1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
3 Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free
5 Software Foundation, Inc.
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 2 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, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 #include "exceptions.h"
26 #include "breakpoint.h"
31 #include "gdb_assert.h"
32 #include "gdb_string.h"
35 const struct gdb_exception exception_none
= { 0, NO_ERROR
, NULL
};
37 /* Possible catcher states. */
39 /* Initial state, a new catcher has just been created. */
41 /* The catch code is running. */
44 /* The catch code threw an exception. */
48 /* Possible catcher actions. */
57 enum catcher_state state
;
58 /* Jump buffer pointing back at the exception handler. */
59 EXCEPTIONS_SIGJMP_BUF buf
;
60 /* Status buffer belonging to the exception handler. */
61 volatile struct gdb_exception
*exception
;
62 /* Saved/current state. */
64 struct ui_out
*saved_uiout
;
65 struct cleanup
*saved_cleanup_chain
;
70 /* Where to go for throw_exception(). */
71 static struct catcher
*current_catcher
;
73 EXCEPTIONS_SIGJMP_BUF
*
74 exceptions_state_mc_init (struct ui_out
*func_uiout
,
75 volatile struct gdb_exception
*exception
,
78 struct catcher
*new_catcher
= XZALLOC (struct catcher
);
80 /* Start with no exception, save it's address. */
81 exception
->reason
= 0;
82 exception
->error
= NO_ERROR
;
83 exception
->message
= NULL
;
84 new_catcher
->exception
= exception
;
86 new_catcher
->mask
= mask
;
88 /* Override the global ``struct ui_out'' builder. */
89 new_catcher
->saved_uiout
= uiout
;
92 /* Prevent error/quit during FUNC from calling cleanups established
94 new_catcher
->saved_cleanup_chain
= save_cleanups ();
96 /* Push this new catcher on the top. */
97 new_catcher
->prev
= current_catcher
;
98 current_catcher
= new_catcher
;
99 new_catcher
->state
= CATCHER_CREATED
;
101 return &new_catcher
->buf
;
107 struct catcher
*old_catcher
= current_catcher
;
108 current_catcher
= old_catcher
->prev
;
110 /* Restore the cleanup chain, the error/quit messages, and the uiout
111 builder, to their original states. */
113 restore_cleanups (old_catcher
->saved_cleanup_chain
);
115 uiout
= old_catcher
->saved_uiout
;
120 /* Catcher state machine. Returns non-zero if the m/c should be run
121 again, zero if it should abort. */
124 exceptions_state_mc (enum catcher_action action
)
126 switch (current_catcher
->state
)
128 case CATCHER_CREATED
:
132 /* Allow the code to run the catcher. */
133 current_catcher
->state
= CATCHER_RUNNING
;
136 internal_error (__FILE__
, __LINE__
, _("bad state"));
138 case CATCHER_RUNNING
:
142 /* No error/quit has occured. Just clean up. */
146 current_catcher
->state
= CATCHER_RUNNING_1
;
149 current_catcher
->state
= CATCHER_ABORTING
;
150 /* See also throw_exception. */
153 internal_error (__FILE__
, __LINE__
, _("bad switch"));
155 case CATCHER_RUNNING_1
:
159 /* The did a "break" from the inner while loop. */
163 current_catcher
->state
= CATCHER_RUNNING
;
166 current_catcher
->state
= CATCHER_ABORTING
;
167 /* See also throw_exception. */
170 internal_error (__FILE__
, __LINE__
, _("bad switch"));
172 case CATCHER_ABORTING
:
177 struct gdb_exception exception
= *current_catcher
->exception
;
178 if (current_catcher
->mask
& RETURN_MASK (exception
.reason
))
180 /* Exit normally if this catcher can handle this
181 exception. The caller analyses the func return
186 /* The caller didn't request that the event be caught,
187 relay the event to the next containing
190 throw_exception (exception
);
193 internal_error (__FILE__
, __LINE__
, _("bad state"));
196 internal_error (__FILE__
, __LINE__
, _("bad switch"));
201 exceptions_state_mc_action_iter (void)
203 return exceptions_state_mc (CATCH_ITER
);
207 exceptions_state_mc_action_iter_1 (void)
209 return exceptions_state_mc (CATCH_ITER_1
);
212 /* Return EXCEPTION to the nearest containing catch_errors(). */
215 throw_exception (struct gdb_exception exception
)
220 /* Perhaps it would be cleaner to do this via the cleanup chain (not sure
221 I can think of a reason why that is vital, though). */
222 bpstat_clear_actions (stop_bpstat
); /* Clear queued breakpoint commands */
224 disable_current_display ();
225 do_cleanups (ALL_CLEANUPS
);
226 if (target_can_async_p () && !target_executing
)
227 do_exec_cleanups (ALL_CLEANUPS
);
229 do_exec_error_cleanups (ALL_CLEANUPS
);
231 /* Jump to the containing catch_errors() call, communicating REASON
232 to that call via setjmp's return value. Note that REASON can't
233 be zero, by definition in defs.h. */
234 exceptions_state_mc (CATCH_THROWING
);
235 *current_catcher
->exception
= exception
;
236 EXCEPTIONS_SIGLONGJMP (current_catcher
->buf
, exception
.reason
);
239 static char *last_message
;
242 deprecated_throw_reason (enum return_reason reason
)
244 struct gdb_exception exception
;
245 memset (&exception
, 0, sizeof exception
);
247 exception
.reason
= reason
;
253 exception
.error
= GENERIC_ERROR
;
256 internal_error (__FILE__
, __LINE__
, _("bad switch"));
259 throw_exception (exception
);
265 struct serial
*gdb_stdout_serial
;
267 if (deprecated_error_begin_hook
)
268 deprecated_error_begin_hook ();
269 target_terminal_ours ();
271 /* We want all output to appear now, before we print the error. We
272 have 3 levels of buffering we have to flush (it's possible that
273 some of these should be changed to flush the lower-level ones
276 /* 1. The _filtered buffer. */
279 /* 2. The stdio buffer. */
280 gdb_flush (gdb_stdout
);
281 gdb_flush (gdb_stderr
);
283 /* 3. The system-level buffer. */
284 gdb_stdout_serial
= serial_fdopen (1);
285 if (gdb_stdout_serial
)
287 serial_drain_output (gdb_stdout_serial
);
288 serial_un_fdopen (gdb_stdout_serial
);
291 annotate_error_begin ();
295 print_exception (struct ui_file
*file
, struct gdb_exception e
)
297 /* KLUGE: cagney/2005-01-13: Write the string out one line at a time
298 as that way the MI's behavior is preserved. */
301 for (start
= e
.message
; start
!= NULL
; start
= end
)
303 end
= strchr (start
, '\n');
305 fputs_filtered (start
, file
);
309 ui_file_write (file
, start
, end
- start
);
312 fprintf_filtered (file
, "\n");
314 /* Now append the annotation. */
321 /* Assume that these are all errors. */
325 internal_error (__FILE__
, __LINE__
, _("Bad switch."));
330 exception_print (struct ui_file
*file
, struct gdb_exception e
)
332 if (e
.reason
< 0 && e
.message
!= NULL
)
335 print_exception (file
, e
);
340 exception_fprintf (struct ui_file
*file
, struct gdb_exception e
,
341 const char *prefix
, ...)
343 if (e
.reason
< 0 && e
.message
!= NULL
)
349 /* Print the prefix. */
350 va_start (args
, prefix
);
351 vfprintf_filtered (file
, prefix
, args
);
354 print_exception (file
, e
);
359 print_any_exception (struct ui_file
*file
, const char *prefix
,
360 struct gdb_exception e
)
362 if (e
.reason
< 0 && e
.message
!= NULL
)
364 target_terminal_ours ();
365 wrap_here (""); /* Force out any buffered output */
366 gdb_flush (gdb_stdout
);
367 annotate_error_begin ();
369 /* Print the prefix. */
370 if (prefix
!= NULL
&& prefix
[0] != '\0')
371 fputs_filtered (prefix
, file
);
372 print_exception (file
, e
);
377 throw_it (enum return_reason reason
, enum errors error
, const char *fmt
,
378 va_list ap
) ATTR_NORETURN
;
380 throw_it (enum return_reason reason
, enum errors error
, const char *fmt
,
383 struct gdb_exception e
;
386 /* Save the message. Create the new message before deleting the
387 old, the new message may include the old message text. */
388 new_message
= xstrvprintf (fmt
, ap
);
389 xfree (last_message
);
390 last_message
= new_message
;
392 /* Create the exception. */
395 e
.message
= last_message
;
397 /* Throw the exception. */
402 throw_verror (enum errors error
, const char *fmt
, va_list ap
)
404 throw_it (RETURN_ERROR
, error
, fmt
, ap
);
408 throw_vfatal (const char *fmt
, va_list ap
)
410 throw_it (RETURN_QUIT
, NO_ERROR
, fmt
, ap
);
414 throw_error (enum errors error
, const char *fmt
, ...)
417 va_start (args
, fmt
);
418 throw_it (RETURN_ERROR
, error
, fmt
, args
);
422 /* Call FUNC() with args FUNC_UIOUT and FUNC_ARGS, catching any
423 errors. Set FUNC_CAUGHT to an ``enum return_reason'' if the
424 function is aborted (using throw_exception() or zero if the
425 function returns normally. Set FUNC_VAL to the value returned by
426 the function or 0 if the function was aborted.
428 Must not be called with immediate_quit in effect (bad things might
429 happen, say we got a signal in the middle of a memcpy to quit_return).
430 This is an OK restriction; with very few exceptions immediate_quit can
431 be replaced by judicious use of QUIT.
433 MASK specifies what to catch; it is normally set to
434 RETURN_MASK_ALL, if for no other reason than that the code which
435 calls catch_errors might not be set up to deal with a quit which
436 isn't caught. But if the code can deal with it, it generally
437 should be RETURN_MASK_ERROR, unless for some reason it is more
438 useful to abort only the portion of the operation inside the
439 catch_errors. Note that quit should return to the command line
440 fairly quickly, even if some further processing is being done. */
442 /* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with
443 error() et.al. could maintain a set of flags that indicate the the
444 current state of each of the longjmp buffers. This would give the
445 longjmp code the chance to detect a longjmp botch (before it gets
446 to longjmperror()). Prior to 1999-11-05 this wasn't possible as
447 code also randomly used a SET_TOP_LEVEL macro that directly
448 initialize the longjmp buffers. */
450 /* MAYBE: cagney/1999-11-05: Should the catch_errors and cleanups code
451 be consolidated into a single file instead of being distributed
452 between utils.c and top.c? */
455 catch_exceptions (struct ui_out
*uiout
,
456 catch_exceptions_ftype
*func
,
460 return catch_exceptions_with_msg (uiout
, func
, func_args
, NULL
, mask
);
464 catch_exception (struct ui_out
*uiout
,
465 catch_exception_ftype
*func
,
469 volatile struct gdb_exception exception
;
470 TRY_CATCH (exception
, mask
)
472 (*func
) (uiout
, func_args
);
478 catch_exceptions_with_msg (struct ui_out
*uiout
,
479 catch_exceptions_ftype
*func
,
484 volatile struct gdb_exception exception
;
485 volatile int val
= 0;
486 TRY_CATCH (exception
, mask
)
488 val
= (*func
) (uiout
, func_args
);
490 print_any_exception (gdb_stderr
, NULL
, exception
);
491 gdb_assert (val
>= 0);
492 gdb_assert (exception
.reason
<= 0);
493 if (exception
.reason
< 0)
495 /* If caller wants a copy of the low-level error message, make
496 one. This is used in the case of a silent error whereby the
497 caller may optionally want to issue the message. */
498 if (gdberrmsg
!= NULL
)
500 if (exception
.message
!= NULL
)
501 *gdberrmsg
= xstrdup (exception
.message
);
505 return exception
.reason
;
511 catch_errors (catch_errors_ftype
*func
, void *func_args
, char *errstring
,
514 volatile int val
= 0;
515 volatile struct gdb_exception exception
;
516 TRY_CATCH (exception
, mask
)
518 val
= func (func_args
);
520 print_any_exception (gdb_stderr
, errstring
, exception
);
521 if (exception
.reason
!= 0)
527 catch_command_errors (catch_command_errors_ftype
* command
,
528 char *arg
, int from_tty
, return_mask mask
)
530 volatile struct gdb_exception e
;
533 command (arg
, from_tty
);
535 print_any_exception (gdb_stderr
, NULL
, e
);