+xcalloc(size_t nmemb, size_t size)
+{
+ void *ptr;
+
+ if (size == 0 || nmemb == 0)
+ fatal("xcalloc: zero size");
+ if (SIZE_T_MAX / nmemb < size)
+ fatal("xcalloc: nmemb * size > SIZE_T_MAX");
+ ptr = calloc(nmemb, size);
+ if (ptr == NULL)
+ fatal("xcalloc: out of memory (allocating %lu bytes)",
+ (u_long)(size * nmemb));
+ return ptr;
+}
+
+void *
+xrealloc(void *ptr, size_t nmemb, size_t size)