1/* realloc() function that is glibc compatible.
2
3   Copyright (C) 1997, 2003-2004, 2006-2007, 2009-2012 Free Software
4   Foundation, Inc.
5
6   This program is free software: you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 3 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18
19/* written by Jim Meyering and Bruno Haible */
20
21#define _GL_USE_STDLIB_ALLOC 1
22#include <config.h>
23
24/* Only the AC_FUNC_REALLOC macro defines 'realloc' already in config.h.  */
25#ifdef realloc
26# define NEED_REALLOC_GNU 1
27/* Whereas the gnulib module 'realloc-gnu' defines HAVE_REALLOC_GNU.  */
28#elif GNULIB_REALLOC_GNU && !HAVE_REALLOC_GNU
29# define NEED_REALLOC_GNU 1
30#endif
31
32/* Infer the properties of the system's malloc function.
33   The gnulib module 'malloc-gnu' defines HAVE_MALLOC_GNU.  */
34#if GNULIB_MALLOC_GNU && HAVE_MALLOC_GNU
35# define SYSTEM_MALLOC_GLIBC_COMPATIBLE 1
36#endif
37
38#include <stdlib.h>
39
40#include <errno.h>
41
42/* Change the size of an allocated block of memory P to N bytes,
43   with error checking.  If N is zero, change it to 1.  If P is NULL,
44   use malloc.  */
45
46void *
47rpl_realloc (void *p, size_t n)
48{
49  void *result;
50
51#if NEED_REALLOC_GNU
52  if (n == 0)
53    {
54      n = 1;
55
56      /* In theory realloc might fail, so don't rely on it to free.  */
57      free (p);
58      p = NULL;
59    }
60#endif
61
62  if (p == NULL)
63    {
64#if GNULIB_REALLOC_GNU && !NEED_REALLOC_GNU && !SYSTEM_MALLOC_GLIBC_COMPATIBLE
65      if (n == 0)
66        n = 1;
67#endif
68      result = malloc (n);
69    }
70  else
71    result = realloc (p, n);
72
73#if !HAVE_REALLOC_POSIX
74  if (result == NULL)
75    errno = ENOMEM;
76#endif
77
78  return result;
79}
80