Added explicit assert for minimum block size of 128 bytes

There was already an assert for this, but because it included the
underlying equation for the requirement it was too confusing for
users that had no prior knowledge for why the assert could trigger.

The math works out such that 128 bytes is a reasonable minimum
requirement, so I've added that number as an explicit assert.
Hopefully this makes this sort of situation easier to debug.

Note that this requirement would need to be increased to 512 bytes if
block addresses are ever increased to 64-bits. DESIGN.md goes into more
detail why this is.

.github/workflows/test.yml

@@ -292,6 +292,27 @@ jobs:
       - name: test-valgrind
         run: make test TESTFLAGS+="-k --valgrind"
 
+  # 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-20.04

Makefile

@@ -41,8 +41,7 @@ override CFLAGS += -DLFS_YES_TRACE
 endif
 override CFLAGS += -g3
 override CFLAGS += -I.
-override CFLAGS += -std=c99 -Wall -pedantic
-override CFLAGS += -Wextra -Wshadow -Wjump-misses-init -Wundef
+override CFLAGS += -std=c99 -Wall -Wextra -pedantic
 
 ifdef VERBOSE
 override TESTFLAGS     += -v

README.md

@@ -252,7 +252,7 @@ License Identifiers that are here available: http://spdx.org/licenses/
 [mklfs]: https://github.com/whitecatboard/Lua-RTOS-ESP32/tree/master/components/mklfs/src
 [Lua RTOS]: https://github.com/whitecatboard/Lua-RTOS-ESP32
 [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
 [littlefs-python]: https://pypi.org/project/littlefs-python/

bd/lfs_filebd.c

@@ -204,7 +204,7 @@ int lfs_filebd_sync(const struct lfs_config *cfg) {
     // file sync
     lfs_filebd_t *bd = cfg->context;
     #ifdef _WIN32
-    int err = FlushFileBuffers((HANDLE) _get_osfhandle(fd)) ? 0 : -1;
+    int err = FlushFileBuffers((HANDLE) _get_osfhandle(bd->fd)) ? 0 : -1;
     #else
     int err = fsync(bd->fd);
     #endif

lfs.c

@@ -865,11 +865,6 @@ static int lfs_dir_traverse(lfs_t *lfs,
                 };
                 sp += 1;
 
-                dir = dir;
-                off = off;
-                ptag = ptag;
-                attrs = attrs;
-                attrcount = attrcount;
                 tmask = 0;
                 ttag = 0;
                 begin = 0;
@@ -2999,12 +2994,14 @@ cleanup:
     return err;
 }
 
+#ifndef LFS_NO_MALLOC
 static int lfs_file_rawopen(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags) {
     static const struct lfs_file_config defaults = {0};
     int err = lfs_file_rawopencfg(lfs, file, path, flags, &defaults);
     return err;
 }
+#endif
 
 static int lfs_file_rawclose(lfs_t *lfs, lfs_file_t *file) {
 #ifndef LFS_READONLY
@@ -3920,7 +3917,10 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     LFS_ASSERT(lfs->cfg->cache_size % lfs->cfg->prog_size == 0);
     LFS_ASSERT(lfs->cfg->block_size % lfs->cfg->cache_size == 0);
 
-    // check that the block size is large enough to fit ctz pointers
+    // check that the block size is large enough to fit all ctz pointers
+    LFS_ASSERT(lfs->cfg->block_size >= 128);
+    // this is the exact calculation for all ctz pointers, if this fails
+    // and the simpler assert above does not, math must be broken
     LFS_ASSERT(4*lfs_npw2(0xffffffff / (lfs->cfg->block_size-2*4))
             <= lfs->cfg->block_size);
 
@@ -4196,7 +4196,7 @@ static int lfs_rawmount(lfs_t *lfs, const struct lfs_config *cfg) {
 
             if (superblock.block_size != lfs->cfg->block_size) {
                 LFS_ERROR("Invalid block size (%"PRIu32" != %"PRIu32")",
-                        superblock.block_count, lfs->cfg->block_count);
+                        superblock.block_size, lfs->cfg->block_size);
                 err = LFS_ERR_INVAL;
                 goto cleanup;
             }

lfs.h

@@ -534,8 +534,8 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
 // 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,

lfs_util.h

@@ -167,10 +167,9 @@ 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  ) || \
@@ -196,10 +195,9 @@ 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) |

scripts/test.py

@@ -93,7 +93,7 @@ PROLOGUE = """
     __attribute__((unused)) lfs_dir_t dir;
     __attribute__((unused)) struct lfs_info info;
     __attribute__((unused)) char path[1024];
-    __attribute__((unused)) uint8_t buffer[1024];
+    __attribute__((unused)) uint8_t buffer[(1024 > LFS_BLOCK_SIZE * 4) ? (1024) : (LFS_BLOCK_SIZE * 4)];
     __attribute__((unused)) lfs_size_t size;
     __attribute__((unused)) int err;