[lib] Make lib compatible with -Wfall-through excepting legacy

Switch to a macro `ZSTD_FALLTHROUGH;` instead of a comment. On supported
compilers this uses an attribute, otherwise it becomes a comment.

This is necessary to be compatible with clang's `-Wfall-through`, and
gcc's `-Wfall-through=2` which don't support comments. Without this the
linux build emits a bunch of warnings.

Also add a test to CI to ensure that we don't regress.
This commit is contained in:
Nick Terrell
2021-09-23 10:51:18 -07:00
parent e3feec74d3
commit 189e87bcbe
11 changed files with 81 additions and 24 deletions
+13 -6
View File
@@ -479,7 +479,9 @@ size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, s
}
switch(dictIDSizeCode)
{
default: assert(0); /* impossible */
default:
assert(0); /* impossible */
ZSTD_FALLTHROUGH;
case 0 : break;
case 1 : dictID = ip[pos]; pos++; break;
case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break;
@@ -487,7 +489,9 @@ size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, s
}
switch(fcsID)
{
default: assert(0); /* impossible */
default:
assert(0); /* impossible */
ZSTD_FALLTHROUGH;
case 0 : if (singleSegment) frameContentSize = ip[pos]; break;
case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
@@ -1052,7 +1056,7 @@ static ZSTD_DDict const* ZSTD_getDDict(ZSTD_DCtx* dctx)
switch (dctx->dictUses) {
default:
assert(0 /* Impossible */);
/* fall-through */
ZSTD_FALLTHROUGH;
case ZSTD_dont_use:
ZSTD_clearDict(dctx);
return NULL;
@@ -1116,7 +1120,9 @@ ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
{
default: /* should not happen */
assert(0);
ZSTD_FALLTHROUGH;
case ZSTDds_getFrameHeaderSize:
ZSTD_FALLTHROUGH;
case ZSTDds_decodeFrameHeader:
return ZSTDnit_frameHeader;
case ZSTDds_decodeBlockHeader:
@@ -1128,6 +1134,7 @@ ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
case ZSTDds_checkChecksum:
return ZSTDnit_checksum;
case ZSTDds_decodeSkippableHeader:
ZSTD_FALLTHROUGH;
case ZSTDds_skipFrame:
return ZSTDnit_skippableFrame;
}
@@ -1943,7 +1950,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
zds->legacyVersion = 0;
zds->hostageByte = 0;
zds->expectedOutBuffer = *output;
/* fall-through */
ZSTD_FALLTHROUGH;
case zdss_loadHeader :
DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip));
@@ -2081,7 +2088,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
zds->outBuffSize = neededOutBuffSize;
} } }
zds->streamStage = zdss_read;
/* fall-through */
ZSTD_FALLTHROUGH;
case zdss_read:
DEBUGLOG(5, "stage zdss_read");
@@ -2100,7 +2107,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
} }
if (ip==iend) { someMoreWork = 0; break; } /* no more input */
zds->streamStage = zdss_load;
/* fall-through */
ZSTD_FALLTHROUGH;
case zdss_load:
{ size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);