1  /* __errno_location -- helper function for locating per-thread errno value
       2     Copyright (C) 2002-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library 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 GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #if IS_IN (rtld)
      20  /* rtld can not access TLS too early, thus rtld_errno.
      21  
      22     Instead of making __open/__close pass errno from TLS to rtld_errno, simply
      23     use a weak __errno_location using rtld_errno, which will be overridden by the
      24     libc definition.  */
      25  static int rtld_errno;
      26  int * weak_function
      27  __errno_location (void)
      28  {
      29    return &rtld_errno;
      30  }
      31  libc_hidden_weak (__errno_location)
      32  #else
      33  #include "../../../csu/errno-loc.c"
      34  #endif