gcc/libgfortran/runtime/main.c

/* Copyright (C) 2002-2003, 2005, 2007 Free Software Foundation, Inc.
   Contributed by Andy Vaught and Paul Brook <paul@nowt.org>

This file is part of the GNU Fortran 95 runtime library (libgfortran).

Libgfortran is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file.  (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)

Libgfortran is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with libgfortran; see the file COPYING.  If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */

#include "libgfortran.h"
#include <stdlib.h>
#include <string.h>
#include <limits.h>


#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

/* Stupid function to be sure the constructor is always linked in, even
   in the case of static linking.  See PR libfortran/22298 for details.  */
void
stupid_function_name_for_static_linking (void)
{
  return;
}

/* This will be 0 for little-endian
   machines and 1 for big-endian machines.  */
int big_endian = 0;


/* Figure out endianness for this machine.  */

static void
determine_endianness (void)
{
  union
  {
    GFC_LOGICAL_8 l8;
    GFC_LOGICAL_4 l4[2];
  } u;

  u.l8 = 1;
  if (u.l4[0])
    big_endian = 0;
  else if (u.l4[1])
    big_endian = 1;
  else
    runtime_error ("Unable to determine machine endianness");
}


static int argc_save;
static char **argv_save;

/* Set the saved values of the command line arguments.  */

void
set_args (int argc, char **argv)
{
  argc_save = argc;
  argv_save = argv;
}

/* Retrieve the saved values of the command line arguments.  */

void
get_args (int *argc, char ***argv)
{
  *argc = argc_save;
  *argv = argv_save;
}


static const char *exe_path;
static int please_free_exe_path_when_done;

/* Save the path under which the program was called, for use in the
   backtrace routines.  */
void
store_exe_path (const char * argv0)
{
#ifndef PATH_MAX
#define PATH_MAX 1024
#endif

#ifndef DIR_SEPARATOR   
#define DIR_SEPARATOR '/'
#endif

  char buf[PATH_MAX], *cwd, *path;

  if (argv0[0] == '/')
    {
      exe_path = argv0;
      please_free_exe_path_when_done = 0;
      return;
    }

  memset (buf, 0, sizeof (buf));
#ifdef HAVE_GETCWD
  cwd = getcwd (buf, sizeof (buf));
#else
  cwd = "";
#endif

  /* exe_path will be cwd + "/" + argv[0] + "\0" */
  path = malloc (strlen (cwd) + 1 + strlen (argv0) + 1);
  sprintf (path, "%s%c%s", cwd, DIR_SEPARATOR, argv0);
  exe_path = path;
  please_free_exe_path_when_done = 1;
}

/* Return the full path of the executable.  */
char *
full_exe_path (void)
{
  return (char *) exe_path;
}

/* Initialize the runtime library.  */

static void __attribute__((constructor))
init (void)
{
  /* Figure out the machine endianness.  */
  determine_endianness ();

  /* Must be first */
  init_variables ();

  init_units ();
  set_fpu ();
  init_compile_options ();

#ifdef DEBUG
  /* Check for special command lines.  */

  if (argc > 1 && strcmp (argv[1], "--help") == 0)
    show_variables ();

  /* if (argc > 1 && strcmp(argv[1], "--resume") == 0) resume();  */
#endif

  random_seed_i4 (NULL, NULL, NULL);
}


/* Cleanup the runtime library.  */

static void __attribute__((destructor))
cleanup (void)
{
  close_units ();
  
  if (please_free_exe_path_when_done)
    free ((char *) exe_path);
}