Import gdb-7.0
[dragonfly.git] / contrib / gdb-7 / gdb / event-top.c
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1/* Top level stuff for GDB, the GNU debugger.
2
3 Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009
4 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
37/* For dont_repeat() */
38#include "gdbcmd.h"
39
40/* readline include files */
41#include "readline/readline.h"
42#include "readline/history.h"
43
44/* readline defines this. */
45#undef savestring
46
47static void rl_callback_read_char_wrapper (gdb_client_data client_data);
48static void command_line_handler (char *rl);
49static void change_line_handler (void);
50static void change_annotation_level (void);
51static void command_handler (char *command);
52
53/* Signal handlers. */
54#ifdef SIGQUIT
55static void handle_sigquit (int sig);
56#endif
57#ifdef SIGHUP
58static void handle_sighup (int sig);
59#endif
60static void handle_sigfpe (int sig);
61#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
62static void handle_sigwinch (int sig);
63#endif
64
65/* Functions to be invoked by the event loop in response to
66 signals. */
67#if defined (SIGQUIT) || defined (SIGHUP)
68static void async_do_nothing (gdb_client_data);
69#endif
70#ifdef SIGHUP
71static void async_disconnect (gdb_client_data);
72#endif
73static void async_float_handler (gdb_client_data);
74#ifdef STOP_SIGNAL
75static void async_stop_sig (gdb_client_data);
76#endif
77
78/* Readline offers an alternate interface, via callback
79 functions. These are all included in the file callback.c in the
80 readline distribution. This file provides (mainly) a function, which
81 the event loop uses as callback (i.e. event handler) whenever an event
82 is detected on the standard input file descriptor.
83 readline_callback_read_char is called (by the GDB event loop) whenever
84 there is a new character ready on the input stream. This function
85 incrementally builds a buffer internal to readline where it
86 accumulates the line read up to the point of invocation. In the
87 special case in which the character read is newline, the function
88 invokes a GDB supplied callback routine, which does the processing of
89 a full command line. This latter routine is the asynchronous analog
90 of the old command_line_input in gdb. Instead of invoking (and waiting
91 for) readline to read the command line and pass it back to
92 command_loop for processing, the new command_line_handler function has
93 the command line already available as its parameter. INPUT_HANDLER is
94 to be set to the function that readline will invoke when a complete
95 line of input is ready. CALL_READLINE is to be set to the function
96 that readline offers as callback to the event_loop. */
97
98void (*input_handler) (char *);
99void (*call_readline) (gdb_client_data);
100
101/* Important variables for the event loop. */
102
103/* This is used to determine if GDB is using the readline library or
104 its own simplified form of readline. It is used by the asynchronous
105 form of the set editing command.
106 ezannoni: as of 1999-04-29 I expect that this
107 variable will not be used after gdb is changed to use the event
108 loop as default engine, and event-top.c is merged into top.c. */
109int async_command_editing_p;
110
111/* This variable contains the new prompt that the user sets with the
112 set prompt command. */
113char *new_async_prompt;
114
115/* This is the annotation suffix that will be used when the
116 annotation_level is 2. */
117char *async_annotation_suffix;
118
119/* This is used to display the notification of the completion of an
120 asynchronous execution command. */
121int exec_done_display_p = 0;
122
123/* This is the file descriptor for the input stream that GDB uses to
124 read commands from. */
125int input_fd;
126
127/* This is the prompt stack. Prompts will be pushed on the stack as
128 needed by the different 'kinds' of user inputs GDB is asking
129 for. See event-loop.h. */
130struct prompts the_prompts;
131
132/* signal handling variables */
133/* Each of these is a pointer to a function that the event loop will
134 invoke if the corresponding signal has received. The real signal
135 handlers mark these functions as ready to be executed and the event
136 loop, in a later iteration, calls them. See the function
137 invoke_async_signal_handler. */
138void *sigint_token;
139#ifdef SIGHUP
140void *sighup_token;
141#endif
142#ifdef SIGQUIT
143void *sigquit_token;
144#endif
145void *sigfpe_token;
146#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
147void *sigwinch_token;
148#endif
149#ifdef STOP_SIGNAL
150void *sigtstp_token;
151#endif
152
153/* Structure to save a partially entered command. This is used when
154 the user types '\' at the end of a command line. This is necessary
155 because each line of input is handled by a different call to
156 command_line_handler, and normally there is no state retained
157 between different calls. */
158int more_to_come = 0;
159
160struct readline_input_state
161 {
162 char *linebuffer;
163 char *linebuffer_ptr;
164 }
165readline_input_state;
166
167/* This hook is called by rl_callback_read_char_wrapper after each
168 character is processed. */
169void (*after_char_processing_hook) ();
170\f
171
172/* Wrapper function for calling into the readline library. The event
173 loop expects the callback function to have a paramter, while readline
174 expects none. */
175static void
176rl_callback_read_char_wrapper (gdb_client_data client_data)
177{
178 rl_callback_read_char ();
179 if (after_char_processing_hook)
180 (*after_char_processing_hook) ();
181}
182
183/* Initialize all the necessary variables, start the event loop,
184 register readline, and stdin, start the loop. */
185void
186cli_command_loop (void)
187{
188 /* If we are using readline, set things up and display the first
189 prompt, otherwise just print the prompt. */
190 if (async_command_editing_p)
191 {
192 int length;
193 char *a_prompt;
194 char *gdb_prompt = get_prompt ();
195
196 /* Tell readline what the prompt to display is and what function it
197 will need to call after a whole line is read. This also displays
198 the first prompt. */
199 length = strlen (PREFIX (0))
200 + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1;
201 a_prompt = (char *) alloca (length);
202 strcpy (a_prompt, PREFIX (0));
203 strcat (a_prompt, gdb_prompt);
204 strcat (a_prompt, SUFFIX (0));
205 rl_callback_handler_install (a_prompt, input_handler);
206 }
207 else
208 display_gdb_prompt (0);
209
210 /* Now it's time to start the event loop. */
211 start_event_loop ();
212}
213
214/* Change the function to be invoked every time there is a character
215 ready on stdin. This is used when the user sets the editing off,
216 therefore bypassing readline, and letting gdb handle the input
217 itself, via gdb_readline2. Also it is used in the opposite case in
218 which the user sets editing on again, by restoring readline
219 handling of the input. */
220static void
221change_line_handler (void)
222{
223 /* NOTE: this operates on input_fd, not instream. If we are reading
224 commands from a file, instream will point to the file. However in
225 async mode, we always read commands from a file with editing
226 off. This means that the 'set editing on/off' will have effect
227 only on the interactive session. */
228
229 if (async_command_editing_p)
230 {
231 /* Turn on editing by using readline. */
232 call_readline = rl_callback_read_char_wrapper;
233 input_handler = command_line_handler;
234 }
235 else
236 {
237 /* Turn off editing by using gdb_readline2. */
238 rl_callback_handler_remove ();
239 call_readline = gdb_readline2;
240
241 /* Set up the command handler as well, in case we are called as
242 first thing from .gdbinit. */
243 input_handler = command_line_handler;
244 }
245}
246
247/* Displays the prompt. The prompt that is displayed is the current
248 top of the prompt stack, if the argument NEW_PROMPT is
249 0. Otherwise, it displays whatever NEW_PROMPT is. This is used
250 after each gdb command has completed, and in the following cases:
251 1. when the user enters a command line which is ended by '\'
252 indicating that the command will continue on the next line.
253 In that case the prompt that is displayed is the empty string.
254 2. When the user is entering 'commands' for a breakpoint, or
255 actions for a tracepoint. In this case the prompt will be '>'
256 3. Other????
257 FIXME: 2. & 3. not implemented yet for async. */
258void
259display_gdb_prompt (char *new_prompt)
260{
261 int prompt_length = 0;
262 char *gdb_prompt = get_prompt ();
263
264 /* Reset the nesting depth used when trace-commands is set. */
265 reset_command_nest_depth ();
266
267 /* Each interpreter has its own rules on displaying the command
268 prompt. */
269 if (!current_interp_display_prompt_p ())
270 return;
271
272 if (sync_execution && is_running (inferior_ptid))
273 {
274 /* This is to trick readline into not trying to display the
275 prompt. Even though we display the prompt using this
276 function, readline still tries to do its own display if we
277 don't call rl_callback_handler_install and
278 rl_callback_handler_remove (which readline detects because a
279 global variable is not set). If readline did that, it could
280 mess up gdb signal handlers for SIGINT. Readline assumes
281 that between calls to rl_set_signals and rl_clear_signals gdb
282 doesn't do anything with the signal handlers. Well, that's
283 not the case, because when the target executes we change the
284 SIGINT signal handler. If we allowed readline to display the
285 prompt, the signal handler change would happen exactly
286 between the calls to the above two functions.
287 Calling rl_callback_handler_remove(), does the job. */
288
289 rl_callback_handler_remove ();
290 return;
291 }
292
293 if (!new_prompt)
294 {
295 /* Just use the top of the prompt stack. */
296 prompt_length = strlen (PREFIX (0)) +
297 strlen (SUFFIX (0)) +
298 strlen (gdb_prompt) + 1;
299
300 new_prompt = (char *) alloca (prompt_length);
301
302 /* Prefix needs to have new line at end. */
303 strcpy (new_prompt, PREFIX (0));
304 strcat (new_prompt, gdb_prompt);
305 /* Suffix needs to have a new line at end and \032 \032 at
306 beginning. */
307 strcat (new_prompt, SUFFIX (0));
308 }
309
310 if (async_command_editing_p)
311 {
312 rl_callback_handler_remove ();
313 rl_callback_handler_install (new_prompt, input_handler);
314 }
315 /* new_prompt at this point can be the top of the stack or the one passed in */
316 else if (new_prompt)
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). */
331static void
332change_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. */
376void
377push_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 for it. */
394void
395pop_prompt (void)
396{
397 /* If we are not during a 'synchronous' execution command, in which
398 case, the top prompt would be empty. */
399 if (strcmp (PROMPT (0), ""))
400 /* This is for the case in which the prompt is set while the
401 annotation level is 2. The top prompt will be changed, but when
402 we return to annotation level < 2, we want that new prompt to be
403 in effect, until the user does another 'set prompt'. */
404 if (strcmp (PROMPT (0), PROMPT (-1)))
405 {
406 xfree (PROMPT (-1));
407 PROMPT (-1) = xstrdup (PROMPT (0));
408 }
409
410 xfree (PREFIX (0));
411 xfree (PROMPT (0));
412 xfree (SUFFIX (0));
413 the_prompts.top--;
414}
415
416/* When there is an event ready on the stdin file desriptor, instead
417 of calling readline directly throught the callback function, or
418 instead of calling gdb_readline2, give gdb a chance to detect
419 errors and do something. */
420void
421stdin_event_handler (int error, gdb_client_data client_data)
422{
423 if (error)
424 {
425 printf_unfiltered (_("error detected on stdin\n"));
426 delete_file_handler (input_fd);
427 discard_all_continuations ();
428 discard_all_intermediate_continuations ();
429 /* If stdin died, we may as well kill gdb. */
430 quit_command ((char *) 0, stdin == instream);
431 }
432 else
433 (*call_readline) (client_data);
434}
435
436/* Re-enable stdin after the end of an execution command in
437 synchronous mode, or after an error from the target, and we aborted
438 the exec operation. */
439
440void
441async_enable_stdin (void)
442{
443 if (sync_execution)
444 {
445 /* See NOTE in async_disable_stdin() */
446 /* FIXME: cagney/1999-09-27: Call this before clearing
447 sync_execution. Current target_terminal_ours() implementations
448 check for sync_execution before switching the terminal. */
449 target_terminal_ours ();
450 pop_prompt ();
451 sync_execution = 0;
452 }
453}
454
455/* Disable reads from stdin (the console) marking the command as
456 synchronous. */
457
458void
459async_disable_stdin (void)
460{
461 if (!sync_execution)
462 {
463 sync_execution = 1;
464 push_prompt ("", "", "");
465 }
466}
467\f
468
469/* Handles a gdb command. This function is called by
470 command_line_handler, which has processed one or more input lines
471 into COMMAND. */
472/* NOTE: 1999-04-30 This is the asynchronous version of the command_loop
473 function. The command_loop function will be obsolete when we
474 switch to use the event loop at every execution of gdb. */
475static void
476command_handler (char *command)
477{
478 int stdin_is_tty = ISATTY (stdin);
479 long time_at_cmd_start;
480#ifdef HAVE_SBRK
481 long space_at_cmd_start = 0;
482#endif
483 extern int display_time;
484 extern int display_space;
485
486 quit_flag = 0;
487 if (instream == stdin && stdin_is_tty)
488 reinitialize_more_filter ();
489
490 /* If readline returned a NULL command, it means that the
491 connection with the terminal is gone. This happens at the
492 end of a testsuite run, after Expect has hung up
493 but GDB is still alive. In such a case, we just quit gdb
494 killing the inferior program too. */
495 if (command == 0)
496 {
497 printf_unfiltered ("quit\n");
498 execute_command ("quit", stdin == instream);
499 }
500
501 time_at_cmd_start = get_run_time ();
502
503 if (display_space)
504 {
505#ifdef HAVE_SBRK
506 char *lim = (char *) sbrk (0);
507 space_at_cmd_start = lim - lim_at_start;
508#endif
509 }
510
511 execute_command (command, instream == stdin);
512
513 /* Do any commands attached to breakpoint we stopped at. */
514 bpstat_do_actions ();
515
516 if (display_time)
517 {
518 long cmd_time = get_run_time () - time_at_cmd_start;
519
520 printf_unfiltered (_("Command execution time: %ld.%06ld\n"),
521 cmd_time / 1000000, cmd_time % 1000000);
522 }
523
524 if (display_space)
525 {
526#ifdef HAVE_SBRK
527 char *lim = (char *) sbrk (0);
528 long space_now = lim - lim_at_start;
529 long space_diff = space_now - space_at_cmd_start;
530
531 printf_unfiltered (_("Space used: %ld (%c%ld for this command)\n"),
532 space_now,
533 (space_diff >= 0 ? '+' : '-'),
534 space_diff);
535#endif
536 }
537}
538
539/* Handle a complete line of input. This is called by the callback
540 mechanism within the readline library. Deal with incomplete commands
541 as well, by saving the partial input in a global buffer. */
542
543/* NOTE: 1999-04-30 This is the asynchronous version of the
544 command_line_input function. command_line_input will become
545 obsolete once we use the event loop as the default mechanism in
546 GDB. */
547static void
548command_line_handler (char *rl)
549{
550 static char *linebuffer = 0;
551 static unsigned linelength = 0;
552 char *p;
553 char *p1;
554 extern char *line;
555 extern int linesize;
556 char *nline;
557 char got_eof = 0;
558
559
560 int repeat = (instream == stdin);
561
562 if (annotation_level > 1 && instream == stdin)
563 {
564 printf_unfiltered (("\n\032\032post-"));
565 puts_unfiltered (async_annotation_suffix);
566 printf_unfiltered (("\n"));
567 }
568
569 if (linebuffer == 0)
570 {
571 linelength = 80;
572 linebuffer = (char *) xmalloc (linelength);
573 }
574
575 p = linebuffer;
576
577 if (more_to_come)
578 {
579 strcpy (linebuffer, readline_input_state.linebuffer);
580 p = readline_input_state.linebuffer_ptr;
581 xfree (readline_input_state.linebuffer);
582 more_to_come = 0;
583 pop_prompt ();
584 }
585
586#ifdef STOP_SIGNAL
587 if (job_control)
588 signal (STOP_SIGNAL, handle_stop_sig);
589#endif
590
591 /* Make sure that all output has been output. Some machines may let
592 you get away with leaving out some of the gdb_flush, but not all. */
593 wrap_here ("");
594 gdb_flush (gdb_stdout);
595 gdb_flush (gdb_stderr);
596
597 if (source_file_name != NULL)
598 ++source_line_number;
599
600 /* If we are in this case, then command_handler will call quit
601 and exit from gdb. */
602 if (!rl || rl == (char *) EOF)
603 {
604 got_eof = 1;
605 command_handler (0);
606 return; /* Lint. */
607 }
608 if (strlen (rl) + 1 + (p - linebuffer) > linelength)
609 {
610 linelength = strlen (rl) + 1 + (p - linebuffer);
611 nline = (char *) xrealloc (linebuffer, linelength);
612 p += nline - linebuffer;
613 linebuffer = nline;
614 }
615 p1 = rl;
616 /* Copy line. Don't copy null at end. (Leaves line alone
617 if this was just a newline) */
618 while (*p1)
619 *p++ = *p1++;
620
621 xfree (rl); /* Allocated in readline. */
622
623 if (p > linebuffer && *(p - 1) == '\\')
624 {
625 *p = '\0';
626 p--; /* Put on top of '\'. */
627
628 readline_input_state.linebuffer = xstrdup (linebuffer);
629 readline_input_state.linebuffer_ptr = p;
630
631 /* We will not invoke a execute_command if there is more
632 input expected to complete the command. So, we need to
633 print an empty prompt here. */
634 more_to_come = 1;
635 push_prompt ("", "", "");
636 display_gdb_prompt (0);
637 return;
638 }
639
640#ifdef STOP_SIGNAL
641 if (job_control)
642 signal (STOP_SIGNAL, SIG_DFL);
643#endif
644
645#define SERVER_COMMAND_LENGTH 7
646 server_command =
647 (p - linebuffer > SERVER_COMMAND_LENGTH)
648 && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0;
649 if (server_command)
650 {
651 /* Note that we don't set `line'. Between this and the check in
652 dont_repeat, this insures that repeating will still do the
653 right thing. */
654 *p = '\0';
655 command_handler (linebuffer + SERVER_COMMAND_LENGTH);
656 display_gdb_prompt (0);
657 return;
658 }
659
660 /* Do history expansion if that is wished. */
661 if (history_expansion_p && instream == stdin
662 && ISATTY (instream))
663 {
664 char *history_value;
665 int expanded;
666
667 *p = '\0'; /* Insert null now. */
668 expanded = history_expand (linebuffer, &history_value);
669 if (expanded)
670 {
671 /* Print the changes. */
672 printf_unfiltered ("%s\n", history_value);
673
674 /* If there was an error, call this function again. */
675 if (expanded < 0)
676 {
677 xfree (history_value);
678 return;
679 }
680 if (strlen (history_value) > linelength)
681 {
682 linelength = strlen (history_value) + 1;
683 linebuffer = (char *) xrealloc (linebuffer, linelength);
684 }
685 strcpy (linebuffer, history_value);
686 p = linebuffer + strlen (linebuffer);
687 }
688 xfree (history_value);
689 }
690
691 /* If we just got an empty line, and that is supposed
692 to repeat the previous command, return the value in the
693 global buffer. */
694 if (repeat && p == linebuffer && *p != '\\')
695 {
696 command_handler (line);
697 display_gdb_prompt (0);
698 return;
699 }
700
701 for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++);
702 if (repeat && !*p1)
703 {
704 command_handler (line);
705 display_gdb_prompt (0);
706 return;
707 }
708
709 *p = 0;
710
711 /* Add line to history if appropriate. */
712 if (instream == stdin
713 && ISATTY (stdin) && *linebuffer)
714 add_history (linebuffer);
715
716 /* Note: lines consisting solely of comments are added to the command
717 history. This is useful when you type a command, and then
718 realize you don't want to execute it quite yet. You can comment
719 out the command and then later fetch it from the value history
720 and remove the '#'. The kill ring is probably better, but some
721 people are in the habit of commenting things out. */
722 if (*p1 == '#')
723 *p1 = '\0'; /* Found a comment. */
724
725 /* Save into global buffer if appropriate. */
726 if (repeat)
727 {
728 if (linelength > linesize)
729 {
730 line = xrealloc (line, linelength);
731 linesize = linelength;
732 }
733 strcpy (line, linebuffer);
734 if (!more_to_come)
735 {
736 command_handler (line);
737 display_gdb_prompt (0);
738 }
739 return;
740 }
741
742 command_handler (linebuffer);
743 display_gdb_prompt (0);
744 return;
745}
746
747/* Does reading of input from terminal w/o the editing features
748 provided by the readline library. */
749
750/* NOTE: 1999-04-30 Asynchronous version of gdb_readline. gdb_readline
751 will become obsolete when the event loop is made the default
752 execution for gdb. */
753void
754gdb_readline2 (gdb_client_data client_data)
755{
756 int c;
757 char *result;
758 int input_index = 0;
759 int result_size = 80;
760 static int done_once = 0;
761
762 /* Unbuffer the input stream, so that, later on, the calls to fgetc
763 fetch only one char at the time from the stream. The fgetc's will
764 get up to the first newline, but there may be more chars in the
765 stream after '\n'. If we buffer the input and fgetc drains the
766 stream, getting stuff beyond the newline as well, a select, done
767 afterwards will not trigger. */
768 if (!done_once && !ISATTY (instream))
769 {
770 setbuf (instream, NULL);
771 done_once = 1;
772 }
773
774 result = (char *) xmalloc (result_size);
775
776 /* We still need the while loop here, even though it would seem
777 obvious to invoke gdb_readline2 at every character entered. If
778 not using the readline library, the terminal is in cooked mode,
779 which sends the characters all at once. Poll will notice that the
780 input fd has changed state only after enter is pressed. At this
781 point we still need to fetch all the chars entered. */
782
783 while (1)
784 {
785 /* Read from stdin if we are executing a user defined command.
786 This is the right thing for prompt_for_continue, at least. */
787 c = fgetc (instream ? instream : stdin);
788
789 if (c == EOF)
790 {
791 if (input_index > 0)
792 /* The last line does not end with a newline. Return it, and
793 if we are called again fgetc will still return EOF and
794 we'll return NULL then. */
795 break;
796 xfree (result);
797 (*input_handler) (0);
798 return;
799 }
800
801 if (c == '\n')
802 {
803 if (input_index > 0 && result[input_index - 1] == '\r')
804 input_index--;
805 break;
806 }
807
808 result[input_index++] = c;
809 while (input_index >= result_size)
810 {
811 result_size *= 2;
812 result = (char *) xrealloc (result, result_size);
813 }
814 }
815
816 result[input_index++] = '\0';
817 (*input_handler) (result);
818}
819\f
820
821/* Initialization of signal handlers and tokens. There is a function
822 handle_sig* for each of the signals GDB cares about. Specifically:
823 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
824 functions are the actual signal handlers associated to the signals
825 via calls to signal(). The only job for these functions is to
826 enqueue the appropriate event/procedure with the event loop. Such
827 procedures are the old signal handlers. The event loop will take
828 care of invoking the queued procedures to perform the usual tasks
829 associated with the reception of the signal. */
830/* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
831 init_signals will become obsolete as we move to have to event loop
832 as the default for gdb. */
833void
834async_init_signals (void)
835{
836 signal (SIGINT, handle_sigint);
837 sigint_token =
838 create_async_signal_handler (async_request_quit, NULL);
839 signal (SIGTERM, handle_sigterm);
840
841 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
842 to the inferior and breakpoints will be ignored. */
843#ifdef SIGTRAP
844 signal (SIGTRAP, SIG_DFL);
845#endif
846
847#ifdef SIGQUIT
848 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
849 passed to the inferior, which we don't want. It would be
850 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
851 on BSD4.3 systems using vfork, that can affect the
852 GDB process as well as the inferior (the signal handling tables
853 might be in memory, shared between the two). Since we establish
854 a handler for SIGQUIT, when we call exec it will set the signal
855 to SIG_DFL for us. */
856 signal (SIGQUIT, handle_sigquit);
857 sigquit_token =
858 create_async_signal_handler (async_do_nothing, NULL);
859#endif
860#ifdef SIGHUP
861 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
862 sighup_token =
863 create_async_signal_handler (async_disconnect, NULL);
864 else
865 sighup_token =
866 create_async_signal_handler (async_do_nothing, NULL);
867#endif
868 signal (SIGFPE, handle_sigfpe);
869 sigfpe_token =
870 create_async_signal_handler (async_float_handler, NULL);
871
872#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
873 signal (SIGWINCH, handle_sigwinch);
874 sigwinch_token =
875 create_async_signal_handler (SIGWINCH_HANDLER, NULL);
876#endif
877#ifdef STOP_SIGNAL
878 sigtstp_token =
879 create_async_signal_handler (async_stop_sig, NULL);
880#endif
881
882}
883
884void
885mark_async_signal_handler_wrapper (void *token)
886{
887 mark_async_signal_handler ((struct async_signal_handler *) token);
888}
889
890/* Tell the event loop what to do if SIGINT is received.
891 See event-signal.c. */
892void
893handle_sigint (int sig)
894{
895 signal (sig, handle_sigint);
896
897 /* We could be running in a loop reading in symfiles or something so
898 it may be quite a while before we get back to the event loop. So
899 set quit_flag to 1 here. Then if QUIT is called before we get to
900 the event loop, we will unwind as expected. */
901
902 quit_flag = 1;
903
904 /* If immediate_quit is set, we go ahead and process the SIGINT right
905 away, even if we usually would defer this to the event loop. The
906 assumption here is that it is safe to process ^C immediately if
907 immediate_quit is set. If we didn't, SIGINT would be really
908 processed only the next time through the event loop. To get to
909 that point, though, the command that we want to interrupt needs to
910 finish first, which is unacceptable. If immediate quit is not set,
911 we process SIGINT the next time through the loop, which is fine. */
912 gdb_call_async_signal_handler (sigint_token, immediate_quit);
913}
914
915/* Quit GDB if SIGTERM is received.
916 GDB would quit anyway, but this way it will clean up properly. */
917void
918handle_sigterm (int sig)
919{
920 signal (sig, handle_sigterm);
921 quit_force ((char *) 0, stdin == instream);
922}
923
924/* Do the quit. All the checks have been done by the caller. */
925void
926async_request_quit (gdb_client_data arg)
927{
928 /* If the quit_flag has gotten reset back to 0 by the time we get
929 back here, that means that an exception was thrown to unwind the
930 current command before we got back to the event loop. So there
931 is no reason to call quit again here, unless immediate_quit is
932 set.*/
933
934 if (quit_flag || immediate_quit)
935 quit ();
936}
937
938#ifdef SIGQUIT
939/* Tell the event loop what to do if SIGQUIT is received.
940 See event-signal.c. */
941static void
942handle_sigquit (int sig)
943{
944 mark_async_signal_handler_wrapper (sigquit_token);
945 signal (sig, handle_sigquit);
946}
947#endif
948
949#if defined (SIGQUIT) || defined (SIGHUP)
950/* Called by the event loop in response to a SIGQUIT or an
951 ignored SIGHUP. */
952static void
953async_do_nothing (gdb_client_data arg)
954{
955 /* Empty function body. */
956}
957#endif
958
959#ifdef SIGHUP
960/* Tell the event loop what to do if SIGHUP is received.
961 See event-signal.c. */
962static void
963handle_sighup (int sig)
964{
965 mark_async_signal_handler_wrapper (sighup_token);
966 signal (sig, handle_sighup);
967}
968
969/* Called by the event loop to process a SIGHUP */
970static void
971async_disconnect (gdb_client_data arg)
972{
973 catch_errors (quit_cover, NULL,
974 "Could not kill the program being debugged",
975 RETURN_MASK_ALL);
976 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
977 raise (SIGHUP);
978}
979#endif
980
981#ifdef STOP_SIGNAL
982void
983handle_stop_sig (int sig)
984{
985 mark_async_signal_handler_wrapper (sigtstp_token);
986 signal (sig, handle_stop_sig);
987}
988
989static void
990async_stop_sig (gdb_client_data arg)
991{
992 char *prompt = get_prompt ();
993#if STOP_SIGNAL == SIGTSTP
994 signal (SIGTSTP, SIG_DFL);
995#if HAVE_SIGPROCMASK
996 {
997 sigset_t zero;
998
999 sigemptyset (&zero);
1000 sigprocmask (SIG_SETMASK, &zero, 0);
1001 }
1002#elif HAVE_SIGSETMASK
1003 sigsetmask (0);
1004#endif
1005 raise (SIGTSTP);
1006 signal (SIGTSTP, handle_stop_sig);
1007#else
1008 signal (STOP_SIGNAL, handle_stop_sig);
1009#endif
1010 printf_unfiltered ("%s", prompt);
1011 gdb_flush (gdb_stdout);
1012
1013 /* Forget about any previous command -- null line now will do nothing. */
1014 dont_repeat ();
1015}
1016#endif /* STOP_SIGNAL */
1017
1018/* Tell the event loop what to do if SIGFPE is received.
1019 See event-signal.c. */
1020static void
1021handle_sigfpe (int sig)
1022{
1023 mark_async_signal_handler_wrapper (sigfpe_token);
1024 signal (sig, handle_sigfpe);
1025}
1026
1027/* Event loop will call this functin to process a SIGFPE. */
1028static void
1029async_float_handler (gdb_client_data arg)
1030{
1031 /* This message is based on ANSI C, section 4.7. Note that integer
1032 divide by zero causes this, so "float" is a misnomer. */
1033 error (_("Erroneous arithmetic operation."));
1034}
1035
1036/* Tell the event loop what to do if SIGWINCH is received.
1037 See event-signal.c. */
1038#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
1039static void
1040handle_sigwinch (int sig)
1041{
1042 mark_async_signal_handler_wrapper (sigwinch_token);
1043 signal (sig, handle_sigwinch);
1044}
1045#endif
1046\f
1047
1048/* Called by do_setshow_command. */
1049void
1050set_async_editing_command (char *args, int from_tty, struct cmd_list_element *c)
1051{
1052 change_line_handler ();
1053}
1054
1055/* Called by do_setshow_command. */
1056void
1057set_async_annotation_level (char *args, int from_tty, struct cmd_list_element *c)
1058{
1059 change_annotation_level ();
1060}
1061
1062/* Called by do_setshow_command. */
1063void
1064set_async_prompt (char *args, int from_tty, struct cmd_list_element *c)
1065{
1066 PROMPT (0) = xstrdup (new_async_prompt);
1067}
1068
1069/* Set things up for readline to be invoked via the alternate
1070 interface, i.e. via a callback function (rl_callback_read_char),
1071 and hook up instream to the event loop. */
1072void
1073gdb_setup_readline (void)
1074{
1075 /* This function is a noop for the sync case. The assumption is
1076 that the sync setup is ALL done in gdb_init, and we would only
1077 mess it up here. The sync stuff should really go away over
1078 time. */
1079 if (!batch_silent)
1080 gdb_stdout = stdio_fileopen (stdout);
1081 gdb_stderr = stdio_fileopen (stderr);
1082 gdb_stdlog = gdb_stderr; /* for moment */
1083 gdb_stdtarg = gdb_stderr; /* for moment */
1084
1085 /* If the input stream is connected to a terminal, turn on
1086 editing. */
1087 if (ISATTY (instream))
1088 {
1089 /* Tell gdb that we will be using the readline library. This
1090 could be overwritten by a command in .gdbinit like 'set
1091 editing on' or 'off'. */
1092 async_command_editing_p = 1;
1093
1094 /* When a character is detected on instream by select or poll,
1095 readline will be invoked via this callback function. */
1096 call_readline = rl_callback_read_char_wrapper;
1097 }
1098 else
1099 {
1100 async_command_editing_p = 0;
1101 call_readline = gdb_readline2;
1102 }
1103
1104 /* When readline has read an end-of-line character, it passes the
1105 complete line to gdb for processing. command_line_handler is the
1106 function that does this. */
1107 input_handler = command_line_handler;
1108
1109 /* Tell readline to use the same input stream that gdb uses. */
1110 rl_instream = instream;
1111
1112 /* Get a file descriptor for the input stream, so that we can
1113 register it with the event loop. */
1114 input_fd = fileno (instream);
1115
1116 /* Now we need to create the event sources for the input file
1117 descriptor. */
1118 /* At this point in time, this is the only event source that we
1119 register with the even loop. Another source is going to be the
1120 target program (inferior), but that must be registered only when
1121 it actually exists (I.e. after we say 'run' or after we connect
1122 to a remote target. */
1123 add_file_handler (input_fd, stdin_event_handler, 0);
1124}
1125
1126/* Disable command input through the standard CLI channels. Used in
1127 the suspend proc for interpreters that use the standard gdb readline
1128 interface, like the cli & the mi. */
1129void
1130gdb_disable_readline (void)
1131{
1132 /* FIXME - It is too heavyweight to delete and remake these every
1133 time you run an interpreter that needs readline. It is probably
1134 better to have the interpreters cache these, which in turn means
1135 that this needs to be moved into interpreter specific code. */
1136
1137#if 0
1138 ui_file_delete (gdb_stdout);
1139 ui_file_delete (gdb_stderr);
1140 gdb_stdlog = NULL;
1141 gdb_stdtarg = NULL;
1142#endif
1143
1144 rl_callback_handler_remove ();
1145 delete_file_handler (input_fd);
1146}