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

   1 /* Initialization code run first thing by the ELF startup code.  Linux version.
   2    Copyright (C) 1995-1999,2000,01,02,03,2004 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 <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 /* The function is called from assembly stubs the compiler can't see.  */
  33 static void init (int, char **, char **) __attribute__ ((used));
  34
  35 /* Set nonzero if we have to be prepared for more then one libc being
  36    used in the process.  Safe assumption if initializer never runs.  */
  37 int __libc_multiple_libcs attribute_hidden = 1;
  38
  39 /* Remember the command line argument and enviroment contents for
  40    later calls of initializers for dynamic libraries.  */
  41 int __libc_argc attribute_hidden;
  42 char **__libc_argv attribute_hidden;
  43
  44
  45 static void
  46 init (int argc, char **argv, char **envp)
  47 {
  48 #ifdef USE_NONOPTION_FLAGS
  49   extern void __getopt_clean_environment (char **);
  50 #endif
  51
  52   __libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up;
  53
  54   /* Make sure we don't initialize twice.  */
  55   if (!__libc_multiple_libcs)
  56     {
  57       /* Set the FPU control word to the proper default value if the
  58          kernel would use a different value.  (In a static program we
  59          don't have this information.)  */
  60 #ifdef SHARED
  61       if (__fpu_control != GLRO(dl_fpu_control))
  62 #endif
  63         __setfpucw (__fpu_control);
  64     }
  65
  66   /* Save the command-line arguments.  */
  67   __libc_argc = argc;
  68   __libc_argv = argv;
  69   __environ = envp;
  70
  71 #ifndef SHARED
  72   __libc_init_secure ();
  73
  74   /* First the initialization which normally would be done by the
  75      dynamic linker.  */
  76   _dl_non_dynamic_init ();
  77 #endif
  78
  79   __init_misc (argc, argv, envp);
  80
  81 #ifdef USE_NONOPTION_FLAGS
  82   /* This is a hack to make the special getopt in GNU libc working.  */
  83   __getopt_clean_environment (envp);
  84 #endif
  85
  86 #ifdef SHARED
  87   __libc_global_ctors ();
  88 #endif
  89 }
  90
  91 #ifdef SHARED
  92
  93 strong_alias (init, _init);
  94
  95 extern void __libc_init_first (void);
  96
  97 void
  98 __libc_init_first (void)
  99 {
 100 }
 101
 102 #else
 103 extern void __libc_init_first (int argc, char **argv, char **envp);
 104
 105 void
 106 __libc_init_first (int argc, char **argv, char **envp)
 107 {
 108   init (argc, argv, envp);
 109 }
 110 #endif
 111
 112
 113 /* This function is defined here so that if this file ever gets into
 114    ld.so we will get a link error.  Having this file silently included
 115    in ld.so causes disaster, because the _init definition above will
 116    cause ld.so to gain an init function, which is not a cool thing. */
 117
 118 extern void _dl_start (void) __attribute__ ((noreturn));
 119
 120 void
 121 _dl_start (void)
 122 {
 123   abort ();
 124 }