libgfortran/runtime/main.c

   1 /* Copyright (C) 2002-2003, 2005, 2007, 2009 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 3, or (at your option)
   9 any later version.
  10
  11 Libgfortran is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 Under Section 7 of GPL version 3, you are granted additional
  17 permissions described in the GCC Runtime Library Exception, version
  18 3.1, as published by the Free Software Foundation.
  19
  20 You should have received a copy of the GNU General Public License and
  21 a copy of the GCC Runtime Library Exception along with this program;
  22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25 #include "libgfortran.h"
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <limits.h>
  29
  30
  31 #ifdef HAVE_UNISTD_H
  32 #include <unistd.h>
  33 #endif
  34
  35 /* Stupid function to be sure the constructor is always linked in, even
  36    in the case of static linking.  See PR libfortran/22298 for details.  */
  37 void
  38 stupid_function_name_for_static_linking (void)
  39 {
  40   return;
  41 }
  42
  43 /* This will be 0 for little-endian
  44    machines and 1 for big-endian machines.  */
  45 int big_endian = 0;
  46
  47
  48 /* Figure out endianness for this machine.  */
  49
  50 static void
  51 determine_endianness (void)
  52 {
  53   union
  54   {
  55     GFC_LOGICAL_8 l8;
  56     GFC_LOGICAL_4 l4[2];
  57   } u;
  58
  59   u.l8 = 1;
  60   if (u.l4[0])
  61     big_endian = 0;
  62   else if (u.l4[1])
  63     big_endian = 1;
  64   else
  65     runtime_error ("Unable to determine machine endianness");
  66 }
  67
  68
  69 static int argc_save;
  70 static char **argv_save;
  71
  72 static const char *exe_path;
  73 static int please_free_exe_path_when_done;
  74
  75 /* Save the path under which the program was called, for use in the
  76    backtrace routines.  */
  77 void
  78 store_exe_path (const char * argv0)
  79 {
  80 #ifndef PATH_MAX
  81 #define PATH_MAX 1024
  82 #endif
  83
  84 #ifndef DIR_SEPARATOR
  85 #define DIR_SEPARATOR '/'
  86 #endif
  87
  88   char buf[PATH_MAX], *cwd, *path;
  89
  90   /* This can only happen if store_exe_path is called multiple times.  */
  91   if (please_free_exe_path_when_done)
  92     free ((char *) exe_path);
  93
  94   /* On the simulator argv is not set.  */
  95   if (argv0 == NULL || argv0[0] == '/')
  96     {
  97       exe_path = argv0;
  98       please_free_exe_path_when_done = 0;
  99       return;
 100     }
 101
 102   memset (buf, 0, sizeof (buf));
 103 #ifdef HAVE_GETCWD
 104   cwd = getcwd (buf, sizeof (buf));
 105 #else
 106   cwd = "";
 107 #endif
 108
 109   /* exe_path will be cwd + "/" + argv[0] + "\0" */
 110   path = malloc (strlen (cwd) + 1 + strlen (argv0) + 1);
 111   sprintf (path, "%s%c%s", cwd, DIR_SEPARATOR, argv0);
 112   exe_path = path;
 113   please_free_exe_path_when_done = 1;
 114 }
 115
 116
 117 /* Return the full path of the executable.  */
 118 char *
 119 full_exe_path (void)
 120 {
 121   return (char *) exe_path;
 122 }
 123
 124
 125 /* Set the saved values of the command line arguments.  */
 126
 127 void
 128 set_args (int argc, char **argv)
 129 {
 130   argc_save = argc;
 131   argv_save = argv;
 132   store_exe_path (argv[0]);
 133 }
 134 iexport(set_args);
 135
 136
 137 /* Retrieve the saved values of the command line arguments.  */
 138
 139 void
 140 get_args (int *argc, char ***argv)
 141 {
 142   *argc = argc_save;
 143   *argv = argv_save;
 144 }
 145
 146
 147 /* Initialize the runtime library.  */
 148
 149 static void __attribute__((constructor))
 150 init (void)
 151 {
 152   /* Figure out the machine endianness.  */
 153   determine_endianness ();
 154
 155   /* Must be first */
 156   init_variables ();
 157
 158   init_units ();
 159   set_fpu ();
 160   init_compile_options ();
 161
 162 #ifdef DEBUG
 163   /* Check for special command lines.  */
 164
 165   if (argc > 1 && strcmp (argv[1], "--help") == 0)
 166     show_variables ();
 167
 168   /* if (argc > 1 && strcmp(argv[1], "--resume") == 0) resume();  */
 169 #endif
 170
 171   random_seed_i4 (NULL, NULL, NULL);
 172 }
 173
 174
 175 /* Cleanup the runtime library.  */
 176
 177 static void __attribute__((destructor))
 178 cleanup (void)
 179 {
 180   close_units ();
 181
 182   if (please_free_exe_path_when_done)
 183     free ((char *) exe_path);
 184 }