libgfortran/runtime/main.c

   1 /* Copyright (C) 2002-2003, 2005 Free Software Foundation, Inc.
   2    Contributed by Andy Vaught and Paul Brook <paul@nowt.org>
   3
   4 This file is part of the GNU Fortran 95 runtime library (libgfortran).
   5
   6 Libgfortran is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 In addition to the permissions in the GNU General Public License, the
  12 Free Software Foundation gives you unlimited permission to link the
  13 compiled version of this file into combinations with other programs,
  14 and to distribute those combinations without any restriction coming
  15 from the use of this file.  (The General Public License restrictions
  16 do apply in other respects; for example, they cover modification of
  17 the file, and distribution when not linked into a combine
  18 executable.)
  19
  20 Libgfortran is distributed in the hope that it will be useful,
  21 but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 GNU General Public License for more details.
  24
  25 You should have received a copy of the GNU General Public License
  26 along with libgfortran; see the file COPYING.  If not, write to
  27 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  28 Boston, MA 02110-1301, USA.  */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <math.h>
  34 #include <stddef.h>
  35
  36 #include "libgfortran.h"
  37
  38 /* Stupid function to be sure the constructor is always linked in, even
  39    in the case of static linking.  See PR libfortran/22298 for details.  */
  40 void
  41 stupid_function_name_for_static_linking (void)
  42 {
  43   return;
  44 }
  45
  46 /* This is the offset (in bytes) required to cast from logical(8)* to
  47    logical(4)*. and still get the same result.  Will be 0 for little-endian
  48    machines and 4 for big-endian machines.  */
  49 int l8_to_l4_offset = 0;
  50
  51
  52 /* Figure out endianness for this machine.  */
  53
  54 static void
  55 determine_endianness (void)
  56 {
  57   union
  58   {
  59     GFC_LOGICAL_8 l8;
  60     GFC_LOGICAL_4 l4[2];
  61   } u;
  62
  63   u.l8 = 1;
  64   if (u.l4[0])
  65     l8_to_l4_offset = 0;
  66   else if (u.l4[1])
  67     l8_to_l4_offset = 1;
  68   else
  69     runtime_error ("Unable to determine machine endianness");
  70 }
  71
  72
  73 static int argc_save;
  74 static char **argv_save;
  75
  76 /* Set the saved values of the command line arguments.  */
  77
  78 void
  79 set_args (int argc, char **argv)
  80 {
  81   argc_save = argc;
  82   argv_save = argv;
  83 }
  84
  85 /* Retrieve the saved values of the command line arguments.  */
  86
  87 void
  88 get_args (int *argc, char ***argv)
  89 {
  90   *argc = argc_save;
  91   *argv = argv_save;
  92 }
  93
  94
  95 /* Initialize the runtime library.  */
  96
  97 static void __attribute__((constructor))
  98 init (void)
  99 {
 100   /* Figure out the machine endianness.  */
 101   determine_endianness ();
 102
 103   /* Must be first */
 104   init_variables ();
 105
 106   init_units ();
 107   set_fpu ();
 108   init_compile_options ();
 109
 110 #ifdef DEBUG
 111   /* Check for special command lines.  */
 112
 113   if (argc > 1 && strcmp (argv[1], "--help") == 0)
 114     show_variables ();
 115
 116   /* if (argc > 1 && strcmp(argv[1], "--resume") == 0) resume();  */
 117 #endif
 118
 119   random_seed(NULL,NULL,NULL);
 120 }
 121
 122
 123 /* Cleanup the runtime library.  */
 124
 125 static void __attribute__((destructor))
 126 cleanup (void)
 127 {
 128   close_units ();
 129 }