csu/errno.c

   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