Create 2D arrays on the heap in a different way (#1169)

* Create 2D arrays on the heap by malloc'ing `struct { TYPE arr[ROWS][COLS];
}`.  This avoids the double-indirection through pointers and the
additional memory of H5TEST_ALLOCATE_2D_ARRAY().

This change will safely quiet the cast warning that PR #1129 was
intended to fix.

* Committing clang-format changes

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

test/h5test.h

@@ -172,60 +172,19 @@ H5TEST_DLLVAR MPI_Info h5_io_info_g; /* MPI INFO object for IO */
 #define H5_EXCLUDE_MULTIPART_DRIVERS     0x01
 #define H5_EXCLUDE_NON_MULTIPART_DRIVERS 0x02
 
-/* Macros to create and fill 2D arrays with a single heap allocation.
- * These can be used to replace large stack and global arrays which raise
- * warnings.
- *
- * The macros make a single heap allocation large enough to hold all the
- * pointers and the data elements. The first part of the allocation holds
- * the pointers, and the second part holds the data as a contiguous block
- * in row-major order.
- *
- * To pass the data block to calls like H5Dread(), pass a pointer to the
- * first array element as the data pointer (e.g., array[0] in a 2D array).
- *
- * The fill macro just fills the array with an increasing count value.
- *
- * Usage:
- *
- * int **array;
- *
- * H5TEST_ALLOCATE_2D_ARRAY(array, int, 5, 10);
- *
- * H5TEST_FILL_2D_ARRAY(array, int, 5, 10);
- *
- * (do stuff)
- *
- * HDfree(array);
+/* Fill an array on the heap with an increasing count value.  BUF
+ * is expected to point to a `struct { TYPE arr[...][...]; }`.
  */
-#define H5TEST_ALLOCATE_2D_ARRAY(ARR, TYPE, DIMS_I, DIMS_J)                                                  \
-    do {                                                                                                     \
-        /* Prefix with h5taa to avoid shadow warnings */                                                     \
-        size_t h5taa_pointers_size = 0;                                                                      \
-        size_t h5taa_data_size     = 0;                                                                      \
-        int    h5taa_i;                                                                                      \
-                                                                                                             \
-        h5taa_pointers_size = (DIMS_I) * sizeof(TYPE *);                                                     \
-        h5taa_data_size     = (DIMS_I) * (DIMS_J) * sizeof(TYPE);                                            \
-                                                                                                             \
-        ARR = (TYPE **)HDmalloc(h5taa_pointers_size + h5taa_data_size);                                      \
-                                                                                                             \
-        ARR[0] = (TYPE *)(ARR + (DIMS_I));                                                                   \
-                                                                                                             \
-        for (h5taa_i = 1; h5taa_i < (DIMS_I); h5taa_i++)                                                     \
-            ARR[h5taa_i] = ARR[h5taa_i - 1] + (DIMS_J);                                                      \
-    } while (0)
-
-#define H5TEST_FILL_2D_ARRAY(ARR, TYPE, DIMS_I, DIMS_J)                                                      \
+#define H5TEST_FILL_2D_HEAP_ARRAY(BUF, TYPE)                                                                 \
     do {                                                                                                     \
         /* Prefix with h5tfa to avoid shadow warnings */                                                     \
-        int  h5tfa_i     = 0;                                                                                \
-        int  h5tfa_j     = 0;                                                                                \
-        TYPE h5tfa_count = 0;                                                                                \
+        size_t h5tfa_i     = 0;                                                                              \
+        size_t h5tfa_j     = 0;                                                                              \
+        TYPE   h5tfa_count = 0;                                                                              \
                                                                                                              \
-        for (h5tfa_i = 0; h5tfa_i < (DIMS_I); h5tfa_i++)                                                     \
-            for (h5tfa_j = 0; h5tfa_j < (DIMS_J); h5tfa_j++) {                                               \
-                ARR[h5tfa_i][h5tfa_j] = h5tfa_count;                                                         \
+        for (h5tfa_i = 0; h5tfa_i < NELMTS((BUF)->arr); h5tfa_i++)                                           \
+            for (h5tfa_j = 0; h5tfa_j < NELMTS((BUF)->arr[0]); h5tfa_j++) {                                  \
+                (BUF)->arr[h5tfa_i][h5tfa_j] = h5tfa_count;                                                  \
                 h5tfa_count++;                                                                               \
             }                                                                                                \
     } while (0)