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;
463 if (instream == stdin)
464 reinitialize_more_filter ();
466 stat_chain = make_command_stats_cleanup (1);
468 /* Do not execute commented lines. */
469 for (c = command; *c == ' ' || *c == '\t'; c++)
473 execute_command (command, instream == stdin);
475 /* Do any commands attached to breakpoint we stopped at. */
476 bpstat_do_actions ();
479 do_cleanups (stat_chain);
482 /* Append RL, an input line returned by readline or one of its
483 emulations, to CMD_LINE_BUFFER. Returns the command line if we
484 have a whole command line ready to be processed by the command
485 interpreter or NULL if the command line isn't complete yet (input
486 line ends in a backslash). Takes ownership of RL. */
489 command_line_append_input_line (struct buffer *cmd_line_buffer, char *rl)
496 if (len > 0 && rl[len - 1] == '\\')
498 /* Don't copy the backslash and wait for more. */
499 buffer_grow (cmd_line_buffer, rl, len - 1);
504 /* Copy whole line including terminating null, and we're
506 buffer_grow (cmd_line_buffer, rl, len + 1);
507 cmd = cmd_line_buffer->buffer;
510 /* Allocated in readline. */
516 /* Handle a line of input coming from readline.
518 If the read line ends with a continuation character (backslash),
519 save the partial input in CMD_LINE_BUFFER (except the backslash),
520 and return NULL. Otherwise, save the partial input and return a
521 pointer to CMD_LINE_BUFFER's buffer (null terminated), indicating a
522 whole command line is ready to be executed.
524 Returns EOF on end of file.
526 If REPEAT, handle command repetitions:
528 - If the input command line is NOT empty, the command returned is
529 copied into the global 'saved_command_line' var so that it can
532 - OTOH, if the input command line IS empty, return the previously
533 saved command instead of the empty input line.
537 handle_line_of_input (struct buffer *cmd_line_buffer,
538 char *rl, int repeat, char *annotation_suffix)
546 cmd = command_line_append_input_line (cmd_line_buffer, rl);
550 /* We have a complete command line now. Prepare for the next
551 command, but leave ownership of memory to the buffer . */
552 cmd_line_buffer->used_size = 0;
554 if (annotation_level > 1 && instream == stdin)
556 printf_unfiltered (("\n\032\032post-"));
557 puts_unfiltered (annotation_suffix);
558 printf_unfiltered (("\n"));
561 #define SERVER_COMMAND_PREFIX "server "
562 if (startswith (cmd, SERVER_COMMAND_PREFIX))
564 /* Note that we don't set `saved_command_line'. Between this
565 and the check in dont_repeat, this insures that repeating
566 will still do the right thing. */
567 return cmd + strlen (SERVER_COMMAND_PREFIX);
570 /* Do history expansion if that is wished. */
571 if (history_expansion_p && instream == stdin
572 && ISATTY (instream))
577 expanded = history_expand (cmd, &history_value);
582 /* Print the changes. */
583 printf_unfiltered ("%s\n", history_value);
585 /* If there was an error, call this function again. */
588 xfree (history_value);
592 /* history_expand returns an allocated string. Just replace
593 our buffer with it. */
594 len = strlen (history_value);
595 xfree (buffer_finish (cmd_line_buffer));
596 cmd_line_buffer->buffer = history_value;
597 cmd_line_buffer->buffer_size = len + 1;
602 /* If we just got an empty line, and that is supposed to repeat the
603 previous command, return the previously saved command. */
604 for (p1 = cmd; *p1 == ' ' || *p1 == '\t'; p1++)
606 if (repeat && *p1 == '\0')
607 return saved_command_line;
609 /* Add command to history if appropriate. Note: lines consisting
610 solely of comments are also added to the command history. This
611 is useful when you type a command, and then realize you don't
612 want to execute it quite yet. You can comment out the command
613 and then later fetch it from the value history and remove the
614 '#'. The kill ring is probably better, but some people are in
615 the habit of commenting things out. */
616 if (*cmd != '\0' && input_from_terminal_p ())
617 gdb_add_history (cmd);
619 /* Save into global buffer if appropriate. */
622 xfree (saved_command_line);
623 saved_command_line = xstrdup (cmd);
624 return saved_command_line;
630 /* Handle a complete line of input. This is called by the callback
631 mechanism within the readline library. Deal with incomplete
632 commands as well, by saving the partial input in a global
635 NOTE: This is the asynchronous version of the command_line_input
639 command_line_handler (char *rl)
641 struct buffer *line_buffer = get_command_line_buffer ();
644 cmd = handle_line_of_input (line_buffer, rl, instream == stdin, "prompt");
645 if (cmd == (char *) EOF)
647 /* stdin closed. The connection with the terminal is gone.
648 This happens at the end of a testsuite run, after Expect has
649 hung up but GDB is still alive. In such a case, we just quit
650 gdb killing the inferior program too. */
651 printf_unfiltered ("quit\n");
652 execute_command ("quit", stdin == instream);
654 else if (cmd == NULL)
656 /* We don't have a full line yet. Print an empty prompt. */
657 display_gdb_prompt ("");
661 command_handler (cmd);
662 display_gdb_prompt (0);
666 /* Does reading of input from terminal w/o the editing features
667 provided by the readline library. Calls the line input handler
668 once we have a whole input line. */
671 gdb_readline_no_editing_callback (gdb_client_data client_data)
675 struct buffer line_buffer;
676 static int done_once = 0;
678 buffer_init (&line_buffer);
680 /* Unbuffer the input stream, so that, later on, the calls to fgetc
681 fetch only one char at the time from the stream. The fgetc's will
682 get up to the first newline, but there may be more chars in the
683 stream after '\n'. If we buffer the input and fgetc drains the
684 stream, getting stuff beyond the newline as well, a select, done
685 afterwards will not trigger. */
686 if (!done_once && !ISATTY (instream))
688 setbuf (instream, NULL);
692 /* We still need the while loop here, even though it would seem
693 obvious to invoke gdb_readline_no_editing_callback at every
694 character entered. If not using the readline library, the
695 terminal is in cooked mode, which sends the characters all at
696 once. Poll will notice that the input fd has changed state only
697 after enter is pressed. At this point we still need to fetch all
698 the chars entered. */
702 /* Read from stdin if we are executing a user defined command.
703 This is the right thing for prompt_for_continue, at least. */
704 c = fgetc (instream ? instream : stdin);
708 if (line_buffer.used_size > 0)
710 /* The last line does not end with a newline. Return it, and
711 if we are called again fgetc will still return EOF and
712 we'll return NULL then. */
715 xfree (buffer_finish (&line_buffer));
716 (*input_handler) (0);
722 if (line_buffer.used_size > 0
723 && line_buffer.buffer[line_buffer.used_size - 1] == '\r')
724 line_buffer.used_size--;
728 buffer_grow_char (&line_buffer, c);
731 buffer_grow_char (&line_buffer, '\0');
732 result = buffer_finish (&line_buffer);
733 (*input_handler) (result);
737 /* The serial event associated with the QUIT flag. set_quit_flag sets
738 this, and check_quit_flag clears it. Used by interruptible_select
739 to be able to do interruptible I/O with no race with the SIGINT
741 static struct serial_event *quit_serial_event;
743 /* Initialization of signal handlers and tokens. There is a function
744 handle_sig* for each of the signals GDB cares about. Specifically:
745 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
746 functions are the actual signal handlers associated to the signals
747 via calls to signal(). The only job for these functions is to
748 enqueue the appropriate event/procedure with the event loop. Such
749 procedures are the old signal handlers. The event loop will take
750 care of invoking the queued procedures to perform the usual tasks
751 associated with the reception of the signal. */
752 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
753 init_signals will become obsolete as we move to have to event loop
754 as the default for gdb. */
756 async_init_signals (void)
758 initialize_async_signal_handlers ();
760 quit_serial_event = make_serial_event ();
762 signal (SIGINT, handle_sigint);
764 create_async_signal_handler (async_request_quit, NULL);
765 signal (SIGTERM, handle_sigterm);
767 = create_async_signal_handler (async_sigterm_handler, NULL);
769 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
770 to the inferior and breakpoints will be ignored. */
772 signal (SIGTRAP, SIG_DFL);
776 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
777 passed to the inferior, which we don't want. It would be
778 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
779 on BSD4.3 systems using vfork, that can affect the
780 GDB process as well as the inferior (the signal handling tables
781 might be in memory, shared between the two). Since we establish
782 a handler for SIGQUIT, when we call exec it will set the signal
783 to SIG_DFL for us. */
784 signal (SIGQUIT, handle_sigquit);
786 create_async_signal_handler (async_do_nothing, NULL);
789 if (signal (SIGHUP, handle_sighup) != SIG_IGN)
791 create_async_signal_handler (async_disconnect, NULL);
794 create_async_signal_handler (async_do_nothing, NULL);
796 signal (SIGFPE, handle_sigfpe);
798 create_async_signal_handler (async_float_handler, NULL);
802 create_async_signal_handler (async_stop_sig, NULL);
809 quit_serial_event_set (void)
811 serial_event_set (quit_serial_event);
817 quit_serial_event_clear (void)
819 serial_event_clear (quit_serial_event);
822 /* Return the selectable file descriptor of the serial event
823 associated with the quit flag. */
826 quit_serial_event_fd (void)
828 return serial_event_fd (quit_serial_event);
831 /* Handle a SIGINT. */
834 handle_sigint (int sig)
836 signal (sig, handle_sigint);
838 /* We could be running in a loop reading in symfiles or something so
839 it may be quite a while before we get back to the event loop. So
840 set quit_flag to 1 here. Then if QUIT is called before we get to
841 the event loop, we will unwind as expected. */
845 /* If immediate_quit is set, we go ahead and process the SIGINT right
846 away, even if we usually would defer this to the event loop. The
847 assumption here is that it is safe to process ^C immediately if
848 immediate_quit is set. If we didn't, SIGINT would be really
849 processed only the next time through the event loop. To get to
850 that point, though, the command that we want to interrupt needs to
851 finish first, which is unacceptable. If immediate quit is not set,
852 we process SIGINT the next time through the loop, which is fine. */
853 gdb_call_async_signal_handler (sigint_token, immediate_quit);
856 /* See gdb_select.h. */
859 interruptible_select (int n,
860 fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
861 struct timeval *timeout)
869 readfds = &my_readfds;
870 FD_ZERO (&my_readfds);
873 fd = quit_serial_event_fd ();
874 FD_SET (fd, readfds);
880 res = gdb_select (n, readfds, writefds, exceptfds, timeout);
882 while (res == -1 && errno == EINTR);
884 if (res == 1 && FD_ISSET (fd, readfds))
892 /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */
895 async_sigterm_handler (gdb_client_data arg)
897 quit_force (NULL, stdin == instream);
901 volatile int sync_quit_force_run;
903 /* Quit GDB if SIGTERM is received.
904 GDB would quit anyway, but this way it will clean up properly. */
906 handle_sigterm (int sig)
908 signal (sig, handle_sigterm);
910 sync_quit_force_run = 1;
913 mark_async_signal_handler (async_sigterm_token);
916 /* Do the quit. All the checks have been done by the caller. */
918 async_request_quit (gdb_client_data arg)
920 /* If the quit_flag has gotten reset back to 0 by the time we get
921 back here, that means that an exception was thrown to unwind the
922 current command before we got back to the event loop. So there
923 is no reason to call quit again here. */
925 if (check_quit_flag ())
930 /* Tell the event loop what to do if SIGQUIT is received.
931 See event-signal.c. */
933 handle_sigquit (int sig)
935 mark_async_signal_handler (sigquit_token);
936 signal (sig, handle_sigquit);
940 #if defined (SIGQUIT) || defined (SIGHUP)
941 /* Called by the event loop in response to a SIGQUIT or an
944 async_do_nothing (gdb_client_data arg)
946 /* Empty function body. */
951 /* Tell the event loop what to do if SIGHUP is received.
952 See event-signal.c. */
954 handle_sighup (int sig)
956 mark_async_signal_handler (sighup_token);
957 signal (sig, handle_sighup);
960 /* Called by the event loop to process a SIGHUP. */
962 async_disconnect (gdb_client_data arg)
970 CATCH (exception, RETURN_MASK_ALL)
972 fputs_filtered ("Could not kill the program being debugged",
974 exception_print (gdb_stderr, exception);
982 CATCH (exception, RETURN_MASK_ALL)
987 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
994 handle_stop_sig (int sig)
996 mark_async_signal_handler (sigtstp_token);
997 signal (sig, handle_stop_sig);
1001 async_stop_sig (gdb_client_data arg)
1003 char *prompt = get_prompt ();
1005 #if STOP_SIGNAL == SIGTSTP
1006 signal (SIGTSTP, SIG_DFL);
1007 #if HAVE_SIGPROCMASK
1011 sigemptyset (&zero);
1012 sigprocmask (SIG_SETMASK, &zero, 0);
1014 #elif HAVE_SIGSETMASK
1018 signal (SIGTSTP, handle_stop_sig);
1020 signal (STOP_SIGNAL, handle_stop_sig);
1022 printf_unfiltered ("%s", prompt);
1023 gdb_flush (gdb_stdout);
1025 /* Forget about any previous command -- null line now will do
1029 #endif /* STOP_SIGNAL */
1031 /* Tell the event loop what to do if SIGFPE is received.
1032 See event-signal.c. */
1034 handle_sigfpe (int sig)
1036 mark_async_signal_handler (sigfpe_token);
1037 signal (sig, handle_sigfpe);
1040 /* Event loop will call this functin to process a SIGFPE. */
1042 async_float_handler (gdb_client_data arg)
1044 /* This message is based on ANSI C, section 4.7. Note that integer
1045 divide by zero causes this, so "float" is a misnomer. */
1046 error (_("Erroneous arithmetic operation."));
1050 /* Called by do_setshow_command. */
1052 set_async_editing_command (char *args, int from_tty,
1053 struct cmd_list_element *c)
1055 change_line_handler ();
1058 /* Set things up for readline to be invoked via the alternate
1059 interface, i.e. via a callback function (rl_callback_read_char),
1060 and hook up instream to the event loop. */
1062 gdb_setup_readline (void)
1064 /* This function is a noop for the sync case. The assumption is
1065 that the sync setup is ALL done in gdb_init, and we would only
1066 mess it up here. The sync stuff should really go away over
1069 gdb_stdout = stdio_fileopen (stdout);
1070 gdb_stderr = stderr_fileopen ();
1071 gdb_stdlog = gdb_stderr; /* for moment */
1072 gdb_stdtarg = gdb_stderr; /* for moment */
1073 gdb_stdtargerr = gdb_stderr; /* for moment */
1075 /* If the input stream is connected to a terminal, turn on
1077 if (ISATTY (instream))
1079 /* Tell gdb that we will be using the readline library. This
1080 could be overwritten by a command in .gdbinit like 'set
1081 editing on' or 'off'. */
1082 async_command_editing_p = 1;
1084 /* When a character is detected on instream by select or poll,
1085 readline will be invoked via this callback function. */
1086 call_readline = rl_callback_read_char_wrapper;
1090 async_command_editing_p = 0;
1091 call_readline = gdb_readline_no_editing_callback;
1094 /* When readline has read an end-of-line character, it passes the
1095 complete line to gdb for processing; command_line_handler is the
1096 function that does this. */
1097 input_handler = command_line_handler;
1099 /* Tell readline to use the same input stream that gdb uses. */
1100 rl_instream = instream;
1102 /* Get a file descriptor for the input stream, so that we can
1103 register it with the event loop. */
1104 input_fd = fileno (instream);
1106 /* Now we need to create the event sources for the input file
1108 /* At this point in time, this is the only event source that we
1109 register with the even loop. Another source is going to be the
1110 target program (inferior), but that must be registered only when
1111 it actually exists (I.e. after we say 'run' or after we connect
1112 to a remote target. */
1113 add_file_handler (input_fd, stdin_event_handler, 0);
1116 /* Disable command input through the standard CLI channels. Used in
1117 the suspend proc for interpreters that use the standard gdb readline
1118 interface, like the cli & the mi. */
1120 gdb_disable_readline (void)
1122 /* FIXME - It is too heavyweight to delete and remake these every
1123 time you run an interpreter that needs readline. It is probably
1124 better to have the interpreters cache these, which in turn means
1125 that this needs to be moved into interpreter specific code. */
1128 ui_file_delete (gdb_stdout);
1129 ui_file_delete (gdb_stderr);
1132 gdb_stdtargerr = NULL;
1135 gdb_rl_callback_handler_remove ();
1136 delete_file_handler (input_fd);