1/* realloc() function that is glibc compatible. 2 3 Copyright (C) 1997, 2003, 2004, 2006, 2007, 2009 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#include <config.h> 22 23/* Only the AC_FUNC_REALLOC macro defines 'realloc' already in config.h. */ 24#ifdef realloc 25# define NEED_REALLOC_GNU 1 26#endif 27 28/* Infer the properties of the system's malloc function. 29 Only the AC_FUNC_MALLOC macro defines 'malloc' already in config.h. */ 30#if GNULIB_MALLOC_GNU && !defined malloc 31# define SYSTEM_MALLOC_GLIBC_COMPATIBLE 1 32#endif 33 34/* Below we want to call the system's malloc and realloc. 35 Undefine the symbols here so that including <stdlib.h> provides a 36 declaration of malloc(), not of rpl_malloc(), and likewise for realloc. */ 37#undef malloc 38#undef realloc 39 40/* Specification. */ 41#include <stdlib.h> 42 43#include <errno.h> 44 45/* Below we want to call the system's malloc and realloc. 46 Undefine the symbols, if they were defined by gnulib's <stdlib.h> 47 replacement. */ 48#undef malloc 49#undef realloc 50 51/* Change the size of an allocated block of memory P to N bytes, 52 with error checking. If N is zero, change it to 1. If P is NULL, 53 use malloc. */ 54 55void * 56rpl_realloc (void *p, size_t n) 57{ 58 void *result; 59 60#if NEED_REALLOC_GNU 61 if (n == 0) 62 { 63 n = 1; 64 65 /* In theory realloc might fail, so don't rely on it to free. */ 66 free (p); 67 p = NULL; 68 } 69#endif 70 71 if (p == NULL) 72 { 73#if GNULIB_REALLOC_GNU && !NEED_REALLOC_GNU && !SYSTEM_MALLOC_GLIBC_COMPATIBLE 74 if (n == 0) 75 n = 1; 76#endif 77 result = malloc (n); 78 } 79 else 80 result = realloc (p, n); 81 82#if !HAVE_REALLOC_POSIX 83 if (result == NULL) 84 errno = ENOMEM; 85#endif 86 87 return result; 88} 89