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/tmp/gdb-7.10/gdb/event-top.c
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1 /* Top level stuff for GDB, the GNU debugger.
2 
3  Copyright (C) 1999-2015 Free Software Foundation, Inc.
4 
5  Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
6 
7  This file is part of GDB.
8 
9  This program is free software; you can redistribute it and/or modify
10  it under the terms of the GNU General Public License as published by
11  the Free Software Foundation; either version 3 of the License, or
12  (at your option) any later version.
13 
14  This program is distributed in the hope that it will be useful,
15  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  GNU General Public License for more details.
18 
19  You should have received a copy of the GNU General Public License
20  along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 
22 #include "defs.h"
23 #include "top.h"
24 #include "inferior.h"
25 #include "infrun.h"
26 #include "target.h"
27 #include "terminal.h" /* for job_control */
28 #include "event-loop.h"
29 #include "event-top.h"
30 #include "interps.h"
31 #include <signal.h>
32 #include "cli/cli-script.h" /* for reset_command_nest_depth */
33 #include "main.h"
34 #include "gdbthread.h"
35 #include "observer.h"
36 #include "continuations.h"
37 #include "gdbcmd.h" /* for dont_repeat() */
38 #include "annotate.h"
39 #include "maint.h"
40 
41 /* readline include files. */
42 #include "readline/readline.h"
43 #include "readline/history.h"
44 
45 /* readline defines this. */
46 #undef savestring
47 
48 static void rl_callback_read_char_wrapper (gdb_client_data client_data);
49 static void command_line_handler (char *rl);
50 static void change_line_handler (void);
51 static void command_handler (char *command);
52 static char *top_level_prompt (void);
53 
54 /* Signal handlers. */
55 #ifdef SIGQUIT
56 static void handle_sigquit (int sig);
57 #endif
58 #ifdef SIGHUP
59 static void handle_sighup (int sig);
60 #endif
61 static void handle_sigfpe (int sig);
62 
63 /* Functions to be invoked by the event loop in response to
64  signals. */
65 #if defined (SIGQUIT) || defined (SIGHUP)
66 static void async_do_nothing (gdb_client_data);
67 #endif
68 #ifdef SIGHUP
69 static void async_disconnect (gdb_client_data);
70 #endif
72 #ifdef STOP_SIGNAL
73 static void async_stop_sig (gdb_client_data);
74 #endif
76 
77 /* Readline offers an alternate interface, via callback
78  functions. These are all included in the file callback.c in the
79  readline distribution. This file provides (mainly) a function, which
80  the event loop uses as callback (i.e. event handler) whenever an event
81  is detected on the standard input file descriptor.
82  readline_callback_read_char is called (by the GDB event loop) whenever
83  there is a new character ready on the input stream. This function
84  incrementally builds a buffer internal to readline where it
85  accumulates the line read up to the point of invocation. In the
86  special case in which the character read is newline, the function
87  invokes a GDB supplied callback routine, which does the processing of
88  a full command line. This latter routine is the asynchronous analog
89  of the old command_line_input in gdb. Instead of invoking (and waiting
90  for) readline to read the command line and pass it back to
91  command_loop for processing, the new command_line_handler function has
92  the command line already available as its parameter. INPUT_HANDLER is
93  to be set to the function that readline will invoke when a complete
94  line of input is ready. CALL_READLINE is to be set to the function
95  that readline offers as callback to the event_loop. */
96 
97 void (*input_handler) (char *);
99 
100 /* Important variables for the event loop. */
101 
102 /* This is used to determine if GDB is using the readline library or
103  its own simplified form of readline. It is used by the asynchronous
104  form of the set editing command.
105  ezannoni: as of 1999-04-29 I expect that this
106  variable will not be used after gdb is changed to use the event
107  loop as default engine, and event-top.c is merged into top.c. */
109 
110 /* This is the annotation suffix that will be used when the
111  annotation_level is 2. */
113 
114 /* This is used to display the notification of the completion of an
115  asynchronous execution command. */
117 
118 /* This is the file descriptor for the input stream that GDB uses to
119  read commands from. */
121 
122 /* Used by the stdin event handler to compensate for missed stdin events.
123  Setting this to a non-zero value inside an stdin callback makes the callback
124  run again. */
126 
127 /* Signal handling variables. */
128 /* Each of these is a pointer to a function that the event loop will
129  invoke if the corresponding signal has received. The real signal
130  handlers mark these functions as ready to be executed and the event
131  loop, in a later iteration, calls them. See the function
132  invoke_async_signal_handler. */
134 #ifdef SIGHUP
135 static struct async_signal_handler *sighup_token;
136 #endif
137 #ifdef SIGQUIT
138 static struct async_signal_handler *sigquit_token;
139 #endif
141 #ifdef STOP_SIGNAL
142 static struct async_signal_handler *sigtstp_token;
143 #endif
145 
146 /* Structure to save a partially entered command. This is used when
147  the user types '\' at the end of a command line. This is necessary
148  because each line of input is handled by a different call to
149  command_line_handler, and normally there is no state retained
150  between different calls. */
151 static int more_to_come = 0;
152 
154  {
155  char *linebuffer;
157  }
159 
160 /* This hook is called by rl_callback_read_char_wrapper after each
161  character is processed. */
163 
164 
165 /* Wrapper function for calling into the readline library. The event
166  loop expects the callback function to have a paramter, while
167  readline expects none. */
168 static void
170 {
171  rl_callback_read_char ();
173  (*after_char_processing_hook) ();
174 }
175 
176 /* Initialize all the necessary variables, start the event loop,
177  register readline, and stdin, start the loop. The DATA is the
178  interpreter data cookie, ignored for now. */
179 
180 void
181 cli_command_loop (void *data)
182 {
183  display_gdb_prompt (0);
184 
185  /* Now it's time to start the event loop. */
186  start_event_loop ();
187 }
188 
189 /* Change the function to be invoked every time there is a character
190  ready on stdin. This is used when the user sets the editing off,
191  therefore bypassing readline, and letting gdb handle the input
192  itself, via gdb_readline2. Also it is used in the opposite case in
193  which the user sets editing on again, by restoring readline
194  handling of the input. */
195 static void
197 {
198  /* NOTE: this operates on input_fd, not instream. If we are reading
199  commands from a file, instream will point to the file. However in
200  async mode, we always read commands from a file with editing
201  off. This means that the 'set editing on/off' will have effect
202  only on the interactive session. */
203 
205  {
206  /* Turn on editing by using readline. */
209  }
210  else
211  {
212  /* Turn off editing by using gdb_readline2. */
215 
216  /* Set up the command handler as well, in case we are called as
217  first thing from .gdbinit. */
219  }
220 }
221 
222 /* The functions below are wrappers for rl_callback_handler_remove and
223  rl_callback_handler_install that keep track of whether the callback
224  handler is installed in readline. This is necessary because after
225  handling a target event of a background execution command, we may
226  need to reinstall the callback handler if it was removed due to a
227  secondary prompt. See gdb_readline_wrapper_line. We don't
228  unconditionally install the handler for every target event because
229  that also clears the line buffer, thus installing it while the user
230  is typing would lose input. */
231 
232 /* Whether we've registered a callback handler with readline. */
234 
235 /* See event-top.h, and above. */
236 
237 void
239 {
240  rl_callback_handler_remove ();
242 }
243 
244 /* See event-top.h, and above. Note this wrapper doesn't have an
245  actual callback parameter because we always install
246  INPUT_HANDLER. */
247 
248 void
250 {
251  /* Calling rl_callback_handler_install resets readline's input
252  buffer. Calling this when we were already processing input
253  therefore loses input. */
255 
256  rl_callback_handler_install (prompt, input_handler);
258 }
259 
260 /* See event-top.h, and above. */
261 
262 void
264 {
266  {
267  /* Passing NULL as prompt argument tells readline to not display
268  a prompt. */
270  }
271 }
272 
273 /* Displays the prompt. If the argument NEW_PROMPT is NULL, the
274  prompt that is displayed is the current top level prompt.
275  Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
276  prompt.
277 
278  This is used after each gdb command has completed, and in the
279  following cases:
280 
281  1. When the user enters a command line which is ended by '\'
282  indicating that the command will continue on the next line. In
283  that case the prompt that is displayed is the empty string.
284 
285  2. When the user is entering 'commands' for a breakpoint, or
286  actions for a tracepoint. In this case the prompt will be '>'
287 
288  3. On prompting for pagination. */
289 
290 void
291 display_gdb_prompt (const char *new_prompt)
292 {
293  char *actual_gdb_prompt = NULL;
294  struct cleanup *old_chain;
295 
297 
298  /* Reset the nesting depth used when trace-commands is set. */
300 
301  old_chain = make_cleanup (free_current_contents, &actual_gdb_prompt);
302 
303  /* Do not call the python hook on an explicit prompt change as
304  passed to this function, as this forms a secondary/local prompt,
305  IE, displayed but not set. */
306  if (! new_prompt)
307  {
308  if (sync_execution)
309  {
310  /* This is to trick readline into not trying to display the
311  prompt. Even though we display the prompt using this
312  function, readline still tries to do its own display if
313  we don't call rl_callback_handler_install and
314  rl_callback_handler_remove (which readline detects
315  because a global variable is not set). If readline did
316  that, it could mess up gdb signal handlers for SIGINT.
317  Readline assumes that between calls to rl_set_signals and
318  rl_clear_signals gdb doesn't do anything with the signal
319  handlers. Well, that's not the case, because when the
320  target executes we change the SIGINT signal handler. If
321  we allowed readline to display the prompt, the signal
322  handler change would happen exactly between the calls to
323  the above two functions. Calling
324  rl_callback_handler_remove(), does the job. */
325 
327  do_cleanups (old_chain);
328  return;
329  }
330  else
331  {
332  /* Display the top level prompt. */
333  actual_gdb_prompt = top_level_prompt ();
334  }
335  }
336  else
337  actual_gdb_prompt = xstrdup (new_prompt);
338 
340  {
342  gdb_rl_callback_handler_install (actual_gdb_prompt);
343  }
344  /* new_prompt at this point can be the top of the stack or the one
345  passed in. It can't be NULL. */
346  else
347  {
348  /* Don't use a _filtered function here. It causes the assumed
349  character position to be off, since the newline we read from
350  the user is not accounted for. */
351  fputs_unfiltered (actual_gdb_prompt, gdb_stdout);
353  }
354 
355  do_cleanups (old_chain);
356 }
357 
358 /* Return the top level prompt, as specified by "set prompt", possibly
359  overriden by the python gdb.prompt_hook hook, and then composed
360  with the prompt prefix and suffix (annotations). The caller is
361  responsible for freeing the returned string. */
362 
363 static char *
365 {
366  char *prefix;
367  char *prompt = NULL;
368  char *suffix;
369  char *composed_prompt;
370  size_t prompt_length;
371 
372  /* Give observers a chance of changing the prompt. E.g., the python
373  `gdb.prompt_hook' is installed as an observer. */
375 
376  prompt = xstrdup (get_prompt ());
377 
378  if (annotation_level >= 2)
379  {
380  /* Prefix needs to have new line at end. */
381  prefix = (char *) alloca (strlen (async_annotation_suffix) + 10);
382  strcpy (prefix, "\n\032\032pre-");
383  strcat (prefix, async_annotation_suffix);
384  strcat (prefix, "\n");
385 
386  /* Suffix needs to have a new line at end and \032 \032 at
387  beginning. */
388  suffix = (char *) alloca (strlen (async_annotation_suffix) + 6);
389  strcpy (suffix, "\n\032\032");
390  strcat (suffix, async_annotation_suffix);
391  strcat (suffix, "\n");
392  }
393  else
394  {
395  prefix = "";
396  suffix = "";
397  }
398 
399  prompt_length = strlen (prefix) + strlen (prompt) + strlen (suffix);
400  composed_prompt = xmalloc (prompt_length + 1);
401 
402  strcpy (composed_prompt, prefix);
403  strcat (composed_prompt, prompt);
404  strcat (composed_prompt, suffix);
405 
406  xfree (prompt);
407 
408  return composed_prompt;
409 }
410 
411 /* When there is an event ready on the stdin file desriptor, instead
412  of calling readline directly throught the callback function, or
413  instead of calling gdb_readline2, give gdb a chance to detect
414  errors and do something. */
415 void
417 {
418  if (error)
419  {
420  printf_unfiltered (_("error detected on stdin\n"));
424  /* If stdin died, we may as well kill gdb. */
425  quit_command ((char *) 0, stdin == instream);
426  }
427  else
428  {
429  do
430  {
432  (*call_readline) (client_data);
433  } while (call_stdin_event_handler_again_p != 0);
434  }
435 }
436 
437 /* Re-enable stdin after the end of an execution command in
438  synchronous mode, or after an error from the target, and we aborted
439  the exec operation. */
440 
441 void
443 {
444  if (sync_execution)
445  {
446  /* See NOTE in async_disable_stdin(). */
447  /* FIXME: cagney/1999-09-27: Call this before clearing
448  sync_execution. Current target_terminal_ours() implementations
449  check for sync_execution before switching the terminal. */
451  sync_execution = 0;
452  }
453 }
454 
455 /* Disable reads from stdin (the console) marking the command as
456  synchronous. */
457 
458 void
460 {
461  sync_execution = 1;
462 }
463 
464 
465 /* Handles a gdb command. This function is called by
466  command_line_handler, which has processed one or more input lines
467  into COMMAND. */
468 /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop
469  function. The command_loop function will be obsolete when we
470  switch to use the event loop at every execution of gdb. */
471 static void
472 command_handler (char *command)
473 {
474  int stdin_is_tty = ISATTY (stdin);
475  struct cleanup *stat_chain;
476 
477  clear_quit_flag ();
478  if (instream == stdin && stdin_is_tty)
480 
481  /* If readline returned a NULL command, it means that the connection
482  with the terminal is gone. This happens at the end of a
483  testsuite run, after Expect has hung up but GDB is still alive.
484  In such a case, we just quit gdb killing the inferior program
485  too. */
486  if (command == 0)
487  {
488  printf_unfiltered ("quit\n");
489  execute_command ("quit", stdin == instream);
490  }
491 
492  stat_chain = make_command_stats_cleanup (1);
493 
494  execute_command (command, instream == stdin);
495 
496  /* Do any commands attached to breakpoint we stopped at. */
498 
499  do_cleanups (stat_chain);
500 }
501 
502 /* Handle a complete line of input. This is called by the callback
503  mechanism within the readline library. Deal with incomplete
504  commands as well, by saving the partial input in a global
505  buffer. */
506 
507 /* NOTE: 1999-04-30 This is the asynchronous version of the
508  command_line_input function; command_line_input will become
509  obsolete once we use the event loop as the default mechanism in
510  GDB. */
511 static void
513 {
514  static char *linebuffer = 0;
515  static unsigned linelength = 0;
516  char *p;
517  char *p1;
518  char *nline;
519  int repeat = (instream == stdin);
520 
521  if (annotation_level > 1 && instream == stdin)
522  {
523  printf_unfiltered (("\n\032\032post-"));
525  printf_unfiltered (("\n"));
526  }
527 
528  if (linebuffer == 0)
529  {
530  linelength = 80;
531  linebuffer = (char *) xmalloc (linelength);
532  linebuffer[0] = '\0';
533  }
534 
535  p = linebuffer;
536 
537  if (more_to_come)
538  {
539  strcpy (linebuffer, readline_input_state.linebuffer);
542  more_to_come = 0;
543  }
544 
545 #ifdef STOP_SIGNAL
546  if (job_control)
547  signal (STOP_SIGNAL, handle_stop_sig);
548 #endif
549 
550  /* Make sure that all output has been output. Some machines may let
551  you get away with leaving out some of the gdb_flush, but not
552  all. */
553  wrap_here ("");
556 
557  if (source_file_name != NULL)
559 
560  /* If we are in this case, then command_handler will call quit
561  and exit from gdb. */
562  if (!rl || rl == (char *) EOF)
563  {
564  command_handler (0);
565  return; /* Lint. */
566  }
567  if (strlen (rl) + 1 + (p - linebuffer) > linelength)
568  {
569  linelength = strlen (rl) + 1 + (p - linebuffer);
570  nline = (char *) xrealloc (linebuffer, linelength);
571  p += nline - linebuffer;
572  linebuffer = nline;
573  }
574  p1 = rl;
575  /* Copy line. Don't copy null at end. (Leaves line alone
576  if this was just a newline). */
577  while (*p1)
578  *p++ = *p1++;
579 
580  xfree (rl); /* Allocated in readline. */
581 
582  if (p > linebuffer && *(p - 1) == '\\')
583  {
584  *p = '\0';
585  p--; /* Put on top of '\'. */
586 
587  readline_input_state.linebuffer = xstrdup (linebuffer);
589 
590  /* We will not invoke a execute_command if there is more
591  input expected to complete the command. So, we need to
592  print an empty prompt here. */
593  more_to_come = 1;
594  display_gdb_prompt ("");
595  return;
596  }
597 
598 #ifdef STOP_SIGNAL
599  if (job_control)
600  signal (STOP_SIGNAL, SIG_DFL);
601 #endif
602 
603 #define SERVER_COMMAND_LENGTH 7
605  (p - linebuffer > SERVER_COMMAND_LENGTH)
606  && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0;
607  if (server_command)
608  {
609  /* Note that we don't set `line'. Between this and the check in
610  dont_repeat, this insures that repeating will still do the
611  right thing. */
612  *p = '\0';
613  command_handler (linebuffer + SERVER_COMMAND_LENGTH);
614  display_gdb_prompt (0);
615  return;
616  }
617 
618  /* Do history expansion if that is wished. */
619  if (history_expansion_p && instream == stdin
620  && ISATTY (instream))
621  {
622  char *history_value;
623  int expanded;
624 
625  *p = '\0'; /* Insert null now. */
626  expanded = history_expand (linebuffer, &history_value);
627  if (expanded)
628  {
629  /* Print the changes. */
630  printf_unfiltered ("%s\n", history_value);
631 
632  /* If there was an error, call this function again. */
633  if (expanded < 0)
634  {
635  xfree (history_value);
636  return;
637  }
638  if (strlen (history_value) > linelength)
639  {
640  linelength = strlen (history_value) + 1;
641  linebuffer = (char *) xrealloc (linebuffer, linelength);
642  }
643  strcpy (linebuffer, history_value);
644  p = linebuffer + strlen (linebuffer);
645  }
646  xfree (history_value);
647  }
648 
649  /* If we just got an empty line, and that is supposed to repeat the
650  previous command, return the value in the global buffer. */
651  if (repeat && p == linebuffer && *p != '\\')
652  {
654  display_gdb_prompt (0);
655  return;
656  }
657 
658  for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++);
659  if (repeat && !*p1)
660  {
662  display_gdb_prompt (0);
663  return;
664  }
665 
666  *p = 0;
667 
668  /* Add line to history if appropriate. */
669  if (*linebuffer && input_from_terminal_p ())
670  gdb_add_history (linebuffer);
671 
672  /* Note: lines consisting solely of comments are added to the command
673  history. This is useful when you type a command, and then
674  realize you don't want to execute it quite yet. You can comment
675  out the command and then later fetch it from the value history
676  and remove the '#'. The kill ring is probably better, but some
677  people are in the habit of commenting things out. */
678  if (*p1 == '#')
679  *p1 = '\0'; /* Found a comment. */
680 
681  /* Save into global buffer if appropriate. */
682  if (repeat)
683  {
684  if (linelength > saved_command_line_size)
685  {
687  saved_command_line_size = linelength;
688  }
689  strcpy (saved_command_line, linebuffer);
690  if (!more_to_come)
691  {
693  display_gdb_prompt (0);
694  }
695  return;
696  }
697 
698  command_handler (linebuffer);
699  display_gdb_prompt (0);
700  return;
701 }
702 
703 /* Does reading of input from terminal w/o the editing features
704  provided by the readline library. */
705 
706 /* NOTE: 1999-04-30 Asynchronous version of gdb_readline; gdb_readline
707  will become obsolete when the event loop is made the default
708  execution for gdb. */
709 void
711 {
712  int c;
713  char *result;
714  int input_index = 0;
715  int result_size = 80;
716  static int done_once = 0;
717 
718  /* Unbuffer the input stream, so that, later on, the calls to fgetc
719  fetch only one char at the time from the stream. The fgetc's will
720  get up to the first newline, but there may be more chars in the
721  stream after '\n'. If we buffer the input and fgetc drains the
722  stream, getting stuff beyond the newline as well, a select, done
723  afterwards will not trigger. */
724  if (!done_once && !ISATTY (instream))
725  {
726  setbuf (instream, NULL);
727  done_once = 1;
728  }
729 
730  result = (char *) xmalloc (result_size);
731 
732  /* We still need the while loop here, even though it would seem
733  obvious to invoke gdb_readline2 at every character entered. If
734  not using the readline library, the terminal is in cooked mode,
735  which sends the characters all at once. Poll will notice that the
736  input fd has changed state only after enter is pressed. At this
737  point we still need to fetch all the chars entered. */
738 
739  while (1)
740  {
741  /* Read from stdin if we are executing a user defined command.
742  This is the right thing for prompt_for_continue, at least. */
743  c = fgetc (instream ? instream : stdin);
744 
745  if (c == EOF)
746  {
747  if (input_index > 0)
748  /* The last line does not end with a newline. Return it,
749  and if we are called again fgetc will still return EOF
750  and we'll return NULL then. */
751  break;
752  xfree (result);
753  (*input_handler) (0);
754  return;
755  }
756 
757  if (c == '\n')
758  {
759  if (input_index > 0 && result[input_index - 1] == '\r')
760  input_index--;
761  break;
762  }
763 
764  result[input_index++] = c;
765  while (input_index >= result_size)
766  {
767  result_size *= 2;
768  result = (char *) xrealloc (result, result_size);
769  }
770  }
771 
772  result[input_index++] = '\0';
773  (*input_handler) (result);
774 }
775 
776 
777 /* Initialization of signal handlers and tokens. There is a function
778  handle_sig* for each of the signals GDB cares about. Specifically:
779  SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
780  functions are the actual signal handlers associated to the signals
781  via calls to signal(). The only job for these functions is to
782  enqueue the appropriate event/procedure with the event loop. Such
783  procedures are the old signal handlers. The event loop will take
784  care of invoking the queued procedures to perform the usual tasks
785  associated with the reception of the signal. */
786 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
787  init_signals will become obsolete as we move to have to event loop
788  as the default for gdb. */
789 void
791 {
792  signal (SIGINT, handle_sigint);
793  sigint_token =
795  signal (SIGTERM, handle_sigterm);
796  async_sigterm_token
798 
799  /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
800  to the inferior and breakpoints will be ignored. */
801 #ifdef SIGTRAP
802  signal (SIGTRAP, SIG_DFL);
803 #endif
804 
805 #ifdef SIGQUIT
806  /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
807  passed to the inferior, which we don't want. It would be
808  possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
809  on BSD4.3 systems using vfork, that can affect the
810  GDB process as well as the inferior (the signal handling tables
811  might be in memory, shared between the two). Since we establish
812  a handler for SIGQUIT, when we call exec it will set the signal
813  to SIG_DFL for us. */
814  signal (SIGQUIT, handle_sigquit);
815  sigquit_token =
816  create_async_signal_handler (async_do_nothing, NULL);
817 #endif
818 #ifdef SIGHUP
819  if (signal (SIGHUP, handle_sighup) != SIG_IGN)
820  sighup_token =
821  create_async_signal_handler (async_disconnect, NULL);
822  else
823  sighup_token =
824  create_async_signal_handler (async_do_nothing, NULL);
825 #endif
826  signal (SIGFPE, handle_sigfpe);
827  sigfpe_token =
829 
830 #ifdef STOP_SIGNAL
831  sigtstp_token =
832  create_async_signal_handler (async_stop_sig, NULL);
833 #endif
834 }
835 
836 /* Tell the event loop what to do if SIGINT is received.
837  See event-signal.c. */
838 void
839 handle_sigint (int sig)
840 {
841  signal (sig, handle_sigint);
842 
843  /* We could be running in a loop reading in symfiles or something so
844  it may be quite a while before we get back to the event loop. So
845  set quit_flag to 1 here. Then if QUIT is called before we get to
846  the event loop, we will unwind as expected. */
847 
848  set_quit_flag ();
849 
850  /* If immediate_quit is set, we go ahead and process the SIGINT right
851  away, even if we usually would defer this to the event loop. The
852  assumption here is that it is safe to process ^C immediately if
853  immediate_quit is set. If we didn't, SIGINT would be really
854  processed only the next time through the event loop. To get to
855  that point, though, the command that we want to interrupt needs to
856  finish first, which is unacceptable. If immediate quit is not set,
857  we process SIGINT the next time through the loop, which is fine. */
859 }
860 
861 /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
862 
863 static void
865 {
866  quit_force (NULL, stdin == instream);
867 }
868 
869 /* See defs.h. */
870 volatile int sync_quit_force_run;
871 
872 /* Quit GDB if SIGTERM is received.
873  GDB would quit anyway, but this way it will clean up properly. */
874 void
875 handle_sigterm (int sig)
876 {
877  signal (sig, handle_sigterm);
878 
879  /* Call quit_force in a signal safe way.
880  quit_force itself is not signal safe. */
881  if (target_can_async_p ())
882  mark_async_signal_handler (async_sigterm_token);
883  else
884  {
886  set_quit_flag ();
887  }
888 }
889 
890 /* Do the quit. All the checks have been done by the caller. */
891 void
893 {
894  /* If the quit_flag has gotten reset back to 0 by the time we get
895  back here, that means that an exception was thrown to unwind the
896  current command before we got back to the event loop. So there
897  is no reason to call quit again here. */
898 
899  if (check_quit_flag ())
900  quit ();
901 }
902 
903 #ifdef SIGQUIT
904 /* Tell the event loop what to do if SIGQUIT is received.
905  See event-signal.c. */
906 static void
907 handle_sigquit (int sig)
908 {
909  mark_async_signal_handler (sigquit_token);
910  signal (sig, handle_sigquit);
911 }
912 #endif
913 
914 #if defined (SIGQUIT) || defined (SIGHUP)
915 /* Called by the event loop in response to a SIGQUIT or an
916  ignored SIGHUP. */
917 static void
918 async_do_nothing (gdb_client_data arg)
919 {
920  /* Empty function body. */
921 }
922 #endif
923 
924 #ifdef SIGHUP
925 /* Tell the event loop what to do if SIGHUP is received.
926  See event-signal.c. */
927 static void
928 handle_sighup (int sig)
929 {
930  mark_async_signal_handler (sighup_token);
931  signal (sig, handle_sighup);
932 }
933 
934 /* Called by the event loop to process a SIGHUP. */
935 static void
936 async_disconnect (gdb_client_data arg)
937 {
938 
939  TRY
940  {
941  quit_cover ();
942  }
943 
944  CATCH (exception, RETURN_MASK_ALL)
945  {
946  fputs_filtered ("Could not kill the program being debugged",
947  gdb_stderr);
948  exception_print (gdb_stderr, exception);
949  }
950  END_CATCH
951 
952  TRY
953  {
954  pop_all_targets ();
955  }
956  CATCH (exception, RETURN_MASK_ALL)
957  {
958  }
959  END_CATCH
960 
961  signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
962  raise (SIGHUP);
963 }
964 #endif
965 
966 #ifdef STOP_SIGNAL
967 void
968 handle_stop_sig (int sig)
969 {
970  mark_async_signal_handler (sigtstp_token);
971  signal (sig, handle_stop_sig);
972 }
973 
974 static void
975 async_stop_sig (gdb_client_data arg)
976 {
977  char *prompt = get_prompt ();
978 
979 #if STOP_SIGNAL == SIGTSTP
980  signal (SIGTSTP, SIG_DFL);
981 #if HAVE_SIGPROCMASK
982  {
983  sigset_t zero;
984 
985  sigemptyset (&zero);
986  sigprocmask (SIG_SETMASK, &zero, 0);
987  }
988 #elif HAVE_SIGSETMASK
989  sigsetmask (0);
990 #endif
991  raise (SIGTSTP);
992  signal (SIGTSTP, handle_stop_sig);
993 #else
994  signal (STOP_SIGNAL, handle_stop_sig);
995 #endif
996  printf_unfiltered ("%s", prompt);
998 
999  /* Forget about any previous command -- null line now will do
1000  nothing. */
1001  dont_repeat ();
1002 }
1003 #endif /* STOP_SIGNAL */
1004 
1005 /* Tell the event loop what to do if SIGFPE is received.
1006  See event-signal.c. */
1007 static void
1008 handle_sigfpe (int sig)
1009 {
1010  mark_async_signal_handler (sigfpe_token);
1011  signal (sig, handle_sigfpe);
1012 }
1013 
1014 /* Event loop will call this functin to process a SIGFPE. */
1015 static void
1017 {
1018  /* This message is based on ANSI C, section 4.7. Note that integer
1019  divide by zero causes this, so "float" is a misnomer. */
1020  error (_("Erroneous arithmetic operation."));
1021 }
1022 
1023 
1024 /* Called by do_setshow_command. */
1025 void
1026 set_async_editing_command (char *args, int from_tty,
1027  struct cmd_list_element *c)
1028 {
1030 }
1031 
1032 /* Set things up for readline to be invoked via the alternate
1033  interface, i.e. via a callback function (rl_callback_read_char),
1034  and hook up instream to the event loop. */
1035 void
1037 {
1038  /* This function is a noop for the sync case. The assumption is
1039  that the sync setup is ALL done in gdb_init, and we would only
1040  mess it up here. The sync stuff should really go away over
1041  time. */
1042  if (!batch_silent)
1043  gdb_stdout = stdio_fileopen (stdout);
1045  gdb_stdlog = gdb_stderr; /* for moment */
1046  gdb_stdtarg = gdb_stderr; /* for moment */
1047  gdb_stdtargerr = gdb_stderr; /* for moment */
1048 
1049  /* If the input stream is connected to a terminal, turn on
1050  editing. */
1051  if (ISATTY (instream))
1052  {
1053  /* Tell gdb that we will be using the readline library. This
1054  could be overwritten by a command in .gdbinit like 'set
1055  editing on' or 'off'. */
1057 
1058  /* When a character is detected on instream by select or poll,
1059  readline will be invoked via this callback function. */
1061  }
1062  else
1063  {
1066  }
1067 
1068  /* When readline has read an end-of-line character, it passes the
1069  complete line to gdb for processing; command_line_handler is the
1070  function that does this. */
1072 
1073  /* Tell readline to use the same input stream that gdb uses. */
1074  rl_instream = instream;
1075 
1076  /* Get a file descriptor for the input stream, so that we can
1077  register it with the event loop. */
1078  input_fd = fileno (instream);
1079 
1080  /* Now we need to create the event sources for the input file
1081  descriptor. */
1082  /* At this point in time, this is the only event source that we
1083  register with the even loop. Another source is going to be the
1084  target program (inferior), but that must be registered only when
1085  it actually exists (I.e. after we say 'run' or after we connect
1086  to a remote target. */
1088 }
1089 
1090 /* Disable command input through the standard CLI channels. Used in
1091  the suspend proc for interpreters that use the standard gdb readline
1092  interface, like the cli & the mi. */
1093 void
1095 {
1096  /* FIXME - It is too heavyweight to delete and remake these every
1097  time you run an interpreter that needs readline. It is probably
1098  better to have the interpreters cache these, which in turn means
1099  that this needs to be moved into interpreter specific code. */
1100 
1101 #if 0
1104  gdb_stdlog = NULL;
1105  gdb_stdtarg = NULL;
1106  gdb_stdtargerr = NULL;
1107 #endif
1108 
1111 }
#define target_can_async_p()
Definition: target.h:1748
void gdb_add_history(const char *command)
Definition: top.c:912
void target_terminal_ours(void)
Definition: target.c:491
void start_event_loop(void)
Definition: event-loop.c:335
void(* after_char_processing_hook)(void)
Definition: event-top.c:162
void discard_all_intermediate_continuations(void)
void async_init_signals(void)
Definition: event-top.c:790
int saved_command_line_size
Definition: top.c:132
FILE * instream
Definition: top.c:109
void gdb_rl_callback_handler_reinstall(void)
Definition: event-top.c:263
void fputs_unfiltered(const char *buf, struct ui_file *file)
Definition: ui-file.c:252
void xfree(void *)
Definition: common-utils.c:97
void gdb_rl_callback_handler_install(const char *prompt)
Definition: event-top.c:249
void(* input_handler)(char *)
Definition: event-top.c:97
void clear_quit_flag(void)
Definition: extension.c:793
void set_quit_flag(void)
Definition: extension.c:816
int input_fd
Definition: event-top.c:120
char * async_annotation_suffix
Definition: event-top.c:112
void async_enable_stdin(void)
Definition: event-top.c:442
void mark_async_signal_handler(async_signal_handler *async_handler_ptr)
Definition: event-loop.c:906
static int more_to_come
Definition: event-top.c:151
void ui_file_delete(struct ui_file *file)
Definition: ui-file.c:76
struct ui_file * gdb_stdout
Definition: main.c:71
int history_expansion_p
Definition: top.c:678
static void command_line_handler(char *rl)
Definition: event-top.c:512
void quit_force(char *args, int from_tty)
Definition: top.c:1497
void gdb_setup_readline(void)
Definition: event-top.c:1036
int batch_silent
Definition: main.c:84
static void rl_callback_read_char_wrapper(gdb_client_data client_data)
Definition: event-top.c:169
#define _(String)
Definition: gdb_locale.h:40
void execute_command(char *, int)
Definition: top.c:388
static int callback_handler_installed
Definition: event-top.c:233
void gdb_disable_readline(void)
Definition: event-top.c:1094
#define END_CATCH
struct readline_input_state readline_input_state
void quit(void)
Definition: utils.c:1021
void add_file_handler(int fd, handler_func *proc, gdb_client_data client_data)
Definition: event-loop.c:388
void async_request_quit(gdb_client_data arg)
Definition: event-top.c:892
#define TRY
struct ui_file * stderr_fileopen(void)
Definition: ui-file.c:683
static struct async_signal_handler * async_sigterm_token
Definition: event-top.c:144
void(* call_readline)(gdb_client_data)
Definition: event-top.c:98
#define CATCH(EXCEPTION, MASK)
const char * source_file_name
Definition: top.c:272
void handle_sigterm(int sig)
Definition: event-top.c:875
static char * top_level_prompt(void)
Definition: event-top.c:364
int job_control
void exception_print(struct ui_file *file, struct gdb_exception e)
Definition: exceptions.c:109
void fputs_filtered(const char *linebuffer, struct ui_file *stream)
Definition: utils.c:2145
void free_current_contents(void *ptr)
Definition: utils.c:476
int async_command_editing_p
Definition: event-top.c:108
struct cleanup * make_cleanup(make_cleanup_ftype *function, void *arg)
Definition: cleanups.c:117
int sync_execution
Definition: infrun.c:117
int annotation_level
Definition: stack.c:109
void pop_all_targets(void)
Definition: target.c:767
void reinitialize_more_filter(void)
Definition: utils.c:1902
async_signal_handler * create_async_signal_handler(sig_handler_func *proc, gdb_client_data client_data)
Definition: event-loop.c:873
#define gdb_assert(expr)
Definition: gdb_assert.h:33
static void change_line_handler(void)
Definition: event-top.c:196
char * get_prompt(void)
Definition: top.c:1386
void wrap_here(char *indent)
Definition: utils.c:1930
void printf_unfiltered(const char *format,...)
Definition: utils.c:2399
#define SERVER_COMMAND_LENGTH
void async_disable_stdin(void)
Definition: event-top.c:459
void gdb_readline2(gdb_client_data client_data)
Definition: event-top.c:710
void * xmalloc(YYSIZE_T)
struct ui_file * gdb_stdlog
Definition: main.c:73
void * gdb_client_data
Definition: event-loop.h:70
void quit_cover(void)
static struct async_signal_handler * sigint_token
Definition: event-top.c:133
PTR xrealloc(PTR ptr, size_t size)
Definition: common-utils.c:51
int input_from_terminal_p(void)
Definition: top.c:1573
void cli_command_loop(void *data)
Definition: event-top.c:181
int immediate_quit
static struct async_signal_handler * sigfpe_token
Definition: event-top.c:140
void puts_unfiltered(const char *string)
Definition: utils.c:2434
struct cleanup * make_command_stats_cleanup(int msg_type)
Definition: maint.c:901
void set_async_editing_command(char *args, int from_tty, struct cmd_list_element *c)
Definition: event-top.c:1026
int check_quit_flag(void)
Definition: extension.c:831
void gdb_rl_callback_handler_remove(void)
Definition: event-top.c:238
struct ui_file * gdb_stderr
Definition: main.c:72
void quit_command(char *args, int from_tty)
Definition: cli-cmds.c:343
int call_stdin_event_handler_again_p
Definition: event-top.c:125
static void handle_sigfpe(int sig)
Definition: event-top.c:1008
struct ui_file * gdb_stdtarg
Definition: main.c:77
void stdin_event_handler(int error, gdb_client_data client_data)
Definition: event-top.c:416
volatile int sync_quit_force_run
Definition: event-top.c:870
static void command_handler(char *command)
Definition: event-top.c:472
void reset_command_nest_depth(void)
Definition: cli-script.c:407
int source_line_number
Definition: top.c:266
void gdb_call_async_signal_handler(struct async_signal_handler *handler, int immediate_p)
Definition: mingw-hdep.c:209
void display_gdb_prompt(const char *new_prompt)
Definition: event-top.c:291
int server_command
Definition: top.c:140
static void async_sigterm_handler(gdb_client_data arg)
Definition: event-top.c:864
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Definition: breakpoint.c:4668
void handle_sigint(int sig)
Definition: event-top.c:839
static void async_float_handler(gdb_client_data)
Definition: event-top.c:1016
struct ui_file * gdb_stdtargerr
Definition: main.c:78
void * arg
Definition: cleanups.c:43
void dont_repeat(void)
Definition: top.c:582
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void gdb_flush(struct ui_file *file)
Definition: ui-file.c:192
struct ui_file * stdio_fileopen(FILE *file)
Definition: ui-file.c:717
char * saved_command_line
Definition: top.c:131
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Definition: annotate.c:588
#define ISATTY(FP)
Definition: defs.h:667
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Definition: errors.c:38
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Definition: event-loop.c:539
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Definition: cleanups.c:175
int exec_done_display_p
Definition: event-top.c:116
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