1: /* Definition of `errno' variable.  Canonical version.
    2:    Copyright (C) 2002, 2004 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, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <errno.h>
   21: #include <tls.h>
   22: #include <dl-sysdep.h>
   23: #undef errno
   24: 
   25: #if RTLD_PRIVATE_ERRNO
   26: 
   27: /* Code compiled for rtld refers only to this name.  */
   28: int rtld_errno attribute_hidden;
   29: 
   30: #elif USE___THREAD
   31: 
   32: __thread int errno;
   33: extern __thread int __libc_errno __attribute__ ((alias ("errno")))
   34:   attribute_hidden;
   35: 
   36: #else
   37: 
   38: /* This differs from plain `int errno;' in that it doesn't create
   39:    a common definition, but a plain symbol that resides in .bss,
   40:    which can have an alias.  */
   41: int errno __attribute__ ((nocommon));
   42: strong_alias (errno, _errno)
   43: 
   44: /* We declare these with compat_symbol so that they are not visible at
   45:    link time.  Programs must use the accessor functions.  RTLD is special,
   46:    since it's not exported from there at any time.  */
   47: # if defined HAVE_ELF && defined SHARED && defined DO_VERSIONING
   48: #  include <shlib-compat.h>
   49: compat_symbol (libc, errno, errno, GLIBC_2_0);
   50: compat_symbol (libc, _errno, _errno, GLIBC_2_0);
   51: # endif
   52: 
   53: #endif