contrib/mdocml/compat_reallocarray.c

0 #include "config.h"
3 #if HAVE_REALLOCARRAY
5 int dummy;
7 #else
9 /*	$Id: compat_reallocarray.c,v 1.4 2014/12/11 09:05:01 schwarze Exp $	*/
10 /*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $	*/
12  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
14  * Permission to use, copy, modify, and distribute this software for any
15  * purpose with or without fee is hereby granted, provided that the above
16  * copyright notice and this permission notice appear in all copies.
18  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
19  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
20  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
21  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
22  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
23  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
24  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
27 #include <sys/types.h>
28 #include <errno.h>
29 #include <stdint.h>
30 #include <stdlib.h>
33  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
34  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
36 #define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
38 void *
39 reallocarray(void *optr, size_t nmemb, size_t size)
41 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
42 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
43 		errno = ENOMEM;
44 		return NULL;
46 	return realloc(optr, size * nmemb);
49 #endif /*!HAVE_REALLOCARRAY*/