Fix races in mi2-console.exp.
[deliverable/binutils-gdb.git] / gdb / event-top.c
1 /* Top level stuff for GDB, the GNU debugger.
2
3 Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009, 2010,
4 2011 Free Software Foundation, Inc.
5
6 Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
7
8 This file is part of GDB.
9
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
14
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22
23 #include "defs.h"
24 #include "top.h"
25 #include "inferior.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 "exceptions.h"
33 #include "cli/cli-script.h" /* for reset_command_nest_depth */
34 #include "main.h"
35 #include "gdbthread.h"
36 #include "continuations.h"
37 #include "gdbcmd.h" /* for dont_repeat() */
38
39 /* readline include files. */
40 #include "readline/readline.h"
41 #include "readline/history.h"
42
43 /* readline defines this. */
44 #undef savestring
45
46 static void rl_callback_read_char_wrapper (gdb_client_data client_data);
47 static void command_line_handler (char *rl);
48 static void change_line_handler (void);
49 static void change_annotation_level (void);
50 static void command_handler (char *command);
51
52 /* Signal handlers. */
53 #ifdef SIGQUIT
54 static void handle_sigquit (int sig);
55 #endif
56 #ifdef SIGHUP
57 static void handle_sighup (int sig);
58 #endif
59 static void handle_sigfpe (int sig);
60 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
61 static void handle_sigwinch (int sig);
62 #endif
63
64 /* Functions to be invoked by the event loop in response to
65 signals. */
66 #if defined (SIGQUIT) || defined (SIGHUP)
67 static void async_do_nothing (gdb_client_data);
68 #endif
69 #ifdef SIGHUP
70 static void async_disconnect (gdb_client_data);
71 #endif
72 static void async_float_handler (gdb_client_data);
73 #ifdef STOP_SIGNAL
74 static void async_stop_sig (gdb_client_data);
75 #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 *);
98 void (*call_readline) (gdb_client_data);
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. */
108 int async_command_editing_p;
109
110 /* This variable contains the new prompt that the user sets with the
111 set prompt command. */
112 char *new_async_prompt;
113
114 /* This is the annotation suffix that will be used when the
115 annotation_level is 2. */
116 char *async_annotation_suffix;
117
118 /* This is used to display the notification of the completion of an
119 asynchronous execution command. */
120 int exec_done_display_p = 0;
121
122 /* This is the file descriptor for the input stream that GDB uses to
123 read commands from. */
124 int input_fd;
125
126 /* This is the prompt stack. Prompts will be pushed on the stack as
127 needed by the different 'kinds' of user inputs GDB is asking
128 for. See event-loop.h. */
129 struct prompts the_prompts;
130
131 /* Signal handling variables. */
132 /* Each of these is a pointer to a function that the event loop will
133 invoke if the corresponding signal has received. The real signal
134 handlers mark these functions as ready to be executed and the event
135 loop, in a later iteration, calls them. See the function
136 invoke_async_signal_handler. */
137 void *sigint_token;
138 #ifdef SIGHUP
139 void *sighup_token;
140 #endif
141 #ifdef SIGQUIT
142 void *sigquit_token;
143 #endif
144 void *sigfpe_token;
145 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
146 void *sigwinch_token;
147 #endif
148 #ifdef STOP_SIGNAL
149 void *sigtstp_token;
150 #endif
151
152 /* Structure to save a partially entered command. This is used when
153 the user types '\' at the end of a command line. This is necessary
154 because each line of input is handled by a different call to
155 command_line_handler, and normally there is no state retained
156 between different calls. */
157 int more_to_come = 0;
158
159 struct readline_input_state
160 {
161 char *linebuffer;
162 char *linebuffer_ptr;
163 }
164 readline_input_state;
165
166 /* This hook is called by rl_callback_read_char_wrapper after each
167 character is processed. */
168 void (*after_char_processing_hook) (void);
169 \f
170
171 /* Wrapper function for calling into the readline library. The event
172 loop expects the callback function to have a paramter, while
173 readline expects none. */
174 static void
175 rl_callback_read_char_wrapper (gdb_client_data client_data)
176 {
177 rl_callback_read_char ();
178 if (after_char_processing_hook)
179 (*after_char_processing_hook) ();
180 }
181
182 /* Initialize all the necessary variables, start the event loop,
183 register readline, and stdin, start the loop. */
184 void
185 cli_command_loop (void)
186 {
187 /* If we are using readline, set things up and display the first
188 prompt, otherwise just print the prompt. */
189 if (async_command_editing_p)
190 {
191 int length;
192 char *a_prompt;
193 char *gdb_prompt = get_prompt ();
194
195 /* Tell readline what the prompt to display is and what function
196 it will need to call after a whole line is read. This also
197 displays the first prompt. */
198 length = strlen (PREFIX (0))
199 + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1;
200 a_prompt = (char *) alloca (length);
201 strcpy (a_prompt, PREFIX (0));
202 strcat (a_prompt, gdb_prompt);
203 strcat (a_prompt, SUFFIX (0));
204 rl_callback_handler_install (a_prompt, input_handler);
205 }
206 else
207 display_gdb_prompt (0);
208
209 /* Now it's time to start the event loop. */
210 start_event_loop ();
211 }
212
213 /* Change the function to be invoked every time there is a character
214 ready on stdin. This is used when the user sets the editing off,
215 therefore bypassing readline, and letting gdb handle the input
216 itself, via gdb_readline2. Also it is used in the opposite case in
217 which the user sets editing on again, by restoring readline
218 handling of the input. */
219 static void
220 change_line_handler (void)
221 {
222 /* NOTE: this operates on input_fd, not instream. If we are reading
223 commands from a file, instream will point to the file. However in
224 async mode, we always read commands from a file with editing
225 off. This means that the 'set editing on/off' will have effect
226 only on the interactive session. */
227
228 if (async_command_editing_p)
229 {
230 /* Turn on editing by using readline. */
231 call_readline = rl_callback_read_char_wrapper;
232 input_handler = command_line_handler;
233 }
234 else
235 {
236 /* Turn off editing by using gdb_readline2. */
237 rl_callback_handler_remove ();
238 call_readline = gdb_readline2;
239
240 /* Set up the command handler as well, in case we are called as
241 first thing from .gdbinit. */
242 input_handler = command_line_handler;
243 }
244 }
245
246 /* Displays the prompt. The prompt that is displayed is the current
247 top of the prompt stack, if the argument NEW_PROMPT is
248 0. Otherwise, it displays whatever NEW_PROMPT is. This is used
249 after each gdb command has completed, and in the following cases:
250 1. When the user enters a command line which is ended by '\'
251 indicating that the command will continue on the next line.
252 In that case the prompt that is displayed is the empty string.
253 2. When the user is entering 'commands' for a breakpoint, or
254 actions for a tracepoint. In this case the prompt will be '>'
255 3. Other????
256 FIXME: 2. & 3. not implemented yet for async. */
257 void
258 display_gdb_prompt (char *new_prompt)
259 {
260 int prompt_length = 0;
261 char *gdb_prompt = get_prompt ();
262
263 /* Reset the nesting depth used when trace-commands is set. */
264 reset_command_nest_depth ();
265
266 /* Each interpreter has its own rules on displaying the command
267 prompt. */
268 if (!current_interp_display_prompt_p ())
269 return;
270
271 if (sync_execution && is_running (inferior_ptid))
272 {
273 /* This is to trick readline into not trying to display the
274 prompt. Even though we display the prompt using this
275 function, readline still tries to do its own display if we
276 don't call rl_callback_handler_install and
277 rl_callback_handler_remove (which readline detects because a
278 global variable is not set). If readline did that, it could
279 mess up gdb signal handlers for SIGINT. Readline assumes
280 that between calls to rl_set_signals and rl_clear_signals gdb
281 doesn't do anything with the signal handlers. Well, that's
282 not the case, because when the target executes we change the
283 SIGINT signal handler. If we allowed readline to display the
284 prompt, the signal handler change would happen exactly
285 between the calls to the above two functions.
286 Calling rl_callback_handler_remove(), does the job. */
287
288 rl_callback_handler_remove ();
289 return;
290 }
291
292 if (!new_prompt)
293 {
294 /* Just use the top of the prompt stack. */
295 prompt_length = strlen (PREFIX (0)) +
296 strlen (SUFFIX (0)) +
297 strlen (gdb_prompt) + 1;
298
299 new_prompt = (char *) alloca (prompt_length);
300
301 /* Prefix needs to have new line at end. */
302 strcpy (new_prompt, PREFIX (0));
303 strcat (new_prompt, gdb_prompt);
304 /* Suffix needs to have a new line at end and \032 \032 at
305 beginning. */
306 strcat (new_prompt, SUFFIX (0));
307 }
308
309 if (async_command_editing_p)
310 {
311 rl_callback_handler_remove ();
312 rl_callback_handler_install (new_prompt, input_handler);
313 }
314 /* new_prompt at this point can be the top of the stack or the one
315 passed in. It can't be NULL. */
316 else
317 {
318 /* Don't use a _filtered function here. It causes the assumed
319 character position to be off, since the newline we read from
320 the user is not accounted for. */
321 fputs_unfiltered (new_prompt, gdb_stdout);
322 gdb_flush (gdb_stdout);
323 }
324 }
325
326 /* Used when the user requests a different annotation level, with
327 'set annotate'. It pushes a new prompt (with prefix and suffix) on top
328 of the prompt stack, if the annotation level desired is 2, otherwise
329 it pops the top of the prompt stack when we want the annotation level
330 to be the normal ones (1 or 0). */
331 static void
332 change_annotation_level (void)
333 {
334 char *prefix, *suffix;
335
336 if (!PREFIX (0) || !PROMPT (0) || !SUFFIX (0))
337 {
338 /* The prompt stack has not been initialized to "", we are
339 using gdb w/o the --async switch. */
340 warning (_("Command has same effect as set annotate"));
341 return;
342 }
343
344 if (annotation_level > 1)
345 {
346 if (!strcmp (PREFIX (0), "") && !strcmp (SUFFIX (0), ""))
347 {
348 /* Push a new prompt if the previous annotation_level was not >1. */
349 prefix = (char *) alloca (strlen (async_annotation_suffix) + 10);
350 strcpy (prefix, "\n\032\032pre-");
351 strcat (prefix, async_annotation_suffix);
352 strcat (prefix, "\n");
353
354 suffix = (char *) alloca (strlen (async_annotation_suffix) + 6);
355 strcpy (suffix, "\n\032\032");
356 strcat (suffix, async_annotation_suffix);
357 strcat (suffix, "\n");
358
359 push_prompt (prefix, (char *) 0, suffix);
360 }
361 }
362 else
363 {
364 if (strcmp (PREFIX (0), "") && strcmp (SUFFIX (0), ""))
365 {
366 /* Pop the top of the stack, we are going back to annotation < 1. */
367 pop_prompt ();
368 }
369 }
370 }
371
372 /* Pushes a new prompt on the prompt stack. Each prompt has three
373 parts: prefix, prompt, suffix. Usually prefix and suffix are empty
374 strings, except when the annotation level is 2. Memory is allocated
375 within xstrdup for the new prompt. */
376 void
377 push_prompt (char *prefix, char *prompt, char *suffix)
378 {
379 the_prompts.top++;
380 PREFIX (0) = xstrdup (prefix);
381
382 /* Note that this function is used by the set annotate 2
383 command. This is why we take care of saving the old prompt
384 in case a new one is not specified. */
385 if (prompt)
386 PROMPT (0) = xstrdup (prompt);
387 else
388 PROMPT (0) = xstrdup (PROMPT (-1));
389
390 SUFFIX (0) = xstrdup (suffix);
391 }
392
393 /* Pops the top of the prompt stack, and frees the memory allocated
394 for it. */
395 void
396 pop_prompt (void)
397 {
398 /* If we are not during a 'synchronous' execution command, in which
399 case, the top prompt would be empty. */
400 if (strcmp (PROMPT (0), ""))
401 /* This is for the case in which the prompt is set while the
402 annotation level is 2. The top prompt will be changed, but when
403 we return to annotation level < 2, we want that new prompt to be
404 in effect, until the user does another 'set prompt'. */
405 if (strcmp (PROMPT (0), PROMPT (-1)))
406 {
407 xfree (PROMPT (-1));
408 PROMPT (-1) = xstrdup (PROMPT (0));
409 }
410
411 xfree (PREFIX (0));
412 xfree (PROMPT (0));
413 xfree (SUFFIX (0));
414 the_prompts.top--;
415 }
416
417 /* When there is an event ready on the stdin file desriptor, instead
418 of calling readline directly throught the callback function, or
419 instead of calling gdb_readline2, give gdb a chance to detect
420 errors and do something. */
421 void
422 stdin_event_handler (int error, gdb_client_data client_data)
423 {
424 if (error)
425 {
426 printf_unfiltered (_("error detected on stdin\n"));
427 delete_file_handler (input_fd);
428 discard_all_continuations ();
429 discard_all_intermediate_continuations ();
430 /* If stdin died, we may as well kill gdb. */
431 quit_command ((char *) 0, stdin == instream);
432 }
433 else
434 (*call_readline) (client_data);
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
442 async_enable_stdin (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. */
450 target_terminal_ours ();
451 pop_prompt ();
452 sync_execution = 0;
453 }
454 }
455
456 /* Disable reads from stdin (the console) marking the command as
457 synchronous. */
458
459 void
460 async_disable_stdin (void)
461 {
462 if (!sync_execution)
463 {
464 sync_execution = 1;
465 push_prompt ("", "", "");
466 }
467 }
468 \f
469
470 /* Handles a gdb command. This function is called by
471 command_line_handler, which has processed one or more input lines
472 into COMMAND. */
473 /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop
474 function. The command_loop function will be obsolete when we
475 switch to use the event loop at every execution of gdb. */
476 static void
477 command_handler (char *command)
478 {
479 int stdin_is_tty = ISATTY (stdin);
480 struct cleanup *stat_chain;
481
482 quit_flag = 0;
483 if (instream == stdin && stdin_is_tty)
484 reinitialize_more_filter ();
485
486 /* If readline returned a NULL command, it means that the connection
487 with the terminal is gone. This happens at the end of a
488 testsuite run, after Expect has hung up but GDB is still alive.
489 In such a case, we just quit gdb killing the inferior program
490 too. */
491 if (command == 0)
492 {
493 printf_unfiltered ("quit\n");
494 execute_command ("quit", stdin == instream);
495 }
496
497 stat_chain = make_command_stats_cleanup (1);
498
499 execute_command (command, instream == stdin);
500
501 /* Do any commands attached to breakpoint we stopped at. */
502 bpstat_do_actions ();
503
504 do_cleanups (stat_chain);
505 }
506
507 /* Handle a complete line of input. This is called by the callback
508 mechanism within the readline library. Deal with incomplete
509 commands as well, by saving the partial input in a global
510 buffer. */
511
512 /* NOTE: 1999-04-30 This is the asynchronous version of the
513 command_line_input function; command_line_input will become
514 obsolete once we use the event loop as the default mechanism in
515 GDB. */
516 static void
517 command_line_handler (char *rl)
518 {
519 static char *linebuffer = 0;
520 static unsigned linelength = 0;
521 char *p;
522 char *p1;
523 char *nline;
524 char got_eof = 0;
525
526 int repeat = (instream == stdin);
527
528 if (annotation_level > 1 && instream == stdin)
529 {
530 printf_unfiltered (("\n\032\032post-"));
531 puts_unfiltered (async_annotation_suffix);
532 printf_unfiltered (("\n"));
533 }
534
535 if (linebuffer == 0)
536 {
537 linelength = 80;
538 linebuffer = (char *) xmalloc (linelength);
539 }
540
541 p = linebuffer;
542
543 if (more_to_come)
544 {
545 strcpy (linebuffer, readline_input_state.linebuffer);
546 p = readline_input_state.linebuffer_ptr;
547 xfree (readline_input_state.linebuffer);
548 more_to_come = 0;
549 pop_prompt ();
550 }
551
552 #ifdef STOP_SIGNAL
553 if (job_control)
554 signal (STOP_SIGNAL, handle_stop_sig);
555 #endif
556
557 /* Make sure that all output has been output. Some machines may let
558 you get away with leaving out some of the gdb_flush, but not
559 all. */
560 wrap_here ("");
561 gdb_flush (gdb_stdout);
562 gdb_flush (gdb_stderr);
563
564 if (source_file_name != NULL)
565 ++source_line_number;
566
567 /* If we are in this case, then command_handler will call quit
568 and exit from gdb. */
569 if (!rl || rl == (char *) EOF)
570 {
571 got_eof = 1;
572 command_handler (0);
573 return; /* Lint. */
574 }
575 if (strlen (rl) + 1 + (p - linebuffer) > linelength)
576 {
577 linelength = strlen (rl) + 1 + (p - linebuffer);
578 nline = (char *) xrealloc (linebuffer, linelength);
579 p += nline - linebuffer;
580 linebuffer = nline;
581 }
582 p1 = rl;
583 /* Copy line. Don't copy null at end. (Leaves line alone
584 if this was just a newline). */
585 while (*p1)
586 *p++ = *p1++;
587
588 xfree (rl); /* Allocated in readline. */
589
590 if (p > linebuffer && *(p - 1) == '\\')
591 {
592 *p = '\0';
593 p--; /* Put on top of '\'. */
594
595 readline_input_state.linebuffer = xstrdup (linebuffer);
596 readline_input_state.linebuffer_ptr = p;
597
598 /* We will not invoke a execute_command if there is more
599 input expected to complete the command. So, we need to
600 print an empty prompt here. */
601 more_to_come = 1;
602 push_prompt ("", "", "");
603 display_gdb_prompt (0);
604 return;
605 }
606
607 #ifdef STOP_SIGNAL
608 if (job_control)
609 signal (STOP_SIGNAL, SIG_DFL);
610 #endif
611
612 #define SERVER_COMMAND_LENGTH 7
613 server_command =
614 (p - linebuffer > SERVER_COMMAND_LENGTH)
615 && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0;
616 if (server_command)
617 {
618 /* Note that we don't set `line'. Between this and the check in
619 dont_repeat, this insures that repeating will still do the
620 right thing. */
621 *p = '\0';
622 command_handler (linebuffer + SERVER_COMMAND_LENGTH);
623 display_gdb_prompt (0);
624 return;
625 }
626
627 /* Do history expansion if that is wished. */
628 if (history_expansion_p && instream == stdin
629 && ISATTY (instream))
630 {
631 char *history_value;
632 int expanded;
633
634 *p = '\0'; /* Insert null now. */
635 expanded = history_expand (linebuffer, &history_value);
636 if (expanded)
637 {
638 /* Print the changes. */
639 printf_unfiltered ("%s\n", history_value);
640
641 /* If there was an error, call this function again. */
642 if (expanded < 0)
643 {
644 xfree (history_value);
645 return;
646 }
647 if (strlen (history_value) > linelength)
648 {
649 linelength = strlen (history_value) + 1;
650 linebuffer = (char *) xrealloc (linebuffer, linelength);
651 }
652 strcpy (linebuffer, history_value);
653 p = linebuffer + strlen (linebuffer);
654 }
655 xfree (history_value);
656 }
657
658 /* If we just got an empty line, and that is supposed to repeat the
659 previous command, return the value in the global buffer. */
660 if (repeat && p == linebuffer && *p != '\\')
661 {
662 command_handler (saved_command_line);
663 display_gdb_prompt (0);
664 return;
665 }
666
667 for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++);
668 if (repeat && !*p1)
669 {
670 command_handler (saved_command_line);
671 display_gdb_prompt (0);
672 return;
673 }
674
675 *p = 0;
676
677 /* Add line to history if appropriate. */
678 if (instream == stdin
679 && ISATTY (stdin) && *linebuffer)
680 add_history (linebuffer);
681
682 /* Note: lines consisting solely of comments are added to the command
683 history. This is useful when you type a command, and then
684 realize you don't want to execute it quite yet. You can comment
685 out the command and then later fetch it from the value history
686 and remove the '#'. The kill ring is probably better, but some
687 people are in the habit of commenting things out. */
688 if (*p1 == '#')
689 *p1 = '\0'; /* Found a comment. */
690
691 /* Save into global buffer if appropriate. */
692 if (repeat)
693 {
694 if (linelength > saved_command_line_size)
695 {
696 saved_command_line = xrealloc (saved_command_line, linelength);
697 saved_command_line_size = linelength;
698 }
699 strcpy (saved_command_line, linebuffer);
700 if (!more_to_come)
701 {
702 command_handler (saved_command_line);
703 display_gdb_prompt (0);
704 }
705 return;
706 }
707
708 command_handler (linebuffer);
709 display_gdb_prompt (0);
710 return;
711 }
712
713 /* Does reading of input from terminal w/o the editing features
714 provided by the readline library. */
715
716 /* NOTE: 1999-04-30 Asynchronous version of gdb_readline; gdb_readline
717 will become obsolete when the event loop is made the default
718 execution for gdb. */
719 void
720 gdb_readline2 (gdb_client_data client_data)
721 {
722 int c;
723 char *result;
724 int input_index = 0;
725 int result_size = 80;
726 static int done_once = 0;
727
728 /* Unbuffer the input stream, so that, later on, the calls to fgetc
729 fetch only one char at the time from the stream. The fgetc's will
730 get up to the first newline, but there may be more chars in the
731 stream after '\n'. If we buffer the input and fgetc drains the
732 stream, getting stuff beyond the newline as well, a select, done
733 afterwards will not trigger. */
734 if (!done_once && !ISATTY (instream))
735 {
736 setbuf (instream, NULL);
737 done_once = 1;
738 }
739
740 result = (char *) xmalloc (result_size);
741
742 /* We still need the while loop here, even though it would seem
743 obvious to invoke gdb_readline2 at every character entered. If
744 not using the readline library, the terminal is in cooked mode,
745 which sends the characters all at once. Poll will notice that the
746 input fd has changed state only after enter is pressed. At this
747 point we still need to fetch all the chars entered. */
748
749 while (1)
750 {
751 /* Read from stdin if we are executing a user defined command.
752 This is the right thing for prompt_for_continue, at least. */
753 c = fgetc (instream ? instream : stdin);
754
755 if (c == EOF)
756 {
757 if (input_index > 0)
758 /* The last line does not end with a newline. Return it,
759 and if we are called again fgetc will still return EOF
760 and we'll return NULL then. */
761 break;
762 xfree (result);
763 (*input_handler) (0);
764 return;
765 }
766
767 if (c == '\n')
768 {
769 if (input_index > 0 && result[input_index - 1] == '\r')
770 input_index--;
771 break;
772 }
773
774 result[input_index++] = c;
775 while (input_index >= result_size)
776 {
777 result_size *= 2;
778 result = (char *) xrealloc (result, result_size);
779 }
780 }
781
782 result[input_index++] = '\0';
783 (*input_handler) (result);
784 }
785 \f
786
787 /* Initialization of signal handlers and tokens. There is a function
788 handle_sig* for each of the signals GDB cares about. Specifically:
789 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
790 functions are the actual signal handlers associated to the signals
791 via calls to signal(). The only job for these functions is to
792 enqueue the appropriate event/procedure with the event loop. Such
793 procedures are the old signal handlers. The event loop will take
794 care of invoking the queued procedures to perform the usual tasks
795 associated with the reception of the signal. */
796 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
797 init_signals will become obsolete as we move to have to event loop
798 as the default for gdb. */
799 void
800 async_init_signals (void)
801 {
802 signal (SIGINT, handle_sigint);
803 sigint_token =
804 create_async_signal_handler (async_request_quit, NULL);
805 signal (SIGTERM, handle_sigterm);
806
807 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
808 to the inferior and breakpoints will be ignored. */
809 #ifdef SIGTRAP
810 signal (SIGTRAP, SIG_DFL);
811 #endif
812
813 #ifdef SIGQUIT
814 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
815 passed to the inferior, which we don't want. It would be
816 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
817 on BSD4.3 systems using vfork, that can affect the
818 GDB process as well as the inferior (the signal handling tables
819 might be in memory, shared between the two). Since we establish
820 a handler for SIGQUIT, when we call exec it will set the signal
821 to SIG_DFL for us. */
822 signal (SIGQUIT, handle_sigquit);
823 sigquit_token =
824 create_async_signal_handler (async_do_nothing, NULL);
825 #endif
826 #ifdef SIGHUP
827 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
828 sighup_token =
829 create_async_signal_handler (async_disconnect, NULL);
830 else
831 sighup_token =
832 create_async_signal_handler (async_do_nothing, NULL);
833 #endif
834 signal (SIGFPE, handle_sigfpe);
835 sigfpe_token =
836 create_async_signal_handler (async_float_handler, NULL);
837
838 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
839 signal (SIGWINCH, handle_sigwinch);
840 sigwinch_token =
841 create_async_signal_handler (SIGWINCH_HANDLER, NULL);
842 #endif
843 #ifdef STOP_SIGNAL
844 sigtstp_token =
845 create_async_signal_handler (async_stop_sig, NULL);
846 #endif
847
848 }
849
850 void
851 mark_async_signal_handler_wrapper (void *token)
852 {
853 mark_async_signal_handler ((struct async_signal_handler *) token);
854 }
855
856 /* Tell the event loop what to do if SIGINT is received.
857 See event-signal.c. */
858 void
859 handle_sigint (int sig)
860 {
861 signal (sig, handle_sigint);
862
863 /* We could be running in a loop reading in symfiles or something so
864 it may be quite a while before we get back to the event loop. So
865 set quit_flag to 1 here. Then if QUIT is called before we get to
866 the event loop, we will unwind as expected. */
867
868 quit_flag = 1;
869
870 /* If immediate_quit is set, we go ahead and process the SIGINT right
871 away, even if we usually would defer this to the event loop. The
872 assumption here is that it is safe to process ^C immediately if
873 immediate_quit is set. If we didn't, SIGINT would be really
874 processed only the next time through the event loop. To get to
875 that point, though, the command that we want to interrupt needs to
876 finish first, which is unacceptable. If immediate quit is not set,
877 we process SIGINT the next time through the loop, which is fine. */
878 gdb_call_async_signal_handler (sigint_token, immediate_quit);
879 }
880
881 /* Quit GDB if SIGTERM is received.
882 GDB would quit anyway, but this way it will clean up properly. */
883 void
884 handle_sigterm (int sig)
885 {
886 signal (sig, handle_sigterm);
887 quit_force ((char *) 0, stdin == instream);
888 }
889
890 /* Do the quit. All the checks have been done by the caller. */
891 void
892 async_request_quit (gdb_client_data arg)
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, unless immediate_quit is
898 set. */
899
900 if (quit_flag || immediate_quit)
901 quit ();
902 }
903
904 #ifdef SIGQUIT
905 /* Tell the event loop what to do if SIGQUIT is received.
906 See event-signal.c. */
907 static void
908 handle_sigquit (int sig)
909 {
910 mark_async_signal_handler_wrapper (sigquit_token);
911 signal (sig, handle_sigquit);
912 }
913 #endif
914
915 #if defined (SIGQUIT) || defined (SIGHUP)
916 /* Called by the event loop in response to a SIGQUIT or an
917 ignored SIGHUP. */
918 static void
919 async_do_nothing (gdb_client_data arg)
920 {
921 /* Empty function body. */
922 }
923 #endif
924
925 #ifdef SIGHUP
926 /* Tell the event loop what to do if SIGHUP is received.
927 See event-signal.c. */
928 static void
929 handle_sighup (int sig)
930 {
931 mark_async_signal_handler_wrapper (sighup_token);
932 signal (sig, handle_sighup);
933 }
934
935 /* Called by the event loop to process a SIGHUP. */
936 static void
937 async_disconnect (gdb_client_data arg)
938 {
939 catch_errors (quit_cover, NULL,
940 "Could not kill the program being debugged",
941 RETURN_MASK_ALL);
942 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
943 raise (SIGHUP);
944 }
945 #endif
946
947 #ifdef STOP_SIGNAL
948 void
949 handle_stop_sig (int sig)
950 {
951 mark_async_signal_handler_wrapper (sigtstp_token);
952 signal (sig, handle_stop_sig);
953 }
954
955 static void
956 async_stop_sig (gdb_client_data arg)
957 {
958 char *prompt = get_prompt ();
959
960 #if STOP_SIGNAL == SIGTSTP
961 signal (SIGTSTP, SIG_DFL);
962 #if HAVE_SIGPROCMASK
963 {
964 sigset_t zero;
965
966 sigemptyset (&zero);
967 sigprocmask (SIG_SETMASK, &zero, 0);
968 }
969 #elif HAVE_SIGSETMASK
970 sigsetmask (0);
971 #endif
972 raise (SIGTSTP);
973 signal (SIGTSTP, handle_stop_sig);
974 #else
975 signal (STOP_SIGNAL, handle_stop_sig);
976 #endif
977 printf_unfiltered ("%s", prompt);
978 gdb_flush (gdb_stdout);
979
980 /* Forget about any previous command -- null line now will do
981 nothing. */
982 dont_repeat ();
983 }
984 #endif /* STOP_SIGNAL */
985
986 /* Tell the event loop what to do if SIGFPE is received.
987 See event-signal.c. */
988 static void
989 handle_sigfpe (int sig)
990 {
991 mark_async_signal_handler_wrapper (sigfpe_token);
992 signal (sig, handle_sigfpe);
993 }
994
995 /* Event loop will call this functin to process a SIGFPE. */
996 static void
997 async_float_handler (gdb_client_data arg)
998 {
999 /* This message is based on ANSI C, section 4.7. Note that integer
1000 divide by zero causes this, so "float" is a misnomer. */
1001 error (_("Erroneous arithmetic operation."));
1002 }
1003
1004 /* Tell the event loop what to do if SIGWINCH is received.
1005 See event-signal.c. */
1006 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
1007 static void
1008 handle_sigwinch (int sig)
1009 {
1010 mark_async_signal_handler_wrapper (sigwinch_token);
1011 signal (sig, handle_sigwinch);
1012 }
1013 #endif
1014 \f
1015
1016 /* Called by do_setshow_command. */
1017 void
1018 set_async_editing_command (char *args, int from_tty,
1019 struct cmd_list_element *c)
1020 {
1021 change_line_handler ();
1022 }
1023
1024 /* Called by do_setshow_command. */
1025 void
1026 set_async_annotation_level (char *args, int from_tty,
1027 struct cmd_list_element *c)
1028 {
1029 change_annotation_level ();
1030 }
1031
1032 /* Called by do_setshow_command. */
1033 void
1034 set_async_prompt (char *args, int from_tty, struct cmd_list_element *c)
1035 {
1036 PROMPT (0) = xstrdup (new_async_prompt);
1037 }
1038
1039 /* Set things up for readline to be invoked via the alternate
1040 interface, i.e. via a callback function (rl_callback_read_char),
1041 and hook up instream to the event loop. */
1042 void
1043 gdb_setup_readline (void)
1044 {
1045 /* This function is a noop for the sync case. The assumption is
1046 that the sync setup is ALL done in gdb_init, and we would only
1047 mess it up here. The sync stuff should really go away over
1048 time. */
1049 if (!batch_silent)
1050 gdb_stdout = stdio_fileopen (stdout);
1051 gdb_stderr = stdio_fileopen (stderr);
1052 gdb_stdlog = gdb_stderr; /* for moment */
1053 gdb_stdtarg = gdb_stderr; /* for moment */
1054 gdb_stdtargerr = gdb_stderr; /* for moment */
1055
1056 /* If the input stream is connected to a terminal, turn on
1057 editing. */
1058 if (ISATTY (instream))
1059 {
1060 /* Tell gdb that we will be using the readline library. This
1061 could be overwritten by a command in .gdbinit like 'set
1062 editing on' or 'off'. */
1063 async_command_editing_p = 1;
1064
1065 /* When a character is detected on instream by select or poll,
1066 readline will be invoked via this callback function. */
1067 call_readline = rl_callback_read_char_wrapper;
1068 }
1069 else
1070 {
1071 async_command_editing_p = 0;
1072 call_readline = gdb_readline2;
1073 }
1074
1075 /* When readline has read an end-of-line character, it passes the
1076 complete line to gdb for processing; command_line_handler is the
1077 function that does this. */
1078 input_handler = command_line_handler;
1079
1080 /* Tell readline to use the same input stream that gdb uses. */
1081 rl_instream = instream;
1082
1083 /* Get a file descriptor for the input stream, so that we can
1084 register it with the event loop. */
1085 input_fd = fileno (instream);
1086
1087 /* Now we need to create the event sources for the input file
1088 descriptor. */
1089 /* At this point in time, this is the only event source that we
1090 register with the even loop. Another source is going to be the
1091 target program (inferior), but that must be registered only when
1092 it actually exists (I.e. after we say 'run' or after we connect
1093 to a remote target. */
1094 add_file_handler (input_fd, stdin_event_handler, 0);
1095 }
1096
1097 /* Disable command input through the standard CLI channels. Used in
1098 the suspend proc for interpreters that use the standard gdb readline
1099 interface, like the cli & the mi. */
1100 void
1101 gdb_disable_readline (void)
1102 {
1103 /* FIXME - It is too heavyweight to delete and remake these every
1104 time you run an interpreter that needs readline. It is probably
1105 better to have the interpreters cache these, which in turn means
1106 that this needs to be moved into interpreter specific code. */
1107
1108 #if 0
1109 ui_file_delete (gdb_stdout);
1110 ui_file_delete (gdb_stderr);
1111 gdb_stdlog = NULL;
1112 gdb_stdtarg = NULL;
1113 gdb_stdtargerr = NULL;
1114 #endif
1115
1116 rl_callback_handler_remove ();
1117 delete_file_handler (input_fd);
1118 }
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