Silence unused-but-set-variable warnings

Clang 13.0.0 added support for `Wunused-but-set-parameter` and
`-Wunused-but-set-variable` which correctly detects two unused
variables in zstd resulting in a build failure.  This commit
annotates these instances accordingly.

  https://releases.llvm.org/13.0.1/tools/clang/docs/ReleaseNotes.html#id6

In FSE_createCTable(), malloc() is intentionally defined as NULL when
compiled in the kernel so the variable is unused.

  zstd/lib/compress/fse_compress.c:307:12: error: variable 'size'
  set but not used [-Werror,-Wunused-but-set-variable]

Additionally, in ZSTD_seqDecompressedSize() the assert is compiled
out similarly resulting in an unused variable.

  zstd/lib/compress/zstd_compress_superblock.c:412:12: error: variable
  'litLengthSum' set but not used [-Werror,-Wunused-but-set-variable]

Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13382
This commit is contained in:
Brian Behlendorf 2022-04-29 14:21:11 -07:00 committed by GitHub
parent f2330bd156
commit 1bf3abc634
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 2 additions and 2 deletions

View File

@ -304,7 +304,7 @@ size_t FSE_writeNCount (void* buffer, size_t bufferSize,
FSE_CTable* FSE_createCTable (unsigned maxSymbolValue, unsigned tableLog)
{
size_t size;
size_t size __attribute__ ((unused));
if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX;
size = FSE_CTABLE_SIZE_U32 (tableLog, maxSymbolValue) * sizeof(U32);
return (FSE_CTable*)malloc(size);

View File

@ -409,7 +409,7 @@ static size_t ZSTD_seqDecompressedSize(seqStore_t const* seqStore, const seqDef*
const seqDef* const send = sequences + nbSeq;
const seqDef* sp = sstart;
size_t matchLengthSum = 0;
size_t litLengthSum = 0;
size_t litLengthSum __attribute__ ((unused)) = 0;
while (send-sp > 0) {
ZSTD_sequenceLength const seqLen = ZSTD_getSequenceLength(seqStore, sp);
litLengthSum += seqLen.litLength;