lib: Revert use of fallthrough pseudo-keyword in lib/

The following build error for powerpc64 was reported by Nathan Chancellor:

  "$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e KERNEL_XZ

   $ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux- distclean powernv_defconfig zImage
   ...
   In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:234,
                    from arch/powerpc/boot/decompress.c:38:
   arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c: In function 'dec_main':
   arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c:586:4: error: 'fallthrough' undeclared (first use in this function)
     586 |    fallthrough;
         |    ^~~~~~~~~~~

   This will end up affecting distribution configurations such as Debian
   and OpenSUSE according to my testing. I am not sure what the solution
   is, the PowerPC wrapper does not set -D__KERNEL__ so I am not sure
   that compiler_attributes.h can be safely included."

In order to avoid these sort of problems, it seems that the best
solution is to use /* fall through */ comments instead of the
fallthrough pseudo-keyword macro in lib/, for now.

Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Fixes: df561f6688 ("treewide: Use fallthrough pseudo-keyword")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Gustavo A. R. Silva
2020-08-24 15:36:14 -05:00
committed by Linus Torvalds
parent 9907ab3714
commit 6a9dc5fd61
16 changed files with 64 additions and 64 deletions

View File

@@ -259,15 +259,15 @@ ZSTD_STATIC size_t BIT_initDStream(BIT_DStream_t *bitD, const void *srcBuffer, s
bitD->bitContainer = *(const BYTE *)(bitD->start);
switch (srcSize) {
case 7: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[6]) << (sizeof(bitD->bitContainer) * 8 - 16);
fallthrough;
/* fall through */
case 6: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[5]) << (sizeof(bitD->bitContainer) * 8 - 24);
fallthrough;
/* fall through */
case 5: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[4]) << (sizeof(bitD->bitContainer) * 8 - 32);
fallthrough;
/* fall through */
case 4: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[3]) << 24;
fallthrough;
/* fall through */
case 3: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[2]) << 16;
fallthrough;
/* fall through */
case 2: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[1]) << 8;
default:;
}