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 Library 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  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library 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  * MT safe ; except for g_on_error_stack_trace, but who wants thread safety
  22  * then
  23  */
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #include <signal.h>
  30 #include <stdarg.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include "glib.h"
  34 #ifdef HAVE_SYS_TIME_H
  35 #include <sys/time.h>
  36 #endif
  37 #ifdef HAVE_SYS_TIMES_H
  38 #include <sys/times.h>
  39 #endif
  40 #include <sys/types.h>
  41
  42 #include <time.h>
  43 #ifdef HAVE_UNISTD_H
  44 #include <unistd.h>
  45 #endif
  46
  47 #ifdef HAVE_SYS_SELECT_H
  48 #include <sys/select.h>
  49 #endif /* HAVE_SYS_SELECT_H */
  50
  51 #ifdef STDC_HEADERS
  52 #include <string.h> /* for bzero on BSD systems */
  53 #endif
  54
  55 #ifdef _MSC_VER
  56 #include <process.h>            /* For _getpid() */
  57 #endif
  58
  59 #ifndef NO_FD_SET
  60 #  define SELECT_MASK fd_set
  61 #else
  62 #  ifndef _AIX
  63      typedef long fd_mask;
  64 #  endif
  65 #  if defined(_IBMR2)
  66 #    define SELECT_MASK void
  67 #  else
  68 #    define SELECT_MASK int
  69 #  endif
  70 #endif
  71
  72
  73 static void stack_trace (char **args);
  74
  75 extern volatile gboolean glib_on_error_halt;
  76 volatile gboolean glib_on_error_halt = TRUE;
  77
  78 void
  79 g_on_error_query (const gchar *prg_name)
  80 {
  81   static const gchar *query1 = "[E]xit, [H]alt";
  82   static const gchar *query2 = ", show [S]tack trace";
  83   static const gchar *query3 = " or [P]roceed";
  84   gchar buf[16];
  85
  86   if (!prg_name)
  87     prg_name = g_get_prgname ();
  88
  89  retry:
  90
  91   if (prg_name)
  92     fprintf (stdout,
  93              "%s (pid:%u): %s%s%s: ",
  94              prg_name,
  95              (guint) getpid (),
  96              query1,
  97              query2,
  98              query3);
  99   else
 100     fprintf (stdout,
 101              "(process:%u): %s%s: ",
 102              (guint) getpid (),
 103              query1,
 104              query3);
 105   fflush (stdout);
 106
 107   fgets (buf, 8, stdin);
 108
 109   if ((buf[0] == 'E' || buf[0] == 'e')
 110       && buf[1] == '\n')
 111     _exit (0);
 112   else if ((buf[0] == 'P' || buf[0] == 'p')
 113            && buf[1] == '\n')
 114     return;
 115   else if (prg_name
 116            && (buf[0] == 'S' || buf[0] == 's')
 117            && buf[1] == '\n')
 118     {
 119       g_on_error_stack_trace (prg_name);
 120       goto retry;
 121     }
 122   else if ((buf[0] == 'H' || buf[0] == 'h')
 123            && buf[1] == '\n')
 124     {
 125       while (glib_on_error_halt)
 126         ;
 127       glib_on_error_halt = TRUE;
 128       return;
 129     }
 130   else
 131     goto retry;
 132 }
 133
 134 void
 135 g_on_error_stack_trace (const gchar *prg_name)
 136 {
 137 #ifndef NATIVE_WIN32
 138   pid_t pid;
 139   gchar buf[16];
 140   gchar *args[4] = { "gdb", NULL, NULL, NULL };
 141
 142   if (!prg_name)
 143     return;
 144
 145   sprintf (buf, "%u", (guint) getpid ());
 146
 147   args[1] = (gchar*) prg_name;
 148   args[2] = buf;
 149
 150   pid = fork ();
 151   if (pid == 0)
 152     {
 153       stack_trace (args);
 154       _exit (0);
 155     }
 156   else if (pid == (pid_t) -1)
 157     {
 158       perror ("unable to fork gdb");
 159       return;
 160     }
 161
 162   while (glib_on_error_halt)
 163     ;
 164   glib_on_error_halt = TRUE;
 165 #else
 166   abort ();
 167 #endif
 168 }
 169
 170 static gboolean stack_trace_done = FALSE;
 171
 172 static void
 173 stack_trace_sigchld (int signum)
 174 {
 175   stack_trace_done = TRUE;
 176 }
 177
 178 static void
 179 stack_trace (char **args)
 180 {
 181 #ifndef NATIVE_WIN32
 182   pid_t pid;
 183   int in_fd[2];
 184   int out_fd[2];
 185   SELECT_MASK fdset;
 186   SELECT_MASK readset;
 187   struct timeval tv;
 188   int sel, index, state;
 189   char buffer[256];
 190   char c;
 191
 192   stack_trace_done = FALSE;
 193   signal (SIGCHLD, stack_trace_sigchld);
 194
 195   if ((pipe (in_fd) == -1) || (pipe (out_fd) == -1))
 196     {
 197       perror ("unable to open pipe");
 198       _exit (0);
 199     }
 200
 201   pid = fork ();
 202   if (pid == 0)
 203     {
 204       close (0); dup (in_fd[0]);   /* set the stdin to the in pipe */
 205       close (1); dup (out_fd[1]);  /* set the stdout to the out pipe */
 206       close (2); dup (out_fd[1]);  /* set the stderr to the out pipe */
 207
 208       execvp (args[0], args);      /* exec gdb */
 209       perror ("exec failed");
 210       _exit (0);
 211     }
 212   else if (pid == (pid_t) -1)
 213     {
 214       perror ("unable to fork");
 215       _exit (0);
 216     }
 217
 218   FD_ZERO (&fdset);
 219   FD_SET (out_fd[0], &fdset);
 220
 221   write (in_fd[1], "backtrace\n", 10);
 222   write (in_fd[1], "p x = 0\n", 8);
 223   write (in_fd[1], "quit\n", 5);
 224
 225   index = 0;
 226   state = 0;
 227
 228   while (1)
 229     {
 230       readset = fdset;
 231       tv.tv_sec = 1;
 232       tv.tv_usec = 0;
 233
 234       sel = select (FD_SETSIZE, &readset, NULL, NULL, &tv);
 235       if (sel == -1)
 236         break;
 237
 238       if ((sel > 0) && (FD_ISSET (out_fd[0], &readset)))
 239         {
 240           if (read (out_fd[0], &c, 1))
 241             {
 242               switch (state)
 243                 {
 244                 case 0:
 245                   if (c == '#')
 246                     {
 247                       state = 1;
 248                       index = 0;
 249                       buffer[index++] = c;
 250                     }
 251                   break;
 252                 case 1:
 253                   buffer[index++] = c;
 254                   if ((c == '\n') || (c == '\r'))
 255                     {
 256                       buffer[index] = 0;
 257                       fprintf (stdout, "%s", buffer);
 258                       state = 0;
 259                       index = 0;
 260                     }
 261                   break;
 262                 default:
 263                   break;
 264                 }
 265             }
 266         }
 267       else if (stack_trace_done)
 268         break;
 269     }
 270
 271   close (in_fd[0]);
 272   close (in_fd[1]);
 273   close (out_fd[0]);
 274   close (out_fd[1]);
 275   _exit (0);
 276 #else
 277   abort ();
 278 #endif
 279 }