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protected impossible switch(){default:} with assert(0)

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can be converted into assume(0) in some future
This commit is contained in:
Yann Collet 2017-06-01 09:44:54 -07:00
parent 06589fe516
commit cd2892fd1e
1 changed files with 65 additions and 60 deletions
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125
lib/compress/zstd_compress.c
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@ -265,80 +265,82 @@ size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned v
switch(param) switch(param)
{ {
case ZSTD_p_compressionLevel : case ZSTD_p_compressionLevel :
if ((int)value > ZSTD_maxCLevel()) value = ZSTD_maxCLevel(); /* cap max compression level */ if ((int)value > ZSTD_maxCLevel()) value = ZSTD_maxCLevel(); /* cap max compression level */
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
cctx->compressionLevel = value; cctx->compressionLevel = value;
return 0; return 0;
case ZSTD_p_windowLog : case ZSTD_p_windowLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX); CLAMPCHECK(value, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
ZSTD_cLevelToCParams(cctx); ZSTD_cLevelToCParams(cctx);
cctx->requestedParams.cParams.windowLog = value; cctx->requestedParams.cParams.windowLog = value;
return 0; return 0;
case ZSTD_p_hashLog : case ZSTD_p_hashLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX); CLAMPCHECK(value, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
ZSTD_cLevelToCParams(cctx); ZSTD_cLevelToCParams(cctx);
cctx->requestedParams.cParams.hashLog = value; cctx->requestedParams.cParams.hashLog = value;
return 0; return 0;
case ZSTD_p_chainLog : case ZSTD_p_chainLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX); CLAMPCHECK(value, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
ZSTD_cLevelToCParams(cctx); ZSTD_cLevelToCParams(cctx);
cctx->requestedParams.cParams.chainLog = value; cctx->requestedParams.cParams.chainLog = value;
return 0; return 0;
case ZSTD_p_searchLog : case ZSTD_p_searchLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX); CLAMPCHECK(value, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
ZSTD_cLevelToCParams(cctx); ZSTD_cLevelToCParams(cctx);
cctx->requestedParams.cParams.searchLog = value; cctx->requestedParams.cParams.searchLog = value;
return 0; return 0;
case ZSTD_p_minMatch : case ZSTD_p_minMatch :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX); CLAMPCHECK(value, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
ZSTD_cLevelToCParams(cctx); ZSTD_cLevelToCParams(cctx);
cctx->requestedParams.cParams.searchLength = value; cctx->requestedParams.cParams.searchLength = value;
return 0; return 0;
case ZSTD_p_targetLength : case ZSTD_p_targetLength :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX); CLAMPCHECK(value, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX);
ZSTD_cLevelToCParams(cctx); ZSTD_cLevelToCParams(cctx);
cctx->requestedParams.cParams.targetLength = value; cctx->requestedParams.cParams.targetLength = value;
return 0; return 0;
case ZSTD_p_compressionStrategy : case ZSTD_p_compressionStrategy :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, (unsigned)ZSTD_fast, (unsigned)ZSTD_btultra); CLAMPCHECK(value, (unsigned)ZSTD_fast, (unsigned)ZSTD_btultra);
ZSTD_cLevelToCParams(cctx); ZSTD_cLevelToCParams(cctx);
cctx->requestedParams.cParams.strategy = (ZSTD_strategy)value; cctx->requestedParams.cParams.strategy = (ZSTD_strategy)value;
return 0; return 0;
#if 0 #if 0
case ZSTD_p_windowSize : /* to be done later */ case ZSTD_p_windowSize : /* to be done later */
return ERROR(compressionParameter_unsupported); return ERROR(compressionParameter_unsupported);
#endif #endif
case ZSTD_p_contentSizeFlag : /* Content size will be written in frame header _when known_ (default:1) */ case ZSTD_p_contentSizeFlag :
cctx->requestedParams.fParams.contentSizeFlag = value>0; /* Content size written in frame header _when known_ (default:1) */
return 0; cctx->requestedParams.fParams.contentSizeFlag = value>0;
return 0;
case ZSTD_p_checksumFlag : /* A 32-bits content checksum will be calculated and written at end of frame (default:0) */ case ZSTD_p_checksumFlag :
cctx->requestedParams.fParams.checksumFlag = value>0; /* A 32-bits content checksum will be calculated and written at end of frame (default:0) */
return 0; cctx->requestedParams.fParams.checksumFlag = value>0;
return 0;
case ZSTD_p_dictIDFlag : /* When applicable, dictionary's dictID is provided in frame header (default:1) */ case ZSTD_p_dictIDFlag : /* When applicable, dictionary's dictID is provided in frame header (default:1) */
DEBUGLOG(5, "set dictIDFlag = %u", (value>0)); DEBUGLOG(5, "set dictIDFlag = %u", (value>0));
cctx->requestedParams.fParams.noDictIDFlag = (value==0); cctx->requestedParams.fParams.noDictIDFlag = (value==0);
return 0; return 0;
case ZSTD_p_refDictContent : /* to be done later */ case ZSTD_p_refDictContent : /* to be done later */
return ERROR(compressionParameter_unsupported); return ERROR(compressionParameter_unsupported);
case ZSTD_p_forceMaxWindow : /* Force back-references to remain < windowSize, case ZSTD_p_forceMaxWindow : /* Force back-references to remain < windowSize,
* even when referencing into Dictionary content * even when referencing into Dictionary content
@ -348,8 +350,8 @@ size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned v
return 0; return 0;
case ZSTD_p_rawContentDict : /* load dictionary in "content-only" mode (no header analysis) (default:0) */ case ZSTD_p_rawContentDict : /* load dictionary in "content-only" mode (no header analysis) (default:0) */
cctx->forceRawDict = value>0; cctx->forceRawDict = value>0;
return 0; return 0;
default: return ERROR(parameter_unknown); default: return ERROR(parameter_unknown);
} }
@ -811,10 +813,11 @@ static size_t ZSTD_noCompressLiterals (void* dst, size_t dstCapacity, const void
case 2: /* 2 - 2 - 12 */ case 2: /* 2 - 2 - 12 */
MEM_writeLE16(ostart, (U16)((U32)set_basic + (1<<2) + (srcSize<<4))); MEM_writeLE16(ostart, (U16)((U32)set_basic + (1<<2) + (srcSize<<4)));
break; break;
default: /*note : should not be necessary : flSize is within {1,2,3} */
case 3: /* 2 - 2 - 20 */ case 3: /* 2 - 2 - 20 */
MEM_writeLE32(ostart, (U32)((U32)set_basic + (3<<2) + (srcSize<<4))); MEM_writeLE32(ostart, (U32)((U32)set_basic + (3<<2) + (srcSize<<4)));
break; break;
default: /* not necessary : flSize is {1,2,3} */
assert(0);
} }
memcpy(ostart + flSize, src, srcSize); memcpy(ostart + flSize, src, srcSize);
@ -836,10 +839,11 @@ static size_t ZSTD_compressRleLiteralsBlock (void* dst, size_t dstCapacity, cons
case 2: /* 2 - 2 - 12 */ case 2: /* 2 - 2 - 12 */
MEM_writeLE16(ostart, (U16)((U32)set_rle + (1<<2) + (srcSize<<4))); MEM_writeLE16(ostart, (U16)((U32)set_rle + (1<<2) + (srcSize<<4)));
break; break;
default: /*note : should not be necessary : flSize is necessarily within {1,2,3} */
case 3: /* 2 - 2 - 20 */ case 3: /* 2 - 2 - 20 */
MEM_writeLE32(ostart, (U32)((U32)set_rle + (3<<2) + (srcSize<<4))); MEM_writeLE32(ostart, (U32)((U32)set_rle + (3<<2) + (srcSize<<4)));
break; break;
default: /* not necessary : flSize is {1,2,3} */
assert(0);
} }
ostart[flSize] = *(const BYTE*)src; ostart[flSize] = *(const BYTE*)src;
@ -901,13 +905,14 @@ static size_t ZSTD_compressLiterals (ZSTD_CCtx* zc,
MEM_writeLE32(ostart, lhc); MEM_writeLE32(ostart, lhc);
break; break;
} }
default: /* should not be necessary, lhSize is only {3,4,5} */
case 5: /* 2 - 2 - 18 - 18 */ case 5: /* 2 - 2 - 18 - 18 */
{ U32 const lhc = hType + (3 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<22); { U32 const lhc = hType + (3 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<22);
MEM_writeLE32(ostart, lhc); MEM_writeLE32(ostart, lhc);
ostart[4] = (BYTE)(cLitSize >> 10); ostart[4] = (BYTE)(cLitSize >> 10);
break; break;
} }
default: /* not possible : lhSize is {3,4,5} */
assert(0);
} }
return lhSize+cLitSize; return lhSize+cLitSize;
} }
@ -2814,7 +2819,7 @@ static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
if (!singleSegment) op[pos++] = windowLogByte; if (!singleSegment) op[pos++] = windowLogByte;
switch(dictIDSizeCode) switch(dictIDSizeCode)
{ {
default: /* impossible */ default: assert(0); /* impossible */
case 0 : break; case 0 : break;
case 1 : op[pos] = (BYTE)(dictID); pos++; break; case 1 : op[pos] = (BYTE)(dictID); pos++; break;
case 2 : MEM_writeLE16(op+pos, (U16)dictID); pos+=2; break; case 2 : MEM_writeLE16(op+pos, (U16)dictID); pos+=2; break;
@ -2822,7 +2827,7 @@ static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
} }
switch(fcsCode) switch(fcsCode)
{ {
default: /* impossible */ default: assert(0); /* impossible */
case 0 : if (singleSegment) op[pos++] = (BYTE)(pledgedSrcSize); break; case 0 : if (singleSegment) op[pos++] = (BYTE)(pledgedSrcSize); break;
case 1 : MEM_writeLE16(op+pos, (U16)(pledgedSrcSize-256)); pos+=2; break; case 1 : MEM_writeLE16(op+pos, (U16)(pledgedSrcSize-256)); pos+=2; break;
case 2 : MEM_writeLE32(op+pos, (U32)(pledgedSrcSize)); pos+=4; break; case 2 : MEM_writeLE32(op+pos, (U32)(pledgedSrcSize)); pos+=4; break;
@ -2951,7 +2956,7 @@ static size_t ZSTD_loadDictionaryContent(ZSTD_CCtx* zc, const void* src, size_t
break; break;
default: default:
return ERROR(GENERIC); /* strategy doesn't exist; impossible */ assert(0); /* not possible : not a valid strategy id */
} }
zc->nextToUpdate = (U32)(iend - zc->base); zc->nextToUpdate = (U32)(iend - zc->base);
@ -3691,8 +3696,8 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
case zcss_final: case zcss_final:
someMoreWork = 0; break; /* useless */ someMoreWork = 0; break; /* useless */
default: default: /* impossible */
return ERROR(GENERIC); /* impossible */ assert(0);
} }
} }