Fixes for production mode gcc warnings (#1873)

* Fixes for production mode gcc warnings

With the strict-overflow changes, this brings the number of warnings
in the C library w/ gcc 12 to zero.

* Fix typo

* Committing clang-format changes

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

2 files changed, 27 insertions, 15 deletions

diff --git a/test/cache_common.c b/test/cache_common.c
index 9becfa8..41aa128 100644
--- a/test/cache_common.c
+++ b/test/cache_common.c
@@ -4977,13 +4977,17 @@ check_and_validate_cache_hit_rate(hid_t file_id, double *hit_rate_ptr, hbool_t d
         else {
 
             cache_ptr = file_ptr->shared->cache;
+            if (NULL == cache_ptr) {
+                pass         = FALSE;
+                failure_mssg = "NULL cache pointer";
+            }
         }
     }
 
     /* verify that we can access the cache data structure */
     if (pass) {
 
-        if ((cache_ptr == NULL) || (cache_ptr->magic != H5C__H5C_T_MAGIC)) {
+        if (cache_ptr->magic != H5C__H5C_T_MAGIC) {
 
             pass         = FALSE;
             failure_mssg = "Can't access cache resize_ctl.";
@@ -5102,13 +5106,17 @@ check_and_validate_cache_size(hid_t file_id, size_t *max_size_ptr, size_t *min_c
         else {
 
             cache_ptr = file_ptr->shared->cache;
+            if (NULL == cache_ptr) {
+                pass         = FALSE;
+                failure_mssg = "NULL cache pointer";
+            }
         }
     }
 
     /* verify that we can access the cache data structure */
     if (pass) {
 
-        if ((cache_ptr == NULL) || (cache_ptr->magic != H5C__H5C_T_MAGIC)) {
+        if (cache_ptr->magic != H5C__H5C_T_MAGIC) {
 
             pass         = FALSE;
             failure_mssg = "Can't access cache data structure.";
diff --git a/test/h5test.c b/test/h5test.c
index f39825c..8ec6047 100644
--- a/test/h5test.c
+++ b/test/h5test.c
@@ -99,10 +99,10 @@ static const char *multi_letters = "msbrglo";
 #define MESSAGE_TIMEOUT 300 /* Timeout in seconds */
 
 /* Buffer to construct path in and return pointer to */
-static char srcdir_path[1024] = "";
+static char srcdir_path[1024];
 
 /* Buffer to construct file in and return pointer to */
-static char srcdir_testpath[1024] = "";
+static char srcdir_testpath[1024];
 
 /*  The strings that correspond to library version bounds H5F_libver_t in H5Fpublic.h */
 /*  This is used by h5_get_version_string() */
@@ -1997,7 +1997,7 @@ done:
  *
  * Purpose:     Append the test file name to the srcdir path and return the whole string
  *
- * Return:      The string
+ * Return:      The string or NULL (errors or not enough space)
  *
  *-------------------------------------------------------------------------
  */
@@ -2008,16 +2008,20 @@ H5_get_srcdir_filename(const char *filename)
 
     /* Check for error */
     if (NULL == srcdir)
-        return (NULL);
-    else {
-        /* Build path to test file */
-        if ((HDstrlen(srcdir) + HDstrlen(filename) + 1) < sizeof(srcdir_testpath)) {
-            HDsnprintf(srcdir_testpath, sizeof(srcdir_testpath), "%s%s", srcdir, filename);
-            return (srcdir_testpath);
-        } /* end if */
-        else
-            return (NULL);
-    } /* end else */
+        return NULL;
+
+    /* Build path to test file. We're checking the length so suppress
+     * the gcc format-truncation warning.
+     */
+    if ((HDstrlen(srcdir) + HDstrlen(filename) + 1) < sizeof(srcdir_testpath)) {
+        H5_GCC_DIAG_OFF("format-truncation")
+        HDsnprintf(srcdir_testpath, sizeof(srcdir_testpath), "%s%s", srcdir, filename);
+        H5_GCC_DIAG_ON("format-truncation")
+        return srcdir_testpath;
+    }
+
+    /* If not enough space, just return NULL */
+    return NULL;
 } /* end H5_get_srcdir_filename() */
 
 /*-------------------------------------------------------------------------