-void *xrealloc (void *p, size_t n);
-char *xstrdup (const char *str);
-
-# define XMALLOC(Type, N_items) xmalloc (sizeof (Type) * (N_items))
-# define XCALLOC(Type, N_items) xcalloc (sizeof (Type), N_items)
-# define XREALLOC(Ptr, Type, N_items) xrealloc (Ptr, sizeof (Type) * (N_items))
-
-/* Declare and alloc memory for VAR of type TYPE. */
-# define NEW(Type, Var) Type *(Var) = XMALLOC (Type, 1)
-
-/* Free VAR only if non NULL. */
-# define XFREE(Var) \
- do { \
- if (Var) \
- free (Var); \
- } while (0)
-
-/* Return a pointer to a malloc'ed copy of the array SRC of NUM elements. */
-# define CCLONE(Src, Num) \
- (memcpy (xmalloc (sizeof *(Src) * (Num)), Src, sizeof *(Src) * (Num)))
-
-/* Return a malloc'ed copy of SRC. */
-# define CLONE(Src) CCLONE (Src, 1)
+void *xrealloc (void *p, size_t s);
+void *xnrealloc (void *p, size_t n, size_t s);
+void *x2realloc (void *p, size_t *pn);
+void *x2nrealloc (void *p, size_t *pn, size_t s);
+void *xmemdup (void const *p, size_t s);
+char *xstrdup (char const *str);
+
+/* Return 1 if an array of N objects, each of size S, cannot exist due
+ to size arithmetic overflow. S must be positive and N must be
+ nonnegative. This is a macro, not an inline function, so that it
+ works correctly even when SIZE_MAX < N.
+
+ By gnulib convention, SIZE_MAX represents overflow in size
+ calculations, so the conservative dividend to use here is
+ SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
+ However, malloc (SIZE_MAX) fails on all known hosts where
+ sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
+ exactly-SIZE_MAX allocations on such hosts; this avoids a test and
+ branch when S is known to be 1. */
+# define xalloc_oversized(n, s) \
+ ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
+
+# ifdef __cplusplus
+}
+# endif