gcc/ada/ctrl_c.c

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                               C T R L _ C                                *
   6  *                                                                          *
   7  *                          C Implementation File                           *
   8  *                                                                          *
   9  *        Copyright (C) 2002-2008, Free Software Foundation, Inc.           *
  10  *                                                                          *
  11  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  12  * terms of the  GNU General Public License as published  by the Free Soft- *
  13  * ware  Foundation;  either version 2,  or (at your option) any later ver- *
  14  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
  15  * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License *
  17  * for  more details.  You should have  received  a copy of the GNU General *
  18  * Public License  distributed with GNAT;  see file COPYING.  If not, write *
  19  * to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, *
  20  * Boston, MA 02110-1301, USA.                                              *
  21  *                                                                          *
  22  * As a  special  exception,  if you  link  this file  with other  files to *
  23  * produce an executable,  this file does not by itself cause the resulting *
  24  * executable to be covered by the GNU General Public License. This except- *
  25  * ion does not  however invalidate  any other reasons  why the  executable *
  26  * file might be covered by the  GNU Public License.                        *
  27  *                                                                          *
  28  * GNAT was originally developed  by the GNAT team at  New York University. *
  29  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  30  *                                                                          *
  31  ****************************************************************************/
  32
  33 #ifdef IN_RTS
  34 #include "tconfig.h"
  35 #include "tsystem.h"
  36 #include <sys/stat.h>
  37 #else
  38 #include "config.h"
  39 #include "system.h"
  40 #endif
  41
  42 /* Services to intercept Ctrl-C */
  43
  44 /* __gnat_install_int_handler will install the specified handler.
  45    If called for the first time, it will also save the original handler */
  46 void __gnat_install_int_handler (void (*) (void));
  47
  48 /* __gnat_uninstall_int_handler will reinstall the original handler */
  49 void __gnat_uninstall_int_handler (void);
  50
  51 /* POSIX implementation */
  52
  53 #if (defined (__unix__) || defined (_AIX) || defined (__APPLE__)) \
  54  && !defined (__vxworks)
  55
  56 #include <signal.h>
  57
  58 void (*sigint_intercepted) (void) = 0;
  59
  60 struct sigaction original_act;
  61
  62 static void
  63 __gnat_int_handler (int sig __attribute__ ((unused)))
  64 {
  65   if (sigint_intercepted != 0)
  66     sigint_intercepted ();
  67 }
  68
  69 /* Install handler and save original handler. */
  70
  71 void
  72 __gnat_install_int_handler (void (*proc) (void))
  73 {
  74   struct sigaction act;
  75
  76   if (sigint_intercepted == 0)
  77     {
  78       act.sa_handler = __gnat_int_handler;
  79 #if defined (__Lynx__)
  80       /* LynxOS does not support SA_RESTART. */
  81       act.sa_flags = 0;
  82 #else
  83       act.sa_flags = SA_RESTART;
  84 #endif
  85       sigemptyset (&act.sa_mask);
  86       sigaction (SIGINT, &act, &original_act);
  87     }
  88
  89   sigint_intercepted = proc;
  90 }
  91
  92 /* Restore original handler */
  93
  94 void
  95 __gnat_uninstall_int_handler (void)
  96 {
  97  if (sigint_intercepted != 0)
  98    {
  99      sigaction (SIGINT, &original_act, 0);
 100      sigint_intercepted = 0;
 101    }
 102 }
 103
 104 /* Windows implementation */
 105
 106 #elif defined (__MINGW32__)
 107
 108 #include "mingw32.h"
 109 #include <windows.h>
 110
 111 void (*sigint_intercepted) (void) = NULL;
 112
 113 static BOOL WINAPI
 114 __gnat_int_handler  (DWORD dwCtrlType)
 115 {
 116   switch (dwCtrlType)
 117     {
 118     case CTRL_C_EVENT:
 119     case CTRL_BREAK_EVENT:
 120       if (sigint_intercepted != 0)
 121         {
 122           sigint_intercepted ();
 123           return TRUE;
 124         }
 125       break;
 126
 127     case CTRL_CLOSE_EVENT:
 128     case CTRL_LOGOFF_EVENT:
 129     case CTRL_SHUTDOWN_EVENT:
 130       break;
 131     }
 132
 133   return FALSE;
 134 }
 135
 136 void
 137 __gnat_install_int_handler (void (*proc) (void))
 138 {
 139   if (sigint_intercepted == NULL)
 140     SetConsoleCtrlHandler (__gnat_int_handler, TRUE);
 141
 142   sigint_intercepted = proc;
 143 }
 144
 145 void
 146 __gnat_uninstall_int_handler (void)
 147 {
 148   if (sigint_intercepted != NULL)
 149     SetConsoleCtrlHandler (__gnat_int_handler, FALSE);
 150
 151   sigint_intercepted = NULL;
 152 }
 153
 154 /* Default implementation: do nothing */
 155
 156 #else
 157
 158 void
 159 __gnat_install_int_handler (void (*proc) (void) __attribute__ ((unused)))
 160 {
 161 }
 162
 163 void
 164 __gnat_uninstall_int_handler (void)
 165 {
 166 }
 167 #endif