/*
 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
 *
 * 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> /* errno EINVAL ENOMEM */
#include <stddef.h> /* NULL size_t */
#include <stdint.h> /* SIZE_MAX */
#include <stdlib.h> /* realloc() */

/* * 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 == 0U)
	{
		errno = EINVAL;
		return NULL;
	}
	if((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
			nmemb > 0U && SIZE_MAX/nmemb < size)
	{
		errno = ENOMEM;
		return NULL;
	}
	return realloc(optr, size*nmemb);
}

/* vim: set tabstop=2 softtabstop=2 shiftwidth=2 noexpandtab cinoptions-=(0 : */
/* vim: set cinoptions+=t0 filetype=c : */