xref: /f-stack/tools/compat/reallocf.c (revision df6ad731)
1*df6ad731Slogwang /*-
2*df6ad731Slogwang  * Copyright (c) 1998, M. Warner Losh <[email protected]>
3*df6ad731Slogwang  * All rights reserved.
4*df6ad731Slogwang  *
5*df6ad731Slogwang  * Redistribution and use in source and binary forms, with or without
6*df6ad731Slogwang  * modification, are permitted provided that the following conditions
7*df6ad731Slogwang  * are met:
8*df6ad731Slogwang  * 1. Redistributions of source code must retain the above copyright
9*df6ad731Slogwang  *    notice, this list of conditions and the following disclaimer.
10*df6ad731Slogwang  * 2. Redistributions in binary form must reproduce the above copyright
11*df6ad731Slogwang  *    notice, this list of conditions and the following disclaimer in the
12*df6ad731Slogwang  *    documentation and/or other materials provided with the distribution.
13*df6ad731Slogwang  *
14*df6ad731Slogwang  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*df6ad731Slogwang  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*df6ad731Slogwang  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*df6ad731Slogwang  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*df6ad731Slogwang  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*df6ad731Slogwang  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*df6ad731Slogwang  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*df6ad731Slogwang  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*df6ad731Slogwang  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*df6ad731Slogwang  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*df6ad731Slogwang  * SUCH DAMAGE.
25*df6ad731Slogwang  */
26*df6ad731Slogwang 
27*df6ad731Slogwang #include <stdlib.h>
28*df6ad731Slogwang #include "compat.h"
29*df6ad731Slogwang 
30*df6ad731Slogwang void *
reallocf(void * ptr,size_t size)31*df6ad731Slogwang reallocf(void *ptr, size_t size)
32*df6ad731Slogwang {
33*df6ad731Slogwang 	void *nptr;
34*df6ad731Slogwang 
35*df6ad731Slogwang 	nptr = realloc(ptr, size);
36*df6ad731Slogwang 
37*df6ad731Slogwang 	/*
38*df6ad731Slogwang 	 * When the System V compatibility option (malloc "V" flag) is
39*df6ad731Slogwang 	 * in effect, realloc(ptr, 0) frees the memory and returns NULL.
40*df6ad731Slogwang 	 * So, to avoid double free, call free() only when size != 0.
41*df6ad731Slogwang 	 * realloc(ptr, 0) can't fail when ptr != NULL.
42*df6ad731Slogwang 	 */
43*df6ad731Slogwang 	if (!nptr && ptr && size != 0)
44*df6ad731Slogwang 		free(ptr);
45*df6ad731Slogwang 	return (nptr);
46*df6ad731Slogwang }
47