Line data    Source code

       1             : /* Make free() preserve errno.
       2             : 
       3             :    Copyright (C) 2003, 2006, 2009-2025 Free Software Foundation, Inc.
       4             : 
       5             :    This file is free software: you can redistribute it and/or modify
       6             :    it under the terms of the GNU Lesser General Public License as
       7             :    published by the Free Software Foundation; either version 2.1 of the
       8             :    License, or (at your option) any later version.
       9             : 
      10             :    This file 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 Lesser General Public License for more details.
      14             : 
      15             :    You should have received a copy of the GNU Lesser 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
      31             : rpl_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    27069826 :   err[0] = errno;
      42    27069826 :   err[1] = errno;
      43    27069826 :   errno = 0;
      44    27069826 :   free (p);
      45    27069826 :   errno = err[errno == 0];
      46             : # else
      47             :   int err = errno;
      48             :   free (p);
      49             :   errno = err;
      50             : # endif
      51    27069826 : }
      52             : 
      53             : #endif