Merge branch 'dev' into coverity_scan

4 files changed, 47 insertions, 40 deletions

diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index 488ab75..b5c868f 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -70,6 +70,14 @@ You can contact the author at :
 /*-************************************
 *  Debug
 **************************************/
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
+#  include <assert.h>
+#else
+#  ifndef assert
+#    define assert(condition) ((void)0)
+#  endif
+#endif
+
 #define LZ4F_STATIC_ASSERT(c)    { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
@@ -281,7 +289,7 @@ static size_t LZ4F_compressBound_internal(size_t srcSize,
         size_t const bufferedSize = MIN(alreadyBuffered, maxBuffered);
         size_t const maxSrcSize = srcSize + bufferedSize;
         unsigned const nbFullBlocks = (unsigned)(maxSrcSize / blockSize);
-        size_t const partialBlockSize = (srcSize - (srcSize==0)) & (blockSize-1);   /* 0 => -1 == MAX => blockSize-1 */
+        size_t const partialBlockSize = maxSrcSize & (blockSize-1);
         size_t const lastBlockSize = flush ? partialBlockSize : 0;
         unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0);
 
@@ -604,10 +612,10 @@ size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr,
 }
 
 
-/* LZ4F_compressBound() :
- *      @ return size of Dst buffer given a srcSize to handle worst case situations.
- *      The LZ4F_frameInfo_t structure is optional : if NULL, preferences will be set to cover worst case situations.
- *      This function cannot fail.
+/*  LZ4F_compressBound() :
+ * @return minimum capacity of dstBuffer for a given srcSize to handle worst case scenario.
+ *  LZ4F_preferences_t structure is optional : if NULL, preferences will be set to cover worst case scenario.
+ *  This function cannot fail.
  */
 size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
 {
@@ -1439,6 +1447,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
         case dstage_decodeCBlock:
             if (dctx->frameInfo.blockChecksumFlag) {
                 dctx->tmpInTarget -= 4;
+                assert(selectedIn != NULL);  /* selectedIn is defined at this stage (either srcPtr, or dctx->tmpIn) */
                 {   U32 const readBlockCrc = LZ4F_readLE32(selectedIn + dctx->tmpInTarget);
                     U32 const calcBlockCrc = XXH32(selectedIn, dctx->tmpInTarget, 0);
                     if (readBlockCrc != calcBlockCrc)
diff --git a/lib/lz4frame.h b/lib/lz4frame.h
index 675aeeb..eb55e45 100644
--- a/lib/lz4frame.h
+++ b/lib/lz4frame.h
@@ -248,19 +248,19 @@ LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx,
                                       const LZ4F_preferences_t* prefsPtr);
 
 /*! LZ4F_compressBound() :
- * Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
- * prefsPtr is optional : you can provide NULL as argument, preferences will be set to cover worst case scenario.
- * Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
- * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
+ *  Provides minimum dstCapacity for a given srcSize to guarantee operation success in worst case situations.
+ *  prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario.
+ *  Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
+ *  When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
  */
 LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
 
 /*! LZ4F_compressUpdate() :
- * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
- * An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations.
- * This value is provided by LZ4F_compressBound().
- * If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
- * LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized.
+ *  LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ *  An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations.
+ *  This value is provided by LZ4F_compressBound().
+ *  If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
+ *  LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized.
  * `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
  * @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
  *           or an error code if it fails (which can be tested using LZ4F_isError())
@@ -268,8 +268,8 @@ LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t*
 LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr);
 
 /*! LZ4F_flush() :
- * When data must be generated and sent immediately, without waiting for a block to be completely filled,
- * it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
+ *  When data must be generated and sent immediately, without waiting for a block to be completely filled,
+ *  it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
  * `dstCapacity` must be large enough to ensure the operation will be successful.
  * `cOptPtr` is optional : it's possible to provide NULL, all options will be set to default.
  * @return : number of bytes written into dstBuffer (it can be zero, which means there was no data stored within cctx)
@@ -303,14 +303,14 @@ typedef struct {
 
 /* Resource management */
 
-/*!LZ4F_createDecompressionContext() :
- * Create an LZ4F_dctx object, to track all decompression operations.
- * The version provided MUST be LZ4F_VERSION.
- * The function provides a pointer to an allocated and initialized LZ4F_dctx object.
- * The result is an errorCode, which can be tested using LZ4F_isError().
- * dctx memory can be released using LZ4F_freeDecompressionContext();
- * The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released.
- * That is, it should be == 0 if decompression has been completed fully and correctly.
+/*! LZ4F_createDecompressionContext() :
+ *  Create an LZ4F_dctx object, to track all decompression operations.
+ *  The version provided MUST be LZ4F_VERSION.
+ *  The function provides a pointer to an allocated and initialized LZ4F_dctx object.
+ *  The result is an errorCode, which can be tested using LZ4F_isError().
+ *  dctx memory can be released using LZ4F_freeDecompressionContext();
+ *  The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released.
+ *  That is, it should be == 0 if decompression has been completed fully and correctly.
  */
 LZ4FLIB_API LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version);
 LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
diff --git a/programs/datagen.c b/programs/datagen.c
index 7285d69..24a2da2 100644
--- a/programs/datagen.c
+++ b/programs/datagen.c
@@ -31,6 +31,7 @@
 #include <stdlib.h>    /* malloc */
 #include <stdio.h>     /* FILE, fwrite */
 #include <string.h>    /* memcpy */
+#include <assert.h>
 
 
 /**************************************
@@ -78,7 +79,10 @@ static void RDG_fillLiteralDistrib(litDistribTable lt, double ld)
     while (u<LTSIZE) {
         U32 const weight = (U32)((double)(LTSIZE - u) * ld) + 1;
         U32 const end = MIN(u+weight, LTSIZE);
-        while (u < end) lt[u++] = character;
+        while (u < end) {
+            assert(u<LTSIZE);  /* try to ease static analyzer. u < end <= LTSIZE */
+            lt[u++] = character;
+        }
         character++;
         if (character > lastChar) character = firstChar;
     }
@@ -103,13 +107,11 @@ void RDG_genBlock(void* buffer, size_t buffSize, size_t prefixSize, double match
     U32* seed = seedPtr;
 
     /* special case */
-    while (matchProba >= 1.0)
-    {
+    while (matchProba >= 1.0) {
         size_t size0 = RDG_rand(seed) & 3;
         size0  = (size_t)1 << (16 + size0 * 2);
         size0 += RDG_rand(seed) & (size0-1);   /* because size0 is power of 2*/
-        if (buffSize < pos + size0)
-        {
+        if (buffSize < pos + size0) {
             memset(buffPtr+pos, 0, buffSize-pos);
             return;
         }
@@ -125,11 +127,9 @@ void RDG_genBlock(void* buffer, size_t buffSize, size_t prefixSize, double match
     }
 
     /* Generate compressible data */
-    while (pos < buffSize)
-    {
+    while (pos < buffSize) {
         /* Select : Literal (char) or Match (within 32K) */
-        if (RDG_RAND15BITS < matchProba32)
-        {
+        if (RDG_RAND15BITS < matchProba32) {
             /* Copy (within 32K) */
             size_t match;
             size_t d;
@@ -140,9 +140,7 @@ void RDG_genBlock(void* buffer, size_t buffSize, size_t prefixSize, double match
             d = pos + length;
             if (d > buffSize) d = buffSize;
             while (pos < d) buffPtr[pos++] = buffPtr[match++];
-        }
-        else
-        {
+        } else {
             /* Literal (noise) */
             size_t d;
             size_t length = RDG_RANDLENGTH;
@@ -180,12 +178,11 @@ void RDG_genOut(unsigned long long size, double matchProba, double litProba, uns
     RDG_genBlock(buff, RDG_DICTSIZE, 0, matchProba, lt, &seed);
 
     /* Generate compressible data */
-    while (total < size)
-    {
+    while (total < size) {
         RDG_genBlock(buff, RDG_DICTSIZE+RDG_BLOCKSIZE, RDG_DICTSIZE, matchProba, lt, &seed);
         if (size-total < RDG_BLOCKSIZE) genBlockSize = (size_t)(size-total);
         total += genBlockSize;
-        fwrite(buff, 1, genBlockSize, stdout);
+        fwrite(buff, 1, genBlockSize, stdout);  /* should check potential write error */
         /* update dict */
         memcpy(buff, buff + RDG_BLOCKSIZE, RDG_DICTSIZE);
     }
diff --git a/programs/lz4io.c b/programs/lz4io.c
index 2cf0c1c..927928a 100644
--- a/programs/lz4io.c
+++ b/programs/lz4io.c
@@ -429,7 +429,7 @@ static void* LZ4IO_createDict(const char* dictFilename, size_t *dictSize) {
     /* opportunistically seek to the part of the file we care about. If this */
     /* fails it's not a problem since we'll just read everything anyways.    */
     if (strcmp(dictFilename, stdinmark)) {
-        UTIL_fseek(dictFile, -LZ4_MAX_DICT_SIZE, SEEK_END);
+        (void)UTIL_fseek(dictFile, -LZ4_MAX_DICT_SIZE, SEEK_END);
     }
 
     do {
@@ -459,6 +459,7 @@ static void* LZ4IO_createDict(const char* dictFilename, size_t *dictSize) {
         memcpy(dictBuf + circularBufSize - dictStart, circularBuf, dictLen - (circularBufSize - dictStart));
     }
 
+    fclose(dictFile);
     free(circularBuf);
 
     return dictBuf;