1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2019 Free Software Foundation, Inc.
6 This file is part of GDB.
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.
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.
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/>. */
27 #include "breakpoint.h"
28 #include "common/gdb_wait.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
41 #include "observable.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
67 #include "progspace-and-thread.h"
68 #include "common/gdb_optional.h"
69 #include "arch-utils.h"
70 #include "common/scope-exit.h"
71 #include "common/forward-scope-exit.h"
73 /* Prototypes for local functions */
75 static void sig_print_info (enum gdb_signal);
77 static void sig_print_header (void);
79 static int follow_fork (void);
81 static int follow_fork_inferior (int follow_child, int detach_fork);
83 static void follow_inferior_reset_breakpoints (void);
85 static int currently_stepping (struct thread_info *tp);
87 void nullify_last_target_wait_ptid (void);
89 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
91 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
93 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
95 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
97 static void resume (gdb_signal sig);
99 /* Asynchronous signal handler registered as event loop source for
100 when we have pending events ready to be passed to the core. */
101 static struct async_event_handler *infrun_async_inferior_event_token;
103 /* Stores whether infrun_async was previously enabled or disabled.
104 Starts off as -1, indicating "never enabled/disabled". */
105 static int infrun_is_async = -1;
110 infrun_async (int enable)
112 if (infrun_is_async != enable)
114 infrun_is_async = enable;
117 fprintf_unfiltered (gdb_stdlog,
118 "infrun: infrun_async(%d)\n",
122 mark_async_event_handler (infrun_async_inferior_event_token);
124 clear_async_event_handler (infrun_async_inferior_event_token);
131 mark_infrun_async_event_handler (void)
133 mark_async_event_handler (infrun_async_inferior_event_token);
136 /* When set, stop the 'step' command if we enter a function which has
137 no line number information. The normal behavior is that we step
138 over such function. */
139 int step_stop_if_no_debug = 0;
141 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
142 struct cmd_list_element *c, const char *value)
144 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
147 /* proceed and normal_stop use this to notify the user when the
148 inferior stopped in a different thread than it had been running
151 static ptid_t previous_inferior_ptid;
153 /* If set (default for legacy reasons), when following a fork, GDB
154 will detach from one of the fork branches, child or parent.
155 Exactly which branch is detached depends on 'set follow-fork-mode'
158 static int detach_fork = 1;
160 int debug_displaced = 0;
162 show_debug_displaced (struct ui_file *file, int from_tty,
163 struct cmd_list_element *c, const char *value)
165 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
168 unsigned int debug_infrun = 0;
170 show_debug_infrun (struct ui_file *file, int from_tty,
171 struct cmd_list_element *c, const char *value)
173 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
177 /* Support for disabling address space randomization. */
179 int disable_randomization = 1;
182 show_disable_randomization (struct ui_file *file, int from_tty,
183 struct cmd_list_element *c, const char *value)
185 if (target_supports_disable_randomization ())
186 fprintf_filtered (file,
187 _("Disabling randomization of debuggee's "
188 "virtual address space is %s.\n"),
191 fputs_filtered (_("Disabling randomization of debuggee's "
192 "virtual address space is unsupported on\n"
193 "this platform.\n"), file);
197 set_disable_randomization (const char *args, int from_tty,
198 struct cmd_list_element *c)
200 if (!target_supports_disable_randomization ())
201 error (_("Disabling randomization of debuggee's "
202 "virtual address space is unsupported on\n"
206 /* User interface for non-stop mode. */
209 static int non_stop_1 = 0;
212 set_non_stop (const char *args, int from_tty,
213 struct cmd_list_element *c)
215 if (target_has_execution)
217 non_stop_1 = non_stop;
218 error (_("Cannot change this setting while the inferior is running."));
221 non_stop = non_stop_1;
225 show_non_stop (struct ui_file *file, int from_tty,
226 struct cmd_list_element *c, const char *value)
228 fprintf_filtered (file,
229 _("Controlling the inferior in non-stop mode is %s.\n"),
233 /* "Observer mode" is somewhat like a more extreme version of
234 non-stop, in which all GDB operations that might affect the
235 target's execution have been disabled. */
237 int observer_mode = 0;
238 static int observer_mode_1 = 0;
241 set_observer_mode (const char *args, int from_tty,
242 struct cmd_list_element *c)
244 if (target_has_execution)
246 observer_mode_1 = observer_mode;
247 error (_("Cannot change this setting while the inferior is running."));
250 observer_mode = observer_mode_1;
252 may_write_registers = !observer_mode;
253 may_write_memory = !observer_mode;
254 may_insert_breakpoints = !observer_mode;
255 may_insert_tracepoints = !observer_mode;
256 /* We can insert fast tracepoints in or out of observer mode,
257 but enable them if we're going into this mode. */
259 may_insert_fast_tracepoints = 1;
260 may_stop = !observer_mode;
261 update_target_permissions ();
263 /* Going *into* observer mode we must force non-stop, then
264 going out we leave it that way. */
267 pagination_enabled = 0;
268 non_stop = non_stop_1 = 1;
272 printf_filtered (_("Observer mode is now %s.\n"),
273 (observer_mode ? "on" : "off"));
277 show_observer_mode (struct ui_file *file, int from_tty,
278 struct cmd_list_element *c, const char *value)
280 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
283 /* This updates the value of observer mode based on changes in
284 permissions. Note that we are deliberately ignoring the values of
285 may-write-registers and may-write-memory, since the user may have
286 reason to enable these during a session, for instance to turn on a
287 debugging-related global. */
290 update_observer_mode (void)
294 newval = (!may_insert_breakpoints
295 && !may_insert_tracepoints
296 && may_insert_fast_tracepoints
300 /* Let the user know if things change. */
301 if (newval != observer_mode)
302 printf_filtered (_("Observer mode is now %s.\n"),
303 (newval ? "on" : "off"));
305 observer_mode = observer_mode_1 = newval;
308 /* Tables of how to react to signals; the user sets them. */
310 static unsigned char signal_stop[GDB_SIGNAL_LAST];
311 static unsigned char signal_print[GDB_SIGNAL_LAST];
312 static unsigned char signal_program[GDB_SIGNAL_LAST];
314 /* Table of signals that are registered with "catch signal". A
315 non-zero entry indicates that the signal is caught by some "catch
317 static unsigned char signal_catch[GDB_SIGNAL_LAST];
319 /* Table of signals that the target may silently handle.
320 This is automatically determined from the flags above,
321 and simply cached here. */
322 static unsigned char signal_pass[GDB_SIGNAL_LAST];
324 #define SET_SIGS(nsigs,sigs,flags) \
326 int signum = (nsigs); \
327 while (signum-- > 0) \
328 if ((sigs)[signum]) \
329 (flags)[signum] = 1; \
332 #define UNSET_SIGS(nsigs,sigs,flags) \
334 int signum = (nsigs); \
335 while (signum-- > 0) \
336 if ((sigs)[signum]) \
337 (flags)[signum] = 0; \
340 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
341 this function is to avoid exporting `signal_program'. */
344 update_signals_program_target (void)
346 target_program_signals (signal_program);
349 /* Value to pass to target_resume() to cause all threads to resume. */
351 #define RESUME_ALL minus_one_ptid
353 /* Command list pointer for the "stop" placeholder. */
355 static struct cmd_list_element *stop_command;
357 /* Nonzero if we want to give control to the user when we're notified
358 of shared library events by the dynamic linker. */
359 int stop_on_solib_events;
361 /* Enable or disable optional shared library event breakpoints
362 as appropriate when the above flag is changed. */
365 set_stop_on_solib_events (const char *args,
366 int from_tty, struct cmd_list_element *c)
368 update_solib_breakpoints ();
372 show_stop_on_solib_events (struct ui_file *file, int from_tty,
373 struct cmd_list_element *c, const char *value)
375 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
379 /* Nonzero after stop if current stack frame should be printed. */
381 static int stop_print_frame;
383 /* This is a cached copy of the pid/waitstatus of the last event
384 returned by target_wait()/deprecated_target_wait_hook(). This
385 information is returned by get_last_target_status(). */
386 static ptid_t target_last_wait_ptid;
387 static struct target_waitstatus target_last_waitstatus;
389 void init_thread_stepping_state (struct thread_info *tss);
391 static const char follow_fork_mode_child[] = "child";
392 static const char follow_fork_mode_parent[] = "parent";
394 static const char *const follow_fork_mode_kind_names[] = {
395 follow_fork_mode_child,
396 follow_fork_mode_parent,
400 static const char *follow_fork_mode_string = follow_fork_mode_parent;
402 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
403 struct cmd_list_element *c, const char *value)
405 fprintf_filtered (file,
406 _("Debugger response to a program "
407 "call of fork or vfork is \"%s\".\n"),
412 /* Handle changes to the inferior list based on the type of fork,
413 which process is being followed, and whether the other process
414 should be detached. On entry inferior_ptid must be the ptid of
415 the fork parent. At return inferior_ptid is the ptid of the
416 followed inferior. */
419 follow_fork_inferior (int follow_child, int detach_fork)
422 ptid_t parent_ptid, child_ptid;
424 has_vforked = (inferior_thread ()->pending_follow.kind
425 == TARGET_WAITKIND_VFORKED);
426 parent_ptid = inferior_ptid;
427 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
430 && !non_stop /* Non-stop always resumes both branches. */
431 && current_ui->prompt_state == PROMPT_BLOCKED
432 && !(follow_child || detach_fork || sched_multi))
434 /* The parent stays blocked inside the vfork syscall until the
435 child execs or exits. If we don't let the child run, then
436 the parent stays blocked. If we're telling the parent to run
437 in the foreground, the user will not be able to ctrl-c to get
438 back the terminal, effectively hanging the debug session. */
439 fprintf_filtered (gdb_stderr, _("\
440 Can not resume the parent process over vfork in the foreground while\n\
441 holding the child stopped. Try \"set detach-on-fork\" or \
442 \"set schedule-multiple\".\n"));
443 /* FIXME output string > 80 columns. */
449 /* Detach new forked process? */
452 /* Before detaching from the child, remove all breakpoints
453 from it. If we forked, then this has already been taken
454 care of by infrun.c. If we vforked however, any
455 breakpoint inserted in the parent is visible in the
456 child, even those added while stopped in a vfork
457 catchpoint. This will remove the breakpoints from the
458 parent also, but they'll be reinserted below. */
461 /* Keep breakpoints list in sync. */
462 remove_breakpoints_inf (current_inferior ());
465 if (print_inferior_events)
467 /* Ensure that we have a process ptid. */
468 ptid_t process_ptid = ptid_t (child_ptid.pid ());
470 target_terminal::ours_for_output ();
471 fprintf_filtered (gdb_stdlog,
472 _("[Detaching after %s from child %s]\n"),
473 has_vforked ? "vfork" : "fork",
474 target_pid_to_str (process_ptid));
479 struct inferior *parent_inf, *child_inf;
481 /* Add process to GDB's tables. */
482 child_inf = add_inferior (child_ptid.pid ());
484 parent_inf = current_inferior ();
485 child_inf->attach_flag = parent_inf->attach_flag;
486 copy_terminal_info (child_inf, parent_inf);
487 child_inf->gdbarch = parent_inf->gdbarch;
488 copy_inferior_target_desc_info (child_inf, parent_inf);
490 scoped_restore_current_pspace_and_thread restore_pspace_thread;
492 inferior_ptid = child_ptid;
493 add_thread_silent (inferior_ptid);
494 set_current_inferior (child_inf);
495 child_inf->symfile_flags = SYMFILE_NO_READ;
497 /* If this is a vfork child, then the address-space is
498 shared with the parent. */
501 child_inf->pspace = parent_inf->pspace;
502 child_inf->aspace = parent_inf->aspace;
504 /* The parent will be frozen until the child is done
505 with the shared region. Keep track of the
507 child_inf->vfork_parent = parent_inf;
508 child_inf->pending_detach = 0;
509 parent_inf->vfork_child = child_inf;
510 parent_inf->pending_detach = 0;
514 child_inf->aspace = new_address_space ();
515 child_inf->pspace = new program_space (child_inf->aspace);
516 child_inf->removable = 1;
517 set_current_program_space (child_inf->pspace);
518 clone_program_space (child_inf->pspace, parent_inf->pspace);
520 /* Let the shared library layer (e.g., solib-svr4) learn
521 about this new process, relocate the cloned exec, pull
522 in shared libraries, and install the solib event
523 breakpoint. If a "cloned-VM" event was propagated
524 better throughout the core, this wouldn't be
526 solib_create_inferior_hook (0);
532 struct inferior *parent_inf;
534 parent_inf = current_inferior ();
536 /* If we detached from the child, then we have to be careful
537 to not insert breakpoints in the parent until the child
538 is done with the shared memory region. However, if we're
539 staying attached to the child, then we can and should
540 insert breakpoints, so that we can debug it. A
541 subsequent child exec or exit is enough to know when does
542 the child stops using the parent's address space. */
543 parent_inf->waiting_for_vfork_done = detach_fork;
544 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
549 /* Follow the child. */
550 struct inferior *parent_inf, *child_inf;
551 struct program_space *parent_pspace;
553 if (print_inferior_events)
555 std::string parent_pid = target_pid_to_str (parent_ptid);
556 std::string child_pid = target_pid_to_str (child_ptid);
558 target_terminal::ours_for_output ();
559 fprintf_filtered (gdb_stdlog,
560 _("[Attaching after %s %s to child %s]\n"),
562 has_vforked ? "vfork" : "fork",
566 /* Add the new inferior first, so that the target_detach below
567 doesn't unpush the target. */
569 child_inf = add_inferior (child_ptid.pid ());
571 parent_inf = current_inferior ();
572 child_inf->attach_flag = parent_inf->attach_flag;
573 copy_terminal_info (child_inf, parent_inf);
574 child_inf->gdbarch = parent_inf->gdbarch;
575 copy_inferior_target_desc_info (child_inf, parent_inf);
577 parent_pspace = parent_inf->pspace;
579 /* If we're vforking, we want to hold on to the parent until the
580 child exits or execs. At child exec or exit time we can
581 remove the old breakpoints from the parent and detach or
582 resume debugging it. Otherwise, detach the parent now; we'll
583 want to reuse it's program/address spaces, but we can't set
584 them to the child before removing breakpoints from the
585 parent, otherwise, the breakpoints module could decide to
586 remove breakpoints from the wrong process (since they'd be
587 assigned to the same address space). */
591 gdb_assert (child_inf->vfork_parent == NULL);
592 gdb_assert (parent_inf->vfork_child == NULL);
593 child_inf->vfork_parent = parent_inf;
594 child_inf->pending_detach = 0;
595 parent_inf->vfork_child = child_inf;
596 parent_inf->pending_detach = detach_fork;
597 parent_inf->waiting_for_vfork_done = 0;
599 else if (detach_fork)
601 if (print_inferior_events)
603 /* Ensure that we have a process ptid. */
604 ptid_t process_ptid = ptid_t (parent_ptid.pid ());
606 target_terminal::ours_for_output ();
607 fprintf_filtered (gdb_stdlog,
608 _("[Detaching after fork from "
610 target_pid_to_str (process_ptid));
613 target_detach (parent_inf, 0);
616 /* Note that the detach above makes PARENT_INF dangling. */
618 /* Add the child thread to the appropriate lists, and switch to
619 this new thread, before cloning the program space, and
620 informing the solib layer about this new process. */
622 inferior_ptid = child_ptid;
623 add_thread_silent (inferior_ptid);
624 set_current_inferior (child_inf);
626 /* If this is a vfork child, then the address-space is shared
627 with the parent. If we detached from the parent, then we can
628 reuse the parent's program/address spaces. */
629 if (has_vforked || detach_fork)
631 child_inf->pspace = parent_pspace;
632 child_inf->aspace = child_inf->pspace->aspace;
636 child_inf->aspace = new_address_space ();
637 child_inf->pspace = new program_space (child_inf->aspace);
638 child_inf->removable = 1;
639 child_inf->symfile_flags = SYMFILE_NO_READ;
640 set_current_program_space (child_inf->pspace);
641 clone_program_space (child_inf->pspace, parent_pspace);
643 /* Let the shared library layer (e.g., solib-svr4) learn
644 about this new process, relocate the cloned exec, pull in
645 shared libraries, and install the solib event breakpoint.
646 If a "cloned-VM" event was propagated better throughout
647 the core, this wouldn't be required. */
648 solib_create_inferior_hook (0);
652 return target_follow_fork (follow_child, detach_fork);
655 /* Tell the target to follow the fork we're stopped at. Returns true
656 if the inferior should be resumed; false, if the target for some
657 reason decided it's best not to resume. */
662 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
663 int should_resume = 1;
664 struct thread_info *tp;
666 /* Copy user stepping state to the new inferior thread. FIXME: the
667 followed fork child thread should have a copy of most of the
668 parent thread structure's run control related fields, not just these.
669 Initialized to avoid "may be used uninitialized" warnings from gcc. */
670 struct breakpoint *step_resume_breakpoint = NULL;
671 struct breakpoint *exception_resume_breakpoint = NULL;
672 CORE_ADDR step_range_start = 0;
673 CORE_ADDR step_range_end = 0;
674 struct frame_id step_frame_id = { 0 };
675 struct thread_fsm *thread_fsm = NULL;
680 struct target_waitstatus wait_status;
682 /* Get the last target status returned by target_wait(). */
683 get_last_target_status (&wait_ptid, &wait_status);
685 /* If not stopped at a fork event, then there's nothing else to
687 if (wait_status.kind != TARGET_WAITKIND_FORKED
688 && wait_status.kind != TARGET_WAITKIND_VFORKED)
691 /* Check if we switched over from WAIT_PTID, since the event was
693 if (wait_ptid != minus_one_ptid
694 && inferior_ptid != wait_ptid)
696 /* We did. Switch back to WAIT_PTID thread, to tell the
697 target to follow it (in either direction). We'll
698 afterwards refuse to resume, and inform the user what
700 thread_info *wait_thread
701 = find_thread_ptid (wait_ptid);
702 switch_to_thread (wait_thread);
707 tp = inferior_thread ();
709 /* If there were any forks/vforks that were caught and are now to be
710 followed, then do so now. */
711 switch (tp->pending_follow.kind)
713 case TARGET_WAITKIND_FORKED:
714 case TARGET_WAITKIND_VFORKED:
716 ptid_t parent, child;
718 /* If the user did a next/step, etc, over a fork call,
719 preserve the stepping state in the fork child. */
720 if (follow_child && should_resume)
722 step_resume_breakpoint = clone_momentary_breakpoint
723 (tp->control.step_resume_breakpoint);
724 step_range_start = tp->control.step_range_start;
725 step_range_end = tp->control.step_range_end;
726 step_frame_id = tp->control.step_frame_id;
727 exception_resume_breakpoint
728 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
729 thread_fsm = tp->thread_fsm;
731 /* For now, delete the parent's sr breakpoint, otherwise,
732 parent/child sr breakpoints are considered duplicates,
733 and the child version will not be installed. Remove
734 this when the breakpoints module becomes aware of
735 inferiors and address spaces. */
736 delete_step_resume_breakpoint (tp);
737 tp->control.step_range_start = 0;
738 tp->control.step_range_end = 0;
739 tp->control.step_frame_id = null_frame_id;
740 delete_exception_resume_breakpoint (tp);
741 tp->thread_fsm = NULL;
744 parent = inferior_ptid;
745 child = tp->pending_follow.value.related_pid;
747 /* Set up inferior(s) as specified by the caller, and tell the
748 target to do whatever is necessary to follow either parent
750 if (follow_fork_inferior (follow_child, detach_fork))
752 /* Target refused to follow, or there's some other reason
753 we shouldn't resume. */
758 /* This pending follow fork event is now handled, one way
759 or another. The previous selected thread may be gone
760 from the lists by now, but if it is still around, need
761 to clear the pending follow request. */
762 tp = find_thread_ptid (parent);
764 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
766 /* This makes sure we don't try to apply the "Switched
767 over from WAIT_PID" logic above. */
768 nullify_last_target_wait_ptid ();
770 /* If we followed the child, switch to it... */
773 thread_info *child_thr = find_thread_ptid (child);
774 switch_to_thread (child_thr);
776 /* ... and preserve the stepping state, in case the
777 user was stepping over the fork call. */
780 tp = inferior_thread ();
781 tp->control.step_resume_breakpoint
782 = step_resume_breakpoint;
783 tp->control.step_range_start = step_range_start;
784 tp->control.step_range_end = step_range_end;
785 tp->control.step_frame_id = step_frame_id;
786 tp->control.exception_resume_breakpoint
787 = exception_resume_breakpoint;
788 tp->thread_fsm = thread_fsm;
792 /* If we get here, it was because we're trying to
793 resume from a fork catchpoint, but, the user
794 has switched threads away from the thread that
795 forked. In that case, the resume command
796 issued is most likely not applicable to the
797 child, so just warn, and refuse to resume. */
798 warning (_("Not resuming: switched threads "
799 "before following fork child."));
802 /* Reset breakpoints in the child as appropriate. */
803 follow_inferior_reset_breakpoints ();
808 case TARGET_WAITKIND_SPURIOUS:
809 /* Nothing to follow. */
812 internal_error (__FILE__, __LINE__,
813 "Unexpected pending_follow.kind %d\n",
814 tp->pending_follow.kind);
818 return should_resume;
822 follow_inferior_reset_breakpoints (void)
824 struct thread_info *tp = inferior_thread ();
826 /* Was there a step_resume breakpoint? (There was if the user
827 did a "next" at the fork() call.) If so, explicitly reset its
828 thread number. Cloned step_resume breakpoints are disabled on
829 creation, so enable it here now that it is associated with the
832 step_resumes are a form of bp that are made to be per-thread.
833 Since we created the step_resume bp when the parent process
834 was being debugged, and now are switching to the child process,
835 from the breakpoint package's viewpoint, that's a switch of
836 "threads". We must update the bp's notion of which thread
837 it is for, or it'll be ignored when it triggers. */
839 if (tp->control.step_resume_breakpoint)
841 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
842 tp->control.step_resume_breakpoint->loc->enabled = 1;
845 /* Treat exception_resume breakpoints like step_resume breakpoints. */
846 if (tp->control.exception_resume_breakpoint)
848 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
849 tp->control.exception_resume_breakpoint->loc->enabled = 1;
852 /* Reinsert all breakpoints in the child. The user may have set
853 breakpoints after catching the fork, in which case those
854 were never set in the child, but only in the parent. This makes
855 sure the inserted breakpoints match the breakpoint list. */
857 breakpoint_re_set ();
858 insert_breakpoints ();
861 /* The child has exited or execed: resume threads of the parent the
862 user wanted to be executing. */
865 proceed_after_vfork_done (struct thread_info *thread,
868 int pid = * (int *) arg;
870 if (thread->ptid.pid () == pid
871 && thread->state == THREAD_RUNNING
872 && !thread->executing
873 && !thread->stop_requested
874 && thread->suspend.stop_signal == GDB_SIGNAL_0)
877 fprintf_unfiltered (gdb_stdlog,
878 "infrun: resuming vfork parent thread %s\n",
879 target_pid_to_str (thread->ptid));
881 switch_to_thread (thread);
882 clear_proceed_status (0);
883 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
889 /* Save/restore inferior_ptid, current program space and current
890 inferior. Only use this if the current context points at an exited
891 inferior (and therefore there's no current thread to save). */
892 class scoped_restore_exited_inferior
895 scoped_restore_exited_inferior ()
896 : m_saved_ptid (&inferior_ptid)
900 scoped_restore_tmpl<ptid_t> m_saved_ptid;
901 scoped_restore_current_program_space m_pspace;
902 scoped_restore_current_inferior m_inferior;
905 /* Called whenever we notice an exec or exit event, to handle
906 detaching or resuming a vfork parent. */
909 handle_vfork_child_exec_or_exit (int exec)
911 struct inferior *inf = current_inferior ();
913 if (inf->vfork_parent)
915 int resume_parent = -1;
917 /* This exec or exit marks the end of the shared memory region
918 between the parent and the child. If the user wanted to
919 detach from the parent, now is the time. */
921 if (inf->vfork_parent->pending_detach)
923 struct thread_info *tp;
924 struct program_space *pspace;
925 struct address_space *aspace;
927 /* follow-fork child, detach-on-fork on. */
929 inf->vfork_parent->pending_detach = 0;
931 gdb::optional<scoped_restore_exited_inferior>
932 maybe_restore_inferior;
933 gdb::optional<scoped_restore_current_pspace_and_thread>
934 maybe_restore_thread;
936 /* If we're handling a child exit, then inferior_ptid points
937 at the inferior's pid, not to a thread. */
939 maybe_restore_inferior.emplace ();
941 maybe_restore_thread.emplace ();
943 /* We're letting loose of the parent. */
944 tp = any_live_thread_of_inferior (inf->vfork_parent);
945 switch_to_thread (tp);
947 /* We're about to detach from the parent, which implicitly
948 removes breakpoints from its address space. There's a
949 catch here: we want to reuse the spaces for the child,
950 but, parent/child are still sharing the pspace at this
951 point, although the exec in reality makes the kernel give
952 the child a fresh set of new pages. The problem here is
953 that the breakpoints module being unaware of this, would
954 likely chose the child process to write to the parent
955 address space. Swapping the child temporarily away from
956 the spaces has the desired effect. Yes, this is "sort
959 pspace = inf->pspace;
960 aspace = inf->aspace;
964 if (print_inferior_events)
967 = target_pid_to_str (ptid_t (inf->vfork_parent->pid));
969 target_terminal::ours_for_output ();
973 fprintf_filtered (gdb_stdlog,
974 _("[Detaching vfork parent %s "
975 "after child exec]\n"), pidstr);
979 fprintf_filtered (gdb_stdlog,
980 _("[Detaching vfork parent %s "
981 "after child exit]\n"), pidstr);
985 target_detach (inf->vfork_parent, 0);
988 inf->pspace = pspace;
989 inf->aspace = aspace;
993 /* We're staying attached to the parent, so, really give the
994 child a new address space. */
995 inf->pspace = new program_space (maybe_new_address_space ());
996 inf->aspace = inf->pspace->aspace;
998 set_current_program_space (inf->pspace);
1000 resume_parent = inf->vfork_parent->pid;
1002 /* Break the bonds. */
1003 inf->vfork_parent->vfork_child = NULL;
1007 struct program_space *pspace;
1009 /* If this is a vfork child exiting, then the pspace and
1010 aspaces were shared with the parent. Since we're
1011 reporting the process exit, we'll be mourning all that is
1012 found in the address space, and switching to null_ptid,
1013 preparing to start a new inferior. But, since we don't
1014 want to clobber the parent's address/program spaces, we
1015 go ahead and create a new one for this exiting
1018 /* Switch to null_ptid while running clone_program_space, so
1019 that clone_program_space doesn't want to read the
1020 selected frame of a dead process. */
1021 scoped_restore restore_ptid
1022 = make_scoped_restore (&inferior_ptid, null_ptid);
1024 /* This inferior is dead, so avoid giving the breakpoints
1025 module the option to write through to it (cloning a
1026 program space resets breakpoints). */
1029 pspace = new program_space (maybe_new_address_space ());
1030 set_current_program_space (pspace);
1032 inf->symfile_flags = SYMFILE_NO_READ;
1033 clone_program_space (pspace, inf->vfork_parent->pspace);
1034 inf->pspace = pspace;
1035 inf->aspace = pspace->aspace;
1037 resume_parent = inf->vfork_parent->pid;
1038 /* Break the bonds. */
1039 inf->vfork_parent->vfork_child = NULL;
1042 inf->vfork_parent = NULL;
1044 gdb_assert (current_program_space == inf->pspace);
1046 if (non_stop && resume_parent != -1)
1048 /* If the user wanted the parent to be running, let it go
1050 scoped_restore_current_thread restore_thread;
1053 fprintf_unfiltered (gdb_stdlog,
1054 "infrun: resuming vfork parent process %d\n",
1057 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1062 /* Enum strings for "set|show follow-exec-mode". */
1064 static const char follow_exec_mode_new[] = "new";
1065 static const char follow_exec_mode_same[] = "same";
1066 static const char *const follow_exec_mode_names[] =
1068 follow_exec_mode_new,
1069 follow_exec_mode_same,
1073 static const char *follow_exec_mode_string = follow_exec_mode_same;
1075 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1076 struct cmd_list_element *c, const char *value)
1078 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1081 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1084 follow_exec (ptid_t ptid, char *exec_file_target)
1086 struct inferior *inf = current_inferior ();
1087 int pid = ptid.pid ();
1088 ptid_t process_ptid;
1090 /* This is an exec event that we actually wish to pay attention to.
1091 Refresh our symbol table to the newly exec'd program, remove any
1092 momentary bp's, etc.
1094 If there are breakpoints, they aren't really inserted now,
1095 since the exec() transformed our inferior into a fresh set
1098 We want to preserve symbolic breakpoints on the list, since
1099 we have hopes that they can be reset after the new a.out's
1100 symbol table is read.
1102 However, any "raw" breakpoints must be removed from the list
1103 (e.g., the solib bp's), since their address is probably invalid
1106 And, we DON'T want to call delete_breakpoints() here, since
1107 that may write the bp's "shadow contents" (the instruction
1108 value that was overwritten witha TRAP instruction). Since
1109 we now have a new a.out, those shadow contents aren't valid. */
1111 mark_breakpoints_out ();
1113 /* The target reports the exec event to the main thread, even if
1114 some other thread does the exec, and even if the main thread was
1115 stopped or already gone. We may still have non-leader threads of
1116 the process on our list. E.g., on targets that don't have thread
1117 exit events (like remote); or on native Linux in non-stop mode if
1118 there were only two threads in the inferior and the non-leader
1119 one is the one that execs (and nothing forces an update of the
1120 thread list up to here). When debugging remotely, it's best to
1121 avoid extra traffic, when possible, so avoid syncing the thread
1122 list with the target, and instead go ahead and delete all threads
1123 of the process but one that reported the event. Note this must
1124 be done before calling update_breakpoints_after_exec, as
1125 otherwise clearing the threads' resources would reference stale
1126 thread breakpoints -- it may have been one of these threads that
1127 stepped across the exec. We could just clear their stepping
1128 states, but as long as we're iterating, might as well delete
1129 them. Deleting them now rather than at the next user-visible
1130 stop provides a nicer sequence of events for user and MI
1132 for (thread_info *th : all_threads_safe ())
1133 if (th->ptid.pid () == pid && th->ptid != ptid)
1136 /* We also need to clear any left over stale state for the
1137 leader/event thread. E.g., if there was any step-resume
1138 breakpoint or similar, it's gone now. We cannot truly
1139 step-to-next statement through an exec(). */
1140 thread_info *th = inferior_thread ();
1141 th->control.step_resume_breakpoint = NULL;
1142 th->control.exception_resume_breakpoint = NULL;
1143 th->control.single_step_breakpoints = NULL;
1144 th->control.step_range_start = 0;
1145 th->control.step_range_end = 0;
1147 /* The user may have had the main thread held stopped in the
1148 previous image (e.g., schedlock on, or non-stop). Release
1150 th->stop_requested = 0;
1152 update_breakpoints_after_exec ();
1154 /* What is this a.out's name? */
1155 process_ptid = ptid_t (pid);
1156 printf_unfiltered (_("%s is executing new program: %s\n"),
1157 target_pid_to_str (process_ptid),
1160 /* We've followed the inferior through an exec. Therefore, the
1161 inferior has essentially been killed & reborn. */
1163 breakpoint_init_inferior (inf_execd);
1165 gdb::unique_xmalloc_ptr<char> exec_file_host
1166 = exec_file_find (exec_file_target, NULL);
1168 /* If we were unable to map the executable target pathname onto a host
1169 pathname, tell the user that. Otherwise GDB's subsequent behavior
1170 is confusing. Maybe it would even be better to stop at this point
1171 so that the user can specify a file manually before continuing. */
1172 if (exec_file_host == NULL)
1173 warning (_("Could not load symbols for executable %s.\n"
1174 "Do you need \"set sysroot\"?"),
1177 /* Reset the shared library package. This ensures that we get a
1178 shlib event when the child reaches "_start", at which point the
1179 dld will have had a chance to initialize the child. */
1180 /* Also, loading a symbol file below may trigger symbol lookups, and
1181 we don't want those to be satisfied by the libraries of the
1182 previous incarnation of this process. */
1183 no_shared_libraries (NULL, 0);
1185 if (follow_exec_mode_string == follow_exec_mode_new)
1187 /* The user wants to keep the old inferior and program spaces
1188 around. Create a new fresh one, and switch to it. */
1190 /* Do exit processing for the original inferior before setting the new
1191 inferior's pid. Having two inferiors with the same pid would confuse
1192 find_inferior_p(t)id. Transfer the terminal state and info from the
1193 old to the new inferior. */
1194 inf = add_inferior_with_spaces ();
1195 swap_terminal_info (inf, current_inferior ());
1196 exit_inferior_silent (current_inferior ());
1199 target_follow_exec (inf, exec_file_target);
1201 set_current_inferior (inf);
1202 set_current_program_space (inf->pspace);
1207 /* The old description may no longer be fit for the new image.
1208 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1209 old description; we'll read a new one below. No need to do
1210 this on "follow-exec-mode new", as the old inferior stays
1211 around (its description is later cleared/refetched on
1213 target_clear_description ();
1216 gdb_assert (current_program_space == inf->pspace);
1218 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1219 because the proper displacement for a PIE (Position Independent
1220 Executable) main symbol file will only be computed by
1221 solib_create_inferior_hook below. breakpoint_re_set would fail
1222 to insert the breakpoints with the zero displacement. */
1223 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1225 /* If the target can specify a description, read it. Must do this
1226 after flipping to the new executable (because the target supplied
1227 description must be compatible with the executable's
1228 architecture, and the old executable may e.g., be 32-bit, while
1229 the new one 64-bit), and before anything involving memory or
1231 target_find_description ();
1233 solib_create_inferior_hook (0);
1235 jit_inferior_created_hook ();
1237 breakpoint_re_set ();
1239 /* Reinsert all breakpoints. (Those which were symbolic have
1240 been reset to the proper address in the new a.out, thanks
1241 to symbol_file_command...). */
1242 insert_breakpoints ();
1244 /* The next resume of this inferior should bring it to the shlib
1245 startup breakpoints. (If the user had also set bp's on
1246 "main" from the old (parent) process, then they'll auto-
1247 matically get reset there in the new process.). */
1250 /* The queue of threads that need to do a step-over operation to get
1251 past e.g., a breakpoint. What technique is used to step over the
1252 breakpoint/watchpoint does not matter -- all threads end up in the
1253 same queue, to maintain rough temporal order of execution, in order
1254 to avoid starvation, otherwise, we could e.g., find ourselves
1255 constantly stepping the same couple threads past their breakpoints
1256 over and over, if the single-step finish fast enough. */
1257 struct thread_info *step_over_queue_head;
1259 /* Bit flags indicating what the thread needs to step over. */
1261 enum step_over_what_flag
1263 /* Step over a breakpoint. */
1264 STEP_OVER_BREAKPOINT = 1,
1266 /* Step past a non-continuable watchpoint, in order to let the
1267 instruction execute so we can evaluate the watchpoint
1269 STEP_OVER_WATCHPOINT = 2
1271 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1273 /* Info about an instruction that is being stepped over. */
1275 struct step_over_info
1277 /* If we're stepping past a breakpoint, this is the address space
1278 and address of the instruction the breakpoint is set at. We'll
1279 skip inserting all breakpoints here. Valid iff ASPACE is
1281 const address_space *aspace;
1284 /* The instruction being stepped over triggers a nonsteppable
1285 watchpoint. If true, we'll skip inserting watchpoints. */
1286 int nonsteppable_watchpoint_p;
1288 /* The thread's global number. */
1292 /* The step-over info of the location that is being stepped over.
1294 Note that with async/breakpoint always-inserted mode, a user might
1295 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1296 being stepped over. As setting a new breakpoint inserts all
1297 breakpoints, we need to make sure the breakpoint being stepped over
1298 isn't inserted then. We do that by only clearing the step-over
1299 info when the step-over is actually finished (or aborted).
1301 Presently GDB can only step over one breakpoint at any given time.
1302 Given threads that can't run code in the same address space as the
1303 breakpoint's can't really miss the breakpoint, GDB could be taught
1304 to step-over at most one breakpoint per address space (so this info
1305 could move to the address space object if/when GDB is extended).
1306 The set of breakpoints being stepped over will normally be much
1307 smaller than the set of all breakpoints, so a flag in the
1308 breakpoint location structure would be wasteful. A separate list
1309 also saves complexity and run-time, as otherwise we'd have to go
1310 through all breakpoint locations clearing their flag whenever we
1311 start a new sequence. Similar considerations weigh against storing
1312 this info in the thread object. Plus, not all step overs actually
1313 have breakpoint locations -- e.g., stepping past a single-step
1314 breakpoint, or stepping to complete a non-continuable
1316 static struct step_over_info step_over_info;
1318 /* Record the address of the breakpoint/instruction we're currently
1320 N.B. We record the aspace and address now, instead of say just the thread,
1321 because when we need the info later the thread may be running. */
1324 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1325 int nonsteppable_watchpoint_p,
1328 step_over_info.aspace = aspace;
1329 step_over_info.address = address;
1330 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1331 step_over_info.thread = thread;
1334 /* Called when we're not longer stepping over a breakpoint / an
1335 instruction, so all breakpoints are free to be (re)inserted. */
1338 clear_step_over_info (void)
1341 fprintf_unfiltered (gdb_stdlog,
1342 "infrun: clear_step_over_info\n");
1343 step_over_info.aspace = NULL;
1344 step_over_info.address = 0;
1345 step_over_info.nonsteppable_watchpoint_p = 0;
1346 step_over_info.thread = -1;
1352 stepping_past_instruction_at (struct address_space *aspace,
1355 return (step_over_info.aspace != NULL
1356 && breakpoint_address_match (aspace, address,
1357 step_over_info.aspace,
1358 step_over_info.address));
1364 thread_is_stepping_over_breakpoint (int thread)
1366 return (step_over_info.thread != -1
1367 && thread == step_over_info.thread);
1373 stepping_past_nonsteppable_watchpoint (void)
1375 return step_over_info.nonsteppable_watchpoint_p;
1378 /* Returns true if step-over info is valid. */
1381 step_over_info_valid_p (void)
1383 return (step_over_info.aspace != NULL
1384 || stepping_past_nonsteppable_watchpoint ());
1388 /* Displaced stepping. */
1390 /* In non-stop debugging mode, we must take special care to manage
1391 breakpoints properly; in particular, the traditional strategy for
1392 stepping a thread past a breakpoint it has hit is unsuitable.
1393 'Displaced stepping' is a tactic for stepping one thread past a
1394 breakpoint it has hit while ensuring that other threads running
1395 concurrently will hit the breakpoint as they should.
1397 The traditional way to step a thread T off a breakpoint in a
1398 multi-threaded program in all-stop mode is as follows:
1400 a0) Initially, all threads are stopped, and breakpoints are not
1402 a1) We single-step T, leaving breakpoints uninserted.
1403 a2) We insert breakpoints, and resume all threads.
1405 In non-stop debugging, however, this strategy is unsuitable: we
1406 don't want to have to stop all threads in the system in order to
1407 continue or step T past a breakpoint. Instead, we use displaced
1410 n0) Initially, T is stopped, other threads are running, and
1411 breakpoints are inserted.
1412 n1) We copy the instruction "under" the breakpoint to a separate
1413 location, outside the main code stream, making any adjustments
1414 to the instruction, register, and memory state as directed by
1416 n2) We single-step T over the instruction at its new location.
1417 n3) We adjust the resulting register and memory state as directed
1418 by T's architecture. This includes resetting T's PC to point
1419 back into the main instruction stream.
1422 This approach depends on the following gdbarch methods:
1424 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1425 indicate where to copy the instruction, and how much space must
1426 be reserved there. We use these in step n1.
1428 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1429 address, and makes any necessary adjustments to the instruction,
1430 register contents, and memory. We use this in step n1.
1432 - gdbarch_displaced_step_fixup adjusts registers and memory after
1433 we have successfuly single-stepped the instruction, to yield the
1434 same effect the instruction would have had if we had executed it
1435 at its original address. We use this in step n3.
1437 The gdbarch_displaced_step_copy_insn and
1438 gdbarch_displaced_step_fixup functions must be written so that
1439 copying an instruction with gdbarch_displaced_step_copy_insn,
1440 single-stepping across the copied instruction, and then applying
1441 gdbarch_displaced_insn_fixup should have the same effects on the
1442 thread's memory and registers as stepping the instruction in place
1443 would have. Exactly which responsibilities fall to the copy and
1444 which fall to the fixup is up to the author of those functions.
1446 See the comments in gdbarch.sh for details.
1448 Note that displaced stepping and software single-step cannot
1449 currently be used in combination, although with some care I think
1450 they could be made to. Software single-step works by placing
1451 breakpoints on all possible subsequent instructions; if the
1452 displaced instruction is a PC-relative jump, those breakpoints
1453 could fall in very strange places --- on pages that aren't
1454 executable, or at addresses that are not proper instruction
1455 boundaries. (We do generally let other threads run while we wait
1456 to hit the software single-step breakpoint, and they might
1457 encounter such a corrupted instruction.) One way to work around
1458 this would be to have gdbarch_displaced_step_copy_insn fully
1459 simulate the effect of PC-relative instructions (and return NULL)
1460 on architectures that use software single-stepping.
1462 In non-stop mode, we can have independent and simultaneous step
1463 requests, so more than one thread may need to simultaneously step
1464 over a breakpoint. The current implementation assumes there is
1465 only one scratch space per process. In this case, we have to
1466 serialize access to the scratch space. If thread A wants to step
1467 over a breakpoint, but we are currently waiting for some other
1468 thread to complete a displaced step, we leave thread A stopped and
1469 place it in the displaced_step_request_queue. Whenever a displaced
1470 step finishes, we pick the next thread in the queue and start a new
1471 displaced step operation on it. See displaced_step_prepare and
1472 displaced_step_fixup for details. */
1474 /* Default destructor for displaced_step_closure. */
1476 displaced_step_closure::~displaced_step_closure () = default;
1478 /* Get the displaced stepping state of process PID. */
1480 static displaced_step_inferior_state *
1481 get_displaced_stepping_state (inferior *inf)
1483 return &inf->displaced_step_state;
1486 /* Returns true if any inferior has a thread doing a displaced
1490 displaced_step_in_progress_any_inferior ()
1492 for (inferior *i : all_inferiors ())
1494 if (i->displaced_step_state.step_thread != nullptr)
1501 /* Return true if thread represented by PTID is doing a displaced
1505 displaced_step_in_progress_thread (thread_info *thread)
1507 gdb_assert (thread != NULL);
1509 return get_displaced_stepping_state (thread->inf)->step_thread == thread;
1512 /* Return true if process PID has a thread doing a displaced step. */
1515 displaced_step_in_progress (inferior *inf)
1517 return get_displaced_stepping_state (inf)->step_thread != nullptr;
1520 /* If inferior is in displaced stepping, and ADDR equals to starting address
1521 of copy area, return corresponding displaced_step_closure. Otherwise,
1524 struct displaced_step_closure*
1525 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1527 displaced_step_inferior_state *displaced
1528 = get_displaced_stepping_state (current_inferior ());
1530 /* If checking the mode of displaced instruction in copy area. */
1531 if (displaced->step_thread != nullptr
1532 && displaced->step_copy == addr)
1533 return displaced->step_closure;
1539 infrun_inferior_exit (struct inferior *inf)
1541 inf->displaced_step_state.reset ();
1544 /* If ON, and the architecture supports it, GDB will use displaced
1545 stepping to step over breakpoints. If OFF, or if the architecture
1546 doesn't support it, GDB will instead use the traditional
1547 hold-and-step approach. If AUTO (which is the default), GDB will
1548 decide which technique to use to step over breakpoints depending on
1549 which of all-stop or non-stop mode is active --- displaced stepping
1550 in non-stop mode; hold-and-step in all-stop mode. */
1552 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1555 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1556 struct cmd_list_element *c,
1559 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1560 fprintf_filtered (file,
1561 _("Debugger's willingness to use displaced stepping "
1562 "to step over breakpoints is %s (currently %s).\n"),
1563 value, target_is_non_stop_p () ? "on" : "off");
1565 fprintf_filtered (file,
1566 _("Debugger's willingness to use displaced stepping "
1567 "to step over breakpoints is %s.\n"), value);
1570 /* Return non-zero if displaced stepping can/should be used to step
1571 over breakpoints of thread TP. */
1574 use_displaced_stepping (struct thread_info *tp)
1576 struct regcache *regcache = get_thread_regcache (tp);
1577 struct gdbarch *gdbarch = regcache->arch ();
1578 displaced_step_inferior_state *displaced_state
1579 = get_displaced_stepping_state (tp->inf);
1581 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1582 && target_is_non_stop_p ())
1583 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1584 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1585 && find_record_target () == NULL
1586 && !displaced_state->failed_before);
1589 /* Clean out any stray displaced stepping state. */
1591 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1593 /* Indicate that there is no cleanup pending. */
1594 displaced->step_thread = nullptr;
1596 delete displaced->step_closure;
1597 displaced->step_closure = NULL;
1600 /* A cleanup that wraps displaced_step_clear. */
1601 using displaced_step_clear_cleanup
1602 = FORWARD_SCOPE_EXIT (displaced_step_clear);
1604 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1606 displaced_step_dump_bytes (struct ui_file *file,
1607 const gdb_byte *buf,
1612 for (i = 0; i < len; i++)
1613 fprintf_unfiltered (file, "%02x ", buf[i]);
1614 fputs_unfiltered ("\n", file);
1617 /* Prepare to single-step, using displaced stepping.
1619 Note that we cannot use displaced stepping when we have a signal to
1620 deliver. If we have a signal to deliver and an instruction to step
1621 over, then after the step, there will be no indication from the
1622 target whether the thread entered a signal handler or ignored the
1623 signal and stepped over the instruction successfully --- both cases
1624 result in a simple SIGTRAP. In the first case we mustn't do a
1625 fixup, and in the second case we must --- but we can't tell which.
1626 Comments in the code for 'random signals' in handle_inferior_event
1627 explain how we handle this case instead.
1629 Returns 1 if preparing was successful -- this thread is going to be
1630 stepped now; 0 if displaced stepping this thread got queued; or -1
1631 if this instruction can't be displaced stepped. */
1634 displaced_step_prepare_throw (thread_info *tp)
1636 regcache *regcache = get_thread_regcache (tp);
1637 struct gdbarch *gdbarch = regcache->arch ();
1638 const address_space *aspace = regcache->aspace ();
1639 CORE_ADDR original, copy;
1641 struct displaced_step_closure *closure;
1644 /* We should never reach this function if the architecture does not
1645 support displaced stepping. */
1646 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1648 /* Nor if the thread isn't meant to step over a breakpoint. */
1649 gdb_assert (tp->control.trap_expected);
1651 /* Disable range stepping while executing in the scratch pad. We
1652 want a single-step even if executing the displaced instruction in
1653 the scratch buffer lands within the stepping range (e.g., a
1655 tp->control.may_range_step = 0;
1657 /* We have to displaced step one thread at a time, as we only have
1658 access to a single scratch space per inferior. */
1660 displaced_step_inferior_state *displaced
1661 = get_displaced_stepping_state (tp->inf);
1663 if (displaced->step_thread != nullptr)
1665 /* Already waiting for a displaced step to finish. Defer this
1666 request and place in queue. */
1668 if (debug_displaced)
1669 fprintf_unfiltered (gdb_stdlog,
1670 "displaced: deferring step of %s\n",
1671 target_pid_to_str (tp->ptid));
1673 thread_step_over_chain_enqueue (tp);
1678 if (debug_displaced)
1679 fprintf_unfiltered (gdb_stdlog,
1680 "displaced: stepping %s now\n",
1681 target_pid_to_str (tp->ptid));
1684 displaced_step_clear (displaced);
1686 scoped_restore_current_thread restore_thread;
1688 switch_to_thread (tp);
1690 original = regcache_read_pc (regcache);
1692 copy = gdbarch_displaced_step_location (gdbarch);
1693 len = gdbarch_max_insn_length (gdbarch);
1695 if (breakpoint_in_range_p (aspace, copy, len))
1697 /* There's a breakpoint set in the scratch pad location range
1698 (which is usually around the entry point). We'd either
1699 install it before resuming, which would overwrite/corrupt the
1700 scratch pad, or if it was already inserted, this displaced
1701 step would overwrite it. The latter is OK in the sense that
1702 we already assume that no thread is going to execute the code
1703 in the scratch pad range (after initial startup) anyway, but
1704 the former is unacceptable. Simply punt and fallback to
1705 stepping over this breakpoint in-line. */
1706 if (debug_displaced)
1708 fprintf_unfiltered (gdb_stdlog,
1709 "displaced: breakpoint set in scratch pad. "
1710 "Stepping over breakpoint in-line instead.\n");
1716 /* Save the original contents of the copy area. */
1717 displaced->step_saved_copy.resize (len);
1718 status = target_read_memory (copy, displaced->step_saved_copy.data (), len);
1720 throw_error (MEMORY_ERROR,
1721 _("Error accessing memory address %s (%s) for "
1722 "displaced-stepping scratch space."),
1723 paddress (gdbarch, copy), safe_strerror (status));
1724 if (debug_displaced)
1726 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1727 paddress (gdbarch, copy));
1728 displaced_step_dump_bytes (gdb_stdlog,
1729 displaced->step_saved_copy.data (),
1733 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1734 original, copy, regcache);
1735 if (closure == NULL)
1737 /* The architecture doesn't know how or want to displaced step
1738 this instruction or instruction sequence. Fallback to
1739 stepping over the breakpoint in-line. */
1743 /* Save the information we need to fix things up if the step
1745 displaced->step_thread = tp;
1746 displaced->step_gdbarch = gdbarch;
1747 displaced->step_closure = closure;
1748 displaced->step_original = original;
1749 displaced->step_copy = copy;
1752 displaced_step_clear_cleanup cleanup (displaced);
1754 /* Resume execution at the copy. */
1755 regcache_write_pc (regcache, copy);
1760 if (debug_displaced)
1761 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1762 paddress (gdbarch, copy));
1767 /* Wrapper for displaced_step_prepare_throw that disabled further
1768 attempts at displaced stepping if we get a memory error. */
1771 displaced_step_prepare (thread_info *thread)
1777 prepared = displaced_step_prepare_throw (thread);
1779 CATCH (ex, RETURN_MASK_ERROR)
1781 struct displaced_step_inferior_state *displaced_state;
1783 if (ex.error != MEMORY_ERROR
1784 && ex.error != NOT_SUPPORTED_ERROR)
1785 throw_exception (ex);
1789 fprintf_unfiltered (gdb_stdlog,
1790 "infrun: disabling displaced stepping: %s\n",
1794 /* Be verbose if "set displaced-stepping" is "on", silent if
1796 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1798 warning (_("disabling displaced stepping: %s"),
1802 /* Disable further displaced stepping attempts. */
1804 = get_displaced_stepping_state (thread->inf);
1805 displaced_state->failed_before = 1;
1813 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1814 const gdb_byte *myaddr, int len)
1816 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1818 inferior_ptid = ptid;
1819 write_memory (memaddr, myaddr, len);
1822 /* Restore the contents of the copy area for thread PTID. */
1825 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1828 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1830 write_memory_ptid (ptid, displaced->step_copy,
1831 displaced->step_saved_copy.data (), len);
1832 if (debug_displaced)
1833 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1834 target_pid_to_str (ptid),
1835 paddress (displaced->step_gdbarch,
1836 displaced->step_copy));
1839 /* If we displaced stepped an instruction successfully, adjust
1840 registers and memory to yield the same effect the instruction would
1841 have had if we had executed it at its original address, and return
1842 1. If the instruction didn't complete, relocate the PC and return
1843 -1. If the thread wasn't displaced stepping, return 0. */
1846 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1848 struct displaced_step_inferior_state *displaced
1849 = get_displaced_stepping_state (event_thread->inf);
1852 /* Was this event for the thread we displaced? */
1853 if (displaced->step_thread != event_thread)
1856 displaced_step_clear_cleanup cleanup (displaced);
1858 displaced_step_restore (displaced, displaced->step_thread->ptid);
1860 /* Fixup may need to read memory/registers. Switch to the thread
1861 that we're fixing up. Also, target_stopped_by_watchpoint checks
1862 the current thread. */
1863 switch_to_thread (event_thread);
1865 /* Did the instruction complete successfully? */
1866 if (signal == GDB_SIGNAL_TRAP
1867 && !(target_stopped_by_watchpoint ()
1868 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1869 || target_have_steppable_watchpoint)))
1871 /* Fix up the resulting state. */
1872 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1873 displaced->step_closure,
1874 displaced->step_original,
1875 displaced->step_copy,
1876 get_thread_regcache (displaced->step_thread));
1881 /* Since the instruction didn't complete, all we can do is
1883 struct regcache *regcache = get_thread_regcache (event_thread);
1884 CORE_ADDR pc = regcache_read_pc (regcache);
1886 pc = displaced->step_original + (pc - displaced->step_copy);
1887 regcache_write_pc (regcache, pc);
1894 /* Data to be passed around while handling an event. This data is
1895 discarded between events. */
1896 struct execution_control_state
1899 /* The thread that got the event, if this was a thread event; NULL
1901 struct thread_info *event_thread;
1903 struct target_waitstatus ws;
1904 int stop_func_filled_in;
1905 CORE_ADDR stop_func_start;
1906 CORE_ADDR stop_func_end;
1907 const char *stop_func_name;
1910 /* True if the event thread hit the single-step breakpoint of
1911 another thread. Thus the event doesn't cause a stop, the thread
1912 needs to be single-stepped past the single-step breakpoint before
1913 we can switch back to the original stepping thread. */
1914 int hit_singlestep_breakpoint;
1917 /* Clear ECS and set it to point at TP. */
1920 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
1922 memset (ecs, 0, sizeof (*ecs));
1923 ecs->event_thread = tp;
1924 ecs->ptid = tp->ptid;
1927 static void keep_going_pass_signal (struct execution_control_state *ecs);
1928 static void prepare_to_wait (struct execution_control_state *ecs);
1929 static int keep_going_stepped_thread (struct thread_info *tp);
1930 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
1932 /* Are there any pending step-over requests? If so, run all we can
1933 now and return true. Otherwise, return false. */
1936 start_step_over (void)
1938 struct thread_info *tp, *next;
1940 /* Don't start a new step-over if we already have an in-line
1941 step-over operation ongoing. */
1942 if (step_over_info_valid_p ())
1945 for (tp = step_over_queue_head; tp != NULL; tp = next)
1947 struct execution_control_state ecss;
1948 struct execution_control_state *ecs = &ecss;
1949 step_over_what step_what;
1950 int must_be_in_line;
1952 gdb_assert (!tp->stop_requested);
1954 next = thread_step_over_chain_next (tp);
1956 /* If this inferior already has a displaced step in process,
1957 don't start a new one. */
1958 if (displaced_step_in_progress (tp->inf))
1961 step_what = thread_still_needs_step_over (tp);
1962 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
1963 || ((step_what & STEP_OVER_BREAKPOINT)
1964 && !use_displaced_stepping (tp)));
1966 /* We currently stop all threads of all processes to step-over
1967 in-line. If we need to start a new in-line step-over, let
1968 any pending displaced steps finish first. */
1969 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
1972 thread_step_over_chain_remove (tp);
1974 if (step_over_queue_head == NULL)
1977 fprintf_unfiltered (gdb_stdlog,
1978 "infrun: step-over queue now empty\n");
1981 if (tp->control.trap_expected
1985 internal_error (__FILE__, __LINE__,
1986 "[%s] has inconsistent state: "
1987 "trap_expected=%d, resumed=%d, executing=%d\n",
1988 target_pid_to_str (tp->ptid),
1989 tp->control.trap_expected,
1995 fprintf_unfiltered (gdb_stdlog,
1996 "infrun: resuming [%s] for step-over\n",
1997 target_pid_to_str (tp->ptid));
1999 /* keep_going_pass_signal skips the step-over if the breakpoint
2000 is no longer inserted. In all-stop, we want to keep looking
2001 for a thread that needs a step-over instead of resuming TP,
2002 because we wouldn't be able to resume anything else until the
2003 target stops again. In non-stop, the resume always resumes
2004 only TP, so it's OK to let the thread resume freely. */
2005 if (!target_is_non_stop_p () && !step_what)
2008 switch_to_thread (tp);
2009 reset_ecs (ecs, tp);
2010 keep_going_pass_signal (ecs);
2012 if (!ecs->wait_some_more)
2013 error (_("Command aborted."));
2015 gdb_assert (tp->resumed);
2017 /* If we started a new in-line step-over, we're done. */
2018 if (step_over_info_valid_p ())
2020 gdb_assert (tp->control.trap_expected);
2024 if (!target_is_non_stop_p ())
2026 /* On all-stop, shouldn't have resumed unless we needed a
2028 gdb_assert (tp->control.trap_expected
2029 || tp->step_after_step_resume_breakpoint);
2031 /* With remote targets (at least), in all-stop, we can't
2032 issue any further remote commands until the program stops
2037 /* Either the thread no longer needed a step-over, or a new
2038 displaced stepping sequence started. Even in the latter
2039 case, continue looking. Maybe we can also start another
2040 displaced step on a thread of other process. */
2046 /* Update global variables holding ptids to hold NEW_PTID if they were
2047 holding OLD_PTID. */
2049 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2051 if (inferior_ptid == old_ptid)
2052 inferior_ptid = new_ptid;
2057 static const char schedlock_off[] = "off";
2058 static const char schedlock_on[] = "on";
2059 static const char schedlock_step[] = "step";
2060 static const char schedlock_replay[] = "replay";
2061 static const char *const scheduler_enums[] = {
2068 static const char *scheduler_mode = schedlock_replay;
2070 show_scheduler_mode (struct ui_file *file, int from_tty,
2071 struct cmd_list_element *c, const char *value)
2073 fprintf_filtered (file,
2074 _("Mode for locking scheduler "
2075 "during execution is \"%s\".\n"),
2080 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2082 if (!target_can_lock_scheduler)
2084 scheduler_mode = schedlock_off;
2085 error (_("Target '%s' cannot support this command."), target_shortname);
2089 /* True if execution commands resume all threads of all processes by
2090 default; otherwise, resume only threads of the current inferior
2092 int sched_multi = 0;
2094 /* Try to setup for software single stepping over the specified location.
2095 Return 1 if target_resume() should use hardware single step.
2097 GDBARCH the current gdbarch.
2098 PC the location to step over. */
2101 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2105 if (execution_direction == EXEC_FORWARD
2106 && gdbarch_software_single_step_p (gdbarch))
2107 hw_step = !insert_single_step_breakpoints (gdbarch);
2115 user_visible_resume_ptid (int step)
2121 /* With non-stop mode on, threads are always handled
2123 resume_ptid = inferior_ptid;
2125 else if ((scheduler_mode == schedlock_on)
2126 || (scheduler_mode == schedlock_step && step))
2128 /* User-settable 'scheduler' mode requires solo thread
2130 resume_ptid = inferior_ptid;
2132 else if ((scheduler_mode == schedlock_replay)
2133 && target_record_will_replay (minus_one_ptid, execution_direction))
2135 /* User-settable 'scheduler' mode requires solo thread resume in replay
2137 resume_ptid = inferior_ptid;
2139 else if (!sched_multi && target_supports_multi_process ())
2141 /* Resume all threads of the current process (and none of other
2143 resume_ptid = ptid_t (inferior_ptid.pid ());
2147 /* Resume all threads of all processes. */
2148 resume_ptid = RESUME_ALL;
2154 /* Return a ptid representing the set of threads that we will resume,
2155 in the perspective of the target, assuming run control handling
2156 does not require leaving some threads stopped (e.g., stepping past
2157 breakpoint). USER_STEP indicates whether we're about to start the
2158 target for a stepping command. */
2161 internal_resume_ptid (int user_step)
2163 /* In non-stop, we always control threads individually. Note that
2164 the target may always work in non-stop mode even with "set
2165 non-stop off", in which case user_visible_resume_ptid could
2166 return a wildcard ptid. */
2167 if (target_is_non_stop_p ())
2168 return inferior_ptid;
2170 return user_visible_resume_ptid (user_step);
2173 /* Wrapper for target_resume, that handles infrun-specific
2177 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2179 struct thread_info *tp = inferior_thread ();
2181 gdb_assert (!tp->stop_requested);
2183 /* Install inferior's terminal modes. */
2184 target_terminal::inferior ();
2186 /* Avoid confusing the next resume, if the next stop/resume
2187 happens to apply to another thread. */
2188 tp->suspend.stop_signal = GDB_SIGNAL_0;
2190 /* Advise target which signals may be handled silently.
2192 If we have removed breakpoints because we are stepping over one
2193 in-line (in any thread), we need to receive all signals to avoid
2194 accidentally skipping a breakpoint during execution of a signal
2197 Likewise if we're displaced stepping, otherwise a trap for a
2198 breakpoint in a signal handler might be confused with the
2199 displaced step finishing. We don't make the displaced_step_fixup
2200 step distinguish the cases instead, because:
2202 - a backtrace while stopped in the signal handler would show the
2203 scratch pad as frame older than the signal handler, instead of
2204 the real mainline code.
2206 - when the thread is later resumed, the signal handler would
2207 return to the scratch pad area, which would no longer be
2209 if (step_over_info_valid_p ()
2210 || displaced_step_in_progress (tp->inf))
2211 target_pass_signals ({});
2213 target_pass_signals (signal_pass);
2215 target_resume (resume_ptid, step, sig);
2217 target_commit_resume ();
2220 /* Resume the inferior. SIG is the signal to give the inferior
2221 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2222 call 'resume', which handles exceptions. */
2225 resume_1 (enum gdb_signal sig)
2227 struct regcache *regcache = get_current_regcache ();
2228 struct gdbarch *gdbarch = regcache->arch ();
2229 struct thread_info *tp = inferior_thread ();
2230 CORE_ADDR pc = regcache_read_pc (regcache);
2231 const address_space *aspace = regcache->aspace ();
2233 /* This represents the user's step vs continue request. When
2234 deciding whether "set scheduler-locking step" applies, it's the
2235 user's intention that counts. */
2236 const int user_step = tp->control.stepping_command;
2237 /* This represents what we'll actually request the target to do.
2238 This can decay from a step to a continue, if e.g., we need to
2239 implement single-stepping with breakpoints (software
2243 gdb_assert (!tp->stop_requested);
2244 gdb_assert (!thread_is_in_step_over_chain (tp));
2246 if (tp->suspend.waitstatus_pending_p)
2251 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2253 fprintf_unfiltered (gdb_stdlog,
2254 "infrun: resume: thread %s has pending wait "
2255 "status %s (currently_stepping=%d).\n",
2256 target_pid_to_str (tp->ptid), statstr.c_str (),
2257 currently_stepping (tp));
2262 /* FIXME: What should we do if we are supposed to resume this
2263 thread with a signal? Maybe we should maintain a queue of
2264 pending signals to deliver. */
2265 if (sig != GDB_SIGNAL_0)
2267 warning (_("Couldn't deliver signal %s to %s."),
2268 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2271 tp->suspend.stop_signal = GDB_SIGNAL_0;
2273 if (target_can_async_p ())
2276 /* Tell the event loop we have an event to process. */
2277 mark_async_event_handler (infrun_async_inferior_event_token);
2282 tp->stepped_breakpoint = 0;
2284 /* Depends on stepped_breakpoint. */
2285 step = currently_stepping (tp);
2287 if (current_inferior ()->waiting_for_vfork_done)
2289 /* Don't try to single-step a vfork parent that is waiting for
2290 the child to get out of the shared memory region (by exec'ing
2291 or exiting). This is particularly important on software
2292 single-step archs, as the child process would trip on the
2293 software single step breakpoint inserted for the parent
2294 process. Since the parent will not actually execute any
2295 instruction until the child is out of the shared region (such
2296 are vfork's semantics), it is safe to simply continue it.
2297 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2298 the parent, and tell it to `keep_going', which automatically
2299 re-sets it stepping. */
2301 fprintf_unfiltered (gdb_stdlog,
2302 "infrun: resume : clear step\n");
2307 fprintf_unfiltered (gdb_stdlog,
2308 "infrun: resume (step=%d, signal=%s), "
2309 "trap_expected=%d, current thread [%s] at %s\n",
2310 step, gdb_signal_to_symbol_string (sig),
2311 tp->control.trap_expected,
2312 target_pid_to_str (inferior_ptid),
2313 paddress (gdbarch, pc));
2315 /* Normally, by the time we reach `resume', the breakpoints are either
2316 removed or inserted, as appropriate. The exception is if we're sitting
2317 at a permanent breakpoint; we need to step over it, but permanent
2318 breakpoints can't be removed. So we have to test for it here. */
2319 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2321 if (sig != GDB_SIGNAL_0)
2323 /* We have a signal to pass to the inferior. The resume
2324 may, or may not take us to the signal handler. If this
2325 is a step, we'll need to stop in the signal handler, if
2326 there's one, (if the target supports stepping into
2327 handlers), or in the next mainline instruction, if
2328 there's no handler. If this is a continue, we need to be
2329 sure to run the handler with all breakpoints inserted.
2330 In all cases, set a breakpoint at the current address
2331 (where the handler returns to), and once that breakpoint
2332 is hit, resume skipping the permanent breakpoint. If
2333 that breakpoint isn't hit, then we've stepped into the
2334 signal handler (or hit some other event). We'll delete
2335 the step-resume breakpoint then. */
2338 fprintf_unfiltered (gdb_stdlog,
2339 "infrun: resume: skipping permanent breakpoint, "
2340 "deliver signal first\n");
2342 clear_step_over_info ();
2343 tp->control.trap_expected = 0;
2345 if (tp->control.step_resume_breakpoint == NULL)
2347 /* Set a "high-priority" step-resume, as we don't want
2348 user breakpoints at PC to trigger (again) when this
2350 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2351 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2353 tp->step_after_step_resume_breakpoint = step;
2356 insert_breakpoints ();
2360 /* There's no signal to pass, we can go ahead and skip the
2361 permanent breakpoint manually. */
2363 fprintf_unfiltered (gdb_stdlog,
2364 "infrun: resume: skipping permanent breakpoint\n");
2365 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2366 /* Update pc to reflect the new address from which we will
2367 execute instructions. */
2368 pc = regcache_read_pc (regcache);
2372 /* We've already advanced the PC, so the stepping part
2373 is done. Now we need to arrange for a trap to be
2374 reported to handle_inferior_event. Set a breakpoint
2375 at the current PC, and run to it. Don't update
2376 prev_pc, because if we end in
2377 switch_back_to_stepped_thread, we want the "expected
2378 thread advanced also" branch to be taken. IOW, we
2379 don't want this thread to step further from PC
2381 gdb_assert (!step_over_info_valid_p ());
2382 insert_single_step_breakpoint (gdbarch, aspace, pc);
2383 insert_breakpoints ();
2385 resume_ptid = internal_resume_ptid (user_step);
2386 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2393 /* If we have a breakpoint to step over, make sure to do a single
2394 step only. Same if we have software watchpoints. */
2395 if (tp->control.trap_expected || bpstat_should_step ())
2396 tp->control.may_range_step = 0;
2398 /* If enabled, step over breakpoints by executing a copy of the
2399 instruction at a different address.
2401 We can't use displaced stepping when we have a signal to deliver;
2402 the comments for displaced_step_prepare explain why. The
2403 comments in the handle_inferior event for dealing with 'random
2404 signals' explain what we do instead.
2406 We can't use displaced stepping when we are waiting for vfork_done
2407 event, displaced stepping breaks the vfork child similarly as single
2408 step software breakpoint. */
2409 if (tp->control.trap_expected
2410 && use_displaced_stepping (tp)
2411 && !step_over_info_valid_p ()
2412 && sig == GDB_SIGNAL_0
2413 && !current_inferior ()->waiting_for_vfork_done)
2415 int prepared = displaced_step_prepare (tp);
2420 fprintf_unfiltered (gdb_stdlog,
2421 "Got placed in step-over queue\n");
2423 tp->control.trap_expected = 0;
2426 else if (prepared < 0)
2428 /* Fallback to stepping over the breakpoint in-line. */
2430 if (target_is_non_stop_p ())
2431 stop_all_threads ();
2433 set_step_over_info (regcache->aspace (),
2434 regcache_read_pc (regcache), 0, tp->global_num);
2436 step = maybe_software_singlestep (gdbarch, pc);
2438 insert_breakpoints ();
2440 else if (prepared > 0)
2442 struct displaced_step_inferior_state *displaced;
2444 /* Update pc to reflect the new address from which we will
2445 execute instructions due to displaced stepping. */
2446 pc = regcache_read_pc (get_thread_regcache (tp));
2448 displaced = get_displaced_stepping_state (tp->inf);
2449 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2450 displaced->step_closure);
2454 /* Do we need to do it the hard way, w/temp breakpoints? */
2456 step = maybe_software_singlestep (gdbarch, pc);
2458 /* Currently, our software single-step implementation leads to different
2459 results than hardware single-stepping in one situation: when stepping
2460 into delivering a signal which has an associated signal handler,
2461 hardware single-step will stop at the first instruction of the handler,
2462 while software single-step will simply skip execution of the handler.
2464 For now, this difference in behavior is accepted since there is no
2465 easy way to actually implement single-stepping into a signal handler
2466 without kernel support.
2468 However, there is one scenario where this difference leads to follow-on
2469 problems: if we're stepping off a breakpoint by removing all breakpoints
2470 and then single-stepping. In this case, the software single-step
2471 behavior means that even if there is a *breakpoint* in the signal
2472 handler, GDB still would not stop.
2474 Fortunately, we can at least fix this particular issue. We detect
2475 here the case where we are about to deliver a signal while software
2476 single-stepping with breakpoints removed. In this situation, we
2477 revert the decisions to remove all breakpoints and insert single-
2478 step breakpoints, and instead we install a step-resume breakpoint
2479 at the current address, deliver the signal without stepping, and
2480 once we arrive back at the step-resume breakpoint, actually step
2481 over the breakpoint we originally wanted to step over. */
2482 if (thread_has_single_step_breakpoints_set (tp)
2483 && sig != GDB_SIGNAL_0
2484 && step_over_info_valid_p ())
2486 /* If we have nested signals or a pending signal is delivered
2487 immediately after a handler returns, might might already have
2488 a step-resume breakpoint set on the earlier handler. We cannot
2489 set another step-resume breakpoint; just continue on until the
2490 original breakpoint is hit. */
2491 if (tp->control.step_resume_breakpoint == NULL)
2493 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2494 tp->step_after_step_resume_breakpoint = 1;
2497 delete_single_step_breakpoints (tp);
2499 clear_step_over_info ();
2500 tp->control.trap_expected = 0;
2502 insert_breakpoints ();
2505 /* If STEP is set, it's a request to use hardware stepping
2506 facilities. But in that case, we should never
2507 use singlestep breakpoint. */
2508 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2510 /* Decide the set of threads to ask the target to resume. */
2511 if (tp->control.trap_expected)
2513 /* We're allowing a thread to run past a breakpoint it has
2514 hit, either by single-stepping the thread with the breakpoint
2515 removed, or by displaced stepping, with the breakpoint inserted.
2516 In the former case, we need to single-step only this thread,
2517 and keep others stopped, as they can miss this breakpoint if
2518 allowed to run. That's not really a problem for displaced
2519 stepping, but, we still keep other threads stopped, in case
2520 another thread is also stopped for a breakpoint waiting for
2521 its turn in the displaced stepping queue. */
2522 resume_ptid = inferior_ptid;
2525 resume_ptid = internal_resume_ptid (user_step);
2527 if (execution_direction != EXEC_REVERSE
2528 && step && breakpoint_inserted_here_p (aspace, pc))
2530 /* There are two cases where we currently need to step a
2531 breakpoint instruction when we have a signal to deliver:
2533 - See handle_signal_stop where we handle random signals that
2534 could take out us out of the stepping range. Normally, in
2535 that case we end up continuing (instead of stepping) over the
2536 signal handler with a breakpoint at PC, but there are cases
2537 where we should _always_ single-step, even if we have a
2538 step-resume breakpoint, like when a software watchpoint is
2539 set. Assuming single-stepping and delivering a signal at the
2540 same time would takes us to the signal handler, then we could
2541 have removed the breakpoint at PC to step over it. However,
2542 some hardware step targets (like e.g., Mac OS) can't step
2543 into signal handlers, and for those, we need to leave the
2544 breakpoint at PC inserted, as otherwise if the handler
2545 recurses and executes PC again, it'll miss the breakpoint.
2546 So we leave the breakpoint inserted anyway, but we need to
2547 record that we tried to step a breakpoint instruction, so
2548 that adjust_pc_after_break doesn't end up confused.
2550 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2551 in one thread after another thread that was stepping had been
2552 momentarily paused for a step-over. When we re-resume the
2553 stepping thread, it may be resumed from that address with a
2554 breakpoint that hasn't trapped yet. Seen with
2555 gdb.threads/non-stop-fair-events.exp, on targets that don't
2556 do displaced stepping. */
2559 fprintf_unfiltered (gdb_stdlog,
2560 "infrun: resume: [%s] stepped breakpoint\n",
2561 target_pid_to_str (tp->ptid));
2563 tp->stepped_breakpoint = 1;
2565 /* Most targets can step a breakpoint instruction, thus
2566 executing it normally. But if this one cannot, just
2567 continue and we will hit it anyway. */
2568 if (gdbarch_cannot_step_breakpoint (gdbarch))
2573 && tp->control.trap_expected
2574 && use_displaced_stepping (tp)
2575 && !step_over_info_valid_p ())
2577 struct regcache *resume_regcache = get_thread_regcache (tp);
2578 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2579 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2582 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2583 paddress (resume_gdbarch, actual_pc));
2584 read_memory (actual_pc, buf, sizeof (buf));
2585 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2588 if (tp->control.may_range_step)
2590 /* If we're resuming a thread with the PC out of the step
2591 range, then we're doing some nested/finer run control
2592 operation, like stepping the thread out of the dynamic
2593 linker or the displaced stepping scratch pad. We
2594 shouldn't have allowed a range step then. */
2595 gdb_assert (pc_in_thread_step_range (pc, tp));
2598 do_target_resume (resume_ptid, step, sig);
2602 /* Resume the inferior. SIG is the signal to give the inferior
2603 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2604 rolls back state on error. */
2607 resume (gdb_signal sig)
2613 CATCH (ex, RETURN_MASK_ALL)
2615 /* If resuming is being aborted for any reason, delete any
2616 single-step breakpoint resume_1 may have created, to avoid
2617 confusing the following resumption, and to avoid leaving
2618 single-step breakpoints perturbing other threads, in case
2619 we're running in non-stop mode. */
2620 if (inferior_ptid != null_ptid)
2621 delete_single_step_breakpoints (inferior_thread ());
2622 throw_exception (ex);
2632 /* Counter that tracks number of user visible stops. This can be used
2633 to tell whether a command has proceeded the inferior past the
2634 current location. This allows e.g., inferior function calls in
2635 breakpoint commands to not interrupt the command list. When the
2636 call finishes successfully, the inferior is standing at the same
2637 breakpoint as if nothing happened (and so we don't call
2639 static ULONGEST current_stop_id;
2646 return current_stop_id;
2649 /* Called when we report a user visible stop. */
2657 /* Clear out all variables saying what to do when inferior is continued.
2658 First do this, then set the ones you want, then call `proceed'. */
2661 clear_proceed_status_thread (struct thread_info *tp)
2664 fprintf_unfiltered (gdb_stdlog,
2665 "infrun: clear_proceed_status_thread (%s)\n",
2666 target_pid_to_str (tp->ptid));
2668 /* If we're starting a new sequence, then the previous finished
2669 single-step is no longer relevant. */
2670 if (tp->suspend.waitstatus_pending_p)
2672 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2675 fprintf_unfiltered (gdb_stdlog,
2676 "infrun: clear_proceed_status: pending "
2677 "event of %s was a finished step. "
2679 target_pid_to_str (tp->ptid));
2681 tp->suspend.waitstatus_pending_p = 0;
2682 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2684 else if (debug_infrun)
2687 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2689 fprintf_unfiltered (gdb_stdlog,
2690 "infrun: clear_proceed_status_thread: thread %s "
2691 "has pending wait status %s "
2692 "(currently_stepping=%d).\n",
2693 target_pid_to_str (tp->ptid), statstr.c_str (),
2694 currently_stepping (tp));
2698 /* If this signal should not be seen by program, give it zero.
2699 Used for debugging signals. */
2700 if (!signal_pass_state (tp->suspend.stop_signal))
2701 tp->suspend.stop_signal = GDB_SIGNAL_0;
2703 delete tp->thread_fsm;
2704 tp->thread_fsm = NULL;
2706 tp->control.trap_expected = 0;
2707 tp->control.step_range_start = 0;
2708 tp->control.step_range_end = 0;
2709 tp->control.may_range_step = 0;
2710 tp->control.step_frame_id = null_frame_id;
2711 tp->control.step_stack_frame_id = null_frame_id;
2712 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2713 tp->control.step_start_function = NULL;
2714 tp->stop_requested = 0;
2716 tp->control.stop_step = 0;
2718 tp->control.proceed_to_finish = 0;
2720 tp->control.stepping_command = 0;
2722 /* Discard any remaining commands or status from previous stop. */
2723 bpstat_clear (&tp->control.stop_bpstat);
2727 clear_proceed_status (int step)
2729 /* With scheduler-locking replay, stop replaying other threads if we're
2730 not replaying the user-visible resume ptid.
2732 This is a convenience feature to not require the user to explicitly
2733 stop replaying the other threads. We're assuming that the user's
2734 intent is to resume tracing the recorded process. */
2735 if (!non_stop && scheduler_mode == schedlock_replay
2736 && target_record_is_replaying (minus_one_ptid)
2737 && !target_record_will_replay (user_visible_resume_ptid (step),
2738 execution_direction))
2739 target_record_stop_replaying ();
2741 if (!non_stop && inferior_ptid != null_ptid)
2743 ptid_t resume_ptid = user_visible_resume_ptid (step);
2745 /* In all-stop mode, delete the per-thread status of all threads
2746 we're about to resume, implicitly and explicitly. */
2747 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2748 clear_proceed_status_thread (tp);
2751 if (inferior_ptid != null_ptid)
2753 struct inferior *inferior;
2757 /* If in non-stop mode, only delete the per-thread status of
2758 the current thread. */
2759 clear_proceed_status_thread (inferior_thread ());
2762 inferior = current_inferior ();
2763 inferior->control.stop_soon = NO_STOP_QUIETLY;
2766 gdb::observers::about_to_proceed.notify ();
2769 /* Returns true if TP is still stopped at a breakpoint that needs
2770 stepping-over in order to make progress. If the breakpoint is gone
2771 meanwhile, we can skip the whole step-over dance. */
2774 thread_still_needs_step_over_bp (struct thread_info *tp)
2776 if (tp->stepping_over_breakpoint)
2778 struct regcache *regcache = get_thread_regcache (tp);
2780 if (breakpoint_here_p (regcache->aspace (),
2781 regcache_read_pc (regcache))
2782 == ordinary_breakpoint_here)
2785 tp->stepping_over_breakpoint = 0;
2791 /* Check whether thread TP still needs to start a step-over in order
2792 to make progress when resumed. Returns an bitwise or of enum
2793 step_over_what bits, indicating what needs to be stepped over. */
2795 static step_over_what
2796 thread_still_needs_step_over (struct thread_info *tp)
2798 step_over_what what = 0;
2800 if (thread_still_needs_step_over_bp (tp))
2801 what |= STEP_OVER_BREAKPOINT;
2803 if (tp->stepping_over_watchpoint
2804 && !target_have_steppable_watchpoint)
2805 what |= STEP_OVER_WATCHPOINT;
2810 /* Returns true if scheduler locking applies. STEP indicates whether
2811 we're about to do a step/next-like command to a thread. */
2814 schedlock_applies (struct thread_info *tp)
2816 return (scheduler_mode == schedlock_on
2817 || (scheduler_mode == schedlock_step
2818 && tp->control.stepping_command)
2819 || (scheduler_mode == schedlock_replay
2820 && target_record_will_replay (minus_one_ptid,
2821 execution_direction)));
2824 /* Basic routine for continuing the program in various fashions.
2826 ADDR is the address to resume at, or -1 for resume where stopped.
2827 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2828 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2830 You should call clear_proceed_status before calling proceed. */
2833 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2835 struct regcache *regcache;
2836 struct gdbarch *gdbarch;
2839 struct execution_control_state ecss;
2840 struct execution_control_state *ecs = &ecss;
2843 /* If we're stopped at a fork/vfork, follow the branch set by the
2844 "set follow-fork-mode" command; otherwise, we'll just proceed
2845 resuming the current thread. */
2846 if (!follow_fork ())
2848 /* The target for some reason decided not to resume. */
2850 if (target_can_async_p ())
2851 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2855 /* We'll update this if & when we switch to a new thread. */
2856 previous_inferior_ptid = inferior_ptid;
2858 regcache = get_current_regcache ();
2859 gdbarch = regcache->arch ();
2860 const address_space *aspace = regcache->aspace ();
2862 pc = regcache_read_pc (regcache);
2863 thread_info *cur_thr = inferior_thread ();
2865 /* Fill in with reasonable starting values. */
2866 init_thread_stepping_state (cur_thr);
2868 gdb_assert (!thread_is_in_step_over_chain (cur_thr));
2870 if (addr == (CORE_ADDR) -1)
2872 if (pc == cur_thr->suspend.stop_pc
2873 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2874 && execution_direction != EXEC_REVERSE)
2875 /* There is a breakpoint at the address we will resume at,
2876 step one instruction before inserting breakpoints so that
2877 we do not stop right away (and report a second hit at this
2880 Note, we don't do this in reverse, because we won't
2881 actually be executing the breakpoint insn anyway.
2882 We'll be (un-)executing the previous instruction. */
2883 cur_thr->stepping_over_breakpoint = 1;
2884 else if (gdbarch_single_step_through_delay_p (gdbarch)
2885 && gdbarch_single_step_through_delay (gdbarch,
2886 get_current_frame ()))
2887 /* We stepped onto an instruction that needs to be stepped
2888 again before re-inserting the breakpoint, do so. */
2889 cur_thr->stepping_over_breakpoint = 1;
2893 regcache_write_pc (regcache, addr);
2896 if (siggnal != GDB_SIGNAL_DEFAULT)
2897 cur_thr->suspend.stop_signal = siggnal;
2899 resume_ptid = user_visible_resume_ptid (cur_thr->control.stepping_command);
2901 /* If an exception is thrown from this point on, make sure to
2902 propagate GDB's knowledge of the executing state to the
2903 frontend/user running state. */
2904 scoped_finish_thread_state finish_state (resume_ptid);
2906 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2907 threads (e.g., we might need to set threads stepping over
2908 breakpoints first), from the user/frontend's point of view, all
2909 threads in RESUME_PTID are now running. Unless we're calling an
2910 inferior function, as in that case we pretend the inferior
2911 doesn't run at all. */
2912 if (!cur_thr->control.in_infcall)
2913 set_running (resume_ptid, 1);
2916 fprintf_unfiltered (gdb_stdlog,
2917 "infrun: proceed (addr=%s, signal=%s)\n",
2918 paddress (gdbarch, addr),
2919 gdb_signal_to_symbol_string (siggnal));
2921 annotate_starting ();
2923 /* Make sure that output from GDB appears before output from the
2925 gdb_flush (gdb_stdout);
2927 /* Since we've marked the inferior running, give it the terminal. A
2928 QUIT/Ctrl-C from here on is forwarded to the target (which can
2929 still detect attempts to unblock a stuck connection with repeated
2930 Ctrl-C from within target_pass_ctrlc). */
2931 target_terminal::inferior ();
2933 /* In a multi-threaded task we may select another thread and
2934 then continue or step.
2936 But if a thread that we're resuming had stopped at a breakpoint,
2937 it will immediately cause another breakpoint stop without any
2938 execution (i.e. it will report a breakpoint hit incorrectly). So
2939 we must step over it first.
2941 Look for threads other than the current (TP) that reported a
2942 breakpoint hit and haven't been resumed yet since. */
2944 /* If scheduler locking applies, we can avoid iterating over all
2946 if (!non_stop && !schedlock_applies (cur_thr))
2948 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2950 /* Ignore the current thread here. It's handled
2955 if (!thread_still_needs_step_over (tp))
2958 gdb_assert (!thread_is_in_step_over_chain (tp));
2961 fprintf_unfiltered (gdb_stdlog,
2962 "infrun: need to step-over [%s] first\n",
2963 target_pid_to_str (tp->ptid));
2965 thread_step_over_chain_enqueue (tp);
2969 /* Enqueue the current thread last, so that we move all other
2970 threads over their breakpoints first. */
2971 if (cur_thr->stepping_over_breakpoint)
2972 thread_step_over_chain_enqueue (cur_thr);
2974 /* If the thread isn't started, we'll still need to set its prev_pc,
2975 so that switch_back_to_stepped_thread knows the thread hasn't
2976 advanced. Must do this before resuming any thread, as in
2977 all-stop/remote, once we resume we can't send any other packet
2978 until the target stops again. */
2979 cur_thr->prev_pc = regcache_read_pc (regcache);
2982 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
2984 started = start_step_over ();
2986 if (step_over_info_valid_p ())
2988 /* Either this thread started a new in-line step over, or some
2989 other thread was already doing one. In either case, don't
2990 resume anything else until the step-over is finished. */
2992 else if (started && !target_is_non_stop_p ())
2994 /* A new displaced stepping sequence was started. In all-stop,
2995 we can't talk to the target anymore until it next stops. */
2997 else if (!non_stop && target_is_non_stop_p ())
2999 /* In all-stop, but the target is always in non-stop mode.
3000 Start all other threads that are implicitly resumed too. */
3001 for (thread_info *tp : all_non_exited_threads (resume_ptid))
3006 fprintf_unfiltered (gdb_stdlog,
3007 "infrun: proceed: [%s] resumed\n",
3008 target_pid_to_str (tp->ptid));
3009 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3013 if (thread_is_in_step_over_chain (tp))
3016 fprintf_unfiltered (gdb_stdlog,
3017 "infrun: proceed: [%s] needs step-over\n",
3018 target_pid_to_str (tp->ptid));
3023 fprintf_unfiltered (gdb_stdlog,
3024 "infrun: proceed: resuming %s\n",
3025 target_pid_to_str (tp->ptid));
3027 reset_ecs (ecs, tp);
3028 switch_to_thread (tp);
3029 keep_going_pass_signal (ecs);
3030 if (!ecs->wait_some_more)
3031 error (_("Command aborted."));
3034 else if (!cur_thr->resumed && !thread_is_in_step_over_chain (cur_thr))
3036 /* The thread wasn't started, and isn't queued, run it now. */
3037 reset_ecs (ecs, cur_thr);
3038 switch_to_thread (cur_thr);
3039 keep_going_pass_signal (ecs);
3040 if (!ecs->wait_some_more)
3041 error (_("Command aborted."));
3045 target_commit_resume ();
3047 finish_state.release ();
3049 /* Tell the event loop to wait for it to stop. If the target
3050 supports asynchronous execution, it'll do this from within
3052 if (!target_can_async_p ())
3053 mark_async_event_handler (infrun_async_inferior_event_token);
3057 /* Start remote-debugging of a machine over a serial link. */
3060 start_remote (int from_tty)
3062 struct inferior *inferior;
3064 inferior = current_inferior ();
3065 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3067 /* Always go on waiting for the target, regardless of the mode. */
3068 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3069 indicate to wait_for_inferior that a target should timeout if
3070 nothing is returned (instead of just blocking). Because of this,
3071 targets expecting an immediate response need to, internally, set
3072 things up so that the target_wait() is forced to eventually
3074 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3075 differentiate to its caller what the state of the target is after
3076 the initial open has been performed. Here we're assuming that
3077 the target has stopped. It should be possible to eventually have
3078 target_open() return to the caller an indication that the target
3079 is currently running and GDB state should be set to the same as
3080 for an async run. */
3081 wait_for_inferior ();
3083 /* Now that the inferior has stopped, do any bookkeeping like
3084 loading shared libraries. We want to do this before normal_stop,
3085 so that the displayed frame is up to date. */
3086 post_create_inferior (current_top_target (), from_tty);
3091 /* Initialize static vars when a new inferior begins. */
3094 init_wait_for_inferior (void)
3096 /* These are meaningless until the first time through wait_for_inferior. */
3098 breakpoint_init_inferior (inf_starting);
3100 clear_proceed_status (0);
3102 target_last_wait_ptid = minus_one_ptid;
3104 previous_inferior_ptid = inferior_ptid;
3109 static void handle_inferior_event (struct execution_control_state *ecs);
3111 static void handle_step_into_function (struct gdbarch *gdbarch,
3112 struct execution_control_state *ecs);
3113 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3114 struct execution_control_state *ecs);
3115 static void handle_signal_stop (struct execution_control_state *ecs);
3116 static void check_exception_resume (struct execution_control_state *,
3117 struct frame_info *);
3119 static void end_stepping_range (struct execution_control_state *ecs);
3120 static void stop_waiting (struct execution_control_state *ecs);
3121 static void keep_going (struct execution_control_state *ecs);
3122 static void process_event_stop_test (struct execution_control_state *ecs);
3123 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3125 /* This function is attached as a "thread_stop_requested" observer.
3126 Cleanup local state that assumed the PTID was to be resumed, and
3127 report the stop to the frontend. */
3130 infrun_thread_stop_requested (ptid_t ptid)
3132 /* PTID was requested to stop. If the thread was already stopped,
3133 but the user/frontend doesn't know about that yet (e.g., the
3134 thread had been temporarily paused for some step-over), set up
3135 for reporting the stop now. */
3136 for (thread_info *tp : all_threads (ptid))
3138 if (tp->state != THREAD_RUNNING)
3143 /* Remove matching threads from the step-over queue, so
3144 start_step_over doesn't try to resume them
3146 if (thread_is_in_step_over_chain (tp))
3147 thread_step_over_chain_remove (tp);
3149 /* If the thread is stopped, but the user/frontend doesn't
3150 know about that yet, queue a pending event, as if the
3151 thread had just stopped now. Unless the thread already had
3153 if (!tp->suspend.waitstatus_pending_p)
3155 tp->suspend.waitstatus_pending_p = 1;
3156 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3157 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3160 /* Clear the inline-frame state, since we're re-processing the
3162 clear_inline_frame_state (tp->ptid);
3164 /* If this thread was paused because some other thread was
3165 doing an inline-step over, let that finish first. Once
3166 that happens, we'll restart all threads and consume pending
3167 stop events then. */
3168 if (step_over_info_valid_p ())
3171 /* Otherwise we can process the (new) pending event now. Set
3172 it so this pending event is considered by
3179 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3181 if (target_last_wait_ptid == tp->ptid)
3182 nullify_last_target_wait_ptid ();
3185 /* Delete the step resume, single-step and longjmp/exception resume
3186 breakpoints of TP. */
3189 delete_thread_infrun_breakpoints (struct thread_info *tp)
3191 delete_step_resume_breakpoint (tp);
3192 delete_exception_resume_breakpoint (tp);
3193 delete_single_step_breakpoints (tp);
3196 /* If the target still has execution, call FUNC for each thread that
3197 just stopped. In all-stop, that's all the non-exited threads; in
3198 non-stop, that's the current thread, only. */
3200 typedef void (*for_each_just_stopped_thread_callback_func)
3201 (struct thread_info *tp);
3204 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3206 if (!target_has_execution || inferior_ptid == null_ptid)
3209 if (target_is_non_stop_p ())
3211 /* If in non-stop mode, only the current thread stopped. */
3212 func (inferior_thread ());
3216 /* In all-stop mode, all threads have stopped. */
3217 for (thread_info *tp : all_non_exited_threads ())
3222 /* Delete the step resume and longjmp/exception resume breakpoints of
3223 the threads that just stopped. */
3226 delete_just_stopped_threads_infrun_breakpoints (void)
3228 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3231 /* Delete the single-step breakpoints of the threads that just
3235 delete_just_stopped_threads_single_step_breakpoints (void)
3237 for_each_just_stopped_thread (delete_single_step_breakpoints);
3243 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3244 const struct target_waitstatus *ws)
3246 std::string status_string = target_waitstatus_to_string (ws);
3249 /* The text is split over several lines because it was getting too long.
3250 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3251 output as a unit; we want only one timestamp printed if debug_timestamp
3254 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3257 waiton_ptid.tid ());
3258 if (waiton_ptid.pid () != -1)
3259 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3260 stb.printf (", status) =\n");
3261 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3265 target_pid_to_str (result_ptid));
3266 stb.printf ("infrun: %s\n", status_string.c_str ());
3268 /* This uses %s in part to handle %'s in the text, but also to avoid
3269 a gcc error: the format attribute requires a string literal. */
3270 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3273 /* Select a thread at random, out of those which are resumed and have
3276 static struct thread_info *
3277 random_pending_event_thread (ptid_t waiton_ptid)
3281 auto has_event = [] (thread_info *tp)
3284 && tp->suspend.waitstatus_pending_p);
3287 /* First see how many events we have. Count only resumed threads
3288 that have an event pending. */
3289 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3293 if (num_events == 0)
3296 /* Now randomly pick a thread out of those that have had events. */
3297 int random_selector = (int) ((num_events * (double) rand ())
3298 / (RAND_MAX + 1.0));
3300 if (debug_infrun && num_events > 1)
3301 fprintf_unfiltered (gdb_stdlog,
3302 "infrun: Found %d events, selecting #%d\n",
3303 num_events, random_selector);
3305 /* Select the Nth thread that has had an event. */
3306 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3308 if (random_selector-- == 0)
3311 gdb_assert_not_reached ("event thread not found");
3314 /* Wrapper for target_wait that first checks whether threads have
3315 pending statuses to report before actually asking the target for
3319 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3322 struct thread_info *tp;
3324 /* First check if there is a resumed thread with a wait status
3326 if (ptid == minus_one_ptid || ptid.is_pid ())
3328 tp = random_pending_event_thread (ptid);
3333 fprintf_unfiltered (gdb_stdlog,
3334 "infrun: Waiting for specific thread %s.\n",
3335 target_pid_to_str (ptid));
3337 /* We have a specific thread to check. */
3338 tp = find_thread_ptid (ptid);
3339 gdb_assert (tp != NULL);
3340 if (!tp->suspend.waitstatus_pending_p)
3345 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3346 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3348 struct regcache *regcache = get_thread_regcache (tp);
3349 struct gdbarch *gdbarch = regcache->arch ();
3353 pc = regcache_read_pc (regcache);
3355 if (pc != tp->suspend.stop_pc)
3358 fprintf_unfiltered (gdb_stdlog,
3359 "infrun: PC of %s changed. was=%s, now=%s\n",
3360 target_pid_to_str (tp->ptid),
3361 paddress (gdbarch, tp->suspend.stop_pc),
3362 paddress (gdbarch, pc));
3365 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3368 fprintf_unfiltered (gdb_stdlog,
3369 "infrun: previous breakpoint of %s, at %s gone\n",
3370 target_pid_to_str (tp->ptid),
3371 paddress (gdbarch, pc));
3379 fprintf_unfiltered (gdb_stdlog,
3380 "infrun: pending event of %s cancelled.\n",
3381 target_pid_to_str (tp->ptid));
3383 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3384 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3393 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3395 fprintf_unfiltered (gdb_stdlog,
3396 "infrun: Using pending wait status %s for %s.\n",
3398 target_pid_to_str (tp->ptid));
3401 /* Now that we've selected our final event LWP, un-adjust its PC
3402 if it was a software breakpoint (and the target doesn't
3403 always adjust the PC itself). */
3404 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3405 && !target_supports_stopped_by_sw_breakpoint ())
3407 struct regcache *regcache;
3408 struct gdbarch *gdbarch;
3411 regcache = get_thread_regcache (tp);
3412 gdbarch = regcache->arch ();
3414 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3419 pc = regcache_read_pc (regcache);
3420 regcache_write_pc (regcache, pc + decr_pc);
3424 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3425 *status = tp->suspend.waitstatus;
3426 tp->suspend.waitstatus_pending_p = 0;
3428 /* Wake up the event loop again, until all pending events are
3430 if (target_is_async_p ())
3431 mark_async_event_handler (infrun_async_inferior_event_token);
3435 /* But if we don't find one, we'll have to wait. */
3437 if (deprecated_target_wait_hook)
3438 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3440 event_ptid = target_wait (ptid, status, options);
3445 /* Prepare and stabilize the inferior for detaching it. E.g.,
3446 detaching while a thread is displaced stepping is a recipe for
3447 crashing it, as nothing would readjust the PC out of the scratch
3451 prepare_for_detach (void)
3453 struct inferior *inf = current_inferior ();
3454 ptid_t pid_ptid = ptid_t (inf->pid);
3456 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3458 /* Is any thread of this process displaced stepping? If not,
3459 there's nothing else to do. */
3460 if (displaced->step_thread == nullptr)
3464 fprintf_unfiltered (gdb_stdlog,
3465 "displaced-stepping in-process while detaching");
3467 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3469 while (displaced->step_thread != nullptr)
3471 struct execution_control_state ecss;
3472 struct execution_control_state *ecs;
3475 memset (ecs, 0, sizeof (*ecs));
3477 overlay_cache_invalid = 1;
3478 /* Flush target cache before starting to handle each event.
3479 Target was running and cache could be stale. This is just a
3480 heuristic. Running threads may modify target memory, but we
3481 don't get any event. */
3482 target_dcache_invalidate ();
3484 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3487 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3489 /* If an error happens while handling the event, propagate GDB's
3490 knowledge of the executing state to the frontend/user running
3492 scoped_finish_thread_state finish_state (minus_one_ptid);
3494 /* Now figure out what to do with the result of the result. */
3495 handle_inferior_event (ecs);
3497 /* No error, don't finish the state yet. */
3498 finish_state.release ();
3500 /* Breakpoints and watchpoints are not installed on the target
3501 at this point, and signals are passed directly to the
3502 inferior, so this must mean the process is gone. */
3503 if (!ecs->wait_some_more)
3505 restore_detaching.release ();
3506 error (_("Program exited while detaching"));
3510 restore_detaching.release ();
3513 /* Wait for control to return from inferior to debugger.
3515 If inferior gets a signal, we may decide to start it up again
3516 instead of returning. That is why there is a loop in this function.
3517 When this function actually returns it means the inferior
3518 should be left stopped and GDB should read more commands. */
3521 wait_for_inferior (void)
3525 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3527 SCOPE_EXIT { delete_just_stopped_threads_infrun_breakpoints (); };
3529 /* If an error happens while handling the event, propagate GDB's
3530 knowledge of the executing state to the frontend/user running
3532 scoped_finish_thread_state finish_state (minus_one_ptid);
3536 struct execution_control_state ecss;
3537 struct execution_control_state *ecs = &ecss;
3538 ptid_t waiton_ptid = minus_one_ptid;
3540 memset (ecs, 0, sizeof (*ecs));
3542 overlay_cache_invalid = 1;
3544 /* Flush target cache before starting to handle each event.
3545 Target was running and cache could be stale. This is just a
3546 heuristic. Running threads may modify target memory, but we
3547 don't get any event. */
3548 target_dcache_invalidate ();
3550 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3553 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3555 /* Now figure out what to do with the result of the result. */
3556 handle_inferior_event (ecs);
3558 if (!ecs->wait_some_more)
3562 /* No error, don't finish the state yet. */
3563 finish_state.release ();
3566 /* Cleanup that reinstalls the readline callback handler, if the
3567 target is running in the background. If while handling the target
3568 event something triggered a secondary prompt, like e.g., a
3569 pagination prompt, we'll have removed the callback handler (see
3570 gdb_readline_wrapper_line). Need to do this as we go back to the
3571 event loop, ready to process further input. Note this has no
3572 effect if the handler hasn't actually been removed, because calling
3573 rl_callback_handler_install resets the line buffer, thus losing
3577 reinstall_readline_callback_handler_cleanup ()
3579 struct ui *ui = current_ui;
3583 /* We're not going back to the top level event loop yet. Don't
3584 install the readline callback, as it'd prep the terminal,
3585 readline-style (raw, noecho) (e.g., --batch). We'll install
3586 it the next time the prompt is displayed, when we're ready
3591 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3592 gdb_rl_callback_handler_reinstall ();
3595 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3596 that's just the event thread. In all-stop, that's all threads. */
3599 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3601 if (ecs->event_thread != NULL
3602 && ecs->event_thread->thread_fsm != NULL)
3603 ecs->event_thread->thread_fsm->clean_up (ecs->event_thread);
3607 for (thread_info *thr : all_non_exited_threads ())
3609 if (thr->thread_fsm == NULL)
3611 if (thr == ecs->event_thread)
3614 switch_to_thread (thr);
3615 thr->thread_fsm->clean_up (thr);
3618 if (ecs->event_thread != NULL)
3619 switch_to_thread (ecs->event_thread);
3623 /* Helper for all_uis_check_sync_execution_done that works on the
3627 check_curr_ui_sync_execution_done (void)
3629 struct ui *ui = current_ui;
3631 if (ui->prompt_state == PROMPT_NEEDED
3633 && !gdb_in_secondary_prompt_p (ui))
3635 target_terminal::ours ();
3636 gdb::observers::sync_execution_done.notify ();
3637 ui_register_input_event_handler (ui);
3644 all_uis_check_sync_execution_done (void)
3646 SWITCH_THRU_ALL_UIS ()
3648 check_curr_ui_sync_execution_done ();
3655 all_uis_on_sync_execution_starting (void)
3657 SWITCH_THRU_ALL_UIS ()
3659 if (current_ui->prompt_state == PROMPT_NEEDED)
3660 async_disable_stdin ();
3664 /* Asynchronous version of wait_for_inferior. It is called by the
3665 event loop whenever a change of state is detected on the file
3666 descriptor corresponding to the target. It can be called more than
3667 once to complete a single execution command. In such cases we need
3668 to keep the state in a global variable ECSS. If it is the last time
3669 that this function is called for a single execution command, then
3670 report to the user that the inferior has stopped, and do the
3671 necessary cleanups. */
3674 fetch_inferior_event (void *client_data)
3676 struct execution_control_state ecss;
3677 struct execution_control_state *ecs = &ecss;
3679 ptid_t waiton_ptid = minus_one_ptid;
3681 memset (ecs, 0, sizeof (*ecs));
3683 /* Events are always processed with the main UI as current UI. This
3684 way, warnings, debug output, etc. are always consistently sent to
3685 the main console. */
3686 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3688 /* End up with readline processing input, if necessary. */
3690 SCOPE_EXIT { reinstall_readline_callback_handler_cleanup (); };
3692 /* We're handling a live event, so make sure we're doing live
3693 debugging. If we're looking at traceframes while the target is
3694 running, we're going to need to get back to that mode after
3695 handling the event. */
3696 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3699 maybe_restore_traceframe.emplace ();
3700 set_current_traceframe (-1);
3703 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3706 /* In non-stop mode, the user/frontend should not notice a thread
3707 switch due to internal events. Make sure we reverse to the
3708 user selected thread and frame after handling the event and
3709 running any breakpoint commands. */
3710 maybe_restore_thread.emplace ();
3712 overlay_cache_invalid = 1;
3713 /* Flush target cache before starting to handle each event. Target
3714 was running and cache could be stale. This is just a heuristic.
3715 Running threads may modify target memory, but we don't get any
3717 target_dcache_invalidate ();
3719 scoped_restore save_exec_dir
3720 = make_scoped_restore (&execution_direction,
3721 target_execution_direction ());
3723 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3724 target_can_async_p () ? TARGET_WNOHANG : 0);
3727 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3729 /* If an error happens while handling the event, propagate GDB's
3730 knowledge of the executing state to the frontend/user running
3732 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3733 scoped_finish_thread_state finish_state (finish_ptid);
3735 /* Get executed before scoped_restore_current_thread above to apply
3736 still for the thread which has thrown the exception. */
3737 auto defer_bpstat_clear
3738 = make_scope_exit (bpstat_clear_actions);
3739 auto defer_delete_threads
3740 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints);
3742 /* Now figure out what to do with the result of the result. */
3743 handle_inferior_event (ecs);
3745 if (!ecs->wait_some_more)
3747 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3748 int should_stop = 1;
3749 struct thread_info *thr = ecs->event_thread;
3751 delete_just_stopped_threads_infrun_breakpoints ();
3755 struct thread_fsm *thread_fsm = thr->thread_fsm;
3757 if (thread_fsm != NULL)
3758 should_stop = thread_fsm->should_stop (thr);
3767 bool should_notify_stop = true;
3770 clean_up_just_stopped_threads_fsms (ecs);
3772 if (thr != NULL && thr->thread_fsm != NULL)
3773 should_notify_stop = thr->thread_fsm->should_notify_stop ();
3775 if (should_notify_stop)
3777 /* We may not find an inferior if this was a process exit. */
3778 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3779 proceeded = normal_stop ();
3784 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3790 defer_delete_threads.release ();
3791 defer_bpstat_clear.release ();
3793 /* No error, don't finish the thread states yet. */
3794 finish_state.release ();
3796 /* This scope is used to ensure that readline callbacks are
3797 reinstalled here. */
3800 /* If a UI was in sync execution mode, and now isn't, restore its
3801 prompt (a synchronous execution command has finished, and we're
3802 ready for input). */
3803 all_uis_check_sync_execution_done ();
3806 && exec_done_display_p
3807 && (inferior_ptid == null_ptid
3808 || inferior_thread ()->state != THREAD_RUNNING))
3809 printf_unfiltered (_("completed.\n"));
3812 /* Record the frame and location we're currently stepping through. */
3814 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3816 struct thread_info *tp = inferior_thread ();
3818 tp->control.step_frame_id = get_frame_id (frame);
3819 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3821 tp->current_symtab = sal.symtab;
3822 tp->current_line = sal.line;
3825 /* Clear context switchable stepping state. */
3828 init_thread_stepping_state (struct thread_info *tss)
3830 tss->stepped_breakpoint = 0;
3831 tss->stepping_over_breakpoint = 0;
3832 tss->stepping_over_watchpoint = 0;
3833 tss->step_after_step_resume_breakpoint = 0;
3836 /* Set the cached copy of the last ptid/waitstatus. */
3839 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3841 target_last_wait_ptid = ptid;
3842 target_last_waitstatus = status;
3845 /* Return the cached copy of the last pid/waitstatus returned by
3846 target_wait()/deprecated_target_wait_hook(). The data is actually
3847 cached by handle_inferior_event(), which gets called immediately
3848 after target_wait()/deprecated_target_wait_hook(). */
3851 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3853 *ptidp = target_last_wait_ptid;
3854 *status = target_last_waitstatus;
3858 nullify_last_target_wait_ptid (void)
3860 target_last_wait_ptid = minus_one_ptid;
3863 /* Switch thread contexts. */
3866 context_switch (execution_control_state *ecs)
3869 && ecs->ptid != inferior_ptid
3870 && ecs->event_thread != inferior_thread ())
3872 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3873 target_pid_to_str (inferior_ptid));
3874 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3875 target_pid_to_str (ecs->ptid));
3878 switch_to_thread (ecs->event_thread);
3881 /* If the target can't tell whether we've hit breakpoints
3882 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3883 check whether that could have been caused by a breakpoint. If so,
3884 adjust the PC, per gdbarch_decr_pc_after_break. */
3887 adjust_pc_after_break (struct thread_info *thread,
3888 struct target_waitstatus *ws)
3890 struct regcache *regcache;
3891 struct gdbarch *gdbarch;
3892 CORE_ADDR breakpoint_pc, decr_pc;
3894 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3895 we aren't, just return.
3897 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3898 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3899 implemented by software breakpoints should be handled through the normal
3902 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3903 different signals (SIGILL or SIGEMT for instance), but it is less
3904 clear where the PC is pointing afterwards. It may not match
3905 gdbarch_decr_pc_after_break. I don't know any specific target that
3906 generates these signals at breakpoints (the code has been in GDB since at
3907 least 1992) so I can not guess how to handle them here.
3909 In earlier versions of GDB, a target with
3910 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3911 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3912 target with both of these set in GDB history, and it seems unlikely to be
3913 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3915 if (ws->kind != TARGET_WAITKIND_STOPPED)
3918 if (ws->value.sig != GDB_SIGNAL_TRAP)
3921 /* In reverse execution, when a breakpoint is hit, the instruction
3922 under it has already been de-executed. The reported PC always
3923 points at the breakpoint address, so adjusting it further would
3924 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3927 B1 0x08000000 : INSN1
3928 B2 0x08000001 : INSN2
3930 PC -> 0x08000003 : INSN4
3932 Say you're stopped at 0x08000003 as above. Reverse continuing
3933 from that point should hit B2 as below. Reading the PC when the
3934 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3935 been de-executed already.
3937 B1 0x08000000 : INSN1
3938 B2 PC -> 0x08000001 : INSN2
3942 We can't apply the same logic as for forward execution, because
3943 we would wrongly adjust the PC to 0x08000000, since there's a
3944 breakpoint at PC - 1. We'd then report a hit on B1, although
3945 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3947 if (execution_direction == EXEC_REVERSE)
3950 /* If the target can tell whether the thread hit a SW breakpoint,
3951 trust it. Targets that can tell also adjust the PC
3953 if (target_supports_stopped_by_sw_breakpoint ())
3956 /* Note that relying on whether a breakpoint is planted in memory to
3957 determine this can fail. E.g,. the breakpoint could have been
3958 removed since. Or the thread could have been told to step an
3959 instruction the size of a breakpoint instruction, and only
3960 _after_ was a breakpoint inserted at its address. */
3962 /* If this target does not decrement the PC after breakpoints, then
3963 we have nothing to do. */
3964 regcache = get_thread_regcache (thread);
3965 gdbarch = regcache->arch ();
3967 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3971 const address_space *aspace = regcache->aspace ();
3973 /* Find the location where (if we've hit a breakpoint) the
3974 breakpoint would be. */
3975 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3977 /* If the target can't tell whether a software breakpoint triggered,
3978 fallback to figuring it out based on breakpoints we think were
3979 inserted in the target, and on whether the thread was stepped or
3982 /* Check whether there actually is a software breakpoint inserted at
3985 If in non-stop mode, a race condition is possible where we've
3986 removed a breakpoint, but stop events for that breakpoint were
3987 already queued and arrive later. To suppress those spurious
3988 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3989 and retire them after a number of stop events are reported. Note
3990 this is an heuristic and can thus get confused. The real fix is
3991 to get the "stopped by SW BP and needs adjustment" info out of
3992 the target/kernel (and thus never reach here; see above). */
3993 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3994 || (target_is_non_stop_p ()
3995 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3997 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
3999 if (record_full_is_used ())
4000 restore_operation_disable.emplace
4001 (record_full_gdb_operation_disable_set ());
4003 /* When using hardware single-step, a SIGTRAP is reported for both
4004 a completed single-step and a software breakpoint. Need to
4005 differentiate between the two, as the latter needs adjusting
4006 but the former does not.
4008 The SIGTRAP can be due to a completed hardware single-step only if
4009 - we didn't insert software single-step breakpoints
4010 - this thread is currently being stepped
4012 If any of these events did not occur, we must have stopped due
4013 to hitting a software breakpoint, and have to back up to the
4016 As a special case, we could have hardware single-stepped a
4017 software breakpoint. In this case (prev_pc == breakpoint_pc),
4018 we also need to back up to the breakpoint address. */
4020 if (thread_has_single_step_breakpoints_set (thread)
4021 || !currently_stepping (thread)
4022 || (thread->stepped_breakpoint
4023 && thread->prev_pc == breakpoint_pc))
4024 regcache_write_pc (regcache, breakpoint_pc);
4029 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4031 for (frame = get_prev_frame (frame);
4033 frame = get_prev_frame (frame))
4035 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4037 if (get_frame_type (frame) != INLINE_FRAME)
4044 /* If the event thread has the stop requested flag set, pretend it
4045 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4049 handle_stop_requested (struct execution_control_state *ecs)
4051 if (ecs->event_thread->stop_requested)
4053 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4054 ecs->ws.value.sig = GDB_SIGNAL_0;
4055 handle_signal_stop (ecs);
4061 /* Auxiliary function that handles syscall entry/return events.
4062 It returns 1 if the inferior should keep going (and GDB
4063 should ignore the event), or 0 if the event deserves to be
4067 handle_syscall_event (struct execution_control_state *ecs)
4069 struct regcache *regcache;
4072 context_switch (ecs);
4074 regcache = get_thread_regcache (ecs->event_thread);
4075 syscall_number = ecs->ws.value.syscall_number;
4076 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4078 if (catch_syscall_enabled () > 0
4079 && catching_syscall_number (syscall_number) > 0)
4082 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4085 ecs->event_thread->control.stop_bpstat
4086 = bpstat_stop_status (regcache->aspace (),
4087 ecs->event_thread->suspend.stop_pc,
4088 ecs->event_thread, &ecs->ws);
4090 if (handle_stop_requested (ecs))
4093 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4095 /* Catchpoint hit. */
4100 if (handle_stop_requested (ecs))
4103 /* If no catchpoint triggered for this, then keep going. */
4108 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4111 fill_in_stop_func (struct gdbarch *gdbarch,
4112 struct execution_control_state *ecs)
4114 if (!ecs->stop_func_filled_in)
4116 /* Don't care about return value; stop_func_start and stop_func_name
4117 will both be 0 if it doesn't work. */
4118 find_function_entry_range_from_pc (ecs->event_thread->suspend.stop_pc,
4119 &ecs->stop_func_name,
4120 &ecs->stop_func_start,
4121 &ecs->stop_func_end);
4122 ecs->stop_func_start
4123 += gdbarch_deprecated_function_start_offset (gdbarch);
4125 if (gdbarch_skip_entrypoint_p (gdbarch))
4126 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4127 ecs->stop_func_start);
4129 ecs->stop_func_filled_in = 1;
4134 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4136 static enum stop_kind
4137 get_inferior_stop_soon (execution_control_state *ecs)
4139 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4141 gdb_assert (inf != NULL);
4142 return inf->control.stop_soon;
4145 /* Wait for one event. Store the resulting waitstatus in WS, and
4146 return the event ptid. */
4149 wait_one (struct target_waitstatus *ws)
4152 ptid_t wait_ptid = minus_one_ptid;
4154 overlay_cache_invalid = 1;
4156 /* Flush target cache before starting to handle each event.
4157 Target was running and cache could be stale. This is just a
4158 heuristic. Running threads may modify target memory, but we
4159 don't get any event. */
4160 target_dcache_invalidate ();
4162 if (deprecated_target_wait_hook)
4163 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4165 event_ptid = target_wait (wait_ptid, ws, 0);
4168 print_target_wait_results (wait_ptid, event_ptid, ws);
4173 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4174 instead of the current thread. */
4175 #define THREAD_STOPPED_BY(REASON) \
4177 thread_stopped_by_ ## REASON (ptid_t ptid) \
4179 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4180 inferior_ptid = ptid; \
4182 return target_stopped_by_ ## REASON (); \
4185 /* Generate thread_stopped_by_watchpoint. */
4186 THREAD_STOPPED_BY (watchpoint)
4187 /* Generate thread_stopped_by_sw_breakpoint. */
4188 THREAD_STOPPED_BY (sw_breakpoint)
4189 /* Generate thread_stopped_by_hw_breakpoint. */
4190 THREAD_STOPPED_BY (hw_breakpoint)
4192 /* Save the thread's event and stop reason to process it later. */
4195 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4199 std::string statstr = target_waitstatus_to_string (ws);
4201 fprintf_unfiltered (gdb_stdlog,
4202 "infrun: saving status %s for %d.%ld.%ld\n",
4209 /* Record for later. */
4210 tp->suspend.waitstatus = *ws;
4211 tp->suspend.waitstatus_pending_p = 1;
4213 struct regcache *regcache = get_thread_regcache (tp);
4214 const address_space *aspace = regcache->aspace ();
4216 if (ws->kind == TARGET_WAITKIND_STOPPED
4217 && ws->value.sig == GDB_SIGNAL_TRAP)
4219 CORE_ADDR pc = regcache_read_pc (regcache);
4221 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4223 if (thread_stopped_by_watchpoint (tp->ptid))
4225 tp->suspend.stop_reason
4226 = TARGET_STOPPED_BY_WATCHPOINT;
4228 else if (target_supports_stopped_by_sw_breakpoint ()
4229 && thread_stopped_by_sw_breakpoint (tp->ptid))
4231 tp->suspend.stop_reason
4232 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4234 else if (target_supports_stopped_by_hw_breakpoint ()
4235 && thread_stopped_by_hw_breakpoint (tp->ptid))
4237 tp->suspend.stop_reason
4238 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4240 else if (!target_supports_stopped_by_hw_breakpoint ()
4241 && hardware_breakpoint_inserted_here_p (aspace,
4244 tp->suspend.stop_reason
4245 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4247 else if (!target_supports_stopped_by_sw_breakpoint ()
4248 && software_breakpoint_inserted_here_p (aspace,
4251 tp->suspend.stop_reason
4252 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4254 else if (!thread_has_single_step_breakpoints_set (tp)
4255 && currently_stepping (tp))
4257 tp->suspend.stop_reason
4258 = TARGET_STOPPED_BY_SINGLE_STEP;
4266 stop_all_threads (void)
4268 /* We may need multiple passes to discover all threads. */
4272 gdb_assert (target_is_non_stop_p ());
4275 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4277 scoped_restore_current_thread restore_thread;
4279 target_thread_events (1);
4280 SCOPE_EXIT { target_thread_events (0); };
4282 /* Request threads to stop, and then wait for the stops. Because
4283 threads we already know about can spawn more threads while we're
4284 trying to stop them, and we only learn about new threads when we
4285 update the thread list, do this in a loop, and keep iterating
4286 until two passes find no threads that need to be stopped. */
4287 for (pass = 0; pass < 2; pass++, iterations++)
4290 fprintf_unfiltered (gdb_stdlog,
4291 "infrun: stop_all_threads, pass=%d, "
4292 "iterations=%d\n", pass, iterations);
4296 struct target_waitstatus ws;
4299 update_thread_list ();
4301 /* Go through all threads looking for threads that we need
4302 to tell the target to stop. */
4303 for (thread_info *t : all_non_exited_threads ())
4307 /* If already stopping, don't request a stop again.
4308 We just haven't seen the notification yet. */
4309 if (!t->stop_requested)
4312 fprintf_unfiltered (gdb_stdlog,
4313 "infrun: %s executing, "
4315 target_pid_to_str (t->ptid));
4316 target_stop (t->ptid);
4317 t->stop_requested = 1;
4322 fprintf_unfiltered (gdb_stdlog,
4323 "infrun: %s executing, "
4324 "already stopping\n",
4325 target_pid_to_str (t->ptid));
4328 if (t->stop_requested)
4334 fprintf_unfiltered (gdb_stdlog,
4335 "infrun: %s not executing\n",
4336 target_pid_to_str (t->ptid));
4338 /* The thread may be not executing, but still be
4339 resumed with a pending status to process. */
4347 /* If we find new threads on the second iteration, restart
4348 over. We want to see two iterations in a row with all
4353 event_ptid = wait_one (&ws);
4355 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4357 /* All resumed threads exited. */
4359 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4360 || ws.kind == TARGET_WAITKIND_EXITED
4361 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4365 ptid_t ptid = ptid_t (ws.value.integer);
4367 fprintf_unfiltered (gdb_stdlog,
4368 "infrun: %s exited while "
4369 "stopping threads\n",
4370 target_pid_to_str (ptid));
4375 thread_info *t = find_thread_ptid (event_ptid);
4377 t = add_thread (event_ptid);
4379 t->stop_requested = 0;
4382 t->control.may_range_step = 0;
4384 /* This may be the first time we see the inferior report
4386 inferior *inf = find_inferior_ptid (event_ptid);
4387 if (inf->needs_setup)
4389 switch_to_thread_no_regs (t);
4393 if (ws.kind == TARGET_WAITKIND_STOPPED
4394 && ws.value.sig == GDB_SIGNAL_0)
4396 /* We caught the event that we intended to catch, so
4397 there's no event pending. */
4398 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4399 t->suspend.waitstatus_pending_p = 0;
4401 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4403 /* Add it back to the step-over queue. */
4406 fprintf_unfiltered (gdb_stdlog,
4407 "infrun: displaced-step of %s "
4408 "canceled: adding back to the "
4409 "step-over queue\n",
4410 target_pid_to_str (t->ptid));
4412 t->control.trap_expected = 0;
4413 thread_step_over_chain_enqueue (t);
4418 enum gdb_signal sig;
4419 struct regcache *regcache;
4423 std::string statstr = target_waitstatus_to_string (&ws);
4425 fprintf_unfiltered (gdb_stdlog,
4426 "infrun: target_wait %s, saving "
4427 "status for %d.%ld.%ld\n",
4434 /* Record for later. */
4435 save_waitstatus (t, &ws);
4437 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4438 ? ws.value.sig : GDB_SIGNAL_0);
4440 if (displaced_step_fixup (t, sig) < 0)
4442 /* Add it back to the step-over queue. */
4443 t->control.trap_expected = 0;
4444 thread_step_over_chain_enqueue (t);
4447 regcache = get_thread_regcache (t);
4448 t->suspend.stop_pc = regcache_read_pc (regcache);
4452 fprintf_unfiltered (gdb_stdlog,
4453 "infrun: saved stop_pc=%s for %s "
4454 "(currently_stepping=%d)\n",
4455 paddress (target_gdbarch (),
4456 t->suspend.stop_pc),
4457 target_pid_to_str (t->ptid),
4458 currently_stepping (t));
4466 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4469 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4472 handle_no_resumed (struct execution_control_state *ecs)
4474 if (target_can_async_p ())
4481 if (ui->prompt_state == PROMPT_BLOCKED)
4489 /* There were no unwaited-for children left in the target, but,
4490 we're not synchronously waiting for events either. Just
4494 fprintf_unfiltered (gdb_stdlog,
4495 "infrun: TARGET_WAITKIND_NO_RESUMED "
4496 "(ignoring: bg)\n");
4497 prepare_to_wait (ecs);
4502 /* Otherwise, if we were running a synchronous execution command, we
4503 may need to cancel it and give the user back the terminal.
4505 In non-stop mode, the target can't tell whether we've already
4506 consumed previous stop events, so it can end up sending us a
4507 no-resumed event like so:
4509 #0 - thread 1 is left stopped
4511 #1 - thread 2 is resumed and hits breakpoint
4512 -> TARGET_WAITKIND_STOPPED
4514 #2 - thread 3 is resumed and exits
4515 this is the last resumed thread, so
4516 -> TARGET_WAITKIND_NO_RESUMED
4518 #3 - gdb processes stop for thread 2 and decides to re-resume
4521 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4522 thread 2 is now resumed, so the event should be ignored.
4524 IOW, if the stop for thread 2 doesn't end a foreground command,
4525 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4526 event. But it could be that the event meant that thread 2 itself
4527 (or whatever other thread was the last resumed thread) exited.
4529 To address this we refresh the thread list and check whether we
4530 have resumed threads _now_. In the example above, this removes
4531 thread 3 from the thread list. If thread 2 was re-resumed, we
4532 ignore this event. If we find no thread resumed, then we cancel
4533 the synchronous command show "no unwaited-for " to the user. */
4534 update_thread_list ();
4536 for (thread_info *thread : all_non_exited_threads ())
4538 if (thread->executing
4539 || thread->suspend.waitstatus_pending_p)
4541 /* There were no unwaited-for children left in the target at
4542 some point, but there are now. Just ignore. */
4544 fprintf_unfiltered (gdb_stdlog,
4545 "infrun: TARGET_WAITKIND_NO_RESUMED "
4546 "(ignoring: found resumed)\n");
4547 prepare_to_wait (ecs);
4552 /* Note however that we may find no resumed thread because the whole
4553 process exited meanwhile (thus updating the thread list results
4554 in an empty thread list). In this case we know we'll be getting
4555 a process exit event shortly. */
4556 for (inferior *inf : all_inferiors ())
4561 thread_info *thread = any_live_thread_of_inferior (inf);
4565 fprintf_unfiltered (gdb_stdlog,
4566 "infrun: TARGET_WAITKIND_NO_RESUMED "
4567 "(expect process exit)\n");
4568 prepare_to_wait (ecs);
4573 /* Go ahead and report the event. */
4577 /* Given an execution control state that has been freshly filled in by
4578 an event from the inferior, figure out what it means and take
4581 The alternatives are:
4583 1) stop_waiting and return; to really stop and return to the
4586 2) keep_going and return; to wait for the next event (set
4587 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4591 handle_inferior_event_1 (struct execution_control_state *ecs)
4593 enum stop_kind stop_soon;
4595 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4597 /* We had an event in the inferior, but we are not interested in
4598 handling it at this level. The lower layers have already
4599 done what needs to be done, if anything.
4601 One of the possible circumstances for this is when the
4602 inferior produces output for the console. The inferior has
4603 not stopped, and we are ignoring the event. Another possible
4604 circumstance is any event which the lower level knows will be
4605 reported multiple times without an intervening resume. */
4607 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4608 prepare_to_wait (ecs);
4612 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4615 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4616 prepare_to_wait (ecs);
4620 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4621 && handle_no_resumed (ecs))
4624 /* Cache the last pid/waitstatus. */
4625 set_last_target_status (ecs->ptid, ecs->ws);
4627 /* Always clear state belonging to the previous time we stopped. */
4628 stop_stack_dummy = STOP_NONE;
4630 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4632 /* No unwaited-for children left. IOW, all resumed children
4635 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4637 stop_print_frame = 0;
4642 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4643 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4645 ecs->event_thread = find_thread_ptid (ecs->ptid);
4646 /* If it's a new thread, add it to the thread database. */
4647 if (ecs->event_thread == NULL)
4648 ecs->event_thread = add_thread (ecs->ptid);
4650 /* Disable range stepping. If the next step request could use a
4651 range, this will be end up re-enabled then. */
4652 ecs->event_thread->control.may_range_step = 0;
4655 /* Dependent on valid ECS->EVENT_THREAD. */
4656 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4658 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4659 reinit_frame_cache ();
4661 breakpoint_retire_moribund ();
4663 /* First, distinguish signals caused by the debugger from signals
4664 that have to do with the program's own actions. Note that
4665 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4666 on the operating system version. Here we detect when a SIGILL or
4667 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4668 something similar for SIGSEGV, since a SIGSEGV will be generated
4669 when we're trying to execute a breakpoint instruction on a
4670 non-executable stack. This happens for call dummy breakpoints
4671 for architectures like SPARC that place call dummies on the
4673 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4674 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4675 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4676 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4678 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4680 if (breakpoint_inserted_here_p (regcache->aspace (),
4681 regcache_read_pc (regcache)))
4684 fprintf_unfiltered (gdb_stdlog,
4685 "infrun: Treating signal as SIGTRAP\n");
4686 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4690 /* Mark the non-executing threads accordingly. In all-stop, all
4691 threads of all processes are stopped when we get any event
4692 reported. In non-stop mode, only the event thread stops. */
4696 if (!target_is_non_stop_p ())
4697 mark_ptid = minus_one_ptid;
4698 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4699 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4701 /* If we're handling a process exit in non-stop mode, even
4702 though threads haven't been deleted yet, one would think
4703 that there is nothing to do, as threads of the dead process
4704 will be soon deleted, and threads of any other process were
4705 left running. However, on some targets, threads survive a
4706 process exit event. E.g., for the "checkpoint" command,
4707 when the current checkpoint/fork exits, linux-fork.c
4708 automatically switches to another fork from within
4709 target_mourn_inferior, by associating the same
4710 inferior/thread to another fork. We haven't mourned yet at
4711 this point, but we must mark any threads left in the
4712 process as not-executing so that finish_thread_state marks
4713 them stopped (in the user's perspective) if/when we present
4714 the stop to the user. */
4715 mark_ptid = ptid_t (ecs->ptid.pid ());
4718 mark_ptid = ecs->ptid;
4720 set_executing (mark_ptid, 0);
4722 /* Likewise the resumed flag. */
4723 set_resumed (mark_ptid, 0);
4726 switch (ecs->ws.kind)
4728 case TARGET_WAITKIND_LOADED:
4730 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4731 context_switch (ecs);
4732 /* Ignore gracefully during startup of the inferior, as it might
4733 be the shell which has just loaded some objects, otherwise
4734 add the symbols for the newly loaded objects. Also ignore at
4735 the beginning of an attach or remote session; we will query
4736 the full list of libraries once the connection is
4739 stop_soon = get_inferior_stop_soon (ecs);
4740 if (stop_soon == NO_STOP_QUIETLY)
4742 struct regcache *regcache;
4744 regcache = get_thread_regcache (ecs->event_thread);
4746 handle_solib_event ();
4748 ecs->event_thread->control.stop_bpstat
4749 = bpstat_stop_status (regcache->aspace (),
4750 ecs->event_thread->suspend.stop_pc,
4751 ecs->event_thread, &ecs->ws);
4753 if (handle_stop_requested (ecs))
4756 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4758 /* A catchpoint triggered. */
4759 process_event_stop_test (ecs);
4763 /* If requested, stop when the dynamic linker notifies
4764 gdb of events. This allows the user to get control
4765 and place breakpoints in initializer routines for
4766 dynamically loaded objects (among other things). */
4767 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4768 if (stop_on_solib_events)
4770 /* Make sure we print "Stopped due to solib-event" in
4772 stop_print_frame = 1;
4779 /* If we are skipping through a shell, or through shared library
4780 loading that we aren't interested in, resume the program. If
4781 we're running the program normally, also resume. */
4782 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4784 /* Loading of shared libraries might have changed breakpoint
4785 addresses. Make sure new breakpoints are inserted. */
4786 if (stop_soon == NO_STOP_QUIETLY)
4787 insert_breakpoints ();
4788 resume (GDB_SIGNAL_0);
4789 prepare_to_wait (ecs);
4793 /* But stop if we're attaching or setting up a remote
4795 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4796 || stop_soon == STOP_QUIETLY_REMOTE)
4799 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4804 internal_error (__FILE__, __LINE__,
4805 _("unhandled stop_soon: %d"), (int) stop_soon);
4807 case TARGET_WAITKIND_SPURIOUS:
4809 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4810 if (handle_stop_requested (ecs))
4812 context_switch (ecs);
4813 resume (GDB_SIGNAL_0);
4814 prepare_to_wait (ecs);
4817 case TARGET_WAITKIND_THREAD_CREATED:
4819 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
4820 if (handle_stop_requested (ecs))
4822 context_switch (ecs);
4823 if (!switch_back_to_stepped_thread (ecs))
4827 case TARGET_WAITKIND_EXITED:
4828 case TARGET_WAITKIND_SIGNALLED:
4831 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4832 fprintf_unfiltered (gdb_stdlog,
4833 "infrun: TARGET_WAITKIND_EXITED\n");
4835 fprintf_unfiltered (gdb_stdlog,
4836 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4839 inferior_ptid = ecs->ptid;
4840 set_current_inferior (find_inferior_ptid (ecs->ptid));
4841 set_current_program_space (current_inferior ()->pspace);
4842 handle_vfork_child_exec_or_exit (0);
4843 target_terminal::ours (); /* Must do this before mourn anyway. */
4845 /* Clearing any previous state of convenience variables. */
4846 clear_exit_convenience_vars ();
4848 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4850 /* Record the exit code in the convenience variable $_exitcode, so
4851 that the user can inspect this again later. */
4852 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4853 (LONGEST) ecs->ws.value.integer);
4855 /* Also record this in the inferior itself. */
4856 current_inferior ()->has_exit_code = 1;
4857 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4859 /* Support the --return-child-result option. */
4860 return_child_result_value = ecs->ws.value.integer;
4862 gdb::observers::exited.notify (ecs->ws.value.integer);
4866 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
4868 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4870 /* Set the value of the internal variable $_exitsignal,
4871 which holds the signal uncaught by the inferior. */
4872 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4873 gdbarch_gdb_signal_to_target (gdbarch,
4874 ecs->ws.value.sig));
4878 /* We don't have access to the target's method used for
4879 converting between signal numbers (GDB's internal
4880 representation <-> target's representation).
4881 Therefore, we cannot do a good job at displaying this
4882 information to the user. It's better to just warn
4883 her about it (if infrun debugging is enabled), and
4886 fprintf_filtered (gdb_stdlog, _("\
4887 Cannot fill $_exitsignal with the correct signal number.\n"));
4890 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
4893 gdb_flush (gdb_stdout);
4894 target_mourn_inferior (inferior_ptid);
4895 stop_print_frame = 0;
4899 /* The following are the only cases in which we keep going;
4900 the above cases end in a continue or goto. */
4901 case TARGET_WAITKIND_FORKED:
4902 case TARGET_WAITKIND_VFORKED:
4905 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4906 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4908 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4911 /* Check whether the inferior is displaced stepping. */
4913 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4914 struct gdbarch *gdbarch = regcache->arch ();
4916 /* If checking displaced stepping is supported, and thread
4917 ecs->ptid is displaced stepping. */
4918 if (displaced_step_in_progress_thread (ecs->event_thread))
4920 struct inferior *parent_inf
4921 = find_inferior_ptid (ecs->ptid);
4922 struct regcache *child_regcache;
4923 CORE_ADDR parent_pc;
4925 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4926 indicating that the displaced stepping of syscall instruction
4927 has been done. Perform cleanup for parent process here. Note
4928 that this operation also cleans up the child process for vfork,
4929 because their pages are shared. */
4930 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
4931 /* Start a new step-over in another thread if there's one
4935 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4937 struct displaced_step_inferior_state *displaced
4938 = get_displaced_stepping_state (parent_inf);
4940 /* Restore scratch pad for child process. */
4941 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4944 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4945 the child's PC is also within the scratchpad. Set the child's PC
4946 to the parent's PC value, which has already been fixed up.
4947 FIXME: we use the parent's aspace here, although we're touching
4948 the child, because the child hasn't been added to the inferior
4949 list yet at this point. */
4952 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4954 parent_inf->aspace);
4955 /* Read PC value of parent process. */
4956 parent_pc = regcache_read_pc (regcache);
4958 if (debug_displaced)
4959 fprintf_unfiltered (gdb_stdlog,
4960 "displaced: write child pc from %s to %s\n",
4962 regcache_read_pc (child_regcache)),
4963 paddress (gdbarch, parent_pc));
4965 regcache_write_pc (child_regcache, parent_pc);
4969 context_switch (ecs);
4971 /* Immediately detach breakpoints from the child before there's
4972 any chance of letting the user delete breakpoints from the
4973 breakpoint lists. If we don't do this early, it's easy to
4974 leave left over traps in the child, vis: "break foo; catch
4975 fork; c; <fork>; del; c; <child calls foo>". We only follow
4976 the fork on the last `continue', and by that time the
4977 breakpoint at "foo" is long gone from the breakpoint table.
4978 If we vforked, then we don't need to unpatch here, since both
4979 parent and child are sharing the same memory pages; we'll
4980 need to unpatch at follow/detach time instead to be certain
4981 that new breakpoints added between catchpoint hit time and
4982 vfork follow are detached. */
4983 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4985 /* This won't actually modify the breakpoint list, but will
4986 physically remove the breakpoints from the child. */
4987 detach_breakpoints (ecs->ws.value.related_pid);
4990 delete_just_stopped_threads_single_step_breakpoints ();
4992 /* In case the event is caught by a catchpoint, remember that
4993 the event is to be followed at the next resume of the thread,
4994 and not immediately. */
4995 ecs->event_thread->pending_follow = ecs->ws;
4997 ecs->event_thread->suspend.stop_pc
4998 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5000 ecs->event_thread->control.stop_bpstat
5001 = bpstat_stop_status (get_current_regcache ()->aspace (),
5002 ecs->event_thread->suspend.stop_pc,
5003 ecs->event_thread, &ecs->ws);
5005 if (handle_stop_requested (ecs))
5008 /* If no catchpoint triggered for this, then keep going. Note
5009 that we're interested in knowing the bpstat actually causes a
5010 stop, not just if it may explain the signal. Software
5011 watchpoints, for example, always appear in the bpstat. */
5012 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5016 = (follow_fork_mode_string == follow_fork_mode_child);
5018 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5020 should_resume = follow_fork ();
5022 thread_info *parent = ecs->event_thread;
5023 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5025 /* At this point, the parent is marked running, and the
5026 child is marked stopped. */
5028 /* If not resuming the parent, mark it stopped. */
5029 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5030 parent->set_running (false);
5032 /* If resuming the child, mark it running. */
5033 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5034 child->set_running (true);
5036 /* In non-stop mode, also resume the other branch. */
5037 if (!detach_fork && (non_stop
5038 || (sched_multi && target_is_non_stop_p ())))
5041 switch_to_thread (parent);
5043 switch_to_thread (child);
5045 ecs->event_thread = inferior_thread ();
5046 ecs->ptid = inferior_ptid;
5051 switch_to_thread (child);
5053 switch_to_thread (parent);
5055 ecs->event_thread = inferior_thread ();
5056 ecs->ptid = inferior_ptid;
5064 process_event_stop_test (ecs);
5067 case TARGET_WAITKIND_VFORK_DONE:
5068 /* Done with the shared memory region. Re-insert breakpoints in
5069 the parent, and keep going. */
5072 fprintf_unfiltered (gdb_stdlog,
5073 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5075 context_switch (ecs);
5077 current_inferior ()->waiting_for_vfork_done = 0;
5078 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5080 if (handle_stop_requested (ecs))
5083 /* This also takes care of reinserting breakpoints in the
5084 previously locked inferior. */
5088 case TARGET_WAITKIND_EXECD:
5090 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5092 /* Note we can't read registers yet (the stop_pc), because we
5093 don't yet know the inferior's post-exec architecture.
5094 'stop_pc' is explicitly read below instead. */
5095 switch_to_thread_no_regs (ecs->event_thread);
5097 /* Do whatever is necessary to the parent branch of the vfork. */
5098 handle_vfork_child_exec_or_exit (1);
5100 /* This causes the eventpoints and symbol table to be reset.
5101 Must do this now, before trying to determine whether to
5103 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5105 /* In follow_exec we may have deleted the original thread and
5106 created a new one. Make sure that the event thread is the
5107 execd thread for that case (this is a nop otherwise). */
5108 ecs->event_thread = inferior_thread ();
5110 ecs->event_thread->suspend.stop_pc
5111 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5113 ecs->event_thread->control.stop_bpstat
5114 = bpstat_stop_status (get_current_regcache ()->aspace (),
5115 ecs->event_thread->suspend.stop_pc,
5116 ecs->event_thread, &ecs->ws);
5118 /* Note that this may be referenced from inside
5119 bpstat_stop_status above, through inferior_has_execd. */
5120 xfree (ecs->ws.value.execd_pathname);
5121 ecs->ws.value.execd_pathname = NULL;
5123 if (handle_stop_requested (ecs))
5126 /* If no catchpoint triggered for this, then keep going. */
5127 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5129 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5133 process_event_stop_test (ecs);
5136 /* Be careful not to try to gather much state about a thread
5137 that's in a syscall. It's frequently a losing proposition. */
5138 case TARGET_WAITKIND_SYSCALL_ENTRY:
5140 fprintf_unfiltered (gdb_stdlog,
5141 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5142 /* Getting the current syscall number. */
5143 if (handle_syscall_event (ecs) == 0)
5144 process_event_stop_test (ecs);
5147 /* Before examining the threads further, step this thread to
5148 get it entirely out of the syscall. (We get notice of the
5149 event when the thread is just on the verge of exiting a
5150 syscall. Stepping one instruction seems to get it back
5152 case TARGET_WAITKIND_SYSCALL_RETURN:
5154 fprintf_unfiltered (gdb_stdlog,
5155 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5156 if (handle_syscall_event (ecs) == 0)
5157 process_event_stop_test (ecs);
5160 case TARGET_WAITKIND_STOPPED:
5162 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5163 handle_signal_stop (ecs);
5166 case TARGET_WAITKIND_NO_HISTORY:
5168 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5169 /* Reverse execution: target ran out of history info. */
5171 /* Switch to the stopped thread. */
5172 context_switch (ecs);
5174 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5176 delete_just_stopped_threads_single_step_breakpoints ();
5177 ecs->event_thread->suspend.stop_pc
5178 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5180 if (handle_stop_requested (ecs))
5183 gdb::observers::no_history.notify ();
5189 /* A wrapper around handle_inferior_event_1, which also makes sure
5190 that all temporary struct value objects that were created during
5191 the handling of the event get deleted at the end. */
5194 handle_inferior_event (struct execution_control_state *ecs)
5196 struct value *mark = value_mark ();
5198 handle_inferior_event_1 (ecs);
5199 /* Purge all temporary values created during the event handling,
5200 as it could be a long time before we return to the command level
5201 where such values would otherwise be purged. */
5202 value_free_to_mark (mark);
5205 /* Restart threads back to what they were trying to do back when we
5206 paused them for an in-line step-over. The EVENT_THREAD thread is
5210 restart_threads (struct thread_info *event_thread)
5212 /* In case the instruction just stepped spawned a new thread. */
5213 update_thread_list ();
5215 for (thread_info *tp : all_non_exited_threads ())
5217 if (tp == event_thread)
5220 fprintf_unfiltered (gdb_stdlog,
5221 "infrun: restart threads: "
5222 "[%s] is event thread\n",
5223 target_pid_to_str (tp->ptid));
5227 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5230 fprintf_unfiltered (gdb_stdlog,
5231 "infrun: restart threads: "
5232 "[%s] not meant to be running\n",
5233 target_pid_to_str (tp->ptid));
5240 fprintf_unfiltered (gdb_stdlog,
5241 "infrun: restart threads: [%s] resumed\n",
5242 target_pid_to_str (tp->ptid));
5243 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5247 if (thread_is_in_step_over_chain (tp))
5250 fprintf_unfiltered (gdb_stdlog,
5251 "infrun: restart threads: "
5252 "[%s] needs step-over\n",
5253 target_pid_to_str (tp->ptid));
5254 gdb_assert (!tp->resumed);
5259 if (tp->suspend.waitstatus_pending_p)
5262 fprintf_unfiltered (gdb_stdlog,
5263 "infrun: restart threads: "
5264 "[%s] has pending status\n",
5265 target_pid_to_str (tp->ptid));
5270 gdb_assert (!tp->stop_requested);
5272 /* If some thread needs to start a step-over at this point, it
5273 should still be in the step-over queue, and thus skipped
5275 if (thread_still_needs_step_over (tp))
5277 internal_error (__FILE__, __LINE__,
5278 "thread [%s] needs a step-over, but not in "
5279 "step-over queue\n",
5280 target_pid_to_str (tp->ptid));
5283 if (currently_stepping (tp))
5286 fprintf_unfiltered (gdb_stdlog,
5287 "infrun: restart threads: [%s] was stepping\n",
5288 target_pid_to_str (tp->ptid));
5289 keep_going_stepped_thread (tp);
5293 struct execution_control_state ecss;
5294 struct execution_control_state *ecs = &ecss;
5297 fprintf_unfiltered (gdb_stdlog,
5298 "infrun: restart threads: [%s] continuing\n",
5299 target_pid_to_str (tp->ptid));
5300 reset_ecs (ecs, tp);
5301 switch_to_thread (tp);
5302 keep_going_pass_signal (ecs);
5307 /* Callback for iterate_over_threads. Find a resumed thread that has
5308 a pending waitstatus. */
5311 resumed_thread_with_pending_status (struct thread_info *tp,
5315 && tp->suspend.waitstatus_pending_p);
5318 /* Called when we get an event that may finish an in-line or
5319 out-of-line (displaced stepping) step-over started previously.
5320 Return true if the event is processed and we should go back to the
5321 event loop; false if the caller should continue processing the
5325 finish_step_over (struct execution_control_state *ecs)
5327 int had_step_over_info;
5329 displaced_step_fixup (ecs->event_thread,
5330 ecs->event_thread->suspend.stop_signal);
5332 had_step_over_info = step_over_info_valid_p ();
5334 if (had_step_over_info)
5336 /* If we're stepping over a breakpoint with all threads locked,
5337 then only the thread that was stepped should be reporting
5339 gdb_assert (ecs->event_thread->control.trap_expected);
5341 clear_step_over_info ();
5344 if (!target_is_non_stop_p ())
5347 /* Start a new step-over in another thread if there's one that
5351 /* If we were stepping over a breakpoint before, and haven't started
5352 a new in-line step-over sequence, then restart all other threads
5353 (except the event thread). We can't do this in all-stop, as then
5354 e.g., we wouldn't be able to issue any other remote packet until
5355 these other threads stop. */
5356 if (had_step_over_info && !step_over_info_valid_p ())
5358 struct thread_info *pending;
5360 /* If we only have threads with pending statuses, the restart
5361 below won't restart any thread and so nothing re-inserts the
5362 breakpoint we just stepped over. But we need it inserted
5363 when we later process the pending events, otherwise if
5364 another thread has a pending event for this breakpoint too,
5365 we'd discard its event (because the breakpoint that
5366 originally caused the event was no longer inserted). */
5367 context_switch (ecs);
5368 insert_breakpoints ();
5370 restart_threads (ecs->event_thread);
5372 /* If we have events pending, go through handle_inferior_event
5373 again, picking up a pending event at random. This avoids
5374 thread starvation. */
5376 /* But not if we just stepped over a watchpoint in order to let
5377 the instruction execute so we can evaluate its expression.
5378 The set of watchpoints that triggered is recorded in the
5379 breakpoint objects themselves (see bp->watchpoint_triggered).
5380 If we processed another event first, that other event could
5381 clobber this info. */
5382 if (ecs->event_thread->stepping_over_watchpoint)
5385 pending = iterate_over_threads (resumed_thread_with_pending_status,
5387 if (pending != NULL)
5389 struct thread_info *tp = ecs->event_thread;
5390 struct regcache *regcache;
5394 fprintf_unfiltered (gdb_stdlog,
5395 "infrun: found resumed threads with "
5396 "pending events, saving status\n");
5399 gdb_assert (pending != tp);
5401 /* Record the event thread's event for later. */
5402 save_waitstatus (tp, &ecs->ws);
5403 /* This was cleared early, by handle_inferior_event. Set it
5404 so this pending event is considered by
5408 gdb_assert (!tp->executing);
5410 regcache = get_thread_regcache (tp);
5411 tp->suspend.stop_pc = regcache_read_pc (regcache);
5415 fprintf_unfiltered (gdb_stdlog,
5416 "infrun: saved stop_pc=%s for %s "
5417 "(currently_stepping=%d)\n",
5418 paddress (target_gdbarch (),
5419 tp->suspend.stop_pc),
5420 target_pid_to_str (tp->ptid),
5421 currently_stepping (tp));
5424 /* This in-line step-over finished; clear this so we won't
5425 start a new one. This is what handle_signal_stop would
5426 do, if we returned false. */
5427 tp->stepping_over_breakpoint = 0;
5429 /* Wake up the event loop again. */
5430 mark_async_event_handler (infrun_async_inferior_event_token);
5432 prepare_to_wait (ecs);
5440 /* Come here when the program has stopped with a signal. */
5443 handle_signal_stop (struct execution_control_state *ecs)
5445 struct frame_info *frame;
5446 struct gdbarch *gdbarch;
5447 int stopped_by_watchpoint;
5448 enum stop_kind stop_soon;
5451 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5453 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5455 /* Do we need to clean up the state of a thread that has
5456 completed a displaced single-step? (Doing so usually affects
5457 the PC, so do it here, before we set stop_pc.) */
5458 if (finish_step_over (ecs))
5461 /* If we either finished a single-step or hit a breakpoint, but
5462 the user wanted this thread to be stopped, pretend we got a
5463 SIG0 (generic unsignaled stop). */
5464 if (ecs->event_thread->stop_requested
5465 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5466 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5468 ecs->event_thread->suspend.stop_pc
5469 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5473 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5474 struct gdbarch *reg_gdbarch = regcache->arch ();
5475 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5477 inferior_ptid = ecs->ptid;
5479 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5480 paddress (reg_gdbarch,
5481 ecs->event_thread->suspend.stop_pc));
5482 if (target_stopped_by_watchpoint ())
5486 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5488 if (target_stopped_data_address (current_top_target (), &addr))
5489 fprintf_unfiltered (gdb_stdlog,
5490 "infrun: stopped data address = %s\n",
5491 paddress (reg_gdbarch, addr));
5493 fprintf_unfiltered (gdb_stdlog,
5494 "infrun: (no data address available)\n");
5498 /* This is originated from start_remote(), start_inferior() and
5499 shared libraries hook functions. */
5500 stop_soon = get_inferior_stop_soon (ecs);
5501 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5503 context_switch (ecs);
5505 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5506 stop_print_frame = 1;
5511 /* This originates from attach_command(). We need to overwrite
5512 the stop_signal here, because some kernels don't ignore a
5513 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5514 See more comments in inferior.h. On the other hand, if we
5515 get a non-SIGSTOP, report it to the user - assume the backend
5516 will handle the SIGSTOP if it should show up later.
5518 Also consider that the attach is complete when we see a
5519 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5520 target extended-remote report it instead of a SIGSTOP
5521 (e.g. gdbserver). We already rely on SIGTRAP being our
5522 signal, so this is no exception.
5524 Also consider that the attach is complete when we see a
5525 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5526 the target to stop all threads of the inferior, in case the
5527 low level attach operation doesn't stop them implicitly. If
5528 they weren't stopped implicitly, then the stub will report a
5529 GDB_SIGNAL_0, meaning: stopped for no particular reason
5530 other than GDB's request. */
5531 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5532 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5533 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5534 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5536 stop_print_frame = 1;
5538 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5542 /* See if something interesting happened to the non-current thread. If
5543 so, then switch to that thread. */
5544 if (ecs->ptid != inferior_ptid)
5547 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5549 context_switch (ecs);
5551 if (deprecated_context_hook)
5552 deprecated_context_hook (ecs->event_thread->global_num);
5555 /* At this point, get hold of the now-current thread's frame. */
5556 frame = get_current_frame ();
5557 gdbarch = get_frame_arch (frame);
5559 /* Pull the single step breakpoints out of the target. */
5560 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5562 struct regcache *regcache;
5565 regcache = get_thread_regcache (ecs->event_thread);
5566 const address_space *aspace = regcache->aspace ();
5568 pc = regcache_read_pc (regcache);
5570 /* However, before doing so, if this single-step breakpoint was
5571 actually for another thread, set this thread up for moving
5573 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5576 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5580 fprintf_unfiltered (gdb_stdlog,
5581 "infrun: [%s] hit another thread's "
5582 "single-step breakpoint\n",
5583 target_pid_to_str (ecs->ptid));
5585 ecs->hit_singlestep_breakpoint = 1;
5592 fprintf_unfiltered (gdb_stdlog,
5593 "infrun: [%s] hit its "
5594 "single-step breakpoint\n",
5595 target_pid_to_str (ecs->ptid));
5599 delete_just_stopped_threads_single_step_breakpoints ();
5601 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5602 && ecs->event_thread->control.trap_expected
5603 && ecs->event_thread->stepping_over_watchpoint)
5604 stopped_by_watchpoint = 0;
5606 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5608 /* If necessary, step over this watchpoint. We'll be back to display
5610 if (stopped_by_watchpoint
5611 && (target_have_steppable_watchpoint
5612 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5614 /* At this point, we are stopped at an instruction which has
5615 attempted to write to a piece of memory under control of
5616 a watchpoint. The instruction hasn't actually executed
5617 yet. If we were to evaluate the watchpoint expression
5618 now, we would get the old value, and therefore no change
5619 would seem to have occurred.
5621 In order to make watchpoints work `right', we really need
5622 to complete the memory write, and then evaluate the
5623 watchpoint expression. We do this by single-stepping the
5626 It may not be necessary to disable the watchpoint to step over
5627 it. For example, the PA can (with some kernel cooperation)
5628 single step over a watchpoint without disabling the watchpoint.
5630 It is far more common to need to disable a watchpoint to step
5631 the inferior over it. If we have non-steppable watchpoints,
5632 we must disable the current watchpoint; it's simplest to
5633 disable all watchpoints.
5635 Any breakpoint at PC must also be stepped over -- if there's
5636 one, it will have already triggered before the watchpoint
5637 triggered, and we either already reported it to the user, or
5638 it didn't cause a stop and we called keep_going. In either
5639 case, if there was a breakpoint at PC, we must be trying to
5641 ecs->event_thread->stepping_over_watchpoint = 1;
5646 ecs->event_thread->stepping_over_breakpoint = 0;
5647 ecs->event_thread->stepping_over_watchpoint = 0;
5648 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5649 ecs->event_thread->control.stop_step = 0;
5650 stop_print_frame = 1;
5651 stopped_by_random_signal = 0;
5652 bpstat stop_chain = NULL;
5654 /* Hide inlined functions starting here, unless we just performed stepi or
5655 nexti. After stepi and nexti, always show the innermost frame (not any
5656 inline function call sites). */
5657 if (ecs->event_thread->control.step_range_end != 1)
5659 const address_space *aspace
5660 = get_thread_regcache (ecs->event_thread)->aspace ();
5662 /* skip_inline_frames is expensive, so we avoid it if we can
5663 determine that the address is one where functions cannot have
5664 been inlined. This improves performance with inferiors that
5665 load a lot of shared libraries, because the solib event
5666 breakpoint is defined as the address of a function (i.e. not
5667 inline). Note that we have to check the previous PC as well
5668 as the current one to catch cases when we have just
5669 single-stepped off a breakpoint prior to reinstating it.
5670 Note that we're assuming that the code we single-step to is
5671 not inline, but that's not definitive: there's nothing
5672 preventing the event breakpoint function from containing
5673 inlined code, and the single-step ending up there. If the
5674 user had set a breakpoint on that inlined code, the missing
5675 skip_inline_frames call would break things. Fortunately
5676 that's an extremely unlikely scenario. */
5677 if (!pc_at_non_inline_function (aspace,
5678 ecs->event_thread->suspend.stop_pc,
5680 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5681 && ecs->event_thread->control.trap_expected
5682 && pc_at_non_inline_function (aspace,
5683 ecs->event_thread->prev_pc,
5686 stop_chain = build_bpstat_chain (aspace,
5687 ecs->event_thread->suspend.stop_pc,
5689 skip_inline_frames (ecs->event_thread, stop_chain);
5691 /* Re-fetch current thread's frame in case that invalidated
5693 frame = get_current_frame ();
5694 gdbarch = get_frame_arch (frame);
5698 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5699 && ecs->event_thread->control.trap_expected
5700 && gdbarch_single_step_through_delay_p (gdbarch)
5701 && currently_stepping (ecs->event_thread))
5703 /* We're trying to step off a breakpoint. Turns out that we're
5704 also on an instruction that needs to be stepped multiple
5705 times before it's been fully executing. E.g., architectures
5706 with a delay slot. It needs to be stepped twice, once for
5707 the instruction and once for the delay slot. */
5708 int step_through_delay
5709 = gdbarch_single_step_through_delay (gdbarch, frame);
5711 if (debug_infrun && step_through_delay)
5712 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5713 if (ecs->event_thread->control.step_range_end == 0
5714 && step_through_delay)
5716 /* The user issued a continue when stopped at a breakpoint.
5717 Set up for another trap and get out of here. */
5718 ecs->event_thread->stepping_over_breakpoint = 1;
5722 else if (step_through_delay)
5724 /* The user issued a step when stopped at a breakpoint.
5725 Maybe we should stop, maybe we should not - the delay
5726 slot *might* correspond to a line of source. In any
5727 case, don't decide that here, just set
5728 ecs->stepping_over_breakpoint, making sure we
5729 single-step again before breakpoints are re-inserted. */
5730 ecs->event_thread->stepping_over_breakpoint = 1;
5734 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5735 handles this event. */
5736 ecs->event_thread->control.stop_bpstat
5737 = bpstat_stop_status (get_current_regcache ()->aspace (),
5738 ecs->event_thread->suspend.stop_pc,
5739 ecs->event_thread, &ecs->ws, stop_chain);
5741 /* Following in case break condition called a
5743 stop_print_frame = 1;
5745 /* This is where we handle "moribund" watchpoints. Unlike
5746 software breakpoints traps, hardware watchpoint traps are
5747 always distinguishable from random traps. If no high-level
5748 watchpoint is associated with the reported stop data address
5749 anymore, then the bpstat does not explain the signal ---
5750 simply make sure to ignore it if `stopped_by_watchpoint' is
5754 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5755 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5757 && stopped_by_watchpoint)
5758 fprintf_unfiltered (gdb_stdlog,
5759 "infrun: no user watchpoint explains "
5760 "watchpoint SIGTRAP, ignoring\n");
5762 /* NOTE: cagney/2003-03-29: These checks for a random signal
5763 at one stage in the past included checks for an inferior
5764 function call's call dummy's return breakpoint. The original
5765 comment, that went with the test, read:
5767 ``End of a stack dummy. Some systems (e.g. Sony news) give
5768 another signal besides SIGTRAP, so check here as well as
5771 If someone ever tries to get call dummys on a
5772 non-executable stack to work (where the target would stop
5773 with something like a SIGSEGV), then those tests might need
5774 to be re-instated. Given, however, that the tests were only
5775 enabled when momentary breakpoints were not being used, I
5776 suspect that it won't be the case.
5778 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5779 be necessary for call dummies on a non-executable stack on
5782 /* See if the breakpoints module can explain the signal. */
5784 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5785 ecs->event_thread->suspend.stop_signal);
5787 /* Maybe this was a trap for a software breakpoint that has since
5789 if (random_signal && target_stopped_by_sw_breakpoint ())
5791 if (program_breakpoint_here_p (gdbarch,
5792 ecs->event_thread->suspend.stop_pc))
5794 struct regcache *regcache;
5797 /* Re-adjust PC to what the program would see if GDB was not
5799 regcache = get_thread_regcache (ecs->event_thread);
5800 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5803 gdb::optional<scoped_restore_tmpl<int>>
5804 restore_operation_disable;
5806 if (record_full_is_used ())
5807 restore_operation_disable.emplace
5808 (record_full_gdb_operation_disable_set ());
5810 regcache_write_pc (regcache,
5811 ecs->event_thread->suspend.stop_pc + decr_pc);
5816 /* A delayed software breakpoint event. Ignore the trap. */
5818 fprintf_unfiltered (gdb_stdlog,
5819 "infrun: delayed software breakpoint "
5820 "trap, ignoring\n");
5825 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5826 has since been removed. */
5827 if (random_signal && target_stopped_by_hw_breakpoint ())
5829 /* A delayed hardware breakpoint event. Ignore the trap. */
5831 fprintf_unfiltered (gdb_stdlog,
5832 "infrun: delayed hardware breakpoint/watchpoint "
5833 "trap, ignoring\n");
5837 /* If not, perhaps stepping/nexting can. */
5839 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5840 && currently_stepping (ecs->event_thread));
5842 /* Perhaps the thread hit a single-step breakpoint of _another_
5843 thread. Single-step breakpoints are transparent to the
5844 breakpoints module. */
5846 random_signal = !ecs->hit_singlestep_breakpoint;
5848 /* No? Perhaps we got a moribund watchpoint. */
5850 random_signal = !stopped_by_watchpoint;
5852 /* Always stop if the user explicitly requested this thread to
5854 if (ecs->event_thread->stop_requested)
5858 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
5861 /* For the program's own signals, act according to
5862 the signal handling tables. */
5866 /* Signal not for debugging purposes. */
5867 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5868 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5871 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5872 gdb_signal_to_symbol_string (stop_signal));
5874 stopped_by_random_signal = 1;
5876 /* Always stop on signals if we're either just gaining control
5877 of the program, or the user explicitly requested this thread
5878 to remain stopped. */
5879 if (stop_soon != NO_STOP_QUIETLY
5880 || ecs->event_thread->stop_requested
5882 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5888 /* Notify observers the signal has "handle print" set. Note we
5889 returned early above if stopping; normal_stop handles the
5890 printing in that case. */
5891 if (signal_print[ecs->event_thread->suspend.stop_signal])
5893 /* The signal table tells us to print about this signal. */
5894 target_terminal::ours_for_output ();
5895 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
5896 target_terminal::inferior ();
5899 /* Clear the signal if it should not be passed. */
5900 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5901 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5903 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
5904 && ecs->event_thread->control.trap_expected
5905 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5907 /* We were just starting a new sequence, attempting to
5908 single-step off of a breakpoint and expecting a SIGTRAP.
5909 Instead this signal arrives. This signal will take us out
5910 of the stepping range so GDB needs to remember to, when
5911 the signal handler returns, resume stepping off that
5913 /* To simplify things, "continue" is forced to use the same
5914 code paths as single-step - set a breakpoint at the
5915 signal return address and then, once hit, step off that
5918 fprintf_unfiltered (gdb_stdlog,
5919 "infrun: signal arrived while stepping over "
5922 insert_hp_step_resume_breakpoint_at_frame (frame);
5923 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5924 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5925 ecs->event_thread->control.trap_expected = 0;
5927 /* If we were nexting/stepping some other thread, switch to
5928 it, so that we don't continue it, losing control. */
5929 if (!switch_back_to_stepped_thread (ecs))
5934 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5935 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
5937 || ecs->event_thread->control.step_range_end == 1)
5938 && frame_id_eq (get_stack_frame_id (frame),
5939 ecs->event_thread->control.step_stack_frame_id)
5940 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5942 /* The inferior is about to take a signal that will take it
5943 out of the single step range. Set a breakpoint at the
5944 current PC (which is presumably where the signal handler
5945 will eventually return) and then allow the inferior to
5948 Note that this is only needed for a signal delivered
5949 while in the single-step range. Nested signals aren't a
5950 problem as they eventually all return. */
5952 fprintf_unfiltered (gdb_stdlog,
5953 "infrun: signal may take us out of "
5954 "single-step range\n");
5956 clear_step_over_info ();
5957 insert_hp_step_resume_breakpoint_at_frame (frame);
5958 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5959 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5960 ecs->event_thread->control.trap_expected = 0;
5965 /* Note: step_resume_breakpoint may be non-NULL. This occures
5966 when either there's a nested signal, or when there's a
5967 pending signal enabled just as the signal handler returns
5968 (leaving the inferior at the step-resume-breakpoint without
5969 actually executing it). Either way continue until the
5970 breakpoint is really hit. */
5972 if (!switch_back_to_stepped_thread (ecs))
5975 fprintf_unfiltered (gdb_stdlog,
5976 "infrun: random signal, keep going\n");
5983 process_event_stop_test (ecs);
5986 /* Come here when we've got some debug event / signal we can explain
5987 (IOW, not a random signal), and test whether it should cause a
5988 stop, or whether we should resume the inferior (transparently).
5989 E.g., could be a breakpoint whose condition evaluates false; we
5990 could be still stepping within the line; etc. */
5993 process_event_stop_test (struct execution_control_state *ecs)
5995 struct symtab_and_line stop_pc_sal;
5996 struct frame_info *frame;
5997 struct gdbarch *gdbarch;
5998 CORE_ADDR jmp_buf_pc;
5999 struct bpstat_what what;
6001 /* Handle cases caused by hitting a breakpoint. */
6003 frame = get_current_frame ();
6004 gdbarch = get_frame_arch (frame);
6006 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6008 if (what.call_dummy)
6010 stop_stack_dummy = what.call_dummy;
6013 /* A few breakpoint types have callbacks associated (e.g.,
6014 bp_jit_event). Run them now. */
6015 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6017 /* If we hit an internal event that triggers symbol changes, the
6018 current frame will be invalidated within bpstat_what (e.g., if we
6019 hit an internal solib event). Re-fetch it. */
6020 frame = get_current_frame ();
6021 gdbarch = get_frame_arch (frame);
6023 switch (what.main_action)
6025 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6026 /* If we hit the breakpoint at longjmp while stepping, we
6027 install a momentary breakpoint at the target of the
6031 fprintf_unfiltered (gdb_stdlog,
6032 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6034 ecs->event_thread->stepping_over_breakpoint = 1;
6036 if (what.is_longjmp)
6038 struct value *arg_value;
6040 /* If we set the longjmp breakpoint via a SystemTap probe,
6041 then use it to extract the arguments. The destination PC
6042 is the third argument to the probe. */
6043 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6046 jmp_buf_pc = value_as_address (arg_value);
6047 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6049 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6050 || !gdbarch_get_longjmp_target (gdbarch,
6051 frame, &jmp_buf_pc))
6054 fprintf_unfiltered (gdb_stdlog,
6055 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6056 "(!gdbarch_get_longjmp_target)\n");
6061 /* Insert a breakpoint at resume address. */
6062 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6065 check_exception_resume (ecs, frame);
6069 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6071 struct frame_info *init_frame;
6073 /* There are several cases to consider.
6075 1. The initiating frame no longer exists. In this case we
6076 must stop, because the exception or longjmp has gone too
6079 2. The initiating frame exists, and is the same as the
6080 current frame. We stop, because the exception or longjmp
6083 3. The initiating frame exists and is different from the
6084 current frame. This means the exception or longjmp has
6085 been caught beneath the initiating frame, so keep going.
6087 4. longjmp breakpoint has been placed just to protect
6088 against stale dummy frames and user is not interested in
6089 stopping around longjmps. */
6092 fprintf_unfiltered (gdb_stdlog,
6093 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6095 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6097 delete_exception_resume_breakpoint (ecs->event_thread);
6099 if (what.is_longjmp)
6101 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6103 if (!frame_id_p (ecs->event_thread->initiating_frame))
6111 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6115 struct frame_id current_id
6116 = get_frame_id (get_current_frame ());
6117 if (frame_id_eq (current_id,
6118 ecs->event_thread->initiating_frame))
6120 /* Case 2. Fall through. */
6130 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6132 delete_step_resume_breakpoint (ecs->event_thread);
6134 end_stepping_range (ecs);
6138 case BPSTAT_WHAT_SINGLE:
6140 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6141 ecs->event_thread->stepping_over_breakpoint = 1;
6142 /* Still need to check other stuff, at least the case where we
6143 are stepping and step out of the right range. */
6146 case BPSTAT_WHAT_STEP_RESUME:
6148 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6150 delete_step_resume_breakpoint (ecs->event_thread);
6151 if (ecs->event_thread->control.proceed_to_finish
6152 && execution_direction == EXEC_REVERSE)
6154 struct thread_info *tp = ecs->event_thread;
6156 /* We are finishing a function in reverse, and just hit the
6157 step-resume breakpoint at the start address of the
6158 function, and we're almost there -- just need to back up
6159 by one more single-step, which should take us back to the
6161 tp->control.step_range_start = tp->control.step_range_end = 1;
6165 fill_in_stop_func (gdbarch, ecs);
6166 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6167 && execution_direction == EXEC_REVERSE)
6169 /* We are stepping over a function call in reverse, and just
6170 hit the step-resume breakpoint at the start address of
6171 the function. Go back to single-stepping, which should
6172 take us back to the function call. */
6173 ecs->event_thread->stepping_over_breakpoint = 1;
6179 case BPSTAT_WHAT_STOP_NOISY:
6181 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6182 stop_print_frame = 1;
6184 /* Assume the thread stopped for a breapoint. We'll still check
6185 whether a/the breakpoint is there when the thread is next
6187 ecs->event_thread->stepping_over_breakpoint = 1;
6192 case BPSTAT_WHAT_STOP_SILENT:
6194 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6195 stop_print_frame = 0;
6197 /* Assume the thread stopped for a breapoint. We'll still check
6198 whether a/the breakpoint is there when the thread is next
6200 ecs->event_thread->stepping_over_breakpoint = 1;
6204 case BPSTAT_WHAT_HP_STEP_RESUME:
6206 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6208 delete_step_resume_breakpoint (ecs->event_thread);
6209 if (ecs->event_thread->step_after_step_resume_breakpoint)
6211 /* Back when the step-resume breakpoint was inserted, we
6212 were trying to single-step off a breakpoint. Go back to
6214 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6215 ecs->event_thread->stepping_over_breakpoint = 1;
6221 case BPSTAT_WHAT_KEEP_CHECKING:
6225 /* If we stepped a permanent breakpoint and we had a high priority
6226 step-resume breakpoint for the address we stepped, but we didn't
6227 hit it, then we must have stepped into the signal handler. The
6228 step-resume was only necessary to catch the case of _not_
6229 stepping into the handler, so delete it, and fall through to
6230 checking whether the step finished. */
6231 if (ecs->event_thread->stepped_breakpoint)
6233 struct breakpoint *sr_bp
6234 = ecs->event_thread->control.step_resume_breakpoint;
6237 && sr_bp->loc->permanent
6238 && sr_bp->type == bp_hp_step_resume
6239 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6242 fprintf_unfiltered (gdb_stdlog,
6243 "infrun: stepped permanent breakpoint, stopped in "
6245 delete_step_resume_breakpoint (ecs->event_thread);
6246 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6250 /* We come here if we hit a breakpoint but should not stop for it.
6251 Possibly we also were stepping and should stop for that. So fall
6252 through and test for stepping. But, if not stepping, do not
6255 /* In all-stop mode, if we're currently stepping but have stopped in
6256 some other thread, we need to switch back to the stepped thread. */
6257 if (switch_back_to_stepped_thread (ecs))
6260 if (ecs->event_thread->control.step_resume_breakpoint)
6263 fprintf_unfiltered (gdb_stdlog,
6264 "infrun: step-resume breakpoint is inserted\n");
6266 /* Having a step-resume breakpoint overrides anything
6267 else having to do with stepping commands until
6268 that breakpoint is reached. */
6273 if (ecs->event_thread->control.step_range_end == 0)
6276 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6277 /* Likewise if we aren't even stepping. */
6282 /* Re-fetch current thread's frame in case the code above caused
6283 the frame cache to be re-initialized, making our FRAME variable
6284 a dangling pointer. */
6285 frame = get_current_frame ();
6286 gdbarch = get_frame_arch (frame);
6287 fill_in_stop_func (gdbarch, ecs);
6289 /* If stepping through a line, keep going if still within it.
6291 Note that step_range_end is the address of the first instruction
6292 beyond the step range, and NOT the address of the last instruction
6295 Note also that during reverse execution, we may be stepping
6296 through a function epilogue and therefore must detect when
6297 the current-frame changes in the middle of a line. */
6299 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6301 && (execution_direction != EXEC_REVERSE
6302 || frame_id_eq (get_frame_id (frame),
6303 ecs->event_thread->control.step_frame_id)))
6307 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6308 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6309 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6311 /* Tentatively re-enable range stepping; `resume' disables it if
6312 necessary (e.g., if we're stepping over a breakpoint or we
6313 have software watchpoints). */
6314 ecs->event_thread->control.may_range_step = 1;
6316 /* When stepping backward, stop at beginning of line range
6317 (unless it's the function entry point, in which case
6318 keep going back to the call point). */
6319 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6320 if (stop_pc == ecs->event_thread->control.step_range_start
6321 && stop_pc != ecs->stop_func_start
6322 && execution_direction == EXEC_REVERSE)
6323 end_stepping_range (ecs);
6330 /* We stepped out of the stepping range. */
6332 /* If we are stepping at the source level and entered the runtime
6333 loader dynamic symbol resolution code...
6335 EXEC_FORWARD: we keep on single stepping until we exit the run
6336 time loader code and reach the callee's address.
6338 EXEC_REVERSE: we've already executed the callee (backward), and
6339 the runtime loader code is handled just like any other
6340 undebuggable function call. Now we need only keep stepping
6341 backward through the trampoline code, and that's handled further
6342 down, so there is nothing for us to do here. */
6344 if (execution_direction != EXEC_REVERSE
6345 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6346 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6348 CORE_ADDR pc_after_resolver =
6349 gdbarch_skip_solib_resolver (gdbarch,
6350 ecs->event_thread->suspend.stop_pc);
6353 fprintf_unfiltered (gdb_stdlog,
6354 "infrun: stepped into dynsym resolve code\n");
6356 if (pc_after_resolver)
6358 /* Set up a step-resume breakpoint at the address
6359 indicated by SKIP_SOLIB_RESOLVER. */
6360 symtab_and_line sr_sal;
6361 sr_sal.pc = pc_after_resolver;
6362 sr_sal.pspace = get_frame_program_space (frame);
6364 insert_step_resume_breakpoint_at_sal (gdbarch,
6365 sr_sal, null_frame_id);
6372 /* Step through an indirect branch thunk. */
6373 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6374 && gdbarch_in_indirect_branch_thunk (gdbarch,
6375 ecs->event_thread->suspend.stop_pc))
6378 fprintf_unfiltered (gdb_stdlog,
6379 "infrun: stepped into indirect branch thunk\n");
6384 if (ecs->event_thread->control.step_range_end != 1
6385 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6386 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6387 && get_frame_type (frame) == SIGTRAMP_FRAME)
6390 fprintf_unfiltered (gdb_stdlog,
6391 "infrun: stepped into signal trampoline\n");
6392 /* The inferior, while doing a "step" or "next", has ended up in
6393 a signal trampoline (either by a signal being delivered or by
6394 the signal handler returning). Just single-step until the
6395 inferior leaves the trampoline (either by calling the handler
6401 /* If we're in the return path from a shared library trampoline,
6402 we want to proceed through the trampoline when stepping. */
6403 /* macro/2012-04-25: This needs to come before the subroutine
6404 call check below as on some targets return trampolines look
6405 like subroutine calls (MIPS16 return thunks). */
6406 if (gdbarch_in_solib_return_trampoline (gdbarch,
6407 ecs->event_thread->suspend.stop_pc,
6408 ecs->stop_func_name)
6409 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6411 /* Determine where this trampoline returns. */
6412 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6413 CORE_ADDR real_stop_pc
6414 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6417 fprintf_unfiltered (gdb_stdlog,
6418 "infrun: stepped into solib return tramp\n");
6420 /* Only proceed through if we know where it's going. */
6423 /* And put the step-breakpoint there and go until there. */
6424 symtab_and_line sr_sal;
6425 sr_sal.pc = real_stop_pc;
6426 sr_sal.section = find_pc_overlay (sr_sal.pc);
6427 sr_sal.pspace = get_frame_program_space (frame);
6429 /* Do not specify what the fp should be when we stop since
6430 on some machines the prologue is where the new fp value
6432 insert_step_resume_breakpoint_at_sal (gdbarch,
6433 sr_sal, null_frame_id);
6435 /* Restart without fiddling with the step ranges or
6442 /* Check for subroutine calls. The check for the current frame
6443 equalling the step ID is not necessary - the check of the
6444 previous frame's ID is sufficient - but it is a common case and
6445 cheaper than checking the previous frame's ID.
6447 NOTE: frame_id_eq will never report two invalid frame IDs as
6448 being equal, so to get into this block, both the current and
6449 previous frame must have valid frame IDs. */
6450 /* The outer_frame_id check is a heuristic to detect stepping
6451 through startup code. If we step over an instruction which
6452 sets the stack pointer from an invalid value to a valid value,
6453 we may detect that as a subroutine call from the mythical
6454 "outermost" function. This could be fixed by marking
6455 outermost frames as !stack_p,code_p,special_p. Then the
6456 initial outermost frame, before sp was valid, would
6457 have code_addr == &_start. See the comment in frame_id_eq
6459 if (!frame_id_eq (get_stack_frame_id (frame),
6460 ecs->event_thread->control.step_stack_frame_id)
6461 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6462 ecs->event_thread->control.step_stack_frame_id)
6463 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6465 || (ecs->event_thread->control.step_start_function
6466 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6468 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6469 CORE_ADDR real_stop_pc;
6472 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6474 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6476 /* I presume that step_over_calls is only 0 when we're
6477 supposed to be stepping at the assembly language level
6478 ("stepi"). Just stop. */
6479 /* And this works the same backward as frontward. MVS */
6480 end_stepping_range (ecs);
6484 /* Reverse stepping through solib trampolines. */
6486 if (execution_direction == EXEC_REVERSE
6487 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6488 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6489 || (ecs->stop_func_start == 0
6490 && in_solib_dynsym_resolve_code (stop_pc))))
6492 /* Any solib trampoline code can be handled in reverse
6493 by simply continuing to single-step. We have already
6494 executed the solib function (backwards), and a few
6495 steps will take us back through the trampoline to the
6501 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6503 /* We're doing a "next".
6505 Normal (forward) execution: set a breakpoint at the
6506 callee's return address (the address at which the caller
6509 Reverse (backward) execution. set the step-resume
6510 breakpoint at the start of the function that we just
6511 stepped into (backwards), and continue to there. When we
6512 get there, we'll need to single-step back to the caller. */
6514 if (execution_direction == EXEC_REVERSE)
6516 /* If we're already at the start of the function, we've either
6517 just stepped backward into a single instruction function,
6518 or stepped back out of a signal handler to the first instruction
6519 of the function. Just keep going, which will single-step back
6521 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6523 /* Normal function call return (static or dynamic). */
6524 symtab_and_line sr_sal;
6525 sr_sal.pc = ecs->stop_func_start;
6526 sr_sal.pspace = get_frame_program_space (frame);
6527 insert_step_resume_breakpoint_at_sal (gdbarch,
6528 sr_sal, null_frame_id);
6532 insert_step_resume_breakpoint_at_caller (frame);
6538 /* If we are in a function call trampoline (a stub between the
6539 calling routine and the real function), locate the real
6540 function. That's what tells us (a) whether we want to step
6541 into it at all, and (b) what prologue we want to run to the
6542 end of, if we do step into it. */
6543 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6544 if (real_stop_pc == 0)
6545 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6546 if (real_stop_pc != 0)
6547 ecs->stop_func_start = real_stop_pc;
6549 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6551 symtab_and_line sr_sal;
6552 sr_sal.pc = ecs->stop_func_start;
6553 sr_sal.pspace = get_frame_program_space (frame);
6555 insert_step_resume_breakpoint_at_sal (gdbarch,
6556 sr_sal, null_frame_id);
6561 /* If we have line number information for the function we are
6562 thinking of stepping into and the function isn't on the skip
6565 If there are several symtabs at that PC (e.g. with include
6566 files), just want to know whether *any* of them have line
6567 numbers. find_pc_line handles this. */
6569 struct symtab_and_line tmp_sal;
6571 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6572 if (tmp_sal.line != 0
6573 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6576 if (execution_direction == EXEC_REVERSE)
6577 handle_step_into_function_backward (gdbarch, ecs);
6579 handle_step_into_function (gdbarch, ecs);
6584 /* If we have no line number and the step-stop-if-no-debug is
6585 set, we stop the step so that the user has a chance to switch
6586 in assembly mode. */
6587 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6588 && step_stop_if_no_debug)
6590 end_stepping_range (ecs);
6594 if (execution_direction == EXEC_REVERSE)
6596 /* If we're already at the start of the function, we've either just
6597 stepped backward into a single instruction function without line
6598 number info, or stepped back out of a signal handler to the first
6599 instruction of the function without line number info. Just keep
6600 going, which will single-step back to the caller. */
6601 if (ecs->stop_func_start != stop_pc)
6603 /* Set a breakpoint at callee's start address.
6604 From there we can step once and be back in the caller. */
6605 symtab_and_line sr_sal;
6606 sr_sal.pc = ecs->stop_func_start;
6607 sr_sal.pspace = get_frame_program_space (frame);
6608 insert_step_resume_breakpoint_at_sal (gdbarch,
6609 sr_sal, null_frame_id);
6613 /* Set a breakpoint at callee's return address (the address
6614 at which the caller will resume). */
6615 insert_step_resume_breakpoint_at_caller (frame);
6621 /* Reverse stepping through solib trampolines. */
6623 if (execution_direction == EXEC_REVERSE
6624 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6626 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6628 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6629 || (ecs->stop_func_start == 0
6630 && in_solib_dynsym_resolve_code (stop_pc)))
6632 /* Any solib trampoline code can be handled in reverse
6633 by simply continuing to single-step. We have already
6634 executed the solib function (backwards), and a few
6635 steps will take us back through the trampoline to the
6640 else if (in_solib_dynsym_resolve_code (stop_pc))
6642 /* Stepped backward into the solib dynsym resolver.
6643 Set a breakpoint at its start and continue, then
6644 one more step will take us out. */
6645 symtab_and_line sr_sal;
6646 sr_sal.pc = ecs->stop_func_start;
6647 sr_sal.pspace = get_frame_program_space (frame);
6648 insert_step_resume_breakpoint_at_sal (gdbarch,
6649 sr_sal, null_frame_id);
6655 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6657 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6658 the trampoline processing logic, however, there are some trampolines
6659 that have no names, so we should do trampoline handling first. */
6660 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6661 && ecs->stop_func_name == NULL
6662 && stop_pc_sal.line == 0)
6665 fprintf_unfiltered (gdb_stdlog,
6666 "infrun: stepped into undebuggable function\n");
6668 /* The inferior just stepped into, or returned to, an
6669 undebuggable function (where there is no debugging information
6670 and no line number corresponding to the address where the
6671 inferior stopped). Since we want to skip this kind of code,
6672 we keep going until the inferior returns from this
6673 function - unless the user has asked us not to (via
6674 set step-mode) or we no longer know how to get back
6675 to the call site. */
6676 if (step_stop_if_no_debug
6677 || !frame_id_p (frame_unwind_caller_id (frame)))
6679 /* If we have no line number and the step-stop-if-no-debug
6680 is set, we stop the step so that the user has a chance to
6681 switch in assembly mode. */
6682 end_stepping_range (ecs);
6687 /* Set a breakpoint at callee's return address (the address
6688 at which the caller will resume). */
6689 insert_step_resume_breakpoint_at_caller (frame);
6695 if (ecs->event_thread->control.step_range_end == 1)
6697 /* It is stepi or nexti. We always want to stop stepping after
6700 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6701 end_stepping_range (ecs);
6705 if (stop_pc_sal.line == 0)
6707 /* We have no line number information. That means to stop
6708 stepping (does this always happen right after one instruction,
6709 when we do "s" in a function with no line numbers,
6710 or can this happen as a result of a return or longjmp?). */
6712 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6713 end_stepping_range (ecs);
6717 /* Look for "calls" to inlined functions, part one. If the inline
6718 frame machinery detected some skipped call sites, we have entered
6719 a new inline function. */
6721 if (frame_id_eq (get_frame_id (get_current_frame ()),
6722 ecs->event_thread->control.step_frame_id)
6723 && inline_skipped_frames (ecs->event_thread))
6726 fprintf_unfiltered (gdb_stdlog,
6727 "infrun: stepped into inlined function\n");
6729 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6731 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6733 /* For "step", we're going to stop. But if the call site
6734 for this inlined function is on the same source line as
6735 we were previously stepping, go down into the function
6736 first. Otherwise stop at the call site. */
6738 if (call_sal.line == ecs->event_thread->current_line
6739 && call_sal.symtab == ecs->event_thread->current_symtab)
6740 step_into_inline_frame (ecs->event_thread);
6742 end_stepping_range (ecs);
6747 /* For "next", we should stop at the call site if it is on a
6748 different source line. Otherwise continue through the
6749 inlined function. */
6750 if (call_sal.line == ecs->event_thread->current_line
6751 && call_sal.symtab == ecs->event_thread->current_symtab)
6754 end_stepping_range (ecs);
6759 /* Look for "calls" to inlined functions, part two. If we are still
6760 in the same real function we were stepping through, but we have
6761 to go further up to find the exact frame ID, we are stepping
6762 through a more inlined call beyond its call site. */
6764 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6765 && !frame_id_eq (get_frame_id (get_current_frame ()),
6766 ecs->event_thread->control.step_frame_id)
6767 && stepped_in_from (get_current_frame (),
6768 ecs->event_thread->control.step_frame_id))
6771 fprintf_unfiltered (gdb_stdlog,
6772 "infrun: stepping through inlined function\n");
6774 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6777 end_stepping_range (ecs);
6781 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6782 && (ecs->event_thread->current_line != stop_pc_sal.line
6783 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6785 /* We are at the start of a different line. So stop. Note that
6786 we don't stop if we step into the middle of a different line.
6787 That is said to make things like for (;;) statements work
6790 fprintf_unfiltered (gdb_stdlog,
6791 "infrun: stepped to a different line\n");
6792 end_stepping_range (ecs);
6796 /* We aren't done stepping.
6798 Optimize by setting the stepping range to the line.
6799 (We might not be in the original line, but if we entered a
6800 new line in mid-statement, we continue stepping. This makes
6801 things like for(;;) statements work better.) */
6803 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6804 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6805 ecs->event_thread->control.may_range_step = 1;
6806 set_step_info (frame, stop_pc_sal);
6809 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6813 /* In all-stop mode, if we're currently stepping but have stopped in
6814 some other thread, we may need to switch back to the stepped
6815 thread. Returns true we set the inferior running, false if we left
6816 it stopped (and the event needs further processing). */
6819 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6821 if (!target_is_non_stop_p ())
6823 struct thread_info *stepping_thread;
6825 /* If any thread is blocked on some internal breakpoint, and we
6826 simply need to step over that breakpoint to get it going
6827 again, do that first. */
6829 /* However, if we see an event for the stepping thread, then we
6830 know all other threads have been moved past their breakpoints
6831 already. Let the caller check whether the step is finished,
6832 etc., before deciding to move it past a breakpoint. */
6833 if (ecs->event_thread->control.step_range_end != 0)
6836 /* Check if the current thread is blocked on an incomplete
6837 step-over, interrupted by a random signal. */
6838 if (ecs->event_thread->control.trap_expected
6839 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6843 fprintf_unfiltered (gdb_stdlog,
6844 "infrun: need to finish step-over of [%s]\n",
6845 target_pid_to_str (ecs->event_thread->ptid));
6851 /* Check if the current thread is blocked by a single-step
6852 breakpoint of another thread. */
6853 if (ecs->hit_singlestep_breakpoint)
6857 fprintf_unfiltered (gdb_stdlog,
6858 "infrun: need to step [%s] over single-step "
6860 target_pid_to_str (ecs->ptid));
6866 /* If this thread needs yet another step-over (e.g., stepping
6867 through a delay slot), do it first before moving on to
6869 if (thread_still_needs_step_over (ecs->event_thread))
6873 fprintf_unfiltered (gdb_stdlog,
6874 "infrun: thread [%s] still needs step-over\n",
6875 target_pid_to_str (ecs->event_thread->ptid));
6881 /* If scheduler locking applies even if not stepping, there's no
6882 need to walk over threads. Above we've checked whether the
6883 current thread is stepping. If some other thread not the
6884 event thread is stepping, then it must be that scheduler
6885 locking is not in effect. */
6886 if (schedlock_applies (ecs->event_thread))
6889 /* Otherwise, we no longer expect a trap in the current thread.
6890 Clear the trap_expected flag before switching back -- this is
6891 what keep_going does as well, if we call it. */
6892 ecs->event_thread->control.trap_expected = 0;
6894 /* Likewise, clear the signal if it should not be passed. */
6895 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6896 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6898 /* Do all pending step-overs before actually proceeding with
6900 if (start_step_over ())
6902 prepare_to_wait (ecs);
6906 /* Look for the stepping/nexting thread. */
6907 stepping_thread = NULL;
6909 for (thread_info *tp : all_non_exited_threads ())
6911 /* Ignore threads of processes the caller is not
6914 && tp->ptid.pid () != ecs->ptid.pid ())
6917 /* When stepping over a breakpoint, we lock all threads
6918 except the one that needs to move past the breakpoint.
6919 If a non-event thread has this set, the "incomplete
6920 step-over" check above should have caught it earlier. */
6921 if (tp->control.trap_expected)
6923 internal_error (__FILE__, __LINE__,
6924 "[%s] has inconsistent state: "
6925 "trap_expected=%d\n",
6926 target_pid_to_str (tp->ptid),
6927 tp->control.trap_expected);
6930 /* Did we find the stepping thread? */
6931 if (tp->control.step_range_end)
6933 /* Yep. There should only one though. */
6934 gdb_assert (stepping_thread == NULL);
6936 /* The event thread is handled at the top, before we
6938 gdb_assert (tp != ecs->event_thread);
6940 /* If some thread other than the event thread is
6941 stepping, then scheduler locking can't be in effect,
6942 otherwise we wouldn't have resumed the current event
6943 thread in the first place. */
6944 gdb_assert (!schedlock_applies (tp));
6946 stepping_thread = tp;
6950 if (stepping_thread != NULL)
6953 fprintf_unfiltered (gdb_stdlog,
6954 "infrun: switching back to stepped thread\n");
6956 if (keep_going_stepped_thread (stepping_thread))
6958 prepare_to_wait (ecs);
6967 /* Set a previously stepped thread back to stepping. Returns true on
6968 success, false if the resume is not possible (e.g., the thread
6972 keep_going_stepped_thread (struct thread_info *tp)
6974 struct frame_info *frame;
6975 struct execution_control_state ecss;
6976 struct execution_control_state *ecs = &ecss;
6978 /* If the stepping thread exited, then don't try to switch back and
6979 resume it, which could fail in several different ways depending
6980 on the target. Instead, just keep going.
6982 We can find a stepping dead thread in the thread list in two
6985 - The target supports thread exit events, and when the target
6986 tries to delete the thread from the thread list, inferior_ptid
6987 pointed at the exiting thread. In such case, calling
6988 delete_thread does not really remove the thread from the list;
6989 instead, the thread is left listed, with 'exited' state.
6991 - The target's debug interface does not support thread exit
6992 events, and so we have no idea whatsoever if the previously
6993 stepping thread is still alive. For that reason, we need to
6994 synchronously query the target now. */
6996 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
6999 fprintf_unfiltered (gdb_stdlog,
7000 "infrun: not resuming previously "
7001 "stepped thread, it has vanished\n");
7008 fprintf_unfiltered (gdb_stdlog,
7009 "infrun: resuming previously stepped thread\n");
7011 reset_ecs (ecs, tp);
7012 switch_to_thread (tp);
7014 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7015 frame = get_current_frame ();
7017 /* If the PC of the thread we were trying to single-step has
7018 changed, then that thread has trapped or been signaled, but the
7019 event has not been reported to GDB yet. Re-poll the target
7020 looking for this particular thread's event (i.e. temporarily
7021 enable schedlock) by:
7023 - setting a break at the current PC
7024 - resuming that particular thread, only (by setting trap
7027 This prevents us continuously moving the single-step breakpoint
7028 forward, one instruction at a time, overstepping. */
7030 if (tp->suspend.stop_pc != tp->prev_pc)
7035 fprintf_unfiltered (gdb_stdlog,
7036 "infrun: expected thread advanced also (%s -> %s)\n",
7037 paddress (target_gdbarch (), tp->prev_pc),
7038 paddress (target_gdbarch (), tp->suspend.stop_pc));
7040 /* Clear the info of the previous step-over, as it's no longer
7041 valid (if the thread was trying to step over a breakpoint, it
7042 has already succeeded). It's what keep_going would do too,
7043 if we called it. Do this before trying to insert the sss
7044 breakpoint, otherwise if we were previously trying to step
7045 over this exact address in another thread, the breakpoint is
7047 clear_step_over_info ();
7048 tp->control.trap_expected = 0;
7050 insert_single_step_breakpoint (get_frame_arch (frame),
7051 get_frame_address_space (frame),
7052 tp->suspend.stop_pc);
7055 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7056 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7061 fprintf_unfiltered (gdb_stdlog,
7062 "infrun: expected thread still hasn't advanced\n");
7064 keep_going_pass_signal (ecs);
7069 /* Is thread TP in the middle of (software or hardware)
7070 single-stepping? (Note the result of this function must never be
7071 passed directly as target_resume's STEP parameter.) */
7074 currently_stepping (struct thread_info *tp)
7076 return ((tp->control.step_range_end
7077 && tp->control.step_resume_breakpoint == NULL)
7078 || tp->control.trap_expected
7079 || tp->stepped_breakpoint
7080 || bpstat_should_step ());
7083 /* Inferior has stepped into a subroutine call with source code that
7084 we should not step over. Do step to the first line of code in
7088 handle_step_into_function (struct gdbarch *gdbarch,
7089 struct execution_control_state *ecs)
7091 fill_in_stop_func (gdbarch, ecs);
7093 compunit_symtab *cust
7094 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7095 if (cust != NULL && compunit_language (cust) != language_asm)
7096 ecs->stop_func_start
7097 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7099 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7100 /* Use the step_resume_break to step until the end of the prologue,
7101 even if that involves jumps (as it seems to on the vax under
7103 /* If the prologue ends in the middle of a source line, continue to
7104 the end of that source line (if it is still within the function).
7105 Otherwise, just go to end of prologue. */
7106 if (stop_func_sal.end
7107 && stop_func_sal.pc != ecs->stop_func_start
7108 && stop_func_sal.end < ecs->stop_func_end)
7109 ecs->stop_func_start = stop_func_sal.end;
7111 /* Architectures which require breakpoint adjustment might not be able
7112 to place a breakpoint at the computed address. If so, the test
7113 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7114 ecs->stop_func_start to an address at which a breakpoint may be
7115 legitimately placed.
7117 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7118 made, GDB will enter an infinite loop when stepping through
7119 optimized code consisting of VLIW instructions which contain
7120 subinstructions corresponding to different source lines. On
7121 FR-V, it's not permitted to place a breakpoint on any but the
7122 first subinstruction of a VLIW instruction. When a breakpoint is
7123 set, GDB will adjust the breakpoint address to the beginning of
7124 the VLIW instruction. Thus, we need to make the corresponding
7125 adjustment here when computing the stop address. */
7127 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7129 ecs->stop_func_start
7130 = gdbarch_adjust_breakpoint_address (gdbarch,
7131 ecs->stop_func_start);
7134 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7136 /* We are already there: stop now. */
7137 end_stepping_range (ecs);
7142 /* Put the step-breakpoint there and go until there. */
7143 symtab_and_line sr_sal;
7144 sr_sal.pc = ecs->stop_func_start;
7145 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7146 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7148 /* Do not specify what the fp should be when we stop since on
7149 some machines the prologue is where the new fp value is
7151 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7153 /* And make sure stepping stops right away then. */
7154 ecs->event_thread->control.step_range_end
7155 = ecs->event_thread->control.step_range_start;
7160 /* Inferior has stepped backward into a subroutine call with source
7161 code that we should not step over. Do step to the beginning of the
7162 last line of code in it. */
7165 handle_step_into_function_backward (struct gdbarch *gdbarch,
7166 struct execution_control_state *ecs)
7168 struct compunit_symtab *cust;
7169 struct symtab_and_line stop_func_sal;
7171 fill_in_stop_func (gdbarch, ecs);
7173 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7174 if (cust != NULL && compunit_language (cust) != language_asm)
7175 ecs->stop_func_start
7176 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7178 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7180 /* OK, we're just going to keep stepping here. */
7181 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7183 /* We're there already. Just stop stepping now. */
7184 end_stepping_range (ecs);
7188 /* Else just reset the step range and keep going.
7189 No step-resume breakpoint, they don't work for
7190 epilogues, which can have multiple entry paths. */
7191 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7192 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7198 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7199 This is used to both functions and to skip over code. */
7202 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7203 struct symtab_and_line sr_sal,
7204 struct frame_id sr_id,
7205 enum bptype sr_type)
7207 /* There should never be more than one step-resume or longjmp-resume
7208 breakpoint per thread, so we should never be setting a new
7209 step_resume_breakpoint when one is already active. */
7210 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7211 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7214 fprintf_unfiltered (gdb_stdlog,
7215 "infrun: inserting step-resume breakpoint at %s\n",
7216 paddress (gdbarch, sr_sal.pc));
7218 inferior_thread ()->control.step_resume_breakpoint
7219 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7223 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7224 struct symtab_and_line sr_sal,
7225 struct frame_id sr_id)
7227 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7232 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7233 This is used to skip a potential signal handler.
7235 This is called with the interrupted function's frame. The signal
7236 handler, when it returns, will resume the interrupted function at
7240 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7242 gdb_assert (return_frame != NULL);
7244 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7246 symtab_and_line sr_sal;
7247 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7248 sr_sal.section = find_pc_overlay (sr_sal.pc);
7249 sr_sal.pspace = get_frame_program_space (return_frame);
7251 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7252 get_stack_frame_id (return_frame),
7256 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7257 is used to skip a function after stepping into it (for "next" or if
7258 the called function has no debugging information).
7260 The current function has almost always been reached by single
7261 stepping a call or return instruction. NEXT_FRAME belongs to the
7262 current function, and the breakpoint will be set at the caller's
7265 This is a separate function rather than reusing
7266 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7267 get_prev_frame, which may stop prematurely (see the implementation
7268 of frame_unwind_caller_id for an example). */
7271 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7273 /* We shouldn't have gotten here if we don't know where the call site
7275 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7277 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7279 symtab_and_line sr_sal;
7280 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7281 frame_unwind_caller_pc (next_frame));
7282 sr_sal.section = find_pc_overlay (sr_sal.pc);
7283 sr_sal.pspace = frame_unwind_program_space (next_frame);
7285 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7286 frame_unwind_caller_id (next_frame));
7289 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7290 new breakpoint at the target of a jmp_buf. The handling of
7291 longjmp-resume uses the same mechanisms used for handling
7292 "step-resume" breakpoints. */
7295 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7297 /* There should never be more than one longjmp-resume breakpoint per
7298 thread, so we should never be setting a new
7299 longjmp_resume_breakpoint when one is already active. */
7300 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7303 fprintf_unfiltered (gdb_stdlog,
7304 "infrun: inserting longjmp-resume breakpoint at %s\n",
7305 paddress (gdbarch, pc));
7307 inferior_thread ()->control.exception_resume_breakpoint =
7308 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7311 /* Insert an exception resume breakpoint. TP is the thread throwing
7312 the exception. The block B is the block of the unwinder debug hook
7313 function. FRAME is the frame corresponding to the call to this
7314 function. SYM is the symbol of the function argument holding the
7315 target PC of the exception. */
7318 insert_exception_resume_breakpoint (struct thread_info *tp,
7319 const struct block *b,
7320 struct frame_info *frame,
7325 struct block_symbol vsym;
7326 struct value *value;
7328 struct breakpoint *bp;
7330 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7332 value = read_var_value (vsym.symbol, vsym.block, frame);
7333 /* If the value was optimized out, revert to the old behavior. */
7334 if (! value_optimized_out (value))
7336 handler = value_as_address (value);
7339 fprintf_unfiltered (gdb_stdlog,
7340 "infrun: exception resume at %lx\n",
7341 (unsigned long) handler);
7343 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7345 bp_exception_resume).release ();
7347 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7350 bp->thread = tp->global_num;
7351 inferior_thread ()->control.exception_resume_breakpoint = bp;
7354 CATCH (e, RETURN_MASK_ERROR)
7356 /* We want to ignore errors here. */
7361 /* A helper for check_exception_resume that sets an
7362 exception-breakpoint based on a SystemTap probe. */
7365 insert_exception_resume_from_probe (struct thread_info *tp,
7366 const struct bound_probe *probe,
7367 struct frame_info *frame)
7369 struct value *arg_value;
7371 struct breakpoint *bp;
7373 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7377 handler = value_as_address (arg_value);
7380 fprintf_unfiltered (gdb_stdlog,
7381 "infrun: exception resume at %s\n",
7382 paddress (get_objfile_arch (probe->objfile),
7385 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7386 handler, bp_exception_resume).release ();
7387 bp->thread = tp->global_num;
7388 inferior_thread ()->control.exception_resume_breakpoint = bp;
7391 /* This is called when an exception has been intercepted. Check to
7392 see whether the exception's destination is of interest, and if so,
7393 set an exception resume breakpoint there. */
7396 check_exception_resume (struct execution_control_state *ecs,
7397 struct frame_info *frame)
7399 struct bound_probe probe;
7400 struct symbol *func;
7402 /* First see if this exception unwinding breakpoint was set via a
7403 SystemTap probe point. If so, the probe has two arguments: the
7404 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7405 set a breakpoint there. */
7406 probe = find_probe_by_pc (get_frame_pc (frame));
7409 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7413 func = get_frame_function (frame);
7419 const struct block *b;
7420 struct block_iterator iter;
7424 /* The exception breakpoint is a thread-specific breakpoint on
7425 the unwinder's debug hook, declared as:
7427 void _Unwind_DebugHook (void *cfa, void *handler);
7429 The CFA argument indicates the frame to which control is
7430 about to be transferred. HANDLER is the destination PC.
7432 We ignore the CFA and set a temporary breakpoint at HANDLER.
7433 This is not extremely efficient but it avoids issues in gdb
7434 with computing the DWARF CFA, and it also works even in weird
7435 cases such as throwing an exception from inside a signal
7438 b = SYMBOL_BLOCK_VALUE (func);
7439 ALL_BLOCK_SYMBOLS (b, iter, sym)
7441 if (!SYMBOL_IS_ARGUMENT (sym))
7448 insert_exception_resume_breakpoint (ecs->event_thread,
7454 CATCH (e, RETURN_MASK_ERROR)
7461 stop_waiting (struct execution_control_state *ecs)
7464 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7466 /* Let callers know we don't want to wait for the inferior anymore. */
7467 ecs->wait_some_more = 0;
7469 /* If all-stop, but the target is always in non-stop mode, stop all
7470 threads now that we're presenting the stop to the user. */
7471 if (!non_stop && target_is_non_stop_p ())
7472 stop_all_threads ();
7475 /* Like keep_going, but passes the signal to the inferior, even if the
7476 signal is set to nopass. */
7479 keep_going_pass_signal (struct execution_control_state *ecs)
7481 gdb_assert (ecs->event_thread->ptid == inferior_ptid);
7482 gdb_assert (!ecs->event_thread->resumed);
7484 /* Save the pc before execution, to compare with pc after stop. */
7485 ecs->event_thread->prev_pc
7486 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7488 if (ecs->event_thread->control.trap_expected)
7490 struct thread_info *tp = ecs->event_thread;
7493 fprintf_unfiltered (gdb_stdlog,
7494 "infrun: %s has trap_expected set, "
7495 "resuming to collect trap\n",
7496 target_pid_to_str (tp->ptid));
7498 /* We haven't yet gotten our trap, and either: intercepted a
7499 non-signal event (e.g., a fork); or took a signal which we
7500 are supposed to pass through to the inferior. Simply
7502 resume (ecs->event_thread->suspend.stop_signal);
7504 else if (step_over_info_valid_p ())
7506 /* Another thread is stepping over a breakpoint in-line. If
7507 this thread needs a step-over too, queue the request. In
7508 either case, this resume must be deferred for later. */
7509 struct thread_info *tp = ecs->event_thread;
7511 if (ecs->hit_singlestep_breakpoint
7512 || thread_still_needs_step_over (tp))
7515 fprintf_unfiltered (gdb_stdlog,
7516 "infrun: step-over already in progress: "
7517 "step-over for %s deferred\n",
7518 target_pid_to_str (tp->ptid));
7519 thread_step_over_chain_enqueue (tp);
7524 fprintf_unfiltered (gdb_stdlog,
7525 "infrun: step-over in progress: "
7526 "resume of %s deferred\n",
7527 target_pid_to_str (tp->ptid));
7532 struct regcache *regcache = get_current_regcache ();
7535 step_over_what step_what;
7537 /* Either the trap was not expected, but we are continuing
7538 anyway (if we got a signal, the user asked it be passed to
7541 We got our expected trap, but decided we should resume from
7544 We're going to run this baby now!
7546 Note that insert_breakpoints won't try to re-insert
7547 already inserted breakpoints. Therefore, we don't
7548 care if breakpoints were already inserted, or not. */
7550 /* If we need to step over a breakpoint, and we're not using
7551 displaced stepping to do so, insert all breakpoints
7552 (watchpoints, etc.) but the one we're stepping over, step one
7553 instruction, and then re-insert the breakpoint when that step
7556 step_what = thread_still_needs_step_over (ecs->event_thread);
7558 remove_bp = (ecs->hit_singlestep_breakpoint
7559 || (step_what & STEP_OVER_BREAKPOINT));
7560 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7562 /* We can't use displaced stepping if we need to step past a
7563 watchpoint. The instruction copied to the scratch pad would
7564 still trigger the watchpoint. */
7566 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7568 set_step_over_info (regcache->aspace (),
7569 regcache_read_pc (regcache), remove_wps,
7570 ecs->event_thread->global_num);
7572 else if (remove_wps)
7573 set_step_over_info (NULL, 0, remove_wps, -1);
7575 /* If we now need to do an in-line step-over, we need to stop
7576 all other threads. Note this must be done before
7577 insert_breakpoints below, because that removes the breakpoint
7578 we're about to step over, otherwise other threads could miss
7580 if (step_over_info_valid_p () && target_is_non_stop_p ())
7581 stop_all_threads ();
7583 /* Stop stepping if inserting breakpoints fails. */
7586 insert_breakpoints ();
7588 CATCH (e, RETURN_MASK_ERROR)
7590 exception_print (gdb_stderr, e);
7592 clear_step_over_info ();
7597 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7599 resume (ecs->event_thread->suspend.stop_signal);
7602 prepare_to_wait (ecs);
7605 /* Called when we should continue running the inferior, because the
7606 current event doesn't cause a user visible stop. This does the
7607 resuming part; waiting for the next event is done elsewhere. */
7610 keep_going (struct execution_control_state *ecs)
7612 if (ecs->event_thread->control.trap_expected
7613 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7614 ecs->event_thread->control.trap_expected = 0;
7616 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7617 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7618 keep_going_pass_signal (ecs);
7621 /* This function normally comes after a resume, before
7622 handle_inferior_event exits. It takes care of any last bits of
7623 housekeeping, and sets the all-important wait_some_more flag. */
7626 prepare_to_wait (struct execution_control_state *ecs)
7629 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7631 ecs->wait_some_more = 1;
7633 if (!target_is_async_p ())
7634 mark_infrun_async_event_handler ();
7637 /* We are done with the step range of a step/next/si/ni command.
7638 Called once for each n of a "step n" operation. */
7641 end_stepping_range (struct execution_control_state *ecs)
7643 ecs->event_thread->control.stop_step = 1;
7647 /* Several print_*_reason functions to print why the inferior has stopped.
7648 We always print something when the inferior exits, or receives a signal.
7649 The rest of the cases are dealt with later on in normal_stop and
7650 print_it_typical. Ideally there should be a call to one of these
7651 print_*_reason functions functions from handle_inferior_event each time
7652 stop_waiting is called.
7654 Note that we don't call these directly, instead we delegate that to
7655 the interpreters, through observers. Interpreters then call these
7656 with whatever uiout is right. */
7659 print_end_stepping_range_reason (struct ui_out *uiout)
7661 /* For CLI-like interpreters, print nothing. */
7663 if (uiout->is_mi_like_p ())
7665 uiout->field_string ("reason",
7666 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7671 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7673 annotate_signalled ();
7674 if (uiout->is_mi_like_p ())
7676 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7677 uiout->text ("\nProgram terminated with signal ");
7678 annotate_signal_name ();
7679 uiout->field_string ("signal-name",
7680 gdb_signal_to_name (siggnal));
7681 annotate_signal_name_end ();
7683 annotate_signal_string ();
7684 uiout->field_string ("signal-meaning",
7685 gdb_signal_to_string (siggnal));
7686 annotate_signal_string_end ();
7687 uiout->text (".\n");
7688 uiout->text ("The program no longer exists.\n");
7692 print_exited_reason (struct ui_out *uiout, int exitstatus)
7694 struct inferior *inf = current_inferior ();
7695 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7697 annotate_exited (exitstatus);
7700 if (uiout->is_mi_like_p ())
7701 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7702 uiout->text ("[Inferior ");
7703 uiout->text (plongest (inf->num));
7705 uiout->text (pidstr);
7706 uiout->text (") exited with code ");
7707 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7708 uiout->text ("]\n");
7712 if (uiout->is_mi_like_p ())
7714 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7715 uiout->text ("[Inferior ");
7716 uiout->text (plongest (inf->num));
7718 uiout->text (pidstr);
7719 uiout->text (") exited normally]\n");
7723 /* Some targets/architectures can do extra processing/display of
7724 segmentation faults. E.g., Intel MPX boundary faults.
7725 Call the architecture dependent function to handle the fault. */
7728 handle_segmentation_fault (struct ui_out *uiout)
7730 struct regcache *regcache = get_current_regcache ();
7731 struct gdbarch *gdbarch = regcache->arch ();
7733 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7734 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7738 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7740 struct thread_info *thr = inferior_thread ();
7744 if (uiout->is_mi_like_p ())
7746 else if (show_thread_that_caused_stop ())
7750 uiout->text ("\nThread ");
7751 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7753 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7756 uiout->text (" \"");
7757 uiout->field_fmt ("name", "%s", name);
7762 uiout->text ("\nProgram");
7764 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7765 uiout->text (" stopped");
7768 uiout->text (" received signal ");
7769 annotate_signal_name ();
7770 if (uiout->is_mi_like_p ())
7772 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7773 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7774 annotate_signal_name_end ();
7776 annotate_signal_string ();
7777 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7779 if (siggnal == GDB_SIGNAL_SEGV)
7780 handle_segmentation_fault (uiout);
7782 annotate_signal_string_end ();
7784 uiout->text (".\n");
7788 print_no_history_reason (struct ui_out *uiout)
7790 uiout->text ("\nNo more reverse-execution history.\n");
7793 /* Print current location without a level number, if we have changed
7794 functions or hit a breakpoint. Print source line if we have one.
7795 bpstat_print contains the logic deciding in detail what to print,
7796 based on the event(s) that just occurred. */
7799 print_stop_location (struct target_waitstatus *ws)
7802 enum print_what source_flag;
7803 int do_frame_printing = 1;
7804 struct thread_info *tp = inferior_thread ();
7806 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7810 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7811 should) carry around the function and does (or should) use
7812 that when doing a frame comparison. */
7813 if (tp->control.stop_step
7814 && frame_id_eq (tp->control.step_frame_id,
7815 get_frame_id (get_current_frame ()))
7816 && (tp->control.step_start_function
7817 == find_pc_function (tp->suspend.stop_pc)))
7819 /* Finished step, just print source line. */
7820 source_flag = SRC_LINE;
7824 /* Print location and source line. */
7825 source_flag = SRC_AND_LOC;
7828 case PRINT_SRC_AND_LOC:
7829 /* Print location and source line. */
7830 source_flag = SRC_AND_LOC;
7832 case PRINT_SRC_ONLY:
7833 source_flag = SRC_LINE;
7836 /* Something bogus. */
7837 source_flag = SRC_LINE;
7838 do_frame_printing = 0;
7841 internal_error (__FILE__, __LINE__, _("Unknown value."));
7844 /* The behavior of this routine with respect to the source
7846 SRC_LINE: Print only source line
7847 LOCATION: Print only location
7848 SRC_AND_LOC: Print location and source line. */
7849 if (do_frame_printing)
7850 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7856 print_stop_event (struct ui_out *uiout)
7858 struct target_waitstatus last;
7860 struct thread_info *tp;
7862 get_last_target_status (&last_ptid, &last);
7865 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
7867 print_stop_location (&last);
7869 /* Display the auto-display expressions. */
7873 tp = inferior_thread ();
7874 if (tp->thread_fsm != NULL
7875 && tp->thread_fsm->finished_p ())
7877 struct return_value_info *rv;
7879 rv = tp->thread_fsm->return_value ();
7881 print_return_value (uiout, rv);
7888 maybe_remove_breakpoints (void)
7890 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7892 if (remove_breakpoints ())
7894 target_terminal::ours_for_output ();
7895 printf_filtered (_("Cannot remove breakpoints because "
7896 "program is no longer writable.\nFurther "
7897 "execution is probably impossible.\n"));
7902 /* The execution context that just caused a normal stop. */
7909 DISABLE_COPY_AND_ASSIGN (stop_context);
7911 bool changed () const;
7916 /* The event PTID. */
7920 /* If stopp for a thread event, this is the thread that caused the
7922 struct thread_info *thread;
7924 /* The inferior that caused the stop. */
7928 /* Initializes a new stop context. If stopped for a thread event, this
7929 takes a strong reference to the thread. */
7931 stop_context::stop_context ()
7933 stop_id = get_stop_id ();
7934 ptid = inferior_ptid;
7935 inf_num = current_inferior ()->num;
7937 if (inferior_ptid != null_ptid)
7939 /* Take a strong reference so that the thread can't be deleted
7941 thread = inferior_thread ();
7948 /* Release a stop context previously created with save_stop_context.
7949 Releases the strong reference to the thread as well. */
7951 stop_context::~stop_context ()
7957 /* Return true if the current context no longer matches the saved stop
7961 stop_context::changed () const
7963 if (ptid != inferior_ptid)
7965 if (inf_num != current_inferior ()->num)
7967 if (thread != NULL && thread->state != THREAD_STOPPED)
7969 if (get_stop_id () != stop_id)
7979 struct target_waitstatus last;
7982 get_last_target_status (&last_ptid, &last);
7986 /* If an exception is thrown from this point on, make sure to
7987 propagate GDB's knowledge of the executing state to the
7988 frontend/user running state. A QUIT is an easy exception to see
7989 here, so do this before any filtered output. */
7991 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
7994 maybe_finish_thread_state.emplace (minus_one_ptid);
7995 else if (last.kind == TARGET_WAITKIND_SIGNALLED
7996 || last.kind == TARGET_WAITKIND_EXITED)
7998 /* On some targets, we may still have live threads in the
7999 inferior when we get a process exit event. E.g., for
8000 "checkpoint", when the current checkpoint/fork exits,
8001 linux-fork.c automatically switches to another fork from
8002 within target_mourn_inferior. */
8003 if (inferior_ptid != null_ptid)
8004 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8006 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8007 maybe_finish_thread_state.emplace (inferior_ptid);
8009 /* As we're presenting a stop, and potentially removing breakpoints,
8010 update the thread list so we can tell whether there are threads
8011 running on the target. With target remote, for example, we can
8012 only learn about new threads when we explicitly update the thread
8013 list. Do this before notifying the interpreters about signal
8014 stops, end of stepping ranges, etc., so that the "new thread"
8015 output is emitted before e.g., "Program received signal FOO",
8016 instead of after. */
8017 update_thread_list ();
8019 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8020 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8022 /* As with the notification of thread events, we want to delay
8023 notifying the user that we've switched thread context until
8024 the inferior actually stops.
8026 There's no point in saying anything if the inferior has exited.
8027 Note that SIGNALLED here means "exited with a signal", not
8028 "received a signal".
8030 Also skip saying anything in non-stop mode. In that mode, as we
8031 don't want GDB to switch threads behind the user's back, to avoid
8032 races where the user is typing a command to apply to thread x,
8033 but GDB switches to thread y before the user finishes entering
8034 the command, fetch_inferior_event installs a cleanup to restore
8035 the current thread back to the thread the user had selected right
8036 after this event is handled, so we're not really switching, only
8037 informing of a stop. */
8039 && previous_inferior_ptid != inferior_ptid
8040 && target_has_execution
8041 && last.kind != TARGET_WAITKIND_SIGNALLED
8042 && last.kind != TARGET_WAITKIND_EXITED
8043 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8045 SWITCH_THRU_ALL_UIS ()
8047 target_terminal::ours_for_output ();
8048 printf_filtered (_("[Switching to %s]\n"),
8049 target_pid_to_str (inferior_ptid));
8050 annotate_thread_changed ();
8052 previous_inferior_ptid = inferior_ptid;
8055 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8057 SWITCH_THRU_ALL_UIS ()
8058 if (current_ui->prompt_state == PROMPT_BLOCKED)
8060 target_terminal::ours_for_output ();
8061 printf_filtered (_("No unwaited-for children left.\n"));
8065 /* Note: this depends on the update_thread_list call above. */
8066 maybe_remove_breakpoints ();
8068 /* If an auto-display called a function and that got a signal,
8069 delete that auto-display to avoid an infinite recursion. */
8071 if (stopped_by_random_signal)
8072 disable_current_display ();
8074 SWITCH_THRU_ALL_UIS ()
8076 async_enable_stdin ();
8079 /* Let the user/frontend see the threads as stopped. */
8080 maybe_finish_thread_state.reset ();
8082 /* Select innermost stack frame - i.e., current frame is frame 0,
8083 and current location is based on that. Handle the case where the
8084 dummy call is returning after being stopped. E.g. the dummy call
8085 previously hit a breakpoint. (If the dummy call returns
8086 normally, we won't reach here.) Do this before the stop hook is
8087 run, so that it doesn't get to see the temporary dummy frame,
8088 which is not where we'll present the stop. */
8089 if (has_stack_frames ())
8091 if (stop_stack_dummy == STOP_STACK_DUMMY)
8093 /* Pop the empty frame that contains the stack dummy. This
8094 also restores inferior state prior to the call (struct
8095 infcall_suspend_state). */
8096 struct frame_info *frame = get_current_frame ();
8098 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8100 /* frame_pop calls reinit_frame_cache as the last thing it
8101 does which means there's now no selected frame. */
8104 select_frame (get_current_frame ());
8106 /* Set the current source location. */
8107 set_current_sal_from_frame (get_current_frame ());
8110 /* Look up the hook_stop and run it (CLI internally handles problem
8111 of stop_command's pre-hook not existing). */
8112 if (stop_command != NULL)
8114 stop_context saved_context;
8118 execute_cmd_pre_hook (stop_command);
8120 CATCH (ex, RETURN_MASK_ALL)
8122 exception_fprintf (gdb_stderr, ex,
8123 "Error while running hook_stop:\n");
8127 /* If the stop hook resumes the target, then there's no point in
8128 trying to notify about the previous stop; its context is
8129 gone. Likewise if the command switches thread or inferior --
8130 the observers would print a stop for the wrong
8132 if (saved_context.changed ())
8136 /* Notify observers about the stop. This is where the interpreters
8137 print the stop event. */
8138 if (inferior_ptid != null_ptid)
8139 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8142 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8144 annotate_stopped ();
8146 if (target_has_execution)
8148 if (last.kind != TARGET_WAITKIND_SIGNALLED
8149 && last.kind != TARGET_WAITKIND_EXITED
8150 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8151 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8152 Delete any breakpoint that is to be deleted at the next stop. */
8153 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8156 /* Try to get rid of automatically added inferiors that are no
8157 longer needed. Keeping those around slows down things linearly.
8158 Note that this never removes the current inferior. */
8165 signal_stop_state (int signo)
8167 return signal_stop[signo];
8171 signal_print_state (int signo)
8173 return signal_print[signo];
8177 signal_pass_state (int signo)
8179 return signal_program[signo];
8183 signal_cache_update (int signo)
8187 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8188 signal_cache_update (signo);
8193 signal_pass[signo] = (signal_stop[signo] == 0
8194 && signal_print[signo] == 0
8195 && signal_program[signo] == 1
8196 && signal_catch[signo] == 0);
8200 signal_stop_update (int signo, int state)
8202 int ret = signal_stop[signo];
8204 signal_stop[signo] = state;
8205 signal_cache_update (signo);
8210 signal_print_update (int signo, int state)
8212 int ret = signal_print[signo];
8214 signal_print[signo] = state;
8215 signal_cache_update (signo);
8220 signal_pass_update (int signo, int state)
8222 int ret = signal_program[signo];
8224 signal_program[signo] = state;
8225 signal_cache_update (signo);
8229 /* Update the global 'signal_catch' from INFO and notify the
8233 signal_catch_update (const unsigned int *info)
8237 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8238 signal_catch[i] = info[i] > 0;
8239 signal_cache_update (-1);
8240 target_pass_signals (signal_pass);
8244 sig_print_header (void)
8246 printf_filtered (_("Signal Stop\tPrint\tPass "
8247 "to program\tDescription\n"));
8251 sig_print_info (enum gdb_signal oursig)
8253 const char *name = gdb_signal_to_name (oursig);
8254 int name_padding = 13 - strlen (name);
8256 if (name_padding <= 0)
8259 printf_filtered ("%s", name);
8260 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8261 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8262 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8263 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8264 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8267 /* Specify how various signals in the inferior should be handled. */
8270 handle_command (const char *args, int from_tty)
8272 int digits, wordlen;
8273 int sigfirst, siglast;
8274 enum gdb_signal oursig;
8279 error_no_arg (_("signal to handle"));
8282 /* Allocate and zero an array of flags for which signals to handle. */
8284 const size_t nsigs = GDB_SIGNAL_LAST;
8285 unsigned char sigs[nsigs] {};
8287 /* Break the command line up into args. */
8289 gdb_argv built_argv (args);
8291 /* Walk through the args, looking for signal oursigs, signal names, and
8292 actions. Signal numbers and signal names may be interspersed with
8293 actions, with the actions being performed for all signals cumulatively
8294 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8296 for (char *arg : built_argv)
8298 wordlen = strlen (arg);
8299 for (digits = 0; isdigit (arg[digits]); digits++)
8303 sigfirst = siglast = -1;
8305 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8307 /* Apply action to all signals except those used by the
8308 debugger. Silently skip those. */
8311 siglast = nsigs - 1;
8313 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8315 SET_SIGS (nsigs, sigs, signal_stop);
8316 SET_SIGS (nsigs, sigs, signal_print);
8318 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8320 UNSET_SIGS (nsigs, sigs, signal_program);
8322 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8324 SET_SIGS (nsigs, sigs, signal_print);
8326 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8328 SET_SIGS (nsigs, sigs, signal_program);
8330 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8332 UNSET_SIGS (nsigs, sigs, signal_stop);
8334 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8336 SET_SIGS (nsigs, sigs, signal_program);
8338 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8340 UNSET_SIGS (nsigs, sigs, signal_print);
8341 UNSET_SIGS (nsigs, sigs, signal_stop);
8343 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8345 UNSET_SIGS (nsigs, sigs, signal_program);
8347 else if (digits > 0)
8349 /* It is numeric. The numeric signal refers to our own
8350 internal signal numbering from target.h, not to host/target
8351 signal number. This is a feature; users really should be
8352 using symbolic names anyway, and the common ones like
8353 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8355 sigfirst = siglast = (int)
8356 gdb_signal_from_command (atoi (arg));
8357 if (arg[digits] == '-')
8360 gdb_signal_from_command (atoi (arg + digits + 1));
8362 if (sigfirst > siglast)
8364 /* Bet he didn't figure we'd think of this case... */
8365 std::swap (sigfirst, siglast);
8370 oursig = gdb_signal_from_name (arg);
8371 if (oursig != GDB_SIGNAL_UNKNOWN)
8373 sigfirst = siglast = (int) oursig;
8377 /* Not a number and not a recognized flag word => complain. */
8378 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8382 /* If any signal numbers or symbol names were found, set flags for
8383 which signals to apply actions to. */
8385 for (int signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8387 switch ((enum gdb_signal) signum)
8389 case GDB_SIGNAL_TRAP:
8390 case GDB_SIGNAL_INT:
8391 if (!allsigs && !sigs[signum])
8393 if (query (_("%s is used by the debugger.\n\
8394 Are you sure you want to change it? "),
8395 gdb_signal_to_name ((enum gdb_signal) signum)))
8400 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8404 case GDB_SIGNAL_DEFAULT:
8405 case GDB_SIGNAL_UNKNOWN:
8406 /* Make sure that "all" doesn't print these. */
8415 for (int signum = 0; signum < nsigs; signum++)
8418 signal_cache_update (-1);
8419 target_pass_signals (signal_pass);
8420 target_program_signals (signal_program);
8424 /* Show the results. */
8425 sig_print_header ();
8426 for (; signum < nsigs; signum++)
8428 sig_print_info ((enum gdb_signal) signum);
8435 /* Complete the "handle" command. */
8438 handle_completer (struct cmd_list_element *ignore,
8439 completion_tracker &tracker,
8440 const char *text, const char *word)
8442 static const char * const keywords[] =
8456 signal_completer (ignore, tracker, text, word);
8457 complete_on_enum (tracker, keywords, word, word);
8461 gdb_signal_from_command (int num)
8463 if (num >= 1 && num <= 15)
8464 return (enum gdb_signal) num;
8465 error (_("Only signals 1-15 are valid as numeric signals.\n\
8466 Use \"info signals\" for a list of symbolic signals."));
8469 /* Print current contents of the tables set by the handle command.
8470 It is possible we should just be printing signals actually used
8471 by the current target (but for things to work right when switching
8472 targets, all signals should be in the signal tables). */
8475 info_signals_command (const char *signum_exp, int from_tty)
8477 enum gdb_signal oursig;
8479 sig_print_header ();
8483 /* First see if this is a symbol name. */
8484 oursig = gdb_signal_from_name (signum_exp);
8485 if (oursig == GDB_SIGNAL_UNKNOWN)
8487 /* No, try numeric. */
8489 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8491 sig_print_info (oursig);
8495 printf_filtered ("\n");
8496 /* These ugly casts brought to you by the native VAX compiler. */
8497 for (oursig = GDB_SIGNAL_FIRST;
8498 (int) oursig < (int) GDB_SIGNAL_LAST;
8499 oursig = (enum gdb_signal) ((int) oursig + 1))
8503 if (oursig != GDB_SIGNAL_UNKNOWN
8504 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8505 sig_print_info (oursig);
8508 printf_filtered (_("\nUse the \"handle\" command "
8509 "to change these tables.\n"));
8512 /* The $_siginfo convenience variable is a bit special. We don't know
8513 for sure the type of the value until we actually have a chance to
8514 fetch the data. The type can change depending on gdbarch, so it is
8515 also dependent on which thread you have selected.
8517 1. making $_siginfo be an internalvar that creates a new value on
8520 2. making the value of $_siginfo be an lval_computed value. */
8522 /* This function implements the lval_computed support for reading a
8526 siginfo_value_read (struct value *v)
8528 LONGEST transferred;
8530 /* If we can access registers, so can we access $_siginfo. Likewise
8532 validate_registers_access ();
8535 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO,
8537 value_contents_all_raw (v),
8539 TYPE_LENGTH (value_type (v)));
8541 if (transferred != TYPE_LENGTH (value_type (v)))
8542 error (_("Unable to read siginfo"));
8545 /* This function implements the lval_computed support for writing a
8549 siginfo_value_write (struct value *v, struct value *fromval)
8551 LONGEST transferred;
8553 /* If we can access registers, so can we access $_siginfo. Likewise
8555 validate_registers_access ();
8557 transferred = target_write (current_top_target (),
8558 TARGET_OBJECT_SIGNAL_INFO,
8560 value_contents_all_raw (fromval),
8562 TYPE_LENGTH (value_type (fromval)));
8564 if (transferred != TYPE_LENGTH (value_type (fromval)))
8565 error (_("Unable to write siginfo"));
8568 static const struct lval_funcs siginfo_value_funcs =
8574 /* Return a new value with the correct type for the siginfo object of
8575 the current thread using architecture GDBARCH. Return a void value
8576 if there's no object available. */
8578 static struct value *
8579 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8582 if (target_has_stack
8583 && inferior_ptid != null_ptid
8584 && gdbarch_get_siginfo_type_p (gdbarch))
8586 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8588 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8591 return allocate_value (builtin_type (gdbarch)->builtin_void);
8595 /* infcall_suspend_state contains state about the program itself like its
8596 registers and any signal it received when it last stopped.
8597 This state must be restored regardless of how the inferior function call
8598 ends (either successfully, or after it hits a breakpoint or signal)
8599 if the program is to properly continue where it left off. */
8601 class infcall_suspend_state
8604 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8605 once the inferior function call has finished. */
8606 infcall_suspend_state (struct gdbarch *gdbarch,
8607 const struct thread_info *tp,
8608 struct regcache *regcache)
8609 : m_thread_suspend (tp->suspend),
8610 m_registers (new readonly_detached_regcache (*regcache))
8612 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8614 if (gdbarch_get_siginfo_type_p (gdbarch))
8616 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8617 size_t len = TYPE_LENGTH (type);
8619 siginfo_data.reset ((gdb_byte *) xmalloc (len));
8621 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8622 siginfo_data.get (), 0, len) != len)
8624 /* Errors ignored. */
8625 siginfo_data.reset (nullptr);
8631 m_siginfo_gdbarch = gdbarch;
8632 m_siginfo_data = std::move (siginfo_data);
8636 /* Return a pointer to the stored register state. */
8638 readonly_detached_regcache *registers () const
8640 return m_registers.get ();
8643 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8645 void restore (struct gdbarch *gdbarch,
8646 struct thread_info *tp,
8647 struct regcache *regcache) const
8649 tp->suspend = m_thread_suspend;
8651 if (m_siginfo_gdbarch == gdbarch)
8653 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8655 /* Errors ignored. */
8656 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8657 m_siginfo_data.get (), 0, TYPE_LENGTH (type));
8660 /* The inferior can be gone if the user types "print exit(0)"
8661 (and perhaps other times). */
8662 if (target_has_execution)
8663 /* NB: The register write goes through to the target. */
8664 regcache->restore (registers ());
8668 /* How the current thread stopped before the inferior function call was
8670 struct thread_suspend_state m_thread_suspend;
8672 /* The registers before the inferior function call was executed. */
8673 std::unique_ptr<readonly_detached_regcache> m_registers;
8675 /* Format of SIGINFO_DATA or NULL if it is not present. */
8676 struct gdbarch *m_siginfo_gdbarch = nullptr;
8678 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8679 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8680 content would be invalid. */
8681 gdb::unique_xmalloc_ptr<gdb_byte> m_siginfo_data;
8684 infcall_suspend_state_up
8685 save_infcall_suspend_state ()
8687 struct thread_info *tp = inferior_thread ();
8688 struct regcache *regcache = get_current_regcache ();
8689 struct gdbarch *gdbarch = regcache->arch ();
8691 infcall_suspend_state_up inf_state
8692 (new struct infcall_suspend_state (gdbarch, tp, regcache));
8694 /* Having saved the current state, adjust the thread state, discarding
8695 any stop signal information. The stop signal is not useful when
8696 starting an inferior function call, and run_inferior_call will not use
8697 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8698 tp->suspend.stop_signal = GDB_SIGNAL_0;
8703 /* Restore inferior session state to INF_STATE. */
8706 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8708 struct thread_info *tp = inferior_thread ();
8709 struct regcache *regcache = get_current_regcache ();
8710 struct gdbarch *gdbarch = regcache->arch ();
8712 inf_state->restore (gdbarch, tp, regcache);
8713 discard_infcall_suspend_state (inf_state);
8717 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8722 readonly_detached_regcache *
8723 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8725 return inf_state->registers ();
8728 /* infcall_control_state contains state regarding gdb's control of the
8729 inferior itself like stepping control. It also contains session state like
8730 the user's currently selected frame. */
8732 struct infcall_control_state
8734 struct thread_control_state thread_control;
8735 struct inferior_control_state inferior_control;
8738 enum stop_stack_kind stop_stack_dummy = STOP_NONE;
8739 int stopped_by_random_signal = 0;
8741 /* ID if the selected frame when the inferior function call was made. */
8742 struct frame_id selected_frame_id {};
8745 /* Save all of the information associated with the inferior<==>gdb
8748 infcall_control_state_up
8749 save_infcall_control_state ()
8751 infcall_control_state_up inf_status (new struct infcall_control_state);
8752 struct thread_info *tp = inferior_thread ();
8753 struct inferior *inf = current_inferior ();
8755 inf_status->thread_control = tp->control;
8756 inf_status->inferior_control = inf->control;
8758 tp->control.step_resume_breakpoint = NULL;
8759 tp->control.exception_resume_breakpoint = NULL;
8761 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8762 chain. If caller's caller is walking the chain, they'll be happier if we
8763 hand them back the original chain when restore_infcall_control_state is
8765 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8768 inf_status->stop_stack_dummy = stop_stack_dummy;
8769 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8771 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8777 restore_selected_frame (const frame_id &fid)
8779 frame_info *frame = frame_find_by_id (fid);
8781 /* If inf_status->selected_frame_id is NULL, there was no previously
8785 warning (_("Unable to restore previously selected frame."));
8789 select_frame (frame);
8792 /* Restore inferior session state to INF_STATUS. */
8795 restore_infcall_control_state (struct infcall_control_state *inf_status)
8797 struct thread_info *tp = inferior_thread ();
8798 struct inferior *inf = current_inferior ();
8800 if (tp->control.step_resume_breakpoint)
8801 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8803 if (tp->control.exception_resume_breakpoint)
8804 tp->control.exception_resume_breakpoint->disposition
8805 = disp_del_at_next_stop;
8807 /* Handle the bpstat_copy of the chain. */
8808 bpstat_clear (&tp->control.stop_bpstat);
8810 tp->control = inf_status->thread_control;
8811 inf->control = inf_status->inferior_control;
8814 stop_stack_dummy = inf_status->stop_stack_dummy;
8815 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8817 if (target_has_stack)
8819 /* The point of the try/catch is that if the stack is clobbered,
8820 walking the stack might encounter a garbage pointer and
8821 error() trying to dereference it. */
8824 restore_selected_frame (inf_status->selected_frame_id);
8826 CATCH (ex, RETURN_MASK_ERROR)
8828 exception_fprintf (gdb_stderr, ex,
8829 "Unable to restore previously selected frame:\n");
8830 /* Error in restoring the selected frame. Select the
8832 select_frame (get_current_frame ());
8841 discard_infcall_control_state (struct infcall_control_state *inf_status)
8843 if (inf_status->thread_control.step_resume_breakpoint)
8844 inf_status->thread_control.step_resume_breakpoint->disposition
8845 = disp_del_at_next_stop;
8847 if (inf_status->thread_control.exception_resume_breakpoint)
8848 inf_status->thread_control.exception_resume_breakpoint->disposition
8849 = disp_del_at_next_stop;
8851 /* See save_infcall_control_state for info on stop_bpstat. */
8852 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8860 clear_exit_convenience_vars (void)
8862 clear_internalvar (lookup_internalvar ("_exitsignal"));
8863 clear_internalvar (lookup_internalvar ("_exitcode"));
8867 /* User interface for reverse debugging:
8868 Set exec-direction / show exec-direction commands
8869 (returns error unless target implements to_set_exec_direction method). */
8871 enum exec_direction_kind execution_direction = EXEC_FORWARD;
8872 static const char exec_forward[] = "forward";
8873 static const char exec_reverse[] = "reverse";
8874 static const char *exec_direction = exec_forward;
8875 static const char *const exec_direction_names[] = {
8882 set_exec_direction_func (const char *args, int from_tty,
8883 struct cmd_list_element *cmd)
8885 if (target_can_execute_reverse)
8887 if (!strcmp (exec_direction, exec_forward))
8888 execution_direction = EXEC_FORWARD;
8889 else if (!strcmp (exec_direction, exec_reverse))
8890 execution_direction = EXEC_REVERSE;
8894 exec_direction = exec_forward;
8895 error (_("Target does not support this operation."));
8900 show_exec_direction_func (struct ui_file *out, int from_tty,
8901 struct cmd_list_element *cmd, const char *value)
8903 switch (execution_direction) {
8905 fprintf_filtered (out, _("Forward.\n"));
8908 fprintf_filtered (out, _("Reverse.\n"));
8911 internal_error (__FILE__, __LINE__,
8912 _("bogus execution_direction value: %d"),
8913 (int) execution_direction);
8918 show_schedule_multiple (struct ui_file *file, int from_tty,
8919 struct cmd_list_element *c, const char *value)
8921 fprintf_filtered (file, _("Resuming the execution of threads "
8922 "of all processes is %s.\n"), value);
8925 /* Implementation of `siginfo' variable. */
8927 static const struct internalvar_funcs siginfo_funcs =
8934 /* Callback for infrun's target events source. This is marked when a
8935 thread has a pending status to process. */
8938 infrun_async_inferior_event_handler (gdb_client_data data)
8940 inferior_event_handler (INF_REG_EVENT, NULL);
8944 _initialize_infrun (void)
8946 struct cmd_list_element *c;
8948 /* Register extra event sources in the event loop. */
8949 infrun_async_inferior_event_token
8950 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8952 add_info ("signals", info_signals_command, _("\
8953 What debugger does when program gets various signals.\n\
8954 Specify a signal as argument to print info on that signal only."));
8955 add_info_alias ("handle", "signals", 0);
8957 c = add_com ("handle", class_run, handle_command, _("\
8958 Specify how to handle signals.\n\
8959 Usage: handle SIGNAL [ACTIONS]\n\
8960 Args are signals and actions to apply to those signals.\n\
8961 If no actions are specified, the current settings for the specified signals\n\
8962 will be displayed instead.\n\
8964 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8965 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8966 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8967 The special arg \"all\" is recognized to mean all signals except those\n\
8968 used by the debugger, typically SIGTRAP and SIGINT.\n\
8970 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8971 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8972 Stop means reenter debugger if this signal happens (implies print).\n\
8973 Print means print a message if this signal happens.\n\
8974 Pass means let program see this signal; otherwise program doesn't know.\n\
8975 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8976 Pass and Stop may be combined.\n\
8978 Multiple signals may be specified. Signal numbers and signal names\n\
8979 may be interspersed with actions, with the actions being performed for\n\
8980 all signals cumulatively specified."));
8981 set_cmd_completer (c, handle_completer);
8984 stop_command = add_cmd ("stop", class_obscure,
8985 not_just_help_class_command, _("\
8986 There is no `stop' command, but you can set a hook on `stop'.\n\
8987 This allows you to set a list of commands to be run each time execution\n\
8988 of the program stops."), &cmdlist);
8990 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
8991 Set inferior debugging."), _("\
8992 Show inferior debugging."), _("\
8993 When non-zero, inferior specific debugging is enabled."),
8996 &setdebuglist, &showdebuglist);
8998 add_setshow_boolean_cmd ("displaced", class_maintenance,
8999 &debug_displaced, _("\
9000 Set displaced stepping debugging."), _("\
9001 Show displaced stepping debugging."), _("\
9002 When non-zero, displaced stepping specific debugging is enabled."),
9004 show_debug_displaced,
9005 &setdebuglist, &showdebuglist);
9007 add_setshow_boolean_cmd ("non-stop", no_class,
9009 Set whether gdb controls the inferior in non-stop mode."), _("\
9010 Show whether gdb controls the inferior in non-stop mode."), _("\
9011 When debugging a multi-threaded program and this setting is\n\
9012 off (the default, also called all-stop mode), when one thread stops\n\
9013 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9014 all other threads in the program while you interact with the thread of\n\
9015 interest. When you continue or step a thread, you can allow the other\n\
9016 threads to run, or have them remain stopped, but while you inspect any\n\
9017 thread's state, all threads stop.\n\
9019 In non-stop mode, when one thread stops, other threads can continue\n\
9020 to run freely. You'll be able to step each thread independently,\n\
9021 leave it stopped or free to run as needed."),
9027 for (size_t i = 0; i < GDB_SIGNAL_LAST; i++)
9030 signal_print[i] = 1;
9031 signal_program[i] = 1;
9032 signal_catch[i] = 0;
9035 /* Signals caused by debugger's own actions should not be given to
9036 the program afterwards.
9038 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9039 explicitly specifies that it should be delivered to the target
9040 program. Typically, that would occur when a user is debugging a
9041 target monitor on a simulator: the target monitor sets a
9042 breakpoint; the simulator encounters this breakpoint and halts
9043 the simulation handing control to GDB; GDB, noting that the stop
9044 address doesn't map to any known breakpoint, returns control back
9045 to the simulator; the simulator then delivers the hardware
9046 equivalent of a GDB_SIGNAL_TRAP to the program being
9048 signal_program[GDB_SIGNAL_TRAP] = 0;
9049 signal_program[GDB_SIGNAL_INT] = 0;
9051 /* Signals that are not errors should not normally enter the debugger. */
9052 signal_stop[GDB_SIGNAL_ALRM] = 0;
9053 signal_print[GDB_SIGNAL_ALRM] = 0;
9054 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9055 signal_print[GDB_SIGNAL_VTALRM] = 0;
9056 signal_stop[GDB_SIGNAL_PROF] = 0;
9057 signal_print[GDB_SIGNAL_PROF] = 0;
9058 signal_stop[GDB_SIGNAL_CHLD] = 0;
9059 signal_print[GDB_SIGNAL_CHLD] = 0;
9060 signal_stop[GDB_SIGNAL_IO] = 0;
9061 signal_print[GDB_SIGNAL_IO] = 0;
9062 signal_stop[GDB_SIGNAL_POLL] = 0;
9063 signal_print[GDB_SIGNAL_POLL] = 0;
9064 signal_stop[GDB_SIGNAL_URG] = 0;
9065 signal_print[GDB_SIGNAL_URG] = 0;
9066 signal_stop[GDB_SIGNAL_WINCH] = 0;
9067 signal_print[GDB_SIGNAL_WINCH] = 0;
9068 signal_stop[GDB_SIGNAL_PRIO] = 0;
9069 signal_print[GDB_SIGNAL_PRIO] = 0;
9071 /* These signals are used internally by user-level thread
9072 implementations. (See signal(5) on Solaris.) Like the above
9073 signals, a healthy program receives and handles them as part of
9074 its normal operation. */
9075 signal_stop[GDB_SIGNAL_LWP] = 0;
9076 signal_print[GDB_SIGNAL_LWP] = 0;
9077 signal_stop[GDB_SIGNAL_WAITING] = 0;
9078 signal_print[GDB_SIGNAL_WAITING] = 0;
9079 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9080 signal_print[GDB_SIGNAL_CANCEL] = 0;
9081 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9082 signal_print[GDB_SIGNAL_LIBRT] = 0;
9084 /* Update cached state. */
9085 signal_cache_update (-1);
9087 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9088 &stop_on_solib_events, _("\
9089 Set stopping for shared library events."), _("\
9090 Show stopping for shared library events."), _("\
9091 If nonzero, gdb will give control to the user when the dynamic linker\n\
9092 notifies gdb of shared library events. The most common event of interest\n\
9093 to the user would be loading/unloading of a new library."),
9094 set_stop_on_solib_events,
9095 show_stop_on_solib_events,
9096 &setlist, &showlist);
9098 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9099 follow_fork_mode_kind_names,
9100 &follow_fork_mode_string, _("\
9101 Set debugger response to a program call of fork or vfork."), _("\
9102 Show debugger response to a program call of fork or vfork."), _("\
9103 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9104 parent - the original process is debugged after a fork\n\
9105 child - the new process is debugged after a fork\n\
9106 The unfollowed process will continue to run.\n\
9107 By default, the debugger will follow the parent process."),
9109 show_follow_fork_mode_string,
9110 &setlist, &showlist);
9112 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9113 follow_exec_mode_names,
9114 &follow_exec_mode_string, _("\
9115 Set debugger response to a program call of exec."), _("\
9116 Show debugger response to a program call of exec."), _("\
9117 An exec call replaces the program image of a process.\n\
9119 follow-exec-mode can be:\n\
9121 new - the debugger creates a new inferior and rebinds the process\n\
9122 to this new inferior. The program the process was running before\n\
9123 the exec call can be restarted afterwards by restarting the original\n\
9126 same - the debugger keeps the process bound to the same inferior.\n\
9127 The new executable image replaces the previous executable loaded in\n\
9128 the inferior. Restarting the inferior after the exec call restarts\n\
9129 the executable the process was running after the exec call.\n\
9131 By default, the debugger will use the same inferior."),
9133 show_follow_exec_mode_string,
9134 &setlist, &showlist);
9136 add_setshow_enum_cmd ("scheduler-locking", class_run,
9137 scheduler_enums, &scheduler_mode, _("\
9138 Set mode for locking scheduler during execution."), _("\
9139 Show mode for locking scheduler during execution."), _("\
9140 off == no locking (threads may preempt at any time)\n\
9141 on == full locking (no thread except the current thread may run)\n\
9142 This applies to both normal execution and replay mode.\n\
9143 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9144 In this mode, other threads may run during other commands.\n\
9145 This applies to both normal execution and replay mode.\n\
9146 replay == scheduler locked in replay mode and unlocked during normal execution."),
9147 set_schedlock_func, /* traps on target vector */
9148 show_scheduler_mode,
9149 &setlist, &showlist);
9151 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9152 Set mode for resuming threads of all processes."), _("\
9153 Show mode for resuming threads of all processes."), _("\
9154 When on, execution commands (such as 'continue' or 'next') resume all\n\
9155 threads of all processes. When off (which is the default), execution\n\
9156 commands only resume the threads of the current process. The set of\n\
9157 threads that are resumed is further refined by the scheduler-locking\n\
9158 mode (see help set scheduler-locking)."),
9160 show_schedule_multiple,
9161 &setlist, &showlist);
9163 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9164 Set mode of the step operation."), _("\
9165 Show mode of the step operation."), _("\
9166 When set, doing a step over a function without debug line information\n\
9167 will stop at the first instruction of that function. Otherwise, the\n\
9168 function is skipped and the step command stops at a different source line."),
9170 show_step_stop_if_no_debug,
9171 &setlist, &showlist);
9173 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9174 &can_use_displaced_stepping, _("\
9175 Set debugger's willingness to use displaced stepping."), _("\
9176 Show debugger's willingness to use displaced stepping."), _("\
9177 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9178 supported by the target architecture. If off, gdb will not use displaced\n\
9179 stepping to step over breakpoints, even if such is supported by the target\n\
9180 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9181 if the target architecture supports it and non-stop mode is active, but will not\n\
9182 use it in all-stop mode (see help set non-stop)."),
9184 show_can_use_displaced_stepping,
9185 &setlist, &showlist);
9187 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9188 &exec_direction, _("Set direction of execution.\n\
9189 Options are 'forward' or 'reverse'."),
9190 _("Show direction of execution (forward/reverse)."),
9191 _("Tells gdb whether to execute forward or backward."),
9192 set_exec_direction_func, show_exec_direction_func,
9193 &setlist, &showlist);
9195 /* Set/show detach-on-fork: user-settable mode. */
9197 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9198 Set whether gdb will detach the child of a fork."), _("\
9199 Show whether gdb will detach the child of a fork."), _("\
9200 Tells gdb whether to detach the child of a fork."),
9201 NULL, NULL, &setlist, &showlist);
9203 /* Set/show disable address space randomization mode. */
9205 add_setshow_boolean_cmd ("disable-randomization", class_support,
9206 &disable_randomization, _("\
9207 Set disabling of debuggee's virtual address space randomization."), _("\
9208 Show disabling of debuggee's virtual address space randomization."), _("\
9209 When this mode is on (which is the default), randomization of the virtual\n\
9210 address space is disabled. Standalone programs run with the randomization\n\
9211 enabled by default on some platforms."),
9212 &set_disable_randomization,
9213 &show_disable_randomization,
9214 &setlist, &showlist);
9216 /* ptid initializations */
9217 inferior_ptid = null_ptid;
9218 target_last_wait_ptid = minus_one_ptid;
9220 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9221 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9222 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9223 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9225 /* Explicitly create without lookup, since that tries to create a
9226 value with a void typed value, and when we get here, gdbarch
9227 isn't initialized yet. At this point, we're quite sure there
9228 isn't another convenience variable of the same name. */
9229 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9231 add_setshow_boolean_cmd ("observer", no_class,
9232 &observer_mode_1, _("\
9233 Set whether gdb controls the inferior in observer mode."), _("\
9234 Show whether gdb controls the inferior in observer mode."), _("\
9235 In observer mode, GDB can get data from the inferior, but not\n\
9236 affect its execution. Registers and memory may not be changed,\n\
9237 breakpoints may not be set, and the program cannot be interrupted\n\