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/*	$OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $	*/
/* 
 * Copyright (c) 2008 Otto Moerbeek <[email protected]> 
 * 
 * Permission to use, copy, modify, and distribute this software for any 
 * purpose with or without fee is hereby granted, provided that the above 
 * copyright notice and this permission notice appear in all copies. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
 */ 
 
#include <sys/types.h> 
#include <errno.h> 
#include <stdint.h> 
#include <stdlib.h> 
 
/* 
 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 
 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 
 */ 
#define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4)) 
 
void * 
reallocarray(void *optr, size_t nmemb, size_t size) 
{ 
	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 
	    nmemb > 0 && SIZE_MAX / nmemb < size) { 
		errno = ENOMEM; 
		return NULL;
	} 
	return realloc(optr, size * nmemb);
}