libgfortran/runtime/main.c

/* Copyright (C) 2002-2016 Free Software Foundation, Inc.
   Contributed by Andy Vaught and Paul Brook <paul@nowt.org>

This file is part of the GNU Fortran 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 3, or (at your option)
any later version.

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.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */

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


void
store_exe_path (const char * argv0 __attribute__ ((unused)))
{
  /* This function is now useless, but is retained due to ABI compatibility.
    Remove when bumping the library ABI.  */
  ;
}


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

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


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

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


/* Initialize the runtime library.  */

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

  /* Must be first */
  init_variables ();

  init_units ();

  /* If (and only if) the user asked for it, set up the FPU state.  */
  if (options.fpe != 0)
    set_fpu ();

  init_compile_options ();

  random_seed_i4 (NULL, NULL, NULL);
}


/* Cleanup the runtime library.  */

static void __attribute__((destructor))
cleanup (void)
{
  close_units ();
}