17612d7adafe5d49de01158bcc728fbd36d48647
[deliverable/binutils-gdb.git] / gdb / infrun.c
1 /* Target-struct-independent code to start (run) and stop an inferior
2 process.
3
4 Copyright (C) 1986-2013 Free Software Foundation, Inc.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20
21 #include "defs.h"
22 #include "gdb_string.h"
23 #include <ctype.h>
24 #include "symtab.h"
25 #include "frame.h"
26 #include "inferior.h"
27 #include "exceptions.h"
28 #include "breakpoint.h"
29 #include "gdb_wait.h"
30 #include "gdbcore.h"
31 #include "gdbcmd.h"
32 #include "cli/cli-script.h"
33 #include "target.h"
34 #include "gdbthread.h"
35 #include "annotate.h"
36 #include "symfile.h"
37 #include "top.h"
38 #include <signal.h>
39 #include "inf-loop.h"
40 #include "regcache.h"
41 #include "value.h"
42 #include "observer.h"
43 #include "language.h"
44 #include "solib.h"
45 #include "main.h"
46 #include "dictionary.h"
47 #include "block.h"
48 #include "gdb_assert.h"
49 #include "mi/mi-common.h"
50 #include "event-top.h"
51 #include "record.h"
52 #include "record-full.h"
53 #include "inline-frame.h"
54 #include "jit.h"
55 #include "tracepoint.h"
56 #include "continuations.h"
57 #include "interps.h"
58 #include "skip.h"
59 #include "probe.h"
60 #include "objfiles.h"
61 #include "completer.h"
62 #include "target-descriptions.h"
63
64 /* Prototypes for local functions */
65
66 static void signals_info (char *, int);
67
68 static void handle_command (char *, int);
69
70 static void sig_print_info (enum gdb_signal);
71
72 static void sig_print_header (void);
73
74 static void resume_cleanups (void *);
75
76 static int hook_stop_stub (void *);
77
78 static int restore_selected_frame (void *);
79
80 static int follow_fork (void);
81
82 static void set_schedlock_func (char *args, int from_tty,
83 struct cmd_list_element *c);
84
85 static int currently_stepping (struct thread_info *tp);
86
87 static int currently_stepping_or_nexting_callback (struct thread_info *tp,
88 void *data);
89
90 static void xdb_handle_command (char *args, int from_tty);
91
92 static int prepare_to_proceed (int);
93
94 static void print_exited_reason (int exitstatus);
95
96 static void print_signal_exited_reason (enum gdb_signal siggnal);
97
98 static void print_no_history_reason (void);
99
100 static void print_signal_received_reason (enum gdb_signal siggnal);
101
102 static void print_end_stepping_range_reason (void);
103
104 void _initialize_infrun (void);
105
106 void nullify_last_target_wait_ptid (void);
107
108 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
109
110 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
111
112 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
113
114 /* When set, stop the 'step' command if we enter a function which has
115 no line number information. The normal behavior is that we step
116 over such function. */
117 int step_stop_if_no_debug = 0;
118 static void
119 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
120 struct cmd_list_element *c, const char *value)
121 {
122 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
123 }
124
125 /* In asynchronous mode, but simulating synchronous execution. */
126
127 int sync_execution = 0;
128
129 /* wait_for_inferior and normal_stop use this to notify the user
130 when the inferior stopped in a different thread than it had been
131 running in. */
132
133 static ptid_t previous_inferior_ptid;
134
135 /* If set (default for legacy reasons), when following a fork, GDB
136 will detach from one of the fork branches, child or parent.
137 Exactly which branch is detached depends on 'set follow-fork-mode'
138 setting. */
139
140 static int detach_fork = 1;
141
142 int debug_displaced = 0;
143 static void
144 show_debug_displaced (struct ui_file *file, int from_tty,
145 struct cmd_list_element *c, const char *value)
146 {
147 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
148 }
149
150 unsigned int debug_infrun = 0;
151 static void
152 show_debug_infrun (struct ui_file *file, int from_tty,
153 struct cmd_list_element *c, const char *value)
154 {
155 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
156 }
157
158
159 /* Support for disabling address space randomization. */
160
161 int disable_randomization = 1;
162
163 static void
164 show_disable_randomization (struct ui_file *file, int from_tty,
165 struct cmd_list_element *c, const char *value)
166 {
167 if (target_supports_disable_randomization ())
168 fprintf_filtered (file,
169 _("Disabling randomization of debuggee's "
170 "virtual address space is %s.\n"),
171 value);
172 else
173 fputs_filtered (_("Disabling randomization of debuggee's "
174 "virtual address space is unsupported on\n"
175 "this platform.\n"), file);
176 }
177
178 static void
179 set_disable_randomization (char *args, int from_tty,
180 struct cmd_list_element *c)
181 {
182 if (!target_supports_disable_randomization ())
183 error (_("Disabling randomization of debuggee's "
184 "virtual address space is unsupported on\n"
185 "this platform."));
186 }
187
188 /* User interface for non-stop mode. */
189
190 int non_stop = 0;
191 static int non_stop_1 = 0;
192
193 static void
194 set_non_stop (char *args, int from_tty,
195 struct cmd_list_element *c)
196 {
197 if (target_has_execution)
198 {
199 non_stop_1 = non_stop;
200 error (_("Cannot change this setting while the inferior is running."));
201 }
202
203 non_stop = non_stop_1;
204 }
205
206 static void
207 show_non_stop (struct ui_file *file, int from_tty,
208 struct cmd_list_element *c, const char *value)
209 {
210 fprintf_filtered (file,
211 _("Controlling the inferior in non-stop mode is %s.\n"),
212 value);
213 }
214
215 /* "Observer mode" is somewhat like a more extreme version of
216 non-stop, in which all GDB operations that might affect the
217 target's execution have been disabled. */
218
219 int observer_mode = 0;
220 static int observer_mode_1 = 0;
221
222 static void
223 set_observer_mode (char *args, int from_tty,
224 struct cmd_list_element *c)
225 {
226 if (target_has_execution)
227 {
228 observer_mode_1 = observer_mode;
229 error (_("Cannot change this setting while the inferior is running."));
230 }
231
232 observer_mode = observer_mode_1;
233
234 may_write_registers = !observer_mode;
235 may_write_memory = !observer_mode;
236 may_insert_breakpoints = !observer_mode;
237 may_insert_tracepoints = !observer_mode;
238 /* We can insert fast tracepoints in or out of observer mode,
239 but enable them if we're going into this mode. */
240 if (observer_mode)
241 may_insert_fast_tracepoints = 1;
242 may_stop = !observer_mode;
243 update_target_permissions ();
244
245 /* Going *into* observer mode we must force non-stop, then
246 going out we leave it that way. */
247 if (observer_mode)
248 {
249 target_async_permitted = 1;
250 pagination_enabled = 0;
251 non_stop = non_stop_1 = 1;
252 }
253
254 if (from_tty)
255 printf_filtered (_("Observer mode is now %s.\n"),
256 (observer_mode ? "on" : "off"));
257 }
258
259 static void
260 show_observer_mode (struct ui_file *file, int from_tty,
261 struct cmd_list_element *c, const char *value)
262 {
263 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
264 }
265
266 /* This updates the value of observer mode based on changes in
267 permissions. Note that we are deliberately ignoring the values of
268 may-write-registers and may-write-memory, since the user may have
269 reason to enable these during a session, for instance to turn on a
270 debugging-related global. */
271
272 void
273 update_observer_mode (void)
274 {
275 int newval;
276
277 newval = (!may_insert_breakpoints
278 && !may_insert_tracepoints
279 && may_insert_fast_tracepoints
280 && !may_stop
281 && non_stop);
282
283 /* Let the user know if things change. */
284 if (newval != observer_mode)
285 printf_filtered (_("Observer mode is now %s.\n"),
286 (newval ? "on" : "off"));
287
288 observer_mode = observer_mode_1 = newval;
289 }
290
291 /* Tables of how to react to signals; the user sets them. */
292
293 static unsigned char *signal_stop;
294 static unsigned char *signal_print;
295 static unsigned char *signal_program;
296
297 /* Table of signals that are registered with "catch signal". A
298 non-zero entry indicates that the signal is caught by some "catch
299 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
300 signals. */
301 static unsigned char *signal_catch;
302
303 /* Table of signals that the target may silently handle.
304 This is automatically determined from the flags above,
305 and simply cached here. */
306 static unsigned char *signal_pass;
307
308 #define SET_SIGS(nsigs,sigs,flags) \
309 do { \
310 int signum = (nsigs); \
311 while (signum-- > 0) \
312 if ((sigs)[signum]) \
313 (flags)[signum] = 1; \
314 } while (0)
315
316 #define UNSET_SIGS(nsigs,sigs,flags) \
317 do { \
318 int signum = (nsigs); \
319 while (signum-- > 0) \
320 if ((sigs)[signum]) \
321 (flags)[signum] = 0; \
322 } while (0)
323
324 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
325 this function is to avoid exporting `signal_program'. */
326
327 void
328 update_signals_program_target (void)
329 {
330 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
331 }
332
333 /* Value to pass to target_resume() to cause all threads to resume. */
334
335 #define RESUME_ALL minus_one_ptid
336
337 /* Command list pointer for the "stop" placeholder. */
338
339 static struct cmd_list_element *stop_command;
340
341 /* Function inferior was in as of last step command. */
342
343 static struct symbol *step_start_function;
344
345 /* Nonzero if we want to give control to the user when we're notified
346 of shared library events by the dynamic linker. */
347 int stop_on_solib_events;
348
349 /* Enable or disable optional shared library event breakpoints
350 as appropriate when the above flag is changed. */
351
352 static void
353 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
354 {
355 update_solib_breakpoints ();
356 }
357
358 static void
359 show_stop_on_solib_events (struct ui_file *file, int from_tty,
360 struct cmd_list_element *c, const char *value)
361 {
362 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
363 value);
364 }
365
366 /* Nonzero means expecting a trace trap
367 and should stop the inferior and return silently when it happens. */
368
369 int stop_after_trap;
370
371 /* Save register contents here when executing a "finish" command or are
372 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
373 Thus this contains the return value from the called function (assuming
374 values are returned in a register). */
375
376 struct regcache *stop_registers;
377
378 /* Nonzero after stop if current stack frame should be printed. */
379
380 static int stop_print_frame;
381
382 /* This is a cached copy of the pid/waitstatus of the last event
383 returned by target_wait()/deprecated_target_wait_hook(). This
384 information is returned by get_last_target_status(). */
385 static ptid_t target_last_wait_ptid;
386 static struct target_waitstatus target_last_waitstatus;
387
388 static void context_switch (ptid_t ptid);
389
390 void init_thread_stepping_state (struct thread_info *tss);
391
392 static void init_infwait_state (void);
393
394 static const char follow_fork_mode_child[] = "child";
395 static const char follow_fork_mode_parent[] = "parent";
396
397 static const char *const follow_fork_mode_kind_names[] = {
398 follow_fork_mode_child,
399 follow_fork_mode_parent,
400 NULL
401 };
402
403 static const char *follow_fork_mode_string = follow_fork_mode_parent;
404 static void
405 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
406 struct cmd_list_element *c, const char *value)
407 {
408 fprintf_filtered (file,
409 _("Debugger response to a program "
410 "call of fork or vfork is \"%s\".\n"),
411 value);
412 }
413 \f
414
415 /* Tell the target to follow the fork we're stopped at. Returns true
416 if the inferior should be resumed; false, if the target for some
417 reason decided it's best not to resume. */
418
419 static int
420 follow_fork (void)
421 {
422 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
423 int should_resume = 1;
424 struct thread_info *tp;
425
426 /* Copy user stepping state to the new inferior thread. FIXME: the
427 followed fork child thread should have a copy of most of the
428 parent thread structure's run control related fields, not just these.
429 Initialized to avoid "may be used uninitialized" warnings from gcc. */
430 struct breakpoint *step_resume_breakpoint = NULL;
431 struct breakpoint *exception_resume_breakpoint = NULL;
432 CORE_ADDR step_range_start = 0;
433 CORE_ADDR step_range_end = 0;
434 struct frame_id step_frame_id = { 0 };
435
436 if (!non_stop)
437 {
438 ptid_t wait_ptid;
439 struct target_waitstatus wait_status;
440
441 /* Get the last target status returned by target_wait(). */
442 get_last_target_status (&wait_ptid, &wait_status);
443
444 /* If not stopped at a fork event, then there's nothing else to
445 do. */
446 if (wait_status.kind != TARGET_WAITKIND_FORKED
447 && wait_status.kind != TARGET_WAITKIND_VFORKED)
448 return 1;
449
450 /* Check if we switched over from WAIT_PTID, since the event was
451 reported. */
452 if (!ptid_equal (wait_ptid, minus_one_ptid)
453 && !ptid_equal (inferior_ptid, wait_ptid))
454 {
455 /* We did. Switch back to WAIT_PTID thread, to tell the
456 target to follow it (in either direction). We'll
457 afterwards refuse to resume, and inform the user what
458 happened. */
459 switch_to_thread (wait_ptid);
460 should_resume = 0;
461 }
462 }
463
464 tp = inferior_thread ();
465
466 /* If there were any forks/vforks that were caught and are now to be
467 followed, then do so now. */
468 switch (tp->pending_follow.kind)
469 {
470 case TARGET_WAITKIND_FORKED:
471 case TARGET_WAITKIND_VFORKED:
472 {
473 ptid_t parent, child;
474
475 /* If the user did a next/step, etc, over a fork call,
476 preserve the stepping state in the fork child. */
477 if (follow_child && should_resume)
478 {
479 step_resume_breakpoint = clone_momentary_breakpoint
480 (tp->control.step_resume_breakpoint);
481 step_range_start = tp->control.step_range_start;
482 step_range_end = tp->control.step_range_end;
483 step_frame_id = tp->control.step_frame_id;
484 exception_resume_breakpoint
485 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
486
487 /* For now, delete the parent's sr breakpoint, otherwise,
488 parent/child sr breakpoints are considered duplicates,
489 and the child version will not be installed. Remove
490 this when the breakpoints module becomes aware of
491 inferiors and address spaces. */
492 delete_step_resume_breakpoint (tp);
493 tp->control.step_range_start = 0;
494 tp->control.step_range_end = 0;
495 tp->control.step_frame_id = null_frame_id;
496 delete_exception_resume_breakpoint (tp);
497 }
498
499 parent = inferior_ptid;
500 child = tp->pending_follow.value.related_pid;
501
502 /* Tell the target to do whatever is necessary to follow
503 either parent or child. */
504 if (target_follow_fork (follow_child, detach_fork))
505 {
506 /* Target refused to follow, or there's some other reason
507 we shouldn't resume. */
508 should_resume = 0;
509 }
510 else
511 {
512 /* This pending follow fork event is now handled, one way
513 or another. The previous selected thread may be gone
514 from the lists by now, but if it is still around, need
515 to clear the pending follow request. */
516 tp = find_thread_ptid (parent);
517 if (tp)
518 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
519
520 /* This makes sure we don't try to apply the "Switched
521 over from WAIT_PID" logic above. */
522 nullify_last_target_wait_ptid ();
523
524 /* If we followed the child, switch to it... */
525 if (follow_child)
526 {
527 switch_to_thread (child);
528
529 /* ... and preserve the stepping state, in case the
530 user was stepping over the fork call. */
531 if (should_resume)
532 {
533 tp = inferior_thread ();
534 tp->control.step_resume_breakpoint
535 = step_resume_breakpoint;
536 tp->control.step_range_start = step_range_start;
537 tp->control.step_range_end = step_range_end;
538 tp->control.step_frame_id = step_frame_id;
539 tp->control.exception_resume_breakpoint
540 = exception_resume_breakpoint;
541 }
542 else
543 {
544 /* If we get here, it was because we're trying to
545 resume from a fork catchpoint, but, the user
546 has switched threads away from the thread that
547 forked. In that case, the resume command
548 issued is most likely not applicable to the
549 child, so just warn, and refuse to resume. */
550 warning (_("Not resuming: switched threads "
551 "before following fork child.\n"));
552 }
553
554 /* Reset breakpoints in the child as appropriate. */
555 follow_inferior_reset_breakpoints ();
556 }
557 else
558 switch_to_thread (parent);
559 }
560 }
561 break;
562 case TARGET_WAITKIND_SPURIOUS:
563 /* Nothing to follow. */
564 break;
565 default:
566 internal_error (__FILE__, __LINE__,
567 "Unexpected pending_follow.kind %d\n",
568 tp->pending_follow.kind);
569 break;
570 }
571
572 return should_resume;
573 }
574
575 void
576 follow_inferior_reset_breakpoints (void)
577 {
578 struct thread_info *tp = inferior_thread ();
579
580 /* Was there a step_resume breakpoint? (There was if the user
581 did a "next" at the fork() call.) If so, explicitly reset its
582 thread number.
583
584 step_resumes are a form of bp that are made to be per-thread.
585 Since we created the step_resume bp when the parent process
586 was being debugged, and now are switching to the child process,
587 from the breakpoint package's viewpoint, that's a switch of
588 "threads". We must update the bp's notion of which thread
589 it is for, or it'll be ignored when it triggers. */
590
591 if (tp->control.step_resume_breakpoint)
592 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
593
594 if (tp->control.exception_resume_breakpoint)
595 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
596
597 /* Reinsert all breakpoints in the child. The user may have set
598 breakpoints after catching the fork, in which case those
599 were never set in the child, but only in the parent. This makes
600 sure the inserted breakpoints match the breakpoint list. */
601
602 breakpoint_re_set ();
603 insert_breakpoints ();
604 }
605
606 /* The child has exited or execed: resume threads of the parent the
607 user wanted to be executing. */
608
609 static int
610 proceed_after_vfork_done (struct thread_info *thread,
611 void *arg)
612 {
613 int pid = * (int *) arg;
614
615 if (ptid_get_pid (thread->ptid) == pid
616 && is_running (thread->ptid)
617 && !is_executing (thread->ptid)
618 && !thread->stop_requested
619 && thread->suspend.stop_signal == GDB_SIGNAL_0)
620 {
621 if (debug_infrun)
622 fprintf_unfiltered (gdb_stdlog,
623 "infrun: resuming vfork parent thread %s\n",
624 target_pid_to_str (thread->ptid));
625
626 switch_to_thread (thread->ptid);
627 clear_proceed_status ();
628 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
629 }
630
631 return 0;
632 }
633
634 /* Called whenever we notice an exec or exit event, to handle
635 detaching or resuming a vfork parent. */
636
637 static void
638 handle_vfork_child_exec_or_exit (int exec)
639 {
640 struct inferior *inf = current_inferior ();
641
642 if (inf->vfork_parent)
643 {
644 int resume_parent = -1;
645
646 /* This exec or exit marks the end of the shared memory region
647 between the parent and the child. If the user wanted to
648 detach from the parent, now is the time. */
649
650 if (inf->vfork_parent->pending_detach)
651 {
652 struct thread_info *tp;
653 struct cleanup *old_chain;
654 struct program_space *pspace;
655 struct address_space *aspace;
656
657 /* follow-fork child, detach-on-fork on. */
658
659 inf->vfork_parent->pending_detach = 0;
660
661 if (!exec)
662 {
663 /* If we're handling a child exit, then inferior_ptid
664 points at the inferior's pid, not to a thread. */
665 old_chain = save_inferior_ptid ();
666 save_current_program_space ();
667 save_current_inferior ();
668 }
669 else
670 old_chain = save_current_space_and_thread ();
671
672 /* We're letting loose of the parent. */
673 tp = any_live_thread_of_process (inf->vfork_parent->pid);
674 switch_to_thread (tp->ptid);
675
676 /* We're about to detach from the parent, which implicitly
677 removes breakpoints from its address space. There's a
678 catch here: we want to reuse the spaces for the child,
679 but, parent/child are still sharing the pspace at this
680 point, although the exec in reality makes the kernel give
681 the child a fresh set of new pages. The problem here is
682 that the breakpoints module being unaware of this, would
683 likely chose the child process to write to the parent
684 address space. Swapping the child temporarily away from
685 the spaces has the desired effect. Yes, this is "sort
686 of" a hack. */
687
688 pspace = inf->pspace;
689 aspace = inf->aspace;
690 inf->aspace = NULL;
691 inf->pspace = NULL;
692
693 if (debug_infrun || info_verbose)
694 {
695 target_terminal_ours ();
696
697 if (exec)
698 fprintf_filtered (gdb_stdlog,
699 "Detaching vfork parent process "
700 "%d after child exec.\n",
701 inf->vfork_parent->pid);
702 else
703 fprintf_filtered (gdb_stdlog,
704 "Detaching vfork parent process "
705 "%d after child exit.\n",
706 inf->vfork_parent->pid);
707 }
708
709 target_detach (NULL, 0);
710
711 /* Put it back. */
712 inf->pspace = pspace;
713 inf->aspace = aspace;
714
715 do_cleanups (old_chain);
716 }
717 else if (exec)
718 {
719 /* We're staying attached to the parent, so, really give the
720 child a new address space. */
721 inf->pspace = add_program_space (maybe_new_address_space ());
722 inf->aspace = inf->pspace->aspace;
723 inf->removable = 1;
724 set_current_program_space (inf->pspace);
725
726 resume_parent = inf->vfork_parent->pid;
727
728 /* Break the bonds. */
729 inf->vfork_parent->vfork_child = NULL;
730 }
731 else
732 {
733 struct cleanup *old_chain;
734 struct program_space *pspace;
735
736 /* If this is a vfork child exiting, then the pspace and
737 aspaces were shared with the parent. Since we're
738 reporting the process exit, we'll be mourning all that is
739 found in the address space, and switching to null_ptid,
740 preparing to start a new inferior. But, since we don't
741 want to clobber the parent's address/program spaces, we
742 go ahead and create a new one for this exiting
743 inferior. */
744
745 /* Switch to null_ptid, so that clone_program_space doesn't want
746 to read the selected frame of a dead process. */
747 old_chain = save_inferior_ptid ();
748 inferior_ptid = null_ptid;
749
750 /* This inferior is dead, so avoid giving the breakpoints
751 module the option to write through to it (cloning a
752 program space resets breakpoints). */
753 inf->aspace = NULL;
754 inf->pspace = NULL;
755 pspace = add_program_space (maybe_new_address_space ());
756 set_current_program_space (pspace);
757 inf->removable = 1;
758 inf->symfile_flags = SYMFILE_NO_READ;
759 clone_program_space (pspace, inf->vfork_parent->pspace);
760 inf->pspace = pspace;
761 inf->aspace = pspace->aspace;
762
763 /* Put back inferior_ptid. We'll continue mourning this
764 inferior. */
765 do_cleanups (old_chain);
766
767 resume_parent = inf->vfork_parent->pid;
768 /* Break the bonds. */
769 inf->vfork_parent->vfork_child = NULL;
770 }
771
772 inf->vfork_parent = NULL;
773
774 gdb_assert (current_program_space == inf->pspace);
775
776 if (non_stop && resume_parent != -1)
777 {
778 /* If the user wanted the parent to be running, let it go
779 free now. */
780 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
781
782 if (debug_infrun)
783 fprintf_unfiltered (gdb_stdlog,
784 "infrun: resuming vfork parent process %d\n",
785 resume_parent);
786
787 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
788
789 do_cleanups (old_chain);
790 }
791 }
792 }
793
794 /* Enum strings for "set|show follow-exec-mode". */
795
796 static const char follow_exec_mode_new[] = "new";
797 static const char follow_exec_mode_same[] = "same";
798 static const char *const follow_exec_mode_names[] =
799 {
800 follow_exec_mode_new,
801 follow_exec_mode_same,
802 NULL,
803 };
804
805 static const char *follow_exec_mode_string = follow_exec_mode_same;
806 static void
807 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
808 struct cmd_list_element *c, const char *value)
809 {
810 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
811 }
812
813 /* EXECD_PATHNAME is assumed to be non-NULL. */
814
815 static void
816 follow_exec (ptid_t pid, char *execd_pathname)
817 {
818 struct thread_info *th = inferior_thread ();
819 struct inferior *inf = current_inferior ();
820
821 /* This is an exec event that we actually wish to pay attention to.
822 Refresh our symbol table to the newly exec'd program, remove any
823 momentary bp's, etc.
824
825 If there are breakpoints, they aren't really inserted now,
826 since the exec() transformed our inferior into a fresh set
827 of instructions.
828
829 We want to preserve symbolic breakpoints on the list, since
830 we have hopes that they can be reset after the new a.out's
831 symbol table is read.
832
833 However, any "raw" breakpoints must be removed from the list
834 (e.g., the solib bp's), since their address is probably invalid
835 now.
836
837 And, we DON'T want to call delete_breakpoints() here, since
838 that may write the bp's "shadow contents" (the instruction
839 value that was overwritten witha TRAP instruction). Since
840 we now have a new a.out, those shadow contents aren't valid. */
841
842 mark_breakpoints_out ();
843
844 update_breakpoints_after_exec ();
845
846 /* If there was one, it's gone now. We cannot truly step-to-next
847 statement through an exec(). */
848 th->control.step_resume_breakpoint = NULL;
849 th->control.exception_resume_breakpoint = NULL;
850 th->control.step_range_start = 0;
851 th->control.step_range_end = 0;
852
853 /* The target reports the exec event to the main thread, even if
854 some other thread does the exec, and even if the main thread was
855 already stopped --- if debugging in non-stop mode, it's possible
856 the user had the main thread held stopped in the previous image
857 --- release it now. This is the same behavior as step-over-exec
858 with scheduler-locking on in all-stop mode. */
859 th->stop_requested = 0;
860
861 /* What is this a.out's name? */
862 printf_unfiltered (_("%s is executing new program: %s\n"),
863 target_pid_to_str (inferior_ptid),
864 execd_pathname);
865
866 /* We've followed the inferior through an exec. Therefore, the
867 inferior has essentially been killed & reborn. */
868
869 gdb_flush (gdb_stdout);
870
871 breakpoint_init_inferior (inf_execd);
872
873 if (gdb_sysroot && *gdb_sysroot)
874 {
875 char *name = alloca (strlen (gdb_sysroot)
876 + strlen (execd_pathname)
877 + 1);
878
879 strcpy (name, gdb_sysroot);
880 strcat (name, execd_pathname);
881 execd_pathname = name;
882 }
883
884 /* Reset the shared library package. This ensures that we get a
885 shlib event when the child reaches "_start", at which point the
886 dld will have had a chance to initialize the child. */
887 /* Also, loading a symbol file below may trigger symbol lookups, and
888 we don't want those to be satisfied by the libraries of the
889 previous incarnation of this process. */
890 no_shared_libraries (NULL, 0);
891
892 if (follow_exec_mode_string == follow_exec_mode_new)
893 {
894 struct program_space *pspace;
895
896 /* The user wants to keep the old inferior and program spaces
897 around. Create a new fresh one, and switch to it. */
898
899 inf = add_inferior (current_inferior ()->pid);
900 pspace = add_program_space (maybe_new_address_space ());
901 inf->pspace = pspace;
902 inf->aspace = pspace->aspace;
903
904 exit_inferior_num_silent (current_inferior ()->num);
905
906 set_current_inferior (inf);
907 set_current_program_space (pspace);
908 }
909 else
910 {
911 /* The old description may no longer be fit for the new image.
912 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
913 old description; we'll read a new one below. No need to do
914 this on "follow-exec-mode new", as the old inferior stays
915 around (its description is later cleared/refetched on
916 restart). */
917 target_clear_description ();
918 }
919
920 gdb_assert (current_program_space == inf->pspace);
921
922 /* That a.out is now the one to use. */
923 exec_file_attach (execd_pathname, 0);
924
925 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
926 (Position Independent Executable) main symbol file will get applied by
927 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
928 the breakpoints with the zero displacement. */
929
930 symbol_file_add (execd_pathname,
931 (inf->symfile_flags
932 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
933 NULL, 0);
934
935 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
936 set_initial_language ();
937
938 /* If the target can specify a description, read it. Must do this
939 after flipping to the new executable (because the target supplied
940 description must be compatible with the executable's
941 architecture, and the old executable may e.g., be 32-bit, while
942 the new one 64-bit), and before anything involving memory or
943 registers. */
944 target_find_description ();
945
946 solib_create_inferior_hook (0);
947
948 jit_inferior_created_hook ();
949
950 breakpoint_re_set ();
951
952 /* Reinsert all breakpoints. (Those which were symbolic have
953 been reset to the proper address in the new a.out, thanks
954 to symbol_file_command...). */
955 insert_breakpoints ();
956
957 /* The next resume of this inferior should bring it to the shlib
958 startup breakpoints. (If the user had also set bp's on
959 "main" from the old (parent) process, then they'll auto-
960 matically get reset there in the new process.). */
961 }
962
963 /* Non-zero if we just simulating a single-step. This is needed
964 because we cannot remove the breakpoints in the inferior process
965 until after the `wait' in `wait_for_inferior'. */
966 static int singlestep_breakpoints_inserted_p = 0;
967
968 /* The thread we inserted single-step breakpoints for. */
969 static ptid_t singlestep_ptid;
970
971 /* PC when we started this single-step. */
972 static CORE_ADDR singlestep_pc;
973
974 /* If another thread hit the singlestep breakpoint, we save the original
975 thread here so that we can resume single-stepping it later. */
976 static ptid_t saved_singlestep_ptid;
977 static int stepping_past_singlestep_breakpoint;
978
979 /* If not equal to null_ptid, this means that after stepping over breakpoint
980 is finished, we need to switch to deferred_step_ptid, and step it.
981
982 The use case is when one thread has hit a breakpoint, and then the user
983 has switched to another thread and issued 'step'. We need to step over
984 breakpoint in the thread which hit the breakpoint, but then continue
985 stepping the thread user has selected. */
986 static ptid_t deferred_step_ptid;
987 \f
988 /* Displaced stepping. */
989
990 /* In non-stop debugging mode, we must take special care to manage
991 breakpoints properly; in particular, the traditional strategy for
992 stepping a thread past a breakpoint it has hit is unsuitable.
993 'Displaced stepping' is a tactic for stepping one thread past a
994 breakpoint it has hit while ensuring that other threads running
995 concurrently will hit the breakpoint as they should.
996
997 The traditional way to step a thread T off a breakpoint in a
998 multi-threaded program in all-stop mode is as follows:
999
1000 a0) Initially, all threads are stopped, and breakpoints are not
1001 inserted.
1002 a1) We single-step T, leaving breakpoints uninserted.
1003 a2) We insert breakpoints, and resume all threads.
1004
1005 In non-stop debugging, however, this strategy is unsuitable: we
1006 don't want to have to stop all threads in the system in order to
1007 continue or step T past a breakpoint. Instead, we use displaced
1008 stepping:
1009
1010 n0) Initially, T is stopped, other threads are running, and
1011 breakpoints are inserted.
1012 n1) We copy the instruction "under" the breakpoint to a separate
1013 location, outside the main code stream, making any adjustments
1014 to the instruction, register, and memory state as directed by
1015 T's architecture.
1016 n2) We single-step T over the instruction at its new location.
1017 n3) We adjust the resulting register and memory state as directed
1018 by T's architecture. This includes resetting T's PC to point
1019 back into the main instruction stream.
1020 n4) We resume T.
1021
1022 This approach depends on the following gdbarch methods:
1023
1024 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1025 indicate where to copy the instruction, and how much space must
1026 be reserved there. We use these in step n1.
1027
1028 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1029 address, and makes any necessary adjustments to the instruction,
1030 register contents, and memory. We use this in step n1.
1031
1032 - gdbarch_displaced_step_fixup adjusts registers and memory after
1033 we have successfuly single-stepped the instruction, to yield the
1034 same effect the instruction would have had if we had executed it
1035 at its original address. We use this in step n3.
1036
1037 - gdbarch_displaced_step_free_closure provides cleanup.
1038
1039 The gdbarch_displaced_step_copy_insn and
1040 gdbarch_displaced_step_fixup functions must be written so that
1041 copying an instruction with gdbarch_displaced_step_copy_insn,
1042 single-stepping across the copied instruction, and then applying
1043 gdbarch_displaced_insn_fixup should have the same effects on the
1044 thread's memory and registers as stepping the instruction in place
1045 would have. Exactly which responsibilities fall to the copy and
1046 which fall to the fixup is up to the author of those functions.
1047
1048 See the comments in gdbarch.sh for details.
1049
1050 Note that displaced stepping and software single-step cannot
1051 currently be used in combination, although with some care I think
1052 they could be made to. Software single-step works by placing
1053 breakpoints on all possible subsequent instructions; if the
1054 displaced instruction is a PC-relative jump, those breakpoints
1055 could fall in very strange places --- on pages that aren't
1056 executable, or at addresses that are not proper instruction
1057 boundaries. (We do generally let other threads run while we wait
1058 to hit the software single-step breakpoint, and they might
1059 encounter such a corrupted instruction.) One way to work around
1060 this would be to have gdbarch_displaced_step_copy_insn fully
1061 simulate the effect of PC-relative instructions (and return NULL)
1062 on architectures that use software single-stepping.
1063
1064 In non-stop mode, we can have independent and simultaneous step
1065 requests, so more than one thread may need to simultaneously step
1066 over a breakpoint. The current implementation assumes there is
1067 only one scratch space per process. In this case, we have to
1068 serialize access to the scratch space. If thread A wants to step
1069 over a breakpoint, but we are currently waiting for some other
1070 thread to complete a displaced step, we leave thread A stopped and
1071 place it in the displaced_step_request_queue. Whenever a displaced
1072 step finishes, we pick the next thread in the queue and start a new
1073 displaced step operation on it. See displaced_step_prepare and
1074 displaced_step_fixup for details. */
1075
1076 struct displaced_step_request
1077 {
1078 ptid_t ptid;
1079 struct displaced_step_request *next;
1080 };
1081
1082 /* Per-inferior displaced stepping state. */
1083 struct displaced_step_inferior_state
1084 {
1085 /* Pointer to next in linked list. */
1086 struct displaced_step_inferior_state *next;
1087
1088 /* The process this displaced step state refers to. */
1089 int pid;
1090
1091 /* A queue of pending displaced stepping requests. One entry per
1092 thread that needs to do a displaced step. */
1093 struct displaced_step_request *step_request_queue;
1094
1095 /* If this is not null_ptid, this is the thread carrying out a
1096 displaced single-step in process PID. This thread's state will
1097 require fixing up once it has completed its step. */
1098 ptid_t step_ptid;
1099
1100 /* The architecture the thread had when we stepped it. */
1101 struct gdbarch *step_gdbarch;
1102
1103 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1104 for post-step cleanup. */
1105 struct displaced_step_closure *step_closure;
1106
1107 /* The address of the original instruction, and the copy we
1108 made. */
1109 CORE_ADDR step_original, step_copy;
1110
1111 /* Saved contents of copy area. */
1112 gdb_byte *step_saved_copy;
1113 };
1114
1115 /* The list of states of processes involved in displaced stepping
1116 presently. */
1117 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1118
1119 /* Get the displaced stepping state of process PID. */
1120
1121 static struct displaced_step_inferior_state *
1122 get_displaced_stepping_state (int pid)
1123 {
1124 struct displaced_step_inferior_state *state;
1125
1126 for (state = displaced_step_inferior_states;
1127 state != NULL;
1128 state = state->next)
1129 if (state->pid == pid)
1130 return state;
1131
1132 return NULL;
1133 }
1134
1135 /* Add a new displaced stepping state for process PID to the displaced
1136 stepping state list, or return a pointer to an already existing
1137 entry, if it already exists. Never returns NULL. */
1138
1139 static struct displaced_step_inferior_state *
1140 add_displaced_stepping_state (int pid)
1141 {
1142 struct displaced_step_inferior_state *state;
1143
1144 for (state = displaced_step_inferior_states;
1145 state != NULL;
1146 state = state->next)
1147 if (state->pid == pid)
1148 return state;
1149
1150 state = xcalloc (1, sizeof (*state));
1151 state->pid = pid;
1152 state->next = displaced_step_inferior_states;
1153 displaced_step_inferior_states = state;
1154
1155 return state;
1156 }
1157
1158 /* If inferior is in displaced stepping, and ADDR equals to starting address
1159 of copy area, return corresponding displaced_step_closure. Otherwise,
1160 return NULL. */
1161
1162 struct displaced_step_closure*
1163 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1164 {
1165 struct displaced_step_inferior_state *displaced
1166 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1167
1168 /* If checking the mode of displaced instruction in copy area. */
1169 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1170 && (displaced->step_copy == addr))
1171 return displaced->step_closure;
1172
1173 return NULL;
1174 }
1175
1176 /* Remove the displaced stepping state of process PID. */
1177
1178 static void
1179 remove_displaced_stepping_state (int pid)
1180 {
1181 struct displaced_step_inferior_state *it, **prev_next_p;
1182
1183 gdb_assert (pid != 0);
1184
1185 it = displaced_step_inferior_states;
1186 prev_next_p = &displaced_step_inferior_states;
1187 while (it)
1188 {
1189 if (it->pid == pid)
1190 {
1191 *prev_next_p = it->next;
1192 xfree (it);
1193 return;
1194 }
1195
1196 prev_next_p = &it->next;
1197 it = *prev_next_p;
1198 }
1199 }
1200
1201 static void
1202 infrun_inferior_exit (struct inferior *inf)
1203 {
1204 remove_displaced_stepping_state (inf->pid);
1205 }
1206
1207 /* If ON, and the architecture supports it, GDB will use displaced
1208 stepping to step over breakpoints. If OFF, or if the architecture
1209 doesn't support it, GDB will instead use the traditional
1210 hold-and-step approach. If AUTO (which is the default), GDB will
1211 decide which technique to use to step over breakpoints depending on
1212 which of all-stop or non-stop mode is active --- displaced stepping
1213 in non-stop mode; hold-and-step in all-stop mode. */
1214
1215 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1216
1217 static void
1218 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1219 struct cmd_list_element *c,
1220 const char *value)
1221 {
1222 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1223 fprintf_filtered (file,
1224 _("Debugger's willingness to use displaced stepping "
1225 "to step over breakpoints is %s (currently %s).\n"),
1226 value, non_stop ? "on" : "off");
1227 else
1228 fprintf_filtered (file,
1229 _("Debugger's willingness to use displaced stepping "
1230 "to step over breakpoints is %s.\n"), value);
1231 }
1232
1233 /* Return non-zero if displaced stepping can/should be used to step
1234 over breakpoints. */
1235
1236 static int
1237 use_displaced_stepping (struct gdbarch *gdbarch)
1238 {
1239 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1240 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1241 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1242 && !RECORD_IS_USED);
1243 }
1244
1245 /* Clean out any stray displaced stepping state. */
1246 static void
1247 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1248 {
1249 /* Indicate that there is no cleanup pending. */
1250 displaced->step_ptid = null_ptid;
1251
1252 if (displaced->step_closure)
1253 {
1254 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1255 displaced->step_closure);
1256 displaced->step_closure = NULL;
1257 }
1258 }
1259
1260 static void
1261 displaced_step_clear_cleanup (void *arg)
1262 {
1263 struct displaced_step_inferior_state *state = arg;
1264
1265 displaced_step_clear (state);
1266 }
1267
1268 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1269 void
1270 displaced_step_dump_bytes (struct ui_file *file,
1271 const gdb_byte *buf,
1272 size_t len)
1273 {
1274 int i;
1275
1276 for (i = 0; i < len; i++)
1277 fprintf_unfiltered (file, "%02x ", buf[i]);
1278 fputs_unfiltered ("\n", file);
1279 }
1280
1281 /* Prepare to single-step, using displaced stepping.
1282
1283 Note that we cannot use displaced stepping when we have a signal to
1284 deliver. If we have a signal to deliver and an instruction to step
1285 over, then after the step, there will be no indication from the
1286 target whether the thread entered a signal handler or ignored the
1287 signal and stepped over the instruction successfully --- both cases
1288 result in a simple SIGTRAP. In the first case we mustn't do a
1289 fixup, and in the second case we must --- but we can't tell which.
1290 Comments in the code for 'random signals' in handle_inferior_event
1291 explain how we handle this case instead.
1292
1293 Returns 1 if preparing was successful -- this thread is going to be
1294 stepped now; or 0 if displaced stepping this thread got queued. */
1295 static int
1296 displaced_step_prepare (ptid_t ptid)
1297 {
1298 struct cleanup *old_cleanups, *ignore_cleanups;
1299 struct thread_info *tp = find_thread_ptid (ptid);
1300 struct regcache *regcache = get_thread_regcache (ptid);
1301 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1302 CORE_ADDR original, copy;
1303 ULONGEST len;
1304 struct displaced_step_closure *closure;
1305 struct displaced_step_inferior_state *displaced;
1306 int status;
1307
1308 /* We should never reach this function if the architecture does not
1309 support displaced stepping. */
1310 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1311
1312 /* Disable range stepping while executing in the scratch pad. We
1313 want a single-step even if executing the displaced instruction in
1314 the scratch buffer lands within the stepping range (e.g., a
1315 jump/branch). */
1316 tp->control.may_range_step = 0;
1317
1318 /* We have to displaced step one thread at a time, as we only have
1319 access to a single scratch space per inferior. */
1320
1321 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1322
1323 if (!ptid_equal (displaced->step_ptid, null_ptid))
1324 {
1325 /* Already waiting for a displaced step to finish. Defer this
1326 request and place in queue. */
1327 struct displaced_step_request *req, *new_req;
1328
1329 if (debug_displaced)
1330 fprintf_unfiltered (gdb_stdlog,
1331 "displaced: defering step of %s\n",
1332 target_pid_to_str (ptid));
1333
1334 new_req = xmalloc (sizeof (*new_req));
1335 new_req->ptid = ptid;
1336 new_req->next = NULL;
1337
1338 if (displaced->step_request_queue)
1339 {
1340 for (req = displaced->step_request_queue;
1341 req && req->next;
1342 req = req->next)
1343 ;
1344 req->next = new_req;
1345 }
1346 else
1347 displaced->step_request_queue = new_req;
1348
1349 return 0;
1350 }
1351 else
1352 {
1353 if (debug_displaced)
1354 fprintf_unfiltered (gdb_stdlog,
1355 "displaced: stepping %s now\n",
1356 target_pid_to_str (ptid));
1357 }
1358
1359 displaced_step_clear (displaced);
1360
1361 old_cleanups = save_inferior_ptid ();
1362 inferior_ptid = ptid;
1363
1364 original = regcache_read_pc (regcache);
1365
1366 copy = gdbarch_displaced_step_location (gdbarch);
1367 len = gdbarch_max_insn_length (gdbarch);
1368
1369 /* Save the original contents of the copy area. */
1370 displaced->step_saved_copy = xmalloc (len);
1371 ignore_cleanups = make_cleanup (free_current_contents,
1372 &displaced->step_saved_copy);
1373 status = target_read_memory (copy, displaced->step_saved_copy, len);
1374 if (status != 0)
1375 throw_error (MEMORY_ERROR,
1376 _("Error accessing memory address %s (%s) for "
1377 "displaced-stepping scratch space."),
1378 paddress (gdbarch, copy), safe_strerror (status));
1379 if (debug_displaced)
1380 {
1381 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1382 paddress (gdbarch, copy));
1383 displaced_step_dump_bytes (gdb_stdlog,
1384 displaced->step_saved_copy,
1385 len);
1386 };
1387
1388 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1389 original, copy, regcache);
1390
1391 /* We don't support the fully-simulated case at present. */
1392 gdb_assert (closure);
1393
1394 /* Save the information we need to fix things up if the step
1395 succeeds. */
1396 displaced->step_ptid = ptid;
1397 displaced->step_gdbarch = gdbarch;
1398 displaced->step_closure = closure;
1399 displaced->step_original = original;
1400 displaced->step_copy = copy;
1401
1402 make_cleanup (displaced_step_clear_cleanup, displaced);
1403
1404 /* Resume execution at the copy. */
1405 regcache_write_pc (regcache, copy);
1406
1407 discard_cleanups (ignore_cleanups);
1408
1409 do_cleanups (old_cleanups);
1410
1411 if (debug_displaced)
1412 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1413 paddress (gdbarch, copy));
1414
1415 return 1;
1416 }
1417
1418 static void
1419 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1420 const gdb_byte *myaddr, int len)
1421 {
1422 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1423
1424 inferior_ptid = ptid;
1425 write_memory (memaddr, myaddr, len);
1426 do_cleanups (ptid_cleanup);
1427 }
1428
1429 /* Restore the contents of the copy area for thread PTID. */
1430
1431 static void
1432 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1433 ptid_t ptid)
1434 {
1435 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1436
1437 write_memory_ptid (ptid, displaced->step_copy,
1438 displaced->step_saved_copy, len);
1439 if (debug_displaced)
1440 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1441 target_pid_to_str (ptid),
1442 paddress (displaced->step_gdbarch,
1443 displaced->step_copy));
1444 }
1445
1446 static void
1447 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1448 {
1449 struct cleanup *old_cleanups;
1450 struct displaced_step_inferior_state *displaced
1451 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1452
1453 /* Was any thread of this process doing a displaced step? */
1454 if (displaced == NULL)
1455 return;
1456
1457 /* Was this event for the pid we displaced? */
1458 if (ptid_equal (displaced->step_ptid, null_ptid)
1459 || ! ptid_equal (displaced->step_ptid, event_ptid))
1460 return;
1461
1462 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1463
1464 displaced_step_restore (displaced, displaced->step_ptid);
1465
1466 /* Did the instruction complete successfully? */
1467 if (signal == GDB_SIGNAL_TRAP)
1468 {
1469 /* Fix up the resulting state. */
1470 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1471 displaced->step_closure,
1472 displaced->step_original,
1473 displaced->step_copy,
1474 get_thread_regcache (displaced->step_ptid));
1475 }
1476 else
1477 {
1478 /* Since the instruction didn't complete, all we can do is
1479 relocate the PC. */
1480 struct regcache *regcache = get_thread_regcache (event_ptid);
1481 CORE_ADDR pc = regcache_read_pc (regcache);
1482
1483 pc = displaced->step_original + (pc - displaced->step_copy);
1484 regcache_write_pc (regcache, pc);
1485 }
1486
1487 do_cleanups (old_cleanups);
1488
1489 displaced->step_ptid = null_ptid;
1490
1491 /* Are there any pending displaced stepping requests? If so, run
1492 one now. Leave the state object around, since we're likely to
1493 need it again soon. */
1494 while (displaced->step_request_queue)
1495 {
1496 struct displaced_step_request *head;
1497 ptid_t ptid;
1498 struct regcache *regcache;
1499 struct gdbarch *gdbarch;
1500 CORE_ADDR actual_pc;
1501 struct address_space *aspace;
1502
1503 head = displaced->step_request_queue;
1504 ptid = head->ptid;
1505 displaced->step_request_queue = head->next;
1506 xfree (head);
1507
1508 context_switch (ptid);
1509
1510 regcache = get_thread_regcache (ptid);
1511 actual_pc = regcache_read_pc (regcache);
1512 aspace = get_regcache_aspace (regcache);
1513
1514 if (breakpoint_here_p (aspace, actual_pc))
1515 {
1516 if (debug_displaced)
1517 fprintf_unfiltered (gdb_stdlog,
1518 "displaced: stepping queued %s now\n",
1519 target_pid_to_str (ptid));
1520
1521 displaced_step_prepare (ptid);
1522
1523 gdbarch = get_regcache_arch (regcache);
1524
1525 if (debug_displaced)
1526 {
1527 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1528 gdb_byte buf[4];
1529
1530 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1531 paddress (gdbarch, actual_pc));
1532 read_memory (actual_pc, buf, sizeof (buf));
1533 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1534 }
1535
1536 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1537 displaced->step_closure))
1538 target_resume (ptid, 1, GDB_SIGNAL_0);
1539 else
1540 target_resume (ptid, 0, GDB_SIGNAL_0);
1541
1542 /* Done, we're stepping a thread. */
1543 break;
1544 }
1545 else
1546 {
1547 int step;
1548 struct thread_info *tp = inferior_thread ();
1549
1550 /* The breakpoint we were sitting under has since been
1551 removed. */
1552 tp->control.trap_expected = 0;
1553
1554 /* Go back to what we were trying to do. */
1555 step = currently_stepping (tp);
1556
1557 if (debug_displaced)
1558 fprintf_unfiltered (gdb_stdlog,
1559 "displaced: breakpoint is gone: %s, step(%d)\n",
1560 target_pid_to_str (tp->ptid), step);
1561
1562 target_resume (ptid, step, GDB_SIGNAL_0);
1563 tp->suspend.stop_signal = GDB_SIGNAL_0;
1564
1565 /* This request was discarded. See if there's any other
1566 thread waiting for its turn. */
1567 }
1568 }
1569 }
1570
1571 /* Update global variables holding ptids to hold NEW_PTID if they were
1572 holding OLD_PTID. */
1573 static void
1574 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1575 {
1576 struct displaced_step_request *it;
1577 struct displaced_step_inferior_state *displaced;
1578
1579 if (ptid_equal (inferior_ptid, old_ptid))
1580 inferior_ptid = new_ptid;
1581
1582 if (ptid_equal (singlestep_ptid, old_ptid))
1583 singlestep_ptid = new_ptid;
1584
1585 if (ptid_equal (deferred_step_ptid, old_ptid))
1586 deferred_step_ptid = new_ptid;
1587
1588 for (displaced = displaced_step_inferior_states;
1589 displaced;
1590 displaced = displaced->next)
1591 {
1592 if (ptid_equal (displaced->step_ptid, old_ptid))
1593 displaced->step_ptid = new_ptid;
1594
1595 for (it = displaced->step_request_queue; it; it = it->next)
1596 if (ptid_equal (it->ptid, old_ptid))
1597 it->ptid = new_ptid;
1598 }
1599 }
1600
1601 \f
1602 /* Resuming. */
1603
1604 /* Things to clean up if we QUIT out of resume (). */
1605 static void
1606 resume_cleanups (void *ignore)
1607 {
1608 normal_stop ();
1609 }
1610
1611 static const char schedlock_off[] = "off";
1612 static const char schedlock_on[] = "on";
1613 static const char schedlock_step[] = "step";
1614 static const char *const scheduler_enums[] = {
1615 schedlock_off,
1616 schedlock_on,
1617 schedlock_step,
1618 NULL
1619 };
1620 static const char *scheduler_mode = schedlock_off;
1621 static void
1622 show_scheduler_mode (struct ui_file *file, int from_tty,
1623 struct cmd_list_element *c, const char *value)
1624 {
1625 fprintf_filtered (file,
1626 _("Mode for locking scheduler "
1627 "during execution is \"%s\".\n"),
1628 value);
1629 }
1630
1631 static void
1632 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1633 {
1634 if (!target_can_lock_scheduler)
1635 {
1636 scheduler_mode = schedlock_off;
1637 error (_("Target '%s' cannot support this command."), target_shortname);
1638 }
1639 }
1640
1641 /* True if execution commands resume all threads of all processes by
1642 default; otherwise, resume only threads of the current inferior
1643 process. */
1644 int sched_multi = 0;
1645
1646 /* Try to setup for software single stepping over the specified location.
1647 Return 1 if target_resume() should use hardware single step.
1648
1649 GDBARCH the current gdbarch.
1650 PC the location to step over. */
1651
1652 static int
1653 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1654 {
1655 int hw_step = 1;
1656
1657 if (execution_direction == EXEC_FORWARD
1658 && gdbarch_software_single_step_p (gdbarch)
1659 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1660 {
1661 hw_step = 0;
1662 /* Do not pull these breakpoints until after a `wait' in
1663 `wait_for_inferior'. */
1664 singlestep_breakpoints_inserted_p = 1;
1665 singlestep_ptid = inferior_ptid;
1666 singlestep_pc = pc;
1667 }
1668 return hw_step;
1669 }
1670
1671 /* Return a ptid representing the set of threads that we will proceed,
1672 in the perspective of the user/frontend. We may actually resume
1673 fewer threads at first, e.g., if a thread is stopped at a
1674 breakpoint that needs stepping-off, but that should not be visible
1675 to the user/frontend, and neither should the frontend/user be
1676 allowed to proceed any of the threads that happen to be stopped for
1677 internal run control handling, if a previous command wanted them
1678 resumed. */
1679
1680 ptid_t
1681 user_visible_resume_ptid (int step)
1682 {
1683 /* By default, resume all threads of all processes. */
1684 ptid_t resume_ptid = RESUME_ALL;
1685
1686 /* Maybe resume only all threads of the current process. */
1687 if (!sched_multi && target_supports_multi_process ())
1688 {
1689 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1690 }
1691
1692 /* Maybe resume a single thread after all. */
1693 if (non_stop)
1694 {
1695 /* With non-stop mode on, threads are always handled
1696 individually. */
1697 resume_ptid = inferior_ptid;
1698 }
1699 else if ((scheduler_mode == schedlock_on)
1700 || (scheduler_mode == schedlock_step
1701 && (step || singlestep_breakpoints_inserted_p)))
1702 {
1703 /* User-settable 'scheduler' mode requires solo thread resume. */
1704 resume_ptid = inferior_ptid;
1705 }
1706
1707 return resume_ptid;
1708 }
1709
1710 /* Resume the inferior, but allow a QUIT. This is useful if the user
1711 wants to interrupt some lengthy single-stepping operation
1712 (for child processes, the SIGINT goes to the inferior, and so
1713 we get a SIGINT random_signal, but for remote debugging and perhaps
1714 other targets, that's not true).
1715
1716 STEP nonzero if we should step (zero to continue instead).
1717 SIG is the signal to give the inferior (zero for none). */
1718 void
1719 resume (int step, enum gdb_signal sig)
1720 {
1721 int should_resume = 1;
1722 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1723 struct regcache *regcache = get_current_regcache ();
1724 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1725 struct thread_info *tp = inferior_thread ();
1726 CORE_ADDR pc = regcache_read_pc (regcache);
1727 struct address_space *aspace = get_regcache_aspace (regcache);
1728
1729 QUIT;
1730
1731 if (current_inferior ()->waiting_for_vfork_done)
1732 {
1733 /* Don't try to single-step a vfork parent that is waiting for
1734 the child to get out of the shared memory region (by exec'ing
1735 or exiting). This is particularly important on software
1736 single-step archs, as the child process would trip on the
1737 software single step breakpoint inserted for the parent
1738 process. Since the parent will not actually execute any
1739 instruction until the child is out of the shared region (such
1740 are vfork's semantics), it is safe to simply continue it.
1741 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
1742 the parent, and tell it to `keep_going', which automatically
1743 re-sets it stepping. */
1744 if (debug_infrun)
1745 fprintf_unfiltered (gdb_stdlog,
1746 "infrun: resume : clear step\n");
1747 step = 0;
1748 }
1749
1750 if (debug_infrun)
1751 fprintf_unfiltered (gdb_stdlog,
1752 "infrun: resume (step=%d, signal=%s), "
1753 "trap_expected=%d, current thread [%s] at %s\n",
1754 step, gdb_signal_to_symbol_string (sig),
1755 tp->control.trap_expected,
1756 target_pid_to_str (inferior_ptid),
1757 paddress (gdbarch, pc));
1758
1759 /* Normally, by the time we reach `resume', the breakpoints are either
1760 removed or inserted, as appropriate. The exception is if we're sitting
1761 at a permanent breakpoint; we need to step over it, but permanent
1762 breakpoints can't be removed. So we have to test for it here. */
1763 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1764 {
1765 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1766 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1767 else
1768 error (_("\
1769 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1770 how to step past a permanent breakpoint on this architecture. Try using\n\
1771 a command like `return' or `jump' to continue execution."));
1772 }
1773
1774 /* If we have a breakpoint to step over, make sure to do a single
1775 step only. Same if we have software watchpoints. */
1776 if (tp->control.trap_expected || bpstat_should_step ())
1777 tp->control.may_range_step = 0;
1778
1779 /* If enabled, step over breakpoints by executing a copy of the
1780 instruction at a different address.
1781
1782 We can't use displaced stepping when we have a signal to deliver;
1783 the comments for displaced_step_prepare explain why. The
1784 comments in the handle_inferior event for dealing with 'random
1785 signals' explain what we do instead.
1786
1787 We can't use displaced stepping when we are waiting for vfork_done
1788 event, displaced stepping breaks the vfork child similarly as single
1789 step software breakpoint. */
1790 if (use_displaced_stepping (gdbarch)
1791 && (tp->control.trap_expected
1792 || (step && gdbarch_software_single_step_p (gdbarch)))
1793 && sig == GDB_SIGNAL_0
1794 && !current_inferior ()->waiting_for_vfork_done)
1795 {
1796 struct displaced_step_inferior_state *displaced;
1797
1798 if (!displaced_step_prepare (inferior_ptid))
1799 {
1800 /* Got placed in displaced stepping queue. Will be resumed
1801 later when all the currently queued displaced stepping
1802 requests finish. The thread is not executing at this point,
1803 and the call to set_executing will be made later. But we
1804 need to call set_running here, since from frontend point of view,
1805 the thread is running. */
1806 set_running (inferior_ptid, 1);
1807 discard_cleanups (old_cleanups);
1808 return;
1809 }
1810
1811 /* Update pc to reflect the new address from which we will execute
1812 instructions due to displaced stepping. */
1813 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
1814
1815 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1816 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1817 displaced->step_closure);
1818 }
1819
1820 /* Do we need to do it the hard way, w/temp breakpoints? */
1821 else if (step)
1822 step = maybe_software_singlestep (gdbarch, pc);
1823
1824 /* Currently, our software single-step implementation leads to different
1825 results than hardware single-stepping in one situation: when stepping
1826 into delivering a signal which has an associated signal handler,
1827 hardware single-step will stop at the first instruction of the handler,
1828 while software single-step will simply skip execution of the handler.
1829
1830 For now, this difference in behavior is accepted since there is no
1831 easy way to actually implement single-stepping into a signal handler
1832 without kernel support.
1833
1834 However, there is one scenario where this difference leads to follow-on
1835 problems: if we're stepping off a breakpoint by removing all breakpoints
1836 and then single-stepping. In this case, the software single-step
1837 behavior means that even if there is a *breakpoint* in the signal
1838 handler, GDB still would not stop.
1839
1840 Fortunately, we can at least fix this particular issue. We detect
1841 here the case where we are about to deliver a signal while software
1842 single-stepping with breakpoints removed. In this situation, we
1843 revert the decisions to remove all breakpoints and insert single-
1844 step breakpoints, and instead we install a step-resume breakpoint
1845 at the current address, deliver the signal without stepping, and
1846 once we arrive back at the step-resume breakpoint, actually step
1847 over the breakpoint we originally wanted to step over. */
1848 if (singlestep_breakpoints_inserted_p
1849 && tp->control.trap_expected && sig != GDB_SIGNAL_0)
1850 {
1851 /* If we have nested signals or a pending signal is delivered
1852 immediately after a handler returns, might might already have
1853 a step-resume breakpoint set on the earlier handler. We cannot
1854 set another step-resume breakpoint; just continue on until the
1855 original breakpoint is hit. */
1856 if (tp->control.step_resume_breakpoint == NULL)
1857 {
1858 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1859 tp->step_after_step_resume_breakpoint = 1;
1860 }
1861
1862 remove_single_step_breakpoints ();
1863 singlestep_breakpoints_inserted_p = 0;
1864
1865 insert_breakpoints ();
1866 tp->control.trap_expected = 0;
1867 }
1868
1869 if (should_resume)
1870 {
1871 ptid_t resume_ptid;
1872
1873 /* If STEP is set, it's a request to use hardware stepping
1874 facilities. But in that case, we should never
1875 use singlestep breakpoint. */
1876 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1877
1878 /* Decide the set of threads to ask the target to resume. Start
1879 by assuming everything will be resumed, than narrow the set
1880 by applying increasingly restricting conditions. */
1881 resume_ptid = user_visible_resume_ptid (step);
1882
1883 /* Maybe resume a single thread after all. */
1884 if (singlestep_breakpoints_inserted_p
1885 && stepping_past_singlestep_breakpoint)
1886 {
1887 /* The situation here is as follows. In thread T1 we wanted to
1888 single-step. Lacking hardware single-stepping we've
1889 set breakpoint at the PC of the next instruction -- call it
1890 P. After resuming, we've hit that breakpoint in thread T2.
1891 Now we've removed original breakpoint, inserted breakpoint
1892 at P+1, and try to step to advance T2 past breakpoint.
1893 We need to step only T2, as if T1 is allowed to freely run,
1894 it can run past P, and if other threads are allowed to run,
1895 they can hit breakpoint at P+1, and nested hits of single-step
1896 breakpoints is not something we'd want -- that's complicated
1897 to support, and has no value. */
1898 resume_ptid = inferior_ptid;
1899 }
1900 else if ((step || singlestep_breakpoints_inserted_p)
1901 && tp->control.trap_expected)
1902 {
1903 /* We're allowing a thread to run past a breakpoint it has
1904 hit, by single-stepping the thread with the breakpoint
1905 removed. In which case, we need to single-step only this
1906 thread, and keep others stopped, as they can miss this
1907 breakpoint if allowed to run.
1908
1909 The current code actually removes all breakpoints when
1910 doing this, not just the one being stepped over, so if we
1911 let other threads run, we can actually miss any
1912 breakpoint, not just the one at PC. */
1913 resume_ptid = inferior_ptid;
1914 }
1915
1916 if (gdbarch_cannot_step_breakpoint (gdbarch))
1917 {
1918 /* Most targets can step a breakpoint instruction, thus
1919 executing it normally. But if this one cannot, just
1920 continue and we will hit it anyway. */
1921 if (step && breakpoint_inserted_here_p (aspace, pc))
1922 step = 0;
1923 }
1924
1925 if (debug_displaced
1926 && use_displaced_stepping (gdbarch)
1927 && tp->control.trap_expected)
1928 {
1929 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1930 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1931 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1932 gdb_byte buf[4];
1933
1934 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1935 paddress (resume_gdbarch, actual_pc));
1936 read_memory (actual_pc, buf, sizeof (buf));
1937 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1938 }
1939
1940 if (tp->control.may_range_step)
1941 {
1942 /* If we're resuming a thread with the PC out of the step
1943 range, then we're doing some nested/finer run control
1944 operation, like stepping the thread out of the dynamic
1945 linker or the displaced stepping scratch pad. We
1946 shouldn't have allowed a range step then. */
1947 gdb_assert (pc_in_thread_step_range (pc, tp));
1948 }
1949
1950 /* Install inferior's terminal modes. */
1951 target_terminal_inferior ();
1952
1953 /* Avoid confusing the next resume, if the next stop/resume
1954 happens to apply to another thread. */
1955 tp->suspend.stop_signal = GDB_SIGNAL_0;
1956
1957 /* Advise target which signals may be handled silently. If we have
1958 removed breakpoints because we are stepping over one (which can
1959 happen only if we are not using displaced stepping), we need to
1960 receive all signals to avoid accidentally skipping a breakpoint
1961 during execution of a signal handler. */
1962 if ((step || singlestep_breakpoints_inserted_p)
1963 && tp->control.trap_expected
1964 && !use_displaced_stepping (gdbarch))
1965 target_pass_signals (0, NULL);
1966 else
1967 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
1968
1969 target_resume (resume_ptid, step, sig);
1970 }
1971
1972 discard_cleanups (old_cleanups);
1973 }
1974 \f
1975 /* Proceeding. */
1976
1977 /* Clear out all variables saying what to do when inferior is continued.
1978 First do this, then set the ones you want, then call `proceed'. */
1979
1980 static void
1981 clear_proceed_status_thread (struct thread_info *tp)
1982 {
1983 if (debug_infrun)
1984 fprintf_unfiltered (gdb_stdlog,
1985 "infrun: clear_proceed_status_thread (%s)\n",
1986 target_pid_to_str (tp->ptid));
1987
1988 tp->control.trap_expected = 0;
1989 tp->control.step_range_start = 0;
1990 tp->control.step_range_end = 0;
1991 tp->control.may_range_step = 0;
1992 tp->control.step_frame_id = null_frame_id;
1993 tp->control.step_stack_frame_id = null_frame_id;
1994 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
1995 tp->stop_requested = 0;
1996
1997 tp->control.stop_step = 0;
1998
1999 tp->control.proceed_to_finish = 0;
2000
2001 /* Discard any remaining commands or status from previous stop. */
2002 bpstat_clear (&tp->control.stop_bpstat);
2003 }
2004
2005 static int
2006 clear_proceed_status_callback (struct thread_info *tp, void *data)
2007 {
2008 if (is_exited (tp->ptid))
2009 return 0;
2010
2011 clear_proceed_status_thread (tp);
2012 return 0;
2013 }
2014
2015 void
2016 clear_proceed_status (void)
2017 {
2018 if (!non_stop)
2019 {
2020 /* In all-stop mode, delete the per-thread status of all
2021 threads, even if inferior_ptid is null_ptid, there may be
2022 threads on the list. E.g., we may be launching a new
2023 process, while selecting the executable. */
2024 iterate_over_threads (clear_proceed_status_callback, NULL);
2025 }
2026
2027 if (!ptid_equal (inferior_ptid, null_ptid))
2028 {
2029 struct inferior *inferior;
2030
2031 if (non_stop)
2032 {
2033 /* If in non-stop mode, only delete the per-thread status of
2034 the current thread. */
2035 clear_proceed_status_thread (inferior_thread ());
2036 }
2037
2038 inferior = current_inferior ();
2039 inferior->control.stop_soon = NO_STOP_QUIETLY;
2040 }
2041
2042 stop_after_trap = 0;
2043
2044 observer_notify_about_to_proceed ();
2045
2046 if (stop_registers)
2047 {
2048 regcache_xfree (stop_registers);
2049 stop_registers = NULL;
2050 }
2051 }
2052
2053 /* Check the current thread against the thread that reported the most recent
2054 event. If a step-over is required return TRUE and set the current thread
2055 to the old thread. Otherwise return FALSE.
2056
2057 This should be suitable for any targets that support threads. */
2058
2059 static int
2060 prepare_to_proceed (int step)
2061 {
2062 ptid_t wait_ptid;
2063 struct target_waitstatus wait_status;
2064 int schedlock_enabled;
2065
2066 /* With non-stop mode on, threads are always handled individually. */
2067 gdb_assert (! non_stop);
2068
2069 /* Get the last target status returned by target_wait(). */
2070 get_last_target_status (&wait_ptid, &wait_status);
2071
2072 /* Make sure we were stopped at a breakpoint. */
2073 if (wait_status.kind != TARGET_WAITKIND_STOPPED
2074 || (wait_status.value.sig != GDB_SIGNAL_TRAP
2075 && wait_status.value.sig != GDB_SIGNAL_ILL
2076 && wait_status.value.sig != GDB_SIGNAL_SEGV
2077 && wait_status.value.sig != GDB_SIGNAL_EMT))
2078 {
2079 return 0;
2080 }
2081
2082 schedlock_enabled = (scheduler_mode == schedlock_on
2083 || (scheduler_mode == schedlock_step
2084 && step));
2085
2086 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
2087 if (schedlock_enabled)
2088 return 0;
2089
2090 /* Don't switch over if we're about to resume some other process
2091 other than WAIT_PTID's, and schedule-multiple is off. */
2092 if (!sched_multi
2093 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
2094 return 0;
2095
2096 /* Switched over from WAIT_PID. */
2097 if (!ptid_equal (wait_ptid, minus_one_ptid)
2098 && !ptid_equal (inferior_ptid, wait_ptid))
2099 {
2100 struct regcache *regcache = get_thread_regcache (wait_ptid);
2101
2102 if (breakpoint_here_p (get_regcache_aspace (regcache),
2103 regcache_read_pc (regcache)))
2104 {
2105 /* If stepping, remember current thread to switch back to. */
2106 if (step)
2107 deferred_step_ptid = inferior_ptid;
2108
2109 /* Switch back to WAIT_PID thread. */
2110 switch_to_thread (wait_ptid);
2111
2112 if (debug_infrun)
2113 fprintf_unfiltered (gdb_stdlog,
2114 "infrun: prepare_to_proceed (step=%d), "
2115 "switched to [%s]\n",
2116 step, target_pid_to_str (inferior_ptid));
2117
2118 /* We return 1 to indicate that there is a breakpoint here,
2119 so we need to step over it before continuing to avoid
2120 hitting it straight away. */
2121 return 1;
2122 }
2123 }
2124
2125 return 0;
2126 }
2127
2128 /* Basic routine for continuing the program in various fashions.
2129
2130 ADDR is the address to resume at, or -1 for resume where stopped.
2131 SIGGNAL is the signal to give it, or 0 for none,
2132 or -1 for act according to how it stopped.
2133 STEP is nonzero if should trap after one instruction.
2134 -1 means return after that and print nothing.
2135 You should probably set various step_... variables
2136 before calling here, if you are stepping.
2137
2138 You should call clear_proceed_status before calling proceed. */
2139
2140 void
2141 proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
2142 {
2143 struct regcache *regcache;
2144 struct gdbarch *gdbarch;
2145 struct thread_info *tp;
2146 CORE_ADDR pc;
2147 struct address_space *aspace;
2148 /* GDB may force the inferior to step due to various reasons. */
2149 int force_step = 0;
2150
2151 /* If we're stopped at a fork/vfork, follow the branch set by the
2152 "set follow-fork-mode" command; otherwise, we'll just proceed
2153 resuming the current thread. */
2154 if (!follow_fork ())
2155 {
2156 /* The target for some reason decided not to resume. */
2157 normal_stop ();
2158 if (target_can_async_p ())
2159 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2160 return;
2161 }
2162
2163 /* We'll update this if & when we switch to a new thread. */
2164 previous_inferior_ptid = inferior_ptid;
2165
2166 regcache = get_current_regcache ();
2167 gdbarch = get_regcache_arch (regcache);
2168 aspace = get_regcache_aspace (regcache);
2169 pc = regcache_read_pc (regcache);
2170
2171 if (step > 0)
2172 step_start_function = find_pc_function (pc);
2173 if (step < 0)
2174 stop_after_trap = 1;
2175
2176 if (addr == (CORE_ADDR) -1)
2177 {
2178 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2179 && execution_direction != EXEC_REVERSE)
2180 /* There is a breakpoint at the address we will resume at,
2181 step one instruction before inserting breakpoints so that
2182 we do not stop right away (and report a second hit at this
2183 breakpoint).
2184
2185 Note, we don't do this in reverse, because we won't
2186 actually be executing the breakpoint insn anyway.
2187 We'll be (un-)executing the previous instruction. */
2188
2189 force_step = 1;
2190 else if (gdbarch_single_step_through_delay_p (gdbarch)
2191 && gdbarch_single_step_through_delay (gdbarch,
2192 get_current_frame ()))
2193 /* We stepped onto an instruction that needs to be stepped
2194 again before re-inserting the breakpoint, do so. */
2195 force_step = 1;
2196 }
2197 else
2198 {
2199 regcache_write_pc (regcache, addr);
2200 }
2201
2202 if (debug_infrun)
2203 fprintf_unfiltered (gdb_stdlog,
2204 "infrun: proceed (addr=%s, signal=%s, step=%d)\n",
2205 paddress (gdbarch, addr),
2206 gdb_signal_to_symbol_string (siggnal), step);
2207
2208 if (non_stop)
2209 /* In non-stop, each thread is handled individually. The context
2210 must already be set to the right thread here. */
2211 ;
2212 else
2213 {
2214 /* In a multi-threaded task we may select another thread and
2215 then continue or step.
2216
2217 But if the old thread was stopped at a breakpoint, it will
2218 immediately cause another breakpoint stop without any
2219 execution (i.e. it will report a breakpoint hit incorrectly).
2220 So we must step over it first.
2221
2222 prepare_to_proceed checks the current thread against the
2223 thread that reported the most recent event. If a step-over
2224 is required it returns TRUE and sets the current thread to
2225 the old thread. */
2226 if (prepare_to_proceed (step))
2227 force_step = 1;
2228 }
2229
2230 /* prepare_to_proceed may change the current thread. */
2231 tp = inferior_thread ();
2232
2233 if (force_step)
2234 {
2235 tp->control.trap_expected = 1;
2236 /* If displaced stepping is enabled, we can step over the
2237 breakpoint without hitting it, so leave all breakpoints
2238 inserted. Otherwise we need to disable all breakpoints, step
2239 one instruction, and then re-add them when that step is
2240 finished. */
2241 if (!use_displaced_stepping (gdbarch))
2242 remove_breakpoints ();
2243 }
2244
2245 /* We can insert breakpoints if we're not trying to step over one,
2246 or if we are stepping over one but we're using displaced stepping
2247 to do so. */
2248 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch))
2249 insert_breakpoints ();
2250
2251 if (!non_stop)
2252 {
2253 /* Pass the last stop signal to the thread we're resuming,
2254 irrespective of whether the current thread is the thread that
2255 got the last event or not. This was historically GDB's
2256 behaviour before keeping a stop_signal per thread. */
2257
2258 struct thread_info *last_thread;
2259 ptid_t last_ptid;
2260 struct target_waitstatus last_status;
2261
2262 get_last_target_status (&last_ptid, &last_status);
2263 if (!ptid_equal (inferior_ptid, last_ptid)
2264 && !ptid_equal (last_ptid, null_ptid)
2265 && !ptid_equal (last_ptid, minus_one_ptid))
2266 {
2267 last_thread = find_thread_ptid (last_ptid);
2268 if (last_thread)
2269 {
2270 tp->suspend.stop_signal = last_thread->suspend.stop_signal;
2271 last_thread->suspend.stop_signal = GDB_SIGNAL_0;
2272 }
2273 }
2274 }
2275
2276 if (siggnal != GDB_SIGNAL_DEFAULT)
2277 tp->suspend.stop_signal = siggnal;
2278 /* If this signal should not be seen by program,
2279 give it zero. Used for debugging signals. */
2280 else if (!signal_program[tp->suspend.stop_signal])
2281 tp->suspend.stop_signal = GDB_SIGNAL_0;
2282
2283 annotate_starting ();
2284
2285 /* Make sure that output from GDB appears before output from the
2286 inferior. */
2287 gdb_flush (gdb_stdout);
2288
2289 /* Refresh prev_pc value just prior to resuming. This used to be
2290 done in stop_stepping, however, setting prev_pc there did not handle
2291 scenarios such as inferior function calls or returning from
2292 a function via the return command. In those cases, the prev_pc
2293 value was not set properly for subsequent commands. The prev_pc value
2294 is used to initialize the starting line number in the ecs. With an
2295 invalid value, the gdb next command ends up stopping at the position
2296 represented by the next line table entry past our start position.
2297 On platforms that generate one line table entry per line, this
2298 is not a problem. However, on the ia64, the compiler generates
2299 extraneous line table entries that do not increase the line number.
2300 When we issue the gdb next command on the ia64 after an inferior call
2301 or a return command, we often end up a few instructions forward, still
2302 within the original line we started.
2303
2304 An attempt was made to refresh the prev_pc at the same time the
2305 execution_control_state is initialized (for instance, just before
2306 waiting for an inferior event). But this approach did not work
2307 because of platforms that use ptrace, where the pc register cannot
2308 be read unless the inferior is stopped. At that point, we are not
2309 guaranteed the inferior is stopped and so the regcache_read_pc() call
2310 can fail. Setting the prev_pc value here ensures the value is updated
2311 correctly when the inferior is stopped. */
2312 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2313
2314 /* Fill in with reasonable starting values. */
2315 init_thread_stepping_state (tp);
2316
2317 /* Reset to normal state. */
2318 init_infwait_state ();
2319
2320 /* Resume inferior. */
2321 resume (force_step || step || bpstat_should_step (),
2322 tp->suspend.stop_signal);
2323
2324 /* Wait for it to stop (if not standalone)
2325 and in any case decode why it stopped, and act accordingly. */
2326 /* Do this only if we are not using the event loop, or if the target
2327 does not support asynchronous execution. */
2328 if (!target_can_async_p ())
2329 {
2330 wait_for_inferior ();
2331 normal_stop ();
2332 }
2333 }
2334 \f
2335
2336 /* Start remote-debugging of a machine over a serial link. */
2337
2338 void
2339 start_remote (int from_tty)
2340 {
2341 struct inferior *inferior;
2342
2343 inferior = current_inferior ();
2344 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2345
2346 /* Always go on waiting for the target, regardless of the mode. */
2347 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2348 indicate to wait_for_inferior that a target should timeout if
2349 nothing is returned (instead of just blocking). Because of this,
2350 targets expecting an immediate response need to, internally, set
2351 things up so that the target_wait() is forced to eventually
2352 timeout. */
2353 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2354 differentiate to its caller what the state of the target is after
2355 the initial open has been performed. Here we're assuming that
2356 the target has stopped. It should be possible to eventually have
2357 target_open() return to the caller an indication that the target
2358 is currently running and GDB state should be set to the same as
2359 for an async run. */
2360 wait_for_inferior ();
2361
2362 /* Now that the inferior has stopped, do any bookkeeping like
2363 loading shared libraries. We want to do this before normal_stop,
2364 so that the displayed frame is up to date. */
2365 post_create_inferior (&current_target, from_tty);
2366
2367 normal_stop ();
2368 }
2369
2370 /* Initialize static vars when a new inferior begins. */
2371
2372 void
2373 init_wait_for_inferior (void)
2374 {
2375 /* These are meaningless until the first time through wait_for_inferior. */
2376
2377 breakpoint_init_inferior (inf_starting);
2378
2379 clear_proceed_status ();
2380
2381 stepping_past_singlestep_breakpoint = 0;
2382 deferred_step_ptid = null_ptid;
2383
2384 target_last_wait_ptid = minus_one_ptid;
2385
2386 previous_inferior_ptid = inferior_ptid;
2387 init_infwait_state ();
2388
2389 /* Discard any skipped inlined frames. */
2390 clear_inline_frame_state (minus_one_ptid);
2391 }
2392
2393 \f
2394 /* This enum encodes possible reasons for doing a target_wait, so that
2395 wfi can call target_wait in one place. (Ultimately the call will be
2396 moved out of the infinite loop entirely.) */
2397
2398 enum infwait_states
2399 {
2400 infwait_normal_state,
2401 infwait_thread_hop_state,
2402 infwait_step_watch_state,
2403 infwait_nonstep_watch_state
2404 };
2405
2406 /* The PTID we'll do a target_wait on.*/
2407 ptid_t waiton_ptid;
2408
2409 /* Current inferior wait state. */
2410 static enum infwait_states infwait_state;
2411
2412 /* Data to be passed around while handling an event. This data is
2413 discarded between events. */
2414 struct execution_control_state
2415 {
2416 ptid_t ptid;
2417 /* The thread that got the event, if this was a thread event; NULL
2418 otherwise. */
2419 struct thread_info *event_thread;
2420
2421 struct target_waitstatus ws;
2422 int random_signal;
2423 int stop_func_filled_in;
2424 CORE_ADDR stop_func_start;
2425 CORE_ADDR stop_func_end;
2426 const char *stop_func_name;
2427 int wait_some_more;
2428 };
2429
2430 static void handle_inferior_event (struct execution_control_state *ecs);
2431
2432 static void handle_step_into_function (struct gdbarch *gdbarch,
2433 struct execution_control_state *ecs);
2434 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2435 struct execution_control_state *ecs);
2436 static void check_exception_resume (struct execution_control_state *,
2437 struct frame_info *);
2438
2439 static void stop_stepping (struct execution_control_state *ecs);
2440 static void prepare_to_wait (struct execution_control_state *ecs);
2441 static void keep_going (struct execution_control_state *ecs);
2442 static void process_event_stop_test (struct execution_control_state *ecs);
2443 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
2444
2445 /* Callback for iterate over threads. If the thread is stopped, but
2446 the user/frontend doesn't know about that yet, go through
2447 normal_stop, as if the thread had just stopped now. ARG points at
2448 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2449 ptid_is_pid(PTID) is true, applies to all threads of the process
2450 pointed at by PTID. Otherwise, apply only to the thread pointed by
2451 PTID. */
2452
2453 static int
2454 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2455 {
2456 ptid_t ptid = * (ptid_t *) arg;
2457
2458 if ((ptid_equal (info->ptid, ptid)
2459 || ptid_equal (minus_one_ptid, ptid)
2460 || (ptid_is_pid (ptid)
2461 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2462 && is_running (info->ptid)
2463 && !is_executing (info->ptid))
2464 {
2465 struct cleanup *old_chain;
2466 struct execution_control_state ecss;
2467 struct execution_control_state *ecs = &ecss;
2468
2469 memset (ecs, 0, sizeof (*ecs));
2470
2471 old_chain = make_cleanup_restore_current_thread ();
2472
2473 /* Go through handle_inferior_event/normal_stop, so we always
2474 have consistent output as if the stop event had been
2475 reported. */
2476 ecs->ptid = info->ptid;
2477 ecs->event_thread = find_thread_ptid (info->ptid);
2478 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2479 ecs->ws.value.sig = GDB_SIGNAL_0;
2480
2481 handle_inferior_event (ecs);
2482
2483 if (!ecs->wait_some_more)
2484 {
2485 struct thread_info *tp;
2486
2487 normal_stop ();
2488
2489 /* Finish off the continuations. */
2490 tp = inferior_thread ();
2491 do_all_intermediate_continuations_thread (tp, 1);
2492 do_all_continuations_thread (tp, 1);
2493 }
2494
2495 do_cleanups (old_chain);
2496 }
2497
2498 return 0;
2499 }
2500
2501 /* This function is attached as a "thread_stop_requested" observer.
2502 Cleanup local state that assumed the PTID was to be resumed, and
2503 report the stop to the frontend. */
2504
2505 static void
2506 infrun_thread_stop_requested (ptid_t ptid)
2507 {
2508 struct displaced_step_inferior_state *displaced;
2509
2510 /* PTID was requested to stop. Remove it from the displaced
2511 stepping queue, so we don't try to resume it automatically. */
2512
2513 for (displaced = displaced_step_inferior_states;
2514 displaced;
2515 displaced = displaced->next)
2516 {
2517 struct displaced_step_request *it, **prev_next_p;
2518
2519 it = displaced->step_request_queue;
2520 prev_next_p = &displaced->step_request_queue;
2521 while (it)
2522 {
2523 if (ptid_match (it->ptid, ptid))
2524 {
2525 *prev_next_p = it->next;
2526 it->next = NULL;
2527 xfree (it);
2528 }
2529 else
2530 {
2531 prev_next_p = &it->next;
2532 }
2533
2534 it = *prev_next_p;
2535 }
2536 }
2537
2538 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2539 }
2540
2541 static void
2542 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2543 {
2544 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2545 nullify_last_target_wait_ptid ();
2546 }
2547
2548 /* Callback for iterate_over_threads. */
2549
2550 static int
2551 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2552 {
2553 if (is_exited (info->ptid))
2554 return 0;
2555
2556 delete_step_resume_breakpoint (info);
2557 delete_exception_resume_breakpoint (info);
2558 return 0;
2559 }
2560
2561 /* In all-stop, delete the step resume breakpoint of any thread that
2562 had one. In non-stop, delete the step resume breakpoint of the
2563 thread that just stopped. */
2564
2565 static void
2566 delete_step_thread_step_resume_breakpoint (void)
2567 {
2568 if (!target_has_execution
2569 || ptid_equal (inferior_ptid, null_ptid))
2570 /* If the inferior has exited, we have already deleted the step
2571 resume breakpoints out of GDB's lists. */
2572 return;
2573
2574 if (non_stop)
2575 {
2576 /* If in non-stop mode, only delete the step-resume or
2577 longjmp-resume breakpoint of the thread that just stopped
2578 stepping. */
2579 struct thread_info *tp = inferior_thread ();
2580
2581 delete_step_resume_breakpoint (tp);
2582 delete_exception_resume_breakpoint (tp);
2583 }
2584 else
2585 /* In all-stop mode, delete all step-resume and longjmp-resume
2586 breakpoints of any thread that had them. */
2587 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2588 }
2589
2590 /* A cleanup wrapper. */
2591
2592 static void
2593 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2594 {
2595 delete_step_thread_step_resume_breakpoint ();
2596 }
2597
2598 /* Pretty print the results of target_wait, for debugging purposes. */
2599
2600 static void
2601 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2602 const struct target_waitstatus *ws)
2603 {
2604 char *status_string = target_waitstatus_to_string (ws);
2605 struct ui_file *tmp_stream = mem_fileopen ();
2606 char *text;
2607
2608 /* The text is split over several lines because it was getting too long.
2609 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2610 output as a unit; we want only one timestamp printed if debug_timestamp
2611 is set. */
2612
2613 fprintf_unfiltered (tmp_stream,
2614 "infrun: target_wait (%d", ptid_get_pid (waiton_ptid));
2615 if (ptid_get_pid (waiton_ptid) != -1)
2616 fprintf_unfiltered (tmp_stream,
2617 " [%s]", target_pid_to_str (waiton_ptid));
2618 fprintf_unfiltered (tmp_stream, ", status) =\n");
2619 fprintf_unfiltered (tmp_stream,
2620 "infrun: %d [%s],\n",
2621 ptid_get_pid (result_ptid),
2622 target_pid_to_str (result_ptid));
2623 fprintf_unfiltered (tmp_stream,
2624 "infrun: %s\n",
2625 status_string);
2626
2627 text = ui_file_xstrdup (tmp_stream, NULL);
2628
2629 /* This uses %s in part to handle %'s in the text, but also to avoid
2630 a gcc error: the format attribute requires a string literal. */
2631 fprintf_unfiltered (gdb_stdlog, "%s", text);
2632
2633 xfree (status_string);
2634 xfree (text);
2635 ui_file_delete (tmp_stream);
2636 }
2637
2638 /* Prepare and stabilize the inferior for detaching it. E.g.,
2639 detaching while a thread is displaced stepping is a recipe for
2640 crashing it, as nothing would readjust the PC out of the scratch
2641 pad. */
2642
2643 void
2644 prepare_for_detach (void)
2645 {
2646 struct inferior *inf = current_inferior ();
2647 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2648 struct cleanup *old_chain_1;
2649 struct displaced_step_inferior_state *displaced;
2650
2651 displaced = get_displaced_stepping_state (inf->pid);
2652
2653 /* Is any thread of this process displaced stepping? If not,
2654 there's nothing else to do. */
2655 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2656 return;
2657
2658 if (debug_infrun)
2659 fprintf_unfiltered (gdb_stdlog,
2660 "displaced-stepping in-process while detaching");
2661
2662 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2663 inf->detaching = 1;
2664
2665 while (!ptid_equal (displaced->step_ptid, null_ptid))
2666 {
2667 struct cleanup *old_chain_2;
2668 struct execution_control_state ecss;
2669 struct execution_control_state *ecs;
2670
2671 ecs = &ecss;
2672 memset (ecs, 0, sizeof (*ecs));
2673
2674 overlay_cache_invalid = 1;
2675
2676 if (deprecated_target_wait_hook)
2677 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2678 else
2679 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2680
2681 if (debug_infrun)
2682 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2683
2684 /* If an error happens while handling the event, propagate GDB's
2685 knowledge of the executing state to the frontend/user running
2686 state. */
2687 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
2688 &minus_one_ptid);
2689
2690 /* Now figure out what to do with the result of the result. */
2691 handle_inferior_event (ecs);
2692
2693 /* No error, don't finish the state yet. */
2694 discard_cleanups (old_chain_2);
2695
2696 /* Breakpoints and watchpoints are not installed on the target
2697 at this point, and signals are passed directly to the
2698 inferior, so this must mean the process is gone. */
2699 if (!ecs->wait_some_more)
2700 {
2701 discard_cleanups (old_chain_1);
2702 error (_("Program exited while detaching"));
2703 }
2704 }
2705
2706 discard_cleanups (old_chain_1);
2707 }
2708
2709 /* Wait for control to return from inferior to debugger.
2710
2711 If inferior gets a signal, we may decide to start it up again
2712 instead of returning. That is why there is a loop in this function.
2713 When this function actually returns it means the inferior
2714 should be left stopped and GDB should read more commands. */
2715
2716 void
2717 wait_for_inferior (void)
2718 {
2719 struct cleanup *old_cleanups;
2720
2721 if (debug_infrun)
2722 fprintf_unfiltered
2723 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
2724
2725 old_cleanups =
2726 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2727
2728 while (1)
2729 {
2730 struct execution_control_state ecss;
2731 struct execution_control_state *ecs = &ecss;
2732 struct cleanup *old_chain;
2733
2734 memset (ecs, 0, sizeof (*ecs));
2735
2736 overlay_cache_invalid = 1;
2737
2738 if (deprecated_target_wait_hook)
2739 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2740 else
2741 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2742
2743 if (debug_infrun)
2744 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2745
2746 /* If an error happens while handling the event, propagate GDB's
2747 knowledge of the executing state to the frontend/user running
2748 state. */
2749 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2750
2751 /* Now figure out what to do with the result of the result. */
2752 handle_inferior_event (ecs);
2753
2754 /* No error, don't finish the state yet. */
2755 discard_cleanups (old_chain);
2756
2757 if (!ecs->wait_some_more)
2758 break;
2759 }
2760
2761 do_cleanups (old_cleanups);
2762 }
2763
2764 /* Asynchronous version of wait_for_inferior. It is called by the
2765 event loop whenever a change of state is detected on the file
2766 descriptor corresponding to the target. It can be called more than
2767 once to complete a single execution command. In such cases we need
2768 to keep the state in a global variable ECSS. If it is the last time
2769 that this function is called for a single execution command, then
2770 report to the user that the inferior has stopped, and do the
2771 necessary cleanups. */
2772
2773 void
2774 fetch_inferior_event (void *client_data)
2775 {
2776 struct execution_control_state ecss;
2777 struct execution_control_state *ecs = &ecss;
2778 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2779 struct cleanup *ts_old_chain;
2780 int was_sync = sync_execution;
2781 int cmd_done = 0;
2782
2783 memset (ecs, 0, sizeof (*ecs));
2784
2785 /* We're handling a live event, so make sure we're doing live
2786 debugging. If we're looking at traceframes while the target is
2787 running, we're going to need to get back to that mode after
2788 handling the event. */
2789 if (non_stop)
2790 {
2791 make_cleanup_restore_current_traceframe ();
2792 set_current_traceframe (-1);
2793 }
2794
2795 if (non_stop)
2796 /* In non-stop mode, the user/frontend should not notice a thread
2797 switch due to internal events. Make sure we reverse to the
2798 user selected thread and frame after handling the event and
2799 running any breakpoint commands. */
2800 make_cleanup_restore_current_thread ();
2801
2802 overlay_cache_invalid = 1;
2803
2804 make_cleanup_restore_integer (&execution_direction);
2805 execution_direction = target_execution_direction ();
2806
2807 if (deprecated_target_wait_hook)
2808 ecs->ptid =
2809 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2810 else
2811 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2812
2813 if (debug_infrun)
2814 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2815
2816 /* If an error happens while handling the event, propagate GDB's
2817 knowledge of the executing state to the frontend/user running
2818 state. */
2819 if (!non_stop)
2820 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2821 else
2822 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2823
2824 /* Get executed before make_cleanup_restore_current_thread above to apply
2825 still for the thread which has thrown the exception. */
2826 make_bpstat_clear_actions_cleanup ();
2827
2828 /* Now figure out what to do with the result of the result. */
2829 handle_inferior_event (ecs);
2830
2831 if (!ecs->wait_some_more)
2832 {
2833 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2834
2835 delete_step_thread_step_resume_breakpoint ();
2836
2837 /* We may not find an inferior if this was a process exit. */
2838 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
2839 normal_stop ();
2840
2841 if (target_has_execution
2842 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
2843 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2844 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2845 && ecs->event_thread->step_multi
2846 && ecs->event_thread->control.stop_step)
2847 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2848 else
2849 {
2850 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2851 cmd_done = 1;
2852 }
2853 }
2854
2855 /* No error, don't finish the thread states yet. */
2856 discard_cleanups (ts_old_chain);
2857
2858 /* Revert thread and frame. */
2859 do_cleanups (old_chain);
2860
2861 /* If the inferior was in sync execution mode, and now isn't,
2862 restore the prompt (a synchronous execution command has finished,
2863 and we're ready for input). */
2864 if (interpreter_async && was_sync && !sync_execution)
2865 display_gdb_prompt (0);
2866
2867 if (cmd_done
2868 && !was_sync
2869 && exec_done_display_p
2870 && (ptid_equal (inferior_ptid, null_ptid)
2871 || !is_running (inferior_ptid)))
2872 printf_unfiltered (_("completed.\n"));
2873 }
2874
2875 /* Record the frame and location we're currently stepping through. */
2876 void
2877 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2878 {
2879 struct thread_info *tp = inferior_thread ();
2880
2881 tp->control.step_frame_id = get_frame_id (frame);
2882 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
2883
2884 tp->current_symtab = sal.symtab;
2885 tp->current_line = sal.line;
2886 }
2887
2888 /* Clear context switchable stepping state. */
2889
2890 void
2891 init_thread_stepping_state (struct thread_info *tss)
2892 {
2893 tss->stepping_over_breakpoint = 0;
2894 tss->step_after_step_resume_breakpoint = 0;
2895 }
2896
2897 /* Return the cached copy of the last pid/waitstatus returned by
2898 target_wait()/deprecated_target_wait_hook(). The data is actually
2899 cached by handle_inferior_event(), which gets called immediately
2900 after target_wait()/deprecated_target_wait_hook(). */
2901
2902 void
2903 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2904 {
2905 *ptidp = target_last_wait_ptid;
2906 *status = target_last_waitstatus;
2907 }
2908
2909 void
2910 nullify_last_target_wait_ptid (void)
2911 {
2912 target_last_wait_ptid = minus_one_ptid;
2913 }
2914
2915 /* Switch thread contexts. */
2916
2917 static void
2918 context_switch (ptid_t ptid)
2919 {
2920 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
2921 {
2922 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2923 target_pid_to_str (inferior_ptid));
2924 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2925 target_pid_to_str (ptid));
2926 }
2927
2928 switch_to_thread (ptid);
2929 }
2930
2931 static void
2932 adjust_pc_after_break (struct execution_control_state *ecs)
2933 {
2934 struct regcache *regcache;
2935 struct gdbarch *gdbarch;
2936 struct address_space *aspace;
2937 CORE_ADDR breakpoint_pc;
2938
2939 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2940 we aren't, just return.
2941
2942 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2943 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2944 implemented by software breakpoints should be handled through the normal
2945 breakpoint layer.
2946
2947 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2948 different signals (SIGILL or SIGEMT for instance), but it is less
2949 clear where the PC is pointing afterwards. It may not match
2950 gdbarch_decr_pc_after_break. I don't know any specific target that
2951 generates these signals at breakpoints (the code has been in GDB since at
2952 least 1992) so I can not guess how to handle them here.
2953
2954 In earlier versions of GDB, a target with
2955 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2956 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2957 target with both of these set in GDB history, and it seems unlikely to be
2958 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2959
2960 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2961 return;
2962
2963 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
2964 return;
2965
2966 /* In reverse execution, when a breakpoint is hit, the instruction
2967 under it has already been de-executed. The reported PC always
2968 points at the breakpoint address, so adjusting it further would
2969 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2970 architecture:
2971
2972 B1 0x08000000 : INSN1
2973 B2 0x08000001 : INSN2
2974 0x08000002 : INSN3
2975 PC -> 0x08000003 : INSN4
2976
2977 Say you're stopped at 0x08000003 as above. Reverse continuing
2978 from that point should hit B2 as below. Reading the PC when the
2979 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2980 been de-executed already.
2981
2982 B1 0x08000000 : INSN1
2983 B2 PC -> 0x08000001 : INSN2
2984 0x08000002 : INSN3
2985 0x08000003 : INSN4
2986
2987 We can't apply the same logic as for forward execution, because
2988 we would wrongly adjust the PC to 0x08000000, since there's a
2989 breakpoint at PC - 1. We'd then report a hit on B1, although
2990 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2991 behaviour. */
2992 if (execution_direction == EXEC_REVERSE)
2993 return;
2994
2995 /* If this target does not decrement the PC after breakpoints, then
2996 we have nothing to do. */
2997 regcache = get_thread_regcache (ecs->ptid);
2998 gdbarch = get_regcache_arch (regcache);
2999 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
3000 return;
3001
3002 aspace = get_regcache_aspace (regcache);
3003
3004 /* Find the location where (if we've hit a breakpoint) the
3005 breakpoint would be. */
3006 breakpoint_pc = regcache_read_pc (regcache)
3007 - gdbarch_decr_pc_after_break (gdbarch);
3008
3009 /* Check whether there actually is a software breakpoint inserted at
3010 that location.
3011
3012 If in non-stop mode, a race condition is possible where we've
3013 removed a breakpoint, but stop events for that breakpoint were
3014 already queued and arrive later. To suppress those spurious
3015 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3016 and retire them after a number of stop events are reported. */
3017 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3018 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3019 {
3020 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
3021
3022 if (RECORD_IS_USED)
3023 record_full_gdb_operation_disable_set ();
3024
3025 /* When using hardware single-step, a SIGTRAP is reported for both
3026 a completed single-step and a software breakpoint. Need to
3027 differentiate between the two, as the latter needs adjusting
3028 but the former does not.
3029
3030 The SIGTRAP can be due to a completed hardware single-step only if
3031 - we didn't insert software single-step breakpoints
3032 - the thread to be examined is still the current thread
3033 - this thread is currently being stepped
3034
3035 If any of these events did not occur, we must have stopped due
3036 to hitting a software breakpoint, and have to back up to the
3037 breakpoint address.
3038
3039 As a special case, we could have hardware single-stepped a
3040 software breakpoint. In this case (prev_pc == breakpoint_pc),
3041 we also need to back up to the breakpoint address. */
3042
3043 if (singlestep_breakpoints_inserted_p
3044 || !ptid_equal (ecs->ptid, inferior_ptid)
3045 || !currently_stepping (ecs->event_thread)
3046 || ecs->event_thread->prev_pc == breakpoint_pc)
3047 regcache_write_pc (regcache, breakpoint_pc);
3048
3049 do_cleanups (old_cleanups);
3050 }
3051 }
3052
3053 static void
3054 init_infwait_state (void)
3055 {
3056 waiton_ptid = pid_to_ptid (-1);
3057 infwait_state = infwait_normal_state;
3058 }
3059
3060 static int
3061 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3062 {
3063 for (frame = get_prev_frame (frame);
3064 frame != NULL;
3065 frame = get_prev_frame (frame))
3066 {
3067 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3068 return 1;
3069 if (get_frame_type (frame) != INLINE_FRAME)
3070 break;
3071 }
3072
3073 return 0;
3074 }
3075
3076 /* Auxiliary function that handles syscall entry/return events.
3077 It returns 1 if the inferior should keep going (and GDB
3078 should ignore the event), or 0 if the event deserves to be
3079 processed. */
3080
3081 static int
3082 handle_syscall_event (struct execution_control_state *ecs)
3083 {
3084 struct regcache *regcache;
3085 int syscall_number;
3086
3087 if (!ptid_equal (ecs->ptid, inferior_ptid))
3088 context_switch (ecs->ptid);
3089
3090 regcache = get_thread_regcache (ecs->ptid);
3091 syscall_number = ecs->ws.value.syscall_number;
3092 stop_pc = regcache_read_pc (regcache);
3093
3094 if (catch_syscall_enabled () > 0
3095 && catching_syscall_number (syscall_number) > 0)
3096 {
3097 enum bpstat_signal_value sval;
3098
3099 if (debug_infrun)
3100 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3101 syscall_number);
3102
3103 ecs->event_thread->control.stop_bpstat
3104 = bpstat_stop_status (get_regcache_aspace (regcache),
3105 stop_pc, ecs->ptid, &ecs->ws);
3106
3107 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3108 GDB_SIGNAL_TRAP);
3109 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3110
3111 if (!ecs->random_signal)
3112 {
3113 /* Catchpoint hit. */
3114 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3115 return 0;
3116 }
3117 }
3118
3119 /* If no catchpoint triggered for this, then keep going. */
3120 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3121 keep_going (ecs);
3122 return 1;
3123 }
3124
3125 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3126
3127 static void
3128 fill_in_stop_func (struct gdbarch *gdbarch,
3129 struct execution_control_state *ecs)
3130 {
3131 if (!ecs->stop_func_filled_in)
3132 {
3133 /* Don't care about return value; stop_func_start and stop_func_name
3134 will both be 0 if it doesn't work. */
3135 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3136 &ecs->stop_func_start, &ecs->stop_func_end);
3137 ecs->stop_func_start
3138 += gdbarch_deprecated_function_start_offset (gdbarch);
3139
3140 ecs->stop_func_filled_in = 1;
3141 }
3142 }
3143
3144 /* Given an execution control state that has been freshly filled in
3145 by an event from the inferior, figure out what it means and take
3146 appropriate action. */
3147
3148 static void
3149 handle_inferior_event (struct execution_control_state *ecs)
3150 {
3151 struct frame_info *frame;
3152 struct gdbarch *gdbarch;
3153 int stopped_by_watchpoint;
3154 int stepped_after_stopped_by_watchpoint = 0;
3155 enum stop_kind stop_soon;
3156
3157 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3158 {
3159 /* We had an event in the inferior, but we are not interested in
3160 handling it at this level. The lower layers have already
3161 done what needs to be done, if anything.
3162
3163 One of the possible circumstances for this is when the
3164 inferior produces output for the console. The inferior has
3165 not stopped, and we are ignoring the event. Another possible
3166 circumstance is any event which the lower level knows will be
3167 reported multiple times without an intervening resume. */
3168 if (debug_infrun)
3169 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3170 prepare_to_wait (ecs);
3171 return;
3172 }
3173
3174 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3175 && target_can_async_p () && !sync_execution)
3176 {
3177 /* There were no unwaited-for children left in the target, but,
3178 we're not synchronously waiting for events either. Just
3179 ignore. Otherwise, if we were running a synchronous
3180 execution command, we need to cancel it and give the user
3181 back the terminal. */
3182 if (debug_infrun)
3183 fprintf_unfiltered (gdb_stdlog,
3184 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3185 prepare_to_wait (ecs);
3186 return;
3187 }
3188
3189 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3190 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3191 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED)
3192 {
3193 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3194
3195 gdb_assert (inf);
3196 stop_soon = inf->control.stop_soon;
3197 }
3198 else
3199 stop_soon = NO_STOP_QUIETLY;
3200
3201 /* Cache the last pid/waitstatus. */
3202 target_last_wait_ptid = ecs->ptid;
3203 target_last_waitstatus = ecs->ws;
3204
3205 /* Always clear state belonging to the previous time we stopped. */
3206 stop_stack_dummy = STOP_NONE;
3207
3208 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3209 {
3210 /* No unwaited-for children left. IOW, all resumed children
3211 have exited. */
3212 if (debug_infrun)
3213 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3214
3215 stop_print_frame = 0;
3216 stop_stepping (ecs);
3217 return;
3218 }
3219
3220 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3221 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3222 {
3223 ecs->event_thread = find_thread_ptid (ecs->ptid);
3224 /* If it's a new thread, add it to the thread database. */
3225 if (ecs->event_thread == NULL)
3226 ecs->event_thread = add_thread (ecs->ptid);
3227
3228 /* Disable range stepping. If the next step request could use a
3229 range, this will be end up re-enabled then. */
3230 ecs->event_thread->control.may_range_step = 0;
3231 }
3232
3233 /* Dependent on valid ECS->EVENT_THREAD. */
3234 adjust_pc_after_break (ecs);
3235
3236 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3237 reinit_frame_cache ();
3238
3239 breakpoint_retire_moribund ();
3240
3241 /* First, distinguish signals caused by the debugger from signals
3242 that have to do with the program's own actions. Note that
3243 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3244 on the operating system version. Here we detect when a SIGILL or
3245 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3246 something similar for SIGSEGV, since a SIGSEGV will be generated
3247 when we're trying to execute a breakpoint instruction on a
3248 non-executable stack. This happens for call dummy breakpoints
3249 for architectures like SPARC that place call dummies on the
3250 stack. */
3251 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3252 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3253 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3254 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3255 {
3256 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3257
3258 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3259 regcache_read_pc (regcache)))
3260 {
3261 if (debug_infrun)
3262 fprintf_unfiltered (gdb_stdlog,
3263 "infrun: Treating signal as SIGTRAP\n");
3264 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3265 }
3266 }
3267
3268 /* Mark the non-executing threads accordingly. In all-stop, all
3269 threads of all processes are stopped when we get any event
3270 reported. In non-stop mode, only the event thread stops. If
3271 we're handling a process exit in non-stop mode, there's nothing
3272 to do, as threads of the dead process are gone, and threads of
3273 any other process were left running. */
3274 if (!non_stop)
3275 set_executing (minus_one_ptid, 0);
3276 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3277 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3278 set_executing (ecs->ptid, 0);
3279
3280 switch (infwait_state)
3281 {
3282 case infwait_thread_hop_state:
3283 if (debug_infrun)
3284 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
3285 break;
3286
3287 case infwait_normal_state:
3288 if (debug_infrun)
3289 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
3290 break;
3291
3292 case infwait_step_watch_state:
3293 if (debug_infrun)
3294 fprintf_unfiltered (gdb_stdlog,
3295 "infrun: infwait_step_watch_state\n");
3296
3297 stepped_after_stopped_by_watchpoint = 1;
3298 break;
3299
3300 case infwait_nonstep_watch_state:
3301 if (debug_infrun)
3302 fprintf_unfiltered (gdb_stdlog,
3303 "infrun: infwait_nonstep_watch_state\n");
3304 insert_breakpoints ();
3305
3306 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3307 handle things like signals arriving and other things happening
3308 in combination correctly? */
3309 stepped_after_stopped_by_watchpoint = 1;
3310 break;
3311
3312 default:
3313 internal_error (__FILE__, __LINE__, _("bad switch"));
3314 }
3315
3316 infwait_state = infwait_normal_state;
3317 waiton_ptid = pid_to_ptid (-1);
3318
3319 switch (ecs->ws.kind)
3320 {
3321 case TARGET_WAITKIND_LOADED:
3322 if (debug_infrun)
3323 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3324 /* Ignore gracefully during startup of the inferior, as it might
3325 be the shell which has just loaded some objects, otherwise
3326 add the symbols for the newly loaded objects. Also ignore at
3327 the beginning of an attach or remote session; we will query
3328 the full list of libraries once the connection is
3329 established. */
3330 if (stop_soon == NO_STOP_QUIETLY)
3331 {
3332 struct regcache *regcache;
3333 enum bpstat_signal_value sval;
3334
3335 if (!ptid_equal (ecs->ptid, inferior_ptid))
3336 context_switch (ecs->ptid);
3337 regcache = get_thread_regcache (ecs->ptid);
3338
3339 handle_solib_event ();
3340
3341 ecs->event_thread->control.stop_bpstat
3342 = bpstat_stop_status (get_regcache_aspace (regcache),
3343 stop_pc, ecs->ptid, &ecs->ws);
3344
3345 sval
3346 = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3347 GDB_SIGNAL_TRAP);
3348 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3349
3350 if (!ecs->random_signal)
3351 {
3352 /* A catchpoint triggered. */
3353 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3354 process_event_stop_test (ecs);
3355 return;
3356 }
3357
3358 /* If requested, stop when the dynamic linker notifies
3359 gdb of events. This allows the user to get control
3360 and place breakpoints in initializer routines for
3361 dynamically loaded objects (among other things). */
3362 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3363 if (stop_on_solib_events)
3364 {
3365 /* Make sure we print "Stopped due to solib-event" in
3366 normal_stop. */
3367 stop_print_frame = 1;
3368
3369 stop_stepping (ecs);
3370 return;
3371 }
3372 }
3373
3374 /* If we are skipping through a shell, or through shared library
3375 loading that we aren't interested in, resume the program. If
3376 we're running the program normally, also resume. But stop if
3377 we're attaching or setting up a remote connection. */
3378 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3379 {
3380 if (!ptid_equal (ecs->ptid, inferior_ptid))
3381 context_switch (ecs->ptid);
3382
3383 /* Loading of shared libraries might have changed breakpoint
3384 addresses. Make sure new breakpoints are inserted. */
3385 if (stop_soon == NO_STOP_QUIETLY
3386 && !breakpoints_always_inserted_mode ())
3387 insert_breakpoints ();
3388 resume (0, GDB_SIGNAL_0);
3389 prepare_to_wait (ecs);
3390 return;
3391 }
3392
3393 break;
3394
3395 case TARGET_WAITKIND_SPURIOUS:
3396 if (debug_infrun)
3397 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3398 if (!ptid_equal (ecs->ptid, inferior_ptid))
3399 context_switch (ecs->ptid);
3400 resume (0, GDB_SIGNAL_0);
3401 prepare_to_wait (ecs);
3402 return;
3403
3404 case TARGET_WAITKIND_EXITED:
3405 case TARGET_WAITKIND_SIGNALLED:
3406 if (debug_infrun)
3407 {
3408 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3409 fprintf_unfiltered (gdb_stdlog,
3410 "infrun: TARGET_WAITKIND_EXITED\n");
3411 else
3412 fprintf_unfiltered (gdb_stdlog,
3413 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3414 }
3415
3416 inferior_ptid = ecs->ptid;
3417 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3418 set_current_program_space (current_inferior ()->pspace);
3419 handle_vfork_child_exec_or_exit (0);
3420 target_terminal_ours (); /* Must do this before mourn anyway. */
3421
3422 /* Clearing any previous state of convenience variables. */
3423 clear_exit_convenience_vars ();
3424
3425 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3426 {
3427 /* Record the exit code in the convenience variable $_exitcode, so
3428 that the user can inspect this again later. */
3429 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3430 (LONGEST) ecs->ws.value.integer);
3431
3432 /* Also record this in the inferior itself. */
3433 current_inferior ()->has_exit_code = 1;
3434 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3435
3436 print_exited_reason (ecs->ws.value.integer);
3437 }
3438 else
3439 {
3440 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3441 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3442
3443 if (gdbarch_gdb_signal_to_target_p (gdbarch))
3444 {
3445 /* Set the value of the internal variable $_exitsignal,
3446 which holds the signal uncaught by the inferior. */
3447 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3448 gdbarch_gdb_signal_to_target (gdbarch,
3449 ecs->ws.value.sig));
3450 }
3451 else
3452 {
3453 /* We don't have access to the target's method used for
3454 converting between signal numbers (GDB's internal
3455 representation <-> target's representation).
3456 Therefore, we cannot do a good job at displaying this
3457 information to the user. It's better to just warn
3458 her about it (if infrun debugging is enabled), and
3459 give up. */
3460 if (debug_infrun)
3461 fprintf_filtered (gdb_stdlog, _("\
3462 Cannot fill $_exitsignal with the correct signal number.\n"));
3463 }
3464
3465 print_signal_exited_reason (ecs->ws.value.sig);
3466 }
3467
3468 gdb_flush (gdb_stdout);
3469 target_mourn_inferior ();
3470 singlestep_breakpoints_inserted_p = 0;
3471 cancel_single_step_breakpoints ();
3472 stop_print_frame = 0;
3473 stop_stepping (ecs);
3474 return;
3475
3476 /* The following are the only cases in which we keep going;
3477 the above cases end in a continue or goto. */
3478 case TARGET_WAITKIND_FORKED:
3479 case TARGET_WAITKIND_VFORKED:
3480 if (debug_infrun)
3481 {
3482 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3483 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3484 else
3485 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3486 }
3487
3488 /* Check whether the inferior is displaced stepping. */
3489 {
3490 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3491 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3492 struct displaced_step_inferior_state *displaced
3493 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3494
3495 /* If checking displaced stepping is supported, and thread
3496 ecs->ptid is displaced stepping. */
3497 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3498 {
3499 struct inferior *parent_inf
3500 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3501 struct regcache *child_regcache;
3502 CORE_ADDR parent_pc;
3503
3504 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3505 indicating that the displaced stepping of syscall instruction
3506 has been done. Perform cleanup for parent process here. Note
3507 that this operation also cleans up the child process for vfork,
3508 because their pages are shared. */
3509 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3510
3511 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3512 {
3513 /* Restore scratch pad for child process. */
3514 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3515 }
3516
3517 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3518 the child's PC is also within the scratchpad. Set the child's PC
3519 to the parent's PC value, which has already been fixed up.
3520 FIXME: we use the parent's aspace here, although we're touching
3521 the child, because the child hasn't been added to the inferior
3522 list yet at this point. */
3523
3524 child_regcache
3525 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3526 gdbarch,
3527 parent_inf->aspace);
3528 /* Read PC value of parent process. */
3529 parent_pc = regcache_read_pc (regcache);
3530
3531 if (debug_displaced)
3532 fprintf_unfiltered (gdb_stdlog,
3533 "displaced: write child pc from %s to %s\n",
3534 paddress (gdbarch,
3535 regcache_read_pc (child_regcache)),
3536 paddress (gdbarch, parent_pc));
3537
3538 regcache_write_pc (child_regcache, parent_pc);
3539 }
3540 }
3541
3542 if (!ptid_equal (ecs->ptid, inferior_ptid))
3543 context_switch (ecs->ptid);
3544
3545 /* Immediately detach breakpoints from the child before there's
3546 any chance of letting the user delete breakpoints from the
3547 breakpoint lists. If we don't do this early, it's easy to
3548 leave left over traps in the child, vis: "break foo; catch
3549 fork; c; <fork>; del; c; <child calls foo>". We only follow
3550 the fork on the last `continue', and by that time the
3551 breakpoint at "foo" is long gone from the breakpoint table.
3552 If we vforked, then we don't need to unpatch here, since both
3553 parent and child are sharing the same memory pages; we'll
3554 need to unpatch at follow/detach time instead to be certain
3555 that new breakpoints added between catchpoint hit time and
3556 vfork follow are detached. */
3557 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3558 {
3559 /* This won't actually modify the breakpoint list, but will
3560 physically remove the breakpoints from the child. */
3561 detach_breakpoints (ecs->ws.value.related_pid);
3562 }
3563
3564 if (singlestep_breakpoints_inserted_p)
3565 {
3566 /* Pull the single step breakpoints out of the target. */
3567 remove_single_step_breakpoints ();
3568 singlestep_breakpoints_inserted_p = 0;
3569 }
3570
3571 /* In case the event is caught by a catchpoint, remember that
3572 the event is to be followed at the next resume of the thread,
3573 and not immediately. */
3574 ecs->event_thread->pending_follow = ecs->ws;
3575
3576 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3577
3578 ecs->event_thread->control.stop_bpstat
3579 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3580 stop_pc, ecs->ptid, &ecs->ws);
3581
3582 /* Note that we're interested in knowing the bpstat actually
3583 causes a stop, not just if it may explain the signal.
3584 Software watchpoints, for example, always appear in the
3585 bpstat. */
3586 ecs->random_signal
3587 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3588
3589 /* If no catchpoint triggered for this, then keep going. */
3590 if (ecs->random_signal)
3591 {
3592 ptid_t parent;
3593 ptid_t child;
3594 int should_resume;
3595 int follow_child
3596 = (follow_fork_mode_string == follow_fork_mode_child);
3597
3598 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3599
3600 should_resume = follow_fork ();
3601
3602 parent = ecs->ptid;
3603 child = ecs->ws.value.related_pid;
3604
3605 /* In non-stop mode, also resume the other branch. */
3606 if (non_stop && !detach_fork)
3607 {
3608 if (follow_child)
3609 switch_to_thread (parent);
3610 else
3611 switch_to_thread (child);
3612
3613 ecs->event_thread = inferior_thread ();
3614 ecs->ptid = inferior_ptid;
3615 keep_going (ecs);
3616 }
3617
3618 if (follow_child)
3619 switch_to_thread (child);
3620 else
3621 switch_to_thread (parent);
3622
3623 ecs->event_thread = inferior_thread ();
3624 ecs->ptid = inferior_ptid;
3625
3626 if (should_resume)
3627 keep_going (ecs);
3628 else
3629 stop_stepping (ecs);
3630 return;
3631 }
3632 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3633 process_event_stop_test (ecs);
3634 return;
3635
3636 case TARGET_WAITKIND_VFORK_DONE:
3637 /* Done with the shared memory region. Re-insert breakpoints in
3638 the parent, and keep going. */
3639
3640 if (debug_infrun)
3641 fprintf_unfiltered (gdb_stdlog,
3642 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3643
3644 if (!ptid_equal (ecs->ptid, inferior_ptid))
3645 context_switch (ecs->ptid);
3646
3647 current_inferior ()->waiting_for_vfork_done = 0;
3648 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3649 /* This also takes care of reinserting breakpoints in the
3650 previously locked inferior. */
3651 keep_going (ecs);
3652 return;
3653
3654 case TARGET_WAITKIND_EXECD:
3655 if (debug_infrun)
3656 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3657
3658 if (!ptid_equal (ecs->ptid, inferior_ptid))
3659 context_switch (ecs->ptid);
3660
3661 singlestep_breakpoints_inserted_p = 0;
3662 cancel_single_step_breakpoints ();
3663
3664 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3665
3666 /* Do whatever is necessary to the parent branch of the vfork. */
3667 handle_vfork_child_exec_or_exit (1);
3668
3669 /* This causes the eventpoints and symbol table to be reset.
3670 Must do this now, before trying to determine whether to
3671 stop. */
3672 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3673
3674 ecs->event_thread->control.stop_bpstat
3675 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3676 stop_pc, ecs->ptid, &ecs->ws);
3677 ecs->random_signal
3678 = (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3679 GDB_SIGNAL_TRAP)
3680 == BPSTAT_SIGNAL_NO);
3681
3682 /* Note that this may be referenced from inside
3683 bpstat_stop_status above, through inferior_has_execd. */
3684 xfree (ecs->ws.value.execd_pathname);
3685 ecs->ws.value.execd_pathname = NULL;
3686
3687 /* If no catchpoint triggered for this, then keep going. */
3688 if (ecs->random_signal)
3689 {
3690 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3691 keep_going (ecs);
3692 return;
3693 }
3694 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3695 process_event_stop_test (ecs);
3696 return;
3697
3698 /* Be careful not to try to gather much state about a thread
3699 that's in a syscall. It's frequently a losing proposition. */
3700 case TARGET_WAITKIND_SYSCALL_ENTRY:
3701 if (debug_infrun)
3702 fprintf_unfiltered (gdb_stdlog,
3703 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3704 /* Getting the current syscall number. */
3705 if (handle_syscall_event (ecs) == 0)
3706 process_event_stop_test (ecs);
3707 return;
3708
3709 /* Before examining the threads further, step this thread to
3710 get it entirely out of the syscall. (We get notice of the
3711 event when the thread is just on the verge of exiting a
3712 syscall. Stepping one instruction seems to get it back
3713 into user code.) */
3714 case TARGET_WAITKIND_SYSCALL_RETURN:
3715 if (debug_infrun)
3716 fprintf_unfiltered (gdb_stdlog,
3717 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3718 if (handle_syscall_event (ecs) == 0)
3719 process_event_stop_test (ecs);
3720 return;
3721
3722 case TARGET_WAITKIND_STOPPED:
3723 if (debug_infrun)
3724 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3725 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3726 break;
3727
3728 case TARGET_WAITKIND_NO_HISTORY:
3729 if (debug_infrun)
3730 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
3731 /* Reverse execution: target ran out of history info. */
3732
3733 /* Pull the single step breakpoints out of the target. */
3734 if (singlestep_breakpoints_inserted_p)
3735 {
3736 if (!ptid_equal (ecs->ptid, inferior_ptid))
3737 context_switch (ecs->ptid);
3738 remove_single_step_breakpoints ();
3739 singlestep_breakpoints_inserted_p = 0;
3740 }
3741 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3742 print_no_history_reason ();
3743 stop_stepping (ecs);
3744 return;
3745 }
3746
3747 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3748 {
3749 /* Do we need to clean up the state of a thread that has
3750 completed a displaced single-step? (Doing so usually affects
3751 the PC, so do it here, before we set stop_pc.) */
3752 displaced_step_fixup (ecs->ptid,
3753 ecs->event_thread->suspend.stop_signal);
3754
3755 /* If we either finished a single-step or hit a breakpoint, but
3756 the user wanted this thread to be stopped, pretend we got a
3757 SIG0 (generic unsignaled stop). */
3758
3759 if (ecs->event_thread->stop_requested
3760 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3761 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3762 }
3763
3764 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3765
3766 if (debug_infrun)
3767 {
3768 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3769 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3770 struct cleanup *old_chain = save_inferior_ptid ();
3771
3772 inferior_ptid = ecs->ptid;
3773
3774 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3775 paddress (gdbarch, stop_pc));
3776 if (target_stopped_by_watchpoint ())
3777 {
3778 CORE_ADDR addr;
3779
3780 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3781
3782 if (target_stopped_data_address (&current_target, &addr))
3783 fprintf_unfiltered (gdb_stdlog,
3784 "infrun: stopped data address = %s\n",
3785 paddress (gdbarch, addr));
3786 else
3787 fprintf_unfiltered (gdb_stdlog,
3788 "infrun: (no data address available)\n");
3789 }
3790
3791 do_cleanups (old_chain);
3792 }
3793
3794 if (stepping_past_singlestep_breakpoint)
3795 {
3796 gdb_assert (singlestep_breakpoints_inserted_p);
3797 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3798 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3799
3800 stepping_past_singlestep_breakpoint = 0;
3801
3802 /* We've either finished single-stepping past the single-step
3803 breakpoint, or stopped for some other reason. It would be nice if
3804 we could tell, but we can't reliably. */
3805 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3806 {
3807 if (debug_infrun)
3808 fprintf_unfiltered (gdb_stdlog,
3809 "infrun: stepping_past_"
3810 "singlestep_breakpoint\n");
3811 /* Pull the single step breakpoints out of the target. */
3812 if (!ptid_equal (ecs->ptid, inferior_ptid))
3813 context_switch (ecs->ptid);
3814 remove_single_step_breakpoints ();
3815 singlestep_breakpoints_inserted_p = 0;
3816
3817 ecs->event_thread->control.trap_expected = 0;
3818
3819 context_switch (saved_singlestep_ptid);
3820 if (deprecated_context_hook)
3821 deprecated_context_hook (pid_to_thread_id (saved_singlestep_ptid));
3822
3823 resume (1, GDB_SIGNAL_0);
3824 prepare_to_wait (ecs);
3825 return;
3826 }
3827 }
3828
3829 if (!ptid_equal (deferred_step_ptid, null_ptid))
3830 {
3831 /* In non-stop mode, there's never a deferred_step_ptid set. */
3832 gdb_assert (!non_stop);
3833
3834 /* If we stopped for some other reason than single-stepping, ignore
3835 the fact that we were supposed to switch back. */
3836 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3837 {
3838 if (debug_infrun)
3839 fprintf_unfiltered (gdb_stdlog,
3840 "infrun: handling deferred step\n");
3841
3842 /* Pull the single step breakpoints out of the target. */
3843 if (singlestep_breakpoints_inserted_p)
3844 {
3845 if (!ptid_equal (ecs->ptid, inferior_ptid))
3846 context_switch (ecs->ptid);
3847 remove_single_step_breakpoints ();
3848 singlestep_breakpoints_inserted_p = 0;
3849 }
3850
3851 ecs->event_thread->control.trap_expected = 0;
3852
3853 context_switch (deferred_step_ptid);
3854 deferred_step_ptid = null_ptid;
3855 /* Suppress spurious "Switching to ..." message. */
3856 previous_inferior_ptid = inferior_ptid;
3857
3858 resume (1, GDB_SIGNAL_0);
3859 prepare_to_wait (ecs);
3860 return;
3861 }
3862
3863 deferred_step_ptid = null_ptid;
3864 }
3865
3866 /* See if a thread hit a thread-specific breakpoint that was meant for
3867 another thread. If so, then step that thread past the breakpoint,
3868 and continue it. */
3869
3870 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3871 {
3872 int thread_hop_needed = 0;
3873 struct address_space *aspace =
3874 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3875
3876 /* Check if a regular breakpoint has been hit before checking
3877 for a potential single step breakpoint. Otherwise, GDB will
3878 not see this breakpoint hit when stepping onto breakpoints. */
3879 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3880 {
3881 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3882 thread_hop_needed = 1;
3883 }
3884 else if (singlestep_breakpoints_inserted_p)
3885 {
3886 /* We have not context switched yet, so this should be true
3887 no matter which thread hit the singlestep breakpoint. */
3888 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3889 if (debug_infrun)
3890 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3891 "trap for %s\n",
3892 target_pid_to_str (ecs->ptid));
3893
3894 /* The call to in_thread_list is necessary because PTIDs sometimes
3895 change when we go from single-threaded to multi-threaded. If
3896 the singlestep_ptid is still in the list, assume that it is
3897 really different from ecs->ptid. */
3898 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3899 && in_thread_list (singlestep_ptid))
3900 {
3901 /* If the PC of the thread we were trying to single-step
3902 has changed, discard this event (which we were going
3903 to ignore anyway), and pretend we saw that thread
3904 trap. This prevents us continuously moving the
3905 single-step breakpoint forward, one instruction at a
3906 time. If the PC has changed, then the thread we were
3907 trying to single-step has trapped or been signalled,
3908 but the event has not been reported to GDB yet.
3909
3910 There might be some cases where this loses signal
3911 information, if a signal has arrived at exactly the
3912 same time that the PC changed, but this is the best
3913 we can do with the information available. Perhaps we
3914 should arrange to report all events for all threads
3915 when they stop, or to re-poll the remote looking for
3916 this particular thread (i.e. temporarily enable
3917 schedlock). */
3918
3919 CORE_ADDR new_singlestep_pc
3920 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3921
3922 if (new_singlestep_pc != singlestep_pc)
3923 {
3924 enum gdb_signal stop_signal;
3925
3926 if (debug_infrun)
3927 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3928 " but expected thread advanced also\n");
3929
3930 /* The current context still belongs to
3931 singlestep_ptid. Don't swap here, since that's
3932 the context we want to use. Just fudge our
3933 state and continue. */
3934 stop_signal = ecs->event_thread->suspend.stop_signal;
3935 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3936 ecs->ptid = singlestep_ptid;
3937 ecs->event_thread = find_thread_ptid (ecs->ptid);
3938 ecs->event_thread->suspend.stop_signal = stop_signal;
3939 stop_pc = new_singlestep_pc;
3940 }
3941 else
3942 {
3943 if (debug_infrun)
3944 fprintf_unfiltered (gdb_stdlog,
3945 "infrun: unexpected thread\n");
3946
3947 thread_hop_needed = 1;
3948 stepping_past_singlestep_breakpoint = 1;
3949 saved_singlestep_ptid = singlestep_ptid;
3950 }
3951 }
3952 }
3953
3954 if (thread_hop_needed)
3955 {
3956 struct regcache *thread_regcache;
3957 int remove_status = 0;
3958
3959 if (debug_infrun)
3960 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3961
3962 /* Switch context before touching inferior memory, the
3963 previous thread may have exited. */
3964 if (!ptid_equal (inferior_ptid, ecs->ptid))
3965 context_switch (ecs->ptid);
3966
3967 /* Saw a breakpoint, but it was hit by the wrong thread.
3968 Just continue. */
3969
3970 if (singlestep_breakpoints_inserted_p)
3971 {
3972 /* Pull the single step breakpoints out of the target. */
3973 remove_single_step_breakpoints ();
3974 singlestep_breakpoints_inserted_p = 0;
3975 }
3976
3977 /* If the arch can displace step, don't remove the
3978 breakpoints. */
3979 thread_regcache = get_thread_regcache (ecs->ptid);
3980 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3981 remove_status = remove_breakpoints ();
3982
3983 /* Did we fail to remove breakpoints? If so, try
3984 to set the PC past the bp. (There's at least
3985 one situation in which we can fail to remove
3986 the bp's: On HP-UX's that use ttrace, we can't
3987 change the address space of a vforking child
3988 process until the child exits (well, okay, not
3989 then either :-) or execs. */
3990 if (remove_status != 0)
3991 error (_("Cannot step over breakpoint hit in wrong thread"));
3992 else
3993 { /* Single step */
3994 if (!non_stop)
3995 {
3996 /* Only need to require the next event from this
3997 thread in all-stop mode. */
3998 waiton_ptid = ecs->ptid;
3999 infwait_state = infwait_thread_hop_state;
4000 }
4001
4002 ecs->event_thread->stepping_over_breakpoint = 1;
4003 keep_going (ecs);
4004 return;
4005 }
4006 }
4007 }
4008
4009 /* See if something interesting happened to the non-current thread. If
4010 so, then switch to that thread. */
4011 if (!ptid_equal (ecs->ptid, inferior_ptid))
4012 {
4013 if (debug_infrun)
4014 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
4015
4016 context_switch (ecs->ptid);
4017
4018 if (deprecated_context_hook)
4019 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
4020 }
4021
4022 /* At this point, get hold of the now-current thread's frame. */
4023 frame = get_current_frame ();
4024 gdbarch = get_frame_arch (frame);
4025
4026 if (singlestep_breakpoints_inserted_p)
4027 {
4028 /* Pull the single step breakpoints out of the target. */
4029 remove_single_step_breakpoints ();
4030 singlestep_breakpoints_inserted_p = 0;
4031 }
4032
4033 if (stepped_after_stopped_by_watchpoint)
4034 stopped_by_watchpoint = 0;
4035 else
4036 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4037
4038 /* If necessary, step over this watchpoint. We'll be back to display
4039 it in a moment. */
4040 if (stopped_by_watchpoint
4041 && (target_have_steppable_watchpoint
4042 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4043 {
4044 /* At this point, we are stopped at an instruction which has
4045 attempted to write to a piece of memory under control of
4046 a watchpoint. The instruction hasn't actually executed
4047 yet. If we were to evaluate the watchpoint expression
4048 now, we would get the old value, and therefore no change
4049 would seem to have occurred.
4050
4051 In order to make watchpoints work `right', we really need
4052 to complete the memory write, and then evaluate the
4053 watchpoint expression. We do this by single-stepping the
4054 target.
4055
4056 It may not be necessary to disable the watchpoint to stop over
4057 it. For example, the PA can (with some kernel cooperation)
4058 single step over a watchpoint without disabling the watchpoint.
4059
4060 It is far more common to need to disable a watchpoint to step
4061 the inferior over it. If we have non-steppable watchpoints,
4062 we must disable the current watchpoint; it's simplest to
4063 disable all watchpoints and breakpoints. */
4064 int hw_step = 1;
4065
4066 if (!target_have_steppable_watchpoint)
4067 {
4068 remove_breakpoints ();
4069 /* See comment in resume why we need to stop bypassing signals
4070 while breakpoints have been removed. */
4071 target_pass_signals (0, NULL);
4072 }
4073 /* Single step */
4074 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4075 target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
4076 waiton_ptid = ecs->ptid;
4077 if (target_have_steppable_watchpoint)
4078 infwait_state = infwait_step_watch_state;
4079 else
4080 infwait_state = infwait_nonstep_watch_state;
4081 prepare_to_wait (ecs);
4082 return;
4083 }
4084
4085 ecs->event_thread->stepping_over_breakpoint = 0;
4086 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4087 ecs->event_thread->control.stop_step = 0;
4088 stop_print_frame = 1;
4089 stopped_by_random_signal = 0;
4090
4091 /* Hide inlined functions starting here, unless we just performed stepi or
4092 nexti. After stepi and nexti, always show the innermost frame (not any
4093 inline function call sites). */
4094 if (ecs->event_thread->control.step_range_end != 1)
4095 {
4096 struct address_space *aspace =
4097 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4098
4099 /* skip_inline_frames is expensive, so we avoid it if we can
4100 determine that the address is one where functions cannot have
4101 been inlined. This improves performance with inferiors that
4102 load a lot of shared libraries, because the solib event
4103 breakpoint is defined as the address of a function (i.e. not
4104 inline). Note that we have to check the previous PC as well
4105 as the current one to catch cases when we have just
4106 single-stepped off a breakpoint prior to reinstating it.
4107 Note that we're assuming that the code we single-step to is
4108 not inline, but that's not definitive: there's nothing
4109 preventing the event breakpoint function from containing
4110 inlined code, and the single-step ending up there. If the
4111 user had set a breakpoint on that inlined code, the missing
4112 skip_inline_frames call would break things. Fortunately
4113 that's an extremely unlikely scenario. */
4114 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4115 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4116 && ecs->event_thread->control.trap_expected
4117 && pc_at_non_inline_function (aspace,
4118 ecs->event_thread->prev_pc,
4119 &ecs->ws)))
4120 {
4121 skip_inline_frames (ecs->ptid);
4122
4123 /* Re-fetch current thread's frame in case that invalidated
4124 the frame cache. */
4125 frame = get_current_frame ();
4126 gdbarch = get_frame_arch (frame);
4127 }
4128 }
4129
4130 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4131 && ecs->event_thread->control.trap_expected
4132 && gdbarch_single_step_through_delay_p (gdbarch)
4133 && currently_stepping (ecs->event_thread))
4134 {
4135 /* We're trying to step off a breakpoint. Turns out that we're
4136 also on an instruction that needs to be stepped multiple
4137 times before it's been fully executing. E.g., architectures
4138 with a delay slot. It needs to be stepped twice, once for
4139 the instruction and once for the delay slot. */
4140 int step_through_delay
4141 = gdbarch_single_step_through_delay (gdbarch, frame);
4142
4143 if (debug_infrun && step_through_delay)
4144 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4145 if (ecs->event_thread->control.step_range_end == 0
4146 && step_through_delay)
4147 {
4148 /* The user issued a continue when stopped at a breakpoint.
4149 Set up for another trap and get out of here. */
4150 ecs->event_thread->stepping_over_breakpoint = 1;
4151 keep_going (ecs);
4152 return;
4153 }
4154 else if (step_through_delay)
4155 {
4156 /* The user issued a step when stopped at a breakpoint.
4157 Maybe we should stop, maybe we should not - the delay
4158 slot *might* correspond to a line of source. In any
4159 case, don't decide that here, just set
4160 ecs->stepping_over_breakpoint, making sure we
4161 single-step again before breakpoints are re-inserted. */
4162 ecs->event_thread->stepping_over_breakpoint = 1;
4163 }
4164 }
4165
4166 /* Look at the cause of the stop, and decide what to do.
4167 The alternatives are:
4168 1) stop_stepping and return; to really stop and return to the debugger,
4169 2) keep_going and return to start up again
4170 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4171 3) set ecs->random_signal to 1, and the decision between 1 and 2
4172 will be made according to the signal handling tables. */
4173
4174 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4175 && stop_after_trap)
4176 {
4177 if (debug_infrun)
4178 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4179 stop_print_frame = 0;
4180 stop_stepping (ecs);
4181 return;
4182 }
4183
4184 /* This is originated from start_remote(), start_inferior() and
4185 shared libraries hook functions. */
4186 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4187 {
4188 if (debug_infrun)
4189 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4190 stop_stepping (ecs);
4191 return;
4192 }
4193
4194 /* This originates from attach_command(). We need to overwrite
4195 the stop_signal here, because some kernels don't ignore a
4196 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4197 See more comments in inferior.h. On the other hand, if we
4198 get a non-SIGSTOP, report it to the user - assume the backend
4199 will handle the SIGSTOP if it should show up later.
4200
4201 Also consider that the attach is complete when we see a
4202 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4203 target extended-remote report it instead of a SIGSTOP
4204 (e.g. gdbserver). We already rely on SIGTRAP being our
4205 signal, so this is no exception.
4206
4207 Also consider that the attach is complete when we see a
4208 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4209 the target to stop all threads of the inferior, in case the
4210 low level attach operation doesn't stop them implicitly. If
4211 they weren't stopped implicitly, then the stub will report a
4212 GDB_SIGNAL_0, meaning: stopped for no particular reason
4213 other than GDB's request. */
4214 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4215 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4216 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4217 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4218 {
4219 stop_stepping (ecs);
4220 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4221 return;
4222 }
4223
4224 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4225 handles this event. */
4226 ecs->event_thread->control.stop_bpstat
4227 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4228 stop_pc, ecs->ptid, &ecs->ws);
4229
4230 /* Following in case break condition called a
4231 function. */
4232 stop_print_frame = 1;
4233
4234 /* This is where we handle "moribund" watchpoints. Unlike
4235 software breakpoints traps, hardware watchpoint traps are
4236 always distinguishable from random traps. If no high-level
4237 watchpoint is associated with the reported stop data address
4238 anymore, then the bpstat does not explain the signal ---
4239 simply make sure to ignore it if `stopped_by_watchpoint' is
4240 set. */
4241
4242 if (debug_infrun
4243 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4244 && (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4245 GDB_SIGNAL_TRAP)
4246 == BPSTAT_SIGNAL_NO)
4247 && stopped_by_watchpoint)
4248 fprintf_unfiltered (gdb_stdlog,
4249 "infrun: no user watchpoint explains "
4250 "watchpoint SIGTRAP, ignoring\n");
4251
4252 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4253 at one stage in the past included checks for an inferior
4254 function call's call dummy's return breakpoint. The original
4255 comment, that went with the test, read:
4256
4257 ``End of a stack dummy. Some systems (e.g. Sony news) give
4258 another signal besides SIGTRAP, so check here as well as
4259 above.''
4260
4261 If someone ever tries to get call dummys on a
4262 non-executable stack to work (where the target would stop
4263 with something like a SIGSEGV), then those tests might need
4264 to be re-instated. Given, however, that the tests were only
4265 enabled when momentary breakpoints were not being used, I
4266 suspect that it won't be the case.
4267
4268 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4269 be necessary for call dummies on a non-executable stack on
4270 SPARC. */
4271
4272 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4273 ecs->random_signal
4274 = !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4275 GDB_SIGNAL_TRAP)
4276 != BPSTAT_SIGNAL_NO)
4277 || stopped_by_watchpoint
4278 || ecs->event_thread->control.trap_expected
4279 || (ecs->event_thread->control.step_range_end
4280 && (ecs->event_thread->control.step_resume_breakpoint
4281 == NULL)));
4282 else
4283 {
4284 enum bpstat_signal_value sval;
4285
4286 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4287 ecs->event_thread->suspend.stop_signal);
4288 ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
4289
4290 if (sval == BPSTAT_SIGNAL_HIDE)
4291 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
4292 }
4293
4294 /* For the program's own signals, act according to
4295 the signal handling tables. */
4296
4297 if (ecs->random_signal)
4298 {
4299 /* Signal not for debugging purposes. */
4300 int printed = 0;
4301 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4302 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
4303
4304 if (debug_infrun)
4305 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
4306 gdb_signal_to_symbol_string (stop_signal));
4307
4308 stopped_by_random_signal = 1;
4309
4310 if (signal_print[ecs->event_thread->suspend.stop_signal])
4311 {
4312 printed = 1;
4313 target_terminal_ours_for_output ();
4314 print_signal_received_reason
4315 (ecs->event_thread->suspend.stop_signal);
4316 }
4317 /* Always stop on signals if we're either just gaining control
4318 of the program, or the user explicitly requested this thread
4319 to remain stopped. */
4320 if (stop_soon != NO_STOP_QUIETLY
4321 || ecs->event_thread->stop_requested
4322 || (!inf->detaching
4323 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4324 {
4325 stop_stepping (ecs);
4326 return;
4327 }
4328 /* If not going to stop, give terminal back
4329 if we took it away. */
4330 else if (printed)
4331 target_terminal_inferior ();
4332
4333 /* Clear the signal if it should not be passed. */
4334 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4335 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4336
4337 if (ecs->event_thread->prev_pc == stop_pc
4338 && ecs->event_thread->control.trap_expected
4339 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4340 {
4341 /* We were just starting a new sequence, attempting to
4342 single-step off of a breakpoint and expecting a SIGTRAP.
4343 Instead this signal arrives. This signal will take us out
4344 of the stepping range so GDB needs to remember to, when
4345 the signal handler returns, resume stepping off that
4346 breakpoint. */
4347 /* To simplify things, "continue" is forced to use the same
4348 code paths as single-step - set a breakpoint at the
4349 signal return address and then, once hit, step off that
4350 breakpoint. */
4351 if (debug_infrun)
4352 fprintf_unfiltered (gdb_stdlog,
4353 "infrun: signal arrived while stepping over "
4354 "breakpoint\n");
4355
4356 insert_hp_step_resume_breakpoint_at_frame (frame);
4357 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4358 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4359 ecs->event_thread->control.trap_expected = 0;
4360 keep_going (ecs);
4361 return;
4362 }
4363
4364 if (ecs->event_thread->control.step_range_end != 0
4365 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4366 && pc_in_thread_step_range (stop_pc, ecs->event_thread)
4367 && frame_id_eq (get_stack_frame_id (frame),
4368 ecs->event_thread->control.step_stack_frame_id)
4369 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4370 {
4371 /* The inferior is about to take a signal that will take it
4372 out of the single step range. Set a breakpoint at the
4373 current PC (which is presumably where the signal handler
4374 will eventually return) and then allow the inferior to
4375 run free.
4376
4377 Note that this is only needed for a signal delivered
4378 while in the single-step range. Nested signals aren't a
4379 problem as they eventually all return. */
4380 if (debug_infrun)
4381 fprintf_unfiltered (gdb_stdlog,
4382 "infrun: signal may take us out of "
4383 "single-step range\n");
4384
4385 insert_hp_step_resume_breakpoint_at_frame (frame);
4386 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4387 ecs->event_thread->control.trap_expected = 0;
4388 keep_going (ecs);
4389 return;
4390 }
4391
4392 /* Note: step_resume_breakpoint may be non-NULL. This occures
4393 when either there's a nested signal, or when there's a
4394 pending signal enabled just as the signal handler returns
4395 (leaving the inferior at the step-resume-breakpoint without
4396 actually executing it). Either way continue until the
4397 breakpoint is really hit. */
4398
4399 if (!switch_back_to_stepped_thread (ecs))
4400 {
4401 if (debug_infrun)
4402 fprintf_unfiltered (gdb_stdlog,
4403 "infrun: random signal, keep going\n");
4404
4405 keep_going (ecs);
4406 }
4407 return;
4408 }
4409
4410 process_event_stop_test (ecs);
4411 }
4412
4413 /* Come here when we've got some debug event / signal we can explain
4414 (IOW, not a random signal), and test whether it should cause a
4415 stop, or whether we should resume the inferior (transparently).
4416 E.g., could be a breakpoint whose condition evaluates false; we
4417 could be still stepping within the line; etc. */
4418
4419 static void
4420 process_event_stop_test (struct execution_control_state *ecs)
4421 {
4422 struct symtab_and_line stop_pc_sal;
4423 struct frame_info *frame;
4424 struct gdbarch *gdbarch;
4425 CORE_ADDR jmp_buf_pc;
4426 struct bpstat_what what;
4427
4428 /* Handle cases caused by hitting a breakpoint. */
4429
4430 frame = get_current_frame ();
4431 gdbarch = get_frame_arch (frame);
4432
4433 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4434
4435 if (what.call_dummy)
4436 {
4437 stop_stack_dummy = what.call_dummy;
4438 }
4439
4440 /* If we hit an internal event that triggers symbol changes, the
4441 current frame will be invalidated within bpstat_what (e.g., if we
4442 hit an internal solib event). Re-fetch it. */
4443 frame = get_current_frame ();
4444 gdbarch = get_frame_arch (frame);
4445
4446 switch (what.main_action)
4447 {
4448 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4449 /* If we hit the breakpoint at longjmp while stepping, we
4450 install a momentary breakpoint at the target of the
4451 jmp_buf. */
4452
4453 if (debug_infrun)
4454 fprintf_unfiltered (gdb_stdlog,
4455 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4456
4457 ecs->event_thread->stepping_over_breakpoint = 1;
4458
4459 if (what.is_longjmp)
4460 {
4461 struct value *arg_value;
4462
4463 /* If we set the longjmp breakpoint via a SystemTap probe,
4464 then use it to extract the arguments. The destination PC
4465 is the third argument to the probe. */
4466 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4467 if (arg_value)
4468 jmp_buf_pc = value_as_address (arg_value);
4469 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4470 || !gdbarch_get_longjmp_target (gdbarch,
4471 frame, &jmp_buf_pc))
4472 {
4473 if (debug_infrun)
4474 fprintf_unfiltered (gdb_stdlog,
4475 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4476 "(!gdbarch_get_longjmp_target)\n");
4477 keep_going (ecs);
4478 return;
4479 }
4480
4481 /* Insert a breakpoint at resume address. */
4482 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4483 }
4484 else
4485 check_exception_resume (ecs, frame);
4486 keep_going (ecs);
4487 return;
4488
4489 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4490 {
4491 struct frame_info *init_frame;
4492
4493 /* There are several cases to consider.
4494
4495 1. The initiating frame no longer exists. In this case we
4496 must stop, because the exception or longjmp has gone too
4497 far.
4498
4499 2. The initiating frame exists, and is the same as the
4500 current frame. We stop, because the exception or longjmp
4501 has been caught.
4502
4503 3. The initiating frame exists and is different from the
4504 current frame. This means the exception or longjmp has
4505 been caught beneath the initiating frame, so keep going.
4506
4507 4. longjmp breakpoint has been placed just to protect
4508 against stale dummy frames and user is not interested in
4509 stopping around longjmps. */
4510
4511 if (debug_infrun)
4512 fprintf_unfiltered (gdb_stdlog,
4513 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4514
4515 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4516 != NULL);
4517 delete_exception_resume_breakpoint (ecs->event_thread);
4518
4519 if (what.is_longjmp)
4520 {
4521 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
4522
4523 if (!frame_id_p (ecs->event_thread->initiating_frame))
4524 {
4525 /* Case 4. */
4526 keep_going (ecs);
4527 return;
4528 }
4529 }
4530
4531 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4532
4533 if (init_frame)
4534 {
4535 struct frame_id current_id
4536 = get_frame_id (get_current_frame ());
4537 if (frame_id_eq (current_id,
4538 ecs->event_thread->initiating_frame))
4539 {
4540 /* Case 2. Fall through. */
4541 }
4542 else
4543 {
4544 /* Case 3. */
4545 keep_going (ecs);
4546 return;
4547 }
4548 }
4549
4550 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
4551 exists. */
4552 delete_step_resume_breakpoint (ecs->event_thread);
4553
4554 ecs->event_thread->control.stop_step = 1;
4555 print_end_stepping_range_reason ();
4556 stop_stepping (ecs);
4557 }
4558 return;
4559
4560 case BPSTAT_WHAT_SINGLE:
4561 if (debug_infrun)
4562 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4563 ecs->event_thread->stepping_over_breakpoint = 1;
4564 /* Still need to check other stuff, at least the case where we
4565 are stepping and step out of the right range. */
4566 break;
4567
4568 case BPSTAT_WHAT_STEP_RESUME:
4569 if (debug_infrun)
4570 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4571
4572 delete_step_resume_breakpoint (ecs->event_thread);
4573 if (ecs->event_thread->control.proceed_to_finish
4574 && execution_direction == EXEC_REVERSE)
4575 {
4576 struct thread_info *tp = ecs->event_thread;
4577
4578 /* We are finishing a function in reverse, and just hit the
4579 step-resume breakpoint at the start address of the
4580 function, and we're almost there -- just need to back up
4581 by one more single-step, which should take us back to the
4582 function call. */
4583 tp->control.step_range_start = tp->control.step_range_end = 1;
4584 keep_going (ecs);
4585 return;
4586 }
4587 fill_in_stop_func (gdbarch, ecs);
4588 if (stop_pc == ecs->stop_func_start
4589 && execution_direction == EXEC_REVERSE)
4590 {
4591 /* We are stepping over a function call in reverse, and just
4592 hit the step-resume breakpoint at the start address of
4593 the function. Go back to single-stepping, which should
4594 take us back to the function call. */
4595 ecs->event_thread->stepping_over_breakpoint = 1;
4596 keep_going (ecs);
4597 return;
4598 }
4599 break;
4600
4601 case BPSTAT_WHAT_STOP_NOISY:
4602 if (debug_infrun)
4603 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4604 stop_print_frame = 1;
4605
4606 /* We are about to nuke the step_resume_breakpointt via the
4607 cleanup chain, so no need to worry about it here. */
4608
4609 stop_stepping (ecs);
4610 return;
4611
4612 case BPSTAT_WHAT_STOP_SILENT:
4613 if (debug_infrun)
4614 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4615 stop_print_frame = 0;
4616
4617 /* We are about to nuke the step_resume_breakpoin via the
4618 cleanup chain, so no need to worry about it here. */
4619
4620 stop_stepping (ecs);
4621 return;
4622
4623 case BPSTAT_WHAT_HP_STEP_RESUME:
4624 if (debug_infrun)
4625 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4626
4627 delete_step_resume_breakpoint (ecs->event_thread);
4628 if (ecs->event_thread->step_after_step_resume_breakpoint)
4629 {
4630 /* Back when the step-resume breakpoint was inserted, we
4631 were trying to single-step off a breakpoint. Go back to
4632 doing that. */
4633 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4634 ecs->event_thread->stepping_over_breakpoint = 1;
4635 keep_going (ecs);
4636 return;
4637 }
4638 break;
4639
4640 case BPSTAT_WHAT_KEEP_CHECKING:
4641 break;
4642 }
4643
4644 /* We come here if we hit a breakpoint but should not stop for it.
4645 Possibly we also were stepping and should stop for that. So fall
4646 through and test for stepping. But, if not stepping, do not
4647 stop. */
4648
4649 /* In all-stop mode, if we're currently stepping but have stopped in
4650 some other thread, we need to switch back to the stepped thread. */
4651 if (switch_back_to_stepped_thread (ecs))
4652 return;
4653
4654 if (ecs->event_thread->control.step_resume_breakpoint)
4655 {
4656 if (debug_infrun)
4657 fprintf_unfiltered (gdb_stdlog,
4658 "infrun: step-resume breakpoint is inserted\n");
4659
4660 /* Having a step-resume breakpoint overrides anything
4661 else having to do with stepping commands until
4662 that breakpoint is reached. */
4663 keep_going (ecs);
4664 return;
4665 }
4666
4667 if (ecs->event_thread->control.step_range_end == 0)
4668 {
4669 if (debug_infrun)
4670 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4671 /* Likewise if we aren't even stepping. */
4672 keep_going (ecs);
4673 return;
4674 }
4675
4676 /* Re-fetch current thread's frame in case the code above caused
4677 the frame cache to be re-initialized, making our FRAME variable
4678 a dangling pointer. */
4679 frame = get_current_frame ();
4680 gdbarch = get_frame_arch (frame);
4681 fill_in_stop_func (gdbarch, ecs);
4682
4683 /* If stepping through a line, keep going if still within it.
4684
4685 Note that step_range_end is the address of the first instruction
4686 beyond the step range, and NOT the address of the last instruction
4687 within it!
4688
4689 Note also that during reverse execution, we may be stepping
4690 through a function epilogue and therefore must detect when
4691 the current-frame changes in the middle of a line. */
4692
4693 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4694 && (execution_direction != EXEC_REVERSE
4695 || frame_id_eq (get_frame_id (frame),
4696 ecs->event_thread->control.step_frame_id)))
4697 {
4698 if (debug_infrun)
4699 fprintf_unfiltered
4700 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4701 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4702 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4703
4704 /* Tentatively re-enable range stepping; `resume' disables it if
4705 necessary (e.g., if we're stepping over a breakpoint or we
4706 have software watchpoints). */
4707 ecs->event_thread->control.may_range_step = 1;
4708
4709 /* When stepping backward, stop at beginning of line range
4710 (unless it's the function entry point, in which case
4711 keep going back to the call point). */
4712 if (stop_pc == ecs->event_thread->control.step_range_start
4713 && stop_pc != ecs->stop_func_start
4714 && execution_direction == EXEC_REVERSE)
4715 {
4716 ecs->event_thread->control.stop_step = 1;
4717 print_end_stepping_range_reason ();
4718 stop_stepping (ecs);
4719 }
4720 else
4721 keep_going (ecs);
4722
4723 return;
4724 }
4725
4726 /* We stepped out of the stepping range. */
4727
4728 /* If we are stepping at the source level and entered the runtime
4729 loader dynamic symbol resolution code...
4730
4731 EXEC_FORWARD: we keep on single stepping until we exit the run
4732 time loader code and reach the callee's address.
4733
4734 EXEC_REVERSE: we've already executed the callee (backward), and
4735 the runtime loader code is handled just like any other
4736 undebuggable function call. Now we need only keep stepping
4737 backward through the trampoline code, and that's handled further
4738 down, so there is nothing for us to do here. */
4739
4740 if (execution_direction != EXEC_REVERSE
4741 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4742 && in_solib_dynsym_resolve_code (stop_pc))
4743 {
4744 CORE_ADDR pc_after_resolver =
4745 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4746
4747 if (debug_infrun)
4748 fprintf_unfiltered (gdb_stdlog,
4749 "infrun: stepped into dynsym resolve code\n");
4750
4751 if (pc_after_resolver)
4752 {
4753 /* Set up a step-resume breakpoint at the address
4754 indicated by SKIP_SOLIB_RESOLVER. */
4755 struct symtab_and_line sr_sal;
4756
4757 init_sal (&sr_sal);
4758 sr_sal.pc = pc_after_resolver;
4759 sr_sal.pspace = get_frame_program_space (frame);
4760
4761 insert_step_resume_breakpoint_at_sal (gdbarch,
4762 sr_sal, null_frame_id);
4763 }
4764
4765 keep_going (ecs);
4766 return;
4767 }
4768
4769 if (ecs->event_thread->control.step_range_end != 1
4770 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4771 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4772 && get_frame_type (frame) == SIGTRAMP_FRAME)
4773 {
4774 if (debug_infrun)
4775 fprintf_unfiltered (gdb_stdlog,
4776 "infrun: stepped into signal trampoline\n");
4777 /* The inferior, while doing a "step" or "next", has ended up in
4778 a signal trampoline (either by a signal being delivered or by
4779 the signal handler returning). Just single-step until the
4780 inferior leaves the trampoline (either by calling the handler
4781 or returning). */
4782 keep_going (ecs);
4783 return;
4784 }
4785
4786 /* If we're in the return path from a shared library trampoline,
4787 we want to proceed through the trampoline when stepping. */
4788 /* macro/2012-04-25: This needs to come before the subroutine
4789 call check below as on some targets return trampolines look
4790 like subroutine calls (MIPS16 return thunks). */
4791 if (gdbarch_in_solib_return_trampoline (gdbarch,
4792 stop_pc, ecs->stop_func_name)
4793 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4794 {
4795 /* Determine where this trampoline returns. */
4796 CORE_ADDR real_stop_pc;
4797
4798 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4799
4800 if (debug_infrun)
4801 fprintf_unfiltered (gdb_stdlog,
4802 "infrun: stepped into solib return tramp\n");
4803
4804 /* Only proceed through if we know where it's going. */
4805 if (real_stop_pc)
4806 {
4807 /* And put the step-breakpoint there and go until there. */
4808 struct symtab_and_line sr_sal;
4809
4810 init_sal (&sr_sal); /* initialize to zeroes */
4811 sr_sal.pc = real_stop_pc;
4812 sr_sal.section = find_pc_overlay (sr_sal.pc);
4813 sr_sal.pspace = get_frame_program_space (frame);
4814
4815 /* Do not specify what the fp should be when we stop since
4816 on some machines the prologue is where the new fp value
4817 is established. */
4818 insert_step_resume_breakpoint_at_sal (gdbarch,
4819 sr_sal, null_frame_id);
4820
4821 /* Restart without fiddling with the step ranges or
4822 other state. */
4823 keep_going (ecs);
4824 return;
4825 }
4826 }
4827
4828 /* Check for subroutine calls. The check for the current frame
4829 equalling the step ID is not necessary - the check of the
4830 previous frame's ID is sufficient - but it is a common case and
4831 cheaper than checking the previous frame's ID.
4832
4833 NOTE: frame_id_eq will never report two invalid frame IDs as
4834 being equal, so to get into this block, both the current and
4835 previous frame must have valid frame IDs. */
4836 /* The outer_frame_id check is a heuristic to detect stepping
4837 through startup code. If we step over an instruction which
4838 sets the stack pointer from an invalid value to a valid value,
4839 we may detect that as a subroutine call from the mythical
4840 "outermost" function. This could be fixed by marking
4841 outermost frames as !stack_p,code_p,special_p. Then the
4842 initial outermost frame, before sp was valid, would
4843 have code_addr == &_start. See the comment in frame_id_eq
4844 for more. */
4845 if (!frame_id_eq (get_stack_frame_id (frame),
4846 ecs->event_thread->control.step_stack_frame_id)
4847 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4848 ecs->event_thread->control.step_stack_frame_id)
4849 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4850 outer_frame_id)
4851 || step_start_function != find_pc_function (stop_pc))))
4852 {
4853 CORE_ADDR real_stop_pc;
4854
4855 if (debug_infrun)
4856 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4857
4858 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4859 || ((ecs->event_thread->control.step_range_end == 1)
4860 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4861 ecs->stop_func_start)))
4862 {
4863 /* I presume that step_over_calls is only 0 when we're
4864 supposed to be stepping at the assembly language level
4865 ("stepi"). Just stop. */
4866 /* Also, maybe we just did a "nexti" inside a prolog, so we
4867 thought it was a subroutine call but it was not. Stop as
4868 well. FENN */
4869 /* And this works the same backward as frontward. MVS */
4870 ecs->event_thread->control.stop_step = 1;
4871 print_end_stepping_range_reason ();
4872 stop_stepping (ecs);
4873 return;
4874 }
4875
4876 /* Reverse stepping through solib trampolines. */
4877
4878 if (execution_direction == EXEC_REVERSE
4879 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4880 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4881 || (ecs->stop_func_start == 0
4882 && in_solib_dynsym_resolve_code (stop_pc))))
4883 {
4884 /* Any solib trampoline code can be handled in reverse
4885 by simply continuing to single-step. We have already
4886 executed the solib function (backwards), and a few
4887 steps will take us back through the trampoline to the
4888 caller. */
4889 keep_going (ecs);
4890 return;
4891 }
4892
4893 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4894 {
4895 /* We're doing a "next".
4896
4897 Normal (forward) execution: set a breakpoint at the
4898 callee's return address (the address at which the caller
4899 will resume).
4900
4901 Reverse (backward) execution. set the step-resume
4902 breakpoint at the start of the function that we just
4903 stepped into (backwards), and continue to there. When we
4904 get there, we'll need to single-step back to the caller. */
4905
4906 if (execution_direction == EXEC_REVERSE)
4907 {
4908 /* If we're already at the start of the function, we've either
4909 just stepped backward into a single instruction function,
4910 or stepped back out of a signal handler to the first instruction
4911 of the function. Just keep going, which will single-step back
4912 to the caller. */
4913 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
4914 {
4915 struct symtab_and_line sr_sal;
4916
4917 /* Normal function call return (static or dynamic). */
4918 init_sal (&sr_sal);
4919 sr_sal.pc = ecs->stop_func_start;
4920 sr_sal.pspace = get_frame_program_space (frame);
4921 insert_step_resume_breakpoint_at_sal (gdbarch,
4922 sr_sal, null_frame_id);
4923 }
4924 }
4925 else
4926 insert_step_resume_breakpoint_at_caller (frame);
4927
4928 keep_going (ecs);
4929 return;
4930 }
4931
4932 /* If we are in a function call trampoline (a stub between the
4933 calling routine and the real function), locate the real
4934 function. That's what tells us (a) whether we want to step
4935 into it at all, and (b) what prologue we want to run to the
4936 end of, if we do step into it. */
4937 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4938 if (real_stop_pc == 0)
4939 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4940 if (real_stop_pc != 0)
4941 ecs->stop_func_start = real_stop_pc;
4942
4943 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4944 {
4945 struct symtab_and_line sr_sal;
4946
4947 init_sal (&sr_sal);
4948 sr_sal.pc = ecs->stop_func_start;
4949 sr_sal.pspace = get_frame_program_space (frame);
4950
4951 insert_step_resume_breakpoint_at_sal (gdbarch,
4952 sr_sal, null_frame_id);
4953 keep_going (ecs);
4954 return;
4955 }
4956
4957 /* If we have line number information for the function we are
4958 thinking of stepping into and the function isn't on the skip
4959 list, step into it.
4960
4961 If there are several symtabs at that PC (e.g. with include
4962 files), just want to know whether *any* of them have line
4963 numbers. find_pc_line handles this. */
4964 {
4965 struct symtab_and_line tmp_sal;
4966
4967 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4968 if (tmp_sal.line != 0
4969 && !function_name_is_marked_for_skip (ecs->stop_func_name,
4970 &tmp_sal))
4971 {
4972 if (execution_direction == EXEC_REVERSE)
4973 handle_step_into_function_backward (gdbarch, ecs);
4974 else
4975 handle_step_into_function (gdbarch, ecs);
4976 return;
4977 }
4978 }
4979
4980 /* If we have no line number and the step-stop-if-no-debug is
4981 set, we stop the step so that the user has a chance to switch
4982 in assembly mode. */
4983 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4984 && step_stop_if_no_debug)
4985 {
4986 ecs->event_thread->control.stop_step = 1;
4987 print_end_stepping_range_reason ();
4988 stop_stepping (ecs);
4989 return;
4990 }
4991
4992 if (execution_direction == EXEC_REVERSE)
4993 {
4994 /* If we're already at the start of the function, we've either just
4995 stepped backward into a single instruction function without line
4996 number info, or stepped back out of a signal handler to the first
4997 instruction of the function without line number info. Just keep
4998 going, which will single-step back to the caller. */
4999 if (ecs->stop_func_start != stop_pc)
5000 {
5001 /* Set a breakpoint at callee's start address.
5002 From there we can step once and be back in the caller. */
5003 struct symtab_and_line sr_sal;
5004
5005 init_sal (&sr_sal);
5006 sr_sal.pc = ecs->stop_func_start;
5007 sr_sal.pspace = get_frame_program_space (frame);
5008 insert_step_resume_breakpoint_at_sal (gdbarch,
5009 sr_sal, null_frame_id);
5010 }
5011 }
5012 else
5013 /* Set a breakpoint at callee's return address (the address
5014 at which the caller will resume). */
5015 insert_step_resume_breakpoint_at_caller (frame);
5016
5017 keep_going (ecs);
5018 return;
5019 }
5020
5021 /* Reverse stepping through solib trampolines. */
5022
5023 if (execution_direction == EXEC_REVERSE
5024 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5025 {
5026 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5027 || (ecs->stop_func_start == 0
5028 && in_solib_dynsym_resolve_code (stop_pc)))
5029 {
5030 /* Any solib trampoline code can be handled in reverse
5031 by simply continuing to single-step. We have already
5032 executed the solib function (backwards), and a few
5033 steps will take us back through the trampoline to the
5034 caller. */
5035 keep_going (ecs);
5036 return;
5037 }
5038 else if (in_solib_dynsym_resolve_code (stop_pc))
5039 {
5040 /* Stepped backward into the solib dynsym resolver.
5041 Set a breakpoint at its start and continue, then
5042 one more step will take us out. */
5043 struct symtab_and_line sr_sal;
5044
5045 init_sal (&sr_sal);
5046 sr_sal.pc = ecs->stop_func_start;
5047 sr_sal.pspace = get_frame_program_space (frame);
5048 insert_step_resume_breakpoint_at_sal (gdbarch,
5049 sr_sal, null_frame_id);
5050 keep_going (ecs);
5051 return;
5052 }
5053 }
5054
5055 stop_pc_sal = find_pc_line (stop_pc, 0);
5056
5057 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5058 the trampoline processing logic, however, there are some trampolines
5059 that have no names, so we should do trampoline handling first. */
5060 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5061 && ecs->stop_func_name == NULL
5062 && stop_pc_sal.line == 0)
5063 {
5064 if (debug_infrun)
5065 fprintf_unfiltered (gdb_stdlog,
5066 "infrun: stepped into undebuggable function\n");
5067
5068 /* The inferior just stepped into, or returned to, an
5069 undebuggable function (where there is no debugging information
5070 and no line number corresponding to the address where the
5071 inferior stopped). Since we want to skip this kind of code,
5072 we keep going until the inferior returns from this
5073 function - unless the user has asked us not to (via
5074 set step-mode) or we no longer know how to get back
5075 to the call site. */
5076 if (step_stop_if_no_debug
5077 || !frame_id_p (frame_unwind_caller_id (frame)))
5078 {
5079 /* If we have no line number and the step-stop-if-no-debug
5080 is set, we stop the step so that the user has a chance to
5081 switch in assembly mode. */
5082 ecs->event_thread->control.stop_step = 1;
5083 print_end_stepping_range_reason ();
5084 stop_stepping (ecs);
5085 return;
5086 }
5087 else
5088 {
5089 /* Set a breakpoint at callee's return address (the address
5090 at which the caller will resume). */
5091 insert_step_resume_breakpoint_at_caller (frame);
5092 keep_going (ecs);
5093 return;
5094 }
5095 }
5096
5097 if (ecs->event_thread->control.step_range_end == 1)
5098 {
5099 /* It is stepi or nexti. We always want to stop stepping after
5100 one instruction. */
5101 if (debug_infrun)
5102 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5103 ecs->event_thread->control.stop_step = 1;
5104 print_end_stepping_range_reason ();
5105 stop_stepping (ecs);
5106 return;
5107 }
5108
5109 if (stop_pc_sal.line == 0)
5110 {
5111 /* We have no line number information. That means to stop
5112 stepping (does this always happen right after one instruction,
5113 when we do "s" in a function with no line numbers,
5114 or can this happen as a result of a return or longjmp?). */
5115 if (debug_infrun)
5116 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5117 ecs->event_thread->control.stop_step = 1;
5118 print_end_stepping_range_reason ();
5119 stop_stepping (ecs);
5120 return;
5121 }
5122
5123 /* Look for "calls" to inlined functions, part one. If the inline
5124 frame machinery detected some skipped call sites, we have entered
5125 a new inline function. */
5126
5127 if (frame_id_eq (get_frame_id (get_current_frame ()),
5128 ecs->event_thread->control.step_frame_id)
5129 && inline_skipped_frames (ecs->ptid))
5130 {
5131 struct symtab_and_line call_sal;
5132
5133 if (debug_infrun)
5134 fprintf_unfiltered (gdb_stdlog,
5135 "infrun: stepped into inlined function\n");
5136
5137 find_frame_sal (get_current_frame (), &call_sal);
5138
5139 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5140 {
5141 /* For "step", we're going to stop. But if the call site
5142 for this inlined function is on the same source line as
5143 we were previously stepping, go down into the function
5144 first. Otherwise stop at the call site. */
5145
5146 if (call_sal.line == ecs->event_thread->current_line
5147 && call_sal.symtab == ecs->event_thread->current_symtab)
5148 step_into_inline_frame (ecs->ptid);
5149
5150 ecs->event_thread->control.stop_step = 1;
5151 print_end_stepping_range_reason ();
5152 stop_stepping (ecs);
5153 return;
5154 }
5155 else
5156 {
5157 /* For "next", we should stop at the call site if it is on a
5158 different source line. Otherwise continue through the
5159 inlined function. */
5160 if (call_sal.line == ecs->event_thread->current_line
5161 && call_sal.symtab == ecs->event_thread->current_symtab)
5162 keep_going (ecs);
5163 else
5164 {
5165 ecs->event_thread->control.stop_step = 1;
5166 print_end_stepping_range_reason ();
5167 stop_stepping (ecs);
5168 }
5169 return;
5170 }
5171 }
5172
5173 /* Look for "calls" to inlined functions, part two. If we are still
5174 in the same real function we were stepping through, but we have
5175 to go further up to find the exact frame ID, we are stepping
5176 through a more inlined call beyond its call site. */
5177
5178 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5179 && !frame_id_eq (get_frame_id (get_current_frame ()),
5180 ecs->event_thread->control.step_frame_id)
5181 && stepped_in_from (get_current_frame (),
5182 ecs->event_thread->control.step_frame_id))
5183 {
5184 if (debug_infrun)
5185 fprintf_unfiltered (gdb_stdlog,
5186 "infrun: stepping through inlined function\n");
5187
5188 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5189 keep_going (ecs);
5190 else
5191 {
5192 ecs->event_thread->control.stop_step = 1;
5193 print_end_stepping_range_reason ();
5194 stop_stepping (ecs);
5195 }
5196 return;
5197 }
5198
5199 if ((stop_pc == stop_pc_sal.pc)
5200 && (ecs->event_thread->current_line != stop_pc_sal.line
5201 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5202 {
5203 /* We are at the start of a different line. So stop. Note that
5204 we don't stop if we step into the middle of a different line.
5205 That is said to make things like for (;;) statements work
5206 better. */
5207 if (debug_infrun)
5208 fprintf_unfiltered (gdb_stdlog,
5209 "infrun: stepped to a different line\n");
5210 ecs->event_thread->control.stop_step = 1;
5211 print_end_stepping_range_reason ();
5212 stop_stepping (ecs);
5213 return;
5214 }
5215
5216 /* We aren't done stepping.
5217
5218 Optimize by setting the stepping range to the line.
5219 (We might not be in the original line, but if we entered a
5220 new line in mid-statement, we continue stepping. This makes
5221 things like for(;;) statements work better.) */
5222
5223 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5224 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5225 ecs->event_thread->control.may_range_step = 1;
5226 set_step_info (frame, stop_pc_sal);
5227
5228 if (debug_infrun)
5229 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5230 keep_going (ecs);
5231 }
5232
5233 /* In all-stop mode, if we're currently stepping but have stopped in
5234 some other thread, we may need to switch back to the stepped
5235 thread. Returns true we set the inferior running, false if we left
5236 it stopped (and the event needs further processing). */
5237
5238 static int
5239 switch_back_to_stepped_thread (struct execution_control_state *ecs)
5240 {
5241 if (!non_stop)
5242 {
5243 struct thread_info *tp;
5244
5245 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
5246 ecs->event_thread);
5247 if (tp)
5248 {
5249 /* However, if the current thread is blocked on some internal
5250 breakpoint, and we simply need to step over that breakpoint
5251 to get it going again, do that first. */
5252 if ((ecs->event_thread->control.trap_expected
5253 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5254 || ecs->event_thread->stepping_over_breakpoint)
5255 {
5256 keep_going (ecs);
5257 return 1;
5258 }
5259
5260 /* If the stepping thread exited, then don't try to switch
5261 back and resume it, which could fail in several different
5262 ways depending on the target. Instead, just keep going.
5263
5264 We can find a stepping dead thread in the thread list in
5265 two cases:
5266
5267 - The target supports thread exit events, and when the
5268 target tries to delete the thread from the thread list,
5269 inferior_ptid pointed at the exiting thread. In such
5270 case, calling delete_thread does not really remove the
5271 thread from the list; instead, the thread is left listed,
5272 with 'exited' state.
5273
5274 - The target's debug interface does not support thread
5275 exit events, and so we have no idea whatsoever if the
5276 previously stepping thread is still alive. For that
5277 reason, we need to synchronously query the target
5278 now. */
5279 if (is_exited (tp->ptid)
5280 || !target_thread_alive (tp->ptid))
5281 {
5282 if (debug_infrun)
5283 fprintf_unfiltered (gdb_stdlog,
5284 "infrun: not switching back to "
5285 "stepped thread, it has vanished\n");
5286
5287 delete_thread (tp->ptid);
5288 keep_going (ecs);
5289 return 1;
5290 }
5291
5292 /* Otherwise, we no longer expect a trap in the current thread.
5293 Clear the trap_expected flag before switching back -- this is
5294 what keep_going would do as well, if we called it. */
5295 ecs->event_thread->control.trap_expected = 0;
5296
5297 if (debug_infrun)
5298 fprintf_unfiltered (gdb_stdlog,
5299 "infrun: switching back to stepped thread\n");
5300
5301 ecs->event_thread = tp;
5302 ecs->ptid = tp->ptid;
5303 context_switch (ecs->ptid);
5304 keep_going (ecs);
5305 return 1;
5306 }
5307 }
5308 return 0;
5309 }
5310
5311 /* Is thread TP in the middle of single-stepping? */
5312
5313 static int
5314 currently_stepping (struct thread_info *tp)
5315 {
5316 return ((tp->control.step_range_end
5317 && tp->control.step_resume_breakpoint == NULL)
5318 || tp->control.trap_expected
5319 || bpstat_should_step ());
5320 }
5321
5322 /* Returns true if any thread *but* the one passed in "data" is in the
5323 middle of stepping or of handling a "next". */
5324
5325 static int
5326 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5327 {
5328 if (tp == data)
5329 return 0;
5330
5331 return (tp->control.step_range_end
5332 || tp->control.trap_expected);
5333 }
5334
5335 /* Inferior has stepped into a subroutine call with source code that
5336 we should not step over. Do step to the first line of code in
5337 it. */
5338
5339 static void
5340 handle_step_into_function (struct gdbarch *gdbarch,
5341 struct execution_control_state *ecs)
5342 {
5343 struct symtab *s;
5344 struct symtab_and_line stop_func_sal, sr_sal;
5345
5346 fill_in_stop_func (gdbarch, ecs);
5347
5348 s = find_pc_symtab (stop_pc);
5349 if (s && s->language != language_asm)
5350 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5351 ecs->stop_func_start);
5352
5353 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5354 /* Use the step_resume_break to step until the end of the prologue,
5355 even if that involves jumps (as it seems to on the vax under
5356 4.2). */
5357 /* If the prologue ends in the middle of a source line, continue to
5358 the end of that source line (if it is still within the function).
5359 Otherwise, just go to end of prologue. */
5360 if (stop_func_sal.end
5361 && stop_func_sal.pc != ecs->stop_func_start
5362 && stop_func_sal.end < ecs->stop_func_end)
5363 ecs->stop_func_start = stop_func_sal.end;
5364
5365 /* Architectures which require breakpoint adjustment might not be able
5366 to place a breakpoint at the computed address. If so, the test
5367 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5368 ecs->stop_func_start to an address at which a breakpoint may be
5369 legitimately placed.
5370
5371 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5372 made, GDB will enter an infinite loop when stepping through
5373 optimized code consisting of VLIW instructions which contain
5374 subinstructions corresponding to different source lines. On
5375 FR-V, it's not permitted to place a breakpoint on any but the
5376 first subinstruction of a VLIW instruction. When a breakpoint is
5377 set, GDB will adjust the breakpoint address to the beginning of
5378 the VLIW instruction. Thus, we need to make the corresponding
5379 adjustment here when computing the stop address. */
5380
5381 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5382 {
5383 ecs->stop_func_start
5384 = gdbarch_adjust_breakpoint_address (gdbarch,
5385 ecs->stop_func_start);
5386 }
5387
5388 if (ecs->stop_func_start == stop_pc)
5389 {
5390 /* We are already there: stop now. */
5391 ecs->event_thread->control.stop_step = 1;
5392 print_end_stepping_range_reason ();
5393 stop_stepping (ecs);
5394 return;
5395 }
5396 else
5397 {
5398 /* Put the step-breakpoint there and go until there. */
5399 init_sal (&sr_sal); /* initialize to zeroes */
5400 sr_sal.pc = ecs->stop_func_start;
5401 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5402 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5403
5404 /* Do not specify what the fp should be when we stop since on
5405 some machines the prologue is where the new fp value is
5406 established. */
5407 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5408
5409 /* And make sure stepping stops right away then. */
5410 ecs->event_thread->control.step_range_end
5411 = ecs->event_thread->control.step_range_start;
5412 }
5413 keep_going (ecs);
5414 }
5415
5416 /* Inferior has stepped backward into a subroutine call with source
5417 code that we should not step over. Do step to the beginning of the
5418 last line of code in it. */
5419
5420 static void
5421 handle_step_into_function_backward (struct gdbarch *gdbarch,
5422 struct execution_control_state *ecs)
5423 {
5424 struct symtab *s;
5425 struct symtab_and_line stop_func_sal;
5426
5427 fill_in_stop_func (gdbarch, ecs);
5428
5429 s = find_pc_symtab (stop_pc);
5430 if (s && s->language != language_asm)
5431 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5432 ecs->stop_func_start);
5433
5434 stop_func_sal = find_pc_line (stop_pc, 0);
5435
5436 /* OK, we're just going to keep stepping here. */
5437 if (stop_func_sal.pc == stop_pc)
5438 {
5439 /* We're there already. Just stop stepping now. */
5440 ecs->event_thread->control.stop_step = 1;
5441 print_end_stepping_range_reason ();
5442 stop_stepping (ecs);
5443 }
5444 else
5445 {
5446 /* Else just reset the step range and keep going.
5447 No step-resume breakpoint, they don't work for
5448 epilogues, which can have multiple entry paths. */
5449 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5450 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5451 keep_going (ecs);
5452 }
5453 return;
5454 }
5455
5456 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5457 This is used to both functions and to skip over code. */
5458
5459 static void
5460 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5461 struct symtab_and_line sr_sal,
5462 struct frame_id sr_id,
5463 enum bptype sr_type)
5464 {
5465 /* There should never be more than one step-resume or longjmp-resume
5466 breakpoint per thread, so we should never be setting a new
5467 step_resume_breakpoint when one is already active. */
5468 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5469 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5470
5471 if (debug_infrun)
5472 fprintf_unfiltered (gdb_stdlog,
5473 "infrun: inserting step-resume breakpoint at %s\n",
5474 paddress (gdbarch, sr_sal.pc));
5475
5476 inferior_thread ()->control.step_resume_breakpoint
5477 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5478 }
5479
5480 void
5481 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5482 struct symtab_and_line sr_sal,
5483 struct frame_id sr_id)
5484 {
5485 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5486 sr_sal, sr_id,
5487 bp_step_resume);
5488 }
5489
5490 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5491 This is used to skip a potential signal handler.
5492
5493 This is called with the interrupted function's frame. The signal
5494 handler, when it returns, will resume the interrupted function at
5495 RETURN_FRAME.pc. */
5496
5497 static void
5498 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5499 {
5500 struct symtab_and_line sr_sal;
5501 struct gdbarch *gdbarch;
5502
5503 gdb_assert (return_frame != NULL);
5504 init_sal (&sr_sal); /* initialize to zeros */
5505
5506 gdbarch = get_frame_arch (return_frame);
5507 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5508 sr_sal.section = find_pc_overlay (sr_sal.pc);
5509 sr_sal.pspace = get_frame_program_space (return_frame);
5510
5511 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5512 get_stack_frame_id (return_frame),
5513 bp_hp_step_resume);
5514 }
5515
5516 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5517 is used to skip a function after stepping into it (for "next" or if
5518 the called function has no debugging information).
5519
5520 The current function has almost always been reached by single
5521 stepping a call or return instruction. NEXT_FRAME belongs to the
5522 current function, and the breakpoint will be set at the caller's
5523 resume address.
5524
5525 This is a separate function rather than reusing
5526 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5527 get_prev_frame, which may stop prematurely (see the implementation
5528 of frame_unwind_caller_id for an example). */
5529
5530 static void
5531 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5532 {
5533 struct symtab_and_line sr_sal;
5534 struct gdbarch *gdbarch;
5535
5536 /* We shouldn't have gotten here if we don't know where the call site
5537 is. */
5538 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5539
5540 init_sal (&sr_sal); /* initialize to zeros */
5541
5542 gdbarch = frame_unwind_caller_arch (next_frame);
5543 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5544 frame_unwind_caller_pc (next_frame));
5545 sr_sal.section = find_pc_overlay (sr_sal.pc);
5546 sr_sal.pspace = frame_unwind_program_space (next_frame);
5547
5548 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5549 frame_unwind_caller_id (next_frame));
5550 }
5551
5552 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5553 new breakpoint at the target of a jmp_buf. The handling of
5554 longjmp-resume uses the same mechanisms used for handling
5555 "step-resume" breakpoints. */
5556
5557 static void
5558 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5559 {
5560 /* There should never be more than one longjmp-resume breakpoint per
5561 thread, so we should never be setting a new
5562 longjmp_resume_breakpoint when one is already active. */
5563 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5564
5565 if (debug_infrun)
5566 fprintf_unfiltered (gdb_stdlog,
5567 "infrun: inserting longjmp-resume breakpoint at %s\n",
5568 paddress (gdbarch, pc));
5569
5570 inferior_thread ()->control.exception_resume_breakpoint =
5571 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5572 }
5573
5574 /* Insert an exception resume breakpoint. TP is the thread throwing
5575 the exception. The block B is the block of the unwinder debug hook
5576 function. FRAME is the frame corresponding to the call to this
5577 function. SYM is the symbol of the function argument holding the
5578 target PC of the exception. */
5579
5580 static void
5581 insert_exception_resume_breakpoint (struct thread_info *tp,
5582 struct block *b,
5583 struct frame_info *frame,
5584 struct symbol *sym)
5585 {
5586 volatile struct gdb_exception e;
5587
5588 /* We want to ignore errors here. */
5589 TRY_CATCH (e, RETURN_MASK_ERROR)
5590 {
5591 struct symbol *vsym;
5592 struct value *value;
5593 CORE_ADDR handler;
5594 struct breakpoint *bp;
5595
5596 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5597 value = read_var_value (vsym, frame);
5598 /* If the value was optimized out, revert to the old behavior. */
5599 if (! value_optimized_out (value))
5600 {
5601 handler = value_as_address (value);
5602
5603 if (debug_infrun)
5604 fprintf_unfiltered (gdb_stdlog,
5605 "infrun: exception resume at %lx\n",
5606 (unsigned long) handler);
5607
5608 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5609 handler, bp_exception_resume);
5610
5611 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5612 frame = NULL;
5613
5614 bp->thread = tp->num;
5615 inferior_thread ()->control.exception_resume_breakpoint = bp;
5616 }
5617 }
5618 }
5619
5620 /* A helper for check_exception_resume that sets an
5621 exception-breakpoint based on a SystemTap probe. */
5622
5623 static void
5624 insert_exception_resume_from_probe (struct thread_info *tp,
5625 const struct probe *probe,
5626 struct frame_info *frame)
5627 {
5628 struct value *arg_value;
5629 CORE_ADDR handler;
5630 struct breakpoint *bp;
5631
5632 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5633 if (!arg_value)
5634 return;
5635
5636 handler = value_as_address (arg_value);
5637
5638 if (debug_infrun)
5639 fprintf_unfiltered (gdb_stdlog,
5640 "infrun: exception resume at %s\n",
5641 paddress (get_objfile_arch (probe->objfile),
5642 handler));
5643
5644 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5645 handler, bp_exception_resume);
5646 bp->thread = tp->num;
5647 inferior_thread ()->control.exception_resume_breakpoint = bp;
5648 }
5649
5650 /* This is called when an exception has been intercepted. Check to
5651 see whether the exception's destination is of interest, and if so,
5652 set an exception resume breakpoint there. */
5653
5654 static void
5655 check_exception_resume (struct execution_control_state *ecs,
5656 struct frame_info *frame)
5657 {
5658 volatile struct gdb_exception e;
5659 const struct probe *probe;
5660 struct symbol *func;
5661
5662 /* First see if this exception unwinding breakpoint was set via a
5663 SystemTap probe point. If so, the probe has two arguments: the
5664 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5665 set a breakpoint there. */
5666 probe = find_probe_by_pc (get_frame_pc (frame));
5667 if (probe)
5668 {
5669 insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
5670 return;
5671 }
5672
5673 func = get_frame_function (frame);
5674 if (!func)
5675 return;
5676
5677 TRY_CATCH (e, RETURN_MASK_ERROR)
5678 {
5679 struct block *b;
5680 struct block_iterator iter;
5681 struct symbol *sym;
5682 int argno = 0;
5683
5684 /* The exception breakpoint is a thread-specific breakpoint on
5685 the unwinder's debug hook, declared as:
5686
5687 void _Unwind_DebugHook (void *cfa, void *handler);
5688
5689 The CFA argument indicates the frame to which control is
5690 about to be transferred. HANDLER is the destination PC.
5691
5692 We ignore the CFA and set a temporary breakpoint at HANDLER.
5693 This is not extremely efficient but it avoids issues in gdb
5694 with computing the DWARF CFA, and it also works even in weird
5695 cases such as throwing an exception from inside a signal
5696 handler. */
5697
5698 b = SYMBOL_BLOCK_VALUE (func);
5699 ALL_BLOCK_SYMBOLS (b, iter, sym)
5700 {
5701 if (!SYMBOL_IS_ARGUMENT (sym))
5702 continue;
5703
5704 if (argno == 0)
5705 ++argno;
5706 else
5707 {
5708 insert_exception_resume_breakpoint (ecs->event_thread,
5709 b, frame, sym);
5710 break;
5711 }
5712 }
5713 }
5714 }
5715
5716 static void
5717 stop_stepping (struct execution_control_state *ecs)
5718 {
5719 if (debug_infrun)
5720 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5721
5722 /* Let callers know we don't want to wait for the inferior anymore. */
5723 ecs->wait_some_more = 0;
5724 }
5725
5726 /* Called when we should continue running the inferior, because the
5727 current event doesn't cause a user visible stop. This does the
5728 resuming part; waiting for the next event is done elsewhere. */
5729
5730 static void
5731 keep_going (struct execution_control_state *ecs)
5732 {
5733 /* Make sure normal_stop is called if we get a QUIT handled before
5734 reaching resume. */
5735 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5736
5737 /* Save the pc before execution, to compare with pc after stop. */
5738 ecs->event_thread->prev_pc
5739 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5740
5741 if (ecs->event_thread->control.trap_expected
5742 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5743 {
5744 /* We haven't yet gotten our trap, and either: intercepted a
5745 non-signal event (e.g., a fork); or took a signal which we
5746 are supposed to pass through to the inferior. Simply
5747 continue. */
5748 discard_cleanups (old_cleanups);
5749 resume (currently_stepping (ecs->event_thread),
5750 ecs->event_thread->suspend.stop_signal);
5751 }
5752 else
5753 {
5754 /* Either the trap was not expected, but we are continuing
5755 anyway (if we got a signal, the user asked it be passed to
5756 the child)
5757 -- or --
5758 We got our expected trap, but decided we should resume from
5759 it.
5760
5761 We're going to run this baby now!
5762
5763 Note that insert_breakpoints won't try to re-insert
5764 already inserted breakpoints. Therefore, we don't
5765 care if breakpoints were already inserted, or not. */
5766
5767 if (ecs->event_thread->stepping_over_breakpoint)
5768 {
5769 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5770
5771 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5772 {
5773 /* Since we can't do a displaced step, we have to remove
5774 the breakpoint while we step it. To keep things
5775 simple, we remove them all. */
5776 remove_breakpoints ();
5777 }
5778 }
5779 else
5780 {
5781 volatile struct gdb_exception e;
5782
5783 /* Stop stepping if inserting breakpoints fails. */
5784 TRY_CATCH (e, RETURN_MASK_ERROR)
5785 {
5786 insert_breakpoints ();
5787 }
5788 if (e.reason < 0)
5789 {
5790 exception_print (gdb_stderr, e);
5791 stop_stepping (ecs);
5792 return;
5793 }
5794 }
5795
5796 ecs->event_thread->control.trap_expected
5797 = ecs->event_thread->stepping_over_breakpoint;
5798
5799 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
5800 explicitly specifies that such a signal should be delivered
5801 to the target program). Typically, that would occur when a
5802 user is debugging a target monitor on a simulator: the target
5803 monitor sets a breakpoint; the simulator encounters this
5804 breakpoint and halts the simulation handing control to GDB;
5805 GDB, noting that the stop address doesn't map to any known
5806 breakpoint, returns control back to the simulator; the
5807 simulator then delivers the hardware equivalent of a
5808 GDB_SIGNAL_TRAP to the program being debugged. */
5809 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5810 && !signal_program[ecs->event_thread->suspend.stop_signal])
5811 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5812
5813 discard_cleanups (old_cleanups);
5814 resume (currently_stepping (ecs->event_thread),
5815 ecs->event_thread->suspend.stop_signal);
5816 }
5817
5818 prepare_to_wait (ecs);
5819 }
5820
5821 /* This function normally comes after a resume, before
5822 handle_inferior_event exits. It takes care of any last bits of
5823 housekeeping, and sets the all-important wait_some_more flag. */
5824
5825 static void
5826 prepare_to_wait (struct execution_control_state *ecs)
5827 {
5828 if (debug_infrun)
5829 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5830
5831 /* This is the old end of the while loop. Let everybody know we
5832 want to wait for the inferior some more and get called again
5833 soon. */
5834 ecs->wait_some_more = 1;
5835 }
5836
5837 /* Several print_*_reason functions to print why the inferior has stopped.
5838 We always print something when the inferior exits, or receives a signal.
5839 The rest of the cases are dealt with later on in normal_stop and
5840 print_it_typical. Ideally there should be a call to one of these
5841 print_*_reason functions functions from handle_inferior_event each time
5842 stop_stepping is called. */
5843
5844 /* Print why the inferior has stopped.
5845 We are done with a step/next/si/ni command, print why the inferior has
5846 stopped. For now print nothing. Print a message only if not in the middle
5847 of doing a "step n" operation for n > 1. */
5848
5849 static void
5850 print_end_stepping_range_reason (void)
5851 {
5852 if ((!inferior_thread ()->step_multi
5853 || !inferior_thread ()->control.stop_step)
5854 && ui_out_is_mi_like_p (current_uiout))
5855 ui_out_field_string (current_uiout, "reason",
5856 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5857 }
5858
5859 /* The inferior was terminated by a signal, print why it stopped. */
5860
5861 static void
5862 print_signal_exited_reason (enum gdb_signal siggnal)
5863 {
5864 struct ui_out *uiout = current_uiout;
5865
5866 annotate_signalled ();
5867 if (ui_out_is_mi_like_p (uiout))
5868 ui_out_field_string
5869 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5870 ui_out_text (uiout, "\nProgram terminated with signal ");
5871 annotate_signal_name ();
5872 ui_out_field_string (uiout, "signal-name",
5873 gdb_signal_to_name (siggnal));
5874 annotate_signal_name_end ();
5875 ui_out_text (uiout, ", ");
5876 annotate_signal_string ();
5877 ui_out_field_string (uiout, "signal-meaning",
5878 gdb_signal_to_string (siggnal));
5879 annotate_signal_string_end ();
5880 ui_out_text (uiout, ".\n");
5881 ui_out_text (uiout, "The program no longer exists.\n");
5882 }
5883
5884 /* The inferior program is finished, print why it stopped. */
5885
5886 static void
5887 print_exited_reason (int exitstatus)
5888 {
5889 struct inferior *inf = current_inferior ();
5890 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5891 struct ui_out *uiout = current_uiout;
5892
5893 annotate_exited (exitstatus);
5894 if (exitstatus)
5895 {
5896 if (ui_out_is_mi_like_p (uiout))
5897 ui_out_field_string (uiout, "reason",
5898 async_reason_lookup (EXEC_ASYNC_EXITED));
5899 ui_out_text (uiout, "[Inferior ");
5900 ui_out_text (uiout, plongest (inf->num));
5901 ui_out_text (uiout, " (");
5902 ui_out_text (uiout, pidstr);
5903 ui_out_text (uiout, ") exited with code ");
5904 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5905 ui_out_text (uiout, "]\n");
5906 }
5907 else
5908 {
5909 if (ui_out_is_mi_like_p (uiout))
5910 ui_out_field_string
5911 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5912 ui_out_text (uiout, "[Inferior ");
5913 ui_out_text (uiout, plongest (inf->num));
5914 ui_out_text (uiout, " (");
5915 ui_out_text (uiout, pidstr);
5916 ui_out_text (uiout, ") exited normally]\n");
5917 }
5918 /* Support the --return-child-result option. */
5919 return_child_result_value = exitstatus;
5920 }
5921
5922 /* Signal received, print why the inferior has stopped. The signal table
5923 tells us to print about it. */
5924
5925 static void
5926 print_signal_received_reason (enum gdb_signal siggnal)
5927 {
5928 struct ui_out *uiout = current_uiout;
5929
5930 annotate_signal ();
5931
5932 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5933 {
5934 struct thread_info *t = inferior_thread ();
5935
5936 ui_out_text (uiout, "\n[");
5937 ui_out_field_string (uiout, "thread-name",
5938 target_pid_to_str (t->ptid));
5939 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5940 ui_out_text (uiout, " stopped");
5941 }
5942 else
5943 {
5944 ui_out_text (uiout, "\nProgram received signal ");
5945 annotate_signal_name ();
5946 if (ui_out_is_mi_like_p (uiout))
5947 ui_out_field_string
5948 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5949 ui_out_field_string (uiout, "signal-name",
5950 gdb_signal_to_name (siggnal));
5951 annotate_signal_name_end ();
5952 ui_out_text (uiout, ", ");
5953 annotate_signal_string ();
5954 ui_out_field_string (uiout, "signal-meaning",
5955 gdb_signal_to_string (siggnal));
5956 annotate_signal_string_end ();
5957 }
5958 ui_out_text (uiout, ".\n");
5959 }
5960
5961 /* Reverse execution: target ran out of history info, print why the inferior
5962 has stopped. */
5963
5964 static void
5965 print_no_history_reason (void)
5966 {
5967 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5968 }
5969
5970 /* Here to return control to GDB when the inferior stops for real.
5971 Print appropriate messages, remove breakpoints, give terminal our modes.
5972
5973 STOP_PRINT_FRAME nonzero means print the executing frame
5974 (pc, function, args, file, line number and line text).
5975 BREAKPOINTS_FAILED nonzero means stop was due to error
5976 attempting to insert breakpoints. */
5977
5978 void
5979 normal_stop (void)
5980 {
5981 struct target_waitstatus last;
5982 ptid_t last_ptid;
5983 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5984
5985 get_last_target_status (&last_ptid, &last);
5986
5987 /* If an exception is thrown from this point on, make sure to
5988 propagate GDB's knowledge of the executing state to the
5989 frontend/user running state. A QUIT is an easy exception to see
5990 here, so do this before any filtered output. */
5991 if (!non_stop)
5992 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5993 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5994 && last.kind != TARGET_WAITKIND_EXITED
5995 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5996 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5997
5998 /* In non-stop mode, we don't want GDB to switch threads behind the
5999 user's back, to avoid races where the user is typing a command to
6000 apply to thread x, but GDB switches to thread y before the user
6001 finishes entering the command. */
6002
6003 /* As with the notification of thread events, we want to delay
6004 notifying the user that we've switched thread context until
6005 the inferior actually stops.
6006
6007 There's no point in saying anything if the inferior has exited.
6008 Note that SIGNALLED here means "exited with a signal", not
6009 "received a signal". */
6010 if (!non_stop
6011 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
6012 && target_has_execution
6013 && last.kind != TARGET_WAITKIND_SIGNALLED
6014 && last.kind != TARGET_WAITKIND_EXITED
6015 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6016 {
6017 target_terminal_ours_for_output ();
6018 printf_filtered (_("[Switching to %s]\n"),
6019 target_pid_to_str (inferior_ptid));
6020 annotate_thread_changed ();
6021 previous_inferior_ptid = inferior_ptid;
6022 }
6023
6024 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
6025 {
6026 gdb_assert (sync_execution || !target_can_async_p ());
6027
6028 target_terminal_ours_for_output ();
6029 printf_filtered (_("No unwaited-for children left.\n"));
6030 }
6031
6032 if (!breakpoints_always_inserted_mode () && target_has_execution)
6033 {
6034 if (remove_breakpoints ())
6035 {
6036 target_terminal_ours_for_output ();
6037 printf_filtered (_("Cannot remove breakpoints because "
6038 "program is no longer writable.\nFurther "
6039 "execution is probably impossible.\n"));
6040 }
6041 }
6042
6043 /* If an auto-display called a function and that got a signal,
6044 delete that auto-display to avoid an infinite recursion. */
6045
6046 if (stopped_by_random_signal)
6047 disable_current_display ();
6048
6049 /* Don't print a message if in the middle of doing a "step n"
6050 operation for n > 1 */
6051 if (target_has_execution
6052 && last.kind != TARGET_WAITKIND_SIGNALLED
6053 && last.kind != TARGET_WAITKIND_EXITED
6054 && inferior_thread ()->step_multi
6055 && inferior_thread ()->control.stop_step)
6056 goto done;
6057
6058 target_terminal_ours ();
6059 async_enable_stdin ();
6060
6061 /* Set the current source location. This will also happen if we
6062 display the frame below, but the current SAL will be incorrect
6063 during a user hook-stop function. */
6064 if (has_stack_frames () && !stop_stack_dummy)
6065 set_current_sal_from_frame (get_current_frame (), 1);
6066
6067 /* Let the user/frontend see the threads as stopped. */
6068 do_cleanups (old_chain);
6069
6070 /* Look up the hook_stop and run it (CLI internally handles problem
6071 of stop_command's pre-hook not existing). */
6072 if (stop_command)
6073 catch_errors (hook_stop_stub, stop_command,
6074 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6075
6076 if (!has_stack_frames ())
6077 goto done;
6078
6079 if (last.kind == TARGET_WAITKIND_SIGNALLED
6080 || last.kind == TARGET_WAITKIND_EXITED)
6081 goto done;
6082
6083 /* Select innermost stack frame - i.e., current frame is frame 0,
6084 and current location is based on that.
6085 Don't do this on return from a stack dummy routine,
6086 or if the program has exited. */
6087
6088 if (!stop_stack_dummy)
6089 {
6090 select_frame (get_current_frame ());
6091
6092 /* Print current location without a level number, if
6093 we have changed functions or hit a breakpoint.
6094 Print source line if we have one.
6095 bpstat_print() contains the logic deciding in detail
6096 what to print, based on the event(s) that just occurred. */
6097
6098 /* If --batch-silent is enabled then there's no need to print the current
6099 source location, and to try risks causing an error message about
6100 missing source files. */
6101 if (stop_print_frame && !batch_silent)
6102 {
6103 int bpstat_ret;
6104 int source_flag;
6105 int do_frame_printing = 1;
6106 struct thread_info *tp = inferior_thread ();
6107
6108 bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind);
6109 switch (bpstat_ret)
6110 {
6111 case PRINT_UNKNOWN:
6112 /* FIXME: cagney/2002-12-01: Given that a frame ID does
6113 (or should) carry around the function and does (or
6114 should) use that when doing a frame comparison. */
6115 if (tp->control.stop_step
6116 && frame_id_eq (tp->control.step_frame_id,
6117 get_frame_id (get_current_frame ()))
6118 && step_start_function == find_pc_function (stop_pc))
6119 source_flag = SRC_LINE; /* Finished step, just
6120 print source line. */
6121 else
6122 source_flag = SRC_AND_LOC; /* Print location and
6123 source line. */
6124 break;
6125 case PRINT_SRC_AND_LOC:
6126 source_flag = SRC_AND_LOC; /* Print location and
6127 source line. */
6128 break;
6129 case PRINT_SRC_ONLY:
6130 source_flag = SRC_LINE;
6131 break;
6132 case PRINT_NOTHING:
6133 source_flag = SRC_LINE; /* something bogus */
6134 do_frame_printing = 0;
6135 break;
6136 default:
6137 internal_error (__FILE__, __LINE__, _("Unknown value."));
6138 }
6139
6140 /* The behavior of this routine with respect to the source
6141 flag is:
6142 SRC_LINE: Print only source line
6143 LOCATION: Print only location
6144 SRC_AND_LOC: Print location and source line. */
6145 if (do_frame_printing)
6146 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
6147
6148 /* Display the auto-display expressions. */
6149 do_displays ();
6150 }
6151 }
6152
6153 /* Save the function value return registers, if we care.
6154 We might be about to restore their previous contents. */
6155 if (inferior_thread ()->control.proceed_to_finish
6156 && execution_direction != EXEC_REVERSE)
6157 {
6158 /* This should not be necessary. */
6159 if (stop_registers)
6160 regcache_xfree (stop_registers);
6161
6162 /* NB: The copy goes through to the target picking up the value of
6163 all the registers. */
6164 stop_registers = regcache_dup (get_current_regcache ());
6165 }
6166
6167 if (stop_stack_dummy == STOP_STACK_DUMMY)
6168 {
6169 /* Pop the empty frame that contains the stack dummy.
6170 This also restores inferior state prior to the call
6171 (struct infcall_suspend_state). */
6172 struct frame_info *frame = get_current_frame ();
6173
6174 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6175 frame_pop (frame);
6176 /* frame_pop() calls reinit_frame_cache as the last thing it
6177 does which means there's currently no selected frame. We
6178 don't need to re-establish a selected frame if the dummy call
6179 returns normally, that will be done by
6180 restore_infcall_control_state. However, we do have to handle
6181 the case where the dummy call is returning after being
6182 stopped (e.g. the dummy call previously hit a breakpoint).
6183 We can't know which case we have so just always re-establish
6184 a selected frame here. */
6185 select_frame (get_current_frame ());
6186 }
6187
6188 done:
6189 annotate_stopped ();
6190
6191 /* Suppress the stop observer if we're in the middle of:
6192
6193 - a step n (n > 1), as there still more steps to be done.
6194
6195 - a "finish" command, as the observer will be called in
6196 finish_command_continuation, so it can include the inferior
6197 function's return value.
6198
6199 - calling an inferior function, as we pretend we inferior didn't
6200 run at all. The return value of the call is handled by the
6201 expression evaluator, through call_function_by_hand. */
6202
6203 if (!target_has_execution
6204 || last.kind == TARGET_WAITKIND_SIGNALLED
6205 || last.kind == TARGET_WAITKIND_EXITED
6206 || last.kind == TARGET_WAITKIND_NO_RESUMED
6207 || (!(inferior_thread ()->step_multi
6208 && inferior_thread ()->control.stop_step)
6209 && !(inferior_thread ()->control.stop_bpstat
6210 && inferior_thread ()->control.proceed_to_finish)
6211 && !inferior_thread ()->control.in_infcall))
6212 {
6213 if (!ptid_equal (inferior_ptid, null_ptid))
6214 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6215 stop_print_frame);
6216 else
6217 observer_notify_normal_stop (NULL, stop_print_frame);
6218 }
6219
6220 if (target_has_execution)
6221 {
6222 if (last.kind != TARGET_WAITKIND_SIGNALLED
6223 && last.kind != TARGET_WAITKIND_EXITED)
6224 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6225 Delete any breakpoint that is to be deleted at the next stop. */
6226 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6227 }
6228
6229 /* Try to get rid of automatically added inferiors that are no
6230 longer needed. Keeping those around slows down things linearly.
6231 Note that this never removes the current inferior. */
6232 prune_inferiors ();
6233 }
6234
6235 static int
6236 hook_stop_stub (void *cmd)
6237 {
6238 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6239 return (0);
6240 }
6241 \f
6242 int
6243 signal_stop_state (int signo)
6244 {
6245 return signal_stop[signo];
6246 }
6247
6248 int
6249 signal_print_state (int signo)
6250 {
6251 return signal_print[signo];
6252 }
6253
6254 int
6255 signal_pass_state (int signo)
6256 {
6257 return signal_program[signo];
6258 }
6259
6260 static void
6261 signal_cache_update (int signo)
6262 {
6263 if (signo == -1)
6264 {
6265 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6266 signal_cache_update (signo);
6267
6268 return;
6269 }
6270
6271 signal_pass[signo] = (signal_stop[signo] == 0
6272 && signal_print[signo] == 0
6273 && signal_program[signo] == 1
6274 && signal_catch[signo] == 0);
6275 }
6276
6277 int
6278 signal_stop_update (int signo, int state)
6279 {
6280 int ret = signal_stop[signo];
6281
6282 signal_stop[signo] = state;
6283 signal_cache_update (signo);
6284 return ret;
6285 }
6286
6287 int
6288 signal_print_update (int signo, int state)
6289 {
6290 int ret = signal_print[signo];
6291
6292 signal_print[signo] = state;
6293 signal_cache_update (signo);
6294 return ret;
6295 }
6296
6297 int
6298 signal_pass_update (int signo, int state)
6299 {
6300 int ret = signal_program[signo];
6301
6302 signal_program[signo] = state;
6303 signal_cache_update (signo);
6304 return ret;
6305 }
6306
6307 /* Update the global 'signal_catch' from INFO and notify the
6308 target. */
6309
6310 void
6311 signal_catch_update (const unsigned int *info)
6312 {
6313 int i;
6314
6315 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6316 signal_catch[i] = info[i] > 0;
6317 signal_cache_update (-1);
6318 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6319 }
6320
6321 static void
6322 sig_print_header (void)
6323 {
6324 printf_filtered (_("Signal Stop\tPrint\tPass "
6325 "to program\tDescription\n"));
6326 }
6327
6328 static void
6329 sig_print_info (enum gdb_signal oursig)
6330 {
6331 const char *name = gdb_signal_to_name (oursig);
6332 int name_padding = 13 - strlen (name);
6333
6334 if (name_padding <= 0)
6335 name_padding = 0;
6336
6337 printf_filtered ("%s", name);
6338 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6339 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6340 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6341 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6342 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6343 }
6344
6345 /* Specify how various signals in the inferior should be handled. */
6346
6347 static void
6348 handle_command (char *args, int from_tty)
6349 {
6350 char **argv;
6351 int digits, wordlen;
6352 int sigfirst, signum, siglast;
6353 enum gdb_signal oursig;
6354 int allsigs;
6355 int nsigs;
6356 unsigned char *sigs;
6357 struct cleanup *old_chain;
6358
6359 if (args == NULL)
6360 {
6361 error_no_arg (_("signal to handle"));
6362 }
6363
6364 /* Allocate and zero an array of flags for which signals to handle. */
6365
6366 nsigs = (int) GDB_SIGNAL_LAST;
6367 sigs = (unsigned char *) alloca (nsigs);
6368 memset (sigs, 0, nsigs);
6369
6370 /* Break the command line up into args. */
6371
6372 argv = gdb_buildargv (args);
6373 old_chain = make_cleanup_freeargv (argv);
6374
6375 /* Walk through the args, looking for signal oursigs, signal names, and
6376 actions. Signal numbers and signal names may be interspersed with
6377 actions, with the actions being performed for all signals cumulatively
6378 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6379
6380 while (*argv != NULL)
6381 {
6382 wordlen = strlen (*argv);
6383 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6384 {;
6385 }
6386 allsigs = 0;
6387 sigfirst = siglast = -1;
6388
6389 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6390 {
6391 /* Apply action to all signals except those used by the
6392 debugger. Silently skip those. */
6393 allsigs = 1;
6394 sigfirst = 0;
6395 siglast = nsigs - 1;
6396 }
6397 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6398 {
6399 SET_SIGS (nsigs, sigs, signal_stop);
6400 SET_SIGS (nsigs, sigs, signal_print);
6401 }
6402 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6403 {
6404 UNSET_SIGS (nsigs, sigs, signal_program);
6405 }
6406 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6407 {
6408 SET_SIGS (nsigs, sigs, signal_print);
6409 }
6410 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6411 {
6412 SET_SIGS (nsigs, sigs, signal_program);
6413 }
6414 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6415 {
6416 UNSET_SIGS (nsigs, sigs, signal_stop);
6417 }
6418 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6419 {
6420 SET_SIGS (nsigs, sigs, signal_program);
6421 }
6422 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6423 {
6424 UNSET_SIGS (nsigs, sigs, signal_print);
6425 UNSET_SIGS (nsigs, sigs, signal_stop);
6426 }
6427 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6428 {
6429 UNSET_SIGS (nsigs, sigs, signal_program);
6430 }
6431 else if (digits > 0)
6432 {
6433 /* It is numeric. The numeric signal refers to our own
6434 internal signal numbering from target.h, not to host/target
6435 signal number. This is a feature; users really should be
6436 using symbolic names anyway, and the common ones like
6437 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6438
6439 sigfirst = siglast = (int)
6440 gdb_signal_from_command (atoi (*argv));
6441 if ((*argv)[digits] == '-')
6442 {
6443 siglast = (int)
6444 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6445 }
6446 if (sigfirst > siglast)
6447 {
6448 /* Bet he didn't figure we'd think of this case... */
6449 signum = sigfirst;
6450 sigfirst = siglast;
6451 siglast = signum;
6452 }
6453 }
6454 else
6455 {
6456 oursig = gdb_signal_from_name (*argv);
6457 if (oursig != GDB_SIGNAL_UNKNOWN)
6458 {
6459 sigfirst = siglast = (int) oursig;
6460 }
6461 else
6462 {
6463 /* Not a number and not a recognized flag word => complain. */
6464 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6465 }
6466 }
6467
6468 /* If any signal numbers or symbol names were found, set flags for
6469 which signals to apply actions to. */
6470
6471 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6472 {
6473 switch ((enum gdb_signal) signum)
6474 {
6475 case GDB_SIGNAL_TRAP:
6476 case GDB_SIGNAL_INT:
6477 if (!allsigs && !sigs[signum])
6478 {
6479 if (query (_("%s is used by the debugger.\n\
6480 Are you sure you want to change it? "),
6481 gdb_signal_to_name ((enum gdb_signal) signum)))
6482 {
6483 sigs[signum] = 1;
6484 }
6485 else
6486 {
6487 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6488 gdb_flush (gdb_stdout);
6489 }
6490 }
6491 break;
6492 case GDB_SIGNAL_0:
6493 case GDB_SIGNAL_DEFAULT:
6494 case GDB_SIGNAL_UNKNOWN:
6495 /* Make sure that "all" doesn't print these. */
6496 break;
6497 default:
6498 sigs[signum] = 1;
6499 break;
6500 }
6501 }
6502
6503 argv++;
6504 }
6505
6506 for (signum = 0; signum < nsigs; signum++)
6507 if (sigs[signum])
6508 {
6509 signal_cache_update (-1);
6510 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6511 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6512
6513 if (from_tty)
6514 {
6515 /* Show the results. */
6516 sig_print_header ();
6517 for (; signum < nsigs; signum++)
6518 if (sigs[signum])
6519 sig_print_info (signum);
6520 }
6521
6522 break;
6523 }
6524
6525 do_cleanups (old_chain);
6526 }
6527
6528 /* Complete the "handle" command. */
6529
6530 static VEC (char_ptr) *
6531 handle_completer (struct cmd_list_element *ignore,
6532 const char *text, const char *word)
6533 {
6534 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6535 static const char * const keywords[] =
6536 {
6537 "all",
6538 "stop",
6539 "ignore",
6540 "print",
6541 "pass",
6542 "nostop",
6543 "noignore",
6544 "noprint",
6545 "nopass",
6546 NULL,
6547 };
6548
6549 vec_signals = signal_completer (ignore, text, word);
6550 vec_keywords = complete_on_enum (keywords, word, word);
6551
6552 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6553 VEC_free (char_ptr, vec_signals);
6554 VEC_free (char_ptr, vec_keywords);
6555 return return_val;
6556 }
6557
6558 static void
6559 xdb_handle_command (char *args, int from_tty)
6560 {
6561 char **argv;
6562 struct cleanup *old_chain;
6563
6564 if (args == NULL)
6565 error_no_arg (_("xdb command"));
6566
6567 /* Break the command line up into args. */
6568
6569 argv = gdb_buildargv (args);
6570 old_chain = make_cleanup_freeargv (argv);
6571 if (argv[1] != (char *) NULL)
6572 {
6573 char *argBuf;
6574 int bufLen;
6575
6576 bufLen = strlen (argv[0]) + 20;
6577 argBuf = (char *) xmalloc (bufLen);
6578 if (argBuf)
6579 {
6580 int validFlag = 1;
6581 enum gdb_signal oursig;
6582
6583 oursig = gdb_signal_from_name (argv[0]);
6584 memset (argBuf, 0, bufLen);
6585 if (strcmp (argv[1], "Q") == 0)
6586 sprintf (argBuf, "%s %s", argv[0], "noprint");
6587 else
6588 {
6589 if (strcmp (argv[1], "s") == 0)
6590 {
6591 if (!signal_stop[oursig])
6592 sprintf (argBuf, "%s %s", argv[0], "stop");
6593 else
6594 sprintf (argBuf, "%s %s", argv[0], "nostop");
6595 }
6596 else if (strcmp (argv[1], "i") == 0)
6597 {
6598 if (!signal_program[oursig])
6599 sprintf (argBuf, "%s %s", argv[0], "pass");
6600 else
6601 sprintf (argBuf, "%s %s", argv[0], "nopass");
6602 }
6603 else if (strcmp (argv[1], "r") == 0)
6604 {
6605 if (!signal_print[oursig])
6606 sprintf (argBuf, "%s %s", argv[0], "print");
6607 else
6608 sprintf (argBuf, "%s %s", argv[0], "noprint");
6609 }
6610 else
6611 validFlag = 0;
6612 }
6613 if (validFlag)
6614 handle_command (argBuf, from_tty);
6615 else
6616 printf_filtered (_("Invalid signal handling flag.\n"));
6617 if (argBuf)
6618 xfree (argBuf);
6619 }
6620 }
6621 do_cleanups (old_chain);
6622 }
6623
6624 enum gdb_signal
6625 gdb_signal_from_command (int num)
6626 {
6627 if (num >= 1 && num <= 15)
6628 return (enum gdb_signal) num;
6629 error (_("Only signals 1-15 are valid as numeric signals.\n\
6630 Use \"info signals\" for a list of symbolic signals."));
6631 }
6632
6633 /* Print current contents of the tables set by the handle command.
6634 It is possible we should just be printing signals actually used
6635 by the current target (but for things to work right when switching
6636 targets, all signals should be in the signal tables). */
6637
6638 static void
6639 signals_info (char *signum_exp, int from_tty)
6640 {
6641 enum gdb_signal oursig;
6642
6643 sig_print_header ();
6644
6645 if (signum_exp)
6646 {
6647 /* First see if this is a symbol name. */
6648 oursig = gdb_signal_from_name (signum_exp);
6649 if (oursig == GDB_SIGNAL_UNKNOWN)
6650 {
6651 /* No, try numeric. */
6652 oursig =
6653 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6654 }
6655 sig_print_info (oursig);
6656 return;
6657 }
6658
6659 printf_filtered ("\n");
6660 /* These ugly casts brought to you by the native VAX compiler. */
6661 for (oursig = GDB_SIGNAL_FIRST;
6662 (int) oursig < (int) GDB_SIGNAL_LAST;
6663 oursig = (enum gdb_signal) ((int) oursig + 1))
6664 {
6665 QUIT;
6666
6667 if (oursig != GDB_SIGNAL_UNKNOWN
6668 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6669 sig_print_info (oursig);
6670 }
6671
6672 printf_filtered (_("\nUse the \"handle\" command "
6673 "to change these tables.\n"));
6674 }
6675
6676 /* Check if it makes sense to read $_siginfo from the current thread
6677 at this point. If not, throw an error. */
6678
6679 static void
6680 validate_siginfo_access (void)
6681 {
6682 /* No current inferior, no siginfo. */
6683 if (ptid_equal (inferior_ptid, null_ptid))
6684 error (_("No thread selected."));
6685
6686 /* Don't try to read from a dead thread. */
6687 if (is_exited (inferior_ptid))
6688 error (_("The current thread has terminated"));
6689
6690 /* ... or from a spinning thread. */
6691 if (is_running (inferior_ptid))
6692 error (_("Selected thread is running."));
6693 }
6694
6695 /* The $_siginfo convenience variable is a bit special. We don't know
6696 for sure the type of the value until we actually have a chance to
6697 fetch the data. The type can change depending on gdbarch, so it is
6698 also dependent on which thread you have selected.
6699
6700 1. making $_siginfo be an internalvar that creates a new value on
6701 access.
6702
6703 2. making the value of $_siginfo be an lval_computed value. */
6704
6705 /* This function implements the lval_computed support for reading a
6706 $_siginfo value. */
6707
6708 static void
6709 siginfo_value_read (struct value *v)
6710 {
6711 LONGEST transferred;
6712
6713 validate_siginfo_access ();
6714
6715 transferred =
6716 target_read (&current_target, TARGET_OBJECT_SIGNAL_INFO,
6717 NULL,
6718 value_contents_all_raw (v),
6719 value_offset (v),
6720 TYPE_LENGTH (value_type (v)));
6721
6722 if (transferred != TYPE_LENGTH (value_type (v)))
6723 error (_("Unable to read siginfo"));
6724 }
6725
6726 /* This function implements the lval_computed support for writing a
6727 $_siginfo value. */
6728
6729 static void
6730 siginfo_value_write (struct value *v, struct value *fromval)
6731 {
6732 LONGEST transferred;
6733
6734 validate_siginfo_access ();
6735
6736 transferred = target_write (&current_target,
6737 TARGET_OBJECT_SIGNAL_INFO,
6738 NULL,
6739 value_contents_all_raw (fromval),
6740 value_offset (v),
6741 TYPE_LENGTH (value_type (fromval)));
6742
6743 if (transferred != TYPE_LENGTH (value_type (fromval)))
6744 error (_("Unable to write siginfo"));
6745 }
6746
6747 static const struct lval_funcs siginfo_value_funcs =
6748 {
6749 siginfo_value_read,
6750 siginfo_value_write
6751 };
6752
6753 /* Return a new value with the correct type for the siginfo object of
6754 the current thread using architecture GDBARCH. Return a void value
6755 if there's no object available. */
6756
6757 static struct value *
6758 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
6759 void *ignore)
6760 {
6761 if (target_has_stack
6762 && !ptid_equal (inferior_ptid, null_ptid)
6763 && gdbarch_get_siginfo_type_p (gdbarch))
6764 {
6765 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6766
6767 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6768 }
6769
6770 return allocate_value (builtin_type (gdbarch)->builtin_void);
6771 }
6772
6773 \f
6774 /* infcall_suspend_state contains state about the program itself like its
6775 registers and any signal it received when it last stopped.
6776 This state must be restored regardless of how the inferior function call
6777 ends (either successfully, or after it hits a breakpoint or signal)
6778 if the program is to properly continue where it left off. */
6779
6780 struct infcall_suspend_state
6781 {
6782 struct thread_suspend_state thread_suspend;
6783 #if 0 /* Currently unused and empty structures are not valid C. */
6784 struct inferior_suspend_state inferior_suspend;
6785 #endif
6786
6787 /* Other fields: */
6788 CORE_ADDR stop_pc;
6789 struct regcache *registers;
6790
6791 /* Format of SIGINFO_DATA or NULL if it is not present. */
6792 struct gdbarch *siginfo_gdbarch;
6793
6794 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6795 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6796 content would be invalid. */
6797 gdb_byte *siginfo_data;
6798 };
6799
6800 struct infcall_suspend_state *
6801 save_infcall_suspend_state (void)
6802 {
6803 struct infcall_suspend_state *inf_state;
6804 struct thread_info *tp = inferior_thread ();
6805 #if 0
6806 struct inferior *inf = current_inferior ();
6807 #endif
6808 struct regcache *regcache = get_current_regcache ();
6809 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6810 gdb_byte *siginfo_data = NULL;
6811
6812 if (gdbarch_get_siginfo_type_p (gdbarch))
6813 {
6814 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6815 size_t len = TYPE_LENGTH (type);
6816 struct cleanup *back_to;
6817
6818 siginfo_data = xmalloc (len);
6819 back_to = make_cleanup (xfree, siginfo_data);
6820
6821 if (target_read (&current_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6822 siginfo_data, 0, len) == len)
6823 discard_cleanups (back_to);
6824 else
6825 {
6826 /* Errors ignored. */
6827 do_cleanups (back_to);
6828 siginfo_data = NULL;
6829 }
6830 }
6831
6832 inf_state = XZALLOC (struct infcall_suspend_state);
6833
6834 if (siginfo_data)
6835 {
6836 inf_state->siginfo_gdbarch = gdbarch;
6837 inf_state->siginfo_data = siginfo_data;
6838 }
6839
6840 inf_state->thread_suspend = tp->suspend;
6841 #if 0 /* Currently unused and empty structures are not valid C. */
6842 inf_state->inferior_suspend = inf->suspend;
6843 #endif
6844
6845 /* run_inferior_call will not use the signal due to its `proceed' call with
6846 GDB_SIGNAL_0 anyway. */
6847 tp->suspend.stop_signal = GDB_SIGNAL_0;
6848
6849 inf_state->stop_pc = stop_pc;
6850
6851 inf_state->registers = regcache_dup (regcache);
6852
6853 return inf_state;
6854 }
6855
6856 /* Restore inferior session state to INF_STATE. */
6857
6858 void
6859 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6860 {
6861 struct thread_info *tp = inferior_thread ();
6862 #if 0
6863 struct inferior *inf = current_inferior ();
6864 #endif
6865 struct regcache *regcache = get_current_regcache ();
6866 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6867
6868 tp->suspend = inf_state->thread_suspend;
6869 #if 0 /* Currently unused and empty structures are not valid C. */
6870 inf->suspend = inf_state->inferior_suspend;
6871 #endif
6872
6873 stop_pc = inf_state->stop_pc;
6874
6875 if (inf_state->siginfo_gdbarch == gdbarch)
6876 {
6877 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6878
6879 /* Errors ignored. */
6880 target_write (&current_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6881 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
6882 }
6883
6884 /* The inferior can be gone if the user types "print exit(0)"
6885 (and perhaps other times). */
6886 if (target_has_execution)
6887 /* NB: The register write goes through to the target. */
6888 regcache_cpy (regcache, inf_state->registers);
6889
6890 discard_infcall_suspend_state (inf_state);
6891 }
6892
6893 static void
6894 do_restore_infcall_suspend_state_cleanup (void *state)
6895 {
6896 restore_infcall_suspend_state (state);
6897 }
6898
6899 struct cleanup *
6900 make_cleanup_restore_infcall_suspend_state
6901 (struct infcall_suspend_state *inf_state)
6902 {
6903 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6904 }
6905
6906 void
6907 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6908 {
6909 regcache_xfree (inf_state->registers);
6910 xfree (inf_state->siginfo_data);
6911 xfree (inf_state);
6912 }
6913
6914 struct regcache *
6915 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6916 {
6917 return inf_state->registers;
6918 }
6919
6920 /* infcall_control_state contains state regarding gdb's control of the
6921 inferior itself like stepping control. It also contains session state like
6922 the user's currently selected frame. */
6923
6924 struct infcall_control_state
6925 {
6926 struct thread_control_state thread_control;
6927 struct inferior_control_state inferior_control;
6928
6929 /* Other fields: */
6930 enum stop_stack_kind stop_stack_dummy;
6931 int stopped_by_random_signal;
6932 int stop_after_trap;
6933
6934 /* ID if the selected frame when the inferior function call was made. */
6935 struct frame_id selected_frame_id;
6936 };
6937
6938 /* Save all of the information associated with the inferior<==>gdb
6939 connection. */
6940
6941 struct infcall_control_state *
6942 save_infcall_control_state (void)
6943 {
6944 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6945 struct thread_info *tp = inferior_thread ();
6946 struct inferior *inf = current_inferior ();
6947
6948 inf_status->thread_control = tp->control;
6949 inf_status->inferior_control = inf->control;
6950
6951 tp->control.step_resume_breakpoint = NULL;
6952 tp->control.exception_resume_breakpoint = NULL;
6953
6954 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6955 chain. If caller's caller is walking the chain, they'll be happier if we
6956 hand them back the original chain when restore_infcall_control_state is
6957 called. */
6958 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6959
6960 /* Other fields: */
6961 inf_status->stop_stack_dummy = stop_stack_dummy;
6962 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6963 inf_status->stop_after_trap = stop_after_trap;
6964
6965 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6966
6967 return inf_status;
6968 }
6969
6970 static int
6971 restore_selected_frame (void *args)
6972 {
6973 struct frame_id *fid = (struct frame_id *) args;
6974 struct frame_info *frame;
6975
6976 frame = frame_find_by_id (*fid);
6977
6978 /* If inf_status->selected_frame_id is NULL, there was no previously
6979 selected frame. */
6980 if (frame == NULL)
6981 {
6982 warning (_("Unable to restore previously selected frame."));
6983 return 0;
6984 }
6985
6986 select_frame (frame);
6987
6988 return (1);
6989 }
6990
6991 /* Restore inferior session state to INF_STATUS. */
6992
6993 void
6994 restore_infcall_control_state (struct infcall_control_state *inf_status)
6995 {
6996 struct thread_info *tp = inferior_thread ();
6997 struct inferior *inf = current_inferior ();
6998
6999 if (tp->control.step_resume_breakpoint)
7000 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
7001
7002 if (tp->control.exception_resume_breakpoint)
7003 tp->control.exception_resume_breakpoint->disposition
7004 = disp_del_at_next_stop;
7005
7006 /* Handle the bpstat_copy of the chain. */
7007 bpstat_clear (&tp->control.stop_bpstat);
7008
7009 tp->control = inf_status->thread_control;
7010 inf->control = inf_status->inferior_control;
7011
7012 /* Other fields: */
7013 stop_stack_dummy = inf_status->stop_stack_dummy;
7014 stopped_by_random_signal = inf_status->stopped_by_random_signal;
7015 stop_after_trap = inf_status->stop_after_trap;
7016
7017 if (target_has_stack)
7018 {
7019 /* The point of catch_errors is that if the stack is clobbered,
7020 walking the stack might encounter a garbage pointer and
7021 error() trying to dereference it. */
7022 if (catch_errors
7023 (restore_selected_frame, &inf_status->selected_frame_id,
7024 "Unable to restore previously selected frame:\n",
7025 RETURN_MASK_ERROR) == 0)
7026 /* Error in restoring the selected frame. Select the innermost
7027 frame. */
7028 select_frame (get_current_frame ());
7029 }
7030
7031 xfree (inf_status);
7032 }
7033
7034 static void
7035 do_restore_infcall_control_state_cleanup (void *sts)
7036 {
7037 restore_infcall_control_state (sts);
7038 }
7039
7040 struct cleanup *
7041 make_cleanup_restore_infcall_control_state
7042 (struct infcall_control_state *inf_status)
7043 {
7044 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
7045 }
7046
7047 void
7048 discard_infcall_control_state (struct infcall_control_state *inf_status)
7049 {
7050 if (inf_status->thread_control.step_resume_breakpoint)
7051 inf_status->thread_control.step_resume_breakpoint->disposition
7052 = disp_del_at_next_stop;
7053
7054 if (inf_status->thread_control.exception_resume_breakpoint)
7055 inf_status->thread_control.exception_resume_breakpoint->disposition
7056 = disp_del_at_next_stop;
7057
7058 /* See save_infcall_control_state for info on stop_bpstat. */
7059 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7060
7061 xfree (inf_status);
7062 }
7063 \f
7064 int
7065 ptid_match (ptid_t ptid, ptid_t filter)
7066 {
7067 if (ptid_equal (filter, minus_one_ptid))
7068 return 1;
7069 if (ptid_is_pid (filter)
7070 && ptid_get_pid (ptid) == ptid_get_pid (filter))
7071 return 1;
7072 else if (ptid_equal (ptid, filter))
7073 return 1;
7074
7075 return 0;
7076 }
7077
7078 /* restore_inferior_ptid() will be used by the cleanup machinery
7079 to restore the inferior_ptid value saved in a call to
7080 save_inferior_ptid(). */
7081
7082 static void
7083 restore_inferior_ptid (void *arg)
7084 {
7085 ptid_t *saved_ptid_ptr = arg;
7086
7087 inferior_ptid = *saved_ptid_ptr;
7088 xfree (arg);
7089 }
7090
7091 /* Save the value of inferior_ptid so that it may be restored by a
7092 later call to do_cleanups(). Returns the struct cleanup pointer
7093 needed for later doing the cleanup. */
7094
7095 struct cleanup *
7096 save_inferior_ptid (void)
7097 {
7098 ptid_t *saved_ptid_ptr;
7099
7100 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7101 *saved_ptid_ptr = inferior_ptid;
7102 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7103 }
7104
7105 /* See inferior.h. */
7106
7107 void
7108 clear_exit_convenience_vars (void)
7109 {
7110 clear_internalvar (lookup_internalvar ("_exitsignal"));
7111 clear_internalvar (lookup_internalvar ("_exitcode"));
7112 }
7113 \f
7114
7115 /* User interface for reverse debugging:
7116 Set exec-direction / show exec-direction commands
7117 (returns error unless target implements to_set_exec_direction method). */
7118
7119 int execution_direction = EXEC_FORWARD;
7120 static const char exec_forward[] = "forward";
7121 static const char exec_reverse[] = "reverse";
7122 static const char *exec_direction = exec_forward;
7123 static const char *const exec_direction_names[] = {
7124 exec_forward,
7125 exec_reverse,
7126 NULL
7127 };
7128
7129 static void
7130 set_exec_direction_func (char *args, int from_tty,
7131 struct cmd_list_element *cmd)
7132 {
7133 if (target_can_execute_reverse)
7134 {
7135 if (!strcmp (exec_direction, exec_forward))
7136 execution_direction = EXEC_FORWARD;
7137 else if (!strcmp (exec_direction, exec_reverse))
7138 execution_direction = EXEC_REVERSE;
7139 }
7140 else
7141 {
7142 exec_direction = exec_forward;
7143 error (_("Target does not support this operation."));
7144 }
7145 }
7146
7147 static void
7148 show_exec_direction_func (struct ui_file *out, int from_tty,
7149 struct cmd_list_element *cmd, const char *value)
7150 {
7151 switch (execution_direction) {
7152 case EXEC_FORWARD:
7153 fprintf_filtered (out, _("Forward.\n"));
7154 break;
7155 case EXEC_REVERSE:
7156 fprintf_filtered (out, _("Reverse.\n"));
7157 break;
7158 default:
7159 internal_error (__FILE__, __LINE__,
7160 _("bogus execution_direction value: %d"),
7161 (int) execution_direction);
7162 }
7163 }
7164
7165 static void
7166 show_schedule_multiple (struct ui_file *file, int from_tty,
7167 struct cmd_list_element *c, const char *value)
7168 {
7169 fprintf_filtered (file, _("Resuming the execution of threads "
7170 "of all processes is %s.\n"), value);
7171 }
7172
7173 /* Implementation of `siginfo' variable. */
7174
7175 static const struct internalvar_funcs siginfo_funcs =
7176 {
7177 siginfo_make_value,
7178 NULL,
7179 NULL
7180 };
7181
7182 void
7183 _initialize_infrun (void)
7184 {
7185 int i;
7186 int numsigs;
7187 struct cmd_list_element *c;
7188
7189 add_info ("signals", signals_info, _("\
7190 What debugger does when program gets various signals.\n\
7191 Specify a signal as argument to print info on that signal only."));
7192 add_info_alias ("handle", "signals", 0);
7193
7194 c = add_com ("handle", class_run, handle_command, _("\
7195 Specify how to handle signals.\n\
7196 Usage: handle SIGNAL [ACTIONS]\n\
7197 Args are signals and actions to apply to those signals.\n\
7198 If no actions are specified, the current settings for the specified signals\n\
7199 will be displayed instead.\n\
7200 \n\
7201 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7202 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7203 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7204 The special arg \"all\" is recognized to mean all signals except those\n\
7205 used by the debugger, typically SIGTRAP and SIGINT.\n\
7206 \n\
7207 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7208 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7209 Stop means reenter debugger if this signal happens (implies print).\n\
7210 Print means print a message if this signal happens.\n\
7211 Pass means let program see this signal; otherwise program doesn't know.\n\
7212 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7213 Pass and Stop may be combined.\n\
7214 \n\
7215 Multiple signals may be specified. Signal numbers and signal names\n\
7216 may be interspersed with actions, with the actions being performed for\n\
7217 all signals cumulatively specified."));
7218 set_cmd_completer (c, handle_completer);
7219
7220 if (xdb_commands)
7221 {
7222 add_com ("lz", class_info, signals_info, _("\
7223 What debugger does when program gets various signals.\n\
7224 Specify a signal as argument to print info on that signal only."));
7225 add_com ("z", class_run, xdb_handle_command, _("\
7226 Specify how to handle a signal.\n\
7227 Args are signals and actions to apply to those signals.\n\
7228 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7229 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7230 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7231 The special arg \"all\" is recognized to mean all signals except those\n\
7232 used by the debugger, typically SIGTRAP and SIGINT.\n\
7233 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7234 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7235 nopass), \"Q\" (noprint)\n\
7236 Stop means reenter debugger if this signal happens (implies print).\n\
7237 Print means print a message if this signal happens.\n\
7238 Pass means let program see this signal; otherwise program doesn't know.\n\
7239 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7240 Pass and Stop may be combined."));
7241 }
7242
7243 if (!dbx_commands)
7244 stop_command = add_cmd ("stop", class_obscure,
7245 not_just_help_class_command, _("\
7246 There is no `stop' command, but you can set a hook on `stop'.\n\
7247 This allows you to set a list of commands to be run each time execution\n\
7248 of the program stops."), &cmdlist);
7249
7250 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7251 Set inferior debugging."), _("\
7252 Show inferior debugging."), _("\
7253 When non-zero, inferior specific debugging is enabled."),
7254 NULL,
7255 show_debug_infrun,
7256 &setdebuglist, &showdebuglist);
7257
7258 add_setshow_boolean_cmd ("displaced", class_maintenance,
7259 &debug_displaced, _("\
7260 Set displaced stepping debugging."), _("\
7261 Show displaced stepping debugging."), _("\
7262 When non-zero, displaced stepping specific debugging is enabled."),
7263 NULL,
7264 show_debug_displaced,
7265 &setdebuglist, &showdebuglist);
7266
7267 add_setshow_boolean_cmd ("non-stop", no_class,
7268 &non_stop_1, _("\
7269 Set whether gdb controls the inferior in non-stop mode."), _("\
7270 Show whether gdb controls the inferior in non-stop mode."), _("\
7271 When debugging a multi-threaded program and this setting is\n\
7272 off (the default, also called all-stop mode), when one thread stops\n\
7273 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7274 all other threads in the program while you interact with the thread of\n\
7275 interest. When you continue or step a thread, you can allow the other\n\
7276 threads to run, or have them remain stopped, but while you inspect any\n\
7277 thread's state, all threads stop.\n\
7278 \n\
7279 In non-stop mode, when one thread stops, other threads can continue\n\
7280 to run freely. You'll be able to step each thread independently,\n\
7281 leave it stopped or free to run as needed."),
7282 set_non_stop,
7283 show_non_stop,
7284 &setlist,
7285 &showlist);
7286
7287 numsigs = (int) GDB_SIGNAL_LAST;
7288 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7289 signal_print = (unsigned char *)
7290 xmalloc (sizeof (signal_print[0]) * numsigs);
7291 signal_program = (unsigned char *)
7292 xmalloc (sizeof (signal_program[0]) * numsigs);
7293 signal_catch = (unsigned char *)
7294 xmalloc (sizeof (signal_catch[0]) * numsigs);
7295 signal_pass = (unsigned char *)
7296 xmalloc (sizeof (signal_program[0]) * numsigs);
7297 for (i = 0; i < numsigs; i++)
7298 {
7299 signal_stop[i] = 1;
7300 signal_print[i] = 1;
7301 signal_program[i] = 1;
7302 signal_catch[i] = 0;
7303 }
7304
7305 /* Signals caused by debugger's own actions
7306 should not be given to the program afterwards. */
7307 signal_program[GDB_SIGNAL_TRAP] = 0;
7308 signal_program[GDB_SIGNAL_INT] = 0;
7309
7310 /* Signals that are not errors should not normally enter the debugger. */
7311 signal_stop[GDB_SIGNAL_ALRM] = 0;
7312 signal_print[GDB_SIGNAL_ALRM] = 0;
7313 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7314 signal_print[GDB_SIGNAL_VTALRM] = 0;
7315 signal_stop[GDB_SIGNAL_PROF] = 0;
7316 signal_print[GDB_SIGNAL_PROF] = 0;
7317 signal_stop[GDB_SIGNAL_CHLD] = 0;
7318 signal_print[GDB_SIGNAL_CHLD] = 0;
7319 signal_stop[GDB_SIGNAL_IO] = 0;
7320 signal_print[GDB_SIGNAL_IO] = 0;
7321 signal_stop[GDB_SIGNAL_POLL] = 0;
7322 signal_print[GDB_SIGNAL_POLL] = 0;
7323 signal_stop[GDB_SIGNAL_URG] = 0;
7324 signal_print[GDB_SIGNAL_URG] = 0;
7325 signal_stop[GDB_SIGNAL_WINCH] = 0;
7326 signal_print[GDB_SIGNAL_WINCH] = 0;
7327 signal_stop[GDB_SIGNAL_PRIO] = 0;
7328 signal_print[GDB_SIGNAL_PRIO] = 0;
7329
7330 /* These signals are used internally by user-level thread
7331 implementations. (See signal(5) on Solaris.) Like the above
7332 signals, a healthy program receives and handles them as part of
7333 its normal operation. */
7334 signal_stop[GDB_SIGNAL_LWP] = 0;
7335 signal_print[GDB_SIGNAL_LWP] = 0;
7336 signal_stop[GDB_SIGNAL_WAITING] = 0;
7337 signal_print[GDB_SIGNAL_WAITING] = 0;
7338 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7339 signal_print[GDB_SIGNAL_CANCEL] = 0;
7340
7341 /* Update cached state. */
7342 signal_cache_update (-1);
7343
7344 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7345 &stop_on_solib_events, _("\
7346 Set stopping for shared library events."), _("\
7347 Show stopping for shared library events."), _("\
7348 If nonzero, gdb will give control to the user when the dynamic linker\n\
7349 notifies gdb of shared library events. The most common event of interest\n\
7350 to the user would be loading/unloading of a new library."),
7351 set_stop_on_solib_events,
7352 show_stop_on_solib_events,
7353 &setlist, &showlist);
7354
7355 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7356 follow_fork_mode_kind_names,
7357 &follow_fork_mode_string, _("\
7358 Set debugger response to a program call of fork or vfork."), _("\
7359 Show debugger response to a program call of fork or vfork."), _("\
7360 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7361 parent - the original process is debugged after a fork\n\
7362 child - the new process is debugged after a fork\n\
7363 The unfollowed process will continue to run.\n\
7364 By default, the debugger will follow the parent process."),
7365 NULL,
7366 show_follow_fork_mode_string,
7367 &setlist, &showlist);
7368
7369 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7370 follow_exec_mode_names,
7371 &follow_exec_mode_string, _("\
7372 Set debugger response to a program call of exec."), _("\
7373 Show debugger response to a program call of exec."), _("\
7374 An exec call replaces the program image of a process.\n\
7375 \n\
7376 follow-exec-mode can be:\n\
7377 \n\
7378 new - the debugger creates a new inferior and rebinds the process\n\
7379 to this new inferior. The program the process was running before\n\
7380 the exec call can be restarted afterwards by restarting the original\n\
7381 inferior.\n\
7382 \n\
7383 same - the debugger keeps the process bound to the same inferior.\n\
7384 The new executable image replaces the previous executable loaded in\n\
7385 the inferior. Restarting the inferior after the exec call restarts\n\
7386 the executable the process was running after the exec call.\n\
7387 \n\
7388 By default, the debugger will use the same inferior."),
7389 NULL,
7390 show_follow_exec_mode_string,
7391 &setlist, &showlist);
7392
7393 add_setshow_enum_cmd ("scheduler-locking", class_run,
7394 scheduler_enums, &scheduler_mode, _("\
7395 Set mode for locking scheduler during execution."), _("\
7396 Show mode for locking scheduler during execution."), _("\
7397 off == no locking (threads may preempt at any time)\n\
7398 on == full locking (no thread except the current thread may run)\n\
7399 step == scheduler locked during every single-step operation.\n\
7400 In this mode, no other thread may run during a step command.\n\
7401 Other threads may run while stepping over a function call ('next')."),
7402 set_schedlock_func, /* traps on target vector */
7403 show_scheduler_mode,
7404 &setlist, &showlist);
7405
7406 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7407 Set mode for resuming threads of all processes."), _("\
7408 Show mode for resuming threads of all processes."), _("\
7409 When on, execution commands (such as 'continue' or 'next') resume all\n\
7410 threads of all processes. When off (which is the default), execution\n\
7411 commands only resume the threads of the current process. The set of\n\
7412 threads that are resumed is further refined by the scheduler-locking\n\
7413 mode (see help set scheduler-locking)."),
7414 NULL,
7415 show_schedule_multiple,
7416 &setlist, &showlist);
7417
7418 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7419 Set mode of the step operation."), _("\
7420 Show mode of the step operation."), _("\
7421 When set, doing a step over a function without debug line information\n\
7422 will stop at the first instruction of that function. Otherwise, the\n\
7423 function is skipped and the step command stops at a different source line."),
7424 NULL,
7425 show_step_stop_if_no_debug,
7426 &setlist, &showlist);
7427
7428 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7429 &can_use_displaced_stepping, _("\
7430 Set debugger's willingness to use displaced stepping."), _("\
7431 Show debugger's willingness to use displaced stepping."), _("\
7432 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7433 supported by the target architecture. If off, gdb will not use displaced\n\
7434 stepping to step over breakpoints, even if such is supported by the target\n\
7435 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7436 if the target architecture supports it and non-stop mode is active, but will not\n\
7437 use it in all-stop mode (see help set non-stop)."),
7438 NULL,
7439 show_can_use_displaced_stepping,
7440 &setlist, &showlist);
7441
7442 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7443 &exec_direction, _("Set direction of execution.\n\
7444 Options are 'forward' or 'reverse'."),
7445 _("Show direction of execution (forward/reverse)."),
7446 _("Tells gdb whether to execute forward or backward."),
7447 set_exec_direction_func, show_exec_direction_func,
7448 &setlist, &showlist);
7449
7450 /* Set/show detach-on-fork: user-settable mode. */
7451
7452 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7453 Set whether gdb will detach the child of a fork."), _("\
7454 Show whether gdb will detach the child of a fork."), _("\
7455 Tells gdb whether to detach the child of a fork."),
7456 NULL, NULL, &setlist, &showlist);
7457
7458 /* Set/show disable address space randomization mode. */
7459
7460 add_setshow_boolean_cmd ("disable-randomization", class_support,
7461 &disable_randomization, _("\
7462 Set disabling of debuggee's virtual address space randomization."), _("\
7463 Show disabling of debuggee's virtual address space randomization."), _("\
7464 When this mode is on (which is the default), randomization of the virtual\n\
7465 address space is disabled. Standalone programs run with the randomization\n\
7466 enabled by default on some platforms."),
7467 &set_disable_randomization,
7468 &show_disable_randomization,
7469 &setlist, &showlist);
7470
7471 /* ptid initializations */
7472 inferior_ptid = null_ptid;
7473 target_last_wait_ptid = minus_one_ptid;
7474
7475 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7476 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7477 observer_attach_thread_exit (infrun_thread_thread_exit);
7478 observer_attach_inferior_exit (infrun_inferior_exit);
7479
7480 /* Explicitly create without lookup, since that tries to create a
7481 value with a void typed value, and when we get here, gdbarch
7482 isn't initialized yet. At this point, we're quite sure there
7483 isn't another convenience variable of the same name. */
7484 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7485
7486 add_setshow_boolean_cmd ("observer", no_class,
7487 &observer_mode_1, _("\
7488 Set whether gdb controls the inferior in observer mode."), _("\
7489 Show whether gdb controls the inferior in observer mode."), _("\
7490 In observer mode, GDB can get data from the inferior, but not\n\
7491 affect its execution. Registers and memory may not be changed,\n\
7492 breakpoints may not be set, and the program cannot be interrupted\n\
7493 or signalled."),
7494 set_observer_mode,
7495 show_observer_mode,
7496 &setlist,
7497 &showlist);
7498 }
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