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
);
441 static struct ui main_ui_
;
443 struct ui
*main_ui
= &main_ui_
;
444 struct ui
*current_ui
= &main_ui_
;
445 struct ui
*ui_list
= &main_ui_
;
447 /* Cleanup that restores the current UI. */
450 restore_ui_cleanup (void *data
)
452 current_ui
= (struct ui
*) data
;
458 switch_thru_all_uis_init (struct switch_thru_all_uis
*state
)
460 state
->iter
= ui_list
;
461 state
->old_chain
= make_cleanup (restore_ui_cleanup
, current_ui
);
467 switch_thru_all_uis_cond (struct switch_thru_all_uis
*state
)
469 if (state
->iter
!= NULL
)
471 current_ui
= state
->iter
;
476 do_cleanups (state
->old_chain
);
484 switch_thru_all_uis_next (struct switch_thru_all_uis
*state
)
486 state
->iter
= state
->iter
->next
;
489 /* Get a pointer to the current UI's line buffer. This is used to
490 construct a whole line of input from partial input. */
492 static struct buffer
*
493 get_command_line_buffer (void)
495 return ¤t_ui
->line_buffer
;
498 /* When there is an event ready on the stdin file descriptor, instead
499 of calling readline directly throught the callback function, or
500 instead of calling gdb_readline_no_editing_callback, give gdb a
501 chance to detect errors and do something. */
504 stdin_event_handler (int error
, gdb_client_data client_data
)
506 struct ui
*ui
= current_ui
;
510 printf_unfiltered (_("error detected on stdin\n"));
511 delete_file_handler (input_fd
);
512 /* If stdin died, we may as well kill gdb. */
513 quit_command ((char *) 0, stdin
== instream
);
517 /* This makes sure a ^C immediately followed by further input is
518 always processed in that order. E.g,. with input like
519 "^Cprint 1\n", the SIGINT handler runs, marks the async signal
520 handler, and then select/poll may return with stdin ready,
521 instead of -1/EINTR. The
522 gdb.base/double-prompt-target-event-error.exp test exercises
528 call_stdin_event_handler_again_p
= 0;
529 ui
->call_readline (client_data
);
530 } while (call_stdin_event_handler_again_p
!= 0);
534 /* Re-enable stdin after the end of an execution command in
535 synchronous mode, or after an error from the target, and we aborted
536 the exec operation. */
539 async_enable_stdin (void)
543 /* See NOTE in async_disable_stdin(). */
544 /* FIXME: cagney/1999-09-27: Call this before clearing
545 sync_execution. Current target_terminal_ours() implementations
546 check for sync_execution before switching the terminal. */
547 target_terminal_ours ();
552 /* Disable reads from stdin (the console) marking the command as
556 async_disable_stdin (void)
562 /* Handle a gdb command line. This function is called when
563 handle_line_of_input has concatenated one or more input lines into
567 command_handler (char *command
)
569 struct cleanup
*stat_chain
;
572 if (instream
== stdin
)
573 reinitialize_more_filter ();
575 stat_chain
= make_command_stats_cleanup (1);
577 /* Do not execute commented lines. */
578 for (c
= command
; *c
== ' ' || *c
== '\t'; c
++)
582 execute_command (command
, instream
== stdin
);
584 /* Do any commands attached to breakpoint we stopped at. */
585 bpstat_do_actions ();
588 do_cleanups (stat_chain
);
591 /* Append RL, an input line returned by readline or one of its
592 emulations, to CMD_LINE_BUFFER. Returns the command line if we
593 have a whole command line ready to be processed by the command
594 interpreter or NULL if the command line isn't complete yet (input
595 line ends in a backslash). Takes ownership of RL. */
598 command_line_append_input_line (struct buffer
*cmd_line_buffer
, char *rl
)
605 if (len
> 0 && rl
[len
- 1] == '\\')
607 /* Don't copy the backslash and wait for more. */
608 buffer_grow (cmd_line_buffer
, rl
, len
- 1);
613 /* Copy whole line including terminating null, and we're
615 buffer_grow (cmd_line_buffer
, rl
, len
+ 1);
616 cmd
= cmd_line_buffer
->buffer
;
619 /* Allocated in readline. */
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 char *rl
, int repeat
, char *annotation_suffix
)
655 cmd
= command_line_append_input_line (cmd_line_buffer
, rl
);
659 /* We have a complete command line now. Prepare for the next
660 command, but leave ownership of memory to the buffer . */
661 cmd_line_buffer
->used_size
= 0;
663 if (annotation_level
> 1 && instream
== stdin
)
665 printf_unfiltered (("\n\032\032post-"));
666 puts_unfiltered (annotation_suffix
);
667 printf_unfiltered (("\n"));
670 #define SERVER_COMMAND_PREFIX "server "
671 if (startswith (cmd
, SERVER_COMMAND_PREFIX
))
673 /* Note that we don't set `saved_command_line'. Between this
674 and the check in dont_repeat, this insures that repeating
675 will still do the right thing. */
676 return cmd
+ strlen (SERVER_COMMAND_PREFIX
);
679 /* Do history expansion if that is wished. */
680 if (history_expansion_p
&& instream
== stdin
681 && ISATTY (instream
))
686 expanded
= history_expand (cmd
, &history_value
);
691 /* Print the changes. */
692 printf_unfiltered ("%s\n", history_value
);
694 /* If there was an error, call this function again. */
697 xfree (history_value
);
701 /* history_expand returns an allocated string. Just replace
702 our buffer with it. */
703 len
= strlen (history_value
);
704 xfree (buffer_finish (cmd_line_buffer
));
705 cmd_line_buffer
->buffer
= history_value
;
706 cmd_line_buffer
->buffer_size
= len
+ 1;
711 /* If we just got an empty line, and that is supposed to repeat the
712 previous command, return the previously saved command. */
713 for (p1
= cmd
; *p1
== ' ' || *p1
== '\t'; p1
++)
715 if (repeat
&& *p1
== '\0')
716 return saved_command_line
;
718 /* Add command to history if appropriate. Note: lines consisting
719 solely of comments are also added to the command history. This
720 is useful when you type a command, and then realize you don't
721 want to execute it quite yet. You can comment out the command
722 and then later fetch it from the value history and remove the
723 '#'. The kill ring is probably better, but some people are in
724 the habit of commenting things out. */
725 if (*cmd
!= '\0' && input_from_terminal_p ())
726 gdb_add_history (cmd
);
728 /* Save into global buffer if appropriate. */
731 xfree (saved_command_line
);
732 saved_command_line
= xstrdup (cmd
);
733 return saved_command_line
;
739 /* Handle a complete line of input. This is called by the callback
740 mechanism within the readline library. Deal with incomplete
741 commands as well, by saving the partial input in a global
744 NOTE: This is the asynchronous version of the command_line_input
748 command_line_handler (char *rl
)
750 struct buffer
*line_buffer
= get_command_line_buffer ();
753 cmd
= handle_line_of_input (line_buffer
, rl
, instream
== stdin
, "prompt");
754 if (cmd
== (char *) EOF
)
756 /* stdin closed. The connection with the terminal is gone.
757 This happens at the end of a testsuite run, after Expect has
758 hung up but GDB is still alive. In such a case, we just quit
759 gdb killing the inferior program too. */
760 printf_unfiltered ("quit\n");
761 execute_command ("quit", stdin
== instream
);
763 else if (cmd
== NULL
)
765 /* We don't have a full line yet. Print an empty prompt. */
766 display_gdb_prompt ("");
770 command_handler (cmd
);
771 display_gdb_prompt (0);
775 /* Does reading of input from terminal w/o the editing features
776 provided by the readline library. Calls the line input handler
777 once we have a whole input line. */
780 gdb_readline_no_editing_callback (gdb_client_data client_data
)
784 struct buffer line_buffer
;
785 static int done_once
= 0;
786 struct ui
*ui
= current_ui
;
788 buffer_init (&line_buffer
);
790 /* Unbuffer the input stream, so that, later on, the calls to fgetc
791 fetch only one char at the time from the stream. The fgetc's will
792 get up to the first newline, but there may be more chars in the
793 stream after '\n'. If we buffer the input and fgetc drains the
794 stream, getting stuff beyond the newline as well, a select, done
795 afterwards will not trigger. */
796 if (!done_once
&& !ISATTY (instream
))
798 setbuf (instream
, NULL
);
802 /* We still need the while loop here, even though it would seem
803 obvious to invoke gdb_readline_no_editing_callback at every
804 character entered. If not using the readline library, the
805 terminal is in cooked mode, which sends the characters all at
806 once. Poll will notice that the input fd has changed state only
807 after enter is pressed. At this point we still need to fetch all
808 the chars entered. */
812 /* Read from stdin if we are executing a user defined command.
813 This is the right thing for prompt_for_continue, at least. */
814 c
= fgetc (instream
? instream
: stdin
);
818 if (line_buffer
.used_size
> 0)
820 /* The last line does not end with a newline. Return it, and
821 if we are called again fgetc will still return EOF and
822 we'll return NULL then. */
825 xfree (buffer_finish (&line_buffer
));
826 ui
->input_handler (NULL
);
832 if (line_buffer
.used_size
> 0
833 && line_buffer
.buffer
[line_buffer
.used_size
- 1] == '\r')
834 line_buffer
.used_size
--;
838 buffer_grow_char (&line_buffer
, c
);
841 buffer_grow_char (&line_buffer
, '\0');
842 result
= buffer_finish (&line_buffer
);
843 ui
->input_handler (result
);
847 /* The serial event associated with the QUIT flag. set_quit_flag sets
848 this, and check_quit_flag clears it. Used by interruptible_select
849 to be able to do interruptible I/O with no race with the SIGINT
851 static struct serial_event
*quit_serial_event
;
853 /* Initialization of signal handlers and tokens. There is a function
854 handle_sig* for each of the signals GDB cares about. Specifically:
855 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
856 functions are the actual signal handlers associated to the signals
857 via calls to signal(). The only job for these functions is to
858 enqueue the appropriate event/procedure with the event loop. Such
859 procedures are the old signal handlers. The event loop will take
860 care of invoking the queued procedures to perform the usual tasks
861 associated with the reception of the signal. */
862 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
863 init_signals will become obsolete as we move to have to event loop
864 as the default for gdb. */
866 async_init_signals (void)
868 initialize_async_signal_handlers ();
870 quit_serial_event
= make_serial_event ();
872 signal (SIGINT
, handle_sigint
);
874 create_async_signal_handler (async_request_quit
, NULL
);
875 signal (SIGTERM
, handle_sigterm
);
877 = create_async_signal_handler (async_sigterm_handler
, NULL
);
879 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
880 to the inferior and breakpoints will be ignored. */
882 signal (SIGTRAP
, SIG_DFL
);
886 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
887 passed to the inferior, which we don't want. It would be
888 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
889 on BSD4.3 systems using vfork, that can affect the
890 GDB process as well as the inferior (the signal handling tables
891 might be in memory, shared between the two). Since we establish
892 a handler for SIGQUIT, when we call exec it will set the signal
893 to SIG_DFL for us. */
894 signal (SIGQUIT
, handle_sigquit
);
896 create_async_signal_handler (async_do_nothing
, NULL
);
899 if (signal (SIGHUP
, handle_sighup
) != SIG_IGN
)
901 create_async_signal_handler (async_disconnect
, NULL
);
904 create_async_signal_handler (async_do_nothing
, NULL
);
906 signal (SIGFPE
, handle_sigfpe
);
908 create_async_signal_handler (async_float_handler
, NULL
);
912 create_async_signal_handler (async_stop_sig
, NULL
);
919 quit_serial_event_set (void)
921 serial_event_set (quit_serial_event
);
927 quit_serial_event_clear (void)
929 serial_event_clear (quit_serial_event
);
932 /* Return the selectable file descriptor of the serial event
933 associated with the quit flag. */
936 quit_serial_event_fd (void)
938 return serial_event_fd (quit_serial_event
);
944 default_quit_handler (void)
946 if (check_quit_flag ())
948 if (target_terminal_is_ours ())
951 target_pass_ctrlc ();
956 quit_handler_ftype
*quit_handler
= default_quit_handler
;
958 /* Data for make_cleanup_override_quit_handler. Wrap the previous
959 handler pointer in a data struct because it's not portable to cast
960 a function pointer to a data pointer, which is what make_cleanup
962 struct quit_handler_cleanup_data
964 /* The previous quit handler. */
965 quit_handler_ftype
*prev_handler
;
968 /* Cleanup call that restores the previous quit handler. */
971 restore_quit_handler (void *arg
)
973 struct quit_handler_cleanup_data
*data
974 = (struct quit_handler_cleanup_data
*) arg
;
976 quit_handler
= data
->prev_handler
;
979 /* Destructor for the quit handler cleanup. */
982 restore_quit_handler_dtor (void *arg
)
990 make_cleanup_override_quit_handler (quit_handler_ftype
*new_quit_handler
)
992 struct cleanup
*old_chain
;
993 struct quit_handler_cleanup_data
*data
;
995 data
= XNEW (struct quit_handler_cleanup_data
);
996 data
->prev_handler
= quit_handler
;
997 old_chain
= make_cleanup_dtor (restore_quit_handler
, data
,
998 restore_quit_handler_dtor
);
999 quit_handler
= new_quit_handler
;
1003 /* Handle a SIGINT. */
1006 handle_sigint (int sig
)
1008 signal (sig
, handle_sigint
);
1010 /* We could be running in a loop reading in symfiles or something so
1011 it may be quite a while before we get back to the event loop. So
1012 set quit_flag to 1 here. Then if QUIT is called before we get to
1013 the event loop, we will unwind as expected. */
1016 /* In case nothing calls QUIT before the event loop is reached, the
1017 event loop handles it. */
1018 mark_async_signal_handler (sigint_token
);
1021 /* See gdb_select.h. */
1024 interruptible_select (int n
,
1025 fd_set
*readfds
, fd_set
*writefds
, fd_set
*exceptfds
,
1026 struct timeval
*timeout
)
1032 if (readfds
== NULL
)
1034 readfds
= &my_readfds
;
1035 FD_ZERO (&my_readfds
);
1038 fd
= quit_serial_event_fd ();
1039 FD_SET (fd
, readfds
);
1045 res
= gdb_select (n
, readfds
, writefds
, exceptfds
, timeout
);
1047 while (res
== -1 && errno
== EINTR
);
1049 if (res
== 1 && FD_ISSET (fd
, readfds
))
1057 /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
1060 async_sigterm_handler (gdb_client_data arg
)
1062 quit_force (NULL
, stdin
== instream
);
1066 volatile int sync_quit_force_run
;
1068 /* Quit GDB if SIGTERM is received.
1069 GDB would quit anyway, but this way it will clean up properly. */
1071 handle_sigterm (int sig
)
1073 signal (sig
, handle_sigterm
);
1075 sync_quit_force_run
= 1;
1078 mark_async_signal_handler (async_sigterm_token
);
1081 /* Do the quit. All the checks have been done by the caller. */
1083 async_request_quit (gdb_client_data arg
)
1085 /* If the quit_flag has gotten reset back to 0 by the time we get
1086 back here, that means that an exception was thrown to unwind the
1087 current command before we got back to the event loop. So there
1088 is no reason to call quit again here. */
1093 /* Tell the event loop what to do if SIGQUIT is received.
1094 See event-signal.c. */
1096 handle_sigquit (int sig
)
1098 mark_async_signal_handler (sigquit_token
);
1099 signal (sig
, handle_sigquit
);
1103 #if defined (SIGQUIT) || defined (SIGHUP)
1104 /* Called by the event loop in response to a SIGQUIT or an
1107 async_do_nothing (gdb_client_data arg
)
1109 /* Empty function body. */
1114 /* Tell the event loop what to do if SIGHUP is received.
1115 See event-signal.c. */
1117 handle_sighup (int sig
)
1119 mark_async_signal_handler (sighup_token
);
1120 signal (sig
, handle_sighup
);
1123 /* Called by the event loop to process a SIGHUP. */
1125 async_disconnect (gdb_client_data arg
)
1133 CATCH (exception
, RETURN_MASK_ALL
)
1135 fputs_filtered ("Could not kill the program being debugged",
1137 exception_print (gdb_stderr
, exception
);
1145 CATCH (exception
, RETURN_MASK_ALL
)
1150 signal (SIGHUP
, SIG_DFL
); /*FIXME: ??????????? */
1157 handle_stop_sig (int sig
)
1159 mark_async_signal_handler (sigtstp_token
);
1160 signal (sig
, handle_stop_sig
);
1164 async_stop_sig (gdb_client_data arg
)
1166 char *prompt
= get_prompt ();
1168 #if STOP_SIGNAL == SIGTSTP
1169 signal (SIGTSTP
, SIG_DFL
);
1170 #if HAVE_SIGPROCMASK
1174 sigemptyset (&zero
);
1175 sigprocmask (SIG_SETMASK
, &zero
, 0);
1177 #elif HAVE_SIGSETMASK
1181 signal (SIGTSTP
, handle_stop_sig
);
1183 signal (STOP_SIGNAL
, handle_stop_sig
);
1185 printf_unfiltered ("%s", prompt
);
1186 gdb_flush (gdb_stdout
);
1188 /* Forget about any previous command -- null line now will do
1192 #endif /* STOP_SIGNAL */
1194 /* Tell the event loop what to do if SIGFPE is received.
1195 See event-signal.c. */
1197 handle_sigfpe (int sig
)
1199 mark_async_signal_handler (sigfpe_token
);
1200 signal (sig
, handle_sigfpe
);
1203 /* Event loop will call this functin to process a SIGFPE. */
1205 async_float_handler (gdb_client_data arg
)
1207 /* This message is based on ANSI C, section 4.7. Note that integer
1208 divide by zero causes this, so "float" is a misnomer. */
1209 error (_("Erroneous arithmetic operation."));
1213 /* Called by do_setshow_command. */
1215 set_async_editing_command (char *args
, int from_tty
,
1216 struct cmd_list_element
*c
)
1218 change_line_handler ();
1221 /* Set things up for readline to be invoked via the alternate
1222 interface, i.e. via a callback function
1223 (gdb_rl_callback_read_char), and hook up instream to the event
1227 gdb_setup_readline (void)
1229 struct ui
*ui
= current_ui
;
1231 /* This function is a noop for the sync case. The assumption is
1232 that the sync setup is ALL done in gdb_init, and we would only
1233 mess it up here. The sync stuff should really go away over
1236 gdb_stdout
= stdio_fileopen (stdout
);
1237 gdb_stderr
= stderr_fileopen ();
1238 gdb_stdlog
= gdb_stderr
; /* for moment */
1239 gdb_stdtarg
= gdb_stderr
; /* for moment */
1240 gdb_stdtargerr
= gdb_stderr
; /* for moment */
1242 /* If the input stream is connected to a terminal, turn on
1244 if (ISATTY (instream
))
1246 /* Tell gdb that we will be using the readline library. This
1247 could be overwritten by a command in .gdbinit like 'set
1248 editing on' or 'off'. */
1249 async_command_editing_p
= 1;
1251 /* When a character is detected on instream by select or poll,
1252 readline will be invoked via this callback function. */
1253 ui
->call_readline
= gdb_rl_callback_read_char_wrapper
;
1257 async_command_editing_p
= 0;
1258 ui
->call_readline
= gdb_readline_no_editing_callback
;
1261 /* When readline has read an end-of-line character, it passes the
1262 complete line to gdb for processing; command_line_handler is the
1263 function that does this. */
1264 ui
->input_handler
= command_line_handler
;
1266 /* Tell readline to use the same input stream that gdb uses. */
1267 rl_instream
= instream
;
1269 /* Get a file descriptor for the input stream, so that we can
1270 register it with the event loop. */
1271 input_fd
= fileno (instream
);
1273 /* Now we need to create the event sources for the input file
1275 /* At this point in time, this is the only event source that we
1276 register with the even loop. Another source is going to be the
1277 target program (inferior), but that must be registered only when
1278 it actually exists (I.e. after we say 'run' or after we connect
1279 to a remote target. */
1280 add_file_handler (input_fd
, stdin_event_handler
, 0);
1283 /* Disable command input through the standard CLI channels. Used in
1284 the suspend proc for interpreters that use the standard gdb readline
1285 interface, like the cli & the mi. */
1287 gdb_disable_readline (void)
1289 /* FIXME - It is too heavyweight to delete and remake these every
1290 time you run an interpreter that needs readline. It is probably
1291 better to have the interpreters cache these, which in turn means
1292 that this needs to be moved into interpreter specific code. */
1295 ui_file_delete (gdb_stdout
);
1296 ui_file_delete (gdb_stderr
);
1299 gdb_stdtargerr
= NULL
;
1302 gdb_rl_callback_handler_remove ();
1303 delete_file_handler (input_fd
);