1 /* Top level stuff for GDB, the GNU debugger.
3 Copyright (C) 1999-2016 Free Software Foundation, Inc.
5 Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
7 This file is part of GDB.
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
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
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.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "terminal.h" /* for job_control */
28 #include "event-loop.h"
29 #include "event-top.h"
32 #include "cli/cli-script.h" /* for reset_command_nest_depth */
34 #include "gdbthread.h"
36 #include "continuations.h"
37 #include "gdbcmd.h" /* for dont_repeat() */
41 #include "ser-event.h"
42 #include "gdb_select.h"
44 /* readline include files. */
45 #include "readline/readline.h"
46 #include "readline/history.h"
48 /* readline defines this. */
51 static void command_line_handler (char *rl
);
52 static void change_line_handler (void);
53 static char *top_level_prompt (void);
55 /* Signal handlers. */
57 static void handle_sigquit (int sig
);
60 static void handle_sighup (int sig
);
62 static void handle_sigfpe (int sig
);
64 /* Functions to be invoked by the event loop in response to
66 #if defined (SIGQUIT) || defined (SIGHUP)
67 static void async_do_nothing (gdb_client_data
);
70 static void async_disconnect (gdb_client_data
);
72 static void async_float_handler (gdb_client_data
);
74 static void async_stop_sig (gdb_client_data
);
76 static void async_sigterm_handler (gdb_client_data arg
);
78 /* Instead of invoking (and waiting for) readline to read the command
79 line and pass it back for processing, we use readline's alternate
80 interface, via callback functions, so that the event loop can react
81 to other event sources while we wait for input. */
83 /* Important variables for the event loop. */
85 /* This is used to determine if GDB is using the readline library or
86 its own simplified form of readline. It is used by the asynchronous
87 form of the set editing command.
88 ezannoni: as of 1999-04-29 I expect that this
89 variable will not be used after gdb is changed to use the event
90 loop as default engine, and event-top.c is merged into top.c. */
91 int async_command_editing_p
;
93 /* This is used to display the notification of the completion of an
94 asynchronous execution command. */
95 int exec_done_display_p
= 0;
97 /* This is the file descriptor for the input stream that GDB uses to
98 read commands from. */
101 /* Used by the stdin event handler to compensate for missed stdin events.
102 Setting this to a non-zero value inside an stdin callback makes the callback
104 int call_stdin_event_handler_again_p
;
106 /* Signal handling variables. */
107 /* Each of these is a pointer to a function that the event loop will
108 invoke if the corresponding signal has received. The real signal
109 handlers mark these functions as ready to be executed and the event
110 loop, in a later iteration, calls them. See the function
111 invoke_async_signal_handler. */
112 static struct async_signal_handler
*sigint_token
;
114 static struct async_signal_handler
*sighup_token
;
117 static struct async_signal_handler
*sigquit_token
;
119 static struct async_signal_handler
*sigfpe_token
;
121 static struct async_signal_handler
*sigtstp_token
;
123 static struct async_signal_handler
*async_sigterm_token
;
125 /* This hook is called by gdb_rl_callback_read_char_wrapper after each
126 character is processed. */
127 void (*after_char_processing_hook
) (void);
130 /* Wrapper function for calling into the readline library. This takes
131 care of a couple things:
133 - The event loop expects the callback function to have a parameter,
134 while readline expects none.
136 - Propagation of GDB exceptions/errors thrown from INPUT_HANDLER
137 across readline requires special handling.
139 On the exceptions issue:
141 DWARF-based unwinding cannot cross code built without -fexceptions.
142 Any exception that tries to propagate through such code will fail
143 and the result is a call to std::terminate. While some ABIs, such
144 as x86-64, require all code to be built with exception tables,
147 This is a problem when GDB calls some non-EH-aware C library code,
148 that calls into GDB again through a callback, and that GDB callback
149 code throws a C++ exception. Turns out this is exactly what
150 happens with GDB's readline callback.
152 In such cases, we must catch and save any C++ exception that might
153 be thrown from the GDB callback before returning to the
154 non-EH-aware code. When the non-EH-aware function itself returns
155 back to GDB, we then rethrow the original C++ exception.
157 In the readline case however, the right thing to do is to longjmp
158 out of the callback, rather than do a normal return -- there's no
159 way for the callback to return to readline an indication that an
160 error happened, so a normal return would have rl_callback_read_char
161 potentially continue processing further input, redisplay the
162 prompt, etc. Instead of raw setjmp/longjmp however, we use our
163 sjlj-based TRY/CATCH mechanism, which knows to handle multiple
164 levels of active setjmp/longjmp frames, needed in order to handle
165 the readline callback recursing, as happens with e.g., secondary
166 prompts / queries, through gdb_readline_wrapper. */
169 gdb_rl_callback_read_char_wrapper (gdb_client_data client_data
)
171 struct gdb_exception gdb_expt
= exception_none
;
173 /* C++ exceptions can't normally be thrown across readline (unless
174 it is built with -fexceptions, but it won't by default on many
175 ABIs). So we instead wrap the readline call with a sjlj-based
176 TRY/CATCH, and rethrow the GDB exception once back in GDB. */
179 rl_callback_read_char ();
180 if (after_char_processing_hook
)
181 (*after_char_processing_hook
) ();
183 CATCH_SJLJ (ex
, RETURN_MASK_ALL
)
189 /* Rethrow using the normal EH mechanism. */
190 if (gdb_expt
.reason
< 0)
191 throw_exception (gdb_expt
);
194 /* GDB's readline callback handler. Calls the current INPUT_HANDLER,
195 and propagates GDB exceptions/errors thrown from INPUT_HANDLER back
196 across readline. See gdb_rl_callback_read_char_wrapper. */
199 gdb_rl_callback_handler (char *rl
)
201 struct gdb_exception gdb_rl_expt
= exception_none
;
202 struct ui
*ui
= current_ui
;
206 ui
->input_handler (rl
);
208 CATCH (ex
, RETURN_MASK_ALL
)
214 /* If we caught a GDB exception, longjmp out of the readline
215 callback. There's no other way for the callback to signal to
216 readline that an error happened. A normal return would have
217 readline potentially continue processing further input, redisplay
218 the prompt, etc. (This is what GDB historically did when it was
219 a C program.) Note that since we're long jumping, local variable
220 dtors are NOT run automatically. */
221 if (gdb_rl_expt
.reason
< 0)
222 throw_exception_sjlj (gdb_rl_expt
);
225 /* Initialize all the necessary variables, start the event loop,
226 register readline, and stdin, start the loop. The DATA is the
227 interpreter data cookie, ignored for now. */
230 cli_command_loop (void *data
)
232 display_gdb_prompt (0);
234 /* Now it's time to start the event loop. */
238 /* Change the function to be invoked every time there is a character
239 ready on stdin. This is used when the user sets the editing off,
240 therefore bypassing readline, and letting gdb handle the input
241 itself, via gdb_readline_no_editing_callback. Also it is used in
242 the opposite case in which the user sets editing on again, by
243 restoring readline handling of the input. */
245 change_line_handler (void)
247 struct ui
*ui
= current_ui
;
249 /* NOTE: this operates on input_fd, not instream. If we are reading
250 commands from a file, instream will point to the file. However in
251 async mode, we always read commands from a file with editing
252 off. This means that the 'set editing on/off' will have effect
253 only on the interactive session. */
255 if (async_command_editing_p
)
257 /* Turn on editing by using readline. */
258 ui
->call_readline
= gdb_rl_callback_read_char_wrapper
;
259 ui
->input_handler
= command_line_handler
;
263 /* Turn off editing by using gdb_readline_no_editing_callback. */
264 gdb_rl_callback_handler_remove ();
265 ui
->call_readline
= gdb_readline_no_editing_callback
;
267 /* Set up the command handler as well, in case we are called as
268 first thing from .gdbinit. */
269 ui
->input_handler
= command_line_handler
;
273 /* The functions below are wrappers for rl_callback_handler_remove and
274 rl_callback_handler_install that keep track of whether the callback
275 handler is installed in readline. This is necessary because after
276 handling a target event of a background execution command, we may
277 need to reinstall the callback handler if it was removed due to a
278 secondary prompt. See gdb_readline_wrapper_line. We don't
279 unconditionally install the handler for every target event because
280 that also clears the line buffer, thus installing it while the user
281 is typing would lose input. */
283 /* Whether we've registered a callback handler with readline. */
284 static int callback_handler_installed
;
286 /* See event-top.h, and above. */
289 gdb_rl_callback_handler_remove (void)
291 rl_callback_handler_remove ();
292 callback_handler_installed
= 0;
295 /* See event-top.h, and above. Note this wrapper doesn't have an
296 actual callback parameter because we always install
300 gdb_rl_callback_handler_install (const char *prompt
)
302 /* Calling rl_callback_handler_install resets readline's input
303 buffer. Calling this when we were already processing input
304 therefore loses input. */
305 gdb_assert (!callback_handler_installed
);
307 rl_callback_handler_install (prompt
, gdb_rl_callback_handler
);
308 callback_handler_installed
= 1;
311 /* See event-top.h, and above. */
314 gdb_rl_callback_handler_reinstall (void)
316 if (!callback_handler_installed
)
318 /* Passing NULL as prompt argument tells readline to not display
320 gdb_rl_callback_handler_install (NULL
);
324 /* Displays the prompt. If the argument NEW_PROMPT is NULL, the
325 prompt that is displayed is the current top level prompt.
326 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
329 This is used after each gdb command has completed, and in the
332 1. When the user enters a command line which is ended by '\'
333 indicating that the command will continue on the next line. In
334 that case the prompt that is displayed is the empty string.
336 2. When the user is entering 'commands' for a breakpoint, or
337 actions for a tracepoint. In this case the prompt will be '>'
339 3. On prompting for pagination. */
342 display_gdb_prompt (const char *new_prompt
)
344 char *actual_gdb_prompt
= NULL
;
345 struct cleanup
*old_chain
;
347 annotate_display_prompt ();
349 /* Reset the nesting depth used when trace-commands is set. */
350 reset_command_nest_depth ();
352 old_chain
= make_cleanup (free_current_contents
, &actual_gdb_prompt
);
354 /* Do not call the python hook on an explicit prompt change as
355 passed to this function, as this forms a secondary/local prompt,
356 IE, displayed but not set. */
361 /* This is to trick readline into not trying to display the
362 prompt. Even though we display the prompt using this
363 function, readline still tries to do its own display if
364 we don't call rl_callback_handler_install and
365 rl_callback_handler_remove (which readline detects
366 because a global variable is not set). If readline did
367 that, it could mess up gdb signal handlers for SIGINT.
368 Readline assumes that between calls to rl_set_signals and
369 rl_clear_signals gdb doesn't do anything with the signal
370 handlers. Well, that's not the case, because when the
371 target executes we change the SIGINT signal handler. If
372 we allowed readline to display the prompt, the signal
373 handler change would happen exactly between the calls to
374 the above two functions. Calling
375 rl_callback_handler_remove(), does the job. */
377 gdb_rl_callback_handler_remove ();
378 do_cleanups (old_chain
);
383 /* Display the top level prompt. */
384 actual_gdb_prompt
= top_level_prompt ();
388 actual_gdb_prompt
= xstrdup (new_prompt
);
390 if (async_command_editing_p
)
392 gdb_rl_callback_handler_remove ();
393 gdb_rl_callback_handler_install (actual_gdb_prompt
);
395 /* new_prompt at this point can be the top of the stack or the one
396 passed in. It can't be NULL. */
399 /* Don't use a _filtered function here. It causes the assumed
400 character position to be off, since the newline we read from
401 the user is not accounted for. */
402 fputs_unfiltered (actual_gdb_prompt
, gdb_stdout
);
403 gdb_flush (gdb_stdout
);
406 do_cleanups (old_chain
);
409 /* Return the top level prompt, as specified by "set prompt", possibly
410 overriden by the python gdb.prompt_hook hook, and then composed
411 with the prompt prefix and suffix (annotations). The caller is
412 responsible for freeing the returned string. */
415 top_level_prompt (void)
419 /* Give observers a chance of changing the prompt. E.g., the python
420 `gdb.prompt_hook' is installed as an observer. */
421 observer_notify_before_prompt (get_prompt ());
423 prompt
= get_prompt ();
425 if (annotation_level
>= 2)
427 /* Prefix needs to have new line at end. */
428 const char prefix
[] = "\n\032\032pre-prompt\n";
430 /* Suffix needs to have a new line at end and \032 \032 at
432 const char suffix
[] = "\n\032\032prompt\n";
434 return concat (prefix
, prompt
, suffix
, (char *) NULL
);
437 return xstrdup (prompt
);
440 static struct ui current_ui_
;
441 struct ui
*current_ui
= ¤t_ui_
;
443 /* Get a pointer to the current UI's line buffer. This is used to
444 construct a whole line of input from partial input. */
446 static struct buffer
*
447 get_command_line_buffer (void)
449 return ¤t_ui
->line_buffer
;
452 /* When there is an event ready on the stdin file descriptor, instead
453 of calling readline directly throught the callback function, or
454 instead of calling gdb_readline_no_editing_callback, give gdb a
455 chance to detect errors and do something. */
458 stdin_event_handler (int error
, gdb_client_data client_data
)
460 struct ui
*ui
= current_ui
;
464 printf_unfiltered (_("error detected on stdin\n"));
465 delete_file_handler (input_fd
);
466 /* If stdin died, we may as well kill gdb. */
467 quit_command ((char *) 0, stdin
== instream
);
471 /* This makes sure a ^C immediately followed by further input is
472 always processed in that order. E.g,. with input like
473 "^Cprint 1\n", the SIGINT handler runs, marks the async signal
474 handler, and then select/poll may return with stdin ready,
475 instead of -1/EINTR. The
476 gdb.base/double-prompt-target-event-error.exp test exercises
482 call_stdin_event_handler_again_p
= 0;
483 ui
->call_readline (client_data
);
484 } while (call_stdin_event_handler_again_p
!= 0);
488 /* Re-enable stdin after the end of an execution command in
489 synchronous mode, or after an error from the target, and we aborted
490 the exec operation. */
493 async_enable_stdin (void)
497 /* See NOTE in async_disable_stdin(). */
498 /* FIXME: cagney/1999-09-27: Call this before clearing
499 sync_execution. Current target_terminal_ours() implementations
500 check for sync_execution before switching the terminal. */
501 target_terminal_ours ();
506 /* Disable reads from stdin (the console) marking the command as
510 async_disable_stdin (void)
516 /* Handle a gdb command line. This function is called when
517 handle_line_of_input has concatenated one or more input lines into
521 command_handler (char *command
)
523 struct cleanup
*stat_chain
;
526 if (instream
== stdin
)
527 reinitialize_more_filter ();
529 stat_chain
= make_command_stats_cleanup (1);
531 /* Do not execute commented lines. */
532 for (c
= command
; *c
== ' ' || *c
== '\t'; c
++)
536 execute_command (command
, instream
== stdin
);
538 /* Do any commands attached to breakpoint we stopped at. */
539 bpstat_do_actions ();
542 do_cleanups (stat_chain
);
545 /* Append RL, an input line returned by readline or one of its
546 emulations, to CMD_LINE_BUFFER. Returns the command line if we
547 have a whole command line ready to be processed by the command
548 interpreter or NULL if the command line isn't complete yet (input
549 line ends in a backslash). Takes ownership of RL. */
552 command_line_append_input_line (struct buffer
*cmd_line_buffer
, char *rl
)
559 if (len
> 0 && rl
[len
- 1] == '\\')
561 /* Don't copy the backslash and wait for more. */
562 buffer_grow (cmd_line_buffer
, rl
, len
- 1);
567 /* Copy whole line including terminating null, and we're
569 buffer_grow (cmd_line_buffer
, rl
, len
+ 1);
570 cmd
= cmd_line_buffer
->buffer
;
573 /* Allocated in readline. */
579 /* Handle a line of input coming from readline.
581 If the read line ends with a continuation character (backslash),
582 save the partial input in CMD_LINE_BUFFER (except the backslash),
583 and return NULL. Otherwise, save the partial input and return a
584 pointer to CMD_LINE_BUFFER's buffer (null terminated), indicating a
585 whole command line is ready to be executed.
587 Returns EOF on end of file.
589 If REPEAT, handle command repetitions:
591 - If the input command line is NOT empty, the command returned is
592 copied into the global 'saved_command_line' var so that it can
595 - OTOH, if the input command line IS empty, return the previously
596 saved command instead of the empty input line.
600 handle_line_of_input (struct buffer
*cmd_line_buffer
,
601 char *rl
, int repeat
, char *annotation_suffix
)
609 cmd
= command_line_append_input_line (cmd_line_buffer
, rl
);
613 /* We have a complete command line now. Prepare for the next
614 command, but leave ownership of memory to the buffer . */
615 cmd_line_buffer
->used_size
= 0;
617 if (annotation_level
> 1 && instream
== stdin
)
619 printf_unfiltered (("\n\032\032post-"));
620 puts_unfiltered (annotation_suffix
);
621 printf_unfiltered (("\n"));
624 #define SERVER_COMMAND_PREFIX "server "
625 if (startswith (cmd
, SERVER_COMMAND_PREFIX
))
627 /* Note that we don't set `saved_command_line'. Between this
628 and the check in dont_repeat, this insures that repeating
629 will still do the right thing. */
630 return cmd
+ strlen (SERVER_COMMAND_PREFIX
);
633 /* Do history expansion if that is wished. */
634 if (history_expansion_p
&& instream
== stdin
635 && ISATTY (instream
))
640 expanded
= history_expand (cmd
, &history_value
);
645 /* Print the changes. */
646 printf_unfiltered ("%s\n", history_value
);
648 /* If there was an error, call this function again. */
651 xfree (history_value
);
655 /* history_expand returns an allocated string. Just replace
656 our buffer with it. */
657 len
= strlen (history_value
);
658 xfree (buffer_finish (cmd_line_buffer
));
659 cmd_line_buffer
->buffer
= history_value
;
660 cmd_line_buffer
->buffer_size
= len
+ 1;
665 /* If we just got an empty line, and that is supposed to repeat the
666 previous command, return the previously saved command. */
667 for (p1
= cmd
; *p1
== ' ' || *p1
== '\t'; p1
++)
669 if (repeat
&& *p1
== '\0')
670 return saved_command_line
;
672 /* Add command to history if appropriate. Note: lines consisting
673 solely of comments are also added to the command history. This
674 is useful when you type a command, and then realize you don't
675 want to execute it quite yet. You can comment out the command
676 and then later fetch it from the value history and remove the
677 '#'. The kill ring is probably better, but some people are in
678 the habit of commenting things out. */
679 if (*cmd
!= '\0' && input_from_terminal_p ())
680 gdb_add_history (cmd
);
682 /* Save into global buffer if appropriate. */
685 xfree (saved_command_line
);
686 saved_command_line
= xstrdup (cmd
);
687 return saved_command_line
;
693 /* Handle a complete line of input. This is called by the callback
694 mechanism within the readline library. Deal with incomplete
695 commands as well, by saving the partial input in a global
698 NOTE: This is the asynchronous version of the command_line_input
702 command_line_handler (char *rl
)
704 struct buffer
*line_buffer
= get_command_line_buffer ();
707 cmd
= handle_line_of_input (line_buffer
, rl
, instream
== stdin
, "prompt");
708 if (cmd
== (char *) EOF
)
710 /* stdin closed. The connection with the terminal is gone.
711 This happens at the end of a testsuite run, after Expect has
712 hung up but GDB is still alive. In such a case, we just quit
713 gdb killing the inferior program too. */
714 printf_unfiltered ("quit\n");
715 execute_command ("quit", stdin
== instream
);
717 else if (cmd
== NULL
)
719 /* We don't have a full line yet. Print an empty prompt. */
720 display_gdb_prompt ("");
724 command_handler (cmd
);
725 display_gdb_prompt (0);
729 /* Does reading of input from terminal w/o the editing features
730 provided by the readline library. Calls the line input handler
731 once we have a whole input line. */
734 gdb_readline_no_editing_callback (gdb_client_data client_data
)
738 struct buffer line_buffer
;
739 static int done_once
= 0;
740 struct ui
*ui
= current_ui
;
742 buffer_init (&line_buffer
);
744 /* Unbuffer the input stream, so that, later on, the calls to fgetc
745 fetch only one char at the time from the stream. The fgetc's will
746 get up to the first newline, but there may be more chars in the
747 stream after '\n'. If we buffer the input and fgetc drains the
748 stream, getting stuff beyond the newline as well, a select, done
749 afterwards will not trigger. */
750 if (!done_once
&& !ISATTY (instream
))
752 setbuf (instream
, NULL
);
756 /* We still need the while loop here, even though it would seem
757 obvious to invoke gdb_readline_no_editing_callback at every
758 character entered. If not using the readline library, the
759 terminal is in cooked mode, which sends the characters all at
760 once. Poll will notice that the input fd has changed state only
761 after enter is pressed. At this point we still need to fetch all
762 the chars entered. */
766 /* Read from stdin if we are executing a user defined command.
767 This is the right thing for prompt_for_continue, at least. */
768 c
= fgetc (instream
? instream
: stdin
);
772 if (line_buffer
.used_size
> 0)
774 /* The last line does not end with a newline. Return it, and
775 if we are called again fgetc will still return EOF and
776 we'll return NULL then. */
779 xfree (buffer_finish (&line_buffer
));
780 ui
->input_handler (NULL
);
786 if (line_buffer
.used_size
> 0
787 && line_buffer
.buffer
[line_buffer
.used_size
- 1] == '\r')
788 line_buffer
.used_size
--;
792 buffer_grow_char (&line_buffer
, c
);
795 buffer_grow_char (&line_buffer
, '\0');
796 result
= buffer_finish (&line_buffer
);
797 ui
->input_handler (result
);
801 /* The serial event associated with the QUIT flag. set_quit_flag sets
802 this, and check_quit_flag clears it. Used by interruptible_select
803 to be able to do interruptible I/O with no race with the SIGINT
805 static struct serial_event
*quit_serial_event
;
807 /* Initialization of signal handlers and tokens. There is a function
808 handle_sig* for each of the signals GDB cares about. Specifically:
809 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
810 functions are the actual signal handlers associated to the signals
811 via calls to signal(). The only job for these functions is to
812 enqueue the appropriate event/procedure with the event loop. Such
813 procedures are the old signal handlers. The event loop will take
814 care of invoking the queued procedures to perform the usual tasks
815 associated with the reception of the signal. */
816 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
817 init_signals will become obsolete as we move to have to event loop
818 as the default for gdb. */
820 async_init_signals (void)
822 initialize_async_signal_handlers ();
824 quit_serial_event
= make_serial_event ();
826 signal (SIGINT
, handle_sigint
);
828 create_async_signal_handler (async_request_quit
, NULL
);
829 signal (SIGTERM
, handle_sigterm
);
831 = create_async_signal_handler (async_sigterm_handler
, NULL
);
833 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
834 to the inferior and breakpoints will be ignored. */
836 signal (SIGTRAP
, SIG_DFL
);
840 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
841 passed to the inferior, which we don't want. It would be
842 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
843 on BSD4.3 systems using vfork, that can affect the
844 GDB process as well as the inferior (the signal handling tables
845 might be in memory, shared between the two). Since we establish
846 a handler for SIGQUIT, when we call exec it will set the signal
847 to SIG_DFL for us. */
848 signal (SIGQUIT
, handle_sigquit
);
850 create_async_signal_handler (async_do_nothing
, NULL
);
853 if (signal (SIGHUP
, handle_sighup
) != SIG_IGN
)
855 create_async_signal_handler (async_disconnect
, NULL
);
858 create_async_signal_handler (async_do_nothing
, NULL
);
860 signal (SIGFPE
, handle_sigfpe
);
862 create_async_signal_handler (async_float_handler
, NULL
);
866 create_async_signal_handler (async_stop_sig
, NULL
);
873 quit_serial_event_set (void)
875 serial_event_set (quit_serial_event
);
881 quit_serial_event_clear (void)
883 serial_event_clear (quit_serial_event
);
886 /* Return the selectable file descriptor of the serial event
887 associated with the quit flag. */
890 quit_serial_event_fd (void)
892 return serial_event_fd (quit_serial_event
);
898 default_quit_handler (void)
900 if (check_quit_flag ())
902 if (target_terminal_is_ours ())
905 target_pass_ctrlc ();
910 quit_handler_ftype
*quit_handler
= default_quit_handler
;
912 /* Data for make_cleanup_override_quit_handler. Wrap the previous
913 handler pointer in a data struct because it's not portable to cast
914 a function pointer to a data pointer, which is what make_cleanup
916 struct quit_handler_cleanup_data
918 /* The previous quit handler. */
919 quit_handler_ftype
*prev_handler
;
922 /* Cleanup call that restores the previous quit handler. */
925 restore_quit_handler (void *arg
)
927 struct quit_handler_cleanup_data
*data
928 = (struct quit_handler_cleanup_data
*) arg
;
930 quit_handler
= data
->prev_handler
;
933 /* Destructor for the quit handler cleanup. */
936 restore_quit_handler_dtor (void *arg
)
944 make_cleanup_override_quit_handler (quit_handler_ftype
*new_quit_handler
)
946 struct cleanup
*old_chain
;
947 struct quit_handler_cleanup_data
*data
;
949 data
= XNEW (struct quit_handler_cleanup_data
);
950 data
->prev_handler
= quit_handler
;
951 old_chain
= make_cleanup_dtor (restore_quit_handler
, data
,
952 restore_quit_handler_dtor
);
953 quit_handler
= new_quit_handler
;
957 /* Handle a SIGINT. */
960 handle_sigint (int sig
)
962 signal (sig
, handle_sigint
);
964 /* We could be running in a loop reading in symfiles or something so
965 it may be quite a while before we get back to the event loop. So
966 set quit_flag to 1 here. Then if QUIT is called before we get to
967 the event loop, we will unwind as expected. */
970 /* In case nothing calls QUIT before the event loop is reached, the
971 event loop handles it. */
972 mark_async_signal_handler (sigint_token
);
975 /* See gdb_select.h. */
978 interruptible_select (int n
,
979 fd_set
*readfds
, fd_set
*writefds
, fd_set
*exceptfds
,
980 struct timeval
*timeout
)
988 readfds
= &my_readfds
;
989 FD_ZERO (&my_readfds
);
992 fd
= quit_serial_event_fd ();
993 FD_SET (fd
, readfds
);
999 res
= gdb_select (n
, readfds
, writefds
, exceptfds
, timeout
);
1001 while (res
== -1 && errno
== EINTR
);
1003 if (res
== 1 && FD_ISSET (fd
, readfds
))
1011 /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
1014 async_sigterm_handler (gdb_client_data arg
)
1016 quit_force (NULL
, stdin
== instream
);
1020 volatile int sync_quit_force_run
;
1022 /* Quit GDB if SIGTERM is received.
1023 GDB would quit anyway, but this way it will clean up properly. */
1025 handle_sigterm (int sig
)
1027 signal (sig
, handle_sigterm
);
1029 sync_quit_force_run
= 1;
1032 mark_async_signal_handler (async_sigterm_token
);
1035 /* Do the quit. All the checks have been done by the caller. */
1037 async_request_quit (gdb_client_data arg
)
1039 /* If the quit_flag has gotten reset back to 0 by the time we get
1040 back here, that means that an exception was thrown to unwind the
1041 current command before we got back to the event loop. So there
1042 is no reason to call quit again here. */
1047 /* Tell the event loop what to do if SIGQUIT is received.
1048 See event-signal.c. */
1050 handle_sigquit (int sig
)
1052 mark_async_signal_handler (sigquit_token
);
1053 signal (sig
, handle_sigquit
);
1057 #if defined (SIGQUIT) || defined (SIGHUP)
1058 /* Called by the event loop in response to a SIGQUIT or an
1061 async_do_nothing (gdb_client_data arg
)
1063 /* Empty function body. */
1068 /* Tell the event loop what to do if SIGHUP is received.
1069 See event-signal.c. */
1071 handle_sighup (int sig
)
1073 mark_async_signal_handler (sighup_token
);
1074 signal (sig
, handle_sighup
);
1077 /* Called by the event loop to process a SIGHUP. */
1079 async_disconnect (gdb_client_data arg
)
1087 CATCH (exception
, RETURN_MASK_ALL
)
1089 fputs_filtered ("Could not kill the program being debugged",
1091 exception_print (gdb_stderr
, exception
);
1099 CATCH (exception
, RETURN_MASK_ALL
)
1104 signal (SIGHUP
, SIG_DFL
); /*FIXME: ??????????? */
1111 handle_stop_sig (int sig
)
1113 mark_async_signal_handler (sigtstp_token
);
1114 signal (sig
, handle_stop_sig
);
1118 async_stop_sig (gdb_client_data arg
)
1120 char *prompt
= get_prompt ();
1122 #if STOP_SIGNAL == SIGTSTP
1123 signal (SIGTSTP
, SIG_DFL
);
1124 #if HAVE_SIGPROCMASK
1128 sigemptyset (&zero
);
1129 sigprocmask (SIG_SETMASK
, &zero
, 0);
1131 #elif HAVE_SIGSETMASK
1135 signal (SIGTSTP
, handle_stop_sig
);
1137 signal (STOP_SIGNAL
, handle_stop_sig
);
1139 printf_unfiltered ("%s", prompt
);
1140 gdb_flush (gdb_stdout
);
1142 /* Forget about any previous command -- null line now will do
1146 #endif /* STOP_SIGNAL */
1148 /* Tell the event loop what to do if SIGFPE is received.
1149 See event-signal.c. */
1151 handle_sigfpe (int sig
)
1153 mark_async_signal_handler (sigfpe_token
);
1154 signal (sig
, handle_sigfpe
);
1157 /* Event loop will call this functin to process a SIGFPE. */
1159 async_float_handler (gdb_client_data arg
)
1161 /* This message is based on ANSI C, section 4.7. Note that integer
1162 divide by zero causes this, so "float" is a misnomer. */
1163 error (_("Erroneous arithmetic operation."));
1167 /* Called by do_setshow_command. */
1169 set_async_editing_command (char *args
, int from_tty
,
1170 struct cmd_list_element
*c
)
1172 change_line_handler ();
1175 /* Set things up for readline to be invoked via the alternate
1176 interface, i.e. via a callback function
1177 (gdb_rl_callback_read_char), and hook up instream to the event
1181 gdb_setup_readline (void)
1183 struct ui
*ui
= current_ui
;
1185 /* This function is a noop for the sync case. The assumption is
1186 that the sync setup is ALL done in gdb_init, and we would only
1187 mess it up here. The sync stuff should really go away over
1190 gdb_stdout
= stdio_fileopen (stdout
);
1191 gdb_stderr
= stderr_fileopen ();
1192 gdb_stdlog
= gdb_stderr
; /* for moment */
1193 gdb_stdtarg
= gdb_stderr
; /* for moment */
1194 gdb_stdtargerr
= gdb_stderr
; /* for moment */
1196 /* If the input stream is connected to a terminal, turn on
1198 if (ISATTY (instream
))
1200 /* Tell gdb that we will be using the readline library. This
1201 could be overwritten by a command in .gdbinit like 'set
1202 editing on' or 'off'. */
1203 async_command_editing_p
= 1;
1205 /* When a character is detected on instream by select or poll,
1206 readline will be invoked via this callback function. */
1207 ui
->call_readline
= gdb_rl_callback_read_char_wrapper
;
1211 async_command_editing_p
= 0;
1212 ui
->call_readline
= gdb_readline_no_editing_callback
;
1215 /* When readline has read an end-of-line character, it passes the
1216 complete line to gdb for processing; command_line_handler is the
1217 function that does this. */
1218 ui
->input_handler
= command_line_handler
;
1220 /* Tell readline to use the same input stream that gdb uses. */
1221 rl_instream
= instream
;
1223 /* Get a file descriptor for the input stream, so that we can
1224 register it with the event loop. */
1225 input_fd
= fileno (instream
);
1227 /* Now we need to create the event sources for the input file
1229 /* At this point in time, this is the only event source that we
1230 register with the even loop. Another source is going to be the
1231 target program (inferior), but that must be registered only when
1232 it actually exists (I.e. after we say 'run' or after we connect
1233 to a remote target. */
1234 add_file_handler (input_fd
, stdin_event_handler
, 0);
1237 /* Disable command input through the standard CLI channels. Used in
1238 the suspend proc for interpreters that use the standard gdb readline
1239 interface, like the cli & the mi. */
1241 gdb_disable_readline (void)
1243 /* FIXME - It is too heavyweight to delete and remake these every
1244 time you run an interpreter that needs readline. It is probably
1245 better to have the interpreters cache these, which in turn means
1246 that this needs to be moved into interpreter specific code. */
1249 ui_file_delete (gdb_stdout
);
1250 ui_file_delete (gdb_stderr
);
1253 gdb_stdtargerr
= NULL
;
1256 gdb_rl_callback_handler_remove ();
1257 delete_file_handler (input_fd
);