1  /* Handling of compile-time options that influence the library.
       2     Copyright (C) 2005-2023 Free Software Foundation, Inc.
       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 <signal.h>
      27  
      28  
      29  /* Useful compile-time options will be stored in here.  */
      30  compile_options_t compile_options;
      31  
      32  #ifndef LIBGFOR_MINIMAL
      33  static volatile sig_atomic_t fatal_error_in_progress = 0;
      34  
      35  
      36  /* Helper function for backtrace_handler to write information about the
      37     received signal to stderr before actually giving the backtrace.  */
      38  static void
      39  show_signal (int signum)
      40  {
      41    const char * name = NULL, * desc = NULL;
      42  
      43    switch (signum)
      44      {
      45  #if defined(SIGQUIT)
      46        case SIGQUIT:
      47  	name = "SIGQUIT";
      48  	desc = "Terminal quit signal";
      49  	break;
      50  #endif
      51  
      52        /* The following 4 signals are defined by C89.  */
      53        case SIGILL:
      54  	name = "SIGILL";
      55  	desc = "Illegal instruction";
      56  	break;
      57  
      58        case SIGABRT:
      59  	name = "SIGABRT";
      60  	desc = "Process abort signal";
      61  	break;
      62  
      63        case SIGFPE:
      64  	name = "SIGFPE";
      65  	desc = "Floating-point exception - erroneous arithmetic operation";
      66  	break;
      67  
      68        case SIGSEGV:
      69  	name = "SIGSEGV";
      70  	desc = "Segmentation fault - invalid memory reference";
      71  	break;
      72  
      73  #if defined(SIGBUS)
      74        case SIGBUS:
      75  	name = "SIGBUS";
      76  	desc = "Access to an undefined portion of a memory object";
      77  	break;
      78  #endif
      79  
      80  #if defined(SIGSYS)
      81        case SIGSYS:
      82  	name = "SIGSYS";
      83  	desc = "Bad system call";
      84  	break;
      85  #endif
      86  
      87  #if defined(SIGTRAP)
      88        case SIGTRAP:
      89  	name = "SIGTRAP";
      90  	desc = "Trace/breakpoint trap";
      91  	break;
      92  #endif
      93  
      94  #if defined(SIGXCPU)
      95        case SIGXCPU:
      96  	name = "SIGXCPU";
      97  	desc = "CPU time limit exceeded";
      98  	break;
      99  #endif
     100  
     101  #if defined(SIGXFSZ)
     102        case SIGXFSZ:
     103  	name = "SIGXFSZ";
     104  	desc = "File size limit exceeded";
     105  	break;
     106  #endif
     107      }
     108  
     109    if (name)
     110      st_printf ("\nProgram received signal %s: %s.\n", name, desc);
     111    else
     112      st_printf ("\nProgram received signal %d.\n", signum);
     113  }
     114  
     115  
     116  /* A signal handler to allow us to output a backtrace.  */
     117  void
     118  backtrace_handler (int signum)
     119  {
     120    /* Since this handler is established for more than one kind of signal, 
     121       it might still get invoked recursively by delivery of some other kind
     122       of signal.  Use a static variable to keep track of that. */
     123    if (fatal_error_in_progress)
     124      raise (signum);
     125    fatal_error_in_progress = 1;
     126  
     127    show_signal (signum);
     128    estr_write ("\nBacktrace for this error:\n");
     129    show_backtrace (true);
     130  
     131    /* Now reraise the signal.  We reactivate the signal's
     132       default handling, which is to terminate the process.
     133       We could just call exit or abort,
     134       but reraising the signal sets the return status
     135       from the process correctly. */
     136    signal (signum, SIG_DFL);
     137    raise (signum);
     138  }
     139  #endif
     140  
     141  /* Set the usual compile-time options.  */
     142  extern void set_options (int , int []);
     143  export_proto(set_options);
     144  
     145  void
     146  set_options (int num, int options[])
     147  {
     148    if (num >= 1)
     149      compile_options.warn_std = options[0];
     150    if (num >= 2)
     151      compile_options.allow_std = options[1];
     152    if (num >= 3)
     153      compile_options.pedantic = options[2];
     154    if (num >= 4)
     155      compile_options.backtrace = options[3];
     156    if (num >= 5)
     157      compile_options.sign_zero = options[4];
     158    if (num >= 6)
     159      compile_options.bounds_check = options[5];
     160    if (num >= 7)
     161      compile_options.fpe_summary = options[6];
     162  
     163  #ifndef LIBGFOR_MINIMAL
     164    /* If backtrace is required, we set signal handlers on the POSIX
     165       2001 signals with core action.  */
     166    if (compile_options.backtrace)
     167      {
     168  #if defined(SIGQUIT)
     169        signal (SIGQUIT, backtrace_handler);
     170  #endif
     171  
     172        /* The following 4 signals are defined by C89.  */
     173        signal (SIGILL, backtrace_handler);
     174        signal (SIGABRT, backtrace_handler);
     175        signal (SIGFPE, backtrace_handler);
     176        signal (SIGSEGV, backtrace_handler);
     177  
     178  #if defined(SIGBUS)
     179        signal (SIGBUS, backtrace_handler);
     180  #endif
     181  
     182  #if defined(SIGSYS)
     183        signal (SIGSYS, backtrace_handler);
     184  #endif
     185  
     186  #if defined(SIGTRAP)
     187        signal (SIGTRAP, backtrace_handler);
     188  #endif
     189  
     190  #if defined(SIGXCPU)
     191        signal (SIGXCPU, backtrace_handler);
     192  #endif
     193  
     194  #if defined(SIGXFSZ)
     195        signal (SIGXFSZ, backtrace_handler);
     196  #endif
     197      }
     198  #endif
     199  }
     200  
     201  
     202  /* Default values for the compile-time options.  Keep in sync with
     203     gcc/fortran/options.c (gfc_init_options).  */
     204  void
     205  init_compile_options (void)
     206  {
     207    compile_options.warn_std = GFC_STD_F95_DEL | GFC_STD_LEGACY;
     208    compile_options.allow_std = GFC_STD_F95_OBS | GFC_STD_F95_DEL
     209      | GFC_STD_F2003 | GFC_STD_F2008 | GFC_STD_F95 | GFC_STD_F77
     210      | GFC_STD_F2008_OBS | GFC_STD_GNU | GFC_STD_LEGACY;
     211    compile_options.pedantic = 0;
     212    compile_options.backtrace = 0;
     213    compile_options.sign_zero = 1;
     214    compile_options.fpe_summary = 0;
     215  }
     216  
     217  /* Function called by the front-end to tell us the
     218     default for unformatted data conversion.  */
     219  
     220  extern void set_convert (int);
     221  export_proto (set_convert);
     222  
     223  void
     224  set_convert (int conv)
     225  {
     226    compile_options.convert = conv;
     227  }
     228  
     229  extern void set_record_marker (int);
     230  export_proto (set_record_marker);
     231  
     232  
     233  void
     234  set_record_marker (int val)
     235  {
     236  
     237    switch(val)
     238      {
     239      case 4:
     240        compile_options.record_marker = sizeof (GFC_INTEGER_4);
     241        break;
     242  
     243      case 8:
     244        compile_options.record_marker = sizeof (GFC_INTEGER_8);
     245        break;
     246  
     247      default:
     248        runtime_error ("Invalid value for record marker");
     249        break;
     250      }
     251  }
     252  
     253  extern void set_max_subrecord_length (int);
     254  export_proto (set_max_subrecord_length);
     255  
     256  void set_max_subrecord_length(int val)
     257  {
     258    if (val > GFC_MAX_SUBRECORD_LENGTH || val < 1)
     259      {
     260        runtime_error ("Invalid value for maximum subrecord length");
     261        return;
     262      }
     263  
     264    compile_options.max_subrecord_length = val;
     265  }