1: /* Startup support for ELF initializers/finalizers in the main executable.
    2:    Copyright (C) 2002, 2003, 2004, 2005 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:    In addition to the permissions in the GNU Lesser General Public
   11:    License, the Free Software Foundation gives you unlimited
   12:    permission to link the compiled version of this file with other
   13:    programs, and to distribute those programs without any restriction
   14:    coming from the use of this file. (The GNU Lesser General Public
   15:    License restrictions do apply in other respects; for example, they
   16:    cover modification of the file, and distribution when not linked
   17:    into another program.)
   18: 
   19:    Note that people who make modified versions of this file are not
   20:    obligated to grant this special exception for their modified
   21:    versions; it is their choice whether to do so. The GNU Lesser
   22:    General Public License gives permission to release a modified
   23:    version without this exception; this exception also makes it
   24:    possible to release a modified version which carries forward this
   25:    exception.
   26: 
   27:    The GNU C Library is distributed in the hope that it will be useful,
   28:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   29:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   30:    Lesser General Public License for more details.
   31: 
   32:    You should have received a copy of the GNU Lesser General Public
   33:    License along with the GNU C Library; if not, write to the Free
   34:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   35:    02111-1307 USA.  */
   36: 
   37: #include <stddef.h>
   38: 
   39: 
   40: /* These magic symbols are provided by the linker.  */
   41: extern void (*__preinit_array_start []) (int, char **, char **)
   42:   attribute_hidden;
   43: extern void (*__preinit_array_end []) (int, char **, char **)
   44:   attribute_hidden;
   45: extern void (*__init_array_start []) (int, char **, char **)
   46:   attribute_hidden;
   47: extern void (*__init_array_end []) (int, char **, char **)
   48:   attribute_hidden;
   49: extern void (*__fini_array_start []) (void) attribute_hidden;
   50: extern void (*__fini_array_end []) (void) attribute_hidden;
   51: 
   52: 
   53: /* These function symbols are provided for the .init/.fini section entry
   54:    points automagically by the linker.  */
   55: extern void _init (void);
   56: extern void _fini (void);
   57: 
   58: /* These functions are passed to __libc_start_main by the startup code.
   59:    These get statically linked into each program.  For dynamically linked
   60:    programs, this module will come from libc_nonshared.a and differs from
   61:    the libc.a module in that it doesn't call the preinit array.  */
   62: 
   63: void
   64: __libc_csu_init (int argc, char **argv, char **envp)
   65: {
   66:   /* For dynamically linked executables the preinit array is executed by
   67:      the dynamic linker (before initializing any shared object.  */
   68: 
   69: #ifndef LIBC_NONSHARED
   70:   /* For static executables, preinit happens rights before init.  */
   71:   {
   72:     const size_t size = __preinit_array_end - __preinit_array_start;
   73:     size_t i;
   74:     for (i = 0; i < size; i++)
   75:       (*__preinit_array_start [i]) (argc, argv, envp);
   76:   }
   77: #endif
   78: 
   79:   _init ();
   80: 
   81:   const size_t size = __init_array_end - __init_array_start;
   82:   for (size_t i = 0; i < size; i++)
   83:       (*__init_array_start [i]) (argc, argv, envp);
   84: }
   85: 
   86: /* This function should not be used anymore.  We run the executable's
   87:    destructor now just like any other.  We cannot remove the function,
   88:    though.  */
   89: void
   90: __libc_csu_fini (void)
   91: {
   92: #ifndef LIBC_NONSHARED
   93:   size_t i = __fini_array_end - __fini_array_start;
   94:   while (i-- > 0)
   95:     (*__fini_array_start [i]) ();
   96: 
   97:   _fini ();
   98: #endif
   99: }