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 54 void * 55 rpl_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
