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
46 void *
rpl_realloc(void * p,size_t n)47 rpl_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