Simplify saved_command_line handling
[deliverable/binutils-gdb.git] / gdb / event-top.c
CommitLineData
b5a0ac70 1/* Top level stuff for GDB, the GNU debugger.
637537d0 2
618f726f 3 Copyright (C) 1999-2016 Free Software Foundation, Inc.
637537d0 4
b5a0ac70
SS
5 Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
6
7 This file is part of GDB.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
a9762ec7 11 the Free Software Foundation; either version 3 of the License, or
b5a0ac70
SS
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
371d5dec 20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
b5a0ac70
SS
21
22#include "defs.h"
0f71a2f6 23#include "top.h"
b5a0ac70 24#include "inferior.h"
45741a9c 25#include "infrun.h"
e514a9d6 26#include "target.h"
c5aa993b 27#include "terminal.h" /* for job_control */
9e0b60a8 28#include "event-loop.h"
c2c6d25f 29#include "event-top.h"
4389a95a 30#include "interps.h"
042be3a9 31#include <signal.h>
16026cd7 32#include "cli/cli-script.h" /* for reset_command_nest_depth */
d01a8610 33#include "main.h"
8ea051c5 34#include "gdbthread.h"
d17b6f81 35#include "observer.h"
be34f849 36#include "continuations.h"
371d5dec 37#include "gdbcmd.h" /* for dont_repeat() */
bd00c694 38#include "annotate.h"
bd712aed 39#include "maint.h"
187212b3 40#include "buffer.h"
104c1213 41
371d5dec 42/* readline include files. */
dbda9972
AC
43#include "readline/readline.h"
44#include "readline/history.h"
b5a0ac70
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45
46/* readline defines this. */
47#undef savestring
48
c2c6d25f
JM
49static void rl_callback_read_char_wrapper (gdb_client_data client_data);
50static void command_line_handler (char *rl);
c2c6d25f 51static void change_line_handler (void);
c2c6d25f 52static void command_handler (char *command);
ab821bc6 53static char *top_level_prompt (void);
b5a0ac70 54
371d5dec 55/* Signal handlers. */
6d318c73 56#ifdef SIGQUIT
c2c6d25f 57static void handle_sigquit (int sig);
6d318c73 58#endif
0f0b8dcd 59#ifdef SIGHUP
c2c6d25f 60static void handle_sighup (int sig);
0f0b8dcd 61#endif
c2c6d25f 62static void handle_sigfpe (int sig);
b5a0ac70
SS
63
64/* Functions to be invoked by the event loop in response to
371d5dec 65 signals. */
0f0b8dcd 66#if defined (SIGQUIT) || defined (SIGHUP)
c2c6d25f 67static void async_do_nothing (gdb_client_data);
0f0b8dcd
DJ
68#endif
69#ifdef SIGHUP
c2c6d25f 70static void async_disconnect (gdb_client_data);
0f0b8dcd 71#endif
c2c6d25f 72static void async_float_handler (gdb_client_data);
0f0b8dcd 73#ifdef STOP_SIGNAL
c2c6d25f 74static void async_stop_sig (gdb_client_data);
0f0b8dcd 75#endif
06c868a8 76static void async_sigterm_handler (gdb_client_data arg);
b5a0ac70 77
b5a0ac70 78/* Readline offers an alternate interface, via callback
371d5dec 79 functions. These are all included in the file callback.c in the
b5a0ac70
SS
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
371d5dec 84 there is a new character ready on the input stream. This function
b5a0ac70
SS
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
371d5dec 90 of the old command_line_input in gdb. Instead of invoking (and waiting
b5a0ac70
SS
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
371d5dec 96 that readline offers as callback to the event_loop. */
b5a0ac70 97
c2c6d25f
JM
98void (*input_handler) (char *);
99void (*call_readline) (gdb_client_data);
b5a0ac70 100
371d5dec 101/* Important variables for the event loop. */
b5a0ac70
SS
102
103/* This is used to determine if GDB is using the readline library or
371d5dec 104 its own simplified form of readline. It is used by the asynchronous
0f71a2f6 105 form of the set editing command.
392a587b 106 ezannoni: as of 1999-04-29 I expect that this
b5a0ac70 107 variable will not be used after gdb is changed to use the event
371d5dec 108 loop as default engine, and event-top.c is merged into top.c. */
b5a0ac70
SS
109int async_command_editing_p;
110
104c1213 111/* This is used to display the notification of the completion of an
371d5dec 112 asynchronous execution command. */
104c1213
JM
113int exec_done_display_p = 0;
114
b5a0ac70 115/* This is the file descriptor for the input stream that GDB uses to
371d5dec 116 read commands from. */
b5a0ac70
SS
117int input_fd;
118
d64e57fa
PP
119/* Used by the stdin event handler to compensate for missed stdin events.
120 Setting this to a non-zero value inside an stdin callback makes the callback
121 run again. */
122int call_stdin_event_handler_again_p;
123
371d5dec 124/* Signal handling variables. */
b5a0ac70 125/* Each of these is a pointer to a function that the event loop will
371d5dec 126 invoke if the corresponding signal has received. The real signal
b5a0ac70 127 handlers mark these functions as ready to be executed and the event
371d5dec
MS
128 loop, in a later iteration, calls them. See the function
129 invoke_async_signal_handler. */
05fa9251 130static struct async_signal_handler *sigint_token;
b5a0ac70 131#ifdef SIGHUP
05fa9251 132static struct async_signal_handler *sighup_token;
b5a0ac70 133#endif
6d318c73 134#ifdef SIGQUIT
05fa9251 135static struct async_signal_handler *sigquit_token;
6d318c73 136#endif
05fa9251 137static struct async_signal_handler *sigfpe_token;
0f71a2f6 138#ifdef STOP_SIGNAL
05fa9251 139static struct async_signal_handler *sigtstp_token;
0f71a2f6 140#endif
06c868a8 141static struct async_signal_handler *async_sigterm_token;
0f71a2f6 142
b5a0ac70 143/* Structure to save a partially entered command. This is used when
371d5dec 144 the user types '\' at the end of a command line. This is necessary
b5a0ac70
SS
145 because each line of input is handled by a different call to
146 command_line_handler, and normally there is no state retained
371d5dec 147 between different calls. */
ab821bc6 148static int more_to_come = 0;
b5a0ac70
SS
149
150struct readline_input_state
151 {
152 char *linebuffer;
153 char *linebuffer_ptr;
154 }
155readline_input_state;
467d8519
TT
156
157/* This hook is called by rl_callback_read_char_wrapper after each
158 character is processed. */
b08ee6a2 159void (*after_char_processing_hook) (void);
b5a0ac70
SS
160\f
161
371d5dec
MS
162/* Wrapper function for calling into the readline library. The event
163 loop expects the callback function to have a paramter, while
164 readline expects none. */
c2c6d25f
JM
165static void
166rl_callback_read_char_wrapper (gdb_client_data client_data)
167{
168 rl_callback_read_char ();
467d8519
TT
169 if (after_char_processing_hook)
170 (*after_char_processing_hook) ();
c2c6d25f
JM
171}
172
b5a0ac70 173/* Initialize all the necessary variables, start the event loop,
4d09c5b4
AB
174 register readline, and stdin, start the loop. The DATA is the
175 interpreter data cookie, ignored for now. */
176
b5a0ac70 177void
4d09c5b4 178cli_command_loop (void *data)
b5a0ac70 179{
7d8e6458 180 display_gdb_prompt (0);
b5a0ac70 181
371d5dec 182 /* Now it's time to start the event loop. */
085dd6e6 183 start_event_loop ();
b5a0ac70
SS
184}
185
186/* Change the function to be invoked every time there is a character
371d5dec 187 ready on stdin. This is used when the user sets the editing off,
b5a0ac70 188 therefore bypassing readline, and letting gdb handle the input
c70061cf
PA
189 itself, via gdb_readline_no_editing_callback. Also it is used in
190 the opposite case in which the user sets editing on again, by
191 restoring readline handling of the input. */
392a587b 192static void
c2c6d25f 193change_line_handler (void)
b5a0ac70 194{
371d5dec
MS
195 /* NOTE: this operates on input_fd, not instream. If we are reading
196 commands from a file, instream will point to the file. However in
c2c6d25f 197 async mode, we always read commands from a file with editing
371d5dec
MS
198 off. This means that the 'set editing on/off' will have effect
199 only on the interactive session. */
c2c6d25f 200
b5a0ac70
SS
201 if (async_command_editing_p)
202 {
371d5dec 203 /* Turn on editing by using readline. */
c2c6d25f 204 call_readline = rl_callback_read_char_wrapper;
0f71a2f6 205 input_handler = command_line_handler;
b5a0ac70
SS
206 }
207 else
208 {
c70061cf 209 /* Turn off editing by using gdb_readline_no_editing_callback. */
d3d4baed 210 gdb_rl_callback_handler_remove ();
c70061cf 211 call_readline = gdb_readline_no_editing_callback;
0f71a2f6
JM
212
213 /* Set up the command handler as well, in case we are called as
371d5dec 214 first thing from .gdbinit. */
0f71a2f6 215 input_handler = command_line_handler;
b5a0ac70 216 }
b5a0ac70
SS
217}
218
d3d4baed
PA
219/* The functions below are wrappers for rl_callback_handler_remove and
220 rl_callback_handler_install that keep track of whether the callback
221 handler is installed in readline. This is necessary because after
222 handling a target event of a background execution command, we may
223 need to reinstall the callback handler if it was removed due to a
224 secondary prompt. See gdb_readline_wrapper_line. We don't
225 unconditionally install the handler for every target event because
226 that also clears the line buffer, thus installing it while the user
227 is typing would lose input. */
228
229/* Whether we've registered a callback handler with readline. */
230static int callback_handler_installed;
231
232/* See event-top.h, and above. */
233
234void
235gdb_rl_callback_handler_remove (void)
236{
237 rl_callback_handler_remove ();
238 callback_handler_installed = 0;
239}
240
241/* See event-top.h, and above. Note this wrapper doesn't have an
242 actual callback parameter because we always install
243 INPUT_HANDLER. */
244
245void
246gdb_rl_callback_handler_install (const char *prompt)
247{
248 /* Calling rl_callback_handler_install resets readline's input
249 buffer. Calling this when we were already processing input
250 therefore loses input. */
251 gdb_assert (!callback_handler_installed);
252
253 rl_callback_handler_install (prompt, input_handler);
254 callback_handler_installed = 1;
255}
256
257/* See event-top.h, and above. */
258
259void
260gdb_rl_callback_handler_reinstall (void)
261{
262 if (!callback_handler_installed)
263 {
264 /* Passing NULL as prompt argument tells readline to not display
265 a prompt. */
266 gdb_rl_callback_handler_install (NULL);
267 }
268}
269
ab821bc6
PA
270/* Displays the prompt. If the argument NEW_PROMPT is NULL, the
271 prompt that is displayed is the current top level prompt.
272 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
273 prompt.
274
275 This is used after each gdb command has completed, and in the
276 following cases:
277
371d5dec 278 1. When the user enters a command line which is ended by '\'
ab821bc6
PA
279 indicating that the command will continue on the next line. In
280 that case the prompt that is displayed is the empty string.
281
0f71a2f6 282 2. When the user is entering 'commands' for a breakpoint, or
371d5dec 283 actions for a tracepoint. In this case the prompt will be '>'
ab821bc6
PA
284
285 3. On prompting for pagination. */
286
b5a0ac70 287void
38bcc89d 288display_gdb_prompt (const char *new_prompt)
b5a0ac70 289{
d17b6f81 290 char *actual_gdb_prompt = NULL;
ab821bc6 291 struct cleanup *old_chain;
b5a0ac70 292
bd00c694
PA
293 annotate_display_prompt ();
294
16026cd7
AS
295 /* Reset the nesting depth used when trace-commands is set. */
296 reset_command_nest_depth ();
297
ab821bc6 298 old_chain = make_cleanup (free_current_contents, &actual_gdb_prompt);
d17b6f81 299
ab821bc6
PA
300 /* Do not call the python hook on an explicit prompt change as
301 passed to this function, as this forms a secondary/local prompt,
302 IE, displayed but not set. */
303 if (! new_prompt)
adf40b2e 304 {
ab821bc6 305 if (sync_execution)
d17b6f81 306 {
ab821bc6
PA
307 /* This is to trick readline into not trying to display the
308 prompt. Even though we display the prompt using this
309 function, readline still tries to do its own display if
310 we don't call rl_callback_handler_install and
311 rl_callback_handler_remove (which readline detects
312 because a global variable is not set). If readline did
313 that, it could mess up gdb signal handlers for SIGINT.
314 Readline assumes that between calls to rl_set_signals and
315 rl_clear_signals gdb doesn't do anything with the signal
316 handlers. Well, that's not the case, because when the
317 target executes we change the SIGINT signal handler. If
318 we allowed readline to display the prompt, the signal
319 handler change would happen exactly between the calls to
320 the above two functions. Calling
321 rl_callback_handler_remove(), does the job. */
322
d3d4baed 323 gdb_rl_callback_handler_remove ();
faab9922 324 do_cleanups (old_chain);
ab821bc6 325 return;
d17b6f81
PM
326 }
327 else
ab821bc6
PA
328 {
329 /* Display the top level prompt. */
330 actual_gdb_prompt = top_level_prompt ();
331 }
b5a0ac70 332 }
ab821bc6
PA
333 else
334 actual_gdb_prompt = xstrdup (new_prompt);
b5a0ac70
SS
335
336 if (async_command_editing_p)
337 {
d3d4baed
PA
338 gdb_rl_callback_handler_remove ();
339 gdb_rl_callback_handler_install (actual_gdb_prompt);
b5a0ac70 340 }
371d5dec 341 /* new_prompt at this point can be the top of the stack or the one
d014929c
MS
342 passed in. It can't be NULL. */
343 else
b5a0ac70
SS
344 {
345 /* Don't use a _filtered function here. It causes the assumed
346 character position to be off, since the newline we read from
347 the user is not accounted for. */
d17b6f81 348 fputs_unfiltered (actual_gdb_prompt, gdb_stdout);
b5a0ac70
SS
349 gdb_flush (gdb_stdout);
350 }
ab821bc6
PA
351
352 do_cleanups (old_chain);
b5a0ac70
SS
353}
354
ab821bc6
PA
355/* Return the top level prompt, as specified by "set prompt", possibly
356 overriden by the python gdb.prompt_hook hook, and then composed
357 with the prompt prefix and suffix (annotations). The caller is
358 responsible for freeing the returned string. */
359
360static char *
361top_level_prompt (void)
b5a0ac70 362{
608ff013 363 char *prompt;
b5a0ac70 364
ab821bc6
PA
365 /* Give observers a chance of changing the prompt. E.g., the python
366 `gdb.prompt_hook' is installed as an observer. */
367 observer_notify_before_prompt (get_prompt ());
368
608ff013 369 prompt = get_prompt ();
b5a0ac70 370
ab821bc6 371 if (annotation_level >= 2)
b5a0ac70 372 {
ab821bc6 373 /* Prefix needs to have new line at end. */
608ff013 374 const char prefix[] = "\n\032\032pre-prompt\n";
ab821bc6
PA
375
376 /* Suffix needs to have a new line at end and \032 \032 at
377 beginning. */
608ff013 378 const char suffix[] = "\n\032\032prompt\n";
b5a0ac70 379
608ff013
PA
380 return concat (prefix, prompt, suffix, NULL);
381 }
ab821bc6 382
608ff013 383 return xstrdup (prompt);
b5a0ac70 384}
c2c6d25f 385
187212b3 386/* When there is an event ready on the stdin file descriptor, instead
c2c6d25f 387 of calling readline directly throught the callback function, or
c70061cf
PA
388 instead of calling gdb_readline_no_editing_callback, give gdb a
389 chance to detect errors and do something. */
390
c2c6d25f 391void
2acceee2 392stdin_event_handler (int error, gdb_client_data client_data)
c2c6d25f
JM
393{
394 if (error)
395 {
a3f17187 396 printf_unfiltered (_("error detected on stdin\n"));
2acceee2 397 delete_file_handler (input_fd);
371d5dec 398 /* If stdin died, we may as well kill gdb. */
c5394b80 399 quit_command ((char *) 0, stdin == instream);
c2c6d25f
JM
400 }
401 else
d64e57fa
PP
402 {
403 do
404 {
405 call_stdin_event_handler_again_p = 0;
406 (*call_readline) (client_data);
407 } while (call_stdin_event_handler_again_p != 0);
408 }
c2c6d25f
JM
409}
410
6426a772
JM
411/* Re-enable stdin after the end of an execution command in
412 synchronous mode, or after an error from the target, and we aborted
371d5dec 413 the exec operation. */
6426a772
JM
414
415void
712af3be 416async_enable_stdin (void)
6426a772 417{
32c1e744
VP
418 if (sync_execution)
419 {
371d5dec 420 /* See NOTE in async_disable_stdin(). */
32c1e744
VP
421 /* FIXME: cagney/1999-09-27: Call this before clearing
422 sync_execution. Current target_terminal_ours() implementations
371d5dec 423 check for sync_execution before switching the terminal. */
32c1e744 424 target_terminal_ours ();
32c1e744
VP
425 sync_execution = 0;
426 }
6426a772
JM
427}
428
429/* Disable reads from stdin (the console) marking the command as
371d5dec 430 synchronous. */
6426a772
JM
431
432void
433async_disable_stdin (void)
434{
ab821bc6 435 sync_execution = 1;
6426a772 436}
b5a0ac70 437\f
6426a772 438
371d5dec 439/* Handles a gdb command. This function is called by
b5a0ac70 440 command_line_handler, which has processed one or more input lines
371d5dec 441 into COMMAND. */
392a587b 442/* NOTE: 1999-04-30 This is the asynchronous version of the command_loop
b5a0ac70 443 function. The command_loop function will be obsolete when we
371d5dec 444 switch to use the event loop at every execution of gdb. */
392a587b 445static void
c2c6d25f 446command_handler (char *command)
b5a0ac70 447{
0f3bb72e 448 struct cleanup *stat_chain;
b5a0ac70 449
522002f9 450 clear_quit_flag ();
bc008695 451 if (instream == stdin)
b5a0ac70 452 reinitialize_more_filter ();
b5a0ac70 453
371d5dec
MS
454 /* If readline returned a NULL command, it means that the connection
455 with the terminal is gone. This happens at the end of a
456 testsuite run, after Expect has hung up but GDB is still alive.
457 In such a case, we just quit gdb killing the inferior program
458 too. */
b5a0ac70 459 if (command == 0)
fa3fd85b
AS
460 {
461 printf_unfiltered ("quit\n");
462 execute_command ("quit", stdin == instream);
463 }
b5a0ac70 464
0f3bb72e 465 stat_chain = make_command_stats_cleanup (1);
b5a0ac70
SS
466
467 execute_command (command, instream == stdin);
c5aa993b 468
347bddb7
PA
469 /* Do any commands attached to breakpoint we stopped at. */
470 bpstat_do_actions ();
c5aa993b 471
0f3bb72e 472 do_cleanups (stat_chain);
43ff13b4
JM
473}
474
371d5dec
MS
475/* Handle a complete line of input. This is called by the callback
476 mechanism within the readline library. Deal with incomplete
477 commands as well, by saving the partial input in a global
478 buffer. */
b5a0ac70 479
392a587b 480/* NOTE: 1999-04-30 This is the asynchronous version of the
371d5dec 481 command_line_input function; command_line_input will become
b5a0ac70 482 obsolete once we use the event loop as the default mechanism in
371d5dec 483 GDB. */
b5a0ac70 484static void
c2c6d25f 485command_line_handler (char *rl)
b5a0ac70
SS
486{
487 static char *linebuffer = 0;
488 static unsigned linelength = 0;
52f0bd74 489 char *p;
b5a0ac70 490 char *p1;
b5a0ac70 491 char *nline;
b5a0ac70
SS
492 int repeat = (instream == stdin);
493
494 if (annotation_level > 1 && instream == stdin)
608ff013 495 printf_unfiltered (("\n\032\032post-prompt\n"));
b5a0ac70
SS
496
497 if (linebuffer == 0)
498 {
499 linelength = 80;
500 linebuffer = (char *) xmalloc (linelength);
6e5d7f39 501 linebuffer[0] = '\0';
b5a0ac70
SS
502 }
503
504 p = linebuffer;
505
506 if (more_to_come)
507 {
508 strcpy (linebuffer, readline_input_state.linebuffer);
509 p = readline_input_state.linebuffer_ptr;
b8c9b27d 510 xfree (readline_input_state.linebuffer);
b5a0ac70 511 more_to_come = 0;
b5a0ac70
SS
512 }
513
514#ifdef STOP_SIGNAL
515 if (job_control)
0f71a2f6 516 signal (STOP_SIGNAL, handle_stop_sig);
b5a0ac70
SS
517#endif
518
519 /* Make sure that all output has been output. Some machines may let
371d5dec
MS
520 you get away with leaving out some of the gdb_flush, but not
521 all. */
b5a0ac70
SS
522 wrap_here ("");
523 gdb_flush (gdb_stdout);
524 gdb_flush (gdb_stderr);
525
526 if (source_file_name != NULL)
637537d0 527 ++source_line_number;
b5a0ac70
SS
528
529 /* If we are in this case, then command_handler will call quit
371d5dec 530 and exit from gdb. */
b5a0ac70
SS
531 if (!rl || rl == (char *) EOF)
532 {
b5a0ac70 533 command_handler (0);
371d5dec 534 return; /* Lint. */
b5a0ac70
SS
535 }
536 if (strlen (rl) + 1 + (p - linebuffer) > linelength)
537 {
538 linelength = strlen (rl) + 1 + (p - linebuffer);
539 nline = (char *) xrealloc (linebuffer, linelength);
540 p += nline - linebuffer;
541 linebuffer = nline;
542 }
543 p1 = rl;
544 /* Copy line. Don't copy null at end. (Leaves line alone
371d5dec 545 if this was just a newline). */
b5a0ac70
SS
546 while (*p1)
547 *p++ = *p1++;
548
b8c9b27d 549 xfree (rl); /* Allocated in readline. */
b5a0ac70 550
4dd79c29 551 if (p > linebuffer && *(p - 1) == '\\')
b5a0ac70 552 {
20bb6bc8 553 *p = '\0';
b5a0ac70
SS
554 p--; /* Put on top of '\'. */
555
1b36a34b 556 readline_input_state.linebuffer = xstrdup (linebuffer);
d96429cd
AS
557 readline_input_state.linebuffer_ptr = p;
558
559 /* We will not invoke a execute_command if there is more
371d5dec
MS
560 input expected to complete the command. So, we need to
561 print an empty prompt here. */
d96429cd 562 more_to_come = 1;
ab821bc6 563 display_gdb_prompt ("");
d96429cd 564 return;
b5a0ac70
SS
565 }
566
567#ifdef STOP_SIGNAL
568 if (job_control)
569 signal (STOP_SIGNAL, SIG_DFL);
570#endif
571
572#define SERVER_COMMAND_LENGTH 7
573 server_command =
574 (p - linebuffer > SERVER_COMMAND_LENGTH)
bf896cb0 575 && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0;
b5a0ac70
SS
576 if (server_command)
577 {
578 /* Note that we don't set `line'. Between this and the check in
579 dont_repeat, this insures that repeating will still do the
580 right thing. */
581 *p = '\0';
582 command_handler (linebuffer + SERVER_COMMAND_LENGTH);
583 display_gdb_prompt (0);
584 return;
585 }
586
587 /* Do history expansion if that is wished. */
588 if (history_expansion_p && instream == stdin
589 && ISATTY (instream))
590 {
591 char *history_value;
592 int expanded;
593
594 *p = '\0'; /* Insert null now. */
595 expanded = history_expand (linebuffer, &history_value);
596 if (expanded)
597 {
598 /* Print the changes. */
599 printf_unfiltered ("%s\n", history_value);
600
601 /* If there was an error, call this function again. */
602 if (expanded < 0)
603 {
b8c9b27d 604 xfree (history_value);
b5a0ac70
SS
605 return;
606 }
607 if (strlen (history_value) > linelength)
608 {
609 linelength = strlen (history_value) + 1;
610 linebuffer = (char *) xrealloc (linebuffer, linelength);
611 }
612 strcpy (linebuffer, history_value);
613 p = linebuffer + strlen (linebuffer);
b5a0ac70 614 }
f5b73fbb 615 xfree (history_value);
b5a0ac70
SS
616 }
617
371d5dec
MS
618 /* If we just got an empty line, and that is supposed to repeat the
619 previous command, return the value in the global buffer. */
b5a0ac70
SS
620 if (repeat && p == linebuffer && *p != '\\')
621 {
dc7eb48e 622 command_handler (saved_command_line);
b5a0ac70
SS
623 display_gdb_prompt (0);
624 return;
625 }
626
627 for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++);
628 if (repeat && !*p1)
629 {
dc7eb48e 630 command_handler (saved_command_line);
b5a0ac70
SS
631 display_gdb_prompt (0);
632 return;
633 }
634
635 *p = 0;
636
637 /* Add line to history if appropriate. */
840da61a 638 if (*linebuffer && input_from_terminal_p ())
08b13bdd 639 gdb_add_history (linebuffer);
b5a0ac70
SS
640
641 /* Note: lines consisting solely of comments are added to the command
642 history. This is useful when you type a command, and then
643 realize you don't want to execute it quite yet. You can comment
644 out the command and then later fetch it from the value history
645 and remove the '#'. The kill ring is probably better, but some
646 people are in the habit of commenting things out. */
647 if (*p1 == '#')
371d5dec 648 *p1 = '\0'; /* Found a comment. */
b5a0ac70
SS
649
650 /* Save into global buffer if appropriate. */
651 if (repeat)
652 {
2669cade
PA
653 xfree (saved_command_line);
654 saved_command_line = xstrdup (linebuffer);
b5a0ac70
SS
655 if (!more_to_come)
656 {
dc7eb48e 657 command_handler (saved_command_line);
b5a0ac70
SS
658 display_gdb_prompt (0);
659 }
660 return;
661 }
662
663 command_handler (linebuffer);
664 display_gdb_prompt (0);
665 return;
666}
667
668/* Does reading of input from terminal w/o the editing features
c70061cf
PA
669 provided by the readline library. Calls the line input handler
670 once we have a whole input line. */
b5a0ac70 671
085dd6e6 672void
c70061cf 673gdb_readline_no_editing_callback (gdb_client_data client_data)
b5a0ac70
SS
674{
675 int c;
676 char *result;
187212b3 677 struct buffer line_buffer;
7be570e7
JM
678 static int done_once = 0;
679
187212b3
PA
680 buffer_init (&line_buffer);
681
7be570e7 682 /* Unbuffer the input stream, so that, later on, the calls to fgetc
371d5dec 683 fetch only one char at the time from the stream. The fgetc's will
7be570e7 684 get up to the first newline, but there may be more chars in the
371d5dec 685 stream after '\n'. If we buffer the input and fgetc drains the
7be570e7 686 stream, getting stuff beyond the newline as well, a select, done
371d5dec 687 afterwards will not trigger. */
7be570e7
JM
688 if (!done_once && !ISATTY (instream))
689 {
690 setbuf (instream, NULL);
691 done_once = 1;
692 }
b5a0ac70 693
b5a0ac70 694 /* We still need the while loop here, even though it would seem
c70061cf
PA
695 obvious to invoke gdb_readline_no_editing_callback at every
696 character entered. If not using the readline library, the
697 terminal is in cooked mode, which sends the characters all at
698 once. Poll will notice that the input fd has changed state only
699 after enter is pressed. At this point we still need to fetch all
700 the chars entered. */
b5a0ac70
SS
701
702 while (1)
703 {
704 /* Read from stdin if we are executing a user defined command.
705 This is the right thing for prompt_for_continue, at least. */
706 c = fgetc (instream ? instream : stdin);
707
708 if (c == EOF)
709 {
187212b3
PA
710 if (line_buffer.used_size > 0)
711 {
712 /* The last line does not end with a newline. Return it, and
713 if we are called again fgetc will still return EOF and
714 we'll return NULL then. */
715 break;
716 }
717 xfree (buffer_finish (&line_buffer));
0f71a2f6 718 (*input_handler) (0);
13ce7133 719 return;
b5a0ac70
SS
720 }
721
722 if (c == '\n')
b5a0ac70 723 {
187212b3
PA
724 if (line_buffer.used_size > 0
725 && line_buffer.buffer[line_buffer.used_size - 1] == '\r')
726 line_buffer.used_size--;
b5a0ac70
SS
727 break;
728 }
b5a0ac70 729
187212b3 730 buffer_grow_char (&line_buffer, c);
b5a0ac70
SS
731 }
732
187212b3
PA
733 buffer_grow_char (&line_buffer, '\0');
734 result = buffer_finish (&line_buffer);
0f71a2f6 735 (*input_handler) (result);
b5a0ac70
SS
736}
737\f
738
739/* Initialization of signal handlers and tokens. There is a function
371d5dec 740 handle_sig* for each of the signals GDB cares about. Specifically:
b5a0ac70
SS
741 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
742 functions are the actual signal handlers associated to the signals
743 via calls to signal(). The only job for these functions is to
744 enqueue the appropriate event/procedure with the event loop. Such
371d5dec 745 procedures are the old signal handlers. The event loop will take
b5a0ac70 746 care of invoking the queued procedures to perform the usual tasks
371d5dec 747 associated with the reception of the signal. */
392a587b 748/* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
b5a0ac70 749 init_signals will become obsolete as we move to have to event loop
371d5dec 750 as the default for gdb. */
b5a0ac70 751void
c2c6d25f 752async_init_signals (void)
c5aa993b 753{
b5a0ac70
SS
754 signal (SIGINT, handle_sigint);
755 sigint_token =
0f71a2f6 756 create_async_signal_handler (async_request_quit, NULL);
a7266fef 757 signal (SIGTERM, handle_sigterm);
06c868a8
JK
758 async_sigterm_token
759 = create_async_signal_handler (async_sigterm_handler, NULL);
b5a0ac70
SS
760
761 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
762 to the inferior and breakpoints will be ignored. */
763#ifdef SIGTRAP
764 signal (SIGTRAP, SIG_DFL);
765#endif
766
6d318c73 767#ifdef SIGQUIT
b5a0ac70
SS
768 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
769 passed to the inferior, which we don't want. It would be
770 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
771 on BSD4.3 systems using vfork, that can affect the
772 GDB process as well as the inferior (the signal handling tables
773 might be in memory, shared between the two). Since we establish
774 a handler for SIGQUIT, when we call exec it will set the signal
775 to SIG_DFL for us. */
776 signal (SIGQUIT, handle_sigquit);
777 sigquit_token =
0f71a2f6 778 create_async_signal_handler (async_do_nothing, NULL);
6d318c73 779#endif
b5a0ac70
SS
780#ifdef SIGHUP
781 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
782 sighup_token =
0f71a2f6 783 create_async_signal_handler (async_disconnect, NULL);
b5a0ac70
SS
784 else
785 sighup_token =
0f71a2f6 786 create_async_signal_handler (async_do_nothing, NULL);
b5a0ac70
SS
787#endif
788 signal (SIGFPE, handle_sigfpe);
789 sigfpe_token =
0f71a2f6 790 create_async_signal_handler (async_float_handler, NULL);
b5a0ac70 791
0f71a2f6
JM
792#ifdef STOP_SIGNAL
793 sigtstp_token =
794 create_async_signal_handler (async_stop_sig, NULL);
795#endif
0f71a2f6
JM
796}
797
371d5dec
MS
798/* Tell the event loop what to do if SIGINT is received.
799 See event-signal.c. */
c5aa993b 800void
c2c6d25f 801handle_sigint (int sig)
b5a0ac70
SS
802{
803 signal (sig, handle_sigint);
804
5f960e00
FF
805 /* We could be running in a loop reading in symfiles or something so
806 it may be quite a while before we get back to the event loop. So
371d5dec 807 set quit_flag to 1 here. Then if QUIT is called before we get to
5f960e00
FF
808 the event loop, we will unwind as expected. */
809
522002f9 810 set_quit_flag ();
5f960e00 811
b5a0ac70 812 /* If immediate_quit is set, we go ahead and process the SIGINT right
371d5dec 813 away, even if we usually would defer this to the event loop. The
b5a0ac70 814 assumption here is that it is safe to process ^C immediately if
371d5dec 815 immediate_quit is set. If we didn't, SIGINT would be really
b5a0ac70
SS
816 processed only the next time through the event loop. To get to
817 that point, though, the command that we want to interrupt needs to
b803fb0f 818 finish first, which is unacceptable. If immediate quit is not set,
371d5dec 819 we process SIGINT the next time through the loop, which is fine. */
b803fb0f 820 gdb_call_async_signal_handler (sigint_token, immediate_quit);
b5a0ac70
SS
821}
822
06c868a8
JK
823/* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
824
825static void
826async_sigterm_handler (gdb_client_data arg)
827{
828 quit_force (NULL, stdin == instream);
829}
830
831/* See defs.h. */
832volatile int sync_quit_force_run;
833
a7266fef
AS
834/* Quit GDB if SIGTERM is received.
835 GDB would quit anyway, but this way it will clean up properly. */
836void
837handle_sigterm (int sig)
838{
839 signal (sig, handle_sigterm);
06c868a8 840
077836f7
PP
841 sync_quit_force_run = 1;
842 set_quit_flag ();
843
844 mark_async_signal_handler (async_sigterm_token);
a7266fef
AS
845}
846
371d5dec 847/* Do the quit. All the checks have been done by the caller. */
c5aa993b 848void
c2c6d25f 849async_request_quit (gdb_client_data arg)
b5a0ac70 850{
5f960e00 851 /* If the quit_flag has gotten reset back to 0 by the time we get
4ac94eda
FF
852 back here, that means that an exception was thrown to unwind the
853 current command before we got back to the event loop. So there
522002f9 854 is no reason to call quit again here. */
5f960e00 855
522002f9 856 if (check_quit_flag ())
4ac94eda 857 quit ();
b5a0ac70
SS
858}
859
6d318c73 860#ifdef SIGQUIT
371d5dec
MS
861/* Tell the event loop what to do if SIGQUIT is received.
862 See event-signal.c. */
c5aa993b 863static void
c2c6d25f 864handle_sigquit (int sig)
b5a0ac70 865{
f6fbab7d 866 mark_async_signal_handler (sigquit_token);
b5a0ac70
SS
867 signal (sig, handle_sigquit);
868}
6d318c73 869#endif
b5a0ac70 870
0f0b8dcd
DJ
871#if defined (SIGQUIT) || defined (SIGHUP)
872/* Called by the event loop in response to a SIGQUIT or an
873 ignored SIGHUP. */
c5aa993b 874static void
c2c6d25f 875async_do_nothing (gdb_client_data arg)
b5a0ac70 876{
371d5dec 877 /* Empty function body. */
b5a0ac70 878}
0f0b8dcd 879#endif
b5a0ac70
SS
880
881#ifdef SIGHUP
371d5dec
MS
882/* Tell the event loop what to do if SIGHUP is received.
883 See event-signal.c. */
c5aa993b 884static void
fba45db2 885handle_sighup (int sig)
b5a0ac70 886{
f6fbab7d 887 mark_async_signal_handler (sighup_token);
b5a0ac70
SS
888 signal (sig, handle_sighup);
889}
890
371d5dec 891/* Called by the event loop to process a SIGHUP. */
c5aa993b 892static void
c2c6d25f 893async_disconnect (gdb_client_data arg)
b5a0ac70 894{
b2cd6b29 895
492d29ea 896 TRY
b2cd6b29
JM
897 {
898 quit_cover ();
899 }
900
492d29ea 901 CATCH (exception, RETURN_MASK_ALL)
b2cd6b29
JM
902 {
903 fputs_filtered ("Could not kill the program being debugged",
904 gdb_stderr);
905 exception_print (gdb_stderr, exception);
906 }
492d29ea 907 END_CATCH
b2cd6b29 908
492d29ea 909 TRY
b2cd6b29 910 {
460014f5 911 pop_all_targets ();
b2cd6b29 912 }
492d29ea
PA
913 CATCH (exception, RETURN_MASK_ALL)
914 {
915 }
916 END_CATCH
b2cd6b29 917
371d5dec 918 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
ec4dfccf 919 raise (SIGHUP);
b5a0ac70
SS
920}
921#endif
922
0f71a2f6 923#ifdef STOP_SIGNAL
c5aa993b 924void
c2c6d25f 925handle_stop_sig (int sig)
0f71a2f6 926{
f6fbab7d 927 mark_async_signal_handler (sigtstp_token);
c5aa993b 928 signal (sig, handle_stop_sig);
0f71a2f6
JM
929}
930
931static void
c2c6d25f 932async_stop_sig (gdb_client_data arg)
0f71a2f6 933{
ab821bc6 934 char *prompt = get_prompt ();
d7f9d729 935
0f71a2f6
JM
936#if STOP_SIGNAL == SIGTSTP
937 signal (SIGTSTP, SIG_DFL);
2acceee2
JM
938#if HAVE_SIGPROCMASK
939 {
940 sigset_t zero;
46711df8 941
2acceee2
JM
942 sigemptyset (&zero);
943 sigprocmask (SIG_SETMASK, &zero, 0);
944 }
46711df8 945#elif HAVE_SIGSETMASK
0f71a2f6 946 sigsetmask (0);
2acceee2 947#endif
ec4dfccf 948 raise (SIGTSTP);
0f71a2f6
JM
949 signal (SIGTSTP, handle_stop_sig);
950#else
951 signal (STOP_SIGNAL, handle_stop_sig);
952#endif
953 printf_unfiltered ("%s", prompt);
954 gdb_flush (gdb_stdout);
955
371d5dec
MS
956 /* Forget about any previous command -- null line now will do
957 nothing. */
0f71a2f6
JM
958 dont_repeat ();
959}
960#endif /* STOP_SIGNAL */
961
371d5dec
MS
962/* Tell the event loop what to do if SIGFPE is received.
963 See event-signal.c. */
c5aa993b 964static void
c2c6d25f 965handle_sigfpe (int sig)
b5a0ac70 966{
f6fbab7d 967 mark_async_signal_handler (sigfpe_token);
b5a0ac70
SS
968 signal (sig, handle_sigfpe);
969}
970
371d5dec 971/* Event loop will call this functin to process a SIGFPE. */
c5aa993b 972static void
c2c6d25f 973async_float_handler (gdb_client_data arg)
b5a0ac70 974{
371d5dec
MS
975 /* This message is based on ANSI C, section 4.7. Note that integer
976 divide by zero causes this, so "float" is a misnomer. */
8a3fe4f8 977 error (_("Erroneous arithmetic operation."));
b5a0ac70 978}
b5a0ac70
SS
979\f
980
981/* Called by do_setshow_command. */
b5a0ac70 982void
371d5dec
MS
983set_async_editing_command (char *args, int from_tty,
984 struct cmd_list_element *c)
b5a0ac70
SS
985{
986 change_line_handler ();
987}
988
0f71a2f6
JM
989/* Set things up for readline to be invoked via the alternate
990 interface, i.e. via a callback function (rl_callback_read_char),
371d5dec 991 and hook up instream to the event loop. */
0f71a2f6 992void
cee6ddeb 993gdb_setup_readline (void)
0f71a2f6 994{
362646f5
AC
995 /* This function is a noop for the sync case. The assumption is
996 that the sync setup is ALL done in gdb_init, and we would only
997 mess it up here. The sync stuff should really go away over
998 time. */
1a088d06
AS
999 if (!batch_silent)
1000 gdb_stdout = stdio_fileopen (stdout);
ffa4ac95 1001 gdb_stderr = stderr_fileopen ();
362646f5
AC
1002 gdb_stdlog = gdb_stderr; /* for moment */
1003 gdb_stdtarg = gdb_stderr; /* for moment */
8d4d924b 1004 gdb_stdtargerr = gdb_stderr; /* for moment */
362646f5
AC
1005
1006 /* If the input stream is connected to a terminal, turn on
1007 editing. */
1008 if (ISATTY (instream))
9e0b60a8 1009 {
371d5dec 1010 /* Tell gdb that we will be using the readline library. This
362646f5
AC
1011 could be overwritten by a command in .gdbinit like 'set
1012 editing on' or 'off'. */
1013 async_command_editing_p = 1;
c5201926 1014
362646f5
AC
1015 /* When a character is detected on instream by select or poll,
1016 readline will be invoked via this callback function. */
1017 call_readline = rl_callback_read_char_wrapper;
9e0b60a8 1018 }
362646f5
AC
1019 else
1020 {
1021 async_command_editing_p = 0;
c70061cf 1022 call_readline = gdb_readline_no_editing_callback;
362646f5
AC
1023 }
1024
1025 /* When readline has read an end-of-line character, it passes the
371d5dec 1026 complete line to gdb for processing; command_line_handler is the
362646f5
AC
1027 function that does this. */
1028 input_handler = command_line_handler;
1029
371d5dec 1030 /* Tell readline to use the same input stream that gdb uses. */
362646f5
AC
1031 rl_instream = instream;
1032
1033 /* Get a file descriptor for the input stream, so that we can
1034 register it with the event loop. */
1035 input_fd = fileno (instream);
1036
1037 /* Now we need to create the event sources for the input file
1038 descriptor. */
1039 /* At this point in time, this is the only event source that we
371d5dec 1040 register with the even loop. Another source is going to be the
362646f5
AC
1041 target program (inferior), but that must be registered only when
1042 it actually exists (I.e. after we say 'run' or after we connect
1043 to a remote target. */
1044 add_file_handler (input_fd, stdin_event_handler, 0);
0f71a2f6 1045}
cee6ddeb 1046
7d5b6fdd
EZ
1047/* Disable command input through the standard CLI channels. Used in
1048 the suspend proc for interpreters that use the standard gdb readline
1049 interface, like the cli & the mi. */
1050void
1051gdb_disable_readline (void)
1052{
362646f5
AC
1053 /* FIXME - It is too heavyweight to delete and remake these every
1054 time you run an interpreter that needs readline. It is probably
1055 better to have the interpreters cache these, which in turn means
1056 that this needs to be moved into interpreter specific code. */
7d5b6fdd
EZ
1057
1058#if 0
362646f5
AC
1059 ui_file_delete (gdb_stdout);
1060 ui_file_delete (gdb_stderr);
1061 gdb_stdlog = NULL;
1062 gdb_stdtarg = NULL;
8d4d924b 1063 gdb_stdtargerr = NULL;
7d5b6fdd
EZ
1064#endif
1065
d3d4baed 1066 gdb_rl_callback_handler_remove ();
362646f5 1067 delete_file_handler (input_fd);
7d5b6fdd 1068}
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