1/* realloc() function that is glibc compatible. 2 3 Copyright (C) 1997, 2003, 2004, 2006, 2007 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18/* written by Jim Meyering and Bruno Haible */ 19 20#include <config.h> 21 22/* Only the AC_FUNC_REALLOC macro defines 'realloc' already in config.h. */ 23#ifdef realloc 24# define NEED_REALLOC_GNU 1 25#endif 26 27/* Infer the properties of the system's malloc function. 28 Only the AC_FUNC_MALLOC macro defines 'malloc' already in config.h. */ 29#if GNULIB_MALLOC_GNU && !defined malloc 30# define SYSTEM_MALLOC_GLIBC_COMPATIBLE 1 31#endif 32 33/* Below we want to call the system's malloc and realloc. 34 Undefine the symbols here so that including <stdlib.h> provides a 35 declaration of malloc(), not of rpl_malloc(), and likewise for realloc. */ 36#undef malloc 37#undef realloc 38 39/* Specification. */ 40#include <stdlib.h> 41 42#include <errno.h> 43 44/* Below we want to call the system's malloc and realloc. 45 Undefine the symbols, if they were defined by gnulib's <stdlib.h> 46 replacement. */ 47#undef malloc 48#undef realloc 49 50/* Change the size of an allocated block of memory P to N bytes, 51 with error checking. If N is zero, change it to 1. If P is NULL, 52 use malloc. */ 53 54void * 55rpl_realloc (void *p, size_t n) 56{ 57 void *result; 58 59#if NEED_REALLOC_GNU 60 if (n == 0) 61 { 62 n = 1; 63 64 /* In theory realloc might fail, so don't rely on it to free. */ 65 free (p); 66 p = NULL; 67 } 68#endif 69 70 if (p == NULL) 71 { 72#if GNULIB_REALLOC_GNU && !NEED_REALLOC_GNU && !SYSTEM_MALLOC_GLIBC_COMPATIBLE 73 if (n == 0) 74 n = 1; 75#endif 76 result = malloc (n); 77 } 78 else 79 result = realloc (p, n); 80 81#if !HAVE_REALLOC_POSIX 82 if (result == NULL) 83 errno = ENOMEM; 84#endif 85 86 return result; 87} 88