compat_reallocarray.c

   1 #ifdef HAVE_CONFIG_H
   2 #include "config.h"
   3 #endif
   4
   5 #ifdef HAVE_REALLOCARRAY
   6
   7 int dummy;
   8
   9 #else
  10
  11 /*      $OpenBSD: malloc.c,v 1.158 2014/04/23 15:07:27 tedu Exp $       */
  12 /*
  13  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  14  *
  15  * Permission to use, copy, modify, and distribute this software for any
  16  * purpose with or without fee is hereby granted, provided that the above
  17  * copyright notice and this permission notice appear in all copies.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  20  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  21  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  22  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  23  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  24  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  25  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  26  */
  27 #include <sys/types.h>
  28 #include <errno.h>
  29 #include <stdint.h>
  30 #include <stdlib.h>
  31
  32 #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 4))
  33
  34 void *
  35 reallocarray(void *optr, size_t nmemb, size_t size)
  36 {
  37         if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
  38             nmemb > 0 && SIZE_MAX / nmemb < size) {
  39                 errno = ENOMEM;
  40                 return NULL;
  41         }
  42         return realloc(optr, size * nmemb);
  43 }
  44
  45 #endif /*!HAVE_REALLOCARRAY*/