reallocarray.c - stagit - static git page generator
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       ---
       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 }