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. Break the bonds. */
918 inferior *vfork_parent = inf->vfork_parent;
919 inf->vfork_parent->vfork_child = NULL;
920 inf->vfork_parent = NULL;
922 /* If the user wanted to detach from the parent, now is the
924 if (vfork_parent->pending_detach)
926 struct thread_info *tp;
927 struct program_space *pspace;
928 struct address_space *aspace;
930 /* follow-fork child, detach-on-fork on. */
932 vfork_parent->pending_detach = 0;
934 gdb::optional<scoped_restore_exited_inferior>
935 maybe_restore_inferior;
936 gdb::optional<scoped_restore_current_pspace_and_thread>
937 maybe_restore_thread;
939 /* If we're handling a child exit, then inferior_ptid points
940 at the inferior's pid, not to a thread. */
942 maybe_restore_inferior.emplace ();
944 maybe_restore_thread.emplace ();
946 /* We're letting loose of the parent. */
947 tp = any_live_thread_of_inferior (vfork_parent);
948 switch_to_thread (tp);
950 /* We're about to detach from the parent, which implicitly
951 removes breakpoints from its address space. There's a
952 catch here: we want to reuse the spaces for the child,
953 but, parent/child are still sharing the pspace at this
954 point, although the exec in reality makes the kernel give
955 the child a fresh set of new pages. The problem here is
956 that the breakpoints module being unaware of this, would
957 likely chose the child process to write to the parent
958 address space. Swapping the child temporarily away from
959 the spaces has the desired effect. Yes, this is "sort
962 pspace = inf->pspace;
963 aspace = inf->aspace;
967 if (print_inferior_events)
970 = target_pid_to_str (ptid_t (vfork_parent->pid));
972 target_terminal::ours_for_output ();
976 fprintf_filtered (gdb_stdlog,
977 _("[Detaching vfork parent %s "
978 "after child exec]\n"), pidstr);
982 fprintf_filtered (gdb_stdlog,
983 _("[Detaching vfork parent %s "
984 "after child exit]\n"), pidstr);
988 target_detach (vfork_parent, 0);
991 inf->pspace = pspace;
992 inf->aspace = aspace;
996 /* We're staying attached to the parent, so, really give the
997 child a new address space. */
998 inf->pspace = new program_space (maybe_new_address_space ());
999 inf->aspace = inf->pspace->aspace;
1001 set_current_program_space (inf->pspace);
1003 resume_parent = vfork_parent->pid;
1007 struct program_space *pspace;
1009 /* If this is a vfork child exiting, then the pspace and
1010 aspaces were shared with the parent. Since we're
1011 reporting the process exit, we'll be mourning all that is
1012 found in the address space, and switching to null_ptid,
1013 preparing to start a new inferior. But, since we don't
1014 want to clobber the parent's address/program spaces, we
1015 go ahead and create a new one for this exiting
1018 /* Switch to null_ptid while running clone_program_space, so
1019 that clone_program_space doesn't want to read the
1020 selected frame of a dead process. */
1021 scoped_restore restore_ptid
1022 = make_scoped_restore (&inferior_ptid, null_ptid);
1024 /* This inferior is dead, so avoid giving the breakpoints
1025 module the option to write through to it (cloning a
1026 program space resets breakpoints). */
1029 pspace = new program_space (maybe_new_address_space ());
1030 set_current_program_space (pspace);
1032 inf->symfile_flags = SYMFILE_NO_READ;
1033 clone_program_space (pspace, vfork_parent->pspace);
1034 inf->pspace = pspace;
1035 inf->aspace = pspace->aspace;
1037 resume_parent = vfork_parent->pid;
1040 gdb_assert (current_program_space == inf->pspace);
1042 if (non_stop && resume_parent != -1)
1044 /* If the user wanted the parent to be running, let it go
1046 scoped_restore_current_thread restore_thread;
1049 fprintf_unfiltered (gdb_stdlog,
1050 "infrun: resuming vfork parent process %d\n",
1053 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1058 /* Enum strings for "set|show follow-exec-mode". */
1060 static const char follow_exec_mode_new[] = "new";
1061 static const char follow_exec_mode_same[] = "same";
1062 static const char *const follow_exec_mode_names[] =
1064 follow_exec_mode_new,
1065 follow_exec_mode_same,
1069 static const char *follow_exec_mode_string = follow_exec_mode_same;
1071 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1072 struct cmd_list_element *c, const char *value)
1074 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1077 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1080 follow_exec (ptid_t ptid, char *exec_file_target)
1082 struct inferior *inf = current_inferior ();
1083 int pid = ptid.pid ();
1084 ptid_t process_ptid;
1086 /* This is an exec event that we actually wish to pay attention to.
1087 Refresh our symbol table to the newly exec'd program, remove any
1088 momentary bp's, etc.
1090 If there are breakpoints, they aren't really inserted now,
1091 since the exec() transformed our inferior into a fresh set
1094 We want to preserve symbolic breakpoints on the list, since
1095 we have hopes that they can be reset after the new a.out's
1096 symbol table is read.
1098 However, any "raw" breakpoints must be removed from the list
1099 (e.g., the solib bp's), since their address is probably invalid
1102 And, we DON'T want to call delete_breakpoints() here, since
1103 that may write the bp's "shadow contents" (the instruction
1104 value that was overwritten witha TRAP instruction). Since
1105 we now have a new a.out, those shadow contents aren't valid. */
1107 mark_breakpoints_out ();
1109 /* The target reports the exec event to the main thread, even if
1110 some other thread does the exec, and even if the main thread was
1111 stopped or already gone. We may still have non-leader threads of
1112 the process on our list. E.g., on targets that don't have thread
1113 exit events (like remote); or on native Linux in non-stop mode if
1114 there were only two threads in the inferior and the non-leader
1115 one is the one that execs (and nothing forces an update of the
1116 thread list up to here). When debugging remotely, it's best to
1117 avoid extra traffic, when possible, so avoid syncing the thread
1118 list with the target, and instead go ahead and delete all threads
1119 of the process but one that reported the event. Note this must
1120 be done before calling update_breakpoints_after_exec, as
1121 otherwise clearing the threads' resources would reference stale
1122 thread breakpoints -- it may have been one of these threads that
1123 stepped across the exec. We could just clear their stepping
1124 states, but as long as we're iterating, might as well delete
1125 them. Deleting them now rather than at the next user-visible
1126 stop provides a nicer sequence of events for user and MI
1128 for (thread_info *th : all_threads_safe ())
1129 if (th->ptid.pid () == pid && th->ptid != ptid)
1132 /* We also need to clear any left over stale state for the
1133 leader/event thread. E.g., if there was any step-resume
1134 breakpoint or similar, it's gone now. We cannot truly
1135 step-to-next statement through an exec(). */
1136 thread_info *th = inferior_thread ();
1137 th->control.step_resume_breakpoint = NULL;
1138 th->control.exception_resume_breakpoint = NULL;
1139 th->control.single_step_breakpoints = NULL;
1140 th->control.step_range_start = 0;
1141 th->control.step_range_end = 0;
1143 /* The user may have had the main thread held stopped in the
1144 previous image (e.g., schedlock on, or non-stop). Release
1146 th->stop_requested = 0;
1148 update_breakpoints_after_exec ();
1150 /* What is this a.out's name? */
1151 process_ptid = ptid_t (pid);
1152 printf_unfiltered (_("%s is executing new program: %s\n"),
1153 target_pid_to_str (process_ptid),
1156 /* We've followed the inferior through an exec. Therefore, the
1157 inferior has essentially been killed & reborn. */
1159 gdb_flush (gdb_stdout);
1161 breakpoint_init_inferior (inf_execd);
1163 gdb::unique_xmalloc_ptr<char> exec_file_host
1164 = exec_file_find (exec_file_target, NULL);
1166 /* If we were unable to map the executable target pathname onto a host
1167 pathname, tell the user that. Otherwise GDB's subsequent behavior
1168 is confusing. Maybe it would even be better to stop at this point
1169 so that the user can specify a file manually before continuing. */
1170 if (exec_file_host == NULL)
1171 warning (_("Could not load symbols for executable %s.\n"
1172 "Do you need \"set sysroot\"?"),
1175 /* Reset the shared library package. This ensures that we get a
1176 shlib event when the child reaches "_start", at which point the
1177 dld will have had a chance to initialize the child. */
1178 /* Also, loading a symbol file below may trigger symbol lookups, and
1179 we don't want those to be satisfied by the libraries of the
1180 previous incarnation of this process. */
1181 no_shared_libraries (NULL, 0);
1183 if (follow_exec_mode_string == follow_exec_mode_new)
1185 /* The user wants to keep the old inferior and program spaces
1186 around. Create a new fresh one, and switch to it. */
1188 /* Do exit processing for the original inferior before setting the new
1189 inferior's pid. Having two inferiors with the same pid would confuse
1190 find_inferior_p(t)id. Transfer the terminal state and info from the
1191 old to the new inferior. */
1192 inf = add_inferior_with_spaces ();
1193 swap_terminal_info (inf, current_inferior ());
1194 exit_inferior_silent (current_inferior ());
1197 target_follow_exec (inf, exec_file_target);
1199 set_current_inferior (inf);
1200 set_current_program_space (inf->pspace);
1205 /* The old description may no longer be fit for the new image.
1206 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1207 old description; we'll read a new one below. No need to do
1208 this on "follow-exec-mode new", as the old inferior stays
1209 around (its description is later cleared/refetched on
1211 target_clear_description ();
1214 gdb_assert (current_program_space == inf->pspace);
1216 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1217 because the proper displacement for a PIE (Position Independent
1218 Executable) main symbol file will only be computed by
1219 solib_create_inferior_hook below. breakpoint_re_set would fail
1220 to insert the breakpoints with the zero displacement. */
1221 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1223 /* If the target can specify a description, read it. Must do this
1224 after flipping to the new executable (because the target supplied
1225 description must be compatible with the executable's
1226 architecture, and the old executable may e.g., be 32-bit, while
1227 the new one 64-bit), and before anything involving memory or
1229 target_find_description ();
1231 solib_create_inferior_hook (0);
1233 jit_inferior_created_hook ();
1235 breakpoint_re_set ();
1237 /* Reinsert all breakpoints. (Those which were symbolic have
1238 been reset to the proper address in the new a.out, thanks
1239 to symbol_file_command...). */
1240 insert_breakpoints ();
1242 /* The next resume of this inferior should bring it to the shlib
1243 startup breakpoints. (If the user had also set bp's on
1244 "main" from the old (parent) process, then they'll auto-
1245 matically get reset there in the new process.). */
1248 /* The queue of threads that need to do a step-over operation to get
1249 past e.g., a breakpoint. What technique is used to step over the
1250 breakpoint/watchpoint does not matter -- all threads end up in the
1251 same queue, to maintain rough temporal order of execution, in order
1252 to avoid starvation, otherwise, we could e.g., find ourselves
1253 constantly stepping the same couple threads past their breakpoints
1254 over and over, if the single-step finish fast enough. */
1255 struct thread_info *step_over_queue_head;
1257 /* Bit flags indicating what the thread needs to step over. */
1259 enum step_over_what_flag
1261 /* Step over a breakpoint. */
1262 STEP_OVER_BREAKPOINT = 1,
1264 /* Step past a non-continuable watchpoint, in order to let the
1265 instruction execute so we can evaluate the watchpoint
1267 STEP_OVER_WATCHPOINT = 2
1269 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1271 /* Info about an instruction that is being stepped over. */
1273 struct step_over_info
1275 /* If we're stepping past a breakpoint, this is the address space
1276 and address of the instruction the breakpoint is set at. We'll
1277 skip inserting all breakpoints here. Valid iff ASPACE is
1279 const address_space *aspace;
1282 /* The instruction being stepped over triggers a nonsteppable
1283 watchpoint. If true, we'll skip inserting watchpoints. */
1284 int nonsteppable_watchpoint_p;
1286 /* The thread's global number. */
1290 /* The step-over info of the location that is being stepped over.
1292 Note that with async/breakpoint always-inserted mode, a user might
1293 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1294 being stepped over. As setting a new breakpoint inserts all
1295 breakpoints, we need to make sure the breakpoint being stepped over
1296 isn't inserted then. We do that by only clearing the step-over
1297 info when the step-over is actually finished (or aborted).
1299 Presently GDB can only step over one breakpoint at any given time.
1300 Given threads that can't run code in the same address space as the
1301 breakpoint's can't really miss the breakpoint, GDB could be taught
1302 to step-over at most one breakpoint per address space (so this info
1303 could move to the address space object if/when GDB is extended).
1304 The set of breakpoints being stepped over will normally be much
1305 smaller than the set of all breakpoints, so a flag in the
1306 breakpoint location structure would be wasteful. A separate list
1307 also saves complexity and run-time, as otherwise we'd have to go
1308 through all breakpoint locations clearing their flag whenever we
1309 start a new sequence. Similar considerations weigh against storing
1310 this info in the thread object. Plus, not all step overs actually
1311 have breakpoint locations -- e.g., stepping past a single-step
1312 breakpoint, or stepping to complete a non-continuable
1314 static struct step_over_info step_over_info;
1316 /* Record the address of the breakpoint/instruction we're currently
1318 N.B. We record the aspace and address now, instead of say just the thread,
1319 because when we need the info later the thread may be running. */
1322 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1323 int nonsteppable_watchpoint_p,
1326 step_over_info.aspace = aspace;
1327 step_over_info.address = address;
1328 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1329 step_over_info.thread = thread;
1332 /* Called when we're not longer stepping over a breakpoint / an
1333 instruction, so all breakpoints are free to be (re)inserted. */
1336 clear_step_over_info (void)
1339 fprintf_unfiltered (gdb_stdlog,
1340 "infrun: clear_step_over_info\n");
1341 step_over_info.aspace = NULL;
1342 step_over_info.address = 0;
1343 step_over_info.nonsteppable_watchpoint_p = 0;
1344 step_over_info.thread = -1;
1350 stepping_past_instruction_at (struct address_space *aspace,
1353 return (step_over_info.aspace != NULL
1354 && breakpoint_address_match (aspace, address,
1355 step_over_info.aspace,
1356 step_over_info.address));
1362 thread_is_stepping_over_breakpoint (int thread)
1364 return (step_over_info.thread != -1
1365 && thread == step_over_info.thread);
1371 stepping_past_nonsteppable_watchpoint (void)
1373 return step_over_info.nonsteppable_watchpoint_p;
1376 /* Returns true if step-over info is valid. */
1379 step_over_info_valid_p (void)
1381 return (step_over_info.aspace != NULL
1382 || stepping_past_nonsteppable_watchpoint ());
1386 /* Displaced stepping. */
1388 /* In non-stop debugging mode, we must take special care to manage
1389 breakpoints properly; in particular, the traditional strategy for
1390 stepping a thread past a breakpoint it has hit is unsuitable.
1391 'Displaced stepping' is a tactic for stepping one thread past a
1392 breakpoint it has hit while ensuring that other threads running
1393 concurrently will hit the breakpoint as they should.
1395 The traditional way to step a thread T off a breakpoint in a
1396 multi-threaded program in all-stop mode is as follows:
1398 a0) Initially, all threads are stopped, and breakpoints are not
1400 a1) We single-step T, leaving breakpoints uninserted.
1401 a2) We insert breakpoints, and resume all threads.
1403 In non-stop debugging, however, this strategy is unsuitable: we
1404 don't want to have to stop all threads in the system in order to
1405 continue or step T past a breakpoint. Instead, we use displaced
1408 n0) Initially, T is stopped, other threads are running, and
1409 breakpoints are inserted.
1410 n1) We copy the instruction "under" the breakpoint to a separate
1411 location, outside the main code stream, making any adjustments
1412 to the instruction, register, and memory state as directed by
1414 n2) We single-step T over the instruction at its new location.
1415 n3) We adjust the resulting register and memory state as directed
1416 by T's architecture. This includes resetting T's PC to point
1417 back into the main instruction stream.
1420 This approach depends on the following gdbarch methods:
1422 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1423 indicate where to copy the instruction, and how much space must
1424 be reserved there. We use these in step n1.
1426 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1427 address, and makes any necessary adjustments to the instruction,
1428 register contents, and memory. We use this in step n1.
1430 - gdbarch_displaced_step_fixup adjusts registers and memory after
1431 we have successfuly single-stepped the instruction, to yield the
1432 same effect the instruction would have had if we had executed it
1433 at its original address. We use this in step n3.
1435 The gdbarch_displaced_step_copy_insn and
1436 gdbarch_displaced_step_fixup functions must be written so that
1437 copying an instruction with gdbarch_displaced_step_copy_insn,
1438 single-stepping across the copied instruction, and then applying
1439 gdbarch_displaced_insn_fixup should have the same effects on the
1440 thread's memory and registers as stepping the instruction in place
1441 would have. Exactly which responsibilities fall to the copy and
1442 which fall to the fixup is up to the author of those functions.
1444 See the comments in gdbarch.sh for details.
1446 Note that displaced stepping and software single-step cannot
1447 currently be used in combination, although with some care I think
1448 they could be made to. Software single-step works by placing
1449 breakpoints on all possible subsequent instructions; if the
1450 displaced instruction is a PC-relative jump, those breakpoints
1451 could fall in very strange places --- on pages that aren't
1452 executable, or at addresses that are not proper instruction
1453 boundaries. (We do generally let other threads run while we wait
1454 to hit the software single-step breakpoint, and they might
1455 encounter such a corrupted instruction.) One way to work around
1456 this would be to have gdbarch_displaced_step_copy_insn fully
1457 simulate the effect of PC-relative instructions (and return NULL)
1458 on architectures that use software single-stepping.
1460 In non-stop mode, we can have independent and simultaneous step
1461 requests, so more than one thread may need to simultaneously step
1462 over a breakpoint. The current implementation assumes there is
1463 only one scratch space per process. In this case, we have to
1464 serialize access to the scratch space. If thread A wants to step
1465 over a breakpoint, but we are currently waiting for some other
1466 thread to complete a displaced step, we leave thread A stopped and
1467 place it in the displaced_step_request_queue. Whenever a displaced
1468 step finishes, we pick the next thread in the queue and start a new
1469 displaced step operation on it. See displaced_step_prepare and
1470 displaced_step_fixup for details. */
1472 /* Default destructor for displaced_step_closure. */
1474 displaced_step_closure::~displaced_step_closure () = default;
1476 /* Get the displaced stepping state of process PID. */
1478 static displaced_step_inferior_state *
1479 get_displaced_stepping_state (inferior *inf)
1481 return &inf->displaced_step_state;
1484 /* Returns true if any inferior has a thread doing a displaced
1488 displaced_step_in_progress_any_inferior ()
1490 for (inferior *i : all_inferiors ())
1492 if (i->displaced_step_state.step_thread != nullptr)
1499 /* Return true if thread represented by PTID is doing a displaced
1503 displaced_step_in_progress_thread (thread_info *thread)
1505 gdb_assert (thread != NULL);
1507 return get_displaced_stepping_state (thread->inf)->step_thread == thread;
1510 /* Return true if process PID has a thread doing a displaced step. */
1513 displaced_step_in_progress (inferior *inf)
1515 return get_displaced_stepping_state (inf)->step_thread != nullptr;
1518 /* If inferior is in displaced stepping, and ADDR equals to starting address
1519 of copy area, return corresponding displaced_step_closure. Otherwise,
1522 struct displaced_step_closure*
1523 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1525 displaced_step_inferior_state *displaced
1526 = get_displaced_stepping_state (current_inferior ());
1528 /* If checking the mode of displaced instruction in copy area. */
1529 if (displaced->step_thread != nullptr
1530 && displaced->step_copy == addr)
1531 return displaced->step_closure;
1537 infrun_inferior_exit (struct inferior *inf)
1539 inf->displaced_step_state.reset ();
1542 /* If ON, and the architecture supports it, GDB will use displaced
1543 stepping to step over breakpoints. If OFF, or if the architecture
1544 doesn't support it, GDB will instead use the traditional
1545 hold-and-step approach. If AUTO (which is the default), GDB will
1546 decide which technique to use to step over breakpoints depending on
1547 which of all-stop or non-stop mode is active --- displaced stepping
1548 in non-stop mode; hold-and-step in all-stop mode. */
1550 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1553 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1554 struct cmd_list_element *c,
1557 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1558 fprintf_filtered (file,
1559 _("Debugger's willingness to use displaced stepping "
1560 "to step over breakpoints is %s (currently %s).\n"),
1561 value, target_is_non_stop_p () ? "on" : "off");
1563 fprintf_filtered (file,
1564 _("Debugger's willingness to use displaced stepping "
1565 "to step over breakpoints is %s.\n"), value);
1568 /* Return non-zero if displaced stepping can/should be used to step
1569 over breakpoints of thread TP. */
1572 use_displaced_stepping (struct thread_info *tp)
1574 struct regcache *regcache = get_thread_regcache (tp);
1575 struct gdbarch *gdbarch = regcache->arch ();
1576 displaced_step_inferior_state *displaced_state
1577 = get_displaced_stepping_state (tp->inf);
1579 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1580 && target_is_non_stop_p ())
1581 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1582 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1583 && find_record_target () == NULL
1584 && !displaced_state->failed_before);
1587 /* Clean out any stray displaced stepping state. */
1589 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1591 /* Indicate that there is no cleanup pending. */
1592 displaced->step_thread = nullptr;
1594 delete displaced->step_closure;
1595 displaced->step_closure = NULL;
1599 displaced_step_clear_cleanup (void *arg)
1601 struct displaced_step_inferior_state *state
1602 = (struct displaced_step_inferior_state *) arg;
1604 displaced_step_clear (state);
1607 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1609 displaced_step_dump_bytes (struct ui_file *file,
1610 const gdb_byte *buf,
1615 for (i = 0; i < len; i++)
1616 fprintf_unfiltered (file, "%02x ", buf[i]);
1617 fputs_unfiltered ("\n", file);
1620 /* Prepare to single-step, using displaced stepping.
1622 Note that we cannot use displaced stepping when we have a signal to
1623 deliver. If we have a signal to deliver and an instruction to step
1624 over, then after the step, there will be no indication from the
1625 target whether the thread entered a signal handler or ignored the
1626 signal and stepped over the instruction successfully --- both cases
1627 result in a simple SIGTRAP. In the first case we mustn't do a
1628 fixup, and in the second case we must --- but we can't tell which.
1629 Comments in the code for 'random signals' in handle_inferior_event
1630 explain how we handle this case instead.
1632 Returns 1 if preparing was successful -- this thread is going to be
1633 stepped now; 0 if displaced stepping this thread got queued; or -1
1634 if this instruction can't be displaced stepped. */
1637 displaced_step_prepare_throw (thread_info *tp)
1639 regcache *regcache = get_thread_regcache (tp);
1640 struct gdbarch *gdbarch = regcache->arch ();
1641 const address_space *aspace = regcache->aspace ();
1642 CORE_ADDR original, copy;
1644 struct displaced_step_closure *closure;
1647 /* We should never reach this function if the architecture does not
1648 support displaced stepping. */
1649 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1651 /* Nor if the thread isn't meant to step over a breakpoint. */
1652 gdb_assert (tp->control.trap_expected);
1654 /* Disable range stepping while executing in the scratch pad. We
1655 want a single-step even if executing the displaced instruction in
1656 the scratch buffer lands within the stepping range (e.g., a
1658 tp->control.may_range_step = 0;
1660 /* We have to displaced step one thread at a time, as we only have
1661 access to a single scratch space per inferior. */
1663 displaced_step_inferior_state *displaced
1664 = get_displaced_stepping_state (tp->inf);
1666 if (displaced->step_thread != nullptr)
1668 /* Already waiting for a displaced step to finish. Defer this
1669 request and place in queue. */
1671 if (debug_displaced)
1672 fprintf_unfiltered (gdb_stdlog,
1673 "displaced: deferring step of %s\n",
1674 target_pid_to_str (tp->ptid));
1676 thread_step_over_chain_enqueue (tp);
1681 if (debug_displaced)
1682 fprintf_unfiltered (gdb_stdlog,
1683 "displaced: stepping %s now\n",
1684 target_pid_to_str (tp->ptid));
1687 displaced_step_clear (displaced);
1689 scoped_restore_current_thread restore_thread;
1691 switch_to_thread (tp);
1693 original = regcache_read_pc (regcache);
1695 copy = gdbarch_displaced_step_location (gdbarch);
1696 len = gdbarch_max_insn_length (gdbarch);
1698 if (breakpoint_in_range_p (aspace, copy, len))
1700 /* There's a breakpoint set in the scratch pad location range
1701 (which is usually around the entry point). We'd either
1702 install it before resuming, which would overwrite/corrupt the
1703 scratch pad, or if it was already inserted, this displaced
1704 step would overwrite it. The latter is OK in the sense that
1705 we already assume that no thread is going to execute the code
1706 in the scratch pad range (after initial startup) anyway, but
1707 the former is unacceptable. Simply punt and fallback to
1708 stepping over this breakpoint in-line. */
1709 if (debug_displaced)
1711 fprintf_unfiltered (gdb_stdlog,
1712 "displaced: breakpoint set in scratch pad. "
1713 "Stepping over breakpoint in-line instead.\n");
1719 /* Save the original contents of the copy area. */
1720 displaced->step_saved_copy.resize (len);
1721 status = target_read_memory (copy, displaced->step_saved_copy.data (), len);
1723 throw_error (MEMORY_ERROR,
1724 _("Error accessing memory address %s (%s) for "
1725 "displaced-stepping scratch space."),
1726 paddress (gdbarch, copy), safe_strerror (status));
1727 if (debug_displaced)
1729 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1730 paddress (gdbarch, copy));
1731 displaced_step_dump_bytes (gdb_stdlog,
1732 displaced->step_saved_copy.data (),
1736 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1737 original, copy, regcache);
1738 if (closure == NULL)
1740 /* The architecture doesn't know how or want to displaced step
1741 this instruction or instruction sequence. Fallback to
1742 stepping over the breakpoint in-line. */
1746 /* Save the information we need to fix things up if the step
1748 displaced->step_thread = tp;
1749 displaced->step_gdbarch = gdbarch;
1750 displaced->step_closure = closure;
1751 displaced->step_original = original;
1752 displaced->step_copy = copy;
1754 cleanup *ignore_cleanups
1755 = make_cleanup (displaced_step_clear_cleanup, displaced);
1757 /* Resume execution at the copy. */
1758 regcache_write_pc (regcache, copy);
1760 discard_cleanups (ignore_cleanups);
1762 if (debug_displaced)
1763 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1764 paddress (gdbarch, copy));
1769 /* Wrapper for displaced_step_prepare_throw that disabled further
1770 attempts at displaced stepping if we get a memory error. */
1773 displaced_step_prepare (thread_info *thread)
1779 prepared = displaced_step_prepare_throw (thread);
1781 CATCH (ex, RETURN_MASK_ERROR)
1783 struct displaced_step_inferior_state *displaced_state;
1785 if (ex.error != MEMORY_ERROR
1786 && ex.error != NOT_SUPPORTED_ERROR)
1787 throw_exception (ex);
1791 fprintf_unfiltered (gdb_stdlog,
1792 "infrun: disabling displaced stepping: %s\n",
1796 /* Be verbose if "set displaced-stepping" is "on", silent if
1798 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1800 warning (_("disabling displaced stepping: %s"),
1804 /* Disable further displaced stepping attempts. */
1806 = get_displaced_stepping_state (thread->inf);
1807 displaced_state->failed_before = 1;
1815 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1816 const gdb_byte *myaddr, int len)
1818 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1820 inferior_ptid = ptid;
1821 write_memory (memaddr, myaddr, len);
1824 /* Restore the contents of the copy area for thread PTID. */
1827 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1830 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1832 write_memory_ptid (ptid, displaced->step_copy,
1833 displaced->step_saved_copy.data (), len);
1834 if (debug_displaced)
1835 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1836 target_pid_to_str (ptid),
1837 paddress (displaced->step_gdbarch,
1838 displaced->step_copy));
1841 /* If we displaced stepped an instruction successfully, adjust
1842 registers and memory to yield the same effect the instruction would
1843 have had if we had executed it at its original address, and return
1844 1. If the instruction didn't complete, relocate the PC and return
1845 -1. If the thread wasn't displaced stepping, return 0. */
1848 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1850 struct cleanup *old_cleanups;
1851 struct displaced_step_inferior_state *displaced
1852 = get_displaced_stepping_state (event_thread->inf);
1855 /* Was this event for the thread we displaced? */
1856 if (displaced->step_thread != event_thread)
1859 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1861 displaced_step_restore (displaced, displaced->step_thread->ptid);
1863 /* Fixup may need to read memory/registers. Switch to the thread
1864 that we're fixing up. Also, target_stopped_by_watchpoint checks
1865 the current thread. */
1866 switch_to_thread (event_thread);
1868 /* Did the instruction complete successfully? */
1869 if (signal == GDB_SIGNAL_TRAP
1870 && !(target_stopped_by_watchpoint ()
1871 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1872 || target_have_steppable_watchpoint)))
1874 /* Fix up the resulting state. */
1875 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1876 displaced->step_closure,
1877 displaced->step_original,
1878 displaced->step_copy,
1879 get_thread_regcache (displaced->step_thread));
1884 /* Since the instruction didn't complete, all we can do is
1886 struct regcache *regcache = get_thread_regcache (event_thread);
1887 CORE_ADDR pc = regcache_read_pc (regcache);
1889 pc = displaced->step_original + (pc - displaced->step_copy);
1890 regcache_write_pc (regcache, pc);
1894 do_cleanups (old_cleanups);
1896 displaced->step_thread = nullptr;
1901 /* Data to be passed around while handling an event. This data is
1902 discarded between events. */
1903 struct execution_control_state
1906 /* The thread that got the event, if this was a thread event; NULL
1908 struct thread_info *event_thread;
1910 struct target_waitstatus ws;
1911 int stop_func_filled_in;
1912 CORE_ADDR stop_func_start;
1913 CORE_ADDR stop_func_end;
1914 const char *stop_func_name;
1917 /* True if the event thread hit the single-step breakpoint of
1918 another thread. Thus the event doesn't cause a stop, the thread
1919 needs to be single-stepped past the single-step breakpoint before
1920 we can switch back to the original stepping thread. */
1921 int hit_singlestep_breakpoint;
1924 /* Clear ECS and set it to point at TP. */
1927 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
1929 memset (ecs, 0, sizeof (*ecs));
1930 ecs->event_thread = tp;
1931 ecs->ptid = tp->ptid;
1934 static void keep_going_pass_signal (struct execution_control_state *ecs);
1935 static void prepare_to_wait (struct execution_control_state *ecs);
1936 static int keep_going_stepped_thread (struct thread_info *tp);
1937 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
1939 /* Are there any pending step-over requests? If so, run all we can
1940 now and return true. Otherwise, return false. */
1943 start_step_over (void)
1945 struct thread_info *tp, *next;
1947 /* Don't start a new step-over if we already have an in-line
1948 step-over operation ongoing. */
1949 if (step_over_info_valid_p ())
1952 for (tp = step_over_queue_head; tp != NULL; tp = next)
1954 struct execution_control_state ecss;
1955 struct execution_control_state *ecs = &ecss;
1956 step_over_what step_what;
1957 int must_be_in_line;
1959 gdb_assert (!tp->stop_requested);
1961 next = thread_step_over_chain_next (tp);
1963 /* If this inferior already has a displaced step in process,
1964 don't start a new one. */
1965 if (displaced_step_in_progress (tp->inf))
1968 step_what = thread_still_needs_step_over (tp);
1969 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
1970 || ((step_what & STEP_OVER_BREAKPOINT)
1971 && !use_displaced_stepping (tp)));
1973 /* We currently stop all threads of all processes to step-over
1974 in-line. If we need to start a new in-line step-over, let
1975 any pending displaced steps finish first. */
1976 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
1979 thread_step_over_chain_remove (tp);
1981 if (step_over_queue_head == NULL)
1984 fprintf_unfiltered (gdb_stdlog,
1985 "infrun: step-over queue now empty\n");
1988 if (tp->control.trap_expected
1992 internal_error (__FILE__, __LINE__,
1993 "[%s] has inconsistent state: "
1994 "trap_expected=%d, resumed=%d, executing=%d\n",
1995 target_pid_to_str (tp->ptid),
1996 tp->control.trap_expected,
2002 fprintf_unfiltered (gdb_stdlog,
2003 "infrun: resuming [%s] for step-over\n",
2004 target_pid_to_str (tp->ptid));
2006 /* keep_going_pass_signal skips the step-over if the breakpoint
2007 is no longer inserted. In all-stop, we want to keep looking
2008 for a thread that needs a step-over instead of resuming TP,
2009 because we wouldn't be able to resume anything else until the
2010 target stops again. In non-stop, the resume always resumes
2011 only TP, so it's OK to let the thread resume freely. */
2012 if (!target_is_non_stop_p () && !step_what)
2015 switch_to_thread (tp);
2016 reset_ecs (ecs, tp);
2017 keep_going_pass_signal (ecs);
2019 if (!ecs->wait_some_more)
2020 error (_("Command aborted."));
2022 gdb_assert (tp->resumed);
2024 /* If we started a new in-line step-over, we're done. */
2025 if (step_over_info_valid_p ())
2027 gdb_assert (tp->control.trap_expected);
2031 if (!target_is_non_stop_p ())
2033 /* On all-stop, shouldn't have resumed unless we needed a
2035 gdb_assert (tp->control.trap_expected
2036 || tp->step_after_step_resume_breakpoint);
2038 /* With remote targets (at least), in all-stop, we can't
2039 issue any further remote commands until the program stops
2044 /* Either the thread no longer needed a step-over, or a new
2045 displaced stepping sequence started. Even in the latter
2046 case, continue looking. Maybe we can also start another
2047 displaced step on a thread of other process. */
2053 /* Update global variables holding ptids to hold NEW_PTID if they were
2054 holding OLD_PTID. */
2056 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2058 if (inferior_ptid == old_ptid)
2059 inferior_ptid = new_ptid;
2064 static const char schedlock_off[] = "off";
2065 static const char schedlock_on[] = "on";
2066 static const char schedlock_step[] = "step";
2067 static const char schedlock_replay[] = "replay";
2068 static const char *const scheduler_enums[] = {
2075 static const char *scheduler_mode = schedlock_replay;
2077 show_scheduler_mode (struct ui_file *file, int from_tty,
2078 struct cmd_list_element *c, const char *value)
2080 fprintf_filtered (file,
2081 _("Mode for locking scheduler "
2082 "during execution is \"%s\".\n"),
2087 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2089 if (!target_can_lock_scheduler)
2091 scheduler_mode = schedlock_off;
2092 error (_("Target '%s' cannot support this command."), target_shortname);
2096 /* True if execution commands resume all threads of all processes by
2097 default; otherwise, resume only threads of the current inferior
2099 int sched_multi = 0;
2101 /* Try to setup for software single stepping over the specified location.
2102 Return 1 if target_resume() should use hardware single step.
2104 GDBARCH the current gdbarch.
2105 PC the location to step over. */
2108 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2112 if (execution_direction == EXEC_FORWARD
2113 && gdbarch_software_single_step_p (gdbarch))
2114 hw_step = !insert_single_step_breakpoints (gdbarch);
2122 user_visible_resume_ptid (int step)
2128 /* With non-stop mode on, threads are always handled
2130 resume_ptid = inferior_ptid;
2132 else if ((scheduler_mode == schedlock_on)
2133 || (scheduler_mode == schedlock_step && step))
2135 /* User-settable 'scheduler' mode requires solo thread
2137 resume_ptid = inferior_ptid;
2139 else if ((scheduler_mode == schedlock_replay)
2140 && target_record_will_replay (minus_one_ptid, execution_direction))
2142 /* User-settable 'scheduler' mode requires solo thread resume in replay
2144 resume_ptid = inferior_ptid;
2146 else if (!sched_multi && target_supports_multi_process ())
2148 /* Resume all threads of the current process (and none of other
2150 resume_ptid = ptid_t (inferior_ptid.pid ());
2154 /* Resume all threads of all processes. */
2155 resume_ptid = RESUME_ALL;
2161 /* Return a ptid representing the set of threads that we will resume,
2162 in the perspective of the target, assuming run control handling
2163 does not require leaving some threads stopped (e.g., stepping past
2164 breakpoint). USER_STEP indicates whether we're about to start the
2165 target for a stepping command. */
2168 internal_resume_ptid (int user_step)
2170 /* In non-stop, we always control threads individually. Note that
2171 the target may always work in non-stop mode even with "set
2172 non-stop off", in which case user_visible_resume_ptid could
2173 return a wildcard ptid. */
2174 if (target_is_non_stop_p ())
2175 return inferior_ptid;
2177 return user_visible_resume_ptid (user_step);
2180 /* Wrapper for target_resume, that handles infrun-specific
2184 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2186 struct thread_info *tp = inferior_thread ();
2188 gdb_assert (!tp->stop_requested);
2190 /* Install inferior's terminal modes. */
2191 target_terminal::inferior ();
2193 /* Avoid confusing the next resume, if the next stop/resume
2194 happens to apply to another thread. */
2195 tp->suspend.stop_signal = GDB_SIGNAL_0;
2197 /* Advise target which signals may be handled silently.
2199 If we have removed breakpoints because we are stepping over one
2200 in-line (in any thread), we need to receive all signals to avoid
2201 accidentally skipping a breakpoint during execution of a signal
2204 Likewise if we're displaced stepping, otherwise a trap for a
2205 breakpoint in a signal handler might be confused with the
2206 displaced step finishing. We don't make the displaced_step_fixup
2207 step distinguish the cases instead, because:
2209 - a backtrace while stopped in the signal handler would show the
2210 scratch pad as frame older than the signal handler, instead of
2211 the real mainline code.
2213 - when the thread is later resumed, the signal handler would
2214 return to the scratch pad area, which would no longer be
2216 if (step_over_info_valid_p ()
2217 || displaced_step_in_progress (tp->inf))
2218 target_pass_signals ({});
2220 target_pass_signals (signal_pass);
2222 target_resume (resume_ptid, step, sig);
2224 target_commit_resume ();
2227 /* Resume the inferior. SIG is the signal to give the inferior
2228 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2229 call 'resume', which handles exceptions. */
2232 resume_1 (enum gdb_signal sig)
2234 struct regcache *regcache = get_current_regcache ();
2235 struct gdbarch *gdbarch = regcache->arch ();
2236 struct thread_info *tp = inferior_thread ();
2237 CORE_ADDR pc = regcache_read_pc (regcache);
2238 const address_space *aspace = regcache->aspace ();
2240 /* This represents the user's step vs continue request. When
2241 deciding whether "set scheduler-locking step" applies, it's the
2242 user's intention that counts. */
2243 const int user_step = tp->control.stepping_command;
2244 /* This represents what we'll actually request the target to do.
2245 This can decay from a step to a continue, if e.g., we need to
2246 implement single-stepping with breakpoints (software
2250 gdb_assert (!tp->stop_requested);
2251 gdb_assert (!thread_is_in_step_over_chain (tp));
2253 if (tp->suspend.waitstatus_pending_p)
2258 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2260 fprintf_unfiltered (gdb_stdlog,
2261 "infrun: resume: thread %s has pending wait "
2262 "status %s (currently_stepping=%d).\n",
2263 target_pid_to_str (tp->ptid), statstr.c_str (),
2264 currently_stepping (tp));
2269 /* FIXME: What should we do if we are supposed to resume this
2270 thread with a signal? Maybe we should maintain a queue of
2271 pending signals to deliver. */
2272 if (sig != GDB_SIGNAL_0)
2274 warning (_("Couldn't deliver signal %s to %s."),
2275 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2278 tp->suspend.stop_signal = GDB_SIGNAL_0;
2280 if (target_can_async_p ())
2283 /* Tell the event loop we have an event to process. */
2284 mark_async_event_handler (infrun_async_inferior_event_token);
2289 tp->stepped_breakpoint = 0;
2291 /* Depends on stepped_breakpoint. */
2292 step = currently_stepping (tp);
2294 if (current_inferior ()->waiting_for_vfork_done)
2296 /* Don't try to single-step a vfork parent that is waiting for
2297 the child to get out of the shared memory region (by exec'ing
2298 or exiting). This is particularly important on software
2299 single-step archs, as the child process would trip on the
2300 software single step breakpoint inserted for the parent
2301 process. Since the parent will not actually execute any
2302 instruction until the child is out of the shared region (such
2303 are vfork's semantics), it is safe to simply continue it.
2304 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2305 the parent, and tell it to `keep_going', which automatically
2306 re-sets it stepping. */
2308 fprintf_unfiltered (gdb_stdlog,
2309 "infrun: resume : clear step\n");
2314 fprintf_unfiltered (gdb_stdlog,
2315 "infrun: resume (step=%d, signal=%s), "
2316 "trap_expected=%d, current thread [%s] at %s\n",
2317 step, gdb_signal_to_symbol_string (sig),
2318 tp->control.trap_expected,
2319 target_pid_to_str (inferior_ptid),
2320 paddress (gdbarch, pc));
2322 /* Normally, by the time we reach `resume', the breakpoints are either
2323 removed or inserted, as appropriate. The exception is if we're sitting
2324 at a permanent breakpoint; we need to step over it, but permanent
2325 breakpoints can't be removed. So we have to test for it here. */
2326 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2328 if (sig != GDB_SIGNAL_0)
2330 /* We have a signal to pass to the inferior. The resume
2331 may, or may not take us to the signal handler. If this
2332 is a step, we'll need to stop in the signal handler, if
2333 there's one, (if the target supports stepping into
2334 handlers), or in the next mainline instruction, if
2335 there's no handler. If this is a continue, we need to be
2336 sure to run the handler with all breakpoints inserted.
2337 In all cases, set a breakpoint at the current address
2338 (where the handler returns to), and once that breakpoint
2339 is hit, resume skipping the permanent breakpoint. If
2340 that breakpoint isn't hit, then we've stepped into the
2341 signal handler (or hit some other event). We'll delete
2342 the step-resume breakpoint then. */
2345 fprintf_unfiltered (gdb_stdlog,
2346 "infrun: resume: skipping permanent breakpoint, "
2347 "deliver signal first\n");
2349 clear_step_over_info ();
2350 tp->control.trap_expected = 0;
2352 if (tp->control.step_resume_breakpoint == NULL)
2354 /* Set a "high-priority" step-resume, as we don't want
2355 user breakpoints at PC to trigger (again) when this
2357 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2358 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2360 tp->step_after_step_resume_breakpoint = step;
2363 insert_breakpoints ();
2367 /* There's no signal to pass, we can go ahead and skip the
2368 permanent breakpoint manually. */
2370 fprintf_unfiltered (gdb_stdlog,
2371 "infrun: resume: skipping permanent breakpoint\n");
2372 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2373 /* Update pc to reflect the new address from which we will
2374 execute instructions. */
2375 pc = regcache_read_pc (regcache);
2379 /* We've already advanced the PC, so the stepping part
2380 is done. Now we need to arrange for a trap to be
2381 reported to handle_inferior_event. Set a breakpoint
2382 at the current PC, and run to it. Don't update
2383 prev_pc, because if we end in
2384 switch_back_to_stepped_thread, we want the "expected
2385 thread advanced also" branch to be taken. IOW, we
2386 don't want this thread to step further from PC
2388 gdb_assert (!step_over_info_valid_p ());
2389 insert_single_step_breakpoint (gdbarch, aspace, pc);
2390 insert_breakpoints ();
2392 resume_ptid = internal_resume_ptid (user_step);
2393 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2400 /* If we have a breakpoint to step over, make sure to do a single
2401 step only. Same if we have software watchpoints. */
2402 if (tp->control.trap_expected || bpstat_should_step ())
2403 tp->control.may_range_step = 0;
2405 /* If enabled, step over breakpoints by executing a copy of the
2406 instruction at a different address.
2408 We can't use displaced stepping when we have a signal to deliver;
2409 the comments for displaced_step_prepare explain why. The
2410 comments in the handle_inferior event for dealing with 'random
2411 signals' explain what we do instead.
2413 We can't use displaced stepping when we are waiting for vfork_done
2414 event, displaced stepping breaks the vfork child similarly as single
2415 step software breakpoint. */
2416 if (tp->control.trap_expected
2417 && use_displaced_stepping (tp)
2418 && !step_over_info_valid_p ()
2419 && sig == GDB_SIGNAL_0
2420 && !current_inferior ()->waiting_for_vfork_done)
2422 int prepared = displaced_step_prepare (tp);
2427 fprintf_unfiltered (gdb_stdlog,
2428 "Got placed in step-over queue\n");
2430 tp->control.trap_expected = 0;
2433 else if (prepared < 0)
2435 /* Fallback to stepping over the breakpoint in-line. */
2437 if (target_is_non_stop_p ())
2438 stop_all_threads ();
2440 set_step_over_info (regcache->aspace (),
2441 regcache_read_pc (regcache), 0, tp->global_num);
2443 step = maybe_software_singlestep (gdbarch, pc);
2445 insert_breakpoints ();
2447 else if (prepared > 0)
2449 struct displaced_step_inferior_state *displaced;
2451 /* Update pc to reflect the new address from which we will
2452 execute instructions due to displaced stepping. */
2453 pc = regcache_read_pc (get_thread_regcache (tp));
2455 displaced = get_displaced_stepping_state (tp->inf);
2456 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2457 displaced->step_closure);
2461 /* Do we need to do it the hard way, w/temp breakpoints? */
2463 step = maybe_software_singlestep (gdbarch, pc);
2465 /* Currently, our software single-step implementation leads to different
2466 results than hardware single-stepping in one situation: when stepping
2467 into delivering a signal which has an associated signal handler,
2468 hardware single-step will stop at the first instruction of the handler,
2469 while software single-step will simply skip execution of the handler.
2471 For now, this difference in behavior is accepted since there is no
2472 easy way to actually implement single-stepping into a signal handler
2473 without kernel support.
2475 However, there is one scenario where this difference leads to follow-on
2476 problems: if we're stepping off a breakpoint by removing all breakpoints
2477 and then single-stepping. In this case, the software single-step
2478 behavior means that even if there is a *breakpoint* in the signal
2479 handler, GDB still would not stop.
2481 Fortunately, we can at least fix this particular issue. We detect
2482 here the case where we are about to deliver a signal while software
2483 single-stepping with breakpoints removed. In this situation, we
2484 revert the decisions to remove all breakpoints and insert single-
2485 step breakpoints, and instead we install a step-resume breakpoint
2486 at the current address, deliver the signal without stepping, and
2487 once we arrive back at the step-resume breakpoint, actually step
2488 over the breakpoint we originally wanted to step over. */
2489 if (thread_has_single_step_breakpoints_set (tp)
2490 && sig != GDB_SIGNAL_0
2491 && step_over_info_valid_p ())
2493 /* If we have nested signals or a pending signal is delivered
2494 immediately after a handler returns, might might already have
2495 a step-resume breakpoint set on the earlier handler. We cannot
2496 set another step-resume breakpoint; just continue on until the
2497 original breakpoint is hit. */
2498 if (tp->control.step_resume_breakpoint == NULL)
2500 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2501 tp->step_after_step_resume_breakpoint = 1;
2504 delete_single_step_breakpoints (tp);
2506 clear_step_over_info ();
2507 tp->control.trap_expected = 0;
2509 insert_breakpoints ();
2512 /* If STEP is set, it's a request to use hardware stepping
2513 facilities. But in that case, we should never
2514 use singlestep breakpoint. */
2515 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2517 /* Decide the set of threads to ask the target to resume. */
2518 if (tp->control.trap_expected)
2520 /* We're allowing a thread to run past a breakpoint it has
2521 hit, either by single-stepping the thread with the breakpoint
2522 removed, or by displaced stepping, with the breakpoint inserted.
2523 In the former case, we need to single-step only this thread,
2524 and keep others stopped, as they can miss this breakpoint if
2525 allowed to run. That's not really a problem for displaced
2526 stepping, but, we still keep other threads stopped, in case
2527 another thread is also stopped for a breakpoint waiting for
2528 its turn in the displaced stepping queue. */
2529 resume_ptid = inferior_ptid;
2532 resume_ptid = internal_resume_ptid (user_step);
2534 if (execution_direction != EXEC_REVERSE
2535 && step && breakpoint_inserted_here_p (aspace, pc))
2537 /* There are two cases where we currently need to step a
2538 breakpoint instruction when we have a signal to deliver:
2540 - See handle_signal_stop where we handle random signals that
2541 could take out us out of the stepping range. Normally, in
2542 that case we end up continuing (instead of stepping) over the
2543 signal handler with a breakpoint at PC, but there are cases
2544 where we should _always_ single-step, even if we have a
2545 step-resume breakpoint, like when a software watchpoint is
2546 set. Assuming single-stepping and delivering a signal at the
2547 same time would takes us to the signal handler, then we could
2548 have removed the breakpoint at PC to step over it. However,
2549 some hardware step targets (like e.g., Mac OS) can't step
2550 into signal handlers, and for those, we need to leave the
2551 breakpoint at PC inserted, as otherwise if the handler
2552 recurses and executes PC again, it'll miss the breakpoint.
2553 So we leave the breakpoint inserted anyway, but we need to
2554 record that we tried to step a breakpoint instruction, so
2555 that adjust_pc_after_break doesn't end up confused.
2557 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2558 in one thread after another thread that was stepping had been
2559 momentarily paused for a step-over. When we re-resume the
2560 stepping thread, it may be resumed from that address with a
2561 breakpoint that hasn't trapped yet. Seen with
2562 gdb.threads/non-stop-fair-events.exp, on targets that don't
2563 do displaced stepping. */
2566 fprintf_unfiltered (gdb_stdlog,
2567 "infrun: resume: [%s] stepped breakpoint\n",
2568 target_pid_to_str (tp->ptid));
2570 tp->stepped_breakpoint = 1;
2572 /* Most targets can step a breakpoint instruction, thus
2573 executing it normally. But if this one cannot, just
2574 continue and we will hit it anyway. */
2575 if (gdbarch_cannot_step_breakpoint (gdbarch))
2580 && tp->control.trap_expected
2581 && use_displaced_stepping (tp)
2582 && !step_over_info_valid_p ())
2584 struct regcache *resume_regcache = get_thread_regcache (tp);
2585 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2586 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2589 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2590 paddress (resume_gdbarch, actual_pc));
2591 read_memory (actual_pc, buf, sizeof (buf));
2592 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2595 if (tp->control.may_range_step)
2597 /* If we're resuming a thread with the PC out of the step
2598 range, then we're doing some nested/finer run control
2599 operation, like stepping the thread out of the dynamic
2600 linker or the displaced stepping scratch pad. We
2601 shouldn't have allowed a range step then. */
2602 gdb_assert (pc_in_thread_step_range (pc, tp));
2605 do_target_resume (resume_ptid, step, sig);
2609 /* Resume the inferior. SIG is the signal to give the inferior
2610 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2611 rolls back state on error. */
2614 resume (gdb_signal sig)
2620 CATCH (ex, RETURN_MASK_ALL)
2622 /* If resuming is being aborted for any reason, delete any
2623 single-step breakpoint resume_1 may have created, to avoid
2624 confusing the following resumption, and to avoid leaving
2625 single-step breakpoints perturbing other threads, in case
2626 we're running in non-stop mode. */
2627 if (inferior_ptid != null_ptid)
2628 delete_single_step_breakpoints (inferior_thread ());
2629 throw_exception (ex);
2639 /* Counter that tracks number of user visible stops. This can be used
2640 to tell whether a command has proceeded the inferior past the
2641 current location. This allows e.g., inferior function calls in
2642 breakpoint commands to not interrupt the command list. When the
2643 call finishes successfully, the inferior is standing at the same
2644 breakpoint as if nothing happened (and so we don't call
2646 static ULONGEST current_stop_id;
2653 return current_stop_id;
2656 /* Called when we report a user visible stop. */
2664 /* Clear out all variables saying what to do when inferior is continued.
2665 First do this, then set the ones you want, then call `proceed'. */
2668 clear_proceed_status_thread (struct thread_info *tp)
2671 fprintf_unfiltered (gdb_stdlog,
2672 "infrun: clear_proceed_status_thread (%s)\n",
2673 target_pid_to_str (tp->ptid));
2675 /* If we're starting a new sequence, then the previous finished
2676 single-step is no longer relevant. */
2677 if (tp->suspend.waitstatus_pending_p)
2679 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2682 fprintf_unfiltered (gdb_stdlog,
2683 "infrun: clear_proceed_status: pending "
2684 "event of %s was a finished step. "
2686 target_pid_to_str (tp->ptid));
2688 tp->suspend.waitstatus_pending_p = 0;
2689 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2691 else if (debug_infrun)
2694 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2696 fprintf_unfiltered (gdb_stdlog,
2697 "infrun: clear_proceed_status_thread: thread %s "
2698 "has pending wait status %s "
2699 "(currently_stepping=%d).\n",
2700 target_pid_to_str (tp->ptid), statstr.c_str (),
2701 currently_stepping (tp));
2705 /* If this signal should not be seen by program, give it zero.
2706 Used for debugging signals. */
2707 if (!signal_pass_state (tp->suspend.stop_signal))
2708 tp->suspend.stop_signal = GDB_SIGNAL_0;
2710 delete tp->thread_fsm;
2711 tp->thread_fsm = NULL;
2713 tp->control.trap_expected = 0;
2714 tp->control.step_range_start = 0;
2715 tp->control.step_range_end = 0;
2716 tp->control.may_range_step = 0;
2717 tp->control.step_frame_id = null_frame_id;
2718 tp->control.step_stack_frame_id = null_frame_id;
2719 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2720 tp->control.step_start_function = NULL;
2721 tp->stop_requested = 0;
2723 tp->control.stop_step = 0;
2725 tp->control.proceed_to_finish = 0;
2727 tp->control.stepping_command = 0;
2729 /* Discard any remaining commands or status from previous stop. */
2730 bpstat_clear (&tp->control.stop_bpstat);
2734 clear_proceed_status (int step)
2736 /* With scheduler-locking replay, stop replaying other threads if we're
2737 not replaying the user-visible resume ptid.
2739 This is a convenience feature to not require the user to explicitly
2740 stop replaying the other threads. We're assuming that the user's
2741 intent is to resume tracing the recorded process. */
2742 if (!non_stop && scheduler_mode == schedlock_replay
2743 && target_record_is_replaying (minus_one_ptid)
2744 && !target_record_will_replay (user_visible_resume_ptid (step),
2745 execution_direction))
2746 target_record_stop_replaying ();
2748 if (!non_stop && inferior_ptid != null_ptid)
2750 ptid_t resume_ptid = user_visible_resume_ptid (step);
2752 /* In all-stop mode, delete the per-thread status of all threads
2753 we're about to resume, implicitly and explicitly. */
2754 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2755 clear_proceed_status_thread (tp);
2758 if (inferior_ptid != null_ptid)
2760 struct inferior *inferior;
2764 /* If in non-stop mode, only delete the per-thread status of
2765 the current thread. */
2766 clear_proceed_status_thread (inferior_thread ());
2769 inferior = current_inferior ();
2770 inferior->control.stop_soon = NO_STOP_QUIETLY;
2773 gdb::observers::about_to_proceed.notify ();
2776 /* Returns true if TP is still stopped at a breakpoint that needs
2777 stepping-over in order to make progress. If the breakpoint is gone
2778 meanwhile, we can skip the whole step-over dance. */
2781 thread_still_needs_step_over_bp (struct thread_info *tp)
2783 if (tp->stepping_over_breakpoint)
2785 struct regcache *regcache = get_thread_regcache (tp);
2787 if (breakpoint_here_p (regcache->aspace (),
2788 regcache_read_pc (regcache))
2789 == ordinary_breakpoint_here)
2792 tp->stepping_over_breakpoint = 0;
2798 /* Check whether thread TP still needs to start a step-over in order
2799 to make progress when resumed. Returns an bitwise or of enum
2800 step_over_what bits, indicating what needs to be stepped over. */
2802 static step_over_what
2803 thread_still_needs_step_over (struct thread_info *tp)
2805 step_over_what what = 0;
2807 if (thread_still_needs_step_over_bp (tp))
2808 what |= STEP_OVER_BREAKPOINT;
2810 if (tp->stepping_over_watchpoint
2811 && !target_have_steppable_watchpoint)
2812 what |= STEP_OVER_WATCHPOINT;
2817 /* Returns true if scheduler locking applies. STEP indicates whether
2818 we're about to do a step/next-like command to a thread. */
2821 schedlock_applies (struct thread_info *tp)
2823 return (scheduler_mode == schedlock_on
2824 || (scheduler_mode == schedlock_step
2825 && tp->control.stepping_command)
2826 || (scheduler_mode == schedlock_replay
2827 && target_record_will_replay (minus_one_ptid,
2828 execution_direction)));
2831 /* Basic routine for continuing the program in various fashions.
2833 ADDR is the address to resume at, or -1 for resume where stopped.
2834 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2835 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2837 You should call clear_proceed_status before calling proceed. */
2840 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2842 struct regcache *regcache;
2843 struct gdbarch *gdbarch;
2846 struct execution_control_state ecss;
2847 struct execution_control_state *ecs = &ecss;
2850 /* If we're stopped at a fork/vfork, follow the branch set by the
2851 "set follow-fork-mode" command; otherwise, we'll just proceed
2852 resuming the current thread. */
2853 if (!follow_fork ())
2855 /* The target for some reason decided not to resume. */
2857 if (target_can_async_p ())
2858 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2862 /* We'll update this if & when we switch to a new thread. */
2863 previous_inferior_ptid = inferior_ptid;
2865 regcache = get_current_regcache ();
2866 gdbarch = regcache->arch ();
2867 const address_space *aspace = regcache->aspace ();
2869 pc = regcache_read_pc (regcache);
2870 thread_info *cur_thr = inferior_thread ();
2872 /* Fill in with reasonable starting values. */
2873 init_thread_stepping_state (cur_thr);
2875 gdb_assert (!thread_is_in_step_over_chain (cur_thr));
2877 if (addr == (CORE_ADDR) -1)
2879 if (pc == cur_thr->suspend.stop_pc
2880 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2881 && execution_direction != EXEC_REVERSE)
2882 /* There is a breakpoint at the address we will resume at,
2883 step one instruction before inserting breakpoints so that
2884 we do not stop right away (and report a second hit at this
2887 Note, we don't do this in reverse, because we won't
2888 actually be executing the breakpoint insn anyway.
2889 We'll be (un-)executing the previous instruction. */
2890 cur_thr->stepping_over_breakpoint = 1;
2891 else if (gdbarch_single_step_through_delay_p (gdbarch)
2892 && gdbarch_single_step_through_delay (gdbarch,
2893 get_current_frame ()))
2894 /* We stepped onto an instruction that needs to be stepped
2895 again before re-inserting the breakpoint, do so. */
2896 cur_thr->stepping_over_breakpoint = 1;
2900 regcache_write_pc (regcache, addr);
2903 if (siggnal != GDB_SIGNAL_DEFAULT)
2904 cur_thr->suspend.stop_signal = siggnal;
2906 resume_ptid = user_visible_resume_ptid (cur_thr->control.stepping_command);
2908 /* If an exception is thrown from this point on, make sure to
2909 propagate GDB's knowledge of the executing state to the
2910 frontend/user running state. */
2911 scoped_finish_thread_state finish_state (resume_ptid);
2913 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2914 threads (e.g., we might need to set threads stepping over
2915 breakpoints first), from the user/frontend's point of view, all
2916 threads in RESUME_PTID are now running. Unless we're calling an
2917 inferior function, as in that case we pretend the inferior
2918 doesn't run at all. */
2919 if (!cur_thr->control.in_infcall)
2920 set_running (resume_ptid, 1);
2923 fprintf_unfiltered (gdb_stdlog,
2924 "infrun: proceed (addr=%s, signal=%s)\n",
2925 paddress (gdbarch, addr),
2926 gdb_signal_to_symbol_string (siggnal));
2928 annotate_starting ();
2930 /* Make sure that output from GDB appears before output from the
2932 gdb_flush (gdb_stdout);
2934 /* Since we've marked the inferior running, give it the terminal. A
2935 QUIT/Ctrl-C from here on is forwarded to the target (which can
2936 still detect attempts to unblock a stuck connection with repeated
2937 Ctrl-C from within target_pass_ctrlc). */
2938 target_terminal::inferior ();
2940 /* In a multi-threaded task we may select another thread and
2941 then continue or step.
2943 But if a thread that we're resuming had stopped at a breakpoint,
2944 it will immediately cause another breakpoint stop without any
2945 execution (i.e. it will report a breakpoint hit incorrectly). So
2946 we must step over it first.
2948 Look for threads other than the current (TP) that reported a
2949 breakpoint hit and haven't been resumed yet since. */
2951 /* If scheduler locking applies, we can avoid iterating over all
2953 if (!non_stop && !schedlock_applies (cur_thr))
2955 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2957 /* Ignore the current thread here. It's handled
2962 if (!thread_still_needs_step_over (tp))
2965 gdb_assert (!thread_is_in_step_over_chain (tp));
2968 fprintf_unfiltered (gdb_stdlog,
2969 "infrun: need to step-over [%s] first\n",
2970 target_pid_to_str (tp->ptid));
2972 thread_step_over_chain_enqueue (tp);
2976 /* Enqueue the current thread last, so that we move all other
2977 threads over their breakpoints first. */
2978 if (cur_thr->stepping_over_breakpoint)
2979 thread_step_over_chain_enqueue (cur_thr);
2981 /* If the thread isn't started, we'll still need to set its prev_pc,
2982 so that switch_back_to_stepped_thread knows the thread hasn't
2983 advanced. Must do this before resuming any thread, as in
2984 all-stop/remote, once we resume we can't send any other packet
2985 until the target stops again. */
2986 cur_thr->prev_pc = regcache_read_pc (regcache);
2989 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
2991 started = start_step_over ();
2993 if (step_over_info_valid_p ())
2995 /* Either this thread started a new in-line step over, or some
2996 other thread was already doing one. In either case, don't
2997 resume anything else until the step-over is finished. */
2999 else if (started && !target_is_non_stop_p ())
3001 /* A new displaced stepping sequence was started. In all-stop,
3002 we can't talk to the target anymore until it next stops. */
3004 else if (!non_stop && target_is_non_stop_p ())
3006 /* In all-stop, but the target is always in non-stop mode.
3007 Start all other threads that are implicitly resumed too. */
3008 for (thread_info *tp : all_non_exited_threads (resume_ptid))
3013 fprintf_unfiltered (gdb_stdlog,
3014 "infrun: proceed: [%s] resumed\n",
3015 target_pid_to_str (tp->ptid));
3016 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3020 if (thread_is_in_step_over_chain (tp))
3023 fprintf_unfiltered (gdb_stdlog,
3024 "infrun: proceed: [%s] needs step-over\n",
3025 target_pid_to_str (tp->ptid));
3030 fprintf_unfiltered (gdb_stdlog,
3031 "infrun: proceed: resuming %s\n",
3032 target_pid_to_str (tp->ptid));
3034 reset_ecs (ecs, tp);
3035 switch_to_thread (tp);
3036 keep_going_pass_signal (ecs);
3037 if (!ecs->wait_some_more)
3038 error (_("Command aborted."));
3041 else if (!cur_thr->resumed && !thread_is_in_step_over_chain (cur_thr))
3043 /* The thread wasn't started, and isn't queued, run it now. */
3044 reset_ecs (ecs, cur_thr);
3045 switch_to_thread (cur_thr);
3046 keep_going_pass_signal (ecs);
3047 if (!ecs->wait_some_more)
3048 error (_("Command aborted."));
3052 target_commit_resume ();
3054 finish_state.release ();
3056 /* Tell the event loop to wait for it to stop. If the target
3057 supports asynchronous execution, it'll do this from within
3059 if (!target_can_async_p ())
3060 mark_async_event_handler (infrun_async_inferior_event_token);
3064 /* Start remote-debugging of a machine over a serial link. */
3067 start_remote (int from_tty)
3069 struct inferior *inferior;
3071 inferior = current_inferior ();
3072 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3074 /* Always go on waiting for the target, regardless of the mode. */
3075 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3076 indicate to wait_for_inferior that a target should timeout if
3077 nothing is returned (instead of just blocking). Because of this,
3078 targets expecting an immediate response need to, internally, set
3079 things up so that the target_wait() is forced to eventually
3081 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3082 differentiate to its caller what the state of the target is after
3083 the initial open has been performed. Here we're assuming that
3084 the target has stopped. It should be possible to eventually have
3085 target_open() return to the caller an indication that the target
3086 is currently running and GDB state should be set to the same as
3087 for an async run. */
3088 wait_for_inferior ();
3090 /* Now that the inferior has stopped, do any bookkeeping like
3091 loading shared libraries. We want to do this before normal_stop,
3092 so that the displayed frame is up to date. */
3093 post_create_inferior (current_top_target (), from_tty);
3098 /* Initialize static vars when a new inferior begins. */
3101 init_wait_for_inferior (void)
3103 /* These are meaningless until the first time through wait_for_inferior. */
3105 breakpoint_init_inferior (inf_starting);
3107 clear_proceed_status (0);
3109 target_last_wait_ptid = minus_one_ptid;
3111 previous_inferior_ptid = inferior_ptid;
3116 static void handle_inferior_event (struct execution_control_state *ecs);
3118 static void handle_step_into_function (struct gdbarch *gdbarch,
3119 struct execution_control_state *ecs);
3120 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3121 struct execution_control_state *ecs);
3122 static void handle_signal_stop (struct execution_control_state *ecs);
3123 static void check_exception_resume (struct execution_control_state *,
3124 struct frame_info *);
3126 static void end_stepping_range (struct execution_control_state *ecs);
3127 static void stop_waiting (struct execution_control_state *ecs);
3128 static void keep_going (struct execution_control_state *ecs);
3129 static void process_event_stop_test (struct execution_control_state *ecs);
3130 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3132 /* This function is attached as a "thread_stop_requested" observer.
3133 Cleanup local state that assumed the PTID was to be resumed, and
3134 report the stop to the frontend. */
3137 infrun_thread_stop_requested (ptid_t ptid)
3139 /* PTID was requested to stop. If the thread was already stopped,
3140 but the user/frontend doesn't know about that yet (e.g., the
3141 thread had been temporarily paused for some step-over), set up
3142 for reporting the stop now. */
3143 for (thread_info *tp : all_threads (ptid))
3145 if (tp->state != THREAD_RUNNING)
3150 /* Remove matching threads from the step-over queue, so
3151 start_step_over doesn't try to resume them
3153 if (thread_is_in_step_over_chain (tp))
3154 thread_step_over_chain_remove (tp);
3156 /* If the thread is stopped, but the user/frontend doesn't
3157 know about that yet, queue a pending event, as if the
3158 thread had just stopped now. Unless the thread already had
3160 if (!tp->suspend.waitstatus_pending_p)
3162 tp->suspend.waitstatus_pending_p = 1;
3163 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3164 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3167 /* Clear the inline-frame state, since we're re-processing the
3169 clear_inline_frame_state (tp->ptid);
3171 /* If this thread was paused because some other thread was
3172 doing an inline-step over, let that finish first. Once
3173 that happens, we'll restart all threads and consume pending
3174 stop events then. */
3175 if (step_over_info_valid_p ())
3178 /* Otherwise we can process the (new) pending event now. Set
3179 it so this pending event is considered by
3186 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3188 if (target_last_wait_ptid == tp->ptid)
3189 nullify_last_target_wait_ptid ();
3192 /* Delete the step resume, single-step and longjmp/exception resume
3193 breakpoints of TP. */
3196 delete_thread_infrun_breakpoints (struct thread_info *tp)
3198 delete_step_resume_breakpoint (tp);
3199 delete_exception_resume_breakpoint (tp);
3200 delete_single_step_breakpoints (tp);
3203 /* If the target still has execution, call FUNC for each thread that
3204 just stopped. In all-stop, that's all the non-exited threads; in
3205 non-stop, that's the current thread, only. */
3207 typedef void (*for_each_just_stopped_thread_callback_func)
3208 (struct thread_info *tp);
3211 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3213 if (!target_has_execution || inferior_ptid == null_ptid)
3216 if (target_is_non_stop_p ())
3218 /* If in non-stop mode, only the current thread stopped. */
3219 func (inferior_thread ());
3223 /* In all-stop mode, all threads have stopped. */
3224 for (thread_info *tp : all_non_exited_threads ())
3229 /* Delete the step resume and longjmp/exception resume breakpoints of
3230 the threads that just stopped. */
3233 delete_just_stopped_threads_infrun_breakpoints (void)
3235 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3238 /* Delete the single-step breakpoints of the threads that just
3242 delete_just_stopped_threads_single_step_breakpoints (void)
3244 for_each_just_stopped_thread (delete_single_step_breakpoints);
3250 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3251 const struct target_waitstatus *ws)
3253 std::string status_string = target_waitstatus_to_string (ws);
3256 /* The text is split over several lines because it was getting too long.
3257 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3258 output as a unit; we want only one timestamp printed if debug_timestamp
3261 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3264 waiton_ptid.tid ());
3265 if (waiton_ptid.pid () != -1)
3266 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3267 stb.printf (", status) =\n");
3268 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3272 target_pid_to_str (result_ptid));
3273 stb.printf ("infrun: %s\n", status_string.c_str ());
3275 /* This uses %s in part to handle %'s in the text, but also to avoid
3276 a gcc error: the format attribute requires a string literal. */
3277 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3280 /* Select a thread at random, out of those which are resumed and have
3283 static struct thread_info *
3284 random_pending_event_thread (ptid_t waiton_ptid)
3288 auto has_event = [] (thread_info *tp)
3291 && tp->suspend.waitstatus_pending_p);
3294 /* First see how many events we have. Count only resumed threads
3295 that have an event pending. */
3296 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3300 if (num_events == 0)
3303 /* Now randomly pick a thread out of those that have had events. */
3304 int random_selector = (int) ((num_events * (double) rand ())
3305 / (RAND_MAX + 1.0));
3307 if (debug_infrun && num_events > 1)
3308 fprintf_unfiltered (gdb_stdlog,
3309 "infrun: Found %d events, selecting #%d\n",
3310 num_events, random_selector);
3312 /* Select the Nth thread that has had an event. */
3313 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3315 if (random_selector-- == 0)
3318 gdb_assert_not_reached ("event thread not found");
3321 /* Wrapper for target_wait that first checks whether threads have
3322 pending statuses to report before actually asking the target for
3326 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3329 struct thread_info *tp;
3331 /* First check if there is a resumed thread with a wait status
3333 if (ptid == minus_one_ptid || ptid.is_pid ())
3335 tp = random_pending_event_thread (ptid);
3340 fprintf_unfiltered (gdb_stdlog,
3341 "infrun: Waiting for specific thread %s.\n",
3342 target_pid_to_str (ptid));
3344 /* We have a specific thread to check. */
3345 tp = find_thread_ptid (ptid);
3346 gdb_assert (tp != NULL);
3347 if (!tp->suspend.waitstatus_pending_p)
3352 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3353 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3355 struct regcache *regcache = get_thread_regcache (tp);
3356 struct gdbarch *gdbarch = regcache->arch ();
3360 pc = regcache_read_pc (regcache);
3362 if (pc != tp->suspend.stop_pc)
3365 fprintf_unfiltered (gdb_stdlog,
3366 "infrun: PC of %s changed. was=%s, now=%s\n",
3367 target_pid_to_str (tp->ptid),
3368 paddress (gdbarch, tp->suspend.stop_pc),
3369 paddress (gdbarch, pc));
3372 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3375 fprintf_unfiltered (gdb_stdlog,
3376 "infrun: previous breakpoint of %s, at %s gone\n",
3377 target_pid_to_str (tp->ptid),
3378 paddress (gdbarch, pc));
3386 fprintf_unfiltered (gdb_stdlog,
3387 "infrun: pending event of %s cancelled.\n",
3388 target_pid_to_str (tp->ptid));
3390 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3391 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3400 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3402 fprintf_unfiltered (gdb_stdlog,
3403 "infrun: Using pending wait status %s for %s.\n",
3405 target_pid_to_str (tp->ptid));
3408 /* Now that we've selected our final event LWP, un-adjust its PC
3409 if it was a software breakpoint (and the target doesn't
3410 always adjust the PC itself). */
3411 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3412 && !target_supports_stopped_by_sw_breakpoint ())
3414 struct regcache *regcache;
3415 struct gdbarch *gdbarch;
3418 regcache = get_thread_regcache (tp);
3419 gdbarch = regcache->arch ();
3421 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3426 pc = regcache_read_pc (regcache);
3427 regcache_write_pc (regcache, pc + decr_pc);
3431 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3432 *status = tp->suspend.waitstatus;
3433 tp->suspend.waitstatus_pending_p = 0;
3435 /* Wake up the event loop again, until all pending events are
3437 if (target_is_async_p ())
3438 mark_async_event_handler (infrun_async_inferior_event_token);
3442 /* But if we don't find one, we'll have to wait. */
3444 if (deprecated_target_wait_hook)
3445 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3447 event_ptid = target_wait (ptid, status, options);
3452 /* Prepare and stabilize the inferior for detaching it. E.g.,
3453 detaching while a thread is displaced stepping is a recipe for
3454 crashing it, as nothing would readjust the PC out of the scratch
3458 prepare_for_detach (void)
3460 struct inferior *inf = current_inferior ();
3461 ptid_t pid_ptid = ptid_t (inf->pid);
3463 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3465 /* Is any thread of this process displaced stepping? If not,
3466 there's nothing else to do. */
3467 if (displaced->step_thread == nullptr)
3471 fprintf_unfiltered (gdb_stdlog,
3472 "displaced-stepping in-process while detaching");
3474 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3476 while (displaced->step_thread != nullptr)
3478 struct execution_control_state ecss;
3479 struct execution_control_state *ecs;
3482 memset (ecs, 0, sizeof (*ecs));
3484 overlay_cache_invalid = 1;
3485 /* Flush target cache before starting to handle each event.
3486 Target was running and cache could be stale. This is just a
3487 heuristic. Running threads may modify target memory, but we
3488 don't get any event. */
3489 target_dcache_invalidate ();
3491 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3494 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3496 /* If an error happens while handling the event, propagate GDB's
3497 knowledge of the executing state to the frontend/user running
3499 scoped_finish_thread_state finish_state (minus_one_ptid);
3501 /* Now figure out what to do with the result of the result. */
3502 handle_inferior_event (ecs);
3504 /* No error, don't finish the state yet. */
3505 finish_state.release ();
3507 /* Breakpoints and watchpoints are not installed on the target
3508 at this point, and signals are passed directly to the
3509 inferior, so this must mean the process is gone. */
3510 if (!ecs->wait_some_more)
3512 restore_detaching.release ();
3513 error (_("Program exited while detaching"));
3517 restore_detaching.release ();
3520 /* Wait for control to return from inferior to debugger.
3522 If inferior gets a signal, we may decide to start it up again
3523 instead of returning. That is why there is a loop in this function.
3524 When this function actually returns it means the inferior
3525 should be left stopped and GDB should read more commands. */
3528 wait_for_inferior (void)
3532 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3534 SCOPE_EXIT { delete_just_stopped_threads_infrun_breakpoints (); };
3536 /* If an error happens while handling the event, propagate GDB's
3537 knowledge of the executing state to the frontend/user running
3539 scoped_finish_thread_state finish_state (minus_one_ptid);
3543 struct execution_control_state ecss;
3544 struct execution_control_state *ecs = &ecss;
3545 ptid_t waiton_ptid = minus_one_ptid;
3547 memset (ecs, 0, sizeof (*ecs));
3549 overlay_cache_invalid = 1;
3551 /* Flush target cache before starting to handle each event.
3552 Target was running and cache could be stale. This is just a
3553 heuristic. Running threads may modify target memory, but we
3554 don't get any event. */
3555 target_dcache_invalidate ();
3557 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3560 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3562 /* Now figure out what to do with the result of the result. */
3563 handle_inferior_event (ecs);
3565 if (!ecs->wait_some_more)
3569 /* No error, don't finish the state yet. */
3570 finish_state.release ();
3573 /* Cleanup that reinstalls the readline callback handler, if the
3574 target is running in the background. If while handling the target
3575 event something triggered a secondary prompt, like e.g., a
3576 pagination prompt, we'll have removed the callback handler (see
3577 gdb_readline_wrapper_line). Need to do this as we go back to the
3578 event loop, ready to process further input. Note this has no
3579 effect if the handler hasn't actually been removed, because calling
3580 rl_callback_handler_install resets the line buffer, thus losing
3584 reinstall_readline_callback_handler_cleanup ()
3586 struct ui *ui = current_ui;
3590 /* We're not going back to the top level event loop yet. Don't
3591 install the readline callback, as it'd prep the terminal,
3592 readline-style (raw, noecho) (e.g., --batch). We'll install
3593 it the next time the prompt is displayed, when we're ready
3598 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3599 gdb_rl_callback_handler_reinstall ();
3602 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3603 that's just the event thread. In all-stop, that's all threads. */
3606 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3608 if (ecs->event_thread != NULL
3609 && ecs->event_thread->thread_fsm != NULL)
3610 ecs->event_thread->thread_fsm->clean_up (ecs->event_thread);
3614 for (thread_info *thr : all_non_exited_threads ())
3616 if (thr->thread_fsm == NULL)
3618 if (thr == ecs->event_thread)
3621 switch_to_thread (thr);
3622 thr->thread_fsm->clean_up (thr);
3625 if (ecs->event_thread != NULL)
3626 switch_to_thread (ecs->event_thread);
3630 /* Helper for all_uis_check_sync_execution_done that works on the
3634 check_curr_ui_sync_execution_done (void)
3636 struct ui *ui = current_ui;
3638 if (ui->prompt_state == PROMPT_NEEDED
3640 && !gdb_in_secondary_prompt_p (ui))
3642 target_terminal::ours ();
3643 gdb::observers::sync_execution_done.notify ();
3644 ui_register_input_event_handler (ui);
3651 all_uis_check_sync_execution_done (void)
3653 SWITCH_THRU_ALL_UIS ()
3655 check_curr_ui_sync_execution_done ();
3662 all_uis_on_sync_execution_starting (void)
3664 SWITCH_THRU_ALL_UIS ()
3666 if (current_ui->prompt_state == PROMPT_NEEDED)
3667 async_disable_stdin ();
3671 /* Asynchronous version of wait_for_inferior. It is called by the
3672 event loop whenever a change of state is detected on the file
3673 descriptor corresponding to the target. It can be called more than
3674 once to complete a single execution command. In such cases we need
3675 to keep the state in a global variable ECSS. If it is the last time
3676 that this function is called for a single execution command, then
3677 report to the user that the inferior has stopped, and do the
3678 necessary cleanups. */
3681 fetch_inferior_event (void *client_data)
3683 struct execution_control_state ecss;
3684 struct execution_control_state *ecs = &ecss;
3686 ptid_t waiton_ptid = minus_one_ptid;
3688 memset (ecs, 0, sizeof (*ecs));
3690 /* Events are always processed with the main UI as current UI. This
3691 way, warnings, debug output, etc. are always consistently sent to
3692 the main console. */
3693 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3695 /* End up with readline processing input, if necessary. */
3697 SCOPE_EXIT { reinstall_readline_callback_handler_cleanup (); };
3699 /* We're handling a live event, so make sure we're doing live
3700 debugging. If we're looking at traceframes while the target is
3701 running, we're going to need to get back to that mode after
3702 handling the event. */
3703 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3706 maybe_restore_traceframe.emplace ();
3707 set_current_traceframe (-1);
3710 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3713 /* In non-stop mode, the user/frontend should not notice a thread
3714 switch due to internal events. Make sure we reverse to the
3715 user selected thread and frame after handling the event and
3716 running any breakpoint commands. */
3717 maybe_restore_thread.emplace ();
3719 overlay_cache_invalid = 1;
3720 /* Flush target cache before starting to handle each event. Target
3721 was running and cache could be stale. This is just a heuristic.
3722 Running threads may modify target memory, but we don't get any
3724 target_dcache_invalidate ();
3726 scoped_restore save_exec_dir
3727 = make_scoped_restore (&execution_direction,
3728 target_execution_direction ());
3730 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3731 target_can_async_p () ? TARGET_WNOHANG : 0);
3734 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3736 /* If an error happens while handling the event, propagate GDB's
3737 knowledge of the executing state to the frontend/user running
3739 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3740 scoped_finish_thread_state finish_state (finish_ptid);
3742 /* Get executed before scoped_restore_current_thread above to apply
3743 still for the thread which has thrown the exception. */
3744 auto defer_bpstat_clear
3745 = make_scope_exit (bpstat_clear_actions);
3746 auto defer_delete_threads
3747 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints);
3749 /* Now figure out what to do with the result of the result. */
3750 handle_inferior_event (ecs);
3752 if (!ecs->wait_some_more)
3754 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3755 int should_stop = 1;
3756 struct thread_info *thr = ecs->event_thread;
3758 delete_just_stopped_threads_infrun_breakpoints ();
3762 struct thread_fsm *thread_fsm = thr->thread_fsm;
3764 if (thread_fsm != NULL)
3765 should_stop = thread_fsm->should_stop (thr);
3774 bool should_notify_stop = true;
3777 clean_up_just_stopped_threads_fsms (ecs);
3779 if (thr != NULL && thr->thread_fsm != NULL)
3780 should_notify_stop = thr->thread_fsm->should_notify_stop ();
3782 if (should_notify_stop)
3784 /* We may not find an inferior if this was a process exit. */
3785 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3786 proceeded = normal_stop ();
3791 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3797 defer_delete_threads.release ();
3798 defer_bpstat_clear.release ();
3800 /* No error, don't finish the thread states yet. */
3801 finish_state.release ();
3803 /* This scope is used to ensure that readline callbacks are
3804 reinstalled here. */
3807 /* If a UI was in sync execution mode, and now isn't, restore its
3808 prompt (a synchronous execution command has finished, and we're
3809 ready for input). */
3810 all_uis_check_sync_execution_done ();
3813 && exec_done_display_p
3814 && (inferior_ptid == null_ptid
3815 || inferior_thread ()->state != THREAD_RUNNING))
3816 printf_unfiltered (_("completed.\n"));
3819 /* Record the frame and location we're currently stepping through. */
3821 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3823 struct thread_info *tp = inferior_thread ();
3825 tp->control.step_frame_id = get_frame_id (frame);
3826 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3828 tp->current_symtab = sal.symtab;
3829 tp->current_line = sal.line;
3832 /* Clear context switchable stepping state. */
3835 init_thread_stepping_state (struct thread_info *tss)
3837 tss->stepped_breakpoint = 0;
3838 tss->stepping_over_breakpoint = 0;
3839 tss->stepping_over_watchpoint = 0;
3840 tss->step_after_step_resume_breakpoint = 0;
3843 /* Set the cached copy of the last ptid/waitstatus. */
3846 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3848 target_last_wait_ptid = ptid;
3849 target_last_waitstatus = status;
3852 /* Return the cached copy of the last pid/waitstatus returned by
3853 target_wait()/deprecated_target_wait_hook(). The data is actually
3854 cached by handle_inferior_event(), which gets called immediately
3855 after target_wait()/deprecated_target_wait_hook(). */
3858 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3860 *ptidp = target_last_wait_ptid;
3861 *status = target_last_waitstatus;
3865 nullify_last_target_wait_ptid (void)
3867 target_last_wait_ptid = minus_one_ptid;
3870 /* Switch thread contexts. */
3873 context_switch (execution_control_state *ecs)
3876 && ecs->ptid != inferior_ptid
3877 && ecs->event_thread != inferior_thread ())
3879 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3880 target_pid_to_str (inferior_ptid));
3881 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3882 target_pid_to_str (ecs->ptid));
3885 switch_to_thread (ecs->event_thread);
3888 /* If the target can't tell whether we've hit breakpoints
3889 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3890 check whether that could have been caused by a breakpoint. If so,
3891 adjust the PC, per gdbarch_decr_pc_after_break. */
3894 adjust_pc_after_break (struct thread_info *thread,
3895 struct target_waitstatus *ws)
3897 struct regcache *regcache;
3898 struct gdbarch *gdbarch;
3899 CORE_ADDR breakpoint_pc, decr_pc;
3901 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3902 we aren't, just return.
3904 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3905 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3906 implemented by software breakpoints should be handled through the normal
3909 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3910 different signals (SIGILL or SIGEMT for instance), but it is less
3911 clear where the PC is pointing afterwards. It may not match
3912 gdbarch_decr_pc_after_break. I don't know any specific target that
3913 generates these signals at breakpoints (the code has been in GDB since at
3914 least 1992) so I can not guess how to handle them here.
3916 In earlier versions of GDB, a target with
3917 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3918 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3919 target with both of these set in GDB history, and it seems unlikely to be
3920 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3922 if (ws->kind != TARGET_WAITKIND_STOPPED)
3925 if (ws->value.sig != GDB_SIGNAL_TRAP)
3928 /* In reverse execution, when a breakpoint is hit, the instruction
3929 under it has already been de-executed. The reported PC always
3930 points at the breakpoint address, so adjusting it further would
3931 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3934 B1 0x08000000 : INSN1
3935 B2 0x08000001 : INSN2
3937 PC -> 0x08000003 : INSN4
3939 Say you're stopped at 0x08000003 as above. Reverse continuing
3940 from that point should hit B2 as below. Reading the PC when the
3941 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3942 been de-executed already.
3944 B1 0x08000000 : INSN1
3945 B2 PC -> 0x08000001 : INSN2
3949 We can't apply the same logic as for forward execution, because
3950 we would wrongly adjust the PC to 0x08000000, since there's a
3951 breakpoint at PC - 1. We'd then report a hit on B1, although
3952 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3954 if (execution_direction == EXEC_REVERSE)
3957 /* If the target can tell whether the thread hit a SW breakpoint,
3958 trust it. Targets that can tell also adjust the PC
3960 if (target_supports_stopped_by_sw_breakpoint ())
3963 /* Note that relying on whether a breakpoint is planted in memory to
3964 determine this can fail. E.g,. the breakpoint could have been
3965 removed since. Or the thread could have been told to step an
3966 instruction the size of a breakpoint instruction, and only
3967 _after_ was a breakpoint inserted at its address. */
3969 /* If this target does not decrement the PC after breakpoints, then
3970 we have nothing to do. */
3971 regcache = get_thread_regcache (thread);
3972 gdbarch = regcache->arch ();
3974 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3978 const address_space *aspace = regcache->aspace ();
3980 /* Find the location where (if we've hit a breakpoint) the
3981 breakpoint would be. */
3982 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3984 /* If the target can't tell whether a software breakpoint triggered,
3985 fallback to figuring it out based on breakpoints we think were
3986 inserted in the target, and on whether the thread was stepped or
3989 /* Check whether there actually is a software breakpoint inserted at
3992 If in non-stop mode, a race condition is possible where we've
3993 removed a breakpoint, but stop events for that breakpoint were
3994 already queued and arrive later. To suppress those spurious
3995 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3996 and retire them after a number of stop events are reported. Note
3997 this is an heuristic and can thus get confused. The real fix is
3998 to get the "stopped by SW BP and needs adjustment" info out of
3999 the target/kernel (and thus never reach here; see above). */
4000 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4001 || (target_is_non_stop_p ()
4002 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4004 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4006 if (record_full_is_used ())
4007 restore_operation_disable.emplace
4008 (record_full_gdb_operation_disable_set ());
4010 /* When using hardware single-step, a SIGTRAP is reported for both
4011 a completed single-step and a software breakpoint. Need to
4012 differentiate between the two, as the latter needs adjusting
4013 but the former does not.
4015 The SIGTRAP can be due to a completed hardware single-step only if
4016 - we didn't insert software single-step breakpoints
4017 - this thread is currently being stepped
4019 If any of these events did not occur, we must have stopped due
4020 to hitting a software breakpoint, and have to back up to the
4023 As a special case, we could have hardware single-stepped a
4024 software breakpoint. In this case (prev_pc == breakpoint_pc),
4025 we also need to back up to the breakpoint address. */
4027 if (thread_has_single_step_breakpoints_set (thread)
4028 || !currently_stepping (thread)
4029 || (thread->stepped_breakpoint
4030 && thread->prev_pc == breakpoint_pc))
4031 regcache_write_pc (regcache, breakpoint_pc);
4036 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4038 for (frame = get_prev_frame (frame);
4040 frame = get_prev_frame (frame))
4042 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4044 if (get_frame_type (frame) != INLINE_FRAME)
4051 /* If the event thread has the stop requested flag set, pretend it
4052 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4056 handle_stop_requested (struct execution_control_state *ecs)
4058 if (ecs->event_thread->stop_requested)
4060 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4061 ecs->ws.value.sig = GDB_SIGNAL_0;
4062 handle_signal_stop (ecs);
4068 /* Auxiliary function that handles syscall entry/return events.
4069 It returns 1 if the inferior should keep going (and GDB
4070 should ignore the event), or 0 if the event deserves to be
4074 handle_syscall_event (struct execution_control_state *ecs)
4076 struct regcache *regcache;
4079 context_switch (ecs);
4081 regcache = get_thread_regcache (ecs->event_thread);
4082 syscall_number = ecs->ws.value.syscall_number;
4083 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4085 if (catch_syscall_enabled () > 0
4086 && catching_syscall_number (syscall_number) > 0)
4089 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4092 ecs->event_thread->control.stop_bpstat
4093 = bpstat_stop_status (regcache->aspace (),
4094 ecs->event_thread->suspend.stop_pc,
4095 ecs->event_thread, &ecs->ws);
4097 if (handle_stop_requested (ecs))
4100 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4102 /* Catchpoint hit. */
4107 if (handle_stop_requested (ecs))
4110 /* If no catchpoint triggered for this, then keep going. */
4115 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4118 fill_in_stop_func (struct gdbarch *gdbarch,
4119 struct execution_control_state *ecs)
4121 if (!ecs->stop_func_filled_in)
4123 /* Don't care about return value; stop_func_start and stop_func_name
4124 will both be 0 if it doesn't work. */
4125 find_function_entry_range_from_pc (ecs->event_thread->suspend.stop_pc,
4126 &ecs->stop_func_name,
4127 &ecs->stop_func_start,
4128 &ecs->stop_func_end);
4129 ecs->stop_func_start
4130 += gdbarch_deprecated_function_start_offset (gdbarch);
4132 if (gdbarch_skip_entrypoint_p (gdbarch))
4133 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4134 ecs->stop_func_start);
4136 ecs->stop_func_filled_in = 1;
4141 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4143 static enum stop_kind
4144 get_inferior_stop_soon (execution_control_state *ecs)
4146 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4148 gdb_assert (inf != NULL);
4149 return inf->control.stop_soon;
4152 /* Wait for one event. Store the resulting waitstatus in WS, and
4153 return the event ptid. */
4156 wait_one (struct target_waitstatus *ws)
4159 ptid_t wait_ptid = minus_one_ptid;
4161 overlay_cache_invalid = 1;
4163 /* Flush target cache before starting to handle each event.
4164 Target was running and cache could be stale. This is just a
4165 heuristic. Running threads may modify target memory, but we
4166 don't get any event. */
4167 target_dcache_invalidate ();
4169 if (deprecated_target_wait_hook)
4170 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4172 event_ptid = target_wait (wait_ptid, ws, 0);
4175 print_target_wait_results (wait_ptid, event_ptid, ws);
4180 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4181 instead of the current thread. */
4182 #define THREAD_STOPPED_BY(REASON) \
4184 thread_stopped_by_ ## REASON (ptid_t ptid) \
4186 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4187 inferior_ptid = ptid; \
4189 return target_stopped_by_ ## REASON (); \
4192 /* Generate thread_stopped_by_watchpoint. */
4193 THREAD_STOPPED_BY (watchpoint)
4194 /* Generate thread_stopped_by_sw_breakpoint. */
4195 THREAD_STOPPED_BY (sw_breakpoint)
4196 /* Generate thread_stopped_by_hw_breakpoint. */
4197 THREAD_STOPPED_BY (hw_breakpoint)
4199 /* Save the thread's event and stop reason to process it later. */
4202 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4206 std::string statstr = target_waitstatus_to_string (ws);
4208 fprintf_unfiltered (gdb_stdlog,
4209 "infrun: saving status %s for %d.%ld.%ld\n",
4216 /* Record for later. */
4217 tp->suspend.waitstatus = *ws;
4218 tp->suspend.waitstatus_pending_p = 1;
4220 struct regcache *regcache = get_thread_regcache (tp);
4221 const address_space *aspace = regcache->aspace ();
4223 if (ws->kind == TARGET_WAITKIND_STOPPED
4224 && ws->value.sig == GDB_SIGNAL_TRAP)
4226 CORE_ADDR pc = regcache_read_pc (regcache);
4228 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4230 if (thread_stopped_by_watchpoint (tp->ptid))
4232 tp->suspend.stop_reason
4233 = TARGET_STOPPED_BY_WATCHPOINT;
4235 else if (target_supports_stopped_by_sw_breakpoint ()
4236 && thread_stopped_by_sw_breakpoint (tp->ptid))
4238 tp->suspend.stop_reason
4239 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4241 else if (target_supports_stopped_by_hw_breakpoint ()
4242 && thread_stopped_by_hw_breakpoint (tp->ptid))
4244 tp->suspend.stop_reason
4245 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4247 else if (!target_supports_stopped_by_hw_breakpoint ()
4248 && hardware_breakpoint_inserted_here_p (aspace,
4251 tp->suspend.stop_reason
4252 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4254 else if (!target_supports_stopped_by_sw_breakpoint ()
4255 && software_breakpoint_inserted_here_p (aspace,
4258 tp->suspend.stop_reason
4259 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4261 else if (!thread_has_single_step_breakpoints_set (tp)
4262 && currently_stepping (tp))
4264 tp->suspend.stop_reason
4265 = TARGET_STOPPED_BY_SINGLE_STEP;
4273 stop_all_threads (void)
4275 /* We may need multiple passes to discover all threads. */
4279 gdb_assert (target_is_non_stop_p ());
4282 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4284 scoped_restore_current_thread restore_thread;
4286 target_thread_events (1);
4287 SCOPE_EXIT { target_thread_events (0); };
4289 /* Request threads to stop, and then wait for the stops. Because
4290 threads we already know about can spawn more threads while we're
4291 trying to stop them, and we only learn about new threads when we
4292 update the thread list, do this in a loop, and keep iterating
4293 until two passes find no threads that need to be stopped. */
4294 for (pass = 0; pass < 2; pass++, iterations++)
4297 fprintf_unfiltered (gdb_stdlog,
4298 "infrun: stop_all_threads, pass=%d, "
4299 "iterations=%d\n", pass, iterations);
4303 struct target_waitstatus ws;
4306 update_thread_list ();
4308 /* Go through all threads looking for threads that we need
4309 to tell the target to stop. */
4310 for (thread_info *t : all_non_exited_threads ())
4314 /* If already stopping, don't request a stop again.
4315 We just haven't seen the notification yet. */
4316 if (!t->stop_requested)
4319 fprintf_unfiltered (gdb_stdlog,
4320 "infrun: %s executing, "
4322 target_pid_to_str (t->ptid));
4323 target_stop (t->ptid);
4324 t->stop_requested = 1;
4329 fprintf_unfiltered (gdb_stdlog,
4330 "infrun: %s executing, "
4331 "already stopping\n",
4332 target_pid_to_str (t->ptid));
4335 if (t->stop_requested)
4341 fprintf_unfiltered (gdb_stdlog,
4342 "infrun: %s not executing\n",
4343 target_pid_to_str (t->ptid));
4345 /* The thread may be not executing, but still be
4346 resumed with a pending status to process. */
4354 /* If we find new threads on the second iteration, restart
4355 over. We want to see two iterations in a row with all
4360 event_ptid = wait_one (&ws);
4362 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4364 /* All resumed threads exited. */
4366 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4367 || ws.kind == TARGET_WAITKIND_EXITED
4368 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4372 ptid_t ptid = ptid_t (ws.value.integer);
4374 fprintf_unfiltered (gdb_stdlog,
4375 "infrun: %s exited while "
4376 "stopping threads\n",
4377 target_pid_to_str (ptid));
4382 thread_info *t = find_thread_ptid (event_ptid);
4384 t = add_thread (event_ptid);
4386 t->stop_requested = 0;
4389 t->control.may_range_step = 0;
4391 /* This may be the first time we see the inferior report
4393 inferior *inf = find_inferior_ptid (event_ptid);
4394 if (inf->needs_setup)
4396 switch_to_thread_no_regs (t);
4400 if (ws.kind == TARGET_WAITKIND_STOPPED
4401 && ws.value.sig == GDB_SIGNAL_0)
4403 /* We caught the event that we intended to catch, so
4404 there's no event pending. */
4405 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4406 t->suspend.waitstatus_pending_p = 0;
4408 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4410 /* Add it back to the step-over queue. */
4413 fprintf_unfiltered (gdb_stdlog,
4414 "infrun: displaced-step of %s "
4415 "canceled: adding back to the "
4416 "step-over queue\n",
4417 target_pid_to_str (t->ptid));
4419 t->control.trap_expected = 0;
4420 thread_step_over_chain_enqueue (t);
4425 enum gdb_signal sig;
4426 struct regcache *regcache;
4430 std::string statstr = target_waitstatus_to_string (&ws);
4432 fprintf_unfiltered (gdb_stdlog,
4433 "infrun: target_wait %s, saving "
4434 "status for %d.%ld.%ld\n",
4441 /* Record for later. */
4442 save_waitstatus (t, &ws);
4444 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4445 ? ws.value.sig : GDB_SIGNAL_0);
4447 if (displaced_step_fixup (t, sig) < 0)
4449 /* Add it back to the step-over queue. */
4450 t->control.trap_expected = 0;
4451 thread_step_over_chain_enqueue (t);
4454 regcache = get_thread_regcache (t);
4455 t->suspend.stop_pc = regcache_read_pc (regcache);
4459 fprintf_unfiltered (gdb_stdlog,
4460 "infrun: saved stop_pc=%s for %s "
4461 "(currently_stepping=%d)\n",
4462 paddress (target_gdbarch (),
4463 t->suspend.stop_pc),
4464 target_pid_to_str (t->ptid),
4465 currently_stepping (t));
4473 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4476 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4479 handle_no_resumed (struct execution_control_state *ecs)
4481 if (target_can_async_p ())
4488 if (ui->prompt_state == PROMPT_BLOCKED)
4496 /* There were no unwaited-for children left in the target, but,
4497 we're not synchronously waiting for events either. Just
4501 fprintf_unfiltered (gdb_stdlog,
4502 "infrun: TARGET_WAITKIND_NO_RESUMED "
4503 "(ignoring: bg)\n");
4504 prepare_to_wait (ecs);
4509 /* Otherwise, if we were running a synchronous execution command, we
4510 may need to cancel it and give the user back the terminal.
4512 In non-stop mode, the target can't tell whether we've already
4513 consumed previous stop events, so it can end up sending us a
4514 no-resumed event like so:
4516 #0 - thread 1 is left stopped
4518 #1 - thread 2 is resumed and hits breakpoint
4519 -> TARGET_WAITKIND_STOPPED
4521 #2 - thread 3 is resumed and exits
4522 this is the last resumed thread, so
4523 -> TARGET_WAITKIND_NO_RESUMED
4525 #3 - gdb processes stop for thread 2 and decides to re-resume
4528 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4529 thread 2 is now resumed, so the event should be ignored.
4531 IOW, if the stop for thread 2 doesn't end a foreground command,
4532 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4533 event. But it could be that the event meant that thread 2 itself
4534 (or whatever other thread was the last resumed thread) exited.
4536 To address this we refresh the thread list and check whether we
4537 have resumed threads _now_. In the example above, this removes
4538 thread 3 from the thread list. If thread 2 was re-resumed, we
4539 ignore this event. If we find no thread resumed, then we cancel
4540 the synchronous command show "no unwaited-for " to the user. */
4541 update_thread_list ();
4543 for (thread_info *thread : all_non_exited_threads ())
4545 if (thread->executing
4546 || thread->suspend.waitstatus_pending_p)
4548 /* There were no unwaited-for children left in the target at
4549 some point, but there are now. Just ignore. */
4551 fprintf_unfiltered (gdb_stdlog,
4552 "infrun: TARGET_WAITKIND_NO_RESUMED "
4553 "(ignoring: found resumed)\n");
4554 prepare_to_wait (ecs);
4559 /* Note however that we may find no resumed thread because the whole
4560 process exited meanwhile (thus updating the thread list results
4561 in an empty thread list). In this case we know we'll be getting
4562 a process exit event shortly. */
4563 for (inferior *inf : all_inferiors ())
4568 thread_info *thread = any_live_thread_of_inferior (inf);
4572 fprintf_unfiltered (gdb_stdlog,
4573 "infrun: TARGET_WAITKIND_NO_RESUMED "
4574 "(expect process exit)\n");
4575 prepare_to_wait (ecs);
4580 /* Go ahead and report the event. */
4584 /* Given an execution control state that has been freshly filled in by
4585 an event from the inferior, figure out what it means and take
4588 The alternatives are:
4590 1) stop_waiting and return; to really stop and return to the
4593 2) keep_going and return; to wait for the next event (set
4594 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4598 handle_inferior_event (struct execution_control_state *ecs)
4600 /* Make sure that all temporary struct value objects that were
4601 created during the handling of the event get deleted at the
4603 scoped_value_mark free_values;
4605 enum stop_kind stop_soon;
4607 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4609 /* We had an event in the inferior, but we are not interested in
4610 handling it at this level. The lower layers have already
4611 done what needs to be done, if anything.
4613 One of the possible circumstances for this is when the
4614 inferior produces output for the console. The inferior has
4615 not stopped, and we are ignoring the event. Another possible
4616 circumstance is any event which the lower level knows will be
4617 reported multiple times without an intervening resume. */
4619 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4620 prepare_to_wait (ecs);
4624 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4627 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4628 prepare_to_wait (ecs);
4632 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4633 && handle_no_resumed (ecs))
4636 /* Cache the last pid/waitstatus. */
4637 set_last_target_status (ecs->ptid, ecs->ws);
4639 /* Always clear state belonging to the previous time we stopped. */
4640 stop_stack_dummy = STOP_NONE;
4642 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4644 /* No unwaited-for children left. IOW, all resumed children
4647 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4649 stop_print_frame = 0;
4654 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4655 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4657 ecs->event_thread = find_thread_ptid (ecs->ptid);
4658 /* If it's a new thread, add it to the thread database. */
4659 if (ecs->event_thread == NULL)
4660 ecs->event_thread = add_thread (ecs->ptid);
4662 /* Disable range stepping. If the next step request could use a
4663 range, this will be end up re-enabled then. */
4664 ecs->event_thread->control.may_range_step = 0;
4667 /* Dependent on valid ECS->EVENT_THREAD. */
4668 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4670 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4671 reinit_frame_cache ();
4673 breakpoint_retire_moribund ();
4675 /* First, distinguish signals caused by the debugger from signals
4676 that have to do with the program's own actions. Note that
4677 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4678 on the operating system version. Here we detect when a SIGILL or
4679 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4680 something similar for SIGSEGV, since a SIGSEGV will be generated
4681 when we're trying to execute a breakpoint instruction on a
4682 non-executable stack. This happens for call dummy breakpoints
4683 for architectures like SPARC that place call dummies on the
4685 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4686 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4687 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4688 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4690 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4692 if (breakpoint_inserted_here_p (regcache->aspace (),
4693 regcache_read_pc (regcache)))
4696 fprintf_unfiltered (gdb_stdlog,
4697 "infrun: Treating signal as SIGTRAP\n");
4698 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4702 /* Mark the non-executing threads accordingly. In all-stop, all
4703 threads of all processes are stopped when we get any event
4704 reported. In non-stop mode, only the event thread stops. */
4708 if (!target_is_non_stop_p ())
4709 mark_ptid = minus_one_ptid;
4710 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4711 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4713 /* If we're handling a process exit in non-stop mode, even
4714 though threads haven't been deleted yet, one would think
4715 that there is nothing to do, as threads of the dead process
4716 will be soon deleted, and threads of any other process were
4717 left running. However, on some targets, threads survive a
4718 process exit event. E.g., for the "checkpoint" command,
4719 when the current checkpoint/fork exits, linux-fork.c
4720 automatically switches to another fork from within
4721 target_mourn_inferior, by associating the same
4722 inferior/thread to another fork. We haven't mourned yet at
4723 this point, but we must mark any threads left in the
4724 process as not-executing so that finish_thread_state marks
4725 them stopped (in the user's perspective) if/when we present
4726 the stop to the user. */
4727 mark_ptid = ptid_t (ecs->ptid.pid ());
4730 mark_ptid = ecs->ptid;
4732 set_executing (mark_ptid, 0);
4734 /* Likewise the resumed flag. */
4735 set_resumed (mark_ptid, 0);
4738 switch (ecs->ws.kind)
4740 case TARGET_WAITKIND_LOADED:
4742 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4743 context_switch (ecs);
4744 /* Ignore gracefully during startup of the inferior, as it might
4745 be the shell which has just loaded some objects, otherwise
4746 add the symbols for the newly loaded objects. Also ignore at
4747 the beginning of an attach or remote session; we will query
4748 the full list of libraries once the connection is
4751 stop_soon = get_inferior_stop_soon (ecs);
4752 if (stop_soon == NO_STOP_QUIETLY)
4754 struct regcache *regcache;
4756 regcache = get_thread_regcache (ecs->event_thread);
4758 handle_solib_event ();
4760 ecs->event_thread->control.stop_bpstat
4761 = bpstat_stop_status (regcache->aspace (),
4762 ecs->event_thread->suspend.stop_pc,
4763 ecs->event_thread, &ecs->ws);
4765 if (handle_stop_requested (ecs))
4768 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4770 /* A catchpoint triggered. */
4771 process_event_stop_test (ecs);
4775 /* If requested, stop when the dynamic linker notifies
4776 gdb of events. This allows the user to get control
4777 and place breakpoints in initializer routines for
4778 dynamically loaded objects (among other things). */
4779 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4780 if (stop_on_solib_events)
4782 /* Make sure we print "Stopped due to solib-event" in
4784 stop_print_frame = 1;
4791 /* If we are skipping through a shell, or through shared library
4792 loading that we aren't interested in, resume the program. If
4793 we're running the program normally, also resume. */
4794 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4796 /* Loading of shared libraries might have changed breakpoint
4797 addresses. Make sure new breakpoints are inserted. */
4798 if (stop_soon == NO_STOP_QUIETLY)
4799 insert_breakpoints ();
4800 resume (GDB_SIGNAL_0);
4801 prepare_to_wait (ecs);
4805 /* But stop if we're attaching or setting up a remote
4807 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4808 || stop_soon == STOP_QUIETLY_REMOTE)
4811 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4816 internal_error (__FILE__, __LINE__,
4817 _("unhandled stop_soon: %d"), (int) stop_soon);
4819 case TARGET_WAITKIND_SPURIOUS:
4821 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4822 if (handle_stop_requested (ecs))
4824 context_switch (ecs);
4825 resume (GDB_SIGNAL_0);
4826 prepare_to_wait (ecs);
4829 case TARGET_WAITKIND_THREAD_CREATED:
4831 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
4832 if (handle_stop_requested (ecs))
4834 context_switch (ecs);
4835 if (!switch_back_to_stepped_thread (ecs))
4839 case TARGET_WAITKIND_EXITED:
4840 case TARGET_WAITKIND_SIGNALLED:
4843 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4844 fprintf_unfiltered (gdb_stdlog,
4845 "infrun: TARGET_WAITKIND_EXITED\n");
4847 fprintf_unfiltered (gdb_stdlog,
4848 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4851 inferior_ptid = ecs->ptid;
4852 set_current_inferior (find_inferior_ptid (ecs->ptid));
4853 set_current_program_space (current_inferior ()->pspace);
4854 handle_vfork_child_exec_or_exit (0);
4855 target_terminal::ours (); /* Must do this before mourn anyway. */
4857 /* Clearing any previous state of convenience variables. */
4858 clear_exit_convenience_vars ();
4860 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4862 /* Record the exit code in the convenience variable $_exitcode, so
4863 that the user can inspect this again later. */
4864 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4865 (LONGEST) ecs->ws.value.integer);
4867 /* Also record this in the inferior itself. */
4868 current_inferior ()->has_exit_code = 1;
4869 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4871 /* Support the --return-child-result option. */
4872 return_child_result_value = ecs->ws.value.integer;
4874 gdb::observers::exited.notify (ecs->ws.value.integer);
4878 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
4880 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4882 /* Set the value of the internal variable $_exitsignal,
4883 which holds the signal uncaught by the inferior. */
4884 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4885 gdbarch_gdb_signal_to_target (gdbarch,
4886 ecs->ws.value.sig));
4890 /* We don't have access to the target's method used for
4891 converting between signal numbers (GDB's internal
4892 representation <-> target's representation).
4893 Therefore, we cannot do a good job at displaying this
4894 information to the user. It's better to just warn
4895 her about it (if infrun debugging is enabled), and
4898 fprintf_filtered (gdb_stdlog, _("\
4899 Cannot fill $_exitsignal with the correct signal number.\n"));
4902 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
4905 gdb_flush (gdb_stdout);
4906 target_mourn_inferior (inferior_ptid);
4907 stop_print_frame = 0;
4911 /* The following are the only cases in which we keep going;
4912 the above cases end in a continue or goto. */
4913 case TARGET_WAITKIND_FORKED:
4914 case TARGET_WAITKIND_VFORKED:
4917 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4918 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4920 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4923 /* Check whether the inferior is displaced stepping. */
4925 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4926 struct gdbarch *gdbarch = regcache->arch ();
4928 /* If checking displaced stepping is supported, and thread
4929 ecs->ptid is displaced stepping. */
4930 if (displaced_step_in_progress_thread (ecs->event_thread))
4932 struct inferior *parent_inf
4933 = find_inferior_ptid (ecs->ptid);
4934 struct regcache *child_regcache;
4935 CORE_ADDR parent_pc;
4937 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4938 indicating that the displaced stepping of syscall instruction
4939 has been done. Perform cleanup for parent process here. Note
4940 that this operation also cleans up the child process for vfork,
4941 because their pages are shared. */
4942 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
4943 /* Start a new step-over in another thread if there's one
4947 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4949 struct displaced_step_inferior_state *displaced
4950 = get_displaced_stepping_state (parent_inf);
4952 /* Restore scratch pad for child process. */
4953 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4956 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4957 the child's PC is also within the scratchpad. Set the child's PC
4958 to the parent's PC value, which has already been fixed up.
4959 FIXME: we use the parent's aspace here, although we're touching
4960 the child, because the child hasn't been added to the inferior
4961 list yet at this point. */
4964 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4966 parent_inf->aspace);
4967 /* Read PC value of parent process. */
4968 parent_pc = regcache_read_pc (regcache);
4970 if (debug_displaced)
4971 fprintf_unfiltered (gdb_stdlog,
4972 "displaced: write child pc from %s to %s\n",
4974 regcache_read_pc (child_regcache)),
4975 paddress (gdbarch, parent_pc));
4977 regcache_write_pc (child_regcache, parent_pc);
4981 context_switch (ecs);
4983 /* Immediately detach breakpoints from the child before there's
4984 any chance of letting the user delete breakpoints from the
4985 breakpoint lists. If we don't do this early, it's easy to
4986 leave left over traps in the child, vis: "break foo; catch
4987 fork; c; <fork>; del; c; <child calls foo>". We only follow
4988 the fork on the last `continue', and by that time the
4989 breakpoint at "foo" is long gone from the breakpoint table.
4990 If we vforked, then we don't need to unpatch here, since both
4991 parent and child are sharing the same memory pages; we'll
4992 need to unpatch at follow/detach time instead to be certain
4993 that new breakpoints added between catchpoint hit time and
4994 vfork follow are detached. */
4995 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4997 /* This won't actually modify the breakpoint list, but will
4998 physically remove the breakpoints from the child. */
4999 detach_breakpoints (ecs->ws.value.related_pid);
5002 delete_just_stopped_threads_single_step_breakpoints ();
5004 /* In case the event is caught by a catchpoint, remember that
5005 the event is to be followed at the next resume of the thread,
5006 and not immediately. */
5007 ecs->event_thread->pending_follow = ecs->ws;
5009 ecs->event_thread->suspend.stop_pc
5010 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5012 ecs->event_thread->control.stop_bpstat
5013 = bpstat_stop_status (get_current_regcache ()->aspace (),
5014 ecs->event_thread->suspend.stop_pc,
5015 ecs->event_thread, &ecs->ws);
5017 if (handle_stop_requested (ecs))
5020 /* If no catchpoint triggered for this, then keep going. Note
5021 that we're interested in knowing the bpstat actually causes a
5022 stop, not just if it may explain the signal. Software
5023 watchpoints, for example, always appear in the bpstat. */
5024 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5028 = (follow_fork_mode_string == follow_fork_mode_child);
5030 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5032 should_resume = follow_fork ();
5034 thread_info *parent = ecs->event_thread;
5035 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5037 /* At this point, the parent is marked running, and the
5038 child is marked stopped. */
5040 /* If not resuming the parent, mark it stopped. */
5041 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5042 parent->set_running (false);
5044 /* If resuming the child, mark it running. */
5045 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5046 child->set_running (true);
5048 /* In non-stop mode, also resume the other branch. */
5049 if (!detach_fork && (non_stop
5050 || (sched_multi && target_is_non_stop_p ())))
5053 switch_to_thread (parent);
5055 switch_to_thread (child);
5057 ecs->event_thread = inferior_thread ();
5058 ecs->ptid = inferior_ptid;
5063 switch_to_thread (child);
5065 switch_to_thread (parent);
5067 ecs->event_thread = inferior_thread ();
5068 ecs->ptid = inferior_ptid;
5076 process_event_stop_test (ecs);
5079 case TARGET_WAITKIND_VFORK_DONE:
5080 /* Done with the shared memory region. Re-insert breakpoints in
5081 the parent, and keep going. */
5084 fprintf_unfiltered (gdb_stdlog,
5085 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5087 context_switch (ecs);
5089 current_inferior ()->waiting_for_vfork_done = 0;
5090 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5092 if (handle_stop_requested (ecs))
5095 /* This also takes care of reinserting breakpoints in the
5096 previously locked inferior. */
5100 case TARGET_WAITKIND_EXECD:
5102 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5104 /* Note we can't read registers yet (the stop_pc), because we
5105 don't yet know the inferior's post-exec architecture.
5106 'stop_pc' is explicitly read below instead. */
5107 switch_to_thread_no_regs (ecs->event_thread);
5109 /* Do whatever is necessary to the parent branch of the vfork. */
5110 handle_vfork_child_exec_or_exit (1);
5112 /* This causes the eventpoints and symbol table to be reset.
5113 Must do this now, before trying to determine whether to
5115 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5117 /* In follow_exec we may have deleted the original thread and
5118 created a new one. Make sure that the event thread is the
5119 execd thread for that case (this is a nop otherwise). */
5120 ecs->event_thread = inferior_thread ();
5122 ecs->event_thread->suspend.stop_pc
5123 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5125 ecs->event_thread->control.stop_bpstat
5126 = bpstat_stop_status (get_current_regcache ()->aspace (),
5127 ecs->event_thread->suspend.stop_pc,
5128 ecs->event_thread, &ecs->ws);
5130 /* Note that this may be referenced from inside
5131 bpstat_stop_status above, through inferior_has_execd. */
5132 xfree (ecs->ws.value.execd_pathname);
5133 ecs->ws.value.execd_pathname = NULL;
5135 if (handle_stop_requested (ecs))
5138 /* If no catchpoint triggered for this, then keep going. */
5139 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5141 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5145 process_event_stop_test (ecs);
5148 /* Be careful not to try to gather much state about a thread
5149 that's in a syscall. It's frequently a losing proposition. */
5150 case TARGET_WAITKIND_SYSCALL_ENTRY:
5152 fprintf_unfiltered (gdb_stdlog,
5153 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5154 /* Getting the current syscall number. */
5155 if (handle_syscall_event (ecs) == 0)
5156 process_event_stop_test (ecs);
5159 /* Before examining the threads further, step this thread to
5160 get it entirely out of the syscall. (We get notice of the
5161 event when the thread is just on the verge of exiting a
5162 syscall. Stepping one instruction seems to get it back
5164 case TARGET_WAITKIND_SYSCALL_RETURN:
5166 fprintf_unfiltered (gdb_stdlog,
5167 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5168 if (handle_syscall_event (ecs) == 0)
5169 process_event_stop_test (ecs);
5172 case TARGET_WAITKIND_STOPPED:
5174 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5175 handle_signal_stop (ecs);
5178 case TARGET_WAITKIND_NO_HISTORY:
5180 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5181 /* Reverse execution: target ran out of history info. */
5183 /* Switch to the stopped thread. */
5184 context_switch (ecs);
5186 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5188 delete_just_stopped_threads_single_step_breakpoints ();
5189 ecs->event_thread->suspend.stop_pc
5190 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5192 if (handle_stop_requested (ecs))
5195 gdb::observers::no_history.notify ();
5201 /* Restart threads back to what they were trying to do back when we
5202 paused them for an in-line step-over. The EVENT_THREAD thread is
5206 restart_threads (struct thread_info *event_thread)
5208 /* In case the instruction just stepped spawned a new thread. */
5209 update_thread_list ();
5211 for (thread_info *tp : all_non_exited_threads ())
5213 if (tp == event_thread)
5216 fprintf_unfiltered (gdb_stdlog,
5217 "infrun: restart threads: "
5218 "[%s] is event thread\n",
5219 target_pid_to_str (tp->ptid));
5223 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5226 fprintf_unfiltered (gdb_stdlog,
5227 "infrun: restart threads: "
5228 "[%s] not meant to be running\n",
5229 target_pid_to_str (tp->ptid));
5236 fprintf_unfiltered (gdb_stdlog,
5237 "infrun: restart threads: [%s] resumed\n",
5238 target_pid_to_str (tp->ptid));
5239 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5243 if (thread_is_in_step_over_chain (tp))
5246 fprintf_unfiltered (gdb_stdlog,
5247 "infrun: restart threads: "
5248 "[%s] needs step-over\n",
5249 target_pid_to_str (tp->ptid));
5250 gdb_assert (!tp->resumed);
5255 if (tp->suspend.waitstatus_pending_p)
5258 fprintf_unfiltered (gdb_stdlog,
5259 "infrun: restart threads: "
5260 "[%s] has pending status\n",
5261 target_pid_to_str (tp->ptid));
5266 gdb_assert (!tp->stop_requested);
5268 /* If some thread needs to start a step-over at this point, it
5269 should still be in the step-over queue, and thus skipped
5271 if (thread_still_needs_step_over (tp))
5273 internal_error (__FILE__, __LINE__,
5274 "thread [%s] needs a step-over, but not in "
5275 "step-over queue\n",
5276 target_pid_to_str (tp->ptid));
5279 if (currently_stepping (tp))
5282 fprintf_unfiltered (gdb_stdlog,
5283 "infrun: restart threads: [%s] was stepping\n",
5284 target_pid_to_str (tp->ptid));
5285 keep_going_stepped_thread (tp);
5289 struct execution_control_state ecss;
5290 struct execution_control_state *ecs = &ecss;
5293 fprintf_unfiltered (gdb_stdlog,
5294 "infrun: restart threads: [%s] continuing\n",
5295 target_pid_to_str (tp->ptid));
5296 reset_ecs (ecs, tp);
5297 switch_to_thread (tp);
5298 keep_going_pass_signal (ecs);
5303 /* Callback for iterate_over_threads. Find a resumed thread that has
5304 a pending waitstatus. */
5307 resumed_thread_with_pending_status (struct thread_info *tp,
5311 && tp->suspend.waitstatus_pending_p);
5314 /* Called when we get an event that may finish an in-line or
5315 out-of-line (displaced stepping) step-over started previously.
5316 Return true if the event is processed and we should go back to the
5317 event loop; false if the caller should continue processing the
5321 finish_step_over (struct execution_control_state *ecs)
5323 int had_step_over_info;
5325 displaced_step_fixup (ecs->event_thread,
5326 ecs->event_thread->suspend.stop_signal);
5328 had_step_over_info = step_over_info_valid_p ();
5330 if (had_step_over_info)
5332 /* If we're stepping over a breakpoint with all threads locked,
5333 then only the thread that was stepped should be reporting
5335 gdb_assert (ecs->event_thread->control.trap_expected);
5337 clear_step_over_info ();
5340 if (!target_is_non_stop_p ())
5343 /* Start a new step-over in another thread if there's one that
5347 /* If we were stepping over a breakpoint before, and haven't started
5348 a new in-line step-over sequence, then restart all other threads
5349 (except the event thread). We can't do this in all-stop, as then
5350 e.g., we wouldn't be able to issue any other remote packet until
5351 these other threads stop. */
5352 if (had_step_over_info && !step_over_info_valid_p ())
5354 struct thread_info *pending;
5356 /* If we only have threads with pending statuses, the restart
5357 below won't restart any thread and so nothing re-inserts the
5358 breakpoint we just stepped over. But we need it inserted
5359 when we later process the pending events, otherwise if
5360 another thread has a pending event for this breakpoint too,
5361 we'd discard its event (because the breakpoint that
5362 originally caused the event was no longer inserted). */
5363 context_switch (ecs);
5364 insert_breakpoints ();
5366 restart_threads (ecs->event_thread);
5368 /* If we have events pending, go through handle_inferior_event
5369 again, picking up a pending event at random. This avoids
5370 thread starvation. */
5372 /* But not if we just stepped over a watchpoint in order to let
5373 the instruction execute so we can evaluate its expression.
5374 The set of watchpoints that triggered is recorded in the
5375 breakpoint objects themselves (see bp->watchpoint_triggered).
5376 If we processed another event first, that other event could
5377 clobber this info. */
5378 if (ecs->event_thread->stepping_over_watchpoint)
5381 pending = iterate_over_threads (resumed_thread_with_pending_status,
5383 if (pending != NULL)
5385 struct thread_info *tp = ecs->event_thread;
5386 struct regcache *regcache;
5390 fprintf_unfiltered (gdb_stdlog,
5391 "infrun: found resumed threads with "
5392 "pending events, saving status\n");
5395 gdb_assert (pending != tp);
5397 /* Record the event thread's event for later. */
5398 save_waitstatus (tp, &ecs->ws);
5399 /* This was cleared early, by handle_inferior_event. Set it
5400 so this pending event is considered by
5404 gdb_assert (!tp->executing);
5406 regcache = get_thread_regcache (tp);
5407 tp->suspend.stop_pc = regcache_read_pc (regcache);
5411 fprintf_unfiltered (gdb_stdlog,
5412 "infrun: saved stop_pc=%s for %s "
5413 "(currently_stepping=%d)\n",
5414 paddress (target_gdbarch (),
5415 tp->suspend.stop_pc),
5416 target_pid_to_str (tp->ptid),
5417 currently_stepping (tp));
5420 /* This in-line step-over finished; clear this so we won't
5421 start a new one. This is what handle_signal_stop would
5422 do, if we returned false. */
5423 tp->stepping_over_breakpoint = 0;
5425 /* Wake up the event loop again. */
5426 mark_async_event_handler (infrun_async_inferior_event_token);
5428 prepare_to_wait (ecs);
5436 /* Come here when the program has stopped with a signal. */
5439 handle_signal_stop (struct execution_control_state *ecs)
5441 struct frame_info *frame;
5442 struct gdbarch *gdbarch;
5443 int stopped_by_watchpoint;
5444 enum stop_kind stop_soon;
5447 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5449 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5451 /* Do we need to clean up the state of a thread that has
5452 completed a displaced single-step? (Doing so usually affects
5453 the PC, so do it here, before we set stop_pc.) */
5454 if (finish_step_over (ecs))
5457 /* If we either finished a single-step or hit a breakpoint, but
5458 the user wanted this thread to be stopped, pretend we got a
5459 SIG0 (generic unsignaled stop). */
5460 if (ecs->event_thread->stop_requested
5461 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5462 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5464 ecs->event_thread->suspend.stop_pc
5465 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5469 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5470 struct gdbarch *reg_gdbarch = regcache->arch ();
5471 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5473 inferior_ptid = ecs->ptid;
5475 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5476 paddress (reg_gdbarch,
5477 ecs->event_thread->suspend.stop_pc));
5478 if (target_stopped_by_watchpoint ())
5482 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5484 if (target_stopped_data_address (current_top_target (), &addr))
5485 fprintf_unfiltered (gdb_stdlog,
5486 "infrun: stopped data address = %s\n",
5487 paddress (reg_gdbarch, addr));
5489 fprintf_unfiltered (gdb_stdlog,
5490 "infrun: (no data address available)\n");
5494 /* This is originated from start_remote(), start_inferior() and
5495 shared libraries hook functions. */
5496 stop_soon = get_inferior_stop_soon (ecs);
5497 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5499 context_switch (ecs);
5501 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5502 stop_print_frame = 1;
5507 /* This originates from attach_command(). We need to overwrite
5508 the stop_signal here, because some kernels don't ignore a
5509 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5510 See more comments in inferior.h. On the other hand, if we
5511 get a non-SIGSTOP, report it to the user - assume the backend
5512 will handle the SIGSTOP if it should show up later.
5514 Also consider that the attach is complete when we see a
5515 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5516 target extended-remote report it instead of a SIGSTOP
5517 (e.g. gdbserver). We already rely on SIGTRAP being our
5518 signal, so this is no exception.
5520 Also consider that the attach is complete when we see a
5521 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5522 the target to stop all threads of the inferior, in case the
5523 low level attach operation doesn't stop them implicitly. If
5524 they weren't stopped implicitly, then the stub will report a
5525 GDB_SIGNAL_0, meaning: stopped for no particular reason
5526 other than GDB's request. */
5527 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5528 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5529 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5530 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5532 stop_print_frame = 1;
5534 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5538 /* See if something interesting happened to the non-current thread. If
5539 so, then switch to that thread. */
5540 if (ecs->ptid != inferior_ptid)
5543 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5545 context_switch (ecs);
5547 if (deprecated_context_hook)
5548 deprecated_context_hook (ecs->event_thread->global_num);
5551 /* At this point, get hold of the now-current thread's frame. */
5552 frame = get_current_frame ();
5553 gdbarch = get_frame_arch (frame);
5555 /* Pull the single step breakpoints out of the target. */
5556 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5558 struct regcache *regcache;
5561 regcache = get_thread_regcache (ecs->event_thread);
5562 const address_space *aspace = regcache->aspace ();
5564 pc = regcache_read_pc (regcache);
5566 /* However, before doing so, if this single-step breakpoint was
5567 actually for another thread, set this thread up for moving
5569 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5572 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5576 fprintf_unfiltered (gdb_stdlog,
5577 "infrun: [%s] hit another thread's "
5578 "single-step breakpoint\n",
5579 target_pid_to_str (ecs->ptid));
5581 ecs->hit_singlestep_breakpoint = 1;
5588 fprintf_unfiltered (gdb_stdlog,
5589 "infrun: [%s] hit its "
5590 "single-step breakpoint\n",
5591 target_pid_to_str (ecs->ptid));
5595 delete_just_stopped_threads_single_step_breakpoints ();
5597 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5598 && ecs->event_thread->control.trap_expected
5599 && ecs->event_thread->stepping_over_watchpoint)
5600 stopped_by_watchpoint = 0;
5602 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5604 /* If necessary, step over this watchpoint. We'll be back to display
5606 if (stopped_by_watchpoint
5607 && (target_have_steppable_watchpoint
5608 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5610 /* At this point, we are stopped at an instruction which has
5611 attempted to write to a piece of memory under control of
5612 a watchpoint. The instruction hasn't actually executed
5613 yet. If we were to evaluate the watchpoint expression
5614 now, we would get the old value, and therefore no change
5615 would seem to have occurred.
5617 In order to make watchpoints work `right', we really need
5618 to complete the memory write, and then evaluate the
5619 watchpoint expression. We do this by single-stepping the
5622 It may not be necessary to disable the watchpoint to step over
5623 it. For example, the PA can (with some kernel cooperation)
5624 single step over a watchpoint without disabling the watchpoint.
5626 It is far more common to need to disable a watchpoint to step
5627 the inferior over it. If we have non-steppable watchpoints,
5628 we must disable the current watchpoint; it's simplest to
5629 disable all watchpoints.
5631 Any breakpoint at PC must also be stepped over -- if there's
5632 one, it will have already triggered before the watchpoint
5633 triggered, and we either already reported it to the user, or
5634 it didn't cause a stop and we called keep_going. In either
5635 case, if there was a breakpoint at PC, we must be trying to
5637 ecs->event_thread->stepping_over_watchpoint = 1;
5642 ecs->event_thread->stepping_over_breakpoint = 0;
5643 ecs->event_thread->stepping_over_watchpoint = 0;
5644 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5645 ecs->event_thread->control.stop_step = 0;
5646 stop_print_frame = 1;
5647 stopped_by_random_signal = 0;
5648 bpstat stop_chain = NULL;
5650 /* Hide inlined functions starting here, unless we just performed stepi or
5651 nexti. After stepi and nexti, always show the innermost frame (not any
5652 inline function call sites). */
5653 if (ecs->event_thread->control.step_range_end != 1)
5655 const address_space *aspace
5656 = get_thread_regcache (ecs->event_thread)->aspace ();
5658 /* skip_inline_frames is expensive, so we avoid it if we can
5659 determine that the address is one where functions cannot have
5660 been inlined. This improves performance with inferiors that
5661 load a lot of shared libraries, because the solib event
5662 breakpoint is defined as the address of a function (i.e. not
5663 inline). Note that we have to check the previous PC as well
5664 as the current one to catch cases when we have just
5665 single-stepped off a breakpoint prior to reinstating it.
5666 Note that we're assuming that the code we single-step to is
5667 not inline, but that's not definitive: there's nothing
5668 preventing the event breakpoint function from containing
5669 inlined code, and the single-step ending up there. If the
5670 user had set a breakpoint on that inlined code, the missing
5671 skip_inline_frames call would break things. Fortunately
5672 that's an extremely unlikely scenario. */
5673 if (!pc_at_non_inline_function (aspace,
5674 ecs->event_thread->suspend.stop_pc,
5676 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5677 && ecs->event_thread->control.trap_expected
5678 && pc_at_non_inline_function (aspace,
5679 ecs->event_thread->prev_pc,
5682 stop_chain = build_bpstat_chain (aspace,
5683 ecs->event_thread->suspend.stop_pc,
5685 skip_inline_frames (ecs->event_thread, stop_chain);
5687 /* Re-fetch current thread's frame in case that invalidated
5689 frame = get_current_frame ();
5690 gdbarch = get_frame_arch (frame);
5694 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5695 && ecs->event_thread->control.trap_expected
5696 && gdbarch_single_step_through_delay_p (gdbarch)
5697 && currently_stepping (ecs->event_thread))
5699 /* We're trying to step off a breakpoint. Turns out that we're
5700 also on an instruction that needs to be stepped multiple
5701 times before it's been fully executing. E.g., architectures
5702 with a delay slot. It needs to be stepped twice, once for
5703 the instruction and once for the delay slot. */
5704 int step_through_delay
5705 = gdbarch_single_step_through_delay (gdbarch, frame);
5707 if (debug_infrun && step_through_delay)
5708 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5709 if (ecs->event_thread->control.step_range_end == 0
5710 && step_through_delay)
5712 /* The user issued a continue when stopped at a breakpoint.
5713 Set up for another trap and get out of here. */
5714 ecs->event_thread->stepping_over_breakpoint = 1;
5718 else if (step_through_delay)
5720 /* The user issued a step when stopped at a breakpoint.
5721 Maybe we should stop, maybe we should not - the delay
5722 slot *might* correspond to a line of source. In any
5723 case, don't decide that here, just set
5724 ecs->stepping_over_breakpoint, making sure we
5725 single-step again before breakpoints are re-inserted. */
5726 ecs->event_thread->stepping_over_breakpoint = 1;
5730 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5731 handles this event. */
5732 ecs->event_thread->control.stop_bpstat
5733 = bpstat_stop_status (get_current_regcache ()->aspace (),
5734 ecs->event_thread->suspend.stop_pc,
5735 ecs->event_thread, &ecs->ws, stop_chain);
5737 /* Following in case break condition called a
5739 stop_print_frame = 1;
5741 /* This is where we handle "moribund" watchpoints. Unlike
5742 software breakpoints traps, hardware watchpoint traps are
5743 always distinguishable from random traps. If no high-level
5744 watchpoint is associated with the reported stop data address
5745 anymore, then the bpstat does not explain the signal ---
5746 simply make sure to ignore it if `stopped_by_watchpoint' is
5750 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5751 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5753 && stopped_by_watchpoint)
5754 fprintf_unfiltered (gdb_stdlog,
5755 "infrun: no user watchpoint explains "
5756 "watchpoint SIGTRAP, ignoring\n");
5758 /* NOTE: cagney/2003-03-29: These checks for a random signal
5759 at one stage in the past included checks for an inferior
5760 function call's call dummy's return breakpoint. The original
5761 comment, that went with the test, read:
5763 ``End of a stack dummy. Some systems (e.g. Sony news) give
5764 another signal besides SIGTRAP, so check here as well as
5767 If someone ever tries to get call dummys on a
5768 non-executable stack to work (where the target would stop
5769 with something like a SIGSEGV), then those tests might need
5770 to be re-instated. Given, however, that the tests were only
5771 enabled when momentary breakpoints were not being used, I
5772 suspect that it won't be the case.
5774 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5775 be necessary for call dummies on a non-executable stack on
5778 /* See if the breakpoints module can explain the signal. */
5780 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5781 ecs->event_thread->suspend.stop_signal);
5783 /* Maybe this was a trap for a software breakpoint that has since
5785 if (random_signal && target_stopped_by_sw_breakpoint ())
5787 if (program_breakpoint_here_p (gdbarch,
5788 ecs->event_thread->suspend.stop_pc))
5790 struct regcache *regcache;
5793 /* Re-adjust PC to what the program would see if GDB was not
5795 regcache = get_thread_regcache (ecs->event_thread);
5796 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5799 gdb::optional<scoped_restore_tmpl<int>>
5800 restore_operation_disable;
5802 if (record_full_is_used ())
5803 restore_operation_disable.emplace
5804 (record_full_gdb_operation_disable_set ());
5806 regcache_write_pc (regcache,
5807 ecs->event_thread->suspend.stop_pc + decr_pc);
5812 /* A delayed software breakpoint event. Ignore the trap. */
5814 fprintf_unfiltered (gdb_stdlog,
5815 "infrun: delayed software breakpoint "
5816 "trap, ignoring\n");
5821 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5822 has since been removed. */
5823 if (random_signal && target_stopped_by_hw_breakpoint ())
5825 /* A delayed hardware breakpoint event. Ignore the trap. */
5827 fprintf_unfiltered (gdb_stdlog,
5828 "infrun: delayed hardware breakpoint/watchpoint "
5829 "trap, ignoring\n");
5833 /* If not, perhaps stepping/nexting can. */
5835 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5836 && currently_stepping (ecs->event_thread));
5838 /* Perhaps the thread hit a single-step breakpoint of _another_
5839 thread. Single-step breakpoints are transparent to the
5840 breakpoints module. */
5842 random_signal = !ecs->hit_singlestep_breakpoint;
5844 /* No? Perhaps we got a moribund watchpoint. */
5846 random_signal = !stopped_by_watchpoint;
5848 /* Always stop if the user explicitly requested this thread to
5850 if (ecs->event_thread->stop_requested)
5854 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
5857 /* For the program's own signals, act according to
5858 the signal handling tables. */
5862 /* Signal not for debugging purposes. */
5863 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5864 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5867 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5868 gdb_signal_to_symbol_string (stop_signal));
5870 stopped_by_random_signal = 1;
5872 /* Always stop on signals if we're either just gaining control
5873 of the program, or the user explicitly requested this thread
5874 to remain stopped. */
5875 if (stop_soon != NO_STOP_QUIETLY
5876 || ecs->event_thread->stop_requested
5878 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5884 /* Notify observers the signal has "handle print" set. Note we
5885 returned early above if stopping; normal_stop handles the
5886 printing in that case. */
5887 if (signal_print[ecs->event_thread->suspend.stop_signal])
5889 /* The signal table tells us to print about this signal. */
5890 target_terminal::ours_for_output ();
5891 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
5892 target_terminal::inferior ();
5895 /* Clear the signal if it should not be passed. */
5896 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5897 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5899 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
5900 && ecs->event_thread->control.trap_expected
5901 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5903 /* We were just starting a new sequence, attempting to
5904 single-step off of a breakpoint and expecting a SIGTRAP.
5905 Instead this signal arrives. This signal will take us out
5906 of the stepping range so GDB needs to remember to, when
5907 the signal handler returns, resume stepping off that
5909 /* To simplify things, "continue" is forced to use the same
5910 code paths as single-step - set a breakpoint at the
5911 signal return address and then, once hit, step off that
5914 fprintf_unfiltered (gdb_stdlog,
5915 "infrun: signal arrived while stepping over "
5918 insert_hp_step_resume_breakpoint_at_frame (frame);
5919 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5920 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5921 ecs->event_thread->control.trap_expected = 0;
5923 /* If we were nexting/stepping some other thread, switch to
5924 it, so that we don't continue it, losing control. */
5925 if (!switch_back_to_stepped_thread (ecs))
5930 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5931 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
5933 || ecs->event_thread->control.step_range_end == 1)
5934 && frame_id_eq (get_stack_frame_id (frame),
5935 ecs->event_thread->control.step_stack_frame_id)
5936 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5938 /* The inferior is about to take a signal that will take it
5939 out of the single step range. Set a breakpoint at the
5940 current PC (which is presumably where the signal handler
5941 will eventually return) and then allow the inferior to
5944 Note that this is only needed for a signal delivered
5945 while in the single-step range. Nested signals aren't a
5946 problem as they eventually all return. */
5948 fprintf_unfiltered (gdb_stdlog,
5949 "infrun: signal may take us out of "
5950 "single-step range\n");
5952 clear_step_over_info ();
5953 insert_hp_step_resume_breakpoint_at_frame (frame);
5954 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5955 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5956 ecs->event_thread->control.trap_expected = 0;
5961 /* Note: step_resume_breakpoint may be non-NULL. This occures
5962 when either there's a nested signal, or when there's a
5963 pending signal enabled just as the signal handler returns
5964 (leaving the inferior at the step-resume-breakpoint without
5965 actually executing it). Either way continue until the
5966 breakpoint is really hit. */
5968 if (!switch_back_to_stepped_thread (ecs))
5971 fprintf_unfiltered (gdb_stdlog,
5972 "infrun: random signal, keep going\n");
5979 process_event_stop_test (ecs);
5982 /* Come here when we've got some debug event / signal we can explain
5983 (IOW, not a random signal), and test whether it should cause a
5984 stop, or whether we should resume the inferior (transparently).
5985 E.g., could be a breakpoint whose condition evaluates false; we
5986 could be still stepping within the line; etc. */
5989 process_event_stop_test (struct execution_control_state *ecs)
5991 struct symtab_and_line stop_pc_sal;
5992 struct frame_info *frame;
5993 struct gdbarch *gdbarch;
5994 CORE_ADDR jmp_buf_pc;
5995 struct bpstat_what what;
5997 /* Handle cases caused by hitting a breakpoint. */
5999 frame = get_current_frame ();
6000 gdbarch = get_frame_arch (frame);
6002 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6004 if (what.call_dummy)
6006 stop_stack_dummy = what.call_dummy;
6009 /* A few breakpoint types have callbacks associated (e.g.,
6010 bp_jit_event). Run them now. */
6011 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6013 /* If we hit an internal event that triggers symbol changes, the
6014 current frame will be invalidated within bpstat_what (e.g., if we
6015 hit an internal solib event). Re-fetch it. */
6016 frame = get_current_frame ();
6017 gdbarch = get_frame_arch (frame);
6019 switch (what.main_action)
6021 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6022 /* If we hit the breakpoint at longjmp while stepping, we
6023 install a momentary breakpoint at the target of the
6027 fprintf_unfiltered (gdb_stdlog,
6028 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6030 ecs->event_thread->stepping_over_breakpoint = 1;
6032 if (what.is_longjmp)
6034 struct value *arg_value;
6036 /* If we set the longjmp breakpoint via a SystemTap probe,
6037 then use it to extract the arguments. The destination PC
6038 is the third argument to the probe. */
6039 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6042 jmp_buf_pc = value_as_address (arg_value);
6043 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6045 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6046 || !gdbarch_get_longjmp_target (gdbarch,
6047 frame, &jmp_buf_pc))
6050 fprintf_unfiltered (gdb_stdlog,
6051 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6052 "(!gdbarch_get_longjmp_target)\n");
6057 /* Insert a breakpoint at resume address. */
6058 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6061 check_exception_resume (ecs, frame);
6065 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6067 struct frame_info *init_frame;
6069 /* There are several cases to consider.
6071 1. The initiating frame no longer exists. In this case we
6072 must stop, because the exception or longjmp has gone too
6075 2. The initiating frame exists, and is the same as the
6076 current frame. We stop, because the exception or longjmp
6079 3. The initiating frame exists and is different from the
6080 current frame. This means the exception or longjmp has
6081 been caught beneath the initiating frame, so keep going.
6083 4. longjmp breakpoint has been placed just to protect
6084 against stale dummy frames and user is not interested in
6085 stopping around longjmps. */
6088 fprintf_unfiltered (gdb_stdlog,
6089 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6091 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6093 delete_exception_resume_breakpoint (ecs->event_thread);
6095 if (what.is_longjmp)
6097 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6099 if (!frame_id_p (ecs->event_thread->initiating_frame))
6107 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6111 struct frame_id current_id
6112 = get_frame_id (get_current_frame ());
6113 if (frame_id_eq (current_id,
6114 ecs->event_thread->initiating_frame))
6116 /* Case 2. Fall through. */
6126 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6128 delete_step_resume_breakpoint (ecs->event_thread);
6130 end_stepping_range (ecs);
6134 case BPSTAT_WHAT_SINGLE:
6136 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6137 ecs->event_thread->stepping_over_breakpoint = 1;
6138 /* Still need to check other stuff, at least the case where we
6139 are stepping and step out of the right range. */
6142 case BPSTAT_WHAT_STEP_RESUME:
6144 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6146 delete_step_resume_breakpoint (ecs->event_thread);
6147 if (ecs->event_thread->control.proceed_to_finish
6148 && execution_direction == EXEC_REVERSE)
6150 struct thread_info *tp = ecs->event_thread;
6152 /* We are finishing a function in reverse, and just hit the
6153 step-resume breakpoint at the start address of the
6154 function, and we're almost there -- just need to back up
6155 by one more single-step, which should take us back to the
6157 tp->control.step_range_start = tp->control.step_range_end = 1;
6161 fill_in_stop_func (gdbarch, ecs);
6162 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6163 && execution_direction == EXEC_REVERSE)
6165 /* We are stepping over a function call in reverse, and just
6166 hit the step-resume breakpoint at the start address of
6167 the function. Go back to single-stepping, which should
6168 take us back to the function call. */
6169 ecs->event_thread->stepping_over_breakpoint = 1;
6175 case BPSTAT_WHAT_STOP_NOISY:
6177 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6178 stop_print_frame = 1;
6180 /* Assume the thread stopped for a breapoint. We'll still check
6181 whether a/the breakpoint is there when the thread is next
6183 ecs->event_thread->stepping_over_breakpoint = 1;
6188 case BPSTAT_WHAT_STOP_SILENT:
6190 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6191 stop_print_frame = 0;
6193 /* Assume the thread stopped for a breapoint. We'll still check
6194 whether a/the breakpoint is there when the thread is next
6196 ecs->event_thread->stepping_over_breakpoint = 1;
6200 case BPSTAT_WHAT_HP_STEP_RESUME:
6202 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6204 delete_step_resume_breakpoint (ecs->event_thread);
6205 if (ecs->event_thread->step_after_step_resume_breakpoint)
6207 /* Back when the step-resume breakpoint was inserted, we
6208 were trying to single-step off a breakpoint. Go back to
6210 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6211 ecs->event_thread->stepping_over_breakpoint = 1;
6217 case BPSTAT_WHAT_KEEP_CHECKING:
6221 /* If we stepped a permanent breakpoint and we had a high priority
6222 step-resume breakpoint for the address we stepped, but we didn't
6223 hit it, then we must have stepped into the signal handler. The
6224 step-resume was only necessary to catch the case of _not_
6225 stepping into the handler, so delete it, and fall through to
6226 checking whether the step finished. */
6227 if (ecs->event_thread->stepped_breakpoint)
6229 struct breakpoint *sr_bp
6230 = ecs->event_thread->control.step_resume_breakpoint;
6233 && sr_bp->loc->permanent
6234 && sr_bp->type == bp_hp_step_resume
6235 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6238 fprintf_unfiltered (gdb_stdlog,
6239 "infrun: stepped permanent breakpoint, stopped in "
6241 delete_step_resume_breakpoint (ecs->event_thread);
6242 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6246 /* We come here if we hit a breakpoint but should not stop for it.
6247 Possibly we also were stepping and should stop for that. So fall
6248 through and test for stepping. But, if not stepping, do not
6251 /* In all-stop mode, if we're currently stepping but have stopped in
6252 some other thread, we need to switch back to the stepped thread. */
6253 if (switch_back_to_stepped_thread (ecs))
6256 if (ecs->event_thread->control.step_resume_breakpoint)
6259 fprintf_unfiltered (gdb_stdlog,
6260 "infrun: step-resume breakpoint is inserted\n");
6262 /* Having a step-resume breakpoint overrides anything
6263 else having to do with stepping commands until
6264 that breakpoint is reached. */
6269 if (ecs->event_thread->control.step_range_end == 0)
6272 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6273 /* Likewise if we aren't even stepping. */
6278 /* Re-fetch current thread's frame in case the code above caused
6279 the frame cache to be re-initialized, making our FRAME variable
6280 a dangling pointer. */
6281 frame = get_current_frame ();
6282 gdbarch = get_frame_arch (frame);
6283 fill_in_stop_func (gdbarch, ecs);
6285 /* If stepping through a line, keep going if still within it.
6287 Note that step_range_end is the address of the first instruction
6288 beyond the step range, and NOT the address of the last instruction
6291 Note also that during reverse execution, we may be stepping
6292 through a function epilogue and therefore must detect when
6293 the current-frame changes in the middle of a line. */
6295 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6297 && (execution_direction != EXEC_REVERSE
6298 || frame_id_eq (get_frame_id (frame),
6299 ecs->event_thread->control.step_frame_id)))
6303 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6304 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6305 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6307 /* Tentatively re-enable range stepping; `resume' disables it if
6308 necessary (e.g., if we're stepping over a breakpoint or we
6309 have software watchpoints). */
6310 ecs->event_thread->control.may_range_step = 1;
6312 /* When stepping backward, stop at beginning of line range
6313 (unless it's the function entry point, in which case
6314 keep going back to the call point). */
6315 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6316 if (stop_pc == ecs->event_thread->control.step_range_start
6317 && stop_pc != ecs->stop_func_start
6318 && execution_direction == EXEC_REVERSE)
6319 end_stepping_range (ecs);
6326 /* We stepped out of the stepping range. */
6328 /* If we are stepping at the source level and entered the runtime
6329 loader dynamic symbol resolution code...
6331 EXEC_FORWARD: we keep on single stepping until we exit the run
6332 time loader code and reach the callee's address.
6334 EXEC_REVERSE: we've already executed the callee (backward), and
6335 the runtime loader code is handled just like any other
6336 undebuggable function call. Now we need only keep stepping
6337 backward through the trampoline code, and that's handled further
6338 down, so there is nothing for us to do here. */
6340 if (execution_direction != EXEC_REVERSE
6341 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6342 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6344 CORE_ADDR pc_after_resolver =
6345 gdbarch_skip_solib_resolver (gdbarch,
6346 ecs->event_thread->suspend.stop_pc);
6349 fprintf_unfiltered (gdb_stdlog,
6350 "infrun: stepped into dynsym resolve code\n");
6352 if (pc_after_resolver)
6354 /* Set up a step-resume breakpoint at the address
6355 indicated by SKIP_SOLIB_RESOLVER. */
6356 symtab_and_line sr_sal;
6357 sr_sal.pc = pc_after_resolver;
6358 sr_sal.pspace = get_frame_program_space (frame);
6360 insert_step_resume_breakpoint_at_sal (gdbarch,
6361 sr_sal, null_frame_id);
6368 /* Step through an indirect branch thunk. */
6369 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6370 && gdbarch_in_indirect_branch_thunk (gdbarch,
6371 ecs->event_thread->suspend.stop_pc))
6374 fprintf_unfiltered (gdb_stdlog,
6375 "infrun: stepped into indirect branch thunk\n");
6380 if (ecs->event_thread->control.step_range_end != 1
6381 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6382 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6383 && get_frame_type (frame) == SIGTRAMP_FRAME)
6386 fprintf_unfiltered (gdb_stdlog,
6387 "infrun: stepped into signal trampoline\n");
6388 /* The inferior, while doing a "step" or "next", has ended up in
6389 a signal trampoline (either by a signal being delivered or by
6390 the signal handler returning). Just single-step until the
6391 inferior leaves the trampoline (either by calling the handler
6397 /* If we're in the return path from a shared library trampoline,
6398 we want to proceed through the trampoline when stepping. */
6399 /* macro/2012-04-25: This needs to come before the subroutine
6400 call check below as on some targets return trampolines look
6401 like subroutine calls (MIPS16 return thunks). */
6402 if (gdbarch_in_solib_return_trampoline (gdbarch,
6403 ecs->event_thread->suspend.stop_pc,
6404 ecs->stop_func_name)
6405 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6407 /* Determine where this trampoline returns. */
6408 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6409 CORE_ADDR real_stop_pc
6410 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6413 fprintf_unfiltered (gdb_stdlog,
6414 "infrun: stepped into solib return tramp\n");
6416 /* Only proceed through if we know where it's going. */
6419 /* And put the step-breakpoint there and go until there. */
6420 symtab_and_line sr_sal;
6421 sr_sal.pc = real_stop_pc;
6422 sr_sal.section = find_pc_overlay (sr_sal.pc);
6423 sr_sal.pspace = get_frame_program_space (frame);
6425 /* Do not specify what the fp should be when we stop since
6426 on some machines the prologue is where the new fp value
6428 insert_step_resume_breakpoint_at_sal (gdbarch,
6429 sr_sal, null_frame_id);
6431 /* Restart without fiddling with the step ranges or
6438 /* Check for subroutine calls. The check for the current frame
6439 equalling the step ID is not necessary - the check of the
6440 previous frame's ID is sufficient - but it is a common case and
6441 cheaper than checking the previous frame's ID.
6443 NOTE: frame_id_eq will never report two invalid frame IDs as
6444 being equal, so to get into this block, both the current and
6445 previous frame must have valid frame IDs. */
6446 /* The outer_frame_id check is a heuristic to detect stepping
6447 through startup code. If we step over an instruction which
6448 sets the stack pointer from an invalid value to a valid value,
6449 we may detect that as a subroutine call from the mythical
6450 "outermost" function. This could be fixed by marking
6451 outermost frames as !stack_p,code_p,special_p. Then the
6452 initial outermost frame, before sp was valid, would
6453 have code_addr == &_start. See the comment in frame_id_eq
6455 if (!frame_id_eq (get_stack_frame_id (frame),
6456 ecs->event_thread->control.step_stack_frame_id)
6457 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6458 ecs->event_thread->control.step_stack_frame_id)
6459 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6461 || (ecs->event_thread->control.step_start_function
6462 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6464 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6465 CORE_ADDR real_stop_pc;
6468 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6470 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6472 /* I presume that step_over_calls is only 0 when we're
6473 supposed to be stepping at the assembly language level
6474 ("stepi"). Just stop. */
6475 /* And this works the same backward as frontward. MVS */
6476 end_stepping_range (ecs);
6480 /* Reverse stepping through solib trampolines. */
6482 if (execution_direction == EXEC_REVERSE
6483 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6484 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6485 || (ecs->stop_func_start == 0
6486 && in_solib_dynsym_resolve_code (stop_pc))))
6488 /* Any solib trampoline code can be handled in reverse
6489 by simply continuing to single-step. We have already
6490 executed the solib function (backwards), and a few
6491 steps will take us back through the trampoline to the
6497 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6499 /* We're doing a "next".
6501 Normal (forward) execution: set a breakpoint at the
6502 callee's return address (the address at which the caller
6505 Reverse (backward) execution. set the step-resume
6506 breakpoint at the start of the function that we just
6507 stepped into (backwards), and continue to there. When we
6508 get there, we'll need to single-step back to the caller. */
6510 if (execution_direction == EXEC_REVERSE)
6512 /* If we're already at the start of the function, we've either
6513 just stepped backward into a single instruction function,
6514 or stepped back out of a signal handler to the first instruction
6515 of the function. Just keep going, which will single-step back
6517 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6519 /* Normal function call return (static or dynamic). */
6520 symtab_and_line sr_sal;
6521 sr_sal.pc = ecs->stop_func_start;
6522 sr_sal.pspace = get_frame_program_space (frame);
6523 insert_step_resume_breakpoint_at_sal (gdbarch,
6524 sr_sal, null_frame_id);
6528 insert_step_resume_breakpoint_at_caller (frame);
6534 /* If we are in a function call trampoline (a stub between the
6535 calling routine and the real function), locate the real
6536 function. That's what tells us (a) whether we want to step
6537 into it at all, and (b) what prologue we want to run to the
6538 end of, if we do step into it. */
6539 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6540 if (real_stop_pc == 0)
6541 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6542 if (real_stop_pc != 0)
6543 ecs->stop_func_start = real_stop_pc;
6545 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6547 symtab_and_line sr_sal;
6548 sr_sal.pc = ecs->stop_func_start;
6549 sr_sal.pspace = get_frame_program_space (frame);
6551 insert_step_resume_breakpoint_at_sal (gdbarch,
6552 sr_sal, null_frame_id);
6557 /* If we have line number information for the function we are
6558 thinking of stepping into and the function isn't on the skip
6561 If there are several symtabs at that PC (e.g. with include
6562 files), just want to know whether *any* of them have line
6563 numbers. find_pc_line handles this. */
6565 struct symtab_and_line tmp_sal;
6567 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6568 if (tmp_sal.line != 0
6569 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6572 if (execution_direction == EXEC_REVERSE)
6573 handle_step_into_function_backward (gdbarch, ecs);
6575 handle_step_into_function (gdbarch, ecs);
6580 /* If we have no line number and the step-stop-if-no-debug is
6581 set, we stop the step so that the user has a chance to switch
6582 in assembly mode. */
6583 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6584 && step_stop_if_no_debug)
6586 end_stepping_range (ecs);
6590 if (execution_direction == EXEC_REVERSE)
6592 /* If we're already at the start of the function, we've either just
6593 stepped backward into a single instruction function without line
6594 number info, or stepped back out of a signal handler to the first
6595 instruction of the function without line number info. Just keep
6596 going, which will single-step back to the caller. */
6597 if (ecs->stop_func_start != stop_pc)
6599 /* Set a breakpoint at callee's start address.
6600 From there we can step once and be back in the caller. */
6601 symtab_and_line sr_sal;
6602 sr_sal.pc = ecs->stop_func_start;
6603 sr_sal.pspace = get_frame_program_space (frame);
6604 insert_step_resume_breakpoint_at_sal (gdbarch,
6605 sr_sal, null_frame_id);
6609 /* Set a breakpoint at callee's return address (the address
6610 at which the caller will resume). */
6611 insert_step_resume_breakpoint_at_caller (frame);
6617 /* Reverse stepping through solib trampolines. */
6619 if (execution_direction == EXEC_REVERSE
6620 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6622 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6624 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6625 || (ecs->stop_func_start == 0
6626 && in_solib_dynsym_resolve_code (stop_pc)))
6628 /* Any solib trampoline code can be handled in reverse
6629 by simply continuing to single-step. We have already
6630 executed the solib function (backwards), and a few
6631 steps will take us back through the trampoline to the
6636 else if (in_solib_dynsym_resolve_code (stop_pc))
6638 /* Stepped backward into the solib dynsym resolver.
6639 Set a breakpoint at its start and continue, then
6640 one more step will take us out. */
6641 symtab_and_line sr_sal;
6642 sr_sal.pc = ecs->stop_func_start;
6643 sr_sal.pspace = get_frame_program_space (frame);
6644 insert_step_resume_breakpoint_at_sal (gdbarch,
6645 sr_sal, null_frame_id);
6651 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6653 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6654 the trampoline processing logic, however, there are some trampolines
6655 that have no names, so we should do trampoline handling first. */
6656 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6657 && ecs->stop_func_name == NULL
6658 && stop_pc_sal.line == 0)
6661 fprintf_unfiltered (gdb_stdlog,
6662 "infrun: stepped into undebuggable function\n");
6664 /* The inferior just stepped into, or returned to, an
6665 undebuggable function (where there is no debugging information
6666 and no line number corresponding to the address where the
6667 inferior stopped). Since we want to skip this kind of code,
6668 we keep going until the inferior returns from this
6669 function - unless the user has asked us not to (via
6670 set step-mode) or we no longer know how to get back
6671 to the call site. */
6672 if (step_stop_if_no_debug
6673 || !frame_id_p (frame_unwind_caller_id (frame)))
6675 /* If we have no line number and the step-stop-if-no-debug
6676 is set, we stop the step so that the user has a chance to
6677 switch in assembly mode. */
6678 end_stepping_range (ecs);
6683 /* Set a breakpoint at callee's return address (the address
6684 at which the caller will resume). */
6685 insert_step_resume_breakpoint_at_caller (frame);
6691 if (ecs->event_thread->control.step_range_end == 1)
6693 /* It is stepi or nexti. We always want to stop stepping after
6696 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6697 end_stepping_range (ecs);
6701 if (stop_pc_sal.line == 0)
6703 /* We have no line number information. That means to stop
6704 stepping (does this always happen right after one instruction,
6705 when we do "s" in a function with no line numbers,
6706 or can this happen as a result of a return or longjmp?). */
6708 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6709 end_stepping_range (ecs);
6713 /* Look for "calls" to inlined functions, part one. If the inline
6714 frame machinery detected some skipped call sites, we have entered
6715 a new inline function. */
6717 if (frame_id_eq (get_frame_id (get_current_frame ()),
6718 ecs->event_thread->control.step_frame_id)
6719 && inline_skipped_frames (ecs->event_thread))
6722 fprintf_unfiltered (gdb_stdlog,
6723 "infrun: stepped into inlined function\n");
6725 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6727 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6729 /* For "step", we're going to stop. But if the call site
6730 for this inlined function is on the same source line as
6731 we were previously stepping, go down into the function
6732 first. Otherwise stop at the call site. */
6734 if (call_sal.line == ecs->event_thread->current_line
6735 && call_sal.symtab == ecs->event_thread->current_symtab)
6736 step_into_inline_frame (ecs->event_thread);
6738 end_stepping_range (ecs);
6743 /* For "next", we should stop at the call site if it is on a
6744 different source line. Otherwise continue through the
6745 inlined function. */
6746 if (call_sal.line == ecs->event_thread->current_line
6747 && call_sal.symtab == ecs->event_thread->current_symtab)
6750 end_stepping_range (ecs);
6755 /* Look for "calls" to inlined functions, part two. If we are still
6756 in the same real function we were stepping through, but we have
6757 to go further up to find the exact frame ID, we are stepping
6758 through a more inlined call beyond its call site. */
6760 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6761 && !frame_id_eq (get_frame_id (get_current_frame ()),
6762 ecs->event_thread->control.step_frame_id)
6763 && stepped_in_from (get_current_frame (),
6764 ecs->event_thread->control.step_frame_id))
6767 fprintf_unfiltered (gdb_stdlog,
6768 "infrun: stepping through inlined function\n");
6770 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6773 end_stepping_range (ecs);
6777 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6778 && (ecs->event_thread->current_line != stop_pc_sal.line
6779 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6781 /* We are at the start of a different line. So stop. Note that
6782 we don't stop if we step into the middle of a different line.
6783 That is said to make things like for (;;) statements work
6786 fprintf_unfiltered (gdb_stdlog,
6787 "infrun: stepped to a different line\n");
6788 end_stepping_range (ecs);
6792 /* We aren't done stepping.
6794 Optimize by setting the stepping range to the line.
6795 (We might not be in the original line, but if we entered a
6796 new line in mid-statement, we continue stepping. This makes
6797 things like for(;;) statements work better.) */
6799 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6800 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6801 ecs->event_thread->control.may_range_step = 1;
6802 set_step_info (frame, stop_pc_sal);
6805 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6809 /* In all-stop mode, if we're currently stepping but have stopped in
6810 some other thread, we may need to switch back to the stepped
6811 thread. Returns true we set the inferior running, false if we left
6812 it stopped (and the event needs further processing). */
6815 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6817 if (!target_is_non_stop_p ())
6819 struct thread_info *stepping_thread;
6821 /* If any thread is blocked on some internal breakpoint, and we
6822 simply need to step over that breakpoint to get it going
6823 again, do that first. */
6825 /* However, if we see an event for the stepping thread, then we
6826 know all other threads have been moved past their breakpoints
6827 already. Let the caller check whether the step is finished,
6828 etc., before deciding to move it past a breakpoint. */
6829 if (ecs->event_thread->control.step_range_end != 0)
6832 /* Check if the current thread is blocked on an incomplete
6833 step-over, interrupted by a random signal. */
6834 if (ecs->event_thread->control.trap_expected
6835 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6839 fprintf_unfiltered (gdb_stdlog,
6840 "infrun: need to finish step-over of [%s]\n",
6841 target_pid_to_str (ecs->event_thread->ptid));
6847 /* Check if the current thread is blocked by a single-step
6848 breakpoint of another thread. */
6849 if (ecs->hit_singlestep_breakpoint)
6853 fprintf_unfiltered (gdb_stdlog,
6854 "infrun: need to step [%s] over single-step "
6856 target_pid_to_str (ecs->ptid));
6862 /* If this thread needs yet another step-over (e.g., stepping
6863 through a delay slot), do it first before moving on to
6865 if (thread_still_needs_step_over (ecs->event_thread))
6869 fprintf_unfiltered (gdb_stdlog,
6870 "infrun: thread [%s] still needs step-over\n",
6871 target_pid_to_str (ecs->event_thread->ptid));
6877 /* If scheduler locking applies even if not stepping, there's no
6878 need to walk over threads. Above we've checked whether the
6879 current thread is stepping. If some other thread not the
6880 event thread is stepping, then it must be that scheduler
6881 locking is not in effect. */
6882 if (schedlock_applies (ecs->event_thread))
6885 /* Otherwise, we no longer expect a trap in the current thread.
6886 Clear the trap_expected flag before switching back -- this is
6887 what keep_going does as well, if we call it. */
6888 ecs->event_thread->control.trap_expected = 0;
6890 /* Likewise, clear the signal if it should not be passed. */
6891 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6892 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6894 /* Do all pending step-overs before actually proceeding with
6896 if (start_step_over ())
6898 prepare_to_wait (ecs);
6902 /* Look for the stepping/nexting thread. */
6903 stepping_thread = NULL;
6905 for (thread_info *tp : all_non_exited_threads ())
6907 /* Ignore threads of processes the caller is not
6910 && tp->ptid.pid () != ecs->ptid.pid ())
6913 /* When stepping over a breakpoint, we lock all threads
6914 except the one that needs to move past the breakpoint.
6915 If a non-event thread has this set, the "incomplete
6916 step-over" check above should have caught it earlier. */
6917 if (tp->control.trap_expected)
6919 internal_error (__FILE__, __LINE__,
6920 "[%s] has inconsistent state: "
6921 "trap_expected=%d\n",
6922 target_pid_to_str (tp->ptid),
6923 tp->control.trap_expected);
6926 /* Did we find the stepping thread? */
6927 if (tp->control.step_range_end)
6929 /* Yep. There should only one though. */
6930 gdb_assert (stepping_thread == NULL);
6932 /* The event thread is handled at the top, before we
6934 gdb_assert (tp != ecs->event_thread);
6936 /* If some thread other than the event thread is
6937 stepping, then scheduler locking can't be in effect,
6938 otherwise we wouldn't have resumed the current event
6939 thread in the first place. */
6940 gdb_assert (!schedlock_applies (tp));
6942 stepping_thread = tp;
6946 if (stepping_thread != NULL)
6949 fprintf_unfiltered (gdb_stdlog,
6950 "infrun: switching back to stepped thread\n");
6952 if (keep_going_stepped_thread (stepping_thread))
6954 prepare_to_wait (ecs);
6963 /* Set a previously stepped thread back to stepping. Returns true on
6964 success, false if the resume is not possible (e.g., the thread
6968 keep_going_stepped_thread (struct thread_info *tp)
6970 struct frame_info *frame;
6971 struct execution_control_state ecss;
6972 struct execution_control_state *ecs = &ecss;
6974 /* If the stepping thread exited, then don't try to switch back and
6975 resume it, which could fail in several different ways depending
6976 on the target. Instead, just keep going.
6978 We can find a stepping dead thread in the thread list in two
6981 - The target supports thread exit events, and when the target
6982 tries to delete the thread from the thread list, inferior_ptid
6983 pointed at the exiting thread. In such case, calling
6984 delete_thread does not really remove the thread from the list;
6985 instead, the thread is left listed, with 'exited' state.
6987 - The target's debug interface does not support thread exit
6988 events, and so we have no idea whatsoever if the previously
6989 stepping thread is still alive. For that reason, we need to
6990 synchronously query the target now. */
6992 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
6995 fprintf_unfiltered (gdb_stdlog,
6996 "infrun: not resuming previously "
6997 "stepped thread, it has vanished\n");
7004 fprintf_unfiltered (gdb_stdlog,
7005 "infrun: resuming previously stepped thread\n");
7007 reset_ecs (ecs, tp);
7008 switch_to_thread (tp);
7010 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7011 frame = get_current_frame ();
7013 /* If the PC of the thread we were trying to single-step has
7014 changed, then that thread has trapped or been signaled, but the
7015 event has not been reported to GDB yet. Re-poll the target
7016 looking for this particular thread's event (i.e. temporarily
7017 enable schedlock) by:
7019 - setting a break at the current PC
7020 - resuming that particular thread, only (by setting trap
7023 This prevents us continuously moving the single-step breakpoint
7024 forward, one instruction at a time, overstepping. */
7026 if (tp->suspend.stop_pc != tp->prev_pc)
7031 fprintf_unfiltered (gdb_stdlog,
7032 "infrun: expected thread advanced also (%s -> %s)\n",
7033 paddress (target_gdbarch (), tp->prev_pc),
7034 paddress (target_gdbarch (), tp->suspend.stop_pc));
7036 /* Clear the info of the previous step-over, as it's no longer
7037 valid (if the thread was trying to step over a breakpoint, it
7038 has already succeeded). It's what keep_going would do too,
7039 if we called it. Do this before trying to insert the sss
7040 breakpoint, otherwise if we were previously trying to step
7041 over this exact address in another thread, the breakpoint is
7043 clear_step_over_info ();
7044 tp->control.trap_expected = 0;
7046 insert_single_step_breakpoint (get_frame_arch (frame),
7047 get_frame_address_space (frame),
7048 tp->suspend.stop_pc);
7051 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7052 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7057 fprintf_unfiltered (gdb_stdlog,
7058 "infrun: expected thread still hasn't advanced\n");
7060 keep_going_pass_signal (ecs);
7065 /* Is thread TP in the middle of (software or hardware)
7066 single-stepping? (Note the result of this function must never be
7067 passed directly as target_resume's STEP parameter.) */
7070 currently_stepping (struct thread_info *tp)
7072 return ((tp->control.step_range_end
7073 && tp->control.step_resume_breakpoint == NULL)
7074 || tp->control.trap_expected
7075 || tp->stepped_breakpoint
7076 || bpstat_should_step ());
7079 /* Inferior has stepped into a subroutine call with source code that
7080 we should not step over. Do step to the first line of code in
7084 handle_step_into_function (struct gdbarch *gdbarch,
7085 struct execution_control_state *ecs)
7087 fill_in_stop_func (gdbarch, ecs);
7089 compunit_symtab *cust
7090 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7091 if (cust != NULL && compunit_language (cust) != language_asm)
7092 ecs->stop_func_start
7093 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7095 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7096 /* Use the step_resume_break to step until the end of the prologue,
7097 even if that involves jumps (as it seems to on the vax under
7099 /* If the prologue ends in the middle of a source line, continue to
7100 the end of that source line (if it is still within the function).
7101 Otherwise, just go to end of prologue. */
7102 if (stop_func_sal.end
7103 && stop_func_sal.pc != ecs->stop_func_start
7104 && stop_func_sal.end < ecs->stop_func_end)
7105 ecs->stop_func_start = stop_func_sal.end;
7107 /* Architectures which require breakpoint adjustment might not be able
7108 to place a breakpoint at the computed address. If so, the test
7109 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7110 ecs->stop_func_start to an address at which a breakpoint may be
7111 legitimately placed.
7113 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7114 made, GDB will enter an infinite loop when stepping through
7115 optimized code consisting of VLIW instructions which contain
7116 subinstructions corresponding to different source lines. On
7117 FR-V, it's not permitted to place a breakpoint on any but the
7118 first subinstruction of a VLIW instruction. When a breakpoint is
7119 set, GDB will adjust the breakpoint address to the beginning of
7120 the VLIW instruction. Thus, we need to make the corresponding
7121 adjustment here when computing the stop address. */
7123 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7125 ecs->stop_func_start
7126 = gdbarch_adjust_breakpoint_address (gdbarch,
7127 ecs->stop_func_start);
7130 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7132 /* We are already there: stop now. */
7133 end_stepping_range (ecs);
7138 /* Put the step-breakpoint there and go until there. */
7139 symtab_and_line sr_sal;
7140 sr_sal.pc = ecs->stop_func_start;
7141 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7142 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7144 /* Do not specify what the fp should be when we stop since on
7145 some machines the prologue is where the new fp value is
7147 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7149 /* And make sure stepping stops right away then. */
7150 ecs->event_thread->control.step_range_end
7151 = ecs->event_thread->control.step_range_start;
7156 /* Inferior has stepped backward into a subroutine call with source
7157 code that we should not step over. Do step to the beginning of the
7158 last line of code in it. */
7161 handle_step_into_function_backward (struct gdbarch *gdbarch,
7162 struct execution_control_state *ecs)
7164 struct compunit_symtab *cust;
7165 struct symtab_and_line stop_func_sal;
7167 fill_in_stop_func (gdbarch, ecs);
7169 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7170 if (cust != NULL && compunit_language (cust) != language_asm)
7171 ecs->stop_func_start
7172 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7174 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7176 /* OK, we're just going to keep stepping here. */
7177 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7179 /* We're there already. Just stop stepping now. */
7180 end_stepping_range (ecs);
7184 /* Else just reset the step range and keep going.
7185 No step-resume breakpoint, they don't work for
7186 epilogues, which can have multiple entry paths. */
7187 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7188 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7194 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7195 This is used to both functions and to skip over code. */
7198 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7199 struct symtab_and_line sr_sal,
7200 struct frame_id sr_id,
7201 enum bptype sr_type)
7203 /* There should never be more than one step-resume or longjmp-resume
7204 breakpoint per thread, so we should never be setting a new
7205 step_resume_breakpoint when one is already active. */
7206 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7207 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7210 fprintf_unfiltered (gdb_stdlog,
7211 "infrun: inserting step-resume breakpoint at %s\n",
7212 paddress (gdbarch, sr_sal.pc));
7214 inferior_thread ()->control.step_resume_breakpoint
7215 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7219 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7220 struct symtab_and_line sr_sal,
7221 struct frame_id sr_id)
7223 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7228 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7229 This is used to skip a potential signal handler.
7231 This is called with the interrupted function's frame. The signal
7232 handler, when it returns, will resume the interrupted function at
7236 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7238 gdb_assert (return_frame != NULL);
7240 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7242 symtab_and_line sr_sal;
7243 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7244 sr_sal.section = find_pc_overlay (sr_sal.pc);
7245 sr_sal.pspace = get_frame_program_space (return_frame);
7247 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7248 get_stack_frame_id (return_frame),
7252 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7253 is used to skip a function after stepping into it (for "next" or if
7254 the called function has no debugging information).
7256 The current function has almost always been reached by single
7257 stepping a call or return instruction. NEXT_FRAME belongs to the
7258 current function, and the breakpoint will be set at the caller's
7261 This is a separate function rather than reusing
7262 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7263 get_prev_frame, which may stop prematurely (see the implementation
7264 of frame_unwind_caller_id for an example). */
7267 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7269 /* We shouldn't have gotten here if we don't know where the call site
7271 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7273 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7275 symtab_and_line sr_sal;
7276 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7277 frame_unwind_caller_pc (next_frame));
7278 sr_sal.section = find_pc_overlay (sr_sal.pc);
7279 sr_sal.pspace = frame_unwind_program_space (next_frame);
7281 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7282 frame_unwind_caller_id (next_frame));
7285 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7286 new breakpoint at the target of a jmp_buf. The handling of
7287 longjmp-resume uses the same mechanisms used for handling
7288 "step-resume" breakpoints. */
7291 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7293 /* There should never be more than one longjmp-resume breakpoint per
7294 thread, so we should never be setting a new
7295 longjmp_resume_breakpoint when one is already active. */
7296 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7299 fprintf_unfiltered (gdb_stdlog,
7300 "infrun: inserting longjmp-resume breakpoint at %s\n",
7301 paddress (gdbarch, pc));
7303 inferior_thread ()->control.exception_resume_breakpoint =
7304 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7307 /* Insert an exception resume breakpoint. TP is the thread throwing
7308 the exception. The block B is the block of the unwinder debug hook
7309 function. FRAME is the frame corresponding to the call to this
7310 function. SYM is the symbol of the function argument holding the
7311 target PC of the exception. */
7314 insert_exception_resume_breakpoint (struct thread_info *tp,
7315 const struct block *b,
7316 struct frame_info *frame,
7321 struct block_symbol vsym;
7322 struct value *value;
7324 struct breakpoint *bp;
7326 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7328 value = read_var_value (vsym.symbol, vsym.block, frame);
7329 /* If the value was optimized out, revert to the old behavior. */
7330 if (! value_optimized_out (value))
7332 handler = value_as_address (value);
7335 fprintf_unfiltered (gdb_stdlog,
7336 "infrun: exception resume at %lx\n",
7337 (unsigned long) handler);
7339 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7341 bp_exception_resume).release ();
7343 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7346 bp->thread = tp->global_num;
7347 inferior_thread ()->control.exception_resume_breakpoint = bp;
7350 CATCH (e, RETURN_MASK_ERROR)
7352 /* We want to ignore errors here. */
7357 /* A helper for check_exception_resume that sets an
7358 exception-breakpoint based on a SystemTap probe. */
7361 insert_exception_resume_from_probe (struct thread_info *tp,
7362 const struct bound_probe *probe,
7363 struct frame_info *frame)
7365 struct value *arg_value;
7367 struct breakpoint *bp;
7369 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7373 handler = value_as_address (arg_value);
7376 fprintf_unfiltered (gdb_stdlog,
7377 "infrun: exception resume at %s\n",
7378 paddress (get_objfile_arch (probe->objfile),
7381 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7382 handler, bp_exception_resume).release ();
7383 bp->thread = tp->global_num;
7384 inferior_thread ()->control.exception_resume_breakpoint = bp;
7387 /* This is called when an exception has been intercepted. Check to
7388 see whether the exception's destination is of interest, and if so,
7389 set an exception resume breakpoint there. */
7392 check_exception_resume (struct execution_control_state *ecs,
7393 struct frame_info *frame)
7395 struct bound_probe probe;
7396 struct symbol *func;
7398 /* First see if this exception unwinding breakpoint was set via a
7399 SystemTap probe point. If so, the probe has two arguments: the
7400 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7401 set a breakpoint there. */
7402 probe = find_probe_by_pc (get_frame_pc (frame));
7405 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7409 func = get_frame_function (frame);
7415 const struct block *b;
7416 struct block_iterator iter;
7420 /* The exception breakpoint is a thread-specific breakpoint on
7421 the unwinder's debug hook, declared as:
7423 void _Unwind_DebugHook (void *cfa, void *handler);
7425 The CFA argument indicates the frame to which control is
7426 about to be transferred. HANDLER is the destination PC.
7428 We ignore the CFA and set a temporary breakpoint at HANDLER.
7429 This is not extremely efficient but it avoids issues in gdb
7430 with computing the DWARF CFA, and it also works even in weird
7431 cases such as throwing an exception from inside a signal
7434 b = SYMBOL_BLOCK_VALUE (func);
7435 ALL_BLOCK_SYMBOLS (b, iter, sym)
7437 if (!SYMBOL_IS_ARGUMENT (sym))
7444 insert_exception_resume_breakpoint (ecs->event_thread,
7450 CATCH (e, RETURN_MASK_ERROR)
7457 stop_waiting (struct execution_control_state *ecs)
7460 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7462 /* Let callers know we don't want to wait for the inferior anymore. */
7463 ecs->wait_some_more = 0;
7465 /* If all-stop, but the target is always in non-stop mode, stop all
7466 threads now that we're presenting the stop to the user. */
7467 if (!non_stop && target_is_non_stop_p ())
7468 stop_all_threads ();
7471 /* Like keep_going, but passes the signal to the inferior, even if the
7472 signal is set to nopass. */
7475 keep_going_pass_signal (struct execution_control_state *ecs)
7477 gdb_assert (ecs->event_thread->ptid == inferior_ptid);
7478 gdb_assert (!ecs->event_thread->resumed);
7480 /* Save the pc before execution, to compare with pc after stop. */
7481 ecs->event_thread->prev_pc
7482 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7484 if (ecs->event_thread->control.trap_expected)
7486 struct thread_info *tp = ecs->event_thread;
7489 fprintf_unfiltered (gdb_stdlog,
7490 "infrun: %s has trap_expected set, "
7491 "resuming to collect trap\n",
7492 target_pid_to_str (tp->ptid));
7494 /* We haven't yet gotten our trap, and either: intercepted a
7495 non-signal event (e.g., a fork); or took a signal which we
7496 are supposed to pass through to the inferior. Simply
7498 resume (ecs->event_thread->suspend.stop_signal);
7500 else if (step_over_info_valid_p ())
7502 /* Another thread is stepping over a breakpoint in-line. If
7503 this thread needs a step-over too, queue the request. In
7504 either case, this resume must be deferred for later. */
7505 struct thread_info *tp = ecs->event_thread;
7507 if (ecs->hit_singlestep_breakpoint
7508 || thread_still_needs_step_over (tp))
7511 fprintf_unfiltered (gdb_stdlog,
7512 "infrun: step-over already in progress: "
7513 "step-over for %s deferred\n",
7514 target_pid_to_str (tp->ptid));
7515 thread_step_over_chain_enqueue (tp);
7520 fprintf_unfiltered (gdb_stdlog,
7521 "infrun: step-over in progress: "
7522 "resume of %s deferred\n",
7523 target_pid_to_str (tp->ptid));
7528 struct regcache *regcache = get_current_regcache ();
7531 step_over_what step_what;
7533 /* Either the trap was not expected, but we are continuing
7534 anyway (if we got a signal, the user asked it be passed to
7537 We got our expected trap, but decided we should resume from
7540 We're going to run this baby now!
7542 Note that insert_breakpoints won't try to re-insert
7543 already inserted breakpoints. Therefore, we don't
7544 care if breakpoints were already inserted, or not. */
7546 /* If we need to step over a breakpoint, and we're not using
7547 displaced stepping to do so, insert all breakpoints
7548 (watchpoints, etc.) but the one we're stepping over, step one
7549 instruction, and then re-insert the breakpoint when that step
7552 step_what = thread_still_needs_step_over (ecs->event_thread);
7554 remove_bp = (ecs->hit_singlestep_breakpoint
7555 || (step_what & STEP_OVER_BREAKPOINT));
7556 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7558 /* We can't use displaced stepping if we need to step past a
7559 watchpoint. The instruction copied to the scratch pad would
7560 still trigger the watchpoint. */
7562 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7564 set_step_over_info (regcache->aspace (),
7565 regcache_read_pc (regcache), remove_wps,
7566 ecs->event_thread->global_num);
7568 else if (remove_wps)
7569 set_step_over_info (NULL, 0, remove_wps, -1);
7571 /* If we now need to do an in-line step-over, we need to stop
7572 all other threads. Note this must be done before
7573 insert_breakpoints below, because that removes the breakpoint
7574 we're about to step over, otherwise other threads could miss
7576 if (step_over_info_valid_p () && target_is_non_stop_p ())
7577 stop_all_threads ();
7579 /* Stop stepping if inserting breakpoints fails. */
7582 insert_breakpoints ();
7584 CATCH (e, RETURN_MASK_ERROR)
7586 exception_print (gdb_stderr, e);
7588 clear_step_over_info ();
7593 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7595 resume (ecs->event_thread->suspend.stop_signal);
7598 prepare_to_wait (ecs);
7601 /* Called when we should continue running the inferior, because the
7602 current event doesn't cause a user visible stop. This does the
7603 resuming part; waiting for the next event is done elsewhere. */
7606 keep_going (struct execution_control_state *ecs)
7608 if (ecs->event_thread->control.trap_expected
7609 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7610 ecs->event_thread->control.trap_expected = 0;
7612 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7613 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7614 keep_going_pass_signal (ecs);
7617 /* This function normally comes after a resume, before
7618 handle_inferior_event exits. It takes care of any last bits of
7619 housekeeping, and sets the all-important wait_some_more flag. */
7622 prepare_to_wait (struct execution_control_state *ecs)
7625 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7627 ecs->wait_some_more = 1;
7629 if (!target_is_async_p ())
7630 mark_infrun_async_event_handler ();
7633 /* We are done with the step range of a step/next/si/ni command.
7634 Called once for each n of a "step n" operation. */
7637 end_stepping_range (struct execution_control_state *ecs)
7639 ecs->event_thread->control.stop_step = 1;
7643 /* Several print_*_reason functions to print why the inferior has stopped.
7644 We always print something when the inferior exits, or receives a signal.
7645 The rest of the cases are dealt with later on in normal_stop and
7646 print_it_typical. Ideally there should be a call to one of these
7647 print_*_reason functions functions from handle_inferior_event each time
7648 stop_waiting is called.
7650 Note that we don't call these directly, instead we delegate that to
7651 the interpreters, through observers. Interpreters then call these
7652 with whatever uiout is right. */
7655 print_end_stepping_range_reason (struct ui_out *uiout)
7657 /* For CLI-like interpreters, print nothing. */
7659 if (uiout->is_mi_like_p ())
7661 uiout->field_string ("reason",
7662 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7667 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7669 annotate_signalled ();
7670 if (uiout->is_mi_like_p ())
7672 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7673 uiout->text ("\nProgram terminated with signal ");
7674 annotate_signal_name ();
7675 uiout->field_string ("signal-name",
7676 gdb_signal_to_name (siggnal));
7677 annotate_signal_name_end ();
7679 annotate_signal_string ();
7680 uiout->field_string ("signal-meaning",
7681 gdb_signal_to_string (siggnal));
7682 annotate_signal_string_end ();
7683 uiout->text (".\n");
7684 uiout->text ("The program no longer exists.\n");
7688 print_exited_reason (struct ui_out *uiout, int exitstatus)
7690 struct inferior *inf = current_inferior ();
7691 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7693 annotate_exited (exitstatus);
7696 if (uiout->is_mi_like_p ())
7697 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7698 uiout->text ("[Inferior ");
7699 uiout->text (plongest (inf->num));
7701 uiout->text (pidstr);
7702 uiout->text (") exited with code ");
7703 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7704 uiout->text ("]\n");
7708 if (uiout->is_mi_like_p ())
7710 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7711 uiout->text ("[Inferior ");
7712 uiout->text (plongest (inf->num));
7714 uiout->text (pidstr);
7715 uiout->text (") exited normally]\n");
7719 /* Some targets/architectures can do extra processing/display of
7720 segmentation faults. E.g., Intel MPX boundary faults.
7721 Call the architecture dependent function to handle the fault. */
7724 handle_segmentation_fault (struct ui_out *uiout)
7726 struct regcache *regcache = get_current_regcache ();
7727 struct gdbarch *gdbarch = regcache->arch ();
7729 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7730 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7734 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7736 struct thread_info *thr = inferior_thread ();
7740 if (uiout->is_mi_like_p ())
7742 else if (show_thread_that_caused_stop ())
7746 uiout->text ("\nThread ");
7747 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7749 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7752 uiout->text (" \"");
7753 uiout->field_fmt ("name", "%s", name);
7758 uiout->text ("\nProgram");
7760 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7761 uiout->text (" stopped");
7764 uiout->text (" received signal ");
7765 annotate_signal_name ();
7766 if (uiout->is_mi_like_p ())
7768 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7769 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7770 annotate_signal_name_end ();
7772 annotate_signal_string ();
7773 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7775 if (siggnal == GDB_SIGNAL_SEGV)
7776 handle_segmentation_fault (uiout);
7778 annotate_signal_string_end ();
7780 uiout->text (".\n");
7784 print_no_history_reason (struct ui_out *uiout)
7786 uiout->text ("\nNo more reverse-execution history.\n");
7789 /* Print current location without a level number, if we have changed
7790 functions or hit a breakpoint. Print source line if we have one.
7791 bpstat_print contains the logic deciding in detail what to print,
7792 based on the event(s) that just occurred. */
7795 print_stop_location (struct target_waitstatus *ws)
7798 enum print_what source_flag;
7799 int do_frame_printing = 1;
7800 struct thread_info *tp = inferior_thread ();
7802 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7806 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7807 should) carry around the function and does (or should) use
7808 that when doing a frame comparison. */
7809 if (tp->control.stop_step
7810 && frame_id_eq (tp->control.step_frame_id,
7811 get_frame_id (get_current_frame ()))
7812 && (tp->control.step_start_function
7813 == find_pc_function (tp->suspend.stop_pc)))
7815 /* Finished step, just print source line. */
7816 source_flag = SRC_LINE;
7820 /* Print location and source line. */
7821 source_flag = SRC_AND_LOC;
7824 case PRINT_SRC_AND_LOC:
7825 /* Print location and source line. */
7826 source_flag = SRC_AND_LOC;
7828 case PRINT_SRC_ONLY:
7829 source_flag = SRC_LINE;
7832 /* Something bogus. */
7833 source_flag = SRC_LINE;
7834 do_frame_printing = 0;
7837 internal_error (__FILE__, __LINE__, _("Unknown value."));
7840 /* The behavior of this routine with respect to the source
7842 SRC_LINE: Print only source line
7843 LOCATION: Print only location
7844 SRC_AND_LOC: Print location and source line. */
7845 if (do_frame_printing)
7846 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7852 print_stop_event (struct ui_out *uiout)
7854 struct target_waitstatus last;
7856 struct thread_info *tp;
7858 get_last_target_status (&last_ptid, &last);
7861 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
7863 print_stop_location (&last);
7865 /* Display the auto-display expressions. */
7869 tp = inferior_thread ();
7870 if (tp->thread_fsm != NULL
7871 && tp->thread_fsm->finished_p ())
7873 struct return_value_info *rv;
7875 rv = tp->thread_fsm->return_value ();
7877 print_return_value (uiout, rv);
7884 maybe_remove_breakpoints (void)
7886 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7888 if (remove_breakpoints ())
7890 target_terminal::ours_for_output ();
7891 printf_filtered (_("Cannot remove breakpoints because "
7892 "program is no longer writable.\nFurther "
7893 "execution is probably impossible.\n"));
7898 /* The execution context that just caused a normal stop. */
7905 DISABLE_COPY_AND_ASSIGN (stop_context);
7907 bool changed () const;
7912 /* The event PTID. */
7916 /* If stopp for a thread event, this is the thread that caused the
7918 struct thread_info *thread;
7920 /* The inferior that caused the stop. */
7924 /* Initializes a new stop context. If stopped for a thread event, this
7925 takes a strong reference to the thread. */
7927 stop_context::stop_context ()
7929 stop_id = get_stop_id ();
7930 ptid = inferior_ptid;
7931 inf_num = current_inferior ()->num;
7933 if (inferior_ptid != null_ptid)
7935 /* Take a strong reference so that the thread can't be deleted
7937 thread = inferior_thread ();
7944 /* Release a stop context previously created with save_stop_context.
7945 Releases the strong reference to the thread as well. */
7947 stop_context::~stop_context ()
7953 /* Return true if the current context no longer matches the saved stop
7957 stop_context::changed () const
7959 if (ptid != inferior_ptid)
7961 if (inf_num != current_inferior ()->num)
7963 if (thread != NULL && thread->state != THREAD_STOPPED)
7965 if (get_stop_id () != stop_id)
7975 struct target_waitstatus last;
7978 get_last_target_status (&last_ptid, &last);
7982 /* If an exception is thrown from this point on, make sure to
7983 propagate GDB's knowledge of the executing state to the
7984 frontend/user running state. A QUIT is an easy exception to see
7985 here, so do this before any filtered output. */
7987 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
7990 maybe_finish_thread_state.emplace (minus_one_ptid);
7991 else if (last.kind == TARGET_WAITKIND_SIGNALLED
7992 || last.kind == TARGET_WAITKIND_EXITED)
7994 /* On some targets, we may still have live threads in the
7995 inferior when we get a process exit event. E.g., for
7996 "checkpoint", when the current checkpoint/fork exits,
7997 linux-fork.c automatically switches to another fork from
7998 within target_mourn_inferior. */
7999 if (inferior_ptid != null_ptid)
8000 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8002 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8003 maybe_finish_thread_state.emplace (inferior_ptid);
8005 /* As we're presenting a stop, and potentially removing breakpoints,
8006 update the thread list so we can tell whether there are threads
8007 running on the target. With target remote, for example, we can
8008 only learn about new threads when we explicitly update the thread
8009 list. Do this before notifying the interpreters about signal
8010 stops, end of stepping ranges, etc., so that the "new thread"
8011 output is emitted before e.g., "Program received signal FOO",
8012 instead of after. */
8013 update_thread_list ();
8015 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8016 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8018 /* As with the notification of thread events, we want to delay
8019 notifying the user that we've switched thread context until
8020 the inferior actually stops.
8022 There's no point in saying anything if the inferior has exited.
8023 Note that SIGNALLED here means "exited with a signal", not
8024 "received a signal".
8026 Also skip saying anything in non-stop mode. In that mode, as we
8027 don't want GDB to switch threads behind the user's back, to avoid
8028 races where the user is typing a command to apply to thread x,
8029 but GDB switches to thread y before the user finishes entering
8030 the command, fetch_inferior_event installs a cleanup to restore
8031 the current thread back to the thread the user had selected right
8032 after this event is handled, so we're not really switching, only
8033 informing of a stop. */
8035 && previous_inferior_ptid != inferior_ptid
8036 && target_has_execution
8037 && last.kind != TARGET_WAITKIND_SIGNALLED
8038 && last.kind != TARGET_WAITKIND_EXITED
8039 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8041 SWITCH_THRU_ALL_UIS ()
8043 target_terminal::ours_for_output ();
8044 printf_filtered (_("[Switching to %s]\n"),
8045 target_pid_to_str (inferior_ptid));
8046 annotate_thread_changed ();
8048 previous_inferior_ptid = inferior_ptid;
8051 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8053 SWITCH_THRU_ALL_UIS ()
8054 if (current_ui->prompt_state == PROMPT_BLOCKED)
8056 target_terminal::ours_for_output ();
8057 printf_filtered (_("No unwaited-for children left.\n"));
8061 /* Note: this depends on the update_thread_list call above. */
8062 maybe_remove_breakpoints ();
8064 /* If an auto-display called a function and that got a signal,
8065 delete that auto-display to avoid an infinite recursion. */
8067 if (stopped_by_random_signal)
8068 disable_current_display ();
8070 SWITCH_THRU_ALL_UIS ()
8072 async_enable_stdin ();
8075 /* Let the user/frontend see the threads as stopped. */
8076 maybe_finish_thread_state.reset ();
8078 /* Select innermost stack frame - i.e., current frame is frame 0,
8079 and current location is based on that. Handle the case where the
8080 dummy call is returning after being stopped. E.g. the dummy call
8081 previously hit a breakpoint. (If the dummy call returns
8082 normally, we won't reach here.) Do this before the stop hook is
8083 run, so that it doesn't get to see the temporary dummy frame,
8084 which is not where we'll present the stop. */
8085 if (has_stack_frames ())
8087 if (stop_stack_dummy == STOP_STACK_DUMMY)
8089 /* Pop the empty frame that contains the stack dummy. This
8090 also restores inferior state prior to the call (struct
8091 infcall_suspend_state). */
8092 struct frame_info *frame = get_current_frame ();
8094 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8096 /* frame_pop calls reinit_frame_cache as the last thing it
8097 does which means there's now no selected frame. */
8100 select_frame (get_current_frame ());
8102 /* Set the current source location. */
8103 set_current_sal_from_frame (get_current_frame ());
8106 /* Look up the hook_stop and run it (CLI internally handles problem
8107 of stop_command's pre-hook not existing). */
8108 if (stop_command != NULL)
8110 stop_context saved_context;
8114 execute_cmd_pre_hook (stop_command);
8116 CATCH (ex, RETURN_MASK_ALL)
8118 exception_fprintf (gdb_stderr, ex,
8119 "Error while running hook_stop:\n");
8123 /* If the stop hook resumes the target, then there's no point in
8124 trying to notify about the previous stop; its context is
8125 gone. Likewise if the command switches thread or inferior --
8126 the observers would print a stop for the wrong
8128 if (saved_context.changed ())
8132 /* Notify observers about the stop. This is where the interpreters
8133 print the stop event. */
8134 if (inferior_ptid != null_ptid)
8135 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8138 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8140 annotate_stopped ();
8142 if (target_has_execution)
8144 if (last.kind != TARGET_WAITKIND_SIGNALLED
8145 && last.kind != TARGET_WAITKIND_EXITED)
8146 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8147 Delete any breakpoint that is to be deleted at the next stop. */
8148 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8151 /* Try to get rid of automatically added inferiors that are no
8152 longer needed. Keeping those around slows down things linearly.
8153 Note that this never removes the current inferior. */
8160 signal_stop_state (int signo)
8162 return signal_stop[signo];
8166 signal_print_state (int signo)
8168 return signal_print[signo];
8172 signal_pass_state (int signo)
8174 return signal_program[signo];
8178 signal_cache_update (int signo)
8182 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8183 signal_cache_update (signo);
8188 signal_pass[signo] = (signal_stop[signo] == 0
8189 && signal_print[signo] == 0
8190 && signal_program[signo] == 1
8191 && signal_catch[signo] == 0);
8195 signal_stop_update (int signo, int state)
8197 int ret = signal_stop[signo];
8199 signal_stop[signo] = state;
8200 signal_cache_update (signo);
8205 signal_print_update (int signo, int state)
8207 int ret = signal_print[signo];
8209 signal_print[signo] = state;
8210 signal_cache_update (signo);
8215 signal_pass_update (int signo, int state)
8217 int ret = signal_program[signo];
8219 signal_program[signo] = state;
8220 signal_cache_update (signo);
8224 /* Update the global 'signal_catch' from INFO and notify the
8228 signal_catch_update (const unsigned int *info)
8232 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8233 signal_catch[i] = info[i] > 0;
8234 signal_cache_update (-1);
8235 target_pass_signals (signal_pass);
8239 sig_print_header (void)
8241 printf_filtered (_("Signal Stop\tPrint\tPass "
8242 "to program\tDescription\n"));
8246 sig_print_info (enum gdb_signal oursig)
8248 const char *name = gdb_signal_to_name (oursig);
8249 int name_padding = 13 - strlen (name);
8251 if (name_padding <= 0)
8254 printf_filtered ("%s", name);
8255 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8256 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8257 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8258 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8259 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8262 /* Specify how various signals in the inferior should be handled. */
8265 handle_command (const char *args, int from_tty)
8267 int digits, wordlen;
8268 int sigfirst, siglast;
8269 enum gdb_signal oursig;
8274 error_no_arg (_("signal to handle"));
8277 /* Allocate and zero an array of flags for which signals to handle. */
8279 const size_t nsigs = GDB_SIGNAL_LAST;
8280 unsigned char sigs[nsigs] {};
8282 /* Break the command line up into args. */
8284 gdb_argv built_argv (args);
8286 /* Walk through the args, looking for signal oursigs, signal names, and
8287 actions. Signal numbers and signal names may be interspersed with
8288 actions, with the actions being performed for all signals cumulatively
8289 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8291 for (char *arg : built_argv)
8293 wordlen = strlen (arg);
8294 for (digits = 0; isdigit (arg[digits]); digits++)
8298 sigfirst = siglast = -1;
8300 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8302 /* Apply action to all signals except those used by the
8303 debugger. Silently skip those. */
8306 siglast = nsigs - 1;
8308 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8310 SET_SIGS (nsigs, sigs, signal_stop);
8311 SET_SIGS (nsigs, sigs, signal_print);
8313 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8315 UNSET_SIGS (nsigs, sigs, signal_program);
8317 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8319 SET_SIGS (nsigs, sigs, signal_print);
8321 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8323 SET_SIGS (nsigs, sigs, signal_program);
8325 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8327 UNSET_SIGS (nsigs, sigs, signal_stop);
8329 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8331 SET_SIGS (nsigs, sigs, signal_program);
8333 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8335 UNSET_SIGS (nsigs, sigs, signal_print);
8336 UNSET_SIGS (nsigs, sigs, signal_stop);
8338 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8340 UNSET_SIGS (nsigs, sigs, signal_program);
8342 else if (digits > 0)
8344 /* It is numeric. The numeric signal refers to our own
8345 internal signal numbering from target.h, not to host/target
8346 signal number. This is a feature; users really should be
8347 using symbolic names anyway, and the common ones like
8348 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8350 sigfirst = siglast = (int)
8351 gdb_signal_from_command (atoi (arg));
8352 if (arg[digits] == '-')
8355 gdb_signal_from_command (atoi (arg + digits + 1));
8357 if (sigfirst > siglast)
8359 /* Bet he didn't figure we'd think of this case... */
8360 std::swap (sigfirst, siglast);
8365 oursig = gdb_signal_from_name (arg);
8366 if (oursig != GDB_SIGNAL_UNKNOWN)
8368 sigfirst = siglast = (int) oursig;
8372 /* Not a number and not a recognized flag word => complain. */
8373 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8377 /* If any signal numbers or symbol names were found, set flags for
8378 which signals to apply actions to. */
8380 for (int signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8382 switch ((enum gdb_signal) signum)
8384 case GDB_SIGNAL_TRAP:
8385 case GDB_SIGNAL_INT:
8386 if (!allsigs && !sigs[signum])
8388 if (query (_("%s is used by the debugger.\n\
8389 Are you sure you want to change it? "),
8390 gdb_signal_to_name ((enum gdb_signal) signum)))
8396 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8397 gdb_flush (gdb_stdout);
8402 case GDB_SIGNAL_DEFAULT:
8403 case GDB_SIGNAL_UNKNOWN:
8404 /* Make sure that "all" doesn't print these. */
8413 for (int signum = 0; signum < nsigs; signum++)
8416 signal_cache_update (-1);
8417 target_pass_signals (signal_pass);
8418 target_program_signals (signal_program);
8422 /* Show the results. */
8423 sig_print_header ();
8424 for (; signum < nsigs; signum++)
8426 sig_print_info ((enum gdb_signal) signum);
8433 /* Complete the "handle" command. */
8436 handle_completer (struct cmd_list_element *ignore,
8437 completion_tracker &tracker,
8438 const char *text, const char *word)
8440 static const char * const keywords[] =
8454 signal_completer (ignore, tracker, text, word);
8455 complete_on_enum (tracker, keywords, word, word);
8459 gdb_signal_from_command (int num)
8461 if (num >= 1 && num <= 15)
8462 return (enum gdb_signal) num;
8463 error (_("Only signals 1-15 are valid as numeric signals.\n\
8464 Use \"info signals\" for a list of symbolic signals."));
8467 /* Print current contents of the tables set by the handle command.
8468 It is possible we should just be printing signals actually used
8469 by the current target (but for things to work right when switching
8470 targets, all signals should be in the signal tables). */
8473 info_signals_command (const char *signum_exp, int from_tty)
8475 enum gdb_signal oursig;
8477 sig_print_header ();
8481 /* First see if this is a symbol name. */
8482 oursig = gdb_signal_from_name (signum_exp);
8483 if (oursig == GDB_SIGNAL_UNKNOWN)
8485 /* No, try numeric. */
8487 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8489 sig_print_info (oursig);
8493 printf_filtered ("\n");
8494 /* These ugly casts brought to you by the native VAX compiler. */
8495 for (oursig = GDB_SIGNAL_FIRST;
8496 (int) oursig < (int) GDB_SIGNAL_LAST;
8497 oursig = (enum gdb_signal) ((int) oursig + 1))
8501 if (oursig != GDB_SIGNAL_UNKNOWN
8502 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8503 sig_print_info (oursig);
8506 printf_filtered (_("\nUse the \"handle\" command "
8507 "to change these tables.\n"));
8510 /* The $_siginfo convenience variable is a bit special. We don't know
8511 for sure the type of the value until we actually have a chance to
8512 fetch the data. The type can change depending on gdbarch, so it is
8513 also dependent on which thread you have selected.
8515 1. making $_siginfo be an internalvar that creates a new value on
8518 2. making the value of $_siginfo be an lval_computed value. */
8520 /* This function implements the lval_computed support for reading a
8524 siginfo_value_read (struct value *v)
8526 LONGEST transferred;
8528 /* If we can access registers, so can we access $_siginfo. Likewise
8530 validate_registers_access ();
8533 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO,
8535 value_contents_all_raw (v),
8537 TYPE_LENGTH (value_type (v)));
8539 if (transferred != TYPE_LENGTH (value_type (v)))
8540 error (_("Unable to read siginfo"));
8543 /* This function implements the lval_computed support for writing a
8547 siginfo_value_write (struct value *v, struct value *fromval)
8549 LONGEST transferred;
8551 /* If we can access registers, so can we access $_siginfo. Likewise
8553 validate_registers_access ();
8555 transferred = target_write (current_top_target (),
8556 TARGET_OBJECT_SIGNAL_INFO,
8558 value_contents_all_raw (fromval),
8560 TYPE_LENGTH (value_type (fromval)));
8562 if (transferred != TYPE_LENGTH (value_type (fromval)))
8563 error (_("Unable to write siginfo"));
8566 static const struct lval_funcs siginfo_value_funcs =
8572 /* Return a new value with the correct type for the siginfo object of
8573 the current thread using architecture GDBARCH. Return a void value
8574 if there's no object available. */
8576 static struct value *
8577 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8580 if (target_has_stack
8581 && inferior_ptid != null_ptid
8582 && gdbarch_get_siginfo_type_p (gdbarch))
8584 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8586 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8589 return allocate_value (builtin_type (gdbarch)->builtin_void);
8593 /* infcall_suspend_state contains state about the program itself like its
8594 registers and any signal it received when it last stopped.
8595 This state must be restored regardless of how the inferior function call
8596 ends (either successfully, or after it hits a breakpoint or signal)
8597 if the program is to properly continue where it left off. */
8599 class infcall_suspend_state
8602 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8603 once the inferior function call has finished. */
8604 infcall_suspend_state (struct gdbarch *gdbarch,
8605 const struct thread_info *tp,
8606 struct regcache *regcache)
8607 : m_thread_suspend (tp->suspend),
8608 m_registers (new readonly_detached_regcache (*regcache))
8610 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8612 if (gdbarch_get_siginfo_type_p (gdbarch))
8614 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8615 size_t len = TYPE_LENGTH (type);
8617 siginfo_data.reset ((gdb_byte *) xmalloc (len));
8619 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8620 siginfo_data.get (), 0, len) != len)
8622 /* Errors ignored. */
8623 siginfo_data.reset (nullptr);
8629 m_siginfo_gdbarch = gdbarch;
8630 m_siginfo_data = std::move (siginfo_data);
8634 /* Return a pointer to the stored register state. */
8636 readonly_detached_regcache *registers () const
8638 return m_registers.get ();
8641 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8643 void restore (struct gdbarch *gdbarch,
8644 struct thread_info *tp,
8645 struct regcache *regcache) const
8647 tp->suspend = m_thread_suspend;
8649 if (m_siginfo_gdbarch == gdbarch)
8651 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8653 /* Errors ignored. */
8654 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8655 m_siginfo_data.get (), 0, TYPE_LENGTH (type));
8658 /* The inferior can be gone if the user types "print exit(0)"
8659 (and perhaps other times). */
8660 if (target_has_execution)
8661 /* NB: The register write goes through to the target. */
8662 regcache->restore (registers ());
8666 /* How the current thread stopped before the inferior function call was
8668 struct thread_suspend_state m_thread_suspend;
8670 /* The registers before the inferior function call was executed. */
8671 std::unique_ptr<readonly_detached_regcache> m_registers;
8673 /* Format of SIGINFO_DATA or NULL if it is not present. */
8674 struct gdbarch *m_siginfo_gdbarch = nullptr;
8676 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8677 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8678 content would be invalid. */
8679 gdb::unique_xmalloc_ptr<gdb_byte> m_siginfo_data;
8682 infcall_suspend_state_up
8683 save_infcall_suspend_state ()
8685 struct thread_info *tp = inferior_thread ();
8686 struct regcache *regcache = get_current_regcache ();
8687 struct gdbarch *gdbarch = regcache->arch ();
8689 infcall_suspend_state_up inf_state
8690 (new struct infcall_suspend_state (gdbarch, tp, regcache));
8692 /* Having saved the current state, adjust the thread state, discarding
8693 any stop signal information. The stop signal is not useful when
8694 starting an inferior function call, and run_inferior_call will not use
8695 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8696 tp->suspend.stop_signal = GDB_SIGNAL_0;
8701 /* Restore inferior session state to INF_STATE. */
8704 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8706 struct thread_info *tp = inferior_thread ();
8707 struct regcache *regcache = get_current_regcache ();
8708 struct gdbarch *gdbarch = regcache->arch ();
8710 inf_state->restore (gdbarch, tp, regcache);
8711 discard_infcall_suspend_state (inf_state);
8715 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8720 readonly_detached_regcache *
8721 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8723 return inf_state->registers ();
8726 /* infcall_control_state contains state regarding gdb's control of the
8727 inferior itself like stepping control. It also contains session state like
8728 the user's currently selected frame. */
8730 struct infcall_control_state
8732 struct thread_control_state thread_control;
8733 struct inferior_control_state inferior_control;
8736 enum stop_stack_kind stop_stack_dummy = STOP_NONE;
8737 int stopped_by_random_signal = 0;
8739 /* ID if the selected frame when the inferior function call was made. */
8740 struct frame_id selected_frame_id {};
8743 /* Save all of the information associated with the inferior<==>gdb
8746 infcall_control_state_up
8747 save_infcall_control_state ()
8749 infcall_control_state_up inf_status (new struct infcall_control_state);
8750 struct thread_info *tp = inferior_thread ();
8751 struct inferior *inf = current_inferior ();
8753 inf_status->thread_control = tp->control;
8754 inf_status->inferior_control = inf->control;
8756 tp->control.step_resume_breakpoint = NULL;
8757 tp->control.exception_resume_breakpoint = NULL;
8759 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8760 chain. If caller's caller is walking the chain, they'll be happier if we
8761 hand them back the original chain when restore_infcall_control_state is
8763 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8766 inf_status->stop_stack_dummy = stop_stack_dummy;
8767 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8769 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8775 restore_selected_frame (const frame_id &fid)
8777 frame_info *frame = frame_find_by_id (fid);
8779 /* If inf_status->selected_frame_id is NULL, there was no previously
8783 warning (_("Unable to restore previously selected frame."));
8787 select_frame (frame);
8790 /* Restore inferior session state to INF_STATUS. */
8793 restore_infcall_control_state (struct infcall_control_state *inf_status)
8795 struct thread_info *tp = inferior_thread ();
8796 struct inferior *inf = current_inferior ();
8798 if (tp->control.step_resume_breakpoint)
8799 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8801 if (tp->control.exception_resume_breakpoint)
8802 tp->control.exception_resume_breakpoint->disposition
8803 = disp_del_at_next_stop;
8805 /* Handle the bpstat_copy of the chain. */
8806 bpstat_clear (&tp->control.stop_bpstat);
8808 tp->control = inf_status->thread_control;
8809 inf->control = inf_status->inferior_control;
8812 stop_stack_dummy = inf_status->stop_stack_dummy;
8813 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8815 if (target_has_stack)
8817 /* The point of the try/catch is that if the stack is clobbered,
8818 walking the stack might encounter a garbage pointer and
8819 error() trying to dereference it. */
8822 restore_selected_frame (inf_status->selected_frame_id);
8824 CATCH (ex, RETURN_MASK_ERROR)
8826 exception_fprintf (gdb_stderr, ex,
8827 "Unable to restore previously selected frame:\n");
8828 /* Error in restoring the selected frame. Select the
8830 select_frame (get_current_frame ());
8839 discard_infcall_control_state (struct infcall_control_state *inf_status)
8841 if (inf_status->thread_control.step_resume_breakpoint)
8842 inf_status->thread_control.step_resume_breakpoint->disposition
8843 = disp_del_at_next_stop;
8845 if (inf_status->thread_control.exception_resume_breakpoint)
8846 inf_status->thread_control.exception_resume_breakpoint->disposition
8847 = disp_del_at_next_stop;
8849 /* See save_infcall_control_state for info on stop_bpstat. */
8850 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8858 clear_exit_convenience_vars (void)
8860 clear_internalvar (lookup_internalvar ("_exitsignal"));
8861 clear_internalvar (lookup_internalvar ("_exitcode"));
8865 /* User interface for reverse debugging:
8866 Set exec-direction / show exec-direction commands
8867 (returns error unless target implements to_set_exec_direction method). */
8869 enum exec_direction_kind execution_direction = EXEC_FORWARD;
8870 static const char exec_forward[] = "forward";
8871 static const char exec_reverse[] = "reverse";
8872 static const char *exec_direction = exec_forward;
8873 static const char *const exec_direction_names[] = {
8880 set_exec_direction_func (const char *args, int from_tty,
8881 struct cmd_list_element *cmd)
8883 if (target_can_execute_reverse)
8885 if (!strcmp (exec_direction, exec_forward))
8886 execution_direction = EXEC_FORWARD;
8887 else if (!strcmp (exec_direction, exec_reverse))
8888 execution_direction = EXEC_REVERSE;
8892 exec_direction = exec_forward;
8893 error (_("Target does not support this operation."));
8898 show_exec_direction_func (struct ui_file *out, int from_tty,
8899 struct cmd_list_element *cmd, const char *value)
8901 switch (execution_direction) {
8903 fprintf_filtered (out, _("Forward.\n"));
8906 fprintf_filtered (out, _("Reverse.\n"));
8909 internal_error (__FILE__, __LINE__,
8910 _("bogus execution_direction value: %d"),
8911 (int) execution_direction);
8916 show_schedule_multiple (struct ui_file *file, int from_tty,
8917 struct cmd_list_element *c, const char *value)
8919 fprintf_filtered (file, _("Resuming the execution of threads "
8920 "of all processes is %s.\n"), value);
8923 /* Implementation of `siginfo' variable. */
8925 static const struct internalvar_funcs siginfo_funcs =
8932 /* Callback for infrun's target events source. This is marked when a
8933 thread has a pending status to process. */
8936 infrun_async_inferior_event_handler (gdb_client_data data)
8938 inferior_event_handler (INF_REG_EVENT, NULL);
8942 _initialize_infrun (void)
8944 struct cmd_list_element *c;
8946 /* Register extra event sources in the event loop. */
8947 infrun_async_inferior_event_token
8948 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8950 add_info ("signals", info_signals_command, _("\
8951 What debugger does when program gets various signals.\n\
8952 Specify a signal as argument to print info on that signal only."));
8953 add_info_alias ("handle", "signals", 0);
8955 c = add_com ("handle", class_run, handle_command, _("\
8956 Specify how to handle signals.\n\
8957 Usage: handle SIGNAL [ACTIONS]\n\
8958 Args are signals and actions to apply to those signals.\n\
8959 If no actions are specified, the current settings for the specified signals\n\
8960 will be displayed instead.\n\
8962 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8963 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8964 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8965 The special arg \"all\" is recognized to mean all signals except those\n\
8966 used by the debugger, typically SIGTRAP and SIGINT.\n\
8968 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8969 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8970 Stop means reenter debugger if this signal happens (implies print).\n\
8971 Print means print a message if this signal happens.\n\
8972 Pass means let program see this signal; otherwise program doesn't know.\n\
8973 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8974 Pass and Stop may be combined.\n\
8976 Multiple signals may be specified. Signal numbers and signal names\n\
8977 may be interspersed with actions, with the actions being performed for\n\
8978 all signals cumulatively specified."));
8979 set_cmd_completer (c, handle_completer);
8982 stop_command = add_cmd ("stop", class_obscure,
8983 not_just_help_class_command, _("\
8984 There is no `stop' command, but you can set a hook on `stop'.\n\
8985 This allows you to set a list of commands to be run each time execution\n\
8986 of the program stops."), &cmdlist);
8988 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
8989 Set inferior debugging."), _("\
8990 Show inferior debugging."), _("\
8991 When non-zero, inferior specific debugging is enabled."),
8994 &setdebuglist, &showdebuglist);
8996 add_setshow_boolean_cmd ("displaced", class_maintenance,
8997 &debug_displaced, _("\
8998 Set displaced stepping debugging."), _("\
8999 Show displaced stepping debugging."), _("\
9000 When non-zero, displaced stepping specific debugging is enabled."),
9002 show_debug_displaced,
9003 &setdebuglist, &showdebuglist);
9005 add_setshow_boolean_cmd ("non-stop", no_class,
9007 Set whether gdb controls the inferior in non-stop mode."), _("\
9008 Show whether gdb controls the inferior in non-stop mode."), _("\
9009 When debugging a multi-threaded program and this setting is\n\
9010 off (the default, also called all-stop mode), when one thread stops\n\
9011 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9012 all other threads in the program while you interact with the thread of\n\
9013 interest. When you continue or step a thread, you can allow the other\n\
9014 threads to run, or have them remain stopped, but while you inspect any\n\
9015 thread's state, all threads stop.\n\
9017 In non-stop mode, when one thread stops, other threads can continue\n\
9018 to run freely. You'll be able to step each thread independently,\n\
9019 leave it stopped or free to run as needed."),
9025 for (size_t i = 0; i < GDB_SIGNAL_LAST; i++)
9028 signal_print[i] = 1;
9029 signal_program[i] = 1;
9030 signal_catch[i] = 0;
9033 /* Signals caused by debugger's own actions should not be given to
9034 the program afterwards.
9036 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9037 explicitly specifies that it should be delivered to the target
9038 program. Typically, that would occur when a user is debugging a
9039 target monitor on a simulator: the target monitor sets a
9040 breakpoint; the simulator encounters this breakpoint and halts
9041 the simulation handing control to GDB; GDB, noting that the stop
9042 address doesn't map to any known breakpoint, returns control back
9043 to the simulator; the simulator then delivers the hardware
9044 equivalent of a GDB_SIGNAL_TRAP to the program being
9046 signal_program[GDB_SIGNAL_TRAP] = 0;
9047 signal_program[GDB_SIGNAL_INT] = 0;
9049 /* Signals that are not errors should not normally enter the debugger. */
9050 signal_stop[GDB_SIGNAL_ALRM] = 0;
9051 signal_print[GDB_SIGNAL_ALRM] = 0;
9052 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9053 signal_print[GDB_SIGNAL_VTALRM] = 0;
9054 signal_stop[GDB_SIGNAL_PROF] = 0;
9055 signal_print[GDB_SIGNAL_PROF] = 0;
9056 signal_stop[GDB_SIGNAL_CHLD] = 0;
9057 signal_print[GDB_SIGNAL_CHLD] = 0;
9058 signal_stop[GDB_SIGNAL_IO] = 0;
9059 signal_print[GDB_SIGNAL_IO] = 0;
9060 signal_stop[GDB_SIGNAL_POLL] = 0;
9061 signal_print[GDB_SIGNAL_POLL] = 0;
9062 signal_stop[GDB_SIGNAL_URG] = 0;
9063 signal_print[GDB_SIGNAL_URG] = 0;
9064 signal_stop[GDB_SIGNAL_WINCH] = 0;
9065 signal_print[GDB_SIGNAL_WINCH] = 0;
9066 signal_stop[GDB_SIGNAL_PRIO] = 0;
9067 signal_print[GDB_SIGNAL_PRIO] = 0;
9069 /* These signals are used internally by user-level thread
9070 implementations. (See signal(5) on Solaris.) Like the above
9071 signals, a healthy program receives and handles them as part of
9072 its normal operation. */
9073 signal_stop[GDB_SIGNAL_LWP] = 0;
9074 signal_print[GDB_SIGNAL_LWP] = 0;
9075 signal_stop[GDB_SIGNAL_WAITING] = 0;
9076 signal_print[GDB_SIGNAL_WAITING] = 0;
9077 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9078 signal_print[GDB_SIGNAL_CANCEL] = 0;
9079 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9080 signal_print[GDB_SIGNAL_LIBRT] = 0;
9082 /* Update cached state. */
9083 signal_cache_update (-1);
9085 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9086 &stop_on_solib_events, _("\
9087 Set stopping for shared library events."), _("\
9088 Show stopping for shared library events."), _("\
9089 If nonzero, gdb will give control to the user when the dynamic linker\n\
9090 notifies gdb of shared library events. The most common event of interest\n\
9091 to the user would be loading/unloading of a new library."),
9092 set_stop_on_solib_events,
9093 show_stop_on_solib_events,
9094 &setlist, &showlist);
9096 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9097 follow_fork_mode_kind_names,
9098 &follow_fork_mode_string, _("\
9099 Set debugger response to a program call of fork or vfork."), _("\
9100 Show debugger response to a program call of fork or vfork."), _("\
9101 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9102 parent - the original process is debugged after a fork\n\
9103 child - the new process is debugged after a fork\n\
9104 The unfollowed process will continue to run.\n\
9105 By default, the debugger will follow the parent process."),
9107 show_follow_fork_mode_string,
9108 &setlist, &showlist);
9110 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9111 follow_exec_mode_names,
9112 &follow_exec_mode_string, _("\
9113 Set debugger response to a program call of exec."), _("\
9114 Show debugger response to a program call of exec."), _("\
9115 An exec call replaces the program image of a process.\n\
9117 follow-exec-mode can be:\n\
9119 new - the debugger creates a new inferior and rebinds the process\n\
9120 to this new inferior. The program the process was running before\n\
9121 the exec call can be restarted afterwards by restarting the original\n\
9124 same - the debugger keeps the process bound to the same inferior.\n\
9125 The new executable image replaces the previous executable loaded in\n\
9126 the inferior. Restarting the inferior after the exec call restarts\n\
9127 the executable the process was running after the exec call.\n\
9129 By default, the debugger will use the same inferior."),
9131 show_follow_exec_mode_string,
9132 &setlist, &showlist);
9134 add_setshow_enum_cmd ("scheduler-locking", class_run,
9135 scheduler_enums, &scheduler_mode, _("\
9136 Set mode for locking scheduler during execution."), _("\
9137 Show mode for locking scheduler during execution."), _("\
9138 off == no locking (threads may preempt at any time)\n\
9139 on == full locking (no thread except the current thread may run)\n\
9140 This applies to both normal execution and replay mode.\n\
9141 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9142 In this mode, other threads may run during other commands.\n\
9143 This applies to both normal execution and replay mode.\n\
9144 replay == scheduler locked in replay mode and unlocked during normal execution."),
9145 set_schedlock_func, /* traps on target vector */
9146 show_scheduler_mode,
9147 &setlist, &showlist);
9149 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9150 Set mode for resuming threads of all processes."), _("\
9151 Show mode for resuming threads of all processes."), _("\
9152 When on, execution commands (such as 'continue' or 'next') resume all\n\
9153 threads of all processes. When off (which is the default), execution\n\
9154 commands only resume the threads of the current process. The set of\n\
9155 threads that are resumed is further refined by the scheduler-locking\n\
9156 mode (see help set scheduler-locking)."),
9158 show_schedule_multiple,
9159 &setlist, &showlist);
9161 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9162 Set mode of the step operation."), _("\
9163 Show mode of the step operation."), _("\
9164 When set, doing a step over a function without debug line information\n\
9165 will stop at the first instruction of that function. Otherwise, the\n\
9166 function is skipped and the step command stops at a different source line."),
9168 show_step_stop_if_no_debug,
9169 &setlist, &showlist);
9171 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9172 &can_use_displaced_stepping, _("\
9173 Set debugger's willingness to use displaced stepping."), _("\
9174 Show debugger's willingness to use displaced stepping."), _("\
9175 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9176 supported by the target architecture. If off, gdb will not use displaced\n\
9177 stepping to step over breakpoints, even if such is supported by the target\n\
9178 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9179 if the target architecture supports it and non-stop mode is active, but will not\n\
9180 use it in all-stop mode (see help set non-stop)."),
9182 show_can_use_displaced_stepping,
9183 &setlist, &showlist);
9185 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9186 &exec_direction, _("Set direction of execution.\n\
9187 Options are 'forward' or 'reverse'."),
9188 _("Show direction of execution (forward/reverse)."),
9189 _("Tells gdb whether to execute forward or backward."),
9190 set_exec_direction_func, show_exec_direction_func,
9191 &setlist, &showlist);
9193 /* Set/show detach-on-fork: user-settable mode. */
9195 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9196 Set whether gdb will detach the child of a fork."), _("\
9197 Show whether gdb will detach the child of a fork."), _("\
9198 Tells gdb whether to detach the child of a fork."),
9199 NULL, NULL, &setlist, &showlist);
9201 /* Set/show disable address space randomization mode. */
9203 add_setshow_boolean_cmd ("disable-randomization", class_support,
9204 &disable_randomization, _("\
9205 Set disabling of debuggee's virtual address space randomization."), _("\
9206 Show disabling of debuggee's virtual address space randomization."), _("\
9207 When this mode is on (which is the default), randomization of the virtual\n\
9208 address space is disabled. Standalone programs run with the randomization\n\
9209 enabled by default on some platforms."),
9210 &set_disable_randomization,
9211 &show_disable_randomization,
9212 &setlist, &showlist);
9214 /* ptid initializations */
9215 inferior_ptid = null_ptid;
9216 target_last_wait_ptid = minus_one_ptid;
9218 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9219 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9220 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9221 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9223 /* Explicitly create without lookup, since that tries to create a
9224 value with a void typed value, and when we get here, gdbarch
9225 isn't initialized yet. At this point, we're quite sure there
9226 isn't another convenience variable of the same name. */
9227 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9229 add_setshow_boolean_cmd ("observer", no_class,
9230 &observer_mode_1, _("\
9231 Set whether gdb controls the inferior in observer mode."), _("\
9232 Show whether gdb controls the inferior in observer mode."), _("\
9233 In observer mode, GDB can get data from the inferior, but not\n\
9234 affect its execution. Registers and memory may not be changed,\n\
9235 breakpoints may not be set, and the program cannot be interrupted\n\