* solib-svr4.c (svr4_truncate_ptr): New function.
[deliverable/binutils-gdb.git] / gdb / event-top.c
1 /* Top level stuff for GDB, the GNU debugger.
2 Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
3 Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
21
22 #include "defs.h"
23 #include "top.h"
24 #include "inferior.h"
25 #include "target.h"
26 #include "terminal.h" /* for job_control */
27 #include "event-loop.h"
28 #include "event-top.h"
29 #include <signal.h>
30
31 /* For dont_repeat() */
32 #include "gdbcmd.h"
33
34 /* readline include files */
35 #include <readline/readline.h>
36 #include <readline/history.h>
37
38 /* readline defines this. */
39 #undef savestring
40
41 extern void _initialize_event_loop (void);
42
43 static void rl_callback_read_char_wrapper (gdb_client_data client_data);
44 static void command_line_handler (char *rl);
45 static void command_line_handler_continuation (struct continuation_arg *arg);
46 static void change_line_handler (void);
47 static void change_annotation_level (void);
48 static void command_handler (char *command);
49 void cli_command_loop (void);
50 static void async_do_nothing (gdb_client_data arg);
51 static void async_disconnect (gdb_client_data arg);
52 static void async_stop_sig (gdb_client_data arg);
53 static void async_float_handler (gdb_client_data arg);
54
55 /* Signal handlers. */
56 static void handle_sigquit (int sig);
57 static void handle_sighup (int sig);
58 static void handle_sigfpe (int sig);
59 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
60 static void handle_sigwinch (int sig);
61 #endif
62
63 /* Functions to be invoked by the event loop in response to
64 signals. */
65 static void async_do_nothing (gdb_client_data);
66 static void async_disconnect (gdb_client_data);
67 static void async_float_handler (gdb_client_data);
68 static void async_stop_sig (gdb_client_data);
69
70 /* Readline offers an alternate interface, via callback
71 functions. These are all included in the file callback.c in the
72 readline distribution. This file provides (mainly) a function, which
73 the event loop uses as callback (i.e. event handler) whenever an event
74 is detected on the standard input file descriptor.
75 readline_callback_read_char is called (by the GDB event loop) whenever
76 there is a new character ready on the input stream. This function
77 incrementally builds a buffer internal to readline where it
78 accumulates the line read up to the point of invocation. In the
79 special case in which the character read is newline, the function
80 invokes a GDB supplied callback routine, which does the processing of
81 a full command line. This latter routine is the asynchronous analog
82 of the old command_line_input in gdb. Instead of invoking (and waiting
83 for) readline to read the command line and pass it back to
84 command_loop for processing, the new command_line_handler function has
85 the command line already available as its parameter. INPUT_HANDLER is
86 to be set to the function that readline will invoke when a complete
87 line of input is ready. CALL_READLINE is to be set to the function
88 that readline offers as callback to the event_loop. */
89
90 void (*input_handler) (char *);
91 void (*call_readline) (gdb_client_data);
92
93 /* Important variables for the event loop. */
94
95 /* This is used to determine if GDB is using the readline library or
96 its own simplified form of readline. It is used by the asynchronous
97 form of the set editing command.
98 ezannoni: as of 1999-04-29 I expect that this
99 variable will not be used after gdb is changed to use the event
100 loop as default engine, and event-top.c is merged into top.c. */
101 int async_command_editing_p;
102
103 /* This variable contains the new prompt that the user sets with the
104 set prompt command. */
105 char *new_async_prompt;
106
107 /* This is the annotation suffix that will be used when the
108 annotation_level is 2. */
109 char *async_annotation_suffix;
110
111 /* This is used to display the notification of the completion of an
112 asynchronous execution command. */
113 int exec_done_display_p = 0;
114
115 /* This is the file descriptor for the input stream that GDB uses to
116 read commands from. */
117 int input_fd;
118
119 /* This is the prompt stack. Prompts will be pushed on the stack as
120 needed by the different 'kinds' of user inputs GDB is asking
121 for. See event-loop.h. */
122 struct prompts the_prompts;
123
124 /* signal handling variables */
125 /* Each of these is a pointer to a function that the event loop will
126 invoke if the corresponding signal has received. The real signal
127 handlers mark these functions as ready to be executed and the event
128 loop, in a later iteration, calls them. See the function
129 invoke_async_signal_handler. */
130 void *sigint_token;
131 #ifdef SIGHUP
132 void *sighup_token;
133 #endif
134 void *sigquit_token;
135 void *sigfpe_token;
136 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
137 void *sigwinch_token;
138 #endif
139 #ifdef STOP_SIGNAL
140 void *sigtstp_token;
141 #endif
142
143 /* Structure to save a partially entered command. This is used when
144 the user types '\' at the end of a command line. This is necessary
145 because each line of input is handled by a different call to
146 command_line_handler, and normally there is no state retained
147 between different calls. */
148 int more_to_come = 0;
149
150 struct readline_input_state
151 {
152 char *linebuffer;
153 char *linebuffer_ptr;
154 }
155 readline_input_state;
156
157 /* This hook is called by rl_callback_read_char_wrapper after each
158 character is processed. */
159 void (*after_char_processing_hook) ();
160 \f
161
162 /* Wrapper function for calling into the readline library. The event
163 loop expects the callback function to have a paramter, while readline
164 expects none. */
165 static void
166 rl_callback_read_char_wrapper (gdb_client_data client_data)
167 {
168 rl_callback_read_char ();
169 if (after_char_processing_hook)
170 (*after_char_processing_hook) ();
171 }
172
173 /* Initialize all the necessary variables, start the event loop,
174 register readline, and stdin, start the loop. */
175 void
176 cli_command_loop (void)
177 {
178 int length;
179 char *a_prompt;
180 char *gdb_prompt = get_prompt ();
181
182 /* If we are using readline, set things up and display the first
183 prompt, otherwise just print the prompt. */
184 if (async_command_editing_p)
185 {
186 /* Tell readline what the prompt to display is and what function it
187 will need to call after a whole line is read. This also displays
188 the first prompt. */
189 length = strlen (PREFIX (0)) + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1;
190 a_prompt = (char *) xmalloc (length);
191 strcpy (a_prompt, PREFIX (0));
192 strcat (a_prompt, gdb_prompt);
193 strcat (a_prompt, SUFFIX (0));
194 rl_callback_handler_install (a_prompt, input_handler);
195 }
196 else
197 display_gdb_prompt (0);
198
199 /* Now it's time to start the event loop. */
200 start_event_loop ();
201 }
202
203 /* Change the function to be invoked every time there is a character
204 ready on stdin. This is used when the user sets the editing off,
205 therefore bypassing readline, and letting gdb handle the input
206 itself, via gdb_readline2. Also it is used in the opposite case in
207 which the user sets editing on again, by restoring readline
208 handling of the input. */
209 static void
210 change_line_handler (void)
211 {
212 /* NOTE: this operates on input_fd, not instream. If we are reading
213 commands from a file, instream will point to the file. However in
214 async mode, we always read commands from a file with editing
215 off. This means that the 'set editing on/off' will have effect
216 only on the interactive session. */
217
218 if (async_command_editing_p)
219 {
220 /* Turn on editing by using readline. */
221 call_readline = rl_callback_read_char_wrapper;
222 input_handler = command_line_handler;
223 }
224 else
225 {
226 /* Turn off editing by using gdb_readline2. */
227 rl_callback_handler_remove ();
228 call_readline = gdb_readline2;
229
230 /* Set up the command handler as well, in case we are called as
231 first thing from .gdbinit. */
232 input_handler = command_line_handler;
233 }
234 }
235
236 /* Displays the prompt. The prompt that is displayed is the current
237 top of the prompt stack, if the argument NEW_PROMPT is
238 0. Otherwise, it displays whatever NEW_PROMPT is. This is used
239 after each gdb command has completed, and in the following cases:
240 1. when the user enters a command line which is ended by '\'
241 indicating that the command will continue on the next line.
242 In that case the prompt that is displayed is the empty string.
243 2. When the user is entering 'commands' for a breakpoint, or
244 actions for a tracepoint. In this case the prompt will be '>'
245 3. Other????
246 FIXME: 2. & 3. not implemented yet for async. */
247 void
248 display_gdb_prompt (char *new_prompt)
249 {
250 int prompt_length = 0;
251 char *gdb_prompt = get_prompt ();
252
253 /* When an alternative interpreter has been installed, do not
254 display the comand prompt. */
255 if (interpreter_p)
256 return;
257
258 if (target_executing && sync_execution)
259 {
260 /* This is to trick readline into not trying to display the
261 prompt. Even though we display the prompt using this
262 function, readline still tries to do its own display if we
263 don't call rl_callback_handler_install and
264 rl_callback_handler_remove (which readline detects because a
265 global variable is not set). If readline did that, it could
266 mess up gdb signal handlers for SIGINT. Readline assumes
267 that between calls to rl_set_signals and rl_clear_signals gdb
268 doesn't do anything with the signal handlers. Well, that's
269 not the case, because when the target executes we change the
270 SIGINT signal handler. If we allowed readline to display the
271 prompt, the signal handler change would happen exactly
272 between the calls to the above two functions.
273 Calling rl_callback_handler_remove(), does the job. */
274
275 rl_callback_handler_remove ();
276 return;
277 }
278
279 if (!new_prompt)
280 {
281 /* Just use the top of the prompt stack. */
282 prompt_length = strlen (PREFIX (0)) +
283 strlen (SUFFIX (0)) +
284 strlen (gdb_prompt) + 1;
285
286 new_prompt = (char *) alloca (prompt_length);
287
288 /* Prefix needs to have new line at end. */
289 strcpy (new_prompt, PREFIX (0));
290 strcat (new_prompt, gdb_prompt);
291 /* Suffix needs to have a new line at end and \032 \032 at
292 beginning. */
293 strcat (new_prompt, SUFFIX (0));
294 }
295
296 if (async_command_editing_p)
297 {
298 rl_callback_handler_remove ();
299 rl_callback_handler_install (new_prompt, input_handler);
300 }
301 /* new_prompt at this point can be the top of the stack or the one passed in */
302 else if (new_prompt)
303 {
304 /* Don't use a _filtered function here. It causes the assumed
305 character position to be off, since the newline we read from
306 the user is not accounted for. */
307 fputs_unfiltered (new_prompt, gdb_stdout);
308 gdb_flush (gdb_stdout);
309 }
310 }
311
312 /* Used when the user requests a different annotation level, with
313 'set annotate'. It pushes a new prompt (with prefix and suffix) on top
314 of the prompt stack, if the annotation level desired is 2, otherwise
315 it pops the top of the prompt stack when we want the annotation level
316 to be the normal ones (1 or 0). */
317 static void
318 change_annotation_level (void)
319 {
320 char *prefix, *suffix;
321
322 if (!PREFIX (0) || !PROMPT (0) || !SUFFIX (0))
323 {
324 /* The prompt stack has not been initialized to "", we are
325 using gdb w/o the --async switch */
326 warning ("Command has same effect as set annotate");
327 return;
328 }
329
330 if (annotation_level > 1)
331 {
332 if (!strcmp (PREFIX (0), "") && !strcmp (SUFFIX (0), ""))
333 {
334 /* Push a new prompt if the previous annotation_level was not >1. */
335 prefix = (char *) alloca (strlen (async_annotation_suffix) + 10);
336 strcpy (prefix, "\n\032\032pre-");
337 strcat (prefix, async_annotation_suffix);
338 strcat (prefix, "\n");
339
340 suffix = (char *) alloca (strlen (async_annotation_suffix) + 6);
341 strcpy (suffix, "\n\032\032");
342 strcat (suffix, async_annotation_suffix);
343 strcat (suffix, "\n");
344
345 push_prompt (prefix, (char *) 0, suffix);
346 }
347 }
348 else
349 {
350 if (strcmp (PREFIX (0), "") && strcmp (SUFFIX (0), ""))
351 {
352 /* Pop the top of the stack, we are going back to annotation < 1. */
353 pop_prompt ();
354 }
355 }
356 }
357
358 /* Pushes a new prompt on the prompt stack. Each prompt has three
359 parts: prefix, prompt, suffix. Usually prefix and suffix are empty
360 strings, except when the annotation level is 2. Memory is allocated
361 within savestring for the new prompt. */
362 void
363 push_prompt (char *prefix, char *prompt, char *suffix)
364 {
365 the_prompts.top++;
366 PREFIX (0) = savestring (prefix, strlen (prefix));
367
368 /* Note that this function is used by the set annotate 2
369 command. This is why we take care of saving the old prompt
370 in case a new one is not specified. */
371 if (prompt)
372 PROMPT (0) = savestring (prompt, strlen (prompt));
373 else
374 PROMPT (0) = savestring (PROMPT (-1), strlen (PROMPT (-1)));
375
376 SUFFIX (0) = savestring (suffix, strlen (suffix));
377 }
378
379 /* Pops the top of the prompt stack, and frees the memory allocated for it. */
380 void
381 pop_prompt (void)
382 {
383 /* If we are not during a 'synchronous' execution command, in which
384 case, the top prompt would be empty. */
385 if (strcmp (PROMPT (0), ""))
386 /* This is for the case in which the prompt is set while the
387 annotation level is 2. The top prompt will be changed, but when
388 we return to annotation level < 2, we want that new prompt to be
389 in effect, until the user does another 'set prompt'. */
390 if (strcmp (PROMPT (0), PROMPT (-1)))
391 {
392 xfree (PROMPT (-1));
393 PROMPT (-1) = savestring (PROMPT (0), strlen (PROMPT (0)));
394 }
395
396 xfree (PREFIX (0));
397 xfree (PROMPT (0));
398 xfree (SUFFIX (0));
399 the_prompts.top--;
400 }
401
402 /* When there is an event ready on the stdin file desriptor, instead
403 of calling readline directly throught the callback function, or
404 instead of calling gdb_readline2, give gdb a chance to detect
405 errors and do something. */
406 void
407 stdin_event_handler (int error, gdb_client_data client_data)
408 {
409 if (error)
410 {
411 printf_unfiltered ("error detected on stdin\n");
412 delete_file_handler (input_fd);
413 discard_all_continuations ();
414 /* If stdin died, we may as well kill gdb. */
415 quit_command ((char *) 0, stdin == instream);
416 }
417 else
418 (*call_readline) (client_data);
419 }
420
421 /* Re-enable stdin after the end of an execution command in
422 synchronous mode, or after an error from the target, and we aborted
423 the exec operation. */
424
425 void
426 async_enable_stdin (void *dummy)
427 {
428 /* See NOTE in async_disable_stdin() */
429 /* FIXME: cagney/1999-09-27: Call this before clearing
430 sync_execution. Current target_terminal_ours() implementations
431 check for sync_execution before switching the terminal. */
432 target_terminal_ours ();
433 pop_prompt ();
434 sync_execution = 0;
435 }
436
437 /* Disable reads from stdin (the console) marking the command as
438 synchronous. */
439
440 void
441 async_disable_stdin (void)
442 {
443 sync_execution = 1;
444 push_prompt ("", "", "");
445 /* FIXME: cagney/1999-09-27: At present this call is technically
446 redundant since infcmd.c and infrun.c both already call
447 target_terminal_inferior(). As the terminal handling (in
448 sync/async mode) is refined, the duplicate calls can be
449 eliminated (Here or in infcmd.c/infrun.c). */
450 target_terminal_inferior ();
451 /* Add the reinstate of stdin to the list of cleanups to be done
452 in case the target errors out and dies. These cleanups are also
453 done in case of normal successful termination of the execution
454 command, by complete_execution(). */
455 make_exec_error_cleanup (async_enable_stdin, NULL);
456 }
457 \f
458
459 /* Handles a gdb command. This function is called by
460 command_line_handler, which has processed one or more input lines
461 into COMMAND. */
462 /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop
463 function. The command_loop function will be obsolete when we
464 switch to use the event loop at every execution of gdb. */
465 static void
466 command_handler (char *command)
467 {
468 struct cleanup *old_chain;
469 int stdin_is_tty = ISATTY (stdin);
470 struct continuation_arg *arg1;
471 struct continuation_arg *arg2;
472 long time_at_cmd_start;
473 #ifdef HAVE_SBRK
474 long space_at_cmd_start = 0;
475 #endif
476 extern int display_time;
477 extern int display_space;
478
479 quit_flag = 0;
480 if (instream == stdin && stdin_is_tty)
481 reinitialize_more_filter ();
482 old_chain = make_cleanup (null_cleanup, 0);
483
484 /* If readline returned a NULL command, it means that the
485 connection with the terminal is gone. This happens at the
486 end of a testsuite run, after Expect has hung up
487 but GDB is still alive. In such a case, we just quit gdb
488 killing the inferior program too. */
489 if (command == 0)
490 quit_command ((char *) 0, stdin == instream);
491
492 time_at_cmd_start = get_run_time ();
493
494 if (display_space)
495 {
496 #ifdef HAVE_SBRK
497 extern char **environ;
498 char *lim = (char *) sbrk (0);
499
500 space_at_cmd_start = (long) (lim - (char *) &environ);
501 #endif
502 }
503
504 execute_command (command, instream == stdin);
505
506 /* Set things up for this function to be compete later, once the
507 execution has completed, if we are doing an execution command,
508 otherwise, just go ahead and finish. */
509 if (target_can_async_p () && target_executing)
510 {
511 arg1 =
512 (struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
513 arg2 =
514 (struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
515 arg1->next = arg2;
516 arg2->next = NULL;
517 arg1->data.integer = time_at_cmd_start;
518 arg2->data.integer = space_at_cmd_start;
519 add_continuation (command_line_handler_continuation, arg1);
520 }
521
522 /* Do any commands attached to breakpoint we stopped at. Only if we
523 are always running synchronously. Or if we have just executed a
524 command that doesn't start the target. */
525 if (!target_can_async_p () || !target_executing)
526 {
527 bpstat_do_actions (&stop_bpstat);
528 do_cleanups (old_chain);
529
530 if (display_time)
531 {
532 long cmd_time = get_run_time () - time_at_cmd_start;
533
534 printf_unfiltered ("Command execution time: %ld.%06ld\n",
535 cmd_time / 1000000, cmd_time % 1000000);
536 }
537
538 if (display_space)
539 {
540 #ifdef HAVE_SBRK
541 extern char **environ;
542 char *lim = (char *) sbrk (0);
543 long space_now = lim - (char *) &environ;
544 long space_diff = space_now - space_at_cmd_start;
545
546 printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
547 space_now,
548 (space_diff >= 0 ? '+' : '-'),
549 space_diff);
550 #endif
551 }
552 }
553 }
554
555 /* Do any commands attached to breakpoint we stopped at. Only if we
556 are always running synchronously. Or if we have just executed a
557 command that doesn't start the target. */
558 void
559 command_line_handler_continuation (struct continuation_arg *arg)
560 {
561 extern int display_time;
562 extern int display_space;
563
564 long time_at_cmd_start = arg->data.longint;
565 long space_at_cmd_start = arg->next->data.longint;
566
567 bpstat_do_actions (&stop_bpstat);
568 /*do_cleanups (old_chain); *//*?????FIXME????? */
569
570 if (display_time)
571 {
572 long cmd_time = get_run_time () - time_at_cmd_start;
573
574 printf_unfiltered ("Command execution time: %ld.%06ld\n",
575 cmd_time / 1000000, cmd_time % 1000000);
576 }
577 if (display_space)
578 {
579 #ifdef HAVE_SBRK
580 extern char **environ;
581 char *lim = (char *) sbrk (0);
582 long space_now = lim - (char *) &environ;
583 long space_diff = space_now - space_at_cmd_start;
584
585 printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
586 space_now,
587 (space_diff >= 0 ? '+' : '-'),
588 space_diff);
589 #endif
590 }
591 }
592
593 /* Handle a complete line of input. This is called by the callback
594 mechanism within the readline library. Deal with incomplete commands
595 as well, by saving the partial input in a global buffer. */
596
597 /* NOTE: 1999-04-30 This is the asynchronous version of the
598 command_line_input function. command_line_input will become
599 obsolete once we use the event loop as the default mechanism in
600 GDB. */
601 static void
602 command_line_handler (char *rl)
603 {
604 static char *linebuffer = 0;
605 static unsigned linelength = 0;
606 register char *p;
607 char *p1;
608 extern char *line;
609 extern int linesize;
610 char *nline;
611 char got_eof = 0;
612
613
614 int repeat = (instream == stdin);
615
616 if (annotation_level > 1 && instream == stdin)
617 {
618 printf_unfiltered ("\n\032\032post-");
619 printf_unfiltered (async_annotation_suffix);
620 printf_unfiltered ("\n");
621 }
622
623 if (linebuffer == 0)
624 {
625 linelength = 80;
626 linebuffer = (char *) xmalloc (linelength);
627 }
628
629 p = linebuffer;
630
631 if (more_to_come)
632 {
633 strcpy (linebuffer, readline_input_state.linebuffer);
634 p = readline_input_state.linebuffer_ptr;
635 xfree (readline_input_state.linebuffer);
636 more_to_come = 0;
637 pop_prompt ();
638 }
639
640 #ifdef STOP_SIGNAL
641 if (job_control)
642 signal (STOP_SIGNAL, handle_stop_sig);
643 #endif
644
645 /* Make sure that all output has been output. Some machines may let
646 you get away with leaving out some of the gdb_flush, but not all. */
647 wrap_here ("");
648 gdb_flush (gdb_stdout);
649 gdb_flush (gdb_stderr);
650
651 if (source_file_name != NULL)
652 {
653 ++source_line_number;
654 sprintf (source_error,
655 "%s%s:%d: Error in sourced command file:\n",
656 source_pre_error,
657 source_file_name,
658 source_line_number);
659 error_pre_print = source_error;
660 }
661
662 /* If we are in this case, then command_handler will call quit
663 and exit from gdb. */
664 if (!rl || rl == (char *) EOF)
665 {
666 got_eof = 1;
667 command_handler (0);
668 }
669 if (strlen (rl) + 1 + (p - linebuffer) > linelength)
670 {
671 linelength = strlen (rl) + 1 + (p - linebuffer);
672 nline = (char *) xrealloc (linebuffer, linelength);
673 p += nline - linebuffer;
674 linebuffer = nline;
675 }
676 p1 = rl;
677 /* Copy line. Don't copy null at end. (Leaves line alone
678 if this was just a newline) */
679 while (*p1)
680 *p++ = *p1++;
681
682 xfree (rl); /* Allocated in readline. */
683
684 if (*(p - 1) == '\\')
685 {
686 p--; /* Put on top of '\'. */
687
688 if (*p == '\\')
689 {
690 readline_input_state.linebuffer = savestring (linebuffer,
691 strlen (linebuffer));
692 readline_input_state.linebuffer_ptr = p;
693
694 /* We will not invoke a execute_command if there is more
695 input expected to complete the command. So, we need to
696 print an empty prompt here. */
697 more_to_come = 1;
698 push_prompt ("", "", "");
699 display_gdb_prompt (0);
700 return;
701 }
702 }
703
704 #ifdef STOP_SIGNAL
705 if (job_control)
706 signal (STOP_SIGNAL, SIG_DFL);
707 #endif
708
709 #define SERVER_COMMAND_LENGTH 7
710 server_command =
711 (p - linebuffer > SERVER_COMMAND_LENGTH)
712 && STREQN (linebuffer, "server ", SERVER_COMMAND_LENGTH);
713 if (server_command)
714 {
715 /* Note that we don't set `line'. Between this and the check in
716 dont_repeat, this insures that repeating will still do the
717 right thing. */
718 *p = '\0';
719 command_handler (linebuffer + SERVER_COMMAND_LENGTH);
720 display_gdb_prompt (0);
721 return;
722 }
723
724 /* Do history expansion if that is wished. */
725 if (history_expansion_p && instream == stdin
726 && ISATTY (instream))
727 {
728 char *history_value;
729 int expanded;
730
731 *p = '\0'; /* Insert null now. */
732 expanded = history_expand (linebuffer, &history_value);
733 if (expanded)
734 {
735 /* Print the changes. */
736 printf_unfiltered ("%s\n", history_value);
737
738 /* If there was an error, call this function again. */
739 if (expanded < 0)
740 {
741 xfree (history_value);
742 return;
743 }
744 if (strlen (history_value) > linelength)
745 {
746 linelength = strlen (history_value) + 1;
747 linebuffer = (char *) xrealloc (linebuffer, linelength);
748 }
749 strcpy (linebuffer, history_value);
750 p = linebuffer + strlen (linebuffer);
751 xfree (history_value);
752 }
753 }
754
755 /* If we just got an empty line, and that is supposed
756 to repeat the previous command, return the value in the
757 global buffer. */
758 if (repeat && p == linebuffer && *p != '\\')
759 {
760 command_handler (line);
761 display_gdb_prompt (0);
762 return;
763 }
764
765 for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++);
766 if (repeat && !*p1)
767 {
768 command_handler (line);
769 display_gdb_prompt (0);
770 return;
771 }
772
773 *p = 0;
774
775 /* Add line to history if appropriate. */
776 if (instream == stdin
777 && ISATTY (stdin) && *linebuffer)
778 add_history (linebuffer);
779
780 /* Note: lines consisting solely of comments are added to the command
781 history. This is useful when you type a command, and then
782 realize you don't want to execute it quite yet. You can comment
783 out the command and then later fetch it from the value history
784 and remove the '#'. The kill ring is probably better, but some
785 people are in the habit of commenting things out. */
786 if (*p1 == '#')
787 *p1 = '\0'; /* Found a comment. */
788
789 /* Save into global buffer if appropriate. */
790 if (repeat)
791 {
792 if (linelength > linesize)
793 {
794 line = xrealloc (line, linelength);
795 linesize = linelength;
796 }
797 strcpy (line, linebuffer);
798 if (!more_to_come)
799 {
800 command_handler (line);
801 display_gdb_prompt (0);
802 }
803 return;
804 }
805
806 command_handler (linebuffer);
807 display_gdb_prompt (0);
808 return;
809 }
810
811 /* Does reading of input from terminal w/o the editing features
812 provided by the readline library. */
813
814 /* NOTE: 1999-04-30 Asynchronous version of gdb_readline. gdb_readline
815 will become obsolete when the event loop is made the default
816 execution for gdb. */
817 void
818 gdb_readline2 (gdb_client_data client_data)
819 {
820 int c;
821 char *result;
822 int input_index = 0;
823 int result_size = 80;
824 static int done_once = 0;
825
826 /* Unbuffer the input stream, so that, later on, the calls to fgetc
827 fetch only one char at the time from the stream. The fgetc's will
828 get up to the first newline, but there may be more chars in the
829 stream after '\n'. If we buffer the input and fgetc drains the
830 stream, getting stuff beyond the newline as well, a select, done
831 afterwards will not trigger. */
832 if (!done_once && !ISATTY (instream))
833 {
834 setbuf (instream, NULL);
835 done_once = 1;
836 }
837
838 result = (char *) xmalloc (result_size);
839
840 /* We still need the while loop here, even though it would seem
841 obvious to invoke gdb_readline2 at every character entered. If
842 not using the readline library, the terminal is in cooked mode,
843 which sends the characters all at once. Poll will notice that the
844 input fd has changed state only after enter is pressed. At this
845 point we still need to fetch all the chars entered. */
846
847 while (1)
848 {
849 /* Read from stdin if we are executing a user defined command.
850 This is the right thing for prompt_for_continue, at least. */
851 c = fgetc (instream ? instream : stdin);
852
853 if (c == EOF)
854 {
855 if (input_index > 0)
856 /* The last line does not end with a newline. Return it, and
857 if we are called again fgetc will still return EOF and
858 we'll return NULL then. */
859 break;
860 xfree (result);
861 (*input_handler) (0);
862 }
863
864 if (c == '\n')
865 #ifndef CRLF_SOURCE_FILES
866 break;
867 #else
868 {
869 if (input_index > 0 && result[input_index - 1] == '\r')
870 input_index--;
871 break;
872 }
873 #endif
874
875 result[input_index++] = c;
876 while (input_index >= result_size)
877 {
878 result_size *= 2;
879 result = (char *) xrealloc (result, result_size);
880 }
881 }
882
883 result[input_index++] = '\0';
884 (*input_handler) (result);
885 }
886 \f
887
888 /* Initialization of signal handlers and tokens. There is a function
889 handle_sig* for each of the signals GDB cares about. Specifically:
890 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
891 functions are the actual signal handlers associated to the signals
892 via calls to signal(). The only job for these functions is to
893 enqueue the appropriate event/procedure with the event loop. Such
894 procedures are the old signal handlers. The event loop will take
895 care of invoking the queued procedures to perform the usual tasks
896 associated with the reception of the signal. */
897 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
898 init_signals will become obsolete as we move to have to event loop
899 as the default for gdb. */
900 void
901 async_init_signals (void)
902 {
903 signal (SIGINT, handle_sigint);
904 sigint_token =
905 create_async_signal_handler (async_request_quit, NULL);
906
907 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
908 to the inferior and breakpoints will be ignored. */
909 #ifdef SIGTRAP
910 signal (SIGTRAP, SIG_DFL);
911 #endif
912
913 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
914 passed to the inferior, which we don't want. It would be
915 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
916 on BSD4.3 systems using vfork, that can affect the
917 GDB process as well as the inferior (the signal handling tables
918 might be in memory, shared between the two). Since we establish
919 a handler for SIGQUIT, when we call exec it will set the signal
920 to SIG_DFL for us. */
921 signal (SIGQUIT, handle_sigquit);
922 sigquit_token =
923 create_async_signal_handler (async_do_nothing, NULL);
924 #ifdef SIGHUP
925 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
926 sighup_token =
927 create_async_signal_handler (async_disconnect, NULL);
928 else
929 sighup_token =
930 create_async_signal_handler (async_do_nothing, NULL);
931 #endif
932 signal (SIGFPE, handle_sigfpe);
933 sigfpe_token =
934 create_async_signal_handler (async_float_handler, NULL);
935
936 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
937 signal (SIGWINCH, handle_sigwinch);
938 sigwinch_token =
939 create_async_signal_handler (SIGWINCH_HANDLER, NULL);
940 #endif
941 #ifdef STOP_SIGNAL
942 sigtstp_token =
943 create_async_signal_handler (async_stop_sig, NULL);
944 #endif
945
946 }
947
948 void
949 mark_async_signal_handler_wrapper (void *token)
950 {
951 mark_async_signal_handler ((struct async_signal_handler *) token);
952 }
953
954 /* Tell the event loop what to do if SIGINT is received.
955 See event-signal.c. */
956 void
957 handle_sigint (int sig)
958 {
959 signal (sig, handle_sigint);
960
961 /* If immediate_quit is set, we go ahead and process the SIGINT right
962 away, even if we usually would defer this to the event loop. The
963 assumption here is that it is safe to process ^C immediately if
964 immediate_quit is set. If we didn't, SIGINT would be really
965 processed only the next time through the event loop. To get to
966 that point, though, the command that we want to interrupt needs to
967 finish first, which is unacceptable. */
968 if (immediate_quit)
969 async_request_quit (0);
970 else
971 /* If immediate quit is not set, we process SIGINT the next time
972 through the loop, which is fine. */
973 mark_async_signal_handler_wrapper (sigint_token);
974 }
975
976 /* Do the quit. All the checks have been done by the caller. */
977 void
978 async_request_quit (gdb_client_data arg)
979 {
980 quit_flag = 1;
981 #ifdef REQUEST_QUIT
982 REQUEST_QUIT;
983 #else
984 quit ();
985 #endif
986 }
987
988 /* Tell the event loop what to do if SIGQUIT is received.
989 See event-signal.c. */
990 static void
991 handle_sigquit (int sig)
992 {
993 mark_async_signal_handler_wrapper (sigquit_token);
994 signal (sig, handle_sigquit);
995 }
996
997 /* Called by the event loop in response to a SIGQUIT. */
998 static void
999 async_do_nothing (gdb_client_data arg)
1000 {
1001 /* Empty function body. */
1002 }
1003
1004 #ifdef SIGHUP
1005 /* Tell the event loop what to do if SIGHUP is received.
1006 See event-signal.c. */
1007 static void
1008 handle_sighup (int sig)
1009 {
1010 mark_async_signal_handler_wrapper (sighup_token);
1011 signal (sig, handle_sighup);
1012 }
1013
1014 /* Called by the event loop to process a SIGHUP */
1015 static void
1016 async_disconnect (gdb_client_data arg)
1017 {
1018 catch_errors (quit_cover, NULL,
1019 "Could not kill the program being debugged",
1020 RETURN_MASK_ALL);
1021 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
1022 kill (getpid (), SIGHUP);
1023 }
1024 #endif
1025
1026 #ifdef STOP_SIGNAL
1027 void
1028 handle_stop_sig (int sig)
1029 {
1030 mark_async_signal_handler_wrapper (sigtstp_token);
1031 signal (sig, handle_stop_sig);
1032 }
1033
1034 static void
1035 async_stop_sig (gdb_client_data arg)
1036 {
1037 char *prompt = get_prompt ();
1038 #if STOP_SIGNAL == SIGTSTP
1039 signal (SIGTSTP, SIG_DFL);
1040 #if HAVE_SIGPROCMASK
1041 {
1042 sigset_t zero;
1043
1044 sigemptyset (&zero);
1045 sigprocmask (SIG_SETMASK, &zero, 0);
1046 }
1047 #elif HAVE_SIGSETMASK
1048 sigsetmask (0);
1049 #endif
1050 kill (getpid (), SIGTSTP);
1051 signal (SIGTSTP, handle_stop_sig);
1052 #else
1053 signal (STOP_SIGNAL, handle_stop_sig);
1054 #endif
1055 printf_unfiltered ("%s", prompt);
1056 gdb_flush (gdb_stdout);
1057
1058 /* Forget about any previous command -- null line now will do nothing. */
1059 dont_repeat ();
1060 }
1061 #endif /* STOP_SIGNAL */
1062
1063 /* Tell the event loop what to do if SIGFPE is received.
1064 See event-signal.c. */
1065 static void
1066 handle_sigfpe (int sig)
1067 {
1068 mark_async_signal_handler_wrapper (sigfpe_token);
1069 signal (sig, handle_sigfpe);
1070 }
1071
1072 /* Event loop will call this functin to process a SIGFPE. */
1073 static void
1074 async_float_handler (gdb_client_data arg)
1075 {
1076 /* This message is based on ANSI C, section 4.7. Note that integer
1077 divide by zero causes this, so "float" is a misnomer. */
1078 error ("Erroneous arithmetic operation.");
1079 }
1080
1081 /* Tell the event loop what to do if SIGWINCH is received.
1082 See event-signal.c. */
1083 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
1084 static void
1085 handle_sigwinch (int sig)
1086 {
1087 mark_async_signal_handler_wrapper (sigwinch_token);
1088 signal (sig, handle_sigwinch);
1089 }
1090 #endif
1091 \f
1092
1093 /* Called by do_setshow_command. */
1094 /* ARGSUSED */
1095 void
1096 set_async_editing_command (char *args, int from_tty, struct cmd_list_element *c)
1097 {
1098 change_line_handler ();
1099 }
1100
1101 /* Called by do_setshow_command. */
1102 /* ARGSUSED */
1103 void
1104 set_async_annotation_level (char *args, int from_tty, struct cmd_list_element *c)
1105 {
1106 change_annotation_level ();
1107 }
1108
1109 /* Called by do_setshow_command. */
1110 /* ARGSUSED */
1111 void
1112 set_async_prompt (char *args, int from_tty, struct cmd_list_element *c)
1113 {
1114 PROMPT (0) = savestring (new_async_prompt, strlen (new_async_prompt));
1115 }
1116
1117 /* Set things up for readline to be invoked via the alternate
1118 interface, i.e. via a callback function (rl_callback_read_char),
1119 and hook up instream to the event loop. */
1120 void
1121 _initialize_event_loop (void)
1122 {
1123 if (event_loop_p)
1124 {
1125 /* If the input stream is connected to a terminal, turn on
1126 editing. */
1127 if (ISATTY (instream))
1128 {
1129 /* Tell gdb that we will be using the readline library. This
1130 could be overwritten by a command in .gdbinit like 'set
1131 editing on' or 'off'. */
1132 async_command_editing_p = 1;
1133
1134 /* When a character is detected on instream by select or
1135 poll, readline will be invoked via this callback
1136 function. */
1137 call_readline = rl_callback_read_char_wrapper;
1138 }
1139 else
1140 {
1141 async_command_editing_p = 0;
1142 call_readline = gdb_readline2;
1143 }
1144
1145 /* When readline has read an end-of-line character, it passes
1146 the complete line to gdb for processing. command_line_handler
1147 is the function that does this. */
1148 input_handler = command_line_handler;
1149
1150 /* Tell readline to use the same input stream that gdb uses. */
1151 rl_instream = instream;
1152
1153 /* Get a file descriptor for the input stream, so that we can
1154 register it with the event loop. */
1155 input_fd = fileno (instream);
1156
1157 /* Tell gdb to use the cli_command_loop as the main loop. */
1158 command_loop_hook = cli_command_loop;
1159
1160 /* Now we need to create the event sources for the input file
1161 descriptor. */
1162 /* At this point in time, this is the only event source that we
1163 register with the even loop. Another source is going to be
1164 the target program (inferior), but that must be registered
1165 only when it actually exists (I.e. after we say 'run' or
1166 after we connect to a remote target. */
1167 add_file_handler (input_fd, stdin_event_handler, 0);
1168 }
1169 }
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