stagit

custom fork of stagit
Index Commits Files Refs README LICENSE
reallocarray.c (1306B)
   1 /*
   2  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 
  17 #include <sys/types.h>
  18 #include <errno.h>
  19 #include <stdint.h>
  20 #include <stdlib.h>
  21 
  22 #include "compat.h"
  23 
  24 /*
  25  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
  26  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
  27  */
  28 #define MUL_NO_OVERFLOW    (1UL << (sizeof(size_t) * 4))
  29 
  30 void *
  31 reallocarray(void *optr, size_t nmemb, size_t size)
  32 {
  33     if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
  34         nmemb > 0 && SIZE_MAX / nmemb < size) {
  35         errno = ENOMEM;
  36         return NULL;
  37     }
  38     return realloc(optr, size * nmemb);
  39 }