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 /* People want to hit this from their debugger... */
  93 GLIB_AVAILABLE_IN_ALL volatile gboolean glib_on_error_halt;
  94 volatile gboolean glib_on_error_halt = TRUE;
  95
  96 /**
  97  * g_on_error_query:
  98  * @prg_name: the program name, needed by <command>gdb</command>
  99  *     for the [S]tack trace option. If @prg_name is %NULL, g_get_prgname()
 100  *     is called to get the program name (which will work correctly if
 101  *     gdk_init() or gtk_init() has been called)
 102  *
 103  * Prompts the user with
 104  * <computeroutput>[E]xit, [H]alt, show [S]tack trace or [P]roceed</computeroutput>.
 105  * This function is intended to be used for debugging use only.
 106  * The following example shows how it can be used together with
 107  * the g_log() functions.
 108  *
 109  * |[
 110  * &num;include &lt;glib.h&gt;
 111  *
 112  * static void
 113  * log_handler (const gchar   *log_domain,
 114  *              GLogLevelFlags log_level,
 115  *              const gchar   *message,
 116  *              gpointer       user_data)
 117  * {
 118  *   g_log_default_handler (log_domain, log_level, message, user_data);
 119  *
 120  *   g_on_error_query (MY_PROGRAM_NAME);
 121  * }
 122  *
 123  * int
 124  * main (int argc, char *argv[])
 125  * {
 126  *   g_log_set_handler (MY_LOG_DOMAIN,
 127  *                      G_LOG_LEVEL_WARNING |
 128  *                      G_LOG_LEVEL_ERROR |
 129  *                      G_LOG_LEVEL_CRITICAL,
 130  *                      log_handler,
 131  *                      NULL);
 132  *   /&ast; ... &ast;/
 133  * ]|
 134  *
 135  * If [E]xit is selected, the application terminates with a call
 136  * to <literal>_exit(0)</literal>.
 137  *
 138  * If [S]tack trace is selected, g_on_error_stack_trace() is called.
 139  * This invokes <command>gdb</command>, which attaches to the current
 140  * process and shows a stack trace. The prompt is then shown again.
 141  *
 142  * If [P]roceed is selected, the function returns.
 143  *
 144  * This function may cause different actions on non-UNIX platforms.
 145  */
 146 void
 147 g_on_error_query (const gchar *prg_name)
 148 {
 149 #ifndef G_OS_WIN32
 150   static const gchar * const query1 = "[E]xit, [H]alt";
 151   static const gchar * const query2 = ", show [S]tack trace";
 152   static const gchar * const query3 = " or [P]roceed";
 153   gchar buf[16];
 154
 155   if (!prg_name)
 156     prg_name = g_get_prgname ();
 157
 158  retry:
 159
 160   if (prg_name)
 161     _g_fprintf (stdout,
 162                 "%s (pid:%u): %s%s%s: ",
 163                 prg_name,
 164                 (guint) getpid (),
 165                 query1,
 166                 query2,
 167                 query3);
 168   else
 169     _g_fprintf (stdout,
 170                 "(process:%u): %s%s: ",
 171                 (guint) getpid (),
 172                 query1,
 173                 query3);
 174   fflush (stdout);
 175
 176   if (isatty(0) && isatty(1))
 177     fgets (buf, 8, stdin);
 178   else
 179     strcpy (buf, "E\n");
 180
 181   if ((buf[0] == 'E' || buf[0] == 'e')
 182       && buf[1] == '\n')
 183     _exit (0);
 184   else if ((buf[0] == 'P' || buf[0] == 'p')
 185            && buf[1] == '\n')
 186     return;
 187   else if (prg_name
 188            && (buf[0] == 'S' || buf[0] == 's')
 189            && buf[1] == '\n')
 190     {
 191       g_on_error_stack_trace (prg_name);
 192       goto retry;
 193     }
 194   else if ((buf[0] == 'H' || buf[0] == 'h')
 195            && buf[1] == '\n')
 196     {
 197       while (glib_on_error_halt)
 198         ;
 199       glib_on_error_halt = TRUE;
 200       return;
 201     }
 202   else
 203     goto retry;
 204 #else
 205   if (!prg_name)
 206     prg_name = g_get_prgname ();
 207
 208   MessageBox (NULL, "g_on_error_query called, program terminating",
 209               (prg_name && *prg_name) ? prg_name : NULL,
 210               MB_OK|MB_ICONERROR);
 211   _exit(0);
 212 #endif
 213 }
 214
 215 /**
 216  * g_on_error_stack_trace:
 217  * @prg_name: the program name, needed by <command>gdb</command>
 218  *     for the [S]tack trace option.
 219  *
 220  * Invokes <command>gdb</command>, which attaches to the current
 221  * process and shows a stack trace. Called by g_on_error_query()
 222  * when the [S]tack trace option is selected. You can get the current
 223  * process's "program name" with g_get_prgname(), assuming that you
 224  * have called gtk_init() or gdk_init().
 225  *
 226  * This function may cause different actions on non-UNIX platforms.
 227  */
 228 void
 229 g_on_error_stack_trace (const gchar *prg_name)
 230 {
 231 #if defined(G_OS_UNIX) || defined(G_OS_BEOS)
 232   pid_t pid;
 233   gchar buf[16];
 234   gchar *args[4] = { "gdb", NULL, NULL, NULL };
 235   int status;
 236
 237   if (!prg_name)
 238     return;
 239
 240   _g_sprintf (buf, "%u", (guint) getpid ());
 241
 242   args[1] = (gchar*) prg_name;
 243   args[2] = buf;
 244
 245   pid = fork ();
 246   if (pid == 0)
 247     {
 248       stack_trace (args);
 249       _exit (0);
 250     }
 251   else if (pid == (pid_t) -1)
 252     {
 253       perror ("unable to fork gdb");
 254       return;
 255     }
 256
 257   waitpid (pid, &status, 0);
 258 #else
 259   if (IsDebuggerPresent ())
 260     G_BREAKPOINT ();
 261   else
 262     abort ();
 263 #endif
 264 }
 265
 266 #ifndef G_OS_WIN32
 267
 268 static gboolean stack_trace_done = FALSE;
 269
 270 static void
 271 stack_trace_sigchld (int signum)
 272 {
 273   stack_trace_done = TRUE;
 274 }
 275
 276 static void
 277 stack_trace (char **args)
 278 {
 279   pid_t pid;
 280   int in_fd[2];
 281   int out_fd[2];
 282   SELECT_MASK fdset;
 283   SELECT_MASK readset;
 284   struct timeval tv;
 285   int sel, idx, state;
 286   char buffer[256];
 287   char c;
 288
 289   stack_trace_done = FALSE;
 290   signal (SIGCHLD, stack_trace_sigchld);
 291
 292   if ((pipe (in_fd) == -1) || (pipe (out_fd) == -1))
 293     {
 294       perror ("unable to open pipe");
 295       _exit (0);
 296     }
 297
 298   pid = fork ();
 299   if (pid == 0)
 300     {
 301       close (0); dup (in_fd[0]);   /* set the stdin to the in pipe */
 302       close (1); dup (out_fd[1]);  /* set the stdout to the out pipe */
 303       close (2); dup (out_fd[1]);  /* set the stderr to the out pipe */
 304
 305       execvp (args[0], args);      /* exec gdb */
 306       perror ("exec failed");
 307       _exit (0);
 308     }
 309   else if (pid == (pid_t) -1)
 310     {
 311       perror ("unable to fork");
 312       _exit (0);
 313     }
 314
 315   FD_ZERO (&fdset);
 316   FD_SET (out_fd[0], &fdset);
 317
 318   write (in_fd[1], "backtrace\n", 10);
 319   write (in_fd[1], "p x = 0\n", 8);
 320   write (in_fd[1], "quit\n", 5);
 321
 322   idx = 0;
 323   state = 0;
 324
 325   while (1)
 326     {
 327       readset = fdset;
 328       tv.tv_sec = 1;
 329       tv.tv_usec = 0;
 330
 331       sel = select (FD_SETSIZE, &readset, NULL, NULL, &tv);
 332       if (sel == -1)
 333         break;
 334
 335       if ((sel > 0) && (FD_ISSET (out_fd[0], &readset)))
 336         {
 337           if (read (out_fd[0], &c, 1))
 338             {
 339               switch (state)
 340                 {
 341                 case 0:
 342                   if (c == '#')
 343                     {
 344                       state = 1;
 345                       idx = 0;
 346                       buffer[idx++] = c;
 347                     }
 348                   break;
 349                 case 1:
 350                   buffer[idx++] = c;
 351                   if ((c == '\n') || (c == '\r'))
 352                     {
 353                       buffer[idx] = 0;
 354                       _g_fprintf (stdout, "%s", buffer);
 355                       state = 0;
 356                       idx = 0;
 357                     }
 358                   break;
 359                 default:
 360                   break;
 361                 }
 362             }
 363         }
 364       else if (stack_trace_done)
 365         break;
 366     }
 367
 368   close (in_fd[0]);
 369   close (in_fd[1]);
 370   close (out_fd[0]);
 371   close (out_fd[1]);
 372   _exit (0);
 373 }
 374
 375 #endif /* !G_OS_WIN32 */