blob: 975598560a9c4a259c19b42d10894061a1c6fabf [file] [log] [blame]
/* xmalloc.c -- malloc with out of memory checking
Copyright (C) 1990-2000, 2002-2006, 2008-2012 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <>. */
#include <config.h>
#include "xalloc.h"
#include <stdlib.h>
#include <string.h>
/* 1 if calloc is known to be compatible with GNU calloc. This
matters if we are not also using the calloc module, which defines
HAVE_CALLOC_GNU and supports the GNU API even on non-GNU platforms. */
#if defined HAVE_CALLOC_GNU || (defined __GLIBC__ && !defined __UCLIBC__)
enum { HAVE_GNU_CALLOC = 1 };
enum { HAVE_GNU_CALLOC = 0 };
/* Allocate N bytes of memory dynamically, with error checking. */
void *
xmalloc (size_t n)
void *p = malloc (n);
if (!p && n != 0)
xalloc_die ();
return p;
/* Change the size of an allocated block of memory P to N bytes,
with error checking. */
void *
xrealloc (void *p, size_t n)
if (!n && p)
/* The GNU and C99 realloc behaviors disagree here. Act like
GNU, even if the underlying realloc is C99. */
free (p);
return NULL;
p = realloc (p, n);
if (!p && n)
xalloc_die ();
return p;
/* If P is null, allocate a block of at least *PN bytes; otherwise,
reallocate P so that it contains more than *PN bytes. *PN must be
nonzero unless P is null. Set *PN to the new block's size, and
return the pointer to the new block. *PN is never set to zero, and
the returned pointer is never null. */
void *
x2realloc (void *p, size_t *pn)
return x2nrealloc (p, pn, 1);
/* Allocate S bytes of zeroed memory dynamically, with error checking.
There's no need for xnzalloc (N, S), since it would be equivalent
to xcalloc (N, S). */
void *
xzalloc (size_t s)
return memset (xmalloc (s), 0, s);
/* Allocate zeroed memory for N elements of S bytes, with error
checking. S must be nonzero. */
void *
xcalloc (size_t n, size_t s)
void *p;
/* Test for overflow, since some calloc implementations don't have
proper overflow checks. But omit overflow and size-zero tests if
HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
returns NULL if successful. */
if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s))
|| (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))
xalloc_die ();
return p;
/* Clone an object P of size S, with error checking. There's no need
for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any
need for an arithmetic overflow check. */
void *
xmemdup (void const *p, size_t s)
return memcpy (xmalloc (s), p, s);
/* Clone STRING. */
char *
xstrdup (char const *string)
return xmemdup (string, strlen (string) + 1);