1 /* Top level stuff for GDB, the GNU debugger.
3 Copyright (C) 1999-2013 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/>. */
26 #include "terminal.h" /* for job_control */
27 #include "event-loop.h"
28 #include "event-top.h"
31 #include "exceptions.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() */
40 /* readline include files. */
41 #include "readline/readline.h"
42 #include "readline/history.h"
44 /* readline defines this. */
47 static void rl_callback_read_char_wrapper (gdb_client_data client_data
);
48 static void command_line_handler (char *rl
);
49 static void change_line_handler (void);
50 static void command_handler (char *command
);
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
);
75 /* Readline offers an alternate interface, via callback
76 functions. These are all included in the file callback.c in the
77 readline distribution. This file provides (mainly) a function, which
78 the event loop uses as callback (i.e. event handler) whenever an event
79 is detected on the standard input file descriptor.
80 readline_callback_read_char is called (by the GDB event loop) whenever
81 there is a new character ready on the input stream. This function
82 incrementally builds a buffer internal to readline where it
83 accumulates the line read up to the point of invocation. In the
84 special case in which the character read is newline, the function
85 invokes a GDB supplied callback routine, which does the processing of
86 a full command line. This latter routine is the asynchronous analog
87 of the old command_line_input in gdb. Instead of invoking (and waiting
88 for) readline to read the command line and pass it back to
89 command_loop for processing, the new command_line_handler function has
90 the command line already available as its parameter. INPUT_HANDLER is
91 to be set to the function that readline will invoke when a complete
92 line of input is ready. CALL_READLINE is to be set to the function
93 that readline offers as callback to the event_loop. */
95 void (*input_handler
) (char *);
96 void (*call_readline
) (gdb_client_data
);
98 /* Important variables for the event loop. */
100 /* This is used to determine if GDB is using the readline library or
101 its own simplified form of readline. It is used by the asynchronous
102 form of the set editing command.
103 ezannoni: as of 1999-04-29 I expect that this
104 variable will not be used after gdb is changed to use the event
105 loop as default engine, and event-top.c is merged into top.c. */
106 int async_command_editing_p
;
108 /* This is the annotation suffix that will be used when the
109 annotation_level is 2. */
110 char *async_annotation_suffix
;
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 /* Signal handling variables. */
121 /* Each of these is a pointer to a function that the event loop will
122 invoke if the corresponding signal has received. The real signal
123 handlers mark these functions as ready to be executed and the event
124 loop, in a later iteration, calls them. See the function
125 invoke_async_signal_handler. */
126 static struct async_signal_handler
*sigint_token
;
128 static struct async_signal_handler
*sighup_token
;
131 static struct async_signal_handler
*sigquit_token
;
133 static struct async_signal_handler
*sigfpe_token
;
135 static struct async_signal_handler
*sigtstp_token
;
138 /* Structure to save a partially entered command. This is used when
139 the user types '\' at the end of a command line. This is necessary
140 because each line of input is handled by a different call to
141 command_line_handler, and normally there is no state retained
142 between different calls. */
143 static int more_to_come
= 0;
145 struct readline_input_state
148 char *linebuffer_ptr
;
150 readline_input_state
;
152 /* This hook is called by rl_callback_read_char_wrapper after each
153 character is processed. */
154 void (*after_char_processing_hook
) (void);
157 /* Wrapper function for calling into the readline library. The event
158 loop expects the callback function to have a paramter, while
159 readline expects none. */
161 rl_callback_read_char_wrapper (gdb_client_data client_data
)
163 rl_callback_read_char ();
164 if (after_char_processing_hook
)
165 (*after_char_processing_hook
) ();
168 /* Initialize all the necessary variables, start the event loop,
169 register readline, and stdin, start the loop. */
171 cli_command_loop (void)
173 display_gdb_prompt (0);
175 /* Now it's time to start the event loop. */
179 /* Change the function to be invoked every time there is a character
180 ready on stdin. This is used when the user sets the editing off,
181 therefore bypassing readline, and letting gdb handle the input
182 itself, via gdb_readline2. Also it is used in the opposite case in
183 which the user sets editing on again, by restoring readline
184 handling of the input. */
186 change_line_handler (void)
188 /* NOTE: this operates on input_fd, not instream. If we are reading
189 commands from a file, instream will point to the file. However in
190 async mode, we always read commands from a file with editing
191 off. This means that the 'set editing on/off' will have effect
192 only on the interactive session. */
194 if (async_command_editing_p
)
196 /* Turn on editing by using readline. */
197 call_readline
= rl_callback_read_char_wrapper
;
198 input_handler
= command_line_handler
;
202 /* Turn off editing by using gdb_readline2. */
203 rl_callback_handler_remove ();
204 call_readline
= gdb_readline2
;
206 /* Set up the command handler as well, in case we are called as
207 first thing from .gdbinit. */
208 input_handler
= command_line_handler
;
212 /* Displays the prompt. If the argument NEW_PROMPT is NULL, the
213 prompt that is displayed is the current top level prompt.
214 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary
217 This is used after each gdb command has completed, and in the
220 1. When the user enters a command line which is ended by '\'
221 indicating that the command will continue on the next line. In
222 that case the prompt that is displayed is the empty string.
224 2. When the user is entering 'commands' for a breakpoint, or
225 actions for a tracepoint. In this case the prompt will be '>'
227 3. On prompting for pagination. */
230 display_gdb_prompt (char *new_prompt
)
232 char *actual_gdb_prompt
= NULL
;
233 struct cleanup
*old_chain
;
235 annotate_display_prompt ();
237 /* Reset the nesting depth used when trace-commands is set. */
238 reset_command_nest_depth ();
240 /* Each interpreter has its own rules on displaying the command
242 if (!current_interp_display_prompt_p ())
245 old_chain
= make_cleanup (free_current_contents
, &actual_gdb_prompt
);
247 /* Do not call the python hook on an explicit prompt change as
248 passed to this function, as this forms a secondary/local prompt,
249 IE, displayed but not set. */
254 /* This is to trick readline into not trying to display the
255 prompt. Even though we display the prompt using this
256 function, readline still tries to do its own display if
257 we don't call rl_callback_handler_install and
258 rl_callback_handler_remove (which readline detects
259 because a global variable is not set). If readline did
260 that, it could mess up gdb signal handlers for SIGINT.
261 Readline assumes that between calls to rl_set_signals and
262 rl_clear_signals gdb doesn't do anything with the signal
263 handlers. Well, that's not the case, because when the
264 target executes we change the SIGINT signal handler. If
265 we allowed readline to display the prompt, the signal
266 handler change would happen exactly between the calls to
267 the above two functions. Calling
268 rl_callback_handler_remove(), does the job. */
270 rl_callback_handler_remove ();
275 /* Display the top level prompt. */
276 actual_gdb_prompt
= top_level_prompt ();
280 actual_gdb_prompt
= xstrdup (new_prompt
);
282 if (async_command_editing_p
)
284 rl_callback_handler_remove ();
285 rl_callback_handler_install (actual_gdb_prompt
, input_handler
);
287 /* new_prompt at this point can be the top of the stack or the one
288 passed in. It can't be NULL. */
291 /* Don't use a _filtered function here. It causes the assumed
292 character position to be off, since the newline we read from
293 the user is not accounted for. */
294 fputs_unfiltered (actual_gdb_prompt
, gdb_stdout
);
295 gdb_flush (gdb_stdout
);
298 do_cleanups (old_chain
);
301 /* Return the top level prompt, as specified by "set prompt", possibly
302 overriden by the python gdb.prompt_hook hook, and then composed
303 with the prompt prefix and suffix (annotations). The caller is
304 responsible for freeing the returned string. */
307 top_level_prompt (void)
312 char *composed_prompt
;
313 size_t prompt_length
;
315 /* Give observers a chance of changing the prompt. E.g., the python
316 `gdb.prompt_hook' is installed as an observer. */
317 observer_notify_before_prompt (get_prompt ());
319 prompt
= xstrdup (get_prompt ());
321 if (annotation_level
>= 2)
323 /* Prefix needs to have new line at end. */
324 prefix
= (char *) alloca (strlen (async_annotation_suffix
) + 10);
325 strcpy (prefix
, "\n\032\032pre-");
326 strcat (prefix
, async_annotation_suffix
);
327 strcat (prefix
, "\n");
329 /* Suffix needs to have a new line at end and \032 \032 at
331 suffix
= (char *) alloca (strlen (async_annotation_suffix
) + 6);
332 strcpy (suffix
, "\n\032\032");
333 strcat (suffix
, async_annotation_suffix
);
334 strcat (suffix
, "\n");
342 prompt_length
= strlen (prefix
) + strlen (prompt
) + strlen (suffix
);
343 composed_prompt
= xmalloc (prompt_length
+ 1);
345 strcpy (composed_prompt
, prefix
);
346 strcat (composed_prompt
, prompt
);
347 strcat (composed_prompt
, suffix
);
351 return composed_prompt
;
354 /* When there is an event ready on the stdin file desriptor, instead
355 of calling readline directly throught the callback function, or
356 instead of calling gdb_readline2, give gdb a chance to detect
357 errors and do something. */
359 stdin_event_handler (int error
, gdb_client_data client_data
)
363 printf_unfiltered (_("error detected on stdin\n"));
364 delete_file_handler (input_fd
);
365 discard_all_continuations ();
366 discard_all_intermediate_continuations ();
367 /* If stdin died, we may as well kill gdb. */
368 quit_command ((char *) 0, stdin
== instream
);
371 (*call_readline
) (client_data
);
374 /* Re-enable stdin after the end of an execution command in
375 synchronous mode, or after an error from the target, and we aborted
376 the exec operation. */
379 async_enable_stdin (void)
383 /* See NOTE in async_disable_stdin(). */
384 /* FIXME: cagney/1999-09-27: Call this before clearing
385 sync_execution. Current target_terminal_ours() implementations
386 check for sync_execution before switching the terminal. */
387 target_terminal_ours ();
392 /* Disable reads from stdin (the console) marking the command as
396 async_disable_stdin (void)
402 /* Handles a gdb command. This function is called by
403 command_line_handler, which has processed one or more input lines
405 /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop
406 function. The command_loop function will be obsolete when we
407 switch to use the event loop at every execution of gdb. */
409 command_handler (char *command
)
411 int stdin_is_tty
= ISATTY (stdin
);
412 struct cleanup
*stat_chain
;
415 if (instream
== stdin
&& stdin_is_tty
)
416 reinitialize_more_filter ();
418 /* If readline returned a NULL command, it means that the connection
419 with the terminal is gone. This happens at the end of a
420 testsuite run, after Expect has hung up but GDB is still alive.
421 In such a case, we just quit gdb killing the inferior program
425 printf_unfiltered ("quit\n");
426 execute_command ("quit", stdin
== instream
);
429 stat_chain
= make_command_stats_cleanup (1);
431 execute_command (command
, instream
== stdin
);
433 /* Do any commands attached to breakpoint we stopped at. */
434 bpstat_do_actions ();
436 do_cleanups (stat_chain
);
439 /* Handle a complete line of input. This is called by the callback
440 mechanism within the readline library. Deal with incomplete
441 commands as well, by saving the partial input in a global
444 /* NOTE: 1999-04-30 This is the asynchronous version of the
445 command_line_input function; command_line_input will become
446 obsolete once we use the event loop as the default mechanism in
449 command_line_handler (char *rl
)
451 static char *linebuffer
= 0;
452 static unsigned linelength
= 0;
458 int repeat
= (instream
== stdin
);
460 if (annotation_level
> 1 && instream
== stdin
)
462 printf_unfiltered (("\n\032\032post-"));
463 puts_unfiltered (async_annotation_suffix
);
464 printf_unfiltered (("\n"));
470 linebuffer
= (char *) xmalloc (linelength
);
477 strcpy (linebuffer
, readline_input_state
.linebuffer
);
478 p
= readline_input_state
.linebuffer_ptr
;
479 xfree (readline_input_state
.linebuffer
);
485 signal (STOP_SIGNAL
, handle_stop_sig
);
488 /* Make sure that all output has been output. Some machines may let
489 you get away with leaving out some of the gdb_flush, but not
492 gdb_flush (gdb_stdout
);
493 gdb_flush (gdb_stderr
);
495 if (source_file_name
!= NULL
)
496 ++source_line_number
;
498 /* If we are in this case, then command_handler will call quit
499 and exit from gdb. */
500 if (!rl
|| rl
== (char *) EOF
)
506 if (strlen (rl
) + 1 + (p
- linebuffer
) > linelength
)
508 linelength
= strlen (rl
) + 1 + (p
- linebuffer
);
509 nline
= (char *) xrealloc (linebuffer
, linelength
);
510 p
+= nline
- linebuffer
;
514 /* Copy line. Don't copy null at end. (Leaves line alone
515 if this was just a newline). */
519 xfree (rl
); /* Allocated in readline. */
521 if (p
> linebuffer
&& *(p
- 1) == '\\')
524 p
--; /* Put on top of '\'. */
526 readline_input_state
.linebuffer
= xstrdup (linebuffer
);
527 readline_input_state
.linebuffer_ptr
= p
;
529 /* We will not invoke a execute_command if there is more
530 input expected to complete the command. So, we need to
531 print an empty prompt here. */
533 display_gdb_prompt ("");
539 signal (STOP_SIGNAL
, SIG_DFL
);
542 #define SERVER_COMMAND_LENGTH 7
544 (p
- linebuffer
> SERVER_COMMAND_LENGTH
)
545 && strncmp (linebuffer
, "server ", SERVER_COMMAND_LENGTH
) == 0;
548 /* Note that we don't set `line'. Between this and the check in
549 dont_repeat, this insures that repeating will still do the
552 command_handler (linebuffer
+ SERVER_COMMAND_LENGTH
);
553 display_gdb_prompt (0);
557 /* Do history expansion if that is wished. */
558 if (history_expansion_p
&& instream
== stdin
559 && ISATTY (instream
))
564 *p
= '\0'; /* Insert null now. */
565 expanded
= history_expand (linebuffer
, &history_value
);
568 /* Print the changes. */
569 printf_unfiltered ("%s\n", history_value
);
571 /* If there was an error, call this function again. */
574 xfree (history_value
);
577 if (strlen (history_value
) > linelength
)
579 linelength
= strlen (history_value
) + 1;
580 linebuffer
= (char *) xrealloc (linebuffer
, linelength
);
582 strcpy (linebuffer
, history_value
);
583 p
= linebuffer
+ strlen (linebuffer
);
585 xfree (history_value
);
588 /* If we just got an empty line, and that is supposed to repeat the
589 previous command, return the value in the global buffer. */
590 if (repeat
&& p
== linebuffer
&& *p
!= '\\')
592 command_handler (saved_command_line
);
593 display_gdb_prompt (0);
597 for (p1
= linebuffer
; *p1
== ' ' || *p1
== '\t'; p1
++);
600 command_handler (saved_command_line
);
601 display_gdb_prompt (0);
607 /* Add line to history if appropriate. */
608 if (instream
== stdin
609 && ISATTY (stdin
) && *linebuffer
)
610 add_history (linebuffer
);
612 /* Note: lines consisting solely of comments are added to the command
613 history. This is useful when you type a command, and then
614 realize you don't want to execute it quite yet. You can comment
615 out the command and then later fetch it from the value history
616 and remove the '#'. The kill ring is probably better, but some
617 people are in the habit of commenting things out. */
619 *p1
= '\0'; /* Found a comment. */
621 /* Save into global buffer if appropriate. */
624 if (linelength
> saved_command_line_size
)
626 saved_command_line
= xrealloc (saved_command_line
, linelength
);
627 saved_command_line_size
= linelength
;
629 strcpy (saved_command_line
, linebuffer
);
632 command_handler (saved_command_line
);
633 display_gdb_prompt (0);
638 command_handler (linebuffer
);
639 display_gdb_prompt (0);
643 /* Does reading of input from terminal w/o the editing features
644 provided by the readline library. */
646 /* NOTE: 1999-04-30 Asynchronous version of gdb_readline; gdb_readline
647 will become obsolete when the event loop is made the default
648 execution for gdb. */
650 gdb_readline2 (gdb_client_data client_data
)
655 int result_size
= 80;
656 static int done_once
= 0;
658 /* Unbuffer the input stream, so that, later on, the calls to fgetc
659 fetch only one char at the time from the stream. The fgetc's will
660 get up to the first newline, but there may be more chars in the
661 stream after '\n'. If we buffer the input and fgetc drains the
662 stream, getting stuff beyond the newline as well, a select, done
663 afterwards will not trigger. */
664 if (!done_once
&& !ISATTY (instream
))
666 setbuf (instream
, NULL
);
670 result
= (char *) xmalloc (result_size
);
672 /* We still need the while loop here, even though it would seem
673 obvious to invoke gdb_readline2 at every character entered. If
674 not using the readline library, the terminal is in cooked mode,
675 which sends the characters all at once. Poll will notice that the
676 input fd has changed state only after enter is pressed. At this
677 point we still need to fetch all the chars entered. */
681 /* Read from stdin if we are executing a user defined command.
682 This is the right thing for prompt_for_continue, at least. */
683 c
= fgetc (instream
? instream
: stdin
);
688 /* The last line does not end with a newline. Return it,
689 and if we are called again fgetc will still return EOF
690 and we'll return NULL then. */
693 (*input_handler
) (0);
699 if (input_index
> 0 && result
[input_index
- 1] == '\r')
704 result
[input_index
++] = c
;
705 while (input_index
>= result_size
)
708 result
= (char *) xrealloc (result
, result_size
);
712 result
[input_index
++] = '\0';
713 (*input_handler
) (result
);
717 /* Initialization of signal handlers and tokens. There is a function
718 handle_sig* for each of the signals GDB cares about. Specifically:
719 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
720 functions are the actual signal handlers associated to the signals
721 via calls to signal(). The only job for these functions is to
722 enqueue the appropriate event/procedure with the event loop. Such
723 procedures are the old signal handlers. The event loop will take
724 care of invoking the queued procedures to perform the usual tasks
725 associated with the reception of the signal. */
726 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals.
727 init_signals will become obsolete as we move to have to event loop
728 as the default for gdb. */
730 async_init_signals (void)
732 signal (SIGINT
, handle_sigint
);
734 create_async_signal_handler (async_request_quit
, NULL
);
735 signal (SIGTERM
, handle_sigterm
);
737 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
738 to the inferior and breakpoints will be ignored. */
740 signal (SIGTRAP
, SIG_DFL
);
744 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
745 passed to the inferior, which we don't want. It would be
746 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
747 on BSD4.3 systems using vfork, that can affect the
748 GDB process as well as the inferior (the signal handling tables
749 might be in memory, shared between the two). Since we establish
750 a handler for SIGQUIT, when we call exec it will set the signal
751 to SIG_DFL for us. */
752 signal (SIGQUIT
, handle_sigquit
);
754 create_async_signal_handler (async_do_nothing
, NULL
);
757 if (signal (SIGHUP
, handle_sighup
) != SIG_IGN
)
759 create_async_signal_handler (async_disconnect
, NULL
);
762 create_async_signal_handler (async_do_nothing
, NULL
);
764 signal (SIGFPE
, handle_sigfpe
);
766 create_async_signal_handler (async_float_handler
, NULL
);
770 create_async_signal_handler (async_stop_sig
, NULL
);
775 /* Tell the event loop what to do if SIGINT is received.
776 See event-signal.c. */
778 handle_sigint (int sig
)
780 signal (sig
, handle_sigint
);
782 /* We could be running in a loop reading in symfiles or something so
783 it may be quite a while before we get back to the event loop. So
784 set quit_flag to 1 here. Then if QUIT is called before we get to
785 the event loop, we will unwind as expected. */
789 /* If immediate_quit is set, we go ahead and process the SIGINT right
790 away, even if we usually would defer this to the event loop. The
791 assumption here is that it is safe to process ^C immediately if
792 immediate_quit is set. If we didn't, SIGINT would be really
793 processed only the next time through the event loop. To get to
794 that point, though, the command that we want to interrupt needs to
795 finish first, which is unacceptable. If immediate quit is not set,
796 we process SIGINT the next time through the loop, which is fine. */
797 gdb_call_async_signal_handler (sigint_token
, immediate_quit
);
800 /* Quit GDB if SIGTERM is received.
801 GDB would quit anyway, but this way it will clean up properly. */
803 handle_sigterm (int sig
)
805 signal (sig
, handle_sigterm
);
806 quit_force ((char *) 0, stdin
== instream
);
809 /* Do the quit. All the checks have been done by the caller. */
811 async_request_quit (gdb_client_data arg
)
813 /* If the quit_flag has gotten reset back to 0 by the time we get
814 back here, that means that an exception was thrown to unwind the
815 current command before we got back to the event loop. So there
816 is no reason to call quit again here. */
818 if (check_quit_flag ())
823 /* Tell the event loop what to do if SIGQUIT is received.
824 See event-signal.c. */
826 handle_sigquit (int sig
)
828 mark_async_signal_handler (sigquit_token
);
829 signal (sig
, handle_sigquit
);
833 #if defined (SIGQUIT) || defined (SIGHUP)
834 /* Called by the event loop in response to a SIGQUIT or an
837 async_do_nothing (gdb_client_data arg
)
839 /* Empty function body. */
844 /* Tell the event loop what to do if SIGHUP is received.
845 See event-signal.c. */
847 handle_sighup (int sig
)
849 mark_async_signal_handler (sighup_token
);
850 signal (sig
, handle_sighup
);
853 /* Called by the event loop to process a SIGHUP. */
855 async_disconnect (gdb_client_data arg
)
857 volatile struct gdb_exception exception
;
859 TRY_CATCH (exception
, RETURN_MASK_ALL
)
864 if (exception
.reason
< 0)
866 fputs_filtered ("Could not kill the program being debugged",
868 exception_print (gdb_stderr
, exception
);
871 TRY_CATCH (exception
, RETURN_MASK_ALL
)
876 signal (SIGHUP
, SIG_DFL
); /*FIXME: ??????????? */
883 handle_stop_sig (int sig
)
885 mark_async_signal_handler (sigtstp_token
);
886 signal (sig
, handle_stop_sig
);
890 async_stop_sig (gdb_client_data arg
)
892 char *prompt
= get_prompt ();
894 #if STOP_SIGNAL == SIGTSTP
895 signal (SIGTSTP
, SIG_DFL
);
901 sigprocmask (SIG_SETMASK
, &zero
, 0);
903 #elif HAVE_SIGSETMASK
907 signal (SIGTSTP
, handle_stop_sig
);
909 signal (STOP_SIGNAL
, handle_stop_sig
);
911 printf_unfiltered ("%s", prompt
);
912 gdb_flush (gdb_stdout
);
914 /* Forget about any previous command -- null line now will do
918 #endif /* STOP_SIGNAL */
920 /* Tell the event loop what to do if SIGFPE is received.
921 See event-signal.c. */
923 handle_sigfpe (int sig
)
925 mark_async_signal_handler (sigfpe_token
);
926 signal (sig
, handle_sigfpe
);
929 /* Event loop will call this functin to process a SIGFPE. */
931 async_float_handler (gdb_client_data arg
)
933 /* This message is based on ANSI C, section 4.7. Note that integer
934 divide by zero causes this, so "float" is a misnomer. */
935 error (_("Erroneous arithmetic operation."));
939 /* Called by do_setshow_command. */
941 set_async_editing_command (char *args
, int from_tty
,
942 struct cmd_list_element
*c
)
944 change_line_handler ();
947 /* Set things up for readline to be invoked via the alternate
948 interface, i.e. via a callback function (rl_callback_read_char),
949 and hook up instream to the event loop. */
951 gdb_setup_readline (void)
953 /* This function is a noop for the sync case. The assumption is
954 that the sync setup is ALL done in gdb_init, and we would only
955 mess it up here. The sync stuff should really go away over
958 gdb_stdout
= stdio_fileopen (stdout
);
959 gdb_stderr
= stdio_fileopen (stderr
);
960 gdb_stdlog
= gdb_stderr
; /* for moment */
961 gdb_stdtarg
= gdb_stderr
; /* for moment */
962 gdb_stdtargerr
= gdb_stderr
; /* for moment */
964 /* If the input stream is connected to a terminal, turn on
966 if (ISATTY (instream
))
968 /* Tell gdb that we will be using the readline library. This
969 could be overwritten by a command in .gdbinit like 'set
970 editing on' or 'off'. */
971 async_command_editing_p
= 1;
973 /* When a character is detected on instream by select or poll,
974 readline will be invoked via this callback function. */
975 call_readline
= rl_callback_read_char_wrapper
;
979 async_command_editing_p
= 0;
980 call_readline
= gdb_readline2
;
983 /* When readline has read an end-of-line character, it passes the
984 complete line to gdb for processing; command_line_handler is the
985 function that does this. */
986 input_handler
= command_line_handler
;
988 /* Tell readline to use the same input stream that gdb uses. */
989 rl_instream
= instream
;
991 /* Get a file descriptor for the input stream, so that we can
992 register it with the event loop. */
993 input_fd
= fileno (instream
);
995 /* Now we need to create the event sources for the input file
997 /* At this point in time, this is the only event source that we
998 register with the even loop. Another source is going to be the
999 target program (inferior), but that must be registered only when
1000 it actually exists (I.e. after we say 'run' or after we connect
1001 to a remote target. */
1002 add_file_handler (input_fd
, stdin_event_handler
, 0);
1005 /* Disable command input through the standard CLI channels. Used in
1006 the suspend proc for interpreters that use the standard gdb readline
1007 interface, like the cli & the mi. */
1009 gdb_disable_readline (void)
1011 /* FIXME - It is too heavyweight to delete and remake these every
1012 time you run an interpreter that needs readline. It is probably
1013 better to have the interpreters cache these, which in turn means
1014 that this needs to be moved into interpreter specific code. */
1017 ui_file_delete (gdb_stdout
);
1018 ui_file_delete (gdb_stderr
);
1021 gdb_stdtargerr
= NULL
;
1024 rl_callback_handler_remove ();
1025 delete_file_handler (input_fd
);