Eliminate make_cleanup_ui_file_delete / make ui_file a class hierarchy
[binutils-gdb.git] / gdb / infrun.c
1 /* Target-struct-independent code to start (run) and stop an inferior
2 process.
3
4 Copyright (C) 1986-2017 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 "infrun.h"
23 #include <ctype.h>
24 #include "symtab.h"
25 #include "frame.h"
26 #include "inferior.h"
27 #include "breakpoint.h"
28 #include "gdb_wait.h"
29 #include "gdbcore.h"
30 #include "gdbcmd.h"
31 #include "cli/cli-script.h"
32 #include "target.h"
33 #include "gdbthread.h"
34 #include "annotate.h"
35 #include "symfile.h"
36 #include "top.h"
37 #include <signal.h>
38 #include "inf-loop.h"
39 #include "regcache.h"
40 #include "value.h"
41 #include "observer.h"
42 #include "language.h"
43 #include "solib.h"
44 #include "main.h"
45 #include "dictionary.h"
46 #include "block.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
49 #include "record.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
52 #include "jit.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
55 #include "interps.h"
56 #include "skip.h"
57 #include "probe.h"
58 #include "objfiles.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
62 #include "terminal.h"
63 #include "solist.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
67
68 /* Prototypes for local functions */
69
70 static void signals_info (char *, int);
71
72 static void handle_command (char *, int);
73
74 static void sig_print_info (enum gdb_signal);
75
76 static void sig_print_header (void);
77
78 static void resume_cleanups (void *);
79
80 static int hook_stop_stub (void *);
81
82 static int restore_selected_frame (void *);
83
84 static int follow_fork (void);
85
86 static int follow_fork_inferior (int follow_child, int detach_fork);
87
88 static void follow_inferior_reset_breakpoints (void);
89
90 static void set_schedlock_func (char *args, int from_tty,
91 struct cmd_list_element *c);
92
93 static int currently_stepping (struct thread_info *tp);
94
95 void _initialize_infrun (void);
96
97 void nullify_last_target_wait_ptid (void);
98
99 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
100
101 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
102
103 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
104
105 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
106
107 /* Asynchronous signal handler registered as event loop source for
108 when we have pending events ready to be passed to the core. */
109 static struct async_event_handler *infrun_async_inferior_event_token;
110
111 /* Stores whether infrun_async was previously enabled or disabled.
112 Starts off as -1, indicating "never enabled/disabled". */
113 static int infrun_is_async = -1;
114
115 /* See infrun.h. */
116
117 void
118 infrun_async (int enable)
119 {
120 if (infrun_is_async != enable)
121 {
122 infrun_is_async = enable;
123
124 if (debug_infrun)
125 fprintf_unfiltered (gdb_stdlog,
126 "infrun: infrun_async(%d)\n",
127 enable);
128
129 if (enable)
130 mark_async_event_handler (infrun_async_inferior_event_token);
131 else
132 clear_async_event_handler (infrun_async_inferior_event_token);
133 }
134 }
135
136 /* See infrun.h. */
137
138 void
139 mark_infrun_async_event_handler (void)
140 {
141 mark_async_event_handler (infrun_async_inferior_event_token);
142 }
143
144 /* When set, stop the 'step' command if we enter a function which has
145 no line number information. The normal behavior is that we step
146 over such function. */
147 int step_stop_if_no_debug = 0;
148 static void
149 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
150 struct cmd_list_element *c, const char *value)
151 {
152 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
153 }
154
155 /* proceed and normal_stop use this to notify the user when the
156 inferior stopped in a different thread than it had been running
157 in. */
158
159 static ptid_t previous_inferior_ptid;
160
161 /* If set (default for legacy reasons), when following a fork, GDB
162 will detach from one of the fork branches, child or parent.
163 Exactly which branch is detached depends on 'set follow-fork-mode'
164 setting. */
165
166 static int detach_fork = 1;
167
168 int debug_displaced = 0;
169 static void
170 show_debug_displaced (struct ui_file *file, int from_tty,
171 struct cmd_list_element *c, const char *value)
172 {
173 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
174 }
175
176 unsigned int debug_infrun = 0;
177 static void
178 show_debug_infrun (struct ui_file *file, int from_tty,
179 struct cmd_list_element *c, const char *value)
180 {
181 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
182 }
183
184
185 /* Support for disabling address space randomization. */
186
187 int disable_randomization = 1;
188
189 static void
190 show_disable_randomization (struct ui_file *file, int from_tty,
191 struct cmd_list_element *c, const char *value)
192 {
193 if (target_supports_disable_randomization ())
194 fprintf_filtered (file,
195 _("Disabling randomization of debuggee's "
196 "virtual address space is %s.\n"),
197 value);
198 else
199 fputs_filtered (_("Disabling randomization of debuggee's "
200 "virtual address space is unsupported on\n"
201 "this platform.\n"), file);
202 }
203
204 static void
205 set_disable_randomization (char *args, int from_tty,
206 struct cmd_list_element *c)
207 {
208 if (!target_supports_disable_randomization ())
209 error (_("Disabling randomization of debuggee's "
210 "virtual address space is unsupported on\n"
211 "this platform."));
212 }
213
214 /* User interface for non-stop mode. */
215
216 int non_stop = 0;
217 static int non_stop_1 = 0;
218
219 static void
220 set_non_stop (char *args, int from_tty,
221 struct cmd_list_element *c)
222 {
223 if (target_has_execution)
224 {
225 non_stop_1 = non_stop;
226 error (_("Cannot change this setting while the inferior is running."));
227 }
228
229 non_stop = non_stop_1;
230 }
231
232 static void
233 show_non_stop (struct ui_file *file, int from_tty,
234 struct cmd_list_element *c, const char *value)
235 {
236 fprintf_filtered (file,
237 _("Controlling the inferior in non-stop mode is %s.\n"),
238 value);
239 }
240
241 /* "Observer mode" is somewhat like a more extreme version of
242 non-stop, in which all GDB operations that might affect the
243 target's execution have been disabled. */
244
245 int observer_mode = 0;
246 static int observer_mode_1 = 0;
247
248 static void
249 set_observer_mode (char *args, int from_tty,
250 struct cmd_list_element *c)
251 {
252 if (target_has_execution)
253 {
254 observer_mode_1 = observer_mode;
255 error (_("Cannot change this setting while the inferior is running."));
256 }
257
258 observer_mode = observer_mode_1;
259
260 may_write_registers = !observer_mode;
261 may_write_memory = !observer_mode;
262 may_insert_breakpoints = !observer_mode;
263 may_insert_tracepoints = !observer_mode;
264 /* We can insert fast tracepoints in or out of observer mode,
265 but enable them if we're going into this mode. */
266 if (observer_mode)
267 may_insert_fast_tracepoints = 1;
268 may_stop = !observer_mode;
269 update_target_permissions ();
270
271 /* Going *into* observer mode we must force non-stop, then
272 going out we leave it that way. */
273 if (observer_mode)
274 {
275 pagination_enabled = 0;
276 non_stop = non_stop_1 = 1;
277 }
278
279 if (from_tty)
280 printf_filtered (_("Observer mode is now %s.\n"),
281 (observer_mode ? "on" : "off"));
282 }
283
284 static void
285 show_observer_mode (struct ui_file *file, int from_tty,
286 struct cmd_list_element *c, const char *value)
287 {
288 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
289 }
290
291 /* This updates the value of observer mode based on changes in
292 permissions. Note that we are deliberately ignoring the values of
293 may-write-registers and may-write-memory, since the user may have
294 reason to enable these during a session, for instance to turn on a
295 debugging-related global. */
296
297 void
298 update_observer_mode (void)
299 {
300 int newval;
301
302 newval = (!may_insert_breakpoints
303 && !may_insert_tracepoints
304 && may_insert_fast_tracepoints
305 && !may_stop
306 && non_stop);
307
308 /* Let the user know if things change. */
309 if (newval != observer_mode)
310 printf_filtered (_("Observer mode is now %s.\n"),
311 (newval ? "on" : "off"));
312
313 observer_mode = observer_mode_1 = newval;
314 }
315
316 /* Tables of how to react to signals; the user sets them. */
317
318 static unsigned char *signal_stop;
319 static unsigned char *signal_print;
320 static unsigned char *signal_program;
321
322 /* Table of signals that are registered with "catch signal". A
323 non-zero entry indicates that the signal is caught by some "catch
324 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
325 signals. */
326 static unsigned char *signal_catch;
327
328 /* Table of signals that the target may silently handle.
329 This is automatically determined from the flags above,
330 and simply cached here. */
331 static unsigned char *signal_pass;
332
333 #define SET_SIGS(nsigs,sigs,flags) \
334 do { \
335 int signum = (nsigs); \
336 while (signum-- > 0) \
337 if ((sigs)[signum]) \
338 (flags)[signum] = 1; \
339 } while (0)
340
341 #define UNSET_SIGS(nsigs,sigs,flags) \
342 do { \
343 int signum = (nsigs); \
344 while (signum-- > 0) \
345 if ((sigs)[signum]) \
346 (flags)[signum] = 0; \
347 } while (0)
348
349 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
350 this function is to avoid exporting `signal_program'. */
351
352 void
353 update_signals_program_target (void)
354 {
355 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
356 }
357
358 /* Value to pass to target_resume() to cause all threads to resume. */
359
360 #define RESUME_ALL minus_one_ptid
361
362 /* Command list pointer for the "stop" placeholder. */
363
364 static struct cmd_list_element *stop_command;
365
366 /* Nonzero if we want to give control to the user when we're notified
367 of shared library events by the dynamic linker. */
368 int stop_on_solib_events;
369
370 /* Enable or disable optional shared library event breakpoints
371 as appropriate when the above flag is changed. */
372
373 static void
374 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
375 {
376 update_solib_breakpoints ();
377 }
378
379 static void
380 show_stop_on_solib_events (struct ui_file *file, int from_tty,
381 struct cmd_list_element *c, const char *value)
382 {
383 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
384 value);
385 }
386
387 /* Nonzero after stop if current stack frame should be printed. */
388
389 static int stop_print_frame;
390
391 /* This is a cached copy of the pid/waitstatus of the last event
392 returned by target_wait()/deprecated_target_wait_hook(). This
393 information is returned by get_last_target_status(). */
394 static ptid_t target_last_wait_ptid;
395 static struct target_waitstatus target_last_waitstatus;
396
397 static void context_switch (ptid_t ptid);
398
399 void init_thread_stepping_state (struct thread_info *tss);
400
401 static const char follow_fork_mode_child[] = "child";
402 static const char follow_fork_mode_parent[] = "parent";
403
404 static const char *const follow_fork_mode_kind_names[] = {
405 follow_fork_mode_child,
406 follow_fork_mode_parent,
407 NULL
408 };
409
410 static const char *follow_fork_mode_string = follow_fork_mode_parent;
411 static void
412 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
413 struct cmd_list_element *c, const char *value)
414 {
415 fprintf_filtered (file,
416 _("Debugger response to a program "
417 "call of fork or vfork is \"%s\".\n"),
418 value);
419 }
420 \f
421
422 /* Handle changes to the inferior list based on the type of fork,
423 which process is being followed, and whether the other process
424 should be detached. On entry inferior_ptid must be the ptid of
425 the fork parent. At return inferior_ptid is the ptid of the
426 followed inferior. */
427
428 static int
429 follow_fork_inferior (int follow_child, int detach_fork)
430 {
431 int has_vforked;
432 ptid_t parent_ptid, child_ptid;
433
434 has_vforked = (inferior_thread ()->pending_follow.kind
435 == TARGET_WAITKIND_VFORKED);
436 parent_ptid = inferior_ptid;
437 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
438
439 if (has_vforked
440 && !non_stop /* Non-stop always resumes both branches. */
441 && current_ui->prompt_state == PROMPT_BLOCKED
442 && !(follow_child || detach_fork || sched_multi))
443 {
444 /* The parent stays blocked inside the vfork syscall until the
445 child execs or exits. If we don't let the child run, then
446 the parent stays blocked. If we're telling the parent to run
447 in the foreground, the user will not be able to ctrl-c to get
448 back the terminal, effectively hanging the debug session. */
449 fprintf_filtered (gdb_stderr, _("\
450 Can not resume the parent process over vfork in the foreground while\n\
451 holding the child stopped. Try \"set detach-on-fork\" or \
452 \"set schedule-multiple\".\n"));
453 /* FIXME output string > 80 columns. */
454 return 1;
455 }
456
457 if (!follow_child)
458 {
459 /* Detach new forked process? */
460 if (detach_fork)
461 {
462 /* Before detaching from the child, remove all breakpoints
463 from it. If we forked, then this has already been taken
464 care of by infrun.c. If we vforked however, any
465 breakpoint inserted in the parent is visible in the
466 child, even those added while stopped in a vfork
467 catchpoint. This will remove the breakpoints from the
468 parent also, but they'll be reinserted below. */
469 if (has_vforked)
470 {
471 /* Keep breakpoints list in sync. */
472 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
473 }
474
475 if (info_verbose || debug_infrun)
476 {
477 /* Ensure that we have a process ptid. */
478 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
479
480 target_terminal_ours_for_output ();
481 fprintf_filtered (gdb_stdlog,
482 _("Detaching after %s from child %s.\n"),
483 has_vforked ? "vfork" : "fork",
484 target_pid_to_str (process_ptid));
485 }
486 }
487 else
488 {
489 struct inferior *parent_inf, *child_inf;
490 struct cleanup *old_chain;
491
492 /* Add process to GDB's tables. */
493 child_inf = add_inferior (ptid_get_pid (child_ptid));
494
495 parent_inf = current_inferior ();
496 child_inf->attach_flag = parent_inf->attach_flag;
497 copy_terminal_info (child_inf, parent_inf);
498 child_inf->gdbarch = parent_inf->gdbarch;
499 copy_inferior_target_desc_info (child_inf, parent_inf);
500
501 old_chain = save_inferior_ptid ();
502 save_current_program_space ();
503
504 inferior_ptid = child_ptid;
505 add_thread (inferior_ptid);
506 child_inf->symfile_flags = SYMFILE_NO_READ;
507
508 /* If this is a vfork child, then the address-space is
509 shared with the parent. */
510 if (has_vforked)
511 {
512 child_inf->pspace = parent_inf->pspace;
513 child_inf->aspace = parent_inf->aspace;
514
515 /* The parent will be frozen until the child is done
516 with the shared region. Keep track of the
517 parent. */
518 child_inf->vfork_parent = parent_inf;
519 child_inf->pending_detach = 0;
520 parent_inf->vfork_child = child_inf;
521 parent_inf->pending_detach = 0;
522 }
523 else
524 {
525 child_inf->aspace = new_address_space ();
526 child_inf->pspace = add_program_space (child_inf->aspace);
527 child_inf->removable = 1;
528 set_current_program_space (child_inf->pspace);
529 clone_program_space (child_inf->pspace, parent_inf->pspace);
530
531 /* Let the shared library layer (e.g., solib-svr4) learn
532 about this new process, relocate the cloned exec, pull
533 in shared libraries, and install the solib event
534 breakpoint. If a "cloned-VM" event was propagated
535 better throughout the core, this wouldn't be
536 required. */
537 solib_create_inferior_hook (0);
538 }
539
540 do_cleanups (old_chain);
541 }
542
543 if (has_vforked)
544 {
545 struct inferior *parent_inf;
546
547 parent_inf = current_inferior ();
548
549 /* If we detached from the child, then we have to be careful
550 to not insert breakpoints in the parent until the child
551 is done with the shared memory region. However, if we're
552 staying attached to the child, then we can and should
553 insert breakpoints, so that we can debug it. A
554 subsequent child exec or exit is enough to know when does
555 the child stops using the parent's address space. */
556 parent_inf->waiting_for_vfork_done = detach_fork;
557 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
558 }
559 }
560 else
561 {
562 /* Follow the child. */
563 struct inferior *parent_inf, *child_inf;
564 struct program_space *parent_pspace;
565
566 if (info_verbose || debug_infrun)
567 {
568 target_terminal_ours_for_output ();
569 fprintf_filtered (gdb_stdlog,
570 _("Attaching after %s %s to child %s.\n"),
571 target_pid_to_str (parent_ptid),
572 has_vforked ? "vfork" : "fork",
573 target_pid_to_str (child_ptid));
574 }
575
576 /* Add the new inferior first, so that the target_detach below
577 doesn't unpush the target. */
578
579 child_inf = add_inferior (ptid_get_pid (child_ptid));
580
581 parent_inf = current_inferior ();
582 child_inf->attach_flag = parent_inf->attach_flag;
583 copy_terminal_info (child_inf, parent_inf);
584 child_inf->gdbarch = parent_inf->gdbarch;
585 copy_inferior_target_desc_info (child_inf, parent_inf);
586
587 parent_pspace = parent_inf->pspace;
588
589 /* If we're vforking, we want to hold on to the parent until the
590 child exits or execs. At child exec or exit time we can
591 remove the old breakpoints from the parent and detach or
592 resume debugging it. Otherwise, detach the parent now; we'll
593 want to reuse it's program/address spaces, but we can't set
594 them to the child before removing breakpoints from the
595 parent, otherwise, the breakpoints module could decide to
596 remove breakpoints from the wrong process (since they'd be
597 assigned to the same address space). */
598
599 if (has_vforked)
600 {
601 gdb_assert (child_inf->vfork_parent == NULL);
602 gdb_assert (parent_inf->vfork_child == NULL);
603 child_inf->vfork_parent = parent_inf;
604 child_inf->pending_detach = 0;
605 parent_inf->vfork_child = child_inf;
606 parent_inf->pending_detach = detach_fork;
607 parent_inf->waiting_for_vfork_done = 0;
608 }
609 else if (detach_fork)
610 {
611 if (info_verbose || debug_infrun)
612 {
613 /* Ensure that we have a process ptid. */
614 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
615
616 target_terminal_ours_for_output ();
617 fprintf_filtered (gdb_stdlog,
618 _("Detaching after fork from "
619 "child %s.\n"),
620 target_pid_to_str (process_ptid));
621 }
622
623 target_detach (NULL, 0);
624 }
625
626 /* Note that the detach above makes PARENT_INF dangling. */
627
628 /* Add the child thread to the appropriate lists, and switch to
629 this new thread, before cloning the program space, and
630 informing the solib layer about this new process. */
631
632 inferior_ptid = child_ptid;
633 add_thread (inferior_ptid);
634
635 /* If this is a vfork child, then the address-space is shared
636 with the parent. If we detached from the parent, then we can
637 reuse the parent's program/address spaces. */
638 if (has_vforked || detach_fork)
639 {
640 child_inf->pspace = parent_pspace;
641 child_inf->aspace = child_inf->pspace->aspace;
642 }
643 else
644 {
645 child_inf->aspace = new_address_space ();
646 child_inf->pspace = add_program_space (child_inf->aspace);
647 child_inf->removable = 1;
648 child_inf->symfile_flags = SYMFILE_NO_READ;
649 set_current_program_space (child_inf->pspace);
650 clone_program_space (child_inf->pspace, parent_pspace);
651
652 /* Let the shared library layer (e.g., solib-svr4) learn
653 about this new process, relocate the cloned exec, pull in
654 shared libraries, and install the solib event breakpoint.
655 If a "cloned-VM" event was propagated better throughout
656 the core, this wouldn't be required. */
657 solib_create_inferior_hook (0);
658 }
659 }
660
661 return target_follow_fork (follow_child, detach_fork);
662 }
663
664 /* Tell the target to follow the fork we're stopped at. Returns true
665 if the inferior should be resumed; false, if the target for some
666 reason decided it's best not to resume. */
667
668 static int
669 follow_fork (void)
670 {
671 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
672 int should_resume = 1;
673 struct thread_info *tp;
674
675 /* Copy user stepping state to the new inferior thread. FIXME: the
676 followed fork child thread should have a copy of most of the
677 parent thread structure's run control related fields, not just these.
678 Initialized to avoid "may be used uninitialized" warnings from gcc. */
679 struct breakpoint *step_resume_breakpoint = NULL;
680 struct breakpoint *exception_resume_breakpoint = NULL;
681 CORE_ADDR step_range_start = 0;
682 CORE_ADDR step_range_end = 0;
683 struct frame_id step_frame_id = { 0 };
684 struct thread_fsm *thread_fsm = NULL;
685
686 if (!non_stop)
687 {
688 ptid_t wait_ptid;
689 struct target_waitstatus wait_status;
690
691 /* Get the last target status returned by target_wait(). */
692 get_last_target_status (&wait_ptid, &wait_status);
693
694 /* If not stopped at a fork event, then there's nothing else to
695 do. */
696 if (wait_status.kind != TARGET_WAITKIND_FORKED
697 && wait_status.kind != TARGET_WAITKIND_VFORKED)
698 return 1;
699
700 /* Check if we switched over from WAIT_PTID, since the event was
701 reported. */
702 if (!ptid_equal (wait_ptid, minus_one_ptid)
703 && !ptid_equal (inferior_ptid, wait_ptid))
704 {
705 /* We did. Switch back to WAIT_PTID thread, to tell the
706 target to follow it (in either direction). We'll
707 afterwards refuse to resume, and inform the user what
708 happened. */
709 switch_to_thread (wait_ptid);
710 should_resume = 0;
711 }
712 }
713
714 tp = inferior_thread ();
715
716 /* If there were any forks/vforks that were caught and are now to be
717 followed, then do so now. */
718 switch (tp->pending_follow.kind)
719 {
720 case TARGET_WAITKIND_FORKED:
721 case TARGET_WAITKIND_VFORKED:
722 {
723 ptid_t parent, child;
724
725 /* If the user did a next/step, etc, over a fork call,
726 preserve the stepping state in the fork child. */
727 if (follow_child && should_resume)
728 {
729 step_resume_breakpoint = clone_momentary_breakpoint
730 (tp->control.step_resume_breakpoint);
731 step_range_start = tp->control.step_range_start;
732 step_range_end = tp->control.step_range_end;
733 step_frame_id = tp->control.step_frame_id;
734 exception_resume_breakpoint
735 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
736 thread_fsm = tp->thread_fsm;
737
738 /* For now, delete the parent's sr breakpoint, otherwise,
739 parent/child sr breakpoints are considered duplicates,
740 and the child version will not be installed. Remove
741 this when the breakpoints module becomes aware of
742 inferiors and address spaces. */
743 delete_step_resume_breakpoint (tp);
744 tp->control.step_range_start = 0;
745 tp->control.step_range_end = 0;
746 tp->control.step_frame_id = null_frame_id;
747 delete_exception_resume_breakpoint (tp);
748 tp->thread_fsm = NULL;
749 }
750
751 parent = inferior_ptid;
752 child = tp->pending_follow.value.related_pid;
753
754 /* Set up inferior(s) as specified by the caller, and tell the
755 target to do whatever is necessary to follow either parent
756 or child. */
757 if (follow_fork_inferior (follow_child, detach_fork))
758 {
759 /* Target refused to follow, or there's some other reason
760 we shouldn't resume. */
761 should_resume = 0;
762 }
763 else
764 {
765 /* This pending follow fork event is now handled, one way
766 or another. The previous selected thread may be gone
767 from the lists by now, but if it is still around, need
768 to clear the pending follow request. */
769 tp = find_thread_ptid (parent);
770 if (tp)
771 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
772
773 /* This makes sure we don't try to apply the "Switched
774 over from WAIT_PID" logic above. */
775 nullify_last_target_wait_ptid ();
776
777 /* If we followed the child, switch to it... */
778 if (follow_child)
779 {
780 switch_to_thread (child);
781
782 /* ... and preserve the stepping state, in case the
783 user was stepping over the fork call. */
784 if (should_resume)
785 {
786 tp = inferior_thread ();
787 tp->control.step_resume_breakpoint
788 = step_resume_breakpoint;
789 tp->control.step_range_start = step_range_start;
790 tp->control.step_range_end = step_range_end;
791 tp->control.step_frame_id = step_frame_id;
792 tp->control.exception_resume_breakpoint
793 = exception_resume_breakpoint;
794 tp->thread_fsm = thread_fsm;
795 }
796 else
797 {
798 /* If we get here, it was because we're trying to
799 resume from a fork catchpoint, but, the user
800 has switched threads away from the thread that
801 forked. In that case, the resume command
802 issued is most likely not applicable to the
803 child, so just warn, and refuse to resume. */
804 warning (_("Not resuming: switched threads "
805 "before following fork child."));
806 }
807
808 /* Reset breakpoints in the child as appropriate. */
809 follow_inferior_reset_breakpoints ();
810 }
811 else
812 switch_to_thread (parent);
813 }
814 }
815 break;
816 case TARGET_WAITKIND_SPURIOUS:
817 /* Nothing to follow. */
818 break;
819 default:
820 internal_error (__FILE__, __LINE__,
821 "Unexpected pending_follow.kind %d\n",
822 tp->pending_follow.kind);
823 break;
824 }
825
826 return should_resume;
827 }
828
829 static void
830 follow_inferior_reset_breakpoints (void)
831 {
832 struct thread_info *tp = inferior_thread ();
833
834 /* Was there a step_resume breakpoint? (There was if the user
835 did a "next" at the fork() call.) If so, explicitly reset its
836 thread number. Cloned step_resume breakpoints are disabled on
837 creation, so enable it here now that it is associated with the
838 correct thread.
839
840 step_resumes are a form of bp that are made to be per-thread.
841 Since we created the step_resume bp when the parent process
842 was being debugged, and now are switching to the child process,
843 from the breakpoint package's viewpoint, that's a switch of
844 "threads". We must update the bp's notion of which thread
845 it is for, or it'll be ignored when it triggers. */
846
847 if (tp->control.step_resume_breakpoint)
848 {
849 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
850 tp->control.step_resume_breakpoint->loc->enabled = 1;
851 }
852
853 /* Treat exception_resume breakpoints like step_resume breakpoints. */
854 if (tp->control.exception_resume_breakpoint)
855 {
856 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
857 tp->control.exception_resume_breakpoint->loc->enabled = 1;
858 }
859
860 /* Reinsert all breakpoints in the child. The user may have set
861 breakpoints after catching the fork, in which case those
862 were never set in the child, but only in the parent. This makes
863 sure the inserted breakpoints match the breakpoint list. */
864
865 breakpoint_re_set ();
866 insert_breakpoints ();
867 }
868
869 /* The child has exited or execed: resume threads of the parent the
870 user wanted to be executing. */
871
872 static int
873 proceed_after_vfork_done (struct thread_info *thread,
874 void *arg)
875 {
876 int pid = * (int *) arg;
877
878 if (ptid_get_pid (thread->ptid) == pid
879 && is_running (thread->ptid)
880 && !is_executing (thread->ptid)
881 && !thread->stop_requested
882 && thread->suspend.stop_signal == GDB_SIGNAL_0)
883 {
884 if (debug_infrun)
885 fprintf_unfiltered (gdb_stdlog,
886 "infrun: resuming vfork parent thread %s\n",
887 target_pid_to_str (thread->ptid));
888
889 switch_to_thread (thread->ptid);
890 clear_proceed_status (0);
891 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
892 }
893
894 return 0;
895 }
896
897 /* Called whenever we notice an exec or exit event, to handle
898 detaching or resuming a vfork parent. */
899
900 static void
901 handle_vfork_child_exec_or_exit (int exec)
902 {
903 struct inferior *inf = current_inferior ();
904
905 if (inf->vfork_parent)
906 {
907 int resume_parent = -1;
908
909 /* This exec or exit marks the end of the shared memory region
910 between the parent and the child. If the user wanted to
911 detach from the parent, now is the time. */
912
913 if (inf->vfork_parent->pending_detach)
914 {
915 struct thread_info *tp;
916 struct cleanup *old_chain;
917 struct program_space *pspace;
918 struct address_space *aspace;
919
920 /* follow-fork child, detach-on-fork on. */
921
922 inf->vfork_parent->pending_detach = 0;
923
924 if (!exec)
925 {
926 /* If we're handling a child exit, then inferior_ptid
927 points at the inferior's pid, not to a thread. */
928 old_chain = save_inferior_ptid ();
929 save_current_program_space ();
930 save_current_inferior ();
931 }
932 else
933 old_chain = save_current_space_and_thread ();
934
935 /* We're letting loose of the parent. */
936 tp = any_live_thread_of_process (inf->vfork_parent->pid);
937 switch_to_thread (tp->ptid);
938
939 /* We're about to detach from the parent, which implicitly
940 removes breakpoints from its address space. There's a
941 catch here: we want to reuse the spaces for the child,
942 but, parent/child are still sharing the pspace at this
943 point, although the exec in reality makes the kernel give
944 the child a fresh set of new pages. The problem here is
945 that the breakpoints module being unaware of this, would
946 likely chose the child process to write to the parent
947 address space. Swapping the child temporarily away from
948 the spaces has the desired effect. Yes, this is "sort
949 of" a hack. */
950
951 pspace = inf->pspace;
952 aspace = inf->aspace;
953 inf->aspace = NULL;
954 inf->pspace = NULL;
955
956 if (debug_infrun || info_verbose)
957 {
958 target_terminal_ours_for_output ();
959
960 if (exec)
961 {
962 fprintf_filtered (gdb_stdlog,
963 _("Detaching vfork parent process "
964 "%d after child exec.\n"),
965 inf->vfork_parent->pid);
966 }
967 else
968 {
969 fprintf_filtered (gdb_stdlog,
970 _("Detaching vfork parent process "
971 "%d after child exit.\n"),
972 inf->vfork_parent->pid);
973 }
974 }
975
976 target_detach (NULL, 0);
977
978 /* Put it back. */
979 inf->pspace = pspace;
980 inf->aspace = aspace;
981
982 do_cleanups (old_chain);
983 }
984 else if (exec)
985 {
986 /* We're staying attached to the parent, so, really give the
987 child a new address space. */
988 inf->pspace = add_program_space (maybe_new_address_space ());
989 inf->aspace = inf->pspace->aspace;
990 inf->removable = 1;
991 set_current_program_space (inf->pspace);
992
993 resume_parent = inf->vfork_parent->pid;
994
995 /* Break the bonds. */
996 inf->vfork_parent->vfork_child = NULL;
997 }
998 else
999 {
1000 struct cleanup *old_chain;
1001 struct program_space *pspace;
1002
1003 /* If this is a vfork child exiting, then the pspace and
1004 aspaces were shared with the parent. Since we're
1005 reporting the process exit, we'll be mourning all that is
1006 found in the address space, and switching to null_ptid,
1007 preparing to start a new inferior. But, since we don't
1008 want to clobber the parent's address/program spaces, we
1009 go ahead and create a new one for this exiting
1010 inferior. */
1011
1012 /* Switch to null_ptid, so that clone_program_space doesn't want
1013 to read the selected frame of a dead process. */
1014 old_chain = save_inferior_ptid ();
1015 inferior_ptid = null_ptid;
1016
1017 /* This inferior is dead, so avoid giving the breakpoints
1018 module the option to write through to it (cloning a
1019 program space resets breakpoints). */
1020 inf->aspace = NULL;
1021 inf->pspace = NULL;
1022 pspace = add_program_space (maybe_new_address_space ());
1023 set_current_program_space (pspace);
1024 inf->removable = 1;
1025 inf->symfile_flags = SYMFILE_NO_READ;
1026 clone_program_space (pspace, inf->vfork_parent->pspace);
1027 inf->pspace = pspace;
1028 inf->aspace = pspace->aspace;
1029
1030 /* Put back inferior_ptid. We'll continue mourning this
1031 inferior. */
1032 do_cleanups (old_chain);
1033
1034 resume_parent = inf->vfork_parent->pid;
1035 /* Break the bonds. */
1036 inf->vfork_parent->vfork_child = NULL;
1037 }
1038
1039 inf->vfork_parent = NULL;
1040
1041 gdb_assert (current_program_space == inf->pspace);
1042
1043 if (non_stop && resume_parent != -1)
1044 {
1045 /* If the user wanted the parent to be running, let it go
1046 free now. */
1047 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
1048
1049 if (debug_infrun)
1050 fprintf_unfiltered (gdb_stdlog,
1051 "infrun: resuming vfork parent process %d\n",
1052 resume_parent);
1053
1054 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1055
1056 do_cleanups (old_chain);
1057 }
1058 }
1059 }
1060
1061 /* Enum strings for "set|show follow-exec-mode". */
1062
1063 static const char follow_exec_mode_new[] = "new";
1064 static const char follow_exec_mode_same[] = "same";
1065 static const char *const follow_exec_mode_names[] =
1066 {
1067 follow_exec_mode_new,
1068 follow_exec_mode_same,
1069 NULL,
1070 };
1071
1072 static const char *follow_exec_mode_string = follow_exec_mode_same;
1073 static void
1074 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1075 struct cmd_list_element *c, const char *value)
1076 {
1077 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1078 }
1079
1080 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1081
1082 static void
1083 follow_exec (ptid_t ptid, char *exec_file_target)
1084 {
1085 struct thread_info *th, *tmp;
1086 struct inferior *inf = current_inferior ();
1087 int pid = ptid_get_pid (ptid);
1088 ptid_t process_ptid;
1089 char *exec_file_host;
1090 struct cleanup *old_chain;
1091
1092 /* This is an exec event that we actually wish to pay attention to.
1093 Refresh our symbol table to the newly exec'd program, remove any
1094 momentary bp's, etc.
1095
1096 If there are breakpoints, they aren't really inserted now,
1097 since the exec() transformed our inferior into a fresh set
1098 of instructions.
1099
1100 We want to preserve symbolic breakpoints on the list, since
1101 we have hopes that they can be reset after the new a.out's
1102 symbol table is read.
1103
1104 However, any "raw" breakpoints must be removed from the list
1105 (e.g., the solib bp's), since their address is probably invalid
1106 now.
1107
1108 And, we DON'T want to call delete_breakpoints() here, since
1109 that may write the bp's "shadow contents" (the instruction
1110 value that was overwritten witha TRAP instruction). Since
1111 we now have a new a.out, those shadow contents aren't valid. */
1112
1113 mark_breakpoints_out ();
1114
1115 /* The target reports the exec event to the main thread, even if
1116 some other thread does the exec, and even if the main thread was
1117 stopped or already gone. We may still have non-leader threads of
1118 the process on our list. E.g., on targets that don't have thread
1119 exit events (like remote); or on native Linux in non-stop mode if
1120 there were only two threads in the inferior and the non-leader
1121 one is the one that execs (and nothing forces an update of the
1122 thread list up to here). When debugging remotely, it's best to
1123 avoid extra traffic, when possible, so avoid syncing the thread
1124 list with the target, and instead go ahead and delete all threads
1125 of the process but one that reported the event. Note this must
1126 be done before calling update_breakpoints_after_exec, as
1127 otherwise clearing the threads' resources would reference stale
1128 thread breakpoints -- it may have been one of these threads that
1129 stepped across the exec. We could just clear their stepping
1130 states, but as long as we're iterating, might as well delete
1131 them. Deleting them now rather than at the next user-visible
1132 stop provides a nicer sequence of events for user and MI
1133 notifications. */
1134 ALL_THREADS_SAFE (th, tmp)
1135 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1136 delete_thread (th->ptid);
1137
1138 /* We also need to clear any left over stale state for the
1139 leader/event thread. E.g., if there was any step-resume
1140 breakpoint or similar, it's gone now. We cannot truly
1141 step-to-next statement through an exec(). */
1142 th = inferior_thread ();
1143 th->control.step_resume_breakpoint = NULL;
1144 th->control.exception_resume_breakpoint = NULL;
1145 th->control.single_step_breakpoints = NULL;
1146 th->control.step_range_start = 0;
1147 th->control.step_range_end = 0;
1148
1149 /* The user may have had the main thread held stopped in the
1150 previous image (e.g., schedlock on, or non-stop). Release
1151 it now. */
1152 th->stop_requested = 0;
1153
1154 update_breakpoints_after_exec ();
1155
1156 /* What is this a.out's name? */
1157 process_ptid = pid_to_ptid (pid);
1158 printf_unfiltered (_("%s is executing new program: %s\n"),
1159 target_pid_to_str (process_ptid),
1160 exec_file_target);
1161
1162 /* We've followed the inferior through an exec. Therefore, the
1163 inferior has essentially been killed & reborn. */
1164
1165 gdb_flush (gdb_stdout);
1166
1167 breakpoint_init_inferior (inf_execd);
1168
1169 exec_file_host = exec_file_find (exec_file_target, NULL);
1170 old_chain = make_cleanup (xfree, exec_file_host);
1171
1172 /* If we were unable to map the executable target pathname onto a host
1173 pathname, tell the user that. Otherwise GDB's subsequent behavior
1174 is confusing. Maybe it would even be better to stop at this point
1175 so that the user can specify a file manually before continuing. */
1176 if (exec_file_host == NULL)
1177 warning (_("Could not load symbols for executable %s.\n"
1178 "Do you need \"set sysroot\"?"),
1179 exec_file_target);
1180
1181 /* Reset the shared library package. This ensures that we get a
1182 shlib event when the child reaches "_start", at which point the
1183 dld will have had a chance to initialize the child. */
1184 /* Also, loading a symbol file below may trigger symbol lookups, and
1185 we don't want those to be satisfied by the libraries of the
1186 previous incarnation of this process. */
1187 no_shared_libraries (NULL, 0);
1188
1189 if (follow_exec_mode_string == follow_exec_mode_new)
1190 {
1191 /* The user wants to keep the old inferior and program spaces
1192 around. Create a new fresh one, and switch to it. */
1193
1194 /* Do exit processing for the original inferior before adding
1195 the new inferior so we don't have two active inferiors with
1196 the same ptid, which can confuse find_inferior_ptid. */
1197 exit_inferior_num_silent (current_inferior ()->num);
1198
1199 inf = add_inferior_with_spaces ();
1200 inf->pid = pid;
1201 target_follow_exec (inf, exec_file_target);
1202
1203 set_current_inferior (inf);
1204 set_current_program_space (inf->pspace);
1205 add_thread (ptid);
1206 }
1207 else
1208 {
1209 /* The old description may no longer be fit for the new image.
1210 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1211 old description; we'll read a new one below. No need to do
1212 this on "follow-exec-mode new", as the old inferior stays
1213 around (its description is later cleared/refetched on
1214 restart). */
1215 target_clear_description ();
1216 }
1217
1218 gdb_assert (current_program_space == inf->pspace);
1219
1220 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1221 because the proper displacement for a PIE (Position Independent
1222 Executable) main symbol file will only be computed by
1223 solib_create_inferior_hook below. breakpoint_re_set would fail
1224 to insert the breakpoints with the zero displacement. */
1225 try_open_exec_file (exec_file_host, inf, SYMFILE_DEFER_BP_RESET);
1226
1227 do_cleanups (old_chain);
1228
1229 /* If the target can specify a description, read it. Must do this
1230 after flipping to the new executable (because the target supplied
1231 description must be compatible with the executable's
1232 architecture, and the old executable may e.g., be 32-bit, while
1233 the new one 64-bit), and before anything involving memory or
1234 registers. */
1235 target_find_description ();
1236
1237 solib_create_inferior_hook (0);
1238
1239 jit_inferior_created_hook ();
1240
1241 breakpoint_re_set ();
1242
1243 /* Reinsert all breakpoints. (Those which were symbolic have
1244 been reset to the proper address in the new a.out, thanks
1245 to symbol_file_command...). */
1246 insert_breakpoints ();
1247
1248 /* The next resume of this inferior should bring it to the shlib
1249 startup breakpoints. (If the user had also set bp's on
1250 "main" from the old (parent) process, then they'll auto-
1251 matically get reset there in the new process.). */
1252 }
1253
1254 /* The queue of threads that need to do a step-over operation to get
1255 past e.g., a breakpoint. What technique is used to step over the
1256 breakpoint/watchpoint does not matter -- all threads end up in the
1257 same queue, to maintain rough temporal order of execution, in order
1258 to avoid starvation, otherwise, we could e.g., find ourselves
1259 constantly stepping the same couple threads past their breakpoints
1260 over and over, if the single-step finish fast enough. */
1261 struct thread_info *step_over_queue_head;
1262
1263 /* Bit flags indicating what the thread needs to step over. */
1264
1265 enum step_over_what_flag
1266 {
1267 /* Step over a breakpoint. */
1268 STEP_OVER_BREAKPOINT = 1,
1269
1270 /* Step past a non-continuable watchpoint, in order to let the
1271 instruction execute so we can evaluate the watchpoint
1272 expression. */
1273 STEP_OVER_WATCHPOINT = 2
1274 };
1275 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1276
1277 /* Info about an instruction that is being stepped over. */
1278
1279 struct step_over_info
1280 {
1281 /* If we're stepping past a breakpoint, this is the address space
1282 and address of the instruction the breakpoint is set at. We'll
1283 skip inserting all breakpoints here. Valid iff ASPACE is
1284 non-NULL. */
1285 struct address_space *aspace;
1286 CORE_ADDR address;
1287
1288 /* The instruction being stepped over triggers a nonsteppable
1289 watchpoint. If true, we'll skip inserting watchpoints. */
1290 int nonsteppable_watchpoint_p;
1291
1292 /* The thread's global number. */
1293 int thread;
1294 };
1295
1296 /* The step-over info of the location that is being stepped over.
1297
1298 Note that with async/breakpoint always-inserted mode, a user might
1299 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1300 being stepped over. As setting a new breakpoint inserts all
1301 breakpoints, we need to make sure the breakpoint being stepped over
1302 isn't inserted then. We do that by only clearing the step-over
1303 info when the step-over is actually finished (or aborted).
1304
1305 Presently GDB can only step over one breakpoint at any given time.
1306 Given threads that can't run code in the same address space as the
1307 breakpoint's can't really miss the breakpoint, GDB could be taught
1308 to step-over at most one breakpoint per address space (so this info
1309 could move to the address space object if/when GDB is extended).
1310 The set of breakpoints being stepped over will normally be much
1311 smaller than the set of all breakpoints, so a flag in the
1312 breakpoint location structure would be wasteful. A separate list
1313 also saves complexity and run-time, as otherwise we'd have to go
1314 through all breakpoint locations clearing their flag whenever we
1315 start a new sequence. Similar considerations weigh against storing
1316 this info in the thread object. Plus, not all step overs actually
1317 have breakpoint locations -- e.g., stepping past a single-step
1318 breakpoint, or stepping to complete a non-continuable
1319 watchpoint. */
1320 static struct step_over_info step_over_info;
1321
1322 /* Record the address of the breakpoint/instruction we're currently
1323 stepping over.
1324 N.B. We record the aspace and address now, instead of say just the thread,
1325 because when we need the info later the thread may be running. */
1326
1327 static void
1328 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1329 int nonsteppable_watchpoint_p,
1330 int thread)
1331 {
1332 step_over_info.aspace = aspace;
1333 step_over_info.address = address;
1334 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1335 step_over_info.thread = thread;
1336 }
1337
1338 /* Called when we're not longer stepping over a breakpoint / an
1339 instruction, so all breakpoints are free to be (re)inserted. */
1340
1341 static void
1342 clear_step_over_info (void)
1343 {
1344 if (debug_infrun)
1345 fprintf_unfiltered (gdb_stdlog,
1346 "infrun: clear_step_over_info\n");
1347 step_over_info.aspace = NULL;
1348 step_over_info.address = 0;
1349 step_over_info.nonsteppable_watchpoint_p = 0;
1350 step_over_info.thread = -1;
1351 }
1352
1353 /* See infrun.h. */
1354
1355 int
1356 stepping_past_instruction_at (struct address_space *aspace,
1357 CORE_ADDR address)
1358 {
1359 return (step_over_info.aspace != NULL
1360 && breakpoint_address_match (aspace, address,
1361 step_over_info.aspace,
1362 step_over_info.address));
1363 }
1364
1365 /* See infrun.h. */
1366
1367 int
1368 thread_is_stepping_over_breakpoint (int thread)
1369 {
1370 return (step_over_info.thread != -1
1371 && thread == step_over_info.thread);
1372 }
1373
1374 /* See infrun.h. */
1375
1376 int
1377 stepping_past_nonsteppable_watchpoint (void)
1378 {
1379 return step_over_info.nonsteppable_watchpoint_p;
1380 }
1381
1382 /* Returns true if step-over info is valid. */
1383
1384 static int
1385 step_over_info_valid_p (void)
1386 {
1387 return (step_over_info.aspace != NULL
1388 || stepping_past_nonsteppable_watchpoint ());
1389 }
1390
1391 \f
1392 /* Displaced stepping. */
1393
1394 /* In non-stop debugging mode, we must take special care to manage
1395 breakpoints properly; in particular, the traditional strategy for
1396 stepping a thread past a breakpoint it has hit is unsuitable.
1397 'Displaced stepping' is a tactic for stepping one thread past a
1398 breakpoint it has hit while ensuring that other threads running
1399 concurrently will hit the breakpoint as they should.
1400
1401 The traditional way to step a thread T off a breakpoint in a
1402 multi-threaded program in all-stop mode is as follows:
1403
1404 a0) Initially, all threads are stopped, and breakpoints are not
1405 inserted.
1406 a1) We single-step T, leaving breakpoints uninserted.
1407 a2) We insert breakpoints, and resume all threads.
1408
1409 In non-stop debugging, however, this strategy is unsuitable: we
1410 don't want to have to stop all threads in the system in order to
1411 continue or step T past a breakpoint. Instead, we use displaced
1412 stepping:
1413
1414 n0) Initially, T is stopped, other threads are running, and
1415 breakpoints are inserted.
1416 n1) We copy the instruction "under" the breakpoint to a separate
1417 location, outside the main code stream, making any adjustments
1418 to the instruction, register, and memory state as directed by
1419 T's architecture.
1420 n2) We single-step T over the instruction at its new location.
1421 n3) We adjust the resulting register and memory state as directed
1422 by T's architecture. This includes resetting T's PC to point
1423 back into the main instruction stream.
1424 n4) We resume T.
1425
1426 This approach depends on the following gdbarch methods:
1427
1428 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1429 indicate where to copy the instruction, and how much space must
1430 be reserved there. We use these in step n1.
1431
1432 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1433 address, and makes any necessary adjustments to the instruction,
1434 register contents, and memory. We use this in step n1.
1435
1436 - gdbarch_displaced_step_fixup adjusts registers and memory after
1437 we have successfuly single-stepped the instruction, to yield the
1438 same effect the instruction would have had if we had executed it
1439 at its original address. We use this in step n3.
1440
1441 - gdbarch_displaced_step_free_closure provides cleanup.
1442
1443 The gdbarch_displaced_step_copy_insn and
1444 gdbarch_displaced_step_fixup functions must be written so that
1445 copying an instruction with gdbarch_displaced_step_copy_insn,
1446 single-stepping across the copied instruction, and then applying
1447 gdbarch_displaced_insn_fixup should have the same effects on the
1448 thread's memory and registers as stepping the instruction in place
1449 would have. Exactly which responsibilities fall to the copy and
1450 which fall to the fixup is up to the author of those functions.
1451
1452 See the comments in gdbarch.sh for details.
1453
1454 Note that displaced stepping and software single-step cannot
1455 currently be used in combination, although with some care I think
1456 they could be made to. Software single-step works by placing
1457 breakpoints on all possible subsequent instructions; if the
1458 displaced instruction is a PC-relative jump, those breakpoints
1459 could fall in very strange places --- on pages that aren't
1460 executable, or at addresses that are not proper instruction
1461 boundaries. (We do generally let other threads run while we wait
1462 to hit the software single-step breakpoint, and they might
1463 encounter such a corrupted instruction.) One way to work around
1464 this would be to have gdbarch_displaced_step_copy_insn fully
1465 simulate the effect of PC-relative instructions (and return NULL)
1466 on architectures that use software single-stepping.
1467
1468 In non-stop mode, we can have independent and simultaneous step
1469 requests, so more than one thread may need to simultaneously step
1470 over a breakpoint. The current implementation assumes there is
1471 only one scratch space per process. In this case, we have to
1472 serialize access to the scratch space. If thread A wants to step
1473 over a breakpoint, but we are currently waiting for some other
1474 thread to complete a displaced step, we leave thread A stopped and
1475 place it in the displaced_step_request_queue. Whenever a displaced
1476 step finishes, we pick the next thread in the queue and start a new
1477 displaced step operation on it. See displaced_step_prepare and
1478 displaced_step_fixup for details. */
1479
1480 /* Per-inferior displaced stepping state. */
1481 struct displaced_step_inferior_state
1482 {
1483 /* Pointer to next in linked list. */
1484 struct displaced_step_inferior_state *next;
1485
1486 /* The process this displaced step state refers to. */
1487 int pid;
1488
1489 /* True if preparing a displaced step ever failed. If so, we won't
1490 try displaced stepping for this inferior again. */
1491 int failed_before;
1492
1493 /* If this is not null_ptid, this is the thread carrying out a
1494 displaced single-step in process PID. This thread's state will
1495 require fixing up once it has completed its step. */
1496 ptid_t step_ptid;
1497
1498 /* The architecture the thread had when we stepped it. */
1499 struct gdbarch *step_gdbarch;
1500
1501 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1502 for post-step cleanup. */
1503 struct displaced_step_closure *step_closure;
1504
1505 /* The address of the original instruction, and the copy we
1506 made. */
1507 CORE_ADDR step_original, step_copy;
1508
1509 /* Saved contents of copy area. */
1510 gdb_byte *step_saved_copy;
1511 };
1512
1513 /* The list of states of processes involved in displaced stepping
1514 presently. */
1515 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1516
1517 /* Get the displaced stepping state of process PID. */
1518
1519 static struct displaced_step_inferior_state *
1520 get_displaced_stepping_state (int pid)
1521 {
1522 struct displaced_step_inferior_state *state;
1523
1524 for (state = displaced_step_inferior_states;
1525 state != NULL;
1526 state = state->next)
1527 if (state->pid == pid)
1528 return state;
1529
1530 return NULL;
1531 }
1532
1533 /* Returns true if any inferior has a thread doing a displaced
1534 step. */
1535
1536 static int
1537 displaced_step_in_progress_any_inferior (void)
1538 {
1539 struct displaced_step_inferior_state *state;
1540
1541 for (state = displaced_step_inferior_states;
1542 state != NULL;
1543 state = state->next)
1544 if (!ptid_equal (state->step_ptid, null_ptid))
1545 return 1;
1546
1547 return 0;
1548 }
1549
1550 /* Return true if thread represented by PTID is doing a displaced
1551 step. */
1552
1553 static int
1554 displaced_step_in_progress_thread (ptid_t ptid)
1555 {
1556 struct displaced_step_inferior_state *displaced;
1557
1558 gdb_assert (!ptid_equal (ptid, null_ptid));
1559
1560 displaced = get_displaced_stepping_state (ptid_get_pid (ptid));
1561
1562 return (displaced != NULL && ptid_equal (displaced->step_ptid, ptid));
1563 }
1564
1565 /* Return true if process PID has a thread doing a displaced step. */
1566
1567 static int
1568 displaced_step_in_progress (int pid)
1569 {
1570 struct displaced_step_inferior_state *displaced;
1571
1572 displaced = get_displaced_stepping_state (pid);
1573 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1574 return 1;
1575
1576 return 0;
1577 }
1578
1579 /* Add a new displaced stepping state for process PID to the displaced
1580 stepping state list, or return a pointer to an already existing
1581 entry, if it already exists. Never returns NULL. */
1582
1583 static struct displaced_step_inferior_state *
1584 add_displaced_stepping_state (int pid)
1585 {
1586 struct displaced_step_inferior_state *state;
1587
1588 for (state = displaced_step_inferior_states;
1589 state != NULL;
1590 state = state->next)
1591 if (state->pid == pid)
1592 return state;
1593
1594 state = XCNEW (struct displaced_step_inferior_state);
1595 state->pid = pid;
1596 state->next = displaced_step_inferior_states;
1597 displaced_step_inferior_states = state;
1598
1599 return state;
1600 }
1601
1602 /* If inferior is in displaced stepping, and ADDR equals to starting address
1603 of copy area, return corresponding displaced_step_closure. Otherwise,
1604 return NULL. */
1605
1606 struct displaced_step_closure*
1607 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1608 {
1609 struct displaced_step_inferior_state *displaced
1610 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1611
1612 /* If checking the mode of displaced instruction in copy area. */
1613 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1614 && (displaced->step_copy == addr))
1615 return displaced->step_closure;
1616
1617 return NULL;
1618 }
1619
1620 /* Remove the displaced stepping state of process PID. */
1621
1622 static void
1623 remove_displaced_stepping_state (int pid)
1624 {
1625 struct displaced_step_inferior_state *it, **prev_next_p;
1626
1627 gdb_assert (pid != 0);
1628
1629 it = displaced_step_inferior_states;
1630 prev_next_p = &displaced_step_inferior_states;
1631 while (it)
1632 {
1633 if (it->pid == pid)
1634 {
1635 *prev_next_p = it->next;
1636 xfree (it);
1637 return;
1638 }
1639
1640 prev_next_p = &it->next;
1641 it = *prev_next_p;
1642 }
1643 }
1644
1645 static void
1646 infrun_inferior_exit (struct inferior *inf)
1647 {
1648 remove_displaced_stepping_state (inf->pid);
1649 }
1650
1651 /* If ON, and the architecture supports it, GDB will use displaced
1652 stepping to step over breakpoints. If OFF, or if the architecture
1653 doesn't support it, GDB will instead use the traditional
1654 hold-and-step approach. If AUTO (which is the default), GDB will
1655 decide which technique to use to step over breakpoints depending on
1656 which of all-stop or non-stop mode is active --- displaced stepping
1657 in non-stop mode; hold-and-step in all-stop mode. */
1658
1659 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1660
1661 static void
1662 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1663 struct cmd_list_element *c,
1664 const char *value)
1665 {
1666 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1667 fprintf_filtered (file,
1668 _("Debugger's willingness to use displaced stepping "
1669 "to step over breakpoints is %s (currently %s).\n"),
1670 value, target_is_non_stop_p () ? "on" : "off");
1671 else
1672 fprintf_filtered (file,
1673 _("Debugger's willingness to use displaced stepping "
1674 "to step over breakpoints is %s.\n"), value);
1675 }
1676
1677 /* Return non-zero if displaced stepping can/should be used to step
1678 over breakpoints of thread TP. */
1679
1680 static int
1681 use_displaced_stepping (struct thread_info *tp)
1682 {
1683 struct regcache *regcache = get_thread_regcache (tp->ptid);
1684 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1685 struct displaced_step_inferior_state *displaced_state;
1686
1687 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1688
1689 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1690 && target_is_non_stop_p ())
1691 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1692 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1693 && find_record_target () == NULL
1694 && (displaced_state == NULL
1695 || !displaced_state->failed_before));
1696 }
1697
1698 /* Clean out any stray displaced stepping state. */
1699 static void
1700 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1701 {
1702 /* Indicate that there is no cleanup pending. */
1703 displaced->step_ptid = null_ptid;
1704
1705 if (displaced->step_closure)
1706 {
1707 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1708 displaced->step_closure);
1709 displaced->step_closure = NULL;
1710 }
1711 }
1712
1713 static void
1714 displaced_step_clear_cleanup (void *arg)
1715 {
1716 struct displaced_step_inferior_state *state
1717 = (struct displaced_step_inferior_state *) arg;
1718
1719 displaced_step_clear (state);
1720 }
1721
1722 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1723 void
1724 displaced_step_dump_bytes (struct ui_file *file,
1725 const gdb_byte *buf,
1726 size_t len)
1727 {
1728 int i;
1729
1730 for (i = 0; i < len; i++)
1731 fprintf_unfiltered (file, "%02x ", buf[i]);
1732 fputs_unfiltered ("\n", file);
1733 }
1734
1735 /* Prepare to single-step, using displaced stepping.
1736
1737 Note that we cannot use displaced stepping when we have a signal to
1738 deliver. If we have a signal to deliver and an instruction to step
1739 over, then after the step, there will be no indication from the
1740 target whether the thread entered a signal handler or ignored the
1741 signal and stepped over the instruction successfully --- both cases
1742 result in a simple SIGTRAP. In the first case we mustn't do a
1743 fixup, and in the second case we must --- but we can't tell which.
1744 Comments in the code for 'random signals' in handle_inferior_event
1745 explain how we handle this case instead.
1746
1747 Returns 1 if preparing was successful -- this thread is going to be
1748 stepped now; 0 if displaced stepping this thread got queued; or -1
1749 if this instruction can't be displaced stepped. */
1750
1751 static int
1752 displaced_step_prepare_throw (ptid_t ptid)
1753 {
1754 struct cleanup *old_cleanups, *ignore_cleanups;
1755 struct thread_info *tp = find_thread_ptid (ptid);
1756 struct regcache *regcache = get_thread_regcache (ptid);
1757 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1758 struct address_space *aspace = get_regcache_aspace (regcache);
1759 CORE_ADDR original, copy;
1760 ULONGEST len;
1761 struct displaced_step_closure *closure;
1762 struct displaced_step_inferior_state *displaced;
1763 int status;
1764
1765 /* We should never reach this function if the architecture does not
1766 support displaced stepping. */
1767 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1768
1769 /* Nor if the thread isn't meant to step over a breakpoint. */
1770 gdb_assert (tp->control.trap_expected);
1771
1772 /* Disable range stepping while executing in the scratch pad. We
1773 want a single-step even if executing the displaced instruction in
1774 the scratch buffer lands within the stepping range (e.g., a
1775 jump/branch). */
1776 tp->control.may_range_step = 0;
1777
1778 /* We have to displaced step one thread at a time, as we only have
1779 access to a single scratch space per inferior. */
1780
1781 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1782
1783 if (!ptid_equal (displaced->step_ptid, null_ptid))
1784 {
1785 /* Already waiting for a displaced step to finish. Defer this
1786 request and place in queue. */
1787
1788 if (debug_displaced)
1789 fprintf_unfiltered (gdb_stdlog,
1790 "displaced: deferring step of %s\n",
1791 target_pid_to_str (ptid));
1792
1793 thread_step_over_chain_enqueue (tp);
1794 return 0;
1795 }
1796 else
1797 {
1798 if (debug_displaced)
1799 fprintf_unfiltered (gdb_stdlog,
1800 "displaced: stepping %s now\n",
1801 target_pid_to_str (ptid));
1802 }
1803
1804 displaced_step_clear (displaced);
1805
1806 old_cleanups = save_inferior_ptid ();
1807 inferior_ptid = ptid;
1808
1809 original = regcache_read_pc (regcache);
1810
1811 copy = gdbarch_displaced_step_location (gdbarch);
1812 len = gdbarch_max_insn_length (gdbarch);
1813
1814 if (breakpoint_in_range_p (aspace, copy, len))
1815 {
1816 /* There's a breakpoint set in the scratch pad location range
1817 (which is usually around the entry point). We'd either
1818 install it before resuming, which would overwrite/corrupt the
1819 scratch pad, or if it was already inserted, this displaced
1820 step would overwrite it. The latter is OK in the sense that
1821 we already assume that no thread is going to execute the code
1822 in the scratch pad range (after initial startup) anyway, but
1823 the former is unacceptable. Simply punt and fallback to
1824 stepping over this breakpoint in-line. */
1825 if (debug_displaced)
1826 {
1827 fprintf_unfiltered (gdb_stdlog,
1828 "displaced: breakpoint set in scratch pad. "
1829 "Stepping over breakpoint in-line instead.\n");
1830 }
1831
1832 do_cleanups (old_cleanups);
1833 return -1;
1834 }
1835
1836 /* Save the original contents of the copy area. */
1837 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1838 ignore_cleanups = make_cleanup (free_current_contents,
1839 &displaced->step_saved_copy);
1840 status = target_read_memory (copy, displaced->step_saved_copy, len);
1841 if (status != 0)
1842 throw_error (MEMORY_ERROR,
1843 _("Error accessing memory address %s (%s) for "
1844 "displaced-stepping scratch space."),
1845 paddress (gdbarch, copy), safe_strerror (status));
1846 if (debug_displaced)
1847 {
1848 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1849 paddress (gdbarch, copy));
1850 displaced_step_dump_bytes (gdb_stdlog,
1851 displaced->step_saved_copy,
1852 len);
1853 };
1854
1855 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1856 original, copy, regcache);
1857 if (closure == NULL)
1858 {
1859 /* The architecture doesn't know how or want to displaced step
1860 this instruction or instruction sequence. Fallback to
1861 stepping over the breakpoint in-line. */
1862 do_cleanups (old_cleanups);
1863 return -1;
1864 }
1865
1866 /* Save the information we need to fix things up if the step
1867 succeeds. */
1868 displaced->step_ptid = ptid;
1869 displaced->step_gdbarch = gdbarch;
1870 displaced->step_closure = closure;
1871 displaced->step_original = original;
1872 displaced->step_copy = copy;
1873
1874 make_cleanup (displaced_step_clear_cleanup, displaced);
1875
1876 /* Resume execution at the copy. */
1877 regcache_write_pc (regcache, copy);
1878
1879 discard_cleanups (ignore_cleanups);
1880
1881 do_cleanups (old_cleanups);
1882
1883 if (debug_displaced)
1884 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1885 paddress (gdbarch, copy));
1886
1887 return 1;
1888 }
1889
1890 /* Wrapper for displaced_step_prepare_throw that disabled further
1891 attempts at displaced stepping if we get a memory error. */
1892
1893 static int
1894 displaced_step_prepare (ptid_t ptid)
1895 {
1896 int prepared = -1;
1897
1898 TRY
1899 {
1900 prepared = displaced_step_prepare_throw (ptid);
1901 }
1902 CATCH (ex, RETURN_MASK_ERROR)
1903 {
1904 struct displaced_step_inferior_state *displaced_state;
1905
1906 if (ex.error != MEMORY_ERROR
1907 && ex.error != NOT_SUPPORTED_ERROR)
1908 throw_exception (ex);
1909
1910 if (debug_infrun)
1911 {
1912 fprintf_unfiltered (gdb_stdlog,
1913 "infrun: disabling displaced stepping: %s\n",
1914 ex.message);
1915 }
1916
1917 /* Be verbose if "set displaced-stepping" is "on", silent if
1918 "auto". */
1919 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1920 {
1921 warning (_("disabling displaced stepping: %s"),
1922 ex.message);
1923 }
1924
1925 /* Disable further displaced stepping attempts. */
1926 displaced_state
1927 = get_displaced_stepping_state (ptid_get_pid (ptid));
1928 displaced_state->failed_before = 1;
1929 }
1930 END_CATCH
1931
1932 return prepared;
1933 }
1934
1935 static void
1936 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1937 const gdb_byte *myaddr, int len)
1938 {
1939 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1940
1941 inferior_ptid = ptid;
1942 write_memory (memaddr, myaddr, len);
1943 do_cleanups (ptid_cleanup);
1944 }
1945
1946 /* Restore the contents of the copy area for thread PTID. */
1947
1948 static void
1949 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1950 ptid_t ptid)
1951 {
1952 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1953
1954 write_memory_ptid (ptid, displaced->step_copy,
1955 displaced->step_saved_copy, len);
1956 if (debug_displaced)
1957 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1958 target_pid_to_str (ptid),
1959 paddress (displaced->step_gdbarch,
1960 displaced->step_copy));
1961 }
1962
1963 /* If we displaced stepped an instruction successfully, adjust
1964 registers and memory to yield the same effect the instruction would
1965 have had if we had executed it at its original address, and return
1966 1. If the instruction didn't complete, relocate the PC and return
1967 -1. If the thread wasn't displaced stepping, return 0. */
1968
1969 static int
1970 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1971 {
1972 struct cleanup *old_cleanups;
1973 struct displaced_step_inferior_state *displaced
1974 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1975 int ret;
1976
1977 /* Was any thread of this process doing a displaced step? */
1978 if (displaced == NULL)
1979 return 0;
1980
1981 /* Was this event for the pid we displaced? */
1982 if (ptid_equal (displaced->step_ptid, null_ptid)
1983 || ! ptid_equal (displaced->step_ptid, event_ptid))
1984 return 0;
1985
1986 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1987
1988 displaced_step_restore (displaced, displaced->step_ptid);
1989
1990 /* Fixup may need to read memory/registers. Switch to the thread
1991 that we're fixing up. Also, target_stopped_by_watchpoint checks
1992 the current thread. */
1993 switch_to_thread (event_ptid);
1994
1995 /* Did the instruction complete successfully? */
1996 if (signal == GDB_SIGNAL_TRAP
1997 && !(target_stopped_by_watchpoint ()
1998 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1999 || target_have_steppable_watchpoint)))
2000 {
2001 /* Fix up the resulting state. */
2002 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
2003 displaced->step_closure,
2004 displaced->step_original,
2005 displaced->step_copy,
2006 get_thread_regcache (displaced->step_ptid));
2007 ret = 1;
2008 }
2009 else
2010 {
2011 /* Since the instruction didn't complete, all we can do is
2012 relocate the PC. */
2013 struct regcache *regcache = get_thread_regcache (event_ptid);
2014 CORE_ADDR pc = regcache_read_pc (regcache);
2015
2016 pc = displaced->step_original + (pc - displaced->step_copy);
2017 regcache_write_pc (regcache, pc);
2018 ret = -1;
2019 }
2020
2021 do_cleanups (old_cleanups);
2022
2023 displaced->step_ptid = null_ptid;
2024
2025 return ret;
2026 }
2027
2028 /* Data to be passed around while handling an event. This data is
2029 discarded between events. */
2030 struct execution_control_state
2031 {
2032 ptid_t ptid;
2033 /* The thread that got the event, if this was a thread event; NULL
2034 otherwise. */
2035 struct thread_info *event_thread;
2036
2037 struct target_waitstatus ws;
2038 int stop_func_filled_in;
2039 CORE_ADDR stop_func_start;
2040 CORE_ADDR stop_func_end;
2041 const char *stop_func_name;
2042 int wait_some_more;
2043
2044 /* True if the event thread hit the single-step breakpoint of
2045 another thread. Thus the event doesn't cause a stop, the thread
2046 needs to be single-stepped past the single-step breakpoint before
2047 we can switch back to the original stepping thread. */
2048 int hit_singlestep_breakpoint;
2049 };
2050
2051 /* Clear ECS and set it to point at TP. */
2052
2053 static void
2054 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2055 {
2056 memset (ecs, 0, sizeof (*ecs));
2057 ecs->event_thread = tp;
2058 ecs->ptid = tp->ptid;
2059 }
2060
2061 static void keep_going_pass_signal (struct execution_control_state *ecs);
2062 static void prepare_to_wait (struct execution_control_state *ecs);
2063 static int keep_going_stepped_thread (struct thread_info *tp);
2064 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2065
2066 /* Are there any pending step-over requests? If so, run all we can
2067 now and return true. Otherwise, return false. */
2068
2069 static int
2070 start_step_over (void)
2071 {
2072 struct thread_info *tp, *next;
2073
2074 /* Don't start a new step-over if we already have an in-line
2075 step-over operation ongoing. */
2076 if (step_over_info_valid_p ())
2077 return 0;
2078
2079 for (tp = step_over_queue_head; tp != NULL; tp = next)
2080 {
2081 struct execution_control_state ecss;
2082 struct execution_control_state *ecs = &ecss;
2083 step_over_what step_what;
2084 int must_be_in_line;
2085
2086 next = thread_step_over_chain_next (tp);
2087
2088 /* If this inferior already has a displaced step in process,
2089 don't start a new one. */
2090 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2091 continue;
2092
2093 step_what = thread_still_needs_step_over (tp);
2094 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2095 || ((step_what & STEP_OVER_BREAKPOINT)
2096 && !use_displaced_stepping (tp)));
2097
2098 /* We currently stop all threads of all processes to step-over
2099 in-line. If we need to start a new in-line step-over, let
2100 any pending displaced steps finish first. */
2101 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2102 return 0;
2103
2104 thread_step_over_chain_remove (tp);
2105
2106 if (step_over_queue_head == NULL)
2107 {
2108 if (debug_infrun)
2109 fprintf_unfiltered (gdb_stdlog,
2110 "infrun: step-over queue now empty\n");
2111 }
2112
2113 if (tp->control.trap_expected
2114 || tp->resumed
2115 || tp->executing)
2116 {
2117 internal_error (__FILE__, __LINE__,
2118 "[%s] has inconsistent state: "
2119 "trap_expected=%d, resumed=%d, executing=%d\n",
2120 target_pid_to_str (tp->ptid),
2121 tp->control.trap_expected,
2122 tp->resumed,
2123 tp->executing);
2124 }
2125
2126 if (debug_infrun)
2127 fprintf_unfiltered (gdb_stdlog,
2128 "infrun: resuming [%s] for step-over\n",
2129 target_pid_to_str (tp->ptid));
2130
2131 /* keep_going_pass_signal skips the step-over if the breakpoint
2132 is no longer inserted. In all-stop, we want to keep looking
2133 for a thread that needs a step-over instead of resuming TP,
2134 because we wouldn't be able to resume anything else until the
2135 target stops again. In non-stop, the resume always resumes
2136 only TP, so it's OK to let the thread resume freely. */
2137 if (!target_is_non_stop_p () && !step_what)
2138 continue;
2139
2140 switch_to_thread (tp->ptid);
2141 reset_ecs (ecs, tp);
2142 keep_going_pass_signal (ecs);
2143
2144 if (!ecs->wait_some_more)
2145 error (_("Command aborted."));
2146
2147 gdb_assert (tp->resumed);
2148
2149 /* If we started a new in-line step-over, we're done. */
2150 if (step_over_info_valid_p ())
2151 {
2152 gdb_assert (tp->control.trap_expected);
2153 return 1;
2154 }
2155
2156 if (!target_is_non_stop_p ())
2157 {
2158 /* On all-stop, shouldn't have resumed unless we needed a
2159 step over. */
2160 gdb_assert (tp->control.trap_expected
2161 || tp->step_after_step_resume_breakpoint);
2162
2163 /* With remote targets (at least), in all-stop, we can't
2164 issue any further remote commands until the program stops
2165 again. */
2166 return 1;
2167 }
2168
2169 /* Either the thread no longer needed a step-over, or a new
2170 displaced stepping sequence started. Even in the latter
2171 case, continue looking. Maybe we can also start another
2172 displaced step on a thread of other process. */
2173 }
2174
2175 return 0;
2176 }
2177
2178 /* Update global variables holding ptids to hold NEW_PTID if they were
2179 holding OLD_PTID. */
2180 static void
2181 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2182 {
2183 struct displaced_step_inferior_state *displaced;
2184
2185 if (ptid_equal (inferior_ptid, old_ptid))
2186 inferior_ptid = new_ptid;
2187
2188 for (displaced = displaced_step_inferior_states;
2189 displaced;
2190 displaced = displaced->next)
2191 {
2192 if (ptid_equal (displaced->step_ptid, old_ptid))
2193 displaced->step_ptid = new_ptid;
2194 }
2195 }
2196
2197 \f
2198 /* Resuming. */
2199
2200 /* Things to clean up if we QUIT out of resume (). */
2201 static void
2202 resume_cleanups (void *ignore)
2203 {
2204 if (!ptid_equal (inferior_ptid, null_ptid))
2205 delete_single_step_breakpoints (inferior_thread ());
2206
2207 normal_stop ();
2208 }
2209
2210 static const char schedlock_off[] = "off";
2211 static const char schedlock_on[] = "on";
2212 static const char schedlock_step[] = "step";
2213 static const char schedlock_replay[] = "replay";
2214 static const char *const scheduler_enums[] = {
2215 schedlock_off,
2216 schedlock_on,
2217 schedlock_step,
2218 schedlock_replay,
2219 NULL
2220 };
2221 static const char *scheduler_mode = schedlock_replay;
2222 static void
2223 show_scheduler_mode (struct ui_file *file, int from_tty,
2224 struct cmd_list_element *c, const char *value)
2225 {
2226 fprintf_filtered (file,
2227 _("Mode for locking scheduler "
2228 "during execution is \"%s\".\n"),
2229 value);
2230 }
2231
2232 static void
2233 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2234 {
2235 if (!target_can_lock_scheduler)
2236 {
2237 scheduler_mode = schedlock_off;
2238 error (_("Target '%s' cannot support this command."), target_shortname);
2239 }
2240 }
2241
2242 /* True if execution commands resume all threads of all processes by
2243 default; otherwise, resume only threads of the current inferior
2244 process. */
2245 int sched_multi = 0;
2246
2247 /* Try to setup for software single stepping over the specified location.
2248 Return 1 if target_resume() should use hardware single step.
2249
2250 GDBARCH the current gdbarch.
2251 PC the location to step over. */
2252
2253 static int
2254 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2255 {
2256 int hw_step = 1;
2257
2258 if (execution_direction == EXEC_FORWARD
2259 && gdbarch_software_single_step_p (gdbarch))
2260 hw_step = !insert_single_step_breakpoints (gdbarch);
2261
2262 return hw_step;
2263 }
2264
2265 /* See infrun.h. */
2266
2267 ptid_t
2268 user_visible_resume_ptid (int step)
2269 {
2270 ptid_t resume_ptid;
2271
2272 if (non_stop)
2273 {
2274 /* With non-stop mode on, threads are always handled
2275 individually. */
2276 resume_ptid = inferior_ptid;
2277 }
2278 else if ((scheduler_mode == schedlock_on)
2279 || (scheduler_mode == schedlock_step && step))
2280 {
2281 /* User-settable 'scheduler' mode requires solo thread
2282 resume. */
2283 resume_ptid = inferior_ptid;
2284 }
2285 else if ((scheduler_mode == schedlock_replay)
2286 && target_record_will_replay (minus_one_ptid, execution_direction))
2287 {
2288 /* User-settable 'scheduler' mode requires solo thread resume in replay
2289 mode. */
2290 resume_ptid = inferior_ptid;
2291 }
2292 else if (!sched_multi && target_supports_multi_process ())
2293 {
2294 /* Resume all threads of the current process (and none of other
2295 processes). */
2296 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2297 }
2298 else
2299 {
2300 /* Resume all threads of all processes. */
2301 resume_ptid = RESUME_ALL;
2302 }
2303
2304 return resume_ptid;
2305 }
2306
2307 /* Return a ptid representing the set of threads that we will resume,
2308 in the perspective of the target, assuming run control handling
2309 does not require leaving some threads stopped (e.g., stepping past
2310 breakpoint). USER_STEP indicates whether we're about to start the
2311 target for a stepping command. */
2312
2313 static ptid_t
2314 internal_resume_ptid (int user_step)
2315 {
2316 /* In non-stop, we always control threads individually. Note that
2317 the target may always work in non-stop mode even with "set
2318 non-stop off", in which case user_visible_resume_ptid could
2319 return a wildcard ptid. */
2320 if (target_is_non_stop_p ())
2321 return inferior_ptid;
2322 else
2323 return user_visible_resume_ptid (user_step);
2324 }
2325
2326 /* Wrapper for target_resume, that handles infrun-specific
2327 bookkeeping. */
2328
2329 static void
2330 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2331 {
2332 struct thread_info *tp = inferior_thread ();
2333
2334 /* Install inferior's terminal modes. */
2335 target_terminal_inferior ();
2336
2337 /* Avoid confusing the next resume, if the next stop/resume
2338 happens to apply to another thread. */
2339 tp->suspend.stop_signal = GDB_SIGNAL_0;
2340
2341 /* Advise target which signals may be handled silently.
2342
2343 If we have removed breakpoints because we are stepping over one
2344 in-line (in any thread), we need to receive all signals to avoid
2345 accidentally skipping a breakpoint during execution of a signal
2346 handler.
2347
2348 Likewise if we're displaced stepping, otherwise a trap for a
2349 breakpoint in a signal handler might be confused with the
2350 displaced step finishing. We don't make the displaced_step_fixup
2351 step distinguish the cases instead, because:
2352
2353 - a backtrace while stopped in the signal handler would show the
2354 scratch pad as frame older than the signal handler, instead of
2355 the real mainline code.
2356
2357 - when the thread is later resumed, the signal handler would
2358 return to the scratch pad area, which would no longer be
2359 valid. */
2360 if (step_over_info_valid_p ()
2361 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2362 target_pass_signals (0, NULL);
2363 else
2364 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2365
2366 target_resume (resume_ptid, step, sig);
2367
2368 target_commit_resume ();
2369 }
2370
2371 /* Resume the inferior, but allow a QUIT. This is useful if the user
2372 wants to interrupt some lengthy single-stepping operation
2373 (for child processes, the SIGINT goes to the inferior, and so
2374 we get a SIGINT random_signal, but for remote debugging and perhaps
2375 other targets, that's not true).
2376
2377 SIG is the signal to give the inferior (zero for none). */
2378 void
2379 resume (enum gdb_signal sig)
2380 {
2381 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2382 struct regcache *regcache = get_current_regcache ();
2383 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2384 struct thread_info *tp = inferior_thread ();
2385 CORE_ADDR pc = regcache_read_pc (regcache);
2386 struct address_space *aspace = get_regcache_aspace (regcache);
2387 ptid_t resume_ptid;
2388 /* This represents the user's step vs continue request. When
2389 deciding whether "set scheduler-locking step" applies, it's the
2390 user's intention that counts. */
2391 const int user_step = tp->control.stepping_command;
2392 /* This represents what we'll actually request the target to do.
2393 This can decay from a step to a continue, if e.g., we need to
2394 implement single-stepping with breakpoints (software
2395 single-step). */
2396 int step;
2397
2398 gdb_assert (!thread_is_in_step_over_chain (tp));
2399
2400 QUIT;
2401
2402 if (tp->suspend.waitstatus_pending_p)
2403 {
2404 if (debug_infrun)
2405 {
2406 char *statstr;
2407
2408 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2409 fprintf_unfiltered (gdb_stdlog,
2410 "infrun: resume: thread %s has pending wait status %s "
2411 "(currently_stepping=%d).\n",
2412 target_pid_to_str (tp->ptid), statstr,
2413 currently_stepping (tp));
2414 xfree (statstr);
2415 }
2416
2417 tp->resumed = 1;
2418
2419 /* FIXME: What should we do if we are supposed to resume this
2420 thread with a signal? Maybe we should maintain a queue of
2421 pending signals to deliver. */
2422 if (sig != GDB_SIGNAL_0)
2423 {
2424 warning (_("Couldn't deliver signal %s to %s."),
2425 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2426 }
2427
2428 tp->suspend.stop_signal = GDB_SIGNAL_0;
2429 discard_cleanups (old_cleanups);
2430
2431 if (target_can_async_p ())
2432 target_async (1);
2433 return;
2434 }
2435
2436 tp->stepped_breakpoint = 0;
2437
2438 /* Depends on stepped_breakpoint. */
2439 step = currently_stepping (tp);
2440
2441 if (current_inferior ()->waiting_for_vfork_done)
2442 {
2443 /* Don't try to single-step a vfork parent that is waiting for
2444 the child to get out of the shared memory region (by exec'ing
2445 or exiting). This is particularly important on software
2446 single-step archs, as the child process would trip on the
2447 software single step breakpoint inserted for the parent
2448 process. Since the parent will not actually execute any
2449 instruction until the child is out of the shared region (such
2450 are vfork's semantics), it is safe to simply continue it.
2451 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2452 the parent, and tell it to `keep_going', which automatically
2453 re-sets it stepping. */
2454 if (debug_infrun)
2455 fprintf_unfiltered (gdb_stdlog,
2456 "infrun: resume : clear step\n");
2457 step = 0;
2458 }
2459
2460 if (debug_infrun)
2461 fprintf_unfiltered (gdb_stdlog,
2462 "infrun: resume (step=%d, signal=%s), "
2463 "trap_expected=%d, current thread [%s] at %s\n",
2464 step, gdb_signal_to_symbol_string (sig),
2465 tp->control.trap_expected,
2466 target_pid_to_str (inferior_ptid),
2467 paddress (gdbarch, pc));
2468
2469 /* Normally, by the time we reach `resume', the breakpoints are either
2470 removed or inserted, as appropriate. The exception is if we're sitting
2471 at a permanent breakpoint; we need to step over it, but permanent
2472 breakpoints can't be removed. So we have to test for it here. */
2473 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2474 {
2475 if (sig != GDB_SIGNAL_0)
2476 {
2477 /* We have a signal to pass to the inferior. The resume
2478 may, or may not take us to the signal handler. If this
2479 is a step, we'll need to stop in the signal handler, if
2480 there's one, (if the target supports stepping into
2481 handlers), or in the next mainline instruction, if
2482 there's no handler. If this is a continue, we need to be
2483 sure to run the handler with all breakpoints inserted.
2484 In all cases, set a breakpoint at the current address
2485 (where the handler returns to), and once that breakpoint
2486 is hit, resume skipping the permanent breakpoint. If
2487 that breakpoint isn't hit, then we've stepped into the
2488 signal handler (or hit some other event). We'll delete
2489 the step-resume breakpoint then. */
2490
2491 if (debug_infrun)
2492 fprintf_unfiltered (gdb_stdlog,
2493 "infrun: resume: skipping permanent breakpoint, "
2494 "deliver signal first\n");
2495
2496 clear_step_over_info ();
2497 tp->control.trap_expected = 0;
2498
2499 if (tp->control.step_resume_breakpoint == NULL)
2500 {
2501 /* Set a "high-priority" step-resume, as we don't want
2502 user breakpoints at PC to trigger (again) when this
2503 hits. */
2504 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2505 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2506
2507 tp->step_after_step_resume_breakpoint = step;
2508 }
2509
2510 insert_breakpoints ();
2511 }
2512 else
2513 {
2514 /* There's no signal to pass, we can go ahead and skip the
2515 permanent breakpoint manually. */
2516 if (debug_infrun)
2517 fprintf_unfiltered (gdb_stdlog,
2518 "infrun: resume: skipping permanent breakpoint\n");
2519 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2520 /* Update pc to reflect the new address from which we will
2521 execute instructions. */
2522 pc = regcache_read_pc (regcache);
2523
2524 if (step)
2525 {
2526 /* We've already advanced the PC, so the stepping part
2527 is done. Now we need to arrange for a trap to be
2528 reported to handle_inferior_event. Set a breakpoint
2529 at the current PC, and run to it. Don't update
2530 prev_pc, because if we end in
2531 switch_back_to_stepped_thread, we want the "expected
2532 thread advanced also" branch to be taken. IOW, we
2533 don't want this thread to step further from PC
2534 (overstep). */
2535 gdb_assert (!step_over_info_valid_p ());
2536 insert_single_step_breakpoint (gdbarch, aspace, pc);
2537 insert_breakpoints ();
2538
2539 resume_ptid = internal_resume_ptid (user_step);
2540 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2541 discard_cleanups (old_cleanups);
2542 tp->resumed = 1;
2543 return;
2544 }
2545 }
2546 }
2547
2548 /* If we have a breakpoint to step over, make sure to do a single
2549 step only. Same if we have software watchpoints. */
2550 if (tp->control.trap_expected || bpstat_should_step ())
2551 tp->control.may_range_step = 0;
2552
2553 /* If enabled, step over breakpoints by executing a copy of the
2554 instruction at a different address.
2555
2556 We can't use displaced stepping when we have a signal to deliver;
2557 the comments for displaced_step_prepare explain why. The
2558 comments in the handle_inferior event for dealing with 'random
2559 signals' explain what we do instead.
2560
2561 We can't use displaced stepping when we are waiting for vfork_done
2562 event, displaced stepping breaks the vfork child similarly as single
2563 step software breakpoint. */
2564 if (tp->control.trap_expected
2565 && use_displaced_stepping (tp)
2566 && !step_over_info_valid_p ()
2567 && sig == GDB_SIGNAL_0
2568 && !current_inferior ()->waiting_for_vfork_done)
2569 {
2570 int prepared = displaced_step_prepare (inferior_ptid);
2571
2572 if (prepared == 0)
2573 {
2574 if (debug_infrun)
2575 fprintf_unfiltered (gdb_stdlog,
2576 "Got placed in step-over queue\n");
2577
2578 tp->control.trap_expected = 0;
2579 discard_cleanups (old_cleanups);
2580 return;
2581 }
2582 else if (prepared < 0)
2583 {
2584 /* Fallback to stepping over the breakpoint in-line. */
2585
2586 if (target_is_non_stop_p ())
2587 stop_all_threads ();
2588
2589 set_step_over_info (get_regcache_aspace (regcache),
2590 regcache_read_pc (regcache), 0, tp->global_num);
2591
2592 step = maybe_software_singlestep (gdbarch, pc);
2593
2594 insert_breakpoints ();
2595 }
2596 else if (prepared > 0)
2597 {
2598 struct displaced_step_inferior_state *displaced;
2599
2600 /* Update pc to reflect the new address from which we will
2601 execute instructions due to displaced stepping. */
2602 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2603
2604 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2605 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2606 displaced->step_closure);
2607 }
2608 }
2609
2610 /* Do we need to do it the hard way, w/temp breakpoints? */
2611 else if (step)
2612 step = maybe_software_singlestep (gdbarch, pc);
2613
2614 /* Currently, our software single-step implementation leads to different
2615 results than hardware single-stepping in one situation: when stepping
2616 into delivering a signal which has an associated signal handler,
2617 hardware single-step will stop at the first instruction of the handler,
2618 while software single-step will simply skip execution of the handler.
2619
2620 For now, this difference in behavior is accepted since there is no
2621 easy way to actually implement single-stepping into a signal handler
2622 without kernel support.
2623
2624 However, there is one scenario where this difference leads to follow-on
2625 problems: if we're stepping off a breakpoint by removing all breakpoints
2626 and then single-stepping. In this case, the software single-step
2627 behavior means that even if there is a *breakpoint* in the signal
2628 handler, GDB still would not stop.
2629
2630 Fortunately, we can at least fix this particular issue. We detect
2631 here the case where we are about to deliver a signal while software
2632 single-stepping with breakpoints removed. In this situation, we
2633 revert the decisions to remove all breakpoints and insert single-
2634 step breakpoints, and instead we install a step-resume breakpoint
2635 at the current address, deliver the signal without stepping, and
2636 once we arrive back at the step-resume breakpoint, actually step
2637 over the breakpoint we originally wanted to step over. */
2638 if (thread_has_single_step_breakpoints_set (tp)
2639 && sig != GDB_SIGNAL_0
2640 && step_over_info_valid_p ())
2641 {
2642 /* If we have nested signals or a pending signal is delivered
2643 immediately after a handler returns, might might already have
2644 a step-resume breakpoint set on the earlier handler. We cannot
2645 set another step-resume breakpoint; just continue on until the
2646 original breakpoint is hit. */
2647 if (tp->control.step_resume_breakpoint == NULL)
2648 {
2649 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2650 tp->step_after_step_resume_breakpoint = 1;
2651 }
2652
2653 delete_single_step_breakpoints (tp);
2654
2655 clear_step_over_info ();
2656 tp->control.trap_expected = 0;
2657
2658 insert_breakpoints ();
2659 }
2660
2661 /* If STEP is set, it's a request to use hardware stepping
2662 facilities. But in that case, we should never
2663 use singlestep breakpoint. */
2664 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2665
2666 /* Decide the set of threads to ask the target to resume. */
2667 if (tp->control.trap_expected)
2668 {
2669 /* We're allowing a thread to run past a breakpoint it has
2670 hit, either by single-stepping the thread with the breakpoint
2671 removed, or by displaced stepping, with the breakpoint inserted.
2672 In the former case, we need to single-step only this thread,
2673 and keep others stopped, as they can miss this breakpoint if
2674 allowed to run. That's not really a problem for displaced
2675 stepping, but, we still keep other threads stopped, in case
2676 another thread is also stopped for a breakpoint waiting for
2677 its turn in the displaced stepping queue. */
2678 resume_ptid = inferior_ptid;
2679 }
2680 else
2681 resume_ptid = internal_resume_ptid (user_step);
2682
2683 if (execution_direction != EXEC_REVERSE
2684 && step && breakpoint_inserted_here_p (aspace, pc))
2685 {
2686 /* There are two cases where we currently need to step a
2687 breakpoint instruction when we have a signal to deliver:
2688
2689 - See handle_signal_stop where we handle random signals that
2690 could take out us out of the stepping range. Normally, in
2691 that case we end up continuing (instead of stepping) over the
2692 signal handler with a breakpoint at PC, but there are cases
2693 where we should _always_ single-step, even if we have a
2694 step-resume breakpoint, like when a software watchpoint is
2695 set. Assuming single-stepping and delivering a signal at the
2696 same time would takes us to the signal handler, then we could
2697 have removed the breakpoint at PC to step over it. However,
2698 some hardware step targets (like e.g., Mac OS) can't step
2699 into signal handlers, and for those, we need to leave the
2700 breakpoint at PC inserted, as otherwise if the handler
2701 recurses and executes PC again, it'll miss the breakpoint.
2702 So we leave the breakpoint inserted anyway, but we need to
2703 record that we tried to step a breakpoint instruction, so
2704 that adjust_pc_after_break doesn't end up confused.
2705
2706 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2707 in one thread after another thread that was stepping had been
2708 momentarily paused for a step-over. When we re-resume the
2709 stepping thread, it may be resumed from that address with a
2710 breakpoint that hasn't trapped yet. Seen with
2711 gdb.threads/non-stop-fair-events.exp, on targets that don't
2712 do displaced stepping. */
2713
2714 if (debug_infrun)
2715 fprintf_unfiltered (gdb_stdlog,
2716 "infrun: resume: [%s] stepped breakpoint\n",
2717 target_pid_to_str (tp->ptid));
2718
2719 tp->stepped_breakpoint = 1;
2720
2721 /* Most targets can step a breakpoint instruction, thus
2722 executing it normally. But if this one cannot, just
2723 continue and we will hit it anyway. */
2724 if (gdbarch_cannot_step_breakpoint (gdbarch))
2725 step = 0;
2726 }
2727
2728 if (debug_displaced
2729 && tp->control.trap_expected
2730 && use_displaced_stepping (tp)
2731 && !step_over_info_valid_p ())
2732 {
2733 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2734 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2735 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2736 gdb_byte buf[4];
2737
2738 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2739 paddress (resume_gdbarch, actual_pc));
2740 read_memory (actual_pc, buf, sizeof (buf));
2741 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2742 }
2743
2744 if (tp->control.may_range_step)
2745 {
2746 /* If we're resuming a thread with the PC out of the step
2747 range, then we're doing some nested/finer run control
2748 operation, like stepping the thread out of the dynamic
2749 linker or the displaced stepping scratch pad. We
2750 shouldn't have allowed a range step then. */
2751 gdb_assert (pc_in_thread_step_range (pc, tp));
2752 }
2753
2754 do_target_resume (resume_ptid, step, sig);
2755 tp->resumed = 1;
2756 discard_cleanups (old_cleanups);
2757 }
2758 \f
2759 /* Proceeding. */
2760
2761 /* See infrun.h. */
2762
2763 /* Counter that tracks number of user visible stops. This can be used
2764 to tell whether a command has proceeded the inferior past the
2765 current location. This allows e.g., inferior function calls in
2766 breakpoint commands to not interrupt the command list. When the
2767 call finishes successfully, the inferior is standing at the same
2768 breakpoint as if nothing happened (and so we don't call
2769 normal_stop). */
2770 static ULONGEST current_stop_id;
2771
2772 /* See infrun.h. */
2773
2774 ULONGEST
2775 get_stop_id (void)
2776 {
2777 return current_stop_id;
2778 }
2779
2780 /* Called when we report a user visible stop. */
2781
2782 static void
2783 new_stop_id (void)
2784 {
2785 current_stop_id++;
2786 }
2787
2788 /* Clear out all variables saying what to do when inferior is continued.
2789 First do this, then set the ones you want, then call `proceed'. */
2790
2791 static void
2792 clear_proceed_status_thread (struct thread_info *tp)
2793 {
2794 if (debug_infrun)
2795 fprintf_unfiltered (gdb_stdlog,
2796 "infrun: clear_proceed_status_thread (%s)\n",
2797 target_pid_to_str (tp->ptid));
2798
2799 /* If we're starting a new sequence, then the previous finished
2800 single-step is no longer relevant. */
2801 if (tp->suspend.waitstatus_pending_p)
2802 {
2803 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2804 {
2805 if (debug_infrun)
2806 fprintf_unfiltered (gdb_stdlog,
2807 "infrun: clear_proceed_status: pending "
2808 "event of %s was a finished step. "
2809 "Discarding.\n",
2810 target_pid_to_str (tp->ptid));
2811
2812 tp->suspend.waitstatus_pending_p = 0;
2813 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2814 }
2815 else if (debug_infrun)
2816 {
2817 char *statstr;
2818
2819 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2820 fprintf_unfiltered (gdb_stdlog,
2821 "infrun: clear_proceed_status_thread: thread %s "
2822 "has pending wait status %s "
2823 "(currently_stepping=%d).\n",
2824 target_pid_to_str (tp->ptid), statstr,
2825 currently_stepping (tp));
2826 xfree (statstr);
2827 }
2828 }
2829
2830 /* If this signal should not be seen by program, give it zero.
2831 Used for debugging signals. */
2832 if (!signal_pass_state (tp->suspend.stop_signal))
2833 tp->suspend.stop_signal = GDB_SIGNAL_0;
2834
2835 thread_fsm_delete (tp->thread_fsm);
2836 tp->thread_fsm = NULL;
2837
2838 tp->control.trap_expected = 0;
2839 tp->control.step_range_start = 0;
2840 tp->control.step_range_end = 0;
2841 tp->control.may_range_step = 0;
2842 tp->control.step_frame_id = null_frame_id;
2843 tp->control.step_stack_frame_id = null_frame_id;
2844 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2845 tp->control.step_start_function = NULL;
2846 tp->stop_requested = 0;
2847
2848 tp->control.stop_step = 0;
2849
2850 tp->control.proceed_to_finish = 0;
2851
2852 tp->control.stepping_command = 0;
2853
2854 /* Discard any remaining commands or status from previous stop. */
2855 bpstat_clear (&tp->control.stop_bpstat);
2856 }
2857
2858 void
2859 clear_proceed_status (int step)
2860 {
2861 /* With scheduler-locking replay, stop replaying other threads if we're
2862 not replaying the user-visible resume ptid.
2863
2864 This is a convenience feature to not require the user to explicitly
2865 stop replaying the other threads. We're assuming that the user's
2866 intent is to resume tracing the recorded process. */
2867 if (!non_stop && scheduler_mode == schedlock_replay
2868 && target_record_is_replaying (minus_one_ptid)
2869 && !target_record_will_replay (user_visible_resume_ptid (step),
2870 execution_direction))
2871 target_record_stop_replaying ();
2872
2873 if (!non_stop)
2874 {
2875 struct thread_info *tp;
2876 ptid_t resume_ptid;
2877
2878 resume_ptid = user_visible_resume_ptid (step);
2879
2880 /* In all-stop mode, delete the per-thread status of all threads
2881 we're about to resume, implicitly and explicitly. */
2882 ALL_NON_EXITED_THREADS (tp)
2883 {
2884 if (!ptid_match (tp->ptid, resume_ptid))
2885 continue;
2886 clear_proceed_status_thread (tp);
2887 }
2888 }
2889
2890 if (!ptid_equal (inferior_ptid, null_ptid))
2891 {
2892 struct inferior *inferior;
2893
2894 if (non_stop)
2895 {
2896 /* If in non-stop mode, only delete the per-thread status of
2897 the current thread. */
2898 clear_proceed_status_thread (inferior_thread ());
2899 }
2900
2901 inferior = current_inferior ();
2902 inferior->control.stop_soon = NO_STOP_QUIETLY;
2903 }
2904
2905 observer_notify_about_to_proceed ();
2906 }
2907
2908 /* Returns true if TP is still stopped at a breakpoint that needs
2909 stepping-over in order to make progress. If the breakpoint is gone
2910 meanwhile, we can skip the whole step-over dance. */
2911
2912 static int
2913 thread_still_needs_step_over_bp (struct thread_info *tp)
2914 {
2915 if (tp->stepping_over_breakpoint)
2916 {
2917 struct regcache *regcache = get_thread_regcache (tp->ptid);
2918
2919 if (breakpoint_here_p (get_regcache_aspace (regcache),
2920 regcache_read_pc (regcache))
2921 == ordinary_breakpoint_here)
2922 return 1;
2923
2924 tp->stepping_over_breakpoint = 0;
2925 }
2926
2927 return 0;
2928 }
2929
2930 /* Check whether thread TP still needs to start a step-over in order
2931 to make progress when resumed. Returns an bitwise or of enum
2932 step_over_what bits, indicating what needs to be stepped over. */
2933
2934 static step_over_what
2935 thread_still_needs_step_over (struct thread_info *tp)
2936 {
2937 step_over_what what = 0;
2938
2939 if (thread_still_needs_step_over_bp (tp))
2940 what |= STEP_OVER_BREAKPOINT;
2941
2942 if (tp->stepping_over_watchpoint
2943 && !target_have_steppable_watchpoint)
2944 what |= STEP_OVER_WATCHPOINT;
2945
2946 return what;
2947 }
2948
2949 /* Returns true if scheduler locking applies. STEP indicates whether
2950 we're about to do a step/next-like command to a thread. */
2951
2952 static int
2953 schedlock_applies (struct thread_info *tp)
2954 {
2955 return (scheduler_mode == schedlock_on
2956 || (scheduler_mode == schedlock_step
2957 && tp->control.stepping_command)
2958 || (scheduler_mode == schedlock_replay
2959 && target_record_will_replay (minus_one_ptid,
2960 execution_direction)));
2961 }
2962
2963 /* Basic routine for continuing the program in various fashions.
2964
2965 ADDR is the address to resume at, or -1 for resume where stopped.
2966 SIGGNAL is the signal to give it, or 0 for none,
2967 or -1 for act according to how it stopped.
2968 STEP is nonzero if should trap after one instruction.
2969 -1 means return after that and print nothing.
2970 You should probably set various step_... variables
2971 before calling here, if you are stepping.
2972
2973 You should call clear_proceed_status before calling proceed. */
2974
2975 void
2976 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2977 {
2978 struct regcache *regcache;
2979 struct gdbarch *gdbarch;
2980 struct thread_info *tp;
2981 CORE_ADDR pc;
2982 struct address_space *aspace;
2983 ptid_t resume_ptid;
2984 struct execution_control_state ecss;
2985 struct execution_control_state *ecs = &ecss;
2986 struct cleanup *old_chain;
2987 struct cleanup *defer_resume_cleanup;
2988 int started;
2989
2990 /* If we're stopped at a fork/vfork, follow the branch set by the
2991 "set follow-fork-mode" command; otherwise, we'll just proceed
2992 resuming the current thread. */
2993 if (!follow_fork ())
2994 {
2995 /* The target for some reason decided not to resume. */
2996 normal_stop ();
2997 if (target_can_async_p ())
2998 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2999 return;
3000 }
3001
3002 /* We'll update this if & when we switch to a new thread. */
3003 previous_inferior_ptid = inferior_ptid;
3004
3005 regcache = get_current_regcache ();
3006 gdbarch = get_regcache_arch (regcache);
3007 aspace = get_regcache_aspace (regcache);
3008 pc = regcache_read_pc (regcache);
3009 tp = inferior_thread ();
3010
3011 /* Fill in with reasonable starting values. */
3012 init_thread_stepping_state (tp);
3013
3014 gdb_assert (!thread_is_in_step_over_chain (tp));
3015
3016 if (addr == (CORE_ADDR) -1)
3017 {
3018 if (pc == stop_pc
3019 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3020 && execution_direction != EXEC_REVERSE)
3021 /* There is a breakpoint at the address we will resume at,
3022 step one instruction before inserting breakpoints so that
3023 we do not stop right away (and report a second hit at this
3024 breakpoint).
3025
3026 Note, we don't do this in reverse, because we won't
3027 actually be executing the breakpoint insn anyway.
3028 We'll be (un-)executing the previous instruction. */
3029 tp->stepping_over_breakpoint = 1;
3030 else if (gdbarch_single_step_through_delay_p (gdbarch)
3031 && gdbarch_single_step_through_delay (gdbarch,
3032 get_current_frame ()))
3033 /* We stepped onto an instruction that needs to be stepped
3034 again before re-inserting the breakpoint, do so. */
3035 tp->stepping_over_breakpoint = 1;
3036 }
3037 else
3038 {
3039 regcache_write_pc (regcache, addr);
3040 }
3041
3042 if (siggnal != GDB_SIGNAL_DEFAULT)
3043 tp->suspend.stop_signal = siggnal;
3044
3045 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3046
3047 /* If an exception is thrown from this point on, make sure to
3048 propagate GDB's knowledge of the executing state to the
3049 frontend/user running state. */
3050 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3051
3052 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3053 threads (e.g., we might need to set threads stepping over
3054 breakpoints first), from the user/frontend's point of view, all
3055 threads in RESUME_PTID are now running. Unless we're calling an
3056 inferior function, as in that case we pretend the inferior
3057 doesn't run at all. */
3058 if (!tp->control.in_infcall)
3059 set_running (resume_ptid, 1);
3060
3061 if (debug_infrun)
3062 fprintf_unfiltered (gdb_stdlog,
3063 "infrun: proceed (addr=%s, signal=%s)\n",
3064 paddress (gdbarch, addr),
3065 gdb_signal_to_symbol_string (siggnal));
3066
3067 annotate_starting ();
3068
3069 /* Make sure that output from GDB appears before output from the
3070 inferior. */
3071 gdb_flush (gdb_stdout);
3072
3073 /* In a multi-threaded task we may select another thread and
3074 then continue or step.
3075
3076 But if a thread that we're resuming had stopped at a breakpoint,
3077 it will immediately cause another breakpoint stop without any
3078 execution (i.e. it will report a breakpoint hit incorrectly). So
3079 we must step over it first.
3080
3081 Look for threads other than the current (TP) that reported a
3082 breakpoint hit and haven't been resumed yet since. */
3083
3084 /* If scheduler locking applies, we can avoid iterating over all
3085 threads. */
3086 if (!non_stop && !schedlock_applies (tp))
3087 {
3088 struct thread_info *current = tp;
3089
3090 ALL_NON_EXITED_THREADS (tp)
3091 {
3092 /* Ignore the current thread here. It's handled
3093 afterwards. */
3094 if (tp == current)
3095 continue;
3096
3097 /* Ignore threads of processes we're not resuming. */
3098 if (!ptid_match (tp->ptid, resume_ptid))
3099 continue;
3100
3101 if (!thread_still_needs_step_over (tp))
3102 continue;
3103
3104 gdb_assert (!thread_is_in_step_over_chain (tp));
3105
3106 if (debug_infrun)
3107 fprintf_unfiltered (gdb_stdlog,
3108 "infrun: need to step-over [%s] first\n",
3109 target_pid_to_str (tp->ptid));
3110
3111 thread_step_over_chain_enqueue (tp);
3112 }
3113
3114 tp = current;
3115 }
3116
3117 /* Enqueue the current thread last, so that we move all other
3118 threads over their breakpoints first. */
3119 if (tp->stepping_over_breakpoint)
3120 thread_step_over_chain_enqueue (tp);
3121
3122 /* If the thread isn't started, we'll still need to set its prev_pc,
3123 so that switch_back_to_stepped_thread knows the thread hasn't
3124 advanced. Must do this before resuming any thread, as in
3125 all-stop/remote, once we resume we can't send any other packet
3126 until the target stops again. */
3127 tp->prev_pc = regcache_read_pc (regcache);
3128
3129 defer_resume_cleanup = make_cleanup_defer_target_commit_resume ();
3130
3131 started = start_step_over ();
3132
3133 if (step_over_info_valid_p ())
3134 {
3135 /* Either this thread started a new in-line step over, or some
3136 other thread was already doing one. In either case, don't
3137 resume anything else until the step-over is finished. */
3138 }
3139 else if (started && !target_is_non_stop_p ())
3140 {
3141 /* A new displaced stepping sequence was started. In all-stop,
3142 we can't talk to the target anymore until it next stops. */
3143 }
3144 else if (!non_stop && target_is_non_stop_p ())
3145 {
3146 /* In all-stop, but the target is always in non-stop mode.
3147 Start all other threads that are implicitly resumed too. */
3148 ALL_NON_EXITED_THREADS (tp)
3149 {
3150 /* Ignore threads of processes we're not resuming. */
3151 if (!ptid_match (tp->ptid, resume_ptid))
3152 continue;
3153
3154 if (tp->resumed)
3155 {
3156 if (debug_infrun)
3157 fprintf_unfiltered (gdb_stdlog,
3158 "infrun: proceed: [%s] resumed\n",
3159 target_pid_to_str (tp->ptid));
3160 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3161 continue;
3162 }
3163
3164 if (thread_is_in_step_over_chain (tp))
3165 {
3166 if (debug_infrun)
3167 fprintf_unfiltered (gdb_stdlog,
3168 "infrun: proceed: [%s] needs step-over\n",
3169 target_pid_to_str (tp->ptid));
3170 continue;
3171 }
3172
3173 if (debug_infrun)
3174 fprintf_unfiltered (gdb_stdlog,
3175 "infrun: proceed: resuming %s\n",
3176 target_pid_to_str (tp->ptid));
3177
3178 reset_ecs (ecs, tp);
3179 switch_to_thread (tp->ptid);
3180 keep_going_pass_signal (ecs);
3181 if (!ecs->wait_some_more)
3182 error (_("Command aborted."));
3183 }
3184 }
3185 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3186 {
3187 /* The thread wasn't started, and isn't queued, run it now. */
3188 reset_ecs (ecs, tp);
3189 switch_to_thread (tp->ptid);
3190 keep_going_pass_signal (ecs);
3191 if (!ecs->wait_some_more)
3192 error (_("Command aborted."));
3193 }
3194
3195 do_cleanups (defer_resume_cleanup);
3196 target_commit_resume ();
3197
3198 discard_cleanups (old_chain);
3199
3200 /* Tell the event loop to wait for it to stop. If the target
3201 supports asynchronous execution, it'll do this from within
3202 target_resume. */
3203 if (!target_can_async_p ())
3204 mark_async_event_handler (infrun_async_inferior_event_token);
3205 }
3206 \f
3207
3208 /* Start remote-debugging of a machine over a serial link. */
3209
3210 void
3211 start_remote (int from_tty)
3212 {
3213 struct inferior *inferior;
3214
3215 inferior = current_inferior ();
3216 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3217
3218 /* Always go on waiting for the target, regardless of the mode. */
3219 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3220 indicate to wait_for_inferior that a target should timeout if
3221 nothing is returned (instead of just blocking). Because of this,
3222 targets expecting an immediate response need to, internally, set
3223 things up so that the target_wait() is forced to eventually
3224 timeout. */
3225 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3226 differentiate to its caller what the state of the target is after
3227 the initial open has been performed. Here we're assuming that
3228 the target has stopped. It should be possible to eventually have
3229 target_open() return to the caller an indication that the target
3230 is currently running and GDB state should be set to the same as
3231 for an async run. */
3232 wait_for_inferior ();
3233
3234 /* Now that the inferior has stopped, do any bookkeeping like
3235 loading shared libraries. We want to do this before normal_stop,
3236 so that the displayed frame is up to date. */
3237 post_create_inferior (&current_target, from_tty);
3238
3239 normal_stop ();
3240 }
3241
3242 /* Initialize static vars when a new inferior begins. */
3243
3244 void
3245 init_wait_for_inferior (void)
3246 {
3247 /* These are meaningless until the first time through wait_for_inferior. */
3248
3249 breakpoint_init_inferior (inf_starting);
3250
3251 clear_proceed_status (0);
3252
3253 target_last_wait_ptid = minus_one_ptid;
3254
3255 previous_inferior_ptid = inferior_ptid;
3256
3257 /* Discard any skipped inlined frames. */
3258 clear_inline_frame_state (minus_one_ptid);
3259 }
3260
3261 \f
3262
3263 static void handle_inferior_event (struct execution_control_state *ecs);
3264
3265 static void handle_step_into_function (struct gdbarch *gdbarch,
3266 struct execution_control_state *ecs);
3267 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3268 struct execution_control_state *ecs);
3269 static void handle_signal_stop (struct execution_control_state *ecs);
3270 static void check_exception_resume (struct execution_control_state *,
3271 struct frame_info *);
3272
3273 static void end_stepping_range (struct execution_control_state *ecs);
3274 static void stop_waiting (struct execution_control_state *ecs);
3275 static void keep_going (struct execution_control_state *ecs);
3276 static void process_event_stop_test (struct execution_control_state *ecs);
3277 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3278
3279 /* Callback for iterate over threads. If the thread is stopped, but
3280 the user/frontend doesn't know about that yet, go through
3281 normal_stop, as if the thread had just stopped now. ARG points at
3282 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
3283 ptid_is_pid(PTID) is true, applies to all threads of the process
3284 pointed at by PTID. Otherwise, apply only to the thread pointed by
3285 PTID. */
3286
3287 static int
3288 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
3289 {
3290 ptid_t ptid = * (ptid_t *) arg;
3291
3292 if ((ptid_equal (info->ptid, ptid)
3293 || ptid_equal (minus_one_ptid, ptid)
3294 || (ptid_is_pid (ptid)
3295 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
3296 && is_running (info->ptid)
3297 && !is_executing (info->ptid))
3298 {
3299 struct cleanup *old_chain;
3300 struct execution_control_state ecss;
3301 struct execution_control_state *ecs = &ecss;
3302
3303 memset (ecs, 0, sizeof (*ecs));
3304
3305 old_chain = make_cleanup_restore_current_thread ();
3306
3307 overlay_cache_invalid = 1;
3308 /* Flush target cache before starting to handle each event.
3309 Target was running and cache could be stale. This is just a
3310 heuristic. Running threads may modify target memory, but we
3311 don't get any event. */
3312 target_dcache_invalidate ();
3313
3314 /* Go through handle_inferior_event/normal_stop, so we always
3315 have consistent output as if the stop event had been
3316 reported. */
3317 ecs->ptid = info->ptid;
3318 ecs->event_thread = info;
3319 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
3320 ecs->ws.value.sig = GDB_SIGNAL_0;
3321
3322 handle_inferior_event (ecs);
3323
3324 if (!ecs->wait_some_more)
3325 {
3326 /* Cancel any running execution command. */
3327 thread_cancel_execution_command (info);
3328
3329 normal_stop ();
3330 }
3331
3332 do_cleanups (old_chain);
3333 }
3334
3335 return 0;
3336 }
3337
3338 /* This function is attached as a "thread_stop_requested" observer.
3339 Cleanup local state that assumed the PTID was to be resumed, and
3340 report the stop to the frontend. */
3341
3342 static void
3343 infrun_thread_stop_requested (ptid_t ptid)
3344 {
3345 struct thread_info *tp;
3346
3347 /* PTID was requested to stop. Remove matching threads from the
3348 step-over queue, so we don't try to resume them
3349 automatically. */
3350 ALL_NON_EXITED_THREADS (tp)
3351 if (ptid_match (tp->ptid, ptid))
3352 {
3353 if (thread_is_in_step_over_chain (tp))
3354 thread_step_over_chain_remove (tp);
3355 }
3356
3357 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
3358 }
3359
3360 static void
3361 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3362 {
3363 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3364 nullify_last_target_wait_ptid ();
3365 }
3366
3367 /* Delete the step resume, single-step and longjmp/exception resume
3368 breakpoints of TP. */
3369
3370 static void
3371 delete_thread_infrun_breakpoints (struct thread_info *tp)
3372 {
3373 delete_step_resume_breakpoint (tp);
3374 delete_exception_resume_breakpoint (tp);
3375 delete_single_step_breakpoints (tp);
3376 }
3377
3378 /* If the target still has execution, call FUNC for each thread that
3379 just stopped. In all-stop, that's all the non-exited threads; in
3380 non-stop, that's the current thread, only. */
3381
3382 typedef void (*for_each_just_stopped_thread_callback_func)
3383 (struct thread_info *tp);
3384
3385 static void
3386 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3387 {
3388 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3389 return;
3390
3391 if (target_is_non_stop_p ())
3392 {
3393 /* If in non-stop mode, only the current thread stopped. */
3394 func (inferior_thread ());
3395 }
3396 else
3397 {
3398 struct thread_info *tp;
3399
3400 /* In all-stop mode, all threads have stopped. */
3401 ALL_NON_EXITED_THREADS (tp)
3402 {
3403 func (tp);
3404 }
3405 }
3406 }
3407
3408 /* Delete the step resume and longjmp/exception resume breakpoints of
3409 the threads that just stopped. */
3410
3411 static void
3412 delete_just_stopped_threads_infrun_breakpoints (void)
3413 {
3414 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3415 }
3416
3417 /* Delete the single-step breakpoints of the threads that just
3418 stopped. */
3419
3420 static void
3421 delete_just_stopped_threads_single_step_breakpoints (void)
3422 {
3423 for_each_just_stopped_thread (delete_single_step_breakpoints);
3424 }
3425
3426 /* A cleanup wrapper. */
3427
3428 static void
3429 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3430 {
3431 delete_just_stopped_threads_infrun_breakpoints ();
3432 }
3433
3434 /* See infrun.h. */
3435
3436 void
3437 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3438 const struct target_waitstatus *ws)
3439 {
3440 char *status_string = target_waitstatus_to_string (ws);
3441 string_file stb;
3442
3443 /* The text is split over several lines because it was getting too long.
3444 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3445 output as a unit; we want only one timestamp printed if debug_timestamp
3446 is set. */
3447
3448 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3449 ptid_get_pid (waiton_ptid),
3450 ptid_get_lwp (waiton_ptid),
3451 ptid_get_tid (waiton_ptid));
3452 if (ptid_get_pid (waiton_ptid) != -1)
3453 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3454 stb.printf (", status) =\n");
3455 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3456 ptid_get_pid (result_ptid),
3457 ptid_get_lwp (result_ptid),
3458 ptid_get_tid (result_ptid),
3459 target_pid_to_str (result_ptid));
3460 stb.printf ("infrun: %s\n", status_string);
3461
3462 /* This uses %s in part to handle %'s in the text, but also to avoid
3463 a gcc error: the format attribute requires a string literal. */
3464 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3465
3466 xfree (status_string);
3467 }
3468
3469 /* Select a thread at random, out of those which are resumed and have
3470 had events. */
3471
3472 static struct thread_info *
3473 random_pending_event_thread (ptid_t waiton_ptid)
3474 {
3475 struct thread_info *event_tp;
3476 int num_events = 0;
3477 int random_selector;
3478
3479 /* First see how many events we have. Count only resumed threads
3480 that have an event pending. */
3481 ALL_NON_EXITED_THREADS (event_tp)
3482 if (ptid_match (event_tp->ptid, waiton_ptid)
3483 && event_tp->resumed
3484 && event_tp->suspend.waitstatus_pending_p)
3485 num_events++;
3486
3487 if (num_events == 0)
3488 return NULL;
3489
3490 /* Now randomly pick a thread out of those that have had events. */
3491 random_selector = (int)
3492 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3493
3494 if (debug_infrun && num_events > 1)
3495 fprintf_unfiltered (gdb_stdlog,
3496 "infrun: Found %d events, selecting #%d\n",
3497 num_events, random_selector);
3498
3499 /* Select the Nth thread that has had an event. */
3500 ALL_NON_EXITED_THREADS (event_tp)
3501 if (ptid_match (event_tp->ptid, waiton_ptid)
3502 && event_tp->resumed
3503 && event_tp->suspend.waitstatus_pending_p)
3504 if (random_selector-- == 0)
3505 break;
3506
3507 return event_tp;
3508 }
3509
3510 /* Wrapper for target_wait that first checks whether threads have
3511 pending statuses to report before actually asking the target for
3512 more events. */
3513
3514 static ptid_t
3515 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3516 {
3517 ptid_t event_ptid;
3518 struct thread_info *tp;
3519
3520 /* First check if there is a resumed thread with a wait status
3521 pending. */
3522 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3523 {
3524 tp = random_pending_event_thread (ptid);
3525 }
3526 else
3527 {
3528 if (debug_infrun)
3529 fprintf_unfiltered (gdb_stdlog,
3530 "infrun: Waiting for specific thread %s.\n",
3531 target_pid_to_str (ptid));
3532
3533 /* We have a specific thread to check. */
3534 tp = find_thread_ptid (ptid);
3535 gdb_assert (tp != NULL);
3536 if (!tp->suspend.waitstatus_pending_p)
3537 tp = NULL;
3538 }
3539
3540 if (tp != NULL
3541 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3542 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3543 {
3544 struct regcache *regcache = get_thread_regcache (tp->ptid);
3545 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3546 CORE_ADDR pc;
3547 int discard = 0;
3548
3549 pc = regcache_read_pc (regcache);
3550
3551 if (pc != tp->suspend.stop_pc)
3552 {
3553 if (debug_infrun)
3554 fprintf_unfiltered (gdb_stdlog,
3555 "infrun: PC of %s changed. was=%s, now=%s\n",
3556 target_pid_to_str (tp->ptid),
3557 paddress (gdbarch, tp->prev_pc),
3558 paddress (gdbarch, pc));
3559 discard = 1;
3560 }
3561 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3562 {
3563 if (debug_infrun)
3564 fprintf_unfiltered (gdb_stdlog,
3565 "infrun: previous breakpoint of %s, at %s gone\n",
3566 target_pid_to_str (tp->ptid),
3567 paddress (gdbarch, pc));
3568
3569 discard = 1;
3570 }
3571
3572 if (discard)
3573 {
3574 if (debug_infrun)
3575 fprintf_unfiltered (gdb_stdlog,
3576 "infrun: pending event of %s cancelled.\n",
3577 target_pid_to_str (tp->ptid));
3578
3579 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3580 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3581 }
3582 }
3583
3584 if (tp != NULL)
3585 {
3586 if (debug_infrun)
3587 {
3588 char *statstr;
3589
3590 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
3591 fprintf_unfiltered (gdb_stdlog,
3592 "infrun: Using pending wait status %s for %s.\n",
3593 statstr,
3594 target_pid_to_str (tp->ptid));
3595 xfree (statstr);
3596 }
3597
3598 /* Now that we've selected our final event LWP, un-adjust its PC
3599 if it was a software breakpoint (and the target doesn't
3600 always adjust the PC itself). */
3601 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3602 && !target_supports_stopped_by_sw_breakpoint ())
3603 {
3604 struct regcache *regcache;
3605 struct gdbarch *gdbarch;
3606 int decr_pc;
3607
3608 regcache = get_thread_regcache (tp->ptid);
3609 gdbarch = get_regcache_arch (regcache);
3610
3611 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3612 if (decr_pc != 0)
3613 {
3614 CORE_ADDR pc;
3615
3616 pc = regcache_read_pc (regcache);
3617 regcache_write_pc (regcache, pc + decr_pc);
3618 }
3619 }
3620
3621 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3622 *status = tp->suspend.waitstatus;
3623 tp->suspend.waitstatus_pending_p = 0;
3624
3625 /* Wake up the event loop again, until all pending events are
3626 processed. */
3627 if (target_is_async_p ())
3628 mark_async_event_handler (infrun_async_inferior_event_token);
3629 return tp->ptid;
3630 }
3631
3632 /* But if we don't find one, we'll have to wait. */
3633
3634 if (deprecated_target_wait_hook)
3635 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3636 else
3637 event_ptid = target_wait (ptid, status, options);
3638
3639 return event_ptid;
3640 }
3641
3642 /* Prepare and stabilize the inferior for detaching it. E.g.,
3643 detaching while a thread is displaced stepping is a recipe for
3644 crashing it, as nothing would readjust the PC out of the scratch
3645 pad. */
3646
3647 void
3648 prepare_for_detach (void)
3649 {
3650 struct inferior *inf = current_inferior ();
3651 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3652 struct cleanup *old_chain_1;
3653 struct displaced_step_inferior_state *displaced;
3654
3655 displaced = get_displaced_stepping_state (inf->pid);
3656
3657 /* Is any thread of this process displaced stepping? If not,
3658 there's nothing else to do. */
3659 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3660 return;
3661
3662 if (debug_infrun)
3663 fprintf_unfiltered (gdb_stdlog,
3664 "displaced-stepping in-process while detaching");
3665
3666 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3667 inf->detaching = 1;
3668
3669 while (!ptid_equal (displaced->step_ptid, null_ptid))
3670 {
3671 struct cleanup *old_chain_2;
3672 struct execution_control_state ecss;
3673 struct execution_control_state *ecs;
3674
3675 ecs = &ecss;
3676 memset (ecs, 0, sizeof (*ecs));
3677
3678 overlay_cache_invalid = 1;
3679 /* Flush target cache before starting to handle each event.
3680 Target was running and cache could be stale. This is just a
3681 heuristic. Running threads may modify target memory, but we
3682 don't get any event. */
3683 target_dcache_invalidate ();
3684
3685 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3686
3687 if (debug_infrun)
3688 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3689
3690 /* If an error happens while handling the event, propagate GDB's
3691 knowledge of the executing state to the frontend/user running
3692 state. */
3693 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3694 &minus_one_ptid);
3695
3696 /* Now figure out what to do with the result of the result. */
3697 handle_inferior_event (ecs);
3698
3699 /* No error, don't finish the state yet. */
3700 discard_cleanups (old_chain_2);
3701
3702 /* Breakpoints and watchpoints are not installed on the target
3703 at this point, and signals are passed directly to the
3704 inferior, so this must mean the process is gone. */
3705 if (!ecs->wait_some_more)
3706 {
3707 discard_cleanups (old_chain_1);
3708 error (_("Program exited while detaching"));
3709 }
3710 }
3711
3712 discard_cleanups (old_chain_1);
3713 }
3714
3715 /* Wait for control to return from inferior to debugger.
3716
3717 If inferior gets a signal, we may decide to start it up again
3718 instead of returning. That is why there is a loop in this function.
3719 When this function actually returns it means the inferior
3720 should be left stopped and GDB should read more commands. */
3721
3722 void
3723 wait_for_inferior (void)
3724 {
3725 struct cleanup *old_cleanups;
3726 struct cleanup *thread_state_chain;
3727
3728 if (debug_infrun)
3729 fprintf_unfiltered
3730 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3731
3732 old_cleanups
3733 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3734 NULL);
3735
3736 /* If an error happens while handling the event, propagate GDB's
3737 knowledge of the executing state to the frontend/user running
3738 state. */
3739 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3740
3741 while (1)
3742 {
3743 struct execution_control_state ecss;
3744 struct execution_control_state *ecs = &ecss;
3745 ptid_t waiton_ptid = minus_one_ptid;
3746
3747 memset (ecs, 0, sizeof (*ecs));
3748
3749 overlay_cache_invalid = 1;
3750
3751 /* Flush target cache before starting to handle each event.
3752 Target was running and cache could be stale. This is just a
3753 heuristic. Running threads may modify target memory, but we
3754 don't get any event. */
3755 target_dcache_invalidate ();
3756
3757 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3758
3759 if (debug_infrun)
3760 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3761
3762 /* Now figure out what to do with the result of the result. */
3763 handle_inferior_event (ecs);
3764
3765 if (!ecs->wait_some_more)
3766 break;
3767 }
3768
3769 /* No error, don't finish the state yet. */
3770 discard_cleanups (thread_state_chain);
3771
3772 do_cleanups (old_cleanups);
3773 }
3774
3775 /* Cleanup that reinstalls the readline callback handler, if the
3776 target is running in the background. If while handling the target
3777 event something triggered a secondary prompt, like e.g., a
3778 pagination prompt, we'll have removed the callback handler (see
3779 gdb_readline_wrapper_line). Need to do this as we go back to the
3780 event loop, ready to process further input. Note this has no
3781 effect if the handler hasn't actually been removed, because calling
3782 rl_callback_handler_install resets the line buffer, thus losing
3783 input. */
3784
3785 static void
3786 reinstall_readline_callback_handler_cleanup (void *arg)
3787 {
3788 struct ui *ui = current_ui;
3789
3790 if (!ui->async)
3791 {
3792 /* We're not going back to the top level event loop yet. Don't
3793 install the readline callback, as it'd prep the terminal,
3794 readline-style (raw, noecho) (e.g., --batch). We'll install
3795 it the next time the prompt is displayed, when we're ready
3796 for input. */
3797 return;
3798 }
3799
3800 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3801 gdb_rl_callback_handler_reinstall ();
3802 }
3803
3804 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3805 that's just the event thread. In all-stop, that's all threads. */
3806
3807 static void
3808 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3809 {
3810 struct thread_info *thr = ecs->event_thread;
3811
3812 if (thr != NULL && thr->thread_fsm != NULL)
3813 thread_fsm_clean_up (thr->thread_fsm, thr);
3814
3815 if (!non_stop)
3816 {
3817 ALL_NON_EXITED_THREADS (thr)
3818 {
3819 if (thr->thread_fsm == NULL)
3820 continue;
3821 if (thr == ecs->event_thread)
3822 continue;
3823
3824 switch_to_thread (thr->ptid);
3825 thread_fsm_clean_up (thr->thread_fsm, thr);
3826 }
3827
3828 if (ecs->event_thread != NULL)
3829 switch_to_thread (ecs->event_thread->ptid);
3830 }
3831 }
3832
3833 /* Helper for all_uis_check_sync_execution_done that works on the
3834 current UI. */
3835
3836 static void
3837 check_curr_ui_sync_execution_done (void)
3838 {
3839 struct ui *ui = current_ui;
3840
3841 if (ui->prompt_state == PROMPT_NEEDED
3842 && ui->async
3843 && !gdb_in_secondary_prompt_p (ui))
3844 {
3845 target_terminal_ours ();
3846 observer_notify_sync_execution_done ();
3847 ui_register_input_event_handler (ui);
3848 }
3849 }
3850
3851 /* See infrun.h. */
3852
3853 void
3854 all_uis_check_sync_execution_done (void)
3855 {
3856 SWITCH_THRU_ALL_UIS ()
3857 {
3858 check_curr_ui_sync_execution_done ();
3859 }
3860 }
3861
3862 /* See infrun.h. */
3863
3864 void
3865 all_uis_on_sync_execution_starting (void)
3866 {
3867 SWITCH_THRU_ALL_UIS ()
3868 {
3869 if (current_ui->prompt_state == PROMPT_NEEDED)
3870 async_disable_stdin ();
3871 }
3872 }
3873
3874 /* Asynchronous version of wait_for_inferior. It is called by the
3875 event loop whenever a change of state is detected on the file
3876 descriptor corresponding to the target. It can be called more than
3877 once to complete a single execution command. In such cases we need
3878 to keep the state in a global variable ECSS. If it is the last time
3879 that this function is called for a single execution command, then
3880 report to the user that the inferior has stopped, and do the
3881 necessary cleanups. */
3882
3883 void
3884 fetch_inferior_event (void *client_data)
3885 {
3886 struct execution_control_state ecss;
3887 struct execution_control_state *ecs = &ecss;
3888 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3889 struct cleanup *ts_old_chain;
3890 int cmd_done = 0;
3891 ptid_t waiton_ptid = minus_one_ptid;
3892
3893 memset (ecs, 0, sizeof (*ecs));
3894
3895 /* Events are always processed with the main UI as current UI. This
3896 way, warnings, debug output, etc. are always consistently sent to
3897 the main console. */
3898 scoped_restore save_ui = make_scoped_restore (&current_ui, main_ui);
3899
3900 /* End up with readline processing input, if necessary. */
3901 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3902
3903 /* We're handling a live event, so make sure we're doing live
3904 debugging. If we're looking at traceframes while the target is
3905 running, we're going to need to get back to that mode after
3906 handling the event. */
3907 if (non_stop)
3908 {
3909 make_cleanup_restore_current_traceframe ();
3910 set_current_traceframe (-1);
3911 }
3912
3913 if (non_stop)
3914 /* In non-stop mode, the user/frontend should not notice a thread
3915 switch due to internal events. Make sure we reverse to the
3916 user selected thread and frame after handling the event and
3917 running any breakpoint commands. */
3918 make_cleanup_restore_current_thread ();
3919
3920 overlay_cache_invalid = 1;
3921 /* Flush target cache before starting to handle each event. Target
3922 was running and cache could be stale. This is just a heuristic.
3923 Running threads may modify target memory, but we don't get any
3924 event. */
3925 target_dcache_invalidate ();
3926
3927 scoped_restore save_exec_dir
3928 = make_scoped_restore (&execution_direction, target_execution_direction ());
3929
3930 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3931 target_can_async_p () ? TARGET_WNOHANG : 0);
3932
3933 if (debug_infrun)
3934 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3935
3936 /* If an error happens while handling the event, propagate GDB's
3937 knowledge of the executing state to the frontend/user running
3938 state. */
3939 if (!target_is_non_stop_p ())
3940 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3941 else
3942 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3943
3944 /* Get executed before make_cleanup_restore_current_thread above to apply
3945 still for the thread which has thrown the exception. */
3946 make_bpstat_clear_actions_cleanup ();
3947
3948 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3949
3950 /* Now figure out what to do with the result of the result. */
3951 handle_inferior_event (ecs);
3952
3953 if (!ecs->wait_some_more)
3954 {
3955 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3956 int should_stop = 1;
3957 struct thread_info *thr = ecs->event_thread;
3958 int should_notify_stop = 1;
3959
3960 delete_just_stopped_threads_infrun_breakpoints ();
3961
3962 if (thr != NULL)
3963 {
3964 struct thread_fsm *thread_fsm = thr->thread_fsm;
3965
3966 if (thread_fsm != NULL)
3967 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3968 }
3969
3970 if (!should_stop)
3971 {
3972 keep_going (ecs);
3973 }
3974 else
3975 {
3976 clean_up_just_stopped_threads_fsms (ecs);
3977
3978 if (thr != NULL && thr->thread_fsm != NULL)
3979 {
3980 should_notify_stop
3981 = thread_fsm_should_notify_stop (thr->thread_fsm);
3982 }
3983
3984 if (should_notify_stop)
3985 {
3986 int proceeded = 0;
3987
3988 /* We may not find an inferior if this was a process exit. */
3989 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3990 proceeded = normal_stop ();
3991
3992 if (!proceeded)
3993 {
3994 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3995 cmd_done = 1;
3996 }
3997 }
3998 }
3999 }
4000
4001 /* No error, don't finish the thread states yet. */
4002 discard_cleanups (ts_old_chain);
4003
4004 /* Revert thread and frame. */
4005 do_cleanups (old_chain);
4006
4007 /* If a UI was in sync execution mode, and now isn't, restore its
4008 prompt (a synchronous execution command has finished, and we're
4009 ready for input). */
4010 all_uis_check_sync_execution_done ();
4011
4012 if (cmd_done
4013 && exec_done_display_p
4014 && (ptid_equal (inferior_ptid, null_ptid)
4015 || !is_running (inferior_ptid)))
4016 printf_unfiltered (_("completed.\n"));
4017 }
4018
4019 /* Record the frame and location we're currently stepping through. */
4020 void
4021 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
4022 {
4023 struct thread_info *tp = inferior_thread ();
4024
4025 tp->control.step_frame_id = get_frame_id (frame);
4026 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
4027
4028 tp->current_symtab = sal.symtab;
4029 tp->current_line = sal.line;
4030 }
4031
4032 /* Clear context switchable stepping state. */
4033
4034 void
4035 init_thread_stepping_state (struct thread_info *tss)
4036 {
4037 tss->stepped_breakpoint = 0;
4038 tss->stepping_over_breakpoint = 0;
4039 tss->stepping_over_watchpoint = 0;
4040 tss->step_after_step_resume_breakpoint = 0;
4041 }
4042
4043 /* Set the cached copy of the last ptid/waitstatus. */
4044
4045 void
4046 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4047 {
4048 target_last_wait_ptid = ptid;
4049 target_last_waitstatus = status;
4050 }
4051
4052 /* Return the cached copy of the last pid/waitstatus returned by
4053 target_wait()/deprecated_target_wait_hook(). The data is actually
4054 cached by handle_inferior_event(), which gets called immediately
4055 after target_wait()/deprecated_target_wait_hook(). */
4056
4057 void
4058 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4059 {
4060 *ptidp = target_last_wait_ptid;
4061 *status = target_last_waitstatus;
4062 }
4063
4064 void
4065 nullify_last_target_wait_ptid (void)
4066 {
4067 target_last_wait_ptid = minus_one_ptid;
4068 }
4069
4070 /* Switch thread contexts. */
4071
4072 static void
4073 context_switch (ptid_t ptid)
4074 {
4075 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4076 {
4077 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4078 target_pid_to_str (inferior_ptid));
4079 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4080 target_pid_to_str (ptid));
4081 }
4082
4083 switch_to_thread (ptid);
4084 }
4085
4086 /* If the target can't tell whether we've hit breakpoints
4087 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4088 check whether that could have been caused by a breakpoint. If so,
4089 adjust the PC, per gdbarch_decr_pc_after_break. */
4090
4091 static void
4092 adjust_pc_after_break (struct thread_info *thread,
4093 struct target_waitstatus *ws)
4094 {
4095 struct regcache *regcache;
4096 struct gdbarch *gdbarch;
4097 struct address_space *aspace;
4098 CORE_ADDR breakpoint_pc, decr_pc;
4099
4100 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4101 we aren't, just return.
4102
4103 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4104 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4105 implemented by software breakpoints should be handled through the normal
4106 breakpoint layer.
4107
4108 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4109 different signals (SIGILL or SIGEMT for instance), but it is less
4110 clear where the PC is pointing afterwards. It may not match
4111 gdbarch_decr_pc_after_break. I don't know any specific target that
4112 generates these signals at breakpoints (the code has been in GDB since at
4113 least 1992) so I can not guess how to handle them here.
4114
4115 In earlier versions of GDB, a target with
4116 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4117 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4118 target with both of these set in GDB history, and it seems unlikely to be
4119 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4120
4121 if (ws->kind != TARGET_WAITKIND_STOPPED)
4122 return;
4123
4124 if (ws->value.sig != GDB_SIGNAL_TRAP)
4125 return;
4126
4127 /* In reverse execution, when a breakpoint is hit, the instruction
4128 under it has already been de-executed. The reported PC always
4129 points at the breakpoint address, so adjusting it further would
4130 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4131 architecture:
4132
4133 B1 0x08000000 : INSN1
4134 B2 0x08000001 : INSN2
4135 0x08000002 : INSN3
4136 PC -> 0x08000003 : INSN4
4137
4138 Say you're stopped at 0x08000003 as above. Reverse continuing
4139 from that point should hit B2 as below. Reading the PC when the
4140 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4141 been de-executed already.
4142
4143 B1 0x08000000 : INSN1
4144 B2 PC -> 0x08000001 : INSN2
4145 0x08000002 : INSN3
4146 0x08000003 : INSN4
4147
4148 We can't apply the same logic as for forward execution, because
4149 we would wrongly adjust the PC to 0x08000000, since there's a
4150 breakpoint at PC - 1. We'd then report a hit on B1, although
4151 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4152 behaviour. */
4153 if (execution_direction == EXEC_REVERSE)
4154 return;
4155
4156 /* If the target can tell whether the thread hit a SW breakpoint,
4157 trust it. Targets that can tell also adjust the PC
4158 themselves. */
4159 if (target_supports_stopped_by_sw_breakpoint ())
4160 return;
4161
4162 /* Note that relying on whether a breakpoint is planted in memory to
4163 determine this can fail. E.g,. the breakpoint could have been
4164 removed since. Or the thread could have been told to step an
4165 instruction the size of a breakpoint instruction, and only
4166 _after_ was a breakpoint inserted at its address. */
4167
4168 /* If this target does not decrement the PC after breakpoints, then
4169 we have nothing to do. */
4170 regcache = get_thread_regcache (thread->ptid);
4171 gdbarch = get_regcache_arch (regcache);
4172
4173 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4174 if (decr_pc == 0)
4175 return;
4176
4177 aspace = get_regcache_aspace (regcache);
4178
4179 /* Find the location where (if we've hit a breakpoint) the
4180 breakpoint would be. */
4181 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4182
4183 /* If the target can't tell whether a software breakpoint triggered,
4184 fallback to figuring it out based on breakpoints we think were
4185 inserted in the target, and on whether the thread was stepped or
4186 continued. */
4187
4188 /* Check whether there actually is a software breakpoint inserted at
4189 that location.
4190
4191 If in non-stop mode, a race condition is possible where we've
4192 removed a breakpoint, but stop events for that breakpoint were
4193 already queued and arrive later. To suppress those spurious
4194 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4195 and retire them after a number of stop events are reported. Note
4196 this is an heuristic and can thus get confused. The real fix is
4197 to get the "stopped by SW BP and needs adjustment" info out of
4198 the target/kernel (and thus never reach here; see above). */
4199 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4200 || (target_is_non_stop_p ()
4201 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4202 {
4203 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4204
4205 if (record_full_is_used ())
4206 record_full_gdb_operation_disable_set ();
4207
4208 /* When using hardware single-step, a SIGTRAP is reported for both
4209 a completed single-step and a software breakpoint. Need to
4210 differentiate between the two, as the latter needs adjusting
4211 but the former does not.
4212
4213 The SIGTRAP can be due to a completed hardware single-step only if
4214 - we didn't insert software single-step breakpoints
4215 - this thread is currently being stepped
4216
4217 If any of these events did not occur, we must have stopped due
4218 to hitting a software breakpoint, and have to back up to the
4219 breakpoint address.
4220
4221 As a special case, we could have hardware single-stepped a
4222 software breakpoint. In this case (prev_pc == breakpoint_pc),
4223 we also need to back up to the breakpoint address. */
4224
4225 if (thread_has_single_step_breakpoints_set (thread)
4226 || !currently_stepping (thread)
4227 || (thread->stepped_breakpoint
4228 && thread->prev_pc == breakpoint_pc))
4229 regcache_write_pc (regcache, breakpoint_pc);
4230
4231 do_cleanups (old_cleanups);
4232 }
4233 }
4234
4235 static int
4236 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4237 {
4238 for (frame = get_prev_frame (frame);
4239 frame != NULL;
4240 frame = get_prev_frame (frame))
4241 {
4242 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4243 return 1;
4244 if (get_frame_type (frame) != INLINE_FRAME)
4245 break;
4246 }
4247
4248 return 0;
4249 }
4250
4251 /* Auxiliary function that handles syscall entry/return events.
4252 It returns 1 if the inferior should keep going (and GDB
4253 should ignore the event), or 0 if the event deserves to be
4254 processed. */
4255
4256 static int
4257 handle_syscall_event (struct execution_control_state *ecs)
4258 {
4259 struct regcache *regcache;
4260 int syscall_number;
4261
4262 if (!ptid_equal (ecs->ptid, inferior_ptid))
4263 context_switch (ecs->ptid);
4264
4265 regcache = get_thread_regcache (ecs->ptid);
4266 syscall_number = ecs->ws.value.syscall_number;
4267 stop_pc = regcache_read_pc (regcache);
4268
4269 if (catch_syscall_enabled () > 0
4270 && catching_syscall_number (syscall_number) > 0)
4271 {
4272 if (debug_infrun)
4273 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4274 syscall_number);
4275
4276 ecs->event_thread->control.stop_bpstat
4277 = bpstat_stop_status (get_regcache_aspace (regcache),
4278 stop_pc, ecs->ptid, &ecs->ws);
4279
4280 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4281 {
4282 /* Catchpoint hit. */
4283 return 0;
4284 }
4285 }
4286
4287 /* If no catchpoint triggered for this, then keep going. */
4288 keep_going (ecs);
4289 return 1;
4290 }
4291
4292 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4293
4294 static void
4295 fill_in_stop_func (struct gdbarch *gdbarch,
4296 struct execution_control_state *ecs)
4297 {
4298 if (!ecs->stop_func_filled_in)
4299 {
4300 /* Don't care about return value; stop_func_start and stop_func_name
4301 will both be 0 if it doesn't work. */
4302 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4303 &ecs->stop_func_start, &ecs->stop_func_end);
4304 ecs->stop_func_start
4305 += gdbarch_deprecated_function_start_offset (gdbarch);
4306
4307 if (gdbarch_skip_entrypoint_p (gdbarch))
4308 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4309 ecs->stop_func_start);
4310
4311 ecs->stop_func_filled_in = 1;
4312 }
4313 }
4314
4315
4316 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4317
4318 static enum stop_kind
4319 get_inferior_stop_soon (ptid_t ptid)
4320 {
4321 struct inferior *inf = find_inferior_ptid (ptid);
4322
4323 gdb_assert (inf != NULL);
4324 return inf->control.stop_soon;
4325 }
4326
4327 /* Wait for one event. Store the resulting waitstatus in WS, and
4328 return the event ptid. */
4329
4330 static ptid_t
4331 wait_one (struct target_waitstatus *ws)
4332 {
4333 ptid_t event_ptid;
4334 ptid_t wait_ptid = minus_one_ptid;
4335
4336 overlay_cache_invalid = 1;
4337
4338 /* Flush target cache before starting to handle each event.
4339 Target was running and cache could be stale. This is just a
4340 heuristic. Running threads may modify target memory, but we
4341 don't get any event. */
4342 target_dcache_invalidate ();
4343
4344 if (deprecated_target_wait_hook)
4345 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4346 else
4347 event_ptid = target_wait (wait_ptid, ws, 0);
4348
4349 if (debug_infrun)
4350 print_target_wait_results (wait_ptid, event_ptid, ws);
4351
4352 return event_ptid;
4353 }
4354
4355 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4356 instead of the current thread. */
4357 #define THREAD_STOPPED_BY(REASON) \
4358 static int \
4359 thread_stopped_by_ ## REASON (ptid_t ptid) \
4360 { \
4361 struct cleanup *old_chain; \
4362 int res; \
4363 \
4364 old_chain = save_inferior_ptid (); \
4365 inferior_ptid = ptid; \
4366 \
4367 res = target_stopped_by_ ## REASON (); \
4368 \
4369 do_cleanups (old_chain); \
4370 \
4371 return res; \
4372 }
4373
4374 /* Generate thread_stopped_by_watchpoint. */
4375 THREAD_STOPPED_BY (watchpoint)
4376 /* Generate thread_stopped_by_sw_breakpoint. */
4377 THREAD_STOPPED_BY (sw_breakpoint)
4378 /* Generate thread_stopped_by_hw_breakpoint. */
4379 THREAD_STOPPED_BY (hw_breakpoint)
4380
4381 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4382
4383 static void
4384 switch_to_thread_cleanup (void *ptid_p)
4385 {
4386 ptid_t ptid = *(ptid_t *) ptid_p;
4387
4388 switch_to_thread (ptid);
4389 }
4390
4391 /* Save the thread's event and stop reason to process it later. */
4392
4393 static void
4394 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4395 {
4396 struct regcache *regcache;
4397 struct address_space *aspace;
4398
4399 if (debug_infrun)
4400 {
4401 char *statstr;
4402
4403 statstr = target_waitstatus_to_string (ws);
4404 fprintf_unfiltered (gdb_stdlog,
4405 "infrun: saving status %s for %d.%ld.%ld\n",
4406 statstr,
4407 ptid_get_pid (tp->ptid),
4408 ptid_get_lwp (tp->ptid),
4409 ptid_get_tid (tp->ptid));
4410 xfree (statstr);
4411 }
4412
4413 /* Record for later. */
4414 tp->suspend.waitstatus = *ws;
4415 tp->suspend.waitstatus_pending_p = 1;
4416
4417 regcache = get_thread_regcache (tp->ptid);
4418 aspace = get_regcache_aspace (regcache);
4419
4420 if (ws->kind == TARGET_WAITKIND_STOPPED
4421 && ws->value.sig == GDB_SIGNAL_TRAP)
4422 {
4423 CORE_ADDR pc = regcache_read_pc (regcache);
4424
4425 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4426
4427 if (thread_stopped_by_watchpoint (tp->ptid))
4428 {
4429 tp->suspend.stop_reason
4430 = TARGET_STOPPED_BY_WATCHPOINT;
4431 }
4432 else if (target_supports_stopped_by_sw_breakpoint ()
4433 && thread_stopped_by_sw_breakpoint (tp->ptid))
4434 {
4435 tp->suspend.stop_reason
4436 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4437 }
4438 else if (target_supports_stopped_by_hw_breakpoint ()
4439 && thread_stopped_by_hw_breakpoint (tp->ptid))
4440 {
4441 tp->suspend.stop_reason
4442 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4443 }
4444 else if (!target_supports_stopped_by_hw_breakpoint ()
4445 && hardware_breakpoint_inserted_here_p (aspace,
4446 pc))
4447 {
4448 tp->suspend.stop_reason
4449 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4450 }
4451 else if (!target_supports_stopped_by_sw_breakpoint ()
4452 && software_breakpoint_inserted_here_p (aspace,
4453 pc))
4454 {
4455 tp->suspend.stop_reason
4456 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4457 }
4458 else if (!thread_has_single_step_breakpoints_set (tp)
4459 && currently_stepping (tp))
4460 {
4461 tp->suspend.stop_reason
4462 = TARGET_STOPPED_BY_SINGLE_STEP;
4463 }
4464 }
4465 }
4466
4467 /* A cleanup that disables thread create/exit events. */
4468
4469 static void
4470 disable_thread_events (void *arg)
4471 {
4472 target_thread_events (0);
4473 }
4474
4475 /* See infrun.h. */
4476
4477 void
4478 stop_all_threads (void)
4479 {
4480 /* We may need multiple passes to discover all threads. */
4481 int pass;
4482 int iterations = 0;
4483 ptid_t entry_ptid;
4484 struct cleanup *old_chain;
4485
4486 gdb_assert (target_is_non_stop_p ());
4487
4488 if (debug_infrun)
4489 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4490
4491 entry_ptid = inferior_ptid;
4492 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4493
4494 target_thread_events (1);
4495 make_cleanup (disable_thread_events, NULL);
4496
4497 /* Request threads to stop, and then wait for the stops. Because
4498 threads we already know about can spawn more threads while we're
4499 trying to stop them, and we only learn about new threads when we
4500 update the thread list, do this in a loop, and keep iterating
4501 until two passes find no threads that need to be stopped. */
4502 for (pass = 0; pass < 2; pass++, iterations++)
4503 {
4504 if (debug_infrun)
4505 fprintf_unfiltered (gdb_stdlog,
4506 "infrun: stop_all_threads, pass=%d, "
4507 "iterations=%d\n", pass, iterations);
4508 while (1)
4509 {
4510 ptid_t event_ptid;
4511 struct target_waitstatus ws;
4512 int need_wait = 0;
4513 struct thread_info *t;
4514
4515 update_thread_list ();
4516
4517 /* Go through all threads looking for threads that we need
4518 to tell the target to stop. */
4519 ALL_NON_EXITED_THREADS (t)
4520 {
4521 if (t->executing)
4522 {
4523 /* If already stopping, don't request a stop again.
4524 We just haven't seen the notification yet. */
4525 if (!t->stop_requested)
4526 {
4527 if (debug_infrun)
4528 fprintf_unfiltered (gdb_stdlog,
4529 "infrun: %s executing, "
4530 "need stop\n",
4531 target_pid_to_str (t->ptid));
4532 target_stop (t->ptid);
4533 t->stop_requested = 1;
4534 }
4535 else
4536 {
4537 if (debug_infrun)
4538 fprintf_unfiltered (gdb_stdlog,
4539 "infrun: %s executing, "
4540 "already stopping\n",
4541 target_pid_to_str (t->ptid));
4542 }
4543
4544 if (t->stop_requested)
4545 need_wait = 1;
4546 }
4547 else
4548 {
4549 if (debug_infrun)
4550 fprintf_unfiltered (gdb_stdlog,
4551 "infrun: %s not executing\n",
4552 target_pid_to_str (t->ptid));
4553
4554 /* The thread may be not executing, but still be
4555 resumed with a pending status to process. */
4556 t->resumed = 0;
4557 }
4558 }
4559
4560 if (!need_wait)
4561 break;
4562
4563 /* If we find new threads on the second iteration, restart
4564 over. We want to see two iterations in a row with all
4565 threads stopped. */
4566 if (pass > 0)
4567 pass = -1;
4568
4569 event_ptid = wait_one (&ws);
4570 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4571 {
4572 /* All resumed threads exited. */
4573 }
4574 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4575 || ws.kind == TARGET_WAITKIND_EXITED
4576 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4577 {
4578 if (debug_infrun)
4579 {
4580 ptid_t ptid = pid_to_ptid (ws.value.integer);
4581
4582 fprintf_unfiltered (gdb_stdlog,
4583 "infrun: %s exited while "
4584 "stopping threads\n",
4585 target_pid_to_str (ptid));
4586 }
4587 }
4588 else
4589 {
4590 struct inferior *inf;
4591
4592 t = find_thread_ptid (event_ptid);
4593 if (t == NULL)
4594 t = add_thread (event_ptid);
4595
4596 t->stop_requested = 0;
4597 t->executing = 0;
4598 t->resumed = 0;
4599 t->control.may_range_step = 0;
4600
4601 /* This may be the first time we see the inferior report
4602 a stop. */
4603 inf = find_inferior_ptid (event_ptid);
4604 if (inf->needs_setup)
4605 {
4606 switch_to_thread_no_regs (t);
4607 setup_inferior (0);
4608 }
4609
4610 if (ws.kind == TARGET_WAITKIND_STOPPED
4611 && ws.value.sig == GDB_SIGNAL_0)
4612 {
4613 /* We caught the event that we intended to catch, so
4614 there's no event pending. */
4615 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4616 t->suspend.waitstatus_pending_p = 0;
4617
4618 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4619 {
4620 /* Add it back to the step-over queue. */
4621 if (debug_infrun)
4622 {
4623 fprintf_unfiltered (gdb_stdlog,
4624 "infrun: displaced-step of %s "
4625 "canceled: adding back to the "
4626 "step-over queue\n",
4627 target_pid_to_str (t->ptid));
4628 }
4629 t->control.trap_expected = 0;
4630 thread_step_over_chain_enqueue (t);
4631 }
4632 }
4633 else
4634 {
4635 enum gdb_signal sig;
4636 struct regcache *regcache;
4637
4638 if (debug_infrun)
4639 {
4640 char *statstr;
4641
4642 statstr = target_waitstatus_to_string (&ws);
4643 fprintf_unfiltered (gdb_stdlog,
4644 "infrun: target_wait %s, saving "
4645 "status for %d.%ld.%ld\n",
4646 statstr,
4647 ptid_get_pid (t->ptid),
4648 ptid_get_lwp (t->ptid),
4649 ptid_get_tid (t->ptid));
4650 xfree (statstr);
4651 }
4652
4653 /* Record for later. */
4654 save_waitstatus (t, &ws);
4655
4656 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4657 ? ws.value.sig : GDB_SIGNAL_0);
4658
4659 if (displaced_step_fixup (t->ptid, sig) < 0)
4660 {
4661 /* Add it back to the step-over queue. */
4662 t->control.trap_expected = 0;
4663 thread_step_over_chain_enqueue (t);
4664 }
4665
4666 regcache = get_thread_regcache (t->ptid);
4667 t->suspend.stop_pc = regcache_read_pc (regcache);
4668
4669 if (debug_infrun)
4670 {
4671 fprintf_unfiltered (gdb_stdlog,
4672 "infrun: saved stop_pc=%s for %s "
4673 "(currently_stepping=%d)\n",
4674 paddress (target_gdbarch (),
4675 t->suspend.stop_pc),
4676 target_pid_to_str (t->ptid),
4677 currently_stepping (t));
4678 }
4679 }
4680 }
4681 }
4682 }
4683
4684 do_cleanups (old_chain);
4685
4686 if (debug_infrun)
4687 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4688 }
4689
4690 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4691
4692 static int
4693 handle_no_resumed (struct execution_control_state *ecs)
4694 {
4695 struct inferior *inf;
4696 struct thread_info *thread;
4697
4698 if (target_can_async_p ())
4699 {
4700 struct ui *ui;
4701 int any_sync = 0;
4702
4703 ALL_UIS (ui)
4704 {
4705 if (ui->prompt_state == PROMPT_BLOCKED)
4706 {
4707 any_sync = 1;
4708 break;
4709 }
4710 }
4711 if (!any_sync)
4712 {
4713 /* There were no unwaited-for children left in the target, but,
4714 we're not synchronously waiting for events either. Just
4715 ignore. */
4716
4717 if (debug_infrun)
4718 fprintf_unfiltered (gdb_stdlog,
4719 "infrun: TARGET_WAITKIND_NO_RESUMED "
4720 "(ignoring: bg)\n");
4721 prepare_to_wait (ecs);
4722 return 1;
4723 }
4724 }
4725
4726 /* Otherwise, if we were running a synchronous execution command, we
4727 may need to cancel it and give the user back the terminal.
4728
4729 In non-stop mode, the target can't tell whether we've already
4730 consumed previous stop events, so it can end up sending us a
4731 no-resumed event like so:
4732
4733 #0 - thread 1 is left stopped
4734
4735 #1 - thread 2 is resumed and hits breakpoint
4736 -> TARGET_WAITKIND_STOPPED
4737
4738 #2 - thread 3 is resumed and exits
4739 this is the last resumed thread, so
4740 -> TARGET_WAITKIND_NO_RESUMED
4741
4742 #3 - gdb processes stop for thread 2 and decides to re-resume
4743 it.
4744
4745 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4746 thread 2 is now resumed, so the event should be ignored.
4747
4748 IOW, if the stop for thread 2 doesn't end a foreground command,
4749 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4750 event. But it could be that the event meant that thread 2 itself
4751 (or whatever other thread was the last resumed thread) exited.
4752
4753 To address this we refresh the thread list and check whether we
4754 have resumed threads _now_. In the example above, this removes
4755 thread 3 from the thread list. If thread 2 was re-resumed, we
4756 ignore this event. If we find no thread resumed, then we cancel
4757 the synchronous command show "no unwaited-for " to the user. */
4758 update_thread_list ();
4759
4760 ALL_NON_EXITED_THREADS (thread)
4761 {
4762 if (thread->executing
4763 || thread->suspend.waitstatus_pending_p)
4764 {
4765 /* There were no unwaited-for children left in the target at
4766 some point, but there are now. Just ignore. */
4767 if (debug_infrun)
4768 fprintf_unfiltered (gdb_stdlog,
4769 "infrun: TARGET_WAITKIND_NO_RESUMED "
4770 "(ignoring: found resumed)\n");
4771 prepare_to_wait (ecs);
4772 return 1;
4773 }
4774 }
4775
4776 /* Note however that we may find no resumed thread because the whole
4777 process exited meanwhile (thus updating the thread list results
4778 in an empty thread list). In this case we know we'll be getting
4779 a process exit event shortly. */
4780 ALL_INFERIORS (inf)
4781 {
4782 if (inf->pid == 0)
4783 continue;
4784
4785 thread = any_live_thread_of_process (inf->pid);
4786 if (thread == NULL)
4787 {
4788 if (debug_infrun)
4789 fprintf_unfiltered (gdb_stdlog,
4790 "infrun: TARGET_WAITKIND_NO_RESUMED "
4791 "(expect process exit)\n");
4792 prepare_to_wait (ecs);
4793 return 1;
4794 }
4795 }
4796
4797 /* Go ahead and report the event. */
4798 return 0;
4799 }
4800
4801 /* Given an execution control state that has been freshly filled in by
4802 an event from the inferior, figure out what it means and take
4803 appropriate action.
4804
4805 The alternatives are:
4806
4807 1) stop_waiting and return; to really stop and return to the
4808 debugger.
4809
4810 2) keep_going and return; to wait for the next event (set
4811 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4812 once). */
4813
4814 static void
4815 handle_inferior_event_1 (struct execution_control_state *ecs)
4816 {
4817 enum stop_kind stop_soon;
4818
4819 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4820 {
4821 /* We had an event in the inferior, but we are not interested in
4822 handling it at this level. The lower layers have already
4823 done what needs to be done, if anything.
4824
4825 One of the possible circumstances for this is when the
4826 inferior produces output for the console. The inferior has
4827 not stopped, and we are ignoring the event. Another possible
4828 circumstance is any event which the lower level knows will be
4829 reported multiple times without an intervening resume. */
4830 if (debug_infrun)
4831 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4832 prepare_to_wait (ecs);
4833 return;
4834 }
4835
4836 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4837 {
4838 if (debug_infrun)
4839 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4840 prepare_to_wait (ecs);
4841 return;
4842 }
4843
4844 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4845 && handle_no_resumed (ecs))
4846 return;
4847
4848 /* Cache the last pid/waitstatus. */
4849 set_last_target_status (ecs->ptid, ecs->ws);
4850
4851 /* Always clear state belonging to the previous time we stopped. */
4852 stop_stack_dummy = STOP_NONE;
4853
4854 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4855 {
4856 /* No unwaited-for children left. IOW, all resumed children
4857 have exited. */
4858 if (debug_infrun)
4859 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4860
4861 stop_print_frame = 0;
4862 stop_waiting (ecs);
4863 return;
4864 }
4865
4866 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4867 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4868 {
4869 ecs->event_thread = find_thread_ptid (ecs->ptid);
4870 /* If it's a new thread, add it to the thread database. */
4871 if (ecs->event_thread == NULL)
4872 ecs->event_thread = add_thread (ecs->ptid);
4873
4874 /* Disable range stepping. If the next step request could use a
4875 range, this will be end up re-enabled then. */
4876 ecs->event_thread->control.may_range_step = 0;
4877 }
4878
4879 /* Dependent on valid ECS->EVENT_THREAD. */
4880 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4881
4882 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4883 reinit_frame_cache ();
4884
4885 breakpoint_retire_moribund ();
4886
4887 /* First, distinguish signals caused by the debugger from signals
4888 that have to do with the program's own actions. Note that
4889 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4890 on the operating system version. Here we detect when a SIGILL or
4891 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4892 something similar for SIGSEGV, since a SIGSEGV will be generated
4893 when we're trying to execute a breakpoint instruction on a
4894 non-executable stack. This happens for call dummy breakpoints
4895 for architectures like SPARC that place call dummies on the
4896 stack. */
4897 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4898 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4899 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4900 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4901 {
4902 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4903
4904 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4905 regcache_read_pc (regcache)))
4906 {
4907 if (debug_infrun)
4908 fprintf_unfiltered (gdb_stdlog,
4909 "infrun: Treating signal as SIGTRAP\n");
4910 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4911 }
4912 }
4913
4914 /* Mark the non-executing threads accordingly. In all-stop, all
4915 threads of all processes are stopped when we get any event
4916 reported. In non-stop mode, only the event thread stops. */
4917 {
4918 ptid_t mark_ptid;
4919
4920 if (!target_is_non_stop_p ())
4921 mark_ptid = minus_one_ptid;
4922 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4923 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4924 {
4925 /* If we're handling a process exit in non-stop mode, even
4926 though threads haven't been deleted yet, one would think
4927 that there is nothing to do, as threads of the dead process
4928 will be soon deleted, and threads of any other process were
4929 left running. However, on some targets, threads survive a
4930 process exit event. E.g., for the "checkpoint" command,
4931 when the current checkpoint/fork exits, linux-fork.c
4932 automatically switches to another fork from within
4933 target_mourn_inferior, by associating the same
4934 inferior/thread to another fork. We haven't mourned yet at
4935 this point, but we must mark any threads left in the
4936 process as not-executing so that finish_thread_state marks
4937 them stopped (in the user's perspective) if/when we present
4938 the stop to the user. */
4939 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4940 }
4941 else
4942 mark_ptid = ecs->ptid;
4943
4944 set_executing (mark_ptid, 0);
4945
4946 /* Likewise the resumed flag. */
4947 set_resumed (mark_ptid, 0);
4948 }
4949
4950 switch (ecs->ws.kind)
4951 {
4952 case TARGET_WAITKIND_LOADED:
4953 if (debug_infrun)
4954 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4955 if (!ptid_equal (ecs->ptid, inferior_ptid))
4956 context_switch (ecs->ptid);
4957 /* Ignore gracefully during startup of the inferior, as it might
4958 be the shell which has just loaded some objects, otherwise
4959 add the symbols for the newly loaded objects. Also ignore at
4960 the beginning of an attach or remote session; we will query
4961 the full list of libraries once the connection is
4962 established. */
4963
4964 stop_soon = get_inferior_stop_soon (ecs->ptid);
4965 if (stop_soon == NO_STOP_QUIETLY)
4966 {
4967 struct regcache *regcache;
4968
4969 regcache = get_thread_regcache (ecs->ptid);
4970
4971 handle_solib_event ();
4972
4973 ecs->event_thread->control.stop_bpstat
4974 = bpstat_stop_status (get_regcache_aspace (regcache),
4975 stop_pc, ecs->ptid, &ecs->ws);
4976
4977 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4978 {
4979 /* A catchpoint triggered. */
4980 process_event_stop_test (ecs);
4981 return;
4982 }
4983
4984 /* If requested, stop when the dynamic linker notifies
4985 gdb of events. This allows the user to get control
4986 and place breakpoints in initializer routines for
4987 dynamically loaded objects (among other things). */
4988 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4989 if (stop_on_solib_events)
4990 {
4991 /* Make sure we print "Stopped due to solib-event" in
4992 normal_stop. */
4993 stop_print_frame = 1;
4994
4995 stop_waiting (ecs);
4996 return;
4997 }
4998 }
4999
5000 /* If we are skipping through a shell, or through shared library
5001 loading that we aren't interested in, resume the program. If
5002 we're running the program normally, also resume. */
5003 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
5004 {
5005 /* Loading of shared libraries might have changed breakpoint
5006 addresses. Make sure new breakpoints are inserted. */
5007 if (stop_soon == NO_STOP_QUIETLY)
5008 insert_breakpoints ();
5009 resume (GDB_SIGNAL_0);
5010 prepare_to_wait (ecs);
5011 return;
5012 }
5013
5014 /* But stop if we're attaching or setting up a remote
5015 connection. */
5016 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5017 || stop_soon == STOP_QUIETLY_REMOTE)
5018 {
5019 if (debug_infrun)
5020 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5021 stop_waiting (ecs);
5022 return;
5023 }
5024
5025 internal_error (__FILE__, __LINE__,
5026 _("unhandled stop_soon: %d"), (int) stop_soon);
5027
5028 case TARGET_WAITKIND_SPURIOUS:
5029 if (debug_infrun)
5030 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5031 if (!ptid_equal (ecs->ptid, inferior_ptid))
5032 context_switch (ecs->ptid);
5033 resume (GDB_SIGNAL_0);
5034 prepare_to_wait (ecs);
5035 return;
5036
5037 case TARGET_WAITKIND_THREAD_CREATED:
5038 if (debug_infrun)
5039 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5040 if (!ptid_equal (ecs->ptid, inferior_ptid))
5041 context_switch (ecs->ptid);
5042 if (!switch_back_to_stepped_thread (ecs))
5043 keep_going (ecs);
5044 return;
5045
5046 case TARGET_WAITKIND_EXITED:
5047 case TARGET_WAITKIND_SIGNALLED:
5048 if (debug_infrun)
5049 {
5050 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5051 fprintf_unfiltered (gdb_stdlog,
5052 "infrun: TARGET_WAITKIND_EXITED\n");
5053 else
5054 fprintf_unfiltered (gdb_stdlog,
5055 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5056 }
5057
5058 inferior_ptid = ecs->ptid;
5059 set_current_inferior (find_inferior_ptid (ecs->ptid));
5060 set_current_program_space (current_inferior ()->pspace);
5061 handle_vfork_child_exec_or_exit (0);
5062 target_terminal_ours (); /* Must do this before mourn anyway. */
5063
5064 /* Clearing any previous state of convenience variables. */
5065 clear_exit_convenience_vars ();
5066
5067 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5068 {
5069 /* Record the exit code in the convenience variable $_exitcode, so
5070 that the user can inspect this again later. */
5071 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5072 (LONGEST) ecs->ws.value.integer);
5073
5074 /* Also record this in the inferior itself. */
5075 current_inferior ()->has_exit_code = 1;
5076 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5077
5078 /* Support the --return-child-result option. */
5079 return_child_result_value = ecs->ws.value.integer;
5080
5081 observer_notify_exited (ecs->ws.value.integer);
5082 }
5083 else
5084 {
5085 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5086 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5087
5088 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5089 {
5090 /* Set the value of the internal variable $_exitsignal,
5091 which holds the signal uncaught by the inferior. */
5092 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5093 gdbarch_gdb_signal_to_target (gdbarch,
5094 ecs->ws.value.sig));
5095 }
5096 else
5097 {
5098 /* We don't have access to the target's method used for
5099 converting between signal numbers (GDB's internal
5100 representation <-> target's representation).
5101 Therefore, we cannot do a good job at displaying this
5102 information to the user. It's better to just warn
5103 her about it (if infrun debugging is enabled), and
5104 give up. */
5105 if (debug_infrun)
5106 fprintf_filtered (gdb_stdlog, _("\
5107 Cannot fill $_exitsignal with the correct signal number.\n"));
5108 }
5109
5110 observer_notify_signal_exited (ecs->ws.value.sig);
5111 }
5112
5113 gdb_flush (gdb_stdout);
5114 target_mourn_inferior (inferior_ptid);
5115 stop_print_frame = 0;
5116 stop_waiting (ecs);
5117 return;
5118
5119 /* The following are the only cases in which we keep going;
5120 the above cases end in a continue or goto. */
5121 case TARGET_WAITKIND_FORKED:
5122 case TARGET_WAITKIND_VFORKED:
5123 if (debug_infrun)
5124 {
5125 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5126 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5127 else
5128 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5129 }
5130
5131 /* Check whether the inferior is displaced stepping. */
5132 {
5133 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5134 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5135
5136 /* If checking displaced stepping is supported, and thread
5137 ecs->ptid is displaced stepping. */
5138 if (displaced_step_in_progress_thread (ecs->ptid))
5139 {
5140 struct inferior *parent_inf
5141 = find_inferior_ptid (ecs->ptid);
5142 struct regcache *child_regcache;
5143 CORE_ADDR parent_pc;
5144
5145 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5146 indicating that the displaced stepping of syscall instruction
5147 has been done. Perform cleanup for parent process here. Note
5148 that this operation also cleans up the child process for vfork,
5149 because their pages are shared. */
5150 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
5151 /* Start a new step-over in another thread if there's one
5152 that needs it. */
5153 start_step_over ();
5154
5155 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5156 {
5157 struct displaced_step_inferior_state *displaced
5158 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
5159
5160 /* Restore scratch pad for child process. */
5161 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5162 }
5163
5164 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5165 the child's PC is also within the scratchpad. Set the child's PC
5166 to the parent's PC value, which has already been fixed up.
5167 FIXME: we use the parent's aspace here, although we're touching
5168 the child, because the child hasn't been added to the inferior
5169 list yet at this point. */
5170
5171 child_regcache
5172 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5173 gdbarch,
5174 parent_inf->aspace);
5175 /* Read PC value of parent process. */
5176 parent_pc = regcache_read_pc (regcache);
5177
5178 if (debug_displaced)
5179 fprintf_unfiltered (gdb_stdlog,
5180 "displaced: write child pc from %s to %s\n",
5181 paddress (gdbarch,
5182 regcache_read_pc (child_regcache)),
5183 paddress (gdbarch, parent_pc));
5184
5185 regcache_write_pc (child_regcache, parent_pc);
5186 }
5187 }
5188
5189 if (!ptid_equal (ecs->ptid, inferior_ptid))
5190 context_switch (ecs->ptid);
5191
5192 /* Immediately detach breakpoints from the child before there's
5193 any chance of letting the user delete breakpoints from the
5194 breakpoint lists. If we don't do this early, it's easy to
5195 leave left over traps in the child, vis: "break foo; catch
5196 fork; c; <fork>; del; c; <child calls foo>". We only follow
5197 the fork on the last `continue', and by that time the
5198 breakpoint at "foo" is long gone from the breakpoint table.
5199 If we vforked, then we don't need to unpatch here, since both
5200 parent and child are sharing the same memory pages; we'll
5201 need to unpatch at follow/detach time instead to be certain
5202 that new breakpoints added between catchpoint hit time and
5203 vfork follow are detached. */
5204 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5205 {
5206 /* This won't actually modify the breakpoint list, but will
5207 physically remove the breakpoints from the child. */
5208 detach_breakpoints (ecs->ws.value.related_pid);
5209 }
5210
5211 delete_just_stopped_threads_single_step_breakpoints ();
5212
5213 /* In case the event is caught by a catchpoint, remember that
5214 the event is to be followed at the next resume of the thread,
5215 and not immediately. */
5216 ecs->event_thread->pending_follow = ecs->ws;
5217
5218 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5219
5220 ecs->event_thread->control.stop_bpstat
5221 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5222 stop_pc, ecs->ptid, &ecs->ws);
5223
5224 /* If no catchpoint triggered for this, then keep going. Note
5225 that we're interested in knowing the bpstat actually causes a
5226 stop, not just if it may explain the signal. Software
5227 watchpoints, for example, always appear in the bpstat. */
5228 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5229 {
5230 ptid_t parent;
5231 ptid_t child;
5232 int should_resume;
5233 int follow_child
5234 = (follow_fork_mode_string == follow_fork_mode_child);
5235
5236 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5237
5238 should_resume = follow_fork ();
5239
5240 parent = ecs->ptid;
5241 child = ecs->ws.value.related_pid;
5242
5243 /* At this point, the parent is marked running, and the
5244 child is marked stopped. */
5245
5246 /* If not resuming the parent, mark it stopped. */
5247 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5248 set_running (parent, 0);
5249
5250 /* If resuming the child, mark it running. */
5251 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5252 set_running (child, 1);
5253
5254 /* In non-stop mode, also resume the other branch. */
5255 if (!detach_fork && (non_stop
5256 || (sched_multi && target_is_non_stop_p ())))
5257 {
5258 if (follow_child)
5259 switch_to_thread (parent);
5260 else
5261 switch_to_thread (child);
5262
5263 ecs->event_thread = inferior_thread ();
5264 ecs->ptid = inferior_ptid;
5265 keep_going (ecs);
5266 }
5267
5268 if (follow_child)
5269 switch_to_thread (child);
5270 else
5271 switch_to_thread (parent);
5272
5273 ecs->event_thread = inferior_thread ();
5274 ecs->ptid = inferior_ptid;
5275
5276 if (should_resume)
5277 keep_going (ecs);
5278 else
5279 stop_waiting (ecs);
5280 return;
5281 }
5282 process_event_stop_test (ecs);
5283 return;
5284
5285 case TARGET_WAITKIND_VFORK_DONE:
5286 /* Done with the shared memory region. Re-insert breakpoints in
5287 the parent, and keep going. */
5288
5289 if (debug_infrun)
5290 fprintf_unfiltered (gdb_stdlog,
5291 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5292
5293 if (!ptid_equal (ecs->ptid, inferior_ptid))
5294 context_switch (ecs->ptid);
5295
5296 current_inferior ()->waiting_for_vfork_done = 0;
5297 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5298 /* This also takes care of reinserting breakpoints in the
5299 previously locked inferior. */
5300 keep_going (ecs);
5301 return;
5302
5303 case TARGET_WAITKIND_EXECD:
5304 if (debug_infrun)
5305 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5306
5307 if (!ptid_equal (ecs->ptid, inferior_ptid))
5308 context_switch (ecs->ptid);
5309
5310 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5311
5312 /* Do whatever is necessary to the parent branch of the vfork. */
5313 handle_vfork_child_exec_or_exit (1);
5314
5315 /* This causes the eventpoints and symbol table to be reset.
5316 Must do this now, before trying to determine whether to
5317 stop. */
5318 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5319
5320 /* In follow_exec we may have deleted the original thread and
5321 created a new one. Make sure that the event thread is the
5322 execd thread for that case (this is a nop otherwise). */
5323 ecs->event_thread = inferior_thread ();
5324
5325 ecs->event_thread->control.stop_bpstat
5326 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5327 stop_pc, ecs->ptid, &ecs->ws);
5328
5329 /* Note that this may be referenced from inside
5330 bpstat_stop_status above, through inferior_has_execd. */
5331 xfree (ecs->ws.value.execd_pathname);
5332 ecs->ws.value.execd_pathname = NULL;
5333
5334 /* If no catchpoint triggered for this, then keep going. */
5335 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5336 {
5337 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5338 keep_going (ecs);
5339 return;
5340 }
5341 process_event_stop_test (ecs);
5342 return;
5343
5344 /* Be careful not to try to gather much state about a thread
5345 that's in a syscall. It's frequently a losing proposition. */
5346 case TARGET_WAITKIND_SYSCALL_ENTRY:
5347 if (debug_infrun)
5348 fprintf_unfiltered (gdb_stdlog,
5349 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5350 /* Getting the current syscall number. */
5351 if (handle_syscall_event (ecs) == 0)
5352 process_event_stop_test (ecs);
5353 return;
5354
5355 /* Before examining the threads further, step this thread to
5356 get it entirely out of the syscall. (We get notice of the
5357 event when the thread is just on the verge of exiting a
5358 syscall. Stepping one instruction seems to get it back
5359 into user code.) */
5360 case TARGET_WAITKIND_SYSCALL_RETURN:
5361 if (debug_infrun)
5362 fprintf_unfiltered (gdb_stdlog,
5363 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5364 if (handle_syscall_event (ecs) == 0)
5365 process_event_stop_test (ecs);
5366 return;
5367
5368 case TARGET_WAITKIND_STOPPED:
5369 if (debug_infrun)
5370 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5371 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5372 handle_signal_stop (ecs);
5373 return;
5374
5375 case TARGET_WAITKIND_NO_HISTORY:
5376 if (debug_infrun)
5377 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5378 /* Reverse execution: target ran out of history info. */
5379
5380 /* Switch to the stopped thread. */
5381 if (!ptid_equal (ecs->ptid, inferior_ptid))
5382 context_switch (ecs->ptid);
5383 if (debug_infrun)
5384 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5385
5386 delete_just_stopped_threads_single_step_breakpoints ();
5387 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5388 observer_notify_no_history ();
5389 stop_waiting (ecs);
5390 return;
5391 }
5392 }
5393
5394 /* A wrapper around handle_inferior_event_1, which also makes sure
5395 that all temporary struct value objects that were created during
5396 the handling of the event get deleted at the end. */
5397
5398 static void
5399 handle_inferior_event (struct execution_control_state *ecs)
5400 {
5401 struct value *mark = value_mark ();
5402
5403 handle_inferior_event_1 (ecs);
5404 /* Purge all temporary values created during the event handling,
5405 as it could be a long time before we return to the command level
5406 where such values would otherwise be purged. */
5407 value_free_to_mark (mark);
5408 }
5409
5410 /* Restart threads back to what they were trying to do back when we
5411 paused them for an in-line step-over. The EVENT_THREAD thread is
5412 ignored. */
5413
5414 static void
5415 restart_threads (struct thread_info *event_thread)
5416 {
5417 struct thread_info *tp;
5418
5419 /* In case the instruction just stepped spawned a new thread. */
5420 update_thread_list ();
5421
5422 ALL_NON_EXITED_THREADS (tp)
5423 {
5424 if (tp == event_thread)
5425 {
5426 if (debug_infrun)
5427 fprintf_unfiltered (gdb_stdlog,
5428 "infrun: restart threads: "
5429 "[%s] is event thread\n",
5430 target_pid_to_str (tp->ptid));
5431 continue;
5432 }
5433
5434 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5435 {
5436 if (debug_infrun)
5437 fprintf_unfiltered (gdb_stdlog,
5438 "infrun: restart threads: "
5439 "[%s] not meant to be running\n",
5440 target_pid_to_str (tp->ptid));
5441 continue;
5442 }
5443
5444 if (tp->resumed)
5445 {
5446 if (debug_infrun)
5447 fprintf_unfiltered (gdb_stdlog,
5448 "infrun: restart threads: [%s] resumed\n",
5449 target_pid_to_str (tp->ptid));
5450 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5451 continue;
5452 }
5453
5454 if (thread_is_in_step_over_chain (tp))
5455 {
5456 if (debug_infrun)
5457 fprintf_unfiltered (gdb_stdlog,
5458 "infrun: restart threads: "
5459 "[%s] needs step-over\n",
5460 target_pid_to_str (tp->ptid));
5461 gdb_assert (!tp->resumed);
5462 continue;
5463 }
5464
5465
5466 if (tp->suspend.waitstatus_pending_p)
5467 {
5468 if (debug_infrun)
5469 fprintf_unfiltered (gdb_stdlog,
5470 "infrun: restart threads: "
5471 "[%s] has pending status\n",
5472 target_pid_to_str (tp->ptid));
5473 tp->resumed = 1;
5474 continue;
5475 }
5476
5477 /* If some thread needs to start a step-over at this point, it
5478 should still be in the step-over queue, and thus skipped
5479 above. */
5480 if (thread_still_needs_step_over (tp))
5481 {
5482 internal_error (__FILE__, __LINE__,
5483 "thread [%s] needs a step-over, but not in "
5484 "step-over queue\n",
5485 target_pid_to_str (tp->ptid));
5486 }
5487
5488 if (currently_stepping (tp))
5489 {
5490 if (debug_infrun)
5491 fprintf_unfiltered (gdb_stdlog,
5492 "infrun: restart threads: [%s] was stepping\n",
5493 target_pid_to_str (tp->ptid));
5494 keep_going_stepped_thread (tp);
5495 }
5496 else
5497 {
5498 struct execution_control_state ecss;
5499 struct execution_control_state *ecs = &ecss;
5500
5501 if (debug_infrun)
5502 fprintf_unfiltered (gdb_stdlog,
5503 "infrun: restart threads: [%s] continuing\n",
5504 target_pid_to_str (tp->ptid));
5505 reset_ecs (ecs, tp);
5506 switch_to_thread (tp->ptid);
5507 keep_going_pass_signal (ecs);
5508 }
5509 }
5510 }
5511
5512 /* Callback for iterate_over_threads. Find a resumed thread that has
5513 a pending waitstatus. */
5514
5515 static int
5516 resumed_thread_with_pending_status (struct thread_info *tp,
5517 void *arg)
5518 {
5519 return (tp->resumed
5520 && tp->suspend.waitstatus_pending_p);
5521 }
5522
5523 /* Called when we get an event that may finish an in-line or
5524 out-of-line (displaced stepping) step-over started previously.
5525 Return true if the event is processed and we should go back to the
5526 event loop; false if the caller should continue processing the
5527 event. */
5528
5529 static int
5530 finish_step_over (struct execution_control_state *ecs)
5531 {
5532 int had_step_over_info;
5533
5534 displaced_step_fixup (ecs->ptid,
5535 ecs->event_thread->suspend.stop_signal);
5536
5537 had_step_over_info = step_over_info_valid_p ();
5538
5539 if (had_step_over_info)
5540 {
5541 /* If we're stepping over a breakpoint with all threads locked,
5542 then only the thread that was stepped should be reporting
5543 back an event. */
5544 gdb_assert (ecs->event_thread->control.trap_expected);
5545
5546 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5547 clear_step_over_info ();
5548 }
5549
5550 if (!target_is_non_stop_p ())
5551 return 0;
5552
5553 /* Start a new step-over in another thread if there's one that
5554 needs it. */
5555 start_step_over ();
5556
5557 /* If we were stepping over a breakpoint before, and haven't started
5558 a new in-line step-over sequence, then restart all other threads
5559 (except the event thread). We can't do this in all-stop, as then
5560 e.g., we wouldn't be able to issue any other remote packet until
5561 these other threads stop. */
5562 if (had_step_over_info && !step_over_info_valid_p ())
5563 {
5564 struct thread_info *pending;
5565
5566 /* If we only have threads with pending statuses, the restart
5567 below won't restart any thread and so nothing re-inserts the
5568 breakpoint we just stepped over. But we need it inserted
5569 when we later process the pending events, otherwise if
5570 another thread has a pending event for this breakpoint too,
5571 we'd discard its event (because the breakpoint that
5572 originally caused the event was no longer inserted). */
5573 context_switch (ecs->ptid);
5574 insert_breakpoints ();
5575
5576 restart_threads (ecs->event_thread);
5577
5578 /* If we have events pending, go through handle_inferior_event
5579 again, picking up a pending event at random. This avoids
5580 thread starvation. */
5581
5582 /* But not if we just stepped over a watchpoint in order to let
5583 the instruction execute so we can evaluate its expression.
5584 The set of watchpoints that triggered is recorded in the
5585 breakpoint objects themselves (see bp->watchpoint_triggered).
5586 If we processed another event first, that other event could
5587 clobber this info. */
5588 if (ecs->event_thread->stepping_over_watchpoint)
5589 return 0;
5590
5591 pending = iterate_over_threads (resumed_thread_with_pending_status,
5592 NULL);
5593 if (pending != NULL)
5594 {
5595 struct thread_info *tp = ecs->event_thread;
5596 struct regcache *regcache;
5597
5598 if (debug_infrun)
5599 {
5600 fprintf_unfiltered (gdb_stdlog,
5601 "infrun: found resumed threads with "
5602 "pending events, saving status\n");
5603 }
5604
5605 gdb_assert (pending != tp);
5606
5607 /* Record the event thread's event for later. */
5608 save_waitstatus (tp, &ecs->ws);
5609 /* This was cleared early, by handle_inferior_event. Set it
5610 so this pending event is considered by
5611 do_target_wait. */
5612 tp->resumed = 1;
5613
5614 gdb_assert (!tp->executing);
5615
5616 regcache = get_thread_regcache (tp->ptid);
5617 tp->suspend.stop_pc = regcache_read_pc (regcache);
5618
5619 if (debug_infrun)
5620 {
5621 fprintf_unfiltered (gdb_stdlog,
5622 "infrun: saved stop_pc=%s for %s "
5623 "(currently_stepping=%d)\n",
5624 paddress (target_gdbarch (),
5625 tp->suspend.stop_pc),
5626 target_pid_to_str (tp->ptid),
5627 currently_stepping (tp));
5628 }
5629
5630 /* This in-line step-over finished; clear this so we won't
5631 start a new one. This is what handle_signal_stop would
5632 do, if we returned false. */
5633 tp->stepping_over_breakpoint = 0;
5634
5635 /* Wake up the event loop again. */
5636 mark_async_event_handler (infrun_async_inferior_event_token);
5637
5638 prepare_to_wait (ecs);
5639 return 1;
5640 }
5641 }
5642
5643 return 0;
5644 }
5645
5646 /* Come here when the program has stopped with a signal. */
5647
5648 static void
5649 handle_signal_stop (struct execution_control_state *ecs)
5650 {
5651 struct frame_info *frame;
5652 struct gdbarch *gdbarch;
5653 int stopped_by_watchpoint;
5654 enum stop_kind stop_soon;
5655 int random_signal;
5656
5657 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5658
5659 /* Do we need to clean up the state of a thread that has
5660 completed a displaced single-step? (Doing so usually affects
5661 the PC, so do it here, before we set stop_pc.) */
5662 if (finish_step_over (ecs))
5663 return;
5664
5665 /* If we either finished a single-step or hit a breakpoint, but
5666 the user wanted this thread to be stopped, pretend we got a
5667 SIG0 (generic unsignaled stop). */
5668 if (ecs->event_thread->stop_requested
5669 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5670 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5671
5672 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5673
5674 if (debug_infrun)
5675 {
5676 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5677 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5678 struct cleanup *old_chain = save_inferior_ptid ();
5679
5680 inferior_ptid = ecs->ptid;
5681
5682 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5683 paddress (gdbarch, stop_pc));
5684 if (target_stopped_by_watchpoint ())
5685 {
5686 CORE_ADDR addr;
5687
5688 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5689
5690 if (target_stopped_data_address (&current_target, &addr))
5691 fprintf_unfiltered (gdb_stdlog,
5692 "infrun: stopped data address = %s\n",
5693 paddress (gdbarch, addr));
5694 else
5695 fprintf_unfiltered (gdb_stdlog,
5696 "infrun: (no data address available)\n");
5697 }
5698
5699 do_cleanups (old_chain);
5700 }
5701
5702 /* This is originated from start_remote(), start_inferior() and
5703 shared libraries hook functions. */
5704 stop_soon = get_inferior_stop_soon (ecs->ptid);
5705 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5706 {
5707 if (!ptid_equal (ecs->ptid, inferior_ptid))
5708 context_switch (ecs->ptid);
5709 if (debug_infrun)
5710 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5711 stop_print_frame = 1;
5712 stop_waiting (ecs);
5713 return;
5714 }
5715
5716 /* This originates from attach_command(). We need to overwrite
5717 the stop_signal here, because some kernels don't ignore a
5718 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5719 See more comments in inferior.h. On the other hand, if we
5720 get a non-SIGSTOP, report it to the user - assume the backend
5721 will handle the SIGSTOP if it should show up later.
5722
5723 Also consider that the attach is complete when we see a
5724 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5725 target extended-remote report it instead of a SIGSTOP
5726 (e.g. gdbserver). We already rely on SIGTRAP being our
5727 signal, so this is no exception.
5728
5729 Also consider that the attach is complete when we see a
5730 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5731 the target to stop all threads of the inferior, in case the
5732 low level attach operation doesn't stop them implicitly. If
5733 they weren't stopped implicitly, then the stub will report a
5734 GDB_SIGNAL_0, meaning: stopped for no particular reason
5735 other than GDB's request. */
5736 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5737 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5738 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5739 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5740 {
5741 stop_print_frame = 1;
5742 stop_waiting (ecs);
5743 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5744 return;
5745 }
5746
5747 /* See if something interesting happened to the non-current thread. If
5748 so, then switch to that thread. */
5749 if (!ptid_equal (ecs->ptid, inferior_ptid))
5750 {
5751 if (debug_infrun)
5752 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5753
5754 context_switch (ecs->ptid);
5755
5756 if (deprecated_context_hook)
5757 deprecated_context_hook (ptid_to_global_thread_id (ecs->ptid));
5758 }
5759
5760 /* At this point, get hold of the now-current thread's frame. */
5761 frame = get_current_frame ();
5762 gdbarch = get_frame_arch (frame);
5763
5764 /* Pull the single step breakpoints out of the target. */
5765 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5766 {
5767 struct regcache *regcache;
5768 struct address_space *aspace;
5769 CORE_ADDR pc;
5770
5771 regcache = get_thread_regcache (ecs->ptid);
5772 aspace = get_regcache_aspace (regcache);
5773 pc = regcache_read_pc (regcache);
5774
5775 /* However, before doing so, if this single-step breakpoint was
5776 actually for another thread, set this thread up for moving
5777 past it. */
5778 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5779 aspace, pc))
5780 {
5781 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5782 {
5783 if (debug_infrun)
5784 {
5785 fprintf_unfiltered (gdb_stdlog,
5786 "infrun: [%s] hit another thread's "
5787 "single-step breakpoint\n",
5788 target_pid_to_str (ecs->ptid));
5789 }
5790 ecs->hit_singlestep_breakpoint = 1;
5791 }
5792 }
5793 else
5794 {
5795 if (debug_infrun)
5796 {
5797 fprintf_unfiltered (gdb_stdlog,
5798 "infrun: [%s] hit its "
5799 "single-step breakpoint\n",
5800 target_pid_to_str (ecs->ptid));
5801 }
5802 }
5803 }
5804 delete_just_stopped_threads_single_step_breakpoints ();
5805
5806 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5807 && ecs->event_thread->control.trap_expected
5808 && ecs->event_thread->stepping_over_watchpoint)
5809 stopped_by_watchpoint = 0;
5810 else
5811 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5812
5813 /* If necessary, step over this watchpoint. We'll be back to display
5814 it in a moment. */
5815 if (stopped_by_watchpoint
5816 && (target_have_steppable_watchpoint
5817 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5818 {
5819 /* At this point, we are stopped at an instruction which has
5820 attempted to write to a piece of memory under control of
5821 a watchpoint. The instruction hasn't actually executed
5822 yet. If we were to evaluate the watchpoint expression
5823 now, we would get the old value, and therefore no change
5824 would seem to have occurred.
5825
5826 In order to make watchpoints work `right', we really need
5827 to complete the memory write, and then evaluate the
5828 watchpoint expression. We do this by single-stepping the
5829 target.
5830
5831 It may not be necessary to disable the watchpoint to step over
5832 it. For example, the PA can (with some kernel cooperation)
5833 single step over a watchpoint without disabling the watchpoint.
5834
5835 It is far more common to need to disable a watchpoint to step
5836 the inferior over it. If we have non-steppable watchpoints,
5837 we must disable the current watchpoint; it's simplest to
5838 disable all watchpoints.
5839
5840 Any breakpoint at PC must also be stepped over -- if there's
5841 one, it will have already triggered before the watchpoint
5842 triggered, and we either already reported it to the user, or
5843 it didn't cause a stop and we called keep_going. In either
5844 case, if there was a breakpoint at PC, we must be trying to
5845 step past it. */
5846 ecs->event_thread->stepping_over_watchpoint = 1;
5847 keep_going (ecs);
5848 return;
5849 }
5850
5851 ecs->event_thread->stepping_over_breakpoint = 0;
5852 ecs->event_thread->stepping_over_watchpoint = 0;
5853 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5854 ecs->event_thread->control.stop_step = 0;
5855 stop_print_frame = 1;
5856 stopped_by_random_signal = 0;
5857
5858 /* Hide inlined functions starting here, unless we just performed stepi or
5859 nexti. After stepi and nexti, always show the innermost frame (not any
5860 inline function call sites). */
5861 if (ecs->event_thread->control.step_range_end != 1)
5862 {
5863 struct address_space *aspace =
5864 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5865
5866 /* skip_inline_frames is expensive, so we avoid it if we can
5867 determine that the address is one where functions cannot have
5868 been inlined. This improves performance with inferiors that
5869 load a lot of shared libraries, because the solib event
5870 breakpoint is defined as the address of a function (i.e. not
5871 inline). Note that we have to check the previous PC as well
5872 as the current one to catch cases when we have just
5873 single-stepped off a breakpoint prior to reinstating it.
5874 Note that we're assuming that the code we single-step to is
5875 not inline, but that's not definitive: there's nothing
5876 preventing the event breakpoint function from containing
5877 inlined code, and the single-step ending up there. If the
5878 user had set a breakpoint on that inlined code, the missing
5879 skip_inline_frames call would break things. Fortunately
5880 that's an extremely unlikely scenario. */
5881 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5882 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5883 && ecs->event_thread->control.trap_expected
5884 && pc_at_non_inline_function (aspace,
5885 ecs->event_thread->prev_pc,
5886 &ecs->ws)))
5887 {
5888 skip_inline_frames (ecs->ptid);
5889
5890 /* Re-fetch current thread's frame in case that invalidated
5891 the frame cache. */
5892 frame = get_current_frame ();
5893 gdbarch = get_frame_arch (frame);
5894 }
5895 }
5896
5897 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5898 && ecs->event_thread->control.trap_expected
5899 && gdbarch_single_step_through_delay_p (gdbarch)
5900 && currently_stepping (ecs->event_thread))
5901 {
5902 /* We're trying to step off a breakpoint. Turns out that we're
5903 also on an instruction that needs to be stepped multiple
5904 times before it's been fully executing. E.g., architectures
5905 with a delay slot. It needs to be stepped twice, once for
5906 the instruction and once for the delay slot. */
5907 int step_through_delay
5908 = gdbarch_single_step_through_delay (gdbarch, frame);
5909
5910 if (debug_infrun && step_through_delay)
5911 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5912 if (ecs->event_thread->control.step_range_end == 0
5913 && step_through_delay)
5914 {
5915 /* The user issued a continue when stopped at a breakpoint.
5916 Set up for another trap and get out of here. */
5917 ecs->event_thread->stepping_over_breakpoint = 1;
5918 keep_going (ecs);
5919 return;
5920 }
5921 else if (step_through_delay)
5922 {
5923 /* The user issued a step when stopped at a breakpoint.
5924 Maybe we should stop, maybe we should not - the delay
5925 slot *might* correspond to a line of source. In any
5926 case, don't decide that here, just set
5927 ecs->stepping_over_breakpoint, making sure we
5928 single-step again before breakpoints are re-inserted. */
5929 ecs->event_thread->stepping_over_breakpoint = 1;
5930 }
5931 }
5932
5933 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5934 handles this event. */
5935 ecs->event_thread->control.stop_bpstat
5936 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5937 stop_pc, ecs->ptid, &ecs->ws);
5938
5939 /* Following in case break condition called a
5940 function. */
5941 stop_print_frame = 1;
5942
5943 /* This is where we handle "moribund" watchpoints. Unlike
5944 software breakpoints traps, hardware watchpoint traps are
5945 always distinguishable from random traps. If no high-level
5946 watchpoint is associated with the reported stop data address
5947 anymore, then the bpstat does not explain the signal ---
5948 simply make sure to ignore it if `stopped_by_watchpoint' is
5949 set. */
5950
5951 if (debug_infrun
5952 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5953 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5954 GDB_SIGNAL_TRAP)
5955 && stopped_by_watchpoint)
5956 fprintf_unfiltered (gdb_stdlog,
5957 "infrun: no user watchpoint explains "
5958 "watchpoint SIGTRAP, ignoring\n");
5959
5960 /* NOTE: cagney/2003-03-29: These checks for a random signal
5961 at one stage in the past included checks for an inferior
5962 function call's call dummy's return breakpoint. The original
5963 comment, that went with the test, read:
5964
5965 ``End of a stack dummy. Some systems (e.g. Sony news) give
5966 another signal besides SIGTRAP, so check here as well as
5967 above.''
5968
5969 If someone ever tries to get call dummys on a
5970 non-executable stack to work (where the target would stop
5971 with something like a SIGSEGV), then those tests might need
5972 to be re-instated. Given, however, that the tests were only
5973 enabled when momentary breakpoints were not being used, I
5974 suspect that it won't be the case.
5975
5976 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5977 be necessary for call dummies on a non-executable stack on
5978 SPARC. */
5979
5980 /* See if the breakpoints module can explain the signal. */
5981 random_signal
5982 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5983 ecs->event_thread->suspend.stop_signal);
5984
5985 /* Maybe this was a trap for a software breakpoint that has since
5986 been removed. */
5987 if (random_signal && target_stopped_by_sw_breakpoint ())
5988 {
5989 if (program_breakpoint_here_p (gdbarch, stop_pc))
5990 {
5991 struct regcache *regcache;
5992 int decr_pc;
5993
5994 /* Re-adjust PC to what the program would see if GDB was not
5995 debugging it. */
5996 regcache = get_thread_regcache (ecs->event_thread->ptid);
5997 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5998 if (decr_pc != 0)
5999 {
6000 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
6001
6002 if (record_full_is_used ())
6003 record_full_gdb_operation_disable_set ();
6004
6005 regcache_write_pc (regcache, stop_pc + decr_pc);
6006
6007 do_cleanups (old_cleanups);
6008 }
6009 }
6010 else
6011 {
6012 /* A delayed software breakpoint event. Ignore the trap. */
6013 if (debug_infrun)
6014 fprintf_unfiltered (gdb_stdlog,
6015 "infrun: delayed software breakpoint "
6016 "trap, ignoring\n");
6017 random_signal = 0;
6018 }
6019 }
6020
6021 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6022 has since been removed. */
6023 if (random_signal && target_stopped_by_hw_breakpoint ())
6024 {
6025 /* A delayed hardware breakpoint event. Ignore the trap. */
6026 if (debug_infrun)
6027 fprintf_unfiltered (gdb_stdlog,
6028 "infrun: delayed hardware breakpoint/watchpoint "
6029 "trap, ignoring\n");
6030 random_signal = 0;
6031 }
6032
6033 /* If not, perhaps stepping/nexting can. */
6034 if (random_signal)
6035 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6036 && currently_stepping (ecs->event_thread));
6037
6038 /* Perhaps the thread hit a single-step breakpoint of _another_
6039 thread. Single-step breakpoints are transparent to the
6040 breakpoints module. */
6041 if (random_signal)
6042 random_signal = !ecs->hit_singlestep_breakpoint;
6043
6044 /* No? Perhaps we got a moribund watchpoint. */
6045 if (random_signal)
6046 random_signal = !stopped_by_watchpoint;
6047
6048 /* For the program's own signals, act according to
6049 the signal handling tables. */
6050
6051 if (random_signal)
6052 {
6053 /* Signal not for debugging purposes. */
6054 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6055 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6056
6057 if (debug_infrun)
6058 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6059 gdb_signal_to_symbol_string (stop_signal));
6060
6061 stopped_by_random_signal = 1;
6062
6063 /* Always stop on signals if we're either just gaining control
6064 of the program, or the user explicitly requested this thread
6065 to remain stopped. */
6066 if (stop_soon != NO_STOP_QUIETLY
6067 || ecs->event_thread->stop_requested
6068 || (!inf->detaching
6069 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6070 {
6071 stop_waiting (ecs);
6072 return;
6073 }
6074
6075 /* Notify observers the signal has "handle print" set. Note we
6076 returned early above if stopping; normal_stop handles the
6077 printing in that case. */
6078 if (signal_print[ecs->event_thread->suspend.stop_signal])
6079 {
6080 /* The signal table tells us to print about this signal. */
6081 target_terminal_ours_for_output ();
6082 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
6083 target_terminal_inferior ();
6084 }
6085
6086 /* Clear the signal if it should not be passed. */
6087 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6088 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6089
6090 if (ecs->event_thread->prev_pc == stop_pc
6091 && ecs->event_thread->control.trap_expected
6092 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6093 {
6094 int was_in_line;
6095
6096 /* We were just starting a new sequence, attempting to
6097 single-step off of a breakpoint and expecting a SIGTRAP.
6098 Instead this signal arrives. This signal will take us out
6099 of the stepping range so GDB needs to remember to, when
6100 the signal handler returns, resume stepping off that
6101 breakpoint. */
6102 /* To simplify things, "continue" is forced to use the same
6103 code paths as single-step - set a breakpoint at the
6104 signal return address and then, once hit, step off that
6105 breakpoint. */
6106 if (debug_infrun)
6107 fprintf_unfiltered (gdb_stdlog,
6108 "infrun: signal arrived while stepping over "
6109 "breakpoint\n");
6110
6111 was_in_line = step_over_info_valid_p ();
6112 clear_step_over_info ();
6113 insert_hp_step_resume_breakpoint_at_frame (frame);
6114 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6115 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6116 ecs->event_thread->control.trap_expected = 0;
6117
6118 if (target_is_non_stop_p ())
6119 {
6120 /* Either "set non-stop" is "on", or the target is
6121 always in non-stop mode. In this case, we have a bit
6122 more work to do. Resume the current thread, and if
6123 we had paused all threads, restart them while the
6124 signal handler runs. */
6125 keep_going (ecs);
6126
6127 if (was_in_line)
6128 {
6129 restart_threads (ecs->event_thread);
6130 }
6131 else if (debug_infrun)
6132 {
6133 fprintf_unfiltered (gdb_stdlog,
6134 "infrun: no need to restart threads\n");
6135 }
6136 return;
6137 }
6138
6139 /* If we were nexting/stepping some other thread, switch to
6140 it, so that we don't continue it, losing control. */
6141 if (!switch_back_to_stepped_thread (ecs))
6142 keep_going (ecs);
6143 return;
6144 }
6145
6146 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6147 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6148 || ecs->event_thread->control.step_range_end == 1)
6149 && frame_id_eq (get_stack_frame_id (frame),
6150 ecs->event_thread->control.step_stack_frame_id)
6151 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6152 {
6153 /* The inferior is about to take a signal that will take it
6154 out of the single step range. Set a breakpoint at the
6155 current PC (which is presumably where the signal handler
6156 will eventually return) and then allow the inferior to
6157 run free.
6158
6159 Note that this is only needed for a signal delivered
6160 while in the single-step range. Nested signals aren't a
6161 problem as they eventually all return. */
6162 if (debug_infrun)
6163 fprintf_unfiltered (gdb_stdlog,
6164 "infrun: signal may take us out of "
6165 "single-step range\n");
6166
6167 clear_step_over_info ();
6168 insert_hp_step_resume_breakpoint_at_frame (frame);
6169 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6170 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6171 ecs->event_thread->control.trap_expected = 0;
6172 keep_going (ecs);
6173 return;
6174 }
6175
6176 /* Note: step_resume_breakpoint may be non-NULL. This occures
6177 when either there's a nested signal, or when there's a
6178 pending signal enabled just as the signal handler returns
6179 (leaving the inferior at the step-resume-breakpoint without
6180 actually executing it). Either way continue until the
6181 breakpoint is really hit. */
6182
6183 if (!switch_back_to_stepped_thread (ecs))
6184 {
6185 if (debug_infrun)
6186 fprintf_unfiltered (gdb_stdlog,
6187 "infrun: random signal, keep going\n");
6188
6189 keep_going (ecs);
6190 }
6191 return;
6192 }
6193
6194 process_event_stop_test (ecs);
6195 }
6196
6197 /* Come here when we've got some debug event / signal we can explain
6198 (IOW, not a random signal), and test whether it should cause a
6199 stop, or whether we should resume the inferior (transparently).
6200 E.g., could be a breakpoint whose condition evaluates false; we
6201 could be still stepping within the line; etc. */
6202
6203 static void
6204 process_event_stop_test (struct execution_control_state *ecs)
6205 {
6206 struct symtab_and_line stop_pc_sal;
6207 struct frame_info *frame;
6208 struct gdbarch *gdbarch;
6209 CORE_ADDR jmp_buf_pc;
6210 struct bpstat_what what;
6211
6212 /* Handle cases caused by hitting a breakpoint. */
6213
6214 frame = get_current_frame ();
6215 gdbarch = get_frame_arch (frame);
6216
6217 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6218
6219 if (what.call_dummy)
6220 {
6221 stop_stack_dummy = what.call_dummy;
6222 }
6223
6224 /* A few breakpoint types have callbacks associated (e.g.,
6225 bp_jit_event). Run them now. */
6226 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6227
6228 /* If we hit an internal event that triggers symbol changes, the
6229 current frame will be invalidated within bpstat_what (e.g., if we
6230 hit an internal solib event). Re-fetch it. */
6231 frame = get_current_frame ();
6232 gdbarch = get_frame_arch (frame);
6233
6234 switch (what.main_action)
6235 {
6236 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6237 /* If we hit the breakpoint at longjmp while stepping, we
6238 install a momentary breakpoint at the target of the
6239 jmp_buf. */
6240
6241 if (debug_infrun)
6242 fprintf_unfiltered (gdb_stdlog,
6243 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6244
6245 ecs->event_thread->stepping_over_breakpoint = 1;
6246
6247 if (what.is_longjmp)
6248 {
6249 struct value *arg_value;
6250
6251 /* If we set the longjmp breakpoint via a SystemTap probe,
6252 then use it to extract the arguments. The destination PC
6253 is the third argument to the probe. */
6254 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6255 if (arg_value)
6256 {
6257 jmp_buf_pc = value_as_address (arg_value);
6258 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6259 }
6260 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6261 || !gdbarch_get_longjmp_target (gdbarch,
6262 frame, &jmp_buf_pc))
6263 {
6264 if (debug_infrun)
6265 fprintf_unfiltered (gdb_stdlog,
6266 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6267 "(!gdbarch_get_longjmp_target)\n");
6268 keep_going (ecs);
6269 return;
6270 }
6271
6272 /* Insert a breakpoint at resume address. */
6273 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6274 }
6275 else
6276 check_exception_resume (ecs, frame);
6277 keep_going (ecs);
6278 return;
6279
6280 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6281 {
6282 struct frame_info *init_frame;
6283
6284 /* There are several cases to consider.
6285
6286 1. The initiating frame no longer exists. In this case we
6287 must stop, because the exception or longjmp has gone too
6288 far.
6289
6290 2. The initiating frame exists, and is the same as the
6291 current frame. We stop, because the exception or longjmp
6292 has been caught.
6293
6294 3. The initiating frame exists and is different from the
6295 current frame. This means the exception or longjmp has
6296 been caught beneath the initiating frame, so keep going.
6297
6298 4. longjmp breakpoint has been placed just to protect
6299 against stale dummy frames and user is not interested in
6300 stopping around longjmps. */
6301
6302 if (debug_infrun)
6303 fprintf_unfiltered (gdb_stdlog,
6304 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6305
6306 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6307 != NULL);
6308 delete_exception_resume_breakpoint (ecs->event_thread);
6309
6310 if (what.is_longjmp)
6311 {
6312 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6313
6314 if (!frame_id_p (ecs->event_thread->initiating_frame))
6315 {
6316 /* Case 4. */
6317 keep_going (ecs);
6318 return;
6319 }
6320 }
6321
6322 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6323
6324 if (init_frame)
6325 {
6326 struct frame_id current_id
6327 = get_frame_id (get_current_frame ());
6328 if (frame_id_eq (current_id,
6329 ecs->event_thread->initiating_frame))
6330 {
6331 /* Case 2. Fall through. */
6332 }
6333 else
6334 {
6335 /* Case 3. */
6336 keep_going (ecs);
6337 return;
6338 }
6339 }
6340
6341 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6342 exists. */
6343 delete_step_resume_breakpoint (ecs->event_thread);
6344
6345 end_stepping_range (ecs);
6346 }
6347 return;
6348
6349 case BPSTAT_WHAT_SINGLE:
6350 if (debug_infrun)
6351 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6352 ecs->event_thread->stepping_over_breakpoint = 1;
6353 /* Still need to check other stuff, at least the case where we
6354 are stepping and step out of the right range. */
6355 break;
6356
6357 case BPSTAT_WHAT_STEP_RESUME:
6358 if (debug_infrun)
6359 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6360
6361 delete_step_resume_breakpoint (ecs->event_thread);
6362 if (ecs->event_thread->control.proceed_to_finish
6363 && execution_direction == EXEC_REVERSE)
6364 {
6365 struct thread_info *tp = ecs->event_thread;
6366
6367 /* We are finishing a function in reverse, and just hit the
6368 step-resume breakpoint at the start address of the
6369 function, and we're almost there -- just need to back up
6370 by one more single-step, which should take us back to the
6371 function call. */
6372 tp->control.step_range_start = tp->control.step_range_end = 1;
6373 keep_going (ecs);
6374 return;
6375 }
6376 fill_in_stop_func (gdbarch, ecs);
6377 if (stop_pc == ecs->stop_func_start
6378 && execution_direction == EXEC_REVERSE)
6379 {
6380 /* We are stepping over a function call in reverse, and just
6381 hit the step-resume breakpoint at the start address of
6382 the function. Go back to single-stepping, which should
6383 take us back to the function call. */
6384 ecs->event_thread->stepping_over_breakpoint = 1;
6385 keep_going (ecs);
6386 return;
6387 }
6388 break;
6389
6390 case BPSTAT_WHAT_STOP_NOISY:
6391 if (debug_infrun)
6392 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6393 stop_print_frame = 1;
6394
6395 /* Assume the thread stopped for a breapoint. We'll still check
6396 whether a/the breakpoint is there when the thread is next
6397 resumed. */
6398 ecs->event_thread->stepping_over_breakpoint = 1;
6399
6400 stop_waiting (ecs);
6401 return;
6402
6403 case BPSTAT_WHAT_STOP_SILENT:
6404 if (debug_infrun)
6405 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6406 stop_print_frame = 0;
6407
6408 /* Assume the thread stopped for a breapoint. We'll still check
6409 whether a/the breakpoint is there when the thread is next
6410 resumed. */
6411 ecs->event_thread->stepping_over_breakpoint = 1;
6412 stop_waiting (ecs);
6413 return;
6414
6415 case BPSTAT_WHAT_HP_STEP_RESUME:
6416 if (debug_infrun)
6417 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6418
6419 delete_step_resume_breakpoint (ecs->event_thread);
6420 if (ecs->event_thread->step_after_step_resume_breakpoint)
6421 {
6422 /* Back when the step-resume breakpoint was inserted, we
6423 were trying to single-step off a breakpoint. Go back to
6424 doing that. */
6425 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6426 ecs->event_thread->stepping_over_breakpoint = 1;
6427 keep_going (ecs);
6428 return;
6429 }
6430 break;
6431
6432 case BPSTAT_WHAT_KEEP_CHECKING:
6433 break;
6434 }
6435
6436 /* If we stepped a permanent breakpoint and we had a high priority
6437 step-resume breakpoint for the address we stepped, but we didn't
6438 hit it, then we must have stepped into the signal handler. The
6439 step-resume was only necessary to catch the case of _not_
6440 stepping into the handler, so delete it, and fall through to
6441 checking whether the step finished. */
6442 if (ecs->event_thread->stepped_breakpoint)
6443 {
6444 struct breakpoint *sr_bp
6445 = ecs->event_thread->control.step_resume_breakpoint;
6446
6447 if (sr_bp != NULL
6448 && sr_bp->loc->permanent
6449 && sr_bp->type == bp_hp_step_resume
6450 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6451 {
6452 if (debug_infrun)
6453 fprintf_unfiltered (gdb_stdlog,
6454 "infrun: stepped permanent breakpoint, stopped in "
6455 "handler\n");
6456 delete_step_resume_breakpoint (ecs->event_thread);
6457 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6458 }
6459 }
6460
6461 /* We come here if we hit a breakpoint but should not stop for it.
6462 Possibly we also were stepping and should stop for that. So fall
6463 through and test for stepping. But, if not stepping, do not
6464 stop. */
6465
6466 /* In all-stop mode, if we're currently stepping but have stopped in
6467 some other thread, we need to switch back to the stepped thread. */
6468 if (switch_back_to_stepped_thread (ecs))
6469 return;
6470
6471 if (ecs->event_thread->control.step_resume_breakpoint)
6472 {
6473 if (debug_infrun)
6474 fprintf_unfiltered (gdb_stdlog,
6475 "infrun: step-resume breakpoint is inserted\n");
6476
6477 /* Having a step-resume breakpoint overrides anything
6478 else having to do with stepping commands until
6479 that breakpoint is reached. */
6480 keep_going (ecs);
6481 return;
6482 }
6483
6484 if (ecs->event_thread->control.step_range_end == 0)
6485 {
6486 if (debug_infrun)
6487 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6488 /* Likewise if we aren't even stepping. */
6489 keep_going (ecs);
6490 return;
6491 }
6492
6493 /* Re-fetch current thread's frame in case the code above caused
6494 the frame cache to be re-initialized, making our FRAME variable
6495 a dangling pointer. */
6496 frame = get_current_frame ();
6497 gdbarch = get_frame_arch (frame);
6498 fill_in_stop_func (gdbarch, ecs);
6499
6500 /* If stepping through a line, keep going if still within it.
6501
6502 Note that step_range_end is the address of the first instruction
6503 beyond the step range, and NOT the address of the last instruction
6504 within it!
6505
6506 Note also that during reverse execution, we may be stepping
6507 through a function epilogue and therefore must detect when
6508 the current-frame changes in the middle of a line. */
6509
6510 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6511 && (execution_direction != EXEC_REVERSE
6512 || frame_id_eq (get_frame_id (frame),
6513 ecs->event_thread->control.step_frame_id)))
6514 {
6515 if (debug_infrun)
6516 fprintf_unfiltered
6517 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6518 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6519 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6520
6521 /* Tentatively re-enable range stepping; `resume' disables it if
6522 necessary (e.g., if we're stepping over a breakpoint or we
6523 have software watchpoints). */
6524 ecs->event_thread->control.may_range_step = 1;
6525
6526 /* When stepping backward, stop at beginning of line range
6527 (unless it's the function entry point, in which case
6528 keep going back to the call point). */
6529 if (stop_pc == ecs->event_thread->control.step_range_start
6530 && stop_pc != ecs->stop_func_start
6531 && execution_direction == EXEC_REVERSE)
6532 end_stepping_range (ecs);
6533 else
6534 keep_going (ecs);
6535
6536 return;
6537 }
6538
6539 /* We stepped out of the stepping range. */
6540
6541 /* If we are stepping at the source level and entered the runtime
6542 loader dynamic symbol resolution code...
6543
6544 EXEC_FORWARD: we keep on single stepping until we exit the run
6545 time loader code and reach the callee's address.
6546
6547 EXEC_REVERSE: we've already executed the callee (backward), and
6548 the runtime loader code is handled just like any other
6549 undebuggable function call. Now we need only keep stepping
6550 backward through the trampoline code, and that's handled further
6551 down, so there is nothing for us to do here. */
6552
6553 if (execution_direction != EXEC_REVERSE
6554 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6555 && in_solib_dynsym_resolve_code (stop_pc))
6556 {
6557 CORE_ADDR pc_after_resolver =
6558 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6559
6560 if (debug_infrun)
6561 fprintf_unfiltered (gdb_stdlog,
6562 "infrun: stepped into dynsym resolve code\n");
6563
6564 if (pc_after_resolver)
6565 {
6566 /* Set up a step-resume breakpoint at the address
6567 indicated by SKIP_SOLIB_RESOLVER. */
6568 struct symtab_and_line sr_sal;
6569
6570 init_sal (&sr_sal);
6571 sr_sal.pc = pc_after_resolver;
6572 sr_sal.pspace = get_frame_program_space (frame);
6573
6574 insert_step_resume_breakpoint_at_sal (gdbarch,
6575 sr_sal, null_frame_id);
6576 }
6577
6578 keep_going (ecs);
6579 return;
6580 }
6581
6582 if (ecs->event_thread->control.step_range_end != 1
6583 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6584 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6585 && get_frame_type (frame) == SIGTRAMP_FRAME)
6586 {
6587 if (debug_infrun)
6588 fprintf_unfiltered (gdb_stdlog,
6589 "infrun: stepped into signal trampoline\n");
6590 /* The inferior, while doing a "step" or "next", has ended up in
6591 a signal trampoline (either by a signal being delivered or by
6592 the signal handler returning). Just single-step until the
6593 inferior leaves the trampoline (either by calling the handler
6594 or returning). */
6595 keep_going (ecs);
6596 return;
6597 }
6598
6599 /* If we're in the return path from a shared library trampoline,
6600 we want to proceed through the trampoline when stepping. */
6601 /* macro/2012-04-25: This needs to come before the subroutine
6602 call check below as on some targets return trampolines look
6603 like subroutine calls (MIPS16 return thunks). */
6604 if (gdbarch_in_solib_return_trampoline (gdbarch,
6605 stop_pc, ecs->stop_func_name)
6606 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6607 {
6608 /* Determine where this trampoline returns. */
6609 CORE_ADDR real_stop_pc;
6610
6611 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6612
6613 if (debug_infrun)
6614 fprintf_unfiltered (gdb_stdlog,
6615 "infrun: stepped into solib return tramp\n");
6616
6617 /* Only proceed through if we know where it's going. */
6618 if (real_stop_pc)
6619 {
6620 /* And put the step-breakpoint there and go until there. */
6621 struct symtab_and_line sr_sal;
6622
6623 init_sal (&sr_sal); /* initialize to zeroes */
6624 sr_sal.pc = real_stop_pc;
6625 sr_sal.section = find_pc_overlay (sr_sal.pc);
6626 sr_sal.pspace = get_frame_program_space (frame);
6627
6628 /* Do not specify what the fp should be when we stop since
6629 on some machines the prologue is where the new fp value
6630 is established. */
6631 insert_step_resume_breakpoint_at_sal (gdbarch,
6632 sr_sal, null_frame_id);
6633
6634 /* Restart without fiddling with the step ranges or
6635 other state. */
6636 keep_going (ecs);
6637 return;
6638 }
6639 }
6640
6641 /* Check for subroutine calls. The check for the current frame
6642 equalling the step ID is not necessary - the check of the
6643 previous frame's ID is sufficient - but it is a common case and
6644 cheaper than checking the previous frame's ID.
6645
6646 NOTE: frame_id_eq will never report two invalid frame IDs as
6647 being equal, so to get into this block, both the current and
6648 previous frame must have valid frame IDs. */
6649 /* The outer_frame_id check is a heuristic to detect stepping
6650 through startup code. If we step over an instruction which
6651 sets the stack pointer from an invalid value to a valid value,
6652 we may detect that as a subroutine call from the mythical
6653 "outermost" function. This could be fixed by marking
6654 outermost frames as !stack_p,code_p,special_p. Then the
6655 initial outermost frame, before sp was valid, would
6656 have code_addr == &_start. See the comment in frame_id_eq
6657 for more. */
6658 if (!frame_id_eq (get_stack_frame_id (frame),
6659 ecs->event_thread->control.step_stack_frame_id)
6660 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6661 ecs->event_thread->control.step_stack_frame_id)
6662 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6663 outer_frame_id)
6664 || (ecs->event_thread->control.step_start_function
6665 != find_pc_function (stop_pc)))))
6666 {
6667 CORE_ADDR real_stop_pc;
6668
6669 if (debug_infrun)
6670 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6671
6672 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6673 {
6674 /* I presume that step_over_calls is only 0 when we're
6675 supposed to be stepping at the assembly language level
6676 ("stepi"). Just stop. */
6677 /* And this works the same backward as frontward. MVS */
6678 end_stepping_range (ecs);
6679 return;
6680 }
6681
6682 /* Reverse stepping through solib trampolines. */
6683
6684 if (execution_direction == EXEC_REVERSE
6685 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6686 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6687 || (ecs->stop_func_start == 0
6688 && in_solib_dynsym_resolve_code (stop_pc))))
6689 {
6690 /* Any solib trampoline code can be handled in reverse
6691 by simply continuing to single-step. We have already
6692 executed the solib function (backwards), and a few
6693 steps will take us back through the trampoline to the
6694 caller. */
6695 keep_going (ecs);
6696 return;
6697 }
6698
6699 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6700 {
6701 /* We're doing a "next".
6702
6703 Normal (forward) execution: set a breakpoint at the
6704 callee's return address (the address at which the caller
6705 will resume).
6706
6707 Reverse (backward) execution. set the step-resume
6708 breakpoint at the start of the function that we just
6709 stepped into (backwards), and continue to there. When we
6710 get there, we'll need to single-step back to the caller. */
6711
6712 if (execution_direction == EXEC_REVERSE)
6713 {
6714 /* If we're already at the start of the function, we've either
6715 just stepped backward into a single instruction function,
6716 or stepped back out of a signal handler to the first instruction
6717 of the function. Just keep going, which will single-step back
6718 to the caller. */
6719 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6720 {
6721 struct symtab_and_line sr_sal;
6722
6723 /* Normal function call return (static or dynamic). */
6724 init_sal (&sr_sal);
6725 sr_sal.pc = ecs->stop_func_start;
6726 sr_sal.pspace = get_frame_program_space (frame);
6727 insert_step_resume_breakpoint_at_sal (gdbarch,
6728 sr_sal, null_frame_id);
6729 }
6730 }
6731 else
6732 insert_step_resume_breakpoint_at_caller (frame);
6733
6734 keep_going (ecs);
6735 return;
6736 }
6737
6738 /* If we are in a function call trampoline (a stub between the
6739 calling routine and the real function), locate the real
6740 function. That's what tells us (a) whether we want to step
6741 into it at all, and (b) what prologue we want to run to the
6742 end of, if we do step into it. */
6743 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6744 if (real_stop_pc == 0)
6745 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6746 if (real_stop_pc != 0)
6747 ecs->stop_func_start = real_stop_pc;
6748
6749 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6750 {
6751 struct symtab_and_line sr_sal;
6752
6753 init_sal (&sr_sal);
6754 sr_sal.pc = ecs->stop_func_start;
6755 sr_sal.pspace = get_frame_program_space (frame);
6756
6757 insert_step_resume_breakpoint_at_sal (gdbarch,
6758 sr_sal, null_frame_id);
6759 keep_going (ecs);
6760 return;
6761 }
6762
6763 /* If we have line number information for the function we are
6764 thinking of stepping into and the function isn't on the skip
6765 list, step into it.
6766
6767 If there are several symtabs at that PC (e.g. with include
6768 files), just want to know whether *any* of them have line
6769 numbers. find_pc_line handles this. */
6770 {
6771 struct symtab_and_line tmp_sal;
6772
6773 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6774 if (tmp_sal.line != 0
6775 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6776 &tmp_sal))
6777 {
6778 if (execution_direction == EXEC_REVERSE)
6779 handle_step_into_function_backward (gdbarch, ecs);
6780 else
6781 handle_step_into_function (gdbarch, ecs);
6782 return;
6783 }
6784 }
6785
6786 /* If we have no line number and the step-stop-if-no-debug is
6787 set, we stop the step so that the user has a chance to switch
6788 in assembly mode. */
6789 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6790 && step_stop_if_no_debug)
6791 {
6792 end_stepping_range (ecs);
6793 return;
6794 }
6795
6796 if (execution_direction == EXEC_REVERSE)
6797 {
6798 /* If we're already at the start of the function, we've either just
6799 stepped backward into a single instruction function without line
6800 number info, or stepped back out of a signal handler to the first
6801 instruction of the function without line number info. Just keep
6802 going, which will single-step back to the caller. */
6803 if (ecs->stop_func_start != stop_pc)
6804 {
6805 /* Set a breakpoint at callee's start address.
6806 From there we can step once and be back in the caller. */
6807 struct symtab_and_line sr_sal;
6808
6809 init_sal (&sr_sal);
6810 sr_sal.pc = ecs->stop_func_start;
6811 sr_sal.pspace = get_frame_program_space (frame);
6812 insert_step_resume_breakpoint_at_sal (gdbarch,
6813 sr_sal, null_frame_id);
6814 }
6815 }
6816 else
6817 /* Set a breakpoint at callee's return address (the address
6818 at which the caller will resume). */
6819 insert_step_resume_breakpoint_at_caller (frame);
6820
6821 keep_going (ecs);
6822 return;
6823 }
6824
6825 /* Reverse stepping through solib trampolines. */
6826
6827 if (execution_direction == EXEC_REVERSE
6828 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6829 {
6830 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6831 || (ecs->stop_func_start == 0
6832 && in_solib_dynsym_resolve_code (stop_pc)))
6833 {
6834 /* Any solib trampoline code can be handled in reverse
6835 by simply continuing to single-step. We have already
6836 executed the solib function (backwards), and a few
6837 steps will take us back through the trampoline to the
6838 caller. */
6839 keep_going (ecs);
6840 return;
6841 }
6842 else if (in_solib_dynsym_resolve_code (stop_pc))
6843 {
6844 /* Stepped backward into the solib dynsym resolver.
6845 Set a breakpoint at its start and continue, then
6846 one more step will take us out. */
6847 struct symtab_and_line sr_sal;
6848
6849 init_sal (&sr_sal);
6850 sr_sal.pc = ecs->stop_func_start;
6851 sr_sal.pspace = get_frame_program_space (frame);
6852 insert_step_resume_breakpoint_at_sal (gdbarch,
6853 sr_sal, null_frame_id);
6854 keep_going (ecs);
6855 return;
6856 }
6857 }
6858
6859 stop_pc_sal = find_pc_line (stop_pc, 0);
6860
6861 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6862 the trampoline processing logic, however, there are some trampolines
6863 that have no names, so we should do trampoline handling first. */
6864 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6865 && ecs->stop_func_name == NULL
6866 && stop_pc_sal.line == 0)
6867 {
6868 if (debug_infrun)
6869 fprintf_unfiltered (gdb_stdlog,
6870 "infrun: stepped into undebuggable function\n");
6871
6872 /* The inferior just stepped into, or returned to, an
6873 undebuggable function (where there is no debugging information
6874 and no line number corresponding to the address where the
6875 inferior stopped). Since we want to skip this kind of code,
6876 we keep going until the inferior returns from this
6877 function - unless the user has asked us not to (via
6878 set step-mode) or we no longer know how to get back
6879 to the call site. */
6880 if (step_stop_if_no_debug
6881 || !frame_id_p (frame_unwind_caller_id (frame)))
6882 {
6883 /* If we have no line number and the step-stop-if-no-debug
6884 is set, we stop the step so that the user has a chance to
6885 switch in assembly mode. */
6886 end_stepping_range (ecs);
6887 return;
6888 }
6889 else
6890 {
6891 /* Set a breakpoint at callee's return address (the address
6892 at which the caller will resume). */
6893 insert_step_resume_breakpoint_at_caller (frame);
6894 keep_going (ecs);
6895 return;
6896 }
6897 }
6898
6899 if (ecs->event_thread->control.step_range_end == 1)
6900 {
6901 /* It is stepi or nexti. We always want to stop stepping after
6902 one instruction. */
6903 if (debug_infrun)
6904 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6905 end_stepping_range (ecs);
6906 return;
6907 }
6908
6909 if (stop_pc_sal.line == 0)
6910 {
6911 /* We have no line number information. That means to stop
6912 stepping (does this always happen right after one instruction,
6913 when we do "s" in a function with no line numbers,
6914 or can this happen as a result of a return or longjmp?). */
6915 if (debug_infrun)
6916 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6917 end_stepping_range (ecs);
6918 return;
6919 }
6920
6921 /* Look for "calls" to inlined functions, part one. If the inline
6922 frame machinery detected some skipped call sites, we have entered
6923 a new inline function. */
6924
6925 if (frame_id_eq (get_frame_id (get_current_frame ()),
6926 ecs->event_thread->control.step_frame_id)
6927 && inline_skipped_frames (ecs->ptid))
6928 {
6929 struct symtab_and_line call_sal;
6930
6931 if (debug_infrun)
6932 fprintf_unfiltered (gdb_stdlog,
6933 "infrun: stepped into inlined function\n");
6934
6935 find_frame_sal (get_current_frame (), &call_sal);
6936
6937 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6938 {
6939 /* For "step", we're going to stop. But if the call site
6940 for this inlined function is on the same source line as
6941 we were previously stepping, go down into the function
6942 first. Otherwise stop at the call site. */
6943
6944 if (call_sal.line == ecs->event_thread->current_line
6945 && call_sal.symtab == ecs->event_thread->current_symtab)
6946 step_into_inline_frame (ecs->ptid);
6947
6948 end_stepping_range (ecs);
6949 return;
6950 }
6951 else
6952 {
6953 /* For "next", we should stop at the call site if it is on a
6954 different source line. Otherwise continue through the
6955 inlined function. */
6956 if (call_sal.line == ecs->event_thread->current_line
6957 && call_sal.symtab == ecs->event_thread->current_symtab)
6958 keep_going (ecs);
6959 else
6960 end_stepping_range (ecs);
6961 return;
6962 }
6963 }
6964
6965 /* Look for "calls" to inlined functions, part two. If we are still
6966 in the same real function we were stepping through, but we have
6967 to go further up to find the exact frame ID, we are stepping
6968 through a more inlined call beyond its call site. */
6969
6970 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6971 && !frame_id_eq (get_frame_id (get_current_frame ()),
6972 ecs->event_thread->control.step_frame_id)
6973 && stepped_in_from (get_current_frame (),
6974 ecs->event_thread->control.step_frame_id))
6975 {
6976 if (debug_infrun)
6977 fprintf_unfiltered (gdb_stdlog,
6978 "infrun: stepping through inlined function\n");
6979
6980 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6981 keep_going (ecs);
6982 else
6983 end_stepping_range (ecs);
6984 return;
6985 }
6986
6987 if ((stop_pc == stop_pc_sal.pc)
6988 && (ecs->event_thread->current_line != stop_pc_sal.line
6989 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6990 {
6991 /* We are at the start of a different line. So stop. Note that
6992 we don't stop if we step into the middle of a different line.
6993 That is said to make things like for (;;) statements work
6994 better. */
6995 if (debug_infrun)
6996 fprintf_unfiltered (gdb_stdlog,
6997 "infrun: stepped to a different line\n");
6998 end_stepping_range (ecs);
6999 return;
7000 }
7001
7002 /* We aren't done stepping.
7003
7004 Optimize by setting the stepping range to the line.
7005 (We might not be in the original line, but if we entered a
7006 new line in mid-statement, we continue stepping. This makes
7007 things like for(;;) statements work better.) */
7008
7009 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
7010 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
7011 ecs->event_thread->control.may_range_step = 1;
7012 set_step_info (frame, stop_pc_sal);
7013
7014 if (debug_infrun)
7015 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
7016 keep_going (ecs);
7017 }
7018
7019 /* In all-stop mode, if we're currently stepping but have stopped in
7020 some other thread, we may need to switch back to the stepped
7021 thread. Returns true we set the inferior running, false if we left
7022 it stopped (and the event needs further processing). */
7023
7024 static int
7025 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7026 {
7027 if (!target_is_non_stop_p ())
7028 {
7029 struct thread_info *tp;
7030 struct thread_info *stepping_thread;
7031
7032 /* If any thread is blocked on some internal breakpoint, and we
7033 simply need to step over that breakpoint to get it going
7034 again, do that first. */
7035
7036 /* However, if we see an event for the stepping thread, then we
7037 know all other threads have been moved past their breakpoints
7038 already. Let the caller check whether the step is finished,
7039 etc., before deciding to move it past a breakpoint. */
7040 if (ecs->event_thread->control.step_range_end != 0)
7041 return 0;
7042
7043 /* Check if the current thread is blocked on an incomplete
7044 step-over, interrupted by a random signal. */
7045 if (ecs->event_thread->control.trap_expected
7046 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7047 {
7048 if (debug_infrun)
7049 {
7050 fprintf_unfiltered (gdb_stdlog,
7051 "infrun: need to finish step-over of [%s]\n",
7052 target_pid_to_str (ecs->event_thread->ptid));
7053 }
7054 keep_going (ecs);
7055 return 1;
7056 }
7057
7058 /* Check if the current thread is blocked by a single-step
7059 breakpoint of another thread. */
7060 if (ecs->hit_singlestep_breakpoint)
7061 {
7062 if (debug_infrun)
7063 {
7064 fprintf_unfiltered (gdb_stdlog,
7065 "infrun: need to step [%s] over single-step "
7066 "breakpoint\n",
7067 target_pid_to_str (ecs->ptid));
7068 }
7069 keep_going (ecs);
7070 return 1;
7071 }
7072
7073 /* If this thread needs yet another step-over (e.g., stepping
7074 through a delay slot), do it first before moving on to
7075 another thread. */
7076 if (thread_still_needs_step_over (ecs->event_thread))
7077 {
7078 if (debug_infrun)
7079 {
7080 fprintf_unfiltered (gdb_stdlog,
7081 "infrun: thread [%s] still needs step-over\n",
7082 target_pid_to_str (ecs->event_thread->ptid));
7083 }
7084 keep_going (ecs);
7085 return 1;
7086 }
7087
7088 /* If scheduler locking applies even if not stepping, there's no
7089 need to walk over threads. Above we've checked whether the
7090 current thread is stepping. If some other thread not the
7091 event thread is stepping, then it must be that scheduler
7092 locking is not in effect. */
7093 if (schedlock_applies (ecs->event_thread))
7094 return 0;
7095
7096 /* Otherwise, we no longer expect a trap in the current thread.
7097 Clear the trap_expected flag before switching back -- this is
7098 what keep_going does as well, if we call it. */
7099 ecs->event_thread->control.trap_expected = 0;
7100
7101 /* Likewise, clear the signal if it should not be passed. */
7102 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7103 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7104
7105 /* Do all pending step-overs before actually proceeding with
7106 step/next/etc. */
7107 if (start_step_over ())
7108 {
7109 prepare_to_wait (ecs);
7110 return 1;
7111 }
7112
7113 /* Look for the stepping/nexting thread. */
7114 stepping_thread = NULL;
7115
7116 ALL_NON_EXITED_THREADS (tp)
7117 {
7118 /* Ignore threads of processes the caller is not
7119 resuming. */
7120 if (!sched_multi
7121 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7122 continue;
7123
7124 /* When stepping over a breakpoint, we lock all threads
7125 except the one that needs to move past the breakpoint.
7126 If a non-event thread has this set, the "incomplete
7127 step-over" check above should have caught it earlier. */
7128 if (tp->control.trap_expected)
7129 {
7130 internal_error (__FILE__, __LINE__,
7131 "[%s] has inconsistent state: "
7132 "trap_expected=%d\n",
7133 target_pid_to_str (tp->ptid),
7134 tp->control.trap_expected);
7135 }
7136
7137 /* Did we find the stepping thread? */
7138 if (tp->control.step_range_end)
7139 {
7140 /* Yep. There should only one though. */
7141 gdb_assert (stepping_thread == NULL);
7142
7143 /* The event thread is handled at the top, before we
7144 enter this loop. */
7145 gdb_assert (tp != ecs->event_thread);
7146
7147 /* If some thread other than the event thread is
7148 stepping, then scheduler locking can't be in effect,
7149 otherwise we wouldn't have resumed the current event
7150 thread in the first place. */
7151 gdb_assert (!schedlock_applies (tp));
7152
7153 stepping_thread = tp;
7154 }
7155 }
7156
7157 if (stepping_thread != NULL)
7158 {
7159 if (debug_infrun)
7160 fprintf_unfiltered (gdb_stdlog,
7161 "infrun: switching back to stepped thread\n");
7162
7163 if (keep_going_stepped_thread (stepping_thread))
7164 {
7165 prepare_to_wait (ecs);
7166 return 1;
7167 }
7168 }
7169 }
7170
7171 return 0;
7172 }
7173
7174 /* Set a previously stepped thread back to stepping. Returns true on
7175 success, false if the resume is not possible (e.g., the thread
7176 vanished). */
7177
7178 static int
7179 keep_going_stepped_thread (struct thread_info *tp)
7180 {
7181 struct frame_info *frame;
7182 struct execution_control_state ecss;
7183 struct execution_control_state *ecs = &ecss;
7184
7185 /* If the stepping thread exited, then don't try to switch back and
7186 resume it, which could fail in several different ways depending
7187 on the target. Instead, just keep going.
7188
7189 We can find a stepping dead thread in the thread list in two
7190 cases:
7191
7192 - The target supports thread exit events, and when the target
7193 tries to delete the thread from the thread list, inferior_ptid
7194 pointed at the exiting thread. In such case, calling
7195 delete_thread does not really remove the thread from the list;
7196 instead, the thread is left listed, with 'exited' state.
7197
7198 - The target's debug interface does not support thread exit
7199 events, and so we have no idea whatsoever if the previously
7200 stepping thread is still alive. For that reason, we need to
7201 synchronously query the target now. */
7202
7203 if (is_exited (tp->ptid)
7204 || !target_thread_alive (tp->ptid))
7205 {
7206 if (debug_infrun)
7207 fprintf_unfiltered (gdb_stdlog,
7208 "infrun: not resuming previously "
7209 "stepped thread, it has vanished\n");
7210
7211 delete_thread (tp->ptid);
7212 return 0;
7213 }
7214
7215 if (debug_infrun)
7216 fprintf_unfiltered (gdb_stdlog,
7217 "infrun: resuming previously stepped thread\n");
7218
7219 reset_ecs (ecs, tp);
7220 switch_to_thread (tp->ptid);
7221
7222 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7223 frame = get_current_frame ();
7224
7225 /* If the PC of the thread we were trying to single-step has
7226 changed, then that thread has trapped or been signaled, but the
7227 event has not been reported to GDB yet. Re-poll the target
7228 looking for this particular thread's event (i.e. temporarily
7229 enable schedlock) by:
7230
7231 - setting a break at the current PC
7232 - resuming that particular thread, only (by setting trap
7233 expected)
7234
7235 This prevents us continuously moving the single-step breakpoint
7236 forward, one instruction at a time, overstepping. */
7237
7238 if (stop_pc != tp->prev_pc)
7239 {
7240 ptid_t resume_ptid;
7241
7242 if (debug_infrun)
7243 fprintf_unfiltered (gdb_stdlog,
7244 "infrun: expected thread advanced also (%s -> %s)\n",
7245 paddress (target_gdbarch (), tp->prev_pc),
7246 paddress (target_gdbarch (), stop_pc));
7247
7248 /* Clear the info of the previous step-over, as it's no longer
7249 valid (if the thread was trying to step over a breakpoint, it
7250 has already succeeded). It's what keep_going would do too,
7251 if we called it. Do this before trying to insert the sss
7252 breakpoint, otherwise if we were previously trying to step
7253 over this exact address in another thread, the breakpoint is
7254 skipped. */
7255 clear_step_over_info ();
7256 tp->control.trap_expected = 0;
7257
7258 insert_single_step_breakpoint (get_frame_arch (frame),
7259 get_frame_address_space (frame),
7260 stop_pc);
7261
7262 tp->resumed = 1;
7263 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7264 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7265 }
7266 else
7267 {
7268 if (debug_infrun)
7269 fprintf_unfiltered (gdb_stdlog,
7270 "infrun: expected thread still hasn't advanced\n");
7271
7272 keep_going_pass_signal (ecs);
7273 }
7274 return 1;
7275 }
7276
7277 /* Is thread TP in the middle of (software or hardware)
7278 single-stepping? (Note the result of this function must never be
7279 passed directly as target_resume's STEP parameter.) */
7280
7281 static int
7282 currently_stepping (struct thread_info *tp)
7283 {
7284 return ((tp->control.step_range_end
7285 && tp->control.step_resume_breakpoint == NULL)
7286 || tp->control.trap_expected
7287 || tp->stepped_breakpoint
7288 || bpstat_should_step ());
7289 }
7290
7291 /* Inferior has stepped into a subroutine call with source code that
7292 we should not step over. Do step to the first line of code in
7293 it. */
7294
7295 static void
7296 handle_step_into_function (struct gdbarch *gdbarch,
7297 struct execution_control_state *ecs)
7298 {
7299 struct compunit_symtab *cust;
7300 struct symtab_and_line stop_func_sal, sr_sal;
7301
7302 fill_in_stop_func (gdbarch, ecs);
7303
7304 cust = find_pc_compunit_symtab (stop_pc);
7305 if (cust != NULL && compunit_language (cust) != language_asm)
7306 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7307 ecs->stop_func_start);
7308
7309 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7310 /* Use the step_resume_break to step until the end of the prologue,
7311 even if that involves jumps (as it seems to on the vax under
7312 4.2). */
7313 /* If the prologue ends in the middle of a source line, continue to
7314 the end of that source line (if it is still within the function).
7315 Otherwise, just go to end of prologue. */
7316 if (stop_func_sal.end
7317 && stop_func_sal.pc != ecs->stop_func_start
7318 && stop_func_sal.end < ecs->stop_func_end)
7319 ecs->stop_func_start = stop_func_sal.end;
7320
7321 /* Architectures which require breakpoint adjustment might not be able
7322 to place a breakpoint at the computed address. If so, the test
7323 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7324 ecs->stop_func_start to an address at which a breakpoint may be
7325 legitimately placed.
7326
7327 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7328 made, GDB will enter an infinite loop when stepping through
7329 optimized code consisting of VLIW instructions which contain
7330 subinstructions corresponding to different source lines. On
7331 FR-V, it's not permitted to place a breakpoint on any but the
7332 first subinstruction of a VLIW instruction. When a breakpoint is
7333 set, GDB will adjust the breakpoint address to the beginning of
7334 the VLIW instruction. Thus, we need to make the corresponding
7335 adjustment here when computing the stop address. */
7336
7337 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7338 {
7339 ecs->stop_func_start
7340 = gdbarch_adjust_breakpoint_address (gdbarch,
7341 ecs->stop_func_start);
7342 }
7343
7344 if (ecs->stop_func_start == stop_pc)
7345 {
7346 /* We are already there: stop now. */
7347 end_stepping_range (ecs);
7348 return;
7349 }
7350 else
7351 {
7352 /* Put the step-breakpoint there and go until there. */
7353 init_sal (&sr_sal); /* initialize to zeroes */
7354 sr_sal.pc = ecs->stop_func_start;
7355 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7356 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7357
7358 /* Do not specify what the fp should be when we stop since on
7359 some machines the prologue is where the new fp value is
7360 established. */
7361 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7362
7363 /* And make sure stepping stops right away then. */
7364 ecs->event_thread->control.step_range_end
7365 = ecs->event_thread->control.step_range_start;
7366 }
7367 keep_going (ecs);
7368 }
7369
7370 /* Inferior has stepped backward into a subroutine call with source
7371 code that we should not step over. Do step to the beginning of the
7372 last line of code in it. */
7373
7374 static void
7375 handle_step_into_function_backward (struct gdbarch *gdbarch,
7376 struct execution_control_state *ecs)
7377 {
7378 struct compunit_symtab *cust;
7379 struct symtab_and_line stop_func_sal;
7380
7381 fill_in_stop_func (gdbarch, ecs);
7382
7383 cust = find_pc_compunit_symtab (stop_pc);
7384 if (cust != NULL && compunit_language (cust) != language_asm)
7385 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7386 ecs->stop_func_start);
7387
7388 stop_func_sal = find_pc_line (stop_pc, 0);
7389
7390 /* OK, we're just going to keep stepping here. */
7391 if (stop_func_sal.pc == stop_pc)
7392 {
7393 /* We're there already. Just stop stepping now. */
7394 end_stepping_range (ecs);
7395 }
7396 else
7397 {
7398 /* Else just reset the step range and keep going.
7399 No step-resume breakpoint, they don't work for
7400 epilogues, which can have multiple entry paths. */
7401 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7402 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7403 keep_going (ecs);
7404 }
7405 return;
7406 }
7407
7408 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7409 This is used to both functions and to skip over code. */
7410
7411 static void
7412 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7413 struct symtab_and_line sr_sal,
7414 struct frame_id sr_id,
7415 enum bptype sr_type)
7416 {
7417 /* There should never be more than one step-resume or longjmp-resume
7418 breakpoint per thread, so we should never be setting a new
7419 step_resume_breakpoint when one is already active. */
7420 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7421 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7422
7423 if (debug_infrun)
7424 fprintf_unfiltered (gdb_stdlog,
7425 "infrun: inserting step-resume breakpoint at %s\n",
7426 paddress (gdbarch, sr_sal.pc));
7427
7428 inferior_thread ()->control.step_resume_breakpoint
7429 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7430 }
7431
7432 void
7433 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7434 struct symtab_and_line sr_sal,
7435 struct frame_id sr_id)
7436 {
7437 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7438 sr_sal, sr_id,
7439 bp_step_resume);
7440 }
7441
7442 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7443 This is used to skip a potential signal handler.
7444
7445 This is called with the interrupted function's frame. The signal
7446 handler, when it returns, will resume the interrupted function at
7447 RETURN_FRAME.pc. */
7448
7449 static void
7450 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7451 {
7452 struct symtab_and_line sr_sal;
7453 struct gdbarch *gdbarch;
7454
7455 gdb_assert (return_frame != NULL);
7456 init_sal (&sr_sal); /* initialize to zeros */
7457
7458 gdbarch = get_frame_arch (return_frame);
7459 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7460 sr_sal.section = find_pc_overlay (sr_sal.pc);
7461 sr_sal.pspace = get_frame_program_space (return_frame);
7462
7463 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7464 get_stack_frame_id (return_frame),
7465 bp_hp_step_resume);
7466 }
7467
7468 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7469 is used to skip a function after stepping into it (for "next" or if
7470 the called function has no debugging information).
7471
7472 The current function has almost always been reached by single
7473 stepping a call or return instruction. NEXT_FRAME belongs to the
7474 current function, and the breakpoint will be set at the caller's
7475 resume address.
7476
7477 This is a separate function rather than reusing
7478 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7479 get_prev_frame, which may stop prematurely (see the implementation
7480 of frame_unwind_caller_id for an example). */
7481
7482 static void
7483 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7484 {
7485 struct symtab_and_line sr_sal;
7486 struct gdbarch *gdbarch;
7487
7488 /* We shouldn't have gotten here if we don't know where the call site
7489 is. */
7490 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7491
7492 init_sal (&sr_sal); /* initialize to zeros */
7493
7494 gdbarch = frame_unwind_caller_arch (next_frame);
7495 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7496 frame_unwind_caller_pc (next_frame));
7497 sr_sal.section = find_pc_overlay (sr_sal.pc);
7498 sr_sal.pspace = frame_unwind_program_space (next_frame);
7499
7500 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7501 frame_unwind_caller_id (next_frame));
7502 }
7503
7504 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7505 new breakpoint at the target of a jmp_buf. The handling of
7506 longjmp-resume uses the same mechanisms used for handling
7507 "step-resume" breakpoints. */
7508
7509 static void
7510 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7511 {
7512 /* There should never be more than one longjmp-resume breakpoint per
7513 thread, so we should never be setting a new
7514 longjmp_resume_breakpoint when one is already active. */
7515 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7516
7517 if (debug_infrun)
7518 fprintf_unfiltered (gdb_stdlog,
7519 "infrun: inserting longjmp-resume breakpoint at %s\n",
7520 paddress (gdbarch, pc));
7521
7522 inferior_thread ()->control.exception_resume_breakpoint =
7523 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7524 }
7525
7526 /* Insert an exception resume breakpoint. TP is the thread throwing
7527 the exception. The block B is the block of the unwinder debug hook
7528 function. FRAME is the frame corresponding to the call to this
7529 function. SYM is the symbol of the function argument holding the
7530 target PC of the exception. */
7531
7532 static void
7533 insert_exception_resume_breakpoint (struct thread_info *tp,
7534 const struct block *b,
7535 struct frame_info *frame,
7536 struct symbol *sym)
7537 {
7538 TRY
7539 {
7540 struct block_symbol vsym;
7541 struct value *value;
7542 CORE_ADDR handler;
7543 struct breakpoint *bp;
7544
7545 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7546 value = read_var_value (vsym.symbol, vsym.block, frame);
7547 /* If the value was optimized out, revert to the old behavior. */
7548 if (! value_optimized_out (value))
7549 {
7550 handler = value_as_address (value);
7551
7552 if (debug_infrun)
7553 fprintf_unfiltered (gdb_stdlog,
7554 "infrun: exception resume at %lx\n",
7555 (unsigned long) handler);
7556
7557 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7558 handler, bp_exception_resume);
7559
7560 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7561 frame = NULL;
7562
7563 bp->thread = tp->global_num;
7564 inferior_thread ()->control.exception_resume_breakpoint = bp;
7565 }
7566 }
7567 CATCH (e, RETURN_MASK_ERROR)
7568 {
7569 /* We want to ignore errors here. */
7570 }
7571 END_CATCH
7572 }
7573
7574 /* A helper for check_exception_resume that sets an
7575 exception-breakpoint based on a SystemTap probe. */
7576
7577 static void
7578 insert_exception_resume_from_probe (struct thread_info *tp,
7579 const struct bound_probe *probe,
7580 struct frame_info *frame)
7581 {
7582 struct value *arg_value;
7583 CORE_ADDR handler;
7584 struct breakpoint *bp;
7585
7586 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7587 if (!arg_value)
7588 return;
7589
7590 handler = value_as_address (arg_value);
7591
7592 if (debug_infrun)
7593 fprintf_unfiltered (gdb_stdlog,
7594 "infrun: exception resume at %s\n",
7595 paddress (get_objfile_arch (probe->objfile),
7596 handler));
7597
7598 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7599 handler, bp_exception_resume);
7600 bp->thread = tp->global_num;
7601 inferior_thread ()->control.exception_resume_breakpoint = bp;
7602 }
7603
7604 /* This is called when an exception has been intercepted. Check to
7605 see whether the exception's destination is of interest, and if so,
7606 set an exception resume breakpoint there. */
7607
7608 static void
7609 check_exception_resume (struct execution_control_state *ecs,
7610 struct frame_info *frame)
7611 {
7612 struct bound_probe probe;
7613 struct symbol *func;
7614
7615 /* First see if this exception unwinding breakpoint was set via a
7616 SystemTap probe point. If so, the probe has two arguments: the
7617 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7618 set a breakpoint there. */
7619 probe = find_probe_by_pc (get_frame_pc (frame));
7620 if (probe.probe)
7621 {
7622 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7623 return;
7624 }
7625
7626 func = get_frame_function (frame);
7627 if (!func)
7628 return;
7629
7630 TRY
7631 {
7632 const struct block *b;
7633 struct block_iterator iter;
7634 struct symbol *sym;
7635 int argno = 0;
7636
7637 /* The exception breakpoint is a thread-specific breakpoint on
7638 the unwinder's debug hook, declared as:
7639
7640 void _Unwind_DebugHook (void *cfa, void *handler);
7641
7642 The CFA argument indicates the frame to which control is
7643 about to be transferred. HANDLER is the destination PC.
7644
7645 We ignore the CFA and set a temporary breakpoint at HANDLER.
7646 This is not extremely efficient but it avoids issues in gdb
7647 with computing the DWARF CFA, and it also works even in weird
7648 cases such as throwing an exception from inside a signal
7649 handler. */
7650
7651 b = SYMBOL_BLOCK_VALUE (func);
7652 ALL_BLOCK_SYMBOLS (b, iter, sym)
7653 {
7654 if (!SYMBOL_IS_ARGUMENT (sym))
7655 continue;
7656
7657 if (argno == 0)
7658 ++argno;
7659 else
7660 {
7661 insert_exception_resume_breakpoint (ecs->event_thread,
7662 b, frame, sym);
7663 break;
7664 }
7665 }
7666 }
7667 CATCH (e, RETURN_MASK_ERROR)
7668 {
7669 }
7670 END_CATCH
7671 }
7672
7673 static void
7674 stop_waiting (struct execution_control_state *ecs)
7675 {
7676 if (debug_infrun)
7677 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7678
7679 clear_step_over_info ();
7680
7681 /* Let callers know we don't want to wait for the inferior anymore. */
7682 ecs->wait_some_more = 0;
7683
7684 /* If all-stop, but the target is always in non-stop mode, stop all
7685 threads now that we're presenting the stop to the user. */
7686 if (!non_stop && target_is_non_stop_p ())
7687 stop_all_threads ();
7688 }
7689
7690 /* Like keep_going, but passes the signal to the inferior, even if the
7691 signal is set to nopass. */
7692
7693 static void
7694 keep_going_pass_signal (struct execution_control_state *ecs)
7695 {
7696 /* Make sure normal_stop is called if we get a QUIT handled before
7697 reaching resume. */
7698 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7699
7700 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7701 gdb_assert (!ecs->event_thread->resumed);
7702
7703 /* Save the pc before execution, to compare with pc after stop. */
7704 ecs->event_thread->prev_pc
7705 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7706
7707 if (ecs->event_thread->control.trap_expected)
7708 {
7709 struct thread_info *tp = ecs->event_thread;
7710
7711 if (debug_infrun)
7712 fprintf_unfiltered (gdb_stdlog,
7713 "infrun: %s has trap_expected set, "
7714 "resuming to collect trap\n",
7715 target_pid_to_str (tp->ptid));
7716
7717 /* We haven't yet gotten our trap, and either: intercepted a
7718 non-signal event (e.g., a fork); or took a signal which we
7719 are supposed to pass through to the inferior. Simply
7720 continue. */
7721 discard_cleanups (old_cleanups);
7722 resume (ecs->event_thread->suspend.stop_signal);
7723 }
7724 else if (step_over_info_valid_p ())
7725 {
7726 /* Another thread is stepping over a breakpoint in-line. If
7727 this thread needs a step-over too, queue the request. In
7728 either case, this resume must be deferred for later. */
7729 struct thread_info *tp = ecs->event_thread;
7730
7731 if (ecs->hit_singlestep_breakpoint
7732 || thread_still_needs_step_over (tp))
7733 {
7734 if (debug_infrun)
7735 fprintf_unfiltered (gdb_stdlog,
7736 "infrun: step-over already in progress: "
7737 "step-over for %s deferred\n",
7738 target_pid_to_str (tp->ptid));
7739 thread_step_over_chain_enqueue (tp);
7740 }
7741 else
7742 {
7743 if (debug_infrun)
7744 fprintf_unfiltered (gdb_stdlog,
7745 "infrun: step-over in progress: "
7746 "resume of %s deferred\n",
7747 target_pid_to_str (tp->ptid));
7748 }
7749
7750 discard_cleanups (old_cleanups);
7751 }
7752 else
7753 {
7754 struct regcache *regcache = get_current_regcache ();
7755 int remove_bp;
7756 int remove_wps;
7757 step_over_what step_what;
7758
7759 /* Either the trap was not expected, but we are continuing
7760 anyway (if we got a signal, the user asked it be passed to
7761 the child)
7762 -- or --
7763 We got our expected trap, but decided we should resume from
7764 it.
7765
7766 We're going to run this baby now!
7767
7768 Note that insert_breakpoints won't try to re-insert
7769 already inserted breakpoints. Therefore, we don't
7770 care if breakpoints were already inserted, or not. */
7771
7772 /* If we need to step over a breakpoint, and we're not using
7773 displaced stepping to do so, insert all breakpoints
7774 (watchpoints, etc.) but the one we're stepping over, step one
7775 instruction, and then re-insert the breakpoint when that step
7776 is finished. */
7777
7778 step_what = thread_still_needs_step_over (ecs->event_thread);
7779
7780 remove_bp = (ecs->hit_singlestep_breakpoint
7781 || (step_what & STEP_OVER_BREAKPOINT));
7782 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7783
7784 /* We can't use displaced stepping if we need to step past a
7785 watchpoint. The instruction copied to the scratch pad would
7786 still trigger the watchpoint. */
7787 if (remove_bp
7788 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7789 {
7790 set_step_over_info (get_regcache_aspace (regcache),
7791 regcache_read_pc (regcache), remove_wps,
7792 ecs->event_thread->global_num);
7793 }
7794 else if (remove_wps)
7795 set_step_over_info (NULL, 0, remove_wps, -1);
7796
7797 /* If we now need to do an in-line step-over, we need to stop
7798 all other threads. Note this must be done before
7799 insert_breakpoints below, because that removes the breakpoint
7800 we're about to step over, otherwise other threads could miss
7801 it. */
7802 if (step_over_info_valid_p () && target_is_non_stop_p ())
7803 stop_all_threads ();
7804
7805 /* Stop stepping if inserting breakpoints fails. */
7806 TRY
7807 {
7808 insert_breakpoints ();
7809 }
7810 CATCH (e, RETURN_MASK_ERROR)
7811 {
7812 exception_print (gdb_stderr, e);
7813 stop_waiting (ecs);
7814 discard_cleanups (old_cleanups);
7815 return;
7816 }
7817 END_CATCH
7818
7819 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7820
7821 discard_cleanups (old_cleanups);
7822 resume (ecs->event_thread->suspend.stop_signal);
7823 }
7824
7825 prepare_to_wait (ecs);
7826 }
7827
7828 /* Called when we should continue running the inferior, because the
7829 current event doesn't cause a user visible stop. This does the
7830 resuming part; waiting for the next event is done elsewhere. */
7831
7832 static void
7833 keep_going (struct execution_control_state *ecs)
7834 {
7835 if (ecs->event_thread->control.trap_expected
7836 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7837 ecs->event_thread->control.trap_expected = 0;
7838
7839 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7840 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7841 keep_going_pass_signal (ecs);
7842 }
7843
7844 /* This function normally comes after a resume, before
7845 handle_inferior_event exits. It takes care of any last bits of
7846 housekeeping, and sets the all-important wait_some_more flag. */
7847
7848 static void
7849 prepare_to_wait (struct execution_control_state *ecs)
7850 {
7851 if (debug_infrun)
7852 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7853
7854 ecs->wait_some_more = 1;
7855
7856 if (!target_is_async_p ())
7857 mark_infrun_async_event_handler ();
7858 }
7859
7860 /* We are done with the step range of a step/next/si/ni command.
7861 Called once for each n of a "step n" operation. */
7862
7863 static void
7864 end_stepping_range (struct execution_control_state *ecs)
7865 {
7866 ecs->event_thread->control.stop_step = 1;
7867 stop_waiting (ecs);
7868 }
7869
7870 /* Several print_*_reason functions to print why the inferior has stopped.
7871 We always print something when the inferior exits, or receives a signal.
7872 The rest of the cases are dealt with later on in normal_stop and
7873 print_it_typical. Ideally there should be a call to one of these
7874 print_*_reason functions functions from handle_inferior_event each time
7875 stop_waiting is called.
7876
7877 Note that we don't call these directly, instead we delegate that to
7878 the interpreters, through observers. Interpreters then call these
7879 with whatever uiout is right. */
7880
7881 void
7882 print_end_stepping_range_reason (struct ui_out *uiout)
7883 {
7884 /* For CLI-like interpreters, print nothing. */
7885
7886 if (uiout->is_mi_like_p ())
7887 {
7888 uiout->field_string ("reason",
7889 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7890 }
7891 }
7892
7893 void
7894 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7895 {
7896 annotate_signalled ();
7897 if (uiout->is_mi_like_p ())
7898 uiout->field_string
7899 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7900 uiout->text ("\nProgram terminated with signal ");
7901 annotate_signal_name ();
7902 uiout->field_string ("signal-name",
7903 gdb_signal_to_name (siggnal));
7904 annotate_signal_name_end ();
7905 uiout->text (", ");
7906 annotate_signal_string ();
7907 uiout->field_string ("signal-meaning",
7908 gdb_signal_to_string (siggnal));
7909 annotate_signal_string_end ();
7910 uiout->text (".\n");
7911 uiout->text ("The program no longer exists.\n");
7912 }
7913
7914 void
7915 print_exited_reason (struct ui_out *uiout, int exitstatus)
7916 {
7917 struct inferior *inf = current_inferior ();
7918 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7919
7920 annotate_exited (exitstatus);
7921 if (exitstatus)
7922 {
7923 if (uiout->is_mi_like_p ())
7924 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7925 uiout->text ("[Inferior ");
7926 uiout->text (plongest (inf->num));
7927 uiout->text (" (");
7928 uiout->text (pidstr);
7929 uiout->text (") exited with code ");
7930 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7931 uiout->text ("]\n");
7932 }
7933 else
7934 {
7935 if (uiout->is_mi_like_p ())
7936 uiout->field_string
7937 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7938 uiout->text ("[Inferior ");
7939 uiout->text (plongest (inf->num));
7940 uiout->text (" (");
7941 uiout->text (pidstr);
7942 uiout->text (") exited normally]\n");
7943 }
7944 }
7945
7946 /* Some targets/architectures can do extra processing/display of
7947 segmentation faults. E.g., Intel MPX boundary faults.
7948 Call the architecture dependent function to handle the fault. */
7949
7950 static void
7951 handle_segmentation_fault (struct ui_out *uiout)
7952 {
7953 struct regcache *regcache = get_current_regcache ();
7954 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7955
7956 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7957 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7958 }
7959
7960 void
7961 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7962 {
7963 struct thread_info *thr = inferior_thread ();
7964
7965 annotate_signal ();
7966
7967 if (uiout->is_mi_like_p ())
7968 ;
7969 else if (show_thread_that_caused_stop ())
7970 {
7971 const char *name;
7972
7973 uiout->text ("\nThread ");
7974 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7975
7976 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7977 if (name != NULL)
7978 {
7979 uiout->text (" \"");
7980 uiout->field_fmt ("name", "%s", name);
7981 uiout->text ("\"");
7982 }
7983 }
7984 else
7985 uiout->text ("\nProgram");
7986
7987 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7988 uiout->text (" stopped");
7989 else
7990 {
7991 uiout->text (" received signal ");
7992 annotate_signal_name ();
7993 if (uiout->is_mi_like_p ())
7994 uiout->field_string
7995 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7996 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7997 annotate_signal_name_end ();
7998 uiout->text (", ");
7999 annotate_signal_string ();
8000 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
8001
8002 if (siggnal == GDB_SIGNAL_SEGV)
8003 handle_segmentation_fault (uiout);
8004
8005 annotate_signal_string_end ();
8006 }
8007 uiout->text (".\n");
8008 }
8009
8010 void
8011 print_no_history_reason (struct ui_out *uiout)
8012 {
8013 uiout->text ("\nNo more reverse-execution history.\n");
8014 }
8015
8016 /* Print current location without a level number, if we have changed
8017 functions or hit a breakpoint. Print source line if we have one.
8018 bpstat_print contains the logic deciding in detail what to print,
8019 based on the event(s) that just occurred. */
8020
8021 static void
8022 print_stop_location (struct target_waitstatus *ws)
8023 {
8024 int bpstat_ret;
8025 enum print_what source_flag;
8026 int do_frame_printing = 1;
8027 struct thread_info *tp = inferior_thread ();
8028
8029 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8030 switch (bpstat_ret)
8031 {
8032 case PRINT_UNKNOWN:
8033 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8034 should) carry around the function and does (or should) use
8035 that when doing a frame comparison. */
8036 if (tp->control.stop_step
8037 && frame_id_eq (tp->control.step_frame_id,
8038 get_frame_id (get_current_frame ()))
8039 && tp->control.step_start_function == find_pc_function (stop_pc))
8040 {
8041 /* Finished step, just print source line. */
8042 source_flag = SRC_LINE;
8043 }
8044 else
8045 {
8046 /* Print location and source line. */
8047 source_flag = SRC_AND_LOC;
8048 }
8049 break;
8050 case PRINT_SRC_AND_LOC:
8051 /* Print location and source line. */
8052 source_flag = SRC_AND_LOC;
8053 break;
8054 case PRINT_SRC_ONLY:
8055 source_flag = SRC_LINE;
8056 break;
8057 case PRINT_NOTHING:
8058 /* Something bogus. */
8059 source_flag = SRC_LINE;
8060 do_frame_printing = 0;
8061 break;
8062 default:
8063 internal_error (__FILE__, __LINE__, _("Unknown value."));
8064 }
8065
8066 /* The behavior of this routine with respect to the source
8067 flag is:
8068 SRC_LINE: Print only source line
8069 LOCATION: Print only location
8070 SRC_AND_LOC: Print location and source line. */
8071 if (do_frame_printing)
8072 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8073 }
8074
8075 /* See infrun.h. */
8076
8077 void
8078 print_stop_event (struct ui_out *uiout)
8079 {
8080 struct target_waitstatus last;
8081 ptid_t last_ptid;
8082 struct thread_info *tp;
8083
8084 get_last_target_status (&last_ptid, &last);
8085
8086 {
8087 scoped_restore save_uiout = make_scoped_restore (&current_uiout, uiout);
8088
8089 print_stop_location (&last);
8090
8091 /* Display the auto-display expressions. */
8092 do_displays ();
8093 }
8094
8095 tp = inferior_thread ();
8096 if (tp->thread_fsm != NULL
8097 && thread_fsm_finished_p (tp->thread_fsm))
8098 {
8099 struct return_value_info *rv;
8100
8101 rv = thread_fsm_return_value (tp->thread_fsm);
8102 if (rv != NULL)
8103 print_return_value (uiout, rv);
8104 }
8105 }
8106
8107 /* See infrun.h. */
8108
8109 void
8110 maybe_remove_breakpoints (void)
8111 {
8112 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8113 {
8114 if (remove_breakpoints ())
8115 {
8116 target_terminal_ours_for_output ();
8117 printf_filtered (_("Cannot remove breakpoints because "
8118 "program is no longer writable.\nFurther "
8119 "execution is probably impossible.\n"));
8120 }
8121 }
8122 }
8123
8124 /* The execution context that just caused a normal stop. */
8125
8126 struct stop_context
8127 {
8128 /* The stop ID. */
8129 ULONGEST stop_id;
8130
8131 /* The event PTID. */
8132
8133 ptid_t ptid;
8134
8135 /* If stopp for a thread event, this is the thread that caused the
8136 stop. */
8137 struct thread_info *thread;
8138
8139 /* The inferior that caused the stop. */
8140 int inf_num;
8141 };
8142
8143 /* Returns a new stop context. If stopped for a thread event, this
8144 takes a strong reference to the thread. */
8145
8146 static struct stop_context *
8147 save_stop_context (void)
8148 {
8149 struct stop_context *sc = XNEW (struct stop_context);
8150
8151 sc->stop_id = get_stop_id ();
8152 sc->ptid = inferior_ptid;
8153 sc->inf_num = current_inferior ()->num;
8154
8155 if (!ptid_equal (inferior_ptid, null_ptid))
8156 {
8157 /* Take a strong reference so that the thread can't be deleted
8158 yet. */
8159 sc->thread = inferior_thread ();
8160 sc->thread->refcount++;
8161 }
8162 else
8163 sc->thread = NULL;
8164
8165 return sc;
8166 }
8167
8168 /* Release a stop context previously created with save_stop_context.
8169 Releases the strong reference to the thread as well. */
8170
8171 static void
8172 release_stop_context_cleanup (void *arg)
8173 {
8174 struct stop_context *sc = (struct stop_context *) arg;
8175
8176 if (sc->thread != NULL)
8177 sc->thread->refcount--;
8178 xfree (sc);
8179 }
8180
8181 /* Return true if the current context no longer matches the saved stop
8182 context. */
8183
8184 static int
8185 stop_context_changed (struct stop_context *prev)
8186 {
8187 if (!ptid_equal (prev->ptid, inferior_ptid))
8188 return 1;
8189 if (prev->inf_num != current_inferior ()->num)
8190 return 1;
8191 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8192 return 1;
8193 if (get_stop_id () != prev->stop_id)
8194 return 1;
8195 return 0;
8196 }
8197
8198 /* See infrun.h. */
8199
8200 int
8201 normal_stop (void)
8202 {
8203 struct target_waitstatus last;
8204 ptid_t last_ptid;
8205 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
8206 ptid_t pid_ptid;
8207
8208 get_last_target_status (&last_ptid, &last);
8209
8210 new_stop_id ();
8211
8212 /* If an exception is thrown from this point on, make sure to
8213 propagate GDB's knowledge of the executing state to the
8214 frontend/user running state. A QUIT is an easy exception to see
8215 here, so do this before any filtered output. */
8216 if (!non_stop)
8217 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
8218 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8219 || last.kind == TARGET_WAITKIND_EXITED)
8220 {
8221 /* On some targets, we may still have live threads in the
8222 inferior when we get a process exit event. E.g., for
8223 "checkpoint", when the current checkpoint/fork exits,
8224 linux-fork.c automatically switches to another fork from
8225 within target_mourn_inferior. */
8226 if (!ptid_equal (inferior_ptid, null_ptid))
8227 {
8228 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
8229 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8230 }
8231 }
8232 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8233 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8234
8235 /* As we're presenting a stop, and potentially removing breakpoints,
8236 update the thread list so we can tell whether there are threads
8237 running on the target. With target remote, for example, we can
8238 only learn about new threads when we explicitly update the thread
8239 list. Do this before notifying the interpreters about signal
8240 stops, end of stepping ranges, etc., so that the "new thread"
8241 output is emitted before e.g., "Program received signal FOO",
8242 instead of after. */
8243 update_thread_list ();
8244
8245 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8246 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8247
8248 /* As with the notification of thread events, we want to delay
8249 notifying the user that we've switched thread context until
8250 the inferior actually stops.
8251
8252 There's no point in saying anything if the inferior has exited.
8253 Note that SIGNALLED here means "exited with a signal", not
8254 "received a signal".
8255
8256 Also skip saying anything in non-stop mode. In that mode, as we
8257 don't want GDB to switch threads behind the user's back, to avoid
8258 races where the user is typing a command to apply to thread x,
8259 but GDB switches to thread y before the user finishes entering
8260 the command, fetch_inferior_event installs a cleanup to restore
8261 the current thread back to the thread the user had selected right
8262 after this event is handled, so we're not really switching, only
8263 informing of a stop. */
8264 if (!non_stop
8265 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8266 && target_has_execution
8267 && last.kind != TARGET_WAITKIND_SIGNALLED
8268 && last.kind != TARGET_WAITKIND_EXITED
8269 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8270 {
8271 SWITCH_THRU_ALL_UIS ()
8272 {
8273 target_terminal_ours_for_output ();
8274 printf_filtered (_("[Switching to %s]\n"),
8275 target_pid_to_str (inferior_ptid));
8276 annotate_thread_changed ();
8277 }
8278 previous_inferior_ptid = inferior_ptid;
8279 }
8280
8281 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8282 {
8283 SWITCH_THRU_ALL_UIS ()
8284 if (current_ui->prompt_state == PROMPT_BLOCKED)
8285 {
8286 target_terminal_ours_for_output ();
8287 printf_filtered (_("No unwaited-for children left.\n"));
8288 }
8289 }
8290
8291 /* Note: this depends on the update_thread_list call above. */
8292 maybe_remove_breakpoints ();
8293
8294 /* If an auto-display called a function and that got a signal,
8295 delete that auto-display to avoid an infinite recursion. */
8296
8297 if (stopped_by_random_signal)
8298 disable_current_display ();
8299
8300 SWITCH_THRU_ALL_UIS ()
8301 {
8302 async_enable_stdin ();
8303 }
8304
8305 /* Let the user/frontend see the threads as stopped. */
8306 do_cleanups (old_chain);
8307
8308 /* Select innermost stack frame - i.e., current frame is frame 0,
8309 and current location is based on that. Handle the case where the
8310 dummy call is returning after being stopped. E.g. the dummy call
8311 previously hit a breakpoint. (If the dummy call returns
8312 normally, we won't reach here.) Do this before the stop hook is
8313 run, so that it doesn't get to see the temporary dummy frame,
8314 which is not where we'll present the stop. */
8315 if (has_stack_frames ())
8316 {
8317 if (stop_stack_dummy == STOP_STACK_DUMMY)
8318 {
8319 /* Pop the empty frame that contains the stack dummy. This
8320 also restores inferior state prior to the call (struct
8321 infcall_suspend_state). */
8322 struct frame_info *frame = get_current_frame ();
8323
8324 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8325 frame_pop (frame);
8326 /* frame_pop calls reinit_frame_cache as the last thing it
8327 does which means there's now no selected frame. */
8328 }
8329
8330 select_frame (get_current_frame ());
8331
8332 /* Set the current source location. */
8333 set_current_sal_from_frame (get_current_frame ());
8334 }
8335
8336 /* Look up the hook_stop and run it (CLI internally handles problem
8337 of stop_command's pre-hook not existing). */
8338 if (stop_command != NULL)
8339 {
8340 struct stop_context *saved_context = save_stop_context ();
8341 struct cleanup *old_chain
8342 = make_cleanup (release_stop_context_cleanup, saved_context);
8343
8344 catch_errors (hook_stop_stub, stop_command,
8345 "Error while running hook_stop:\n", RETURN_MASK_ALL);
8346
8347 /* If the stop hook resumes the target, then there's no point in
8348 trying to notify about the previous stop; its context is
8349 gone. Likewise if the command switches thread or inferior --
8350 the observers would print a stop for the wrong
8351 thread/inferior. */
8352 if (stop_context_changed (saved_context))
8353 {
8354 do_cleanups (old_chain);
8355 return 1;
8356 }
8357 do_cleanups (old_chain);
8358 }
8359
8360 /* Notify observers about the stop. This is where the interpreters
8361 print the stop event. */
8362 if (!ptid_equal (inferior_ptid, null_ptid))
8363 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8364 stop_print_frame);
8365 else
8366 observer_notify_normal_stop (NULL, stop_print_frame);
8367
8368 annotate_stopped ();
8369
8370 if (target_has_execution)
8371 {
8372 if (last.kind != TARGET_WAITKIND_SIGNALLED
8373 && last.kind != TARGET_WAITKIND_EXITED)
8374 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8375 Delete any breakpoint that is to be deleted at the next stop. */
8376 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8377 }
8378
8379 /* Try to get rid of automatically added inferiors that are no
8380 longer needed. Keeping those around slows down things linearly.
8381 Note that this never removes the current inferior. */
8382 prune_inferiors ();
8383
8384 return 0;
8385 }
8386
8387 static int
8388 hook_stop_stub (void *cmd)
8389 {
8390 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
8391 return (0);
8392 }
8393 \f
8394 int
8395 signal_stop_state (int signo)
8396 {
8397 return signal_stop[signo];
8398 }
8399
8400 int
8401 signal_print_state (int signo)
8402 {
8403 return signal_print[signo];
8404 }
8405
8406 int
8407 signal_pass_state (int signo)
8408 {
8409 return signal_program[signo];
8410 }
8411
8412 static void
8413 signal_cache_update (int signo)
8414 {
8415 if (signo == -1)
8416 {
8417 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8418 signal_cache_update (signo);
8419
8420 return;
8421 }
8422
8423 signal_pass[signo] = (signal_stop[signo] == 0
8424 && signal_print[signo] == 0
8425 && signal_program[signo] == 1
8426 && signal_catch[signo] == 0);
8427 }
8428
8429 int
8430 signal_stop_update (int signo, int state)
8431 {
8432 int ret = signal_stop[signo];
8433
8434 signal_stop[signo] = state;
8435 signal_cache_update (signo);
8436 return ret;
8437 }
8438
8439 int
8440 signal_print_update (int signo, int state)
8441 {
8442 int ret = signal_print[signo];
8443
8444 signal_print[signo] = state;
8445 signal_cache_update (signo);
8446 return ret;
8447 }
8448
8449 int
8450 signal_pass_update (int signo, int state)
8451 {
8452 int ret = signal_program[signo];
8453
8454 signal_program[signo] = state;
8455 signal_cache_update (signo);
8456 return ret;
8457 }
8458
8459 /* Update the global 'signal_catch' from INFO and notify the
8460 target. */
8461
8462 void
8463 signal_catch_update (const unsigned int *info)
8464 {
8465 int i;
8466
8467 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8468 signal_catch[i] = info[i] > 0;
8469 signal_cache_update (-1);
8470 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8471 }
8472
8473 static void
8474 sig_print_header (void)
8475 {
8476 printf_filtered (_("Signal Stop\tPrint\tPass "
8477 "to program\tDescription\n"));
8478 }
8479
8480 static void
8481 sig_print_info (enum gdb_signal oursig)
8482 {
8483 const char *name = gdb_signal_to_name (oursig);
8484 int name_padding = 13 - strlen (name);
8485
8486 if (name_padding <= 0)
8487 name_padding = 0;
8488
8489 printf_filtered ("%s", name);
8490 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8491 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8492 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8493 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8494 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8495 }
8496
8497 /* Specify how various signals in the inferior should be handled. */
8498
8499 static void
8500 handle_command (char *args, int from_tty)
8501 {
8502 char **argv;
8503 int digits, wordlen;
8504 int sigfirst, signum, siglast;
8505 enum gdb_signal oursig;
8506 int allsigs;
8507 int nsigs;
8508 unsigned char *sigs;
8509 struct cleanup *old_chain;
8510
8511 if (args == NULL)
8512 {
8513 error_no_arg (_("signal to handle"));
8514 }
8515
8516 /* Allocate and zero an array of flags for which signals to handle. */
8517
8518 nsigs = (int) GDB_SIGNAL_LAST;
8519 sigs = (unsigned char *) alloca (nsigs);
8520 memset (sigs, 0, nsigs);
8521
8522 /* Break the command line up into args. */
8523
8524 argv = gdb_buildargv (args);
8525 old_chain = make_cleanup_freeargv (argv);
8526
8527 /* Walk through the args, looking for signal oursigs, signal names, and
8528 actions. Signal numbers and signal names may be interspersed with
8529 actions, with the actions being performed for all signals cumulatively
8530 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8531
8532 while (*argv != NULL)
8533 {
8534 wordlen = strlen (*argv);
8535 for (digits = 0; isdigit ((*argv)[digits]); digits++)
8536 {;
8537 }
8538 allsigs = 0;
8539 sigfirst = siglast = -1;
8540
8541 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
8542 {
8543 /* Apply action to all signals except those used by the
8544 debugger. Silently skip those. */
8545 allsigs = 1;
8546 sigfirst = 0;
8547 siglast = nsigs - 1;
8548 }
8549 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
8550 {
8551 SET_SIGS (nsigs, sigs, signal_stop);
8552 SET_SIGS (nsigs, sigs, signal_print);
8553 }
8554 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
8555 {
8556 UNSET_SIGS (nsigs, sigs, signal_program);
8557 }
8558 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
8559 {
8560 SET_SIGS (nsigs, sigs, signal_print);
8561 }
8562 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
8563 {
8564 SET_SIGS (nsigs, sigs, signal_program);
8565 }
8566 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
8567 {
8568 UNSET_SIGS (nsigs, sigs, signal_stop);
8569 }
8570 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
8571 {
8572 SET_SIGS (nsigs, sigs, signal_program);
8573 }
8574 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
8575 {
8576 UNSET_SIGS (nsigs, sigs, signal_print);
8577 UNSET_SIGS (nsigs, sigs, signal_stop);
8578 }
8579 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
8580 {
8581 UNSET_SIGS (nsigs, sigs, signal_program);
8582 }
8583 else if (digits > 0)
8584 {
8585 /* It is numeric. The numeric signal refers to our own
8586 internal signal numbering from target.h, not to host/target
8587 signal number. This is a feature; users really should be
8588 using symbolic names anyway, and the common ones like
8589 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8590
8591 sigfirst = siglast = (int)
8592 gdb_signal_from_command (atoi (*argv));
8593 if ((*argv)[digits] == '-')
8594 {
8595 siglast = (int)
8596 gdb_signal_from_command (atoi ((*argv) + digits + 1));
8597 }
8598 if (sigfirst > siglast)
8599 {
8600 /* Bet he didn't figure we'd think of this case... */
8601 signum = sigfirst;
8602 sigfirst = siglast;
8603 siglast = signum;
8604 }
8605 }
8606 else
8607 {
8608 oursig = gdb_signal_from_name (*argv);
8609 if (oursig != GDB_SIGNAL_UNKNOWN)
8610 {
8611 sigfirst = siglast = (int) oursig;
8612 }
8613 else
8614 {
8615 /* Not a number and not a recognized flag word => complain. */
8616 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
8617 }
8618 }
8619
8620 /* If any signal numbers or symbol names were found, set flags for
8621 which signals to apply actions to. */
8622
8623 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8624 {
8625 switch ((enum gdb_signal) signum)
8626 {
8627 case GDB_SIGNAL_TRAP:
8628 case GDB_SIGNAL_INT:
8629 if (!allsigs && !sigs[signum])
8630 {
8631 if (query (_("%s is used by the debugger.\n\
8632 Are you sure you want to change it? "),
8633 gdb_signal_to_name ((enum gdb_signal) signum)))
8634 {
8635 sigs[signum] = 1;
8636 }
8637 else
8638 {
8639 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8640 gdb_flush (gdb_stdout);
8641 }
8642 }
8643 break;
8644 case GDB_SIGNAL_0:
8645 case GDB_SIGNAL_DEFAULT:
8646 case GDB_SIGNAL_UNKNOWN:
8647 /* Make sure that "all" doesn't print these. */
8648 break;
8649 default:
8650 sigs[signum] = 1;
8651 break;
8652 }
8653 }
8654
8655 argv++;
8656 }
8657
8658 for (signum = 0; signum < nsigs; signum++)
8659 if (sigs[signum])
8660 {
8661 signal_cache_update (-1);
8662 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8663 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8664
8665 if (from_tty)
8666 {
8667 /* Show the results. */
8668 sig_print_header ();
8669 for (; signum < nsigs; signum++)
8670 if (sigs[signum])
8671 sig_print_info ((enum gdb_signal) signum);
8672 }
8673
8674 break;
8675 }
8676
8677 do_cleanups (old_chain);
8678 }
8679
8680 /* Complete the "handle" command. */
8681
8682 static VEC (char_ptr) *
8683 handle_completer (struct cmd_list_element *ignore,
8684 const char *text, const char *word)
8685 {
8686 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
8687 static const char * const keywords[] =
8688 {
8689 "all",
8690 "stop",
8691 "ignore",
8692 "print",
8693 "pass",
8694 "nostop",
8695 "noignore",
8696 "noprint",
8697 "nopass",
8698 NULL,
8699 };
8700
8701 vec_signals = signal_completer (ignore, text, word);
8702 vec_keywords = complete_on_enum (keywords, word, word);
8703
8704 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
8705 VEC_free (char_ptr, vec_signals);
8706 VEC_free (char_ptr, vec_keywords);
8707 return return_val;
8708 }
8709
8710 enum gdb_signal
8711 gdb_signal_from_command (int num)
8712 {
8713 if (num >= 1 && num <= 15)
8714 return (enum gdb_signal) num;
8715 error (_("Only signals 1-15 are valid as numeric signals.\n\
8716 Use \"info signals\" for a list of symbolic signals."));
8717 }
8718
8719 /* Print current contents of the tables set by the handle command.
8720 It is possible we should just be printing signals actually used
8721 by the current target (but for things to work right when switching
8722 targets, all signals should be in the signal tables). */
8723
8724 static void
8725 signals_info (char *signum_exp, int from_tty)
8726 {
8727 enum gdb_signal oursig;
8728
8729 sig_print_header ();
8730
8731 if (signum_exp)
8732 {
8733 /* First see if this is a symbol name. */
8734 oursig = gdb_signal_from_name (signum_exp);
8735 if (oursig == GDB_SIGNAL_UNKNOWN)
8736 {
8737 /* No, try numeric. */
8738 oursig =
8739 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8740 }
8741 sig_print_info (oursig);
8742 return;
8743 }
8744
8745 printf_filtered ("\n");
8746 /* These ugly casts brought to you by the native VAX compiler. */
8747 for (oursig = GDB_SIGNAL_FIRST;
8748 (int) oursig < (int) GDB_SIGNAL_LAST;
8749 oursig = (enum gdb_signal) ((int) oursig + 1))
8750 {
8751 QUIT;
8752
8753 if (oursig != GDB_SIGNAL_UNKNOWN
8754 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8755 sig_print_info (oursig);
8756 }
8757
8758 printf_filtered (_("\nUse the \"handle\" command "
8759 "to change these tables.\n"));
8760 }
8761
8762 /* The $_siginfo convenience variable is a bit special. We don't know
8763 for sure the type of the value until we actually have a chance to
8764 fetch the data. The type can change depending on gdbarch, so it is
8765 also dependent on which thread you have selected.
8766
8767 1. making $_siginfo be an internalvar that creates a new value on
8768 access.
8769
8770 2. making the value of $_siginfo be an lval_computed value. */
8771
8772 /* This function implements the lval_computed support for reading a
8773 $_siginfo value. */
8774
8775 static void
8776 siginfo_value_read (struct value *v)
8777 {
8778 LONGEST transferred;
8779
8780 /* If we can access registers, so can we access $_siginfo. Likewise
8781 vice versa. */
8782 validate_registers_access ();
8783
8784 transferred =
8785 target_read (&current_target, TARGET_OBJECT_SIGNAL_INFO,
8786 NULL,
8787 value_contents_all_raw (v),
8788 value_offset (v),
8789 TYPE_LENGTH (value_type (v)));
8790
8791 if (transferred != TYPE_LENGTH (value_type (v)))
8792 error (_("Unable to read siginfo"));
8793 }
8794
8795 /* This function implements the lval_computed support for writing a
8796 $_siginfo value. */
8797
8798 static void
8799 siginfo_value_write (struct value *v, struct value *fromval)
8800 {
8801 LONGEST transferred;
8802
8803 /* If we can access registers, so can we access $_siginfo. Likewise
8804 vice versa. */
8805 validate_registers_access ();
8806
8807 transferred = target_write (&current_target,
8808 TARGET_OBJECT_SIGNAL_INFO,
8809 NULL,
8810 value_contents_all_raw (fromval),
8811 value_offset (v),
8812 TYPE_LENGTH (value_type (fromval)));
8813
8814 if (transferred != TYPE_LENGTH (value_type (fromval)))
8815 error (_("Unable to write siginfo"));
8816 }
8817
8818 static const struct lval_funcs siginfo_value_funcs =
8819 {
8820 siginfo_value_read,
8821 siginfo_value_write
8822 };
8823
8824 /* Return a new value with the correct type for the siginfo object of
8825 the current thread using architecture GDBARCH. Return a void value
8826 if there's no object available. */
8827
8828 static struct value *
8829 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8830 void *ignore)
8831 {
8832 if (target_has_stack
8833 && !ptid_equal (inferior_ptid, null_ptid)
8834 && gdbarch_get_siginfo_type_p (gdbarch))
8835 {
8836 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8837
8838 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8839 }
8840
8841 return allocate_value (builtin_type (gdbarch)->builtin_void);
8842 }
8843
8844 \f
8845 /* infcall_suspend_state contains state about the program itself like its
8846 registers and any signal it received when it last stopped.
8847 This state must be restored regardless of how the inferior function call
8848 ends (either successfully, or after it hits a breakpoint or signal)
8849 if the program is to properly continue where it left off. */
8850
8851 struct infcall_suspend_state
8852 {
8853 struct thread_suspend_state thread_suspend;
8854
8855 /* Other fields: */
8856 CORE_ADDR stop_pc;
8857 struct regcache *registers;
8858
8859 /* Format of SIGINFO_DATA or NULL if it is not present. */
8860 struct gdbarch *siginfo_gdbarch;
8861
8862 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8863 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8864 content would be invalid. */
8865 gdb_byte *siginfo_data;
8866 };
8867
8868 struct infcall_suspend_state *
8869 save_infcall_suspend_state (void)
8870 {
8871 struct infcall_suspend_state *inf_state;
8872 struct thread_info *tp = inferior_thread ();
8873 struct regcache *regcache = get_current_regcache ();
8874 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8875 gdb_byte *siginfo_data = NULL;
8876
8877 if (gdbarch_get_siginfo_type_p (gdbarch))
8878 {
8879 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8880 size_t len = TYPE_LENGTH (type);
8881 struct cleanup *back_to;
8882
8883 siginfo_data = (gdb_byte *) xmalloc (len);
8884 back_to = make_cleanup (xfree, siginfo_data);
8885
8886 if (target_read (&current_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8887 siginfo_data, 0, len) == len)
8888 discard_cleanups (back_to);
8889 else
8890 {
8891 /* Errors ignored. */
8892 do_cleanups (back_to);
8893 siginfo_data = NULL;
8894 }
8895 }
8896
8897 inf_state = XCNEW (struct infcall_suspend_state);
8898
8899 if (siginfo_data)
8900 {
8901 inf_state->siginfo_gdbarch = gdbarch;
8902 inf_state->siginfo_data = siginfo_data;
8903 }
8904
8905 inf_state->thread_suspend = tp->suspend;
8906
8907 /* run_inferior_call will not use the signal due to its `proceed' call with
8908 GDB_SIGNAL_0 anyway. */
8909 tp->suspend.stop_signal = GDB_SIGNAL_0;
8910
8911 inf_state->stop_pc = stop_pc;
8912
8913 inf_state->registers = regcache_dup (regcache);
8914
8915 return inf_state;
8916 }
8917
8918 /* Restore inferior session state to INF_STATE. */
8919
8920 void
8921 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8922 {
8923 struct thread_info *tp = inferior_thread ();
8924 struct regcache *regcache = get_current_regcache ();
8925 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8926
8927 tp->suspend = inf_state->thread_suspend;
8928
8929 stop_pc = inf_state->stop_pc;
8930
8931 if (inf_state->siginfo_gdbarch == gdbarch)
8932 {
8933 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8934
8935 /* Errors ignored. */
8936 target_write (&current_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8937 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8938 }
8939
8940 /* The inferior can be gone if the user types "print exit(0)"
8941 (and perhaps other times). */
8942 if (target_has_execution)
8943 /* NB: The register write goes through to the target. */
8944 regcache_cpy (regcache, inf_state->registers);
8945
8946 discard_infcall_suspend_state (inf_state);
8947 }
8948
8949 static void
8950 do_restore_infcall_suspend_state_cleanup (void *state)
8951 {
8952 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8953 }
8954
8955 struct cleanup *
8956 make_cleanup_restore_infcall_suspend_state
8957 (struct infcall_suspend_state *inf_state)
8958 {
8959 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8960 }
8961
8962 void
8963 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8964 {
8965 regcache_xfree (inf_state->registers);
8966 xfree (inf_state->siginfo_data);
8967 xfree (inf_state);
8968 }
8969
8970 struct regcache *
8971 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8972 {
8973 return inf_state->registers;
8974 }
8975
8976 /* infcall_control_state contains state regarding gdb's control of the
8977 inferior itself like stepping control. It also contains session state like
8978 the user's currently selected frame. */
8979
8980 struct infcall_control_state
8981 {
8982 struct thread_control_state thread_control;
8983 struct inferior_control_state inferior_control;
8984
8985 /* Other fields: */
8986 enum stop_stack_kind stop_stack_dummy;
8987 int stopped_by_random_signal;
8988
8989 /* ID if the selected frame when the inferior function call was made. */
8990 struct frame_id selected_frame_id;
8991 };
8992
8993 /* Save all of the information associated with the inferior<==>gdb
8994 connection. */
8995
8996 struct infcall_control_state *
8997 save_infcall_control_state (void)
8998 {
8999 struct infcall_control_state *inf_status =
9000 XNEW (struct infcall_control_state);
9001 struct thread_info *tp = inferior_thread ();
9002 struct inferior *inf = current_inferior ();
9003
9004 inf_status->thread_control = tp->control;
9005 inf_status->inferior_control = inf->control;
9006
9007 tp->control.step_resume_breakpoint = NULL;
9008 tp->control.exception_resume_breakpoint = NULL;
9009
9010 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9011 chain. If caller's caller is walking the chain, they'll be happier if we
9012 hand them back the original chain when restore_infcall_control_state is
9013 called. */
9014 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
9015
9016 /* Other fields: */
9017 inf_status->stop_stack_dummy = stop_stack_dummy;
9018 inf_status->stopped_by_random_signal = stopped_by_random_signal;
9019
9020 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
9021
9022 return inf_status;
9023 }
9024
9025 static int
9026 restore_selected_frame (void *args)
9027 {
9028 struct frame_id *fid = (struct frame_id *) args;
9029 struct frame_info *frame;
9030
9031 frame = frame_find_by_id (*fid);
9032
9033 /* If inf_status->selected_frame_id is NULL, there was no previously
9034 selected frame. */
9035 if (frame == NULL)
9036 {
9037 warning (_("Unable to restore previously selected frame."));
9038 return 0;
9039 }
9040
9041 select_frame (frame);
9042
9043 return (1);
9044 }
9045
9046 /* Restore inferior session state to INF_STATUS. */
9047
9048 void
9049 restore_infcall_control_state (struct infcall_control_state *inf_status)
9050 {
9051 struct thread_info *tp = inferior_thread ();
9052 struct inferior *inf = current_inferior ();
9053
9054 if (tp->control.step_resume_breakpoint)
9055 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
9056
9057 if (tp->control.exception_resume_breakpoint)
9058 tp->control.exception_resume_breakpoint->disposition
9059 = disp_del_at_next_stop;
9060
9061 /* Handle the bpstat_copy of the chain. */
9062 bpstat_clear (&tp->control.stop_bpstat);
9063
9064 tp->control = inf_status->thread_control;
9065 inf->control = inf_status->inferior_control;
9066
9067 /* Other fields: */
9068 stop_stack_dummy = inf_status->stop_stack_dummy;
9069 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9070
9071 if (target_has_stack)
9072 {
9073 /* The point of catch_errors is that if the stack is clobbered,
9074 walking the stack might encounter a garbage pointer and
9075 error() trying to dereference it. */
9076 if (catch_errors
9077 (restore_selected_frame, &inf_status->selected_frame_id,
9078 "Unable to restore previously selected frame:\n",
9079 RETURN_MASK_ERROR) == 0)
9080 /* Error in restoring the selected frame. Select the innermost
9081 frame. */
9082 select_frame (get_current_frame ());
9083 }
9084
9085 xfree (inf_status);
9086 }
9087
9088 static void
9089 do_restore_infcall_control_state_cleanup (void *sts)
9090 {
9091 restore_infcall_control_state ((struct infcall_control_state *) sts);
9092 }
9093
9094 struct cleanup *
9095 make_cleanup_restore_infcall_control_state
9096 (struct infcall_control_state *inf_status)
9097 {
9098 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9099 }
9100
9101 void
9102 discard_infcall_control_state (struct infcall_control_state *inf_status)
9103 {
9104 if (inf_status->thread_control.step_resume_breakpoint)
9105 inf_status->thread_control.step_resume_breakpoint->disposition
9106 = disp_del_at_next_stop;
9107
9108 if (inf_status->thread_control.exception_resume_breakpoint)
9109 inf_status->thread_control.exception_resume_breakpoint->disposition
9110 = disp_del_at_next_stop;
9111
9112 /* See save_infcall_control_state for info on stop_bpstat. */
9113 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9114
9115 xfree (inf_status);
9116 }
9117 \f
9118 /* restore_inferior_ptid() will be used by the cleanup machinery
9119 to restore the inferior_ptid value saved in a call to
9120 save_inferior_ptid(). */
9121
9122 static void
9123 restore_inferior_ptid (void *arg)
9124 {
9125 ptid_t *saved_ptid_ptr = (ptid_t *) arg;
9126
9127 inferior_ptid = *saved_ptid_ptr;
9128 xfree (arg);
9129 }
9130
9131 /* Save the value of inferior_ptid so that it may be restored by a
9132 later call to do_cleanups(). Returns the struct cleanup pointer
9133 needed for later doing the cleanup. */
9134
9135 struct cleanup *
9136 save_inferior_ptid (void)
9137 {
9138 ptid_t *saved_ptid_ptr = XNEW (ptid_t);
9139
9140 *saved_ptid_ptr = inferior_ptid;
9141 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
9142 }
9143
9144 /* See infrun.h. */
9145
9146 void
9147 clear_exit_convenience_vars (void)
9148 {
9149 clear_internalvar (lookup_internalvar ("_exitsignal"));
9150 clear_internalvar (lookup_internalvar ("_exitcode"));
9151 }
9152 \f
9153
9154 /* User interface for reverse debugging:
9155 Set exec-direction / show exec-direction commands
9156 (returns error unless target implements to_set_exec_direction method). */
9157
9158 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9159 static const char exec_forward[] = "forward";
9160 static const char exec_reverse[] = "reverse";
9161 static const char *exec_direction = exec_forward;
9162 static const char *const exec_direction_names[] = {
9163 exec_forward,
9164 exec_reverse,
9165 NULL
9166 };
9167
9168 static void
9169 set_exec_direction_func (char *args, int from_tty,
9170 struct cmd_list_element *cmd)
9171 {
9172 if (target_can_execute_reverse)
9173 {
9174 if (!strcmp (exec_direction, exec_forward))
9175 execution_direction = EXEC_FORWARD;
9176 else if (!strcmp (exec_direction, exec_reverse))
9177 execution_direction = EXEC_REVERSE;
9178 }
9179 else
9180 {
9181 exec_direction = exec_forward;
9182 error (_("Target does not support this operation."));
9183 }
9184 }
9185
9186 static void
9187 show_exec_direction_func (struct ui_file *out, int from_tty,
9188 struct cmd_list_element *cmd, const char *value)
9189 {
9190 switch (execution_direction) {
9191 case EXEC_FORWARD:
9192 fprintf_filtered (out, _("Forward.\n"));
9193 break;
9194 case EXEC_REVERSE:
9195 fprintf_filtered (out, _("Reverse.\n"));
9196 break;
9197 default:
9198 internal_error (__FILE__, __LINE__,
9199 _("bogus execution_direction value: %d"),
9200 (int) execution_direction);
9201 }
9202 }
9203
9204 static void
9205 show_schedule_multiple (struct ui_file *file, int from_tty,
9206 struct cmd_list_element *c, const char *value)
9207 {
9208 fprintf_filtered (file, _("Resuming the execution of threads "
9209 "of all processes is %s.\n"), value);
9210 }
9211
9212 /* Implementation of `siginfo' variable. */
9213
9214 static const struct internalvar_funcs siginfo_funcs =
9215 {
9216 siginfo_make_value,
9217 NULL,
9218 NULL
9219 };
9220
9221 /* Callback for infrun's target events source. This is marked when a
9222 thread has a pending status to process. */
9223
9224 static void
9225 infrun_async_inferior_event_handler (gdb_client_data data)
9226 {
9227 inferior_event_handler (INF_REG_EVENT, NULL);
9228 }
9229
9230 void
9231 _initialize_infrun (void)
9232 {
9233 int i;
9234 int numsigs;
9235 struct cmd_list_element *c;
9236
9237 /* Register extra event sources in the event loop. */
9238 infrun_async_inferior_event_token
9239 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9240
9241 add_info ("signals", signals_info, _("\
9242 What debugger does when program gets various signals.\n\
9243 Specify a signal as argument to print info on that signal only."));
9244 add_info_alias ("handle", "signals", 0);
9245
9246 c = add_com ("handle", class_run, handle_command, _("\
9247 Specify how to handle signals.\n\
9248 Usage: handle SIGNAL [ACTIONS]\n\
9249 Args are signals and actions to apply to those signals.\n\
9250 If no actions are specified, the current settings for the specified signals\n\
9251 will be displayed instead.\n\
9252 \n\
9253 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9254 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9255 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9256 The special arg \"all\" is recognized to mean all signals except those\n\
9257 used by the debugger, typically SIGTRAP and SIGINT.\n\
9258 \n\
9259 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9260 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9261 Stop means reenter debugger if this signal happens (implies print).\n\
9262 Print means print a message if this signal happens.\n\
9263 Pass means let program see this signal; otherwise program doesn't know.\n\
9264 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9265 Pass and Stop may be combined.\n\
9266 \n\
9267 Multiple signals may be specified. Signal numbers and signal names\n\
9268 may be interspersed with actions, with the actions being performed for\n\
9269 all signals cumulatively specified."));
9270 set_cmd_completer (c, handle_completer);
9271
9272 if (!dbx_commands)
9273 stop_command = add_cmd ("stop", class_obscure,
9274 not_just_help_class_command, _("\
9275 There is no `stop' command, but you can set a hook on `stop'.\n\
9276 This allows you to set a list of commands to be run each time execution\n\
9277 of the program stops."), &cmdlist);
9278
9279 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9280 Set inferior debugging."), _("\
9281 Show inferior debugging."), _("\
9282 When non-zero, inferior specific debugging is enabled."),
9283 NULL,
9284 show_debug_infrun,
9285 &setdebuglist, &showdebuglist);
9286
9287 add_setshow_boolean_cmd ("displaced", class_maintenance,
9288 &debug_displaced, _("\
9289 Set displaced stepping debugging."), _("\
9290 Show displaced stepping debugging."), _("\
9291 When non-zero, displaced stepping specific debugging is enabled."),
9292 NULL,
9293 show_debug_displaced,
9294 &setdebuglist, &showdebuglist);
9295
9296 add_setshow_boolean_cmd ("non-stop", no_class,
9297 &non_stop_1, _("\
9298 Set whether gdb controls the inferior in non-stop mode."), _("\
9299 Show whether gdb controls the inferior in non-stop mode."), _("\
9300 When debugging a multi-threaded program and this setting is\n\
9301 off (the default, also called all-stop mode), when one thread stops\n\
9302 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9303 all other threads in the program while you interact with the thread of\n\
9304 interest. When you continue or step a thread, you can allow the other\n\
9305 threads to run, or have them remain stopped, but while you inspect any\n\
9306 thread's state, all threads stop.\n\
9307 \n\
9308 In non-stop mode, when one thread stops, other threads can continue\n\
9309 to run freely. You'll be able to step each thread independently,\n\
9310 leave it stopped or free to run as needed."),
9311 set_non_stop,
9312 show_non_stop,
9313 &setlist,
9314 &showlist);
9315
9316 numsigs = (int) GDB_SIGNAL_LAST;
9317 signal_stop = XNEWVEC (unsigned char, numsigs);
9318 signal_print = XNEWVEC (unsigned char, numsigs);
9319 signal_program = XNEWVEC (unsigned char, numsigs);
9320 signal_catch = XNEWVEC (unsigned char, numsigs);
9321 signal_pass = XNEWVEC (unsigned char, numsigs);
9322 for (i = 0; i < numsigs; i++)
9323 {
9324 signal_stop[i] = 1;
9325 signal_print[i] = 1;
9326 signal_program[i] = 1;
9327 signal_catch[i] = 0;
9328 }
9329
9330 /* Signals caused by debugger's own actions should not be given to
9331 the program afterwards.
9332
9333 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9334 explicitly specifies that it should be delivered to the target
9335 program. Typically, that would occur when a user is debugging a
9336 target monitor on a simulator: the target monitor sets a
9337 breakpoint; the simulator encounters this breakpoint and halts
9338 the simulation handing control to GDB; GDB, noting that the stop
9339 address doesn't map to any known breakpoint, returns control back
9340 to the simulator; the simulator then delivers the hardware
9341 equivalent of a GDB_SIGNAL_TRAP to the program being
9342 debugged. */
9343 signal_program[GDB_SIGNAL_TRAP] = 0;
9344 signal_program[GDB_SIGNAL_INT] = 0;
9345
9346 /* Signals that are not errors should not normally enter the debugger. */
9347 signal_stop[GDB_SIGNAL_ALRM] = 0;
9348 signal_print[GDB_SIGNAL_ALRM] = 0;
9349 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9350 signal_print[GDB_SIGNAL_VTALRM] = 0;
9351 signal_stop[GDB_SIGNAL_PROF] = 0;
9352 signal_print[GDB_SIGNAL_PROF] = 0;
9353 signal_stop[GDB_SIGNAL_CHLD] = 0;
9354 signal_print[GDB_SIGNAL_CHLD] = 0;
9355 signal_stop[GDB_SIGNAL_IO] = 0;
9356 signal_print[GDB_SIGNAL_IO] = 0;
9357 signal_stop[GDB_SIGNAL_POLL] = 0;
9358 signal_print[GDB_SIGNAL_POLL] = 0;
9359 signal_stop[GDB_SIGNAL_URG] = 0;
9360 signal_print[GDB_SIGNAL_URG] = 0;
9361 signal_stop[GDB_SIGNAL_WINCH] = 0;
9362 signal_print[GDB_SIGNAL_WINCH] = 0;
9363 signal_stop[GDB_SIGNAL_PRIO] = 0;
9364 signal_print[GDB_SIGNAL_PRIO] = 0;
9365
9366 /* These signals are used internally by user-level thread
9367 implementations. (See signal(5) on Solaris.) Like the above
9368 signals, a healthy program receives and handles them as part of
9369 its normal operation. */
9370 signal_stop[GDB_SIGNAL_LWP] = 0;
9371 signal_print[GDB_SIGNAL_LWP] = 0;
9372 signal_stop[GDB_SIGNAL_WAITING] = 0;
9373 signal_print[GDB_SIGNAL_WAITING] = 0;
9374 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9375 signal_print[GDB_SIGNAL_CANCEL] = 0;
9376 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9377 signal_print[GDB_SIGNAL_LIBRT] = 0;
9378
9379 /* Update cached state. */
9380 signal_cache_update (-1);
9381
9382 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9383 &stop_on_solib_events, _("\
9384 Set stopping for shared library events."), _("\
9385 Show stopping for shared library events."), _("\
9386 If nonzero, gdb will give control to the user when the dynamic linker\n\
9387 notifies gdb of shared library events. The most common event of interest\n\
9388 to the user would be loading/unloading of a new library."),
9389 set_stop_on_solib_events,
9390 show_stop_on_solib_events,
9391 &setlist, &showlist);
9392
9393 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9394 follow_fork_mode_kind_names,
9395 &follow_fork_mode_string, _("\
9396 Set debugger response to a program call of fork or vfork."), _("\
9397 Show debugger response to a program call of fork or vfork."), _("\
9398 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9399 parent - the original process is debugged after a fork\n\
9400 child - the new process is debugged after a fork\n\
9401 The unfollowed process will continue to run.\n\
9402 By default, the debugger will follow the parent process."),
9403 NULL,
9404 show_follow_fork_mode_string,
9405 &setlist, &showlist);
9406
9407 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9408 follow_exec_mode_names,
9409 &follow_exec_mode_string, _("\
9410 Set debugger response to a program call of exec."), _("\
9411 Show debugger response to a program call of exec."), _("\
9412 An exec call replaces the program image of a process.\n\
9413 \n\
9414 follow-exec-mode can be:\n\
9415 \n\
9416 new - the debugger creates a new inferior and rebinds the process\n\
9417 to this new inferior. The program the process was running before\n\
9418 the exec call can be restarted afterwards by restarting the original\n\
9419 inferior.\n\
9420 \n\
9421 same - the debugger keeps the process bound to the same inferior.\n\
9422 The new executable image replaces the previous executable loaded in\n\
9423 the inferior. Restarting the inferior after the exec call restarts\n\
9424 the executable the process was running after the exec call.\n\
9425 \n\
9426 By default, the debugger will use the same inferior."),
9427 NULL,
9428 show_follow_exec_mode_string,
9429 &setlist, &showlist);
9430
9431 add_setshow_enum_cmd ("scheduler-locking", class_run,
9432 scheduler_enums, &scheduler_mode, _("\
9433 Set mode for locking scheduler during execution."), _("\
9434 Show mode for locking scheduler during execution."), _("\
9435 off == no locking (threads may preempt at any time)\n\
9436 on == full locking (no thread except the current thread may run)\n\
9437 This applies to both normal execution and replay mode.\n\
9438 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9439 In this mode, other threads may run during other commands.\n\
9440 This applies to both normal execution and replay mode.\n\
9441 replay == scheduler locked in replay mode and unlocked during normal execution."),
9442 set_schedlock_func, /* traps on target vector */
9443 show_scheduler_mode,
9444 &setlist, &showlist);
9445
9446 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9447 Set mode for resuming threads of all processes."), _("\
9448 Show mode for resuming threads of all processes."), _("\
9449 When on, execution commands (such as 'continue' or 'next') resume all\n\
9450 threads of all processes. When off (which is the default), execution\n\
9451 commands only resume the threads of the current process. The set of\n\
9452 threads that are resumed is further refined by the scheduler-locking\n\
9453 mode (see help set scheduler-locking)."),
9454 NULL,
9455 show_schedule_multiple,
9456 &setlist, &showlist);
9457
9458 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9459 Set mode of the step operation."), _("\
9460 Show mode of the step operation."), _("\
9461 When set, doing a step over a function without debug line information\n\
9462 will stop at the first instruction of that function. Otherwise, the\n\
9463 function is skipped and the step command stops at a different source line."),
9464 NULL,
9465 show_step_stop_if_no_debug,
9466 &setlist, &showlist);
9467
9468 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9469 &can_use_displaced_stepping, _("\
9470 Set debugger's willingness to use displaced stepping."), _("\
9471 Show debugger's willingness to use displaced stepping."), _("\
9472 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9473 supported by the target architecture. If off, gdb will not use displaced\n\
9474 stepping to step over breakpoints, even if such is supported by the target\n\
9475 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9476 if the target architecture supports it and non-stop mode is active, but will not\n\
9477 use it in all-stop mode (see help set non-stop)."),
9478 NULL,
9479 show_can_use_displaced_stepping,
9480 &setlist, &showlist);
9481
9482 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9483 &exec_direction, _("Set direction of execution.\n\
9484 Options are 'forward' or 'reverse'."),
9485 _("Show direction of execution (forward/reverse)."),
9486 _("Tells gdb whether to execute forward or backward."),
9487 set_exec_direction_func, show_exec_direction_func,
9488 &setlist, &showlist);
9489
9490 /* Set/show detach-on-fork: user-settable mode. */
9491
9492 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9493 Set whether gdb will detach the child of a fork."), _("\
9494 Show whether gdb will detach the child of a fork."), _("\
9495 Tells gdb whether to detach the child of a fork."),
9496 NULL, NULL, &setlist, &showlist);
9497
9498 /* Set/show disable address space randomization mode. */
9499
9500 add_setshow_boolean_cmd ("disable-randomization", class_support,
9501 &disable_randomization, _("\
9502 Set disabling of debuggee's virtual address space randomization."), _("\
9503 Show disabling of debuggee's virtual address space randomization."), _("\
9504 When this mode is on (which is the default), randomization of the virtual\n\
9505 address space is disabled. Standalone programs run with the randomization\n\
9506 enabled by default on some platforms."),
9507 &set_disable_randomization,
9508 &show_disable_randomization,
9509 &setlist, &showlist);
9510
9511 /* ptid initializations */
9512 inferior_ptid = null_ptid;
9513 target_last_wait_ptid = minus_one_ptid;
9514
9515 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9516 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9517 observer_attach_thread_exit (infrun_thread_thread_exit);
9518 observer_attach_inferior_exit (infrun_inferior_exit);
9519
9520 /* Explicitly create without lookup, since that tries to create a
9521 value with a void typed value, and when we get here, gdbarch
9522 isn't initialized yet. At this point, we're quite sure there
9523 isn't another convenience variable of the same name. */
9524 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9525
9526 add_setshow_boolean_cmd ("observer", no_class,
9527 &observer_mode_1, _("\
9528 Set whether gdb controls the inferior in observer mode."), _("\
9529 Show whether gdb controls the inferior in observer mode."), _("\
9530 In observer mode, GDB can get data from the inferior, but not\n\
9531 affect its execution. Registers and memory may not be changed,\n\
9532 breakpoints may not be set, and the program cannot be interrupted\n\
9533 or signalled."),
9534 set_observer_mode,
9535 show_observer_mode,
9536 &setlist,
9537 &showlist);
9538 }