libgfortran/runtime/main.c

   1 /* Copyright (C) 2002-2015 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 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 #include <errno.h>
  30
  31
  32 #ifdef HAVE_UNISTD_H
  33 #include <unistd.h>
  34 #endif
  35
  36 /* Stupid function to be sure the constructor is always linked in, even
  37    in the case of static linking.  See PR libfortran/22298 for details.  */
  38 void
  39 stupid_function_name_for_static_linking (void)
  40 {
  41   return;
  42 }
  43
  44 /* This will be 0 for little-endian
  45    machines and 1 for big-endian machines.  */
  46 int big_endian = 0;
  47
  48
  49 /* Figure out endianness for this machine.  */
  50
  51 static void
  52 determine_endianness (void)
  53 {
  54   union
  55   {
  56     GFC_LOGICAL_8 l8;
  57     GFC_LOGICAL_4 l4[2];
  58   } u;
  59
  60   u.l8 = 1;
  61   if (u.l4[0])
  62     big_endian = 0;
  63   else if (u.l4[1])
  64     big_endian = 1;
  65   else
  66     runtime_error ("Unable to determine machine endianness");
  67 }
  68
  69
  70 static int argc_save;
  71 static char **argv_save;
  72
  73
  74 void
  75 store_exe_path (const char * argv0 __attribute__ ((unused)))
  76 {
  77   /* This function is now useless, but is retained due to ABI compatibility.
  78     Remove when bumping the library ABI.  */
  79   ;
  80 }
  81
  82
  83 /* Set the saved values of the command line arguments.  */
  84
  85 void
  86 set_args (int argc, char **argv)
  87 {
  88   argc_save = argc;
  89   argv_save = argv;
  90 }
  91 iexport(set_args);
  92
  93
  94 /* Retrieve the saved values of the command line arguments.  */
  95
  96 void
  97 get_args (int *argc, char ***argv)
  98 {
  99   *argc = argc_save;
 100   *argv = argv_save;
 101 }
 102
 103
 104 /* Initialize the runtime library.  */
 105
 106 static void __attribute__((constructor))
 107 init (void)
 108 {
 109   /* Figure out the machine endianness.  */
 110   determine_endianness ();
 111
 112   /* Must be first */
 113   init_variables ();
 114
 115   init_units ();
 116
 117   /* If (and only if) the user asked for it, set up the FPU state.  */
 118   if (options.fpe != 0)
 119     set_fpu ();
 120
 121   init_compile_options ();
 122
 123   random_seed_i4 (NULL, NULL, NULL);
 124 }
 125
 126
 127 /* Cleanup the runtime library.  */
 128
 129 static void __attribute__((destructor))
 130 cleanup (void)
 131 {
 132   close_units ();
 133 }