1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
3 Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
5 2009, 2010, 2011 Free 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 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/>. */
23 #include "exceptions.h"
24 #include "breakpoint.h"
29 #include "gdb_assert.h"
30 #include "gdb_string.h"
32 #include "gdbthread.h"
34 const struct gdb_exception exception_none
= { 0, GDB_NO_ERROR
, NULL
};
36 /* Possible catcher states. */
38 /* Initial state, a new catcher has just been created. */
40 /* The catch code is running. */
43 /* The catch code threw an exception. */
47 /* Possible catcher actions. */
56 enum catcher_state state
;
57 /* Jump buffer pointing back at the exception handler. */
58 EXCEPTIONS_SIGJMP_BUF buf
;
59 /* Status buffer belonging to the exception handler. */
60 volatile struct gdb_exception
*exception
;
61 /* Saved/current state. */
63 struct cleanup
*saved_cleanup_chain
;
68 /* Where to go for throw_exception(). */
69 static struct catcher
*current_catcher
;
71 EXCEPTIONS_SIGJMP_BUF
*
72 exceptions_state_mc_init (volatile struct gdb_exception
*exception
,
75 struct catcher
*new_catcher
= XZALLOC (struct catcher
);
77 /* Start with no exception, save it's address. */
78 exception
->reason
= 0;
79 exception
->error
= GDB_NO_ERROR
;
80 exception
->message
= NULL
;
81 new_catcher
->exception
= exception
;
83 new_catcher
->mask
= mask
;
85 /* Prevent error/quit during FUNC from calling cleanups established
87 new_catcher
->saved_cleanup_chain
= save_cleanups ();
89 /* Push this new catcher on the top. */
90 new_catcher
->prev
= current_catcher
;
91 current_catcher
= new_catcher
;
92 new_catcher
->state
= CATCHER_CREATED
;
94 return &new_catcher
->buf
;
100 struct catcher
*old_catcher
= current_catcher
;
102 current_catcher
= old_catcher
->prev
;
104 /* Restore the cleanup chain, the error/quit messages, and the uiout
105 builder, to their original states. */
107 restore_cleanups (old_catcher
->saved_cleanup_chain
);
112 /* Catcher state machine. Returns non-zero if the m/c should be run
113 again, zero if it should abort. */
116 exceptions_state_mc (enum catcher_action action
)
118 switch (current_catcher
->state
)
120 case CATCHER_CREATED
:
124 /* Allow the code to run the catcher. */
125 current_catcher
->state
= CATCHER_RUNNING
;
128 internal_error (__FILE__
, __LINE__
, _("bad state"));
130 case CATCHER_RUNNING
:
134 /* No error/quit has occured. Just clean up. */
138 current_catcher
->state
= CATCHER_RUNNING_1
;
141 current_catcher
->state
= CATCHER_ABORTING
;
142 /* See also throw_exception. */
145 internal_error (__FILE__
, __LINE__
, _("bad switch"));
147 case CATCHER_RUNNING_1
:
151 /* The did a "break" from the inner while loop. */
155 current_catcher
->state
= CATCHER_RUNNING
;
158 current_catcher
->state
= CATCHER_ABORTING
;
159 /* See also throw_exception. */
162 internal_error (__FILE__
, __LINE__
, _("bad switch"));
164 case CATCHER_ABORTING
:
169 struct gdb_exception exception
= *current_catcher
->exception
;
171 if (current_catcher
->mask
& RETURN_MASK (exception
.reason
))
173 /* Exit normally if this catcher can handle this
174 exception. The caller analyses the func return
179 /* The caller didn't request that the event be caught,
180 relay the event to the next containing
183 throw_exception (exception
);
186 internal_error (__FILE__
, __LINE__
, _("bad state"));
189 internal_error (__FILE__
, __LINE__
, _("bad switch"));
194 exceptions_state_mc_action_iter (void)
196 return exceptions_state_mc (CATCH_ITER
);
200 exceptions_state_mc_action_iter_1 (void)
202 return exceptions_state_mc (CATCH_ITER_1
);
205 /* Return EXCEPTION to the nearest containing catch_errors(). */
208 throw_exception (struct gdb_exception exception
)
210 struct thread_info
*tp
= NULL
;
215 if (!ptid_equal (inferior_ptid
, null_ptid
))
216 tp
= find_thread_ptid (inferior_ptid
);
218 /* Perhaps it would be cleaner to do this via the cleanup chain (not sure
219 I can think of a reason why that is vital, though). */
222 /* Clear queued breakpoint commands. */
223 bpstat_clear_actions (tp
->control
.stop_bpstat
);
226 do_cleanups (ALL_CLEANUPS
);
228 /* Jump to the containing catch_errors() call, communicating REASON
229 to that call via setjmp's return value. Note that REASON can't
230 be zero, by definition in defs.h. */
231 exceptions_state_mc (CATCH_THROWING
);
232 *current_catcher
->exception
= exception
;
233 EXCEPTIONS_SIGLONGJMP (current_catcher
->buf
, exception
.reason
);
236 static char *last_message
;
239 deprecated_throw_reason (enum return_reason reason
)
241 struct gdb_exception exception
;
243 memset (&exception
, 0, sizeof exception
);
245 exception
.reason
= reason
;
251 exception
.error
= GENERIC_ERROR
;
254 internal_error (__FILE__
, __LINE__
, _("bad switch"));
257 throw_exception (exception
);
263 struct serial
*gdb_stdout_serial
;
265 if (deprecated_error_begin_hook
)
266 deprecated_error_begin_hook ();
267 target_terminal_ours ();
269 /* We want all output to appear now, before we print the error. We
270 have 3 levels of buffering we have to flush (it's possible that
271 some of these should be changed to flush the lower-level ones
274 /* 1. The _filtered buffer. */
277 /* 2. The stdio buffer. */
278 gdb_flush (gdb_stdout
);
279 gdb_flush (gdb_stderr
);
281 /* 3. The system-level buffer. */
282 gdb_stdout_serial
= serial_fdopen (1);
283 if (gdb_stdout_serial
)
285 serial_drain_output (gdb_stdout_serial
);
286 serial_un_fdopen (gdb_stdout_serial
);
289 annotate_error_begin ();
293 print_exception (struct ui_file
*file
, struct gdb_exception e
)
295 /* KLUGE: cagney/2005-01-13: Write the string out one line at a time
296 as that way the MI's behavior is preserved. */
300 for (start
= e
.message
; start
!= NULL
; start
= end
)
302 end
= strchr (start
, '\n');
304 fputs_filtered (start
, file
);
308 ui_file_write (file
, start
, end
- start
);
311 fprintf_filtered (file
, "\n");
313 /* Now append the annotation. */
320 /* Assume that these are all errors. */
324 internal_error (__FILE__
, __LINE__
, _("Bad switch."));
329 exception_print (struct ui_file
*file
, struct gdb_exception e
)
331 if (e
.reason
< 0 && e
.message
!= NULL
)
334 print_exception (file
, e
);
339 exception_fprintf (struct ui_file
*file
, struct gdb_exception e
,
340 const char *prefix
, ...)
342 if (e
.reason
< 0 && e
.message
!= NULL
)
348 /* Print the prefix. */
349 va_start (args
, prefix
);
350 vfprintf_filtered (file
, prefix
, args
);
353 print_exception (file
, e
);
358 print_any_exception (struct ui_file
*file
, const char *prefix
,
359 struct gdb_exception e
)
361 if (e
.reason
< 0 && e
.message
!= NULL
)
363 target_terminal_ours ();
364 wrap_here (""); /* Force out any buffered output. */
365 gdb_flush (gdb_stdout
);
366 annotate_error_begin ();
368 /* Print the prefix. */
369 if (prefix
!= NULL
&& prefix
[0] != '\0')
370 fputs_filtered (prefix
, file
);
371 print_exception (file
, e
);
375 static void ATTRIBUTE_NORETURN
ATTRIBUTE_PRINTF (3, 0)
376 throw_it (enum return_reason reason
, enum errors error
, const char *fmt
,
379 struct gdb_exception e
;
382 /* Save the message. Create the new message before deleting the
383 old, the new message may include the old message text. */
384 new_message
= xstrvprintf (fmt
, ap
);
385 xfree (last_message
);
386 last_message
= new_message
;
388 /* Create the exception. */
391 e
.message
= last_message
;
393 /* Throw the exception. */
398 throw_verror (enum errors error
, const char *fmt
, va_list ap
)
400 throw_it (RETURN_ERROR
, error
, fmt
, ap
);
404 throw_vfatal (const char *fmt
, va_list ap
)
406 throw_it (RETURN_QUIT
, GDB_NO_ERROR
, fmt
, ap
);
410 throw_error (enum errors error
, const char *fmt
, ...)
414 va_start (args
, fmt
);
415 throw_it (RETURN_ERROR
, error
, fmt
, args
);
419 /* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
420 handler. If an exception (enum return_reason) is thrown using
421 throw_exception() than all cleanups installed since
422 catch_exceptions() was entered are invoked, the (-ve) exception
423 value is then returned by catch_exceptions. If FUNC() returns
424 normally (with a positive or zero return value) then that value is
425 returned by catch_exceptions(). It is an internal_error() for
426 FUNC() to return a negative value.
428 See exceptions.h for further usage details.
430 Must not be called with immediate_quit in effect (bad things might
431 happen, say we got a signal in the middle of a memcpy to quit_return).
432 This is an OK restriction; with very few exceptions immediate_quit can
433 be replaced by judicious use of QUIT. */
435 /* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with
436 error() et al. could maintain a set of flags that indicate the
437 current state of each of the longjmp buffers. This would give the
438 longjmp code the chance to detect a longjmp botch (before it gets
439 to longjmperror()). Prior to 1999-11-05 this wasn't possible as
440 code also randomly used a SET_TOP_LEVEL macro that directly
441 initialized the longjmp buffers. */
444 catch_exceptions (struct ui_out
*uiout
,
445 catch_exceptions_ftype
*func
,
449 return catch_exceptions_with_msg (uiout
, func
, func_args
, NULL
, mask
);
453 catch_exceptions_with_msg (struct ui_out
*func_uiout
,
454 catch_exceptions_ftype
*func
,
459 volatile struct gdb_exception exception
;
460 volatile int val
= 0;
461 struct ui_out
*saved_uiout
;
463 /* Save and override the global ``struct ui_out'' builder. */
464 saved_uiout
= current_uiout
;
465 current_uiout
= func_uiout
;
467 TRY_CATCH (exception
, RETURN_MASK_ALL
)
469 val
= (*func
) (current_uiout
, func_args
);
472 /* Restore the global builder. */
473 current_uiout
= saved_uiout
;
475 if (exception
.reason
< 0 && (mask
& RETURN_MASK (exception
.reason
)) == 0)
477 /* The caller didn't request that the event be caught.
479 throw_exception (exception
);
482 print_any_exception (gdb_stderr
, NULL
, exception
);
483 gdb_assert (val
>= 0);
484 gdb_assert (exception
.reason
<= 0);
485 if (exception
.reason
< 0)
487 /* If caller wants a copy of the low-level error message, make
488 one. This is used in the case of a silent error whereby the
489 caller may optionally want to issue the message. */
490 if (gdberrmsg
!= NULL
)
492 if (exception
.message
!= NULL
)
493 *gdberrmsg
= xstrdup (exception
.message
);
497 return exception
.reason
;
502 /* This function is superseded by catch_exceptions(). */
505 catch_errors (catch_errors_ftype
*func
, void *func_args
, char *errstring
,
508 volatile int val
= 0;
509 volatile struct gdb_exception exception
;
510 struct ui_out
*saved_uiout
;
512 /* Save the global ``struct ui_out'' builder. */
513 saved_uiout
= current_uiout
;
515 TRY_CATCH (exception
, RETURN_MASK_ALL
)
517 val
= func (func_args
);
520 /* Restore the global builder. */
521 current_uiout
= saved_uiout
;
523 if (exception
.reason
< 0 && (mask
& RETURN_MASK (exception
.reason
)) == 0)
525 /* The caller didn't request that the event be caught.
527 throw_exception (exception
);
530 print_any_exception (gdb_stderr
, errstring
, exception
);
531 if (exception
.reason
!= 0)
537 catch_command_errors (catch_command_errors_ftype
* command
,
538 char *arg
, int from_tty
, return_mask mask
)
540 volatile struct gdb_exception e
;
544 command (arg
, from_tty
);
546 print_any_exception (gdb_stderr
, NULL
, e
);