+void *xmalloc(size_t size) ATTRIBUTE_MALLOC ATTRIBUTE_ALLOC_SIZE((1));
+void *xcalloc(size_t nmemb, size_t size)
+ ATTRIBUTE_MALLOC ATTRIBUTE_ALLOC_SIZE((1, 2));
+void *xreallocarray(void *ptr, size_t nmemb, size_t size)
+ ATTRIBUTE_ALLOC_SIZE((2, 3));
+char *xstrdup(const char *str) ATTRIBUTE_MALLOC;
+