glib/gbacktrace.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 /*
  28  * MT safe ; except for g_on_error_stack_trace, but who wants thread safety
  29  * then
  30  */
  31
  32 #include "config.h"
  33 #include "glibconfig.h"
  34
  35 #include <signal.h>
  36 #include <stdarg.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39
  40 #ifdef HAVE_SYS_TIME_H
  41 #include <sys/time.h>
  42 #endif
  43 #ifdef HAVE_SYS_TIMES_H
  44 #include <sys/times.h>
  45 #endif
  46 #include <sys/types.h>
  47 #ifdef HAVE_SYS_WAIT_H
  48 #include <sys/wait.h>
  49 #endif
  50
  51 #include <time.h>
  52 #ifdef HAVE_UNISTD_H
  53 #include <unistd.h>
  54 #endif
  55
  56 #ifdef HAVE_SYS_SELECT_H
  57 #include <sys/select.h>
  58 #endif /* HAVE_SYS_SELECT_H */
  59
  60 #include <string.h> /* for bzero on BSD systems */
  61
  62 #ifdef G_OS_WIN32
  63 #  define STRICT                /* Strict typing, please */
  64 #  define _WIN32_WINDOWS 0x0401 /* to get IsDebuggerPresent */
  65 #  include <windows.h>
  66 #  undef STRICT
  67 #endif
  68
  69 #include "gbacktrace.h"
  70
  71 #include "gtypes.h"
  72 #include "gmain.h"
  73 #include "gprintfint.h"
  74 #include "gutils.h"
  75
  76
  77 #ifndef NO_FD_SET
  78 #  define SELECT_MASK fd_set
  79 #else
  80 #  if defined(_IBMR2)
  81 #    define SELECT_MASK void
  82 #  else
  83 #    define SELECT_MASK int
  84 #  endif
  85 #endif
  86
  87
  88 #ifndef G_OS_WIN32
  89 static void stack_trace (char **args);
  90 #endif
  91
  92 extern volatile gboolean glib_on_error_halt;
  93 volatile gboolean glib_on_error_halt = TRUE;
  94
  95 /**
  96  * g_on_error_query:
  97  * @prg_name: the program name, needed by <command>gdb</command>
  98  *     for the [S]tack trace option. If @prg_name is %NULL, g_get_prgname()
  99  *     is called to get the program name (which will work correctly if
 100  *     gdk_init() or gtk_init() has been called)
 101  *
 102  * Prompts the user with
 103  * <computeroutput>[E]xit, [H]alt, show [S]tack trace or [P]roceed</computeroutput>.
 104  * This function is intended to be used for debugging use only.
 105  * The following example shows how it can be used together with
 106  * the g_log() functions.
 107  *
 108  * |[
 109  * &num;include &lt;glib.h&gt;
 110  *
 111  * static void
 112  * log_handler (const gchar   *log_domain,
 113  *              GLogLevelFlags log_level,
 114  *              const gchar   *message,
 115  *              gpointer       user_data)
 116  * {
 117  *   g_log_default_handler (log_domain, log_level, message, user_data);
 118  *
 119  *   g_on_error_query (MY_PROGRAM_NAME);
 120  * }
 121  *
 122  * int
 123  * main (int argc, char *argv[])
 124  * {
 125  *   g_log_set_handler (MY_LOG_DOMAIN,
 126  *                      G_LOG_LEVEL_WARNING |
 127  *                      G_LOG_LEVEL_ERROR |
 128  *                      G_LOG_LEVEL_CRITICAL,
 129  *                      log_handler,
 130  *                      NULL);
 131  *   /&ast; ... &ast;/
 132  * ]|
 133  *
 134  * If [E]xit is selected, the application terminates with a call
 135  * to <literal>_exit(0)</literal>.
 136  *
 137  * If [S]tack trace is selected, g_on_error_stack_trace() is called.
 138  * This invokes <command>gdb</command>, which attaches to the current
 139  * process and shows a stack trace. The prompt is then shown again.
 140  *
 141  * If [P]roceed is selected, the function returns.
 142  *
 143  * This function may cause different actions on non-UNIX platforms.
 144  */
 145 void
 146 g_on_error_query (const gchar *prg_name)
 147 {
 148 #ifndef G_OS_WIN32
 149   static const gchar * const query1 = "[E]xit, [H]alt";
 150   static const gchar * const query2 = ", show [S]tack trace";
 151   static const gchar * const query3 = " or [P]roceed";
 152   gchar buf[16];
 153
 154   if (!prg_name)
 155     prg_name = g_get_prgname ();
 156
 157  retry:
 158
 159   if (prg_name)
 160     _g_fprintf (stdout,
 161                 "%s (pid:%u): %s%s%s: ",
 162                 prg_name,
 163                 (guint) getpid (),
 164                 query1,
 165                 query2,
 166                 query3);
 167   else
 168     _g_fprintf (stdout,
 169                 "(process:%u): %s%s: ",
 170                 (guint) getpid (),
 171                 query1,
 172                 query3);
 173   fflush (stdout);
 174
 175   if (isatty(0) && isatty(1))
 176     fgets (buf, 8, stdin);
 177   else
 178     strcpy (buf, "E\n");
 179
 180   if ((buf[0] == 'E' || buf[0] == 'e')
 181       && buf[1] == '\n')
 182     _exit (0);
 183   else if ((buf[0] == 'P' || buf[0] == 'p')
 184            && buf[1] == '\n')
 185     return;
 186   else if (prg_name
 187            && (buf[0] == 'S' || buf[0] == 's')
 188            && buf[1] == '\n')
 189     {
 190       g_on_error_stack_trace (prg_name);
 191       goto retry;
 192     }
 193   else if ((buf[0] == 'H' || buf[0] == 'h')
 194            && buf[1] == '\n')
 195     {
 196       while (glib_on_error_halt)
 197         ;
 198       glib_on_error_halt = TRUE;
 199       return;
 200     }
 201   else
 202     goto retry;
 203 #else
 204   if (!prg_name)
 205     prg_name = g_get_prgname ();
 206
 207   MessageBox (NULL, "g_on_error_query called, program terminating",
 208               (prg_name && *prg_name) ? prg_name : NULL,
 209               MB_OK|MB_ICONERROR);
 210   _exit(0);
 211 #endif
 212 }
 213
 214 /**
 215  * g_on_error_stack_trace:
 216  * @prg_name: the program name, needed by <command>gdb</command>
 217  *     for the [S]tack trace option.
 218  *
 219  * Invokes <command>gdb</command>, which attaches to the current
 220  * process and shows a stack trace. Called by g_on_error_query()
 221  * when the [S]tack trace option is selected. You can get the current
 222  * process's "program name" with g_get_prgname(), assuming that you
 223  * have called gtk_init() or gdk_init().
 224  *
 225  * This function may cause different actions on non-UNIX platforms.
 226  */
 227 void
 228 g_on_error_stack_trace (const gchar *prg_name)
 229 {
 230 #if defined(G_OS_UNIX) || defined(G_OS_BEOS)
 231   pid_t pid;
 232   gchar buf[16];
 233   gchar *args[4] = { "gdb", NULL, NULL, NULL };
 234   int status;
 235
 236   if (!prg_name)
 237     return;
 238
 239   _g_sprintf (buf, "%u", (guint) getpid ());
 240
 241   args[1] = (gchar*) prg_name;
 242   args[2] = buf;
 243
 244   pid = fork ();
 245   if (pid == 0)
 246     {
 247       stack_trace (args);
 248       _exit (0);
 249     }
 250   else if (pid == (pid_t) -1)
 251     {
 252       perror ("unable to fork gdb");
 253       return;
 254     }
 255
 256   waitpid (pid, &status, 0);
 257 #else
 258   if (IsDebuggerPresent ())
 259     G_BREAKPOINT ();
 260   else
 261     abort ();
 262 #endif
 263 }
 264
 265 #ifndef G_OS_WIN32
 266
 267 static gboolean stack_trace_done = FALSE;
 268
 269 static void
 270 stack_trace_sigchld (int signum)
 271 {
 272   stack_trace_done = TRUE;
 273 }
 274
 275 static void
 276 stack_trace (char **args)
 277 {
 278   pid_t pid;
 279   int in_fd[2];
 280   int out_fd[2];
 281   SELECT_MASK fdset;
 282   SELECT_MASK readset;
 283   struct timeval tv;
 284   int sel, idx, state;
 285   char buffer[256];
 286   char c;
 287
 288   stack_trace_done = FALSE;
 289   signal (SIGCHLD, stack_trace_sigchld);
 290
 291   if ((pipe (in_fd) == -1) || (pipe (out_fd) == -1))
 292     {
 293       perror ("unable to open pipe");
 294       _exit (0);
 295     }
 296
 297   pid = fork ();
 298   if (pid == 0)
 299     {
 300       close (0); dup (in_fd[0]);   /* set the stdin to the in pipe */
 301       close (1); dup (out_fd[1]);  /* set the stdout to the out pipe */
 302       close (2); dup (out_fd[1]);  /* set the stderr to the out pipe */
 303
 304       execvp (args[0], args);      /* exec gdb */
 305       perror ("exec failed");
 306       _exit (0);
 307     }
 308   else if (pid == (pid_t) -1)
 309     {
 310       perror ("unable to fork");
 311       _exit (0);
 312     }
 313
 314   FD_ZERO (&fdset);
 315   FD_SET (out_fd[0], &fdset);
 316
 317   write (in_fd[1], "backtrace\n", 10);
 318   write (in_fd[1], "p x = 0\n", 8);
 319   write (in_fd[1], "quit\n", 5);
 320
 321   idx = 0;
 322   state = 0;
 323
 324   while (1)
 325     {
 326       readset = fdset;
 327       tv.tv_sec = 1;
 328       tv.tv_usec = 0;
 329
 330       sel = select (FD_SETSIZE, &readset, NULL, NULL, &tv);
 331       if (sel == -1)
 332         break;
 333
 334       if ((sel > 0) && (FD_ISSET (out_fd[0], &readset)))
 335         {
 336           if (read (out_fd[0], &c, 1))
 337             {
 338               switch (state)
 339                 {
 340                 case 0:
 341                   if (c == '#')
 342                     {
 343                       state = 1;
 344                       idx = 0;
 345                       buffer[idx++] = c;
 346                     }
 347                   break;
 348                 case 1:
 349                   buffer[idx++] = c;
 350                   if ((c == '\n') || (c == '\r'))
 351                     {
 352                       buffer[idx] = 0;
 353                       _g_fprintf (stdout, "%s", buffer);
 354                       state = 0;
 355                       idx = 0;
 356                     }
 357                   break;
 358                 default:
 359                   break;
 360                 }
 361             }
 362         }
 363       else if (stack_trace_done)
 364         break;
 365     }
 366
 367   close (in_fd[0]);
 368   close (in_fd[1]);
 369   close (out_fd[0]);
 370   close (out_fd[1]);
 371   _exit (0);
 372 }
 373
 374 #endif /* !G_OS_WIN32 */