1 /* Make free() preserve errno. 2 3 Copyright (C) 2003, 2006, 2009-2021 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 <https://www.gnu.org/licenses/>. */ 17 18 /* written by Paul Eggert */ 19 20 #include <config.h> 21 22 /* Specification. */ 23 #include <stdlib.h> 24 25 /* A function definition is only needed if HAVE_FREE_POSIX is not defined. */ 26 #if !HAVE_FREE_POSIX 27 28 # include <errno.h> 29 30 void rpl_free(void * p)31rpl_free (void *p) 32 # undef free 33 { 34 # if defined __GNUC__ && !defined __clang__ 35 /* An invalid GCC optimization 36 <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98396> 37 would optimize away the assignments in the code below, when link-time 38 optimization (LTO) is enabled. Make the code more complicated, so that 39 GCC does not grok how to optimize it. */ 40 int err[2]; 41 err[0] = errno; 42 err[1] = errno; 43 errno = 0; 44 free (p); 45 errno = err[errno == 0]; 46 # else 47 int err = errno; 48 free (p); 49 errno = err; 50 # endif 51 } 52 53 #endif 54