+# ifndef __attribute__
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
+# define __attribute__(x)
+# endif
+# endif
+
+# ifndef ATTRIBUTE_NORETURN
+# define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
+# endif
+
+/* This function is always triggered when memory is exhausted.
+ It must be defined by the application, either explicitly
+ or by using gnulib's xalloc-die module. This is the
+ function to call when one wants the program to die because of a
+ memory allocation failure. */
+extern void xalloc_die (void) ATTRIBUTE_NORETURN;
+
+void *xmalloc (size_t s);
+void *xnmalloc (size_t n, size_t s);
+void *xzalloc (size_t s);
+void *xcalloc (size_t n, size_t s);
+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