Implement test_realloc

Change-Id: I87149ac233572dece7f3ec8b7d3320d07544f855

Author: chensheep

harness.c

@@ -187,6 +187,33 @@ void *test_calloc(size_t nelem, size_t elsize)
     return alloc(TEST_CALLOC, nelem * elsize);
 }
 
+void *test_realloc(void *p, size_t size)
+{
+    /* Reference: Malloc tutorial
+     * https://danluu.com/malloc-tutorial/
+     */
+
+    if (!p) {
+        return alloc(TEST_MALLOC, size);
+    }
+
+    const block_element_t *b = find_header(p);
+    if (b->payload_size >= size) {
+        return p;
+    }
+
+    void *new_ptr;
+    new_ptr = alloc(TEST_MALLOC, size);
+    if (!new_ptr) {
+        return NULL;
+    }
+    memcpy(new_ptr, p, b->payload_size);
+    test_free(p);
+
+    return new_ptr;
+}
+
+
 void test_free(void *p)
 {
     if (noallocate_mode) {

harness.h

@@ -12,9 +12,9 @@
 
 void *test_malloc(size_t size);
 void *test_calloc(size_t nmemb, size_t size);
+void *test_realloc(void *p, size_t new_size);
 void test_free(void *p);
 char *test_strdup(const char *s);
-/* FIXME: provide test_realloc as well */
 
 #ifdef INTERNAL
 
@@ -56,6 +56,7 @@ void trigger_exception(char *msg);
 /* Tested program use our versions of malloc and free */
 #define malloc test_malloc
 #define calloc test_calloc
+#define realloc test_realloc
 #define free test_free
 
 /* Use undef to avoid strdup redefined error */