compat_reallocarray.c

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