Fixed Clang testing in CI, removed override vars in Makefile

Two flags introduced: -fcallgraph-info=su for stack analysis, and
-ftrack-macro-expansions=0 for cleaner prettyassert.py warnings, are
unfortunately not supported in Clang.

The override vars in the Makefile meant it wasn't actually possible to
remove these flags for Clang testing, so this commit changes those vars
to normal, non-overriding vars. This means `make CFLAGS=-Werror` and
`CFLAGS=-Werror make` behave _very_ differently, but this is just an
unfortunate quirk of make that needs to be worked around.

.github/workflows/test.yml

@@ -9,6 +9,7 @@ env:
   CFLAGS: -Werror
   MAKEFLAGS: -j
   TESTFLAGS: -k
+  BENCHFLAGS:
 
 jobs:
   # run tests
@@ -78,12 +79,13 @@ jobs:
         run: |
           make clean
           sed -n '/``` c/,/```/{/```/d; p}' README.md > test.c
-          make all CFLAGS+=" \
+          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"
+            -include stdio.h" \
+            make all
           rm test.c
 
       # run the tests!
@@ -91,7 +93,7 @@ jobs:
         run: |
           make clean
           # TODO include this by default?
-          make test TESTFLAGS+='-Pnone,linear'
+          TESTFLAGS="$TESTFLAGS -Pnone,linear" make test
 
       # collect coverage info
       #
@@ -110,12 +112,12 @@ jobs:
       - name: sizes
         run: |
           make clean
-          make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.struct.csv \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR"
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_ASSERT \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.struct.csv
           ./scripts/summary.py lfs.struct.csv \
             -bstruct \
             -fsize=struct_size
@@ -133,13 +135,13 @@ jobs:
       - name: sizes-readonly
         run: |
           make clean
-          make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.struct.csv \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -DLFS_READONLY"
+          CFLAGS="$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.struct.csv
           ./scripts/summary.py lfs.struct.csv \
             -bstruct \
             -fsize=struct_size
@@ -157,13 +159,13 @@ jobs:
       - name: sizes-threadsafe
         run: |
           make clean
-          make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.struct.csv \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -DLFS_THREADSAFE"
+          CFLAGS="$CFLAGS \
+            -DLFS_NO_ASSERT \
+            -DLFS_NO_DEBUG \
+            -DLFS_NO_WARN \
+            -DLFS_NO_ERROR \
+            -DLFS_THREADSAFE" \
+            make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.struct.csv
           ./scripts/summary.py lfs.struct.csv \
             -bstruct \
             -fsize=struct_size
@@ -181,13 +183,13 @@ jobs:
       - name: sizes-migrate
         run: |
           make clean
-          make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.struct.csv \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -DLFS_MIGRATE"
+          CFLAGS="$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.struct.csv
           ./scripts/summary.py lfs.struct.csv \
             -bstruct \
             -fsize=struct_size
@@ -205,12 +207,12 @@ jobs:
       - name: sizes-error-asserts
         run: |
           make clean
-          make lfs.code.csv lfs.data.csv lfs.stack.csv lfs.struct.csv \
-            CFLAGS+=" \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -D'LFS_ASSERT(test)=do {if(!(test)) {return -1;}} while(0)'"
+          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.struct.csv
           ./scripts/summary.py lfs.struct.csv \
             -bstruct \
             -fsize=struct_size
@@ -341,13 +343,14 @@ jobs:
       - name: test-pls
         if: ${{matrix.pls <= 1}}
         run: |
-          make test TESTFLAGS+="-P${{matrix.pls}}"
+          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: ${{matrix.pls > 1}}
         run: |
-          make test TESTFLAGS+="-P${{matrix.pls}} test_dirs test_relocations"
+          TESTFLAGS="$TESTFLAGS -P${{matrix.pls}} test_dirs test_relocations" \
+            make test
 
   # run with LFS_NO_INTRINSICS to make sure that works
   test-no-intrinsics:
@@ -364,7 +367,7 @@ jobs:
           python3 --version
       - name: test-no-intrinsics
         run: |
-          make test CFLAGS+="-DLFS_NO_INTRINSICS"
+          CFLAGS="$CFLAGS -DLFS_NO_INTRINSICS" make test
 
   # run under Valgrind to check for memory errors
   test-valgrind:
@@ -384,7 +387,29 @@ jobs:
       # on one geometry
       - name: test-valgrind
         run: |
-          make test TESTFLAGS+="-Gdefault --valgrind"
+          TESTFLAGS="$TESTFLAGS -Gdefault --valgrind" make test
+
+  # test that compilation is warning free under clang
+  # run with Clang, mostly to check for Clang-specific warnings
+  test-clang:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v2
+      - name: install
+        run: |
+          # need a few things
+          sudo apt-get install -qq clang python3 python3-pip
+          pip3 install toml
+          clang --version
+          python3 --version
+      - name: test-clang
+        run: |
+          # override CFLAGS since Clang does not support -fcallgraph-info
+          # and -ftrack-macro-expansions
+          make \
+            CC=clang \
+            CFLAGS="$CFLAGS -MMD -g3 -I. -std=c99 -Wall -Wextra -pedantic" \
+            test
 
   # run benchmarks
   #
@@ -404,7 +429,7 @@ jobs:
           valgrind --version
       - name: bench
         run: |
-          make bench BENCHFLAGS+="-o lfs.bench.csv"
+          BENCHFLAGS="$BENCHFLAGS -o lfs.bench.csv" make bench
 
           # find bench results
           ./scripts/summary.py lfs.bench.csv \
@@ -463,27 +488,6 @@ jobs:
           path: status
           retention-days: 1
 
-  # test that compilation is warning free under clang
-  clang:
-    runs-on: ubuntu-20.04
-    steps:
-      - uses: actions/checkout@v2
-      - name: install
-        run: |
-          # need toml, also pip3 isn't installed by default?
-          sudo apt-get update -qq
-          sudo apt-get install -qq python3 python3-pip
-          sudo pip3 install toml
-      - name: install-clang
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -qq clang
-          echo "CC=clang" >> $GITHUB_ENV
-          clang --version
-      # no reason to not test again
-      - name: test-clang
-        run: make test TESTFLAGS+="-k"
-
   # self-host with littlefs-fuse for a fuzz-like test
   fuse:
     runs-on: ubuntu-22.04