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 gdb_flush (gdb_stdout);
1164 breakpoint_init_inferior (inf_execd);
1166 gdb::unique_xmalloc_ptr<char> exec_file_host
1167 = exec_file_find (exec_file_target, NULL);
1169 /* If we were unable to map the executable target pathname onto a host
1170 pathname, tell the user that. Otherwise GDB's subsequent behavior
1171 is confusing. Maybe it would even be better to stop at this point
1172 so that the user can specify a file manually before continuing. */
1173 if (exec_file_host == NULL)
1174 warning (_("Could not load symbols for executable %s.\n"
1175 "Do you need \"set sysroot\"?"),
1178 /* Reset the shared library package. This ensures that we get a
1179 shlib event when the child reaches "_start", at which point the
1180 dld will have had a chance to initialize the child. */
1181 /* Also, loading a symbol file below may trigger symbol lookups, and
1182 we don't want those to be satisfied by the libraries of the
1183 previous incarnation of this process. */
1184 no_shared_libraries (NULL, 0);
1186 if (follow_exec_mode_string == follow_exec_mode_new)
1188 /* The user wants to keep the old inferior and program spaces
1189 around. Create a new fresh one, and switch to it. */
1191 /* Do exit processing for the original inferior before setting the new
1192 inferior's pid. Having two inferiors with the same pid would confuse
1193 find_inferior_p(t)id. Transfer the terminal state and info from the
1194 old to the new inferior. */
1195 inf = add_inferior_with_spaces ();
1196 swap_terminal_info (inf, current_inferior ());
1197 exit_inferior_silent (current_inferior ());
1200 target_follow_exec (inf, exec_file_target);
1202 set_current_inferior (inf);
1203 set_current_program_space (inf->pspace);
1208 /* The old description may no longer be fit for the new image.
1209 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1210 old description; we'll read a new one below. No need to do
1211 this on "follow-exec-mode new", as the old inferior stays
1212 around (its description is later cleared/refetched on
1214 target_clear_description ();
1217 gdb_assert (current_program_space == inf->pspace);
1219 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1220 because the proper displacement for a PIE (Position Independent
1221 Executable) main symbol file will only be computed by
1222 solib_create_inferior_hook below. breakpoint_re_set would fail
1223 to insert the breakpoints with the zero displacement. */
1224 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1226 /* If the target can specify a description, read it. Must do this
1227 after flipping to the new executable (because the target supplied
1228 description must be compatible with the executable's
1229 architecture, and the old executable may e.g., be 32-bit, while
1230 the new one 64-bit), and before anything involving memory or
1232 target_find_description ();
1234 solib_create_inferior_hook (0);
1236 jit_inferior_created_hook ();
1238 breakpoint_re_set ();
1240 /* Reinsert all breakpoints. (Those which were symbolic have
1241 been reset to the proper address in the new a.out, thanks
1242 to symbol_file_command...). */
1243 insert_breakpoints ();
1245 /* The next resume of this inferior should bring it to the shlib
1246 startup breakpoints. (If the user had also set bp's on
1247 "main" from the old (parent) process, then they'll auto-
1248 matically get reset there in the new process.). */
1251 /* The queue of threads that need to do a step-over operation to get
1252 past e.g., a breakpoint. What technique is used to step over the
1253 breakpoint/watchpoint does not matter -- all threads end up in the
1254 same queue, to maintain rough temporal order of execution, in order
1255 to avoid starvation, otherwise, we could e.g., find ourselves
1256 constantly stepping the same couple threads past their breakpoints
1257 over and over, if the single-step finish fast enough. */
1258 struct thread_info *step_over_queue_head;
1260 /* Bit flags indicating what the thread needs to step over. */
1262 enum step_over_what_flag
1264 /* Step over a breakpoint. */
1265 STEP_OVER_BREAKPOINT = 1,
1267 /* Step past a non-continuable watchpoint, in order to let the
1268 instruction execute so we can evaluate the watchpoint
1270 STEP_OVER_WATCHPOINT = 2
1272 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1274 /* Info about an instruction that is being stepped over. */
1276 struct step_over_info
1278 /* If we're stepping past a breakpoint, this is the address space
1279 and address of the instruction the breakpoint is set at. We'll
1280 skip inserting all breakpoints here. Valid iff ASPACE is
1282 const address_space *aspace;
1285 /* The instruction being stepped over triggers a nonsteppable
1286 watchpoint. If true, we'll skip inserting watchpoints. */
1287 int nonsteppable_watchpoint_p;
1289 /* The thread's global number. */
1293 /* The step-over info of the location that is being stepped over.
1295 Note that with async/breakpoint always-inserted mode, a user might
1296 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1297 being stepped over. As setting a new breakpoint inserts all
1298 breakpoints, we need to make sure the breakpoint being stepped over
1299 isn't inserted then. We do that by only clearing the step-over
1300 info when the step-over is actually finished (or aborted).
1302 Presently GDB can only step over one breakpoint at any given time.
1303 Given threads that can't run code in the same address space as the
1304 breakpoint's can't really miss the breakpoint, GDB could be taught
1305 to step-over at most one breakpoint per address space (so this info
1306 could move to the address space object if/when GDB is extended).
1307 The set of breakpoints being stepped over will normally be much
1308 smaller than the set of all breakpoints, so a flag in the
1309 breakpoint location structure would be wasteful. A separate list
1310 also saves complexity and run-time, as otherwise we'd have to go
1311 through all breakpoint locations clearing their flag whenever we
1312 start a new sequence. Similar considerations weigh against storing
1313 this info in the thread object. Plus, not all step overs actually
1314 have breakpoint locations -- e.g., stepping past a single-step
1315 breakpoint, or stepping to complete a non-continuable
1317 static struct step_over_info step_over_info;
1319 /* Record the address of the breakpoint/instruction we're currently
1321 N.B. We record the aspace and address now, instead of say just the thread,
1322 because when we need the info later the thread may be running. */
1325 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1326 int nonsteppable_watchpoint_p,
1329 step_over_info.aspace = aspace;
1330 step_over_info.address = address;
1331 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1332 step_over_info.thread = thread;
1335 /* Called when we're not longer stepping over a breakpoint / an
1336 instruction, so all breakpoints are free to be (re)inserted. */
1339 clear_step_over_info (void)
1342 fprintf_unfiltered (gdb_stdlog,
1343 "infrun: clear_step_over_info\n");
1344 step_over_info.aspace = NULL;
1345 step_over_info.address = 0;
1346 step_over_info.nonsteppable_watchpoint_p = 0;
1347 step_over_info.thread = -1;
1353 stepping_past_instruction_at (struct address_space *aspace,
1356 return (step_over_info.aspace != NULL
1357 && breakpoint_address_match (aspace, address,
1358 step_over_info.aspace,
1359 step_over_info.address));
1365 thread_is_stepping_over_breakpoint (int thread)
1367 return (step_over_info.thread != -1
1368 && thread == step_over_info.thread);
1374 stepping_past_nonsteppable_watchpoint (void)
1376 return step_over_info.nonsteppable_watchpoint_p;
1379 /* Returns true if step-over info is valid. */
1382 step_over_info_valid_p (void)
1384 return (step_over_info.aspace != NULL
1385 || stepping_past_nonsteppable_watchpoint ());
1389 /* Displaced stepping. */
1391 /* In non-stop debugging mode, we must take special care to manage
1392 breakpoints properly; in particular, the traditional strategy for
1393 stepping a thread past a breakpoint it has hit is unsuitable.
1394 'Displaced stepping' is a tactic for stepping one thread past a
1395 breakpoint it has hit while ensuring that other threads running
1396 concurrently will hit the breakpoint as they should.
1398 The traditional way to step a thread T off a breakpoint in a
1399 multi-threaded program in all-stop mode is as follows:
1401 a0) Initially, all threads are stopped, and breakpoints are not
1403 a1) We single-step T, leaving breakpoints uninserted.
1404 a2) We insert breakpoints, and resume all threads.
1406 In non-stop debugging, however, this strategy is unsuitable: we
1407 don't want to have to stop all threads in the system in order to
1408 continue or step T past a breakpoint. Instead, we use displaced
1411 n0) Initially, T is stopped, other threads are running, and
1412 breakpoints are inserted.
1413 n1) We copy the instruction "under" the breakpoint to a separate
1414 location, outside the main code stream, making any adjustments
1415 to the instruction, register, and memory state as directed by
1417 n2) We single-step T over the instruction at its new location.
1418 n3) We adjust the resulting register and memory state as directed
1419 by T's architecture. This includes resetting T's PC to point
1420 back into the main instruction stream.
1423 This approach depends on the following gdbarch methods:
1425 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1426 indicate where to copy the instruction, and how much space must
1427 be reserved there. We use these in step n1.
1429 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1430 address, and makes any necessary adjustments to the instruction,
1431 register contents, and memory. We use this in step n1.
1433 - gdbarch_displaced_step_fixup adjusts registers and memory after
1434 we have successfuly single-stepped the instruction, to yield the
1435 same effect the instruction would have had if we had executed it
1436 at its original address. We use this in step n3.
1438 The gdbarch_displaced_step_copy_insn and
1439 gdbarch_displaced_step_fixup functions must be written so that
1440 copying an instruction with gdbarch_displaced_step_copy_insn,
1441 single-stepping across the copied instruction, and then applying
1442 gdbarch_displaced_insn_fixup should have the same effects on the
1443 thread's memory and registers as stepping the instruction in place
1444 would have. Exactly which responsibilities fall to the copy and
1445 which fall to the fixup is up to the author of those functions.
1447 See the comments in gdbarch.sh for details.
1449 Note that displaced stepping and software single-step cannot
1450 currently be used in combination, although with some care I think
1451 they could be made to. Software single-step works by placing
1452 breakpoints on all possible subsequent instructions; if the
1453 displaced instruction is a PC-relative jump, those breakpoints
1454 could fall in very strange places --- on pages that aren't
1455 executable, or at addresses that are not proper instruction
1456 boundaries. (We do generally let other threads run while we wait
1457 to hit the software single-step breakpoint, and they might
1458 encounter such a corrupted instruction.) One way to work around
1459 this would be to have gdbarch_displaced_step_copy_insn fully
1460 simulate the effect of PC-relative instructions (and return NULL)
1461 on architectures that use software single-stepping.
1463 In non-stop mode, we can have independent and simultaneous step
1464 requests, so more than one thread may need to simultaneously step
1465 over a breakpoint. The current implementation assumes there is
1466 only one scratch space per process. In this case, we have to
1467 serialize access to the scratch space. If thread A wants to step
1468 over a breakpoint, but we are currently waiting for some other
1469 thread to complete a displaced step, we leave thread A stopped and
1470 place it in the displaced_step_request_queue. Whenever a displaced
1471 step finishes, we pick the next thread in the queue and start a new
1472 displaced step operation on it. See displaced_step_prepare and
1473 displaced_step_fixup for details. */
1475 /* Default destructor for displaced_step_closure. */
1477 displaced_step_closure::~displaced_step_closure () = default;
1479 /* Get the displaced stepping state of process PID. */
1481 static displaced_step_inferior_state *
1482 get_displaced_stepping_state (inferior *inf)
1484 return &inf->displaced_step_state;
1487 /* Returns true if any inferior has a thread doing a displaced
1491 displaced_step_in_progress_any_inferior ()
1493 for (inferior *i : all_inferiors ())
1495 if (i->displaced_step_state.step_thread != nullptr)
1502 /* Return true if thread represented by PTID is doing a displaced
1506 displaced_step_in_progress_thread (thread_info *thread)
1508 gdb_assert (thread != NULL);
1510 return get_displaced_stepping_state (thread->inf)->step_thread == thread;
1513 /* Return true if process PID has a thread doing a displaced step. */
1516 displaced_step_in_progress (inferior *inf)
1518 return get_displaced_stepping_state (inf)->step_thread != nullptr;
1521 /* If inferior is in displaced stepping, and ADDR equals to starting address
1522 of copy area, return corresponding displaced_step_closure. Otherwise,
1525 struct displaced_step_closure*
1526 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1528 displaced_step_inferior_state *displaced
1529 = get_displaced_stepping_state (current_inferior ());
1531 /* If checking the mode of displaced instruction in copy area. */
1532 if (displaced->step_thread != nullptr
1533 && displaced->step_copy == addr)
1534 return displaced->step_closure;
1540 infrun_inferior_exit (struct inferior *inf)
1542 inf->displaced_step_state.reset ();
1545 /* If ON, and the architecture supports it, GDB will use displaced
1546 stepping to step over breakpoints. If OFF, or if the architecture
1547 doesn't support it, GDB will instead use the traditional
1548 hold-and-step approach. If AUTO (which is the default), GDB will
1549 decide which technique to use to step over breakpoints depending on
1550 which of all-stop or non-stop mode is active --- displaced stepping
1551 in non-stop mode; hold-and-step in all-stop mode. */
1553 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1556 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1557 struct cmd_list_element *c,
1560 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1561 fprintf_filtered (file,
1562 _("Debugger's willingness to use displaced stepping "
1563 "to step over breakpoints is %s (currently %s).\n"),
1564 value, target_is_non_stop_p () ? "on" : "off");
1566 fprintf_filtered (file,
1567 _("Debugger's willingness to use displaced stepping "
1568 "to step over breakpoints is %s.\n"), value);
1571 /* Return non-zero if displaced stepping can/should be used to step
1572 over breakpoints of thread TP. */
1575 use_displaced_stepping (struct thread_info *tp)
1577 struct regcache *regcache = get_thread_regcache (tp);
1578 struct gdbarch *gdbarch = regcache->arch ();
1579 displaced_step_inferior_state *displaced_state
1580 = get_displaced_stepping_state (tp->inf);
1582 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1583 && target_is_non_stop_p ())
1584 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1585 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1586 && find_record_target () == NULL
1587 && !displaced_state->failed_before);
1590 /* Clean out any stray displaced stepping state. */
1592 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1594 /* Indicate that there is no cleanup pending. */
1595 displaced->step_thread = nullptr;
1597 delete displaced->step_closure;
1598 displaced->step_closure = NULL;
1602 displaced_step_clear_cleanup (void *arg)
1604 struct displaced_step_inferior_state *state
1605 = (struct displaced_step_inferior_state *) arg;
1607 displaced_step_clear (state);
1610 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1612 displaced_step_dump_bytes (struct ui_file *file,
1613 const gdb_byte *buf,
1618 for (i = 0; i < len; i++)
1619 fprintf_unfiltered (file, "%02x ", buf[i]);
1620 fputs_unfiltered ("\n", file);
1623 /* Prepare to single-step, using displaced stepping.
1625 Note that we cannot use displaced stepping when we have a signal to
1626 deliver. If we have a signal to deliver and an instruction to step
1627 over, then after the step, there will be no indication from the
1628 target whether the thread entered a signal handler or ignored the
1629 signal and stepped over the instruction successfully --- both cases
1630 result in a simple SIGTRAP. In the first case we mustn't do a
1631 fixup, and in the second case we must --- but we can't tell which.
1632 Comments in the code for 'random signals' in handle_inferior_event
1633 explain how we handle this case instead.
1635 Returns 1 if preparing was successful -- this thread is going to be
1636 stepped now; 0 if displaced stepping this thread got queued; or -1
1637 if this instruction can't be displaced stepped. */
1640 displaced_step_prepare_throw (thread_info *tp)
1642 regcache *regcache = get_thread_regcache (tp);
1643 struct gdbarch *gdbarch = regcache->arch ();
1644 const address_space *aspace = regcache->aspace ();
1645 CORE_ADDR original, copy;
1647 struct displaced_step_closure *closure;
1650 /* We should never reach this function if the architecture does not
1651 support displaced stepping. */
1652 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1654 /* Nor if the thread isn't meant to step over a breakpoint. */
1655 gdb_assert (tp->control.trap_expected);
1657 /* Disable range stepping while executing in the scratch pad. We
1658 want a single-step even if executing the displaced instruction in
1659 the scratch buffer lands within the stepping range (e.g., a
1661 tp->control.may_range_step = 0;
1663 /* We have to displaced step one thread at a time, as we only have
1664 access to a single scratch space per inferior. */
1666 displaced_step_inferior_state *displaced
1667 = get_displaced_stepping_state (tp->inf);
1669 if (displaced->step_thread != nullptr)
1671 /* Already waiting for a displaced step to finish. Defer this
1672 request and place in queue. */
1674 if (debug_displaced)
1675 fprintf_unfiltered (gdb_stdlog,
1676 "displaced: deferring step of %s\n",
1677 target_pid_to_str (tp->ptid));
1679 thread_step_over_chain_enqueue (tp);
1684 if (debug_displaced)
1685 fprintf_unfiltered (gdb_stdlog,
1686 "displaced: stepping %s now\n",
1687 target_pid_to_str (tp->ptid));
1690 displaced_step_clear (displaced);
1692 scoped_restore_current_thread restore_thread;
1694 switch_to_thread (tp);
1696 original = regcache_read_pc (regcache);
1698 copy = gdbarch_displaced_step_location (gdbarch);
1699 len = gdbarch_max_insn_length (gdbarch);
1701 if (breakpoint_in_range_p (aspace, copy, len))
1703 /* There's a breakpoint set in the scratch pad location range
1704 (which is usually around the entry point). We'd either
1705 install it before resuming, which would overwrite/corrupt the
1706 scratch pad, or if it was already inserted, this displaced
1707 step would overwrite it. The latter is OK in the sense that
1708 we already assume that no thread is going to execute the code
1709 in the scratch pad range (after initial startup) anyway, but
1710 the former is unacceptable. Simply punt and fallback to
1711 stepping over this breakpoint in-line. */
1712 if (debug_displaced)
1714 fprintf_unfiltered (gdb_stdlog,
1715 "displaced: breakpoint set in scratch pad. "
1716 "Stepping over breakpoint in-line instead.\n");
1722 /* Save the original contents of the copy area. */
1723 displaced->step_saved_copy.resize (len);
1724 status = target_read_memory (copy, displaced->step_saved_copy.data (), len);
1726 throw_error (MEMORY_ERROR,
1727 _("Error accessing memory address %s (%s) for "
1728 "displaced-stepping scratch space."),
1729 paddress (gdbarch, copy), safe_strerror (status));
1730 if (debug_displaced)
1732 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1733 paddress (gdbarch, copy));
1734 displaced_step_dump_bytes (gdb_stdlog,
1735 displaced->step_saved_copy.data (),
1739 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1740 original, copy, regcache);
1741 if (closure == NULL)
1743 /* The architecture doesn't know how or want to displaced step
1744 this instruction or instruction sequence. Fallback to
1745 stepping over the breakpoint in-line. */
1749 /* Save the information we need to fix things up if the step
1751 displaced->step_thread = tp;
1752 displaced->step_gdbarch = gdbarch;
1753 displaced->step_closure = closure;
1754 displaced->step_original = original;
1755 displaced->step_copy = copy;
1757 cleanup *ignore_cleanups
1758 = make_cleanup (displaced_step_clear_cleanup, displaced);
1760 /* Resume execution at the copy. */
1761 regcache_write_pc (regcache, copy);
1763 discard_cleanups (ignore_cleanups);
1765 if (debug_displaced)
1766 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1767 paddress (gdbarch, copy));
1772 /* Wrapper for displaced_step_prepare_throw that disabled further
1773 attempts at displaced stepping if we get a memory error. */
1776 displaced_step_prepare (thread_info *thread)
1782 prepared = displaced_step_prepare_throw (thread);
1784 CATCH (ex, RETURN_MASK_ERROR)
1786 struct displaced_step_inferior_state *displaced_state;
1788 if (ex.error != MEMORY_ERROR
1789 && ex.error != NOT_SUPPORTED_ERROR)
1790 throw_exception (ex);
1794 fprintf_unfiltered (gdb_stdlog,
1795 "infrun: disabling displaced stepping: %s\n",
1799 /* Be verbose if "set displaced-stepping" is "on", silent if
1801 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1803 warning (_("disabling displaced stepping: %s"),
1807 /* Disable further displaced stepping attempts. */
1809 = get_displaced_stepping_state (thread->inf);
1810 displaced_state->failed_before = 1;
1818 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1819 const gdb_byte *myaddr, int len)
1821 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1823 inferior_ptid = ptid;
1824 write_memory (memaddr, myaddr, len);
1827 /* Restore the contents of the copy area for thread PTID. */
1830 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1833 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1835 write_memory_ptid (ptid, displaced->step_copy,
1836 displaced->step_saved_copy.data (), len);
1837 if (debug_displaced)
1838 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1839 target_pid_to_str (ptid),
1840 paddress (displaced->step_gdbarch,
1841 displaced->step_copy));
1844 /* If we displaced stepped an instruction successfully, adjust
1845 registers and memory to yield the same effect the instruction would
1846 have had if we had executed it at its original address, and return
1847 1. If the instruction didn't complete, relocate the PC and return
1848 -1. If the thread wasn't displaced stepping, return 0. */
1851 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1853 struct cleanup *old_cleanups;
1854 struct displaced_step_inferior_state *displaced
1855 = get_displaced_stepping_state (event_thread->inf);
1858 /* Was this event for the thread we displaced? */
1859 if (displaced->step_thread != event_thread)
1862 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1864 displaced_step_restore (displaced, displaced->step_thread->ptid);
1866 /* Fixup may need to read memory/registers. Switch to the thread
1867 that we're fixing up. Also, target_stopped_by_watchpoint checks
1868 the current thread. */
1869 switch_to_thread (event_thread);
1871 /* Did the instruction complete successfully? */
1872 if (signal == GDB_SIGNAL_TRAP
1873 && !(target_stopped_by_watchpoint ()
1874 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1875 || target_have_steppable_watchpoint)))
1877 /* Fix up the resulting state. */
1878 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1879 displaced->step_closure,
1880 displaced->step_original,
1881 displaced->step_copy,
1882 get_thread_regcache (displaced->step_thread));
1887 /* Since the instruction didn't complete, all we can do is
1889 struct regcache *regcache = get_thread_regcache (event_thread);
1890 CORE_ADDR pc = regcache_read_pc (regcache);
1892 pc = displaced->step_original + (pc - displaced->step_copy);
1893 regcache_write_pc (regcache, pc);
1897 do_cleanups (old_cleanups);
1899 displaced->step_thread = nullptr;
1904 /* Data to be passed around while handling an event. This data is
1905 discarded between events. */
1906 struct execution_control_state
1909 /* The thread that got the event, if this was a thread event; NULL
1911 struct thread_info *event_thread;
1913 struct target_waitstatus ws;
1914 int stop_func_filled_in;
1915 CORE_ADDR stop_func_start;
1916 CORE_ADDR stop_func_end;
1917 const char *stop_func_name;
1920 /* True if the event thread hit the single-step breakpoint of
1921 another thread. Thus the event doesn't cause a stop, the thread
1922 needs to be single-stepped past the single-step breakpoint before
1923 we can switch back to the original stepping thread. */
1924 int hit_singlestep_breakpoint;
1927 /* Clear ECS and set it to point at TP. */
1930 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
1932 memset (ecs, 0, sizeof (*ecs));
1933 ecs->event_thread = tp;
1934 ecs->ptid = tp->ptid;
1937 static void keep_going_pass_signal (struct execution_control_state *ecs);
1938 static void prepare_to_wait (struct execution_control_state *ecs);
1939 static int keep_going_stepped_thread (struct thread_info *tp);
1940 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
1942 /* Are there any pending step-over requests? If so, run all we can
1943 now and return true. Otherwise, return false. */
1946 start_step_over (void)
1948 struct thread_info *tp, *next;
1950 /* Don't start a new step-over if we already have an in-line
1951 step-over operation ongoing. */
1952 if (step_over_info_valid_p ())
1955 for (tp = step_over_queue_head; tp != NULL; tp = next)
1957 struct execution_control_state ecss;
1958 struct execution_control_state *ecs = &ecss;
1959 step_over_what step_what;
1960 int must_be_in_line;
1962 gdb_assert (!tp->stop_requested);
1964 next = thread_step_over_chain_next (tp);
1966 /* If this inferior already has a displaced step in process,
1967 don't start a new one. */
1968 if (displaced_step_in_progress (tp->inf))
1971 step_what = thread_still_needs_step_over (tp);
1972 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
1973 || ((step_what & STEP_OVER_BREAKPOINT)
1974 && !use_displaced_stepping (tp)));
1976 /* We currently stop all threads of all processes to step-over
1977 in-line. If we need to start a new in-line step-over, let
1978 any pending displaced steps finish first. */
1979 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
1982 thread_step_over_chain_remove (tp);
1984 if (step_over_queue_head == NULL)
1987 fprintf_unfiltered (gdb_stdlog,
1988 "infrun: step-over queue now empty\n");
1991 if (tp->control.trap_expected
1995 internal_error (__FILE__, __LINE__,
1996 "[%s] has inconsistent state: "
1997 "trap_expected=%d, resumed=%d, executing=%d\n",
1998 target_pid_to_str (tp->ptid),
1999 tp->control.trap_expected,
2005 fprintf_unfiltered (gdb_stdlog,
2006 "infrun: resuming [%s] for step-over\n",
2007 target_pid_to_str (tp->ptid));
2009 /* keep_going_pass_signal skips the step-over if the breakpoint
2010 is no longer inserted. In all-stop, we want to keep looking
2011 for a thread that needs a step-over instead of resuming TP,
2012 because we wouldn't be able to resume anything else until the
2013 target stops again. In non-stop, the resume always resumes
2014 only TP, so it's OK to let the thread resume freely. */
2015 if (!target_is_non_stop_p () && !step_what)
2018 switch_to_thread (tp);
2019 reset_ecs (ecs, tp);
2020 keep_going_pass_signal (ecs);
2022 if (!ecs->wait_some_more)
2023 error (_("Command aborted."));
2025 gdb_assert (tp->resumed);
2027 /* If we started a new in-line step-over, we're done. */
2028 if (step_over_info_valid_p ())
2030 gdb_assert (tp->control.trap_expected);
2034 if (!target_is_non_stop_p ())
2036 /* On all-stop, shouldn't have resumed unless we needed a
2038 gdb_assert (tp->control.trap_expected
2039 || tp->step_after_step_resume_breakpoint);
2041 /* With remote targets (at least), in all-stop, we can't
2042 issue any further remote commands until the program stops
2047 /* Either the thread no longer needed a step-over, or a new
2048 displaced stepping sequence started. Even in the latter
2049 case, continue looking. Maybe we can also start another
2050 displaced step on a thread of other process. */
2056 /* Update global variables holding ptids to hold NEW_PTID if they were
2057 holding OLD_PTID. */
2059 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2061 if (inferior_ptid == old_ptid)
2062 inferior_ptid = new_ptid;
2067 static const char schedlock_off[] = "off";
2068 static const char schedlock_on[] = "on";
2069 static const char schedlock_step[] = "step";
2070 static const char schedlock_replay[] = "replay";
2071 static const char *const scheduler_enums[] = {
2078 static const char *scheduler_mode = schedlock_replay;
2080 show_scheduler_mode (struct ui_file *file, int from_tty,
2081 struct cmd_list_element *c, const char *value)
2083 fprintf_filtered (file,
2084 _("Mode for locking scheduler "
2085 "during execution is \"%s\".\n"),
2090 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2092 if (!target_can_lock_scheduler)
2094 scheduler_mode = schedlock_off;
2095 error (_("Target '%s' cannot support this command."), target_shortname);
2099 /* True if execution commands resume all threads of all processes by
2100 default; otherwise, resume only threads of the current inferior
2102 int sched_multi = 0;
2104 /* Try to setup for software single stepping over the specified location.
2105 Return 1 if target_resume() should use hardware single step.
2107 GDBARCH the current gdbarch.
2108 PC the location to step over. */
2111 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2115 if (execution_direction == EXEC_FORWARD
2116 && gdbarch_software_single_step_p (gdbarch))
2117 hw_step = !insert_single_step_breakpoints (gdbarch);
2125 user_visible_resume_ptid (int step)
2131 /* With non-stop mode on, threads are always handled
2133 resume_ptid = inferior_ptid;
2135 else if ((scheduler_mode == schedlock_on)
2136 || (scheduler_mode == schedlock_step && step))
2138 /* User-settable 'scheduler' mode requires solo thread
2140 resume_ptid = inferior_ptid;
2142 else if ((scheduler_mode == schedlock_replay)
2143 && target_record_will_replay (minus_one_ptid, execution_direction))
2145 /* User-settable 'scheduler' mode requires solo thread resume in replay
2147 resume_ptid = inferior_ptid;
2149 else if (!sched_multi && target_supports_multi_process ())
2151 /* Resume all threads of the current process (and none of other
2153 resume_ptid = ptid_t (inferior_ptid.pid ());
2157 /* Resume all threads of all processes. */
2158 resume_ptid = RESUME_ALL;
2164 /* Return a ptid representing the set of threads that we will resume,
2165 in the perspective of the target, assuming run control handling
2166 does not require leaving some threads stopped (e.g., stepping past
2167 breakpoint). USER_STEP indicates whether we're about to start the
2168 target for a stepping command. */
2171 internal_resume_ptid (int user_step)
2173 /* In non-stop, we always control threads individually. Note that
2174 the target may always work in non-stop mode even with "set
2175 non-stop off", in which case user_visible_resume_ptid could
2176 return a wildcard ptid. */
2177 if (target_is_non_stop_p ())
2178 return inferior_ptid;
2180 return user_visible_resume_ptid (user_step);
2183 /* Wrapper for target_resume, that handles infrun-specific
2187 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2189 struct thread_info *tp = inferior_thread ();
2191 gdb_assert (!tp->stop_requested);
2193 /* Install inferior's terminal modes. */
2194 target_terminal::inferior ();
2196 /* Avoid confusing the next resume, if the next stop/resume
2197 happens to apply to another thread. */
2198 tp->suspend.stop_signal = GDB_SIGNAL_0;
2200 /* Advise target which signals may be handled silently.
2202 If we have removed breakpoints because we are stepping over one
2203 in-line (in any thread), we need to receive all signals to avoid
2204 accidentally skipping a breakpoint during execution of a signal
2207 Likewise if we're displaced stepping, otherwise a trap for a
2208 breakpoint in a signal handler might be confused with the
2209 displaced step finishing. We don't make the displaced_step_fixup
2210 step distinguish the cases instead, because:
2212 - a backtrace while stopped in the signal handler would show the
2213 scratch pad as frame older than the signal handler, instead of
2214 the real mainline code.
2216 - when the thread is later resumed, the signal handler would
2217 return to the scratch pad area, which would no longer be
2219 if (step_over_info_valid_p ()
2220 || displaced_step_in_progress (tp->inf))
2221 target_pass_signals ({});
2223 target_pass_signals (signal_pass);
2225 target_resume (resume_ptid, step, sig);
2227 target_commit_resume ();
2230 /* Resume the inferior. SIG is the signal to give the inferior
2231 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2232 call 'resume', which handles exceptions. */
2235 resume_1 (enum gdb_signal sig)
2237 struct regcache *regcache = get_current_regcache ();
2238 struct gdbarch *gdbarch = regcache->arch ();
2239 struct thread_info *tp = inferior_thread ();
2240 CORE_ADDR pc = regcache_read_pc (regcache);
2241 const address_space *aspace = regcache->aspace ();
2243 /* This represents the user's step vs continue request. When
2244 deciding whether "set scheduler-locking step" applies, it's the
2245 user's intention that counts. */
2246 const int user_step = tp->control.stepping_command;
2247 /* This represents what we'll actually request the target to do.
2248 This can decay from a step to a continue, if e.g., we need to
2249 implement single-stepping with breakpoints (software
2253 gdb_assert (!tp->stop_requested);
2254 gdb_assert (!thread_is_in_step_over_chain (tp));
2256 if (tp->suspend.waitstatus_pending_p)
2261 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2263 fprintf_unfiltered (gdb_stdlog,
2264 "infrun: resume: thread %s has pending wait "
2265 "status %s (currently_stepping=%d).\n",
2266 target_pid_to_str (tp->ptid), statstr.c_str (),
2267 currently_stepping (tp));
2272 /* FIXME: What should we do if we are supposed to resume this
2273 thread with a signal? Maybe we should maintain a queue of
2274 pending signals to deliver. */
2275 if (sig != GDB_SIGNAL_0)
2277 warning (_("Couldn't deliver signal %s to %s."),
2278 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2281 tp->suspend.stop_signal = GDB_SIGNAL_0;
2283 if (target_can_async_p ())
2286 /* Tell the event loop we have an event to process. */
2287 mark_async_event_handler (infrun_async_inferior_event_token);
2292 tp->stepped_breakpoint = 0;
2294 /* Depends on stepped_breakpoint. */
2295 step = currently_stepping (tp);
2297 if (current_inferior ()->waiting_for_vfork_done)
2299 /* Don't try to single-step a vfork parent that is waiting for
2300 the child to get out of the shared memory region (by exec'ing
2301 or exiting). This is particularly important on software
2302 single-step archs, as the child process would trip on the
2303 software single step breakpoint inserted for the parent
2304 process. Since the parent will not actually execute any
2305 instruction until the child is out of the shared region (such
2306 are vfork's semantics), it is safe to simply continue it.
2307 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2308 the parent, and tell it to `keep_going', which automatically
2309 re-sets it stepping. */
2311 fprintf_unfiltered (gdb_stdlog,
2312 "infrun: resume : clear step\n");
2317 fprintf_unfiltered (gdb_stdlog,
2318 "infrun: resume (step=%d, signal=%s), "
2319 "trap_expected=%d, current thread [%s] at %s\n",
2320 step, gdb_signal_to_symbol_string (sig),
2321 tp->control.trap_expected,
2322 target_pid_to_str (inferior_ptid),
2323 paddress (gdbarch, pc));
2325 /* Normally, by the time we reach `resume', the breakpoints are either
2326 removed or inserted, as appropriate. The exception is if we're sitting
2327 at a permanent breakpoint; we need to step over it, but permanent
2328 breakpoints can't be removed. So we have to test for it here. */
2329 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2331 if (sig != GDB_SIGNAL_0)
2333 /* We have a signal to pass to the inferior. The resume
2334 may, or may not take us to the signal handler. If this
2335 is a step, we'll need to stop in the signal handler, if
2336 there's one, (if the target supports stepping into
2337 handlers), or in the next mainline instruction, if
2338 there's no handler. If this is a continue, we need to be
2339 sure to run the handler with all breakpoints inserted.
2340 In all cases, set a breakpoint at the current address
2341 (where the handler returns to), and once that breakpoint
2342 is hit, resume skipping the permanent breakpoint. If
2343 that breakpoint isn't hit, then we've stepped into the
2344 signal handler (or hit some other event). We'll delete
2345 the step-resume breakpoint then. */
2348 fprintf_unfiltered (gdb_stdlog,
2349 "infrun: resume: skipping permanent breakpoint, "
2350 "deliver signal first\n");
2352 clear_step_over_info ();
2353 tp->control.trap_expected = 0;
2355 if (tp->control.step_resume_breakpoint == NULL)
2357 /* Set a "high-priority" step-resume, as we don't want
2358 user breakpoints at PC to trigger (again) when this
2360 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2361 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2363 tp->step_after_step_resume_breakpoint = step;
2366 insert_breakpoints ();
2370 /* There's no signal to pass, we can go ahead and skip the
2371 permanent breakpoint manually. */
2373 fprintf_unfiltered (gdb_stdlog,
2374 "infrun: resume: skipping permanent breakpoint\n");
2375 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2376 /* Update pc to reflect the new address from which we will
2377 execute instructions. */
2378 pc = regcache_read_pc (regcache);
2382 /* We've already advanced the PC, so the stepping part
2383 is done. Now we need to arrange for a trap to be
2384 reported to handle_inferior_event. Set a breakpoint
2385 at the current PC, and run to it. Don't update
2386 prev_pc, because if we end in
2387 switch_back_to_stepped_thread, we want the "expected
2388 thread advanced also" branch to be taken. IOW, we
2389 don't want this thread to step further from PC
2391 gdb_assert (!step_over_info_valid_p ());
2392 insert_single_step_breakpoint (gdbarch, aspace, pc);
2393 insert_breakpoints ();
2395 resume_ptid = internal_resume_ptid (user_step);
2396 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2403 /* If we have a breakpoint to step over, make sure to do a single
2404 step only. Same if we have software watchpoints. */
2405 if (tp->control.trap_expected || bpstat_should_step ())
2406 tp->control.may_range_step = 0;
2408 /* If enabled, step over breakpoints by executing a copy of the
2409 instruction at a different address.
2411 We can't use displaced stepping when we have a signal to deliver;
2412 the comments for displaced_step_prepare explain why. The
2413 comments in the handle_inferior event for dealing with 'random
2414 signals' explain what we do instead.
2416 We can't use displaced stepping when we are waiting for vfork_done
2417 event, displaced stepping breaks the vfork child similarly as single
2418 step software breakpoint. */
2419 if (tp->control.trap_expected
2420 && use_displaced_stepping (tp)
2421 && !step_over_info_valid_p ()
2422 && sig == GDB_SIGNAL_0
2423 && !current_inferior ()->waiting_for_vfork_done)
2425 int prepared = displaced_step_prepare (tp);
2430 fprintf_unfiltered (gdb_stdlog,
2431 "Got placed in step-over queue\n");
2433 tp->control.trap_expected = 0;
2436 else if (prepared < 0)
2438 /* Fallback to stepping over the breakpoint in-line. */
2440 if (target_is_non_stop_p ())
2441 stop_all_threads ();
2443 set_step_over_info (regcache->aspace (),
2444 regcache_read_pc (regcache), 0, tp->global_num);
2446 step = maybe_software_singlestep (gdbarch, pc);
2448 insert_breakpoints ();
2450 else if (prepared > 0)
2452 struct displaced_step_inferior_state *displaced;
2454 /* Update pc to reflect the new address from which we will
2455 execute instructions due to displaced stepping. */
2456 pc = regcache_read_pc (get_thread_regcache (tp));
2458 displaced = get_displaced_stepping_state (tp->inf);
2459 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2460 displaced->step_closure);
2464 /* Do we need to do it the hard way, w/temp breakpoints? */
2466 step = maybe_software_singlestep (gdbarch, pc);
2468 /* Currently, our software single-step implementation leads to different
2469 results than hardware single-stepping in one situation: when stepping
2470 into delivering a signal which has an associated signal handler,
2471 hardware single-step will stop at the first instruction of the handler,
2472 while software single-step will simply skip execution of the handler.
2474 For now, this difference in behavior is accepted since there is no
2475 easy way to actually implement single-stepping into a signal handler
2476 without kernel support.
2478 However, there is one scenario where this difference leads to follow-on
2479 problems: if we're stepping off a breakpoint by removing all breakpoints
2480 and then single-stepping. In this case, the software single-step
2481 behavior means that even if there is a *breakpoint* in the signal
2482 handler, GDB still would not stop.
2484 Fortunately, we can at least fix this particular issue. We detect
2485 here the case where we are about to deliver a signal while software
2486 single-stepping with breakpoints removed. In this situation, we
2487 revert the decisions to remove all breakpoints and insert single-
2488 step breakpoints, and instead we install a step-resume breakpoint
2489 at the current address, deliver the signal without stepping, and
2490 once we arrive back at the step-resume breakpoint, actually step
2491 over the breakpoint we originally wanted to step over. */
2492 if (thread_has_single_step_breakpoints_set (tp)
2493 && sig != GDB_SIGNAL_0
2494 && step_over_info_valid_p ())
2496 /* If we have nested signals or a pending signal is delivered
2497 immediately after a handler returns, might might already have
2498 a step-resume breakpoint set on the earlier handler. We cannot
2499 set another step-resume breakpoint; just continue on until the
2500 original breakpoint is hit. */
2501 if (tp->control.step_resume_breakpoint == NULL)
2503 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2504 tp->step_after_step_resume_breakpoint = 1;
2507 delete_single_step_breakpoints (tp);
2509 clear_step_over_info ();
2510 tp->control.trap_expected = 0;
2512 insert_breakpoints ();
2515 /* If STEP is set, it's a request to use hardware stepping
2516 facilities. But in that case, we should never
2517 use singlestep breakpoint. */
2518 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2520 /* Decide the set of threads to ask the target to resume. */
2521 if (tp->control.trap_expected)
2523 /* We're allowing a thread to run past a breakpoint it has
2524 hit, either by single-stepping the thread with the breakpoint
2525 removed, or by displaced stepping, with the breakpoint inserted.
2526 In the former case, we need to single-step only this thread,
2527 and keep others stopped, as they can miss this breakpoint if
2528 allowed to run. That's not really a problem for displaced
2529 stepping, but, we still keep other threads stopped, in case
2530 another thread is also stopped for a breakpoint waiting for
2531 its turn in the displaced stepping queue. */
2532 resume_ptid = inferior_ptid;
2535 resume_ptid = internal_resume_ptid (user_step);
2537 if (execution_direction != EXEC_REVERSE
2538 && step && breakpoint_inserted_here_p (aspace, pc))
2540 /* There are two cases where we currently need to step a
2541 breakpoint instruction when we have a signal to deliver:
2543 - See handle_signal_stop where we handle random signals that
2544 could take out us out of the stepping range. Normally, in
2545 that case we end up continuing (instead of stepping) over the
2546 signal handler with a breakpoint at PC, but there are cases
2547 where we should _always_ single-step, even if we have a
2548 step-resume breakpoint, like when a software watchpoint is
2549 set. Assuming single-stepping and delivering a signal at the
2550 same time would takes us to the signal handler, then we could
2551 have removed the breakpoint at PC to step over it. However,
2552 some hardware step targets (like e.g., Mac OS) can't step
2553 into signal handlers, and for those, we need to leave the
2554 breakpoint at PC inserted, as otherwise if the handler
2555 recurses and executes PC again, it'll miss the breakpoint.
2556 So we leave the breakpoint inserted anyway, but we need to
2557 record that we tried to step a breakpoint instruction, so
2558 that adjust_pc_after_break doesn't end up confused.
2560 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2561 in one thread after another thread that was stepping had been
2562 momentarily paused for a step-over. When we re-resume the
2563 stepping thread, it may be resumed from that address with a
2564 breakpoint that hasn't trapped yet. Seen with
2565 gdb.threads/non-stop-fair-events.exp, on targets that don't
2566 do displaced stepping. */
2569 fprintf_unfiltered (gdb_stdlog,
2570 "infrun: resume: [%s] stepped breakpoint\n",
2571 target_pid_to_str (tp->ptid));
2573 tp->stepped_breakpoint = 1;
2575 /* Most targets can step a breakpoint instruction, thus
2576 executing it normally. But if this one cannot, just
2577 continue and we will hit it anyway. */
2578 if (gdbarch_cannot_step_breakpoint (gdbarch))
2583 && tp->control.trap_expected
2584 && use_displaced_stepping (tp)
2585 && !step_over_info_valid_p ())
2587 struct regcache *resume_regcache = get_thread_regcache (tp);
2588 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2589 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2592 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2593 paddress (resume_gdbarch, actual_pc));
2594 read_memory (actual_pc, buf, sizeof (buf));
2595 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2598 if (tp->control.may_range_step)
2600 /* If we're resuming a thread with the PC out of the step
2601 range, then we're doing some nested/finer run control
2602 operation, like stepping the thread out of the dynamic
2603 linker or the displaced stepping scratch pad. We
2604 shouldn't have allowed a range step then. */
2605 gdb_assert (pc_in_thread_step_range (pc, tp));
2608 do_target_resume (resume_ptid, step, sig);
2612 /* Resume the inferior. SIG is the signal to give the inferior
2613 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2614 rolls back state on error. */
2617 resume (gdb_signal sig)
2623 CATCH (ex, RETURN_MASK_ALL)
2625 /* If resuming is being aborted for any reason, delete any
2626 single-step breakpoint resume_1 may have created, to avoid
2627 confusing the following resumption, and to avoid leaving
2628 single-step breakpoints perturbing other threads, in case
2629 we're running in non-stop mode. */
2630 if (inferior_ptid != null_ptid)
2631 delete_single_step_breakpoints (inferior_thread ());
2632 throw_exception (ex);
2642 /* Counter that tracks number of user visible stops. This can be used
2643 to tell whether a command has proceeded the inferior past the
2644 current location. This allows e.g., inferior function calls in
2645 breakpoint commands to not interrupt the command list. When the
2646 call finishes successfully, the inferior is standing at the same
2647 breakpoint as if nothing happened (and so we don't call
2649 static ULONGEST current_stop_id;
2656 return current_stop_id;
2659 /* Called when we report a user visible stop. */
2667 /* Clear out all variables saying what to do when inferior is continued.
2668 First do this, then set the ones you want, then call `proceed'. */
2671 clear_proceed_status_thread (struct thread_info *tp)
2674 fprintf_unfiltered (gdb_stdlog,
2675 "infrun: clear_proceed_status_thread (%s)\n",
2676 target_pid_to_str (tp->ptid));
2678 /* If we're starting a new sequence, then the previous finished
2679 single-step is no longer relevant. */
2680 if (tp->suspend.waitstatus_pending_p)
2682 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2685 fprintf_unfiltered (gdb_stdlog,
2686 "infrun: clear_proceed_status: pending "
2687 "event of %s was a finished step. "
2689 target_pid_to_str (tp->ptid));
2691 tp->suspend.waitstatus_pending_p = 0;
2692 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2694 else if (debug_infrun)
2697 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2699 fprintf_unfiltered (gdb_stdlog,
2700 "infrun: clear_proceed_status_thread: thread %s "
2701 "has pending wait status %s "
2702 "(currently_stepping=%d).\n",
2703 target_pid_to_str (tp->ptid), statstr.c_str (),
2704 currently_stepping (tp));
2708 /* If this signal should not be seen by program, give it zero.
2709 Used for debugging signals. */
2710 if (!signal_pass_state (tp->suspend.stop_signal))
2711 tp->suspend.stop_signal = GDB_SIGNAL_0;
2713 delete tp->thread_fsm;
2714 tp->thread_fsm = NULL;
2716 tp->control.trap_expected = 0;
2717 tp->control.step_range_start = 0;
2718 tp->control.step_range_end = 0;
2719 tp->control.may_range_step = 0;
2720 tp->control.step_frame_id = null_frame_id;
2721 tp->control.step_stack_frame_id = null_frame_id;
2722 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2723 tp->control.step_start_function = NULL;
2724 tp->stop_requested = 0;
2726 tp->control.stop_step = 0;
2728 tp->control.proceed_to_finish = 0;
2730 tp->control.stepping_command = 0;
2732 /* Discard any remaining commands or status from previous stop. */
2733 bpstat_clear (&tp->control.stop_bpstat);
2737 clear_proceed_status (int step)
2739 /* With scheduler-locking replay, stop replaying other threads if we're
2740 not replaying the user-visible resume ptid.
2742 This is a convenience feature to not require the user to explicitly
2743 stop replaying the other threads. We're assuming that the user's
2744 intent is to resume tracing the recorded process. */
2745 if (!non_stop && scheduler_mode == schedlock_replay
2746 && target_record_is_replaying (minus_one_ptid)
2747 && !target_record_will_replay (user_visible_resume_ptid (step),
2748 execution_direction))
2749 target_record_stop_replaying ();
2751 if (!non_stop && inferior_ptid != null_ptid)
2753 ptid_t resume_ptid = user_visible_resume_ptid (step);
2755 /* In all-stop mode, delete the per-thread status of all threads
2756 we're about to resume, implicitly and explicitly. */
2757 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2758 clear_proceed_status_thread (tp);
2761 if (inferior_ptid != null_ptid)
2763 struct inferior *inferior;
2767 /* If in non-stop mode, only delete the per-thread status of
2768 the current thread. */
2769 clear_proceed_status_thread (inferior_thread ());
2772 inferior = current_inferior ();
2773 inferior->control.stop_soon = NO_STOP_QUIETLY;
2776 gdb::observers::about_to_proceed.notify ();
2779 /* Returns true if TP is still stopped at a breakpoint that needs
2780 stepping-over in order to make progress. If the breakpoint is gone
2781 meanwhile, we can skip the whole step-over dance. */
2784 thread_still_needs_step_over_bp (struct thread_info *tp)
2786 if (tp->stepping_over_breakpoint)
2788 struct regcache *regcache = get_thread_regcache (tp);
2790 if (breakpoint_here_p (regcache->aspace (),
2791 regcache_read_pc (regcache))
2792 == ordinary_breakpoint_here)
2795 tp->stepping_over_breakpoint = 0;
2801 /* Check whether thread TP still needs to start a step-over in order
2802 to make progress when resumed. Returns an bitwise or of enum
2803 step_over_what bits, indicating what needs to be stepped over. */
2805 static step_over_what
2806 thread_still_needs_step_over (struct thread_info *tp)
2808 step_over_what what = 0;
2810 if (thread_still_needs_step_over_bp (tp))
2811 what |= STEP_OVER_BREAKPOINT;
2813 if (tp->stepping_over_watchpoint
2814 && !target_have_steppable_watchpoint)
2815 what |= STEP_OVER_WATCHPOINT;
2820 /* Returns true if scheduler locking applies. STEP indicates whether
2821 we're about to do a step/next-like command to a thread. */
2824 schedlock_applies (struct thread_info *tp)
2826 return (scheduler_mode == schedlock_on
2827 || (scheduler_mode == schedlock_step
2828 && tp->control.stepping_command)
2829 || (scheduler_mode == schedlock_replay
2830 && target_record_will_replay (minus_one_ptid,
2831 execution_direction)));
2834 /* Basic routine for continuing the program in various fashions.
2836 ADDR is the address to resume at, or -1 for resume where stopped.
2837 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2838 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2840 You should call clear_proceed_status before calling proceed. */
2843 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2845 struct regcache *regcache;
2846 struct gdbarch *gdbarch;
2849 struct execution_control_state ecss;
2850 struct execution_control_state *ecs = &ecss;
2853 /* If we're stopped at a fork/vfork, follow the branch set by the
2854 "set follow-fork-mode" command; otherwise, we'll just proceed
2855 resuming the current thread. */
2856 if (!follow_fork ())
2858 /* The target for some reason decided not to resume. */
2860 if (target_can_async_p ())
2861 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2865 /* We'll update this if & when we switch to a new thread. */
2866 previous_inferior_ptid = inferior_ptid;
2868 regcache = get_current_regcache ();
2869 gdbarch = regcache->arch ();
2870 const address_space *aspace = regcache->aspace ();
2872 pc = regcache_read_pc (regcache);
2873 thread_info *cur_thr = inferior_thread ();
2875 /* Fill in with reasonable starting values. */
2876 init_thread_stepping_state (cur_thr);
2878 gdb_assert (!thread_is_in_step_over_chain (cur_thr));
2880 if (addr == (CORE_ADDR) -1)
2882 if (pc == cur_thr->suspend.stop_pc
2883 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2884 && execution_direction != EXEC_REVERSE)
2885 /* There is a breakpoint at the address we will resume at,
2886 step one instruction before inserting breakpoints so that
2887 we do not stop right away (and report a second hit at this
2890 Note, we don't do this in reverse, because we won't
2891 actually be executing the breakpoint insn anyway.
2892 We'll be (un-)executing the previous instruction. */
2893 cur_thr->stepping_over_breakpoint = 1;
2894 else if (gdbarch_single_step_through_delay_p (gdbarch)
2895 && gdbarch_single_step_through_delay (gdbarch,
2896 get_current_frame ()))
2897 /* We stepped onto an instruction that needs to be stepped
2898 again before re-inserting the breakpoint, do so. */
2899 cur_thr->stepping_over_breakpoint = 1;
2903 regcache_write_pc (regcache, addr);
2906 if (siggnal != GDB_SIGNAL_DEFAULT)
2907 cur_thr->suspend.stop_signal = siggnal;
2909 resume_ptid = user_visible_resume_ptid (cur_thr->control.stepping_command);
2911 /* If an exception is thrown from this point on, make sure to
2912 propagate GDB's knowledge of the executing state to the
2913 frontend/user running state. */
2914 scoped_finish_thread_state finish_state (resume_ptid);
2916 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2917 threads (e.g., we might need to set threads stepping over
2918 breakpoints first), from the user/frontend's point of view, all
2919 threads in RESUME_PTID are now running. Unless we're calling an
2920 inferior function, as in that case we pretend the inferior
2921 doesn't run at all. */
2922 if (!cur_thr->control.in_infcall)
2923 set_running (resume_ptid, 1);
2926 fprintf_unfiltered (gdb_stdlog,
2927 "infrun: proceed (addr=%s, signal=%s)\n",
2928 paddress (gdbarch, addr),
2929 gdb_signal_to_symbol_string (siggnal));
2931 annotate_starting ();
2933 /* Make sure that output from GDB appears before output from the
2935 gdb_flush (gdb_stdout);
2937 /* Since we've marked the inferior running, give it the terminal. A
2938 QUIT/Ctrl-C from here on is forwarded to the target (which can
2939 still detect attempts to unblock a stuck connection with repeated
2940 Ctrl-C from within target_pass_ctrlc). */
2941 target_terminal::inferior ();
2943 /* In a multi-threaded task we may select another thread and
2944 then continue or step.
2946 But if a thread that we're resuming had stopped at a breakpoint,
2947 it will immediately cause another breakpoint stop without any
2948 execution (i.e. it will report a breakpoint hit incorrectly). So
2949 we must step over it first.
2951 Look for threads other than the current (TP) that reported a
2952 breakpoint hit and haven't been resumed yet since. */
2954 /* If scheduler locking applies, we can avoid iterating over all
2956 if (!non_stop && !schedlock_applies (cur_thr))
2958 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2960 /* Ignore the current thread here. It's handled
2965 if (!thread_still_needs_step_over (tp))
2968 gdb_assert (!thread_is_in_step_over_chain (tp));
2971 fprintf_unfiltered (gdb_stdlog,
2972 "infrun: need to step-over [%s] first\n",
2973 target_pid_to_str (tp->ptid));
2975 thread_step_over_chain_enqueue (tp);
2979 /* Enqueue the current thread last, so that we move all other
2980 threads over their breakpoints first. */
2981 if (cur_thr->stepping_over_breakpoint)
2982 thread_step_over_chain_enqueue (cur_thr);
2984 /* If the thread isn't started, we'll still need to set its prev_pc,
2985 so that switch_back_to_stepped_thread knows the thread hasn't
2986 advanced. Must do this before resuming any thread, as in
2987 all-stop/remote, once we resume we can't send any other packet
2988 until the target stops again. */
2989 cur_thr->prev_pc = regcache_read_pc (regcache);
2992 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
2994 started = start_step_over ();
2996 if (step_over_info_valid_p ())
2998 /* Either this thread started a new in-line step over, or some
2999 other thread was already doing one. In either case, don't
3000 resume anything else until the step-over is finished. */
3002 else if (started && !target_is_non_stop_p ())
3004 /* A new displaced stepping sequence was started. In all-stop,
3005 we can't talk to the target anymore until it next stops. */
3007 else if (!non_stop && target_is_non_stop_p ())
3009 /* In all-stop, but the target is always in non-stop mode.
3010 Start all other threads that are implicitly resumed too. */
3011 for (thread_info *tp : all_non_exited_threads (resume_ptid))
3016 fprintf_unfiltered (gdb_stdlog,
3017 "infrun: proceed: [%s] resumed\n",
3018 target_pid_to_str (tp->ptid));
3019 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3023 if (thread_is_in_step_over_chain (tp))
3026 fprintf_unfiltered (gdb_stdlog,
3027 "infrun: proceed: [%s] needs step-over\n",
3028 target_pid_to_str (tp->ptid));
3033 fprintf_unfiltered (gdb_stdlog,
3034 "infrun: proceed: resuming %s\n",
3035 target_pid_to_str (tp->ptid));
3037 reset_ecs (ecs, tp);
3038 switch_to_thread (tp);
3039 keep_going_pass_signal (ecs);
3040 if (!ecs->wait_some_more)
3041 error (_("Command aborted."));
3044 else if (!cur_thr->resumed && !thread_is_in_step_over_chain (cur_thr))
3046 /* The thread wasn't started, and isn't queued, run it now. */
3047 reset_ecs (ecs, cur_thr);
3048 switch_to_thread (cur_thr);
3049 keep_going_pass_signal (ecs);
3050 if (!ecs->wait_some_more)
3051 error (_("Command aborted."));
3055 target_commit_resume ();
3057 finish_state.release ();
3059 /* Tell the event loop to wait for it to stop. If the target
3060 supports asynchronous execution, it'll do this from within
3062 if (!target_can_async_p ())
3063 mark_async_event_handler (infrun_async_inferior_event_token);
3067 /* Start remote-debugging of a machine over a serial link. */
3070 start_remote (int from_tty)
3072 struct inferior *inferior;
3074 inferior = current_inferior ();
3075 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3077 /* Always go on waiting for the target, regardless of the mode. */
3078 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3079 indicate to wait_for_inferior that a target should timeout if
3080 nothing is returned (instead of just blocking). Because of this,
3081 targets expecting an immediate response need to, internally, set
3082 things up so that the target_wait() is forced to eventually
3084 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3085 differentiate to its caller what the state of the target is after
3086 the initial open has been performed. Here we're assuming that
3087 the target has stopped. It should be possible to eventually have
3088 target_open() return to the caller an indication that the target
3089 is currently running and GDB state should be set to the same as
3090 for an async run. */
3091 wait_for_inferior ();
3093 /* Now that the inferior has stopped, do any bookkeeping like
3094 loading shared libraries. We want to do this before normal_stop,
3095 so that the displayed frame is up to date. */
3096 post_create_inferior (current_top_target (), from_tty);
3101 /* Initialize static vars when a new inferior begins. */
3104 init_wait_for_inferior (void)
3106 /* These are meaningless until the first time through wait_for_inferior. */
3108 breakpoint_init_inferior (inf_starting);
3110 clear_proceed_status (0);
3112 target_last_wait_ptid = minus_one_ptid;
3114 previous_inferior_ptid = inferior_ptid;
3119 static void handle_inferior_event (struct execution_control_state *ecs);
3121 static void handle_step_into_function (struct gdbarch *gdbarch,
3122 struct execution_control_state *ecs);
3123 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3124 struct execution_control_state *ecs);
3125 static void handle_signal_stop (struct execution_control_state *ecs);
3126 static void check_exception_resume (struct execution_control_state *,
3127 struct frame_info *);
3129 static void end_stepping_range (struct execution_control_state *ecs);
3130 static void stop_waiting (struct execution_control_state *ecs);
3131 static void keep_going (struct execution_control_state *ecs);
3132 static void process_event_stop_test (struct execution_control_state *ecs);
3133 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3135 /* This function is attached as a "thread_stop_requested" observer.
3136 Cleanup local state that assumed the PTID was to be resumed, and
3137 report the stop to the frontend. */
3140 infrun_thread_stop_requested (ptid_t ptid)
3142 /* PTID was requested to stop. If the thread was already stopped,
3143 but the user/frontend doesn't know about that yet (e.g., the
3144 thread had been temporarily paused for some step-over), set up
3145 for reporting the stop now. */
3146 for (thread_info *tp : all_threads (ptid))
3148 if (tp->state != THREAD_RUNNING)
3153 /* Remove matching threads from the step-over queue, so
3154 start_step_over doesn't try to resume them
3156 if (thread_is_in_step_over_chain (tp))
3157 thread_step_over_chain_remove (tp);
3159 /* If the thread is stopped, but the user/frontend doesn't
3160 know about that yet, queue a pending event, as if the
3161 thread had just stopped now. Unless the thread already had
3163 if (!tp->suspend.waitstatus_pending_p)
3165 tp->suspend.waitstatus_pending_p = 1;
3166 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3167 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3170 /* Clear the inline-frame state, since we're re-processing the
3172 clear_inline_frame_state (tp->ptid);
3174 /* If this thread was paused because some other thread was
3175 doing an inline-step over, let that finish first. Once
3176 that happens, we'll restart all threads and consume pending
3177 stop events then. */
3178 if (step_over_info_valid_p ())
3181 /* Otherwise we can process the (new) pending event now. Set
3182 it so this pending event is considered by
3189 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3191 if (target_last_wait_ptid == tp->ptid)
3192 nullify_last_target_wait_ptid ();
3195 /* Delete the step resume, single-step and longjmp/exception resume
3196 breakpoints of TP. */
3199 delete_thread_infrun_breakpoints (struct thread_info *tp)
3201 delete_step_resume_breakpoint (tp);
3202 delete_exception_resume_breakpoint (tp);
3203 delete_single_step_breakpoints (tp);
3206 /* If the target still has execution, call FUNC for each thread that
3207 just stopped. In all-stop, that's all the non-exited threads; in
3208 non-stop, that's the current thread, only. */
3210 typedef void (*for_each_just_stopped_thread_callback_func)
3211 (struct thread_info *tp);
3214 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3216 if (!target_has_execution || inferior_ptid == null_ptid)
3219 if (target_is_non_stop_p ())
3221 /* If in non-stop mode, only the current thread stopped. */
3222 func (inferior_thread ());
3226 /* In all-stop mode, all threads have stopped. */
3227 for (thread_info *tp : all_non_exited_threads ())
3232 /* Delete the step resume and longjmp/exception resume breakpoints of
3233 the threads that just stopped. */
3236 delete_just_stopped_threads_infrun_breakpoints (void)
3238 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3241 /* Delete the single-step breakpoints of the threads that just
3245 delete_just_stopped_threads_single_step_breakpoints (void)
3247 for_each_just_stopped_thread (delete_single_step_breakpoints);
3253 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3254 const struct target_waitstatus *ws)
3256 std::string status_string = target_waitstatus_to_string (ws);
3259 /* The text is split over several lines because it was getting too long.
3260 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3261 output as a unit; we want only one timestamp printed if debug_timestamp
3264 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3267 waiton_ptid.tid ());
3268 if (waiton_ptid.pid () != -1)
3269 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3270 stb.printf (", status) =\n");
3271 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3275 target_pid_to_str (result_ptid));
3276 stb.printf ("infrun: %s\n", status_string.c_str ());
3278 /* This uses %s in part to handle %'s in the text, but also to avoid
3279 a gcc error: the format attribute requires a string literal. */
3280 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3283 /* Select a thread at random, out of those which are resumed and have
3286 static struct thread_info *
3287 random_pending_event_thread (ptid_t waiton_ptid)
3291 auto has_event = [] (thread_info *tp)
3294 && tp->suspend.waitstatus_pending_p);
3297 /* First see how many events we have. Count only resumed threads
3298 that have an event pending. */
3299 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3303 if (num_events == 0)
3306 /* Now randomly pick a thread out of those that have had events. */
3307 int random_selector = (int) ((num_events * (double) rand ())
3308 / (RAND_MAX + 1.0));
3310 if (debug_infrun && num_events > 1)
3311 fprintf_unfiltered (gdb_stdlog,
3312 "infrun: Found %d events, selecting #%d\n",
3313 num_events, random_selector);
3315 /* Select the Nth thread that has had an event. */
3316 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3318 if (random_selector-- == 0)
3321 gdb_assert_not_reached ("event thread not found");
3324 /* Wrapper for target_wait that first checks whether threads have
3325 pending statuses to report before actually asking the target for
3329 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3332 struct thread_info *tp;
3334 /* First check if there is a resumed thread with a wait status
3336 if (ptid == minus_one_ptid || ptid.is_pid ())
3338 tp = random_pending_event_thread (ptid);
3343 fprintf_unfiltered (gdb_stdlog,
3344 "infrun: Waiting for specific thread %s.\n",
3345 target_pid_to_str (ptid));
3347 /* We have a specific thread to check. */
3348 tp = find_thread_ptid (ptid);
3349 gdb_assert (tp != NULL);
3350 if (!tp->suspend.waitstatus_pending_p)
3355 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3356 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3358 struct regcache *regcache = get_thread_regcache (tp);
3359 struct gdbarch *gdbarch = regcache->arch ();
3363 pc = regcache_read_pc (regcache);
3365 if (pc != tp->suspend.stop_pc)
3368 fprintf_unfiltered (gdb_stdlog,
3369 "infrun: PC of %s changed. was=%s, now=%s\n",
3370 target_pid_to_str (tp->ptid),
3371 paddress (gdbarch, tp->suspend.stop_pc),
3372 paddress (gdbarch, pc));
3375 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3378 fprintf_unfiltered (gdb_stdlog,
3379 "infrun: previous breakpoint of %s, at %s gone\n",
3380 target_pid_to_str (tp->ptid),
3381 paddress (gdbarch, pc));
3389 fprintf_unfiltered (gdb_stdlog,
3390 "infrun: pending event of %s cancelled.\n",
3391 target_pid_to_str (tp->ptid));
3393 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3394 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3403 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3405 fprintf_unfiltered (gdb_stdlog,
3406 "infrun: Using pending wait status %s for %s.\n",
3408 target_pid_to_str (tp->ptid));
3411 /* Now that we've selected our final event LWP, un-adjust its PC
3412 if it was a software breakpoint (and the target doesn't
3413 always adjust the PC itself). */
3414 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3415 && !target_supports_stopped_by_sw_breakpoint ())
3417 struct regcache *regcache;
3418 struct gdbarch *gdbarch;
3421 regcache = get_thread_regcache (tp);
3422 gdbarch = regcache->arch ();
3424 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3429 pc = regcache_read_pc (regcache);
3430 regcache_write_pc (regcache, pc + decr_pc);
3434 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3435 *status = tp->suspend.waitstatus;
3436 tp->suspend.waitstatus_pending_p = 0;
3438 /* Wake up the event loop again, until all pending events are
3440 if (target_is_async_p ())
3441 mark_async_event_handler (infrun_async_inferior_event_token);
3445 /* But if we don't find one, we'll have to wait. */
3447 if (deprecated_target_wait_hook)
3448 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3450 event_ptid = target_wait (ptid, status, options);
3455 /* Prepare and stabilize the inferior for detaching it. E.g.,
3456 detaching while a thread is displaced stepping is a recipe for
3457 crashing it, as nothing would readjust the PC out of the scratch
3461 prepare_for_detach (void)
3463 struct inferior *inf = current_inferior ();
3464 ptid_t pid_ptid = ptid_t (inf->pid);
3466 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3468 /* Is any thread of this process displaced stepping? If not,
3469 there's nothing else to do. */
3470 if (displaced->step_thread == nullptr)
3474 fprintf_unfiltered (gdb_stdlog,
3475 "displaced-stepping in-process while detaching");
3477 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3479 while (displaced->step_thread != nullptr)
3481 struct execution_control_state ecss;
3482 struct execution_control_state *ecs;
3485 memset (ecs, 0, sizeof (*ecs));
3487 overlay_cache_invalid = 1;
3488 /* Flush target cache before starting to handle each event.
3489 Target was running and cache could be stale. This is just a
3490 heuristic. Running threads may modify target memory, but we
3491 don't get any event. */
3492 target_dcache_invalidate ();
3494 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3497 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3499 /* If an error happens while handling the event, propagate GDB's
3500 knowledge of the executing state to the frontend/user running
3502 scoped_finish_thread_state finish_state (minus_one_ptid);
3504 /* Now figure out what to do with the result of the result. */
3505 handle_inferior_event (ecs);
3507 /* No error, don't finish the state yet. */
3508 finish_state.release ();
3510 /* Breakpoints and watchpoints are not installed on the target
3511 at this point, and signals are passed directly to the
3512 inferior, so this must mean the process is gone. */
3513 if (!ecs->wait_some_more)
3515 restore_detaching.release ();
3516 error (_("Program exited while detaching"));
3520 restore_detaching.release ();
3523 /* Wait for control to return from inferior to debugger.
3525 If inferior gets a signal, we may decide to start it up again
3526 instead of returning. That is why there is a loop in this function.
3527 When this function actually returns it means the inferior
3528 should be left stopped and GDB should read more commands. */
3531 wait_for_inferior (void)
3535 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3537 SCOPE_EXIT { delete_just_stopped_threads_infrun_breakpoints (); };
3539 /* If an error happens while handling the event, propagate GDB's
3540 knowledge of the executing state to the frontend/user running
3542 scoped_finish_thread_state finish_state (minus_one_ptid);
3546 struct execution_control_state ecss;
3547 struct execution_control_state *ecs = &ecss;
3548 ptid_t waiton_ptid = minus_one_ptid;
3550 memset (ecs, 0, sizeof (*ecs));
3552 overlay_cache_invalid = 1;
3554 /* Flush target cache before starting to handle each event.
3555 Target was running and cache could be stale. This is just a
3556 heuristic. Running threads may modify target memory, but we
3557 don't get any event. */
3558 target_dcache_invalidate ();
3560 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3563 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3565 /* Now figure out what to do with the result of the result. */
3566 handle_inferior_event (ecs);
3568 if (!ecs->wait_some_more)
3572 /* No error, don't finish the state yet. */
3573 finish_state.release ();
3576 /* Cleanup that reinstalls the readline callback handler, if the
3577 target is running in the background. If while handling the target
3578 event something triggered a secondary prompt, like e.g., a
3579 pagination prompt, we'll have removed the callback handler (see
3580 gdb_readline_wrapper_line). Need to do this as we go back to the
3581 event loop, ready to process further input. Note this has no
3582 effect if the handler hasn't actually been removed, because calling
3583 rl_callback_handler_install resets the line buffer, thus losing
3587 reinstall_readline_callback_handler_cleanup ()
3589 struct ui *ui = current_ui;
3593 /* We're not going back to the top level event loop yet. Don't
3594 install the readline callback, as it'd prep the terminal,
3595 readline-style (raw, noecho) (e.g., --batch). We'll install
3596 it the next time the prompt is displayed, when we're ready
3601 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3602 gdb_rl_callback_handler_reinstall ();
3605 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3606 that's just the event thread. In all-stop, that's all threads. */
3609 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3611 if (ecs->event_thread != NULL
3612 && ecs->event_thread->thread_fsm != NULL)
3613 ecs->event_thread->thread_fsm->clean_up (ecs->event_thread);
3617 for (thread_info *thr : all_non_exited_threads ())
3619 if (thr->thread_fsm == NULL)
3621 if (thr == ecs->event_thread)
3624 switch_to_thread (thr);
3625 thr->thread_fsm->clean_up (thr);
3628 if (ecs->event_thread != NULL)
3629 switch_to_thread (ecs->event_thread);
3633 /* Helper for all_uis_check_sync_execution_done that works on the
3637 check_curr_ui_sync_execution_done (void)
3639 struct ui *ui = current_ui;
3641 if (ui->prompt_state == PROMPT_NEEDED
3643 && !gdb_in_secondary_prompt_p (ui))
3645 target_terminal::ours ();
3646 gdb::observers::sync_execution_done.notify ();
3647 ui_register_input_event_handler (ui);
3654 all_uis_check_sync_execution_done (void)
3656 SWITCH_THRU_ALL_UIS ()
3658 check_curr_ui_sync_execution_done ();
3665 all_uis_on_sync_execution_starting (void)
3667 SWITCH_THRU_ALL_UIS ()
3669 if (current_ui->prompt_state == PROMPT_NEEDED)
3670 async_disable_stdin ();
3674 /* Asynchronous version of wait_for_inferior. It is called by the
3675 event loop whenever a change of state is detected on the file
3676 descriptor corresponding to the target. It can be called more than
3677 once to complete a single execution command. In such cases we need
3678 to keep the state in a global variable ECSS. If it is the last time
3679 that this function is called for a single execution command, then
3680 report to the user that the inferior has stopped, and do the
3681 necessary cleanups. */
3684 fetch_inferior_event (void *client_data)
3686 struct execution_control_state ecss;
3687 struct execution_control_state *ecs = &ecss;
3689 ptid_t waiton_ptid = minus_one_ptid;
3691 memset (ecs, 0, sizeof (*ecs));
3693 /* Events are always processed with the main UI as current UI. This
3694 way, warnings, debug output, etc. are always consistently sent to
3695 the main console. */
3696 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3698 /* End up with readline processing input, if necessary. */
3700 SCOPE_EXIT { reinstall_readline_callback_handler_cleanup (); };
3702 /* We're handling a live event, so make sure we're doing live
3703 debugging. If we're looking at traceframes while the target is
3704 running, we're going to need to get back to that mode after
3705 handling the event. */
3706 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3709 maybe_restore_traceframe.emplace ();
3710 set_current_traceframe (-1);
3713 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3716 /* In non-stop mode, the user/frontend should not notice a thread
3717 switch due to internal events. Make sure we reverse to the
3718 user selected thread and frame after handling the event and
3719 running any breakpoint commands. */
3720 maybe_restore_thread.emplace ();
3722 overlay_cache_invalid = 1;
3723 /* Flush target cache before starting to handle each event. Target
3724 was running and cache could be stale. This is just a heuristic.
3725 Running threads may modify target memory, but we don't get any
3727 target_dcache_invalidate ();
3729 scoped_restore save_exec_dir
3730 = make_scoped_restore (&execution_direction,
3731 target_execution_direction ());
3733 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3734 target_can_async_p () ? TARGET_WNOHANG : 0);
3737 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3739 /* If an error happens while handling the event, propagate GDB's
3740 knowledge of the executing state to the frontend/user running
3742 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3743 scoped_finish_thread_state finish_state (finish_ptid);
3745 /* Get executed before scoped_restore_current_thread above to apply
3746 still for the thread which has thrown the exception. */
3747 auto defer_bpstat_clear
3748 = make_scope_exit (bpstat_clear_actions);
3749 auto defer_delete_threads
3750 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints);
3752 /* Now figure out what to do with the result of the result. */
3753 handle_inferior_event (ecs);
3755 if (!ecs->wait_some_more)
3757 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3758 int should_stop = 1;
3759 struct thread_info *thr = ecs->event_thread;
3761 delete_just_stopped_threads_infrun_breakpoints ();
3765 struct thread_fsm *thread_fsm = thr->thread_fsm;
3767 if (thread_fsm != NULL)
3768 should_stop = thread_fsm->should_stop (thr);
3777 bool should_notify_stop = true;
3780 clean_up_just_stopped_threads_fsms (ecs);
3782 if (thr != NULL && thr->thread_fsm != NULL)
3783 should_notify_stop = thr->thread_fsm->should_notify_stop ();
3785 if (should_notify_stop)
3787 /* We may not find an inferior if this was a process exit. */
3788 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3789 proceeded = normal_stop ();
3794 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3800 defer_delete_threads.release ();
3801 defer_bpstat_clear.release ();
3803 /* No error, don't finish the thread states yet. */
3804 finish_state.release ();
3806 /* This scope is used to ensure that readline callbacks are
3807 reinstalled here. */
3810 /* If a UI was in sync execution mode, and now isn't, restore its
3811 prompt (a synchronous execution command has finished, and we're
3812 ready for input). */
3813 all_uis_check_sync_execution_done ();
3816 && exec_done_display_p
3817 && (inferior_ptid == null_ptid
3818 || inferior_thread ()->state != THREAD_RUNNING))
3819 printf_unfiltered (_("completed.\n"));
3822 /* Record the frame and location we're currently stepping through. */
3824 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3826 struct thread_info *tp = inferior_thread ();
3828 tp->control.step_frame_id = get_frame_id (frame);
3829 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3831 tp->current_symtab = sal.symtab;
3832 tp->current_line = sal.line;
3835 /* Clear context switchable stepping state. */
3838 init_thread_stepping_state (struct thread_info *tss)
3840 tss->stepped_breakpoint = 0;
3841 tss->stepping_over_breakpoint = 0;
3842 tss->stepping_over_watchpoint = 0;
3843 tss->step_after_step_resume_breakpoint = 0;
3846 /* Set the cached copy of the last ptid/waitstatus. */
3849 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3851 target_last_wait_ptid = ptid;
3852 target_last_waitstatus = status;
3855 /* Return the cached copy of the last pid/waitstatus returned by
3856 target_wait()/deprecated_target_wait_hook(). The data is actually
3857 cached by handle_inferior_event(), which gets called immediately
3858 after target_wait()/deprecated_target_wait_hook(). */
3861 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3863 *ptidp = target_last_wait_ptid;
3864 *status = target_last_waitstatus;
3868 nullify_last_target_wait_ptid (void)
3870 target_last_wait_ptid = minus_one_ptid;
3873 /* Switch thread contexts. */
3876 context_switch (execution_control_state *ecs)
3879 && ecs->ptid != inferior_ptid
3880 && ecs->event_thread != inferior_thread ())
3882 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3883 target_pid_to_str (inferior_ptid));
3884 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3885 target_pid_to_str (ecs->ptid));
3888 switch_to_thread (ecs->event_thread);
3891 /* If the target can't tell whether we've hit breakpoints
3892 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3893 check whether that could have been caused by a breakpoint. If so,
3894 adjust the PC, per gdbarch_decr_pc_after_break. */
3897 adjust_pc_after_break (struct thread_info *thread,
3898 struct target_waitstatus *ws)
3900 struct regcache *regcache;
3901 struct gdbarch *gdbarch;
3902 CORE_ADDR breakpoint_pc, decr_pc;
3904 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3905 we aren't, just return.
3907 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3908 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3909 implemented by software breakpoints should be handled through the normal
3912 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3913 different signals (SIGILL or SIGEMT for instance), but it is less
3914 clear where the PC is pointing afterwards. It may not match
3915 gdbarch_decr_pc_after_break. I don't know any specific target that
3916 generates these signals at breakpoints (the code has been in GDB since at
3917 least 1992) so I can not guess how to handle them here.
3919 In earlier versions of GDB, a target with
3920 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3921 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3922 target with both of these set in GDB history, and it seems unlikely to be
3923 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3925 if (ws->kind != TARGET_WAITKIND_STOPPED)
3928 if (ws->value.sig != GDB_SIGNAL_TRAP)
3931 /* In reverse execution, when a breakpoint is hit, the instruction
3932 under it has already been de-executed. The reported PC always
3933 points at the breakpoint address, so adjusting it further would
3934 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3937 B1 0x08000000 : INSN1
3938 B2 0x08000001 : INSN2
3940 PC -> 0x08000003 : INSN4
3942 Say you're stopped at 0x08000003 as above. Reverse continuing
3943 from that point should hit B2 as below. Reading the PC when the
3944 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3945 been de-executed already.
3947 B1 0x08000000 : INSN1
3948 B2 PC -> 0x08000001 : INSN2
3952 We can't apply the same logic as for forward execution, because
3953 we would wrongly adjust the PC to 0x08000000, since there's a
3954 breakpoint at PC - 1. We'd then report a hit on B1, although
3955 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3957 if (execution_direction == EXEC_REVERSE)
3960 /* If the target can tell whether the thread hit a SW breakpoint,
3961 trust it. Targets that can tell also adjust the PC
3963 if (target_supports_stopped_by_sw_breakpoint ())
3966 /* Note that relying on whether a breakpoint is planted in memory to
3967 determine this can fail. E.g,. the breakpoint could have been
3968 removed since. Or the thread could have been told to step an
3969 instruction the size of a breakpoint instruction, and only
3970 _after_ was a breakpoint inserted at its address. */
3972 /* If this target does not decrement the PC after breakpoints, then
3973 we have nothing to do. */
3974 regcache = get_thread_regcache (thread);
3975 gdbarch = regcache->arch ();
3977 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3981 const address_space *aspace = regcache->aspace ();
3983 /* Find the location where (if we've hit a breakpoint) the
3984 breakpoint would be. */
3985 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3987 /* If the target can't tell whether a software breakpoint triggered,
3988 fallback to figuring it out based on breakpoints we think were
3989 inserted in the target, and on whether the thread was stepped or
3992 /* Check whether there actually is a software breakpoint inserted at
3995 If in non-stop mode, a race condition is possible where we've
3996 removed a breakpoint, but stop events for that breakpoint were
3997 already queued and arrive later. To suppress those spurious
3998 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3999 and retire them after a number of stop events are reported. Note
4000 this is an heuristic and can thus get confused. The real fix is
4001 to get the "stopped by SW BP and needs adjustment" info out of
4002 the target/kernel (and thus never reach here; see above). */
4003 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4004 || (target_is_non_stop_p ()
4005 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4007 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4009 if (record_full_is_used ())
4010 restore_operation_disable.emplace
4011 (record_full_gdb_operation_disable_set ());
4013 /* When using hardware single-step, a SIGTRAP is reported for both
4014 a completed single-step and a software breakpoint. Need to
4015 differentiate between the two, as the latter needs adjusting
4016 but the former does not.
4018 The SIGTRAP can be due to a completed hardware single-step only if
4019 - we didn't insert software single-step breakpoints
4020 - this thread is currently being stepped
4022 If any of these events did not occur, we must have stopped due
4023 to hitting a software breakpoint, and have to back up to the
4026 As a special case, we could have hardware single-stepped a
4027 software breakpoint. In this case (prev_pc == breakpoint_pc),
4028 we also need to back up to the breakpoint address. */
4030 if (thread_has_single_step_breakpoints_set (thread)
4031 || !currently_stepping (thread)
4032 || (thread->stepped_breakpoint
4033 && thread->prev_pc == breakpoint_pc))
4034 regcache_write_pc (regcache, breakpoint_pc);
4039 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4041 for (frame = get_prev_frame (frame);
4043 frame = get_prev_frame (frame))
4045 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4047 if (get_frame_type (frame) != INLINE_FRAME)
4054 /* If the event thread has the stop requested flag set, pretend it
4055 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4059 handle_stop_requested (struct execution_control_state *ecs)
4061 if (ecs->event_thread->stop_requested)
4063 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4064 ecs->ws.value.sig = GDB_SIGNAL_0;
4065 handle_signal_stop (ecs);
4071 /* Auxiliary function that handles syscall entry/return events.
4072 It returns 1 if the inferior should keep going (and GDB
4073 should ignore the event), or 0 if the event deserves to be
4077 handle_syscall_event (struct execution_control_state *ecs)
4079 struct regcache *regcache;
4082 context_switch (ecs);
4084 regcache = get_thread_regcache (ecs->event_thread);
4085 syscall_number = ecs->ws.value.syscall_number;
4086 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4088 if (catch_syscall_enabled () > 0
4089 && catching_syscall_number (syscall_number) > 0)
4092 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4095 ecs->event_thread->control.stop_bpstat
4096 = bpstat_stop_status (regcache->aspace (),
4097 ecs->event_thread->suspend.stop_pc,
4098 ecs->event_thread, &ecs->ws);
4100 if (handle_stop_requested (ecs))
4103 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4105 /* Catchpoint hit. */
4110 if (handle_stop_requested (ecs))
4113 /* If no catchpoint triggered for this, then keep going. */
4118 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4121 fill_in_stop_func (struct gdbarch *gdbarch,
4122 struct execution_control_state *ecs)
4124 if (!ecs->stop_func_filled_in)
4126 /* Don't care about return value; stop_func_start and stop_func_name
4127 will both be 0 if it doesn't work. */
4128 find_function_entry_range_from_pc (ecs->event_thread->suspend.stop_pc,
4129 &ecs->stop_func_name,
4130 &ecs->stop_func_start,
4131 &ecs->stop_func_end);
4132 ecs->stop_func_start
4133 += gdbarch_deprecated_function_start_offset (gdbarch);
4135 if (gdbarch_skip_entrypoint_p (gdbarch))
4136 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4137 ecs->stop_func_start);
4139 ecs->stop_func_filled_in = 1;
4144 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4146 static enum stop_kind
4147 get_inferior_stop_soon (execution_control_state *ecs)
4149 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4151 gdb_assert (inf != NULL);
4152 return inf->control.stop_soon;
4155 /* Wait for one event. Store the resulting waitstatus in WS, and
4156 return the event ptid. */
4159 wait_one (struct target_waitstatus *ws)
4162 ptid_t wait_ptid = minus_one_ptid;
4164 overlay_cache_invalid = 1;
4166 /* Flush target cache before starting to handle each event.
4167 Target was running and cache could be stale. This is just a
4168 heuristic. Running threads may modify target memory, but we
4169 don't get any event. */
4170 target_dcache_invalidate ();
4172 if (deprecated_target_wait_hook)
4173 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4175 event_ptid = target_wait (wait_ptid, ws, 0);
4178 print_target_wait_results (wait_ptid, event_ptid, ws);
4183 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4184 instead of the current thread. */
4185 #define THREAD_STOPPED_BY(REASON) \
4187 thread_stopped_by_ ## REASON (ptid_t ptid) \
4189 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4190 inferior_ptid = ptid; \
4192 return target_stopped_by_ ## REASON (); \
4195 /* Generate thread_stopped_by_watchpoint. */
4196 THREAD_STOPPED_BY (watchpoint)
4197 /* Generate thread_stopped_by_sw_breakpoint. */
4198 THREAD_STOPPED_BY (sw_breakpoint)
4199 /* Generate thread_stopped_by_hw_breakpoint. */
4200 THREAD_STOPPED_BY (hw_breakpoint)
4202 /* Save the thread's event and stop reason to process it later. */
4205 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4209 std::string statstr = target_waitstatus_to_string (ws);
4211 fprintf_unfiltered (gdb_stdlog,
4212 "infrun: saving status %s for %d.%ld.%ld\n",
4219 /* Record for later. */
4220 tp->suspend.waitstatus = *ws;
4221 tp->suspend.waitstatus_pending_p = 1;
4223 struct regcache *regcache = get_thread_regcache (tp);
4224 const address_space *aspace = regcache->aspace ();
4226 if (ws->kind == TARGET_WAITKIND_STOPPED
4227 && ws->value.sig == GDB_SIGNAL_TRAP)
4229 CORE_ADDR pc = regcache_read_pc (regcache);
4231 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4233 if (thread_stopped_by_watchpoint (tp->ptid))
4235 tp->suspend.stop_reason
4236 = TARGET_STOPPED_BY_WATCHPOINT;
4238 else if (target_supports_stopped_by_sw_breakpoint ()
4239 && thread_stopped_by_sw_breakpoint (tp->ptid))
4241 tp->suspend.stop_reason
4242 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4244 else if (target_supports_stopped_by_hw_breakpoint ()
4245 && thread_stopped_by_hw_breakpoint (tp->ptid))
4247 tp->suspend.stop_reason
4248 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4250 else if (!target_supports_stopped_by_hw_breakpoint ()
4251 && hardware_breakpoint_inserted_here_p (aspace,
4254 tp->suspend.stop_reason
4255 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4257 else if (!target_supports_stopped_by_sw_breakpoint ()
4258 && software_breakpoint_inserted_here_p (aspace,
4261 tp->suspend.stop_reason
4262 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4264 else if (!thread_has_single_step_breakpoints_set (tp)
4265 && currently_stepping (tp))
4267 tp->suspend.stop_reason
4268 = TARGET_STOPPED_BY_SINGLE_STEP;
4276 stop_all_threads (void)
4278 /* We may need multiple passes to discover all threads. */
4282 gdb_assert (target_is_non_stop_p ());
4285 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4287 scoped_restore_current_thread restore_thread;
4289 target_thread_events (1);
4290 SCOPE_EXIT { target_thread_events (0); };
4292 /* Request threads to stop, and then wait for the stops. Because
4293 threads we already know about can spawn more threads while we're
4294 trying to stop them, and we only learn about new threads when we
4295 update the thread list, do this in a loop, and keep iterating
4296 until two passes find no threads that need to be stopped. */
4297 for (pass = 0; pass < 2; pass++, iterations++)
4300 fprintf_unfiltered (gdb_stdlog,
4301 "infrun: stop_all_threads, pass=%d, "
4302 "iterations=%d\n", pass, iterations);
4306 struct target_waitstatus ws;
4309 update_thread_list ();
4311 /* Go through all threads looking for threads that we need
4312 to tell the target to stop. */
4313 for (thread_info *t : all_non_exited_threads ())
4317 /* If already stopping, don't request a stop again.
4318 We just haven't seen the notification yet. */
4319 if (!t->stop_requested)
4322 fprintf_unfiltered (gdb_stdlog,
4323 "infrun: %s executing, "
4325 target_pid_to_str (t->ptid));
4326 target_stop (t->ptid);
4327 t->stop_requested = 1;
4332 fprintf_unfiltered (gdb_stdlog,
4333 "infrun: %s executing, "
4334 "already stopping\n",
4335 target_pid_to_str (t->ptid));
4338 if (t->stop_requested)
4344 fprintf_unfiltered (gdb_stdlog,
4345 "infrun: %s not executing\n",
4346 target_pid_to_str (t->ptid));
4348 /* The thread may be not executing, but still be
4349 resumed with a pending status to process. */
4357 /* If we find new threads on the second iteration, restart
4358 over. We want to see two iterations in a row with all
4363 event_ptid = wait_one (&ws);
4365 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4367 /* All resumed threads exited. */
4369 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4370 || ws.kind == TARGET_WAITKIND_EXITED
4371 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4375 ptid_t ptid = ptid_t (ws.value.integer);
4377 fprintf_unfiltered (gdb_stdlog,
4378 "infrun: %s exited while "
4379 "stopping threads\n",
4380 target_pid_to_str (ptid));
4385 thread_info *t = find_thread_ptid (event_ptid);
4387 t = add_thread (event_ptid);
4389 t->stop_requested = 0;
4392 t->control.may_range_step = 0;
4394 /* This may be the first time we see the inferior report
4396 inferior *inf = find_inferior_ptid (event_ptid);
4397 if (inf->needs_setup)
4399 switch_to_thread_no_regs (t);
4403 if (ws.kind == TARGET_WAITKIND_STOPPED
4404 && ws.value.sig == GDB_SIGNAL_0)
4406 /* We caught the event that we intended to catch, so
4407 there's no event pending. */
4408 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4409 t->suspend.waitstatus_pending_p = 0;
4411 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4413 /* Add it back to the step-over queue. */
4416 fprintf_unfiltered (gdb_stdlog,
4417 "infrun: displaced-step of %s "
4418 "canceled: adding back to the "
4419 "step-over queue\n",
4420 target_pid_to_str (t->ptid));
4422 t->control.trap_expected = 0;
4423 thread_step_over_chain_enqueue (t);
4428 enum gdb_signal sig;
4429 struct regcache *regcache;
4433 std::string statstr = target_waitstatus_to_string (&ws);
4435 fprintf_unfiltered (gdb_stdlog,
4436 "infrun: target_wait %s, saving "
4437 "status for %d.%ld.%ld\n",
4444 /* Record for later. */
4445 save_waitstatus (t, &ws);
4447 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4448 ? ws.value.sig : GDB_SIGNAL_0);
4450 if (displaced_step_fixup (t, sig) < 0)
4452 /* Add it back to the step-over queue. */
4453 t->control.trap_expected = 0;
4454 thread_step_over_chain_enqueue (t);
4457 regcache = get_thread_regcache (t);
4458 t->suspend.stop_pc = regcache_read_pc (regcache);
4462 fprintf_unfiltered (gdb_stdlog,
4463 "infrun: saved stop_pc=%s for %s "
4464 "(currently_stepping=%d)\n",
4465 paddress (target_gdbarch (),
4466 t->suspend.stop_pc),
4467 target_pid_to_str (t->ptid),
4468 currently_stepping (t));
4476 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4479 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4482 handle_no_resumed (struct execution_control_state *ecs)
4484 if (target_can_async_p ())
4491 if (ui->prompt_state == PROMPT_BLOCKED)
4499 /* There were no unwaited-for children left in the target, but,
4500 we're not synchronously waiting for events either. Just
4504 fprintf_unfiltered (gdb_stdlog,
4505 "infrun: TARGET_WAITKIND_NO_RESUMED "
4506 "(ignoring: bg)\n");
4507 prepare_to_wait (ecs);
4512 /* Otherwise, if we were running a synchronous execution command, we
4513 may need to cancel it and give the user back the terminal.
4515 In non-stop mode, the target can't tell whether we've already
4516 consumed previous stop events, so it can end up sending us a
4517 no-resumed event like so:
4519 #0 - thread 1 is left stopped
4521 #1 - thread 2 is resumed and hits breakpoint
4522 -> TARGET_WAITKIND_STOPPED
4524 #2 - thread 3 is resumed and exits
4525 this is the last resumed thread, so
4526 -> TARGET_WAITKIND_NO_RESUMED
4528 #3 - gdb processes stop for thread 2 and decides to re-resume
4531 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4532 thread 2 is now resumed, so the event should be ignored.
4534 IOW, if the stop for thread 2 doesn't end a foreground command,
4535 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4536 event. But it could be that the event meant that thread 2 itself
4537 (or whatever other thread was the last resumed thread) exited.
4539 To address this we refresh the thread list and check whether we
4540 have resumed threads _now_. In the example above, this removes
4541 thread 3 from the thread list. If thread 2 was re-resumed, we
4542 ignore this event. If we find no thread resumed, then we cancel
4543 the synchronous command show "no unwaited-for " to the user. */
4544 update_thread_list ();
4546 for (thread_info *thread : all_non_exited_threads ())
4548 if (thread->executing
4549 || thread->suspend.waitstatus_pending_p)
4551 /* There were no unwaited-for children left in the target at
4552 some point, but there are now. Just ignore. */
4554 fprintf_unfiltered (gdb_stdlog,
4555 "infrun: TARGET_WAITKIND_NO_RESUMED "
4556 "(ignoring: found resumed)\n");
4557 prepare_to_wait (ecs);
4562 /* Note however that we may find no resumed thread because the whole
4563 process exited meanwhile (thus updating the thread list results
4564 in an empty thread list). In this case we know we'll be getting
4565 a process exit event shortly. */
4566 for (inferior *inf : all_inferiors ())
4571 thread_info *thread = any_live_thread_of_inferior (inf);
4575 fprintf_unfiltered (gdb_stdlog,
4576 "infrun: TARGET_WAITKIND_NO_RESUMED "
4577 "(expect process exit)\n");
4578 prepare_to_wait (ecs);
4583 /* Go ahead and report the event. */
4587 /* Given an execution control state that has been freshly filled in by
4588 an event from the inferior, figure out what it means and take
4591 The alternatives are:
4593 1) stop_waiting and return; to really stop and return to the
4596 2) keep_going and return; to wait for the next event (set
4597 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4601 handle_inferior_event_1 (struct execution_control_state *ecs)
4603 enum stop_kind stop_soon;
4605 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4607 /* We had an event in the inferior, but we are not interested in
4608 handling it at this level. The lower layers have already
4609 done what needs to be done, if anything.
4611 One of the possible circumstances for this is when the
4612 inferior produces output for the console. The inferior has
4613 not stopped, and we are ignoring the event. Another possible
4614 circumstance is any event which the lower level knows will be
4615 reported multiple times without an intervening resume. */
4617 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4618 prepare_to_wait (ecs);
4622 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4625 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4626 prepare_to_wait (ecs);
4630 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4631 && handle_no_resumed (ecs))
4634 /* Cache the last pid/waitstatus. */
4635 set_last_target_status (ecs->ptid, ecs->ws);
4637 /* Always clear state belonging to the previous time we stopped. */
4638 stop_stack_dummy = STOP_NONE;
4640 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4642 /* No unwaited-for children left. IOW, all resumed children
4645 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4647 stop_print_frame = 0;
4652 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4653 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4655 ecs->event_thread = find_thread_ptid (ecs->ptid);
4656 /* If it's a new thread, add it to the thread database. */
4657 if (ecs->event_thread == NULL)
4658 ecs->event_thread = add_thread (ecs->ptid);
4660 /* Disable range stepping. If the next step request could use a
4661 range, this will be end up re-enabled then. */
4662 ecs->event_thread->control.may_range_step = 0;
4665 /* Dependent on valid ECS->EVENT_THREAD. */
4666 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4668 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4669 reinit_frame_cache ();
4671 breakpoint_retire_moribund ();
4673 /* First, distinguish signals caused by the debugger from signals
4674 that have to do with the program's own actions. Note that
4675 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4676 on the operating system version. Here we detect when a SIGILL or
4677 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4678 something similar for SIGSEGV, since a SIGSEGV will be generated
4679 when we're trying to execute a breakpoint instruction on a
4680 non-executable stack. This happens for call dummy breakpoints
4681 for architectures like SPARC that place call dummies on the
4683 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4684 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4685 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4686 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4688 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4690 if (breakpoint_inserted_here_p (regcache->aspace (),
4691 regcache_read_pc (regcache)))
4694 fprintf_unfiltered (gdb_stdlog,
4695 "infrun: Treating signal as SIGTRAP\n");
4696 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4700 /* Mark the non-executing threads accordingly. In all-stop, all
4701 threads of all processes are stopped when we get any event
4702 reported. In non-stop mode, only the event thread stops. */
4706 if (!target_is_non_stop_p ())
4707 mark_ptid = minus_one_ptid;
4708 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4709 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4711 /* If we're handling a process exit in non-stop mode, even
4712 though threads haven't been deleted yet, one would think
4713 that there is nothing to do, as threads of the dead process
4714 will be soon deleted, and threads of any other process were
4715 left running. However, on some targets, threads survive a
4716 process exit event. E.g., for the "checkpoint" command,
4717 when the current checkpoint/fork exits, linux-fork.c
4718 automatically switches to another fork from within
4719 target_mourn_inferior, by associating the same
4720 inferior/thread to another fork. We haven't mourned yet at
4721 this point, but we must mark any threads left in the
4722 process as not-executing so that finish_thread_state marks
4723 them stopped (in the user's perspective) if/when we present
4724 the stop to the user. */
4725 mark_ptid = ptid_t (ecs->ptid.pid ());
4728 mark_ptid = ecs->ptid;
4730 set_executing (mark_ptid, 0);
4732 /* Likewise the resumed flag. */
4733 set_resumed (mark_ptid, 0);
4736 switch (ecs->ws.kind)
4738 case TARGET_WAITKIND_LOADED:
4740 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4741 context_switch (ecs);
4742 /* Ignore gracefully during startup of the inferior, as it might
4743 be the shell which has just loaded some objects, otherwise
4744 add the symbols for the newly loaded objects. Also ignore at
4745 the beginning of an attach or remote session; we will query
4746 the full list of libraries once the connection is
4749 stop_soon = get_inferior_stop_soon (ecs);
4750 if (stop_soon == NO_STOP_QUIETLY)
4752 struct regcache *regcache;
4754 regcache = get_thread_regcache (ecs->event_thread);
4756 handle_solib_event ();
4758 ecs->event_thread->control.stop_bpstat
4759 = bpstat_stop_status (regcache->aspace (),
4760 ecs->event_thread->suspend.stop_pc,
4761 ecs->event_thread, &ecs->ws);
4763 if (handle_stop_requested (ecs))
4766 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4768 /* A catchpoint triggered. */
4769 process_event_stop_test (ecs);
4773 /* If requested, stop when the dynamic linker notifies
4774 gdb of events. This allows the user to get control
4775 and place breakpoints in initializer routines for
4776 dynamically loaded objects (among other things). */
4777 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4778 if (stop_on_solib_events)
4780 /* Make sure we print "Stopped due to solib-event" in
4782 stop_print_frame = 1;
4789 /* If we are skipping through a shell, or through shared library
4790 loading that we aren't interested in, resume the program. If
4791 we're running the program normally, also resume. */
4792 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4794 /* Loading of shared libraries might have changed breakpoint
4795 addresses. Make sure new breakpoints are inserted. */
4796 if (stop_soon == NO_STOP_QUIETLY)
4797 insert_breakpoints ();
4798 resume (GDB_SIGNAL_0);
4799 prepare_to_wait (ecs);
4803 /* But stop if we're attaching or setting up a remote
4805 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4806 || stop_soon == STOP_QUIETLY_REMOTE)
4809 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4814 internal_error (__FILE__, __LINE__,
4815 _("unhandled stop_soon: %d"), (int) stop_soon);
4817 case TARGET_WAITKIND_SPURIOUS:
4819 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4820 if (handle_stop_requested (ecs))
4822 context_switch (ecs);
4823 resume (GDB_SIGNAL_0);
4824 prepare_to_wait (ecs);
4827 case TARGET_WAITKIND_THREAD_CREATED:
4829 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
4830 if (handle_stop_requested (ecs))
4832 context_switch (ecs);
4833 if (!switch_back_to_stepped_thread (ecs))
4837 case TARGET_WAITKIND_EXITED:
4838 case TARGET_WAITKIND_SIGNALLED:
4841 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4842 fprintf_unfiltered (gdb_stdlog,
4843 "infrun: TARGET_WAITKIND_EXITED\n");
4845 fprintf_unfiltered (gdb_stdlog,
4846 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4849 inferior_ptid = ecs->ptid;
4850 set_current_inferior (find_inferior_ptid (ecs->ptid));
4851 set_current_program_space (current_inferior ()->pspace);
4852 handle_vfork_child_exec_or_exit (0);
4853 target_terminal::ours (); /* Must do this before mourn anyway. */
4855 /* Clearing any previous state of convenience variables. */
4856 clear_exit_convenience_vars ();
4858 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4860 /* Record the exit code in the convenience variable $_exitcode, so
4861 that the user can inspect this again later. */
4862 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4863 (LONGEST) ecs->ws.value.integer);
4865 /* Also record this in the inferior itself. */
4866 current_inferior ()->has_exit_code = 1;
4867 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4869 /* Support the --return-child-result option. */
4870 return_child_result_value = ecs->ws.value.integer;
4872 gdb::observers::exited.notify (ecs->ws.value.integer);
4876 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
4878 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4880 /* Set the value of the internal variable $_exitsignal,
4881 which holds the signal uncaught by the inferior. */
4882 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4883 gdbarch_gdb_signal_to_target (gdbarch,
4884 ecs->ws.value.sig));
4888 /* We don't have access to the target's method used for
4889 converting between signal numbers (GDB's internal
4890 representation <-> target's representation).
4891 Therefore, we cannot do a good job at displaying this
4892 information to the user. It's better to just warn
4893 her about it (if infrun debugging is enabled), and
4896 fprintf_filtered (gdb_stdlog, _("\
4897 Cannot fill $_exitsignal with the correct signal number.\n"));
4900 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
4903 gdb_flush (gdb_stdout);
4904 target_mourn_inferior (inferior_ptid);
4905 stop_print_frame = 0;
4909 /* The following are the only cases in which we keep going;
4910 the above cases end in a continue or goto. */
4911 case TARGET_WAITKIND_FORKED:
4912 case TARGET_WAITKIND_VFORKED:
4915 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4916 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4918 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4921 /* Check whether the inferior is displaced stepping. */
4923 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4924 struct gdbarch *gdbarch = regcache->arch ();
4926 /* If checking displaced stepping is supported, and thread
4927 ecs->ptid is displaced stepping. */
4928 if (displaced_step_in_progress_thread (ecs->event_thread))
4930 struct inferior *parent_inf
4931 = find_inferior_ptid (ecs->ptid);
4932 struct regcache *child_regcache;
4933 CORE_ADDR parent_pc;
4935 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4936 indicating that the displaced stepping of syscall instruction
4937 has been done. Perform cleanup for parent process here. Note
4938 that this operation also cleans up the child process for vfork,
4939 because their pages are shared. */
4940 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
4941 /* Start a new step-over in another thread if there's one
4945 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4947 struct displaced_step_inferior_state *displaced
4948 = get_displaced_stepping_state (parent_inf);
4950 /* Restore scratch pad for child process. */
4951 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4954 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4955 the child's PC is also within the scratchpad. Set the child's PC
4956 to the parent's PC value, which has already been fixed up.
4957 FIXME: we use the parent's aspace here, although we're touching
4958 the child, because the child hasn't been added to the inferior
4959 list yet at this point. */
4962 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4964 parent_inf->aspace);
4965 /* Read PC value of parent process. */
4966 parent_pc = regcache_read_pc (regcache);
4968 if (debug_displaced)
4969 fprintf_unfiltered (gdb_stdlog,
4970 "displaced: write child pc from %s to %s\n",
4972 regcache_read_pc (child_regcache)),
4973 paddress (gdbarch, parent_pc));
4975 regcache_write_pc (child_regcache, parent_pc);
4979 context_switch (ecs);
4981 /* Immediately detach breakpoints from the child before there's
4982 any chance of letting the user delete breakpoints from the
4983 breakpoint lists. If we don't do this early, it's easy to
4984 leave left over traps in the child, vis: "break foo; catch
4985 fork; c; <fork>; del; c; <child calls foo>". We only follow
4986 the fork on the last `continue', and by that time the
4987 breakpoint at "foo" is long gone from the breakpoint table.
4988 If we vforked, then we don't need to unpatch here, since both
4989 parent and child are sharing the same memory pages; we'll
4990 need to unpatch at follow/detach time instead to be certain
4991 that new breakpoints added between catchpoint hit time and
4992 vfork follow are detached. */
4993 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4995 /* This won't actually modify the breakpoint list, but will
4996 physically remove the breakpoints from the child. */
4997 detach_breakpoints (ecs->ws.value.related_pid);
5000 delete_just_stopped_threads_single_step_breakpoints ();
5002 /* In case the event is caught by a catchpoint, remember that
5003 the event is to be followed at the next resume of the thread,
5004 and not immediately. */
5005 ecs->event_thread->pending_follow = ecs->ws;
5007 ecs->event_thread->suspend.stop_pc
5008 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5010 ecs->event_thread->control.stop_bpstat
5011 = bpstat_stop_status (get_current_regcache ()->aspace (),
5012 ecs->event_thread->suspend.stop_pc,
5013 ecs->event_thread, &ecs->ws);
5015 if (handle_stop_requested (ecs))
5018 /* If no catchpoint triggered for this, then keep going. Note
5019 that we're interested in knowing the bpstat actually causes a
5020 stop, not just if it may explain the signal. Software
5021 watchpoints, for example, always appear in the bpstat. */
5022 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5026 = (follow_fork_mode_string == follow_fork_mode_child);
5028 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5030 should_resume = follow_fork ();
5032 thread_info *parent = ecs->event_thread;
5033 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5035 /* At this point, the parent is marked running, and the
5036 child is marked stopped. */
5038 /* If not resuming the parent, mark it stopped. */
5039 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5040 parent->set_running (false);
5042 /* If resuming the child, mark it running. */
5043 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5044 child->set_running (true);
5046 /* In non-stop mode, also resume the other branch. */
5047 if (!detach_fork && (non_stop
5048 || (sched_multi && target_is_non_stop_p ())))
5051 switch_to_thread (parent);
5053 switch_to_thread (child);
5055 ecs->event_thread = inferior_thread ();
5056 ecs->ptid = inferior_ptid;
5061 switch_to_thread (child);
5063 switch_to_thread (parent);
5065 ecs->event_thread = inferior_thread ();
5066 ecs->ptid = inferior_ptid;
5074 process_event_stop_test (ecs);
5077 case TARGET_WAITKIND_VFORK_DONE:
5078 /* Done with the shared memory region. Re-insert breakpoints in
5079 the parent, and keep going. */
5082 fprintf_unfiltered (gdb_stdlog,
5083 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5085 context_switch (ecs);
5087 current_inferior ()->waiting_for_vfork_done = 0;
5088 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5090 if (handle_stop_requested (ecs))
5093 /* This also takes care of reinserting breakpoints in the
5094 previously locked inferior. */
5098 case TARGET_WAITKIND_EXECD:
5100 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5102 /* Note we can't read registers yet (the stop_pc), because we
5103 don't yet know the inferior's post-exec architecture.
5104 'stop_pc' is explicitly read below instead. */
5105 switch_to_thread_no_regs (ecs->event_thread);
5107 /* Do whatever is necessary to the parent branch of the vfork. */
5108 handle_vfork_child_exec_or_exit (1);
5110 /* This causes the eventpoints and symbol table to be reset.
5111 Must do this now, before trying to determine whether to
5113 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5115 /* In follow_exec we may have deleted the original thread and
5116 created a new one. Make sure that the event thread is the
5117 execd thread for that case (this is a nop otherwise). */
5118 ecs->event_thread = inferior_thread ();
5120 ecs->event_thread->suspend.stop_pc
5121 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5123 ecs->event_thread->control.stop_bpstat
5124 = bpstat_stop_status (get_current_regcache ()->aspace (),
5125 ecs->event_thread->suspend.stop_pc,
5126 ecs->event_thread, &ecs->ws);
5128 /* Note that this may be referenced from inside
5129 bpstat_stop_status above, through inferior_has_execd. */
5130 xfree (ecs->ws.value.execd_pathname);
5131 ecs->ws.value.execd_pathname = NULL;
5133 if (handle_stop_requested (ecs))
5136 /* If no catchpoint triggered for this, then keep going. */
5137 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5139 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5143 process_event_stop_test (ecs);
5146 /* Be careful not to try to gather much state about a thread
5147 that's in a syscall. It's frequently a losing proposition. */
5148 case TARGET_WAITKIND_SYSCALL_ENTRY:
5150 fprintf_unfiltered (gdb_stdlog,
5151 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5152 /* Getting the current syscall number. */
5153 if (handle_syscall_event (ecs) == 0)
5154 process_event_stop_test (ecs);
5157 /* Before examining the threads further, step this thread to
5158 get it entirely out of the syscall. (We get notice of the
5159 event when the thread is just on the verge of exiting a
5160 syscall. Stepping one instruction seems to get it back
5162 case TARGET_WAITKIND_SYSCALL_RETURN:
5164 fprintf_unfiltered (gdb_stdlog,
5165 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5166 if (handle_syscall_event (ecs) == 0)
5167 process_event_stop_test (ecs);
5170 case TARGET_WAITKIND_STOPPED:
5172 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5173 handle_signal_stop (ecs);
5176 case TARGET_WAITKIND_NO_HISTORY:
5178 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5179 /* Reverse execution: target ran out of history info. */
5181 /* Switch to the stopped thread. */
5182 context_switch (ecs);
5184 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5186 delete_just_stopped_threads_single_step_breakpoints ();
5187 ecs->event_thread->suspend.stop_pc
5188 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5190 if (handle_stop_requested (ecs))
5193 gdb::observers::no_history.notify ();
5199 /* A wrapper around handle_inferior_event_1, which also makes sure
5200 that all temporary struct value objects that were created during
5201 the handling of the event get deleted at the end. */
5204 handle_inferior_event (struct execution_control_state *ecs)
5206 struct value *mark = value_mark ();
5208 handle_inferior_event_1 (ecs);
5209 /* Purge all temporary values created during the event handling,
5210 as it could be a long time before we return to the command level
5211 where such values would otherwise be purged. */
5212 value_free_to_mark (mark);
5215 /* Restart threads back to what they were trying to do back when we
5216 paused them for an in-line step-over. The EVENT_THREAD thread is
5220 restart_threads (struct thread_info *event_thread)
5222 /* In case the instruction just stepped spawned a new thread. */
5223 update_thread_list ();
5225 for (thread_info *tp : all_non_exited_threads ())
5227 if (tp == event_thread)
5230 fprintf_unfiltered (gdb_stdlog,
5231 "infrun: restart threads: "
5232 "[%s] is event thread\n",
5233 target_pid_to_str (tp->ptid));
5237 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5240 fprintf_unfiltered (gdb_stdlog,
5241 "infrun: restart threads: "
5242 "[%s] not meant to be running\n",
5243 target_pid_to_str (tp->ptid));
5250 fprintf_unfiltered (gdb_stdlog,
5251 "infrun: restart threads: [%s] resumed\n",
5252 target_pid_to_str (tp->ptid));
5253 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5257 if (thread_is_in_step_over_chain (tp))
5260 fprintf_unfiltered (gdb_stdlog,
5261 "infrun: restart threads: "
5262 "[%s] needs step-over\n",
5263 target_pid_to_str (tp->ptid));
5264 gdb_assert (!tp->resumed);
5269 if (tp->suspend.waitstatus_pending_p)
5272 fprintf_unfiltered (gdb_stdlog,
5273 "infrun: restart threads: "
5274 "[%s] has pending status\n",
5275 target_pid_to_str (tp->ptid));
5280 gdb_assert (!tp->stop_requested);
5282 /* If some thread needs to start a step-over at this point, it
5283 should still be in the step-over queue, and thus skipped
5285 if (thread_still_needs_step_over (tp))
5287 internal_error (__FILE__, __LINE__,
5288 "thread [%s] needs a step-over, but not in "
5289 "step-over queue\n",
5290 target_pid_to_str (tp->ptid));
5293 if (currently_stepping (tp))
5296 fprintf_unfiltered (gdb_stdlog,
5297 "infrun: restart threads: [%s] was stepping\n",
5298 target_pid_to_str (tp->ptid));
5299 keep_going_stepped_thread (tp);
5303 struct execution_control_state ecss;
5304 struct execution_control_state *ecs = &ecss;
5307 fprintf_unfiltered (gdb_stdlog,
5308 "infrun: restart threads: [%s] continuing\n",
5309 target_pid_to_str (tp->ptid));
5310 reset_ecs (ecs, tp);
5311 switch_to_thread (tp);
5312 keep_going_pass_signal (ecs);
5317 /* Callback for iterate_over_threads. Find a resumed thread that has
5318 a pending waitstatus. */
5321 resumed_thread_with_pending_status (struct thread_info *tp,
5325 && tp->suspend.waitstatus_pending_p);
5328 /* Called when we get an event that may finish an in-line or
5329 out-of-line (displaced stepping) step-over started previously.
5330 Return true if the event is processed and we should go back to the
5331 event loop; false if the caller should continue processing the
5335 finish_step_over (struct execution_control_state *ecs)
5337 int had_step_over_info;
5339 displaced_step_fixup (ecs->event_thread,
5340 ecs->event_thread->suspend.stop_signal);
5342 had_step_over_info = step_over_info_valid_p ();
5344 if (had_step_over_info)
5346 /* If we're stepping over a breakpoint with all threads locked,
5347 then only the thread that was stepped should be reporting
5349 gdb_assert (ecs->event_thread->control.trap_expected);
5351 clear_step_over_info ();
5354 if (!target_is_non_stop_p ())
5357 /* Start a new step-over in another thread if there's one that
5361 /* If we were stepping over a breakpoint before, and haven't started
5362 a new in-line step-over sequence, then restart all other threads
5363 (except the event thread). We can't do this in all-stop, as then
5364 e.g., we wouldn't be able to issue any other remote packet until
5365 these other threads stop. */
5366 if (had_step_over_info && !step_over_info_valid_p ())
5368 struct thread_info *pending;
5370 /* If we only have threads with pending statuses, the restart
5371 below won't restart any thread and so nothing re-inserts the
5372 breakpoint we just stepped over. But we need it inserted
5373 when we later process the pending events, otherwise if
5374 another thread has a pending event for this breakpoint too,
5375 we'd discard its event (because the breakpoint that
5376 originally caused the event was no longer inserted). */
5377 context_switch (ecs);
5378 insert_breakpoints ();
5380 restart_threads (ecs->event_thread);
5382 /* If we have events pending, go through handle_inferior_event
5383 again, picking up a pending event at random. This avoids
5384 thread starvation. */
5386 /* But not if we just stepped over a watchpoint in order to let
5387 the instruction execute so we can evaluate its expression.
5388 The set of watchpoints that triggered is recorded in the
5389 breakpoint objects themselves (see bp->watchpoint_triggered).
5390 If we processed another event first, that other event could
5391 clobber this info. */
5392 if (ecs->event_thread->stepping_over_watchpoint)
5395 pending = iterate_over_threads (resumed_thread_with_pending_status,
5397 if (pending != NULL)
5399 struct thread_info *tp = ecs->event_thread;
5400 struct regcache *regcache;
5404 fprintf_unfiltered (gdb_stdlog,
5405 "infrun: found resumed threads with "
5406 "pending events, saving status\n");
5409 gdb_assert (pending != tp);
5411 /* Record the event thread's event for later. */
5412 save_waitstatus (tp, &ecs->ws);
5413 /* This was cleared early, by handle_inferior_event. Set it
5414 so this pending event is considered by
5418 gdb_assert (!tp->executing);
5420 regcache = get_thread_regcache (tp);
5421 tp->suspend.stop_pc = regcache_read_pc (regcache);
5425 fprintf_unfiltered (gdb_stdlog,
5426 "infrun: saved stop_pc=%s for %s "
5427 "(currently_stepping=%d)\n",
5428 paddress (target_gdbarch (),
5429 tp->suspend.stop_pc),
5430 target_pid_to_str (tp->ptid),
5431 currently_stepping (tp));
5434 /* This in-line step-over finished; clear this so we won't
5435 start a new one. This is what handle_signal_stop would
5436 do, if we returned false. */
5437 tp->stepping_over_breakpoint = 0;
5439 /* Wake up the event loop again. */
5440 mark_async_event_handler (infrun_async_inferior_event_token);
5442 prepare_to_wait (ecs);
5450 /* Come here when the program has stopped with a signal. */
5453 handle_signal_stop (struct execution_control_state *ecs)
5455 struct frame_info *frame;
5456 struct gdbarch *gdbarch;
5457 int stopped_by_watchpoint;
5458 enum stop_kind stop_soon;
5461 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5463 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5465 /* Do we need to clean up the state of a thread that has
5466 completed a displaced single-step? (Doing so usually affects
5467 the PC, so do it here, before we set stop_pc.) */
5468 if (finish_step_over (ecs))
5471 /* If we either finished a single-step or hit a breakpoint, but
5472 the user wanted this thread to be stopped, pretend we got a
5473 SIG0 (generic unsignaled stop). */
5474 if (ecs->event_thread->stop_requested
5475 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5476 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5478 ecs->event_thread->suspend.stop_pc
5479 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5483 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5484 struct gdbarch *reg_gdbarch = regcache->arch ();
5485 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5487 inferior_ptid = ecs->ptid;
5489 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5490 paddress (reg_gdbarch,
5491 ecs->event_thread->suspend.stop_pc));
5492 if (target_stopped_by_watchpoint ())
5496 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5498 if (target_stopped_data_address (current_top_target (), &addr))
5499 fprintf_unfiltered (gdb_stdlog,
5500 "infrun: stopped data address = %s\n",
5501 paddress (reg_gdbarch, addr));
5503 fprintf_unfiltered (gdb_stdlog,
5504 "infrun: (no data address available)\n");
5508 /* This is originated from start_remote(), start_inferior() and
5509 shared libraries hook functions. */
5510 stop_soon = get_inferior_stop_soon (ecs);
5511 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5513 context_switch (ecs);
5515 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5516 stop_print_frame = 1;
5521 /* This originates from attach_command(). We need to overwrite
5522 the stop_signal here, because some kernels don't ignore a
5523 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5524 See more comments in inferior.h. On the other hand, if we
5525 get a non-SIGSTOP, report it to the user - assume the backend
5526 will handle the SIGSTOP if it should show up later.
5528 Also consider that the attach is complete when we see a
5529 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5530 target extended-remote report it instead of a SIGSTOP
5531 (e.g. gdbserver). We already rely on SIGTRAP being our
5532 signal, so this is no exception.
5534 Also consider that the attach is complete when we see a
5535 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5536 the target to stop all threads of the inferior, in case the
5537 low level attach operation doesn't stop them implicitly. If
5538 they weren't stopped implicitly, then the stub will report a
5539 GDB_SIGNAL_0, meaning: stopped for no particular reason
5540 other than GDB's request. */
5541 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5542 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5543 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5544 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5546 stop_print_frame = 1;
5548 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5552 /* See if something interesting happened to the non-current thread. If
5553 so, then switch to that thread. */
5554 if (ecs->ptid != inferior_ptid)
5557 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5559 context_switch (ecs);
5561 if (deprecated_context_hook)
5562 deprecated_context_hook (ecs->event_thread->global_num);
5565 /* At this point, get hold of the now-current thread's frame. */
5566 frame = get_current_frame ();
5567 gdbarch = get_frame_arch (frame);
5569 /* Pull the single step breakpoints out of the target. */
5570 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5572 struct regcache *regcache;
5575 regcache = get_thread_regcache (ecs->event_thread);
5576 const address_space *aspace = regcache->aspace ();
5578 pc = regcache_read_pc (regcache);
5580 /* However, before doing so, if this single-step breakpoint was
5581 actually for another thread, set this thread up for moving
5583 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5586 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5590 fprintf_unfiltered (gdb_stdlog,
5591 "infrun: [%s] hit another thread's "
5592 "single-step breakpoint\n",
5593 target_pid_to_str (ecs->ptid));
5595 ecs->hit_singlestep_breakpoint = 1;
5602 fprintf_unfiltered (gdb_stdlog,
5603 "infrun: [%s] hit its "
5604 "single-step breakpoint\n",
5605 target_pid_to_str (ecs->ptid));
5609 delete_just_stopped_threads_single_step_breakpoints ();
5611 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5612 && ecs->event_thread->control.trap_expected
5613 && ecs->event_thread->stepping_over_watchpoint)
5614 stopped_by_watchpoint = 0;
5616 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5618 /* If necessary, step over this watchpoint. We'll be back to display
5620 if (stopped_by_watchpoint
5621 && (target_have_steppable_watchpoint
5622 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5624 /* At this point, we are stopped at an instruction which has
5625 attempted to write to a piece of memory under control of
5626 a watchpoint. The instruction hasn't actually executed
5627 yet. If we were to evaluate the watchpoint expression
5628 now, we would get the old value, and therefore no change
5629 would seem to have occurred.
5631 In order to make watchpoints work `right', we really need
5632 to complete the memory write, and then evaluate the
5633 watchpoint expression. We do this by single-stepping the
5636 It may not be necessary to disable the watchpoint to step over
5637 it. For example, the PA can (with some kernel cooperation)
5638 single step over a watchpoint without disabling the watchpoint.
5640 It is far more common to need to disable a watchpoint to step
5641 the inferior over it. If we have non-steppable watchpoints,
5642 we must disable the current watchpoint; it's simplest to
5643 disable all watchpoints.
5645 Any breakpoint at PC must also be stepped over -- if there's
5646 one, it will have already triggered before the watchpoint
5647 triggered, and we either already reported it to the user, or
5648 it didn't cause a stop and we called keep_going. In either
5649 case, if there was a breakpoint at PC, we must be trying to
5651 ecs->event_thread->stepping_over_watchpoint = 1;
5656 ecs->event_thread->stepping_over_breakpoint = 0;
5657 ecs->event_thread->stepping_over_watchpoint = 0;
5658 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5659 ecs->event_thread->control.stop_step = 0;
5660 stop_print_frame = 1;
5661 stopped_by_random_signal = 0;
5662 bpstat stop_chain = NULL;
5664 /* Hide inlined functions starting here, unless we just performed stepi or
5665 nexti. After stepi and nexti, always show the innermost frame (not any
5666 inline function call sites). */
5667 if (ecs->event_thread->control.step_range_end != 1)
5669 const address_space *aspace
5670 = get_thread_regcache (ecs->event_thread)->aspace ();
5672 /* skip_inline_frames is expensive, so we avoid it if we can
5673 determine that the address is one where functions cannot have
5674 been inlined. This improves performance with inferiors that
5675 load a lot of shared libraries, because the solib event
5676 breakpoint is defined as the address of a function (i.e. not
5677 inline). Note that we have to check the previous PC as well
5678 as the current one to catch cases when we have just
5679 single-stepped off a breakpoint prior to reinstating it.
5680 Note that we're assuming that the code we single-step to is
5681 not inline, but that's not definitive: there's nothing
5682 preventing the event breakpoint function from containing
5683 inlined code, and the single-step ending up there. If the
5684 user had set a breakpoint on that inlined code, the missing
5685 skip_inline_frames call would break things. Fortunately
5686 that's an extremely unlikely scenario. */
5687 if (!pc_at_non_inline_function (aspace,
5688 ecs->event_thread->suspend.stop_pc,
5690 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5691 && ecs->event_thread->control.trap_expected
5692 && pc_at_non_inline_function (aspace,
5693 ecs->event_thread->prev_pc,
5696 stop_chain = build_bpstat_chain (aspace,
5697 ecs->event_thread->suspend.stop_pc,
5699 skip_inline_frames (ecs->event_thread, stop_chain);
5701 /* Re-fetch current thread's frame in case that invalidated
5703 frame = get_current_frame ();
5704 gdbarch = get_frame_arch (frame);
5708 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5709 && ecs->event_thread->control.trap_expected
5710 && gdbarch_single_step_through_delay_p (gdbarch)
5711 && currently_stepping (ecs->event_thread))
5713 /* We're trying to step off a breakpoint. Turns out that we're
5714 also on an instruction that needs to be stepped multiple
5715 times before it's been fully executing. E.g., architectures
5716 with a delay slot. It needs to be stepped twice, once for
5717 the instruction and once for the delay slot. */
5718 int step_through_delay
5719 = gdbarch_single_step_through_delay (gdbarch, frame);
5721 if (debug_infrun && step_through_delay)
5722 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5723 if (ecs->event_thread->control.step_range_end == 0
5724 && step_through_delay)
5726 /* The user issued a continue when stopped at a breakpoint.
5727 Set up for another trap and get out of here. */
5728 ecs->event_thread->stepping_over_breakpoint = 1;
5732 else if (step_through_delay)
5734 /* The user issued a step when stopped at a breakpoint.
5735 Maybe we should stop, maybe we should not - the delay
5736 slot *might* correspond to a line of source. In any
5737 case, don't decide that here, just set
5738 ecs->stepping_over_breakpoint, making sure we
5739 single-step again before breakpoints are re-inserted. */
5740 ecs->event_thread->stepping_over_breakpoint = 1;
5744 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5745 handles this event. */
5746 ecs->event_thread->control.stop_bpstat
5747 = bpstat_stop_status (get_current_regcache ()->aspace (),
5748 ecs->event_thread->suspend.stop_pc,
5749 ecs->event_thread, &ecs->ws, stop_chain);
5751 /* Following in case break condition called a
5753 stop_print_frame = 1;
5755 /* This is where we handle "moribund" watchpoints. Unlike
5756 software breakpoints traps, hardware watchpoint traps are
5757 always distinguishable from random traps. If no high-level
5758 watchpoint is associated with the reported stop data address
5759 anymore, then the bpstat does not explain the signal ---
5760 simply make sure to ignore it if `stopped_by_watchpoint' is
5764 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5765 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5767 && stopped_by_watchpoint)
5768 fprintf_unfiltered (gdb_stdlog,
5769 "infrun: no user watchpoint explains "
5770 "watchpoint SIGTRAP, ignoring\n");
5772 /* NOTE: cagney/2003-03-29: These checks for a random signal
5773 at one stage in the past included checks for an inferior
5774 function call's call dummy's return breakpoint. The original
5775 comment, that went with the test, read:
5777 ``End of a stack dummy. Some systems (e.g. Sony news) give
5778 another signal besides SIGTRAP, so check here as well as
5781 If someone ever tries to get call dummys on a
5782 non-executable stack to work (where the target would stop
5783 with something like a SIGSEGV), then those tests might need
5784 to be re-instated. Given, however, that the tests were only
5785 enabled when momentary breakpoints were not being used, I
5786 suspect that it won't be the case.
5788 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5789 be necessary for call dummies on a non-executable stack on
5792 /* See if the breakpoints module can explain the signal. */
5794 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5795 ecs->event_thread->suspend.stop_signal);
5797 /* Maybe this was a trap for a software breakpoint that has since
5799 if (random_signal && target_stopped_by_sw_breakpoint ())
5801 if (program_breakpoint_here_p (gdbarch,
5802 ecs->event_thread->suspend.stop_pc))
5804 struct regcache *regcache;
5807 /* Re-adjust PC to what the program would see if GDB was not
5809 regcache = get_thread_regcache (ecs->event_thread);
5810 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5813 gdb::optional<scoped_restore_tmpl<int>>
5814 restore_operation_disable;
5816 if (record_full_is_used ())
5817 restore_operation_disable.emplace
5818 (record_full_gdb_operation_disable_set ());
5820 regcache_write_pc (regcache,
5821 ecs->event_thread->suspend.stop_pc + decr_pc);
5826 /* A delayed software breakpoint event. Ignore the trap. */
5828 fprintf_unfiltered (gdb_stdlog,
5829 "infrun: delayed software breakpoint "
5830 "trap, ignoring\n");
5835 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5836 has since been removed. */
5837 if (random_signal && target_stopped_by_hw_breakpoint ())
5839 /* A delayed hardware breakpoint event. Ignore the trap. */
5841 fprintf_unfiltered (gdb_stdlog,
5842 "infrun: delayed hardware breakpoint/watchpoint "
5843 "trap, ignoring\n");
5847 /* If not, perhaps stepping/nexting can. */
5849 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5850 && currently_stepping (ecs->event_thread));
5852 /* Perhaps the thread hit a single-step breakpoint of _another_
5853 thread. Single-step breakpoints are transparent to the
5854 breakpoints module. */
5856 random_signal = !ecs->hit_singlestep_breakpoint;
5858 /* No? Perhaps we got a moribund watchpoint. */
5860 random_signal = !stopped_by_watchpoint;
5862 /* Always stop if the user explicitly requested this thread to
5864 if (ecs->event_thread->stop_requested)
5868 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
5871 /* For the program's own signals, act according to
5872 the signal handling tables. */
5876 /* Signal not for debugging purposes. */
5877 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5878 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5881 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5882 gdb_signal_to_symbol_string (stop_signal));
5884 stopped_by_random_signal = 1;
5886 /* Always stop on signals if we're either just gaining control
5887 of the program, or the user explicitly requested this thread
5888 to remain stopped. */
5889 if (stop_soon != NO_STOP_QUIETLY
5890 || ecs->event_thread->stop_requested
5892 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5898 /* Notify observers the signal has "handle print" set. Note we
5899 returned early above if stopping; normal_stop handles the
5900 printing in that case. */
5901 if (signal_print[ecs->event_thread->suspend.stop_signal])
5903 /* The signal table tells us to print about this signal. */
5904 target_terminal::ours_for_output ();
5905 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
5906 target_terminal::inferior ();
5909 /* Clear the signal if it should not be passed. */
5910 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5911 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5913 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
5914 && ecs->event_thread->control.trap_expected
5915 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5917 /* We were just starting a new sequence, attempting to
5918 single-step off of a breakpoint and expecting a SIGTRAP.
5919 Instead this signal arrives. This signal will take us out
5920 of the stepping range so GDB needs to remember to, when
5921 the signal handler returns, resume stepping off that
5923 /* To simplify things, "continue" is forced to use the same
5924 code paths as single-step - set a breakpoint at the
5925 signal return address and then, once hit, step off that
5928 fprintf_unfiltered (gdb_stdlog,
5929 "infrun: signal arrived while stepping over "
5932 insert_hp_step_resume_breakpoint_at_frame (frame);
5933 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5934 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5935 ecs->event_thread->control.trap_expected = 0;
5937 /* If we were nexting/stepping some other thread, switch to
5938 it, so that we don't continue it, losing control. */
5939 if (!switch_back_to_stepped_thread (ecs))
5944 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5945 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
5947 || ecs->event_thread->control.step_range_end == 1)
5948 && frame_id_eq (get_stack_frame_id (frame),
5949 ecs->event_thread->control.step_stack_frame_id)
5950 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5952 /* The inferior is about to take a signal that will take it
5953 out of the single step range. Set a breakpoint at the
5954 current PC (which is presumably where the signal handler
5955 will eventually return) and then allow the inferior to
5958 Note that this is only needed for a signal delivered
5959 while in the single-step range. Nested signals aren't a
5960 problem as they eventually all return. */
5962 fprintf_unfiltered (gdb_stdlog,
5963 "infrun: signal may take us out of "
5964 "single-step range\n");
5966 clear_step_over_info ();
5967 insert_hp_step_resume_breakpoint_at_frame (frame);
5968 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5969 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5970 ecs->event_thread->control.trap_expected = 0;
5975 /* Note: step_resume_breakpoint may be non-NULL. This occures
5976 when either there's a nested signal, or when there's a
5977 pending signal enabled just as the signal handler returns
5978 (leaving the inferior at the step-resume-breakpoint without
5979 actually executing it). Either way continue until the
5980 breakpoint is really hit. */
5982 if (!switch_back_to_stepped_thread (ecs))
5985 fprintf_unfiltered (gdb_stdlog,
5986 "infrun: random signal, keep going\n");
5993 process_event_stop_test (ecs);
5996 /* Come here when we've got some debug event / signal we can explain
5997 (IOW, not a random signal), and test whether it should cause a
5998 stop, or whether we should resume the inferior (transparently).
5999 E.g., could be a breakpoint whose condition evaluates false; we
6000 could be still stepping within the line; etc. */
6003 process_event_stop_test (struct execution_control_state *ecs)
6005 struct symtab_and_line stop_pc_sal;
6006 struct frame_info *frame;
6007 struct gdbarch *gdbarch;
6008 CORE_ADDR jmp_buf_pc;
6009 struct bpstat_what what;
6011 /* Handle cases caused by hitting a breakpoint. */
6013 frame = get_current_frame ();
6014 gdbarch = get_frame_arch (frame);
6016 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6018 if (what.call_dummy)
6020 stop_stack_dummy = what.call_dummy;
6023 /* A few breakpoint types have callbacks associated (e.g.,
6024 bp_jit_event). Run them now. */
6025 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6027 /* If we hit an internal event that triggers symbol changes, the
6028 current frame will be invalidated within bpstat_what (e.g., if we
6029 hit an internal solib event). Re-fetch it. */
6030 frame = get_current_frame ();
6031 gdbarch = get_frame_arch (frame);
6033 switch (what.main_action)
6035 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6036 /* If we hit the breakpoint at longjmp while stepping, we
6037 install a momentary breakpoint at the target of the
6041 fprintf_unfiltered (gdb_stdlog,
6042 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6044 ecs->event_thread->stepping_over_breakpoint = 1;
6046 if (what.is_longjmp)
6048 struct value *arg_value;
6050 /* If we set the longjmp breakpoint via a SystemTap probe,
6051 then use it to extract the arguments. The destination PC
6052 is the third argument to the probe. */
6053 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6056 jmp_buf_pc = value_as_address (arg_value);
6057 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6059 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6060 || !gdbarch_get_longjmp_target (gdbarch,
6061 frame, &jmp_buf_pc))
6064 fprintf_unfiltered (gdb_stdlog,
6065 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6066 "(!gdbarch_get_longjmp_target)\n");
6071 /* Insert a breakpoint at resume address. */
6072 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6075 check_exception_resume (ecs, frame);
6079 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6081 struct frame_info *init_frame;
6083 /* There are several cases to consider.
6085 1. The initiating frame no longer exists. In this case we
6086 must stop, because the exception or longjmp has gone too
6089 2. The initiating frame exists, and is the same as the
6090 current frame. We stop, because the exception or longjmp
6093 3. The initiating frame exists and is different from the
6094 current frame. This means the exception or longjmp has
6095 been caught beneath the initiating frame, so keep going.
6097 4. longjmp breakpoint has been placed just to protect
6098 against stale dummy frames and user is not interested in
6099 stopping around longjmps. */
6102 fprintf_unfiltered (gdb_stdlog,
6103 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6105 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6107 delete_exception_resume_breakpoint (ecs->event_thread);
6109 if (what.is_longjmp)
6111 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6113 if (!frame_id_p (ecs->event_thread->initiating_frame))
6121 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6125 struct frame_id current_id
6126 = get_frame_id (get_current_frame ());
6127 if (frame_id_eq (current_id,
6128 ecs->event_thread->initiating_frame))
6130 /* Case 2. Fall through. */
6140 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6142 delete_step_resume_breakpoint (ecs->event_thread);
6144 end_stepping_range (ecs);
6148 case BPSTAT_WHAT_SINGLE:
6150 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6151 ecs->event_thread->stepping_over_breakpoint = 1;
6152 /* Still need to check other stuff, at least the case where we
6153 are stepping and step out of the right range. */
6156 case BPSTAT_WHAT_STEP_RESUME:
6158 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6160 delete_step_resume_breakpoint (ecs->event_thread);
6161 if (ecs->event_thread->control.proceed_to_finish
6162 && execution_direction == EXEC_REVERSE)
6164 struct thread_info *tp = ecs->event_thread;
6166 /* We are finishing a function in reverse, and just hit the
6167 step-resume breakpoint at the start address of the
6168 function, and we're almost there -- just need to back up
6169 by one more single-step, which should take us back to the
6171 tp->control.step_range_start = tp->control.step_range_end = 1;
6175 fill_in_stop_func (gdbarch, ecs);
6176 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6177 && execution_direction == EXEC_REVERSE)
6179 /* We are stepping over a function call in reverse, and just
6180 hit the step-resume breakpoint at the start address of
6181 the function. Go back to single-stepping, which should
6182 take us back to the function call. */
6183 ecs->event_thread->stepping_over_breakpoint = 1;
6189 case BPSTAT_WHAT_STOP_NOISY:
6191 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6192 stop_print_frame = 1;
6194 /* Assume the thread stopped for a breapoint. We'll still check
6195 whether a/the breakpoint is there when the thread is next
6197 ecs->event_thread->stepping_over_breakpoint = 1;
6202 case BPSTAT_WHAT_STOP_SILENT:
6204 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6205 stop_print_frame = 0;
6207 /* Assume the thread stopped for a breapoint. We'll still check
6208 whether a/the breakpoint is there when the thread is next
6210 ecs->event_thread->stepping_over_breakpoint = 1;
6214 case BPSTAT_WHAT_HP_STEP_RESUME:
6216 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6218 delete_step_resume_breakpoint (ecs->event_thread);
6219 if (ecs->event_thread->step_after_step_resume_breakpoint)
6221 /* Back when the step-resume breakpoint was inserted, we
6222 were trying to single-step off a breakpoint. Go back to
6224 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6225 ecs->event_thread->stepping_over_breakpoint = 1;
6231 case BPSTAT_WHAT_KEEP_CHECKING:
6235 /* If we stepped a permanent breakpoint and we had a high priority
6236 step-resume breakpoint for the address we stepped, but we didn't
6237 hit it, then we must have stepped into the signal handler. The
6238 step-resume was only necessary to catch the case of _not_
6239 stepping into the handler, so delete it, and fall through to
6240 checking whether the step finished. */
6241 if (ecs->event_thread->stepped_breakpoint)
6243 struct breakpoint *sr_bp
6244 = ecs->event_thread->control.step_resume_breakpoint;
6247 && sr_bp->loc->permanent
6248 && sr_bp->type == bp_hp_step_resume
6249 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6252 fprintf_unfiltered (gdb_stdlog,
6253 "infrun: stepped permanent breakpoint, stopped in "
6255 delete_step_resume_breakpoint (ecs->event_thread);
6256 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6260 /* We come here if we hit a breakpoint but should not stop for it.
6261 Possibly we also were stepping and should stop for that. So fall
6262 through and test for stepping. But, if not stepping, do not
6265 /* In all-stop mode, if we're currently stepping but have stopped in
6266 some other thread, we need to switch back to the stepped thread. */
6267 if (switch_back_to_stepped_thread (ecs))
6270 if (ecs->event_thread->control.step_resume_breakpoint)
6273 fprintf_unfiltered (gdb_stdlog,
6274 "infrun: step-resume breakpoint is inserted\n");
6276 /* Having a step-resume breakpoint overrides anything
6277 else having to do with stepping commands until
6278 that breakpoint is reached. */
6283 if (ecs->event_thread->control.step_range_end == 0)
6286 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6287 /* Likewise if we aren't even stepping. */
6292 /* Re-fetch current thread's frame in case the code above caused
6293 the frame cache to be re-initialized, making our FRAME variable
6294 a dangling pointer. */
6295 frame = get_current_frame ();
6296 gdbarch = get_frame_arch (frame);
6297 fill_in_stop_func (gdbarch, ecs);
6299 /* If stepping through a line, keep going if still within it.
6301 Note that step_range_end is the address of the first instruction
6302 beyond the step range, and NOT the address of the last instruction
6305 Note also that during reverse execution, we may be stepping
6306 through a function epilogue and therefore must detect when
6307 the current-frame changes in the middle of a line. */
6309 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6311 && (execution_direction != EXEC_REVERSE
6312 || frame_id_eq (get_frame_id (frame),
6313 ecs->event_thread->control.step_frame_id)))
6317 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6318 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6319 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6321 /* Tentatively re-enable range stepping; `resume' disables it if
6322 necessary (e.g., if we're stepping over a breakpoint or we
6323 have software watchpoints). */
6324 ecs->event_thread->control.may_range_step = 1;
6326 /* When stepping backward, stop at beginning of line range
6327 (unless it's the function entry point, in which case
6328 keep going back to the call point). */
6329 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6330 if (stop_pc == ecs->event_thread->control.step_range_start
6331 && stop_pc != ecs->stop_func_start
6332 && execution_direction == EXEC_REVERSE)
6333 end_stepping_range (ecs);
6340 /* We stepped out of the stepping range. */
6342 /* If we are stepping at the source level and entered the runtime
6343 loader dynamic symbol resolution code...
6345 EXEC_FORWARD: we keep on single stepping until we exit the run
6346 time loader code and reach the callee's address.
6348 EXEC_REVERSE: we've already executed the callee (backward), and
6349 the runtime loader code is handled just like any other
6350 undebuggable function call. Now we need only keep stepping
6351 backward through the trampoline code, and that's handled further
6352 down, so there is nothing for us to do here. */
6354 if (execution_direction != EXEC_REVERSE
6355 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6356 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6358 CORE_ADDR pc_after_resolver =
6359 gdbarch_skip_solib_resolver (gdbarch,
6360 ecs->event_thread->suspend.stop_pc);
6363 fprintf_unfiltered (gdb_stdlog,
6364 "infrun: stepped into dynsym resolve code\n");
6366 if (pc_after_resolver)
6368 /* Set up a step-resume breakpoint at the address
6369 indicated by SKIP_SOLIB_RESOLVER. */
6370 symtab_and_line sr_sal;
6371 sr_sal.pc = pc_after_resolver;
6372 sr_sal.pspace = get_frame_program_space (frame);
6374 insert_step_resume_breakpoint_at_sal (gdbarch,
6375 sr_sal, null_frame_id);
6382 /* Step through an indirect branch thunk. */
6383 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6384 && gdbarch_in_indirect_branch_thunk (gdbarch,
6385 ecs->event_thread->suspend.stop_pc))
6388 fprintf_unfiltered (gdb_stdlog,
6389 "infrun: stepped into indirect branch thunk\n");
6394 if (ecs->event_thread->control.step_range_end != 1
6395 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6396 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6397 && get_frame_type (frame) == SIGTRAMP_FRAME)
6400 fprintf_unfiltered (gdb_stdlog,
6401 "infrun: stepped into signal trampoline\n");
6402 /* The inferior, while doing a "step" or "next", has ended up in
6403 a signal trampoline (either by a signal being delivered or by
6404 the signal handler returning). Just single-step until the
6405 inferior leaves the trampoline (either by calling the handler
6411 /* If we're in the return path from a shared library trampoline,
6412 we want to proceed through the trampoline when stepping. */
6413 /* macro/2012-04-25: This needs to come before the subroutine
6414 call check below as on some targets return trampolines look
6415 like subroutine calls (MIPS16 return thunks). */
6416 if (gdbarch_in_solib_return_trampoline (gdbarch,
6417 ecs->event_thread->suspend.stop_pc,
6418 ecs->stop_func_name)
6419 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6421 /* Determine where this trampoline returns. */
6422 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6423 CORE_ADDR real_stop_pc
6424 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6427 fprintf_unfiltered (gdb_stdlog,
6428 "infrun: stepped into solib return tramp\n");
6430 /* Only proceed through if we know where it's going. */
6433 /* And put the step-breakpoint there and go until there. */
6434 symtab_and_line sr_sal;
6435 sr_sal.pc = real_stop_pc;
6436 sr_sal.section = find_pc_overlay (sr_sal.pc);
6437 sr_sal.pspace = get_frame_program_space (frame);
6439 /* Do not specify what the fp should be when we stop since
6440 on some machines the prologue is where the new fp value
6442 insert_step_resume_breakpoint_at_sal (gdbarch,
6443 sr_sal, null_frame_id);
6445 /* Restart without fiddling with the step ranges or
6452 /* Check for subroutine calls. The check for the current frame
6453 equalling the step ID is not necessary - the check of the
6454 previous frame's ID is sufficient - but it is a common case and
6455 cheaper than checking the previous frame's ID.
6457 NOTE: frame_id_eq will never report two invalid frame IDs as
6458 being equal, so to get into this block, both the current and
6459 previous frame must have valid frame IDs. */
6460 /* The outer_frame_id check is a heuristic to detect stepping
6461 through startup code. If we step over an instruction which
6462 sets the stack pointer from an invalid value to a valid value,
6463 we may detect that as a subroutine call from the mythical
6464 "outermost" function. This could be fixed by marking
6465 outermost frames as !stack_p,code_p,special_p. Then the
6466 initial outermost frame, before sp was valid, would
6467 have code_addr == &_start. See the comment in frame_id_eq
6469 if (!frame_id_eq (get_stack_frame_id (frame),
6470 ecs->event_thread->control.step_stack_frame_id)
6471 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6472 ecs->event_thread->control.step_stack_frame_id)
6473 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6475 || (ecs->event_thread->control.step_start_function
6476 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6478 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6479 CORE_ADDR real_stop_pc;
6482 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6484 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6486 /* I presume that step_over_calls is only 0 when we're
6487 supposed to be stepping at the assembly language level
6488 ("stepi"). Just stop. */
6489 /* And this works the same backward as frontward. MVS */
6490 end_stepping_range (ecs);
6494 /* Reverse stepping through solib trampolines. */
6496 if (execution_direction == EXEC_REVERSE
6497 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6498 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6499 || (ecs->stop_func_start == 0
6500 && in_solib_dynsym_resolve_code (stop_pc))))
6502 /* Any solib trampoline code can be handled in reverse
6503 by simply continuing to single-step. We have already
6504 executed the solib function (backwards), and a few
6505 steps will take us back through the trampoline to the
6511 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6513 /* We're doing a "next".
6515 Normal (forward) execution: set a breakpoint at the
6516 callee's return address (the address at which the caller
6519 Reverse (backward) execution. set the step-resume
6520 breakpoint at the start of the function that we just
6521 stepped into (backwards), and continue to there. When we
6522 get there, we'll need to single-step back to the caller. */
6524 if (execution_direction == EXEC_REVERSE)
6526 /* If we're already at the start of the function, we've either
6527 just stepped backward into a single instruction function,
6528 or stepped back out of a signal handler to the first instruction
6529 of the function. Just keep going, which will single-step back
6531 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6533 /* Normal function call return (static or dynamic). */
6534 symtab_and_line sr_sal;
6535 sr_sal.pc = ecs->stop_func_start;
6536 sr_sal.pspace = get_frame_program_space (frame);
6537 insert_step_resume_breakpoint_at_sal (gdbarch,
6538 sr_sal, null_frame_id);
6542 insert_step_resume_breakpoint_at_caller (frame);
6548 /* If we are in a function call trampoline (a stub between the
6549 calling routine and the real function), locate the real
6550 function. That's what tells us (a) whether we want to step
6551 into it at all, and (b) what prologue we want to run to the
6552 end of, if we do step into it. */
6553 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6554 if (real_stop_pc == 0)
6555 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6556 if (real_stop_pc != 0)
6557 ecs->stop_func_start = real_stop_pc;
6559 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6561 symtab_and_line sr_sal;
6562 sr_sal.pc = ecs->stop_func_start;
6563 sr_sal.pspace = get_frame_program_space (frame);
6565 insert_step_resume_breakpoint_at_sal (gdbarch,
6566 sr_sal, null_frame_id);
6571 /* If we have line number information for the function we are
6572 thinking of stepping into and the function isn't on the skip
6575 If there are several symtabs at that PC (e.g. with include
6576 files), just want to know whether *any* of them have line
6577 numbers. find_pc_line handles this. */
6579 struct symtab_and_line tmp_sal;
6581 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6582 if (tmp_sal.line != 0
6583 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6586 if (execution_direction == EXEC_REVERSE)
6587 handle_step_into_function_backward (gdbarch, ecs);
6589 handle_step_into_function (gdbarch, ecs);
6594 /* If we have no line number and the step-stop-if-no-debug is
6595 set, we stop the step so that the user has a chance to switch
6596 in assembly mode. */
6597 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6598 && step_stop_if_no_debug)
6600 end_stepping_range (ecs);
6604 if (execution_direction == EXEC_REVERSE)
6606 /* If we're already at the start of the function, we've either just
6607 stepped backward into a single instruction function without line
6608 number info, or stepped back out of a signal handler to the first
6609 instruction of the function without line number info. Just keep
6610 going, which will single-step back to the caller. */
6611 if (ecs->stop_func_start != stop_pc)
6613 /* Set a breakpoint at callee's start address.
6614 From there we can step once and be back in the caller. */
6615 symtab_and_line sr_sal;
6616 sr_sal.pc = ecs->stop_func_start;
6617 sr_sal.pspace = get_frame_program_space (frame);
6618 insert_step_resume_breakpoint_at_sal (gdbarch,
6619 sr_sal, null_frame_id);
6623 /* Set a breakpoint at callee's return address (the address
6624 at which the caller will resume). */
6625 insert_step_resume_breakpoint_at_caller (frame);
6631 /* Reverse stepping through solib trampolines. */
6633 if (execution_direction == EXEC_REVERSE
6634 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6636 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6638 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6639 || (ecs->stop_func_start == 0
6640 && in_solib_dynsym_resolve_code (stop_pc)))
6642 /* Any solib trampoline code can be handled in reverse
6643 by simply continuing to single-step. We have already
6644 executed the solib function (backwards), and a few
6645 steps will take us back through the trampoline to the
6650 else if (in_solib_dynsym_resolve_code (stop_pc))
6652 /* Stepped backward into the solib dynsym resolver.
6653 Set a breakpoint at its start and continue, then
6654 one more step will take us out. */
6655 symtab_and_line sr_sal;
6656 sr_sal.pc = ecs->stop_func_start;
6657 sr_sal.pspace = get_frame_program_space (frame);
6658 insert_step_resume_breakpoint_at_sal (gdbarch,
6659 sr_sal, null_frame_id);
6665 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6667 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6668 the trampoline processing logic, however, there are some trampolines
6669 that have no names, so we should do trampoline handling first. */
6670 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6671 && ecs->stop_func_name == NULL
6672 && stop_pc_sal.line == 0)
6675 fprintf_unfiltered (gdb_stdlog,
6676 "infrun: stepped into undebuggable function\n");
6678 /* The inferior just stepped into, or returned to, an
6679 undebuggable function (where there is no debugging information
6680 and no line number corresponding to the address where the
6681 inferior stopped). Since we want to skip this kind of code,
6682 we keep going until the inferior returns from this
6683 function - unless the user has asked us not to (via
6684 set step-mode) or we no longer know how to get back
6685 to the call site. */
6686 if (step_stop_if_no_debug
6687 || !frame_id_p (frame_unwind_caller_id (frame)))
6689 /* If we have no line number and the step-stop-if-no-debug
6690 is set, we stop the step so that the user has a chance to
6691 switch in assembly mode. */
6692 end_stepping_range (ecs);
6697 /* Set a breakpoint at callee's return address (the address
6698 at which the caller will resume). */
6699 insert_step_resume_breakpoint_at_caller (frame);
6705 if (ecs->event_thread->control.step_range_end == 1)
6707 /* It is stepi or nexti. We always want to stop stepping after
6710 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6711 end_stepping_range (ecs);
6715 if (stop_pc_sal.line == 0)
6717 /* We have no line number information. That means to stop
6718 stepping (does this always happen right after one instruction,
6719 when we do "s" in a function with no line numbers,
6720 or can this happen as a result of a return or longjmp?). */
6722 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6723 end_stepping_range (ecs);
6727 /* Look for "calls" to inlined functions, part one. If the inline
6728 frame machinery detected some skipped call sites, we have entered
6729 a new inline function. */
6731 if (frame_id_eq (get_frame_id (get_current_frame ()),
6732 ecs->event_thread->control.step_frame_id)
6733 && inline_skipped_frames (ecs->event_thread))
6736 fprintf_unfiltered (gdb_stdlog,
6737 "infrun: stepped into inlined function\n");
6739 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6741 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6743 /* For "step", we're going to stop. But if the call site
6744 for this inlined function is on the same source line as
6745 we were previously stepping, go down into the function
6746 first. Otherwise stop at the call site. */
6748 if (call_sal.line == ecs->event_thread->current_line
6749 && call_sal.symtab == ecs->event_thread->current_symtab)
6750 step_into_inline_frame (ecs->event_thread);
6752 end_stepping_range (ecs);
6757 /* For "next", we should stop at the call site if it is on a
6758 different source line. Otherwise continue through the
6759 inlined function. */
6760 if (call_sal.line == ecs->event_thread->current_line
6761 && call_sal.symtab == ecs->event_thread->current_symtab)
6764 end_stepping_range (ecs);
6769 /* Look for "calls" to inlined functions, part two. If we are still
6770 in the same real function we were stepping through, but we have
6771 to go further up to find the exact frame ID, we are stepping
6772 through a more inlined call beyond its call site. */
6774 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6775 && !frame_id_eq (get_frame_id (get_current_frame ()),
6776 ecs->event_thread->control.step_frame_id)
6777 && stepped_in_from (get_current_frame (),
6778 ecs->event_thread->control.step_frame_id))
6781 fprintf_unfiltered (gdb_stdlog,
6782 "infrun: stepping through inlined function\n");
6784 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6787 end_stepping_range (ecs);
6791 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6792 && (ecs->event_thread->current_line != stop_pc_sal.line
6793 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6795 /* We are at the start of a different line. So stop. Note that
6796 we don't stop if we step into the middle of a different line.
6797 That is said to make things like for (;;) statements work
6800 fprintf_unfiltered (gdb_stdlog,
6801 "infrun: stepped to a different line\n");
6802 end_stepping_range (ecs);
6806 /* We aren't done stepping.
6808 Optimize by setting the stepping range to the line.
6809 (We might not be in the original line, but if we entered a
6810 new line in mid-statement, we continue stepping. This makes
6811 things like for(;;) statements work better.) */
6813 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6814 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6815 ecs->event_thread->control.may_range_step = 1;
6816 set_step_info (frame, stop_pc_sal);
6819 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6823 /* In all-stop mode, if we're currently stepping but have stopped in
6824 some other thread, we may need to switch back to the stepped
6825 thread. Returns true we set the inferior running, false if we left
6826 it stopped (and the event needs further processing). */
6829 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6831 if (!target_is_non_stop_p ())
6833 struct thread_info *stepping_thread;
6835 /* If any thread is blocked on some internal breakpoint, and we
6836 simply need to step over that breakpoint to get it going
6837 again, do that first. */
6839 /* However, if we see an event for the stepping thread, then we
6840 know all other threads have been moved past their breakpoints
6841 already. Let the caller check whether the step is finished,
6842 etc., before deciding to move it past a breakpoint. */
6843 if (ecs->event_thread->control.step_range_end != 0)
6846 /* Check if the current thread is blocked on an incomplete
6847 step-over, interrupted by a random signal. */
6848 if (ecs->event_thread->control.trap_expected
6849 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6853 fprintf_unfiltered (gdb_stdlog,
6854 "infrun: need to finish step-over of [%s]\n",
6855 target_pid_to_str (ecs->event_thread->ptid));
6861 /* Check if the current thread is blocked by a single-step
6862 breakpoint of another thread. */
6863 if (ecs->hit_singlestep_breakpoint)
6867 fprintf_unfiltered (gdb_stdlog,
6868 "infrun: need to step [%s] over single-step "
6870 target_pid_to_str (ecs->ptid));
6876 /* If this thread needs yet another step-over (e.g., stepping
6877 through a delay slot), do it first before moving on to
6879 if (thread_still_needs_step_over (ecs->event_thread))
6883 fprintf_unfiltered (gdb_stdlog,
6884 "infrun: thread [%s] still needs step-over\n",
6885 target_pid_to_str (ecs->event_thread->ptid));
6891 /* If scheduler locking applies even if not stepping, there's no
6892 need to walk over threads. Above we've checked whether the
6893 current thread is stepping. If some other thread not the
6894 event thread is stepping, then it must be that scheduler
6895 locking is not in effect. */
6896 if (schedlock_applies (ecs->event_thread))
6899 /* Otherwise, we no longer expect a trap in the current thread.
6900 Clear the trap_expected flag before switching back -- this is
6901 what keep_going does as well, if we call it. */
6902 ecs->event_thread->control.trap_expected = 0;
6904 /* Likewise, clear the signal if it should not be passed. */
6905 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6906 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6908 /* Do all pending step-overs before actually proceeding with
6910 if (start_step_over ())
6912 prepare_to_wait (ecs);
6916 /* Look for the stepping/nexting thread. */
6917 stepping_thread = NULL;
6919 for (thread_info *tp : all_non_exited_threads ())
6921 /* Ignore threads of processes the caller is not
6924 && tp->ptid.pid () != ecs->ptid.pid ())
6927 /* When stepping over a breakpoint, we lock all threads
6928 except the one that needs to move past the breakpoint.
6929 If a non-event thread has this set, the "incomplete
6930 step-over" check above should have caught it earlier. */
6931 if (tp->control.trap_expected)
6933 internal_error (__FILE__, __LINE__,
6934 "[%s] has inconsistent state: "
6935 "trap_expected=%d\n",
6936 target_pid_to_str (tp->ptid),
6937 tp->control.trap_expected);
6940 /* Did we find the stepping thread? */
6941 if (tp->control.step_range_end)
6943 /* Yep. There should only one though. */
6944 gdb_assert (stepping_thread == NULL);
6946 /* The event thread is handled at the top, before we
6948 gdb_assert (tp != ecs->event_thread);
6950 /* If some thread other than the event thread is
6951 stepping, then scheduler locking can't be in effect,
6952 otherwise we wouldn't have resumed the current event
6953 thread in the first place. */
6954 gdb_assert (!schedlock_applies (tp));
6956 stepping_thread = tp;
6960 if (stepping_thread != NULL)
6963 fprintf_unfiltered (gdb_stdlog,
6964 "infrun: switching back to stepped thread\n");
6966 if (keep_going_stepped_thread (stepping_thread))
6968 prepare_to_wait (ecs);
6977 /* Set a previously stepped thread back to stepping. Returns true on
6978 success, false if the resume is not possible (e.g., the thread
6982 keep_going_stepped_thread (struct thread_info *tp)
6984 struct frame_info *frame;
6985 struct execution_control_state ecss;
6986 struct execution_control_state *ecs = &ecss;
6988 /* If the stepping thread exited, then don't try to switch back and
6989 resume it, which could fail in several different ways depending
6990 on the target. Instead, just keep going.
6992 We can find a stepping dead thread in the thread list in two
6995 - The target supports thread exit events, and when the target
6996 tries to delete the thread from the thread list, inferior_ptid
6997 pointed at the exiting thread. In such case, calling
6998 delete_thread does not really remove the thread from the list;
6999 instead, the thread is left listed, with 'exited' state.
7001 - The target's debug interface does not support thread exit
7002 events, and so we have no idea whatsoever if the previously
7003 stepping thread is still alive. For that reason, we need to
7004 synchronously query the target now. */
7006 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
7009 fprintf_unfiltered (gdb_stdlog,
7010 "infrun: not resuming previously "
7011 "stepped thread, it has vanished\n");
7018 fprintf_unfiltered (gdb_stdlog,
7019 "infrun: resuming previously stepped thread\n");
7021 reset_ecs (ecs, tp);
7022 switch_to_thread (tp);
7024 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7025 frame = get_current_frame ();
7027 /* If the PC of the thread we were trying to single-step has
7028 changed, then that thread has trapped or been signaled, but the
7029 event has not been reported to GDB yet. Re-poll the target
7030 looking for this particular thread's event (i.e. temporarily
7031 enable schedlock) by:
7033 - setting a break at the current PC
7034 - resuming that particular thread, only (by setting trap
7037 This prevents us continuously moving the single-step breakpoint
7038 forward, one instruction at a time, overstepping. */
7040 if (tp->suspend.stop_pc != tp->prev_pc)
7045 fprintf_unfiltered (gdb_stdlog,
7046 "infrun: expected thread advanced also (%s -> %s)\n",
7047 paddress (target_gdbarch (), tp->prev_pc),
7048 paddress (target_gdbarch (), tp->suspend.stop_pc));
7050 /* Clear the info of the previous step-over, as it's no longer
7051 valid (if the thread was trying to step over a breakpoint, it
7052 has already succeeded). It's what keep_going would do too,
7053 if we called it. Do this before trying to insert the sss
7054 breakpoint, otherwise if we were previously trying to step
7055 over this exact address in another thread, the breakpoint is
7057 clear_step_over_info ();
7058 tp->control.trap_expected = 0;
7060 insert_single_step_breakpoint (get_frame_arch (frame),
7061 get_frame_address_space (frame),
7062 tp->suspend.stop_pc);
7065 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7066 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7071 fprintf_unfiltered (gdb_stdlog,
7072 "infrun: expected thread still hasn't advanced\n");
7074 keep_going_pass_signal (ecs);
7079 /* Is thread TP in the middle of (software or hardware)
7080 single-stepping? (Note the result of this function must never be
7081 passed directly as target_resume's STEP parameter.) */
7084 currently_stepping (struct thread_info *tp)
7086 return ((tp->control.step_range_end
7087 && tp->control.step_resume_breakpoint == NULL)
7088 || tp->control.trap_expected
7089 || tp->stepped_breakpoint
7090 || bpstat_should_step ());
7093 /* Inferior has stepped into a subroutine call with source code that
7094 we should not step over. Do step to the first line of code in
7098 handle_step_into_function (struct gdbarch *gdbarch,
7099 struct execution_control_state *ecs)
7101 fill_in_stop_func (gdbarch, ecs);
7103 compunit_symtab *cust
7104 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7105 if (cust != NULL && compunit_language (cust) != language_asm)
7106 ecs->stop_func_start
7107 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7109 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7110 /* Use the step_resume_break to step until the end of the prologue,
7111 even if that involves jumps (as it seems to on the vax under
7113 /* If the prologue ends in the middle of a source line, continue to
7114 the end of that source line (if it is still within the function).
7115 Otherwise, just go to end of prologue. */
7116 if (stop_func_sal.end
7117 && stop_func_sal.pc != ecs->stop_func_start
7118 && stop_func_sal.end < ecs->stop_func_end)
7119 ecs->stop_func_start = stop_func_sal.end;
7121 /* Architectures which require breakpoint adjustment might not be able
7122 to place a breakpoint at the computed address. If so, the test
7123 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7124 ecs->stop_func_start to an address at which a breakpoint may be
7125 legitimately placed.
7127 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7128 made, GDB will enter an infinite loop when stepping through
7129 optimized code consisting of VLIW instructions which contain
7130 subinstructions corresponding to different source lines. On
7131 FR-V, it's not permitted to place a breakpoint on any but the
7132 first subinstruction of a VLIW instruction. When a breakpoint is
7133 set, GDB will adjust the breakpoint address to the beginning of
7134 the VLIW instruction. Thus, we need to make the corresponding
7135 adjustment here when computing the stop address. */
7137 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7139 ecs->stop_func_start
7140 = gdbarch_adjust_breakpoint_address (gdbarch,
7141 ecs->stop_func_start);
7144 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7146 /* We are already there: stop now. */
7147 end_stepping_range (ecs);
7152 /* Put the step-breakpoint there and go until there. */
7153 symtab_and_line sr_sal;
7154 sr_sal.pc = ecs->stop_func_start;
7155 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7156 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7158 /* Do not specify what the fp should be when we stop since on
7159 some machines the prologue is where the new fp value is
7161 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7163 /* And make sure stepping stops right away then. */
7164 ecs->event_thread->control.step_range_end
7165 = ecs->event_thread->control.step_range_start;
7170 /* Inferior has stepped backward into a subroutine call with source
7171 code that we should not step over. Do step to the beginning of the
7172 last line of code in it. */
7175 handle_step_into_function_backward (struct gdbarch *gdbarch,
7176 struct execution_control_state *ecs)
7178 struct compunit_symtab *cust;
7179 struct symtab_and_line stop_func_sal;
7181 fill_in_stop_func (gdbarch, ecs);
7183 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7184 if (cust != NULL && compunit_language (cust) != language_asm)
7185 ecs->stop_func_start
7186 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7188 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7190 /* OK, we're just going to keep stepping here. */
7191 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7193 /* We're there already. Just stop stepping now. */
7194 end_stepping_range (ecs);
7198 /* Else just reset the step range and keep going.
7199 No step-resume breakpoint, they don't work for
7200 epilogues, which can have multiple entry paths. */
7201 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7202 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7208 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7209 This is used to both functions and to skip over code. */
7212 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7213 struct symtab_and_line sr_sal,
7214 struct frame_id sr_id,
7215 enum bptype sr_type)
7217 /* There should never be more than one step-resume or longjmp-resume
7218 breakpoint per thread, so we should never be setting a new
7219 step_resume_breakpoint when one is already active. */
7220 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7221 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7224 fprintf_unfiltered (gdb_stdlog,
7225 "infrun: inserting step-resume breakpoint at %s\n",
7226 paddress (gdbarch, sr_sal.pc));
7228 inferior_thread ()->control.step_resume_breakpoint
7229 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7233 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7234 struct symtab_and_line sr_sal,
7235 struct frame_id sr_id)
7237 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7242 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7243 This is used to skip a potential signal handler.
7245 This is called with the interrupted function's frame. The signal
7246 handler, when it returns, will resume the interrupted function at
7250 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7252 gdb_assert (return_frame != NULL);
7254 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7256 symtab_and_line sr_sal;
7257 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7258 sr_sal.section = find_pc_overlay (sr_sal.pc);
7259 sr_sal.pspace = get_frame_program_space (return_frame);
7261 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7262 get_stack_frame_id (return_frame),
7266 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7267 is used to skip a function after stepping into it (for "next" or if
7268 the called function has no debugging information).
7270 The current function has almost always been reached by single
7271 stepping a call or return instruction. NEXT_FRAME belongs to the
7272 current function, and the breakpoint will be set at the caller's
7275 This is a separate function rather than reusing
7276 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7277 get_prev_frame, which may stop prematurely (see the implementation
7278 of frame_unwind_caller_id for an example). */
7281 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7283 /* We shouldn't have gotten here if we don't know where the call site
7285 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7287 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7289 symtab_and_line sr_sal;
7290 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7291 frame_unwind_caller_pc (next_frame));
7292 sr_sal.section = find_pc_overlay (sr_sal.pc);
7293 sr_sal.pspace = frame_unwind_program_space (next_frame);
7295 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7296 frame_unwind_caller_id (next_frame));
7299 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7300 new breakpoint at the target of a jmp_buf. The handling of
7301 longjmp-resume uses the same mechanisms used for handling
7302 "step-resume" breakpoints. */
7305 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7307 /* There should never be more than one longjmp-resume breakpoint per
7308 thread, so we should never be setting a new
7309 longjmp_resume_breakpoint when one is already active. */
7310 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7313 fprintf_unfiltered (gdb_stdlog,
7314 "infrun: inserting longjmp-resume breakpoint at %s\n",
7315 paddress (gdbarch, pc));
7317 inferior_thread ()->control.exception_resume_breakpoint =
7318 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7321 /* Insert an exception resume breakpoint. TP is the thread throwing
7322 the exception. The block B is the block of the unwinder debug hook
7323 function. FRAME is the frame corresponding to the call to this
7324 function. SYM is the symbol of the function argument holding the
7325 target PC of the exception. */
7328 insert_exception_resume_breakpoint (struct thread_info *tp,
7329 const struct block *b,
7330 struct frame_info *frame,
7335 struct block_symbol vsym;
7336 struct value *value;
7338 struct breakpoint *bp;
7340 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7342 value = read_var_value (vsym.symbol, vsym.block, frame);
7343 /* If the value was optimized out, revert to the old behavior. */
7344 if (! value_optimized_out (value))
7346 handler = value_as_address (value);
7349 fprintf_unfiltered (gdb_stdlog,
7350 "infrun: exception resume at %lx\n",
7351 (unsigned long) handler);
7353 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7355 bp_exception_resume).release ();
7357 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7360 bp->thread = tp->global_num;
7361 inferior_thread ()->control.exception_resume_breakpoint = bp;
7364 CATCH (e, RETURN_MASK_ERROR)
7366 /* We want to ignore errors here. */
7371 /* A helper for check_exception_resume that sets an
7372 exception-breakpoint based on a SystemTap probe. */
7375 insert_exception_resume_from_probe (struct thread_info *tp,
7376 const struct bound_probe *probe,
7377 struct frame_info *frame)
7379 struct value *arg_value;
7381 struct breakpoint *bp;
7383 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7387 handler = value_as_address (arg_value);
7390 fprintf_unfiltered (gdb_stdlog,
7391 "infrun: exception resume at %s\n",
7392 paddress (get_objfile_arch (probe->objfile),
7395 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7396 handler, bp_exception_resume).release ();
7397 bp->thread = tp->global_num;
7398 inferior_thread ()->control.exception_resume_breakpoint = bp;
7401 /* This is called when an exception has been intercepted. Check to
7402 see whether the exception's destination is of interest, and if so,
7403 set an exception resume breakpoint there. */
7406 check_exception_resume (struct execution_control_state *ecs,
7407 struct frame_info *frame)
7409 struct bound_probe probe;
7410 struct symbol *func;
7412 /* First see if this exception unwinding breakpoint was set via a
7413 SystemTap probe point. If so, the probe has two arguments: the
7414 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7415 set a breakpoint there. */
7416 probe = find_probe_by_pc (get_frame_pc (frame));
7419 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7423 func = get_frame_function (frame);
7429 const struct block *b;
7430 struct block_iterator iter;
7434 /* The exception breakpoint is a thread-specific breakpoint on
7435 the unwinder's debug hook, declared as:
7437 void _Unwind_DebugHook (void *cfa, void *handler);
7439 The CFA argument indicates the frame to which control is
7440 about to be transferred. HANDLER is the destination PC.
7442 We ignore the CFA and set a temporary breakpoint at HANDLER.
7443 This is not extremely efficient but it avoids issues in gdb
7444 with computing the DWARF CFA, and it also works even in weird
7445 cases such as throwing an exception from inside a signal
7448 b = SYMBOL_BLOCK_VALUE (func);
7449 ALL_BLOCK_SYMBOLS (b, iter, sym)
7451 if (!SYMBOL_IS_ARGUMENT (sym))
7458 insert_exception_resume_breakpoint (ecs->event_thread,
7464 CATCH (e, RETURN_MASK_ERROR)
7471 stop_waiting (struct execution_control_state *ecs)
7474 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7476 /* Let callers know we don't want to wait for the inferior anymore. */
7477 ecs->wait_some_more = 0;
7479 /* If all-stop, but the target is always in non-stop mode, stop all
7480 threads now that we're presenting the stop to the user. */
7481 if (!non_stop && target_is_non_stop_p ())
7482 stop_all_threads ();
7485 /* Like keep_going, but passes the signal to the inferior, even if the
7486 signal is set to nopass. */
7489 keep_going_pass_signal (struct execution_control_state *ecs)
7491 gdb_assert (ecs->event_thread->ptid == inferior_ptid);
7492 gdb_assert (!ecs->event_thread->resumed);
7494 /* Save the pc before execution, to compare with pc after stop. */
7495 ecs->event_thread->prev_pc
7496 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7498 if (ecs->event_thread->control.trap_expected)
7500 struct thread_info *tp = ecs->event_thread;
7503 fprintf_unfiltered (gdb_stdlog,
7504 "infrun: %s has trap_expected set, "
7505 "resuming to collect trap\n",
7506 target_pid_to_str (tp->ptid));
7508 /* We haven't yet gotten our trap, and either: intercepted a
7509 non-signal event (e.g., a fork); or took a signal which we
7510 are supposed to pass through to the inferior. Simply
7512 resume (ecs->event_thread->suspend.stop_signal);
7514 else if (step_over_info_valid_p ())
7516 /* Another thread is stepping over a breakpoint in-line. If
7517 this thread needs a step-over too, queue the request. In
7518 either case, this resume must be deferred for later. */
7519 struct thread_info *tp = ecs->event_thread;
7521 if (ecs->hit_singlestep_breakpoint
7522 || thread_still_needs_step_over (tp))
7525 fprintf_unfiltered (gdb_stdlog,
7526 "infrun: step-over already in progress: "
7527 "step-over for %s deferred\n",
7528 target_pid_to_str (tp->ptid));
7529 thread_step_over_chain_enqueue (tp);
7534 fprintf_unfiltered (gdb_stdlog,
7535 "infrun: step-over in progress: "
7536 "resume of %s deferred\n",
7537 target_pid_to_str (tp->ptid));
7542 struct regcache *regcache = get_current_regcache ();
7545 step_over_what step_what;
7547 /* Either the trap was not expected, but we are continuing
7548 anyway (if we got a signal, the user asked it be passed to
7551 We got our expected trap, but decided we should resume from
7554 We're going to run this baby now!
7556 Note that insert_breakpoints won't try to re-insert
7557 already inserted breakpoints. Therefore, we don't
7558 care if breakpoints were already inserted, or not. */
7560 /* If we need to step over a breakpoint, and we're not using
7561 displaced stepping to do so, insert all breakpoints
7562 (watchpoints, etc.) but the one we're stepping over, step one
7563 instruction, and then re-insert the breakpoint when that step
7566 step_what = thread_still_needs_step_over (ecs->event_thread);
7568 remove_bp = (ecs->hit_singlestep_breakpoint
7569 || (step_what & STEP_OVER_BREAKPOINT));
7570 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7572 /* We can't use displaced stepping if we need to step past a
7573 watchpoint. The instruction copied to the scratch pad would
7574 still trigger the watchpoint. */
7576 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7578 set_step_over_info (regcache->aspace (),
7579 regcache_read_pc (regcache), remove_wps,
7580 ecs->event_thread->global_num);
7582 else if (remove_wps)
7583 set_step_over_info (NULL, 0, remove_wps, -1);
7585 /* If we now need to do an in-line step-over, we need to stop
7586 all other threads. Note this must be done before
7587 insert_breakpoints below, because that removes the breakpoint
7588 we're about to step over, otherwise other threads could miss
7590 if (step_over_info_valid_p () && target_is_non_stop_p ())
7591 stop_all_threads ();
7593 /* Stop stepping if inserting breakpoints fails. */
7596 insert_breakpoints ();
7598 CATCH (e, RETURN_MASK_ERROR)
7600 exception_print (gdb_stderr, e);
7602 clear_step_over_info ();
7607 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7609 resume (ecs->event_thread->suspend.stop_signal);
7612 prepare_to_wait (ecs);
7615 /* Called when we should continue running the inferior, because the
7616 current event doesn't cause a user visible stop. This does the
7617 resuming part; waiting for the next event is done elsewhere. */
7620 keep_going (struct execution_control_state *ecs)
7622 if (ecs->event_thread->control.trap_expected
7623 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7624 ecs->event_thread->control.trap_expected = 0;
7626 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7627 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7628 keep_going_pass_signal (ecs);
7631 /* This function normally comes after a resume, before
7632 handle_inferior_event exits. It takes care of any last bits of
7633 housekeeping, and sets the all-important wait_some_more flag. */
7636 prepare_to_wait (struct execution_control_state *ecs)
7639 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7641 ecs->wait_some_more = 1;
7643 if (!target_is_async_p ())
7644 mark_infrun_async_event_handler ();
7647 /* We are done with the step range of a step/next/si/ni command.
7648 Called once for each n of a "step n" operation. */
7651 end_stepping_range (struct execution_control_state *ecs)
7653 ecs->event_thread->control.stop_step = 1;
7657 /* Several print_*_reason functions to print why the inferior has stopped.
7658 We always print something when the inferior exits, or receives a signal.
7659 The rest of the cases are dealt with later on in normal_stop and
7660 print_it_typical. Ideally there should be a call to one of these
7661 print_*_reason functions functions from handle_inferior_event each time
7662 stop_waiting is called.
7664 Note that we don't call these directly, instead we delegate that to
7665 the interpreters, through observers. Interpreters then call these
7666 with whatever uiout is right. */
7669 print_end_stepping_range_reason (struct ui_out *uiout)
7671 /* For CLI-like interpreters, print nothing. */
7673 if (uiout->is_mi_like_p ())
7675 uiout->field_string ("reason",
7676 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7681 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7683 annotate_signalled ();
7684 if (uiout->is_mi_like_p ())
7686 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7687 uiout->text ("\nProgram terminated with signal ");
7688 annotate_signal_name ();
7689 uiout->field_string ("signal-name",
7690 gdb_signal_to_name (siggnal));
7691 annotate_signal_name_end ();
7693 annotate_signal_string ();
7694 uiout->field_string ("signal-meaning",
7695 gdb_signal_to_string (siggnal));
7696 annotate_signal_string_end ();
7697 uiout->text (".\n");
7698 uiout->text ("The program no longer exists.\n");
7702 print_exited_reason (struct ui_out *uiout, int exitstatus)
7704 struct inferior *inf = current_inferior ();
7705 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7707 annotate_exited (exitstatus);
7710 if (uiout->is_mi_like_p ())
7711 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7712 uiout->text ("[Inferior ");
7713 uiout->text (plongest (inf->num));
7715 uiout->text (pidstr);
7716 uiout->text (") exited with code ");
7717 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7718 uiout->text ("]\n");
7722 if (uiout->is_mi_like_p ())
7724 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7725 uiout->text ("[Inferior ");
7726 uiout->text (plongest (inf->num));
7728 uiout->text (pidstr);
7729 uiout->text (") exited normally]\n");
7733 /* Some targets/architectures can do extra processing/display of
7734 segmentation faults. E.g., Intel MPX boundary faults.
7735 Call the architecture dependent function to handle the fault. */
7738 handle_segmentation_fault (struct ui_out *uiout)
7740 struct regcache *regcache = get_current_regcache ();
7741 struct gdbarch *gdbarch = regcache->arch ();
7743 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7744 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7748 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7750 struct thread_info *thr = inferior_thread ();
7754 if (uiout->is_mi_like_p ())
7756 else if (show_thread_that_caused_stop ())
7760 uiout->text ("\nThread ");
7761 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7763 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7766 uiout->text (" \"");
7767 uiout->field_fmt ("name", "%s", name);
7772 uiout->text ("\nProgram");
7774 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7775 uiout->text (" stopped");
7778 uiout->text (" received signal ");
7779 annotate_signal_name ();
7780 if (uiout->is_mi_like_p ())
7782 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7783 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7784 annotate_signal_name_end ();
7786 annotate_signal_string ();
7787 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7789 if (siggnal == GDB_SIGNAL_SEGV)
7790 handle_segmentation_fault (uiout);
7792 annotate_signal_string_end ();
7794 uiout->text (".\n");
7798 print_no_history_reason (struct ui_out *uiout)
7800 uiout->text ("\nNo more reverse-execution history.\n");
7803 /* Print current location without a level number, if we have changed
7804 functions or hit a breakpoint. Print source line if we have one.
7805 bpstat_print contains the logic deciding in detail what to print,
7806 based on the event(s) that just occurred. */
7809 print_stop_location (struct target_waitstatus *ws)
7812 enum print_what source_flag;
7813 int do_frame_printing = 1;
7814 struct thread_info *tp = inferior_thread ();
7816 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7820 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7821 should) carry around the function and does (or should) use
7822 that when doing a frame comparison. */
7823 if (tp->control.stop_step
7824 && frame_id_eq (tp->control.step_frame_id,
7825 get_frame_id (get_current_frame ()))
7826 && (tp->control.step_start_function
7827 == find_pc_function (tp->suspend.stop_pc)))
7829 /* Finished step, just print source line. */
7830 source_flag = SRC_LINE;
7834 /* Print location and source line. */
7835 source_flag = SRC_AND_LOC;
7838 case PRINT_SRC_AND_LOC:
7839 /* Print location and source line. */
7840 source_flag = SRC_AND_LOC;
7842 case PRINT_SRC_ONLY:
7843 source_flag = SRC_LINE;
7846 /* Something bogus. */
7847 source_flag = SRC_LINE;
7848 do_frame_printing = 0;
7851 internal_error (__FILE__, __LINE__, _("Unknown value."));
7854 /* The behavior of this routine with respect to the source
7856 SRC_LINE: Print only source line
7857 LOCATION: Print only location
7858 SRC_AND_LOC: Print location and source line. */
7859 if (do_frame_printing)
7860 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7866 print_stop_event (struct ui_out *uiout)
7868 struct target_waitstatus last;
7870 struct thread_info *tp;
7872 get_last_target_status (&last_ptid, &last);
7875 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
7877 print_stop_location (&last);
7879 /* Display the auto-display expressions. */
7883 tp = inferior_thread ();
7884 if (tp->thread_fsm != NULL
7885 && tp->thread_fsm->finished_p ())
7887 struct return_value_info *rv;
7889 rv = tp->thread_fsm->return_value ();
7891 print_return_value (uiout, rv);
7898 maybe_remove_breakpoints (void)
7900 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7902 if (remove_breakpoints ())
7904 target_terminal::ours_for_output ();
7905 printf_filtered (_("Cannot remove breakpoints because "
7906 "program is no longer writable.\nFurther "
7907 "execution is probably impossible.\n"));
7912 /* The execution context that just caused a normal stop. */
7919 DISABLE_COPY_AND_ASSIGN (stop_context);
7921 bool changed () const;
7926 /* The event PTID. */
7930 /* If stopp for a thread event, this is the thread that caused the
7932 struct thread_info *thread;
7934 /* The inferior that caused the stop. */
7938 /* Initializes a new stop context. If stopped for a thread event, this
7939 takes a strong reference to the thread. */
7941 stop_context::stop_context ()
7943 stop_id = get_stop_id ();
7944 ptid = inferior_ptid;
7945 inf_num = current_inferior ()->num;
7947 if (inferior_ptid != null_ptid)
7949 /* Take a strong reference so that the thread can't be deleted
7951 thread = inferior_thread ();
7958 /* Release a stop context previously created with save_stop_context.
7959 Releases the strong reference to the thread as well. */
7961 stop_context::~stop_context ()
7967 /* Return true if the current context no longer matches the saved stop
7971 stop_context::changed () const
7973 if (ptid != inferior_ptid)
7975 if (inf_num != current_inferior ()->num)
7977 if (thread != NULL && thread->state != THREAD_STOPPED)
7979 if (get_stop_id () != stop_id)
7989 struct target_waitstatus last;
7992 get_last_target_status (&last_ptid, &last);
7996 /* If an exception is thrown from this point on, make sure to
7997 propagate GDB's knowledge of the executing state to the
7998 frontend/user running state. A QUIT is an easy exception to see
7999 here, so do this before any filtered output. */
8001 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
8004 maybe_finish_thread_state.emplace (minus_one_ptid);
8005 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8006 || last.kind == TARGET_WAITKIND_EXITED)
8008 /* On some targets, we may still have live threads in the
8009 inferior when we get a process exit event. E.g., for
8010 "checkpoint", when the current checkpoint/fork exits,
8011 linux-fork.c automatically switches to another fork from
8012 within target_mourn_inferior. */
8013 if (inferior_ptid != null_ptid)
8014 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8016 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8017 maybe_finish_thread_state.emplace (inferior_ptid);
8019 /* As we're presenting a stop, and potentially removing breakpoints,
8020 update the thread list so we can tell whether there are threads
8021 running on the target. With target remote, for example, we can
8022 only learn about new threads when we explicitly update the thread
8023 list. Do this before notifying the interpreters about signal
8024 stops, end of stepping ranges, etc., so that the "new thread"
8025 output is emitted before e.g., "Program received signal FOO",
8026 instead of after. */
8027 update_thread_list ();
8029 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8030 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8032 /* As with the notification of thread events, we want to delay
8033 notifying the user that we've switched thread context until
8034 the inferior actually stops.
8036 There's no point in saying anything if the inferior has exited.
8037 Note that SIGNALLED here means "exited with a signal", not
8038 "received a signal".
8040 Also skip saying anything in non-stop mode. In that mode, as we
8041 don't want GDB to switch threads behind the user's back, to avoid
8042 races where the user is typing a command to apply to thread x,
8043 but GDB switches to thread y before the user finishes entering
8044 the command, fetch_inferior_event installs a cleanup to restore
8045 the current thread back to the thread the user had selected right
8046 after this event is handled, so we're not really switching, only
8047 informing of a stop. */
8049 && previous_inferior_ptid != inferior_ptid
8050 && target_has_execution
8051 && last.kind != TARGET_WAITKIND_SIGNALLED
8052 && last.kind != TARGET_WAITKIND_EXITED
8053 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8055 SWITCH_THRU_ALL_UIS ()
8057 target_terminal::ours_for_output ();
8058 printf_filtered (_("[Switching to %s]\n"),
8059 target_pid_to_str (inferior_ptid));
8060 annotate_thread_changed ();
8062 previous_inferior_ptid = inferior_ptid;
8065 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8067 SWITCH_THRU_ALL_UIS ()
8068 if (current_ui->prompt_state == PROMPT_BLOCKED)
8070 target_terminal::ours_for_output ();
8071 printf_filtered (_("No unwaited-for children left.\n"));
8075 /* Note: this depends on the update_thread_list call above. */
8076 maybe_remove_breakpoints ();
8078 /* If an auto-display called a function and that got a signal,
8079 delete that auto-display to avoid an infinite recursion. */
8081 if (stopped_by_random_signal)
8082 disable_current_display ();
8084 SWITCH_THRU_ALL_UIS ()
8086 async_enable_stdin ();
8089 /* Let the user/frontend see the threads as stopped. */
8090 maybe_finish_thread_state.reset ();
8092 /* Select innermost stack frame - i.e., current frame is frame 0,
8093 and current location is based on that. Handle the case where the
8094 dummy call is returning after being stopped. E.g. the dummy call
8095 previously hit a breakpoint. (If the dummy call returns
8096 normally, we won't reach here.) Do this before the stop hook is
8097 run, so that it doesn't get to see the temporary dummy frame,
8098 which is not where we'll present the stop. */
8099 if (has_stack_frames ())
8101 if (stop_stack_dummy == STOP_STACK_DUMMY)
8103 /* Pop the empty frame that contains the stack dummy. This
8104 also restores inferior state prior to the call (struct
8105 infcall_suspend_state). */
8106 struct frame_info *frame = get_current_frame ();
8108 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8110 /* frame_pop calls reinit_frame_cache as the last thing it
8111 does which means there's now no selected frame. */
8114 select_frame (get_current_frame ());
8116 /* Set the current source location. */
8117 set_current_sal_from_frame (get_current_frame ());
8120 /* Look up the hook_stop and run it (CLI internally handles problem
8121 of stop_command's pre-hook not existing). */
8122 if (stop_command != NULL)
8124 stop_context saved_context;
8128 execute_cmd_pre_hook (stop_command);
8130 CATCH (ex, RETURN_MASK_ALL)
8132 exception_fprintf (gdb_stderr, ex,
8133 "Error while running hook_stop:\n");
8137 /* If the stop hook resumes the target, then there's no point in
8138 trying to notify about the previous stop; its context is
8139 gone. Likewise if the command switches thread or inferior --
8140 the observers would print a stop for the wrong
8142 if (saved_context.changed ())
8146 /* Notify observers about the stop. This is where the interpreters
8147 print the stop event. */
8148 if (inferior_ptid != null_ptid)
8149 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8152 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8154 annotate_stopped ();
8156 if (target_has_execution)
8158 if (last.kind != TARGET_WAITKIND_SIGNALLED
8159 && last.kind != TARGET_WAITKIND_EXITED)
8160 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8161 Delete any breakpoint that is to be deleted at the next stop. */
8162 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8165 /* Try to get rid of automatically added inferiors that are no
8166 longer needed. Keeping those around slows down things linearly.
8167 Note that this never removes the current inferior. */
8174 signal_stop_state (int signo)
8176 return signal_stop[signo];
8180 signal_print_state (int signo)
8182 return signal_print[signo];
8186 signal_pass_state (int signo)
8188 return signal_program[signo];
8192 signal_cache_update (int signo)
8196 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8197 signal_cache_update (signo);
8202 signal_pass[signo] = (signal_stop[signo] == 0
8203 && signal_print[signo] == 0
8204 && signal_program[signo] == 1
8205 && signal_catch[signo] == 0);
8209 signal_stop_update (int signo, int state)
8211 int ret = signal_stop[signo];
8213 signal_stop[signo] = state;
8214 signal_cache_update (signo);
8219 signal_print_update (int signo, int state)
8221 int ret = signal_print[signo];
8223 signal_print[signo] = state;
8224 signal_cache_update (signo);
8229 signal_pass_update (int signo, int state)
8231 int ret = signal_program[signo];
8233 signal_program[signo] = state;
8234 signal_cache_update (signo);
8238 /* Update the global 'signal_catch' from INFO and notify the
8242 signal_catch_update (const unsigned int *info)
8246 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8247 signal_catch[i] = info[i] > 0;
8248 signal_cache_update (-1);
8249 target_pass_signals (signal_pass);
8253 sig_print_header (void)
8255 printf_filtered (_("Signal Stop\tPrint\tPass "
8256 "to program\tDescription\n"));
8260 sig_print_info (enum gdb_signal oursig)
8262 const char *name = gdb_signal_to_name (oursig);
8263 int name_padding = 13 - strlen (name);
8265 if (name_padding <= 0)
8268 printf_filtered ("%s", name);
8269 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8270 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8271 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8272 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8273 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8276 /* Specify how various signals in the inferior should be handled. */
8279 handle_command (const char *args, int from_tty)
8281 int digits, wordlen;
8282 int sigfirst, siglast;
8283 enum gdb_signal oursig;
8288 error_no_arg (_("signal to handle"));
8291 /* Allocate and zero an array of flags for which signals to handle. */
8293 const size_t nsigs = GDB_SIGNAL_LAST;
8294 unsigned char sigs[nsigs] {};
8296 /* Break the command line up into args. */
8298 gdb_argv built_argv (args);
8300 /* Walk through the args, looking for signal oursigs, signal names, and
8301 actions. Signal numbers and signal names may be interspersed with
8302 actions, with the actions being performed for all signals cumulatively
8303 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8305 for (char *arg : built_argv)
8307 wordlen = strlen (arg);
8308 for (digits = 0; isdigit (arg[digits]); digits++)
8312 sigfirst = siglast = -1;
8314 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8316 /* Apply action to all signals except those used by the
8317 debugger. Silently skip those. */
8320 siglast = nsigs - 1;
8322 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8324 SET_SIGS (nsigs, sigs, signal_stop);
8325 SET_SIGS (nsigs, sigs, signal_print);
8327 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8329 UNSET_SIGS (nsigs, sigs, signal_program);
8331 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8333 SET_SIGS (nsigs, sigs, signal_print);
8335 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8337 SET_SIGS (nsigs, sigs, signal_program);
8339 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8341 UNSET_SIGS (nsigs, sigs, signal_stop);
8343 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8345 SET_SIGS (nsigs, sigs, signal_program);
8347 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8349 UNSET_SIGS (nsigs, sigs, signal_print);
8350 UNSET_SIGS (nsigs, sigs, signal_stop);
8352 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8354 UNSET_SIGS (nsigs, sigs, signal_program);
8356 else if (digits > 0)
8358 /* It is numeric. The numeric signal refers to our own
8359 internal signal numbering from target.h, not to host/target
8360 signal number. This is a feature; users really should be
8361 using symbolic names anyway, and the common ones like
8362 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8364 sigfirst = siglast = (int)
8365 gdb_signal_from_command (atoi (arg));
8366 if (arg[digits] == '-')
8369 gdb_signal_from_command (atoi (arg + digits + 1));
8371 if (sigfirst > siglast)
8373 /* Bet he didn't figure we'd think of this case... */
8374 std::swap (sigfirst, siglast);
8379 oursig = gdb_signal_from_name (arg);
8380 if (oursig != GDB_SIGNAL_UNKNOWN)
8382 sigfirst = siglast = (int) oursig;
8386 /* Not a number and not a recognized flag word => complain. */
8387 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8391 /* If any signal numbers or symbol names were found, set flags for
8392 which signals to apply actions to. */
8394 for (int signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8396 switch ((enum gdb_signal) signum)
8398 case GDB_SIGNAL_TRAP:
8399 case GDB_SIGNAL_INT:
8400 if (!allsigs && !sigs[signum])
8402 if (query (_("%s is used by the debugger.\n\
8403 Are you sure you want to change it? "),
8404 gdb_signal_to_name ((enum gdb_signal) signum)))
8410 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8411 gdb_flush (gdb_stdout);
8416 case GDB_SIGNAL_DEFAULT:
8417 case GDB_SIGNAL_UNKNOWN:
8418 /* Make sure that "all" doesn't print these. */
8427 for (int signum = 0; signum < nsigs; signum++)
8430 signal_cache_update (-1);
8431 target_pass_signals (signal_pass);
8432 target_program_signals (signal_program);
8436 /* Show the results. */
8437 sig_print_header ();
8438 for (; signum < nsigs; signum++)
8440 sig_print_info ((enum gdb_signal) signum);
8447 /* Complete the "handle" command. */
8450 handle_completer (struct cmd_list_element *ignore,
8451 completion_tracker &tracker,
8452 const char *text, const char *word)
8454 static const char * const keywords[] =
8468 signal_completer (ignore, tracker, text, word);
8469 complete_on_enum (tracker, keywords, word, word);
8473 gdb_signal_from_command (int num)
8475 if (num >= 1 && num <= 15)
8476 return (enum gdb_signal) num;
8477 error (_("Only signals 1-15 are valid as numeric signals.\n\
8478 Use \"info signals\" for a list of symbolic signals."));
8481 /* Print current contents of the tables set by the handle command.
8482 It is possible we should just be printing signals actually used
8483 by the current target (but for things to work right when switching
8484 targets, all signals should be in the signal tables). */
8487 info_signals_command (const char *signum_exp, int from_tty)
8489 enum gdb_signal oursig;
8491 sig_print_header ();
8495 /* First see if this is a symbol name. */
8496 oursig = gdb_signal_from_name (signum_exp);
8497 if (oursig == GDB_SIGNAL_UNKNOWN)
8499 /* No, try numeric. */
8501 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8503 sig_print_info (oursig);
8507 printf_filtered ("\n");
8508 /* These ugly casts brought to you by the native VAX compiler. */
8509 for (oursig = GDB_SIGNAL_FIRST;
8510 (int) oursig < (int) GDB_SIGNAL_LAST;
8511 oursig = (enum gdb_signal) ((int) oursig + 1))
8515 if (oursig != GDB_SIGNAL_UNKNOWN
8516 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8517 sig_print_info (oursig);
8520 printf_filtered (_("\nUse the \"handle\" command "
8521 "to change these tables.\n"));
8524 /* The $_siginfo convenience variable is a bit special. We don't know
8525 for sure the type of the value until we actually have a chance to
8526 fetch the data. The type can change depending on gdbarch, so it is
8527 also dependent on which thread you have selected.
8529 1. making $_siginfo be an internalvar that creates a new value on
8532 2. making the value of $_siginfo be an lval_computed value. */
8534 /* This function implements the lval_computed support for reading a
8538 siginfo_value_read (struct value *v)
8540 LONGEST transferred;
8542 /* If we can access registers, so can we access $_siginfo. Likewise
8544 validate_registers_access ();
8547 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO,
8549 value_contents_all_raw (v),
8551 TYPE_LENGTH (value_type (v)));
8553 if (transferred != TYPE_LENGTH (value_type (v)))
8554 error (_("Unable to read siginfo"));
8557 /* This function implements the lval_computed support for writing a
8561 siginfo_value_write (struct value *v, struct value *fromval)
8563 LONGEST transferred;
8565 /* If we can access registers, so can we access $_siginfo. Likewise
8567 validate_registers_access ();
8569 transferred = target_write (current_top_target (),
8570 TARGET_OBJECT_SIGNAL_INFO,
8572 value_contents_all_raw (fromval),
8574 TYPE_LENGTH (value_type (fromval)));
8576 if (transferred != TYPE_LENGTH (value_type (fromval)))
8577 error (_("Unable to write siginfo"));
8580 static const struct lval_funcs siginfo_value_funcs =
8586 /* Return a new value with the correct type for the siginfo object of
8587 the current thread using architecture GDBARCH. Return a void value
8588 if there's no object available. */
8590 static struct value *
8591 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8594 if (target_has_stack
8595 && inferior_ptid != null_ptid
8596 && gdbarch_get_siginfo_type_p (gdbarch))
8598 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8600 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8603 return allocate_value (builtin_type (gdbarch)->builtin_void);
8607 /* infcall_suspend_state contains state about the program itself like its
8608 registers and any signal it received when it last stopped.
8609 This state must be restored regardless of how the inferior function call
8610 ends (either successfully, or after it hits a breakpoint or signal)
8611 if the program is to properly continue where it left off. */
8613 class infcall_suspend_state
8616 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8617 once the inferior function call has finished. */
8618 infcall_suspend_state (struct gdbarch *gdbarch,
8619 const struct thread_info *tp,
8620 struct regcache *regcache)
8621 : m_thread_suspend (tp->suspend),
8622 m_registers (new readonly_detached_regcache (*regcache))
8624 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8626 if (gdbarch_get_siginfo_type_p (gdbarch))
8628 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8629 size_t len = TYPE_LENGTH (type);
8631 siginfo_data.reset ((gdb_byte *) xmalloc (len));
8633 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8634 siginfo_data.get (), 0, len) != len)
8636 /* Errors ignored. */
8637 siginfo_data.reset (nullptr);
8643 m_siginfo_gdbarch = gdbarch;
8644 m_siginfo_data = std::move (siginfo_data);
8648 /* Return a pointer to the stored register state. */
8650 readonly_detached_regcache *registers () const
8652 return m_registers.get ();
8655 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8657 void restore (struct gdbarch *gdbarch,
8658 struct thread_info *tp,
8659 struct regcache *regcache) const
8661 tp->suspend = m_thread_suspend;
8663 if (m_siginfo_gdbarch == gdbarch)
8665 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8667 /* Errors ignored. */
8668 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8669 m_siginfo_data.get (), 0, TYPE_LENGTH (type));
8672 /* The inferior can be gone if the user types "print exit(0)"
8673 (and perhaps other times). */
8674 if (target_has_execution)
8675 /* NB: The register write goes through to the target. */
8676 regcache->restore (registers ());
8680 /* How the current thread stopped before the inferior function call was
8682 struct thread_suspend_state m_thread_suspend;
8684 /* The registers before the inferior function call was executed. */
8685 std::unique_ptr<readonly_detached_regcache> m_registers;
8687 /* Format of SIGINFO_DATA or NULL if it is not present. */
8688 struct gdbarch *m_siginfo_gdbarch = nullptr;
8690 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8691 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8692 content would be invalid. */
8693 gdb::unique_xmalloc_ptr<gdb_byte> m_siginfo_data;
8696 infcall_suspend_state_up
8697 save_infcall_suspend_state ()
8699 struct thread_info *tp = inferior_thread ();
8700 struct regcache *regcache = get_current_regcache ();
8701 struct gdbarch *gdbarch = regcache->arch ();
8703 infcall_suspend_state_up inf_state
8704 (new struct infcall_suspend_state (gdbarch, tp, regcache));
8706 /* Having saved the current state, adjust the thread state, discarding
8707 any stop signal information. The stop signal is not useful when
8708 starting an inferior function call, and run_inferior_call will not use
8709 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8710 tp->suspend.stop_signal = GDB_SIGNAL_0;
8715 /* Restore inferior session state to INF_STATE. */
8718 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8720 struct thread_info *tp = inferior_thread ();
8721 struct regcache *regcache = get_current_regcache ();
8722 struct gdbarch *gdbarch = regcache->arch ();
8724 inf_state->restore (gdbarch, tp, regcache);
8725 discard_infcall_suspend_state (inf_state);
8729 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8734 readonly_detached_regcache *
8735 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8737 return inf_state->registers ();
8740 /* infcall_control_state contains state regarding gdb's control of the
8741 inferior itself like stepping control. It also contains session state like
8742 the user's currently selected frame. */
8744 struct infcall_control_state
8746 struct thread_control_state thread_control;
8747 struct inferior_control_state inferior_control;
8750 enum stop_stack_kind stop_stack_dummy = STOP_NONE;
8751 int stopped_by_random_signal = 0;
8753 /* ID if the selected frame when the inferior function call was made. */
8754 struct frame_id selected_frame_id {};
8757 /* Save all of the information associated with the inferior<==>gdb
8760 infcall_control_state_up
8761 save_infcall_control_state ()
8763 infcall_control_state_up inf_status (new struct infcall_control_state);
8764 struct thread_info *tp = inferior_thread ();
8765 struct inferior *inf = current_inferior ();
8767 inf_status->thread_control = tp->control;
8768 inf_status->inferior_control = inf->control;
8770 tp->control.step_resume_breakpoint = NULL;
8771 tp->control.exception_resume_breakpoint = NULL;
8773 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8774 chain. If caller's caller is walking the chain, they'll be happier if we
8775 hand them back the original chain when restore_infcall_control_state is
8777 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8780 inf_status->stop_stack_dummy = stop_stack_dummy;
8781 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8783 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8789 restore_selected_frame (const frame_id &fid)
8791 frame_info *frame = frame_find_by_id (fid);
8793 /* If inf_status->selected_frame_id is NULL, there was no previously
8797 warning (_("Unable to restore previously selected frame."));
8801 select_frame (frame);
8804 /* Restore inferior session state to INF_STATUS. */
8807 restore_infcall_control_state (struct infcall_control_state *inf_status)
8809 struct thread_info *tp = inferior_thread ();
8810 struct inferior *inf = current_inferior ();
8812 if (tp->control.step_resume_breakpoint)
8813 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8815 if (tp->control.exception_resume_breakpoint)
8816 tp->control.exception_resume_breakpoint->disposition
8817 = disp_del_at_next_stop;
8819 /* Handle the bpstat_copy of the chain. */
8820 bpstat_clear (&tp->control.stop_bpstat);
8822 tp->control = inf_status->thread_control;
8823 inf->control = inf_status->inferior_control;
8826 stop_stack_dummy = inf_status->stop_stack_dummy;
8827 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8829 if (target_has_stack)
8831 /* The point of the try/catch is that if the stack is clobbered,
8832 walking the stack might encounter a garbage pointer and
8833 error() trying to dereference it. */
8836 restore_selected_frame (inf_status->selected_frame_id);
8838 CATCH (ex, RETURN_MASK_ERROR)
8840 exception_fprintf (gdb_stderr, ex,
8841 "Unable to restore previously selected frame:\n");
8842 /* Error in restoring the selected frame. Select the
8844 select_frame (get_current_frame ());
8853 discard_infcall_control_state (struct infcall_control_state *inf_status)
8855 if (inf_status->thread_control.step_resume_breakpoint)
8856 inf_status->thread_control.step_resume_breakpoint->disposition
8857 = disp_del_at_next_stop;
8859 if (inf_status->thread_control.exception_resume_breakpoint)
8860 inf_status->thread_control.exception_resume_breakpoint->disposition
8861 = disp_del_at_next_stop;
8863 /* See save_infcall_control_state for info on stop_bpstat. */
8864 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8872 clear_exit_convenience_vars (void)
8874 clear_internalvar (lookup_internalvar ("_exitsignal"));
8875 clear_internalvar (lookup_internalvar ("_exitcode"));
8879 /* User interface for reverse debugging:
8880 Set exec-direction / show exec-direction commands
8881 (returns error unless target implements to_set_exec_direction method). */
8883 enum exec_direction_kind execution_direction = EXEC_FORWARD;
8884 static const char exec_forward[] = "forward";
8885 static const char exec_reverse[] = "reverse";
8886 static const char *exec_direction = exec_forward;
8887 static const char *const exec_direction_names[] = {
8894 set_exec_direction_func (const char *args, int from_tty,
8895 struct cmd_list_element *cmd)
8897 if (target_can_execute_reverse)
8899 if (!strcmp (exec_direction, exec_forward))
8900 execution_direction = EXEC_FORWARD;
8901 else if (!strcmp (exec_direction, exec_reverse))
8902 execution_direction = EXEC_REVERSE;
8906 exec_direction = exec_forward;
8907 error (_("Target does not support this operation."));
8912 show_exec_direction_func (struct ui_file *out, int from_tty,
8913 struct cmd_list_element *cmd, const char *value)
8915 switch (execution_direction) {
8917 fprintf_filtered (out, _("Forward.\n"));
8920 fprintf_filtered (out, _("Reverse.\n"));
8923 internal_error (__FILE__, __LINE__,
8924 _("bogus execution_direction value: %d"),
8925 (int) execution_direction);
8930 show_schedule_multiple (struct ui_file *file, int from_tty,
8931 struct cmd_list_element *c, const char *value)
8933 fprintf_filtered (file, _("Resuming the execution of threads "
8934 "of all processes is %s.\n"), value);
8937 /* Implementation of `siginfo' variable. */
8939 static const struct internalvar_funcs siginfo_funcs =
8946 /* Callback for infrun's target events source. This is marked when a
8947 thread has a pending status to process. */
8950 infrun_async_inferior_event_handler (gdb_client_data data)
8952 inferior_event_handler (INF_REG_EVENT, NULL);
8956 _initialize_infrun (void)
8958 struct cmd_list_element *c;
8960 /* Register extra event sources in the event loop. */
8961 infrun_async_inferior_event_token
8962 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8964 add_info ("signals", info_signals_command, _("\
8965 What debugger does when program gets various signals.\n\
8966 Specify a signal as argument to print info on that signal only."));
8967 add_info_alias ("handle", "signals", 0);
8969 c = add_com ("handle", class_run, handle_command, _("\
8970 Specify how to handle signals.\n\
8971 Usage: handle SIGNAL [ACTIONS]\n\
8972 Args are signals and actions to apply to those signals.\n\
8973 If no actions are specified, the current settings for the specified signals\n\
8974 will be displayed instead.\n\
8976 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8977 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8978 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8979 The special arg \"all\" is recognized to mean all signals except those\n\
8980 used by the debugger, typically SIGTRAP and SIGINT.\n\
8982 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8983 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8984 Stop means reenter debugger if this signal happens (implies print).\n\
8985 Print means print a message if this signal happens.\n\
8986 Pass means let program see this signal; otherwise program doesn't know.\n\
8987 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8988 Pass and Stop may be combined.\n\
8990 Multiple signals may be specified. Signal numbers and signal names\n\
8991 may be interspersed with actions, with the actions being performed for\n\
8992 all signals cumulatively specified."));
8993 set_cmd_completer (c, handle_completer);
8996 stop_command = add_cmd ("stop", class_obscure,
8997 not_just_help_class_command, _("\
8998 There is no `stop' command, but you can set a hook on `stop'.\n\
8999 This allows you to set a list of commands to be run each time execution\n\
9000 of the program stops."), &cmdlist);
9002 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9003 Set inferior debugging."), _("\
9004 Show inferior debugging."), _("\
9005 When non-zero, inferior specific debugging is enabled."),
9008 &setdebuglist, &showdebuglist);
9010 add_setshow_boolean_cmd ("displaced", class_maintenance,
9011 &debug_displaced, _("\
9012 Set displaced stepping debugging."), _("\
9013 Show displaced stepping debugging."), _("\
9014 When non-zero, displaced stepping specific debugging is enabled."),
9016 show_debug_displaced,
9017 &setdebuglist, &showdebuglist);
9019 add_setshow_boolean_cmd ("non-stop", no_class,
9021 Set whether gdb controls the inferior in non-stop mode."), _("\
9022 Show whether gdb controls the inferior in non-stop mode."), _("\
9023 When debugging a multi-threaded program and this setting is\n\
9024 off (the default, also called all-stop mode), when one thread stops\n\
9025 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9026 all other threads in the program while you interact with the thread of\n\
9027 interest. When you continue or step a thread, you can allow the other\n\
9028 threads to run, or have them remain stopped, but while you inspect any\n\
9029 thread's state, all threads stop.\n\
9031 In non-stop mode, when one thread stops, other threads can continue\n\
9032 to run freely. You'll be able to step each thread independently,\n\
9033 leave it stopped or free to run as needed."),
9039 for (size_t i = 0; i < GDB_SIGNAL_LAST; i++)
9042 signal_print[i] = 1;
9043 signal_program[i] = 1;
9044 signal_catch[i] = 0;
9047 /* Signals caused by debugger's own actions should not be given to
9048 the program afterwards.
9050 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9051 explicitly specifies that it should be delivered to the target
9052 program. Typically, that would occur when a user is debugging a
9053 target monitor on a simulator: the target monitor sets a
9054 breakpoint; the simulator encounters this breakpoint and halts
9055 the simulation handing control to GDB; GDB, noting that the stop
9056 address doesn't map to any known breakpoint, returns control back
9057 to the simulator; the simulator then delivers the hardware
9058 equivalent of a GDB_SIGNAL_TRAP to the program being
9060 signal_program[GDB_SIGNAL_TRAP] = 0;
9061 signal_program[GDB_SIGNAL_INT] = 0;
9063 /* Signals that are not errors should not normally enter the debugger. */
9064 signal_stop[GDB_SIGNAL_ALRM] = 0;
9065 signal_print[GDB_SIGNAL_ALRM] = 0;
9066 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9067 signal_print[GDB_SIGNAL_VTALRM] = 0;
9068 signal_stop[GDB_SIGNAL_PROF] = 0;
9069 signal_print[GDB_SIGNAL_PROF] = 0;
9070 signal_stop[GDB_SIGNAL_CHLD] = 0;
9071 signal_print[GDB_SIGNAL_CHLD] = 0;
9072 signal_stop[GDB_SIGNAL_IO] = 0;
9073 signal_print[GDB_SIGNAL_IO] = 0;
9074 signal_stop[GDB_SIGNAL_POLL] = 0;
9075 signal_print[GDB_SIGNAL_POLL] = 0;
9076 signal_stop[GDB_SIGNAL_URG] = 0;
9077 signal_print[GDB_SIGNAL_URG] = 0;
9078 signal_stop[GDB_SIGNAL_WINCH] = 0;
9079 signal_print[GDB_SIGNAL_WINCH] = 0;
9080 signal_stop[GDB_SIGNAL_PRIO] = 0;
9081 signal_print[GDB_SIGNAL_PRIO] = 0;
9083 /* These signals are used internally by user-level thread
9084 implementations. (See signal(5) on Solaris.) Like the above
9085 signals, a healthy program receives and handles them as part of
9086 its normal operation. */
9087 signal_stop[GDB_SIGNAL_LWP] = 0;
9088 signal_print[GDB_SIGNAL_LWP] = 0;
9089 signal_stop[GDB_SIGNAL_WAITING] = 0;
9090 signal_print[GDB_SIGNAL_WAITING] = 0;
9091 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9092 signal_print[GDB_SIGNAL_CANCEL] = 0;
9093 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9094 signal_print[GDB_SIGNAL_LIBRT] = 0;
9096 /* Update cached state. */
9097 signal_cache_update (-1);
9099 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9100 &stop_on_solib_events, _("\
9101 Set stopping for shared library events."), _("\
9102 Show stopping for shared library events."), _("\
9103 If nonzero, gdb will give control to the user when the dynamic linker\n\
9104 notifies gdb of shared library events. The most common event of interest\n\
9105 to the user would be loading/unloading of a new library."),
9106 set_stop_on_solib_events,
9107 show_stop_on_solib_events,
9108 &setlist, &showlist);
9110 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9111 follow_fork_mode_kind_names,
9112 &follow_fork_mode_string, _("\
9113 Set debugger response to a program call of fork or vfork."), _("\
9114 Show debugger response to a program call of fork or vfork."), _("\
9115 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9116 parent - the original process is debugged after a fork\n\
9117 child - the new process is debugged after a fork\n\
9118 The unfollowed process will continue to run.\n\
9119 By default, the debugger will follow the parent process."),
9121 show_follow_fork_mode_string,
9122 &setlist, &showlist);
9124 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9125 follow_exec_mode_names,
9126 &follow_exec_mode_string, _("\
9127 Set debugger response to a program call of exec."), _("\
9128 Show debugger response to a program call of exec."), _("\
9129 An exec call replaces the program image of a process.\n\
9131 follow-exec-mode can be:\n\
9133 new - the debugger creates a new inferior and rebinds the process\n\
9134 to this new inferior. The program the process was running before\n\
9135 the exec call can be restarted afterwards by restarting the original\n\
9138 same - the debugger keeps the process bound to the same inferior.\n\
9139 The new executable image replaces the previous executable loaded in\n\
9140 the inferior. Restarting the inferior after the exec call restarts\n\
9141 the executable the process was running after the exec call.\n\
9143 By default, the debugger will use the same inferior."),
9145 show_follow_exec_mode_string,
9146 &setlist, &showlist);
9148 add_setshow_enum_cmd ("scheduler-locking", class_run,
9149 scheduler_enums, &scheduler_mode, _("\
9150 Set mode for locking scheduler during execution."), _("\
9151 Show mode for locking scheduler during execution."), _("\
9152 off == no locking (threads may preempt at any time)\n\
9153 on == full locking (no thread except the current thread may run)\n\
9154 This applies to both normal execution and replay mode.\n\
9155 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9156 In this mode, other threads may run during other commands.\n\
9157 This applies to both normal execution and replay mode.\n\
9158 replay == scheduler locked in replay mode and unlocked during normal execution."),
9159 set_schedlock_func, /* traps on target vector */
9160 show_scheduler_mode,
9161 &setlist, &showlist);
9163 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9164 Set mode for resuming threads of all processes."), _("\
9165 Show mode for resuming threads of all processes."), _("\
9166 When on, execution commands (such as 'continue' or 'next') resume all\n\
9167 threads of all processes. When off (which is the default), execution\n\
9168 commands only resume the threads of the current process. The set of\n\
9169 threads that are resumed is further refined by the scheduler-locking\n\
9170 mode (see help set scheduler-locking)."),
9172 show_schedule_multiple,
9173 &setlist, &showlist);
9175 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9176 Set mode of the step operation."), _("\
9177 Show mode of the step operation."), _("\
9178 When set, doing a step over a function without debug line information\n\
9179 will stop at the first instruction of that function. Otherwise, the\n\
9180 function is skipped and the step command stops at a different source line."),
9182 show_step_stop_if_no_debug,
9183 &setlist, &showlist);
9185 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9186 &can_use_displaced_stepping, _("\
9187 Set debugger's willingness to use displaced stepping."), _("\
9188 Show debugger's willingness to use displaced stepping."), _("\
9189 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9190 supported by the target architecture. If off, gdb will not use displaced\n\
9191 stepping to step over breakpoints, even if such is supported by the target\n\
9192 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9193 if the target architecture supports it and non-stop mode is active, but will not\n\
9194 use it in all-stop mode (see help set non-stop)."),
9196 show_can_use_displaced_stepping,
9197 &setlist, &showlist);
9199 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9200 &exec_direction, _("Set direction of execution.\n\
9201 Options are 'forward' or 'reverse'."),
9202 _("Show direction of execution (forward/reverse)."),
9203 _("Tells gdb whether to execute forward or backward."),
9204 set_exec_direction_func, show_exec_direction_func,
9205 &setlist, &showlist);
9207 /* Set/show detach-on-fork: user-settable mode. */
9209 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9210 Set whether gdb will detach the child of a fork."), _("\
9211 Show whether gdb will detach the child of a fork."), _("\
9212 Tells gdb whether to detach the child of a fork."),
9213 NULL, NULL, &setlist, &showlist);
9215 /* Set/show disable address space randomization mode. */
9217 add_setshow_boolean_cmd ("disable-randomization", class_support,
9218 &disable_randomization, _("\
9219 Set disabling of debuggee's virtual address space randomization."), _("\
9220 Show disabling of debuggee's virtual address space randomization."), _("\
9221 When this mode is on (which is the default), randomization of the virtual\n\
9222 address space is disabled. Standalone programs run with the randomization\n\
9223 enabled by default on some platforms."),
9224 &set_disable_randomization,
9225 &show_disable_randomization,
9226 &setlist, &showlist);
9228 /* ptid initializations */
9229 inferior_ptid = null_ptid;
9230 target_last_wait_ptid = minus_one_ptid;
9232 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9233 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9234 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9235 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9237 /* Explicitly create without lookup, since that tries to create a
9238 value with a void typed value, and when we get here, gdbarch
9239 isn't initialized yet. At this point, we're quite sure there
9240 isn't another convenience variable of the same name. */
9241 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9243 add_setshow_boolean_cmd ("observer", no_class,
9244 &observer_mode_1, _("\
9245 Set whether gdb controls the inferior in observer mode."), _("\
9246 Show whether gdb controls the inferior in observer mode."), _("\
9247 In observer mode, GDB can get data from the inferior, but not\n\
9248 affect its execution. Registers and memory may not be changed,\n\
9249 breakpoints may not be set, and the program cannot be interrupted\n\