xref: /titanic_51/usr/src/cmd/mandoc/compat_reallocarray.c (revision 260e9a87725c090ba5835b1f9f0b62fa2f96036f)
1 #include "config.h"
2 
3 #if HAVE_REALLOCARRAY
4 
5 int dummy;
6 
7 #else
8 
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 $	*/
11 /*
12  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
13  *
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.
17  *
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.
25  */
26 
27 #include <sys/types.h>
28 #include <errno.h>
29 #include <stdint.h>
30 #include <stdlib.h>
31 
32 /*
33  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
34  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
35  */
36 #define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
37 
38 void *
39 reallocarray(void *optr, size_t nmemb, size_t size)
40 {
41 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
42 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
43 		errno = ENOMEM;
44 		return NULL;
45 	}
46 	return realloc(optr, size * nmemb);
47 }
48 
49 #endif /*!HAVE_REALLOCARRAY*/
50