reentrant = true
+defines.POWERLOSS_BEHAVIOR = [
+    'LFS_EMUBD_POWERLOSS_NOOP',
+    'LFS_EMUBD_POWERLOSS_OOO',
+]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    lfs_t lfs;
+    int err = lfs_mount(&lfs, cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_format(&lfs, cfg) => 0;
+        lfs_mount(&lfs, cfg) => 0;
     }
+    lfs_file_t file;
     err = lfs_file_open(&lfs, &file, "baldy", LFS_O_RDONLY);
     assert(!err || err == LFS_ERR_NOENT);
     if (!err) {
-        size = lfs_file_size(&lfs, &file);
+        size_t size = lfs_file_size(&lfs, &file);
         assert(size == 0 ||
-                size == LARGESIZE ||
-                size == MEDIUMSIZE ||
-                size == SMALLSIZE);
+                size == (size_t)LARGESIZE ||
+                size == (size_t)MEDIUMSIZE ||
+                size == (size_t)SMALLSIZE);
         for (lfs_off_t j = 0; j < size; j += 4) {
-            lfs_file_read(&lfs, &file, buffer, 4) => 4;
-            assert(memcmp(buffer, "hair", 4) == 0 ||
-                   memcmp(buffer, "bald", 4) == 0 ||
-                   memcmp(buffer, "comb", 4) == 0);
+            uint8_t buffer[1024];
+            lfs_file_read(&lfs, &file, buffer, lfs_min(4, size-j))
+                    => lfs_min(4, size-j);
+            assert(memcmp(buffer, "hair", lfs_min(4, size-j)) == 0 ||
+                   memcmp(buffer, "bald", lfs_min(4, size-j)) == 0 ||
+                   memcmp(buffer, "comb", lfs_min(4, size-j)) == 0);
         }
         lfs_file_close(&lfs, &file) => 0;
     }
@@ -227,22 +265,27 @@ code = '''
     lfs_file_open(&lfs, &file, "baldy",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
     lfs_file_size(&lfs, &file) => 0;
+    uint8_t buffer[1024];
     strcpy((char*)buffer, "hair");
-    size = strlen((char*)buffer);
+    size_t size = strlen((char*)buffer);
     for (lfs_off_t j = 0; j < LARGESIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, LARGESIZE-j))
+                => lfs_min(size, LARGESIZE-j);
     }
     lfs_file_size(&lfs, &file) => LARGESIZE;
     lfs_file_close(&lfs, &file) => 0;
 
     lfs_file_open(&lfs, &file, "baldy", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => LARGESIZE;
+    /* truncate */
     lfs_file_truncate(&lfs, &file, MEDIUMSIZE) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
+    /* and write */
     strcpy((char*)buffer, "bald");
     size = strlen((char*)buffer);
     for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
     }
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
     lfs_file_close(&lfs, &file) => 0;
@@ -254,7 +297,8 @@ code = '''
     strcpy((char*)buffer, "comb");
     size = strlen((char*)buffer);
     for (lfs_off_t j = 0; j < SMALLSIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, SMALLSIZE-j))
+                => lfs_min(size, SMALLSIZE-j);
     }
     lfs_file_size(&lfs, &file) => SMALLSIZE;
     lfs_file_close(&lfs, &file) => 0;
@@ -262,12 +306,14 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
-[[case]] # more aggressive general truncation tests
-define.CONFIG = 'range(6)'
-define.SMALLSIZE = 32
-define.MEDIUMSIZE = 2048
-define.LARGESIZE = 8192
+# more aggressive general truncation tests
+[cases.test_truncate_aggressive]
+defines.CONFIG = 'range(6)'
+defines.SMALLSIZE = 32
+defines.MEDIUMSIZE = 2048
+defines.LARGESIZE = 8192
 code = '''
+    lfs_t lfs;
     #define COUNT 5
     const struct {
         lfs_off_t startsizes[COUNT];
@@ -312,16 +358,19 @@ code = '''
     const lfs_off_t *hotsizes   = configs[CONFIG].hotsizes;
     const lfs_off_t *coldsizes  = configs[CONFIG].coldsizes;
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     for (unsigned i = 0; i < COUNT; i++) {
+        char path[1024];
         sprintf(path, "hairyhead%d", i);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
+        uint8_t buffer[1024];
         strcpy((char*)buffer, "hair");
-        size = strlen((char*)buffer);
+        size_t size = strlen((char*)buffer);
         for (lfs_off_t j = 0; j < startsizes[i]; j += size) {
             lfs_file_write(&lfs, &file, buffer, size) => size;
         }
@@ -340,21 +389,25 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     for (unsigned i = 0; i < COUNT; i++) {
+        char path[1024];
         sprintf(path, "hairyhead%d", i);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path, LFS_O_RDWR) => 0;
         lfs_file_size(&lfs, &file) => hotsizes[i];
 
-        size = strlen("hair");
+        size_t size = strlen("hair");
         lfs_off_t j = 0;
         for (; j < startsizes[i] && j < hotsizes[i]; j += size) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &file, buffer, size) => size;
             memcmp(buffer, "hair", size) => 0;
         }
 
         for (; j < hotsizes[i]; j += size) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &file, buffer, size) => size;
             memcmp(buffer, "\0\0\0\0", size) => 0;
         }
@@ -367,22 +420,26 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
 
     for (unsigned i = 0; i < COUNT; i++) {
+        char path[1024];
         sprintf(path, "hairyhead%d", i);
+        lfs_file_t file;
         lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
         lfs_file_size(&lfs, &file) => coldsizes[i];
 
-        size = strlen("hair");
+        size_t size = strlen("hair");
         lfs_off_t j = 0;
         for (; j < startsizes[i] && j < hotsizes[i] && j < coldsizes[i];
                 j += size) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &file, buffer, size) => size;
             memcmp(buffer, "hair", size) => 0;
         }
 
         for (; j < coldsizes[i]; j += size) {
+            uint8_t buffer[1024];
             lfs_file_read(&lfs, &file, buffer, size) => size;
             memcmp(buffer, "\0\0\0\0", size) => 0;
         }
@@ -392,3 +449,55 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 '''
+
+# noop truncate
+[cases.test_truncate_nop]
+defines.MEDIUMSIZE = [32, 33, 512, 513, 2048, 2049, 8192, 8193]
+code = '''
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_t file;
+    lfs_file_open(&lfs, &file, "baldynoop",
+            LFS_O_RDWR | LFS_O_CREAT) => 0;
+
+    uint8_t buffer[1024];
+    strcpy((char*)buffer, "hair");
+    size_t size = strlen((char*)buffer);
+    for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
+        lfs_file_write(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
+
+        // this truncate should do nothing
+        lfs_file_truncate(&lfs, &file, j+lfs_min(size, MEDIUMSIZE-j)) => 0;
+    }
+    lfs_file_size(&lfs, &file) => MEDIUMSIZE;
+
+    lfs_file_seek(&lfs, &file, 0, LFS_SEEK_SET) => 0;
+    // should do nothing again
+    lfs_file_truncate(&lfs, &file, MEDIUMSIZE) => 0;
+    lfs_file_size(&lfs, &file) => MEDIUMSIZE;
+
+    for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
+        lfs_file_read(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
+        memcmp(buffer, "hair", lfs_min(size, MEDIUMSIZE-j)) => 0;
+    }
+    lfs_file_read(&lfs, &file, buffer, size) => 0;
+
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // still there after reboot?
+    lfs_mount(&lfs, cfg) => 0;
+    lfs_file_open(&lfs, &file, "baldynoop", LFS_O_RDWR) => 0;
+    lfs_file_size(&lfs, &file) => MEDIUMSIZE;
+    for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
+        lfs_file_read(&lfs, &file, buffer, lfs_min(size, MEDIUMSIZE-j))
+                => lfs_min(size, MEDIUMSIZE-j);
+        memcmp(buffer, "hair", lfs_min(size, MEDIUMSIZE-j)) => 0;
+    }
+    lfs_file_read(&lfs, &file, buffer, size) => 0;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''