sysdeps/unix/sysv/linux/init-first.c

   1 /* Initialization code run first thing by the ELF startup code.  Linux version.
   2    Copyright (C) 1995-2004, 2005, 2007 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 <stdio.h>
  21 #include <stdlib.h>
  22 #include <fcntl.h>
  23 #include <unistd.h>
  24 #include <sysdep.h>
  25 #include <fpu_control.h>
  26 #include <sys/param.h>
  27 #include <sys/types.h>
  28 #include <libc-internal.h>
  29
  30 #include <ldsodefs.h>
  31
  32 /* Set nonzero if we have to be prepared for more then one libc being
  33    used in the process.  Safe assumption if initializer never runs.  */
  34 int __libc_multiple_libcs attribute_hidden = 1;
  35
  36 /* Remember the command line argument and enviroment contents for
  37    later calls of initializers for dynamic libraries.  */
  38 int __libc_argc attribute_hidden;
  39 char **__libc_argv attribute_hidden;
  40
  41
  42 void
  43 __libc_init_first (int argc, char **argv, char **envp)
  44 {
  45 #ifdef SHARED
  46   /* For DSOs we do not need __libc_init_first but instead _init.  */
  47 }
  48
  49 void
  50 attribute_hidden
  51 _init (int argc, char **argv, char **envp)
  52 {
  53 #endif
  54 #ifdef USE_NONOPTION_FLAGS
  55   extern void __getopt_clean_environment (char **);
  56 #endif
  57
  58   __libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up;
  59
  60   /* Make sure we don't initialize twice.  */
  61   if (!__libc_multiple_libcs)
  62     {
  63       /* Set the FPU control word to the proper default value if the
  64          kernel would use a different value.  (In a static program we
  65          don't have this information.)  */
  66 #ifdef SHARED
  67       if (__fpu_control != GLRO(dl_fpu_control))
  68 #endif
  69         __setfpucw (__fpu_control);
  70     }
  71
  72   /* Save the command-line arguments.  */
  73   __libc_argc = argc;
  74   __libc_argv = argv;
  75   __environ = envp;
  76
  77 #ifndef SHARED
  78   __libc_init_secure ();
  79
  80   /* First the initialization which normally would be done by the
  81      dynamic linker.  */
  82   _dl_non_dynamic_init ();
  83 #endif
  84
  85 #ifdef VDSO_SETUP
  86   VDSO_SETUP ();
  87 #endif
  88
  89   __init_misc (argc, argv, envp);
  90
  91 #ifdef USE_NONOPTION_FLAGS
  92   /* This is a hack to make the special getopt in GNU libc working.  */
  93   __getopt_clean_environment (envp);
  94 #endif
  95
  96 #ifdef SHARED
  97   __libc_global_ctors ();
  98 #endif
  99 }
 100
 101
 102 /* This function is defined here so that if this file ever gets into
 103    ld.so we will get a link error.  Having this file silently included
 104    in ld.so causes disaster, because the _init definition above will
 105    cause ld.so to gain an init function, which is not a cool thing. */
 106
 107 extern void _dl_start (void) __attribute__ ((noreturn));
 108
 109 void
 110 _dl_start (void)
 111 {
 112   abort ();
 113 }