gdb vendor branch: Bring in additional source files
[dragonfly.git] / contrib / gdb-7 / gdb / event-top.c
CommitLineData
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1/* Top level stuff for GDB, the GNU debugger.
2
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3 Copyright (C) 1999-2002, 2004-2005, 2007-2012 Free Software
4 Foundation, Inc.
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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
c50c785c 21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
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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"
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36#include "observer.h"
37#include "continuations.h"
c50c785c 38#include "gdbcmd.h" /* for dont_repeat() */
5796c8dc 39
c50c785c 40/* readline include files. */
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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);
5796c8dc 50static void command_handler (char *command);
a45ae5f8 51static char *top_level_prompt (void);
5796c8dc 52
c50c785c 53/* Signal handlers. */
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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
c50c785c 66 signals. */
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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
c50c785c 79 functions. These are all included in the file callback.c in the
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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
c50c785c 84 there is a new character ready on the input stream. This function
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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
c50c785c 90 of the old command_line_input in gdb. Instead of invoking (and waiting
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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
c50c785c 96 that readline offers as callback to the event_loop. */
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97
98void (*input_handler) (char *);
99void (*call_readline) (gdb_client_data);
100
c50c785c 101/* Important variables for the event loop. */
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102
103/* This is used to determine if GDB is using the readline library or
c50c785c 104 its own simplified form of readline. It is used by the asynchronous
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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
c50c785c 108 loop as default engine, and event-top.c is merged into top.c. */
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109int async_command_editing_p;
110
5796c8dc 111/* This is the annotation suffix that will be used when the
c50c785c 112 annotation_level is 2. */
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113char *async_annotation_suffix;
114
115/* This is used to display the notification of the completion of an
c50c785c 116 asynchronous execution command. */
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117int exec_done_display_p = 0;
118
119/* This is the file descriptor for the input stream that GDB uses to
c50c785c 120 read commands from. */
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121int input_fd;
122
c50c785c 123/* Signal handling variables. */
5796c8dc 124/* Each of these is a pointer to a function that the event loop will
c50c785c 125 invoke if the corresponding signal has received. The real signal
5796c8dc 126 handlers mark these functions as ready to be executed and the event
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127 loop, in a later iteration, calls them. See the function
128 invoke_async_signal_handler. */
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129void *sigint_token;
130#ifdef SIGHUP
131void *sighup_token;
132#endif
133#ifdef SIGQUIT
134void *sigquit_token;
135#endif
136void *sigfpe_token;
137#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
138void *sigwinch_token;
139#endif
140#ifdef STOP_SIGNAL
141void *sigtstp_token;
142#endif
143
144/* Structure to save a partially entered command. This is used when
c50c785c 145 the user types '\' at the end of a command line. This is necessary
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146 because each line of input is handled by a different call to
147 command_line_handler, and normally there is no state retained
c50c785c 148 between different calls. */
a45ae5f8 149static int more_to_come = 0;
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150
151struct readline_input_state
152 {
153 char *linebuffer;
154 char *linebuffer_ptr;
155 }
156readline_input_state;
157
158/* This hook is called by rl_callback_read_char_wrapper after each
159 character is processed. */
c50c785c 160void (*after_char_processing_hook) (void);
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161\f
162
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163/* Wrapper function for calling into the readline library. The event
164 loop expects the callback function to have a paramter, while
165 readline expects none. */
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166static void
167rl_callback_read_char_wrapper (gdb_client_data client_data)
168{
169 rl_callback_read_char ();
170 if (after_char_processing_hook)
171 (*after_char_processing_hook) ();
172}
173
174/* Initialize all the necessary variables, start the event loop,
c50c785c 175 register readline, and stdin, start the loop. */
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176void
177cli_command_loop (void)
178{
a45ae5f8 179 display_gdb_prompt (0);
5796c8dc 180
c50c785c 181 /* Now it's time to start the event loop. */
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182 start_event_loop ();
183}
184
185/* Change the function to be invoked every time there is a character
c50c785c 186 ready on stdin. This is used when the user sets the editing off,
5796c8dc 187 therefore bypassing readline, and letting gdb handle the input
c50c785c 188 itself, via gdb_readline2. Also it is used in the opposite case in
5796c8dc 189 which the user sets editing on again, by restoring readline
c50c785c 190 handling of the input. */
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191static void
192change_line_handler (void)
193{
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194 /* NOTE: this operates on input_fd, not instream. If we are reading
195 commands from a file, instream will point to the file. However in
5796c8dc 196 async mode, we always read commands from a file with editing
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197 off. This means that the 'set editing on/off' will have effect
198 only on the interactive session. */
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199
200 if (async_command_editing_p)
201 {
c50c785c 202 /* Turn on editing by using readline. */
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203 call_readline = rl_callback_read_char_wrapper;
204 input_handler = command_line_handler;
205 }
206 else
207 {
c50c785c 208 /* Turn off editing by using gdb_readline2. */
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209 rl_callback_handler_remove ();
210 call_readline = gdb_readline2;
211
212 /* Set up the command handler as well, in case we are called as
c50c785c 213 first thing from .gdbinit. */
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214 input_handler = command_line_handler;
215 }
216}
217
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218/* Displays the prompt. If the argument NEW_PROMPT is NULL, the
219 prompt that is displayed is the current top level prompt.
220 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
221 prompt.
222
223 This is used after each gdb command has completed, and in the
224 following cases:
225
c50c785c 226 1. When the user enters a command line which is ended by '\'
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227 indicating that the command will continue on the next line. In
228 that case the prompt that is displayed is the empty string.
229
5796c8dc 230 2. When the user is entering 'commands' for a breakpoint, or
c50c785c 231 actions for a tracepoint. In this case the prompt will be '>'
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232
233 3. On prompting for pagination. */
234
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235void
236display_gdb_prompt (char *new_prompt)
237{
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238 char *actual_gdb_prompt = NULL;
239 struct cleanup *old_chain;
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240
241 /* Reset the nesting depth used when trace-commands is set. */
242 reset_command_nest_depth ();
243
244 /* Each interpreter has its own rules on displaying the command
245 prompt. */
246 if (!current_interp_display_prompt_p ())
247 return;
248
a45ae5f8 249 old_chain = make_cleanup (free_current_contents, &actual_gdb_prompt);
5796c8dc 250
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251 /* Do not call the python hook on an explicit prompt change as
252 passed to this function, as this forms a secondary/local prompt,
253 IE, displayed but not set. */
254 if (! new_prompt)
5796c8dc 255 {
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256 if (sync_execution)
257 {
258 /* This is to trick readline into not trying to display the
259 prompt. Even though we display the prompt using this
260 function, readline still tries to do its own display if
261 we don't call rl_callback_handler_install and
262 rl_callback_handler_remove (which readline detects
263 because a global variable is not set). If readline did
264 that, it could mess up gdb signal handlers for SIGINT.
265 Readline assumes that between calls to rl_set_signals and
266 rl_clear_signals gdb doesn't do anything with the signal
267 handlers. Well, that's not the case, because when the
268 target executes we change the SIGINT signal handler. If
269 we allowed readline to display the prompt, the signal
270 handler change would happen exactly between the calls to
271 the above two functions. Calling
272 rl_callback_handler_remove(), does the job. */
273
274 rl_callback_handler_remove ();
275 return;
276 }
277 else
278 {
279 /* Display the top level prompt. */
280 actual_gdb_prompt = top_level_prompt ();
281 }
5796c8dc 282 }
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283 else
284 actual_gdb_prompt = xstrdup (new_prompt);
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285
286 if (async_command_editing_p)
287 {
288 rl_callback_handler_remove ();
a45ae5f8 289 rl_callback_handler_install (actual_gdb_prompt, input_handler);
5796c8dc 290 }
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291 /* new_prompt at this point can be the top of the stack or the one
292 passed in. It can't be NULL. */
293 else
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294 {
295 /* Don't use a _filtered function here. It causes the assumed
296 character position to be off, since the newline we read from
297 the user is not accounted for. */
a45ae5f8 298 fputs_unfiltered (actual_gdb_prompt, gdb_stdout);
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299 gdb_flush (gdb_stdout);
300 }
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301
302 do_cleanups (old_chain);
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303}
304
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305/* Return the top level prompt, as specified by "set prompt", possibly
306 overriden by the python gdb.prompt_hook hook, and then composed
307 with the prompt prefix and suffix (annotations). The caller is
308 responsible for freeing the returned string. */
309
310static char *
311top_level_prompt (void)
5796c8dc 312{
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313 char *prefix;
314 char *prompt = NULL;
315 char *suffix;
316 char *composed_prompt;
317 size_t prompt_length;
5796c8dc 318
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319 /* Give observers a chance of changing the prompt. E.g., the python
320 `gdb.prompt_hook' is installed as an observer. */
321 observer_notify_before_prompt (get_prompt ());
322
323 prompt = xstrdup (get_prompt ());
5796c8dc 324
a45ae5f8 325 if (annotation_level >= 2)
5796c8dc 326 {
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327 /* Prefix needs to have new line at end. */
328 prefix = (char *) alloca (strlen (async_annotation_suffix) + 10);
329 strcpy (prefix, "\n\032\032pre-");
330 strcat (prefix, async_annotation_suffix);
331 strcat (prefix, "\n");
332
333 /* Suffix needs to have a new line at end and \032 \032 at
334 beginning. */
335 suffix = (char *) alloca (strlen (async_annotation_suffix) + 6);
336 strcpy (suffix, "\n\032\032");
337 strcat (suffix, async_annotation_suffix);
338 strcat (suffix, "\n");
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339 }
340 else
341 {
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342 prefix = "";
343 suffix = "";
5796c8dc 344 }
5796c8dc 345
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346 prompt_length = strlen (prefix) + strlen (prompt) + strlen (suffix);
347 composed_prompt = xmalloc (prompt_length + 1);
5796c8dc 348
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349 strcpy (composed_prompt, prefix);
350 strcat (composed_prompt, prompt);
351 strcat (composed_prompt, suffix);
5796c8dc 352
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353 xfree (prompt);
354
355 return composed_prompt;
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356}
357
358/* When there is an event ready on the stdin file desriptor, instead
359 of calling readline directly throught the callback function, or
360 instead of calling gdb_readline2, give gdb a chance to detect
c50c785c 361 errors and do something. */
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362void
363stdin_event_handler (int error, gdb_client_data client_data)
364{
365 if (error)
366 {
367 printf_unfiltered (_("error detected on stdin\n"));
368 delete_file_handler (input_fd);
369 discard_all_continuations ();
370 discard_all_intermediate_continuations ();
c50c785c 371 /* If stdin died, we may as well kill gdb. */
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372 quit_command ((char *) 0, stdin == instream);
373 }
374 else
375 (*call_readline) (client_data);
376}
377
378/* Re-enable stdin after the end of an execution command in
379 synchronous mode, or after an error from the target, and we aborted
c50c785c 380 the exec operation. */
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381
382void
383async_enable_stdin (void)
384{
385 if (sync_execution)
386 {
c50c785c 387 /* See NOTE in async_disable_stdin(). */
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388 /* FIXME: cagney/1999-09-27: Call this before clearing
389 sync_execution. Current target_terminal_ours() implementations
c50c785c 390 check for sync_execution before switching the terminal. */
5796c8dc 391 target_terminal_ours ();
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392 sync_execution = 0;
393 }
394}
395
396/* Disable reads from stdin (the console) marking the command as
c50c785c 397 synchronous. */
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398
399void
400async_disable_stdin (void)
401{
a45ae5f8 402 sync_execution = 1;
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403}
404\f
405
c50c785c 406/* Handles a gdb command. This function is called by
5796c8dc 407 command_line_handler, which has processed one or more input lines
c50c785c 408 into COMMAND. */
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409/* NOTE: 1999-04-30 This is the asynchronous version of the command_loop
410 function. The command_loop function will be obsolete when we
c50c785c 411 switch to use the event loop at every execution of gdb. */
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412static void
413command_handler (char *command)
414{
415 int stdin_is_tty = ISATTY (stdin);
cf7f2e2d 416 struct cleanup *stat_chain;
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417
418 quit_flag = 0;
419 if (instream == stdin && stdin_is_tty)
420 reinitialize_more_filter ();
421
c50c785c
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422 /* If readline returned a NULL command, it means that the connection
423 with the terminal is gone. This happens at the end of a
424 testsuite run, after Expect has hung up but GDB is still alive.
425 In such a case, we just quit gdb killing the inferior program
426 too. */
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427 if (command == 0)
428 {
429 printf_unfiltered ("quit\n");
430 execute_command ("quit", stdin == instream);
431 }
432
cf7f2e2d 433 stat_chain = make_command_stats_cleanup (1);
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434
435 execute_command (command, instream == stdin);
436
437 /* Do any commands attached to breakpoint we stopped at. */
438 bpstat_do_actions ();
439
cf7f2e2d 440 do_cleanups (stat_chain);
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441}
442
c50c785c
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443/* Handle a complete line of input. This is called by the callback
444 mechanism within the readline library. Deal with incomplete
445 commands as well, by saving the partial input in a global
446 buffer. */
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447
448/* NOTE: 1999-04-30 This is the asynchronous version of the
c50c785c 449 command_line_input function; command_line_input will become
5796c8dc 450 obsolete once we use the event loop as the default mechanism in
c50c785c 451 GDB. */
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452static void
453command_line_handler (char *rl)
454{
455 static char *linebuffer = 0;
456 static unsigned linelength = 0;
457 char *p;
458 char *p1;
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459 char *nline;
460 char got_eof = 0;
461
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462 int repeat = (instream == stdin);
463
464 if (annotation_level > 1 && instream == stdin)
465 {
466 printf_unfiltered (("\n\032\032post-"));
467 puts_unfiltered (async_annotation_suffix);
468 printf_unfiltered (("\n"));
469 }
470
471 if (linebuffer == 0)
472 {
473 linelength = 80;
474 linebuffer = (char *) xmalloc (linelength);
475 }
476
477 p = linebuffer;
478
479 if (more_to_come)
480 {
481 strcpy (linebuffer, readline_input_state.linebuffer);
482 p = readline_input_state.linebuffer_ptr;
483 xfree (readline_input_state.linebuffer);
484 more_to_come = 0;
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485 }
486
487#ifdef STOP_SIGNAL
488 if (job_control)
489 signal (STOP_SIGNAL, handle_stop_sig);
490#endif
491
492 /* Make sure that all output has been output. Some machines may let
c50c785c
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493 you get away with leaving out some of the gdb_flush, but not
494 all. */
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495 wrap_here ("");
496 gdb_flush (gdb_stdout);
497 gdb_flush (gdb_stderr);
498
499 if (source_file_name != NULL)
500 ++source_line_number;
501
502 /* If we are in this case, then command_handler will call quit
c50c785c 503 and exit from gdb. */
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504 if (!rl || rl == (char *) EOF)
505 {
506 got_eof = 1;
507 command_handler (0);
c50c785c 508 return; /* Lint. */
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509 }
510 if (strlen (rl) + 1 + (p - linebuffer) > linelength)
511 {
512 linelength = strlen (rl) + 1 + (p - linebuffer);
513 nline = (char *) xrealloc (linebuffer, linelength);
514 p += nline - linebuffer;
515 linebuffer = nline;
516 }
517 p1 = rl;
518 /* Copy line. Don't copy null at end. (Leaves line alone
c50c785c 519 if this was just a newline). */
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520 while (*p1)
521 *p++ = *p1++;
522
523 xfree (rl); /* Allocated in readline. */
524
525 if (p > linebuffer && *(p - 1) == '\\')
526 {
527 *p = '\0';
528 p--; /* Put on top of '\'. */
529
530 readline_input_state.linebuffer = xstrdup (linebuffer);
531 readline_input_state.linebuffer_ptr = p;
532
533 /* We will not invoke a execute_command if there is more
c50c785c
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534 input expected to complete the command. So, we need to
535 print an empty prompt here. */
5796c8dc 536 more_to_come = 1;
a45ae5f8 537 display_gdb_prompt ("");
5796c8dc
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538 return;
539 }
540
541#ifdef STOP_SIGNAL
542 if (job_control)
543 signal (STOP_SIGNAL, SIG_DFL);
544#endif
545
546#define SERVER_COMMAND_LENGTH 7
547 server_command =
548 (p - linebuffer > SERVER_COMMAND_LENGTH)
549 && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0;
550 if (server_command)
551 {
552 /* Note that we don't set `line'. Between this and the check in
553 dont_repeat, this insures that repeating will still do the
554 right thing. */
555 *p = '\0';
556 command_handler (linebuffer + SERVER_COMMAND_LENGTH);
557 display_gdb_prompt (0);
558 return;
559 }
560
561 /* Do history expansion if that is wished. */
562 if (history_expansion_p && instream == stdin
563 && ISATTY (instream))
564 {
565 char *history_value;
566 int expanded;
567
568 *p = '\0'; /* Insert null now. */
569 expanded = history_expand (linebuffer, &history_value);
570 if (expanded)
571 {
572 /* Print the changes. */
573 printf_unfiltered ("%s\n", history_value);
574
575 /* If there was an error, call this function again. */
576 if (expanded < 0)
577 {
578 xfree (history_value);
579 return;
580 }
581 if (strlen (history_value) > linelength)
582 {
583 linelength = strlen (history_value) + 1;
584 linebuffer = (char *) xrealloc (linebuffer, linelength);
585 }
586 strcpy (linebuffer, history_value);
587 p = linebuffer + strlen (linebuffer);
588 }
589 xfree (history_value);
590 }
591
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592 /* If we just got an empty line, and that is supposed to repeat the
593 previous command, return the value in the global buffer. */
5796c8dc
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594 if (repeat && p == linebuffer && *p != '\\')
595 {
a45ae5f8 596 command_handler (saved_command_line);
5796c8dc
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597 display_gdb_prompt (0);
598 return;
599 }
600
601 for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++);
602 if (repeat && !*p1)
603 {
a45ae5f8 604 command_handler (saved_command_line);
5796c8dc
SS
605 display_gdb_prompt (0);
606 return;
607 }
608
609 *p = 0;
610
611 /* Add line to history if appropriate. */
612 if (instream == stdin
613 && ISATTY (stdin) && *linebuffer)
614 add_history (linebuffer);
615
616 /* Note: lines consisting solely of comments are added to the command
617 history. This is useful when you type a command, and then
618 realize you don't want to execute it quite yet. You can comment
619 out the command and then later fetch it from the value history
620 and remove the '#'. The kill ring is probably better, but some
621 people are in the habit of commenting things out. */
622 if (*p1 == '#')
c50c785c 623 *p1 = '\0'; /* Found a comment. */
5796c8dc
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624
625 /* Save into global buffer if appropriate. */
626 if (repeat)
627 {
a45ae5f8 628 if (linelength > saved_command_line_size)
5796c8dc 629 {
a45ae5f8
JM
630 saved_command_line = xrealloc (saved_command_line, linelength);
631 saved_command_line_size = linelength;
5796c8dc 632 }
a45ae5f8 633 strcpy (saved_command_line, linebuffer);
5796c8dc
SS
634 if (!more_to_come)
635 {
a45ae5f8 636 command_handler (saved_command_line);
5796c8dc
SS
637 display_gdb_prompt (0);
638 }
639 return;
640 }
641
642 command_handler (linebuffer);
643 display_gdb_prompt (0);
644 return;
645}
646
647/* Does reading of input from terminal w/o the editing features
c50c785c 648 provided by the readline library. */
5796c8dc 649
c50c785c 650/* NOTE: 1999-04-30 Asynchronous version of gdb_readline; gdb_readline
5796c8dc 651 will become obsolete when the event loop is made the default
c50c785c 652 execution for gdb. */
5796c8dc
SS
653void
654gdb_readline2 (gdb_client_data client_data)
655{
656 int c;
657 char *result;
658 int input_index = 0;
659 int result_size = 80;
660 static int done_once = 0;
661
662 /* Unbuffer the input stream, so that, later on, the calls to fgetc
c50c785c 663 fetch only one char at the time from the stream. The fgetc's will
5796c8dc 664 get up to the first newline, but there may be more chars in the
c50c785c 665 stream after '\n'. If we buffer the input and fgetc drains the
5796c8dc 666 stream, getting stuff beyond the newline as well, a select, done
c50c785c 667 afterwards will not trigger. */
5796c8dc
SS
668 if (!done_once && !ISATTY (instream))
669 {
670 setbuf (instream, NULL);
671 done_once = 1;
672 }
673
674 result = (char *) xmalloc (result_size);
675
676 /* We still need the while loop here, even though it would seem
677 obvious to invoke gdb_readline2 at every character entered. If
678 not using the readline library, the terminal is in cooked mode,
c50c785c
JM
679 which sends the characters all at once. Poll will notice that the
680 input fd has changed state only after enter is pressed. At this
681 point we still need to fetch all the chars entered. */
5796c8dc
SS
682
683 while (1)
684 {
685 /* Read from stdin if we are executing a user defined command.
686 This is the right thing for prompt_for_continue, at least. */
687 c = fgetc (instream ? instream : stdin);
688
689 if (c == EOF)
690 {
691 if (input_index > 0)
c50c785c
JM
692 /* The last line does not end with a newline. Return it,
693 and if we are called again fgetc will still return EOF
694 and we'll return NULL then. */
5796c8dc
SS
695 break;
696 xfree (result);
697 (*input_handler) (0);
698 return;
699 }
700
701 if (c == '\n')
702 {
703 if (input_index > 0 && result[input_index - 1] == '\r')
704 input_index--;
705 break;
706 }
707
708 result[input_index++] = c;
709 while (input_index >= result_size)
710 {
711 result_size *= 2;
712 result = (char *) xrealloc (result, result_size);
713 }
714 }
715
716 result[input_index++] = '\0';
717 (*input_handler) (result);
718}
719\f
720
721/* Initialization of signal handlers and tokens. There is a function
c50c785c 722 handle_sig* for each of the signals GDB cares about. Specifically:
5796c8dc
SS
723 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
724 functions are the actual signal handlers associated to the signals
725 via calls to signal(). The only job for these functions is to
726 enqueue the appropriate event/procedure with the event loop. Such
c50c785c 727 procedures are the old signal handlers. The event loop will take
5796c8dc 728 care of invoking the queued procedures to perform the usual tasks
c50c785c 729 associated with the reception of the signal. */
5796c8dc
SS
730/* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
731 init_signals will become obsolete as we move to have to event loop
c50c785c 732 as the default for gdb. */
5796c8dc
SS
733void
734async_init_signals (void)
735{
736 signal (SIGINT, handle_sigint);
737 sigint_token =
738 create_async_signal_handler (async_request_quit, NULL);
739 signal (SIGTERM, handle_sigterm);
740
741 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
742 to the inferior and breakpoints will be ignored. */
743#ifdef SIGTRAP
744 signal (SIGTRAP, SIG_DFL);
745#endif
746
747#ifdef SIGQUIT
748 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
749 passed to the inferior, which we don't want. It would be
750 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
751 on BSD4.3 systems using vfork, that can affect the
752 GDB process as well as the inferior (the signal handling tables
753 might be in memory, shared between the two). Since we establish
754 a handler for SIGQUIT, when we call exec it will set the signal
755 to SIG_DFL for us. */
756 signal (SIGQUIT, handle_sigquit);
757 sigquit_token =
758 create_async_signal_handler (async_do_nothing, NULL);
759#endif
760#ifdef SIGHUP
761 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
762 sighup_token =
763 create_async_signal_handler (async_disconnect, NULL);
764 else
765 sighup_token =
766 create_async_signal_handler (async_do_nothing, NULL);
767#endif
768 signal (SIGFPE, handle_sigfpe);
769 sigfpe_token =
770 create_async_signal_handler (async_float_handler, NULL);
771
772#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
773 signal (SIGWINCH, handle_sigwinch);
774 sigwinch_token =
775 create_async_signal_handler (SIGWINCH_HANDLER, NULL);
776#endif
777#ifdef STOP_SIGNAL
778 sigtstp_token =
779 create_async_signal_handler (async_stop_sig, NULL);
780#endif
781
782}
783
784void
785mark_async_signal_handler_wrapper (void *token)
786{
787 mark_async_signal_handler ((struct async_signal_handler *) token);
788}
789
c50c785c
JM
790/* Tell the event loop what to do if SIGINT is received.
791 See event-signal.c. */
5796c8dc
SS
792void
793handle_sigint (int sig)
794{
795 signal (sig, handle_sigint);
796
797 /* We could be running in a loop reading in symfiles or something so
798 it may be quite a while before we get back to the event loop. So
c50c785c 799 set quit_flag to 1 here. Then if QUIT is called before we get to
5796c8dc
SS
800 the event loop, we will unwind as expected. */
801
802 quit_flag = 1;
803
804 /* If immediate_quit is set, we go ahead and process the SIGINT right
c50c785c 805 away, even if we usually would defer this to the event loop. The
5796c8dc 806 assumption here is that it is safe to process ^C immediately if
c50c785c 807 immediate_quit is set. If we didn't, SIGINT would be really
5796c8dc
SS
808 processed only the next time through the event loop. To get to
809 that point, though, the command that we want to interrupt needs to
810 finish first, which is unacceptable. If immediate quit is not set,
c50c785c 811 we process SIGINT the next time through the loop, which is fine. */
5796c8dc
SS
812 gdb_call_async_signal_handler (sigint_token, immediate_quit);
813}
814
815/* Quit GDB if SIGTERM is received.
816 GDB would quit anyway, but this way it will clean up properly. */
817void
818handle_sigterm (int sig)
819{
820 signal (sig, handle_sigterm);
821 quit_force ((char *) 0, stdin == instream);
822}
823
c50c785c 824/* Do the quit. All the checks have been done by the caller. */
5796c8dc
SS
825void
826async_request_quit (gdb_client_data arg)
827{
828 /* If the quit_flag has gotten reset back to 0 by the time we get
829 back here, that means that an exception was thrown to unwind the
830 current command before we got back to the event loop. So there
831 is no reason to call quit again here, unless immediate_quit is
c50c785c 832 set. */
5796c8dc
SS
833
834 if (quit_flag || immediate_quit)
835 quit ();
836}
837
838#ifdef SIGQUIT
c50c785c
JM
839/* Tell the event loop what to do if SIGQUIT is received.
840 See event-signal.c. */
5796c8dc
SS
841static void
842handle_sigquit (int sig)
843{
844 mark_async_signal_handler_wrapper (sigquit_token);
845 signal (sig, handle_sigquit);
846}
847#endif
848
849#if defined (SIGQUIT) || defined (SIGHUP)
850/* Called by the event loop in response to a SIGQUIT or an
851 ignored SIGHUP. */
852static void
853async_do_nothing (gdb_client_data arg)
854{
c50c785c 855 /* Empty function body. */
5796c8dc
SS
856}
857#endif
858
859#ifdef SIGHUP
c50c785c
JM
860/* Tell the event loop what to do if SIGHUP is received.
861 See event-signal.c. */
5796c8dc
SS
862static void
863handle_sighup (int sig)
864{
865 mark_async_signal_handler_wrapper (sighup_token);
866 signal (sig, handle_sighup);
867}
868
c50c785c 869/* Called by the event loop to process a SIGHUP. */
5796c8dc
SS
870static void
871async_disconnect (gdb_client_data arg)
872{
a45ae5f8
JM
873 volatile struct gdb_exception exception;
874
875 TRY_CATCH (exception, RETURN_MASK_ALL)
876 {
877 quit_cover ();
878 }
879
880 if (exception.reason < 0)
881 {
882 fputs_filtered ("Could not kill the program being debugged",
883 gdb_stderr);
884 exception_print (gdb_stderr, exception);
885 }
886
887 TRY_CATCH (exception, RETURN_MASK_ALL)
888 {
889 pop_all_targets (1);
890 }
891
c50c785c 892 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
5796c8dc
SS
893 raise (SIGHUP);
894}
895#endif
896
897#ifdef STOP_SIGNAL
898void
899handle_stop_sig (int sig)
900{
901 mark_async_signal_handler_wrapper (sigtstp_token);
902 signal (sig, handle_stop_sig);
903}
904
905static void
906async_stop_sig (gdb_client_data arg)
907{
908 char *prompt = get_prompt ();
cf7f2e2d 909
5796c8dc
SS
910#if STOP_SIGNAL == SIGTSTP
911 signal (SIGTSTP, SIG_DFL);
912#if HAVE_SIGPROCMASK
913 {
914 sigset_t zero;
915
916 sigemptyset (&zero);
917 sigprocmask (SIG_SETMASK, &zero, 0);
918 }
919#elif HAVE_SIGSETMASK
920 sigsetmask (0);
921#endif
922 raise (SIGTSTP);
923 signal (SIGTSTP, handle_stop_sig);
924#else
925 signal (STOP_SIGNAL, handle_stop_sig);
926#endif
927 printf_unfiltered ("%s", prompt);
928 gdb_flush (gdb_stdout);
929
c50c785c
JM
930 /* Forget about any previous command -- null line now will do
931 nothing. */
5796c8dc
SS
932 dont_repeat ();
933}
934#endif /* STOP_SIGNAL */
935
c50c785c
JM
936/* Tell the event loop what to do if SIGFPE is received.
937 See event-signal.c. */
5796c8dc
SS
938static void
939handle_sigfpe (int sig)
940{
941 mark_async_signal_handler_wrapper (sigfpe_token);
942 signal (sig, handle_sigfpe);
943}
944
c50c785c 945/* Event loop will call this functin to process a SIGFPE. */
5796c8dc
SS
946static void
947async_float_handler (gdb_client_data arg)
948{
c50c785c
JM
949 /* This message is based on ANSI C, section 4.7. Note that integer
950 divide by zero causes this, so "float" is a misnomer. */
5796c8dc
SS
951 error (_("Erroneous arithmetic operation."));
952}
953
c50c785c
JM
954/* Tell the event loop what to do if SIGWINCH is received.
955 See event-signal.c. */
5796c8dc
SS
956#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
957static void
958handle_sigwinch (int sig)
959{
960 mark_async_signal_handler_wrapper (sigwinch_token);
961 signal (sig, handle_sigwinch);
962}
963#endif
964\f
965
966/* Called by do_setshow_command. */
967void
c50c785c
JM
968set_async_editing_command (char *args, int from_tty,
969 struct cmd_list_element *c)
5796c8dc
SS
970{
971 change_line_handler ();
972}
973
5796c8dc
SS
974/* Set things up for readline to be invoked via the alternate
975 interface, i.e. via a callback function (rl_callback_read_char),
c50c785c 976 and hook up instream to the event loop. */
5796c8dc
SS
977void
978gdb_setup_readline (void)
979{
980 /* This function is a noop for the sync case. The assumption is
981 that the sync setup is ALL done in gdb_init, and we would only
982 mess it up here. The sync stuff should really go away over
983 time. */
984 if (!batch_silent)
985 gdb_stdout = stdio_fileopen (stdout);
986 gdb_stderr = stdio_fileopen (stderr);
987 gdb_stdlog = gdb_stderr; /* for moment */
988 gdb_stdtarg = gdb_stderr; /* for moment */
c50c785c 989 gdb_stdtargerr = gdb_stderr; /* for moment */
5796c8dc
SS
990
991 /* If the input stream is connected to a terminal, turn on
992 editing. */
993 if (ISATTY (instream))
994 {
c50c785c 995 /* Tell gdb that we will be using the readline library. This
5796c8dc
SS
996 could be overwritten by a command in .gdbinit like 'set
997 editing on' or 'off'. */
998 async_command_editing_p = 1;
999
1000 /* When a character is detected on instream by select or poll,
1001 readline will be invoked via this callback function. */
1002 call_readline = rl_callback_read_char_wrapper;
1003 }
1004 else
1005 {
1006 async_command_editing_p = 0;
1007 call_readline = gdb_readline2;
1008 }
1009
1010 /* When readline has read an end-of-line character, it passes the
c50c785c 1011 complete line to gdb for processing; command_line_handler is the
5796c8dc
SS
1012 function that does this. */
1013 input_handler = command_line_handler;
1014
c50c785c 1015 /* Tell readline to use the same input stream that gdb uses. */
5796c8dc
SS
1016 rl_instream = instream;
1017
1018 /* Get a file descriptor for the input stream, so that we can
1019 register it with the event loop. */
1020 input_fd = fileno (instream);
1021
1022 /* Now we need to create the event sources for the input file
1023 descriptor. */
1024 /* At this point in time, this is the only event source that we
c50c785c 1025 register with the even loop. Another source is going to be the
5796c8dc
SS
1026 target program (inferior), but that must be registered only when
1027 it actually exists (I.e. after we say 'run' or after we connect
1028 to a remote target. */
1029 add_file_handler (input_fd, stdin_event_handler, 0);
1030}
1031
1032/* Disable command input through the standard CLI channels. Used in
1033 the suspend proc for interpreters that use the standard gdb readline
1034 interface, like the cli & the mi. */
1035void
1036gdb_disable_readline (void)
1037{
1038 /* FIXME - It is too heavyweight to delete and remake these every
1039 time you run an interpreter that needs readline. It is probably
1040 better to have the interpreters cache these, which in turn means
1041 that this needs to be moved into interpreter specific code. */
1042
1043#if 0
1044 ui_file_delete (gdb_stdout);
1045 ui_file_delete (gdb_stderr);
1046 gdb_stdlog = NULL;
1047 gdb_stdtarg = NULL;
c50c785c 1048 gdb_stdtargerr = NULL;
5796c8dc
SS
1049#endif
1050
1051 rl_callback_handler_remove ();
1052 delete_file_handler (input_fd);
1053}