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"
72 /* Prototypes for local functions */
74 static void sig_print_info (enum gdb_signal);
76 static void sig_print_header (void);
78 static int follow_fork (void);
80 static int follow_fork_inferior (int follow_child, int detach_fork);
82 static void follow_inferior_reset_breakpoints (void);
84 static int currently_stepping (struct thread_info *tp);
86 void nullify_last_target_wait_ptid (void);
88 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
90 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
92 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
94 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
96 static void resume (gdb_signal sig);
98 /* Asynchronous signal handler registered as event loop source for
99 when we have pending events ready to be passed to the core. */
100 static struct async_event_handler *infrun_async_inferior_event_token;
102 /* Stores whether infrun_async was previously enabled or disabled.
103 Starts off as -1, indicating "never enabled/disabled". */
104 static int infrun_is_async = -1;
109 infrun_async (int enable)
111 if (infrun_is_async != enable)
113 infrun_is_async = enable;
116 fprintf_unfiltered (gdb_stdlog,
117 "infrun: infrun_async(%d)\n",
121 mark_async_event_handler (infrun_async_inferior_event_token);
123 clear_async_event_handler (infrun_async_inferior_event_token);
130 mark_infrun_async_event_handler (void)
132 mark_async_event_handler (infrun_async_inferior_event_token);
135 /* When set, stop the 'step' command if we enter a function which has
136 no line number information. The normal behavior is that we step
137 over such function. */
138 int step_stop_if_no_debug = 0;
140 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
141 struct cmd_list_element *c, const char *value)
143 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
146 /* proceed and normal_stop use this to notify the user when the
147 inferior stopped in a different thread than it had been running
150 static ptid_t previous_inferior_ptid;
152 /* If set (default for legacy reasons), when following a fork, GDB
153 will detach from one of the fork branches, child or parent.
154 Exactly which branch is detached depends on 'set follow-fork-mode'
157 static int detach_fork = 1;
159 int debug_displaced = 0;
161 show_debug_displaced (struct ui_file *file, int from_tty,
162 struct cmd_list_element *c, const char *value)
164 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
167 unsigned int debug_infrun = 0;
169 show_debug_infrun (struct ui_file *file, int from_tty,
170 struct cmd_list_element *c, const char *value)
172 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
176 /* Support for disabling address space randomization. */
178 int disable_randomization = 1;
181 show_disable_randomization (struct ui_file *file, int from_tty,
182 struct cmd_list_element *c, const char *value)
184 if (target_supports_disable_randomization ())
185 fprintf_filtered (file,
186 _("Disabling randomization of debuggee's "
187 "virtual address space is %s.\n"),
190 fputs_filtered (_("Disabling randomization of debuggee's "
191 "virtual address space is unsupported on\n"
192 "this platform.\n"), file);
196 set_disable_randomization (const char *args, int from_tty,
197 struct cmd_list_element *c)
199 if (!target_supports_disable_randomization ())
200 error (_("Disabling randomization of debuggee's "
201 "virtual address space is unsupported on\n"
205 /* User interface for non-stop mode. */
208 static int non_stop_1 = 0;
211 set_non_stop (const char *args, int from_tty,
212 struct cmd_list_element *c)
214 if (target_has_execution)
216 non_stop_1 = non_stop;
217 error (_("Cannot change this setting while the inferior is running."));
220 non_stop = non_stop_1;
224 show_non_stop (struct ui_file *file, int from_tty,
225 struct cmd_list_element *c, const char *value)
227 fprintf_filtered (file,
228 _("Controlling the inferior in non-stop mode is %s.\n"),
232 /* "Observer mode" is somewhat like a more extreme version of
233 non-stop, in which all GDB operations that might affect the
234 target's execution have been disabled. */
236 int observer_mode = 0;
237 static int observer_mode_1 = 0;
240 set_observer_mode (const char *args, int from_tty,
241 struct cmd_list_element *c)
243 if (target_has_execution)
245 observer_mode_1 = observer_mode;
246 error (_("Cannot change this setting while the inferior is running."));
249 observer_mode = observer_mode_1;
251 may_write_registers = !observer_mode;
252 may_write_memory = !observer_mode;
253 may_insert_breakpoints = !observer_mode;
254 may_insert_tracepoints = !observer_mode;
255 /* We can insert fast tracepoints in or out of observer mode,
256 but enable them if we're going into this mode. */
258 may_insert_fast_tracepoints = 1;
259 may_stop = !observer_mode;
260 update_target_permissions ();
262 /* Going *into* observer mode we must force non-stop, then
263 going out we leave it that way. */
266 pagination_enabled = 0;
267 non_stop = non_stop_1 = 1;
271 printf_filtered (_("Observer mode is now %s.\n"),
272 (observer_mode ? "on" : "off"));
276 show_observer_mode (struct ui_file *file, int from_tty,
277 struct cmd_list_element *c, const char *value)
279 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
282 /* This updates the value of observer mode based on changes in
283 permissions. Note that we are deliberately ignoring the values of
284 may-write-registers and may-write-memory, since the user may have
285 reason to enable these during a session, for instance to turn on a
286 debugging-related global. */
289 update_observer_mode (void)
293 newval = (!may_insert_breakpoints
294 && !may_insert_tracepoints
295 && may_insert_fast_tracepoints
299 /* Let the user know if things change. */
300 if (newval != observer_mode)
301 printf_filtered (_("Observer mode is now %s.\n"),
302 (newval ? "on" : "off"));
304 observer_mode = observer_mode_1 = newval;
307 /* Tables of how to react to signals; the user sets them. */
309 static unsigned char signal_stop[GDB_SIGNAL_LAST];
310 static unsigned char signal_print[GDB_SIGNAL_LAST];
311 static unsigned char signal_program[GDB_SIGNAL_LAST];
313 /* Table of signals that are registered with "catch signal". A
314 non-zero entry indicates that the signal is caught by some "catch
316 static unsigned char signal_catch[GDB_SIGNAL_LAST];
318 /* Table of signals that the target may silently handle.
319 This is automatically determined from the flags above,
320 and simply cached here. */
321 static unsigned char signal_pass[GDB_SIGNAL_LAST];
323 #define SET_SIGS(nsigs,sigs,flags) \
325 int signum = (nsigs); \
326 while (signum-- > 0) \
327 if ((sigs)[signum]) \
328 (flags)[signum] = 1; \
331 #define UNSET_SIGS(nsigs,sigs,flags) \
333 int signum = (nsigs); \
334 while (signum-- > 0) \
335 if ((sigs)[signum]) \
336 (flags)[signum] = 0; \
339 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
340 this function is to avoid exporting `signal_program'. */
343 update_signals_program_target (void)
345 target_program_signals (signal_program);
348 /* Value to pass to target_resume() to cause all threads to resume. */
350 #define RESUME_ALL minus_one_ptid
352 /* Command list pointer for the "stop" placeholder. */
354 static struct cmd_list_element *stop_command;
356 /* Nonzero if we want to give control to the user when we're notified
357 of shared library events by the dynamic linker. */
358 int stop_on_solib_events;
360 /* Enable or disable optional shared library event breakpoints
361 as appropriate when the above flag is changed. */
364 set_stop_on_solib_events (const char *args,
365 int from_tty, struct cmd_list_element *c)
367 update_solib_breakpoints ();
371 show_stop_on_solib_events (struct ui_file *file, int from_tty,
372 struct cmd_list_element *c, const char *value)
374 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
378 /* Nonzero after stop if current stack frame should be printed. */
380 static int stop_print_frame;
382 /* This is a cached copy of the pid/waitstatus of the last event
383 returned by target_wait()/deprecated_target_wait_hook(). This
384 information is returned by get_last_target_status(). */
385 static ptid_t target_last_wait_ptid;
386 static struct target_waitstatus target_last_waitstatus;
388 void init_thread_stepping_state (struct thread_info *tss);
390 static const char follow_fork_mode_child[] = "child";
391 static const char follow_fork_mode_parent[] = "parent";
393 static const char *const follow_fork_mode_kind_names[] = {
394 follow_fork_mode_child,
395 follow_fork_mode_parent,
399 static const char *follow_fork_mode_string = follow_fork_mode_parent;
401 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
402 struct cmd_list_element *c, const char *value)
404 fprintf_filtered (file,
405 _("Debugger response to a program "
406 "call of fork or vfork is \"%s\".\n"),
411 /* Handle changes to the inferior list based on the type of fork,
412 which process is being followed, and whether the other process
413 should be detached. On entry inferior_ptid must be the ptid of
414 the fork parent. At return inferior_ptid is the ptid of the
415 followed inferior. */
418 follow_fork_inferior (int follow_child, int detach_fork)
421 ptid_t parent_ptid, child_ptid;
423 has_vforked = (inferior_thread ()->pending_follow.kind
424 == TARGET_WAITKIND_VFORKED);
425 parent_ptid = inferior_ptid;
426 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
429 && !non_stop /* Non-stop always resumes both branches. */
430 && current_ui->prompt_state == PROMPT_BLOCKED
431 && !(follow_child || detach_fork || sched_multi))
433 /* The parent stays blocked inside the vfork syscall until the
434 child execs or exits. If we don't let the child run, then
435 the parent stays blocked. If we're telling the parent to run
436 in the foreground, the user will not be able to ctrl-c to get
437 back the terminal, effectively hanging the debug session. */
438 fprintf_filtered (gdb_stderr, _("\
439 Can not resume the parent process over vfork in the foreground while\n\
440 holding the child stopped. Try \"set detach-on-fork\" or \
441 \"set schedule-multiple\".\n"));
442 /* FIXME output string > 80 columns. */
448 /* Detach new forked process? */
451 /* Before detaching from the child, remove all breakpoints
452 from it. If we forked, then this has already been taken
453 care of by infrun.c. If we vforked however, any
454 breakpoint inserted in the parent is visible in the
455 child, even those added while stopped in a vfork
456 catchpoint. This will remove the breakpoints from the
457 parent also, but they'll be reinserted below. */
460 /* Keep breakpoints list in sync. */
461 remove_breakpoints_inf (current_inferior ());
464 if (print_inferior_events)
466 /* Ensure that we have a process ptid. */
467 ptid_t process_ptid = ptid_t (child_ptid.pid ());
469 target_terminal::ours_for_output ();
470 fprintf_filtered (gdb_stdlog,
471 _("[Detaching after %s from child %s]\n"),
472 has_vforked ? "vfork" : "fork",
473 target_pid_to_str (process_ptid));
478 struct inferior *parent_inf, *child_inf;
480 /* Add process to GDB's tables. */
481 child_inf = add_inferior (child_ptid.pid ());
483 parent_inf = current_inferior ();
484 child_inf->attach_flag = parent_inf->attach_flag;
485 copy_terminal_info (child_inf, parent_inf);
486 child_inf->gdbarch = parent_inf->gdbarch;
487 copy_inferior_target_desc_info (child_inf, parent_inf);
489 scoped_restore_current_pspace_and_thread restore_pspace_thread;
491 inferior_ptid = child_ptid;
492 add_thread_silent (inferior_ptid);
493 set_current_inferior (child_inf);
494 child_inf->symfile_flags = SYMFILE_NO_READ;
496 /* If this is a vfork child, then the address-space is
497 shared with the parent. */
500 child_inf->pspace = parent_inf->pspace;
501 child_inf->aspace = parent_inf->aspace;
503 /* The parent will be frozen until the child is done
504 with the shared region. Keep track of the
506 child_inf->vfork_parent = parent_inf;
507 child_inf->pending_detach = 0;
508 parent_inf->vfork_child = child_inf;
509 parent_inf->pending_detach = 0;
513 child_inf->aspace = new_address_space ();
514 child_inf->pspace = new program_space (child_inf->aspace);
515 child_inf->removable = 1;
516 set_current_program_space (child_inf->pspace);
517 clone_program_space (child_inf->pspace, parent_inf->pspace);
519 /* Let the shared library layer (e.g., solib-svr4) learn
520 about this new process, relocate the cloned exec, pull
521 in shared libraries, and install the solib event
522 breakpoint. If a "cloned-VM" event was propagated
523 better throughout the core, this wouldn't be
525 solib_create_inferior_hook (0);
531 struct inferior *parent_inf;
533 parent_inf = current_inferior ();
535 /* If we detached from the child, then we have to be careful
536 to not insert breakpoints in the parent until the child
537 is done with the shared memory region. However, if we're
538 staying attached to the child, then we can and should
539 insert breakpoints, so that we can debug it. A
540 subsequent child exec or exit is enough to know when does
541 the child stops using the parent's address space. */
542 parent_inf->waiting_for_vfork_done = detach_fork;
543 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
548 /* Follow the child. */
549 struct inferior *parent_inf, *child_inf;
550 struct program_space *parent_pspace;
552 if (print_inferior_events)
554 std::string parent_pid = target_pid_to_str (parent_ptid);
555 std::string child_pid = target_pid_to_str (child_ptid);
557 target_terminal::ours_for_output ();
558 fprintf_filtered (gdb_stdlog,
559 _("[Attaching after %s %s to child %s]\n"),
561 has_vforked ? "vfork" : "fork",
565 /* Add the new inferior first, so that the target_detach below
566 doesn't unpush the target. */
568 child_inf = add_inferior (child_ptid.pid ());
570 parent_inf = current_inferior ();
571 child_inf->attach_flag = parent_inf->attach_flag;
572 copy_terminal_info (child_inf, parent_inf);
573 child_inf->gdbarch = parent_inf->gdbarch;
574 copy_inferior_target_desc_info (child_inf, parent_inf);
576 parent_pspace = parent_inf->pspace;
578 /* If we're vforking, we want to hold on to the parent until the
579 child exits or execs. At child exec or exit time we can
580 remove the old breakpoints from the parent and detach or
581 resume debugging it. Otherwise, detach the parent now; we'll
582 want to reuse it's program/address spaces, but we can't set
583 them to the child before removing breakpoints from the
584 parent, otherwise, the breakpoints module could decide to
585 remove breakpoints from the wrong process (since they'd be
586 assigned to the same address space). */
590 gdb_assert (child_inf->vfork_parent == NULL);
591 gdb_assert (parent_inf->vfork_child == NULL);
592 child_inf->vfork_parent = parent_inf;
593 child_inf->pending_detach = 0;
594 parent_inf->vfork_child = child_inf;
595 parent_inf->pending_detach = detach_fork;
596 parent_inf->waiting_for_vfork_done = 0;
598 else if (detach_fork)
600 if (print_inferior_events)
602 /* Ensure that we have a process ptid. */
603 ptid_t process_ptid = ptid_t (parent_ptid.pid ());
605 target_terminal::ours_for_output ();
606 fprintf_filtered (gdb_stdlog,
607 _("[Detaching after fork from "
609 target_pid_to_str (process_ptid));
612 target_detach (parent_inf, 0);
615 /* Note that the detach above makes PARENT_INF dangling. */
617 /* Add the child thread to the appropriate lists, and switch to
618 this new thread, before cloning the program space, and
619 informing the solib layer about this new process. */
621 inferior_ptid = child_ptid;
622 add_thread_silent (inferior_ptid);
623 set_current_inferior (child_inf);
625 /* If this is a vfork child, then the address-space is shared
626 with the parent. If we detached from the parent, then we can
627 reuse the parent's program/address spaces. */
628 if (has_vforked || detach_fork)
630 child_inf->pspace = parent_pspace;
631 child_inf->aspace = child_inf->pspace->aspace;
635 child_inf->aspace = new_address_space ();
636 child_inf->pspace = new program_space (child_inf->aspace);
637 child_inf->removable = 1;
638 child_inf->symfile_flags = SYMFILE_NO_READ;
639 set_current_program_space (child_inf->pspace);
640 clone_program_space (child_inf->pspace, parent_pspace);
642 /* Let the shared library layer (e.g., solib-svr4) learn
643 about this new process, relocate the cloned exec, pull in
644 shared libraries, and install the solib event breakpoint.
645 If a "cloned-VM" event was propagated better throughout
646 the core, this wouldn't be required. */
647 solib_create_inferior_hook (0);
651 return target_follow_fork (follow_child, detach_fork);
654 /* Tell the target to follow the fork we're stopped at. Returns true
655 if the inferior should be resumed; false, if the target for some
656 reason decided it's best not to resume. */
661 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
662 int should_resume = 1;
663 struct thread_info *tp;
665 /* Copy user stepping state to the new inferior thread. FIXME: the
666 followed fork child thread should have a copy of most of the
667 parent thread structure's run control related fields, not just these.
668 Initialized to avoid "may be used uninitialized" warnings from gcc. */
669 struct breakpoint *step_resume_breakpoint = NULL;
670 struct breakpoint *exception_resume_breakpoint = NULL;
671 CORE_ADDR step_range_start = 0;
672 CORE_ADDR step_range_end = 0;
673 struct frame_id step_frame_id = { 0 };
674 struct thread_fsm *thread_fsm = NULL;
679 struct target_waitstatus wait_status;
681 /* Get the last target status returned by target_wait(). */
682 get_last_target_status (&wait_ptid, &wait_status);
684 /* If not stopped at a fork event, then there's nothing else to
686 if (wait_status.kind != TARGET_WAITKIND_FORKED
687 && wait_status.kind != TARGET_WAITKIND_VFORKED)
690 /* Check if we switched over from WAIT_PTID, since the event was
692 if (wait_ptid != minus_one_ptid
693 && inferior_ptid != wait_ptid)
695 /* We did. Switch back to WAIT_PTID thread, to tell the
696 target to follow it (in either direction). We'll
697 afterwards refuse to resume, and inform the user what
699 thread_info *wait_thread
700 = find_thread_ptid (wait_ptid);
701 switch_to_thread (wait_thread);
706 tp = inferior_thread ();
708 /* If there were any forks/vforks that were caught and are now to be
709 followed, then do so now. */
710 switch (tp->pending_follow.kind)
712 case TARGET_WAITKIND_FORKED:
713 case TARGET_WAITKIND_VFORKED:
715 ptid_t parent, child;
717 /* If the user did a next/step, etc, over a fork call,
718 preserve the stepping state in the fork child. */
719 if (follow_child && should_resume)
721 step_resume_breakpoint = clone_momentary_breakpoint
722 (tp->control.step_resume_breakpoint);
723 step_range_start = tp->control.step_range_start;
724 step_range_end = tp->control.step_range_end;
725 step_frame_id = tp->control.step_frame_id;
726 exception_resume_breakpoint
727 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
728 thread_fsm = tp->thread_fsm;
730 /* For now, delete the parent's sr breakpoint, otherwise,
731 parent/child sr breakpoints are considered duplicates,
732 and the child version will not be installed. Remove
733 this when the breakpoints module becomes aware of
734 inferiors and address spaces. */
735 delete_step_resume_breakpoint (tp);
736 tp->control.step_range_start = 0;
737 tp->control.step_range_end = 0;
738 tp->control.step_frame_id = null_frame_id;
739 delete_exception_resume_breakpoint (tp);
740 tp->thread_fsm = NULL;
743 parent = inferior_ptid;
744 child = tp->pending_follow.value.related_pid;
746 /* Set up inferior(s) as specified by the caller, and tell the
747 target to do whatever is necessary to follow either parent
749 if (follow_fork_inferior (follow_child, detach_fork))
751 /* Target refused to follow, or there's some other reason
752 we shouldn't resume. */
757 /* This pending follow fork event is now handled, one way
758 or another. The previous selected thread may be gone
759 from the lists by now, but if it is still around, need
760 to clear the pending follow request. */
761 tp = find_thread_ptid (parent);
763 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
765 /* This makes sure we don't try to apply the "Switched
766 over from WAIT_PID" logic above. */
767 nullify_last_target_wait_ptid ();
769 /* If we followed the child, switch to it... */
772 thread_info *child_thr = find_thread_ptid (child);
773 switch_to_thread (child_thr);
775 /* ... and preserve the stepping state, in case the
776 user was stepping over the fork call. */
779 tp = inferior_thread ();
780 tp->control.step_resume_breakpoint
781 = step_resume_breakpoint;
782 tp->control.step_range_start = step_range_start;
783 tp->control.step_range_end = step_range_end;
784 tp->control.step_frame_id = step_frame_id;
785 tp->control.exception_resume_breakpoint
786 = exception_resume_breakpoint;
787 tp->thread_fsm = thread_fsm;
791 /* If we get here, it was because we're trying to
792 resume from a fork catchpoint, but, the user
793 has switched threads away from the thread that
794 forked. In that case, the resume command
795 issued is most likely not applicable to the
796 child, so just warn, and refuse to resume. */
797 warning (_("Not resuming: switched threads "
798 "before following fork child."));
801 /* Reset breakpoints in the child as appropriate. */
802 follow_inferior_reset_breakpoints ();
807 case TARGET_WAITKIND_SPURIOUS:
808 /* Nothing to follow. */
811 internal_error (__FILE__, __LINE__,
812 "Unexpected pending_follow.kind %d\n",
813 tp->pending_follow.kind);
817 return should_resume;
821 follow_inferior_reset_breakpoints (void)
823 struct thread_info *tp = inferior_thread ();
825 /* Was there a step_resume breakpoint? (There was if the user
826 did a "next" at the fork() call.) If so, explicitly reset its
827 thread number. Cloned step_resume breakpoints are disabled on
828 creation, so enable it here now that it is associated with the
831 step_resumes are a form of bp that are made to be per-thread.
832 Since we created the step_resume bp when the parent process
833 was being debugged, and now are switching to the child process,
834 from the breakpoint package's viewpoint, that's a switch of
835 "threads". We must update the bp's notion of which thread
836 it is for, or it'll be ignored when it triggers. */
838 if (tp->control.step_resume_breakpoint)
840 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
841 tp->control.step_resume_breakpoint->loc->enabled = 1;
844 /* Treat exception_resume breakpoints like step_resume breakpoints. */
845 if (tp->control.exception_resume_breakpoint)
847 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
848 tp->control.exception_resume_breakpoint->loc->enabled = 1;
851 /* Reinsert all breakpoints in the child. The user may have set
852 breakpoints after catching the fork, in which case those
853 were never set in the child, but only in the parent. This makes
854 sure the inserted breakpoints match the breakpoint list. */
856 breakpoint_re_set ();
857 insert_breakpoints ();
860 /* The child has exited or execed: resume threads of the parent the
861 user wanted to be executing. */
864 proceed_after_vfork_done (struct thread_info *thread,
867 int pid = * (int *) arg;
869 if (thread->ptid.pid () == pid
870 && thread->state == THREAD_RUNNING
871 && !thread->executing
872 && !thread->stop_requested
873 && thread->suspend.stop_signal == GDB_SIGNAL_0)
876 fprintf_unfiltered (gdb_stdlog,
877 "infrun: resuming vfork parent thread %s\n",
878 target_pid_to_str (thread->ptid));
880 switch_to_thread (thread);
881 clear_proceed_status (0);
882 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
888 /* Save/restore inferior_ptid, current program space and current
889 inferior. Only use this if the current context points at an exited
890 inferior (and therefore there's no current thread to save). */
891 class scoped_restore_exited_inferior
894 scoped_restore_exited_inferior ()
895 : m_saved_ptid (&inferior_ptid)
899 scoped_restore_tmpl<ptid_t> m_saved_ptid;
900 scoped_restore_current_program_space m_pspace;
901 scoped_restore_current_inferior m_inferior;
904 /* Called whenever we notice an exec or exit event, to handle
905 detaching or resuming a vfork parent. */
908 handle_vfork_child_exec_or_exit (int exec)
910 struct inferior *inf = current_inferior ();
912 if (inf->vfork_parent)
914 int resume_parent = -1;
916 /* This exec or exit marks the end of the shared memory region
917 between the parent and the child. If the user wanted to
918 detach from the parent, now is the time. */
920 if (inf->vfork_parent->pending_detach)
922 struct thread_info *tp;
923 struct program_space *pspace;
924 struct address_space *aspace;
926 /* follow-fork child, detach-on-fork on. */
928 inf->vfork_parent->pending_detach = 0;
930 gdb::optional<scoped_restore_exited_inferior>
931 maybe_restore_inferior;
932 gdb::optional<scoped_restore_current_pspace_and_thread>
933 maybe_restore_thread;
935 /* If we're handling a child exit, then inferior_ptid points
936 at the inferior's pid, not to a thread. */
938 maybe_restore_inferior.emplace ();
940 maybe_restore_thread.emplace ();
942 /* We're letting loose of the parent. */
943 tp = any_live_thread_of_inferior (inf->vfork_parent);
944 switch_to_thread (tp);
946 /* We're about to detach from the parent, which implicitly
947 removes breakpoints from its address space. There's a
948 catch here: we want to reuse the spaces for the child,
949 but, parent/child are still sharing the pspace at this
950 point, although the exec in reality makes the kernel give
951 the child a fresh set of new pages. The problem here is
952 that the breakpoints module being unaware of this, would
953 likely chose the child process to write to the parent
954 address space. Swapping the child temporarily away from
955 the spaces has the desired effect. Yes, this is "sort
958 pspace = inf->pspace;
959 aspace = inf->aspace;
963 if (print_inferior_events)
966 = target_pid_to_str (ptid_t (inf->vfork_parent->pid));
968 target_terminal::ours_for_output ();
972 fprintf_filtered (gdb_stdlog,
973 _("[Detaching vfork parent %s "
974 "after child exec]\n"), pidstr);
978 fprintf_filtered (gdb_stdlog,
979 _("[Detaching vfork parent %s "
980 "after child exit]\n"), pidstr);
984 target_detach (inf->vfork_parent, 0);
987 inf->pspace = pspace;
988 inf->aspace = aspace;
992 /* We're staying attached to the parent, so, really give the
993 child a new address space. */
994 inf->pspace = new program_space (maybe_new_address_space ());
995 inf->aspace = inf->pspace->aspace;
997 set_current_program_space (inf->pspace);
999 resume_parent = inf->vfork_parent->pid;
1001 /* Break the bonds. */
1002 inf->vfork_parent->vfork_child = NULL;
1006 struct program_space *pspace;
1008 /* If this is a vfork child exiting, then the pspace and
1009 aspaces were shared with the parent. Since we're
1010 reporting the process exit, we'll be mourning all that is
1011 found in the address space, and switching to null_ptid,
1012 preparing to start a new inferior. But, since we don't
1013 want to clobber the parent's address/program spaces, we
1014 go ahead and create a new one for this exiting
1017 /* Switch to null_ptid while running clone_program_space, so
1018 that clone_program_space doesn't want to read the
1019 selected frame of a dead process. */
1020 scoped_restore restore_ptid
1021 = make_scoped_restore (&inferior_ptid, null_ptid);
1023 /* This inferior is dead, so avoid giving the breakpoints
1024 module the option to write through to it (cloning a
1025 program space resets breakpoints). */
1028 pspace = new program_space (maybe_new_address_space ());
1029 set_current_program_space (pspace);
1031 inf->symfile_flags = SYMFILE_NO_READ;
1032 clone_program_space (pspace, inf->vfork_parent->pspace);
1033 inf->pspace = pspace;
1034 inf->aspace = pspace->aspace;
1036 resume_parent = inf->vfork_parent->pid;
1037 /* Break the bonds. */
1038 inf->vfork_parent->vfork_child = NULL;
1041 inf->vfork_parent = NULL;
1043 gdb_assert (current_program_space == inf->pspace);
1045 if (non_stop && resume_parent != -1)
1047 /* If the user wanted the parent to be running, let it go
1049 scoped_restore_current_thread restore_thread;
1052 fprintf_unfiltered (gdb_stdlog,
1053 "infrun: resuming vfork parent process %d\n",
1056 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1061 /* Enum strings for "set|show follow-exec-mode". */
1063 static const char follow_exec_mode_new[] = "new";
1064 static const char follow_exec_mode_same[] = "same";
1065 static const char *const follow_exec_mode_names[] =
1067 follow_exec_mode_new,
1068 follow_exec_mode_same,
1072 static const char *follow_exec_mode_string = follow_exec_mode_same;
1074 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1075 struct cmd_list_element *c, const char *value)
1077 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1080 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1083 follow_exec (ptid_t ptid, char *exec_file_target)
1085 struct inferior *inf = current_inferior ();
1086 int pid = ptid.pid ();
1087 ptid_t process_ptid;
1089 /* This is an exec event that we actually wish to pay attention to.
1090 Refresh our symbol table to the newly exec'd program, remove any
1091 momentary bp's, etc.
1093 If there are breakpoints, they aren't really inserted now,
1094 since the exec() transformed our inferior into a fresh set
1097 We want to preserve symbolic breakpoints on the list, since
1098 we have hopes that they can be reset after the new a.out's
1099 symbol table is read.
1101 However, any "raw" breakpoints must be removed from the list
1102 (e.g., the solib bp's), since their address is probably invalid
1105 And, we DON'T want to call delete_breakpoints() here, since
1106 that may write the bp's "shadow contents" (the instruction
1107 value that was overwritten witha TRAP instruction). Since
1108 we now have a new a.out, those shadow contents aren't valid. */
1110 mark_breakpoints_out ();
1112 /* The target reports the exec event to the main thread, even if
1113 some other thread does the exec, and even if the main thread was
1114 stopped or already gone. We may still have non-leader threads of
1115 the process on our list. E.g., on targets that don't have thread
1116 exit events (like remote); or on native Linux in non-stop mode if
1117 there were only two threads in the inferior and the non-leader
1118 one is the one that execs (and nothing forces an update of the
1119 thread list up to here). When debugging remotely, it's best to
1120 avoid extra traffic, when possible, so avoid syncing the thread
1121 list with the target, and instead go ahead and delete all threads
1122 of the process but one that reported the event. Note this must
1123 be done before calling update_breakpoints_after_exec, as
1124 otherwise clearing the threads' resources would reference stale
1125 thread breakpoints -- it may have been one of these threads that
1126 stepped across the exec. We could just clear their stepping
1127 states, but as long as we're iterating, might as well delete
1128 them. Deleting them now rather than at the next user-visible
1129 stop provides a nicer sequence of events for user and MI
1131 for (thread_info *th : all_threads_safe ())
1132 if (th->ptid.pid () == pid && th->ptid != ptid)
1135 /* We also need to clear any left over stale state for the
1136 leader/event thread. E.g., if there was any step-resume
1137 breakpoint or similar, it's gone now. We cannot truly
1138 step-to-next statement through an exec(). */
1139 thread_info *th = inferior_thread ();
1140 th->control.step_resume_breakpoint = NULL;
1141 th->control.exception_resume_breakpoint = NULL;
1142 th->control.single_step_breakpoints = NULL;
1143 th->control.step_range_start = 0;
1144 th->control.step_range_end = 0;
1146 /* The user may have had the main thread held stopped in the
1147 previous image (e.g., schedlock on, or non-stop). Release
1149 th->stop_requested = 0;
1151 update_breakpoints_after_exec ();
1153 /* What is this a.out's name? */
1154 process_ptid = ptid_t (pid);
1155 printf_unfiltered (_("%s is executing new program: %s\n"),
1156 target_pid_to_str (process_ptid),
1159 /* We've followed the inferior through an exec. Therefore, the
1160 inferior has essentially been killed & reborn. */
1162 breakpoint_init_inferior (inf_execd);
1164 gdb::unique_xmalloc_ptr<char> exec_file_host
1165 = exec_file_find (exec_file_target, NULL);
1167 /* If we were unable to map the executable target pathname onto a host
1168 pathname, tell the user that. Otherwise GDB's subsequent behavior
1169 is confusing. Maybe it would even be better to stop at this point
1170 so that the user can specify a file manually before continuing. */
1171 if (exec_file_host == NULL)
1172 warning (_("Could not load symbols for executable %s.\n"
1173 "Do you need \"set sysroot\"?"),
1176 /* Reset the shared library package. This ensures that we get a
1177 shlib event when the child reaches "_start", at which point the
1178 dld will have had a chance to initialize the child. */
1179 /* Also, loading a symbol file below may trigger symbol lookups, and
1180 we don't want those to be satisfied by the libraries of the
1181 previous incarnation of this process. */
1182 no_shared_libraries (NULL, 0);
1184 if (follow_exec_mode_string == follow_exec_mode_new)
1186 /* The user wants to keep the old inferior and program spaces
1187 around. Create a new fresh one, and switch to it. */
1189 /* Do exit processing for the original inferior before setting the new
1190 inferior's pid. Having two inferiors with the same pid would confuse
1191 find_inferior_p(t)id. Transfer the terminal state and info from the
1192 old to the new inferior. */
1193 inf = add_inferior_with_spaces ();
1194 swap_terminal_info (inf, current_inferior ());
1195 exit_inferior_silent (current_inferior ());
1198 target_follow_exec (inf, exec_file_target);
1200 set_current_inferior (inf);
1201 set_current_program_space (inf->pspace);
1206 /* The old description may no longer be fit for the new image.
1207 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1208 old description; we'll read a new one below. No need to do
1209 this on "follow-exec-mode new", as the old inferior stays
1210 around (its description is later cleared/refetched on
1212 target_clear_description ();
1215 gdb_assert (current_program_space == inf->pspace);
1217 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1218 because the proper displacement for a PIE (Position Independent
1219 Executable) main symbol file will only be computed by
1220 solib_create_inferior_hook below. breakpoint_re_set would fail
1221 to insert the breakpoints with the zero displacement. */
1222 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1224 /* If the target can specify a description, read it. Must do this
1225 after flipping to the new executable (because the target supplied
1226 description must be compatible with the executable's
1227 architecture, and the old executable may e.g., be 32-bit, while
1228 the new one 64-bit), and before anything involving memory or
1230 target_find_description ();
1232 solib_create_inferior_hook (0);
1234 jit_inferior_created_hook ();
1236 breakpoint_re_set ();
1238 /* Reinsert all breakpoints. (Those which were symbolic have
1239 been reset to the proper address in the new a.out, thanks
1240 to symbol_file_command...). */
1241 insert_breakpoints ();
1243 /* The next resume of this inferior should bring it to the shlib
1244 startup breakpoints. (If the user had also set bp's on
1245 "main" from the old (parent) process, then they'll auto-
1246 matically get reset there in the new process.). */
1249 /* The queue of threads that need to do a step-over operation to get
1250 past e.g., a breakpoint. What technique is used to step over the
1251 breakpoint/watchpoint does not matter -- all threads end up in the
1252 same queue, to maintain rough temporal order of execution, in order
1253 to avoid starvation, otherwise, we could e.g., find ourselves
1254 constantly stepping the same couple threads past their breakpoints
1255 over and over, if the single-step finish fast enough. */
1256 struct thread_info *step_over_queue_head;
1258 /* Bit flags indicating what the thread needs to step over. */
1260 enum step_over_what_flag
1262 /* Step over a breakpoint. */
1263 STEP_OVER_BREAKPOINT = 1,
1265 /* Step past a non-continuable watchpoint, in order to let the
1266 instruction execute so we can evaluate the watchpoint
1268 STEP_OVER_WATCHPOINT = 2
1270 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1272 /* Info about an instruction that is being stepped over. */
1274 struct step_over_info
1276 /* If we're stepping past a breakpoint, this is the address space
1277 and address of the instruction the breakpoint is set at. We'll
1278 skip inserting all breakpoints here. Valid iff ASPACE is
1280 const address_space *aspace;
1283 /* The instruction being stepped over triggers a nonsteppable
1284 watchpoint. If true, we'll skip inserting watchpoints. */
1285 int nonsteppable_watchpoint_p;
1287 /* The thread's global number. */
1291 /* The step-over info of the location that is being stepped over.
1293 Note that with async/breakpoint always-inserted mode, a user might
1294 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1295 being stepped over. As setting a new breakpoint inserts all
1296 breakpoints, we need to make sure the breakpoint being stepped over
1297 isn't inserted then. We do that by only clearing the step-over
1298 info when the step-over is actually finished (or aborted).
1300 Presently GDB can only step over one breakpoint at any given time.
1301 Given threads that can't run code in the same address space as the
1302 breakpoint's can't really miss the breakpoint, GDB could be taught
1303 to step-over at most one breakpoint per address space (so this info
1304 could move to the address space object if/when GDB is extended).
1305 The set of breakpoints being stepped over will normally be much
1306 smaller than the set of all breakpoints, so a flag in the
1307 breakpoint location structure would be wasteful. A separate list
1308 also saves complexity and run-time, as otherwise we'd have to go
1309 through all breakpoint locations clearing their flag whenever we
1310 start a new sequence. Similar considerations weigh against storing
1311 this info in the thread object. Plus, not all step overs actually
1312 have breakpoint locations -- e.g., stepping past a single-step
1313 breakpoint, or stepping to complete a non-continuable
1315 static struct step_over_info step_over_info;
1317 /* Record the address of the breakpoint/instruction we're currently
1319 N.B. We record the aspace and address now, instead of say just the thread,
1320 because when we need the info later the thread may be running. */
1323 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1324 int nonsteppable_watchpoint_p,
1327 step_over_info.aspace = aspace;
1328 step_over_info.address = address;
1329 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1330 step_over_info.thread = thread;
1333 /* Called when we're not longer stepping over a breakpoint / an
1334 instruction, so all breakpoints are free to be (re)inserted. */
1337 clear_step_over_info (void)
1340 fprintf_unfiltered (gdb_stdlog,
1341 "infrun: clear_step_over_info\n");
1342 step_over_info.aspace = NULL;
1343 step_over_info.address = 0;
1344 step_over_info.nonsteppable_watchpoint_p = 0;
1345 step_over_info.thread = -1;
1351 stepping_past_instruction_at (struct address_space *aspace,
1354 return (step_over_info.aspace != NULL
1355 && breakpoint_address_match (aspace, address,
1356 step_over_info.aspace,
1357 step_over_info.address));
1363 thread_is_stepping_over_breakpoint (int thread)
1365 return (step_over_info.thread != -1
1366 && thread == step_over_info.thread);
1372 stepping_past_nonsteppable_watchpoint (void)
1374 return step_over_info.nonsteppable_watchpoint_p;
1377 /* Returns true if step-over info is valid. */
1380 step_over_info_valid_p (void)
1382 return (step_over_info.aspace != NULL
1383 || stepping_past_nonsteppable_watchpoint ());
1387 /* Displaced stepping. */
1389 /* In non-stop debugging mode, we must take special care to manage
1390 breakpoints properly; in particular, the traditional strategy for
1391 stepping a thread past a breakpoint it has hit is unsuitable.
1392 'Displaced stepping' is a tactic for stepping one thread past a
1393 breakpoint it has hit while ensuring that other threads running
1394 concurrently will hit the breakpoint as they should.
1396 The traditional way to step a thread T off a breakpoint in a
1397 multi-threaded program in all-stop mode is as follows:
1399 a0) Initially, all threads are stopped, and breakpoints are not
1401 a1) We single-step T, leaving breakpoints uninserted.
1402 a2) We insert breakpoints, and resume all threads.
1404 In non-stop debugging, however, this strategy is unsuitable: we
1405 don't want to have to stop all threads in the system in order to
1406 continue or step T past a breakpoint. Instead, we use displaced
1409 n0) Initially, T is stopped, other threads are running, and
1410 breakpoints are inserted.
1411 n1) We copy the instruction "under" the breakpoint to a separate
1412 location, outside the main code stream, making any adjustments
1413 to the instruction, register, and memory state as directed by
1415 n2) We single-step T over the instruction at its new location.
1416 n3) We adjust the resulting register and memory state as directed
1417 by T's architecture. This includes resetting T's PC to point
1418 back into the main instruction stream.
1421 This approach depends on the following gdbarch methods:
1423 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1424 indicate where to copy the instruction, and how much space must
1425 be reserved there. We use these in step n1.
1427 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1428 address, and makes any necessary adjustments to the instruction,
1429 register contents, and memory. We use this in step n1.
1431 - gdbarch_displaced_step_fixup adjusts registers and memory after
1432 we have successfuly single-stepped the instruction, to yield the
1433 same effect the instruction would have had if we had executed it
1434 at its original address. We use this in step n3.
1436 The gdbarch_displaced_step_copy_insn and
1437 gdbarch_displaced_step_fixup functions must be written so that
1438 copying an instruction with gdbarch_displaced_step_copy_insn,
1439 single-stepping across the copied instruction, and then applying
1440 gdbarch_displaced_insn_fixup should have the same effects on the
1441 thread's memory and registers as stepping the instruction in place
1442 would have. Exactly which responsibilities fall to the copy and
1443 which fall to the fixup is up to the author of those functions.
1445 See the comments in gdbarch.sh for details.
1447 Note that displaced stepping and software single-step cannot
1448 currently be used in combination, although with some care I think
1449 they could be made to. Software single-step works by placing
1450 breakpoints on all possible subsequent instructions; if the
1451 displaced instruction is a PC-relative jump, those breakpoints
1452 could fall in very strange places --- on pages that aren't
1453 executable, or at addresses that are not proper instruction
1454 boundaries. (We do generally let other threads run while we wait
1455 to hit the software single-step breakpoint, and they might
1456 encounter such a corrupted instruction.) One way to work around
1457 this would be to have gdbarch_displaced_step_copy_insn fully
1458 simulate the effect of PC-relative instructions (and return NULL)
1459 on architectures that use software single-stepping.
1461 In non-stop mode, we can have independent and simultaneous step
1462 requests, so more than one thread may need to simultaneously step
1463 over a breakpoint. The current implementation assumes there is
1464 only one scratch space per process. In this case, we have to
1465 serialize access to the scratch space. If thread A wants to step
1466 over a breakpoint, but we are currently waiting for some other
1467 thread to complete a displaced step, we leave thread A stopped and
1468 place it in the displaced_step_request_queue. Whenever a displaced
1469 step finishes, we pick the next thread in the queue and start a new
1470 displaced step operation on it. See displaced_step_prepare and
1471 displaced_step_fixup for details. */
1473 /* Default destructor for displaced_step_closure. */
1475 displaced_step_closure::~displaced_step_closure () = default;
1477 /* Get the displaced stepping state of process PID. */
1479 static displaced_step_inferior_state *
1480 get_displaced_stepping_state (inferior *inf)
1482 return &inf->displaced_step_state;
1485 /* Returns true if any inferior has a thread doing a displaced
1489 displaced_step_in_progress_any_inferior ()
1491 for (inferior *i : all_inferiors ())
1493 if (i->displaced_step_state.step_thread != nullptr)
1500 /* Return true if thread represented by PTID is doing a displaced
1504 displaced_step_in_progress_thread (thread_info *thread)
1506 gdb_assert (thread != NULL);
1508 return get_displaced_stepping_state (thread->inf)->step_thread == thread;
1511 /* Return true if process PID has a thread doing a displaced step. */
1514 displaced_step_in_progress (inferior *inf)
1516 return get_displaced_stepping_state (inf)->step_thread != nullptr;
1519 /* If inferior is in displaced stepping, and ADDR equals to starting address
1520 of copy area, return corresponding displaced_step_closure. Otherwise,
1523 struct displaced_step_closure*
1524 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1526 displaced_step_inferior_state *displaced
1527 = get_displaced_stepping_state (current_inferior ());
1529 /* If checking the mode of displaced instruction in copy area. */
1530 if (displaced->step_thread != nullptr
1531 && displaced->step_copy == addr)
1532 return displaced->step_closure;
1538 infrun_inferior_exit (struct inferior *inf)
1540 inf->displaced_step_state.reset ();
1543 /* If ON, and the architecture supports it, GDB will use displaced
1544 stepping to step over breakpoints. If OFF, or if the architecture
1545 doesn't support it, GDB will instead use the traditional
1546 hold-and-step approach. If AUTO (which is the default), GDB will
1547 decide which technique to use to step over breakpoints depending on
1548 which of all-stop or non-stop mode is active --- displaced stepping
1549 in non-stop mode; hold-and-step in all-stop mode. */
1551 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1554 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1555 struct cmd_list_element *c,
1558 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1559 fprintf_filtered (file,
1560 _("Debugger's willingness to use displaced stepping "
1561 "to step over breakpoints is %s (currently %s).\n"),
1562 value, target_is_non_stop_p () ? "on" : "off");
1564 fprintf_filtered (file,
1565 _("Debugger's willingness to use displaced stepping "
1566 "to step over breakpoints is %s.\n"), value);
1569 /* Return non-zero if displaced stepping can/should be used to step
1570 over breakpoints of thread TP. */
1573 use_displaced_stepping (struct thread_info *tp)
1575 struct regcache *regcache = get_thread_regcache (tp);
1576 struct gdbarch *gdbarch = regcache->arch ();
1577 displaced_step_inferior_state *displaced_state
1578 = get_displaced_stepping_state (tp->inf);
1580 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1581 && target_is_non_stop_p ())
1582 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1583 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1584 && find_record_target () == NULL
1585 && !displaced_state->failed_before);
1588 /* Clean out any stray displaced stepping state. */
1590 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1592 /* Indicate that there is no cleanup pending. */
1593 displaced->step_thread = nullptr;
1595 delete displaced->step_closure;
1596 displaced->step_closure = NULL;
1600 displaced_step_clear_cleanup (void *arg)
1602 struct displaced_step_inferior_state *state
1603 = (struct displaced_step_inferior_state *) arg;
1605 displaced_step_clear (state);
1608 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1610 displaced_step_dump_bytes (struct ui_file *file,
1611 const gdb_byte *buf,
1616 for (i = 0; i < len; i++)
1617 fprintf_unfiltered (file, "%02x ", buf[i]);
1618 fputs_unfiltered ("\n", file);
1621 /* Prepare to single-step, using displaced stepping.
1623 Note that we cannot use displaced stepping when we have a signal to
1624 deliver. If we have a signal to deliver and an instruction to step
1625 over, then after the step, there will be no indication from the
1626 target whether the thread entered a signal handler or ignored the
1627 signal and stepped over the instruction successfully --- both cases
1628 result in a simple SIGTRAP. In the first case we mustn't do a
1629 fixup, and in the second case we must --- but we can't tell which.
1630 Comments in the code for 'random signals' in handle_inferior_event
1631 explain how we handle this case instead.
1633 Returns 1 if preparing was successful -- this thread is going to be
1634 stepped now; 0 if displaced stepping this thread got queued; or -1
1635 if this instruction can't be displaced stepped. */
1638 displaced_step_prepare_throw (thread_info *tp)
1640 regcache *regcache = get_thread_regcache (tp);
1641 struct gdbarch *gdbarch = regcache->arch ();
1642 const address_space *aspace = regcache->aspace ();
1643 CORE_ADDR original, copy;
1645 struct displaced_step_closure *closure;
1648 /* We should never reach this function if the architecture does not
1649 support displaced stepping. */
1650 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1652 /* Nor if the thread isn't meant to step over a breakpoint. */
1653 gdb_assert (tp->control.trap_expected);
1655 /* Disable range stepping while executing in the scratch pad. We
1656 want a single-step even if executing the displaced instruction in
1657 the scratch buffer lands within the stepping range (e.g., a
1659 tp->control.may_range_step = 0;
1661 /* We have to displaced step one thread at a time, as we only have
1662 access to a single scratch space per inferior. */
1664 displaced_step_inferior_state *displaced
1665 = get_displaced_stepping_state (tp->inf);
1667 if (displaced->step_thread != nullptr)
1669 /* Already waiting for a displaced step to finish. Defer this
1670 request and place in queue. */
1672 if (debug_displaced)
1673 fprintf_unfiltered (gdb_stdlog,
1674 "displaced: deferring step of %s\n",
1675 target_pid_to_str (tp->ptid));
1677 thread_step_over_chain_enqueue (tp);
1682 if (debug_displaced)
1683 fprintf_unfiltered (gdb_stdlog,
1684 "displaced: stepping %s now\n",
1685 target_pid_to_str (tp->ptid));
1688 displaced_step_clear (displaced);
1690 scoped_restore_current_thread restore_thread;
1692 switch_to_thread (tp);
1694 original = regcache_read_pc (regcache);
1696 copy = gdbarch_displaced_step_location (gdbarch);
1697 len = gdbarch_max_insn_length (gdbarch);
1699 if (breakpoint_in_range_p (aspace, copy, len))
1701 /* There's a breakpoint set in the scratch pad location range
1702 (which is usually around the entry point). We'd either
1703 install it before resuming, which would overwrite/corrupt the
1704 scratch pad, or if it was already inserted, this displaced
1705 step would overwrite it. The latter is OK in the sense that
1706 we already assume that no thread is going to execute the code
1707 in the scratch pad range (after initial startup) anyway, but
1708 the former is unacceptable. Simply punt and fallback to
1709 stepping over this breakpoint in-line. */
1710 if (debug_displaced)
1712 fprintf_unfiltered (gdb_stdlog,
1713 "displaced: breakpoint set in scratch pad. "
1714 "Stepping over breakpoint in-line instead.\n");
1720 /* Save the original contents of the copy area. */
1721 displaced->step_saved_copy.resize (len);
1722 status = target_read_memory (copy, displaced->step_saved_copy.data (), len);
1724 throw_error (MEMORY_ERROR,
1725 _("Error accessing memory address %s (%s) for "
1726 "displaced-stepping scratch space."),
1727 paddress (gdbarch, copy), safe_strerror (status));
1728 if (debug_displaced)
1730 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1731 paddress (gdbarch, copy));
1732 displaced_step_dump_bytes (gdb_stdlog,
1733 displaced->step_saved_copy.data (),
1737 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1738 original, copy, regcache);
1739 if (closure == NULL)
1741 /* The architecture doesn't know how or want to displaced step
1742 this instruction or instruction sequence. Fallback to
1743 stepping over the breakpoint in-line. */
1747 /* Save the information we need to fix things up if the step
1749 displaced->step_thread = tp;
1750 displaced->step_gdbarch = gdbarch;
1751 displaced->step_closure = closure;
1752 displaced->step_original = original;
1753 displaced->step_copy = copy;
1755 cleanup *ignore_cleanups
1756 = make_cleanup (displaced_step_clear_cleanup, displaced);
1758 /* Resume execution at the copy. */
1759 regcache_write_pc (regcache, copy);
1761 discard_cleanups (ignore_cleanups);
1763 if (debug_displaced)
1764 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1765 paddress (gdbarch, copy));
1770 /* Wrapper for displaced_step_prepare_throw that disabled further
1771 attempts at displaced stepping if we get a memory error. */
1774 displaced_step_prepare (thread_info *thread)
1780 prepared = displaced_step_prepare_throw (thread);
1782 CATCH (ex, RETURN_MASK_ERROR)
1784 struct displaced_step_inferior_state *displaced_state;
1786 if (ex.error != MEMORY_ERROR
1787 && ex.error != NOT_SUPPORTED_ERROR)
1788 throw_exception (ex);
1792 fprintf_unfiltered (gdb_stdlog,
1793 "infrun: disabling displaced stepping: %s\n",
1797 /* Be verbose if "set displaced-stepping" is "on", silent if
1799 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1801 warning (_("disabling displaced stepping: %s"),
1805 /* Disable further displaced stepping attempts. */
1807 = get_displaced_stepping_state (thread->inf);
1808 displaced_state->failed_before = 1;
1816 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1817 const gdb_byte *myaddr, int len)
1819 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1821 inferior_ptid = ptid;
1822 write_memory (memaddr, myaddr, len);
1825 /* Restore the contents of the copy area for thread PTID. */
1828 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1831 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1833 write_memory_ptid (ptid, displaced->step_copy,
1834 displaced->step_saved_copy.data (), len);
1835 if (debug_displaced)
1836 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1837 target_pid_to_str (ptid),
1838 paddress (displaced->step_gdbarch,
1839 displaced->step_copy));
1842 /* If we displaced stepped an instruction successfully, adjust
1843 registers and memory to yield the same effect the instruction would
1844 have had if we had executed it at its original address, and return
1845 1. If the instruction didn't complete, relocate the PC and return
1846 -1. If the thread wasn't displaced stepping, return 0. */
1849 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1851 struct cleanup *old_cleanups;
1852 struct displaced_step_inferior_state *displaced
1853 = get_displaced_stepping_state (event_thread->inf);
1856 /* Was this event for the thread we displaced? */
1857 if (displaced->step_thread != event_thread)
1860 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1862 displaced_step_restore (displaced, displaced->step_thread->ptid);
1864 /* Fixup may need to read memory/registers. Switch to the thread
1865 that we're fixing up. Also, target_stopped_by_watchpoint checks
1866 the current thread. */
1867 switch_to_thread (event_thread);
1869 /* Did the instruction complete successfully? */
1870 if (signal == GDB_SIGNAL_TRAP
1871 && !(target_stopped_by_watchpoint ()
1872 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1873 || target_have_steppable_watchpoint)))
1875 /* Fix up the resulting state. */
1876 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1877 displaced->step_closure,
1878 displaced->step_original,
1879 displaced->step_copy,
1880 get_thread_regcache (displaced->step_thread));
1885 /* Since the instruction didn't complete, all we can do is
1887 struct regcache *regcache = get_thread_regcache (event_thread);
1888 CORE_ADDR pc = regcache_read_pc (regcache);
1890 pc = displaced->step_original + (pc - displaced->step_copy);
1891 regcache_write_pc (regcache, pc);
1895 do_cleanups (old_cleanups);
1897 displaced->step_thread = nullptr;
1902 /* Data to be passed around while handling an event. This data is
1903 discarded between events. */
1904 struct execution_control_state
1907 /* The thread that got the event, if this was a thread event; NULL
1909 struct thread_info *event_thread;
1911 struct target_waitstatus ws;
1912 int stop_func_filled_in;
1913 CORE_ADDR stop_func_start;
1914 CORE_ADDR stop_func_end;
1915 const char *stop_func_name;
1918 /* True if the event thread hit the single-step breakpoint of
1919 another thread. Thus the event doesn't cause a stop, the thread
1920 needs to be single-stepped past the single-step breakpoint before
1921 we can switch back to the original stepping thread. */
1922 int hit_singlestep_breakpoint;
1925 /* Clear ECS and set it to point at TP. */
1928 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
1930 memset (ecs, 0, sizeof (*ecs));
1931 ecs->event_thread = tp;
1932 ecs->ptid = tp->ptid;
1935 static void keep_going_pass_signal (struct execution_control_state *ecs);
1936 static void prepare_to_wait (struct execution_control_state *ecs);
1937 static int keep_going_stepped_thread (struct thread_info *tp);
1938 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
1940 /* Are there any pending step-over requests? If so, run all we can
1941 now and return true. Otherwise, return false. */
1944 start_step_over (void)
1946 struct thread_info *tp, *next;
1948 /* Don't start a new step-over if we already have an in-line
1949 step-over operation ongoing. */
1950 if (step_over_info_valid_p ())
1953 for (tp = step_over_queue_head; tp != NULL; tp = next)
1955 struct execution_control_state ecss;
1956 struct execution_control_state *ecs = &ecss;
1957 step_over_what step_what;
1958 int must_be_in_line;
1960 gdb_assert (!tp->stop_requested);
1962 next = thread_step_over_chain_next (tp);
1964 /* If this inferior already has a displaced step in process,
1965 don't start a new one. */
1966 if (displaced_step_in_progress (tp->inf))
1969 step_what = thread_still_needs_step_over (tp);
1970 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
1971 || ((step_what & STEP_OVER_BREAKPOINT)
1972 && !use_displaced_stepping (tp)));
1974 /* We currently stop all threads of all processes to step-over
1975 in-line. If we need to start a new in-line step-over, let
1976 any pending displaced steps finish first. */
1977 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
1980 thread_step_over_chain_remove (tp);
1982 if (step_over_queue_head == NULL)
1985 fprintf_unfiltered (gdb_stdlog,
1986 "infrun: step-over queue now empty\n");
1989 if (tp->control.trap_expected
1993 internal_error (__FILE__, __LINE__,
1994 "[%s] has inconsistent state: "
1995 "trap_expected=%d, resumed=%d, executing=%d\n",
1996 target_pid_to_str (tp->ptid),
1997 tp->control.trap_expected,
2003 fprintf_unfiltered (gdb_stdlog,
2004 "infrun: resuming [%s] for step-over\n",
2005 target_pid_to_str (tp->ptid));
2007 /* keep_going_pass_signal skips the step-over if the breakpoint
2008 is no longer inserted. In all-stop, we want to keep looking
2009 for a thread that needs a step-over instead of resuming TP,
2010 because we wouldn't be able to resume anything else until the
2011 target stops again. In non-stop, the resume always resumes
2012 only TP, so it's OK to let the thread resume freely. */
2013 if (!target_is_non_stop_p () && !step_what)
2016 switch_to_thread (tp);
2017 reset_ecs (ecs, tp);
2018 keep_going_pass_signal (ecs);
2020 if (!ecs->wait_some_more)
2021 error (_("Command aborted."));
2023 gdb_assert (tp->resumed);
2025 /* If we started a new in-line step-over, we're done. */
2026 if (step_over_info_valid_p ())
2028 gdb_assert (tp->control.trap_expected);
2032 if (!target_is_non_stop_p ())
2034 /* On all-stop, shouldn't have resumed unless we needed a
2036 gdb_assert (tp->control.trap_expected
2037 || tp->step_after_step_resume_breakpoint);
2039 /* With remote targets (at least), in all-stop, we can't
2040 issue any further remote commands until the program stops
2045 /* Either the thread no longer needed a step-over, or a new
2046 displaced stepping sequence started. Even in the latter
2047 case, continue looking. Maybe we can also start another
2048 displaced step on a thread of other process. */
2054 /* Update global variables holding ptids to hold NEW_PTID if they were
2055 holding OLD_PTID. */
2057 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2059 if (inferior_ptid == old_ptid)
2060 inferior_ptid = new_ptid;
2065 static const char schedlock_off[] = "off";
2066 static const char schedlock_on[] = "on";
2067 static const char schedlock_step[] = "step";
2068 static const char schedlock_replay[] = "replay";
2069 static const char *const scheduler_enums[] = {
2076 static const char *scheduler_mode = schedlock_replay;
2078 show_scheduler_mode (struct ui_file *file, int from_tty,
2079 struct cmd_list_element *c, const char *value)
2081 fprintf_filtered (file,
2082 _("Mode for locking scheduler "
2083 "during execution is \"%s\".\n"),
2088 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2090 if (!target_can_lock_scheduler)
2092 scheduler_mode = schedlock_off;
2093 error (_("Target '%s' cannot support this command."), target_shortname);
2097 /* True if execution commands resume all threads of all processes by
2098 default; otherwise, resume only threads of the current inferior
2100 int sched_multi = 0;
2102 /* Try to setup for software single stepping over the specified location.
2103 Return 1 if target_resume() should use hardware single step.
2105 GDBARCH the current gdbarch.
2106 PC the location to step over. */
2109 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2113 if (execution_direction == EXEC_FORWARD
2114 && gdbarch_software_single_step_p (gdbarch))
2115 hw_step = !insert_single_step_breakpoints (gdbarch);
2123 user_visible_resume_ptid (int step)
2129 /* With non-stop mode on, threads are always handled
2131 resume_ptid = inferior_ptid;
2133 else if ((scheduler_mode == schedlock_on)
2134 || (scheduler_mode == schedlock_step && step))
2136 /* User-settable 'scheduler' mode requires solo thread
2138 resume_ptid = inferior_ptid;
2140 else if ((scheduler_mode == schedlock_replay)
2141 && target_record_will_replay (minus_one_ptid, execution_direction))
2143 /* User-settable 'scheduler' mode requires solo thread resume in replay
2145 resume_ptid = inferior_ptid;
2147 else if (!sched_multi && target_supports_multi_process ())
2149 /* Resume all threads of the current process (and none of other
2151 resume_ptid = ptid_t (inferior_ptid.pid ());
2155 /* Resume all threads of all processes. */
2156 resume_ptid = RESUME_ALL;
2162 /* Return a ptid representing the set of threads that we will resume,
2163 in the perspective of the target, assuming run control handling
2164 does not require leaving some threads stopped (e.g., stepping past
2165 breakpoint). USER_STEP indicates whether we're about to start the
2166 target for a stepping command. */
2169 internal_resume_ptid (int user_step)
2171 /* In non-stop, we always control threads individually. Note that
2172 the target may always work in non-stop mode even with "set
2173 non-stop off", in which case user_visible_resume_ptid could
2174 return a wildcard ptid. */
2175 if (target_is_non_stop_p ())
2176 return inferior_ptid;
2178 return user_visible_resume_ptid (user_step);
2181 /* Wrapper for target_resume, that handles infrun-specific
2185 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2187 struct thread_info *tp = inferior_thread ();
2189 gdb_assert (!tp->stop_requested);
2191 /* Install inferior's terminal modes. */
2192 target_terminal::inferior ();
2194 /* Avoid confusing the next resume, if the next stop/resume
2195 happens to apply to another thread. */
2196 tp->suspend.stop_signal = GDB_SIGNAL_0;
2198 /* Advise target which signals may be handled silently.
2200 If we have removed breakpoints because we are stepping over one
2201 in-line (in any thread), we need to receive all signals to avoid
2202 accidentally skipping a breakpoint during execution of a signal
2205 Likewise if we're displaced stepping, otherwise a trap for a
2206 breakpoint in a signal handler might be confused with the
2207 displaced step finishing. We don't make the displaced_step_fixup
2208 step distinguish the cases instead, because:
2210 - a backtrace while stopped in the signal handler would show the
2211 scratch pad as frame older than the signal handler, instead of
2212 the real mainline code.
2214 - when the thread is later resumed, the signal handler would
2215 return to the scratch pad area, which would no longer be
2217 if (step_over_info_valid_p ()
2218 || displaced_step_in_progress (tp->inf))
2219 target_pass_signals ({});
2221 target_pass_signals (signal_pass);
2223 target_resume (resume_ptid, step, sig);
2225 target_commit_resume ();
2228 /* Resume the inferior. SIG is the signal to give the inferior
2229 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2230 call 'resume', which handles exceptions. */
2233 resume_1 (enum gdb_signal sig)
2235 struct regcache *regcache = get_current_regcache ();
2236 struct gdbarch *gdbarch = regcache->arch ();
2237 struct thread_info *tp = inferior_thread ();
2238 CORE_ADDR pc = regcache_read_pc (regcache);
2239 const address_space *aspace = regcache->aspace ();
2241 /* This represents the user's step vs continue request. When
2242 deciding whether "set scheduler-locking step" applies, it's the
2243 user's intention that counts. */
2244 const int user_step = tp->control.stepping_command;
2245 /* This represents what we'll actually request the target to do.
2246 This can decay from a step to a continue, if e.g., we need to
2247 implement single-stepping with breakpoints (software
2251 gdb_assert (!tp->stop_requested);
2252 gdb_assert (!thread_is_in_step_over_chain (tp));
2254 if (tp->suspend.waitstatus_pending_p)
2259 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2261 fprintf_unfiltered (gdb_stdlog,
2262 "infrun: resume: thread %s has pending wait "
2263 "status %s (currently_stepping=%d).\n",
2264 target_pid_to_str (tp->ptid), statstr.c_str (),
2265 currently_stepping (tp));
2270 /* FIXME: What should we do if we are supposed to resume this
2271 thread with a signal? Maybe we should maintain a queue of
2272 pending signals to deliver. */
2273 if (sig != GDB_SIGNAL_0)
2275 warning (_("Couldn't deliver signal %s to %s."),
2276 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2279 tp->suspend.stop_signal = GDB_SIGNAL_0;
2281 if (target_can_async_p ())
2284 /* Tell the event loop we have an event to process. */
2285 mark_async_event_handler (infrun_async_inferior_event_token);
2290 tp->stepped_breakpoint = 0;
2292 /* Depends on stepped_breakpoint. */
2293 step = currently_stepping (tp);
2295 if (current_inferior ()->waiting_for_vfork_done)
2297 /* Don't try to single-step a vfork parent that is waiting for
2298 the child to get out of the shared memory region (by exec'ing
2299 or exiting). This is particularly important on software
2300 single-step archs, as the child process would trip on the
2301 software single step breakpoint inserted for the parent
2302 process. Since the parent will not actually execute any
2303 instruction until the child is out of the shared region (such
2304 are vfork's semantics), it is safe to simply continue it.
2305 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2306 the parent, and tell it to `keep_going', which automatically
2307 re-sets it stepping. */
2309 fprintf_unfiltered (gdb_stdlog,
2310 "infrun: resume : clear step\n");
2315 fprintf_unfiltered (gdb_stdlog,
2316 "infrun: resume (step=%d, signal=%s), "
2317 "trap_expected=%d, current thread [%s] at %s\n",
2318 step, gdb_signal_to_symbol_string (sig),
2319 tp->control.trap_expected,
2320 target_pid_to_str (inferior_ptid),
2321 paddress (gdbarch, pc));
2323 /* Normally, by the time we reach `resume', the breakpoints are either
2324 removed or inserted, as appropriate. The exception is if we're sitting
2325 at a permanent breakpoint; we need to step over it, but permanent
2326 breakpoints can't be removed. So we have to test for it here. */
2327 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2329 if (sig != GDB_SIGNAL_0)
2331 /* We have a signal to pass to the inferior. The resume
2332 may, or may not take us to the signal handler. If this
2333 is a step, we'll need to stop in the signal handler, if
2334 there's one, (if the target supports stepping into
2335 handlers), or in the next mainline instruction, if
2336 there's no handler. If this is a continue, we need to be
2337 sure to run the handler with all breakpoints inserted.
2338 In all cases, set a breakpoint at the current address
2339 (where the handler returns to), and once that breakpoint
2340 is hit, resume skipping the permanent breakpoint. If
2341 that breakpoint isn't hit, then we've stepped into the
2342 signal handler (or hit some other event). We'll delete
2343 the step-resume breakpoint then. */
2346 fprintf_unfiltered (gdb_stdlog,
2347 "infrun: resume: skipping permanent breakpoint, "
2348 "deliver signal first\n");
2350 clear_step_over_info ();
2351 tp->control.trap_expected = 0;
2353 if (tp->control.step_resume_breakpoint == NULL)
2355 /* Set a "high-priority" step-resume, as we don't want
2356 user breakpoints at PC to trigger (again) when this
2358 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2359 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2361 tp->step_after_step_resume_breakpoint = step;
2364 insert_breakpoints ();
2368 /* There's no signal to pass, we can go ahead and skip the
2369 permanent breakpoint manually. */
2371 fprintf_unfiltered (gdb_stdlog,
2372 "infrun: resume: skipping permanent breakpoint\n");
2373 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2374 /* Update pc to reflect the new address from which we will
2375 execute instructions. */
2376 pc = regcache_read_pc (regcache);
2380 /* We've already advanced the PC, so the stepping part
2381 is done. Now we need to arrange for a trap to be
2382 reported to handle_inferior_event. Set a breakpoint
2383 at the current PC, and run to it. Don't update
2384 prev_pc, because if we end in
2385 switch_back_to_stepped_thread, we want the "expected
2386 thread advanced also" branch to be taken. IOW, we
2387 don't want this thread to step further from PC
2389 gdb_assert (!step_over_info_valid_p ());
2390 insert_single_step_breakpoint (gdbarch, aspace, pc);
2391 insert_breakpoints ();
2393 resume_ptid = internal_resume_ptid (user_step);
2394 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2401 /* If we have a breakpoint to step over, make sure to do a single
2402 step only. Same if we have software watchpoints. */
2403 if (tp->control.trap_expected || bpstat_should_step ())
2404 tp->control.may_range_step = 0;
2406 /* If enabled, step over breakpoints by executing a copy of the
2407 instruction at a different address.
2409 We can't use displaced stepping when we have a signal to deliver;
2410 the comments for displaced_step_prepare explain why. The
2411 comments in the handle_inferior event for dealing with 'random
2412 signals' explain what we do instead.
2414 We can't use displaced stepping when we are waiting for vfork_done
2415 event, displaced stepping breaks the vfork child similarly as single
2416 step software breakpoint. */
2417 if (tp->control.trap_expected
2418 && use_displaced_stepping (tp)
2419 && !step_over_info_valid_p ()
2420 && sig == GDB_SIGNAL_0
2421 && !current_inferior ()->waiting_for_vfork_done)
2423 int prepared = displaced_step_prepare (tp);
2428 fprintf_unfiltered (gdb_stdlog,
2429 "Got placed in step-over queue\n");
2431 tp->control.trap_expected = 0;
2434 else if (prepared < 0)
2436 /* Fallback to stepping over the breakpoint in-line. */
2438 if (target_is_non_stop_p ())
2439 stop_all_threads ();
2441 set_step_over_info (regcache->aspace (),
2442 regcache_read_pc (regcache), 0, tp->global_num);
2444 step = maybe_software_singlestep (gdbarch, pc);
2446 insert_breakpoints ();
2448 else if (prepared > 0)
2450 struct displaced_step_inferior_state *displaced;
2452 /* Update pc to reflect the new address from which we will
2453 execute instructions due to displaced stepping. */
2454 pc = regcache_read_pc (get_thread_regcache (tp));
2456 displaced = get_displaced_stepping_state (tp->inf);
2457 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2458 displaced->step_closure);
2462 /* Do we need to do it the hard way, w/temp breakpoints? */
2464 step = maybe_software_singlestep (gdbarch, pc);
2466 /* Currently, our software single-step implementation leads to different
2467 results than hardware single-stepping in one situation: when stepping
2468 into delivering a signal which has an associated signal handler,
2469 hardware single-step will stop at the first instruction of the handler,
2470 while software single-step will simply skip execution of the handler.
2472 For now, this difference in behavior is accepted since there is no
2473 easy way to actually implement single-stepping into a signal handler
2474 without kernel support.
2476 However, there is one scenario where this difference leads to follow-on
2477 problems: if we're stepping off a breakpoint by removing all breakpoints
2478 and then single-stepping. In this case, the software single-step
2479 behavior means that even if there is a *breakpoint* in the signal
2480 handler, GDB still would not stop.
2482 Fortunately, we can at least fix this particular issue. We detect
2483 here the case where we are about to deliver a signal while software
2484 single-stepping with breakpoints removed. In this situation, we
2485 revert the decisions to remove all breakpoints and insert single-
2486 step breakpoints, and instead we install a step-resume breakpoint
2487 at the current address, deliver the signal without stepping, and
2488 once we arrive back at the step-resume breakpoint, actually step
2489 over the breakpoint we originally wanted to step over. */
2490 if (thread_has_single_step_breakpoints_set (tp)
2491 && sig != GDB_SIGNAL_0
2492 && step_over_info_valid_p ())
2494 /* If we have nested signals or a pending signal is delivered
2495 immediately after a handler returns, might might already have
2496 a step-resume breakpoint set on the earlier handler. We cannot
2497 set another step-resume breakpoint; just continue on until the
2498 original breakpoint is hit. */
2499 if (tp->control.step_resume_breakpoint == NULL)
2501 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2502 tp->step_after_step_resume_breakpoint = 1;
2505 delete_single_step_breakpoints (tp);
2507 clear_step_over_info ();
2508 tp->control.trap_expected = 0;
2510 insert_breakpoints ();
2513 /* If STEP is set, it's a request to use hardware stepping
2514 facilities. But in that case, we should never
2515 use singlestep breakpoint. */
2516 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2518 /* Decide the set of threads to ask the target to resume. */
2519 if (tp->control.trap_expected)
2521 /* We're allowing a thread to run past a breakpoint it has
2522 hit, either by single-stepping the thread with the breakpoint
2523 removed, or by displaced stepping, with the breakpoint inserted.
2524 In the former case, we need to single-step only this thread,
2525 and keep others stopped, as they can miss this breakpoint if
2526 allowed to run. That's not really a problem for displaced
2527 stepping, but, we still keep other threads stopped, in case
2528 another thread is also stopped for a breakpoint waiting for
2529 its turn in the displaced stepping queue. */
2530 resume_ptid = inferior_ptid;
2533 resume_ptid = internal_resume_ptid (user_step);
2535 if (execution_direction != EXEC_REVERSE
2536 && step && breakpoint_inserted_here_p (aspace, pc))
2538 /* There are two cases where we currently need to step a
2539 breakpoint instruction when we have a signal to deliver:
2541 - See handle_signal_stop where we handle random signals that
2542 could take out us out of the stepping range. Normally, in
2543 that case we end up continuing (instead of stepping) over the
2544 signal handler with a breakpoint at PC, but there are cases
2545 where we should _always_ single-step, even if we have a
2546 step-resume breakpoint, like when a software watchpoint is
2547 set. Assuming single-stepping and delivering a signal at the
2548 same time would takes us to the signal handler, then we could
2549 have removed the breakpoint at PC to step over it. However,
2550 some hardware step targets (like e.g., Mac OS) can't step
2551 into signal handlers, and for those, we need to leave the
2552 breakpoint at PC inserted, as otherwise if the handler
2553 recurses and executes PC again, it'll miss the breakpoint.
2554 So we leave the breakpoint inserted anyway, but we need to
2555 record that we tried to step a breakpoint instruction, so
2556 that adjust_pc_after_break doesn't end up confused.
2558 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2559 in one thread after another thread that was stepping had been
2560 momentarily paused for a step-over. When we re-resume the
2561 stepping thread, it may be resumed from that address with a
2562 breakpoint that hasn't trapped yet. Seen with
2563 gdb.threads/non-stop-fair-events.exp, on targets that don't
2564 do displaced stepping. */
2567 fprintf_unfiltered (gdb_stdlog,
2568 "infrun: resume: [%s] stepped breakpoint\n",
2569 target_pid_to_str (tp->ptid));
2571 tp->stepped_breakpoint = 1;
2573 /* Most targets can step a breakpoint instruction, thus
2574 executing it normally. But if this one cannot, just
2575 continue and we will hit it anyway. */
2576 if (gdbarch_cannot_step_breakpoint (gdbarch))
2581 && tp->control.trap_expected
2582 && use_displaced_stepping (tp)
2583 && !step_over_info_valid_p ())
2585 struct regcache *resume_regcache = get_thread_regcache (tp);
2586 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2587 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2590 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2591 paddress (resume_gdbarch, actual_pc));
2592 read_memory (actual_pc, buf, sizeof (buf));
2593 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2596 if (tp->control.may_range_step)
2598 /* If we're resuming a thread with the PC out of the step
2599 range, then we're doing some nested/finer run control
2600 operation, like stepping the thread out of the dynamic
2601 linker or the displaced stepping scratch pad. We
2602 shouldn't have allowed a range step then. */
2603 gdb_assert (pc_in_thread_step_range (pc, tp));
2606 do_target_resume (resume_ptid, step, sig);
2610 /* Resume the inferior. SIG is the signal to give the inferior
2611 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2612 rolls back state on error. */
2615 resume (gdb_signal sig)
2621 CATCH (ex, RETURN_MASK_ALL)
2623 /* If resuming is being aborted for any reason, delete any
2624 single-step breakpoint resume_1 may have created, to avoid
2625 confusing the following resumption, and to avoid leaving
2626 single-step breakpoints perturbing other threads, in case
2627 we're running in non-stop mode. */
2628 if (inferior_ptid != null_ptid)
2629 delete_single_step_breakpoints (inferior_thread ());
2630 throw_exception (ex);
2640 /* Counter that tracks number of user visible stops. This can be used
2641 to tell whether a command has proceeded the inferior past the
2642 current location. This allows e.g., inferior function calls in
2643 breakpoint commands to not interrupt the command list. When the
2644 call finishes successfully, the inferior is standing at the same
2645 breakpoint as if nothing happened (and so we don't call
2647 static ULONGEST current_stop_id;
2654 return current_stop_id;
2657 /* Called when we report a user visible stop. */
2665 /* Clear out all variables saying what to do when inferior is continued.
2666 First do this, then set the ones you want, then call `proceed'. */
2669 clear_proceed_status_thread (struct thread_info *tp)
2672 fprintf_unfiltered (gdb_stdlog,
2673 "infrun: clear_proceed_status_thread (%s)\n",
2674 target_pid_to_str (tp->ptid));
2676 /* If we're starting a new sequence, then the previous finished
2677 single-step is no longer relevant. */
2678 if (tp->suspend.waitstatus_pending_p)
2680 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2683 fprintf_unfiltered (gdb_stdlog,
2684 "infrun: clear_proceed_status: pending "
2685 "event of %s was a finished step. "
2687 target_pid_to_str (tp->ptid));
2689 tp->suspend.waitstatus_pending_p = 0;
2690 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2692 else if (debug_infrun)
2695 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2697 fprintf_unfiltered (gdb_stdlog,
2698 "infrun: clear_proceed_status_thread: thread %s "
2699 "has pending wait status %s "
2700 "(currently_stepping=%d).\n",
2701 target_pid_to_str (tp->ptid), statstr.c_str (),
2702 currently_stepping (tp));
2706 /* If this signal should not be seen by program, give it zero.
2707 Used for debugging signals. */
2708 if (!signal_pass_state (tp->suspend.stop_signal))
2709 tp->suspend.stop_signal = GDB_SIGNAL_0;
2711 delete tp->thread_fsm;
2712 tp->thread_fsm = NULL;
2714 tp->control.trap_expected = 0;
2715 tp->control.step_range_start = 0;
2716 tp->control.step_range_end = 0;
2717 tp->control.may_range_step = 0;
2718 tp->control.step_frame_id = null_frame_id;
2719 tp->control.step_stack_frame_id = null_frame_id;
2720 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2721 tp->control.step_start_function = NULL;
2722 tp->stop_requested = 0;
2724 tp->control.stop_step = 0;
2726 tp->control.proceed_to_finish = 0;
2728 tp->control.stepping_command = 0;
2730 /* Discard any remaining commands or status from previous stop. */
2731 bpstat_clear (&tp->control.stop_bpstat);
2735 clear_proceed_status (int step)
2737 /* With scheduler-locking replay, stop replaying other threads if we're
2738 not replaying the user-visible resume ptid.
2740 This is a convenience feature to not require the user to explicitly
2741 stop replaying the other threads. We're assuming that the user's
2742 intent is to resume tracing the recorded process. */
2743 if (!non_stop && scheduler_mode == schedlock_replay
2744 && target_record_is_replaying (minus_one_ptid)
2745 && !target_record_will_replay (user_visible_resume_ptid (step),
2746 execution_direction))
2747 target_record_stop_replaying ();
2749 if (!non_stop && inferior_ptid != null_ptid)
2751 ptid_t resume_ptid = user_visible_resume_ptid (step);
2753 /* In all-stop mode, delete the per-thread status of all threads
2754 we're about to resume, implicitly and explicitly. */
2755 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2756 clear_proceed_status_thread (tp);
2759 if (inferior_ptid != null_ptid)
2761 struct inferior *inferior;
2765 /* If in non-stop mode, only delete the per-thread status of
2766 the current thread. */
2767 clear_proceed_status_thread (inferior_thread ());
2770 inferior = current_inferior ();
2771 inferior->control.stop_soon = NO_STOP_QUIETLY;
2774 gdb::observers::about_to_proceed.notify ();
2777 /* Returns true if TP is still stopped at a breakpoint that needs
2778 stepping-over in order to make progress. If the breakpoint is gone
2779 meanwhile, we can skip the whole step-over dance. */
2782 thread_still_needs_step_over_bp (struct thread_info *tp)
2784 if (tp->stepping_over_breakpoint)
2786 struct regcache *regcache = get_thread_regcache (tp);
2788 if (breakpoint_here_p (regcache->aspace (),
2789 regcache_read_pc (regcache))
2790 == ordinary_breakpoint_here)
2793 tp->stepping_over_breakpoint = 0;
2799 /* Check whether thread TP still needs to start a step-over in order
2800 to make progress when resumed. Returns an bitwise or of enum
2801 step_over_what bits, indicating what needs to be stepped over. */
2803 static step_over_what
2804 thread_still_needs_step_over (struct thread_info *tp)
2806 step_over_what what = 0;
2808 if (thread_still_needs_step_over_bp (tp))
2809 what |= STEP_OVER_BREAKPOINT;
2811 if (tp->stepping_over_watchpoint
2812 && !target_have_steppable_watchpoint)
2813 what |= STEP_OVER_WATCHPOINT;
2818 /* Returns true if scheduler locking applies. STEP indicates whether
2819 we're about to do a step/next-like command to a thread. */
2822 schedlock_applies (struct thread_info *tp)
2824 return (scheduler_mode == schedlock_on
2825 || (scheduler_mode == schedlock_step
2826 && tp->control.stepping_command)
2827 || (scheduler_mode == schedlock_replay
2828 && target_record_will_replay (minus_one_ptid,
2829 execution_direction)));
2832 /* Basic routine for continuing the program in various fashions.
2834 ADDR is the address to resume at, or -1 for resume where stopped.
2835 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2836 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2838 You should call clear_proceed_status before calling proceed. */
2841 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2843 struct regcache *regcache;
2844 struct gdbarch *gdbarch;
2847 struct execution_control_state ecss;
2848 struct execution_control_state *ecs = &ecss;
2851 /* If we're stopped at a fork/vfork, follow the branch set by the
2852 "set follow-fork-mode" command; otherwise, we'll just proceed
2853 resuming the current thread. */
2854 if (!follow_fork ())
2856 /* The target for some reason decided not to resume. */
2858 if (target_can_async_p ())
2859 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2863 /* We'll update this if & when we switch to a new thread. */
2864 previous_inferior_ptid = inferior_ptid;
2866 regcache = get_current_regcache ();
2867 gdbarch = regcache->arch ();
2868 const address_space *aspace = regcache->aspace ();
2870 pc = regcache_read_pc (regcache);
2871 thread_info *cur_thr = inferior_thread ();
2873 /* Fill in with reasonable starting values. */
2874 init_thread_stepping_state (cur_thr);
2876 gdb_assert (!thread_is_in_step_over_chain (cur_thr));
2878 if (addr == (CORE_ADDR) -1)
2880 if (pc == cur_thr->suspend.stop_pc
2881 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2882 && execution_direction != EXEC_REVERSE)
2883 /* There is a breakpoint at the address we will resume at,
2884 step one instruction before inserting breakpoints so that
2885 we do not stop right away (and report a second hit at this
2888 Note, we don't do this in reverse, because we won't
2889 actually be executing the breakpoint insn anyway.
2890 We'll be (un-)executing the previous instruction. */
2891 cur_thr->stepping_over_breakpoint = 1;
2892 else if (gdbarch_single_step_through_delay_p (gdbarch)
2893 && gdbarch_single_step_through_delay (gdbarch,
2894 get_current_frame ()))
2895 /* We stepped onto an instruction that needs to be stepped
2896 again before re-inserting the breakpoint, do so. */
2897 cur_thr->stepping_over_breakpoint = 1;
2901 regcache_write_pc (regcache, addr);
2904 if (siggnal != GDB_SIGNAL_DEFAULT)
2905 cur_thr->suspend.stop_signal = siggnal;
2907 resume_ptid = user_visible_resume_ptid (cur_thr->control.stepping_command);
2909 /* If an exception is thrown from this point on, make sure to
2910 propagate GDB's knowledge of the executing state to the
2911 frontend/user running state. */
2912 scoped_finish_thread_state finish_state (resume_ptid);
2914 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2915 threads (e.g., we might need to set threads stepping over
2916 breakpoints first), from the user/frontend's point of view, all
2917 threads in RESUME_PTID are now running. Unless we're calling an
2918 inferior function, as in that case we pretend the inferior
2919 doesn't run at all. */
2920 if (!cur_thr->control.in_infcall)
2921 set_running (resume_ptid, 1);
2924 fprintf_unfiltered (gdb_stdlog,
2925 "infrun: proceed (addr=%s, signal=%s)\n",
2926 paddress (gdbarch, addr),
2927 gdb_signal_to_symbol_string (siggnal));
2929 annotate_starting ();
2931 /* Make sure that output from GDB appears before output from the
2933 gdb_flush (gdb_stdout);
2935 /* Since we've marked the inferior running, give it the terminal. A
2936 QUIT/Ctrl-C from here on is forwarded to the target (which can
2937 still detect attempts to unblock a stuck connection with repeated
2938 Ctrl-C from within target_pass_ctrlc). */
2939 target_terminal::inferior ();
2941 /* In a multi-threaded task we may select another thread and
2942 then continue or step.
2944 But if a thread that we're resuming had stopped at a breakpoint,
2945 it will immediately cause another breakpoint stop without any
2946 execution (i.e. it will report a breakpoint hit incorrectly). So
2947 we must step over it first.
2949 Look for threads other than the current (TP) that reported a
2950 breakpoint hit and haven't been resumed yet since. */
2952 /* If scheduler locking applies, we can avoid iterating over all
2954 if (!non_stop && !schedlock_applies (cur_thr))
2956 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2958 /* Ignore the current thread here. It's handled
2963 if (!thread_still_needs_step_over (tp))
2966 gdb_assert (!thread_is_in_step_over_chain (tp));
2969 fprintf_unfiltered (gdb_stdlog,
2970 "infrun: need to step-over [%s] first\n",
2971 target_pid_to_str (tp->ptid));
2973 thread_step_over_chain_enqueue (tp);
2977 /* Enqueue the current thread last, so that we move all other
2978 threads over their breakpoints first. */
2979 if (cur_thr->stepping_over_breakpoint)
2980 thread_step_over_chain_enqueue (cur_thr);
2982 /* If the thread isn't started, we'll still need to set its prev_pc,
2983 so that switch_back_to_stepped_thread knows the thread hasn't
2984 advanced. Must do this before resuming any thread, as in
2985 all-stop/remote, once we resume we can't send any other packet
2986 until the target stops again. */
2987 cur_thr->prev_pc = regcache_read_pc (regcache);
2990 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
2992 started = start_step_over ();
2994 if (step_over_info_valid_p ())
2996 /* Either this thread started a new in-line step over, or some
2997 other thread was already doing one. In either case, don't
2998 resume anything else until the step-over is finished. */
3000 else if (started && !target_is_non_stop_p ())
3002 /* A new displaced stepping sequence was started. In all-stop,
3003 we can't talk to the target anymore until it next stops. */
3005 else if (!non_stop && target_is_non_stop_p ())
3007 /* In all-stop, but the target is always in non-stop mode.
3008 Start all other threads that are implicitly resumed too. */
3009 for (thread_info *tp : all_non_exited_threads (resume_ptid))
3014 fprintf_unfiltered (gdb_stdlog,
3015 "infrun: proceed: [%s] resumed\n",
3016 target_pid_to_str (tp->ptid));
3017 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3021 if (thread_is_in_step_over_chain (tp))
3024 fprintf_unfiltered (gdb_stdlog,
3025 "infrun: proceed: [%s] needs step-over\n",
3026 target_pid_to_str (tp->ptid));
3031 fprintf_unfiltered (gdb_stdlog,
3032 "infrun: proceed: resuming %s\n",
3033 target_pid_to_str (tp->ptid));
3035 reset_ecs (ecs, tp);
3036 switch_to_thread (tp);
3037 keep_going_pass_signal (ecs);
3038 if (!ecs->wait_some_more)
3039 error (_("Command aborted."));
3042 else if (!cur_thr->resumed && !thread_is_in_step_over_chain (cur_thr))
3044 /* The thread wasn't started, and isn't queued, run it now. */
3045 reset_ecs (ecs, cur_thr);
3046 switch_to_thread (cur_thr);
3047 keep_going_pass_signal (ecs);
3048 if (!ecs->wait_some_more)
3049 error (_("Command aborted."));
3053 target_commit_resume ();
3055 finish_state.release ();
3057 /* Tell the event loop to wait for it to stop. If the target
3058 supports asynchronous execution, it'll do this from within
3060 if (!target_can_async_p ())
3061 mark_async_event_handler (infrun_async_inferior_event_token);
3065 /* Start remote-debugging of a machine over a serial link. */
3068 start_remote (int from_tty)
3070 struct inferior *inferior;
3072 inferior = current_inferior ();
3073 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3075 /* Always go on waiting for the target, regardless of the mode. */
3076 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3077 indicate to wait_for_inferior that a target should timeout if
3078 nothing is returned (instead of just blocking). Because of this,
3079 targets expecting an immediate response need to, internally, set
3080 things up so that the target_wait() is forced to eventually
3082 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3083 differentiate to its caller what the state of the target is after
3084 the initial open has been performed. Here we're assuming that
3085 the target has stopped. It should be possible to eventually have
3086 target_open() return to the caller an indication that the target
3087 is currently running and GDB state should be set to the same as
3088 for an async run. */
3089 wait_for_inferior ();
3091 /* Now that the inferior has stopped, do any bookkeeping like
3092 loading shared libraries. We want to do this before normal_stop,
3093 so that the displayed frame is up to date. */
3094 post_create_inferior (current_top_target (), from_tty);
3099 /* Initialize static vars when a new inferior begins. */
3102 init_wait_for_inferior (void)
3104 /* These are meaningless until the first time through wait_for_inferior. */
3106 breakpoint_init_inferior (inf_starting);
3108 clear_proceed_status (0);
3110 target_last_wait_ptid = minus_one_ptid;
3112 previous_inferior_ptid = inferior_ptid;
3117 static void handle_inferior_event (struct execution_control_state *ecs);
3119 static void handle_step_into_function (struct gdbarch *gdbarch,
3120 struct execution_control_state *ecs);
3121 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3122 struct execution_control_state *ecs);
3123 static void handle_signal_stop (struct execution_control_state *ecs);
3124 static void check_exception_resume (struct execution_control_state *,
3125 struct frame_info *);
3127 static void end_stepping_range (struct execution_control_state *ecs);
3128 static void stop_waiting (struct execution_control_state *ecs);
3129 static void keep_going (struct execution_control_state *ecs);
3130 static void process_event_stop_test (struct execution_control_state *ecs);
3131 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3133 /* This function is attached as a "thread_stop_requested" observer.
3134 Cleanup local state that assumed the PTID was to be resumed, and
3135 report the stop to the frontend. */
3138 infrun_thread_stop_requested (ptid_t ptid)
3140 /* PTID was requested to stop. If the thread was already stopped,
3141 but the user/frontend doesn't know about that yet (e.g., the
3142 thread had been temporarily paused for some step-over), set up
3143 for reporting the stop now. */
3144 for (thread_info *tp : all_threads (ptid))
3146 if (tp->state != THREAD_RUNNING)
3151 /* Remove matching threads from the step-over queue, so
3152 start_step_over doesn't try to resume them
3154 if (thread_is_in_step_over_chain (tp))
3155 thread_step_over_chain_remove (tp);
3157 /* If the thread is stopped, but the user/frontend doesn't
3158 know about that yet, queue a pending event, as if the
3159 thread had just stopped now. Unless the thread already had
3161 if (!tp->suspend.waitstatus_pending_p)
3163 tp->suspend.waitstatus_pending_p = 1;
3164 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3165 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3168 /* Clear the inline-frame state, since we're re-processing the
3170 clear_inline_frame_state (tp->ptid);
3172 /* If this thread was paused because some other thread was
3173 doing an inline-step over, let that finish first. Once
3174 that happens, we'll restart all threads and consume pending
3175 stop events then. */
3176 if (step_over_info_valid_p ())
3179 /* Otherwise we can process the (new) pending event now. Set
3180 it so this pending event is considered by
3187 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3189 if (target_last_wait_ptid == tp->ptid)
3190 nullify_last_target_wait_ptid ();
3193 /* Delete the step resume, single-step and longjmp/exception resume
3194 breakpoints of TP. */
3197 delete_thread_infrun_breakpoints (struct thread_info *tp)
3199 delete_step_resume_breakpoint (tp);
3200 delete_exception_resume_breakpoint (tp);
3201 delete_single_step_breakpoints (tp);
3204 /* If the target still has execution, call FUNC for each thread that
3205 just stopped. In all-stop, that's all the non-exited threads; in
3206 non-stop, that's the current thread, only. */
3208 typedef void (*for_each_just_stopped_thread_callback_func)
3209 (struct thread_info *tp);
3212 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3214 if (!target_has_execution || inferior_ptid == null_ptid)
3217 if (target_is_non_stop_p ())
3219 /* If in non-stop mode, only the current thread stopped. */
3220 func (inferior_thread ());
3224 /* In all-stop mode, all threads have stopped. */
3225 for (thread_info *tp : all_non_exited_threads ())
3230 /* Delete the step resume and longjmp/exception resume breakpoints of
3231 the threads that just stopped. */
3234 delete_just_stopped_threads_infrun_breakpoints (void)
3236 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3239 /* Delete the single-step breakpoints of the threads that just
3243 delete_just_stopped_threads_single_step_breakpoints (void)
3245 for_each_just_stopped_thread (delete_single_step_breakpoints);
3251 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3252 const struct target_waitstatus *ws)
3254 std::string status_string = target_waitstatus_to_string (ws);
3257 /* The text is split over several lines because it was getting too long.
3258 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3259 output as a unit; we want only one timestamp printed if debug_timestamp
3262 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3265 waiton_ptid.tid ());
3266 if (waiton_ptid.pid () != -1)
3267 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3268 stb.printf (", status) =\n");
3269 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3273 target_pid_to_str (result_ptid));
3274 stb.printf ("infrun: %s\n", status_string.c_str ());
3276 /* This uses %s in part to handle %'s in the text, but also to avoid
3277 a gcc error: the format attribute requires a string literal. */
3278 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3281 /* Select a thread at random, out of those which are resumed and have
3284 static struct thread_info *
3285 random_pending_event_thread (ptid_t waiton_ptid)
3289 auto has_event = [] (thread_info *tp)
3292 && tp->suspend.waitstatus_pending_p);
3295 /* First see how many events we have. Count only resumed threads
3296 that have an event pending. */
3297 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3301 if (num_events == 0)
3304 /* Now randomly pick a thread out of those that have had events. */
3305 int random_selector = (int) ((num_events * (double) rand ())
3306 / (RAND_MAX + 1.0));
3308 if (debug_infrun && num_events > 1)
3309 fprintf_unfiltered (gdb_stdlog,
3310 "infrun: Found %d events, selecting #%d\n",
3311 num_events, random_selector);
3313 /* Select the Nth thread that has had an event. */
3314 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3316 if (random_selector-- == 0)
3319 gdb_assert_not_reached ("event thread not found");
3322 /* Wrapper for target_wait that first checks whether threads have
3323 pending statuses to report before actually asking the target for
3327 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3330 struct thread_info *tp;
3332 /* First check if there is a resumed thread with a wait status
3334 if (ptid == minus_one_ptid || ptid.is_pid ())
3336 tp = random_pending_event_thread (ptid);
3341 fprintf_unfiltered (gdb_stdlog,
3342 "infrun: Waiting for specific thread %s.\n",
3343 target_pid_to_str (ptid));
3345 /* We have a specific thread to check. */
3346 tp = find_thread_ptid (ptid);
3347 gdb_assert (tp != NULL);
3348 if (!tp->suspend.waitstatus_pending_p)
3353 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3354 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3356 struct regcache *regcache = get_thread_regcache (tp);
3357 struct gdbarch *gdbarch = regcache->arch ();
3361 pc = regcache_read_pc (regcache);
3363 if (pc != tp->suspend.stop_pc)
3366 fprintf_unfiltered (gdb_stdlog,
3367 "infrun: PC of %s changed. was=%s, now=%s\n",
3368 target_pid_to_str (tp->ptid),
3369 paddress (gdbarch, tp->suspend.stop_pc),
3370 paddress (gdbarch, pc));
3373 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3376 fprintf_unfiltered (gdb_stdlog,
3377 "infrun: previous breakpoint of %s, at %s gone\n",
3378 target_pid_to_str (tp->ptid),
3379 paddress (gdbarch, pc));
3387 fprintf_unfiltered (gdb_stdlog,
3388 "infrun: pending event of %s cancelled.\n",
3389 target_pid_to_str (tp->ptid));
3391 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3392 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3401 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3403 fprintf_unfiltered (gdb_stdlog,
3404 "infrun: Using pending wait status %s for %s.\n",
3406 target_pid_to_str (tp->ptid));
3409 /* Now that we've selected our final event LWP, un-adjust its PC
3410 if it was a software breakpoint (and the target doesn't
3411 always adjust the PC itself). */
3412 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3413 && !target_supports_stopped_by_sw_breakpoint ())
3415 struct regcache *regcache;
3416 struct gdbarch *gdbarch;
3419 regcache = get_thread_regcache (tp);
3420 gdbarch = regcache->arch ();
3422 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3427 pc = regcache_read_pc (regcache);
3428 regcache_write_pc (regcache, pc + decr_pc);
3432 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3433 *status = tp->suspend.waitstatus;
3434 tp->suspend.waitstatus_pending_p = 0;
3436 /* Wake up the event loop again, until all pending events are
3438 if (target_is_async_p ())
3439 mark_async_event_handler (infrun_async_inferior_event_token);
3443 /* But if we don't find one, we'll have to wait. */
3445 if (deprecated_target_wait_hook)
3446 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3448 event_ptid = target_wait (ptid, status, options);
3453 /* Prepare and stabilize the inferior for detaching it. E.g.,
3454 detaching while a thread is displaced stepping is a recipe for
3455 crashing it, as nothing would readjust the PC out of the scratch
3459 prepare_for_detach (void)
3461 struct inferior *inf = current_inferior ();
3462 ptid_t pid_ptid = ptid_t (inf->pid);
3464 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3466 /* Is any thread of this process displaced stepping? If not,
3467 there's nothing else to do. */
3468 if (displaced->step_thread == nullptr)
3472 fprintf_unfiltered (gdb_stdlog,
3473 "displaced-stepping in-process while detaching");
3475 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3477 while (displaced->step_thread != nullptr)
3479 struct execution_control_state ecss;
3480 struct execution_control_state *ecs;
3483 memset (ecs, 0, sizeof (*ecs));
3485 overlay_cache_invalid = 1;
3486 /* Flush target cache before starting to handle each event.
3487 Target was running and cache could be stale. This is just a
3488 heuristic. Running threads may modify target memory, but we
3489 don't get any event. */
3490 target_dcache_invalidate ();
3492 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3495 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3497 /* If an error happens while handling the event, propagate GDB's
3498 knowledge of the executing state to the frontend/user running
3500 scoped_finish_thread_state finish_state (minus_one_ptid);
3502 /* Now figure out what to do with the result of the result. */
3503 handle_inferior_event (ecs);
3505 /* No error, don't finish the state yet. */
3506 finish_state.release ();
3508 /* Breakpoints and watchpoints are not installed on the target
3509 at this point, and signals are passed directly to the
3510 inferior, so this must mean the process is gone. */
3511 if (!ecs->wait_some_more)
3513 restore_detaching.release ();
3514 error (_("Program exited while detaching"));
3518 restore_detaching.release ();
3521 /* Wait for control to return from inferior to debugger.
3523 If inferior gets a signal, we may decide to start it up again
3524 instead of returning. That is why there is a loop in this function.
3525 When this function actually returns it means the inferior
3526 should be left stopped and GDB should read more commands. */
3529 wait_for_inferior (void)
3533 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3535 SCOPE_EXIT { delete_just_stopped_threads_infrun_breakpoints (); };
3537 /* If an error happens while handling the event, propagate GDB's
3538 knowledge of the executing state to the frontend/user running
3540 scoped_finish_thread_state finish_state (minus_one_ptid);
3544 struct execution_control_state ecss;
3545 struct execution_control_state *ecs = &ecss;
3546 ptid_t waiton_ptid = minus_one_ptid;
3548 memset (ecs, 0, sizeof (*ecs));
3550 overlay_cache_invalid = 1;
3552 /* Flush target cache before starting to handle each event.
3553 Target was running and cache could be stale. This is just a
3554 heuristic. Running threads may modify target memory, but we
3555 don't get any event. */
3556 target_dcache_invalidate ();
3558 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3561 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3563 /* Now figure out what to do with the result of the result. */
3564 handle_inferior_event (ecs);
3566 if (!ecs->wait_some_more)
3570 /* No error, don't finish the state yet. */
3571 finish_state.release ();
3574 /* Cleanup that reinstalls the readline callback handler, if the
3575 target is running in the background. If while handling the target
3576 event something triggered a secondary prompt, like e.g., a
3577 pagination prompt, we'll have removed the callback handler (see
3578 gdb_readline_wrapper_line). Need to do this as we go back to the
3579 event loop, ready to process further input. Note this has no
3580 effect if the handler hasn't actually been removed, because calling
3581 rl_callback_handler_install resets the line buffer, thus losing
3585 reinstall_readline_callback_handler_cleanup ()
3587 struct ui *ui = current_ui;
3591 /* We're not going back to the top level event loop yet. Don't
3592 install the readline callback, as it'd prep the terminal,
3593 readline-style (raw, noecho) (e.g., --batch). We'll install
3594 it the next time the prompt is displayed, when we're ready
3599 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3600 gdb_rl_callback_handler_reinstall ();
3603 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3604 that's just the event thread. In all-stop, that's all threads. */
3607 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3609 if (ecs->event_thread != NULL
3610 && ecs->event_thread->thread_fsm != NULL)
3611 ecs->event_thread->thread_fsm->clean_up (ecs->event_thread);
3615 for (thread_info *thr : all_non_exited_threads ())
3617 if (thr->thread_fsm == NULL)
3619 if (thr == ecs->event_thread)
3622 switch_to_thread (thr);
3623 thr->thread_fsm->clean_up (thr);
3626 if (ecs->event_thread != NULL)
3627 switch_to_thread (ecs->event_thread);
3631 /* Helper for all_uis_check_sync_execution_done that works on the
3635 check_curr_ui_sync_execution_done (void)
3637 struct ui *ui = current_ui;
3639 if (ui->prompt_state == PROMPT_NEEDED
3641 && !gdb_in_secondary_prompt_p (ui))
3643 target_terminal::ours ();
3644 gdb::observers::sync_execution_done.notify ();
3645 ui_register_input_event_handler (ui);
3652 all_uis_check_sync_execution_done (void)
3654 SWITCH_THRU_ALL_UIS ()
3656 check_curr_ui_sync_execution_done ();
3663 all_uis_on_sync_execution_starting (void)
3665 SWITCH_THRU_ALL_UIS ()
3667 if (current_ui->prompt_state == PROMPT_NEEDED)
3668 async_disable_stdin ();
3672 /* Asynchronous version of wait_for_inferior. It is called by the
3673 event loop whenever a change of state is detected on the file
3674 descriptor corresponding to the target. It can be called more than
3675 once to complete a single execution command. In such cases we need
3676 to keep the state in a global variable ECSS. If it is the last time
3677 that this function is called for a single execution command, then
3678 report to the user that the inferior has stopped, and do the
3679 necessary cleanups. */
3682 fetch_inferior_event (void *client_data)
3684 struct execution_control_state ecss;
3685 struct execution_control_state *ecs = &ecss;
3687 ptid_t waiton_ptid = minus_one_ptid;
3689 memset (ecs, 0, sizeof (*ecs));
3691 /* Events are always processed with the main UI as current UI. This
3692 way, warnings, debug output, etc. are always consistently sent to
3693 the main console. */
3694 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3696 /* End up with readline processing input, if necessary. */
3698 SCOPE_EXIT { reinstall_readline_callback_handler_cleanup (); };
3700 /* We're handling a live event, so make sure we're doing live
3701 debugging. If we're looking at traceframes while the target is
3702 running, we're going to need to get back to that mode after
3703 handling the event. */
3704 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3707 maybe_restore_traceframe.emplace ();
3708 set_current_traceframe (-1);
3711 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3714 /* In non-stop mode, the user/frontend should not notice a thread
3715 switch due to internal events. Make sure we reverse to the
3716 user selected thread and frame after handling the event and
3717 running any breakpoint commands. */
3718 maybe_restore_thread.emplace ();
3720 overlay_cache_invalid = 1;
3721 /* Flush target cache before starting to handle each event. Target
3722 was running and cache could be stale. This is just a heuristic.
3723 Running threads may modify target memory, but we don't get any
3725 target_dcache_invalidate ();
3727 scoped_restore save_exec_dir
3728 = make_scoped_restore (&execution_direction,
3729 target_execution_direction ());
3731 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3732 target_can_async_p () ? TARGET_WNOHANG : 0);
3735 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3737 /* If an error happens while handling the event, propagate GDB's
3738 knowledge of the executing state to the frontend/user running
3740 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3741 scoped_finish_thread_state finish_state (finish_ptid);
3743 /* Get executed before scoped_restore_current_thread above to apply
3744 still for the thread which has thrown the exception. */
3745 auto defer_bpstat_clear
3746 = make_scope_exit (bpstat_clear_actions);
3747 auto defer_delete_threads
3748 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints);
3750 /* Now figure out what to do with the result of the result. */
3751 handle_inferior_event (ecs);
3753 if (!ecs->wait_some_more)
3755 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3756 int should_stop = 1;
3757 struct thread_info *thr = ecs->event_thread;
3759 delete_just_stopped_threads_infrun_breakpoints ();
3763 struct thread_fsm *thread_fsm = thr->thread_fsm;
3765 if (thread_fsm != NULL)
3766 should_stop = thread_fsm->should_stop (thr);
3775 bool should_notify_stop = true;
3778 clean_up_just_stopped_threads_fsms (ecs);
3780 if (thr != NULL && thr->thread_fsm != NULL)
3781 should_notify_stop = thr->thread_fsm->should_notify_stop ();
3783 if (should_notify_stop)
3785 /* We may not find an inferior if this was a process exit. */
3786 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3787 proceeded = normal_stop ();
3792 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3798 defer_delete_threads.release ();
3799 defer_bpstat_clear.release ();
3801 /* No error, don't finish the thread states yet. */
3802 finish_state.release ();
3804 /* This scope is used to ensure that readline callbacks are
3805 reinstalled here. */
3808 /* If a UI was in sync execution mode, and now isn't, restore its
3809 prompt (a synchronous execution command has finished, and we're
3810 ready for input). */
3811 all_uis_check_sync_execution_done ();
3814 && exec_done_display_p
3815 && (inferior_ptid == null_ptid
3816 || inferior_thread ()->state != THREAD_RUNNING))
3817 printf_unfiltered (_("completed.\n"));
3820 /* Record the frame and location we're currently stepping through. */
3822 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3824 struct thread_info *tp = inferior_thread ();
3826 tp->control.step_frame_id = get_frame_id (frame);
3827 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3829 tp->current_symtab = sal.symtab;
3830 tp->current_line = sal.line;
3833 /* Clear context switchable stepping state. */
3836 init_thread_stepping_state (struct thread_info *tss)
3838 tss->stepped_breakpoint = 0;
3839 tss->stepping_over_breakpoint = 0;
3840 tss->stepping_over_watchpoint = 0;
3841 tss->step_after_step_resume_breakpoint = 0;
3844 /* Set the cached copy of the last ptid/waitstatus. */
3847 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3849 target_last_wait_ptid = ptid;
3850 target_last_waitstatus = status;
3853 /* Return the cached copy of the last pid/waitstatus returned by
3854 target_wait()/deprecated_target_wait_hook(). The data is actually
3855 cached by handle_inferior_event(), which gets called immediately
3856 after target_wait()/deprecated_target_wait_hook(). */
3859 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3861 *ptidp = target_last_wait_ptid;
3862 *status = target_last_waitstatus;
3866 nullify_last_target_wait_ptid (void)
3868 target_last_wait_ptid = minus_one_ptid;
3871 /* Switch thread contexts. */
3874 context_switch (execution_control_state *ecs)
3877 && ecs->ptid != inferior_ptid
3878 && ecs->event_thread != inferior_thread ())
3880 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3881 target_pid_to_str (inferior_ptid));
3882 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3883 target_pid_to_str (ecs->ptid));
3886 switch_to_thread (ecs->event_thread);
3889 /* If the target can't tell whether we've hit breakpoints
3890 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3891 check whether that could have been caused by a breakpoint. If so,
3892 adjust the PC, per gdbarch_decr_pc_after_break. */
3895 adjust_pc_after_break (struct thread_info *thread,
3896 struct target_waitstatus *ws)
3898 struct regcache *regcache;
3899 struct gdbarch *gdbarch;
3900 CORE_ADDR breakpoint_pc, decr_pc;
3902 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3903 we aren't, just return.
3905 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3906 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3907 implemented by software breakpoints should be handled through the normal
3910 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3911 different signals (SIGILL or SIGEMT for instance), but it is less
3912 clear where the PC is pointing afterwards. It may not match
3913 gdbarch_decr_pc_after_break. I don't know any specific target that
3914 generates these signals at breakpoints (the code has been in GDB since at
3915 least 1992) so I can not guess how to handle them here.
3917 In earlier versions of GDB, a target with
3918 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3919 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3920 target with both of these set in GDB history, and it seems unlikely to be
3921 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3923 if (ws->kind != TARGET_WAITKIND_STOPPED)
3926 if (ws->value.sig != GDB_SIGNAL_TRAP)
3929 /* In reverse execution, when a breakpoint is hit, the instruction
3930 under it has already been de-executed. The reported PC always
3931 points at the breakpoint address, so adjusting it further would
3932 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3935 B1 0x08000000 : INSN1
3936 B2 0x08000001 : INSN2
3938 PC -> 0x08000003 : INSN4
3940 Say you're stopped at 0x08000003 as above. Reverse continuing
3941 from that point should hit B2 as below. Reading the PC when the
3942 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3943 been de-executed already.
3945 B1 0x08000000 : INSN1
3946 B2 PC -> 0x08000001 : INSN2
3950 We can't apply the same logic as for forward execution, because
3951 we would wrongly adjust the PC to 0x08000000, since there's a
3952 breakpoint at PC - 1. We'd then report a hit on B1, although
3953 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3955 if (execution_direction == EXEC_REVERSE)
3958 /* If the target can tell whether the thread hit a SW breakpoint,
3959 trust it. Targets that can tell also adjust the PC
3961 if (target_supports_stopped_by_sw_breakpoint ())
3964 /* Note that relying on whether a breakpoint is planted in memory to
3965 determine this can fail. E.g,. the breakpoint could have been
3966 removed since. Or the thread could have been told to step an
3967 instruction the size of a breakpoint instruction, and only
3968 _after_ was a breakpoint inserted at its address. */
3970 /* If this target does not decrement the PC after breakpoints, then
3971 we have nothing to do. */
3972 regcache = get_thread_regcache (thread);
3973 gdbarch = regcache->arch ();
3975 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3979 const address_space *aspace = regcache->aspace ();
3981 /* Find the location where (if we've hit a breakpoint) the
3982 breakpoint would be. */
3983 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3985 /* If the target can't tell whether a software breakpoint triggered,
3986 fallback to figuring it out based on breakpoints we think were
3987 inserted in the target, and on whether the thread was stepped or
3990 /* Check whether there actually is a software breakpoint inserted at
3993 If in non-stop mode, a race condition is possible where we've
3994 removed a breakpoint, but stop events for that breakpoint were
3995 already queued and arrive later. To suppress those spurious
3996 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3997 and retire them after a number of stop events are reported. Note
3998 this is an heuristic and can thus get confused. The real fix is
3999 to get the "stopped by SW BP and needs adjustment" info out of
4000 the target/kernel (and thus never reach here; see above). */
4001 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4002 || (target_is_non_stop_p ()
4003 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4005 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4007 if (record_full_is_used ())
4008 restore_operation_disable.emplace
4009 (record_full_gdb_operation_disable_set ());
4011 /* When using hardware single-step, a SIGTRAP is reported for both
4012 a completed single-step and a software breakpoint. Need to
4013 differentiate between the two, as the latter needs adjusting
4014 but the former does not.
4016 The SIGTRAP can be due to a completed hardware single-step only if
4017 - we didn't insert software single-step breakpoints
4018 - this thread is currently being stepped
4020 If any of these events did not occur, we must have stopped due
4021 to hitting a software breakpoint, and have to back up to the
4024 As a special case, we could have hardware single-stepped a
4025 software breakpoint. In this case (prev_pc == breakpoint_pc),
4026 we also need to back up to the breakpoint address. */
4028 if (thread_has_single_step_breakpoints_set (thread)
4029 || !currently_stepping (thread)
4030 || (thread->stepped_breakpoint
4031 && thread->prev_pc == breakpoint_pc))
4032 regcache_write_pc (regcache, breakpoint_pc);
4037 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4039 for (frame = get_prev_frame (frame);
4041 frame = get_prev_frame (frame))
4043 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4045 if (get_frame_type (frame) != INLINE_FRAME)
4052 /* If the event thread has the stop requested flag set, pretend it
4053 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4057 handle_stop_requested (struct execution_control_state *ecs)
4059 if (ecs->event_thread->stop_requested)
4061 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4062 ecs->ws.value.sig = GDB_SIGNAL_0;
4063 handle_signal_stop (ecs);
4069 /* Auxiliary function that handles syscall entry/return events.
4070 It returns 1 if the inferior should keep going (and GDB
4071 should ignore the event), or 0 if the event deserves to be
4075 handle_syscall_event (struct execution_control_state *ecs)
4077 struct regcache *regcache;
4080 context_switch (ecs);
4082 regcache = get_thread_regcache (ecs->event_thread);
4083 syscall_number = ecs->ws.value.syscall_number;
4084 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4086 if (catch_syscall_enabled () > 0
4087 && catching_syscall_number (syscall_number) > 0)
4090 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4093 ecs->event_thread->control.stop_bpstat
4094 = bpstat_stop_status (regcache->aspace (),
4095 ecs->event_thread->suspend.stop_pc,
4096 ecs->event_thread, &ecs->ws);
4098 if (handle_stop_requested (ecs))
4101 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4103 /* Catchpoint hit. */
4108 if (handle_stop_requested (ecs))
4111 /* If no catchpoint triggered for this, then keep going. */
4116 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4119 fill_in_stop_func (struct gdbarch *gdbarch,
4120 struct execution_control_state *ecs)
4122 if (!ecs->stop_func_filled_in)
4124 /* Don't care about return value; stop_func_start and stop_func_name
4125 will both be 0 if it doesn't work. */
4126 find_function_entry_range_from_pc (ecs->event_thread->suspend.stop_pc,
4127 &ecs->stop_func_name,
4128 &ecs->stop_func_start,
4129 &ecs->stop_func_end);
4130 ecs->stop_func_start
4131 += gdbarch_deprecated_function_start_offset (gdbarch);
4133 if (gdbarch_skip_entrypoint_p (gdbarch))
4134 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4135 ecs->stop_func_start);
4137 ecs->stop_func_filled_in = 1;
4142 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4144 static enum stop_kind
4145 get_inferior_stop_soon (execution_control_state *ecs)
4147 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4149 gdb_assert (inf != NULL);
4150 return inf->control.stop_soon;
4153 /* Wait for one event. Store the resulting waitstatus in WS, and
4154 return the event ptid. */
4157 wait_one (struct target_waitstatus *ws)
4160 ptid_t wait_ptid = minus_one_ptid;
4162 overlay_cache_invalid = 1;
4164 /* Flush target cache before starting to handle each event.
4165 Target was running and cache could be stale. This is just a
4166 heuristic. Running threads may modify target memory, but we
4167 don't get any event. */
4168 target_dcache_invalidate ();
4170 if (deprecated_target_wait_hook)
4171 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4173 event_ptid = target_wait (wait_ptid, ws, 0);
4176 print_target_wait_results (wait_ptid, event_ptid, ws);
4181 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4182 instead of the current thread. */
4183 #define THREAD_STOPPED_BY(REASON) \
4185 thread_stopped_by_ ## REASON (ptid_t ptid) \
4187 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4188 inferior_ptid = ptid; \
4190 return target_stopped_by_ ## REASON (); \
4193 /* Generate thread_stopped_by_watchpoint. */
4194 THREAD_STOPPED_BY (watchpoint)
4195 /* Generate thread_stopped_by_sw_breakpoint. */
4196 THREAD_STOPPED_BY (sw_breakpoint)
4197 /* Generate thread_stopped_by_hw_breakpoint. */
4198 THREAD_STOPPED_BY (hw_breakpoint)
4200 /* Save the thread's event and stop reason to process it later. */
4203 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4207 std::string statstr = target_waitstatus_to_string (ws);
4209 fprintf_unfiltered (gdb_stdlog,
4210 "infrun: saving status %s for %d.%ld.%ld\n",
4217 /* Record for later. */
4218 tp->suspend.waitstatus = *ws;
4219 tp->suspend.waitstatus_pending_p = 1;
4221 struct regcache *regcache = get_thread_regcache (tp);
4222 const address_space *aspace = regcache->aspace ();
4224 if (ws->kind == TARGET_WAITKIND_STOPPED
4225 && ws->value.sig == GDB_SIGNAL_TRAP)
4227 CORE_ADDR pc = regcache_read_pc (regcache);
4229 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4231 if (thread_stopped_by_watchpoint (tp->ptid))
4233 tp->suspend.stop_reason
4234 = TARGET_STOPPED_BY_WATCHPOINT;
4236 else if (target_supports_stopped_by_sw_breakpoint ()
4237 && thread_stopped_by_sw_breakpoint (tp->ptid))
4239 tp->suspend.stop_reason
4240 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4242 else if (target_supports_stopped_by_hw_breakpoint ()
4243 && thread_stopped_by_hw_breakpoint (tp->ptid))
4245 tp->suspend.stop_reason
4246 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4248 else if (!target_supports_stopped_by_hw_breakpoint ()
4249 && hardware_breakpoint_inserted_here_p (aspace,
4252 tp->suspend.stop_reason
4253 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4255 else if (!target_supports_stopped_by_sw_breakpoint ()
4256 && software_breakpoint_inserted_here_p (aspace,
4259 tp->suspend.stop_reason
4260 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4262 else if (!thread_has_single_step_breakpoints_set (tp)
4263 && currently_stepping (tp))
4265 tp->suspend.stop_reason
4266 = TARGET_STOPPED_BY_SINGLE_STEP;
4274 stop_all_threads (void)
4276 /* We may need multiple passes to discover all threads. */
4280 gdb_assert (target_is_non_stop_p ());
4283 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4285 scoped_restore_current_thread restore_thread;
4287 target_thread_events (1);
4288 SCOPE_EXIT { target_thread_events (0); };
4290 /* Request threads to stop, and then wait for the stops. Because
4291 threads we already know about can spawn more threads while we're
4292 trying to stop them, and we only learn about new threads when we
4293 update the thread list, do this in a loop, and keep iterating
4294 until two passes find no threads that need to be stopped. */
4295 for (pass = 0; pass < 2; pass++, iterations++)
4298 fprintf_unfiltered (gdb_stdlog,
4299 "infrun: stop_all_threads, pass=%d, "
4300 "iterations=%d\n", pass, iterations);
4304 struct target_waitstatus ws;
4307 update_thread_list ();
4309 /* Go through all threads looking for threads that we need
4310 to tell the target to stop. */
4311 for (thread_info *t : all_non_exited_threads ())
4315 /* If already stopping, don't request a stop again.
4316 We just haven't seen the notification yet. */
4317 if (!t->stop_requested)
4320 fprintf_unfiltered (gdb_stdlog,
4321 "infrun: %s executing, "
4323 target_pid_to_str (t->ptid));
4324 target_stop (t->ptid);
4325 t->stop_requested = 1;
4330 fprintf_unfiltered (gdb_stdlog,
4331 "infrun: %s executing, "
4332 "already stopping\n",
4333 target_pid_to_str (t->ptid));
4336 if (t->stop_requested)
4342 fprintf_unfiltered (gdb_stdlog,
4343 "infrun: %s not executing\n",
4344 target_pid_to_str (t->ptid));
4346 /* The thread may be not executing, but still be
4347 resumed with a pending status to process. */
4355 /* If we find new threads on the second iteration, restart
4356 over. We want to see two iterations in a row with all
4361 event_ptid = wait_one (&ws);
4363 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4365 /* All resumed threads exited. */
4367 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4368 || ws.kind == TARGET_WAITKIND_EXITED
4369 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4373 ptid_t ptid = ptid_t (ws.value.integer);
4375 fprintf_unfiltered (gdb_stdlog,
4376 "infrun: %s exited while "
4377 "stopping threads\n",
4378 target_pid_to_str (ptid));
4383 thread_info *t = find_thread_ptid (event_ptid);
4385 t = add_thread (event_ptid);
4387 t->stop_requested = 0;
4390 t->control.may_range_step = 0;
4392 /* This may be the first time we see the inferior report
4394 inferior *inf = find_inferior_ptid (event_ptid);
4395 if (inf->needs_setup)
4397 switch_to_thread_no_regs (t);
4401 if (ws.kind == TARGET_WAITKIND_STOPPED
4402 && ws.value.sig == GDB_SIGNAL_0)
4404 /* We caught the event that we intended to catch, so
4405 there's no event pending. */
4406 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4407 t->suspend.waitstatus_pending_p = 0;
4409 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4411 /* Add it back to the step-over queue. */
4414 fprintf_unfiltered (gdb_stdlog,
4415 "infrun: displaced-step of %s "
4416 "canceled: adding back to the "
4417 "step-over queue\n",
4418 target_pid_to_str (t->ptid));
4420 t->control.trap_expected = 0;
4421 thread_step_over_chain_enqueue (t);
4426 enum gdb_signal sig;
4427 struct regcache *regcache;
4431 std::string statstr = target_waitstatus_to_string (&ws);
4433 fprintf_unfiltered (gdb_stdlog,
4434 "infrun: target_wait %s, saving "
4435 "status for %d.%ld.%ld\n",
4442 /* Record for later. */
4443 save_waitstatus (t, &ws);
4445 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4446 ? ws.value.sig : GDB_SIGNAL_0);
4448 if (displaced_step_fixup (t, sig) < 0)
4450 /* Add it back to the step-over queue. */
4451 t->control.trap_expected = 0;
4452 thread_step_over_chain_enqueue (t);
4455 regcache = get_thread_regcache (t);
4456 t->suspend.stop_pc = regcache_read_pc (regcache);
4460 fprintf_unfiltered (gdb_stdlog,
4461 "infrun: saved stop_pc=%s for %s "
4462 "(currently_stepping=%d)\n",
4463 paddress (target_gdbarch (),
4464 t->suspend.stop_pc),
4465 target_pid_to_str (t->ptid),
4466 currently_stepping (t));
4474 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4477 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4480 handle_no_resumed (struct execution_control_state *ecs)
4482 if (target_can_async_p ())
4489 if (ui->prompt_state == PROMPT_BLOCKED)
4497 /* There were no unwaited-for children left in the target, but,
4498 we're not synchronously waiting for events either. Just
4502 fprintf_unfiltered (gdb_stdlog,
4503 "infrun: TARGET_WAITKIND_NO_RESUMED "
4504 "(ignoring: bg)\n");
4505 prepare_to_wait (ecs);
4510 /* Otherwise, if we were running a synchronous execution command, we
4511 may need to cancel it and give the user back the terminal.
4513 In non-stop mode, the target can't tell whether we've already
4514 consumed previous stop events, so it can end up sending us a
4515 no-resumed event like so:
4517 #0 - thread 1 is left stopped
4519 #1 - thread 2 is resumed and hits breakpoint
4520 -> TARGET_WAITKIND_STOPPED
4522 #2 - thread 3 is resumed and exits
4523 this is the last resumed thread, so
4524 -> TARGET_WAITKIND_NO_RESUMED
4526 #3 - gdb processes stop for thread 2 and decides to re-resume
4529 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4530 thread 2 is now resumed, so the event should be ignored.
4532 IOW, if the stop for thread 2 doesn't end a foreground command,
4533 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4534 event. But it could be that the event meant that thread 2 itself
4535 (or whatever other thread was the last resumed thread) exited.
4537 To address this we refresh the thread list and check whether we
4538 have resumed threads _now_. In the example above, this removes
4539 thread 3 from the thread list. If thread 2 was re-resumed, we
4540 ignore this event. If we find no thread resumed, then we cancel
4541 the synchronous command show "no unwaited-for " to the user. */
4542 update_thread_list ();
4544 for (thread_info *thread : all_non_exited_threads ())
4546 if (thread->executing
4547 || thread->suspend.waitstatus_pending_p)
4549 /* There were no unwaited-for children left in the target at
4550 some point, but there are now. Just ignore. */
4552 fprintf_unfiltered (gdb_stdlog,
4553 "infrun: TARGET_WAITKIND_NO_RESUMED "
4554 "(ignoring: found resumed)\n");
4555 prepare_to_wait (ecs);
4560 /* Note however that we may find no resumed thread because the whole
4561 process exited meanwhile (thus updating the thread list results
4562 in an empty thread list). In this case we know we'll be getting
4563 a process exit event shortly. */
4564 for (inferior *inf : all_inferiors ())
4569 thread_info *thread = any_live_thread_of_inferior (inf);
4573 fprintf_unfiltered (gdb_stdlog,
4574 "infrun: TARGET_WAITKIND_NO_RESUMED "
4575 "(expect process exit)\n");
4576 prepare_to_wait (ecs);
4581 /* Go ahead and report the event. */
4585 /* Given an execution control state that has been freshly filled in by
4586 an event from the inferior, figure out what it means and take
4589 The alternatives are:
4591 1) stop_waiting and return; to really stop and return to the
4594 2) keep_going and return; to wait for the next event (set
4595 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4599 handle_inferior_event_1 (struct execution_control_state *ecs)
4601 enum stop_kind stop_soon;
4603 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4605 /* We had an event in the inferior, but we are not interested in
4606 handling it at this level. The lower layers have already
4607 done what needs to be done, if anything.
4609 One of the possible circumstances for this is when the
4610 inferior produces output for the console. The inferior has
4611 not stopped, and we are ignoring the event. Another possible
4612 circumstance is any event which the lower level knows will be
4613 reported multiple times without an intervening resume. */
4615 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4616 prepare_to_wait (ecs);
4620 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4623 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4624 prepare_to_wait (ecs);
4628 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4629 && handle_no_resumed (ecs))
4632 /* Cache the last pid/waitstatus. */
4633 set_last_target_status (ecs->ptid, ecs->ws);
4635 /* Always clear state belonging to the previous time we stopped. */
4636 stop_stack_dummy = STOP_NONE;
4638 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4640 /* No unwaited-for children left. IOW, all resumed children
4643 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4645 stop_print_frame = 0;
4650 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4651 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4653 ecs->event_thread = find_thread_ptid (ecs->ptid);
4654 /* If it's a new thread, add it to the thread database. */
4655 if (ecs->event_thread == NULL)
4656 ecs->event_thread = add_thread (ecs->ptid);
4658 /* Disable range stepping. If the next step request could use a
4659 range, this will be end up re-enabled then. */
4660 ecs->event_thread->control.may_range_step = 0;
4663 /* Dependent on valid ECS->EVENT_THREAD. */
4664 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4666 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4667 reinit_frame_cache ();
4669 breakpoint_retire_moribund ();
4671 /* First, distinguish signals caused by the debugger from signals
4672 that have to do with the program's own actions. Note that
4673 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4674 on the operating system version. Here we detect when a SIGILL or
4675 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4676 something similar for SIGSEGV, since a SIGSEGV will be generated
4677 when we're trying to execute a breakpoint instruction on a
4678 non-executable stack. This happens for call dummy breakpoints
4679 for architectures like SPARC that place call dummies on the
4681 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4682 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4683 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4684 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4686 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4688 if (breakpoint_inserted_here_p (regcache->aspace (),
4689 regcache_read_pc (regcache)))
4692 fprintf_unfiltered (gdb_stdlog,
4693 "infrun: Treating signal as SIGTRAP\n");
4694 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4698 /* Mark the non-executing threads accordingly. In all-stop, all
4699 threads of all processes are stopped when we get any event
4700 reported. In non-stop mode, only the event thread stops. */
4704 if (!target_is_non_stop_p ())
4705 mark_ptid = minus_one_ptid;
4706 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4707 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4709 /* If we're handling a process exit in non-stop mode, even
4710 though threads haven't been deleted yet, one would think
4711 that there is nothing to do, as threads of the dead process
4712 will be soon deleted, and threads of any other process were
4713 left running. However, on some targets, threads survive a
4714 process exit event. E.g., for the "checkpoint" command,
4715 when the current checkpoint/fork exits, linux-fork.c
4716 automatically switches to another fork from within
4717 target_mourn_inferior, by associating the same
4718 inferior/thread to another fork. We haven't mourned yet at
4719 this point, but we must mark any threads left in the
4720 process as not-executing so that finish_thread_state marks
4721 them stopped (in the user's perspective) if/when we present
4722 the stop to the user. */
4723 mark_ptid = ptid_t (ecs->ptid.pid ());
4726 mark_ptid = ecs->ptid;
4728 set_executing (mark_ptid, 0);
4730 /* Likewise the resumed flag. */
4731 set_resumed (mark_ptid, 0);
4734 switch (ecs->ws.kind)
4736 case TARGET_WAITKIND_LOADED:
4738 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4739 context_switch (ecs);
4740 /* Ignore gracefully during startup of the inferior, as it might
4741 be the shell which has just loaded some objects, otherwise
4742 add the symbols for the newly loaded objects. Also ignore at
4743 the beginning of an attach or remote session; we will query
4744 the full list of libraries once the connection is
4747 stop_soon = get_inferior_stop_soon (ecs);
4748 if (stop_soon == NO_STOP_QUIETLY)
4750 struct regcache *regcache;
4752 regcache = get_thread_regcache (ecs->event_thread);
4754 handle_solib_event ();
4756 ecs->event_thread->control.stop_bpstat
4757 = bpstat_stop_status (regcache->aspace (),
4758 ecs->event_thread->suspend.stop_pc,
4759 ecs->event_thread, &ecs->ws);
4761 if (handle_stop_requested (ecs))
4764 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4766 /* A catchpoint triggered. */
4767 process_event_stop_test (ecs);
4771 /* If requested, stop when the dynamic linker notifies
4772 gdb of events. This allows the user to get control
4773 and place breakpoints in initializer routines for
4774 dynamically loaded objects (among other things). */
4775 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4776 if (stop_on_solib_events)
4778 /* Make sure we print "Stopped due to solib-event" in
4780 stop_print_frame = 1;
4787 /* If we are skipping through a shell, or through shared library
4788 loading that we aren't interested in, resume the program. If
4789 we're running the program normally, also resume. */
4790 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4792 /* Loading of shared libraries might have changed breakpoint
4793 addresses. Make sure new breakpoints are inserted. */
4794 if (stop_soon == NO_STOP_QUIETLY)
4795 insert_breakpoints ();
4796 resume (GDB_SIGNAL_0);
4797 prepare_to_wait (ecs);
4801 /* But stop if we're attaching or setting up a remote
4803 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4804 || stop_soon == STOP_QUIETLY_REMOTE)
4807 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4812 internal_error (__FILE__, __LINE__,
4813 _("unhandled stop_soon: %d"), (int) stop_soon);
4815 case TARGET_WAITKIND_SPURIOUS:
4817 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4818 if (handle_stop_requested (ecs))
4820 context_switch (ecs);
4821 resume (GDB_SIGNAL_0);
4822 prepare_to_wait (ecs);
4825 case TARGET_WAITKIND_THREAD_CREATED:
4827 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
4828 if (handle_stop_requested (ecs))
4830 context_switch (ecs);
4831 if (!switch_back_to_stepped_thread (ecs))
4835 case TARGET_WAITKIND_EXITED:
4836 case TARGET_WAITKIND_SIGNALLED:
4839 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4840 fprintf_unfiltered (gdb_stdlog,
4841 "infrun: TARGET_WAITKIND_EXITED\n");
4843 fprintf_unfiltered (gdb_stdlog,
4844 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4847 inferior_ptid = ecs->ptid;
4848 set_current_inferior (find_inferior_ptid (ecs->ptid));
4849 set_current_program_space (current_inferior ()->pspace);
4850 handle_vfork_child_exec_or_exit (0);
4851 target_terminal::ours (); /* Must do this before mourn anyway. */
4853 /* Clearing any previous state of convenience variables. */
4854 clear_exit_convenience_vars ();
4856 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4858 /* Record the exit code in the convenience variable $_exitcode, so
4859 that the user can inspect this again later. */
4860 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4861 (LONGEST) ecs->ws.value.integer);
4863 /* Also record this in the inferior itself. */
4864 current_inferior ()->has_exit_code = 1;
4865 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4867 /* Support the --return-child-result option. */
4868 return_child_result_value = ecs->ws.value.integer;
4870 gdb::observers::exited.notify (ecs->ws.value.integer);
4874 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
4876 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4878 /* Set the value of the internal variable $_exitsignal,
4879 which holds the signal uncaught by the inferior. */
4880 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4881 gdbarch_gdb_signal_to_target (gdbarch,
4882 ecs->ws.value.sig));
4886 /* We don't have access to the target's method used for
4887 converting between signal numbers (GDB's internal
4888 representation <-> target's representation).
4889 Therefore, we cannot do a good job at displaying this
4890 information to the user. It's better to just warn
4891 her about it (if infrun debugging is enabled), and
4894 fprintf_filtered (gdb_stdlog, _("\
4895 Cannot fill $_exitsignal with the correct signal number.\n"));
4898 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
4901 gdb_flush (gdb_stdout);
4902 target_mourn_inferior (inferior_ptid);
4903 stop_print_frame = 0;
4907 /* The following are the only cases in which we keep going;
4908 the above cases end in a continue or goto. */
4909 case TARGET_WAITKIND_FORKED:
4910 case TARGET_WAITKIND_VFORKED:
4913 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4914 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4916 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4919 /* Check whether the inferior is displaced stepping. */
4921 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4922 struct gdbarch *gdbarch = regcache->arch ();
4924 /* If checking displaced stepping is supported, and thread
4925 ecs->ptid is displaced stepping. */
4926 if (displaced_step_in_progress_thread (ecs->event_thread))
4928 struct inferior *parent_inf
4929 = find_inferior_ptid (ecs->ptid);
4930 struct regcache *child_regcache;
4931 CORE_ADDR parent_pc;
4933 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4934 indicating that the displaced stepping of syscall instruction
4935 has been done. Perform cleanup for parent process here. Note
4936 that this operation also cleans up the child process for vfork,
4937 because their pages are shared. */
4938 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
4939 /* Start a new step-over in another thread if there's one
4943 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4945 struct displaced_step_inferior_state *displaced
4946 = get_displaced_stepping_state (parent_inf);
4948 /* Restore scratch pad for child process. */
4949 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4952 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4953 the child's PC is also within the scratchpad. Set the child's PC
4954 to the parent's PC value, which has already been fixed up.
4955 FIXME: we use the parent's aspace here, although we're touching
4956 the child, because the child hasn't been added to the inferior
4957 list yet at this point. */
4960 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4962 parent_inf->aspace);
4963 /* Read PC value of parent process. */
4964 parent_pc = regcache_read_pc (regcache);
4966 if (debug_displaced)
4967 fprintf_unfiltered (gdb_stdlog,
4968 "displaced: write child pc from %s to %s\n",
4970 regcache_read_pc (child_regcache)),
4971 paddress (gdbarch, parent_pc));
4973 regcache_write_pc (child_regcache, parent_pc);
4977 context_switch (ecs);
4979 /* Immediately detach breakpoints from the child before there's
4980 any chance of letting the user delete breakpoints from the
4981 breakpoint lists. If we don't do this early, it's easy to
4982 leave left over traps in the child, vis: "break foo; catch
4983 fork; c; <fork>; del; c; <child calls foo>". We only follow
4984 the fork on the last `continue', and by that time the
4985 breakpoint at "foo" is long gone from the breakpoint table.
4986 If we vforked, then we don't need to unpatch here, since both
4987 parent and child are sharing the same memory pages; we'll
4988 need to unpatch at follow/detach time instead to be certain
4989 that new breakpoints added between catchpoint hit time and
4990 vfork follow are detached. */
4991 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4993 /* This won't actually modify the breakpoint list, but will
4994 physically remove the breakpoints from the child. */
4995 detach_breakpoints (ecs->ws.value.related_pid);
4998 delete_just_stopped_threads_single_step_breakpoints ();
5000 /* In case the event is caught by a catchpoint, remember that
5001 the event is to be followed at the next resume of the thread,
5002 and not immediately. */
5003 ecs->event_thread->pending_follow = ecs->ws;
5005 ecs->event_thread->suspend.stop_pc
5006 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5008 ecs->event_thread->control.stop_bpstat
5009 = bpstat_stop_status (get_current_regcache ()->aspace (),
5010 ecs->event_thread->suspend.stop_pc,
5011 ecs->event_thread, &ecs->ws);
5013 if (handle_stop_requested (ecs))
5016 /* If no catchpoint triggered for this, then keep going. Note
5017 that we're interested in knowing the bpstat actually causes a
5018 stop, not just if it may explain the signal. Software
5019 watchpoints, for example, always appear in the bpstat. */
5020 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5024 = (follow_fork_mode_string == follow_fork_mode_child);
5026 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5028 should_resume = follow_fork ();
5030 thread_info *parent = ecs->event_thread;
5031 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5033 /* At this point, the parent is marked running, and the
5034 child is marked stopped. */
5036 /* If not resuming the parent, mark it stopped. */
5037 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5038 parent->set_running (false);
5040 /* If resuming the child, mark it running. */
5041 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5042 child->set_running (true);
5044 /* In non-stop mode, also resume the other branch. */
5045 if (!detach_fork && (non_stop
5046 || (sched_multi && target_is_non_stop_p ())))
5049 switch_to_thread (parent);
5051 switch_to_thread (child);
5053 ecs->event_thread = inferior_thread ();
5054 ecs->ptid = inferior_ptid;
5059 switch_to_thread (child);
5061 switch_to_thread (parent);
5063 ecs->event_thread = inferior_thread ();
5064 ecs->ptid = inferior_ptid;
5072 process_event_stop_test (ecs);
5075 case TARGET_WAITKIND_VFORK_DONE:
5076 /* Done with the shared memory region. Re-insert breakpoints in
5077 the parent, and keep going. */
5080 fprintf_unfiltered (gdb_stdlog,
5081 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5083 context_switch (ecs);
5085 current_inferior ()->waiting_for_vfork_done = 0;
5086 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5088 if (handle_stop_requested (ecs))
5091 /* This also takes care of reinserting breakpoints in the
5092 previously locked inferior. */
5096 case TARGET_WAITKIND_EXECD:
5098 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5100 /* Note we can't read registers yet (the stop_pc), because we
5101 don't yet know the inferior's post-exec architecture.
5102 'stop_pc' is explicitly read below instead. */
5103 switch_to_thread_no_regs (ecs->event_thread);
5105 /* Do whatever is necessary to the parent branch of the vfork. */
5106 handle_vfork_child_exec_or_exit (1);
5108 /* This causes the eventpoints and symbol table to be reset.
5109 Must do this now, before trying to determine whether to
5111 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5113 /* In follow_exec we may have deleted the original thread and
5114 created a new one. Make sure that the event thread is the
5115 execd thread for that case (this is a nop otherwise). */
5116 ecs->event_thread = inferior_thread ();
5118 ecs->event_thread->suspend.stop_pc
5119 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5121 ecs->event_thread->control.stop_bpstat
5122 = bpstat_stop_status (get_current_regcache ()->aspace (),
5123 ecs->event_thread->suspend.stop_pc,
5124 ecs->event_thread, &ecs->ws);
5126 /* Note that this may be referenced from inside
5127 bpstat_stop_status above, through inferior_has_execd. */
5128 xfree (ecs->ws.value.execd_pathname);
5129 ecs->ws.value.execd_pathname = NULL;
5131 if (handle_stop_requested (ecs))
5134 /* If no catchpoint triggered for this, then keep going. */
5135 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5137 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5141 process_event_stop_test (ecs);
5144 /* Be careful not to try to gather much state about a thread
5145 that's in a syscall. It's frequently a losing proposition. */
5146 case TARGET_WAITKIND_SYSCALL_ENTRY:
5148 fprintf_unfiltered (gdb_stdlog,
5149 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5150 /* Getting the current syscall number. */
5151 if (handle_syscall_event (ecs) == 0)
5152 process_event_stop_test (ecs);
5155 /* Before examining the threads further, step this thread to
5156 get it entirely out of the syscall. (We get notice of the
5157 event when the thread is just on the verge of exiting a
5158 syscall. Stepping one instruction seems to get it back
5160 case TARGET_WAITKIND_SYSCALL_RETURN:
5162 fprintf_unfiltered (gdb_stdlog,
5163 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5164 if (handle_syscall_event (ecs) == 0)
5165 process_event_stop_test (ecs);
5168 case TARGET_WAITKIND_STOPPED:
5170 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5171 handle_signal_stop (ecs);
5174 case TARGET_WAITKIND_NO_HISTORY:
5176 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5177 /* Reverse execution: target ran out of history info. */
5179 /* Switch to the stopped thread. */
5180 context_switch (ecs);
5182 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5184 delete_just_stopped_threads_single_step_breakpoints ();
5185 ecs->event_thread->suspend.stop_pc
5186 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5188 if (handle_stop_requested (ecs))
5191 gdb::observers::no_history.notify ();
5197 /* A wrapper around handle_inferior_event_1, which also makes sure
5198 that all temporary struct value objects that were created during
5199 the handling of the event get deleted at the end. */
5202 handle_inferior_event (struct execution_control_state *ecs)
5204 struct value *mark = value_mark ();
5206 handle_inferior_event_1 (ecs);
5207 /* Purge all temporary values created during the event handling,
5208 as it could be a long time before we return to the command level
5209 where such values would otherwise be purged. */
5210 value_free_to_mark (mark);
5213 /* Restart threads back to what they were trying to do back when we
5214 paused them for an in-line step-over. The EVENT_THREAD thread is
5218 restart_threads (struct thread_info *event_thread)
5220 /* In case the instruction just stepped spawned a new thread. */
5221 update_thread_list ();
5223 for (thread_info *tp : all_non_exited_threads ())
5225 if (tp == event_thread)
5228 fprintf_unfiltered (gdb_stdlog,
5229 "infrun: restart threads: "
5230 "[%s] is event thread\n",
5231 target_pid_to_str (tp->ptid));
5235 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5238 fprintf_unfiltered (gdb_stdlog,
5239 "infrun: restart threads: "
5240 "[%s] not meant to be running\n",
5241 target_pid_to_str (tp->ptid));
5248 fprintf_unfiltered (gdb_stdlog,
5249 "infrun: restart threads: [%s] resumed\n",
5250 target_pid_to_str (tp->ptid));
5251 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5255 if (thread_is_in_step_over_chain (tp))
5258 fprintf_unfiltered (gdb_stdlog,
5259 "infrun: restart threads: "
5260 "[%s] needs step-over\n",
5261 target_pid_to_str (tp->ptid));
5262 gdb_assert (!tp->resumed);
5267 if (tp->suspend.waitstatus_pending_p)
5270 fprintf_unfiltered (gdb_stdlog,
5271 "infrun: restart threads: "
5272 "[%s] has pending status\n",
5273 target_pid_to_str (tp->ptid));
5278 gdb_assert (!tp->stop_requested);
5280 /* If some thread needs to start a step-over at this point, it
5281 should still be in the step-over queue, and thus skipped
5283 if (thread_still_needs_step_over (tp))
5285 internal_error (__FILE__, __LINE__,
5286 "thread [%s] needs a step-over, but not in "
5287 "step-over queue\n",
5288 target_pid_to_str (tp->ptid));
5291 if (currently_stepping (tp))
5294 fprintf_unfiltered (gdb_stdlog,
5295 "infrun: restart threads: [%s] was stepping\n",
5296 target_pid_to_str (tp->ptid));
5297 keep_going_stepped_thread (tp);
5301 struct execution_control_state ecss;
5302 struct execution_control_state *ecs = &ecss;
5305 fprintf_unfiltered (gdb_stdlog,
5306 "infrun: restart threads: [%s] continuing\n",
5307 target_pid_to_str (tp->ptid));
5308 reset_ecs (ecs, tp);
5309 switch_to_thread (tp);
5310 keep_going_pass_signal (ecs);
5315 /* Callback for iterate_over_threads. Find a resumed thread that has
5316 a pending waitstatus. */
5319 resumed_thread_with_pending_status (struct thread_info *tp,
5323 && tp->suspend.waitstatus_pending_p);
5326 /* Called when we get an event that may finish an in-line or
5327 out-of-line (displaced stepping) step-over started previously.
5328 Return true if the event is processed and we should go back to the
5329 event loop; false if the caller should continue processing the
5333 finish_step_over (struct execution_control_state *ecs)
5335 int had_step_over_info;
5337 displaced_step_fixup (ecs->event_thread,
5338 ecs->event_thread->suspend.stop_signal);
5340 had_step_over_info = step_over_info_valid_p ();
5342 if (had_step_over_info)
5344 /* If we're stepping over a breakpoint with all threads locked,
5345 then only the thread that was stepped should be reporting
5347 gdb_assert (ecs->event_thread->control.trap_expected);
5349 clear_step_over_info ();
5352 if (!target_is_non_stop_p ())
5355 /* Start a new step-over in another thread if there's one that
5359 /* If we were stepping over a breakpoint before, and haven't started
5360 a new in-line step-over sequence, then restart all other threads
5361 (except the event thread). We can't do this in all-stop, as then
5362 e.g., we wouldn't be able to issue any other remote packet until
5363 these other threads stop. */
5364 if (had_step_over_info && !step_over_info_valid_p ())
5366 struct thread_info *pending;
5368 /* If we only have threads with pending statuses, the restart
5369 below won't restart any thread and so nothing re-inserts the
5370 breakpoint we just stepped over. But we need it inserted
5371 when we later process the pending events, otherwise if
5372 another thread has a pending event for this breakpoint too,
5373 we'd discard its event (because the breakpoint that
5374 originally caused the event was no longer inserted). */
5375 context_switch (ecs);
5376 insert_breakpoints ();
5378 restart_threads (ecs->event_thread);
5380 /* If we have events pending, go through handle_inferior_event
5381 again, picking up a pending event at random. This avoids
5382 thread starvation. */
5384 /* But not if we just stepped over a watchpoint in order to let
5385 the instruction execute so we can evaluate its expression.
5386 The set of watchpoints that triggered is recorded in the
5387 breakpoint objects themselves (see bp->watchpoint_triggered).
5388 If we processed another event first, that other event could
5389 clobber this info. */
5390 if (ecs->event_thread->stepping_over_watchpoint)
5393 pending = iterate_over_threads (resumed_thread_with_pending_status,
5395 if (pending != NULL)
5397 struct thread_info *tp = ecs->event_thread;
5398 struct regcache *regcache;
5402 fprintf_unfiltered (gdb_stdlog,
5403 "infrun: found resumed threads with "
5404 "pending events, saving status\n");
5407 gdb_assert (pending != tp);
5409 /* Record the event thread's event for later. */
5410 save_waitstatus (tp, &ecs->ws);
5411 /* This was cleared early, by handle_inferior_event. Set it
5412 so this pending event is considered by
5416 gdb_assert (!tp->executing);
5418 regcache = get_thread_regcache (tp);
5419 tp->suspend.stop_pc = regcache_read_pc (regcache);
5423 fprintf_unfiltered (gdb_stdlog,
5424 "infrun: saved stop_pc=%s for %s "
5425 "(currently_stepping=%d)\n",
5426 paddress (target_gdbarch (),
5427 tp->suspend.stop_pc),
5428 target_pid_to_str (tp->ptid),
5429 currently_stepping (tp));
5432 /* This in-line step-over finished; clear this so we won't
5433 start a new one. This is what handle_signal_stop would
5434 do, if we returned false. */
5435 tp->stepping_over_breakpoint = 0;
5437 /* Wake up the event loop again. */
5438 mark_async_event_handler (infrun_async_inferior_event_token);
5440 prepare_to_wait (ecs);
5448 /* Come here when the program has stopped with a signal. */
5451 handle_signal_stop (struct execution_control_state *ecs)
5453 struct frame_info *frame;
5454 struct gdbarch *gdbarch;
5455 int stopped_by_watchpoint;
5456 enum stop_kind stop_soon;
5459 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5461 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5463 /* Do we need to clean up the state of a thread that has
5464 completed a displaced single-step? (Doing so usually affects
5465 the PC, so do it here, before we set stop_pc.) */
5466 if (finish_step_over (ecs))
5469 /* If we either finished a single-step or hit a breakpoint, but
5470 the user wanted this thread to be stopped, pretend we got a
5471 SIG0 (generic unsignaled stop). */
5472 if (ecs->event_thread->stop_requested
5473 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5474 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5476 ecs->event_thread->suspend.stop_pc
5477 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5481 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5482 struct gdbarch *reg_gdbarch = regcache->arch ();
5483 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5485 inferior_ptid = ecs->ptid;
5487 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5488 paddress (reg_gdbarch,
5489 ecs->event_thread->suspend.stop_pc));
5490 if (target_stopped_by_watchpoint ())
5494 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5496 if (target_stopped_data_address (current_top_target (), &addr))
5497 fprintf_unfiltered (gdb_stdlog,
5498 "infrun: stopped data address = %s\n",
5499 paddress (reg_gdbarch, addr));
5501 fprintf_unfiltered (gdb_stdlog,
5502 "infrun: (no data address available)\n");
5506 /* This is originated from start_remote(), start_inferior() and
5507 shared libraries hook functions. */
5508 stop_soon = get_inferior_stop_soon (ecs);
5509 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5511 context_switch (ecs);
5513 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5514 stop_print_frame = 1;
5519 /* This originates from attach_command(). We need to overwrite
5520 the stop_signal here, because some kernels don't ignore a
5521 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5522 See more comments in inferior.h. On the other hand, if we
5523 get a non-SIGSTOP, report it to the user - assume the backend
5524 will handle the SIGSTOP if it should show up later.
5526 Also consider that the attach is complete when we see a
5527 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5528 target extended-remote report it instead of a SIGSTOP
5529 (e.g. gdbserver). We already rely on SIGTRAP being our
5530 signal, so this is no exception.
5532 Also consider that the attach is complete when we see a
5533 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5534 the target to stop all threads of the inferior, in case the
5535 low level attach operation doesn't stop them implicitly. If
5536 they weren't stopped implicitly, then the stub will report a
5537 GDB_SIGNAL_0, meaning: stopped for no particular reason
5538 other than GDB's request. */
5539 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5540 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5541 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5542 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5544 stop_print_frame = 1;
5546 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5550 /* See if something interesting happened to the non-current thread. If
5551 so, then switch to that thread. */
5552 if (ecs->ptid != inferior_ptid)
5555 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5557 context_switch (ecs);
5559 if (deprecated_context_hook)
5560 deprecated_context_hook (ecs->event_thread->global_num);
5563 /* At this point, get hold of the now-current thread's frame. */
5564 frame = get_current_frame ();
5565 gdbarch = get_frame_arch (frame);
5567 /* Pull the single step breakpoints out of the target. */
5568 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5570 struct regcache *regcache;
5573 regcache = get_thread_regcache (ecs->event_thread);
5574 const address_space *aspace = regcache->aspace ();
5576 pc = regcache_read_pc (regcache);
5578 /* However, before doing so, if this single-step breakpoint was
5579 actually for another thread, set this thread up for moving
5581 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5584 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5588 fprintf_unfiltered (gdb_stdlog,
5589 "infrun: [%s] hit another thread's "
5590 "single-step breakpoint\n",
5591 target_pid_to_str (ecs->ptid));
5593 ecs->hit_singlestep_breakpoint = 1;
5600 fprintf_unfiltered (gdb_stdlog,
5601 "infrun: [%s] hit its "
5602 "single-step breakpoint\n",
5603 target_pid_to_str (ecs->ptid));
5607 delete_just_stopped_threads_single_step_breakpoints ();
5609 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5610 && ecs->event_thread->control.trap_expected
5611 && ecs->event_thread->stepping_over_watchpoint)
5612 stopped_by_watchpoint = 0;
5614 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5616 /* If necessary, step over this watchpoint. We'll be back to display
5618 if (stopped_by_watchpoint
5619 && (target_have_steppable_watchpoint
5620 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5622 /* At this point, we are stopped at an instruction which has
5623 attempted to write to a piece of memory under control of
5624 a watchpoint. The instruction hasn't actually executed
5625 yet. If we were to evaluate the watchpoint expression
5626 now, we would get the old value, and therefore no change
5627 would seem to have occurred.
5629 In order to make watchpoints work `right', we really need
5630 to complete the memory write, and then evaluate the
5631 watchpoint expression. We do this by single-stepping the
5634 It may not be necessary to disable the watchpoint to step over
5635 it. For example, the PA can (with some kernel cooperation)
5636 single step over a watchpoint without disabling the watchpoint.
5638 It is far more common to need to disable a watchpoint to step
5639 the inferior over it. If we have non-steppable watchpoints,
5640 we must disable the current watchpoint; it's simplest to
5641 disable all watchpoints.
5643 Any breakpoint at PC must also be stepped over -- if there's
5644 one, it will have already triggered before the watchpoint
5645 triggered, and we either already reported it to the user, or
5646 it didn't cause a stop and we called keep_going. In either
5647 case, if there was a breakpoint at PC, we must be trying to
5649 ecs->event_thread->stepping_over_watchpoint = 1;
5654 ecs->event_thread->stepping_over_breakpoint = 0;
5655 ecs->event_thread->stepping_over_watchpoint = 0;
5656 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5657 ecs->event_thread->control.stop_step = 0;
5658 stop_print_frame = 1;
5659 stopped_by_random_signal = 0;
5660 bpstat stop_chain = NULL;
5662 /* Hide inlined functions starting here, unless we just performed stepi or
5663 nexti. After stepi and nexti, always show the innermost frame (not any
5664 inline function call sites). */
5665 if (ecs->event_thread->control.step_range_end != 1)
5667 const address_space *aspace
5668 = get_thread_regcache (ecs->event_thread)->aspace ();
5670 /* skip_inline_frames is expensive, so we avoid it if we can
5671 determine that the address is one where functions cannot have
5672 been inlined. This improves performance with inferiors that
5673 load a lot of shared libraries, because the solib event
5674 breakpoint is defined as the address of a function (i.e. not
5675 inline). Note that we have to check the previous PC as well
5676 as the current one to catch cases when we have just
5677 single-stepped off a breakpoint prior to reinstating it.
5678 Note that we're assuming that the code we single-step to is
5679 not inline, but that's not definitive: there's nothing
5680 preventing the event breakpoint function from containing
5681 inlined code, and the single-step ending up there. If the
5682 user had set a breakpoint on that inlined code, the missing
5683 skip_inline_frames call would break things. Fortunately
5684 that's an extremely unlikely scenario. */
5685 if (!pc_at_non_inline_function (aspace,
5686 ecs->event_thread->suspend.stop_pc,
5688 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5689 && ecs->event_thread->control.trap_expected
5690 && pc_at_non_inline_function (aspace,
5691 ecs->event_thread->prev_pc,
5694 stop_chain = build_bpstat_chain (aspace,
5695 ecs->event_thread->suspend.stop_pc,
5697 skip_inline_frames (ecs->event_thread, stop_chain);
5699 /* Re-fetch current thread's frame in case that invalidated
5701 frame = get_current_frame ();
5702 gdbarch = get_frame_arch (frame);
5706 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5707 && ecs->event_thread->control.trap_expected
5708 && gdbarch_single_step_through_delay_p (gdbarch)
5709 && currently_stepping (ecs->event_thread))
5711 /* We're trying to step off a breakpoint. Turns out that we're
5712 also on an instruction that needs to be stepped multiple
5713 times before it's been fully executing. E.g., architectures
5714 with a delay slot. It needs to be stepped twice, once for
5715 the instruction and once for the delay slot. */
5716 int step_through_delay
5717 = gdbarch_single_step_through_delay (gdbarch, frame);
5719 if (debug_infrun && step_through_delay)
5720 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5721 if (ecs->event_thread->control.step_range_end == 0
5722 && step_through_delay)
5724 /* The user issued a continue when stopped at a breakpoint.
5725 Set up for another trap and get out of here. */
5726 ecs->event_thread->stepping_over_breakpoint = 1;
5730 else if (step_through_delay)
5732 /* The user issued a step when stopped at a breakpoint.
5733 Maybe we should stop, maybe we should not - the delay
5734 slot *might* correspond to a line of source. In any
5735 case, don't decide that here, just set
5736 ecs->stepping_over_breakpoint, making sure we
5737 single-step again before breakpoints are re-inserted. */
5738 ecs->event_thread->stepping_over_breakpoint = 1;
5742 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5743 handles this event. */
5744 ecs->event_thread->control.stop_bpstat
5745 = bpstat_stop_status (get_current_regcache ()->aspace (),
5746 ecs->event_thread->suspend.stop_pc,
5747 ecs->event_thread, &ecs->ws, stop_chain);
5749 /* Following in case break condition called a
5751 stop_print_frame = 1;
5753 /* This is where we handle "moribund" watchpoints. Unlike
5754 software breakpoints traps, hardware watchpoint traps are
5755 always distinguishable from random traps. If no high-level
5756 watchpoint is associated with the reported stop data address
5757 anymore, then the bpstat does not explain the signal ---
5758 simply make sure to ignore it if `stopped_by_watchpoint' is
5762 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5763 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5765 && stopped_by_watchpoint)
5766 fprintf_unfiltered (gdb_stdlog,
5767 "infrun: no user watchpoint explains "
5768 "watchpoint SIGTRAP, ignoring\n");
5770 /* NOTE: cagney/2003-03-29: These checks for a random signal
5771 at one stage in the past included checks for an inferior
5772 function call's call dummy's return breakpoint. The original
5773 comment, that went with the test, read:
5775 ``End of a stack dummy. Some systems (e.g. Sony news) give
5776 another signal besides SIGTRAP, so check here as well as
5779 If someone ever tries to get call dummys on a
5780 non-executable stack to work (where the target would stop
5781 with something like a SIGSEGV), then those tests might need
5782 to be re-instated. Given, however, that the tests were only
5783 enabled when momentary breakpoints were not being used, I
5784 suspect that it won't be the case.
5786 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5787 be necessary for call dummies on a non-executable stack on
5790 /* See if the breakpoints module can explain the signal. */
5792 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5793 ecs->event_thread->suspend.stop_signal);
5795 /* Maybe this was a trap for a software breakpoint that has since
5797 if (random_signal && target_stopped_by_sw_breakpoint ())
5799 if (program_breakpoint_here_p (gdbarch,
5800 ecs->event_thread->suspend.stop_pc))
5802 struct regcache *regcache;
5805 /* Re-adjust PC to what the program would see if GDB was not
5807 regcache = get_thread_regcache (ecs->event_thread);
5808 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5811 gdb::optional<scoped_restore_tmpl<int>>
5812 restore_operation_disable;
5814 if (record_full_is_used ())
5815 restore_operation_disable.emplace
5816 (record_full_gdb_operation_disable_set ());
5818 regcache_write_pc (regcache,
5819 ecs->event_thread->suspend.stop_pc + decr_pc);
5824 /* A delayed software breakpoint event. Ignore the trap. */
5826 fprintf_unfiltered (gdb_stdlog,
5827 "infrun: delayed software breakpoint "
5828 "trap, ignoring\n");
5833 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5834 has since been removed. */
5835 if (random_signal && target_stopped_by_hw_breakpoint ())
5837 /* A delayed hardware breakpoint event. Ignore the trap. */
5839 fprintf_unfiltered (gdb_stdlog,
5840 "infrun: delayed hardware breakpoint/watchpoint "
5841 "trap, ignoring\n");
5845 /* If not, perhaps stepping/nexting can. */
5847 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5848 && currently_stepping (ecs->event_thread));
5850 /* Perhaps the thread hit a single-step breakpoint of _another_
5851 thread. Single-step breakpoints are transparent to the
5852 breakpoints module. */
5854 random_signal = !ecs->hit_singlestep_breakpoint;
5856 /* No? Perhaps we got a moribund watchpoint. */
5858 random_signal = !stopped_by_watchpoint;
5860 /* Always stop if the user explicitly requested this thread to
5862 if (ecs->event_thread->stop_requested)
5866 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
5869 /* For the program's own signals, act according to
5870 the signal handling tables. */
5874 /* Signal not for debugging purposes. */
5875 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5876 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5879 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5880 gdb_signal_to_symbol_string (stop_signal));
5882 stopped_by_random_signal = 1;
5884 /* Always stop on signals if we're either just gaining control
5885 of the program, or the user explicitly requested this thread
5886 to remain stopped. */
5887 if (stop_soon != NO_STOP_QUIETLY
5888 || ecs->event_thread->stop_requested
5890 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5896 /* Notify observers the signal has "handle print" set. Note we
5897 returned early above if stopping; normal_stop handles the
5898 printing in that case. */
5899 if (signal_print[ecs->event_thread->suspend.stop_signal])
5901 /* The signal table tells us to print about this signal. */
5902 target_terminal::ours_for_output ();
5903 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
5904 target_terminal::inferior ();
5907 /* Clear the signal if it should not be passed. */
5908 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5909 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5911 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
5912 && ecs->event_thread->control.trap_expected
5913 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5915 /* We were just starting a new sequence, attempting to
5916 single-step off of a breakpoint and expecting a SIGTRAP.
5917 Instead this signal arrives. This signal will take us out
5918 of the stepping range so GDB needs to remember to, when
5919 the signal handler returns, resume stepping off that
5921 /* To simplify things, "continue" is forced to use the same
5922 code paths as single-step - set a breakpoint at the
5923 signal return address and then, once hit, step off that
5926 fprintf_unfiltered (gdb_stdlog,
5927 "infrun: signal arrived while stepping over "
5930 insert_hp_step_resume_breakpoint_at_frame (frame);
5931 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5932 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5933 ecs->event_thread->control.trap_expected = 0;
5935 /* If we were nexting/stepping some other thread, switch to
5936 it, so that we don't continue it, losing control. */
5937 if (!switch_back_to_stepped_thread (ecs))
5942 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5943 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
5945 || ecs->event_thread->control.step_range_end == 1)
5946 && frame_id_eq (get_stack_frame_id (frame),
5947 ecs->event_thread->control.step_stack_frame_id)
5948 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5950 /* The inferior is about to take a signal that will take it
5951 out of the single step range. Set a breakpoint at the
5952 current PC (which is presumably where the signal handler
5953 will eventually return) and then allow the inferior to
5956 Note that this is only needed for a signal delivered
5957 while in the single-step range. Nested signals aren't a
5958 problem as they eventually all return. */
5960 fprintf_unfiltered (gdb_stdlog,
5961 "infrun: signal may take us out of "
5962 "single-step range\n");
5964 clear_step_over_info ();
5965 insert_hp_step_resume_breakpoint_at_frame (frame);
5966 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5967 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5968 ecs->event_thread->control.trap_expected = 0;
5973 /* Note: step_resume_breakpoint may be non-NULL. This occures
5974 when either there's a nested signal, or when there's a
5975 pending signal enabled just as the signal handler returns
5976 (leaving the inferior at the step-resume-breakpoint without
5977 actually executing it). Either way continue until the
5978 breakpoint is really hit. */
5980 if (!switch_back_to_stepped_thread (ecs))
5983 fprintf_unfiltered (gdb_stdlog,
5984 "infrun: random signal, keep going\n");
5991 process_event_stop_test (ecs);
5994 /* Come here when we've got some debug event / signal we can explain
5995 (IOW, not a random signal), and test whether it should cause a
5996 stop, or whether we should resume the inferior (transparently).
5997 E.g., could be a breakpoint whose condition evaluates false; we
5998 could be still stepping within the line; etc. */
6001 process_event_stop_test (struct execution_control_state *ecs)
6003 struct symtab_and_line stop_pc_sal;
6004 struct frame_info *frame;
6005 struct gdbarch *gdbarch;
6006 CORE_ADDR jmp_buf_pc;
6007 struct bpstat_what what;
6009 /* Handle cases caused by hitting a breakpoint. */
6011 frame = get_current_frame ();
6012 gdbarch = get_frame_arch (frame);
6014 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6016 if (what.call_dummy)
6018 stop_stack_dummy = what.call_dummy;
6021 /* A few breakpoint types have callbacks associated (e.g.,
6022 bp_jit_event). Run them now. */
6023 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6025 /* If we hit an internal event that triggers symbol changes, the
6026 current frame will be invalidated within bpstat_what (e.g., if we
6027 hit an internal solib event). Re-fetch it. */
6028 frame = get_current_frame ();
6029 gdbarch = get_frame_arch (frame);
6031 switch (what.main_action)
6033 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6034 /* If we hit the breakpoint at longjmp while stepping, we
6035 install a momentary breakpoint at the target of the
6039 fprintf_unfiltered (gdb_stdlog,
6040 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6042 ecs->event_thread->stepping_over_breakpoint = 1;
6044 if (what.is_longjmp)
6046 struct value *arg_value;
6048 /* If we set the longjmp breakpoint via a SystemTap probe,
6049 then use it to extract the arguments. The destination PC
6050 is the third argument to the probe. */
6051 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6054 jmp_buf_pc = value_as_address (arg_value);
6055 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6057 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6058 || !gdbarch_get_longjmp_target (gdbarch,
6059 frame, &jmp_buf_pc))
6062 fprintf_unfiltered (gdb_stdlog,
6063 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6064 "(!gdbarch_get_longjmp_target)\n");
6069 /* Insert a breakpoint at resume address. */
6070 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6073 check_exception_resume (ecs, frame);
6077 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6079 struct frame_info *init_frame;
6081 /* There are several cases to consider.
6083 1. The initiating frame no longer exists. In this case we
6084 must stop, because the exception or longjmp has gone too
6087 2. The initiating frame exists, and is the same as the
6088 current frame. We stop, because the exception or longjmp
6091 3. The initiating frame exists and is different from the
6092 current frame. This means the exception or longjmp has
6093 been caught beneath the initiating frame, so keep going.
6095 4. longjmp breakpoint has been placed just to protect
6096 against stale dummy frames and user is not interested in
6097 stopping around longjmps. */
6100 fprintf_unfiltered (gdb_stdlog,
6101 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6103 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6105 delete_exception_resume_breakpoint (ecs->event_thread);
6107 if (what.is_longjmp)
6109 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6111 if (!frame_id_p (ecs->event_thread->initiating_frame))
6119 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6123 struct frame_id current_id
6124 = get_frame_id (get_current_frame ());
6125 if (frame_id_eq (current_id,
6126 ecs->event_thread->initiating_frame))
6128 /* Case 2. Fall through. */
6138 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6140 delete_step_resume_breakpoint (ecs->event_thread);
6142 end_stepping_range (ecs);
6146 case BPSTAT_WHAT_SINGLE:
6148 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6149 ecs->event_thread->stepping_over_breakpoint = 1;
6150 /* Still need to check other stuff, at least the case where we
6151 are stepping and step out of the right range. */
6154 case BPSTAT_WHAT_STEP_RESUME:
6156 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6158 delete_step_resume_breakpoint (ecs->event_thread);
6159 if (ecs->event_thread->control.proceed_to_finish
6160 && execution_direction == EXEC_REVERSE)
6162 struct thread_info *tp = ecs->event_thread;
6164 /* We are finishing a function in reverse, and just hit the
6165 step-resume breakpoint at the start address of the
6166 function, and we're almost there -- just need to back up
6167 by one more single-step, which should take us back to the
6169 tp->control.step_range_start = tp->control.step_range_end = 1;
6173 fill_in_stop_func (gdbarch, ecs);
6174 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6175 && execution_direction == EXEC_REVERSE)
6177 /* We are stepping over a function call in reverse, and just
6178 hit the step-resume breakpoint at the start address of
6179 the function. Go back to single-stepping, which should
6180 take us back to the function call. */
6181 ecs->event_thread->stepping_over_breakpoint = 1;
6187 case BPSTAT_WHAT_STOP_NOISY:
6189 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6190 stop_print_frame = 1;
6192 /* Assume the thread stopped for a breapoint. We'll still check
6193 whether a/the breakpoint is there when the thread is next
6195 ecs->event_thread->stepping_over_breakpoint = 1;
6200 case BPSTAT_WHAT_STOP_SILENT:
6202 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6203 stop_print_frame = 0;
6205 /* Assume the thread stopped for a breapoint. We'll still check
6206 whether a/the breakpoint is there when the thread is next
6208 ecs->event_thread->stepping_over_breakpoint = 1;
6212 case BPSTAT_WHAT_HP_STEP_RESUME:
6214 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6216 delete_step_resume_breakpoint (ecs->event_thread);
6217 if (ecs->event_thread->step_after_step_resume_breakpoint)
6219 /* Back when the step-resume breakpoint was inserted, we
6220 were trying to single-step off a breakpoint. Go back to
6222 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6223 ecs->event_thread->stepping_over_breakpoint = 1;
6229 case BPSTAT_WHAT_KEEP_CHECKING:
6233 /* If we stepped a permanent breakpoint and we had a high priority
6234 step-resume breakpoint for the address we stepped, but we didn't
6235 hit it, then we must have stepped into the signal handler. The
6236 step-resume was only necessary to catch the case of _not_
6237 stepping into the handler, so delete it, and fall through to
6238 checking whether the step finished. */
6239 if (ecs->event_thread->stepped_breakpoint)
6241 struct breakpoint *sr_bp
6242 = ecs->event_thread->control.step_resume_breakpoint;
6245 && sr_bp->loc->permanent
6246 && sr_bp->type == bp_hp_step_resume
6247 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6250 fprintf_unfiltered (gdb_stdlog,
6251 "infrun: stepped permanent breakpoint, stopped in "
6253 delete_step_resume_breakpoint (ecs->event_thread);
6254 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6258 /* We come here if we hit a breakpoint but should not stop for it.
6259 Possibly we also were stepping and should stop for that. So fall
6260 through and test for stepping. But, if not stepping, do not
6263 /* In all-stop mode, if we're currently stepping but have stopped in
6264 some other thread, we need to switch back to the stepped thread. */
6265 if (switch_back_to_stepped_thread (ecs))
6268 if (ecs->event_thread->control.step_resume_breakpoint)
6271 fprintf_unfiltered (gdb_stdlog,
6272 "infrun: step-resume breakpoint is inserted\n");
6274 /* Having a step-resume breakpoint overrides anything
6275 else having to do with stepping commands until
6276 that breakpoint is reached. */
6281 if (ecs->event_thread->control.step_range_end == 0)
6284 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6285 /* Likewise if we aren't even stepping. */
6290 /* Re-fetch current thread's frame in case the code above caused
6291 the frame cache to be re-initialized, making our FRAME variable
6292 a dangling pointer. */
6293 frame = get_current_frame ();
6294 gdbarch = get_frame_arch (frame);
6295 fill_in_stop_func (gdbarch, ecs);
6297 /* If stepping through a line, keep going if still within it.
6299 Note that step_range_end is the address of the first instruction
6300 beyond the step range, and NOT the address of the last instruction
6303 Note also that during reverse execution, we may be stepping
6304 through a function epilogue and therefore must detect when
6305 the current-frame changes in the middle of a line. */
6307 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6309 && (execution_direction != EXEC_REVERSE
6310 || frame_id_eq (get_frame_id (frame),
6311 ecs->event_thread->control.step_frame_id)))
6315 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6316 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6317 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6319 /* Tentatively re-enable range stepping; `resume' disables it if
6320 necessary (e.g., if we're stepping over a breakpoint or we
6321 have software watchpoints). */
6322 ecs->event_thread->control.may_range_step = 1;
6324 /* When stepping backward, stop at beginning of line range
6325 (unless it's the function entry point, in which case
6326 keep going back to the call point). */
6327 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6328 if (stop_pc == ecs->event_thread->control.step_range_start
6329 && stop_pc != ecs->stop_func_start
6330 && execution_direction == EXEC_REVERSE)
6331 end_stepping_range (ecs);
6338 /* We stepped out of the stepping range. */
6340 /* If we are stepping at the source level and entered the runtime
6341 loader dynamic symbol resolution code...
6343 EXEC_FORWARD: we keep on single stepping until we exit the run
6344 time loader code and reach the callee's address.
6346 EXEC_REVERSE: we've already executed the callee (backward), and
6347 the runtime loader code is handled just like any other
6348 undebuggable function call. Now we need only keep stepping
6349 backward through the trampoline code, and that's handled further
6350 down, so there is nothing for us to do here. */
6352 if (execution_direction != EXEC_REVERSE
6353 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6354 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6356 CORE_ADDR pc_after_resolver =
6357 gdbarch_skip_solib_resolver (gdbarch,
6358 ecs->event_thread->suspend.stop_pc);
6361 fprintf_unfiltered (gdb_stdlog,
6362 "infrun: stepped into dynsym resolve code\n");
6364 if (pc_after_resolver)
6366 /* Set up a step-resume breakpoint at the address
6367 indicated by SKIP_SOLIB_RESOLVER. */
6368 symtab_and_line sr_sal;
6369 sr_sal.pc = pc_after_resolver;
6370 sr_sal.pspace = get_frame_program_space (frame);
6372 insert_step_resume_breakpoint_at_sal (gdbarch,
6373 sr_sal, null_frame_id);
6380 /* Step through an indirect branch thunk. */
6381 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6382 && gdbarch_in_indirect_branch_thunk (gdbarch,
6383 ecs->event_thread->suspend.stop_pc))
6386 fprintf_unfiltered (gdb_stdlog,
6387 "infrun: stepped into indirect branch thunk\n");
6392 if (ecs->event_thread->control.step_range_end != 1
6393 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6394 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6395 && get_frame_type (frame) == SIGTRAMP_FRAME)
6398 fprintf_unfiltered (gdb_stdlog,
6399 "infrun: stepped into signal trampoline\n");
6400 /* The inferior, while doing a "step" or "next", has ended up in
6401 a signal trampoline (either by a signal being delivered or by
6402 the signal handler returning). Just single-step until the
6403 inferior leaves the trampoline (either by calling the handler
6409 /* If we're in the return path from a shared library trampoline,
6410 we want to proceed through the trampoline when stepping. */
6411 /* macro/2012-04-25: This needs to come before the subroutine
6412 call check below as on some targets return trampolines look
6413 like subroutine calls (MIPS16 return thunks). */
6414 if (gdbarch_in_solib_return_trampoline (gdbarch,
6415 ecs->event_thread->suspend.stop_pc,
6416 ecs->stop_func_name)
6417 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6419 /* Determine where this trampoline returns. */
6420 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6421 CORE_ADDR real_stop_pc
6422 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6425 fprintf_unfiltered (gdb_stdlog,
6426 "infrun: stepped into solib return tramp\n");
6428 /* Only proceed through if we know where it's going. */
6431 /* And put the step-breakpoint there and go until there. */
6432 symtab_and_line sr_sal;
6433 sr_sal.pc = real_stop_pc;
6434 sr_sal.section = find_pc_overlay (sr_sal.pc);
6435 sr_sal.pspace = get_frame_program_space (frame);
6437 /* Do not specify what the fp should be when we stop since
6438 on some machines the prologue is where the new fp value
6440 insert_step_resume_breakpoint_at_sal (gdbarch,
6441 sr_sal, null_frame_id);
6443 /* Restart without fiddling with the step ranges or
6450 /* Check for subroutine calls. The check for the current frame
6451 equalling the step ID is not necessary - the check of the
6452 previous frame's ID is sufficient - but it is a common case and
6453 cheaper than checking the previous frame's ID.
6455 NOTE: frame_id_eq will never report two invalid frame IDs as
6456 being equal, so to get into this block, both the current and
6457 previous frame must have valid frame IDs. */
6458 /* The outer_frame_id check is a heuristic to detect stepping
6459 through startup code. If we step over an instruction which
6460 sets the stack pointer from an invalid value to a valid value,
6461 we may detect that as a subroutine call from the mythical
6462 "outermost" function. This could be fixed by marking
6463 outermost frames as !stack_p,code_p,special_p. Then the
6464 initial outermost frame, before sp was valid, would
6465 have code_addr == &_start. See the comment in frame_id_eq
6467 if (!frame_id_eq (get_stack_frame_id (frame),
6468 ecs->event_thread->control.step_stack_frame_id)
6469 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6470 ecs->event_thread->control.step_stack_frame_id)
6471 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6473 || (ecs->event_thread->control.step_start_function
6474 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6476 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6477 CORE_ADDR real_stop_pc;
6480 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6482 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6484 /* I presume that step_over_calls is only 0 when we're
6485 supposed to be stepping at the assembly language level
6486 ("stepi"). Just stop. */
6487 /* And this works the same backward as frontward. MVS */
6488 end_stepping_range (ecs);
6492 /* Reverse stepping through solib trampolines. */
6494 if (execution_direction == EXEC_REVERSE
6495 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6496 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6497 || (ecs->stop_func_start == 0
6498 && in_solib_dynsym_resolve_code (stop_pc))))
6500 /* Any solib trampoline code can be handled in reverse
6501 by simply continuing to single-step. We have already
6502 executed the solib function (backwards), and a few
6503 steps will take us back through the trampoline to the
6509 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6511 /* We're doing a "next".
6513 Normal (forward) execution: set a breakpoint at the
6514 callee's return address (the address at which the caller
6517 Reverse (backward) execution. set the step-resume
6518 breakpoint at the start of the function that we just
6519 stepped into (backwards), and continue to there. When we
6520 get there, we'll need to single-step back to the caller. */
6522 if (execution_direction == EXEC_REVERSE)
6524 /* If we're already at the start of the function, we've either
6525 just stepped backward into a single instruction function,
6526 or stepped back out of a signal handler to the first instruction
6527 of the function. Just keep going, which will single-step back
6529 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6531 /* Normal function call return (static or dynamic). */
6532 symtab_and_line sr_sal;
6533 sr_sal.pc = ecs->stop_func_start;
6534 sr_sal.pspace = get_frame_program_space (frame);
6535 insert_step_resume_breakpoint_at_sal (gdbarch,
6536 sr_sal, null_frame_id);
6540 insert_step_resume_breakpoint_at_caller (frame);
6546 /* If we are in a function call trampoline (a stub between the
6547 calling routine and the real function), locate the real
6548 function. That's what tells us (a) whether we want to step
6549 into it at all, and (b) what prologue we want to run to the
6550 end of, if we do step into it. */
6551 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6552 if (real_stop_pc == 0)
6553 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6554 if (real_stop_pc != 0)
6555 ecs->stop_func_start = real_stop_pc;
6557 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6559 symtab_and_line sr_sal;
6560 sr_sal.pc = ecs->stop_func_start;
6561 sr_sal.pspace = get_frame_program_space (frame);
6563 insert_step_resume_breakpoint_at_sal (gdbarch,
6564 sr_sal, null_frame_id);
6569 /* If we have line number information for the function we are
6570 thinking of stepping into and the function isn't on the skip
6573 If there are several symtabs at that PC (e.g. with include
6574 files), just want to know whether *any* of them have line
6575 numbers. find_pc_line handles this. */
6577 struct symtab_and_line tmp_sal;
6579 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6580 if (tmp_sal.line != 0
6581 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6584 if (execution_direction == EXEC_REVERSE)
6585 handle_step_into_function_backward (gdbarch, ecs);
6587 handle_step_into_function (gdbarch, ecs);
6592 /* If we have no line number and the step-stop-if-no-debug is
6593 set, we stop the step so that the user has a chance to switch
6594 in assembly mode. */
6595 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6596 && step_stop_if_no_debug)
6598 end_stepping_range (ecs);
6602 if (execution_direction == EXEC_REVERSE)
6604 /* If we're already at the start of the function, we've either just
6605 stepped backward into a single instruction function without line
6606 number info, or stepped back out of a signal handler to the first
6607 instruction of the function without line number info. Just keep
6608 going, which will single-step back to the caller. */
6609 if (ecs->stop_func_start != stop_pc)
6611 /* Set a breakpoint at callee's start address.
6612 From there we can step once and be back in the caller. */
6613 symtab_and_line sr_sal;
6614 sr_sal.pc = ecs->stop_func_start;
6615 sr_sal.pspace = get_frame_program_space (frame);
6616 insert_step_resume_breakpoint_at_sal (gdbarch,
6617 sr_sal, null_frame_id);
6621 /* Set a breakpoint at callee's return address (the address
6622 at which the caller will resume). */
6623 insert_step_resume_breakpoint_at_caller (frame);
6629 /* Reverse stepping through solib trampolines. */
6631 if (execution_direction == EXEC_REVERSE
6632 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6634 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6636 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6637 || (ecs->stop_func_start == 0
6638 && in_solib_dynsym_resolve_code (stop_pc)))
6640 /* Any solib trampoline code can be handled in reverse
6641 by simply continuing to single-step. We have already
6642 executed the solib function (backwards), and a few
6643 steps will take us back through the trampoline to the
6648 else if (in_solib_dynsym_resolve_code (stop_pc))
6650 /* Stepped backward into the solib dynsym resolver.
6651 Set a breakpoint at its start and continue, then
6652 one more step will take us out. */
6653 symtab_and_line sr_sal;
6654 sr_sal.pc = ecs->stop_func_start;
6655 sr_sal.pspace = get_frame_program_space (frame);
6656 insert_step_resume_breakpoint_at_sal (gdbarch,
6657 sr_sal, null_frame_id);
6663 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6665 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6666 the trampoline processing logic, however, there are some trampolines
6667 that have no names, so we should do trampoline handling first. */
6668 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6669 && ecs->stop_func_name == NULL
6670 && stop_pc_sal.line == 0)
6673 fprintf_unfiltered (gdb_stdlog,
6674 "infrun: stepped into undebuggable function\n");
6676 /* The inferior just stepped into, or returned to, an
6677 undebuggable function (where there is no debugging information
6678 and no line number corresponding to the address where the
6679 inferior stopped). Since we want to skip this kind of code,
6680 we keep going until the inferior returns from this
6681 function - unless the user has asked us not to (via
6682 set step-mode) or we no longer know how to get back
6683 to the call site. */
6684 if (step_stop_if_no_debug
6685 || !frame_id_p (frame_unwind_caller_id (frame)))
6687 /* If we have no line number and the step-stop-if-no-debug
6688 is set, we stop the step so that the user has a chance to
6689 switch in assembly mode. */
6690 end_stepping_range (ecs);
6695 /* Set a breakpoint at callee's return address (the address
6696 at which the caller will resume). */
6697 insert_step_resume_breakpoint_at_caller (frame);
6703 if (ecs->event_thread->control.step_range_end == 1)
6705 /* It is stepi or nexti. We always want to stop stepping after
6708 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6709 end_stepping_range (ecs);
6713 if (stop_pc_sal.line == 0)
6715 /* We have no line number information. That means to stop
6716 stepping (does this always happen right after one instruction,
6717 when we do "s" in a function with no line numbers,
6718 or can this happen as a result of a return or longjmp?). */
6720 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6721 end_stepping_range (ecs);
6725 /* Look for "calls" to inlined functions, part one. If the inline
6726 frame machinery detected some skipped call sites, we have entered
6727 a new inline function. */
6729 if (frame_id_eq (get_frame_id (get_current_frame ()),
6730 ecs->event_thread->control.step_frame_id)
6731 && inline_skipped_frames (ecs->event_thread))
6734 fprintf_unfiltered (gdb_stdlog,
6735 "infrun: stepped into inlined function\n");
6737 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6739 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6741 /* For "step", we're going to stop. But if the call site
6742 for this inlined function is on the same source line as
6743 we were previously stepping, go down into the function
6744 first. Otherwise stop at the call site. */
6746 if (call_sal.line == ecs->event_thread->current_line
6747 && call_sal.symtab == ecs->event_thread->current_symtab)
6748 step_into_inline_frame (ecs->event_thread);
6750 end_stepping_range (ecs);
6755 /* For "next", we should stop at the call site if it is on a
6756 different source line. Otherwise continue through the
6757 inlined function. */
6758 if (call_sal.line == ecs->event_thread->current_line
6759 && call_sal.symtab == ecs->event_thread->current_symtab)
6762 end_stepping_range (ecs);
6767 /* Look for "calls" to inlined functions, part two. If we are still
6768 in the same real function we were stepping through, but we have
6769 to go further up to find the exact frame ID, we are stepping
6770 through a more inlined call beyond its call site. */
6772 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6773 && !frame_id_eq (get_frame_id (get_current_frame ()),
6774 ecs->event_thread->control.step_frame_id)
6775 && stepped_in_from (get_current_frame (),
6776 ecs->event_thread->control.step_frame_id))
6779 fprintf_unfiltered (gdb_stdlog,
6780 "infrun: stepping through inlined function\n");
6782 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6785 end_stepping_range (ecs);
6789 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6790 && (ecs->event_thread->current_line != stop_pc_sal.line
6791 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6793 /* We are at the start of a different line. So stop. Note that
6794 we don't stop if we step into the middle of a different line.
6795 That is said to make things like for (;;) statements work
6798 fprintf_unfiltered (gdb_stdlog,
6799 "infrun: stepped to a different line\n");
6800 end_stepping_range (ecs);
6804 /* We aren't done stepping.
6806 Optimize by setting the stepping range to the line.
6807 (We might not be in the original line, but if we entered a
6808 new line in mid-statement, we continue stepping. This makes
6809 things like for(;;) statements work better.) */
6811 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6812 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6813 ecs->event_thread->control.may_range_step = 1;
6814 set_step_info (frame, stop_pc_sal);
6817 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6821 /* In all-stop mode, if we're currently stepping but have stopped in
6822 some other thread, we may need to switch back to the stepped
6823 thread. Returns true we set the inferior running, false if we left
6824 it stopped (and the event needs further processing). */
6827 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6829 if (!target_is_non_stop_p ())
6831 struct thread_info *stepping_thread;
6833 /* If any thread is blocked on some internal breakpoint, and we
6834 simply need to step over that breakpoint to get it going
6835 again, do that first. */
6837 /* However, if we see an event for the stepping thread, then we
6838 know all other threads have been moved past their breakpoints
6839 already. Let the caller check whether the step is finished,
6840 etc., before deciding to move it past a breakpoint. */
6841 if (ecs->event_thread->control.step_range_end != 0)
6844 /* Check if the current thread is blocked on an incomplete
6845 step-over, interrupted by a random signal. */
6846 if (ecs->event_thread->control.trap_expected
6847 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6851 fprintf_unfiltered (gdb_stdlog,
6852 "infrun: need to finish step-over of [%s]\n",
6853 target_pid_to_str (ecs->event_thread->ptid));
6859 /* Check if the current thread is blocked by a single-step
6860 breakpoint of another thread. */
6861 if (ecs->hit_singlestep_breakpoint)
6865 fprintf_unfiltered (gdb_stdlog,
6866 "infrun: need to step [%s] over single-step "
6868 target_pid_to_str (ecs->ptid));
6874 /* If this thread needs yet another step-over (e.g., stepping
6875 through a delay slot), do it first before moving on to
6877 if (thread_still_needs_step_over (ecs->event_thread))
6881 fprintf_unfiltered (gdb_stdlog,
6882 "infrun: thread [%s] still needs step-over\n",
6883 target_pid_to_str (ecs->event_thread->ptid));
6889 /* If scheduler locking applies even if not stepping, there's no
6890 need to walk over threads. Above we've checked whether the
6891 current thread is stepping. If some other thread not the
6892 event thread is stepping, then it must be that scheduler
6893 locking is not in effect. */
6894 if (schedlock_applies (ecs->event_thread))
6897 /* Otherwise, we no longer expect a trap in the current thread.
6898 Clear the trap_expected flag before switching back -- this is
6899 what keep_going does as well, if we call it. */
6900 ecs->event_thread->control.trap_expected = 0;
6902 /* Likewise, clear the signal if it should not be passed. */
6903 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6904 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6906 /* Do all pending step-overs before actually proceeding with
6908 if (start_step_over ())
6910 prepare_to_wait (ecs);
6914 /* Look for the stepping/nexting thread. */
6915 stepping_thread = NULL;
6917 for (thread_info *tp : all_non_exited_threads ())
6919 /* Ignore threads of processes the caller is not
6922 && tp->ptid.pid () != ecs->ptid.pid ())
6925 /* When stepping over a breakpoint, we lock all threads
6926 except the one that needs to move past the breakpoint.
6927 If a non-event thread has this set, the "incomplete
6928 step-over" check above should have caught it earlier. */
6929 if (tp->control.trap_expected)
6931 internal_error (__FILE__, __LINE__,
6932 "[%s] has inconsistent state: "
6933 "trap_expected=%d\n",
6934 target_pid_to_str (tp->ptid),
6935 tp->control.trap_expected);
6938 /* Did we find the stepping thread? */
6939 if (tp->control.step_range_end)
6941 /* Yep. There should only one though. */
6942 gdb_assert (stepping_thread == NULL);
6944 /* The event thread is handled at the top, before we
6946 gdb_assert (tp != ecs->event_thread);
6948 /* If some thread other than the event thread is
6949 stepping, then scheduler locking can't be in effect,
6950 otherwise we wouldn't have resumed the current event
6951 thread in the first place. */
6952 gdb_assert (!schedlock_applies (tp));
6954 stepping_thread = tp;
6958 if (stepping_thread != NULL)
6961 fprintf_unfiltered (gdb_stdlog,
6962 "infrun: switching back to stepped thread\n");
6964 if (keep_going_stepped_thread (stepping_thread))
6966 prepare_to_wait (ecs);
6975 /* Set a previously stepped thread back to stepping. Returns true on
6976 success, false if the resume is not possible (e.g., the thread
6980 keep_going_stepped_thread (struct thread_info *tp)
6982 struct frame_info *frame;
6983 struct execution_control_state ecss;
6984 struct execution_control_state *ecs = &ecss;
6986 /* If the stepping thread exited, then don't try to switch back and
6987 resume it, which could fail in several different ways depending
6988 on the target. Instead, just keep going.
6990 We can find a stepping dead thread in the thread list in two
6993 - The target supports thread exit events, and when the target
6994 tries to delete the thread from the thread list, inferior_ptid
6995 pointed at the exiting thread. In such case, calling
6996 delete_thread does not really remove the thread from the list;
6997 instead, the thread is left listed, with 'exited' state.
6999 - The target's debug interface does not support thread exit
7000 events, and so we have no idea whatsoever if the previously
7001 stepping thread is still alive. For that reason, we need to
7002 synchronously query the target now. */
7004 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
7007 fprintf_unfiltered (gdb_stdlog,
7008 "infrun: not resuming previously "
7009 "stepped thread, it has vanished\n");
7016 fprintf_unfiltered (gdb_stdlog,
7017 "infrun: resuming previously stepped thread\n");
7019 reset_ecs (ecs, tp);
7020 switch_to_thread (tp);
7022 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7023 frame = get_current_frame ();
7025 /* If the PC of the thread we were trying to single-step has
7026 changed, then that thread has trapped or been signaled, but the
7027 event has not been reported to GDB yet. Re-poll the target
7028 looking for this particular thread's event (i.e. temporarily
7029 enable schedlock) by:
7031 - setting a break at the current PC
7032 - resuming that particular thread, only (by setting trap
7035 This prevents us continuously moving the single-step breakpoint
7036 forward, one instruction at a time, overstepping. */
7038 if (tp->suspend.stop_pc != tp->prev_pc)
7043 fprintf_unfiltered (gdb_stdlog,
7044 "infrun: expected thread advanced also (%s -> %s)\n",
7045 paddress (target_gdbarch (), tp->prev_pc),
7046 paddress (target_gdbarch (), tp->suspend.stop_pc));
7048 /* Clear the info of the previous step-over, as it's no longer
7049 valid (if the thread was trying to step over a breakpoint, it
7050 has already succeeded). It's what keep_going would do too,
7051 if we called it. Do this before trying to insert the sss
7052 breakpoint, otherwise if we were previously trying to step
7053 over this exact address in another thread, the breakpoint is
7055 clear_step_over_info ();
7056 tp->control.trap_expected = 0;
7058 insert_single_step_breakpoint (get_frame_arch (frame),
7059 get_frame_address_space (frame),
7060 tp->suspend.stop_pc);
7063 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7064 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7069 fprintf_unfiltered (gdb_stdlog,
7070 "infrun: expected thread still hasn't advanced\n");
7072 keep_going_pass_signal (ecs);
7077 /* Is thread TP in the middle of (software or hardware)
7078 single-stepping? (Note the result of this function must never be
7079 passed directly as target_resume's STEP parameter.) */
7082 currently_stepping (struct thread_info *tp)
7084 return ((tp->control.step_range_end
7085 && tp->control.step_resume_breakpoint == NULL)
7086 || tp->control.trap_expected
7087 || tp->stepped_breakpoint
7088 || bpstat_should_step ());
7091 /* Inferior has stepped into a subroutine call with source code that
7092 we should not step over. Do step to the first line of code in
7096 handle_step_into_function (struct gdbarch *gdbarch,
7097 struct execution_control_state *ecs)
7099 fill_in_stop_func (gdbarch, ecs);
7101 compunit_symtab *cust
7102 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7103 if (cust != NULL && compunit_language (cust) != language_asm)
7104 ecs->stop_func_start
7105 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7107 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7108 /* Use the step_resume_break to step until the end of the prologue,
7109 even if that involves jumps (as it seems to on the vax under
7111 /* If the prologue ends in the middle of a source line, continue to
7112 the end of that source line (if it is still within the function).
7113 Otherwise, just go to end of prologue. */
7114 if (stop_func_sal.end
7115 && stop_func_sal.pc != ecs->stop_func_start
7116 && stop_func_sal.end < ecs->stop_func_end)
7117 ecs->stop_func_start = stop_func_sal.end;
7119 /* Architectures which require breakpoint adjustment might not be able
7120 to place a breakpoint at the computed address. If so, the test
7121 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7122 ecs->stop_func_start to an address at which a breakpoint may be
7123 legitimately placed.
7125 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7126 made, GDB will enter an infinite loop when stepping through
7127 optimized code consisting of VLIW instructions which contain
7128 subinstructions corresponding to different source lines. On
7129 FR-V, it's not permitted to place a breakpoint on any but the
7130 first subinstruction of a VLIW instruction. When a breakpoint is
7131 set, GDB will adjust the breakpoint address to the beginning of
7132 the VLIW instruction. Thus, we need to make the corresponding
7133 adjustment here when computing the stop address. */
7135 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7137 ecs->stop_func_start
7138 = gdbarch_adjust_breakpoint_address (gdbarch,
7139 ecs->stop_func_start);
7142 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7144 /* We are already there: stop now. */
7145 end_stepping_range (ecs);
7150 /* Put the step-breakpoint there and go until there. */
7151 symtab_and_line sr_sal;
7152 sr_sal.pc = ecs->stop_func_start;
7153 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7154 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7156 /* Do not specify what the fp should be when we stop since on
7157 some machines the prologue is where the new fp value is
7159 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7161 /* And make sure stepping stops right away then. */
7162 ecs->event_thread->control.step_range_end
7163 = ecs->event_thread->control.step_range_start;
7168 /* Inferior has stepped backward into a subroutine call with source
7169 code that we should not step over. Do step to the beginning of the
7170 last line of code in it. */
7173 handle_step_into_function_backward (struct gdbarch *gdbarch,
7174 struct execution_control_state *ecs)
7176 struct compunit_symtab *cust;
7177 struct symtab_and_line stop_func_sal;
7179 fill_in_stop_func (gdbarch, ecs);
7181 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7182 if (cust != NULL && compunit_language (cust) != language_asm)
7183 ecs->stop_func_start
7184 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7186 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7188 /* OK, we're just going to keep stepping here. */
7189 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7191 /* We're there already. Just stop stepping now. */
7192 end_stepping_range (ecs);
7196 /* Else just reset the step range and keep going.
7197 No step-resume breakpoint, they don't work for
7198 epilogues, which can have multiple entry paths. */
7199 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7200 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7206 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7207 This is used to both functions and to skip over code. */
7210 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7211 struct symtab_and_line sr_sal,
7212 struct frame_id sr_id,
7213 enum bptype sr_type)
7215 /* There should never be more than one step-resume or longjmp-resume
7216 breakpoint per thread, so we should never be setting a new
7217 step_resume_breakpoint when one is already active. */
7218 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7219 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7222 fprintf_unfiltered (gdb_stdlog,
7223 "infrun: inserting step-resume breakpoint at %s\n",
7224 paddress (gdbarch, sr_sal.pc));
7226 inferior_thread ()->control.step_resume_breakpoint
7227 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7231 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7232 struct symtab_and_line sr_sal,
7233 struct frame_id sr_id)
7235 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7240 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7241 This is used to skip a potential signal handler.
7243 This is called with the interrupted function's frame. The signal
7244 handler, when it returns, will resume the interrupted function at
7248 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7250 gdb_assert (return_frame != NULL);
7252 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7254 symtab_and_line sr_sal;
7255 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7256 sr_sal.section = find_pc_overlay (sr_sal.pc);
7257 sr_sal.pspace = get_frame_program_space (return_frame);
7259 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7260 get_stack_frame_id (return_frame),
7264 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7265 is used to skip a function after stepping into it (for "next" or if
7266 the called function has no debugging information).
7268 The current function has almost always been reached by single
7269 stepping a call or return instruction. NEXT_FRAME belongs to the
7270 current function, and the breakpoint will be set at the caller's
7273 This is a separate function rather than reusing
7274 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7275 get_prev_frame, which may stop prematurely (see the implementation
7276 of frame_unwind_caller_id for an example). */
7279 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7281 /* We shouldn't have gotten here if we don't know where the call site
7283 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7285 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7287 symtab_and_line sr_sal;
7288 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7289 frame_unwind_caller_pc (next_frame));
7290 sr_sal.section = find_pc_overlay (sr_sal.pc);
7291 sr_sal.pspace = frame_unwind_program_space (next_frame);
7293 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7294 frame_unwind_caller_id (next_frame));
7297 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7298 new breakpoint at the target of a jmp_buf. The handling of
7299 longjmp-resume uses the same mechanisms used for handling
7300 "step-resume" breakpoints. */
7303 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7305 /* There should never be more than one longjmp-resume breakpoint per
7306 thread, so we should never be setting a new
7307 longjmp_resume_breakpoint when one is already active. */
7308 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7311 fprintf_unfiltered (gdb_stdlog,
7312 "infrun: inserting longjmp-resume breakpoint at %s\n",
7313 paddress (gdbarch, pc));
7315 inferior_thread ()->control.exception_resume_breakpoint =
7316 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7319 /* Insert an exception resume breakpoint. TP is the thread throwing
7320 the exception. The block B is the block of the unwinder debug hook
7321 function. FRAME is the frame corresponding to the call to this
7322 function. SYM is the symbol of the function argument holding the
7323 target PC of the exception. */
7326 insert_exception_resume_breakpoint (struct thread_info *tp,
7327 const struct block *b,
7328 struct frame_info *frame,
7333 struct block_symbol vsym;
7334 struct value *value;
7336 struct breakpoint *bp;
7338 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7340 value = read_var_value (vsym.symbol, vsym.block, frame);
7341 /* If the value was optimized out, revert to the old behavior. */
7342 if (! value_optimized_out (value))
7344 handler = value_as_address (value);
7347 fprintf_unfiltered (gdb_stdlog,
7348 "infrun: exception resume at %lx\n",
7349 (unsigned long) handler);
7351 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7353 bp_exception_resume).release ();
7355 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7358 bp->thread = tp->global_num;
7359 inferior_thread ()->control.exception_resume_breakpoint = bp;
7362 CATCH (e, RETURN_MASK_ERROR)
7364 /* We want to ignore errors here. */
7369 /* A helper for check_exception_resume that sets an
7370 exception-breakpoint based on a SystemTap probe. */
7373 insert_exception_resume_from_probe (struct thread_info *tp,
7374 const struct bound_probe *probe,
7375 struct frame_info *frame)
7377 struct value *arg_value;
7379 struct breakpoint *bp;
7381 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7385 handler = value_as_address (arg_value);
7388 fprintf_unfiltered (gdb_stdlog,
7389 "infrun: exception resume at %s\n",
7390 paddress (get_objfile_arch (probe->objfile),
7393 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7394 handler, bp_exception_resume).release ();
7395 bp->thread = tp->global_num;
7396 inferior_thread ()->control.exception_resume_breakpoint = bp;
7399 /* This is called when an exception has been intercepted. Check to
7400 see whether the exception's destination is of interest, and if so,
7401 set an exception resume breakpoint there. */
7404 check_exception_resume (struct execution_control_state *ecs,
7405 struct frame_info *frame)
7407 struct bound_probe probe;
7408 struct symbol *func;
7410 /* First see if this exception unwinding breakpoint was set via a
7411 SystemTap probe point. If so, the probe has two arguments: the
7412 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7413 set a breakpoint there. */
7414 probe = find_probe_by_pc (get_frame_pc (frame));
7417 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7421 func = get_frame_function (frame);
7427 const struct block *b;
7428 struct block_iterator iter;
7432 /* The exception breakpoint is a thread-specific breakpoint on
7433 the unwinder's debug hook, declared as:
7435 void _Unwind_DebugHook (void *cfa, void *handler);
7437 The CFA argument indicates the frame to which control is
7438 about to be transferred. HANDLER is the destination PC.
7440 We ignore the CFA and set a temporary breakpoint at HANDLER.
7441 This is not extremely efficient but it avoids issues in gdb
7442 with computing the DWARF CFA, and it also works even in weird
7443 cases such as throwing an exception from inside a signal
7446 b = SYMBOL_BLOCK_VALUE (func);
7447 ALL_BLOCK_SYMBOLS (b, iter, sym)
7449 if (!SYMBOL_IS_ARGUMENT (sym))
7456 insert_exception_resume_breakpoint (ecs->event_thread,
7462 CATCH (e, RETURN_MASK_ERROR)
7469 stop_waiting (struct execution_control_state *ecs)
7472 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7474 /* Let callers know we don't want to wait for the inferior anymore. */
7475 ecs->wait_some_more = 0;
7477 /* If all-stop, but the target is always in non-stop mode, stop all
7478 threads now that we're presenting the stop to the user. */
7479 if (!non_stop && target_is_non_stop_p ())
7480 stop_all_threads ();
7483 /* Like keep_going, but passes the signal to the inferior, even if the
7484 signal is set to nopass. */
7487 keep_going_pass_signal (struct execution_control_state *ecs)
7489 gdb_assert (ecs->event_thread->ptid == inferior_ptid);
7490 gdb_assert (!ecs->event_thread->resumed);
7492 /* Save the pc before execution, to compare with pc after stop. */
7493 ecs->event_thread->prev_pc
7494 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7496 if (ecs->event_thread->control.trap_expected)
7498 struct thread_info *tp = ecs->event_thread;
7501 fprintf_unfiltered (gdb_stdlog,
7502 "infrun: %s has trap_expected set, "
7503 "resuming to collect trap\n",
7504 target_pid_to_str (tp->ptid));
7506 /* We haven't yet gotten our trap, and either: intercepted a
7507 non-signal event (e.g., a fork); or took a signal which we
7508 are supposed to pass through to the inferior. Simply
7510 resume (ecs->event_thread->suspend.stop_signal);
7512 else if (step_over_info_valid_p ())
7514 /* Another thread is stepping over a breakpoint in-line. If
7515 this thread needs a step-over too, queue the request. In
7516 either case, this resume must be deferred for later. */
7517 struct thread_info *tp = ecs->event_thread;
7519 if (ecs->hit_singlestep_breakpoint
7520 || thread_still_needs_step_over (tp))
7523 fprintf_unfiltered (gdb_stdlog,
7524 "infrun: step-over already in progress: "
7525 "step-over for %s deferred\n",
7526 target_pid_to_str (tp->ptid));
7527 thread_step_over_chain_enqueue (tp);
7532 fprintf_unfiltered (gdb_stdlog,
7533 "infrun: step-over in progress: "
7534 "resume of %s deferred\n",
7535 target_pid_to_str (tp->ptid));
7540 struct regcache *regcache = get_current_regcache ();
7543 step_over_what step_what;
7545 /* Either the trap was not expected, but we are continuing
7546 anyway (if we got a signal, the user asked it be passed to
7549 We got our expected trap, but decided we should resume from
7552 We're going to run this baby now!
7554 Note that insert_breakpoints won't try to re-insert
7555 already inserted breakpoints. Therefore, we don't
7556 care if breakpoints were already inserted, or not. */
7558 /* If we need to step over a breakpoint, and we're not using
7559 displaced stepping to do so, insert all breakpoints
7560 (watchpoints, etc.) but the one we're stepping over, step one
7561 instruction, and then re-insert the breakpoint when that step
7564 step_what = thread_still_needs_step_over (ecs->event_thread);
7566 remove_bp = (ecs->hit_singlestep_breakpoint
7567 || (step_what & STEP_OVER_BREAKPOINT));
7568 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7570 /* We can't use displaced stepping if we need to step past a
7571 watchpoint. The instruction copied to the scratch pad would
7572 still trigger the watchpoint. */
7574 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7576 set_step_over_info (regcache->aspace (),
7577 regcache_read_pc (regcache), remove_wps,
7578 ecs->event_thread->global_num);
7580 else if (remove_wps)
7581 set_step_over_info (NULL, 0, remove_wps, -1);
7583 /* If we now need to do an in-line step-over, we need to stop
7584 all other threads. Note this must be done before
7585 insert_breakpoints below, because that removes the breakpoint
7586 we're about to step over, otherwise other threads could miss
7588 if (step_over_info_valid_p () && target_is_non_stop_p ())
7589 stop_all_threads ();
7591 /* Stop stepping if inserting breakpoints fails. */
7594 insert_breakpoints ();
7596 CATCH (e, RETURN_MASK_ERROR)
7598 exception_print (gdb_stderr, e);
7600 clear_step_over_info ();
7605 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7607 resume (ecs->event_thread->suspend.stop_signal);
7610 prepare_to_wait (ecs);
7613 /* Called when we should continue running the inferior, because the
7614 current event doesn't cause a user visible stop. This does the
7615 resuming part; waiting for the next event is done elsewhere. */
7618 keep_going (struct execution_control_state *ecs)
7620 if (ecs->event_thread->control.trap_expected
7621 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7622 ecs->event_thread->control.trap_expected = 0;
7624 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7625 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7626 keep_going_pass_signal (ecs);
7629 /* This function normally comes after a resume, before
7630 handle_inferior_event exits. It takes care of any last bits of
7631 housekeeping, and sets the all-important wait_some_more flag. */
7634 prepare_to_wait (struct execution_control_state *ecs)
7637 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7639 ecs->wait_some_more = 1;
7641 if (!target_is_async_p ())
7642 mark_infrun_async_event_handler ();
7645 /* We are done with the step range of a step/next/si/ni command.
7646 Called once for each n of a "step n" operation. */
7649 end_stepping_range (struct execution_control_state *ecs)
7651 ecs->event_thread->control.stop_step = 1;
7655 /* Several print_*_reason functions to print why the inferior has stopped.
7656 We always print something when the inferior exits, or receives a signal.
7657 The rest of the cases are dealt with later on in normal_stop and
7658 print_it_typical. Ideally there should be a call to one of these
7659 print_*_reason functions functions from handle_inferior_event each time
7660 stop_waiting is called.
7662 Note that we don't call these directly, instead we delegate that to
7663 the interpreters, through observers. Interpreters then call these
7664 with whatever uiout is right. */
7667 print_end_stepping_range_reason (struct ui_out *uiout)
7669 /* For CLI-like interpreters, print nothing. */
7671 if (uiout->is_mi_like_p ())
7673 uiout->field_string ("reason",
7674 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7679 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7681 annotate_signalled ();
7682 if (uiout->is_mi_like_p ())
7684 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7685 uiout->text ("\nProgram terminated with signal ");
7686 annotate_signal_name ();
7687 uiout->field_string ("signal-name",
7688 gdb_signal_to_name (siggnal));
7689 annotate_signal_name_end ();
7691 annotate_signal_string ();
7692 uiout->field_string ("signal-meaning",
7693 gdb_signal_to_string (siggnal));
7694 annotate_signal_string_end ();
7695 uiout->text (".\n");
7696 uiout->text ("The program no longer exists.\n");
7700 print_exited_reason (struct ui_out *uiout, int exitstatus)
7702 struct inferior *inf = current_inferior ();
7703 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7705 annotate_exited (exitstatus);
7708 if (uiout->is_mi_like_p ())
7709 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7710 uiout->text ("[Inferior ");
7711 uiout->text (plongest (inf->num));
7713 uiout->text (pidstr);
7714 uiout->text (") exited with code ");
7715 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7716 uiout->text ("]\n");
7720 if (uiout->is_mi_like_p ())
7722 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7723 uiout->text ("[Inferior ");
7724 uiout->text (plongest (inf->num));
7726 uiout->text (pidstr);
7727 uiout->text (") exited normally]\n");
7731 /* Some targets/architectures can do extra processing/display of
7732 segmentation faults. E.g., Intel MPX boundary faults.
7733 Call the architecture dependent function to handle the fault. */
7736 handle_segmentation_fault (struct ui_out *uiout)
7738 struct regcache *regcache = get_current_regcache ();
7739 struct gdbarch *gdbarch = regcache->arch ();
7741 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7742 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7746 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7748 struct thread_info *thr = inferior_thread ();
7752 if (uiout->is_mi_like_p ())
7754 else if (show_thread_that_caused_stop ())
7758 uiout->text ("\nThread ");
7759 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7761 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7764 uiout->text (" \"");
7765 uiout->field_fmt ("name", "%s", name);
7770 uiout->text ("\nProgram");
7772 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7773 uiout->text (" stopped");
7776 uiout->text (" received signal ");
7777 annotate_signal_name ();
7778 if (uiout->is_mi_like_p ())
7780 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7781 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7782 annotate_signal_name_end ();
7784 annotate_signal_string ();
7785 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7787 if (siggnal == GDB_SIGNAL_SEGV)
7788 handle_segmentation_fault (uiout);
7790 annotate_signal_string_end ();
7792 uiout->text (".\n");
7796 print_no_history_reason (struct ui_out *uiout)
7798 uiout->text ("\nNo more reverse-execution history.\n");
7801 /* Print current location without a level number, if we have changed
7802 functions or hit a breakpoint. Print source line if we have one.
7803 bpstat_print contains the logic deciding in detail what to print,
7804 based on the event(s) that just occurred. */
7807 print_stop_location (struct target_waitstatus *ws)
7810 enum print_what source_flag;
7811 int do_frame_printing = 1;
7812 struct thread_info *tp = inferior_thread ();
7814 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7818 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7819 should) carry around the function and does (or should) use
7820 that when doing a frame comparison. */
7821 if (tp->control.stop_step
7822 && frame_id_eq (tp->control.step_frame_id,
7823 get_frame_id (get_current_frame ()))
7824 && (tp->control.step_start_function
7825 == find_pc_function (tp->suspend.stop_pc)))
7827 /* Finished step, just print source line. */
7828 source_flag = SRC_LINE;
7832 /* Print location and source line. */
7833 source_flag = SRC_AND_LOC;
7836 case PRINT_SRC_AND_LOC:
7837 /* Print location and source line. */
7838 source_flag = SRC_AND_LOC;
7840 case PRINT_SRC_ONLY:
7841 source_flag = SRC_LINE;
7844 /* Something bogus. */
7845 source_flag = SRC_LINE;
7846 do_frame_printing = 0;
7849 internal_error (__FILE__, __LINE__, _("Unknown value."));
7852 /* The behavior of this routine with respect to the source
7854 SRC_LINE: Print only source line
7855 LOCATION: Print only location
7856 SRC_AND_LOC: Print location and source line. */
7857 if (do_frame_printing)
7858 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7864 print_stop_event (struct ui_out *uiout)
7866 struct target_waitstatus last;
7868 struct thread_info *tp;
7870 get_last_target_status (&last_ptid, &last);
7873 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
7875 print_stop_location (&last);
7877 /* Display the auto-display expressions. */
7881 tp = inferior_thread ();
7882 if (tp->thread_fsm != NULL
7883 && tp->thread_fsm->finished_p ())
7885 struct return_value_info *rv;
7887 rv = tp->thread_fsm->return_value ();
7889 print_return_value (uiout, rv);
7896 maybe_remove_breakpoints (void)
7898 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7900 if (remove_breakpoints ())
7902 target_terminal::ours_for_output ();
7903 printf_filtered (_("Cannot remove breakpoints because "
7904 "program is no longer writable.\nFurther "
7905 "execution is probably impossible.\n"));
7910 /* The execution context that just caused a normal stop. */
7917 DISABLE_COPY_AND_ASSIGN (stop_context);
7919 bool changed () const;
7924 /* The event PTID. */
7928 /* If stopp for a thread event, this is the thread that caused the
7930 struct thread_info *thread;
7932 /* The inferior that caused the stop. */
7936 /* Initializes a new stop context. If stopped for a thread event, this
7937 takes a strong reference to the thread. */
7939 stop_context::stop_context ()
7941 stop_id = get_stop_id ();
7942 ptid = inferior_ptid;
7943 inf_num = current_inferior ()->num;
7945 if (inferior_ptid != null_ptid)
7947 /* Take a strong reference so that the thread can't be deleted
7949 thread = inferior_thread ();
7956 /* Release a stop context previously created with save_stop_context.
7957 Releases the strong reference to the thread as well. */
7959 stop_context::~stop_context ()
7965 /* Return true if the current context no longer matches the saved stop
7969 stop_context::changed () const
7971 if (ptid != inferior_ptid)
7973 if (inf_num != current_inferior ()->num)
7975 if (thread != NULL && thread->state != THREAD_STOPPED)
7977 if (get_stop_id () != stop_id)
7987 struct target_waitstatus last;
7990 get_last_target_status (&last_ptid, &last);
7994 /* If an exception is thrown from this point on, make sure to
7995 propagate GDB's knowledge of the executing state to the
7996 frontend/user running state. A QUIT is an easy exception to see
7997 here, so do this before any filtered output. */
7999 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
8002 maybe_finish_thread_state.emplace (minus_one_ptid);
8003 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8004 || last.kind == TARGET_WAITKIND_EXITED)
8006 /* On some targets, we may still have live threads in the
8007 inferior when we get a process exit event. E.g., for
8008 "checkpoint", when the current checkpoint/fork exits,
8009 linux-fork.c automatically switches to another fork from
8010 within target_mourn_inferior. */
8011 if (inferior_ptid != null_ptid)
8012 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8014 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8015 maybe_finish_thread_state.emplace (inferior_ptid);
8017 /* As we're presenting a stop, and potentially removing breakpoints,
8018 update the thread list so we can tell whether there are threads
8019 running on the target. With target remote, for example, we can
8020 only learn about new threads when we explicitly update the thread
8021 list. Do this before notifying the interpreters about signal
8022 stops, end of stepping ranges, etc., so that the "new thread"
8023 output is emitted before e.g., "Program received signal FOO",
8024 instead of after. */
8025 update_thread_list ();
8027 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8028 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8030 /* As with the notification of thread events, we want to delay
8031 notifying the user that we've switched thread context until
8032 the inferior actually stops.
8034 There's no point in saying anything if the inferior has exited.
8035 Note that SIGNALLED here means "exited with a signal", not
8036 "received a signal".
8038 Also skip saying anything in non-stop mode. In that mode, as we
8039 don't want GDB to switch threads behind the user's back, to avoid
8040 races where the user is typing a command to apply to thread x,
8041 but GDB switches to thread y before the user finishes entering
8042 the command, fetch_inferior_event installs a cleanup to restore
8043 the current thread back to the thread the user had selected right
8044 after this event is handled, so we're not really switching, only
8045 informing of a stop. */
8047 && previous_inferior_ptid != inferior_ptid
8048 && target_has_execution
8049 && last.kind != TARGET_WAITKIND_SIGNALLED
8050 && last.kind != TARGET_WAITKIND_EXITED
8051 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8053 SWITCH_THRU_ALL_UIS ()
8055 target_terminal::ours_for_output ();
8056 printf_filtered (_("[Switching to %s]\n"),
8057 target_pid_to_str (inferior_ptid));
8058 annotate_thread_changed ();
8060 previous_inferior_ptid = inferior_ptid;
8063 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8065 SWITCH_THRU_ALL_UIS ()
8066 if (current_ui->prompt_state == PROMPT_BLOCKED)
8068 target_terminal::ours_for_output ();
8069 printf_filtered (_("No unwaited-for children left.\n"));
8073 /* Note: this depends on the update_thread_list call above. */
8074 maybe_remove_breakpoints ();
8076 /* If an auto-display called a function and that got a signal,
8077 delete that auto-display to avoid an infinite recursion. */
8079 if (stopped_by_random_signal)
8080 disable_current_display ();
8082 SWITCH_THRU_ALL_UIS ()
8084 async_enable_stdin ();
8087 /* Let the user/frontend see the threads as stopped. */
8088 maybe_finish_thread_state.reset ();
8090 /* Select innermost stack frame - i.e., current frame is frame 0,
8091 and current location is based on that. Handle the case where the
8092 dummy call is returning after being stopped. E.g. the dummy call
8093 previously hit a breakpoint. (If the dummy call returns
8094 normally, we won't reach here.) Do this before the stop hook is
8095 run, so that it doesn't get to see the temporary dummy frame,
8096 which is not where we'll present the stop. */
8097 if (has_stack_frames ())
8099 if (stop_stack_dummy == STOP_STACK_DUMMY)
8101 /* Pop the empty frame that contains the stack dummy. This
8102 also restores inferior state prior to the call (struct
8103 infcall_suspend_state). */
8104 struct frame_info *frame = get_current_frame ();
8106 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8108 /* frame_pop calls reinit_frame_cache as the last thing it
8109 does which means there's now no selected frame. */
8112 select_frame (get_current_frame ());
8114 /* Set the current source location. */
8115 set_current_sal_from_frame (get_current_frame ());
8118 /* Look up the hook_stop and run it (CLI internally handles problem
8119 of stop_command's pre-hook not existing). */
8120 if (stop_command != NULL)
8122 stop_context saved_context;
8126 execute_cmd_pre_hook (stop_command);
8128 CATCH (ex, RETURN_MASK_ALL)
8130 exception_fprintf (gdb_stderr, ex,
8131 "Error while running hook_stop:\n");
8135 /* If the stop hook resumes the target, then there's no point in
8136 trying to notify about the previous stop; its context is
8137 gone. Likewise if the command switches thread or inferior --
8138 the observers would print a stop for the wrong
8140 if (saved_context.changed ())
8144 /* Notify observers about the stop. This is where the interpreters
8145 print the stop event. */
8146 if (inferior_ptid != null_ptid)
8147 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8150 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8152 annotate_stopped ();
8154 if (target_has_execution)
8156 if (last.kind != TARGET_WAITKIND_SIGNALLED
8157 && last.kind != TARGET_WAITKIND_EXITED)
8158 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8159 Delete any breakpoint that is to be deleted at the next stop. */
8160 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8163 /* Try to get rid of automatically added inferiors that are no
8164 longer needed. Keeping those around slows down things linearly.
8165 Note that this never removes the current inferior. */
8172 signal_stop_state (int signo)
8174 return signal_stop[signo];
8178 signal_print_state (int signo)
8180 return signal_print[signo];
8184 signal_pass_state (int signo)
8186 return signal_program[signo];
8190 signal_cache_update (int signo)
8194 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8195 signal_cache_update (signo);
8200 signal_pass[signo] = (signal_stop[signo] == 0
8201 && signal_print[signo] == 0
8202 && signal_program[signo] == 1
8203 && signal_catch[signo] == 0);
8207 signal_stop_update (int signo, int state)
8209 int ret = signal_stop[signo];
8211 signal_stop[signo] = state;
8212 signal_cache_update (signo);
8217 signal_print_update (int signo, int state)
8219 int ret = signal_print[signo];
8221 signal_print[signo] = state;
8222 signal_cache_update (signo);
8227 signal_pass_update (int signo, int state)
8229 int ret = signal_program[signo];
8231 signal_program[signo] = state;
8232 signal_cache_update (signo);
8236 /* Update the global 'signal_catch' from INFO and notify the
8240 signal_catch_update (const unsigned int *info)
8244 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8245 signal_catch[i] = info[i] > 0;
8246 signal_cache_update (-1);
8247 target_pass_signals (signal_pass);
8251 sig_print_header (void)
8253 printf_filtered (_("Signal Stop\tPrint\tPass "
8254 "to program\tDescription\n"));
8258 sig_print_info (enum gdb_signal oursig)
8260 const char *name = gdb_signal_to_name (oursig);
8261 int name_padding = 13 - strlen (name);
8263 if (name_padding <= 0)
8266 printf_filtered ("%s", name);
8267 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8268 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8269 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8270 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8271 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8274 /* Specify how various signals in the inferior should be handled. */
8277 handle_command (const char *args, int from_tty)
8279 int digits, wordlen;
8280 int sigfirst, siglast;
8281 enum gdb_signal oursig;
8286 error_no_arg (_("signal to handle"));
8289 /* Allocate and zero an array of flags for which signals to handle. */
8291 const size_t nsigs = GDB_SIGNAL_LAST;
8292 unsigned char sigs[nsigs] {};
8294 /* Break the command line up into args. */
8296 gdb_argv built_argv (args);
8298 /* Walk through the args, looking for signal oursigs, signal names, and
8299 actions. Signal numbers and signal names may be interspersed with
8300 actions, with the actions being performed for all signals cumulatively
8301 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8303 for (char *arg : built_argv)
8305 wordlen = strlen (arg);
8306 for (digits = 0; isdigit (arg[digits]); digits++)
8310 sigfirst = siglast = -1;
8312 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8314 /* Apply action to all signals except those used by the
8315 debugger. Silently skip those. */
8318 siglast = nsigs - 1;
8320 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8322 SET_SIGS (nsigs, sigs, signal_stop);
8323 SET_SIGS (nsigs, sigs, signal_print);
8325 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8327 UNSET_SIGS (nsigs, sigs, signal_program);
8329 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8331 SET_SIGS (nsigs, sigs, signal_print);
8333 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8335 SET_SIGS (nsigs, sigs, signal_program);
8337 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8339 UNSET_SIGS (nsigs, sigs, signal_stop);
8341 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8343 SET_SIGS (nsigs, sigs, signal_program);
8345 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8347 UNSET_SIGS (nsigs, sigs, signal_print);
8348 UNSET_SIGS (nsigs, sigs, signal_stop);
8350 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8352 UNSET_SIGS (nsigs, sigs, signal_program);
8354 else if (digits > 0)
8356 /* It is numeric. The numeric signal refers to our own
8357 internal signal numbering from target.h, not to host/target
8358 signal number. This is a feature; users really should be
8359 using symbolic names anyway, and the common ones like
8360 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8362 sigfirst = siglast = (int)
8363 gdb_signal_from_command (atoi (arg));
8364 if (arg[digits] == '-')
8367 gdb_signal_from_command (atoi (arg + digits + 1));
8369 if (sigfirst > siglast)
8371 /* Bet he didn't figure we'd think of this case... */
8372 std::swap (sigfirst, siglast);
8377 oursig = gdb_signal_from_name (arg);
8378 if (oursig != GDB_SIGNAL_UNKNOWN)
8380 sigfirst = siglast = (int) oursig;
8384 /* Not a number and not a recognized flag word => complain. */
8385 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8389 /* If any signal numbers or symbol names were found, set flags for
8390 which signals to apply actions to. */
8392 for (int signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8394 switch ((enum gdb_signal) signum)
8396 case GDB_SIGNAL_TRAP:
8397 case GDB_SIGNAL_INT:
8398 if (!allsigs && !sigs[signum])
8400 if (query (_("%s is used by the debugger.\n\
8401 Are you sure you want to change it? "),
8402 gdb_signal_to_name ((enum gdb_signal) signum)))
8407 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8411 case GDB_SIGNAL_DEFAULT:
8412 case GDB_SIGNAL_UNKNOWN:
8413 /* Make sure that "all" doesn't print these. */
8422 for (int signum = 0; signum < nsigs; signum++)
8425 signal_cache_update (-1);
8426 target_pass_signals (signal_pass);
8427 target_program_signals (signal_program);
8431 /* Show the results. */
8432 sig_print_header ();
8433 for (; signum < nsigs; signum++)
8435 sig_print_info ((enum gdb_signal) signum);
8442 /* Complete the "handle" command. */
8445 handle_completer (struct cmd_list_element *ignore,
8446 completion_tracker &tracker,
8447 const char *text, const char *word)
8449 static const char * const keywords[] =
8463 signal_completer (ignore, tracker, text, word);
8464 complete_on_enum (tracker, keywords, word, word);
8468 gdb_signal_from_command (int num)
8470 if (num >= 1 && num <= 15)
8471 return (enum gdb_signal) num;
8472 error (_("Only signals 1-15 are valid as numeric signals.\n\
8473 Use \"info signals\" for a list of symbolic signals."));
8476 /* Print current contents of the tables set by the handle command.
8477 It is possible we should just be printing signals actually used
8478 by the current target (but for things to work right when switching
8479 targets, all signals should be in the signal tables). */
8482 info_signals_command (const char *signum_exp, int from_tty)
8484 enum gdb_signal oursig;
8486 sig_print_header ();
8490 /* First see if this is a symbol name. */
8491 oursig = gdb_signal_from_name (signum_exp);
8492 if (oursig == GDB_SIGNAL_UNKNOWN)
8494 /* No, try numeric. */
8496 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8498 sig_print_info (oursig);
8502 printf_filtered ("\n");
8503 /* These ugly casts brought to you by the native VAX compiler. */
8504 for (oursig = GDB_SIGNAL_FIRST;
8505 (int) oursig < (int) GDB_SIGNAL_LAST;
8506 oursig = (enum gdb_signal) ((int) oursig + 1))
8510 if (oursig != GDB_SIGNAL_UNKNOWN
8511 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8512 sig_print_info (oursig);
8515 printf_filtered (_("\nUse the \"handle\" command "
8516 "to change these tables.\n"));
8519 /* The $_siginfo convenience variable is a bit special. We don't know
8520 for sure the type of the value until we actually have a chance to
8521 fetch the data. The type can change depending on gdbarch, so it is
8522 also dependent on which thread you have selected.
8524 1. making $_siginfo be an internalvar that creates a new value on
8527 2. making the value of $_siginfo be an lval_computed value. */
8529 /* This function implements the lval_computed support for reading a
8533 siginfo_value_read (struct value *v)
8535 LONGEST transferred;
8537 /* If we can access registers, so can we access $_siginfo. Likewise
8539 validate_registers_access ();
8542 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO,
8544 value_contents_all_raw (v),
8546 TYPE_LENGTH (value_type (v)));
8548 if (transferred != TYPE_LENGTH (value_type (v)))
8549 error (_("Unable to read siginfo"));
8552 /* This function implements the lval_computed support for writing a
8556 siginfo_value_write (struct value *v, struct value *fromval)
8558 LONGEST transferred;
8560 /* If we can access registers, so can we access $_siginfo. Likewise
8562 validate_registers_access ();
8564 transferred = target_write (current_top_target (),
8565 TARGET_OBJECT_SIGNAL_INFO,
8567 value_contents_all_raw (fromval),
8569 TYPE_LENGTH (value_type (fromval)));
8571 if (transferred != TYPE_LENGTH (value_type (fromval)))
8572 error (_("Unable to write siginfo"));
8575 static const struct lval_funcs siginfo_value_funcs =
8581 /* Return a new value with the correct type for the siginfo object of
8582 the current thread using architecture GDBARCH. Return a void value
8583 if there's no object available. */
8585 static struct value *
8586 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8589 if (target_has_stack
8590 && inferior_ptid != null_ptid
8591 && gdbarch_get_siginfo_type_p (gdbarch))
8593 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8595 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8598 return allocate_value (builtin_type (gdbarch)->builtin_void);
8602 /* infcall_suspend_state contains state about the program itself like its
8603 registers and any signal it received when it last stopped.
8604 This state must be restored regardless of how the inferior function call
8605 ends (either successfully, or after it hits a breakpoint or signal)
8606 if the program is to properly continue where it left off. */
8608 class infcall_suspend_state
8611 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8612 once the inferior function call has finished. */
8613 infcall_suspend_state (struct gdbarch *gdbarch,
8614 const struct thread_info *tp,
8615 struct regcache *regcache)
8616 : m_thread_suspend (tp->suspend),
8617 m_registers (new readonly_detached_regcache (*regcache))
8619 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8621 if (gdbarch_get_siginfo_type_p (gdbarch))
8623 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8624 size_t len = TYPE_LENGTH (type);
8626 siginfo_data.reset ((gdb_byte *) xmalloc (len));
8628 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8629 siginfo_data.get (), 0, len) != len)
8631 /* Errors ignored. */
8632 siginfo_data.reset (nullptr);
8638 m_siginfo_gdbarch = gdbarch;
8639 m_siginfo_data = std::move (siginfo_data);
8643 /* Return a pointer to the stored register state. */
8645 readonly_detached_regcache *registers () const
8647 return m_registers.get ();
8650 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8652 void restore (struct gdbarch *gdbarch,
8653 struct thread_info *tp,
8654 struct regcache *regcache) const
8656 tp->suspend = m_thread_suspend;
8658 if (m_siginfo_gdbarch == gdbarch)
8660 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8662 /* Errors ignored. */
8663 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8664 m_siginfo_data.get (), 0, TYPE_LENGTH (type));
8667 /* The inferior can be gone if the user types "print exit(0)"
8668 (and perhaps other times). */
8669 if (target_has_execution)
8670 /* NB: The register write goes through to the target. */
8671 regcache->restore (registers ());
8675 /* How the current thread stopped before the inferior function call was
8677 struct thread_suspend_state m_thread_suspend;
8679 /* The registers before the inferior function call was executed. */
8680 std::unique_ptr<readonly_detached_regcache> m_registers;
8682 /* Format of SIGINFO_DATA or NULL if it is not present. */
8683 struct gdbarch *m_siginfo_gdbarch = nullptr;
8685 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8686 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8687 content would be invalid. */
8688 gdb::unique_xmalloc_ptr<gdb_byte> m_siginfo_data;
8691 infcall_suspend_state_up
8692 save_infcall_suspend_state ()
8694 struct thread_info *tp = inferior_thread ();
8695 struct regcache *regcache = get_current_regcache ();
8696 struct gdbarch *gdbarch = regcache->arch ();
8698 infcall_suspend_state_up inf_state
8699 (new struct infcall_suspend_state (gdbarch, tp, regcache));
8701 /* Having saved the current state, adjust the thread state, discarding
8702 any stop signal information. The stop signal is not useful when
8703 starting an inferior function call, and run_inferior_call will not use
8704 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8705 tp->suspend.stop_signal = GDB_SIGNAL_0;
8710 /* Restore inferior session state to INF_STATE. */
8713 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8715 struct thread_info *tp = inferior_thread ();
8716 struct regcache *regcache = get_current_regcache ();
8717 struct gdbarch *gdbarch = regcache->arch ();
8719 inf_state->restore (gdbarch, tp, regcache);
8720 discard_infcall_suspend_state (inf_state);
8724 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8729 readonly_detached_regcache *
8730 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8732 return inf_state->registers ();
8735 /* infcall_control_state contains state regarding gdb's control of the
8736 inferior itself like stepping control. It also contains session state like
8737 the user's currently selected frame. */
8739 struct infcall_control_state
8741 struct thread_control_state thread_control;
8742 struct inferior_control_state inferior_control;
8745 enum stop_stack_kind stop_stack_dummy = STOP_NONE;
8746 int stopped_by_random_signal = 0;
8748 /* ID if the selected frame when the inferior function call was made. */
8749 struct frame_id selected_frame_id {};
8752 /* Save all of the information associated with the inferior<==>gdb
8755 infcall_control_state_up
8756 save_infcall_control_state ()
8758 infcall_control_state_up inf_status (new struct infcall_control_state);
8759 struct thread_info *tp = inferior_thread ();
8760 struct inferior *inf = current_inferior ();
8762 inf_status->thread_control = tp->control;
8763 inf_status->inferior_control = inf->control;
8765 tp->control.step_resume_breakpoint = NULL;
8766 tp->control.exception_resume_breakpoint = NULL;
8768 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8769 chain. If caller's caller is walking the chain, they'll be happier if we
8770 hand them back the original chain when restore_infcall_control_state is
8772 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8775 inf_status->stop_stack_dummy = stop_stack_dummy;
8776 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8778 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8784 restore_selected_frame (const frame_id &fid)
8786 frame_info *frame = frame_find_by_id (fid);
8788 /* If inf_status->selected_frame_id is NULL, there was no previously
8792 warning (_("Unable to restore previously selected frame."));
8796 select_frame (frame);
8799 /* Restore inferior session state to INF_STATUS. */
8802 restore_infcall_control_state (struct infcall_control_state *inf_status)
8804 struct thread_info *tp = inferior_thread ();
8805 struct inferior *inf = current_inferior ();
8807 if (tp->control.step_resume_breakpoint)
8808 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8810 if (tp->control.exception_resume_breakpoint)
8811 tp->control.exception_resume_breakpoint->disposition
8812 = disp_del_at_next_stop;
8814 /* Handle the bpstat_copy of the chain. */
8815 bpstat_clear (&tp->control.stop_bpstat);
8817 tp->control = inf_status->thread_control;
8818 inf->control = inf_status->inferior_control;
8821 stop_stack_dummy = inf_status->stop_stack_dummy;
8822 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8824 if (target_has_stack)
8826 /* The point of the try/catch is that if the stack is clobbered,
8827 walking the stack might encounter a garbage pointer and
8828 error() trying to dereference it. */
8831 restore_selected_frame (inf_status->selected_frame_id);
8833 CATCH (ex, RETURN_MASK_ERROR)
8835 exception_fprintf (gdb_stderr, ex,
8836 "Unable to restore previously selected frame:\n");
8837 /* Error in restoring the selected frame. Select the
8839 select_frame (get_current_frame ());
8848 discard_infcall_control_state (struct infcall_control_state *inf_status)
8850 if (inf_status->thread_control.step_resume_breakpoint)
8851 inf_status->thread_control.step_resume_breakpoint->disposition
8852 = disp_del_at_next_stop;
8854 if (inf_status->thread_control.exception_resume_breakpoint)
8855 inf_status->thread_control.exception_resume_breakpoint->disposition
8856 = disp_del_at_next_stop;
8858 /* See save_infcall_control_state for info on stop_bpstat. */
8859 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8867 clear_exit_convenience_vars (void)
8869 clear_internalvar (lookup_internalvar ("_exitsignal"));
8870 clear_internalvar (lookup_internalvar ("_exitcode"));
8874 /* User interface for reverse debugging:
8875 Set exec-direction / show exec-direction commands
8876 (returns error unless target implements to_set_exec_direction method). */
8878 enum exec_direction_kind execution_direction = EXEC_FORWARD;
8879 static const char exec_forward[] = "forward";
8880 static const char exec_reverse[] = "reverse";
8881 static const char *exec_direction = exec_forward;
8882 static const char *const exec_direction_names[] = {
8889 set_exec_direction_func (const char *args, int from_tty,
8890 struct cmd_list_element *cmd)
8892 if (target_can_execute_reverse)
8894 if (!strcmp (exec_direction, exec_forward))
8895 execution_direction = EXEC_FORWARD;
8896 else if (!strcmp (exec_direction, exec_reverse))
8897 execution_direction = EXEC_REVERSE;
8901 exec_direction = exec_forward;
8902 error (_("Target does not support this operation."));
8907 show_exec_direction_func (struct ui_file *out, int from_tty,
8908 struct cmd_list_element *cmd, const char *value)
8910 switch (execution_direction) {
8912 fprintf_filtered (out, _("Forward.\n"));
8915 fprintf_filtered (out, _("Reverse.\n"));
8918 internal_error (__FILE__, __LINE__,
8919 _("bogus execution_direction value: %d"),
8920 (int) execution_direction);
8925 show_schedule_multiple (struct ui_file *file, int from_tty,
8926 struct cmd_list_element *c, const char *value)
8928 fprintf_filtered (file, _("Resuming the execution of threads "
8929 "of all processes is %s.\n"), value);
8932 /* Implementation of `siginfo' variable. */
8934 static const struct internalvar_funcs siginfo_funcs =
8941 /* Callback for infrun's target events source. This is marked when a
8942 thread has a pending status to process. */
8945 infrun_async_inferior_event_handler (gdb_client_data data)
8947 inferior_event_handler (INF_REG_EVENT, NULL);
8951 _initialize_infrun (void)
8953 struct cmd_list_element *c;
8955 /* Register extra event sources in the event loop. */
8956 infrun_async_inferior_event_token
8957 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8959 add_info ("signals", info_signals_command, _("\
8960 What debugger does when program gets various signals.\n\
8961 Specify a signal as argument to print info on that signal only."));
8962 add_info_alias ("handle", "signals", 0);
8964 c = add_com ("handle", class_run, handle_command, _("\
8965 Specify how to handle signals.\n\
8966 Usage: handle SIGNAL [ACTIONS]\n\
8967 Args are signals and actions to apply to those signals.\n\
8968 If no actions are specified, the current settings for the specified signals\n\
8969 will be displayed instead.\n\
8971 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8972 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8973 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8974 The special arg \"all\" is recognized to mean all signals except those\n\
8975 used by the debugger, typically SIGTRAP and SIGINT.\n\
8977 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8978 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8979 Stop means reenter debugger if this signal happens (implies print).\n\
8980 Print means print a message if this signal happens.\n\
8981 Pass means let program see this signal; otherwise program doesn't know.\n\
8982 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8983 Pass and Stop may be combined.\n\
8985 Multiple signals may be specified. Signal numbers and signal names\n\
8986 may be interspersed with actions, with the actions being performed for\n\
8987 all signals cumulatively specified."));
8988 set_cmd_completer (c, handle_completer);
8991 stop_command = add_cmd ("stop", class_obscure,
8992 not_just_help_class_command, _("\
8993 There is no `stop' command, but you can set a hook on `stop'.\n\
8994 This allows you to set a list of commands to be run each time execution\n\
8995 of the program stops."), &cmdlist);
8997 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
8998 Set inferior debugging."), _("\
8999 Show inferior debugging."), _("\
9000 When non-zero, inferior specific debugging is enabled."),
9003 &setdebuglist, &showdebuglist);
9005 add_setshow_boolean_cmd ("displaced", class_maintenance,
9006 &debug_displaced, _("\
9007 Set displaced stepping debugging."), _("\
9008 Show displaced stepping debugging."), _("\
9009 When non-zero, displaced stepping specific debugging is enabled."),
9011 show_debug_displaced,
9012 &setdebuglist, &showdebuglist);
9014 add_setshow_boolean_cmd ("non-stop", no_class,
9016 Set whether gdb controls the inferior in non-stop mode."), _("\
9017 Show whether gdb controls the inferior in non-stop mode."), _("\
9018 When debugging a multi-threaded program and this setting is\n\
9019 off (the default, also called all-stop mode), when one thread stops\n\
9020 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9021 all other threads in the program while you interact with the thread of\n\
9022 interest. When you continue or step a thread, you can allow the other\n\
9023 threads to run, or have them remain stopped, but while you inspect any\n\
9024 thread's state, all threads stop.\n\
9026 In non-stop mode, when one thread stops, other threads can continue\n\
9027 to run freely. You'll be able to step each thread independently,\n\
9028 leave it stopped or free to run as needed."),
9034 for (size_t i = 0; i < GDB_SIGNAL_LAST; i++)
9037 signal_print[i] = 1;
9038 signal_program[i] = 1;
9039 signal_catch[i] = 0;
9042 /* Signals caused by debugger's own actions should not be given to
9043 the program afterwards.
9045 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9046 explicitly specifies that it should be delivered to the target
9047 program. Typically, that would occur when a user is debugging a
9048 target monitor on a simulator: the target monitor sets a
9049 breakpoint; the simulator encounters this breakpoint and halts
9050 the simulation handing control to GDB; GDB, noting that the stop
9051 address doesn't map to any known breakpoint, returns control back
9052 to the simulator; the simulator then delivers the hardware
9053 equivalent of a GDB_SIGNAL_TRAP to the program being
9055 signal_program[GDB_SIGNAL_TRAP] = 0;
9056 signal_program[GDB_SIGNAL_INT] = 0;
9058 /* Signals that are not errors should not normally enter the debugger. */
9059 signal_stop[GDB_SIGNAL_ALRM] = 0;
9060 signal_print[GDB_SIGNAL_ALRM] = 0;
9061 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9062 signal_print[GDB_SIGNAL_VTALRM] = 0;
9063 signal_stop[GDB_SIGNAL_PROF] = 0;
9064 signal_print[GDB_SIGNAL_PROF] = 0;
9065 signal_stop[GDB_SIGNAL_CHLD] = 0;
9066 signal_print[GDB_SIGNAL_CHLD] = 0;
9067 signal_stop[GDB_SIGNAL_IO] = 0;
9068 signal_print[GDB_SIGNAL_IO] = 0;
9069 signal_stop[GDB_SIGNAL_POLL] = 0;
9070 signal_print[GDB_SIGNAL_POLL] = 0;
9071 signal_stop[GDB_SIGNAL_URG] = 0;
9072 signal_print[GDB_SIGNAL_URG] = 0;
9073 signal_stop[GDB_SIGNAL_WINCH] = 0;
9074 signal_print[GDB_SIGNAL_WINCH] = 0;
9075 signal_stop[GDB_SIGNAL_PRIO] = 0;
9076 signal_print[GDB_SIGNAL_PRIO] = 0;
9078 /* These signals are used internally by user-level thread
9079 implementations. (See signal(5) on Solaris.) Like the above
9080 signals, a healthy program receives and handles them as part of
9081 its normal operation. */
9082 signal_stop[GDB_SIGNAL_LWP] = 0;
9083 signal_print[GDB_SIGNAL_LWP] = 0;
9084 signal_stop[GDB_SIGNAL_WAITING] = 0;
9085 signal_print[GDB_SIGNAL_WAITING] = 0;
9086 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9087 signal_print[GDB_SIGNAL_CANCEL] = 0;
9088 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9089 signal_print[GDB_SIGNAL_LIBRT] = 0;
9091 /* Update cached state. */
9092 signal_cache_update (-1);
9094 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9095 &stop_on_solib_events, _("\
9096 Set stopping for shared library events."), _("\
9097 Show stopping for shared library events."), _("\
9098 If nonzero, gdb will give control to the user when the dynamic linker\n\
9099 notifies gdb of shared library events. The most common event of interest\n\
9100 to the user would be loading/unloading of a new library."),
9101 set_stop_on_solib_events,
9102 show_stop_on_solib_events,
9103 &setlist, &showlist);
9105 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9106 follow_fork_mode_kind_names,
9107 &follow_fork_mode_string, _("\
9108 Set debugger response to a program call of fork or vfork."), _("\
9109 Show debugger response to a program call of fork or vfork."), _("\
9110 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9111 parent - the original process is debugged after a fork\n\
9112 child - the new process is debugged after a fork\n\
9113 The unfollowed process will continue to run.\n\
9114 By default, the debugger will follow the parent process."),
9116 show_follow_fork_mode_string,
9117 &setlist, &showlist);
9119 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9120 follow_exec_mode_names,
9121 &follow_exec_mode_string, _("\
9122 Set debugger response to a program call of exec."), _("\
9123 Show debugger response to a program call of exec."), _("\
9124 An exec call replaces the program image of a process.\n\
9126 follow-exec-mode can be:\n\
9128 new - the debugger creates a new inferior and rebinds the process\n\
9129 to this new inferior. The program the process was running before\n\
9130 the exec call can be restarted afterwards by restarting the original\n\
9133 same - the debugger keeps the process bound to the same inferior.\n\
9134 The new executable image replaces the previous executable loaded in\n\
9135 the inferior. Restarting the inferior after the exec call restarts\n\
9136 the executable the process was running after the exec call.\n\
9138 By default, the debugger will use the same inferior."),
9140 show_follow_exec_mode_string,
9141 &setlist, &showlist);
9143 add_setshow_enum_cmd ("scheduler-locking", class_run,
9144 scheduler_enums, &scheduler_mode, _("\
9145 Set mode for locking scheduler during execution."), _("\
9146 Show mode for locking scheduler during execution."), _("\
9147 off == no locking (threads may preempt at any time)\n\
9148 on == full locking (no thread except the current thread may run)\n\
9149 This applies to both normal execution and replay mode.\n\
9150 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9151 In this mode, other threads may run during other commands.\n\
9152 This applies to both normal execution and replay mode.\n\
9153 replay == scheduler locked in replay mode and unlocked during normal execution."),
9154 set_schedlock_func, /* traps on target vector */
9155 show_scheduler_mode,
9156 &setlist, &showlist);
9158 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9159 Set mode for resuming threads of all processes."), _("\
9160 Show mode for resuming threads of all processes."), _("\
9161 When on, execution commands (such as 'continue' or 'next') resume all\n\
9162 threads of all processes. When off (which is the default), execution\n\
9163 commands only resume the threads of the current process. The set of\n\
9164 threads that are resumed is further refined by the scheduler-locking\n\
9165 mode (see help set scheduler-locking)."),
9167 show_schedule_multiple,
9168 &setlist, &showlist);
9170 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9171 Set mode of the step operation."), _("\
9172 Show mode of the step operation."), _("\
9173 When set, doing a step over a function without debug line information\n\
9174 will stop at the first instruction of that function. Otherwise, the\n\
9175 function is skipped and the step command stops at a different source line."),
9177 show_step_stop_if_no_debug,
9178 &setlist, &showlist);
9180 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9181 &can_use_displaced_stepping, _("\
9182 Set debugger's willingness to use displaced stepping."), _("\
9183 Show debugger's willingness to use displaced stepping."), _("\
9184 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9185 supported by the target architecture. If off, gdb will not use displaced\n\
9186 stepping to step over breakpoints, even if such is supported by the target\n\
9187 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9188 if the target architecture supports it and non-stop mode is active, but will not\n\
9189 use it in all-stop mode (see help set non-stop)."),
9191 show_can_use_displaced_stepping,
9192 &setlist, &showlist);
9194 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9195 &exec_direction, _("Set direction of execution.\n\
9196 Options are 'forward' or 'reverse'."),
9197 _("Show direction of execution (forward/reverse)."),
9198 _("Tells gdb whether to execute forward or backward."),
9199 set_exec_direction_func, show_exec_direction_func,
9200 &setlist, &showlist);
9202 /* Set/show detach-on-fork: user-settable mode. */
9204 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9205 Set whether gdb will detach the child of a fork."), _("\
9206 Show whether gdb will detach the child of a fork."), _("\
9207 Tells gdb whether to detach the child of a fork."),
9208 NULL, NULL, &setlist, &showlist);
9210 /* Set/show disable address space randomization mode. */
9212 add_setshow_boolean_cmd ("disable-randomization", class_support,
9213 &disable_randomization, _("\
9214 Set disabling of debuggee's virtual address space randomization."), _("\
9215 Show disabling of debuggee's virtual address space randomization."), _("\
9216 When this mode is on (which is the default), randomization of the virtual\n\
9217 address space is disabled. Standalone programs run with the randomization\n\
9218 enabled by default on some platforms."),
9219 &set_disable_randomization,
9220 &show_disable_randomization,
9221 &setlist, &showlist);
9223 /* ptid initializations */
9224 inferior_ptid = null_ptid;
9225 target_last_wait_ptid = minus_one_ptid;
9227 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9228 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9229 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9230 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9232 /* Explicitly create without lookup, since that tries to create a
9233 value with a void typed value, and when we get here, gdbarch
9234 isn't initialized yet. At this point, we're quite sure there
9235 isn't another convenience variable of the same name. */
9236 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9238 add_setshow_boolean_cmd ("observer", no_class,
9239 &observer_mode_1, _("\
9240 Set whether gdb controls the inferior in observer mode."), _("\
9241 Show whether gdb controls the inferior in observer mode."), _("\
9242 In observer mode, GDB can get data from the inferior, but not\n\
9243 affect its execution. Registers and memory may not be changed,\n\
9244 breakpoints may not be set, and the program cannot be interrupted\n\