libgfortran/runtime/main.c

   1 /* Copyright (C) 2002-2003, 2005, 2007 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 "libgfortran.h"
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <limits.h>
  34
  35
  36 #ifdef HAVE_UNISTD_H
  37 #include <unistd.h>
  38 #endif
  39
  40 /* Stupid function to be sure the constructor is always linked in, even
  41    in the case of static linking.  See PR libfortran/22298 for details.  */
  42 void
  43 stupid_function_name_for_static_linking (void)
  44 {
  45   return;
  46 }
  47
  48 /* This is the offset (in bytes) required to cast from logical(8)* to
  49    logical(4)*. and still get the same result.  Will be 0 for little-endian
  50    machines and 4 for big-endian machines.  */
  51 int l8_to_l4_offset = 0;
  52
  53
  54 /* Figure out endianness for this machine.  */
  55
  56 static void
  57 determine_endianness (void)
  58 {
  59   union
  60   {
  61     GFC_LOGICAL_8 l8;
  62     GFC_LOGICAL_4 l4[2];
  63   } u;
  64
  65   u.l8 = 1;
  66   if (u.l4[0])
  67     l8_to_l4_offset = 0;
  68   else if (u.l4[1])
  69     l8_to_l4_offset = 1;
  70   else
  71     runtime_error ("Unable to determine machine endianness");
  72 }
  73
  74
  75 static int argc_save;
  76 static char **argv_save;
  77
  78 /* Set the saved values of the command line arguments.  */
  79
  80 void
  81 set_args (int argc, char **argv)
  82 {
  83   argc_save = argc;
  84   argv_save = argv;
  85 }
  86
  87 /* Retrieve the saved values of the command line arguments.  */
  88
  89 void
  90 get_args (int *argc, char ***argv)
  91 {
  92   *argc = argc_save;
  93   *argv = argv_save;
  94 }
  95
  96
  97 static const char *exe_path;
  98 static int please_free_exe_path_when_done;
  99
 100 /* Save the path under which the program was called, for use in the
 101    backtrace routines.  */
 102 void
 103 store_exe_path (const char * argv0)
 104 {
 105 #ifndef PATH_MAX
 106 #define PATH_MAX 1024
 107 #endif
 108
 109 #ifndef DIR_SEPARATOR
 110 #define DIR_SEPARATOR '/'
 111 #endif
 112
 113   char buf[PATH_MAX], *cwd, *path;
 114
 115   if (argv0[0] == '/')
 116     {
 117       exe_path = argv0;
 118       please_free_exe_path_when_done = 0;
 119       return;
 120     }
 121
 122   memset (buf, 0, sizeof (buf));
 123 #ifdef HAVE_GETCWD
 124   cwd = getcwd (buf, sizeof (buf));
 125 #else
 126   cwd = "";
 127 #endif
 128
 129   /* exe_path will be cwd + "/" + argv[0] + "\0" */
 130   path = malloc (strlen (cwd) + 1 + strlen (argv0) + 1);
 131   sprintf (path, "%s%c%s", cwd, DIR_SEPARATOR, argv0);
 132   exe_path = path;
 133   please_free_exe_path_when_done = 1;
 134 }
 135
 136 /* Return the full path of the executable.  */
 137 char *
 138 full_exe_path (void)
 139 {
 140   return (char *) exe_path;
 141 }
 142
 143 /* Initialize the runtime library.  */
 144
 145 static void __attribute__((constructor))
 146 init (void)
 147 {
 148   /* Figure out the machine endianness.  */
 149   determine_endianness ();
 150
 151   /* Must be first */
 152   init_variables ();
 153
 154   init_units ();
 155   set_fpu ();
 156   init_compile_options ();
 157
 158 #ifdef DEBUG
 159   /* Check for special command lines.  */
 160
 161   if (argc > 1 && strcmp (argv[1], "--help") == 0)
 162     show_variables ();
 163
 164   /* if (argc > 1 && strcmp(argv[1], "--resume") == 0) resume();  */
 165 #endif
 166
 167   random_seed_i4 (NULL, NULL, NULL);
 168 }
 169
 170
 171 /* Cleanup the runtime library.  */
 172
 173 static void __attribute__((destructor))
 174 cleanup (void)
 175 {
 176   close_units ();
 177
 178   if (please_free_exe_path_when_done)
 179     free ((char *) exe_path);
 180 }