sysdeps/i386/init-first.c

   1 /* Initialization code run first thing by the ELF startup code.  For i386/Unix.
   2    Copyright (C) 1995,1996,1997,2000,2001,2002 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 <unistd.h>
  21
  22 extern void __libc_init (int, char **, char **);
  23 #ifdef USE_NONOPTION_FLAGS
  24 extern void __getopt_clean_environment (char **);
  25 #endif
  26 extern void __libc_global_ctors (void);
  27
  28 int __libc_multiple_libcs attribute_hidden = 1;
  29
  30 static void
  31 init (int *data)
  32 {
  33   int argc = *data;
  34   char **argv = (void *) (data + 1);
  35   char **envp = &argv[argc + 1];
  36
  37   __environ = envp;
  38   __libc_init (argc, argv, envp);
  39
  40 #ifdef USE_NONOPTION_FLAGS
  41   /* This is a hack to make the special getopt in GNU libc working.  */
  42   __getopt_clean_environment (envp);
  43 #endif
  44 }
  45
  46 #ifdef SHARED
  47 /* This function is called to initialize the shared C library.
  48    It is called just before the user _start code from i386/elf/start.S,
  49    with the stack set up as that code gets it.  */
  50
  51 /* NOTE!  The linker notices the magical name `_init' and sets the DT_INIT
  52    pointer in the dynamic section based solely on that.  It is convention
  53    for this function to be in the `.init' section, but the symbol name is
  54    the only thing that really matters!!  */
  55 /*void _init (int argc, ...) __attribute__ ((unused, section (".init")));*/
  56
  57 void
  58 _init (int argc, ...)
  59 {
  60   init (&argc);
  61
  62   __libc_global_ctors ();
  63 }
  64 #endif
  65
  66
  67 void
  68 __libc_init_first (int argc __attribute__ ((unused)), ...)
  69 {
  70 #ifndef SHARED
  71   init (&argc);
  72 #endif
  73 }