fixed minor warnings issued by scan-build

Makefile

@@ -351,7 +351,7 @@ bmi32build: clean
 	$(CC) -v
 	CFLAGS="-O3 -mbmi -m32 -Werror" $(MAKE) -C $(TESTDIR) test
 
-staticAnalyze: clean
+staticAnalyze:
 	$(CC) -v
 	CPPFLAGS=-g scan-build --status-bugs -v $(MAKE) all
 endif

contrib/seekable_format/zstdseek_decompress.c

@@ -56,6 +56,7 @@
 
 #include <stdlib.h> /* malloc, free */
 #include <stdio.h>  /* FILE* */
+#include <assert.h>
 
 #define XXH_STATIC_LINKING_ONLY
 #define XXH_NAMESPACE ZSTD_
@@ -112,7 +113,7 @@ static int ZSTD_seekable_read_buff(void* opaque, void* buffer, size_t n)
 
 static int ZSTD_seekable_seek_buff(void* opaque, long long offset, int origin)
 {
-    buffWrapper_t* buff = (buffWrapper_t*) opaque;
+    buffWrapper_t* const buff = (buffWrapper_t*) opaque;
     unsigned long long newOffset;
     switch (origin) {
     case SEEK_SET:
@@ -124,6 +125,8 @@ static int ZSTD_seekable_seek_buff(void* opaque, long long offset, int origin)
     case SEEK_END:
         newOffset = (unsigned long long)buff->size - offset;
         break;
+    default:
+        assert(0);  /* not possible */
     }
     if (newOffset > buff->size) {
         return -1;

lib/decompress/zstd_decompress.c

@@ -330,6 +330,7 @@ size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, s
     const BYTE* ip = (const BYTE*)src;
     size_t const minInputSize = ZSTD_startingInputLength(format);
 
+    memset(zfhPtr, 0, sizeof(*zfhPtr));   /* not strictly necessary, but static analyzer do not understand that zfhPtr is only going to be read only if return value is zero, since they are 2 different signals */
     if (srcSize < minInputSize) return minInputSize;
     if (src==NULL) return ERROR(GENERIC);   /* invalid parameter */
 

programs/dibio.c

@@ -27,6 +27,7 @@
 #include <string.h>         /* memset */
 #include <stdio.h>          /* fprintf, fopen, ftello64 */
 #include <errno.h>          /* errno */
+#include <assert.h>
 
 #include "mem.h"            /* read */
 #include "error_private.h"
@@ -165,6 +166,7 @@ static U32 DiB_rand(U32* src)
 static void DiB_shuffle(const char** fileNamesTable, unsigned nbFiles) {
     U32 seed = 0xFD2FB528;
     unsigned i;
+    assert(nbFiles >= 1);
     for (i = nbFiles - 1; i > 0; --i) {
         unsigned const j = DiB_rand(&seed) % (i + 1);
         const char* const tmp = fileNamesTable[j];
@@ -310,7 +312,7 @@ int DiB_trainFromFiles(const char* dictFileName, unsigned maxDictSize,
     /* Load input buffer */
     DISPLAYLEVEL(3, "Shuffling input files\n");
     DiB_shuffle(fileNamesTable, nbFiles);
-    nbFiles = DiB_loadFiles(srcBuffer, &loadedSize, sampleSizes, fs.nbSamples, fileNamesTable, nbFiles, chunkSize, displayLevel);
+    DiB_loadFiles(srcBuffer, &loadedSize, sampleSizes, fs.nbSamples, fileNamesTable, nbFiles, chunkSize, displayLevel);
 
     {   size_t dictSize;
         if (params) {
@@ -319,6 +321,7 @@ int DiB_trainFromFiles(const char* dictFileName, unsigned maxDictSize,
                                                            srcBuffer, sampleSizes, fs.nbSamples,
                                                            *params);
         } else if (optimizeCover) {
+            assert(coverParams != NULL);
             dictSize = ZDICT_optimizeTrainFromBuffer_cover(dictBuffer, maxDictSize,
                                                            srcBuffer, sampleSizes, fs.nbSamples,
                                                            coverParams);
@@ -327,6 +330,7 @@ int DiB_trainFromFiles(const char* dictFileName, unsigned maxDictSize,
                 DISPLAYLEVEL(2, "k=%u\nd=%u\nsteps=%u\nsplit=%u\n", coverParams->k, coverParams->d, coverParams->steps, splitPercentage);
             }
         } else {
+            assert(coverParams != NULL);
             dictSize = ZDICT_trainFromBuffer_cover(dictBuffer, maxDictSize, srcBuffer,
                                                    sampleSizes, fs.nbSamples, *coverParams);
         }