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) 2002-2009, 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 3,  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.                                     *
  17  *                                                                          *
  18  * As a special exception under Section 7 of GPL version 3, you are granted *
  19  * additional permissions described in the GCC Runtime Library Exception,   *
  20  * version 3.1, as published by the Free Software Foundation.               *
  21  *                                                                          *
  22  * You should have received a copy of the GNU General Public License and    *
  23  * a copy of the GCC Runtime Library Exception along with this program;     *
  24  * see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    *
  25  * <http://www.gnu.org/licenses/>.                                          *
  26  *                                                                          *
  27  * GNAT was originally developed  by the GNAT team at  New York University. *
  28  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  29  *                                                                          *
  30  ****************************************************************************/
  31
  32 #ifdef IN_RTS
  33 #include "tconfig.h"
  34 #include "tsystem.h"
  35 #include <sys/stat.h>
  36 #else
  37 #include "config.h"
  38 #include "system.h"
  39 #endif
  40
  41 /* Services to intercept Ctrl-C */
  42
  43 /* __gnat_install_int_handler will install the specified handler.
  44    If called for the first time, it will also save the original handler */
  45 void __gnat_install_int_handler (void (*) (void));
  46
  47 /* __gnat_uninstall_int_handler will reinstall the original handler */
  48 void __gnat_uninstall_int_handler (void);
  49
  50 /* POSIX implementation */
  51
  52 #if (defined (__unix__) || defined (_AIX) || defined (__APPLE__)) \
  53  && !defined (__vxworks)
  54
  55 #include <signal.h>
  56
  57 void (*sigint_intercepted) (void) = 0;
  58
  59 struct sigaction original_act;
  60
  61 static void
  62 __gnat_int_handler (int sig __attribute__ ((unused)))
  63 {
  64   if (sigint_intercepted != 0)
  65     sigint_intercepted ();
  66 }
  67
  68 /* Install handler and save original handler. */
  69
  70 void
  71 __gnat_install_int_handler (void (*proc) (void))
  72 {
  73   struct sigaction act;
  74
  75   if (sigint_intercepted == 0)
  76     {
  77       act.sa_handler = __gnat_int_handler;
  78 #if defined (__Lynx__)
  79       /* LynxOS does not support SA_RESTART. */
  80       act.sa_flags = 0;
  81 #else
  82       act.sa_flags = SA_RESTART;
  83 #endif
  84       sigemptyset (&act.sa_mask);
  85       sigaction (SIGINT, &act, &original_act);
  86     }
  87
  88   sigint_intercepted = proc;
  89 }
  90
  91 /* Restore original handler */
  92
  93 void
  94 __gnat_uninstall_int_handler (void)
  95 {
  96  if (sigint_intercepted != 0)
  97    {
  98      sigaction (SIGINT, &original_act, 0);
  99      sigint_intercepted = 0;
 100    }
 101 }
 102
 103 /* Windows implementation */
 104
 105 #elif defined (__MINGW32__)
 106
 107 #include "mingw32.h"
 108 #include <windows.h>
 109
 110 void (*sigint_intercepted) (void) = NULL;
 111
 112 static BOOL WINAPI
 113 __gnat_int_handler  (DWORD dwCtrlType)
 114 {
 115   switch (dwCtrlType)
 116     {
 117     case CTRL_C_EVENT:
 118     case CTRL_BREAK_EVENT:
 119       if (sigint_intercepted != 0)
 120         {
 121           sigint_intercepted ();
 122           return TRUE;
 123         }
 124       break;
 125
 126     case CTRL_CLOSE_EVENT:
 127     case CTRL_LOGOFF_EVENT:
 128     case CTRL_SHUTDOWN_EVENT:
 129       break;
 130     }
 131
 132   return FALSE;
 133 }
 134
 135 void
 136 __gnat_install_int_handler (void (*proc) (void))
 137 {
 138   if (sigint_intercepted == NULL)
 139     SetConsoleCtrlHandler (__gnat_int_handler, TRUE);
 140
 141   sigint_intercepted = proc;
 142 }
 143
 144 void
 145 __gnat_uninstall_int_handler (void)
 146 {
 147   if (sigint_intercepted != NULL)
 148     SetConsoleCtrlHandler (__gnat_int_handler, FALSE);
 149
 150   sigint_intercepted = NULL;
 151 }
 152
 153 /* Default implementation: do nothing */
 154
 155 #else
 156
 157 void
 158 __gnat_install_int_handler (void (*proc) (void) __attribute__ ((unused)))
 159 {
 160 }
 161
 162 void
 163 __gnat_uninstall_int_handler (void)
 164 {
 165 }
 166 #endif