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 rl_callback_read_char_wrapper (gdb_client_data client_data);
52 static void command_line_handler (char *rl);
53 static void change_line_handler (void);
54 static char *top_level_prompt (void);
56 /* Signal handlers. */
58 static void handle_sigquit (int sig);
61 static void handle_sighup (int sig);
63 static void handle_sigfpe (int sig);
65 /* Functions to be invoked by the event loop in response to
67 #if defined (SIGQUIT) || defined (SIGHUP)
68 static void async_do_nothing (gdb_client_data);
71 static void async_disconnect (gdb_client_data);
73 static void async_float_handler (gdb_client_data);
75 static void async_stop_sig (gdb_client_data);
77 static void async_sigterm_handler (gdb_client_data arg);
79 /* Readline offers an alternate interface, via callback
80 functions. These are all included in the file callback.c in the
81 readline distribution. This file provides (mainly) a function, which
82 the event loop uses as callback (i.e. event handler) whenever an event
83 is detected on the standard input file descriptor.
84 readline_callback_read_char is called (by the GDB event loop) whenever
85 there is a new character ready on the input stream. This function
86 incrementally builds a buffer internal to readline where it
87 accumulates the line read up to the point of invocation. In the
88 special case in which the character read is newline, the function
89 invokes a GDB supplied callback routine, which does the processing of
90 a full command line. This latter routine is the asynchronous analog
91 of the old command_line_input in gdb. Instead of invoking (and waiting
92 for) readline to read the command line and pass it back to
93 command_loop for processing, the new command_line_handler function has
94 the command line already available as its parameter. INPUT_HANDLER is
95 to be set to the function that readline will invoke when a complete
96 line of input is ready. CALL_READLINE is to be set to the function
97 that readline offers as callback to the event_loop. */
99 void (*input_handler) (char *);
100 void (*call_readline) (gdb_client_data);
102 /* Important variables for the event loop. */
104 /* This is used to determine if GDB is using the readline library or
105 its own simplified form of readline. It is used by the asynchronous
106 form of the set editing command.
107 ezannoni: as of 1999-04-29 I expect that this
108 variable will not be used after gdb is changed to use the event
109 loop as default engine, and event-top.c is merged into top.c. */
110 int async_command_editing_p;
112 /* This is used to display the notification of the completion of an
113 asynchronous execution command. */
114 int exec_done_display_p = 0;
116 /* This is the file descriptor for the input stream that GDB uses to
117 read commands from. */
120 /* Used by the stdin event handler to compensate for missed stdin events.
121 Setting this to a non-zero value inside an stdin callback makes the callback
123 int call_stdin_event_handler_again_p;
125 /* Signal handling variables. */
126 /* Each of these is a pointer to a function that the event loop will
127 invoke if the corresponding signal has received. The real signal
128 handlers mark these functions as ready to be executed and the event
129 loop, in a later iteration, calls them. See the function
130 invoke_async_signal_handler. */
131 static struct async_signal_handler *sigint_token;
133 static struct async_signal_handler *sighup_token;
136 static struct async_signal_handler *sigquit_token;
138 static struct async_signal_handler *sigfpe_token;
140 static struct async_signal_handler *sigtstp_token;
142 static struct async_signal_handler *async_sigterm_token;
144 /* This hook is called by rl_callback_read_char_wrapper after each
145 character is processed. */
146 void (*after_char_processing_hook) (void);
149 /* Wrapper function for calling into the readline library. The event
150 loop expects the callback function to have a paramter, while
151 readline expects none. */
153 rl_callback_read_char_wrapper (gdb_client_data client_data)
155 rl_callback_read_char ();
156 if (after_char_processing_hook)
157 (*after_char_processing_hook) ();
160 /* Initialize all the necessary variables, start the event loop,
161 register readline, and stdin, start the loop. The DATA is the
162 interpreter data cookie, ignored for now. */
165 cli_command_loop (void *data)
167 display_gdb_prompt (0);
169 /* Now it's time to start the event loop. */
173 /* Change the function to be invoked every time there is a character
174 ready on stdin. This is used when the user sets the editing off,
175 therefore bypassing readline, and letting gdb handle the input
176 itself, via gdb_readline_no_editing_callback. Also it is used in
177 the opposite case in which the user sets editing on again, by
178 restoring readline handling of the input. */
180 change_line_handler (void)
182 /* NOTE: this operates on input_fd, not instream. If we are reading
183 commands from a file, instream will point to the file. However in
184 async mode, we always read commands from a file with editing
185 off. This means that the 'set editing on/off' will have effect
186 only on the interactive session. */
188 if (async_command_editing_p)
190 /* Turn on editing by using readline. */
191 call_readline = rl_callback_read_char_wrapper;
192 input_handler = command_line_handler;
196 /* Turn off editing by using gdb_readline_no_editing_callback. */
197 gdb_rl_callback_handler_remove ();
198 call_readline = gdb_readline_no_editing_callback;
200 /* Set up the command handler as well, in case we are called as
201 first thing from .gdbinit. */
202 input_handler = command_line_handler;
206 /* The functions below are wrappers for rl_callback_handler_remove and
207 rl_callback_handler_install that keep track of whether the callback
208 handler is installed in readline. This is necessary because after
209 handling a target event of a background execution command, we may
210 need to reinstall the callback handler if it was removed due to a
211 secondary prompt. See gdb_readline_wrapper_line. We don't
212 unconditionally install the handler for every target event because
213 that also clears the line buffer, thus installing it while the user
214 is typing would lose input. */
216 /* Whether we've registered a callback handler with readline. */
217 static int callback_handler_installed;
219 /* See event-top.h, and above. */
222 gdb_rl_callback_handler_remove (void)
224 rl_callback_handler_remove ();
225 callback_handler_installed = 0;
228 /* See event-top.h, and above. Note this wrapper doesn't have an
229 actual callback parameter because we always install
233 gdb_rl_callback_handler_install (const char *prompt)
235 /* Calling rl_callback_handler_install resets readline's input
236 buffer. Calling this when we were already processing input
237 therefore loses input. */
238 gdb_assert (!callback_handler_installed);
240 rl_callback_handler_install (prompt, input_handler);
241 callback_handler_installed = 1;
244 /* See event-top.h, and above. */
247 gdb_rl_callback_handler_reinstall (void)
249 if (!callback_handler_installed)
251 /* Passing NULL as prompt argument tells readline to not display
253 gdb_rl_callback_handler_install (NULL);
257 /* Displays the prompt. If the argument NEW_PROMPT is NULL, the
258 prompt that is displayed is the current top level prompt.
259 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
262 This is used after each gdb command has completed, and in the
265 1. When the user enters a command line which is ended by '\'
266 indicating that the command will continue on the next line. In
267 that case the prompt that is displayed is the empty string.
269 2. When the user is entering 'commands' for a breakpoint, or
270 actions for a tracepoint. In this case the prompt will be '>'
272 3. On prompting for pagination. */
275 display_gdb_prompt (const char *new_prompt)
277 char *actual_gdb_prompt = NULL;
278 struct cleanup *old_chain;
280 annotate_display_prompt ();
282 /* Reset the nesting depth used when trace-commands is set. */
283 reset_command_nest_depth ();
285 old_chain = make_cleanup (free_current_contents, &actual_gdb_prompt);
287 /* Do not call the python hook on an explicit prompt change as
288 passed to this function, as this forms a secondary/local prompt,
289 IE, displayed but not set. */
294 /* This is to trick readline into not trying to display the
295 prompt. Even though we display the prompt using this
296 function, readline still tries to do its own display if
297 we don't call rl_callback_handler_install and
298 rl_callback_handler_remove (which readline detects
299 because a global variable is not set). If readline did
300 that, it could mess up gdb signal handlers for SIGINT.
301 Readline assumes that between calls to rl_set_signals and
302 rl_clear_signals gdb doesn't do anything with the signal
303 handlers. Well, that's not the case, because when the
304 target executes we change the SIGINT signal handler. If
305 we allowed readline to display the prompt, the signal
306 handler change would happen exactly between the calls to
307 the above two functions. Calling
308 rl_callback_handler_remove(), does the job. */
310 gdb_rl_callback_handler_remove ();
311 do_cleanups (old_chain);
316 /* Display the top level prompt. */
317 actual_gdb_prompt = top_level_prompt ();
321 actual_gdb_prompt = xstrdup (new_prompt);
323 if (async_command_editing_p)
325 gdb_rl_callback_handler_remove ();
326 gdb_rl_callback_handler_install (actual_gdb_prompt);
328 /* new_prompt at this point can be the top of the stack or the one
329 passed in. It can't be NULL. */
332 /* Don't use a _filtered function here. It causes the assumed
333 character position to be off, since the newline we read from
334 the user is not accounted for. */
335 fputs_unfiltered (actual_gdb_prompt, gdb_stdout);
336 gdb_flush (gdb_stdout);
339 do_cleanups (old_chain);
342 /* Return the top level prompt, as specified by "set prompt", possibly
343 overriden by the python gdb.prompt_hook hook, and then composed
344 with the prompt prefix and suffix (annotations). The caller is
345 responsible for freeing the returned string. */
348 top_level_prompt (void)
352 /* Give observers a chance of changing the prompt. E.g., the python
353 `gdb.prompt_hook' is installed as an observer. */
354 observer_notify_before_prompt (get_prompt ());
356 prompt = get_prompt ();
358 if (annotation_level >= 2)
360 /* Prefix needs to have new line at end. */
361 const char prefix[] = "\n\032\032pre-prompt\n";
363 /* Suffix needs to have a new line at end and \032 \032 at
365 const char suffix[] = "\n\032\032prompt\n";
367 return concat (prefix, prompt, suffix, NULL);
370 return xstrdup (prompt);
373 /* Get a pointer to the command line buffer. This is used to
374 construct a whole line of input from partial input. */
376 static struct buffer *
377 get_command_line_buffer (void)
379 static struct buffer line_buffer;
380 static int line_buffer_initialized;
382 if (!line_buffer_initialized)
384 buffer_init (&line_buffer);
385 line_buffer_initialized = 1;
391 /* When there is an event ready on the stdin file descriptor, instead
392 of calling readline directly throught the callback function, or
393 instead of calling gdb_readline_no_editing_callback, give gdb a
394 chance to detect errors and do something. */
397 stdin_event_handler (int error, gdb_client_data client_data)
401 printf_unfiltered (_("error detected on stdin\n"));
402 delete_file_handler (input_fd);
403 /* If stdin died, we may as well kill gdb. */
404 quit_command ((char *) 0, stdin == instream);
408 /* This makes sure a ^C immediately followed by further input is
409 always processed in that order. E.g,. with input like
410 "^Cprint 1\n", the SIGINT handler runs, marks the async signal
411 handler, and then select/poll may return with stdin ready,
412 instead of -1/EINTR. The
413 gdb.base/double-prompt-target-event-error.exp test exercises
419 call_stdin_event_handler_again_p = 0;
420 (*call_readline) (client_data);
421 } while (call_stdin_event_handler_again_p != 0);
425 /* Re-enable stdin after the end of an execution command in
426 synchronous mode, or after an error from the target, and we aborted
427 the exec operation. */
430 async_enable_stdin (void)
434 /* See NOTE in async_disable_stdin(). */
435 /* FIXME: cagney/1999-09-27: Call this before clearing
436 sync_execution. Current target_terminal_ours() implementations
437 check for sync_execution before switching the terminal. */
438 target_terminal_ours ();
443 /* Disable reads from stdin (the console) marking the command as
447 async_disable_stdin (void)
453 /* Handle a gdb command line. This function is called when
454 handle_line_of_input has concatenated one or more input lines into
458 command_handler (char *command)
460 struct cleanup *stat_chain;
464 if (instream == stdin)
465 reinitialize_more_filter ();
467 stat_chain = make_command_stats_cleanup (1);
469 /* Do not execute commented lines. */
470 for (c = command; *c == ' ' || *c == '\t'; c++)
474 execute_command (command, instream == stdin);
476 /* Do any commands attached to breakpoint we stopped at. */
477 bpstat_do_actions ();
480 do_cleanups (stat_chain);
483 /* Append RL, an input line returned by readline or one of its
484 emulations, to CMD_LINE_BUFFER. Returns the command line if we
485 have a whole command line ready to be processed by the command
486 interpreter or NULL if the command line isn't complete yet (input
487 line ends in a backslash). Takes ownership of RL. */
490 command_line_append_input_line (struct buffer *cmd_line_buffer, char *rl)
497 if (len > 0 && rl[len - 1] == '\\')
499 /* Don't copy the backslash and wait for more. */
500 buffer_grow (cmd_line_buffer, rl, len - 1);
505 /* Copy whole line including terminating null, and we're
507 buffer_grow (cmd_line_buffer, rl, len + 1);
508 cmd = cmd_line_buffer->buffer;
511 /* Allocated in readline. */
517 /* Handle a line of input coming from readline.
519 If the read line ends with a continuation character (backslash),
520 save the partial input in CMD_LINE_BUFFER (except the backslash),
521 and return NULL. Otherwise, save the partial input and return a
522 pointer to CMD_LINE_BUFFER's buffer (null terminated), indicating a
523 whole command line is ready to be executed.
525 Returns EOF on end of file.
527 If REPEAT, handle command repetitions:
529 - If the input command line is NOT empty, the command returned is
530 copied into the global 'saved_command_line' var so that it can
533 - OTOH, if the input command line IS empty, return the previously
534 saved command instead of the empty input line.
538 handle_line_of_input (struct buffer *cmd_line_buffer,
539 char *rl, int repeat, char *annotation_suffix)
547 cmd = command_line_append_input_line (cmd_line_buffer, rl);
551 /* We have a complete command line now. Prepare for the next
552 command, but leave ownership of memory to the buffer . */
553 cmd_line_buffer->used_size = 0;
555 if (annotation_level > 1 && instream == stdin)
557 printf_unfiltered (("\n\032\032post-"));
558 puts_unfiltered (annotation_suffix);
559 printf_unfiltered (("\n"));
562 #define SERVER_COMMAND_PREFIX "server "
563 if (startswith (cmd, SERVER_COMMAND_PREFIX))
565 /* Note that we don't set `saved_command_line'. Between this
566 and the check in dont_repeat, this insures that repeating
567 will still do the right thing. */
568 return cmd + strlen (SERVER_COMMAND_PREFIX);
571 /* Do history expansion if that is wished. */
572 if (history_expansion_p && instream == stdin
573 && ISATTY (instream))
578 expanded = history_expand (cmd, &history_value);
583 /* Print the changes. */
584 printf_unfiltered ("%s\n", history_value);
586 /* If there was an error, call this function again. */
589 xfree (history_value);
593 /* history_expand returns an allocated string. Just replace
594 our buffer with it. */
595 len = strlen (history_value);
596 xfree (buffer_finish (cmd_line_buffer));
597 cmd_line_buffer->buffer = history_value;
598 cmd_line_buffer->buffer_size = len + 1;
603 /* If we just got an empty line, and that is supposed to repeat the
604 previous command, return the previously saved command. */
605 for (p1 = cmd; *p1 == ' ' || *p1 == '\t'; p1++)
607 if (repeat && *p1 == '\0')
608 return saved_command_line;
610 /* Add command to history if appropriate. Note: lines consisting
611 solely of comments are also added to the command history. This
612 is useful when you type a command, and then realize you don't
613 want to execute it quite yet. You can comment out the command
614 and then later fetch it from the value history and remove the
615 '#'. The kill ring is probably better, but some people are in
616 the habit of commenting things out. */
617 if (*cmd != '\0' && input_from_terminal_p ())
618 gdb_add_history (cmd);
620 /* Save into global buffer if appropriate. */
623 xfree (saved_command_line);
624 saved_command_line = xstrdup (cmd);
625 return saved_command_line;
631 /* Handle a complete line of input. This is called by the callback
632 mechanism within the readline library. Deal with incomplete
633 commands as well, by saving the partial input in a global
636 NOTE: This is the asynchronous version of the command_line_input
640 command_line_handler (char *rl)
642 struct buffer *line_buffer = get_command_line_buffer ();
645 cmd = handle_line_of_input (line_buffer, rl, instream == stdin, "prompt");
646 if (cmd == (char *) EOF)
648 /* stdin closed. The connection with the terminal is gone.
649 This happens at the end of a testsuite run, after Expect has
650 hung up but GDB is still alive. In such a case, we just quit
651 gdb killing the inferior program too. */
652 printf_unfiltered ("quit\n");
653 execute_command ("quit", stdin == instream);
655 else if (cmd == NULL)
657 /* We don't have a full line yet. Print an empty prompt. */
658 display_gdb_prompt ("");
662 command_handler (cmd);
663 display_gdb_prompt (0);
667 /* Does reading of input from terminal w/o the editing features
668 provided by the readline library. Calls the line input handler
669 once we have a whole input line. */
672 gdb_readline_no_editing_callback (gdb_client_data client_data)
676 struct buffer line_buffer;
677 static int done_once = 0;
679 buffer_init (&line_buffer);
681 /* Unbuffer the input stream, so that, later on, the calls to fgetc
682 fetch only one char at the time from the stream. The fgetc's will
683 get up to the first newline, but there may be more chars in the
684 stream after '\n'. If we buffer the input and fgetc drains the
685 stream, getting stuff beyond the newline as well, a select, done
686 afterwards will not trigger. */
687 if (!done_once && !ISATTY (instream))
689 setbuf (instream, NULL);
693 /* We still need the while loop here, even though it would seem
694 obvious to invoke gdb_readline_no_editing_callback at every
695 character entered. If not using the readline library, the
696 terminal is in cooked mode, which sends the characters all at
697 once. Poll will notice that the input fd has changed state only
698 after enter is pressed. At this point we still need to fetch all
699 the chars entered. */
703 /* Read from stdin if we are executing a user defined command.
704 This is the right thing for prompt_for_continue, at least. */
705 c = fgetc (instream ? instream : stdin);
709 if (line_buffer.used_size > 0)
711 /* The last line does not end with a newline. Return it, and
712 if we are called again fgetc will still return EOF and
713 we'll return NULL then. */
716 xfree (buffer_finish (&line_buffer));
717 (*input_handler) (0);
723 if (line_buffer.used_size > 0
724 && line_buffer.buffer[line_buffer.used_size - 1] == '\r')
725 line_buffer.used_size--;
729 buffer_grow_char (&line_buffer, c);
732 buffer_grow_char (&line_buffer, '\0');
733 result = buffer_finish (&line_buffer);
734 (*input_handler) (result);
738 /* The serial event associated with the QUIT flag. set_quit_flag sets
739 this, and check_quit_flag clears it. Used by interruptible_select
740 to be able to do interruptible I/O with no race with the SIGINT
742 static struct serial_event *quit_serial_event;
744 /* Initialization of signal handlers and tokens. There is a function
745 handle_sig* for each of the signals GDB cares about. Specifically:
746 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
747 functions are the actual signal handlers associated to the signals
748 via calls to signal(). The only job for these functions is to
749 enqueue the appropriate event/procedure with the event loop. Such
750 procedures are the old signal handlers. The event loop will take
751 care of invoking the queued procedures to perform the usual tasks
752 associated with the reception of the signal. */
753 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
754 init_signals will become obsolete as we move to have to event loop
755 as the default for gdb. */
757 async_init_signals (void)
759 initialize_async_signal_handlers ();
761 quit_serial_event = make_serial_event ();
763 signal (SIGINT, handle_sigint);
765 create_async_signal_handler (async_request_quit, NULL);
766 signal (SIGTERM, handle_sigterm);
768 = create_async_signal_handler (async_sigterm_handler, NULL);
770 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
771 to the inferior and breakpoints will be ignored. */
773 signal (SIGTRAP, SIG_DFL);
777 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
778 passed to the inferior, which we don't want. It would be
779 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
780 on BSD4.3 systems using vfork, that can affect the
781 GDB process as well as the inferior (the signal handling tables
782 might be in memory, shared between the two). Since we establish
783 a handler for SIGQUIT, when we call exec it will set the signal
784 to SIG_DFL for us. */
785 signal (SIGQUIT, handle_sigquit);
787 create_async_signal_handler (async_do_nothing, NULL);
790 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
792 create_async_signal_handler (async_disconnect, NULL);
795 create_async_signal_handler (async_do_nothing, NULL);
797 signal (SIGFPE, handle_sigfpe);
799 create_async_signal_handler (async_float_handler, NULL);
803 create_async_signal_handler (async_stop_sig, NULL);
810 quit_serial_event_set (void)
812 serial_event_set (quit_serial_event);
818 quit_serial_event_clear (void)
820 serial_event_clear (quit_serial_event);
823 /* Return the selectable file descriptor of the serial event
824 associated with the quit flag. */
827 quit_serial_event_fd (void)
829 return serial_event_fd (quit_serial_event);
832 /* Handle a SIGINT. */
835 handle_sigint (int sig)
837 signal (sig, handle_sigint);
839 /* We could be running in a loop reading in symfiles or something so
840 it may be quite a while before we get back to the event loop. So
841 set quit_flag to 1 here. Then if QUIT is called before we get to
842 the event loop, we will unwind as expected. */
846 /* If immediate_quit is set, we go ahead and process the SIGINT right
847 away, even if we usually would defer this to the event loop. The
848 assumption here is that it is safe to process ^C immediately if
849 immediate_quit is set. If we didn't, SIGINT would be really
850 processed only the next time through the event loop. To get to
851 that point, though, the command that we want to interrupt needs to
852 finish first, which is unacceptable. If immediate quit is not set,
853 we process SIGINT the next time through the loop, which is fine. */
854 gdb_call_async_signal_handler (sigint_token, immediate_quit);
857 /* See gdb_select.h. */
860 interruptible_select (int n,
861 fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
862 struct timeval *timeout)
870 readfds = &my_readfds;
871 FD_ZERO (&my_readfds);
874 fd = quit_serial_event_fd ();
875 FD_SET (fd, readfds);
881 res = gdb_select (n, readfds, writefds, exceptfds, timeout);
883 while (res == -1 && errno == EINTR);
885 if (res == 1 && FD_ISSET (fd, readfds))
893 /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
896 async_sigterm_handler (gdb_client_data arg)
898 quit_force (NULL, stdin == instream);
902 volatile int sync_quit_force_run;
904 /* Quit GDB if SIGTERM is received.
905 GDB would quit anyway, but this way it will clean up properly. */
907 handle_sigterm (int sig)
909 signal (sig, handle_sigterm);
911 sync_quit_force_run = 1;
914 mark_async_signal_handler (async_sigterm_token);
917 /* Do the quit. All the checks have been done by the caller. */
919 async_request_quit (gdb_client_data arg)
921 /* If the quit_flag has gotten reset back to 0 by the time we get
922 back here, that means that an exception was thrown to unwind the
923 current command before we got back to the event loop. So there
924 is no reason to call quit again here. */
926 if (check_quit_flag ())
931 /* Tell the event loop what to do if SIGQUIT is received.
932 See event-signal.c. */
934 handle_sigquit (int sig)
936 mark_async_signal_handler (sigquit_token);
937 signal (sig, handle_sigquit);
941 #if defined (SIGQUIT) || defined (SIGHUP)
942 /* Called by the event loop in response to a SIGQUIT or an
945 async_do_nothing (gdb_client_data arg)
947 /* Empty function body. */
952 /* Tell the event loop what to do if SIGHUP is received.
953 See event-signal.c. */
955 handle_sighup (int sig)
957 mark_async_signal_handler (sighup_token);
958 signal (sig, handle_sighup);
961 /* Called by the event loop to process a SIGHUP. */
963 async_disconnect (gdb_client_data arg)
971 CATCH (exception, RETURN_MASK_ALL)
973 fputs_filtered ("Could not kill the program being debugged",
975 exception_print (gdb_stderr, exception);
983 CATCH (exception, RETURN_MASK_ALL)
988 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
995 handle_stop_sig (int sig)
997 mark_async_signal_handler (sigtstp_token);
998 signal (sig, handle_stop_sig);
1002 async_stop_sig (gdb_client_data arg)
1004 char *prompt = get_prompt ();
1006 #if STOP_SIGNAL == SIGTSTP
1007 signal (SIGTSTP, SIG_DFL);
1008 #if HAVE_SIGPROCMASK
1012 sigemptyset (&zero);
1013 sigprocmask (SIG_SETMASK, &zero, 0);
1015 #elif HAVE_SIGSETMASK
1019 signal (SIGTSTP, handle_stop_sig);
1021 signal (STOP_SIGNAL, handle_stop_sig);
1023 printf_unfiltered ("%s", prompt);
1024 gdb_flush (gdb_stdout);
1026 /* Forget about any previous command -- null line now will do
1030 #endif /* STOP_SIGNAL */
1032 /* Tell the event loop what to do if SIGFPE is received.
1033 See event-signal.c. */
1035 handle_sigfpe (int sig)
1037 mark_async_signal_handler (sigfpe_token);
1038 signal (sig, handle_sigfpe);
1041 /* Event loop will call this functin to process a SIGFPE. */
1043 async_float_handler (gdb_client_data arg)
1045 /* This message is based on ANSI C, section 4.7. Note that integer
1046 divide by zero causes this, so "float" is a misnomer. */
1047 error (_("Erroneous arithmetic operation."));
1051 /* Called by do_setshow_command. */
1053 set_async_editing_command (char *args, int from_tty,
1054 struct cmd_list_element *c)
1056 change_line_handler ();
1059 /* Set things up for readline to be invoked via the alternate
1060 interface, i.e. via a callback function (rl_callback_read_char),
1061 and hook up instream to the event loop. */
1063 gdb_setup_readline (void)
1065 /* This function is a noop for the sync case. The assumption is
1066 that the sync setup is ALL done in gdb_init, and we would only
1067 mess it up here. The sync stuff should really go away over
1070 gdb_stdout = stdio_fileopen (stdout);
1071 gdb_stderr = stderr_fileopen ();
1072 gdb_stdlog = gdb_stderr; /* for moment */
1073 gdb_stdtarg = gdb_stderr; /* for moment */
1074 gdb_stdtargerr = gdb_stderr; /* for moment */
1076 /* If the input stream is connected to a terminal, turn on
1078 if (ISATTY (instream))
1080 /* Tell gdb that we will be using the readline library. This
1081 could be overwritten by a command in .gdbinit like 'set
1082 editing on' or 'off'. */
1083 async_command_editing_p = 1;
1085 /* When a character is detected on instream by select or poll,
1086 readline will be invoked via this callback function. */
1087 call_readline = rl_callback_read_char_wrapper;
1091 async_command_editing_p = 0;
1092 call_readline = gdb_readline_no_editing_callback;
1095 /* When readline has read an end-of-line character, it passes the
1096 complete line to gdb for processing; command_line_handler is the
1097 function that does this. */
1098 input_handler = command_line_handler;
1100 /* Tell readline to use the same input stream that gdb uses. */
1101 rl_instream = instream;
1103 /* Get a file descriptor for the input stream, so that we can
1104 register it with the event loop. */
1105 input_fd = fileno (instream);
1107 /* Now we need to create the event sources for the input file
1109 /* At this point in time, this is the only event source that we
1110 register with the even loop. Another source is going to be the
1111 target program (inferior), but that must be registered only when
1112 it actually exists (I.e. after we say 'run' or after we connect
1113 to a remote target. */
1114 add_file_handler (input_fd, stdin_event_handler, 0);
1117 /* Disable command input through the standard CLI channels. Used in
1118 the suspend proc for interpreters that use the standard gdb readline
1119 interface, like the cli & the mi. */
1121 gdb_disable_readline (void)
1123 /* FIXME - It is too heavyweight to delete and remake these every
1124 time you run an interpreter that needs readline. It is probably
1125 better to have the interpreters cache these, which in turn means
1126 that this needs to be moved into interpreter specific code. */
1129 ui_file_delete (gdb_stdout);
1130 ui_file_delete (gdb_stderr);
1133 gdb_stdtargerr = NULL;
1136 gdb_rl_callback_handler_remove ();
1137 delete_file_handler (input_fd);