1 /* Top level stuff for GDB, the GNU debugger.
3 Copyright (C) 1999-2019 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/>. */
24 /* Standard C includes. */
27 /* Local non-gdb includes. */
29 #include "cli/cli-script.h"
30 #include "common/buffer.h"
31 #include "continuations.h"
32 #include "event-loop.h"
33 #include "event-top.h"
34 #include "gdb_select.h"
36 #include "gdbthread.h"
42 #include "observable.h"
43 #include "ser-event.h"
48 /* readline include files. */
49 #include "readline/readline.h"
50 #include "readline/history.h"
52 /* readline defines this. */
55 static std::string
top_level_prompt ();
57 /* Signal handlers. */
59 static void handle_sigquit (int sig
);
62 static void handle_sighup (int sig
);
64 static void handle_sigfpe (int sig
);
66 /* Functions to be invoked by the event loop in response to
68 #if defined (SIGQUIT) || defined (SIGHUP)
69 static void async_do_nothing (gdb_client_data
);
72 static void async_disconnect (gdb_client_data
);
74 static void async_float_handler (gdb_client_data
);
76 static void async_sigtstp_handler (gdb_client_data
);
78 static void async_sigterm_handler (gdb_client_data arg
);
80 /* Instead of invoking (and waiting for) readline to read the command
81 line and pass it back for processing, we use readline's alternate
82 interface, via callback functions, so that the event loop can react
83 to other event sources while we wait for input. */
85 /* Important variables for the event loop. */
87 /* This is used to determine if GDB is using the readline library or
88 its own simplified form of readline. It is used by the asynchronous
89 form of the set editing command.
90 ezannoni: as of 1999-04-29 I expect that this
91 variable will not be used after gdb is changed to use the event
92 loop as default engine, and event-top.c is merged into top.c. */
93 int set_editing_cmd_var
;
95 /* This is used to display the notification of the completion of an
96 asynchronous execution command. */
97 int exec_done_display_p
= 0;
99 /* Used by the stdin event handler to compensate for missed stdin events.
100 Setting this to a non-zero value inside an stdin callback makes the callback
102 int call_stdin_event_handler_again_p
;
104 /* Signal handling variables. */
105 /* Each of these is a pointer to a function that the event loop will
106 invoke if the corresponding signal has received. The real signal
107 handlers mark these functions as ready to be executed and the event
108 loop, in a later iteration, calls them. See the function
109 invoke_async_signal_handler. */
110 static struct async_signal_handler
*sigint_token
;
112 static struct async_signal_handler
*sighup_token
;
115 static struct async_signal_handler
*sigquit_token
;
117 static struct async_signal_handler
*sigfpe_token
;
119 static struct async_signal_handler
*sigtstp_token
;
121 static struct async_signal_handler
*async_sigterm_token
;
123 /* This hook is called by gdb_rl_callback_read_char_wrapper after each
124 character is processed. */
125 void (*after_char_processing_hook
) (void);
128 /* Wrapper function for calling into the readline library. This takes
129 care of a couple things:
131 - The event loop expects the callback function to have a parameter,
132 while readline expects none.
134 - Propagation of GDB exceptions/errors thrown from INPUT_HANDLER
135 across readline requires special handling.
137 On the exceptions issue:
139 DWARF-based unwinding cannot cross code built without -fexceptions.
140 Any exception that tries to propagate through such code will fail
141 and the result is a call to std::terminate. While some ABIs, such
142 as x86-64, require all code to be built with exception tables,
145 This is a problem when GDB calls some non-EH-aware C library code,
146 that calls into GDB again through a callback, and that GDB callback
147 code throws a C++ exception. Turns out this is exactly what
148 happens with GDB's readline callback.
150 In such cases, we must catch and save any C++ exception that might
151 be thrown from the GDB callback before returning to the
152 non-EH-aware code. When the non-EH-aware function itself returns
153 back to GDB, we then rethrow the original C++ exception.
155 In the readline case however, the right thing to do is to longjmp
156 out of the callback, rather than do a normal return -- there's no
157 way for the callback to return to readline an indication that an
158 error happened, so a normal return would have rl_callback_read_char
159 potentially continue processing further input, redisplay the
160 prompt, etc. Instead of raw setjmp/longjmp however, we use our
161 sjlj-based TRY/CATCH mechanism, which knows to handle multiple
162 levels of active setjmp/longjmp frames, needed in order to handle
163 the readline callback recursing, as happens with e.g., secondary
164 prompts / queries, through gdb_readline_wrapper. This must be
165 noexcept in order to avoid problems with mixing sjlj and
166 (sjlj-based) C++ exceptions. */
168 static struct gdb_exception
169 gdb_rl_callback_read_char_wrapper_noexcept () noexcept
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
)
193 gdb_rl_callback_read_char_wrapper (gdb_client_data client_data
)
195 struct gdb_exception gdb_expt
196 = gdb_rl_callback_read_char_wrapper_noexcept ();
198 /* Rethrow using the normal EH mechanism. */
199 if (gdb_expt
.reason
< 0)
200 throw_exception (gdb_expt
);
203 /* GDB's readline callback handler. Calls the current INPUT_HANDLER,
204 and propagates GDB exceptions/errors thrown from INPUT_HANDLER back
205 across readline. See gdb_rl_callback_read_char_wrapper. This must
206 be noexcept in order to avoid problems with mixing sjlj and
207 (sjlj-based) C++ exceptions. */
210 gdb_rl_callback_handler (char *rl
) noexcept
212 struct gdb_exception gdb_rl_expt
= exception_none
;
213 struct ui
*ui
= current_ui
;
217 ui
->input_handler (gdb::unique_xmalloc_ptr
<char> (rl
));
219 CATCH (ex
, RETURN_MASK_ALL
)
225 /* If we caught a GDB exception, longjmp out of the readline
226 callback. There's no other way for the callback to signal to
227 readline that an error happened. A normal return would have
228 readline potentially continue processing further input, redisplay
229 the prompt, etc. (This is what GDB historically did when it was
230 a C program.) Note that since we're long jumping, local variable
231 dtors are NOT run automatically. */
232 if (gdb_rl_expt
.reason
< 0)
233 throw_exception_sjlj (gdb_rl_expt
);
236 /* Change the function to be invoked every time there is a character
237 ready on stdin. This is used when the user sets the editing off,
238 therefore bypassing readline, and letting gdb handle the input
239 itself, via gdb_readline_no_editing_callback. Also it is used in
240 the opposite case in which the user sets editing on again, by
241 restoring readline handling of the input.
243 NOTE: this operates on input_fd, not instream. If we are reading
244 commands from a file, instream will point to the file. However, we
245 always read commands from a file with editing off. This means that
246 the 'set editing on/off' will have effect only on the interactive
250 change_line_handler (int editing
)
252 struct ui
*ui
= current_ui
;
254 /* We can only have one instance of readline, so we only allow
255 editing on the main UI. */
259 /* Don't try enabling editing if the interpreter doesn't support it
261 if (!interp_supports_command_editing (top_level_interpreter ())
262 || !interp_supports_command_editing (command_interp ()))
267 gdb_assert (ui
== main_ui
);
269 /* Turn on editing by using readline. */
270 ui
->call_readline
= gdb_rl_callback_read_char_wrapper
;
274 /* Turn off editing by using gdb_readline_no_editing_callback. */
275 if (ui
->command_editing
)
276 gdb_rl_callback_handler_remove ();
277 ui
->call_readline
= gdb_readline_no_editing_callback
;
279 ui
->command_editing
= editing
;
282 /* The functions below are wrappers for rl_callback_handler_remove and
283 rl_callback_handler_install that keep track of whether the callback
284 handler is installed in readline. This is necessary because after
285 handling a target event of a background execution command, we may
286 need to reinstall the callback handler if it was removed due to a
287 secondary prompt. See gdb_readline_wrapper_line. We don't
288 unconditionally install the handler for every target event because
289 that also clears the line buffer, thus installing it while the user
290 is typing would lose input. */
292 /* Whether we've registered a callback handler with readline. */
293 static int callback_handler_installed
;
295 /* See event-top.h, and above. */
298 gdb_rl_callback_handler_remove (void)
300 gdb_assert (current_ui
== main_ui
);
302 rl_callback_handler_remove ();
303 callback_handler_installed
= 0;
306 /* See event-top.h, and above. Note this wrapper doesn't have an
307 actual callback parameter because we always install
311 gdb_rl_callback_handler_install (const char *prompt
)
313 gdb_assert (current_ui
== main_ui
);
315 /* Calling rl_callback_handler_install resets readline's input
316 buffer. Calling this when we were already processing input
317 therefore loses input. */
318 gdb_assert (!callback_handler_installed
);
320 rl_callback_handler_install (prompt
, gdb_rl_callback_handler
);
321 callback_handler_installed
= 1;
324 /* See event-top.h, and above. */
327 gdb_rl_callback_handler_reinstall (void)
329 gdb_assert (current_ui
== main_ui
);
331 if (!callback_handler_installed
)
333 /* Passing NULL as prompt argument tells readline to not display
335 gdb_rl_callback_handler_install (NULL
);
339 /* Displays the prompt. If the argument NEW_PROMPT is NULL, the
340 prompt that is displayed is the current top level prompt.
341 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
344 This is used after each gdb command has completed, and in the
347 1. When the user enters a command line which is ended by '\'
348 indicating that the command will continue on the next line. In
349 that case the prompt that is displayed is the empty string.
351 2. When the user is entering 'commands' for a breakpoint, or
352 actions for a tracepoint. In this case the prompt will be '>'
354 3. On prompting for pagination. */
357 display_gdb_prompt (const char *new_prompt
)
359 std::string actual_gdb_prompt
;
361 annotate_display_prompt ();
363 /* Reset the nesting depth used when trace-commands is set. */
364 reset_command_nest_depth ();
366 /* Do not call the python hook on an explicit prompt change as
367 passed to this function, as this forms a secondary/local prompt,
368 IE, displayed but not set. */
371 struct ui
*ui
= current_ui
;
373 if (ui
->prompt_state
== PROMPTED
)
374 internal_error (__FILE__
, __LINE__
, _("double prompt"));
375 else if (ui
->prompt_state
== PROMPT_BLOCKED
)
377 /* This is to trick readline into not trying to display the
378 prompt. Even though we display the prompt using this
379 function, readline still tries to do its own display if
380 we don't call rl_callback_handler_install and
381 rl_callback_handler_remove (which readline detects
382 because a global variable is not set). If readline did
383 that, it could mess up gdb signal handlers for SIGINT.
384 Readline assumes that between calls to rl_set_signals and
385 rl_clear_signals gdb doesn't do anything with the signal
386 handlers. Well, that's not the case, because when the
387 target executes we change the SIGINT signal handler. If
388 we allowed readline to display the prompt, the signal
389 handler change would happen exactly between the calls to
390 the above two functions. Calling
391 rl_callback_handler_remove(), does the job. */
393 if (current_ui
->command_editing
)
394 gdb_rl_callback_handler_remove ();
397 else if (ui
->prompt_state
== PROMPT_NEEDED
)
399 /* Display the top level prompt. */
400 actual_gdb_prompt
= top_level_prompt ();
401 ui
->prompt_state
= PROMPTED
;
405 actual_gdb_prompt
= new_prompt
;
407 if (current_ui
->command_editing
)
409 gdb_rl_callback_handler_remove ();
410 gdb_rl_callback_handler_install (actual_gdb_prompt
.c_str ());
412 /* new_prompt at this point can be the top of the stack or the one
413 passed in. It can't be NULL. */
416 /* Don't use a _filtered function here. It causes the assumed
417 character position to be off, since the newline we read from
418 the user is not accounted for. */
419 fputs_unfiltered (actual_gdb_prompt
.c_str (), gdb_stdout
);
420 gdb_flush (gdb_stdout
);
424 /* Return the top level prompt, as specified by "set prompt", possibly
425 overriden by the python gdb.prompt_hook hook, and then composed
426 with the prompt prefix and suffix (annotations). */
429 top_level_prompt (void)
433 /* Give observers a chance of changing the prompt. E.g., the python
434 `gdb.prompt_hook' is installed as an observer. */
435 gdb::observers::before_prompt
.notify (get_prompt ());
437 prompt
= get_prompt ();
439 if (annotation_level
>= 2)
441 /* Prefix needs to have new line at end. */
442 const char prefix
[] = "\n\032\032pre-prompt\n";
444 /* Suffix needs to have a new line at end and \032 \032 at
446 const char suffix
[] = "\n\032\032prompt\n";
448 return std::string (prefix
) + prompt
+ suffix
;
457 struct ui
*current_ui
;
460 /* Get a pointer to the current UI's line buffer. This is used to
461 construct a whole line of input from partial input. */
463 static struct buffer
*
464 get_command_line_buffer (void)
466 return ¤t_ui
->line_buffer
;
469 /* When there is an event ready on the stdin file descriptor, instead
470 of calling readline directly throught the callback function, or
471 instead of calling gdb_readline_no_editing_callback, give gdb a
472 chance to detect errors and do something. */
475 stdin_event_handler (int error
, gdb_client_data client_data
)
477 struct ui
*ui
= (struct ui
*) client_data
;
481 /* Switch to the main UI, so diagnostics always go there. */
482 current_ui
= main_ui
;
484 delete_file_handler (ui
->input_fd
);
487 /* If stdin died, we may as well kill gdb. */
488 printf_unfiltered (_("error detected on stdin\n"));
489 quit_command ((char *) 0, 0);
493 /* Simply delete the UI. */
499 /* Switch to the UI whose input descriptor woke up the event
503 /* This makes sure a ^C immediately followed by further input is
504 always processed in that order. E.g,. with input like
505 "^Cprint 1\n", the SIGINT handler runs, marks the async
506 signal handler, and then select/poll may return with stdin
507 ready, instead of -1/EINTR. The
508 gdb.base/double-prompt-target-event-error.exp test exercises
514 call_stdin_event_handler_again_p
= 0;
515 ui
->call_readline (client_data
);
517 while (call_stdin_event_handler_again_p
!= 0);
524 ui_register_input_event_handler (struct ui
*ui
)
526 add_file_handler (ui
->input_fd
, stdin_event_handler
, ui
);
532 ui_unregister_input_event_handler (struct ui
*ui
)
534 delete_file_handler (ui
->input_fd
);
537 /* Re-enable stdin after the end of an execution command in
538 synchronous mode, or after an error from the target, and we aborted
539 the exec operation. */
542 async_enable_stdin (void)
544 struct ui
*ui
= current_ui
;
546 if (ui
->prompt_state
== PROMPT_BLOCKED
)
548 target_terminal::ours ();
549 ui_register_input_event_handler (ui
);
550 ui
->prompt_state
= PROMPT_NEEDED
;
554 /* Disable reads from stdin (the console) marking the command as
558 async_disable_stdin (void)
560 struct ui
*ui
= current_ui
;
562 ui
->prompt_state
= PROMPT_BLOCKED
;
563 delete_file_handler (ui
->input_fd
);
567 /* Handle a gdb command line. This function is called when
568 handle_line_of_input has concatenated one or more input lines into
572 command_handler (const char *command
)
574 struct ui
*ui
= current_ui
;
577 if (ui
->instream
== ui
->stdin_stream
)
578 reinitialize_more_filter ();
580 scoped_command_stats
stat_reporter (true);
582 /* Do not execute commented lines. */
583 for (c
= command
; *c
== ' ' || *c
== '\t'; c
++)
587 execute_command (command
, ui
->instream
== ui
->stdin_stream
);
589 /* Do any commands attached to breakpoint we stopped at. */
590 bpstat_do_actions ();
594 /* Append RL, an input line returned by readline or one of its
595 emulations, to CMD_LINE_BUFFER. Returns the command line if we
596 have a whole command line ready to be processed by the command
597 interpreter or NULL if the command line isn't complete yet (input
598 line ends in a backslash). */
601 command_line_append_input_line (struct buffer
*cmd_line_buffer
, const char *rl
)
608 if (len
> 0 && rl
[len
- 1] == '\\')
610 /* Don't copy the backslash and wait for more. */
611 buffer_grow (cmd_line_buffer
, rl
, len
- 1);
616 /* Copy whole line including terminating null, and we're
618 buffer_grow (cmd_line_buffer
, rl
, len
+ 1);
619 cmd
= cmd_line_buffer
->buffer
;
625 /* Handle a line of input coming from readline.
627 If the read line ends with a continuation character (backslash),
628 save the partial input in CMD_LINE_BUFFER (except the backslash),
629 and return NULL. Otherwise, save the partial input and return a
630 pointer to CMD_LINE_BUFFER's buffer (null terminated), indicating a
631 whole command line is ready to be executed.
633 Returns EOF on end of file.
635 If REPEAT, handle command repetitions:
637 - If the input command line is NOT empty, the command returned is
638 copied into the global 'saved_command_line' var so that it can
641 - OTOH, if the input command line IS empty, return the previously
642 saved command instead of the empty input line.
646 handle_line_of_input (struct buffer
*cmd_line_buffer
,
647 const char *rl
, int repeat
,
648 const char *annotation_suffix
)
650 struct ui
*ui
= current_ui
;
651 int from_tty
= ui
->instream
== ui
->stdin_stream
;
658 cmd
= command_line_append_input_line (cmd_line_buffer
, rl
);
662 /* We have a complete command line now. Prepare for the next
663 command, but leave ownership of memory to the buffer . */
664 cmd_line_buffer
->used_size
= 0;
666 if (from_tty
&& annotation_level
> 1)
668 printf_unfiltered (("\n\032\032post-"));
669 puts_unfiltered (annotation_suffix
);
670 printf_unfiltered (("\n"));
673 #define SERVER_COMMAND_PREFIX "server "
674 server_command
= startswith (cmd
, SERVER_COMMAND_PREFIX
);
677 /* Note that we don't set `saved_command_line'. Between this
678 and the check in dont_repeat, this insures that repeating
679 will still do the right thing. */
680 return cmd
+ strlen (SERVER_COMMAND_PREFIX
);
683 /* Do history expansion if that is wished. */
684 if (history_expansion_p
&& from_tty
&& input_interactive_p (current_ui
))
689 expanded
= history_expand (cmd
, &cmd_expansion
);
690 gdb::unique_xmalloc_ptr
<char> history_value (cmd_expansion
);
695 /* Print the changes. */
696 printf_unfiltered ("%s\n", history_value
.get ());
698 /* If there was an error, call this function again. */
702 /* history_expand returns an allocated string. Just replace
703 our buffer with it. */
704 len
= strlen (history_value
.get ());
705 xfree (buffer_finish (cmd_line_buffer
));
706 cmd_line_buffer
->buffer
= history_value
.get ();
707 cmd_line_buffer
->buffer_size
= len
+ 1;
708 cmd
= history_value
.release ();
712 /* If we just got an empty line, and that is supposed to repeat the
713 previous command, return the previously saved command. */
714 for (p1
= cmd
; *p1
== ' ' || *p1
== '\t'; p1
++)
716 if (repeat
&& *p1
== '\0')
717 return saved_command_line
;
719 /* Add command to history if appropriate. Note: lines consisting
720 solely of comments are also added to the command history. This
721 is useful when you type a command, and then realize you don't
722 want to execute it quite yet. You can comment out the command
723 and then later fetch it from the value history and remove the
724 '#'. The kill ring is probably better, but some people are in
725 the habit of commenting things out. */
726 if (*cmd
!= '\0' && from_tty
&& input_interactive_p (current_ui
))
727 gdb_add_history (cmd
);
729 /* Save into global buffer if appropriate. */
732 xfree (saved_command_line
);
733 saved_command_line
= xstrdup (cmd
);
734 return saved_command_line
;
740 /* Handle a complete line of input. This is called by the callback
741 mechanism within the readline library. Deal with incomplete
742 commands as well, by saving the partial input in a global
745 NOTE: This is the asynchronous version of the command_line_input
749 command_line_handler (gdb::unique_xmalloc_ptr
<char> &&rl
)
751 struct buffer
*line_buffer
= get_command_line_buffer ();
752 struct ui
*ui
= current_ui
;
755 cmd
= handle_line_of_input (line_buffer
, rl
.get (), 1, "prompt");
756 if (cmd
== (char *) EOF
)
758 /* stdin closed. The connection with the terminal is gone.
759 This happens at the end of a testsuite run, after Expect has
760 hung up but GDB is still alive. In such a case, we just quit
761 gdb killing the inferior program too. */
762 printf_unfiltered ("quit\n");
763 execute_command ("quit", 1);
765 else if (cmd
== NULL
)
767 /* We don't have a full line yet. Print an empty prompt. */
768 display_gdb_prompt ("");
772 ui
->prompt_state
= PROMPT_NEEDED
;
774 command_handler (cmd
);
776 if (ui
->prompt_state
!= PROMPTED
)
777 display_gdb_prompt (0);
781 /* Does reading of input from terminal w/o the editing features
782 provided by the readline library. Calls the line input handler
783 once we have a whole input line. */
786 gdb_readline_no_editing_callback (gdb_client_data client_data
)
790 struct buffer line_buffer
;
791 static int done_once
= 0;
792 struct ui
*ui
= current_ui
;
794 buffer_init (&line_buffer
);
796 /* Unbuffer the input stream, so that, later on, the calls to fgetc
797 fetch only one char at the time from the stream. The fgetc's will
798 get up to the first newline, but there may be more chars in the
799 stream after '\n'. If we buffer the input and fgetc drains the
800 stream, getting stuff beyond the newline as well, a select, done
801 afterwards will not trigger. */
802 if (!done_once
&& !ISATTY (ui
->instream
))
804 setbuf (ui
->instream
, NULL
);
808 /* We still need the while loop here, even though it would seem
809 obvious to invoke gdb_readline_no_editing_callback at every
810 character entered. If not using the readline library, the
811 terminal is in cooked mode, which sends the characters all at
812 once. Poll will notice that the input fd has changed state only
813 after enter is pressed. At this point we still need to fetch all
814 the chars entered. */
818 /* Read from stdin if we are executing a user defined command.
819 This is the right thing for prompt_for_continue, at least. */
820 c
= fgetc (ui
->instream
!= NULL
? ui
->instream
: ui
->stdin_stream
);
824 if (line_buffer
.used_size
> 0)
826 /* The last line does not end with a newline. Return it, and
827 if we are called again fgetc will still return EOF and
828 we'll return NULL then. */
831 xfree (buffer_finish (&line_buffer
));
832 ui
->input_handler (NULL
);
838 if (line_buffer
.used_size
> 0
839 && line_buffer
.buffer
[line_buffer
.used_size
- 1] == '\r')
840 line_buffer
.used_size
--;
844 buffer_grow_char (&line_buffer
, c
);
847 buffer_grow_char (&line_buffer
, '\0');
848 result
= buffer_finish (&line_buffer
);
849 ui
->input_handler (gdb::unique_xmalloc_ptr
<char> (result
));
853 /* The serial event associated with the QUIT flag. set_quit_flag sets
854 this, and check_quit_flag clears it. Used by interruptible_select
855 to be able to do interruptible I/O with no race with the SIGINT
857 static struct serial_event
*quit_serial_event
;
859 /* Initialization of signal handlers and tokens. There is a function
860 handle_sig* for each of the signals GDB cares about. Specifically:
861 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
862 functions are the actual signal handlers associated to the signals
863 via calls to signal(). The only job for these functions is to
864 enqueue the appropriate event/procedure with the event loop. Such
865 procedures are the old signal handlers. The event loop will take
866 care of invoking the queued procedures to perform the usual tasks
867 associated with the reception of the signal. */
868 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
869 init_signals will become obsolete as we move to have to event loop
870 as the default for gdb. */
872 async_init_signals (void)
874 initialize_async_signal_handlers ();
876 quit_serial_event
= make_serial_event ();
878 signal (SIGINT
, handle_sigint
);
880 create_async_signal_handler (async_request_quit
, NULL
);
881 signal (SIGTERM
, handle_sigterm
);
883 = create_async_signal_handler (async_sigterm_handler
, NULL
);
885 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
886 to the inferior and breakpoints will be ignored. */
888 signal (SIGTRAP
, SIG_DFL
);
892 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
893 passed to the inferior, which we don't want. It would be
894 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
895 on BSD4.3 systems using vfork, that can affect the
896 GDB process as well as the inferior (the signal handling tables
897 might be in memory, shared between the two). Since we establish
898 a handler for SIGQUIT, when we call exec it will set the signal
899 to SIG_DFL for us. */
900 signal (SIGQUIT
, handle_sigquit
);
902 create_async_signal_handler (async_do_nothing
, NULL
);
905 if (signal (SIGHUP
, handle_sighup
) != SIG_IGN
)
907 create_async_signal_handler (async_disconnect
, NULL
);
910 create_async_signal_handler (async_do_nothing
, NULL
);
912 signal (SIGFPE
, handle_sigfpe
);
914 create_async_signal_handler (async_float_handler
, NULL
);
918 create_async_signal_handler (async_sigtstp_handler
, NULL
);
925 quit_serial_event_set (void)
927 serial_event_set (quit_serial_event
);
933 quit_serial_event_clear (void)
935 serial_event_clear (quit_serial_event
);
938 /* Return the selectable file descriptor of the serial event
939 associated with the quit flag. */
942 quit_serial_event_fd (void)
944 return serial_event_fd (quit_serial_event
);
950 default_quit_handler (void)
952 if (check_quit_flag ())
954 if (target_terminal::is_ours ())
957 target_pass_ctrlc ();
962 quit_handler_ftype
*quit_handler
= default_quit_handler
;
964 /* Handle a SIGINT. */
967 handle_sigint (int sig
)
969 signal (sig
, handle_sigint
);
971 /* We could be running in a loop reading in symfiles or something so
972 it may be quite a while before we get back to the event loop. So
973 set quit_flag to 1 here. Then if QUIT is called before we get to
974 the event loop, we will unwind as expected. */
977 /* In case nothing calls QUIT before the event loop is reached, the
978 event loop handles it. */
979 mark_async_signal_handler (sigint_token
);
982 /* See gdb_select.h. */
985 interruptible_select (int n
,
986 fd_set
*readfds
, fd_set
*writefds
, fd_set
*exceptfds
,
987 struct timeval
*timeout
)
995 readfds
= &my_readfds
;
996 FD_ZERO (&my_readfds
);
999 fd
= quit_serial_event_fd ();
1000 FD_SET (fd
, readfds
);
1006 res
= gdb_select (n
, readfds
, writefds
, exceptfds
, timeout
);
1008 while (res
== -1 && errno
== EINTR
);
1010 if (res
== 1 && FD_ISSET (fd
, readfds
))
1018 /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
1021 async_sigterm_handler (gdb_client_data arg
)
1023 quit_force (NULL
, 0);
1027 volatile int sync_quit_force_run
;
1029 /* Quit GDB if SIGTERM is received.
1030 GDB would quit anyway, but this way it will clean up properly. */
1032 handle_sigterm (int sig
)
1034 signal (sig
, handle_sigterm
);
1036 sync_quit_force_run
= 1;
1039 mark_async_signal_handler (async_sigterm_token
);
1042 /* Do the quit. All the checks have been done by the caller. */
1044 async_request_quit (gdb_client_data arg
)
1046 /* If the quit_flag has gotten reset back to 0 by the time we get
1047 back here, that means that an exception was thrown to unwind the
1048 current command before we got back to the event loop. So there
1049 is no reason to call quit again here. */
1054 /* Tell the event loop what to do if SIGQUIT is received.
1055 See event-signal.c. */
1057 handle_sigquit (int sig
)
1059 mark_async_signal_handler (sigquit_token
);
1060 signal (sig
, handle_sigquit
);
1064 #if defined (SIGQUIT) || defined (SIGHUP)
1065 /* Called by the event loop in response to a SIGQUIT or an
1068 async_do_nothing (gdb_client_data arg
)
1070 /* Empty function body. */
1075 /* Tell the event loop what to do if SIGHUP is received.
1076 See event-signal.c. */
1078 handle_sighup (int sig
)
1080 mark_async_signal_handler (sighup_token
);
1081 signal (sig
, handle_sighup
);
1084 /* Called by the event loop to process a SIGHUP. */
1086 async_disconnect (gdb_client_data arg
)
1094 CATCH (exception
, RETURN_MASK_ALL
)
1096 fputs_filtered ("Could not kill the program being debugged",
1098 exception_print (gdb_stderr
, exception
);
1106 CATCH (exception
, RETURN_MASK_ALL
)
1111 signal (SIGHUP
, SIG_DFL
); /*FIXME: ??????????? */
1118 handle_sigtstp (int sig
)
1120 mark_async_signal_handler (sigtstp_token
);
1121 signal (sig
, handle_sigtstp
);
1125 async_sigtstp_handler (gdb_client_data arg
)
1127 char *prompt
= get_prompt ();
1129 signal (SIGTSTP
, SIG_DFL
);
1130 #if HAVE_SIGPROCMASK
1134 sigemptyset (&zero
);
1135 sigprocmask (SIG_SETMASK
, &zero
, 0);
1137 #elif HAVE_SIGSETMASK
1141 signal (SIGTSTP
, handle_sigtstp
);
1142 printf_unfiltered ("%s", prompt
);
1143 gdb_flush (gdb_stdout
);
1145 /* Forget about any previous command -- null line now will do
1149 #endif /* SIGTSTP */
1151 /* Tell the event loop what to do if SIGFPE is received.
1152 See event-signal.c. */
1154 handle_sigfpe (int sig
)
1156 mark_async_signal_handler (sigfpe_token
);
1157 signal (sig
, handle_sigfpe
);
1160 /* Event loop will call this functin to process a SIGFPE. */
1162 async_float_handler (gdb_client_data arg
)
1164 /* This message is based on ANSI C, section 4.7. Note that integer
1165 divide by zero causes this, so "float" is a misnomer. */
1166 error (_("Erroneous arithmetic operation."));
1170 /* Set things up for readline to be invoked via the alternate
1171 interface, i.e. via a callback function
1172 (gdb_rl_callback_read_char), and hook up instream to the event
1176 gdb_setup_readline (int editing
)
1178 struct ui
*ui
= current_ui
;
1180 /* This function is a noop for the sync case. The assumption is
1181 that the sync setup is ALL done in gdb_init, and we would only
1182 mess it up here. The sync stuff should really go away over
1185 gdb_stdout
= new stdio_file (ui
->outstream
);
1186 gdb_stderr
= new stderr_file (ui
->errstream
);
1187 gdb_stdlog
= gdb_stderr
; /* for moment */
1188 gdb_stdtarg
= gdb_stderr
; /* for moment */
1189 gdb_stdtargerr
= gdb_stderr
; /* for moment */
1191 /* If the input stream is connected to a terminal, turn on editing.
1192 However, that is only allowed on the main UI, as we can only have
1193 one instance of readline. */
1194 if (ISATTY (ui
->instream
) && editing
&& ui
== main_ui
)
1196 /* Tell gdb that we will be using the readline library. This
1197 could be overwritten by a command in .gdbinit like 'set
1198 editing on' or 'off'. */
1199 ui
->command_editing
= 1;
1201 /* When a character is detected on instream by select or poll,
1202 readline will be invoked via this callback function. */
1203 ui
->call_readline
= gdb_rl_callback_read_char_wrapper
;
1205 /* Tell readline to use the same input stream that gdb uses. */
1206 rl_instream
= ui
->instream
;
1210 ui
->command_editing
= 0;
1211 ui
->call_readline
= gdb_readline_no_editing_callback
;
1214 /* Now create the event source for this UI's input file descriptor.
1215 Another source is going to be the target program (inferior), but
1216 that must be registered only when it actually exists (I.e. after
1217 we say 'run' or after we connect to a remote target. */
1218 ui_register_input_event_handler (ui
);
1221 /* Disable command input through the standard CLI channels. Used in
1222 the suspend proc for interpreters that use the standard gdb readline
1223 interface, like the cli & the mi. */
1226 gdb_disable_readline (void)
1228 struct ui
*ui
= current_ui
;
1230 /* FIXME - It is too heavyweight to delete and remake these every
1231 time you run an interpreter that needs readline. It is probably
1232 better to have the interpreters cache these, which in turn means
1233 that this needs to be moved into interpreter specific code. */
1236 ui_file_delete (gdb_stdout
);
1237 ui_file_delete (gdb_stderr
);
1240 gdb_stdtargerr
= NULL
;
1243 if (ui
->command_editing
)
1244 gdb_rl_callback_handler_remove ();
1245 delete_file_handler (ui
->input_fd
);