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 char *top_level_prompt (void);
53 /* Signal handlers. */
55 static void handle_sigquit (int sig);
58 static void handle_sighup (int sig);
60 static void handle_sigfpe (int sig);
62 /* Functions to be invoked by the event loop in response to
64 #if defined (SIGQUIT) || defined (SIGHUP)
65 static void async_do_nothing (gdb_client_data);
68 static void async_disconnect (gdb_client_data);
70 static void async_float_handler (gdb_client_data);
72 static void async_stop_sig (gdb_client_data);
74 static void async_sigterm_handler (gdb_client_data arg);
76 /* Instead of invoking (and waiting for) readline to read the command
77 line and pass it back for processing, we use readline's alternate
78 interface, via callback functions, so that the event loop can react
79 to other event sources while we wait for input. */
81 /* Important variables for the event loop. */
83 /* This is used to determine if GDB is using the readline library or
84 its own simplified form of readline. It is used by the asynchronous
85 form of the set editing command.
86 ezannoni: as of 1999-04-29 I expect that this
87 variable will not be used after gdb is changed to use the event
88 loop as default engine, and event-top.c is merged into top.c. */
89 int set_editing_cmd_var;
91 /* This is used to display the notification of the completion of an
92 asynchronous execution command. */
93 int exec_done_display_p = 0;
95 /* Used by the stdin event handler to compensate for missed stdin events.
96 Setting this to a non-zero value inside an stdin callback makes the callback
98 int call_stdin_event_handler_again_p;
100 /* Signal handling variables. */
101 /* Each of these is a pointer to a function that the event loop will
102 invoke if the corresponding signal has received. The real signal
103 handlers mark these functions as ready to be executed and the event
104 loop, in a later iteration, calls them. See the function
105 invoke_async_signal_handler. */
106 static struct async_signal_handler *sigint_token;
108 static struct async_signal_handler *sighup_token;
111 static struct async_signal_handler *sigquit_token;
113 static struct async_signal_handler *sigfpe_token;
115 static struct async_signal_handler *sigtstp_token;
117 static struct async_signal_handler *async_sigterm_token;
119 /* This hook is called by gdb_rl_callback_read_char_wrapper after each
120 character is processed. */
121 void (*after_char_processing_hook) (void);
124 /* Wrapper function for calling into the readline library. This takes
125 care of a couple things:
127 - The event loop expects the callback function to have a parameter,
128 while readline expects none.
130 - Propagation of GDB exceptions/errors thrown from INPUT_HANDLER
131 across readline requires special handling.
133 On the exceptions issue:
135 DWARF-based unwinding cannot cross code built without -fexceptions.
136 Any exception that tries to propagate through such code will fail
137 and the result is a call to std::terminate. While some ABIs, such
138 as x86-64, require all code to be built with exception tables,
141 This is a problem when GDB calls some non-EH-aware C library code,
142 that calls into GDB again through a callback, and that GDB callback
143 code throws a C++ exception. Turns out this is exactly what
144 happens with GDB's readline callback.
146 In such cases, we must catch and save any C++ exception that might
147 be thrown from the GDB callback before returning to the
148 non-EH-aware code. When the non-EH-aware function itself returns
149 back to GDB, we then rethrow the original C++ exception.
151 In the readline case however, the right thing to do is to longjmp
152 out of the callback, rather than do a normal return -- there's no
153 way for the callback to return to readline an indication that an
154 error happened, so a normal return would have rl_callback_read_char
155 potentially continue processing further input, redisplay the
156 prompt, etc. Instead of raw setjmp/longjmp however, we use our
157 sjlj-based TRY/CATCH mechanism, which knows to handle multiple
158 levels of active setjmp/longjmp frames, needed in order to handle
159 the readline callback recursing, as happens with e.g., secondary
160 prompts / queries, through gdb_readline_wrapper. */
163 gdb_rl_callback_read_char_wrapper (gdb_client_data client_data)
165 struct gdb_exception gdb_expt = exception_none;
167 /* C++ exceptions can't normally be thrown across readline (unless
168 it is built with -fexceptions, but it won't by default on many
169 ABIs). So we instead wrap the readline call with a sjlj-based
170 TRY/CATCH, and rethrow the GDB exception once back in GDB. */
173 rl_callback_read_char ();
174 if (after_char_processing_hook)
175 (*after_char_processing_hook) ();
177 CATCH_SJLJ (ex, RETURN_MASK_ALL)
183 /* Rethrow using the normal EH mechanism. */
184 if (gdb_expt.reason < 0)
185 throw_exception (gdb_expt);
188 /* GDB's readline callback handler. Calls the current INPUT_HANDLER,
189 and propagates GDB exceptions/errors thrown from INPUT_HANDLER back
190 across readline. See gdb_rl_callback_read_char_wrapper. */
193 gdb_rl_callback_handler (char *rl)
195 struct gdb_exception gdb_rl_expt = exception_none;
196 struct ui *ui = current_ui;
200 ui->input_handler (rl);
202 CATCH (ex, RETURN_MASK_ALL)
208 /* If we caught a GDB exception, longjmp out of the readline
209 callback. There's no other way for the callback to signal to
210 readline that an error happened. A normal return would have
211 readline potentially continue processing further input, redisplay
212 the prompt, etc. (This is what GDB historically did when it was
213 a C program.) Note that since we're long jumping, local variable
214 dtors are NOT run automatically. */
215 if (gdb_rl_expt.reason < 0)
216 throw_exception_sjlj (gdb_rl_expt);
219 /* Change the function to be invoked every time there is a character
220 ready on stdin. This is used when the user sets the editing off,
221 therefore bypassing readline, and letting gdb handle the input
222 itself, via gdb_readline_no_editing_callback. Also it is used in
223 the opposite case in which the user sets editing on again, by
224 restoring readline handling of the input.
226 NOTE: this operates on input_fd, not instream. If we are reading
227 commands from a file, instream will point to the file. However, we
228 always read commands from a file with editing off. This means that
229 the 'set editing on/off' will have effect only on the interactive
233 change_line_handler (int editing)
235 struct ui *ui = current_ui;
237 /* We can only have one instance of readline, so we only allow
238 editing on the main UI. */
242 /* Don't try enabling editing if the interpreter doesn't support it
244 if (!interp_supports_command_editing (top_level_interpreter ())
245 || !interp_supports_command_editing (command_interp ()))
250 gdb_assert (ui == main_ui);
252 /* Turn on editing by using readline. */
253 ui->call_readline = gdb_rl_callback_read_char_wrapper;
257 /* Turn off editing by using gdb_readline_no_editing_callback. */
258 if (ui->command_editing)
259 gdb_rl_callback_handler_remove ();
260 ui->call_readline = gdb_readline_no_editing_callback;
262 ui->command_editing = editing;
265 /* The functions below are wrappers for rl_callback_handler_remove and
266 rl_callback_handler_install that keep track of whether the callback
267 handler is installed in readline. This is necessary because after
268 handling a target event of a background execution command, we may
269 need to reinstall the callback handler if it was removed due to a
270 secondary prompt. See gdb_readline_wrapper_line. We don't
271 unconditionally install the handler for every target event because
272 that also clears the line buffer, thus installing it while the user
273 is typing would lose input. */
275 /* Whether we've registered a callback handler with readline. */
276 static int callback_handler_installed;
278 /* See event-top.h, and above. */
281 gdb_rl_callback_handler_remove (void)
283 gdb_assert (current_ui == main_ui);
285 rl_callback_handler_remove ();
286 callback_handler_installed = 0;
289 /* See event-top.h, and above. Note this wrapper doesn't have an
290 actual callback parameter because we always install
294 gdb_rl_callback_handler_install (const char *prompt)
296 gdb_assert (current_ui == main_ui);
298 /* Calling rl_callback_handler_install resets readline's input
299 buffer. Calling this when we were already processing input
300 therefore loses input. */
301 gdb_assert (!callback_handler_installed);
303 rl_callback_handler_install (prompt, gdb_rl_callback_handler);
304 callback_handler_installed = 1;
307 /* See event-top.h, and above. */
310 gdb_rl_callback_handler_reinstall (void)
312 gdb_assert (current_ui == main_ui);
314 if (!callback_handler_installed)
316 /* Passing NULL as prompt argument tells readline to not display
318 gdb_rl_callback_handler_install (NULL);
322 /* Displays the prompt. If the argument NEW_PROMPT is NULL, the
323 prompt that is displayed is the current top level prompt.
324 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
327 This is used after each gdb command has completed, and in the
330 1. When the user enters a command line which is ended by '\'
331 indicating that the command will continue on the next line. In
332 that case the prompt that is displayed is the empty string.
334 2. When the user is entering 'commands' for a breakpoint, or
335 actions for a tracepoint. In this case the prompt will be '>'
337 3. On prompting for pagination. */
340 display_gdb_prompt (const char *new_prompt)
342 char *actual_gdb_prompt = NULL;
343 struct cleanup *old_chain;
345 annotate_display_prompt ();
347 /* Reset the nesting depth used when trace-commands is set. */
348 reset_command_nest_depth ();
350 old_chain = make_cleanup (free_current_contents, &actual_gdb_prompt);
352 /* Do not call the python hook on an explicit prompt change as
353 passed to this function, as this forms a secondary/local prompt,
354 IE, displayed but not set. */
357 struct ui *ui = current_ui;
359 if (ui->prompt_state == PROMPTED)
360 internal_error (__FILE__, __LINE__, _("double prompt"));
361 else if (ui->prompt_state == PROMPT_BLOCKED)
363 /* This is to trick readline into not trying to display the
364 prompt. Even though we display the prompt using this
365 function, readline still tries to do its own display if
366 we don't call rl_callback_handler_install and
367 rl_callback_handler_remove (which readline detects
368 because a global variable is not set). If readline did
369 that, it could mess up gdb signal handlers for SIGINT.
370 Readline assumes that between calls to rl_set_signals and
371 rl_clear_signals gdb doesn't do anything with the signal
372 handlers. Well, that's not the case, because when the
373 target executes we change the SIGINT signal handler. If
374 we allowed readline to display the prompt, the signal
375 handler change would happen exactly between the calls to
376 the above two functions. Calling
377 rl_callback_handler_remove(), does the job. */
379 if (current_ui->command_editing)
380 gdb_rl_callback_handler_remove ();
381 do_cleanups (old_chain);
384 else if (ui->prompt_state == PROMPT_NEEDED)
386 /* Display the top level prompt. */
387 actual_gdb_prompt = top_level_prompt ();
388 ui->prompt_state = PROMPTED;
392 actual_gdb_prompt = xstrdup (new_prompt);
394 if (current_ui->command_editing)
396 gdb_rl_callback_handler_remove ();
397 gdb_rl_callback_handler_install (actual_gdb_prompt);
399 /* new_prompt at this point can be the top of the stack or the one
400 passed in. It can't be NULL. */
403 /* Don't use a _filtered function here. It causes the assumed
404 character position to be off, since the newline we read from
405 the user is not accounted for. */
406 fputs_unfiltered (actual_gdb_prompt, gdb_stdout);
407 gdb_flush (gdb_stdout);
410 do_cleanups (old_chain);
413 /* Return the top level prompt, as specified by "set prompt", possibly
414 overriden by the python gdb.prompt_hook hook, and then composed
415 with the prompt prefix and suffix (annotations). The caller is
416 responsible for freeing the returned string. */
419 top_level_prompt (void)
423 /* Give observers a chance of changing the prompt. E.g., the python
424 `gdb.prompt_hook' is installed as an observer. */
425 observer_notify_before_prompt (get_prompt ());
427 prompt = get_prompt ();
429 if (annotation_level >= 2)
431 /* Prefix needs to have new line at end. */
432 const char prefix[] = "\n\032\032pre-prompt\n";
434 /* Suffix needs to have a new line at end and \032 \032 at
436 const char suffix[] = "\n\032\032prompt\n";
438 return concat (prefix, prompt, suffix, (char *) NULL);
441 return xstrdup (prompt);
447 struct ui *current_ui;
453 restore_ui_cleanup (void *data)
455 current_ui = (struct ui *) data;
461 switch_thru_all_uis_init (struct switch_thru_all_uis *state)
463 state->iter = ui_list;
464 state->old_chain = make_cleanup (restore_ui_cleanup, current_ui);
470 switch_thru_all_uis_cond (struct switch_thru_all_uis *state)
472 if (state->iter != NULL)
474 current_ui = state->iter;
479 do_cleanups (state->old_chain);
487 switch_thru_all_uis_next (struct switch_thru_all_uis *state)
489 state->iter = state->iter->next;
492 /* Get a pointer to the current UI's line buffer. This is used to
493 construct a whole line of input from partial input. */
495 static struct buffer *
496 get_command_line_buffer (void)
498 return ¤t_ui->line_buffer;
501 /* When there is an event ready on the stdin file descriptor, instead
502 of calling readline directly throught the callback function, or
503 instead of calling gdb_readline_no_editing_callback, give gdb a
504 chance to detect errors and do something. */
507 stdin_event_handler (int error, gdb_client_data client_data)
509 struct ui *ui = (struct ui *) client_data;
513 /* Switch to the main UI, so diagnostics always go there. */
514 current_ui = main_ui;
516 delete_file_handler (ui->input_fd);
519 /* If stdin died, we may as well kill gdb. */
520 printf_unfiltered (_("error detected on stdin\n"));
521 quit_command ((char *) 0, stdin == ui->instream);
525 /* Simply delete the UI. */
531 /* Switch to the UI whose input descriptor woke up the event
535 /* This makes sure a ^C immediately followed by further input is
536 always processed in that order. E.g,. with input like
537 "^Cprint 1\n", the SIGINT handler runs, marks the async
538 signal handler, and then select/poll may return with stdin
539 ready, instead of -1/EINTR. The
540 gdb.base/double-prompt-target-event-error.exp test exercises
546 call_stdin_event_handler_again_p = 0;
547 ui->call_readline (client_data);
549 while (call_stdin_event_handler_again_p != 0);
553 /* Re-enable stdin after the end of an execution command in
554 synchronous mode, or after an error from the target, and we aborted
555 the exec operation. */
558 async_enable_stdin (void)
560 struct ui *ui = current_ui;
562 if (ui->prompt_state == PROMPT_BLOCKED)
564 target_terminal_ours ();
565 ui->prompt_state = PROMPT_NEEDED;
569 /* Disable reads from stdin (the console) marking the command as
573 async_disable_stdin (void)
575 struct ui *ui = current_ui;
577 ui->prompt_state = PROMPT_BLOCKED;
581 /* Handle a gdb command line. This function is called when
582 handle_line_of_input has concatenated one or more input lines into
586 command_handler (char *command)
588 struct ui *ui = current_ui;
589 struct cleanup *stat_chain;
592 if (ui->instream == stdin)
593 reinitialize_more_filter ();
595 stat_chain = make_command_stats_cleanup (1);
597 /* Do not execute commented lines. */
598 for (c = command; *c == ' ' || *c == '\t'; c++)
602 execute_command (command, ui->instream == stdin);
604 /* Do any commands attached to breakpoint we stopped at. */
605 bpstat_do_actions ();
608 do_cleanups (stat_chain);
611 /* Append RL, an input line returned by readline or one of its
612 emulations, to CMD_LINE_BUFFER. Returns the command line if we
613 have a whole command line ready to be processed by the command
614 interpreter or NULL if the command line isn't complete yet (input
615 line ends in a backslash). Takes ownership of RL. */
618 command_line_append_input_line (struct buffer *cmd_line_buffer, char *rl)
625 if (len > 0 && rl[len - 1] == '\\')
627 /* Don't copy the backslash and wait for more. */
628 buffer_grow (cmd_line_buffer, rl, len - 1);
633 /* Copy whole line including terminating null, and we're
635 buffer_grow (cmd_line_buffer, rl, len + 1);
636 cmd = cmd_line_buffer->buffer;
639 /* Allocated in readline. */
645 /* Handle a line of input coming from readline.
647 If the read line ends with a continuation character (backslash),
648 save the partial input in CMD_LINE_BUFFER (except the backslash),
649 and return NULL. Otherwise, save the partial input and return a
650 pointer to CMD_LINE_BUFFER's buffer (null terminated), indicating a
651 whole command line is ready to be executed.
653 Returns EOF on end of file.
655 If REPEAT, handle command repetitions:
657 - If the input command line is NOT empty, the command returned is
658 copied into the global 'saved_command_line' var so that it can
661 - OTOH, if the input command line IS empty, return the previously
662 saved command instead of the empty input line.
666 handle_line_of_input (struct buffer *cmd_line_buffer,
667 char *rl, int repeat, char *annotation_suffix)
669 struct ui *ui = current_ui;
676 cmd = command_line_append_input_line (cmd_line_buffer, rl);
680 /* We have a complete command line now. Prepare for the next
681 command, but leave ownership of memory to the buffer . */
682 cmd_line_buffer->used_size = 0;
684 if (annotation_level > 1 && ui->instream == stdin)
686 printf_unfiltered (("\n\032\032post-"));
687 puts_unfiltered (annotation_suffix);
688 printf_unfiltered (("\n"));
691 #define SERVER_COMMAND_PREFIX "server "
692 if (startswith (cmd, SERVER_COMMAND_PREFIX))
694 /* Note that we don't set `saved_command_line'. Between this
695 and the check in dont_repeat, this insures that repeating
696 will still do the right thing. */
697 return cmd + strlen (SERVER_COMMAND_PREFIX);
700 /* Do history expansion if that is wished. */
701 if (history_expansion_p && ui->instream == stdin
702 && ISATTY (ui->instream))
707 expanded = history_expand (cmd, &history_value);
712 /* Print the changes. */
713 printf_unfiltered ("%s\n", history_value);
715 /* If there was an error, call this function again. */
718 xfree (history_value);
722 /* history_expand returns an allocated string. Just replace
723 our buffer with it. */
724 len = strlen (history_value);
725 xfree (buffer_finish (cmd_line_buffer));
726 cmd_line_buffer->buffer = history_value;
727 cmd_line_buffer->buffer_size = len + 1;
732 /* If we just got an empty line, and that is supposed to repeat the
733 previous command, return the previously saved command. */
734 for (p1 = cmd; *p1 == ' ' || *p1 == '\t'; p1++)
736 if (repeat && *p1 == '\0')
737 return saved_command_line;
739 /* Add command to history if appropriate. Note: lines consisting
740 solely of comments are also added to the command history. This
741 is useful when you type a command, and then realize you don't
742 want to execute it quite yet. You can comment out the command
743 and then later fetch it from the value history and remove the
744 '#'. The kill ring is probably better, but some people are in
745 the habit of commenting things out. */
746 if (*cmd != '\0' && input_from_terminal_p ())
747 gdb_add_history (cmd);
749 /* Save into global buffer if appropriate. */
752 xfree (saved_command_line);
753 saved_command_line = xstrdup (cmd);
754 return saved_command_line;
760 /* Handle a complete line of input. This is called by the callback
761 mechanism within the readline library. Deal with incomplete
762 commands as well, by saving the partial input in a global
765 NOTE: This is the asynchronous version of the command_line_input
769 command_line_handler (char *rl)
771 struct buffer *line_buffer = get_command_line_buffer ();
772 struct ui *ui = current_ui;
775 cmd = handle_line_of_input (line_buffer, rl, ui->instream == stdin,
777 if (cmd == (char *) EOF)
779 /* stdin closed. The connection with the terminal is gone.
780 This happens at the end of a testsuite run, after Expect has
781 hung up but GDB is still alive. In such a case, we just quit
782 gdb killing the inferior program too. */
783 printf_unfiltered ("quit\n");
784 execute_command ("quit", stdin == ui->instream);
786 else if (cmd == NULL)
788 /* We don't have a full line yet. Print an empty prompt. */
789 display_gdb_prompt ("");
793 ui->prompt_state = PROMPT_NEEDED;
795 command_handler (cmd);
797 if (ui->prompt_state != PROMPTED)
798 display_gdb_prompt (0);
802 /* Does reading of input from terminal w/o the editing features
803 provided by the readline library. Calls the line input handler
804 once we have a whole input line. */
807 gdb_readline_no_editing_callback (gdb_client_data client_data)
811 struct buffer line_buffer;
812 static int done_once = 0;
813 struct ui *ui = current_ui;
815 buffer_init (&line_buffer);
817 /* Unbuffer the input stream, so that, later on, the calls to fgetc
818 fetch only one char at the time from the stream. The fgetc's will
819 get up to the first newline, but there may be more chars in the
820 stream after '\n'. If we buffer the input and fgetc drains the
821 stream, getting stuff beyond the newline as well, a select, done
822 afterwards will not trigger. */
823 if (!done_once && !ISATTY (ui->instream))
825 setbuf (ui->instream, NULL);
829 /* We still need the while loop here, even though it would seem
830 obvious to invoke gdb_readline_no_editing_callback at every
831 character entered. If not using the readline library, the
832 terminal is in cooked mode, which sends the characters all at
833 once. Poll will notice that the input fd has changed state only
834 after enter is pressed. At this point we still need to fetch all
835 the chars entered. */
839 /* Read from stdin if we are executing a user defined command.
840 This is the right thing for prompt_for_continue, at least. */
841 c = fgetc (ui->instream ? ui->instream : stdin);
845 if (line_buffer.used_size > 0)
847 /* The last line does not end with a newline. Return it, and
848 if we are called again fgetc will still return EOF and
849 we'll return NULL then. */
852 xfree (buffer_finish (&line_buffer));
853 ui->input_handler (NULL);
859 if (line_buffer.used_size > 0
860 && line_buffer.buffer[line_buffer.used_size - 1] == '\r')
861 line_buffer.used_size--;
865 buffer_grow_char (&line_buffer, c);
868 buffer_grow_char (&line_buffer, '\0');
869 result = buffer_finish (&line_buffer);
870 ui->input_handler (result);
874 /* The serial event associated with the QUIT flag. set_quit_flag sets
875 this, and check_quit_flag clears it. Used by interruptible_select
876 to be able to do interruptible I/O with no race with the SIGINT
878 static struct serial_event *quit_serial_event;
880 /* Initialization of signal handlers and tokens. There is a function
881 handle_sig* for each of the signals GDB cares about. Specifically:
882 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
883 functions are the actual signal handlers associated to the signals
884 via calls to signal(). The only job for these functions is to
885 enqueue the appropriate event/procedure with the event loop. Such
886 procedures are the old signal handlers. The event loop will take
887 care of invoking the queued procedures to perform the usual tasks
888 associated with the reception of the signal. */
889 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
890 init_signals will become obsolete as we move to have to event loop
891 as the default for gdb. */
893 async_init_signals (void)
895 initialize_async_signal_handlers ();
897 quit_serial_event = make_serial_event ();
899 signal (SIGINT, handle_sigint);
901 create_async_signal_handler (async_request_quit, NULL);
902 signal (SIGTERM, handle_sigterm);
904 = create_async_signal_handler (async_sigterm_handler, NULL);
906 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
907 to the inferior and breakpoints will be ignored. */
909 signal (SIGTRAP, SIG_DFL);
913 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
914 passed to the inferior, which we don't want. It would be
915 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
916 on BSD4.3 systems using vfork, that can affect the
917 GDB process as well as the inferior (the signal handling tables
918 might be in memory, shared between the two). Since we establish
919 a handler for SIGQUIT, when we call exec it will set the signal
920 to SIG_DFL for us. */
921 signal (SIGQUIT, handle_sigquit);
923 create_async_signal_handler (async_do_nothing, NULL);
926 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
928 create_async_signal_handler (async_disconnect, NULL);
931 create_async_signal_handler (async_do_nothing, NULL);
933 signal (SIGFPE, handle_sigfpe);
935 create_async_signal_handler (async_float_handler, NULL);
939 create_async_signal_handler (async_stop_sig, NULL);
946 quit_serial_event_set (void)
948 serial_event_set (quit_serial_event);
954 quit_serial_event_clear (void)
956 serial_event_clear (quit_serial_event);
959 /* Return the selectable file descriptor of the serial event
960 associated with the quit flag. */
963 quit_serial_event_fd (void)
965 return serial_event_fd (quit_serial_event);
971 default_quit_handler (void)
973 if (check_quit_flag ())
975 if (target_terminal_is_ours ())
978 target_pass_ctrlc ();
983 quit_handler_ftype *quit_handler = default_quit_handler;
985 /* Data for make_cleanup_override_quit_handler. Wrap the previous
986 handler pointer in a data struct because it's not portable to cast
987 a function pointer to a data pointer, which is what make_cleanup
989 struct quit_handler_cleanup_data
991 /* The previous quit handler. */
992 quit_handler_ftype *prev_handler;
995 /* Cleanup call that restores the previous quit handler. */
998 restore_quit_handler (void *arg)
1000 struct quit_handler_cleanup_data *data
1001 = (struct quit_handler_cleanup_data *) arg;
1003 quit_handler = data->prev_handler;
1006 /* Destructor for the quit handler cleanup. */
1009 restore_quit_handler_dtor (void *arg)
1017 make_cleanup_override_quit_handler (quit_handler_ftype *new_quit_handler)
1019 struct cleanup *old_chain;
1020 struct quit_handler_cleanup_data *data;
1022 data = XNEW (struct quit_handler_cleanup_data);
1023 data->prev_handler = quit_handler;
1024 old_chain = make_cleanup_dtor (restore_quit_handler, data,
1025 restore_quit_handler_dtor);
1026 quit_handler = new_quit_handler;
1030 /* Handle a SIGINT. */
1033 handle_sigint (int sig)
1035 signal (sig, handle_sigint);
1037 /* We could be running in a loop reading in symfiles or something so
1038 it may be quite a while before we get back to the event loop. So
1039 set quit_flag to 1 here. Then if QUIT is called before we get to
1040 the event loop, we will unwind as expected. */
1043 /* In case nothing calls QUIT before the event loop is reached, the
1044 event loop handles it. */
1045 mark_async_signal_handler (sigint_token);
1048 /* See gdb_select.h. */
1051 interruptible_select (int n,
1052 fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
1053 struct timeval *timeout)
1059 if (readfds == NULL)
1061 readfds = &my_readfds;
1062 FD_ZERO (&my_readfds);
1065 fd = quit_serial_event_fd ();
1066 FD_SET (fd, readfds);
1072 res = gdb_select (n, readfds, writefds, exceptfds, timeout);
1074 while (res == -1 && errno == EINTR);
1076 if (res == 1 && FD_ISSET (fd, readfds))
1084 /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
1087 async_sigterm_handler (gdb_client_data arg)
1089 quit_force (NULL, stdin == current_ui->instream);
1093 volatile int sync_quit_force_run;
1095 /* Quit GDB if SIGTERM is received.
1096 GDB would quit anyway, but this way it will clean up properly. */
1098 handle_sigterm (int sig)
1100 signal (sig, handle_sigterm);
1102 sync_quit_force_run = 1;
1105 mark_async_signal_handler (async_sigterm_token);
1108 /* Do the quit. All the checks have been done by the caller. */
1110 async_request_quit (gdb_client_data arg)
1112 /* If the quit_flag has gotten reset back to 0 by the time we get
1113 back here, that means that an exception was thrown to unwind the
1114 current command before we got back to the event loop. So there
1115 is no reason to call quit again here. */
1120 /* Tell the event loop what to do if SIGQUIT is received.
1121 See event-signal.c. */
1123 handle_sigquit (int sig)
1125 mark_async_signal_handler (sigquit_token);
1126 signal (sig, handle_sigquit);
1130 #if defined (SIGQUIT) || defined (SIGHUP)
1131 /* Called by the event loop in response to a SIGQUIT or an
1134 async_do_nothing (gdb_client_data arg)
1136 /* Empty function body. */
1141 /* Tell the event loop what to do if SIGHUP is received.
1142 See event-signal.c. */
1144 handle_sighup (int sig)
1146 mark_async_signal_handler (sighup_token);
1147 signal (sig, handle_sighup);
1150 /* Called by the event loop to process a SIGHUP. */
1152 async_disconnect (gdb_client_data arg)
1160 CATCH (exception, RETURN_MASK_ALL)
1162 fputs_filtered ("Could not kill the program being debugged",
1164 exception_print (gdb_stderr, exception);
1172 CATCH (exception, RETURN_MASK_ALL)
1177 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
1184 handle_stop_sig (int sig)
1186 mark_async_signal_handler (sigtstp_token);
1187 signal (sig, handle_stop_sig);
1191 async_stop_sig (gdb_client_data arg)
1193 char *prompt = get_prompt ();
1195 #if STOP_SIGNAL == SIGTSTP
1196 signal (SIGTSTP, SIG_DFL);
1197 #if HAVE_SIGPROCMASK
1201 sigemptyset (&zero);
1202 sigprocmask (SIG_SETMASK, &zero, 0);
1204 #elif HAVE_SIGSETMASK
1208 signal (SIGTSTP, handle_stop_sig);
1210 signal (STOP_SIGNAL, handle_stop_sig);
1212 printf_unfiltered ("%s", prompt);
1213 gdb_flush (gdb_stdout);
1215 /* Forget about any previous command -- null line now will do
1219 #endif /* STOP_SIGNAL */
1221 /* Tell the event loop what to do if SIGFPE is received.
1222 See event-signal.c. */
1224 handle_sigfpe (int sig)
1226 mark_async_signal_handler (sigfpe_token);
1227 signal (sig, handle_sigfpe);
1230 /* Event loop will call this functin to process a SIGFPE. */
1232 async_float_handler (gdb_client_data arg)
1234 /* This message is based on ANSI C, section 4.7. Note that integer
1235 divide by zero causes this, so "float" is a misnomer. */
1236 error (_("Erroneous arithmetic operation."));
1240 /* Set things up for readline to be invoked via the alternate
1241 interface, i.e. via a callback function
1242 (gdb_rl_callback_read_char), and hook up instream to the event
1246 gdb_setup_readline (int editing)
1248 struct ui *ui = current_ui;
1250 /* This function is a noop for the sync case. The assumption is
1251 that the sync setup is ALL done in gdb_init, and we would only
1252 mess it up here. The sync stuff should really go away over
1255 gdb_stdout = stdio_fileopen (ui->outstream);
1256 gdb_stderr = stderr_fileopen (ui->errstream);
1257 gdb_stdlog = gdb_stderr; /* for moment */
1258 gdb_stdtarg = gdb_stderr; /* for moment */
1259 gdb_stdtargerr = gdb_stderr; /* for moment */
1261 /* If the input stream is connected to a terminal, turn on editing.
1262 However, that is only allowed on the main UI, as we can only have
1263 one instance of readline. */
1264 if (ISATTY (ui->instream) && editing && ui == main_ui)
1266 /* Tell gdb that we will be using the readline library. This
1267 could be overwritten by a command in .gdbinit like 'set
1268 editing on' or 'off'. */
1269 ui->command_editing = 1;
1271 /* When a character is detected on instream by select or poll,
1272 readline will be invoked via this callback function. */
1273 ui->call_readline = gdb_rl_callback_read_char_wrapper;
1275 /* Tell readline to use the same input stream that gdb uses. */
1276 rl_instream = ui->instream;
1280 ui->command_editing = 0;
1281 ui->call_readline = gdb_readline_no_editing_callback;
1284 /* Now create the event source for this UI's input file descriptor.
1285 Another source is going to be the target program (inferior), but
1286 that must be registered only when it actually exists (I.e. after
1287 we say 'run' or after we connect to a remote target. */
1288 add_file_handler (ui->input_fd, stdin_event_handler, ui);
1291 /* Disable command input through the standard CLI channels. Used in
1292 the suspend proc for interpreters that use the standard gdb readline
1293 interface, like the cli & the mi. */
1296 gdb_disable_readline (void)
1298 struct ui *ui = current_ui;
1300 /* FIXME - It is too heavyweight to delete and remake these every
1301 time you run an interpreter that needs readline. It is probably
1302 better to have the interpreters cache these, which in turn means
1303 that this needs to be moved into interpreter specific code. */
1306 ui_file_delete (gdb_stdout);
1307 ui_file_delete (gdb_stderr);
1310 gdb_stdtargerr = NULL;
1313 if (ui->command_editing)
1314 gdb_rl_callback_handler_remove ();
1315 delete_file_handler (ui->input_fd);