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"
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;
310 static unsigned char *signal_print;
311 static unsigned char *signal_program;
313 /* Table of signals that are registered with "catch signal". A
314 non-zero entry indicates that the signal is caught by some "catch
315 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
317 static unsigned char *signal_catch;
319 /* Table of signals that the target may silently handle.
320 This is automatically determined from the flags above,
321 and simply cached here. */
322 static unsigned char *signal_pass;
324 #define SET_SIGS(nsigs,sigs,flags) \
326 int signum = (nsigs); \
327 while (signum-- > 0) \
328 if ((sigs)[signum]) \
329 (flags)[signum] = 1; \
332 #define UNSET_SIGS(nsigs,sigs,flags) \
334 int signum = (nsigs); \
335 while (signum-- > 0) \
336 if ((sigs)[signum]) \
337 (flags)[signum] = 0; \
340 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
341 this function is to avoid exporting `signal_program'. */
344 update_signals_program_target (void)
346 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
349 /* Value to pass to target_resume() to cause all threads to resume. */
351 #define RESUME_ALL minus_one_ptid
353 /* Command list pointer for the "stop" placeholder. */
355 static struct cmd_list_element *stop_command;
357 /* Nonzero if we want to give control to the user when we're notified
358 of shared library events by the dynamic linker. */
359 int stop_on_solib_events;
361 /* Enable or disable optional shared library event breakpoints
362 as appropriate when the above flag is changed. */
365 set_stop_on_solib_events (const char *args,
366 int from_tty, struct cmd_list_element *c)
368 update_solib_breakpoints ();
372 show_stop_on_solib_events (struct ui_file *file, int from_tty,
373 struct cmd_list_element *c, const char *value)
375 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
379 /* Nonzero after stop if current stack frame should be printed. */
381 static int stop_print_frame;
383 /* This is a cached copy of the pid/waitstatus of the last event
384 returned by target_wait()/deprecated_target_wait_hook(). This
385 information is returned by get_last_target_status(). */
386 static ptid_t target_last_wait_ptid;
387 static struct target_waitstatus target_last_waitstatus;
389 void init_thread_stepping_state (struct thread_info *tss);
391 static const char follow_fork_mode_child[] = "child";
392 static const char follow_fork_mode_parent[] = "parent";
394 static const char *const follow_fork_mode_kind_names[] = {
395 follow_fork_mode_child,
396 follow_fork_mode_parent,
400 static const char *follow_fork_mode_string = follow_fork_mode_parent;
402 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
403 struct cmd_list_element *c, const char *value)
405 fprintf_filtered (file,
406 _("Debugger response to a program "
407 "call of fork or vfork is \"%s\".\n"),
412 /* Handle changes to the inferior list based on the type of fork,
413 which process is being followed, and whether the other process
414 should be detached. On entry inferior_ptid must be the ptid of
415 the fork parent. At return inferior_ptid is the ptid of the
416 followed inferior. */
419 follow_fork_inferior (int follow_child, int detach_fork)
422 ptid_t parent_ptid, child_ptid;
424 has_vforked = (inferior_thread ()->pending_follow.kind
425 == TARGET_WAITKIND_VFORKED);
426 parent_ptid = inferior_ptid;
427 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
430 && !non_stop /* Non-stop always resumes both branches. */
431 && current_ui->prompt_state == PROMPT_BLOCKED
432 && !(follow_child || detach_fork || sched_multi))
434 /* The parent stays blocked inside the vfork syscall until the
435 child execs or exits. If we don't let the child run, then
436 the parent stays blocked. If we're telling the parent to run
437 in the foreground, the user will not be able to ctrl-c to get
438 back the terminal, effectively hanging the debug session. */
439 fprintf_filtered (gdb_stderr, _("\
440 Can not resume the parent process over vfork in the foreground while\n\
441 holding the child stopped. Try \"set detach-on-fork\" or \
442 \"set schedule-multiple\".\n"));
443 /* FIXME output string > 80 columns. */
449 /* Detach new forked process? */
452 /* Before detaching from the child, remove all breakpoints
453 from it. If we forked, then this has already been taken
454 care of by infrun.c. If we vforked however, any
455 breakpoint inserted in the parent is visible in the
456 child, even those added while stopped in a vfork
457 catchpoint. This will remove the breakpoints from the
458 parent also, but they'll be reinserted below. */
461 /* Keep breakpoints list in sync. */
462 remove_breakpoints_inf (current_inferior ());
465 if (print_inferior_events)
467 /* Ensure that we have a process ptid. */
468 ptid_t process_ptid = ptid_t (child_ptid.pid ());
470 target_terminal::ours_for_output ();
471 fprintf_filtered (gdb_stdlog,
472 _("[Detaching after %s from child %s]\n"),
473 has_vforked ? "vfork" : "fork",
474 target_pid_to_str (process_ptid));
479 struct inferior *parent_inf, *child_inf;
481 /* Add process to GDB's tables. */
482 child_inf = add_inferior (child_ptid.pid ());
484 parent_inf = current_inferior ();
485 child_inf->attach_flag = parent_inf->attach_flag;
486 copy_terminal_info (child_inf, parent_inf);
487 child_inf->gdbarch = parent_inf->gdbarch;
488 copy_inferior_target_desc_info (child_inf, parent_inf);
490 scoped_restore_current_pspace_and_thread restore_pspace_thread;
492 inferior_ptid = child_ptid;
493 add_thread_silent (inferior_ptid);
494 set_current_inferior (child_inf);
495 child_inf->symfile_flags = SYMFILE_NO_READ;
497 /* If this is a vfork child, then the address-space is
498 shared with the parent. */
501 child_inf->pspace = parent_inf->pspace;
502 child_inf->aspace = parent_inf->aspace;
504 /* The parent will be frozen until the child is done
505 with the shared region. Keep track of the
507 child_inf->vfork_parent = parent_inf;
508 child_inf->pending_detach = 0;
509 parent_inf->vfork_child = child_inf;
510 parent_inf->pending_detach = 0;
514 child_inf->aspace = new_address_space ();
515 child_inf->pspace = new program_space (child_inf->aspace);
516 child_inf->removable = 1;
517 set_current_program_space (child_inf->pspace);
518 clone_program_space (child_inf->pspace, parent_inf->pspace);
520 /* Let the shared library layer (e.g., solib-svr4) learn
521 about this new process, relocate the cloned exec, pull
522 in shared libraries, and install the solib event
523 breakpoint. If a "cloned-VM" event was propagated
524 better throughout the core, this wouldn't be
526 solib_create_inferior_hook (0);
532 struct inferior *parent_inf;
534 parent_inf = current_inferior ();
536 /* If we detached from the child, then we have to be careful
537 to not insert breakpoints in the parent until the child
538 is done with the shared memory region. However, if we're
539 staying attached to the child, then we can and should
540 insert breakpoints, so that we can debug it. A
541 subsequent child exec or exit is enough to know when does
542 the child stops using the parent's address space. */
543 parent_inf->waiting_for_vfork_done = detach_fork;
544 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
549 /* Follow the child. */
550 struct inferior *parent_inf, *child_inf;
551 struct program_space *parent_pspace;
553 if (print_inferior_events)
555 std::string parent_pid = target_pid_to_str (parent_ptid);
556 std::string child_pid = target_pid_to_str (child_ptid);
558 target_terminal::ours_for_output ();
559 fprintf_filtered (gdb_stdlog,
560 _("[Attaching after %s %s to child %s]\n"),
562 has_vforked ? "vfork" : "fork",
566 /* Add the new inferior first, so that the target_detach below
567 doesn't unpush the target. */
569 child_inf = add_inferior (child_ptid.pid ());
571 parent_inf = current_inferior ();
572 child_inf->attach_flag = parent_inf->attach_flag;
573 copy_terminal_info (child_inf, parent_inf);
574 child_inf->gdbarch = parent_inf->gdbarch;
575 copy_inferior_target_desc_info (child_inf, parent_inf);
577 parent_pspace = parent_inf->pspace;
579 /* If we're vforking, we want to hold on to the parent until the
580 child exits or execs. At child exec or exit time we can
581 remove the old breakpoints from the parent and detach or
582 resume debugging it. Otherwise, detach the parent now; we'll
583 want to reuse it's program/address spaces, but we can't set
584 them to the child before removing breakpoints from the
585 parent, otherwise, the breakpoints module could decide to
586 remove breakpoints from the wrong process (since they'd be
587 assigned to the same address space). */
591 gdb_assert (child_inf->vfork_parent == NULL);
592 gdb_assert (parent_inf->vfork_child == NULL);
593 child_inf->vfork_parent = parent_inf;
594 child_inf->pending_detach = 0;
595 parent_inf->vfork_child = child_inf;
596 parent_inf->pending_detach = detach_fork;
597 parent_inf->waiting_for_vfork_done = 0;
599 else if (detach_fork)
601 if (print_inferior_events)
603 /* Ensure that we have a process ptid. */
604 ptid_t process_ptid = ptid_t (parent_ptid.pid ());
606 target_terminal::ours_for_output ();
607 fprintf_filtered (gdb_stdlog,
608 _("[Detaching after fork from "
610 target_pid_to_str (process_ptid));
613 target_detach (parent_inf, 0);
616 /* Note that the detach above makes PARENT_INF dangling. */
618 /* Add the child thread to the appropriate lists, and switch to
619 this new thread, before cloning the program space, and
620 informing the solib layer about this new process. */
622 inferior_ptid = child_ptid;
623 add_thread_silent (inferior_ptid);
624 set_current_inferior (child_inf);
626 /* If this is a vfork child, then the address-space is shared
627 with the parent. If we detached from the parent, then we can
628 reuse the parent's program/address spaces. */
629 if (has_vforked || detach_fork)
631 child_inf->pspace = parent_pspace;
632 child_inf->aspace = child_inf->pspace->aspace;
636 child_inf->aspace = new_address_space ();
637 child_inf->pspace = new program_space (child_inf->aspace);
638 child_inf->removable = 1;
639 child_inf->symfile_flags = SYMFILE_NO_READ;
640 set_current_program_space (child_inf->pspace);
641 clone_program_space (child_inf->pspace, parent_pspace);
643 /* Let the shared library layer (e.g., solib-svr4) learn
644 about this new process, relocate the cloned exec, pull in
645 shared libraries, and install the solib event breakpoint.
646 If a "cloned-VM" event was propagated better throughout
647 the core, this wouldn't be required. */
648 solib_create_inferior_hook (0);
652 return target_follow_fork (follow_child, detach_fork);
655 /* Tell the target to follow the fork we're stopped at. Returns true
656 if the inferior should be resumed; false, if the target for some
657 reason decided it's best not to resume. */
662 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
663 int should_resume = 1;
664 struct thread_info *tp;
666 /* Copy user stepping state to the new inferior thread. FIXME: the
667 followed fork child thread should have a copy of most of the
668 parent thread structure's run control related fields, not just these.
669 Initialized to avoid "may be used uninitialized" warnings from gcc. */
670 struct breakpoint *step_resume_breakpoint = NULL;
671 struct breakpoint *exception_resume_breakpoint = NULL;
672 CORE_ADDR step_range_start = 0;
673 CORE_ADDR step_range_end = 0;
674 struct frame_id step_frame_id = { 0 };
675 struct thread_fsm *thread_fsm = NULL;
680 struct target_waitstatus wait_status;
682 /* Get the last target status returned by target_wait(). */
683 get_last_target_status (&wait_ptid, &wait_status);
685 /* If not stopped at a fork event, then there's nothing else to
687 if (wait_status.kind != TARGET_WAITKIND_FORKED
688 && wait_status.kind != TARGET_WAITKIND_VFORKED)
691 /* Check if we switched over from WAIT_PTID, since the event was
693 if (wait_ptid != minus_one_ptid
694 && inferior_ptid != wait_ptid)
696 /* We did. Switch back to WAIT_PTID thread, to tell the
697 target to follow it (in either direction). We'll
698 afterwards refuse to resume, and inform the user what
700 thread_info *wait_thread
701 = find_thread_ptid (wait_ptid);
702 switch_to_thread (wait_thread);
707 tp = inferior_thread ();
709 /* If there were any forks/vforks that were caught and are now to be
710 followed, then do so now. */
711 switch (tp->pending_follow.kind)
713 case TARGET_WAITKIND_FORKED:
714 case TARGET_WAITKIND_VFORKED:
716 ptid_t parent, child;
718 /* If the user did a next/step, etc, over a fork call,
719 preserve the stepping state in the fork child. */
720 if (follow_child && should_resume)
722 step_resume_breakpoint = clone_momentary_breakpoint
723 (tp->control.step_resume_breakpoint);
724 step_range_start = tp->control.step_range_start;
725 step_range_end = tp->control.step_range_end;
726 step_frame_id = tp->control.step_frame_id;
727 exception_resume_breakpoint
728 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
729 thread_fsm = tp->thread_fsm;
731 /* For now, delete the parent's sr breakpoint, otherwise,
732 parent/child sr breakpoints are considered duplicates,
733 and the child version will not be installed. Remove
734 this when the breakpoints module becomes aware of
735 inferiors and address spaces. */
736 delete_step_resume_breakpoint (tp);
737 tp->control.step_range_start = 0;
738 tp->control.step_range_end = 0;
739 tp->control.step_frame_id = null_frame_id;
740 delete_exception_resume_breakpoint (tp);
741 tp->thread_fsm = NULL;
744 parent = inferior_ptid;
745 child = tp->pending_follow.value.related_pid;
747 /* Set up inferior(s) as specified by the caller, and tell the
748 target to do whatever is necessary to follow either parent
750 if (follow_fork_inferior (follow_child, detach_fork))
752 /* Target refused to follow, or there's some other reason
753 we shouldn't resume. */
758 /* This pending follow fork event is now handled, one way
759 or another. The previous selected thread may be gone
760 from the lists by now, but if it is still around, need
761 to clear the pending follow request. */
762 tp = find_thread_ptid (parent);
764 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
766 /* This makes sure we don't try to apply the "Switched
767 over from WAIT_PID" logic above. */
768 nullify_last_target_wait_ptid ();
770 /* If we followed the child, switch to it... */
773 thread_info *child_thr = find_thread_ptid (child);
774 switch_to_thread (child_thr);
776 /* ... and preserve the stepping state, in case the
777 user was stepping over the fork call. */
780 tp = inferior_thread ();
781 tp->control.step_resume_breakpoint
782 = step_resume_breakpoint;
783 tp->control.step_range_start = step_range_start;
784 tp->control.step_range_end = step_range_end;
785 tp->control.step_frame_id = step_frame_id;
786 tp->control.exception_resume_breakpoint
787 = exception_resume_breakpoint;
788 tp->thread_fsm = thread_fsm;
792 /* If we get here, it was because we're trying to
793 resume from a fork catchpoint, but, the user
794 has switched threads away from the thread that
795 forked. In that case, the resume command
796 issued is most likely not applicable to the
797 child, so just warn, and refuse to resume. */
798 warning (_("Not resuming: switched threads "
799 "before following fork child."));
802 /* Reset breakpoints in the child as appropriate. */
803 follow_inferior_reset_breakpoints ();
808 case TARGET_WAITKIND_SPURIOUS:
809 /* Nothing to follow. */
812 internal_error (__FILE__, __LINE__,
813 "Unexpected pending_follow.kind %d\n",
814 tp->pending_follow.kind);
818 return should_resume;
822 follow_inferior_reset_breakpoints (void)
824 struct thread_info *tp = inferior_thread ();
826 /* Was there a step_resume breakpoint? (There was if the user
827 did a "next" at the fork() call.) If so, explicitly reset its
828 thread number. Cloned step_resume breakpoints are disabled on
829 creation, so enable it here now that it is associated with the
832 step_resumes are a form of bp that are made to be per-thread.
833 Since we created the step_resume bp when the parent process
834 was being debugged, and now are switching to the child process,
835 from the breakpoint package's viewpoint, that's a switch of
836 "threads". We must update the bp's notion of which thread
837 it is for, or it'll be ignored when it triggers. */
839 if (tp->control.step_resume_breakpoint)
841 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
842 tp->control.step_resume_breakpoint->loc->enabled = 1;
845 /* Treat exception_resume breakpoints like step_resume breakpoints. */
846 if (tp->control.exception_resume_breakpoint)
848 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
849 tp->control.exception_resume_breakpoint->loc->enabled = 1;
852 /* Reinsert all breakpoints in the child. The user may have set
853 breakpoints after catching the fork, in which case those
854 were never set in the child, but only in the parent. This makes
855 sure the inserted breakpoints match the breakpoint list. */
857 breakpoint_re_set ();
858 insert_breakpoints ();
861 /* The child has exited or execed: resume threads of the parent the
862 user wanted to be executing. */
865 proceed_after_vfork_done (struct thread_info *thread,
868 int pid = * (int *) arg;
870 if (thread->ptid.pid () == pid
871 && thread->state == THREAD_RUNNING
872 && !thread->executing
873 && !thread->stop_requested
874 && thread->suspend.stop_signal == GDB_SIGNAL_0)
877 fprintf_unfiltered (gdb_stdlog,
878 "infrun: resuming vfork parent thread %s\n",
879 target_pid_to_str (thread->ptid));
881 switch_to_thread (thread);
882 clear_proceed_status (0);
883 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
889 /* Save/restore inferior_ptid, current program space and current
890 inferior. Only use this if the current context points at an exited
891 inferior (and therefore there's no current thread to save). */
892 class scoped_restore_exited_inferior
895 scoped_restore_exited_inferior ()
896 : m_saved_ptid (&inferior_ptid)
900 scoped_restore_tmpl<ptid_t> m_saved_ptid;
901 scoped_restore_current_program_space m_pspace;
902 scoped_restore_current_inferior m_inferior;
905 /* Called whenever we notice an exec or exit event, to handle
906 detaching or resuming a vfork parent. */
909 handle_vfork_child_exec_or_exit (int exec)
911 struct inferior *inf = current_inferior ();
913 if (inf->vfork_parent)
915 int resume_parent = -1;
917 /* This exec or exit marks the end of the shared memory region
918 between the parent and the child. If the user wanted to
919 detach from the parent, now is the time. */
921 if (inf->vfork_parent->pending_detach)
923 struct thread_info *tp;
924 struct program_space *pspace;
925 struct address_space *aspace;
927 /* follow-fork child, detach-on-fork on. */
929 inf->vfork_parent->pending_detach = 0;
931 gdb::optional<scoped_restore_exited_inferior>
932 maybe_restore_inferior;
933 gdb::optional<scoped_restore_current_pspace_and_thread>
934 maybe_restore_thread;
936 /* If we're handling a child exit, then inferior_ptid points
937 at the inferior's pid, not to a thread. */
939 maybe_restore_inferior.emplace ();
941 maybe_restore_thread.emplace ();
943 /* We're letting loose of the parent. */
944 tp = any_live_thread_of_inferior (inf->vfork_parent);
945 switch_to_thread (tp);
947 /* We're about to detach from the parent, which implicitly
948 removes breakpoints from its address space. There's a
949 catch here: we want to reuse the spaces for the child,
950 but, parent/child are still sharing the pspace at this
951 point, although the exec in reality makes the kernel give
952 the child a fresh set of new pages. The problem here is
953 that the breakpoints module being unaware of this, would
954 likely chose the child process to write to the parent
955 address space. Swapping the child temporarily away from
956 the spaces has the desired effect. Yes, this is "sort
959 pspace = inf->pspace;
960 aspace = inf->aspace;
964 if (print_inferior_events)
967 = target_pid_to_str (ptid_t (inf->vfork_parent->pid));
969 target_terminal::ours_for_output ();
973 fprintf_filtered (gdb_stdlog,
974 _("[Detaching vfork parent %s "
975 "after child exec]\n"), pidstr);
979 fprintf_filtered (gdb_stdlog,
980 _("[Detaching vfork parent %s "
981 "after child exit]\n"), pidstr);
985 target_detach (inf->vfork_parent, 0);
988 inf->pspace = pspace;
989 inf->aspace = aspace;
993 /* We're staying attached to the parent, so, really give the
994 child a new address space. */
995 inf->pspace = new program_space (maybe_new_address_space ());
996 inf->aspace = inf->pspace->aspace;
998 set_current_program_space (inf->pspace);
1000 resume_parent = inf->vfork_parent->pid;
1002 /* Break the bonds. */
1003 inf->vfork_parent->vfork_child = NULL;
1007 struct program_space *pspace;
1009 /* If this is a vfork child exiting, then the pspace and
1010 aspaces were shared with the parent. Since we're
1011 reporting the process exit, we'll be mourning all that is
1012 found in the address space, and switching to null_ptid,
1013 preparing to start a new inferior. But, since we don't
1014 want to clobber the parent's address/program spaces, we
1015 go ahead and create a new one for this exiting
1018 /* Switch to null_ptid while running clone_program_space, so
1019 that clone_program_space doesn't want to read the
1020 selected frame of a dead process. */
1021 scoped_restore restore_ptid
1022 = make_scoped_restore (&inferior_ptid, null_ptid);
1024 /* This inferior is dead, so avoid giving the breakpoints
1025 module the option to write through to it (cloning a
1026 program space resets breakpoints). */
1029 pspace = new program_space (maybe_new_address_space ());
1030 set_current_program_space (pspace);
1032 inf->symfile_flags = SYMFILE_NO_READ;
1033 clone_program_space (pspace, inf->vfork_parent->pspace);
1034 inf->pspace = pspace;
1035 inf->aspace = pspace->aspace;
1037 resume_parent = inf->vfork_parent->pid;
1038 /* Break the bonds. */
1039 inf->vfork_parent->vfork_child = NULL;
1042 inf->vfork_parent = NULL;
1044 gdb_assert (current_program_space == inf->pspace);
1046 if (non_stop && resume_parent != -1)
1048 /* If the user wanted the parent to be running, let it go
1050 scoped_restore_current_thread restore_thread;
1053 fprintf_unfiltered (gdb_stdlog,
1054 "infrun: resuming vfork parent process %d\n",
1057 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1062 /* Enum strings for "set|show follow-exec-mode". */
1064 static const char follow_exec_mode_new[] = "new";
1065 static const char follow_exec_mode_same[] = "same";
1066 static const char *const follow_exec_mode_names[] =
1068 follow_exec_mode_new,
1069 follow_exec_mode_same,
1073 static const char *follow_exec_mode_string = follow_exec_mode_same;
1075 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1076 struct cmd_list_element *c, const char *value)
1078 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1081 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1084 follow_exec (ptid_t ptid, char *exec_file_target)
1086 struct inferior *inf = current_inferior ();
1087 int pid = ptid.pid ();
1088 ptid_t process_ptid;
1090 /* This is an exec event that we actually wish to pay attention to.
1091 Refresh our symbol table to the newly exec'd program, remove any
1092 momentary bp's, etc.
1094 If there are breakpoints, they aren't really inserted now,
1095 since the exec() transformed our inferior into a fresh set
1098 We want to preserve symbolic breakpoints on the list, since
1099 we have hopes that they can be reset after the new a.out's
1100 symbol table is read.
1102 However, any "raw" breakpoints must be removed from the list
1103 (e.g., the solib bp's), since their address is probably invalid
1106 And, we DON'T want to call delete_breakpoints() here, since
1107 that may write the bp's "shadow contents" (the instruction
1108 value that was overwritten witha TRAP instruction). Since
1109 we now have a new a.out, those shadow contents aren't valid. */
1111 mark_breakpoints_out ();
1113 /* The target reports the exec event to the main thread, even if
1114 some other thread does the exec, and even if the main thread was
1115 stopped or already gone. We may still have non-leader threads of
1116 the process on our list. E.g., on targets that don't have thread
1117 exit events (like remote); or on native Linux in non-stop mode if
1118 there were only two threads in the inferior and the non-leader
1119 one is the one that execs (and nothing forces an update of the
1120 thread list up to here). When debugging remotely, it's best to
1121 avoid extra traffic, when possible, so avoid syncing the thread
1122 list with the target, and instead go ahead and delete all threads
1123 of the process but one that reported the event. Note this must
1124 be done before calling update_breakpoints_after_exec, as
1125 otherwise clearing the threads' resources would reference stale
1126 thread breakpoints -- it may have been one of these threads that
1127 stepped across the exec. We could just clear their stepping
1128 states, but as long as we're iterating, might as well delete
1129 them. Deleting them now rather than at the next user-visible
1130 stop provides a nicer sequence of events for user and MI
1132 for (thread_info *th : all_threads_safe ())
1133 if (th->ptid.pid () == pid && th->ptid != ptid)
1136 /* We also need to clear any left over stale state for the
1137 leader/event thread. E.g., if there was any step-resume
1138 breakpoint or similar, it's gone now. We cannot truly
1139 step-to-next statement through an exec(). */
1140 thread_info *th = inferior_thread ();
1141 th->control.step_resume_breakpoint = NULL;
1142 th->control.exception_resume_breakpoint = NULL;
1143 th->control.single_step_breakpoints = NULL;
1144 th->control.step_range_start = 0;
1145 th->control.step_range_end = 0;
1147 /* The user may have had the main thread held stopped in the
1148 previous image (e.g., schedlock on, or non-stop). Release
1150 th->stop_requested = 0;
1152 update_breakpoints_after_exec ();
1154 /* What is this a.out's name? */
1155 process_ptid = ptid_t (pid);
1156 printf_unfiltered (_("%s is executing new program: %s\n"),
1157 target_pid_to_str (process_ptid),
1160 /* We've followed the inferior through an exec. Therefore, the
1161 inferior has essentially been killed & reborn. */
1163 gdb_flush (gdb_stdout);
1165 breakpoint_init_inferior (inf_execd);
1167 gdb::unique_xmalloc_ptr<char> exec_file_host
1168 = exec_file_find (exec_file_target, NULL);
1170 /* If we were unable to map the executable target pathname onto a host
1171 pathname, tell the user that. Otherwise GDB's subsequent behavior
1172 is confusing. Maybe it would even be better to stop at this point
1173 so that the user can specify a file manually before continuing. */
1174 if (exec_file_host == NULL)
1175 warning (_("Could not load symbols for executable %s.\n"
1176 "Do you need \"set sysroot\"?"),
1179 /* Reset the shared library package. This ensures that we get a
1180 shlib event when the child reaches "_start", at which point the
1181 dld will have had a chance to initialize the child. */
1182 /* Also, loading a symbol file below may trigger symbol lookups, and
1183 we don't want those to be satisfied by the libraries of the
1184 previous incarnation of this process. */
1185 no_shared_libraries (NULL, 0);
1187 if (follow_exec_mode_string == follow_exec_mode_new)
1189 /* The user wants to keep the old inferior and program spaces
1190 around. Create a new fresh one, and switch to it. */
1192 /* Do exit processing for the original inferior before setting the new
1193 inferior's pid. Having two inferiors with the same pid would confuse
1194 find_inferior_p(t)id. Transfer the terminal state and info from the
1195 old to the new inferior. */
1196 inf = add_inferior_with_spaces ();
1197 swap_terminal_info (inf, current_inferior ());
1198 exit_inferior_silent (current_inferior ());
1201 target_follow_exec (inf, exec_file_target);
1203 set_current_inferior (inf);
1204 set_current_program_space (inf->pspace);
1209 /* The old description may no longer be fit for the new image.
1210 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1211 old description; we'll read a new one below. No need to do
1212 this on "follow-exec-mode new", as the old inferior stays
1213 around (its description is later cleared/refetched on
1215 target_clear_description ();
1218 gdb_assert (current_program_space == inf->pspace);
1220 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1221 because the proper displacement for a PIE (Position Independent
1222 Executable) main symbol file will only be computed by
1223 solib_create_inferior_hook below. breakpoint_re_set would fail
1224 to insert the breakpoints with the zero displacement. */
1225 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1227 /* If the target can specify a description, read it. Must do this
1228 after flipping to the new executable (because the target supplied
1229 description must be compatible with the executable's
1230 architecture, and the old executable may e.g., be 32-bit, while
1231 the new one 64-bit), and before anything involving memory or
1233 target_find_description ();
1235 solib_create_inferior_hook (0);
1237 jit_inferior_created_hook ();
1239 breakpoint_re_set ();
1241 /* Reinsert all breakpoints. (Those which were symbolic have
1242 been reset to the proper address in the new a.out, thanks
1243 to symbol_file_command...). */
1244 insert_breakpoints ();
1246 /* The next resume of this inferior should bring it to the shlib
1247 startup breakpoints. (If the user had also set bp's on
1248 "main" from the old (parent) process, then they'll auto-
1249 matically get reset there in the new process.). */
1252 /* The queue of threads that need to do a step-over operation to get
1253 past e.g., a breakpoint. What technique is used to step over the
1254 breakpoint/watchpoint does not matter -- all threads end up in the
1255 same queue, to maintain rough temporal order of execution, in order
1256 to avoid starvation, otherwise, we could e.g., find ourselves
1257 constantly stepping the same couple threads past their breakpoints
1258 over and over, if the single-step finish fast enough. */
1259 struct thread_info *step_over_queue_head;
1261 /* Bit flags indicating what the thread needs to step over. */
1263 enum step_over_what_flag
1265 /* Step over a breakpoint. */
1266 STEP_OVER_BREAKPOINT = 1,
1268 /* Step past a non-continuable watchpoint, in order to let the
1269 instruction execute so we can evaluate the watchpoint
1271 STEP_OVER_WATCHPOINT = 2
1273 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1275 /* Info about an instruction that is being stepped over. */
1277 struct step_over_info
1279 /* If we're stepping past a breakpoint, this is the address space
1280 and address of the instruction the breakpoint is set at. We'll
1281 skip inserting all breakpoints here. Valid iff ASPACE is
1283 const address_space *aspace;
1286 /* The instruction being stepped over triggers a nonsteppable
1287 watchpoint. If true, we'll skip inserting watchpoints. */
1288 int nonsteppable_watchpoint_p;
1290 /* The thread's global number. */
1294 /* The step-over info of the location that is being stepped over.
1296 Note that with async/breakpoint always-inserted mode, a user might
1297 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1298 being stepped over. As setting a new breakpoint inserts all
1299 breakpoints, we need to make sure the breakpoint being stepped over
1300 isn't inserted then. We do that by only clearing the step-over
1301 info when the step-over is actually finished (or aborted).
1303 Presently GDB can only step over one breakpoint at any given time.
1304 Given threads that can't run code in the same address space as the
1305 breakpoint's can't really miss the breakpoint, GDB could be taught
1306 to step-over at most one breakpoint per address space (so this info
1307 could move to the address space object if/when GDB is extended).
1308 The set of breakpoints being stepped over will normally be much
1309 smaller than the set of all breakpoints, so a flag in the
1310 breakpoint location structure would be wasteful. A separate list
1311 also saves complexity and run-time, as otherwise we'd have to go
1312 through all breakpoint locations clearing their flag whenever we
1313 start a new sequence. Similar considerations weigh against storing
1314 this info in the thread object. Plus, not all step overs actually
1315 have breakpoint locations -- e.g., stepping past a single-step
1316 breakpoint, or stepping to complete a non-continuable
1318 static struct step_over_info step_over_info;
1320 /* Record the address of the breakpoint/instruction we're currently
1322 N.B. We record the aspace and address now, instead of say just the thread,
1323 because when we need the info later the thread may be running. */
1326 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1327 int nonsteppable_watchpoint_p,
1330 step_over_info.aspace = aspace;
1331 step_over_info.address = address;
1332 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1333 step_over_info.thread = thread;
1336 /* Called when we're not longer stepping over a breakpoint / an
1337 instruction, so all breakpoints are free to be (re)inserted. */
1340 clear_step_over_info (void)
1343 fprintf_unfiltered (gdb_stdlog,
1344 "infrun: clear_step_over_info\n");
1345 step_over_info.aspace = NULL;
1346 step_over_info.address = 0;
1347 step_over_info.nonsteppable_watchpoint_p = 0;
1348 step_over_info.thread = -1;
1354 stepping_past_instruction_at (struct address_space *aspace,
1357 return (step_over_info.aspace != NULL
1358 && breakpoint_address_match (aspace, address,
1359 step_over_info.aspace,
1360 step_over_info.address));
1366 thread_is_stepping_over_breakpoint (int thread)
1368 return (step_over_info.thread != -1
1369 && thread == step_over_info.thread);
1375 stepping_past_nonsteppable_watchpoint (void)
1377 return step_over_info.nonsteppable_watchpoint_p;
1380 /* Returns true if step-over info is valid. */
1383 step_over_info_valid_p (void)
1385 return (step_over_info.aspace != NULL
1386 || stepping_past_nonsteppable_watchpoint ());
1390 /* Displaced stepping. */
1392 /* In non-stop debugging mode, we must take special care to manage
1393 breakpoints properly; in particular, the traditional strategy for
1394 stepping a thread past a breakpoint it has hit is unsuitable.
1395 'Displaced stepping' is a tactic for stepping one thread past a
1396 breakpoint it has hit while ensuring that other threads running
1397 concurrently will hit the breakpoint as they should.
1399 The traditional way to step a thread T off a breakpoint in a
1400 multi-threaded program in all-stop mode is as follows:
1402 a0) Initially, all threads are stopped, and breakpoints are not
1404 a1) We single-step T, leaving breakpoints uninserted.
1405 a2) We insert breakpoints, and resume all threads.
1407 In non-stop debugging, however, this strategy is unsuitable: we
1408 don't want to have to stop all threads in the system in order to
1409 continue or step T past a breakpoint. Instead, we use displaced
1412 n0) Initially, T is stopped, other threads are running, and
1413 breakpoints are inserted.
1414 n1) We copy the instruction "under" the breakpoint to a separate
1415 location, outside the main code stream, making any adjustments
1416 to the instruction, register, and memory state as directed by
1418 n2) We single-step T over the instruction at its new location.
1419 n3) We adjust the resulting register and memory state as directed
1420 by T's architecture. This includes resetting T's PC to point
1421 back into the main instruction stream.
1424 This approach depends on the following gdbarch methods:
1426 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1427 indicate where to copy the instruction, and how much space must
1428 be reserved there. We use these in step n1.
1430 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1431 address, and makes any necessary adjustments to the instruction,
1432 register contents, and memory. We use this in step n1.
1434 - gdbarch_displaced_step_fixup adjusts registers and memory after
1435 we have successfuly single-stepped the instruction, to yield the
1436 same effect the instruction would have had if we had executed it
1437 at its original address. We use this in step n3.
1439 The gdbarch_displaced_step_copy_insn and
1440 gdbarch_displaced_step_fixup functions must be written so that
1441 copying an instruction with gdbarch_displaced_step_copy_insn,
1442 single-stepping across the copied instruction, and then applying
1443 gdbarch_displaced_insn_fixup should have the same effects on the
1444 thread's memory and registers as stepping the instruction in place
1445 would have. Exactly which responsibilities fall to the copy and
1446 which fall to the fixup is up to the author of those functions.
1448 See the comments in gdbarch.sh for details.
1450 Note that displaced stepping and software single-step cannot
1451 currently be used in combination, although with some care I think
1452 they could be made to. Software single-step works by placing
1453 breakpoints on all possible subsequent instructions; if the
1454 displaced instruction is a PC-relative jump, those breakpoints
1455 could fall in very strange places --- on pages that aren't
1456 executable, or at addresses that are not proper instruction
1457 boundaries. (We do generally let other threads run while we wait
1458 to hit the software single-step breakpoint, and they might
1459 encounter such a corrupted instruction.) One way to work around
1460 this would be to have gdbarch_displaced_step_copy_insn fully
1461 simulate the effect of PC-relative instructions (and return NULL)
1462 on architectures that use software single-stepping.
1464 In non-stop mode, we can have independent and simultaneous step
1465 requests, so more than one thread may need to simultaneously step
1466 over a breakpoint. The current implementation assumes there is
1467 only one scratch space per process. In this case, we have to
1468 serialize access to the scratch space. If thread A wants to step
1469 over a breakpoint, but we are currently waiting for some other
1470 thread to complete a displaced step, we leave thread A stopped and
1471 place it in the displaced_step_request_queue. Whenever a displaced
1472 step finishes, we pick the next thread in the queue and start a new
1473 displaced step operation on it. See displaced_step_prepare and
1474 displaced_step_fixup for details. */
1476 /* Default destructor for displaced_step_closure. */
1478 displaced_step_closure::~displaced_step_closure () = default;
1480 /* Get the displaced stepping state of process PID. */
1482 static displaced_step_inferior_state *
1483 get_displaced_stepping_state (inferior *inf)
1485 return &inf->displaced_step_state;
1488 /* Returns true if any inferior has a thread doing a displaced
1492 displaced_step_in_progress_any_inferior ()
1494 for (inferior *i : all_inferiors ())
1496 if (i->displaced_step_state.step_thread != nullptr)
1503 /* Return true if thread represented by PTID is doing a displaced
1507 displaced_step_in_progress_thread (thread_info *thread)
1509 gdb_assert (thread != NULL);
1511 return get_displaced_stepping_state (thread->inf)->step_thread == thread;
1514 /* Return true if process PID has a thread doing a displaced step. */
1517 displaced_step_in_progress (inferior *inf)
1519 return get_displaced_stepping_state (inf)->step_thread != nullptr;
1522 /* If inferior is in displaced stepping, and ADDR equals to starting address
1523 of copy area, return corresponding displaced_step_closure. Otherwise,
1526 struct displaced_step_closure*
1527 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1529 displaced_step_inferior_state *displaced
1530 = get_displaced_stepping_state (current_inferior ());
1532 /* If checking the mode of displaced instruction in copy area. */
1533 if (displaced->step_thread != nullptr
1534 && displaced->step_copy == addr)
1535 return displaced->step_closure;
1541 infrun_inferior_exit (struct inferior *inf)
1543 inf->displaced_step_state.reset ();
1546 /* If ON, and the architecture supports it, GDB will use displaced
1547 stepping to step over breakpoints. If OFF, or if the architecture
1548 doesn't support it, GDB will instead use the traditional
1549 hold-and-step approach. If AUTO (which is the default), GDB will
1550 decide which technique to use to step over breakpoints depending on
1551 which of all-stop or non-stop mode is active --- displaced stepping
1552 in non-stop mode; hold-and-step in all-stop mode. */
1554 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1557 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1558 struct cmd_list_element *c,
1561 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1562 fprintf_filtered (file,
1563 _("Debugger's willingness to use displaced stepping "
1564 "to step over breakpoints is %s (currently %s).\n"),
1565 value, target_is_non_stop_p () ? "on" : "off");
1567 fprintf_filtered (file,
1568 _("Debugger's willingness to use displaced stepping "
1569 "to step over breakpoints is %s.\n"), value);
1572 /* Return non-zero if displaced stepping can/should be used to step
1573 over breakpoints of thread TP. */
1576 use_displaced_stepping (struct thread_info *tp)
1578 struct regcache *regcache = get_thread_regcache (tp);
1579 struct gdbarch *gdbarch = regcache->arch ();
1580 displaced_step_inferior_state *displaced_state
1581 = get_displaced_stepping_state (tp->inf);
1583 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1584 && target_is_non_stop_p ())
1585 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1586 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1587 && find_record_target () == NULL
1588 && !displaced_state->failed_before);
1591 /* Clean out any stray displaced stepping state. */
1593 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1595 /* Indicate that there is no cleanup pending. */
1596 displaced->step_thread = nullptr;
1598 delete displaced->step_closure;
1599 displaced->step_closure = NULL;
1603 displaced_step_clear_cleanup (void *arg)
1605 struct displaced_step_inferior_state *state
1606 = (struct displaced_step_inferior_state *) arg;
1608 displaced_step_clear (state);
1611 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1613 displaced_step_dump_bytes (struct ui_file *file,
1614 const gdb_byte *buf,
1619 for (i = 0; i < len; i++)
1620 fprintf_unfiltered (file, "%02x ", buf[i]);
1621 fputs_unfiltered ("\n", file);
1624 /* Prepare to single-step, using displaced stepping.
1626 Note that we cannot use displaced stepping when we have a signal to
1627 deliver. If we have a signal to deliver and an instruction to step
1628 over, then after the step, there will be no indication from the
1629 target whether the thread entered a signal handler or ignored the
1630 signal and stepped over the instruction successfully --- both cases
1631 result in a simple SIGTRAP. In the first case we mustn't do a
1632 fixup, and in the second case we must --- but we can't tell which.
1633 Comments in the code for 'random signals' in handle_inferior_event
1634 explain how we handle this case instead.
1636 Returns 1 if preparing was successful -- this thread is going to be
1637 stepped now; 0 if displaced stepping this thread got queued; or -1
1638 if this instruction can't be displaced stepped. */
1641 displaced_step_prepare_throw (thread_info *tp)
1643 regcache *regcache = get_thread_regcache (tp);
1644 struct gdbarch *gdbarch = regcache->arch ();
1645 const address_space *aspace = regcache->aspace ();
1646 CORE_ADDR original, copy;
1648 struct displaced_step_closure *closure;
1651 /* We should never reach this function if the architecture does not
1652 support displaced stepping. */
1653 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1655 /* Nor if the thread isn't meant to step over a breakpoint. */
1656 gdb_assert (tp->control.trap_expected);
1658 /* Disable range stepping while executing in the scratch pad. We
1659 want a single-step even if executing the displaced instruction in
1660 the scratch buffer lands within the stepping range (e.g., a
1662 tp->control.may_range_step = 0;
1664 /* We have to displaced step one thread at a time, as we only have
1665 access to a single scratch space per inferior. */
1667 displaced_step_inferior_state *displaced
1668 = get_displaced_stepping_state (tp->inf);
1670 if (displaced->step_thread != nullptr)
1672 /* Already waiting for a displaced step to finish. Defer this
1673 request and place in queue. */
1675 if (debug_displaced)
1676 fprintf_unfiltered (gdb_stdlog,
1677 "displaced: deferring step of %s\n",
1678 target_pid_to_str (tp->ptid));
1680 thread_step_over_chain_enqueue (tp);
1685 if (debug_displaced)
1686 fprintf_unfiltered (gdb_stdlog,
1687 "displaced: stepping %s now\n",
1688 target_pid_to_str (tp->ptid));
1691 displaced_step_clear (displaced);
1693 scoped_restore_current_thread restore_thread;
1695 switch_to_thread (tp);
1697 original = regcache_read_pc (regcache);
1699 copy = gdbarch_displaced_step_location (gdbarch);
1700 len = gdbarch_max_insn_length (gdbarch);
1702 if (breakpoint_in_range_p (aspace, copy, len))
1704 /* There's a breakpoint set in the scratch pad location range
1705 (which is usually around the entry point). We'd either
1706 install it before resuming, which would overwrite/corrupt the
1707 scratch pad, or if it was already inserted, this displaced
1708 step would overwrite it. The latter is OK in the sense that
1709 we already assume that no thread is going to execute the code
1710 in the scratch pad range (after initial startup) anyway, but
1711 the former is unacceptable. Simply punt and fallback to
1712 stepping over this breakpoint in-line. */
1713 if (debug_displaced)
1715 fprintf_unfiltered (gdb_stdlog,
1716 "displaced: breakpoint set in scratch pad. "
1717 "Stepping over breakpoint in-line instead.\n");
1723 /* Save the original contents of the copy area. */
1724 displaced->step_saved_copy.resize (len);
1725 status = target_read_memory (copy, displaced->step_saved_copy.data (), len);
1727 throw_error (MEMORY_ERROR,
1728 _("Error accessing memory address %s (%s) for "
1729 "displaced-stepping scratch space."),
1730 paddress (gdbarch, copy), safe_strerror (status));
1731 if (debug_displaced)
1733 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1734 paddress (gdbarch, copy));
1735 displaced_step_dump_bytes (gdb_stdlog,
1736 displaced->step_saved_copy.data (),
1740 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1741 original, copy, regcache);
1742 if (closure == NULL)
1744 /* The architecture doesn't know how or want to displaced step
1745 this instruction or instruction sequence. Fallback to
1746 stepping over the breakpoint in-line. */
1750 /* Save the information we need to fix things up if the step
1752 displaced->step_thread = tp;
1753 displaced->step_gdbarch = gdbarch;
1754 displaced->step_closure = closure;
1755 displaced->step_original = original;
1756 displaced->step_copy = copy;
1758 cleanup *ignore_cleanups
1759 = make_cleanup (displaced_step_clear_cleanup, displaced);
1761 /* Resume execution at the copy. */
1762 regcache_write_pc (regcache, copy);
1764 discard_cleanups (ignore_cleanups);
1766 if (debug_displaced)
1767 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1768 paddress (gdbarch, copy));
1773 /* Wrapper for displaced_step_prepare_throw that disabled further
1774 attempts at displaced stepping if we get a memory error. */
1777 displaced_step_prepare (thread_info *thread)
1783 prepared = displaced_step_prepare_throw (thread);
1785 CATCH (ex, RETURN_MASK_ERROR)
1787 struct displaced_step_inferior_state *displaced_state;
1789 if (ex.error != MEMORY_ERROR
1790 && ex.error != NOT_SUPPORTED_ERROR)
1791 throw_exception (ex);
1795 fprintf_unfiltered (gdb_stdlog,
1796 "infrun: disabling displaced stepping: %s\n",
1800 /* Be verbose if "set displaced-stepping" is "on", silent if
1802 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1804 warning (_("disabling displaced stepping: %s"),
1808 /* Disable further displaced stepping attempts. */
1810 = get_displaced_stepping_state (thread->inf);
1811 displaced_state->failed_before = 1;
1819 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1820 const gdb_byte *myaddr, int len)
1822 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1824 inferior_ptid = ptid;
1825 write_memory (memaddr, myaddr, len);
1828 /* Restore the contents of the copy area for thread PTID. */
1831 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1834 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1836 write_memory_ptid (ptid, displaced->step_copy,
1837 displaced->step_saved_copy.data (), len);
1838 if (debug_displaced)
1839 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1840 target_pid_to_str (ptid),
1841 paddress (displaced->step_gdbarch,
1842 displaced->step_copy));
1845 /* If we displaced stepped an instruction successfully, adjust
1846 registers and memory to yield the same effect the instruction would
1847 have had if we had executed it at its original address, and return
1848 1. If the instruction didn't complete, relocate the PC and return
1849 -1. If the thread wasn't displaced stepping, return 0. */
1852 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1854 struct cleanup *old_cleanups;
1855 struct displaced_step_inferior_state *displaced
1856 = get_displaced_stepping_state (event_thread->inf);
1859 /* Was this event for the thread we displaced? */
1860 if (displaced->step_thread != event_thread)
1863 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1865 displaced_step_restore (displaced, displaced->step_thread->ptid);
1867 /* Fixup may need to read memory/registers. Switch to the thread
1868 that we're fixing up. Also, target_stopped_by_watchpoint checks
1869 the current thread. */
1870 switch_to_thread (event_thread);
1872 /* Did the instruction complete successfully? */
1873 if (signal == GDB_SIGNAL_TRAP
1874 && !(target_stopped_by_watchpoint ()
1875 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1876 || target_have_steppable_watchpoint)))
1878 /* Fix up the resulting state. */
1879 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1880 displaced->step_closure,
1881 displaced->step_original,
1882 displaced->step_copy,
1883 get_thread_regcache (displaced->step_thread));
1888 /* Since the instruction didn't complete, all we can do is
1890 struct regcache *regcache = get_thread_regcache (event_thread);
1891 CORE_ADDR pc = regcache_read_pc (regcache);
1893 pc = displaced->step_original + (pc - displaced->step_copy);
1894 regcache_write_pc (regcache, pc);
1898 do_cleanups (old_cleanups);
1900 displaced->step_thread = nullptr;
1905 /* Data to be passed around while handling an event. This data is
1906 discarded between events. */
1907 struct execution_control_state
1910 /* The thread that got the event, if this was a thread event; NULL
1912 struct thread_info *event_thread;
1914 struct target_waitstatus ws;
1915 int stop_func_filled_in;
1916 CORE_ADDR stop_func_start;
1917 CORE_ADDR stop_func_end;
1918 const char *stop_func_name;
1921 /* True if the event thread hit the single-step breakpoint of
1922 another thread. Thus the event doesn't cause a stop, the thread
1923 needs to be single-stepped past the single-step breakpoint before
1924 we can switch back to the original stepping thread. */
1925 int hit_singlestep_breakpoint;
1928 /* Clear ECS and set it to point at TP. */
1931 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
1933 memset (ecs, 0, sizeof (*ecs));
1934 ecs->event_thread = tp;
1935 ecs->ptid = tp->ptid;
1938 static void keep_going_pass_signal (struct execution_control_state *ecs);
1939 static void prepare_to_wait (struct execution_control_state *ecs);
1940 static int keep_going_stepped_thread (struct thread_info *tp);
1941 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
1943 /* Are there any pending step-over requests? If so, run all we can
1944 now and return true. Otherwise, return false. */
1947 start_step_over (void)
1949 struct thread_info *tp, *next;
1951 /* Don't start a new step-over if we already have an in-line
1952 step-over operation ongoing. */
1953 if (step_over_info_valid_p ())
1956 for (tp = step_over_queue_head; tp != NULL; tp = next)
1958 struct execution_control_state ecss;
1959 struct execution_control_state *ecs = &ecss;
1960 step_over_what step_what;
1961 int must_be_in_line;
1963 gdb_assert (!tp->stop_requested);
1965 next = thread_step_over_chain_next (tp);
1967 /* If this inferior already has a displaced step in process,
1968 don't start a new one. */
1969 if (displaced_step_in_progress (tp->inf))
1972 step_what = thread_still_needs_step_over (tp);
1973 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
1974 || ((step_what & STEP_OVER_BREAKPOINT)
1975 && !use_displaced_stepping (tp)));
1977 /* We currently stop all threads of all processes to step-over
1978 in-line. If we need to start a new in-line step-over, let
1979 any pending displaced steps finish first. */
1980 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
1983 thread_step_over_chain_remove (tp);
1985 if (step_over_queue_head == NULL)
1988 fprintf_unfiltered (gdb_stdlog,
1989 "infrun: step-over queue now empty\n");
1992 if (tp->control.trap_expected
1996 internal_error (__FILE__, __LINE__,
1997 "[%s] has inconsistent state: "
1998 "trap_expected=%d, resumed=%d, executing=%d\n",
1999 target_pid_to_str (tp->ptid),
2000 tp->control.trap_expected,
2006 fprintf_unfiltered (gdb_stdlog,
2007 "infrun: resuming [%s] for step-over\n",
2008 target_pid_to_str (tp->ptid));
2010 /* keep_going_pass_signal skips the step-over if the breakpoint
2011 is no longer inserted. In all-stop, we want to keep looking
2012 for a thread that needs a step-over instead of resuming TP,
2013 because we wouldn't be able to resume anything else until the
2014 target stops again. In non-stop, the resume always resumes
2015 only TP, so it's OK to let the thread resume freely. */
2016 if (!target_is_non_stop_p () && !step_what)
2019 switch_to_thread (tp);
2020 reset_ecs (ecs, tp);
2021 keep_going_pass_signal (ecs);
2023 if (!ecs->wait_some_more)
2024 error (_("Command aborted."));
2026 gdb_assert (tp->resumed);
2028 /* If we started a new in-line step-over, we're done. */
2029 if (step_over_info_valid_p ())
2031 gdb_assert (tp->control.trap_expected);
2035 if (!target_is_non_stop_p ())
2037 /* On all-stop, shouldn't have resumed unless we needed a
2039 gdb_assert (tp->control.trap_expected
2040 || tp->step_after_step_resume_breakpoint);
2042 /* With remote targets (at least), in all-stop, we can't
2043 issue any further remote commands until the program stops
2048 /* Either the thread no longer needed a step-over, or a new
2049 displaced stepping sequence started. Even in the latter
2050 case, continue looking. Maybe we can also start another
2051 displaced step on a thread of other process. */
2057 /* Update global variables holding ptids to hold NEW_PTID if they were
2058 holding OLD_PTID. */
2060 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2062 if (inferior_ptid == old_ptid)
2063 inferior_ptid = new_ptid;
2068 static const char schedlock_off[] = "off";
2069 static const char schedlock_on[] = "on";
2070 static const char schedlock_step[] = "step";
2071 static const char schedlock_replay[] = "replay";
2072 static const char *const scheduler_enums[] = {
2079 static const char *scheduler_mode = schedlock_replay;
2081 show_scheduler_mode (struct ui_file *file, int from_tty,
2082 struct cmd_list_element *c, const char *value)
2084 fprintf_filtered (file,
2085 _("Mode for locking scheduler "
2086 "during execution is \"%s\".\n"),
2091 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2093 if (!target_can_lock_scheduler)
2095 scheduler_mode = schedlock_off;
2096 error (_("Target '%s' cannot support this command."), target_shortname);
2100 /* True if execution commands resume all threads of all processes by
2101 default; otherwise, resume only threads of the current inferior
2103 int sched_multi = 0;
2105 /* Try to setup for software single stepping over the specified location.
2106 Return 1 if target_resume() should use hardware single step.
2108 GDBARCH the current gdbarch.
2109 PC the location to step over. */
2112 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2116 if (execution_direction == EXEC_FORWARD
2117 && gdbarch_software_single_step_p (gdbarch))
2118 hw_step = !insert_single_step_breakpoints (gdbarch);
2126 user_visible_resume_ptid (int step)
2132 /* With non-stop mode on, threads are always handled
2134 resume_ptid = inferior_ptid;
2136 else if ((scheduler_mode == schedlock_on)
2137 || (scheduler_mode == schedlock_step && step))
2139 /* User-settable 'scheduler' mode requires solo thread
2141 resume_ptid = inferior_ptid;
2143 else if ((scheduler_mode == schedlock_replay)
2144 && target_record_will_replay (minus_one_ptid, execution_direction))
2146 /* User-settable 'scheduler' mode requires solo thread resume in replay
2148 resume_ptid = inferior_ptid;
2150 else if (!sched_multi && target_supports_multi_process ())
2152 /* Resume all threads of the current process (and none of other
2154 resume_ptid = ptid_t (inferior_ptid.pid ());
2158 /* Resume all threads of all processes. */
2159 resume_ptid = RESUME_ALL;
2165 /* Return a ptid representing the set of threads that we will resume,
2166 in the perspective of the target, assuming run control handling
2167 does not require leaving some threads stopped (e.g., stepping past
2168 breakpoint). USER_STEP indicates whether we're about to start the
2169 target for a stepping command. */
2172 internal_resume_ptid (int user_step)
2174 /* In non-stop, we always control threads individually. Note that
2175 the target may always work in non-stop mode even with "set
2176 non-stop off", in which case user_visible_resume_ptid could
2177 return a wildcard ptid. */
2178 if (target_is_non_stop_p ())
2179 return inferior_ptid;
2181 return user_visible_resume_ptid (user_step);
2184 /* Wrapper for target_resume, that handles infrun-specific
2188 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2190 struct thread_info *tp = inferior_thread ();
2192 gdb_assert (!tp->stop_requested);
2194 /* Install inferior's terminal modes. */
2195 target_terminal::inferior ();
2197 /* Avoid confusing the next resume, if the next stop/resume
2198 happens to apply to another thread. */
2199 tp->suspend.stop_signal = GDB_SIGNAL_0;
2201 /* Advise target which signals may be handled silently.
2203 If we have removed breakpoints because we are stepping over one
2204 in-line (in any thread), we need to receive all signals to avoid
2205 accidentally skipping a breakpoint during execution of a signal
2208 Likewise if we're displaced stepping, otherwise a trap for a
2209 breakpoint in a signal handler might be confused with the
2210 displaced step finishing. We don't make the displaced_step_fixup
2211 step distinguish the cases instead, because:
2213 - a backtrace while stopped in the signal handler would show the
2214 scratch pad as frame older than the signal handler, instead of
2215 the real mainline code.
2217 - when the thread is later resumed, the signal handler would
2218 return to the scratch pad area, which would no longer be
2220 if (step_over_info_valid_p ()
2221 || displaced_step_in_progress (tp->inf))
2222 target_pass_signals (0, NULL);
2224 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2226 target_resume (resume_ptid, step, sig);
2228 target_commit_resume ();
2231 /* Resume the inferior. SIG is the signal to give the inferior
2232 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2233 call 'resume', which handles exceptions. */
2236 resume_1 (enum gdb_signal sig)
2238 struct regcache *regcache = get_current_regcache ();
2239 struct gdbarch *gdbarch = regcache->arch ();
2240 struct thread_info *tp = inferior_thread ();
2241 CORE_ADDR pc = regcache_read_pc (regcache);
2242 const address_space *aspace = regcache->aspace ();
2244 /* This represents the user's step vs continue request. When
2245 deciding whether "set scheduler-locking step" applies, it's the
2246 user's intention that counts. */
2247 const int user_step = tp->control.stepping_command;
2248 /* This represents what we'll actually request the target to do.
2249 This can decay from a step to a continue, if e.g., we need to
2250 implement single-stepping with breakpoints (software
2254 gdb_assert (!tp->stop_requested);
2255 gdb_assert (!thread_is_in_step_over_chain (tp));
2257 if (tp->suspend.waitstatus_pending_p)
2262 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2264 fprintf_unfiltered (gdb_stdlog,
2265 "infrun: resume: thread %s has pending wait "
2266 "status %s (currently_stepping=%d).\n",
2267 target_pid_to_str (tp->ptid), statstr.c_str (),
2268 currently_stepping (tp));
2273 /* FIXME: What should we do if we are supposed to resume this
2274 thread with a signal? Maybe we should maintain a queue of
2275 pending signals to deliver. */
2276 if (sig != GDB_SIGNAL_0)
2278 warning (_("Couldn't deliver signal %s to %s."),
2279 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2282 tp->suspend.stop_signal = GDB_SIGNAL_0;
2284 if (target_can_async_p ())
2287 /* Tell the event loop we have an event to process. */
2288 mark_async_event_handler (infrun_async_inferior_event_token);
2293 tp->stepped_breakpoint = 0;
2295 /* Depends on stepped_breakpoint. */
2296 step = currently_stepping (tp);
2298 if (current_inferior ()->waiting_for_vfork_done)
2300 /* Don't try to single-step a vfork parent that is waiting for
2301 the child to get out of the shared memory region (by exec'ing
2302 or exiting). This is particularly important on software
2303 single-step archs, as the child process would trip on the
2304 software single step breakpoint inserted for the parent
2305 process. Since the parent will not actually execute any
2306 instruction until the child is out of the shared region (such
2307 are vfork's semantics), it is safe to simply continue it.
2308 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2309 the parent, and tell it to `keep_going', which automatically
2310 re-sets it stepping. */
2312 fprintf_unfiltered (gdb_stdlog,
2313 "infrun: resume : clear step\n");
2318 fprintf_unfiltered (gdb_stdlog,
2319 "infrun: resume (step=%d, signal=%s), "
2320 "trap_expected=%d, current thread [%s] at %s\n",
2321 step, gdb_signal_to_symbol_string (sig),
2322 tp->control.trap_expected,
2323 target_pid_to_str (inferior_ptid),
2324 paddress (gdbarch, pc));
2326 /* Normally, by the time we reach `resume', the breakpoints are either
2327 removed or inserted, as appropriate. The exception is if we're sitting
2328 at a permanent breakpoint; we need to step over it, but permanent
2329 breakpoints can't be removed. So we have to test for it here. */
2330 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2332 if (sig != GDB_SIGNAL_0)
2334 /* We have a signal to pass to the inferior. The resume
2335 may, or may not take us to the signal handler. If this
2336 is a step, we'll need to stop in the signal handler, if
2337 there's one, (if the target supports stepping into
2338 handlers), or in the next mainline instruction, if
2339 there's no handler. If this is a continue, we need to be
2340 sure to run the handler with all breakpoints inserted.
2341 In all cases, set a breakpoint at the current address
2342 (where the handler returns to), and once that breakpoint
2343 is hit, resume skipping the permanent breakpoint. If
2344 that breakpoint isn't hit, then we've stepped into the
2345 signal handler (or hit some other event). We'll delete
2346 the step-resume breakpoint then. */
2349 fprintf_unfiltered (gdb_stdlog,
2350 "infrun: resume: skipping permanent breakpoint, "
2351 "deliver signal first\n");
2353 clear_step_over_info ();
2354 tp->control.trap_expected = 0;
2356 if (tp->control.step_resume_breakpoint == NULL)
2358 /* Set a "high-priority" step-resume, as we don't want
2359 user breakpoints at PC to trigger (again) when this
2361 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2362 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2364 tp->step_after_step_resume_breakpoint = step;
2367 insert_breakpoints ();
2371 /* There's no signal to pass, we can go ahead and skip the
2372 permanent breakpoint manually. */
2374 fprintf_unfiltered (gdb_stdlog,
2375 "infrun: resume: skipping permanent breakpoint\n");
2376 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2377 /* Update pc to reflect the new address from which we will
2378 execute instructions. */
2379 pc = regcache_read_pc (regcache);
2383 /* We've already advanced the PC, so the stepping part
2384 is done. Now we need to arrange for a trap to be
2385 reported to handle_inferior_event. Set a breakpoint
2386 at the current PC, and run to it. Don't update
2387 prev_pc, because if we end in
2388 switch_back_to_stepped_thread, we want the "expected
2389 thread advanced also" branch to be taken. IOW, we
2390 don't want this thread to step further from PC
2392 gdb_assert (!step_over_info_valid_p ());
2393 insert_single_step_breakpoint (gdbarch, aspace, pc);
2394 insert_breakpoints ();
2396 resume_ptid = internal_resume_ptid (user_step);
2397 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2404 /* If we have a breakpoint to step over, make sure to do a single
2405 step only. Same if we have software watchpoints. */
2406 if (tp->control.trap_expected || bpstat_should_step ())
2407 tp->control.may_range_step = 0;
2409 /* If enabled, step over breakpoints by executing a copy of the
2410 instruction at a different address.
2412 We can't use displaced stepping when we have a signal to deliver;
2413 the comments for displaced_step_prepare explain why. The
2414 comments in the handle_inferior event for dealing with 'random
2415 signals' explain what we do instead.
2417 We can't use displaced stepping when we are waiting for vfork_done
2418 event, displaced stepping breaks the vfork child similarly as single
2419 step software breakpoint. */
2420 if (tp->control.trap_expected
2421 && use_displaced_stepping (tp)
2422 && !step_over_info_valid_p ()
2423 && sig == GDB_SIGNAL_0
2424 && !current_inferior ()->waiting_for_vfork_done)
2426 int prepared = displaced_step_prepare (tp);
2431 fprintf_unfiltered (gdb_stdlog,
2432 "Got placed in step-over queue\n");
2434 tp->control.trap_expected = 0;
2437 else if (prepared < 0)
2439 /* Fallback to stepping over the breakpoint in-line. */
2441 if (target_is_non_stop_p ())
2442 stop_all_threads ();
2444 set_step_over_info (regcache->aspace (),
2445 regcache_read_pc (regcache), 0, tp->global_num);
2447 step = maybe_software_singlestep (gdbarch, pc);
2449 insert_breakpoints ();
2451 else if (prepared > 0)
2453 struct displaced_step_inferior_state *displaced;
2455 /* Update pc to reflect the new address from which we will
2456 execute instructions due to displaced stepping. */
2457 pc = regcache_read_pc (get_thread_regcache (tp));
2459 displaced = get_displaced_stepping_state (tp->inf);
2460 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2461 displaced->step_closure);
2465 /* Do we need to do it the hard way, w/temp breakpoints? */
2467 step = maybe_software_singlestep (gdbarch, pc);
2469 /* Currently, our software single-step implementation leads to different
2470 results than hardware single-stepping in one situation: when stepping
2471 into delivering a signal which has an associated signal handler,
2472 hardware single-step will stop at the first instruction of the handler,
2473 while software single-step will simply skip execution of the handler.
2475 For now, this difference in behavior is accepted since there is no
2476 easy way to actually implement single-stepping into a signal handler
2477 without kernel support.
2479 However, there is one scenario where this difference leads to follow-on
2480 problems: if we're stepping off a breakpoint by removing all breakpoints
2481 and then single-stepping. In this case, the software single-step
2482 behavior means that even if there is a *breakpoint* in the signal
2483 handler, GDB still would not stop.
2485 Fortunately, we can at least fix this particular issue. We detect
2486 here the case where we are about to deliver a signal while software
2487 single-stepping with breakpoints removed. In this situation, we
2488 revert the decisions to remove all breakpoints and insert single-
2489 step breakpoints, and instead we install a step-resume breakpoint
2490 at the current address, deliver the signal without stepping, and
2491 once we arrive back at the step-resume breakpoint, actually step
2492 over the breakpoint we originally wanted to step over. */
2493 if (thread_has_single_step_breakpoints_set (tp)
2494 && sig != GDB_SIGNAL_0
2495 && step_over_info_valid_p ())
2497 /* If we have nested signals or a pending signal is delivered
2498 immediately after a handler returns, might might already have
2499 a step-resume breakpoint set on the earlier handler. We cannot
2500 set another step-resume breakpoint; just continue on until the
2501 original breakpoint is hit. */
2502 if (tp->control.step_resume_breakpoint == NULL)
2504 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2505 tp->step_after_step_resume_breakpoint = 1;
2508 delete_single_step_breakpoints (tp);
2510 clear_step_over_info ();
2511 tp->control.trap_expected = 0;
2513 insert_breakpoints ();
2516 /* If STEP is set, it's a request to use hardware stepping
2517 facilities. But in that case, we should never
2518 use singlestep breakpoint. */
2519 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2521 /* Decide the set of threads to ask the target to resume. */
2522 if (tp->control.trap_expected)
2524 /* We're allowing a thread to run past a breakpoint it has
2525 hit, either by single-stepping the thread with the breakpoint
2526 removed, or by displaced stepping, with the breakpoint inserted.
2527 In the former case, we need to single-step only this thread,
2528 and keep others stopped, as they can miss this breakpoint if
2529 allowed to run. That's not really a problem for displaced
2530 stepping, but, we still keep other threads stopped, in case
2531 another thread is also stopped for a breakpoint waiting for
2532 its turn in the displaced stepping queue. */
2533 resume_ptid = inferior_ptid;
2536 resume_ptid = internal_resume_ptid (user_step);
2538 if (execution_direction != EXEC_REVERSE
2539 && step && breakpoint_inserted_here_p (aspace, pc))
2541 /* There are two cases where we currently need to step a
2542 breakpoint instruction when we have a signal to deliver:
2544 - See handle_signal_stop where we handle random signals that
2545 could take out us out of the stepping range. Normally, in
2546 that case we end up continuing (instead of stepping) over the
2547 signal handler with a breakpoint at PC, but there are cases
2548 where we should _always_ single-step, even if we have a
2549 step-resume breakpoint, like when a software watchpoint is
2550 set. Assuming single-stepping and delivering a signal at the
2551 same time would takes us to the signal handler, then we could
2552 have removed the breakpoint at PC to step over it. However,
2553 some hardware step targets (like e.g., Mac OS) can't step
2554 into signal handlers, and for those, we need to leave the
2555 breakpoint at PC inserted, as otherwise if the handler
2556 recurses and executes PC again, it'll miss the breakpoint.
2557 So we leave the breakpoint inserted anyway, but we need to
2558 record that we tried to step a breakpoint instruction, so
2559 that adjust_pc_after_break doesn't end up confused.
2561 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2562 in one thread after another thread that was stepping had been
2563 momentarily paused for a step-over. When we re-resume the
2564 stepping thread, it may be resumed from that address with a
2565 breakpoint that hasn't trapped yet. Seen with
2566 gdb.threads/non-stop-fair-events.exp, on targets that don't
2567 do displaced stepping. */
2570 fprintf_unfiltered (gdb_stdlog,
2571 "infrun: resume: [%s] stepped breakpoint\n",
2572 target_pid_to_str (tp->ptid));
2574 tp->stepped_breakpoint = 1;
2576 /* Most targets can step a breakpoint instruction, thus
2577 executing it normally. But if this one cannot, just
2578 continue and we will hit it anyway. */
2579 if (gdbarch_cannot_step_breakpoint (gdbarch))
2584 && tp->control.trap_expected
2585 && use_displaced_stepping (tp)
2586 && !step_over_info_valid_p ())
2588 struct regcache *resume_regcache = get_thread_regcache (tp);
2589 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2590 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2593 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2594 paddress (resume_gdbarch, actual_pc));
2595 read_memory (actual_pc, buf, sizeof (buf));
2596 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2599 if (tp->control.may_range_step)
2601 /* If we're resuming a thread with the PC out of the step
2602 range, then we're doing some nested/finer run control
2603 operation, like stepping the thread out of the dynamic
2604 linker or the displaced stepping scratch pad. We
2605 shouldn't have allowed a range step then. */
2606 gdb_assert (pc_in_thread_step_range (pc, tp));
2609 do_target_resume (resume_ptid, step, sig);
2613 /* Resume the inferior. SIG is the signal to give the inferior
2614 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2615 rolls back state on error. */
2618 resume (gdb_signal sig)
2624 CATCH (ex, RETURN_MASK_ALL)
2626 /* If resuming is being aborted for any reason, delete any
2627 single-step breakpoint resume_1 may have created, to avoid
2628 confusing the following resumption, and to avoid leaving
2629 single-step breakpoints perturbing other threads, in case
2630 we're running in non-stop mode. */
2631 if (inferior_ptid != null_ptid)
2632 delete_single_step_breakpoints (inferior_thread ());
2633 throw_exception (ex);
2643 /* Counter that tracks number of user visible stops. This can be used
2644 to tell whether a command has proceeded the inferior past the
2645 current location. This allows e.g., inferior function calls in
2646 breakpoint commands to not interrupt the command list. When the
2647 call finishes successfully, the inferior is standing at the same
2648 breakpoint as if nothing happened (and so we don't call
2650 static ULONGEST current_stop_id;
2657 return current_stop_id;
2660 /* Called when we report a user visible stop. */
2668 /* Clear out all variables saying what to do when inferior is continued.
2669 First do this, then set the ones you want, then call `proceed'. */
2672 clear_proceed_status_thread (struct thread_info *tp)
2675 fprintf_unfiltered (gdb_stdlog,
2676 "infrun: clear_proceed_status_thread (%s)\n",
2677 target_pid_to_str (tp->ptid));
2679 /* If we're starting a new sequence, then the previous finished
2680 single-step is no longer relevant. */
2681 if (tp->suspend.waitstatus_pending_p)
2683 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2686 fprintf_unfiltered (gdb_stdlog,
2687 "infrun: clear_proceed_status: pending "
2688 "event of %s was a finished step. "
2690 target_pid_to_str (tp->ptid));
2692 tp->suspend.waitstatus_pending_p = 0;
2693 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2695 else if (debug_infrun)
2698 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2700 fprintf_unfiltered (gdb_stdlog,
2701 "infrun: clear_proceed_status_thread: thread %s "
2702 "has pending wait status %s "
2703 "(currently_stepping=%d).\n",
2704 target_pid_to_str (tp->ptid), statstr.c_str (),
2705 currently_stepping (tp));
2709 /* If this signal should not be seen by program, give it zero.
2710 Used for debugging signals. */
2711 if (!signal_pass_state (tp->suspend.stop_signal))
2712 tp->suspend.stop_signal = GDB_SIGNAL_0;
2714 thread_fsm_delete (tp->thread_fsm);
2715 tp->thread_fsm = NULL;
2717 tp->control.trap_expected = 0;
2718 tp->control.step_range_start = 0;
2719 tp->control.step_range_end = 0;
2720 tp->control.may_range_step = 0;
2721 tp->control.step_frame_id = null_frame_id;
2722 tp->control.step_stack_frame_id = null_frame_id;
2723 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2724 tp->control.step_start_function = NULL;
2725 tp->stop_requested = 0;
2727 tp->control.stop_step = 0;
2729 tp->control.proceed_to_finish = 0;
2731 tp->control.stepping_command = 0;
2733 /* Discard any remaining commands or status from previous stop. */
2734 bpstat_clear (&tp->control.stop_bpstat);
2738 clear_proceed_status (int step)
2740 /* With scheduler-locking replay, stop replaying other threads if we're
2741 not replaying the user-visible resume ptid.
2743 This is a convenience feature to not require the user to explicitly
2744 stop replaying the other threads. We're assuming that the user's
2745 intent is to resume tracing the recorded process. */
2746 if (!non_stop && scheduler_mode == schedlock_replay
2747 && target_record_is_replaying (minus_one_ptid)
2748 && !target_record_will_replay (user_visible_resume_ptid (step),
2749 execution_direction))
2750 target_record_stop_replaying ();
2752 if (!non_stop && inferior_ptid != null_ptid)
2754 ptid_t resume_ptid = user_visible_resume_ptid (step);
2756 /* In all-stop mode, delete the per-thread status of all threads
2757 we're about to resume, implicitly and explicitly. */
2758 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2759 clear_proceed_status_thread (tp);
2762 if (inferior_ptid != null_ptid)
2764 struct inferior *inferior;
2768 /* If in non-stop mode, only delete the per-thread status of
2769 the current thread. */
2770 clear_proceed_status_thread (inferior_thread ());
2773 inferior = current_inferior ();
2774 inferior->control.stop_soon = NO_STOP_QUIETLY;
2777 gdb::observers::about_to_proceed.notify ();
2780 /* Returns true if TP is still stopped at a breakpoint that needs
2781 stepping-over in order to make progress. If the breakpoint is gone
2782 meanwhile, we can skip the whole step-over dance. */
2785 thread_still_needs_step_over_bp (struct thread_info *tp)
2787 if (tp->stepping_over_breakpoint)
2789 struct regcache *regcache = get_thread_regcache (tp);
2791 if (breakpoint_here_p (regcache->aspace (),
2792 regcache_read_pc (regcache))
2793 == ordinary_breakpoint_here)
2796 tp->stepping_over_breakpoint = 0;
2802 /* Check whether thread TP still needs to start a step-over in order
2803 to make progress when resumed. Returns an bitwise or of enum
2804 step_over_what bits, indicating what needs to be stepped over. */
2806 static step_over_what
2807 thread_still_needs_step_over (struct thread_info *tp)
2809 step_over_what what = 0;
2811 if (thread_still_needs_step_over_bp (tp))
2812 what |= STEP_OVER_BREAKPOINT;
2814 if (tp->stepping_over_watchpoint
2815 && !target_have_steppable_watchpoint)
2816 what |= STEP_OVER_WATCHPOINT;
2821 /* Returns true if scheduler locking applies. STEP indicates whether
2822 we're about to do a step/next-like command to a thread. */
2825 schedlock_applies (struct thread_info *tp)
2827 return (scheduler_mode == schedlock_on
2828 || (scheduler_mode == schedlock_step
2829 && tp->control.stepping_command)
2830 || (scheduler_mode == schedlock_replay
2831 && target_record_will_replay (minus_one_ptid,
2832 execution_direction)));
2835 /* Basic routine for continuing the program in various fashions.
2837 ADDR is the address to resume at, or -1 for resume where stopped.
2838 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2839 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2841 You should call clear_proceed_status before calling proceed. */
2844 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2846 struct regcache *regcache;
2847 struct gdbarch *gdbarch;
2850 struct execution_control_state ecss;
2851 struct execution_control_state *ecs = &ecss;
2854 /* If we're stopped at a fork/vfork, follow the branch set by the
2855 "set follow-fork-mode" command; otherwise, we'll just proceed
2856 resuming the current thread. */
2857 if (!follow_fork ())
2859 /* The target for some reason decided not to resume. */
2861 if (target_can_async_p ())
2862 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2866 /* We'll update this if & when we switch to a new thread. */
2867 previous_inferior_ptid = inferior_ptid;
2869 regcache = get_current_regcache ();
2870 gdbarch = regcache->arch ();
2871 const address_space *aspace = regcache->aspace ();
2873 pc = regcache_read_pc (regcache);
2874 thread_info *cur_thr = inferior_thread ();
2876 /* Fill in with reasonable starting values. */
2877 init_thread_stepping_state (cur_thr);
2879 gdb_assert (!thread_is_in_step_over_chain (cur_thr));
2881 if (addr == (CORE_ADDR) -1)
2883 if (pc == cur_thr->suspend.stop_pc
2884 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2885 && execution_direction != EXEC_REVERSE)
2886 /* There is a breakpoint at the address we will resume at,
2887 step one instruction before inserting breakpoints so that
2888 we do not stop right away (and report a second hit at this
2891 Note, we don't do this in reverse, because we won't
2892 actually be executing the breakpoint insn anyway.
2893 We'll be (un-)executing the previous instruction. */
2894 cur_thr->stepping_over_breakpoint = 1;
2895 else if (gdbarch_single_step_through_delay_p (gdbarch)
2896 && gdbarch_single_step_through_delay (gdbarch,
2897 get_current_frame ()))
2898 /* We stepped onto an instruction that needs to be stepped
2899 again before re-inserting the breakpoint, do so. */
2900 cur_thr->stepping_over_breakpoint = 1;
2904 regcache_write_pc (regcache, addr);
2907 if (siggnal != GDB_SIGNAL_DEFAULT)
2908 cur_thr->suspend.stop_signal = siggnal;
2910 resume_ptid = user_visible_resume_ptid (cur_thr->control.stepping_command);
2912 /* If an exception is thrown from this point on, make sure to
2913 propagate GDB's knowledge of the executing state to the
2914 frontend/user running state. */
2915 scoped_finish_thread_state finish_state (resume_ptid);
2917 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2918 threads (e.g., we might need to set threads stepping over
2919 breakpoints first), from the user/frontend's point of view, all
2920 threads in RESUME_PTID are now running. Unless we're calling an
2921 inferior function, as in that case we pretend the inferior
2922 doesn't run at all. */
2923 if (!cur_thr->control.in_infcall)
2924 set_running (resume_ptid, 1);
2927 fprintf_unfiltered (gdb_stdlog,
2928 "infrun: proceed (addr=%s, signal=%s)\n",
2929 paddress (gdbarch, addr),
2930 gdb_signal_to_symbol_string (siggnal));
2932 annotate_starting ();
2934 /* Make sure that output from GDB appears before output from the
2936 gdb_flush (gdb_stdout);
2938 /* Since we've marked the inferior running, give it the terminal. A
2939 QUIT/Ctrl-C from here on is forwarded to the target (which can
2940 still detect attempts to unblock a stuck connection with repeated
2941 Ctrl-C from within target_pass_ctrlc). */
2942 target_terminal::inferior ();
2944 /* In a multi-threaded task we may select another thread and
2945 then continue or step.
2947 But if a thread that we're resuming had stopped at a breakpoint,
2948 it will immediately cause another breakpoint stop without any
2949 execution (i.e. it will report a breakpoint hit incorrectly). So
2950 we must step over it first.
2952 Look for threads other than the current (TP) that reported a
2953 breakpoint hit and haven't been resumed yet since. */
2955 /* If scheduler locking applies, we can avoid iterating over all
2957 if (!non_stop && !schedlock_applies (cur_thr))
2959 for (thread_info *tp : all_non_exited_threads (resume_ptid))
2961 /* Ignore the current thread here. It's handled
2966 if (!thread_still_needs_step_over (tp))
2969 gdb_assert (!thread_is_in_step_over_chain (tp));
2972 fprintf_unfiltered (gdb_stdlog,
2973 "infrun: need to step-over [%s] first\n",
2974 target_pid_to_str (tp->ptid));
2976 thread_step_over_chain_enqueue (tp);
2980 /* Enqueue the current thread last, so that we move all other
2981 threads over their breakpoints first. */
2982 if (cur_thr->stepping_over_breakpoint)
2983 thread_step_over_chain_enqueue (cur_thr);
2985 /* If the thread isn't started, we'll still need to set its prev_pc,
2986 so that switch_back_to_stepped_thread knows the thread hasn't
2987 advanced. Must do this before resuming any thread, as in
2988 all-stop/remote, once we resume we can't send any other packet
2989 until the target stops again. */
2990 cur_thr->prev_pc = regcache_read_pc (regcache);
2993 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
2995 started = start_step_over ();
2997 if (step_over_info_valid_p ())
2999 /* Either this thread started a new in-line step over, or some
3000 other thread was already doing one. In either case, don't
3001 resume anything else until the step-over is finished. */
3003 else if (started && !target_is_non_stop_p ())
3005 /* A new displaced stepping sequence was started. In all-stop,
3006 we can't talk to the target anymore until it next stops. */
3008 else if (!non_stop && target_is_non_stop_p ())
3010 /* In all-stop, but the target is always in non-stop mode.
3011 Start all other threads that are implicitly resumed too. */
3012 for (thread_info *tp : all_non_exited_threads (resume_ptid))
3017 fprintf_unfiltered (gdb_stdlog,
3018 "infrun: proceed: [%s] resumed\n",
3019 target_pid_to_str (tp->ptid));
3020 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3024 if (thread_is_in_step_over_chain (tp))
3027 fprintf_unfiltered (gdb_stdlog,
3028 "infrun: proceed: [%s] needs step-over\n",
3029 target_pid_to_str (tp->ptid));
3034 fprintf_unfiltered (gdb_stdlog,
3035 "infrun: proceed: resuming %s\n",
3036 target_pid_to_str (tp->ptid));
3038 reset_ecs (ecs, tp);
3039 switch_to_thread (tp);
3040 keep_going_pass_signal (ecs);
3041 if (!ecs->wait_some_more)
3042 error (_("Command aborted."));
3045 else if (!cur_thr->resumed && !thread_is_in_step_over_chain (cur_thr))
3047 /* The thread wasn't started, and isn't queued, run it now. */
3048 reset_ecs (ecs, cur_thr);
3049 switch_to_thread (cur_thr);
3050 keep_going_pass_signal (ecs);
3051 if (!ecs->wait_some_more)
3052 error (_("Command aborted."));
3056 target_commit_resume ();
3058 finish_state.release ();
3060 /* Tell the event loop to wait for it to stop. If the target
3061 supports asynchronous execution, it'll do this from within
3063 if (!target_can_async_p ())
3064 mark_async_event_handler (infrun_async_inferior_event_token);
3068 /* Start remote-debugging of a machine over a serial link. */
3071 start_remote (int from_tty)
3073 struct inferior *inferior;
3075 inferior = current_inferior ();
3076 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3078 /* Always go on waiting for the target, regardless of the mode. */
3079 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3080 indicate to wait_for_inferior that a target should timeout if
3081 nothing is returned (instead of just blocking). Because of this,
3082 targets expecting an immediate response need to, internally, set
3083 things up so that the target_wait() is forced to eventually
3085 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3086 differentiate to its caller what the state of the target is after
3087 the initial open has been performed. Here we're assuming that
3088 the target has stopped. It should be possible to eventually have
3089 target_open() return to the caller an indication that the target
3090 is currently running and GDB state should be set to the same as
3091 for an async run. */
3092 wait_for_inferior ();
3094 /* Now that the inferior has stopped, do any bookkeeping like
3095 loading shared libraries. We want to do this before normal_stop,
3096 so that the displayed frame is up to date. */
3097 post_create_inferior (current_top_target (), from_tty);
3102 /* Initialize static vars when a new inferior begins. */
3105 init_wait_for_inferior (void)
3107 /* These are meaningless until the first time through wait_for_inferior. */
3109 breakpoint_init_inferior (inf_starting);
3111 clear_proceed_status (0);
3113 target_last_wait_ptid = minus_one_ptid;
3115 previous_inferior_ptid = inferior_ptid;
3120 static void handle_inferior_event (struct execution_control_state *ecs);
3122 static void handle_step_into_function (struct gdbarch *gdbarch,
3123 struct execution_control_state *ecs);
3124 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3125 struct execution_control_state *ecs);
3126 static void handle_signal_stop (struct execution_control_state *ecs);
3127 static void check_exception_resume (struct execution_control_state *,
3128 struct frame_info *);
3130 static void end_stepping_range (struct execution_control_state *ecs);
3131 static void stop_waiting (struct execution_control_state *ecs);
3132 static void keep_going (struct execution_control_state *ecs);
3133 static void process_event_stop_test (struct execution_control_state *ecs);
3134 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3136 /* This function is attached as a "thread_stop_requested" observer.
3137 Cleanup local state that assumed the PTID was to be resumed, and
3138 report the stop to the frontend. */
3141 infrun_thread_stop_requested (ptid_t ptid)
3143 /* PTID was requested to stop. If the thread was already stopped,
3144 but the user/frontend doesn't know about that yet (e.g., the
3145 thread had been temporarily paused for some step-over), set up
3146 for reporting the stop now. */
3147 for (thread_info *tp : all_threads (ptid))
3149 if (tp->state != THREAD_RUNNING)
3154 /* Remove matching threads from the step-over queue, so
3155 start_step_over doesn't try to resume them
3157 if (thread_is_in_step_over_chain (tp))
3158 thread_step_over_chain_remove (tp);
3160 /* If the thread is stopped, but the user/frontend doesn't
3161 know about that yet, queue a pending event, as if the
3162 thread had just stopped now. Unless the thread already had
3164 if (!tp->suspend.waitstatus_pending_p)
3166 tp->suspend.waitstatus_pending_p = 1;
3167 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3168 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3171 /* Clear the inline-frame state, since we're re-processing the
3173 clear_inline_frame_state (tp->ptid);
3175 /* If this thread was paused because some other thread was
3176 doing an inline-step over, let that finish first. Once
3177 that happens, we'll restart all threads and consume pending
3178 stop events then. */
3179 if (step_over_info_valid_p ())
3182 /* Otherwise we can process the (new) pending event now. Set
3183 it so this pending event is considered by
3190 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3192 if (target_last_wait_ptid == tp->ptid)
3193 nullify_last_target_wait_ptid ();
3196 /* Delete the step resume, single-step and longjmp/exception resume
3197 breakpoints of TP. */
3200 delete_thread_infrun_breakpoints (struct thread_info *tp)
3202 delete_step_resume_breakpoint (tp);
3203 delete_exception_resume_breakpoint (tp);
3204 delete_single_step_breakpoints (tp);
3207 /* If the target still has execution, call FUNC for each thread that
3208 just stopped. In all-stop, that's all the non-exited threads; in
3209 non-stop, that's the current thread, only. */
3211 typedef void (*for_each_just_stopped_thread_callback_func)
3212 (struct thread_info *tp);
3215 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3217 if (!target_has_execution || inferior_ptid == null_ptid)
3220 if (target_is_non_stop_p ())
3222 /* If in non-stop mode, only the current thread stopped. */
3223 func (inferior_thread ());
3227 /* In all-stop mode, all threads have stopped. */
3228 for (thread_info *tp : all_non_exited_threads ())
3233 /* Delete the step resume and longjmp/exception resume breakpoints of
3234 the threads that just stopped. */
3237 delete_just_stopped_threads_infrun_breakpoints (void)
3239 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3242 /* Delete the single-step breakpoints of the threads that just
3246 delete_just_stopped_threads_single_step_breakpoints (void)
3248 for_each_just_stopped_thread (delete_single_step_breakpoints);
3254 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3255 const struct target_waitstatus *ws)
3257 std::string status_string = target_waitstatus_to_string (ws);
3260 /* The text is split over several lines because it was getting too long.
3261 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3262 output as a unit; we want only one timestamp printed if debug_timestamp
3265 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3268 waiton_ptid.tid ());
3269 if (waiton_ptid.pid () != -1)
3270 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3271 stb.printf (", status) =\n");
3272 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3276 target_pid_to_str (result_ptid));
3277 stb.printf ("infrun: %s\n", status_string.c_str ());
3279 /* This uses %s in part to handle %'s in the text, but also to avoid
3280 a gcc error: the format attribute requires a string literal. */
3281 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3284 /* Select a thread at random, out of those which are resumed and have
3287 static struct thread_info *
3288 random_pending_event_thread (ptid_t waiton_ptid)
3292 auto has_event = [] (thread_info *tp)
3295 && tp->suspend.waitstatus_pending_p);
3298 /* First see how many events we have. Count only resumed threads
3299 that have an event pending. */
3300 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3304 if (num_events == 0)
3307 /* Now randomly pick a thread out of those that have had events. */
3308 int random_selector = (int) ((num_events * (double) rand ())
3309 / (RAND_MAX + 1.0));
3311 if (debug_infrun && num_events > 1)
3312 fprintf_unfiltered (gdb_stdlog,
3313 "infrun: Found %d events, selecting #%d\n",
3314 num_events, random_selector);
3316 /* Select the Nth thread that has had an event. */
3317 for (thread_info *tp : all_non_exited_threads (waiton_ptid))
3319 if (random_selector-- == 0)
3322 gdb_assert_not_reached ("event thread not found");
3325 /* Wrapper for target_wait that first checks whether threads have
3326 pending statuses to report before actually asking the target for
3330 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3333 struct thread_info *tp;
3335 /* First check if there is a resumed thread with a wait status
3337 if (ptid == minus_one_ptid || ptid.is_pid ())
3339 tp = random_pending_event_thread (ptid);
3344 fprintf_unfiltered (gdb_stdlog,
3345 "infrun: Waiting for specific thread %s.\n",
3346 target_pid_to_str (ptid));
3348 /* We have a specific thread to check. */
3349 tp = find_thread_ptid (ptid);
3350 gdb_assert (tp != NULL);
3351 if (!tp->suspend.waitstatus_pending_p)
3356 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3357 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3359 struct regcache *regcache = get_thread_regcache (tp);
3360 struct gdbarch *gdbarch = regcache->arch ();
3364 pc = regcache_read_pc (regcache);
3366 if (pc != tp->suspend.stop_pc)
3369 fprintf_unfiltered (gdb_stdlog,
3370 "infrun: PC of %s changed. was=%s, now=%s\n",
3371 target_pid_to_str (tp->ptid),
3372 paddress (gdbarch, tp->suspend.stop_pc),
3373 paddress (gdbarch, pc));
3376 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3379 fprintf_unfiltered (gdb_stdlog,
3380 "infrun: previous breakpoint of %s, at %s gone\n",
3381 target_pid_to_str (tp->ptid),
3382 paddress (gdbarch, pc));
3390 fprintf_unfiltered (gdb_stdlog,
3391 "infrun: pending event of %s cancelled.\n",
3392 target_pid_to_str (tp->ptid));
3394 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3395 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3404 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3406 fprintf_unfiltered (gdb_stdlog,
3407 "infrun: Using pending wait status %s for %s.\n",
3409 target_pid_to_str (tp->ptid));
3412 /* Now that we've selected our final event LWP, un-adjust its PC
3413 if it was a software breakpoint (and the target doesn't
3414 always adjust the PC itself). */
3415 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3416 && !target_supports_stopped_by_sw_breakpoint ())
3418 struct regcache *regcache;
3419 struct gdbarch *gdbarch;
3422 regcache = get_thread_regcache (tp);
3423 gdbarch = regcache->arch ();
3425 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3430 pc = regcache_read_pc (regcache);
3431 regcache_write_pc (regcache, pc + decr_pc);
3435 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3436 *status = tp->suspend.waitstatus;
3437 tp->suspend.waitstatus_pending_p = 0;
3439 /* Wake up the event loop again, until all pending events are
3441 if (target_is_async_p ())
3442 mark_async_event_handler (infrun_async_inferior_event_token);
3446 /* But if we don't find one, we'll have to wait. */
3448 if (deprecated_target_wait_hook)
3449 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3451 event_ptid = target_wait (ptid, status, options);
3456 /* Prepare and stabilize the inferior for detaching it. E.g.,
3457 detaching while a thread is displaced stepping is a recipe for
3458 crashing it, as nothing would readjust the PC out of the scratch
3462 prepare_for_detach (void)
3464 struct inferior *inf = current_inferior ();
3465 ptid_t pid_ptid = ptid_t (inf->pid);
3467 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3469 /* Is any thread of this process displaced stepping? If not,
3470 there's nothing else to do. */
3471 if (displaced->step_thread == nullptr)
3475 fprintf_unfiltered (gdb_stdlog,
3476 "displaced-stepping in-process while detaching");
3478 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3480 while (displaced->step_thread != nullptr)
3482 struct execution_control_state ecss;
3483 struct execution_control_state *ecs;
3486 memset (ecs, 0, sizeof (*ecs));
3488 overlay_cache_invalid = 1;
3489 /* Flush target cache before starting to handle each event.
3490 Target was running and cache could be stale. This is just a
3491 heuristic. Running threads may modify target memory, but we
3492 don't get any event. */
3493 target_dcache_invalidate ();
3495 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3498 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3500 /* If an error happens while handling the event, propagate GDB's
3501 knowledge of the executing state to the frontend/user running
3503 scoped_finish_thread_state finish_state (minus_one_ptid);
3505 /* Now figure out what to do with the result of the result. */
3506 handle_inferior_event (ecs);
3508 /* No error, don't finish the state yet. */
3509 finish_state.release ();
3511 /* Breakpoints and watchpoints are not installed on the target
3512 at this point, and signals are passed directly to the
3513 inferior, so this must mean the process is gone. */
3514 if (!ecs->wait_some_more)
3516 restore_detaching.release ();
3517 error (_("Program exited while detaching"));
3521 restore_detaching.release ();
3524 /* Wait for control to return from inferior to debugger.
3526 If inferior gets a signal, we may decide to start it up again
3527 instead of returning. That is why there is a loop in this function.
3528 When this function actually returns it means the inferior
3529 should be left stopped and GDB should read more commands. */
3532 wait_for_inferior (void)
3536 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3538 SCOPE_EXIT { delete_just_stopped_threads_infrun_breakpoints (); };
3540 /* If an error happens while handling the event, propagate GDB's
3541 knowledge of the executing state to the frontend/user running
3543 scoped_finish_thread_state finish_state (minus_one_ptid);
3547 struct execution_control_state ecss;
3548 struct execution_control_state *ecs = &ecss;
3549 ptid_t waiton_ptid = minus_one_ptid;
3551 memset (ecs, 0, sizeof (*ecs));
3553 overlay_cache_invalid = 1;
3555 /* Flush target cache before starting to handle each event.
3556 Target was running and cache could be stale. This is just a
3557 heuristic. Running threads may modify target memory, but we
3558 don't get any event. */
3559 target_dcache_invalidate ();
3561 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3564 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3566 /* Now figure out what to do with the result of the result. */
3567 handle_inferior_event (ecs);
3569 if (!ecs->wait_some_more)
3573 /* No error, don't finish the state yet. */
3574 finish_state.release ();
3577 /* Cleanup that reinstalls the readline callback handler, if the
3578 target is running in the background. If while handling the target
3579 event something triggered a secondary prompt, like e.g., a
3580 pagination prompt, we'll have removed the callback handler (see
3581 gdb_readline_wrapper_line). Need to do this as we go back to the
3582 event loop, ready to process further input. Note this has no
3583 effect if the handler hasn't actually been removed, because calling
3584 rl_callback_handler_install resets the line buffer, thus losing
3588 reinstall_readline_callback_handler_cleanup (void *arg)
3590 struct ui *ui = current_ui;
3594 /* We're not going back to the top level event loop yet. Don't
3595 install the readline callback, as it'd prep the terminal,
3596 readline-style (raw, noecho) (e.g., --batch). We'll install
3597 it the next time the prompt is displayed, when we're ready
3602 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3603 gdb_rl_callback_handler_reinstall ();
3606 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3607 that's just the event thread. In all-stop, that's all threads. */
3610 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3612 if (ecs->event_thread != NULL
3613 && ecs->event_thread->thread_fsm != NULL)
3614 thread_fsm_clean_up (ecs->event_thread->thread_fsm,
3619 for (thread_info *thr : all_non_exited_threads ())
3621 if (thr->thread_fsm == NULL)
3623 if (thr == ecs->event_thread)
3626 switch_to_thread (thr);
3627 thread_fsm_clean_up (thr->thread_fsm, thr);
3630 if (ecs->event_thread != NULL)
3631 switch_to_thread (ecs->event_thread);
3635 /* Helper for all_uis_check_sync_execution_done that works on the
3639 check_curr_ui_sync_execution_done (void)
3641 struct ui *ui = current_ui;
3643 if (ui->prompt_state == PROMPT_NEEDED
3645 && !gdb_in_secondary_prompt_p (ui))
3647 target_terminal::ours ();
3648 gdb::observers::sync_execution_done.notify ();
3649 ui_register_input_event_handler (ui);
3656 all_uis_check_sync_execution_done (void)
3658 SWITCH_THRU_ALL_UIS ()
3660 check_curr_ui_sync_execution_done ();
3667 all_uis_on_sync_execution_starting (void)
3669 SWITCH_THRU_ALL_UIS ()
3671 if (current_ui->prompt_state == PROMPT_NEEDED)
3672 async_disable_stdin ();
3676 /* Asynchronous version of wait_for_inferior. It is called by the
3677 event loop whenever a change of state is detected on the file
3678 descriptor corresponding to the target. It can be called more than
3679 once to complete a single execution command. In such cases we need
3680 to keep the state in a global variable ECSS. If it is the last time
3681 that this function is called for a single execution command, then
3682 report to the user that the inferior has stopped, and do the
3683 necessary cleanups. */
3686 fetch_inferior_event (void *client_data)
3688 struct execution_control_state ecss;
3689 struct execution_control_state *ecs = &ecss;
3690 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3692 ptid_t waiton_ptid = minus_one_ptid;
3694 memset (ecs, 0, sizeof (*ecs));
3696 /* Events are always processed with the main UI as current UI. This
3697 way, warnings, debug output, etc. are always consistently sent to
3698 the main console. */
3699 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3701 /* End up with readline processing input, if necessary. */
3702 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3704 /* We're handling a live event, so make sure we're doing live
3705 debugging. If we're looking at traceframes while the target is
3706 running, we're going to need to get back to that mode after
3707 handling the event. */
3708 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3711 maybe_restore_traceframe.emplace ();
3712 set_current_traceframe (-1);
3715 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3718 /* In non-stop mode, the user/frontend should not notice a thread
3719 switch due to internal events. Make sure we reverse to the
3720 user selected thread and frame after handling the event and
3721 running any breakpoint commands. */
3722 maybe_restore_thread.emplace ();
3724 overlay_cache_invalid = 1;
3725 /* Flush target cache before starting to handle each event. Target
3726 was running and cache could be stale. This is just a heuristic.
3727 Running threads may modify target memory, but we don't get any
3729 target_dcache_invalidate ();
3731 scoped_restore save_exec_dir
3732 = make_scoped_restore (&execution_direction, target_execution_direction ());
3734 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3735 target_can_async_p () ? TARGET_WNOHANG : 0);
3738 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3740 /* If an error happens while handling the event, propagate GDB's
3741 knowledge of the executing state to the frontend/user running
3743 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3744 scoped_finish_thread_state finish_state (finish_ptid);
3746 /* Get executed before make_cleanup_restore_current_thread above to apply
3747 still for the thread which has thrown the exception. */
3748 auto defer_bpstat_clear
3749 = make_scope_exit (bpstat_clear_actions);
3750 auto defer_delete_threads
3751 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints);
3753 /* Now figure out what to do with the result of the result. */
3754 handle_inferior_event (ecs);
3756 if (!ecs->wait_some_more)
3758 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3759 int should_stop = 1;
3760 struct thread_info *thr = ecs->event_thread;
3762 delete_just_stopped_threads_infrun_breakpoints ();
3766 struct thread_fsm *thread_fsm = thr->thread_fsm;
3768 if (thread_fsm != NULL)
3769 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3778 int should_notify_stop = 1;
3781 clean_up_just_stopped_threads_fsms (ecs);
3783 if (thr != NULL && thr->thread_fsm != NULL)
3786 = thread_fsm_should_notify_stop (thr->thread_fsm);
3789 if (should_notify_stop)
3791 /* We may not find an inferior if this was a process exit. */
3792 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3793 proceeded = normal_stop ();
3798 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3804 defer_delete_threads.release ();
3805 defer_bpstat_clear.release ();
3807 /* No error, don't finish the thread states yet. */
3808 finish_state.release ();
3810 /* Revert thread and frame. */
3811 do_cleanups (old_chain);
3813 /* If a UI was in sync execution mode, and now isn't, restore its
3814 prompt (a synchronous execution command has finished, and we're
3815 ready for input). */
3816 all_uis_check_sync_execution_done ();
3819 && exec_done_display_p
3820 && (inferior_ptid == null_ptid
3821 || inferior_thread ()->state != THREAD_RUNNING))
3822 printf_unfiltered (_("completed.\n"));
3825 /* Record the frame and location we're currently stepping through. */
3827 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3829 struct thread_info *tp = inferior_thread ();
3831 tp->control.step_frame_id = get_frame_id (frame);
3832 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3834 tp->current_symtab = sal.symtab;
3835 tp->current_line = sal.line;
3838 /* Clear context switchable stepping state. */
3841 init_thread_stepping_state (struct thread_info *tss)
3843 tss->stepped_breakpoint = 0;
3844 tss->stepping_over_breakpoint = 0;
3845 tss->stepping_over_watchpoint = 0;
3846 tss->step_after_step_resume_breakpoint = 0;
3849 /* Set the cached copy of the last ptid/waitstatus. */
3852 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3854 target_last_wait_ptid = ptid;
3855 target_last_waitstatus = status;
3858 /* Return the cached copy of the last pid/waitstatus returned by
3859 target_wait()/deprecated_target_wait_hook(). The data is actually
3860 cached by handle_inferior_event(), which gets called immediately
3861 after target_wait()/deprecated_target_wait_hook(). */
3864 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3866 *ptidp = target_last_wait_ptid;
3867 *status = target_last_waitstatus;
3871 nullify_last_target_wait_ptid (void)
3873 target_last_wait_ptid = minus_one_ptid;
3876 /* Switch thread contexts. */
3879 context_switch (execution_control_state *ecs)
3882 && ecs->ptid != inferior_ptid
3883 && ecs->event_thread != inferior_thread ())
3885 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3886 target_pid_to_str (inferior_ptid));
3887 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3888 target_pid_to_str (ecs->ptid));
3891 switch_to_thread (ecs->event_thread);
3894 /* If the target can't tell whether we've hit breakpoints
3895 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3896 check whether that could have been caused by a breakpoint. If so,
3897 adjust the PC, per gdbarch_decr_pc_after_break. */
3900 adjust_pc_after_break (struct thread_info *thread,
3901 struct target_waitstatus *ws)
3903 struct regcache *regcache;
3904 struct gdbarch *gdbarch;
3905 CORE_ADDR breakpoint_pc, decr_pc;
3907 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3908 we aren't, just return.
3910 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3911 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3912 implemented by software breakpoints should be handled through the normal
3915 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3916 different signals (SIGILL or SIGEMT for instance), but it is less
3917 clear where the PC is pointing afterwards. It may not match
3918 gdbarch_decr_pc_after_break. I don't know any specific target that
3919 generates these signals at breakpoints (the code has been in GDB since at
3920 least 1992) so I can not guess how to handle them here.
3922 In earlier versions of GDB, a target with
3923 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3924 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3925 target with both of these set in GDB history, and it seems unlikely to be
3926 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3928 if (ws->kind != TARGET_WAITKIND_STOPPED)
3931 if (ws->value.sig != GDB_SIGNAL_TRAP)
3934 /* In reverse execution, when a breakpoint is hit, the instruction
3935 under it has already been de-executed. The reported PC always
3936 points at the breakpoint address, so adjusting it further would
3937 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3940 B1 0x08000000 : INSN1
3941 B2 0x08000001 : INSN2
3943 PC -> 0x08000003 : INSN4
3945 Say you're stopped at 0x08000003 as above. Reverse continuing
3946 from that point should hit B2 as below. Reading the PC when the
3947 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3948 been de-executed already.
3950 B1 0x08000000 : INSN1
3951 B2 PC -> 0x08000001 : INSN2
3955 We can't apply the same logic as for forward execution, because
3956 we would wrongly adjust the PC to 0x08000000, since there's a
3957 breakpoint at PC - 1. We'd then report a hit on B1, although
3958 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3960 if (execution_direction == EXEC_REVERSE)
3963 /* If the target can tell whether the thread hit a SW breakpoint,
3964 trust it. Targets that can tell also adjust the PC
3966 if (target_supports_stopped_by_sw_breakpoint ())
3969 /* Note that relying on whether a breakpoint is planted in memory to
3970 determine this can fail. E.g,. the breakpoint could have been
3971 removed since. Or the thread could have been told to step an
3972 instruction the size of a breakpoint instruction, and only
3973 _after_ was a breakpoint inserted at its address. */
3975 /* If this target does not decrement the PC after breakpoints, then
3976 we have nothing to do. */
3977 regcache = get_thread_regcache (thread);
3978 gdbarch = regcache->arch ();
3980 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3984 const address_space *aspace = regcache->aspace ();
3986 /* Find the location where (if we've hit a breakpoint) the
3987 breakpoint would be. */
3988 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3990 /* If the target can't tell whether a software breakpoint triggered,
3991 fallback to figuring it out based on breakpoints we think were
3992 inserted in the target, and on whether the thread was stepped or
3995 /* Check whether there actually is a software breakpoint inserted at
3998 If in non-stop mode, a race condition is possible where we've
3999 removed a breakpoint, but stop events for that breakpoint were
4000 already queued and arrive later. To suppress those spurious
4001 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4002 and retire them after a number of stop events are reported. Note
4003 this is an heuristic and can thus get confused. The real fix is
4004 to get the "stopped by SW BP and needs adjustment" info out of
4005 the target/kernel (and thus never reach here; see above). */
4006 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4007 || (target_is_non_stop_p ()
4008 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4010 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4012 if (record_full_is_used ())
4013 restore_operation_disable.emplace
4014 (record_full_gdb_operation_disable_set ());
4016 /* When using hardware single-step, a SIGTRAP is reported for both
4017 a completed single-step and a software breakpoint. Need to
4018 differentiate between the two, as the latter needs adjusting
4019 but the former does not.
4021 The SIGTRAP can be due to a completed hardware single-step only if
4022 - we didn't insert software single-step breakpoints
4023 - this thread is currently being stepped
4025 If any of these events did not occur, we must have stopped due
4026 to hitting a software breakpoint, and have to back up to the
4029 As a special case, we could have hardware single-stepped a
4030 software breakpoint. In this case (prev_pc == breakpoint_pc),
4031 we also need to back up to the breakpoint address. */
4033 if (thread_has_single_step_breakpoints_set (thread)
4034 || !currently_stepping (thread)
4035 || (thread->stepped_breakpoint
4036 && thread->prev_pc == breakpoint_pc))
4037 regcache_write_pc (regcache, breakpoint_pc);
4042 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4044 for (frame = get_prev_frame (frame);
4046 frame = get_prev_frame (frame))
4048 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4050 if (get_frame_type (frame) != INLINE_FRAME)
4057 /* If the event thread has the stop requested flag set, pretend it
4058 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4062 handle_stop_requested (struct execution_control_state *ecs)
4064 if (ecs->event_thread->stop_requested)
4066 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4067 ecs->ws.value.sig = GDB_SIGNAL_0;
4068 handle_signal_stop (ecs);
4074 /* Auxiliary function that handles syscall entry/return events.
4075 It returns 1 if the inferior should keep going (and GDB
4076 should ignore the event), or 0 if the event deserves to be
4080 handle_syscall_event (struct execution_control_state *ecs)
4082 struct regcache *regcache;
4085 context_switch (ecs);
4087 regcache = get_thread_regcache (ecs->event_thread);
4088 syscall_number = ecs->ws.value.syscall_number;
4089 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4091 if (catch_syscall_enabled () > 0
4092 && catching_syscall_number (syscall_number) > 0)
4095 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4098 ecs->event_thread->control.stop_bpstat
4099 = bpstat_stop_status (regcache->aspace (),
4100 ecs->event_thread->suspend.stop_pc,
4101 ecs->event_thread, &ecs->ws);
4103 if (handle_stop_requested (ecs))
4106 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4108 /* Catchpoint hit. */
4113 if (handle_stop_requested (ecs))
4116 /* If no catchpoint triggered for this, then keep going. */
4121 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4124 fill_in_stop_func (struct gdbarch *gdbarch,
4125 struct execution_control_state *ecs)
4127 if (!ecs->stop_func_filled_in)
4129 /* Don't care about return value; stop_func_start and stop_func_name
4130 will both be 0 if it doesn't work. */
4131 find_function_entry_range_from_pc (ecs->event_thread->suspend.stop_pc,
4132 &ecs->stop_func_name,
4133 &ecs->stop_func_start,
4134 &ecs->stop_func_end);
4135 ecs->stop_func_start
4136 += gdbarch_deprecated_function_start_offset (gdbarch);
4138 if (gdbarch_skip_entrypoint_p (gdbarch))
4139 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4140 ecs->stop_func_start);
4142 ecs->stop_func_filled_in = 1;
4147 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4149 static enum stop_kind
4150 get_inferior_stop_soon (execution_control_state *ecs)
4152 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4154 gdb_assert (inf != NULL);
4155 return inf->control.stop_soon;
4158 /* Wait for one event. Store the resulting waitstatus in WS, and
4159 return the event ptid. */
4162 wait_one (struct target_waitstatus *ws)
4165 ptid_t wait_ptid = minus_one_ptid;
4167 overlay_cache_invalid = 1;
4169 /* Flush target cache before starting to handle each event.
4170 Target was running and cache could be stale. This is just a
4171 heuristic. Running threads may modify target memory, but we
4172 don't get any event. */
4173 target_dcache_invalidate ();
4175 if (deprecated_target_wait_hook)
4176 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4178 event_ptid = target_wait (wait_ptid, ws, 0);
4181 print_target_wait_results (wait_ptid, event_ptid, ws);
4186 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4187 instead of the current thread. */
4188 #define THREAD_STOPPED_BY(REASON) \
4190 thread_stopped_by_ ## REASON (ptid_t ptid) \
4192 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4193 inferior_ptid = ptid; \
4195 return target_stopped_by_ ## REASON (); \
4198 /* Generate thread_stopped_by_watchpoint. */
4199 THREAD_STOPPED_BY (watchpoint)
4200 /* Generate thread_stopped_by_sw_breakpoint. */
4201 THREAD_STOPPED_BY (sw_breakpoint)
4202 /* Generate thread_stopped_by_hw_breakpoint. */
4203 THREAD_STOPPED_BY (hw_breakpoint)
4205 /* Save the thread's event and stop reason to process it later. */
4208 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4212 std::string statstr = target_waitstatus_to_string (ws);
4214 fprintf_unfiltered (gdb_stdlog,
4215 "infrun: saving status %s for %d.%ld.%ld\n",
4222 /* Record for later. */
4223 tp->suspend.waitstatus = *ws;
4224 tp->suspend.waitstatus_pending_p = 1;
4226 struct regcache *regcache = get_thread_regcache (tp);
4227 const address_space *aspace = regcache->aspace ();
4229 if (ws->kind == TARGET_WAITKIND_STOPPED
4230 && ws->value.sig == GDB_SIGNAL_TRAP)
4232 CORE_ADDR pc = regcache_read_pc (regcache);
4234 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4236 if (thread_stopped_by_watchpoint (tp->ptid))
4238 tp->suspend.stop_reason
4239 = TARGET_STOPPED_BY_WATCHPOINT;
4241 else if (target_supports_stopped_by_sw_breakpoint ()
4242 && thread_stopped_by_sw_breakpoint (tp->ptid))
4244 tp->suspend.stop_reason
4245 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4247 else if (target_supports_stopped_by_hw_breakpoint ()
4248 && thread_stopped_by_hw_breakpoint (tp->ptid))
4250 tp->suspend.stop_reason
4251 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4253 else if (!target_supports_stopped_by_hw_breakpoint ()
4254 && hardware_breakpoint_inserted_here_p (aspace,
4257 tp->suspend.stop_reason
4258 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4260 else if (!target_supports_stopped_by_sw_breakpoint ()
4261 && software_breakpoint_inserted_here_p (aspace,
4264 tp->suspend.stop_reason
4265 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4267 else if (!thread_has_single_step_breakpoints_set (tp)
4268 && currently_stepping (tp))
4270 tp->suspend.stop_reason
4271 = TARGET_STOPPED_BY_SINGLE_STEP;
4276 /* A cleanup that disables thread create/exit events. */
4279 disable_thread_events (void *arg)
4281 target_thread_events (0);
4287 stop_all_threads (void)
4289 /* We may need multiple passes to discover all threads. */
4292 struct cleanup *old_chain;
4294 gdb_assert (target_is_non_stop_p ());
4297 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4299 scoped_restore_current_thread restore_thread;
4301 target_thread_events (1);
4302 old_chain = make_cleanup (disable_thread_events, NULL);
4304 /* Request threads to stop, and then wait for the stops. Because
4305 threads we already know about can spawn more threads while we're
4306 trying to stop them, and we only learn about new threads when we
4307 update the thread list, do this in a loop, and keep iterating
4308 until two passes find no threads that need to be stopped. */
4309 for (pass = 0; pass < 2; pass++, iterations++)
4312 fprintf_unfiltered (gdb_stdlog,
4313 "infrun: stop_all_threads, pass=%d, "
4314 "iterations=%d\n", pass, iterations);
4318 struct target_waitstatus ws;
4321 update_thread_list ();
4323 /* Go through all threads looking for threads that we need
4324 to tell the target to stop. */
4325 for (thread_info *t : all_non_exited_threads ())
4329 /* If already stopping, don't request a stop again.
4330 We just haven't seen the notification yet. */
4331 if (!t->stop_requested)
4334 fprintf_unfiltered (gdb_stdlog,
4335 "infrun: %s executing, "
4337 target_pid_to_str (t->ptid));
4338 target_stop (t->ptid);
4339 t->stop_requested = 1;
4344 fprintf_unfiltered (gdb_stdlog,
4345 "infrun: %s executing, "
4346 "already stopping\n",
4347 target_pid_to_str (t->ptid));
4350 if (t->stop_requested)
4356 fprintf_unfiltered (gdb_stdlog,
4357 "infrun: %s not executing\n",
4358 target_pid_to_str (t->ptid));
4360 /* The thread may be not executing, but still be
4361 resumed with a pending status to process. */
4369 /* If we find new threads on the second iteration, restart
4370 over. We want to see two iterations in a row with all
4375 event_ptid = wait_one (&ws);
4377 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4379 /* All resumed threads exited. */
4381 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4382 || ws.kind == TARGET_WAITKIND_EXITED
4383 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4387 ptid_t ptid = ptid_t (ws.value.integer);
4389 fprintf_unfiltered (gdb_stdlog,
4390 "infrun: %s exited while "
4391 "stopping threads\n",
4392 target_pid_to_str (ptid));
4397 thread_info *t = find_thread_ptid (event_ptid);
4399 t = add_thread (event_ptid);
4401 t->stop_requested = 0;
4404 t->control.may_range_step = 0;
4406 /* This may be the first time we see the inferior report
4408 inferior *inf = find_inferior_ptid (event_ptid);
4409 if (inf->needs_setup)
4411 switch_to_thread_no_regs (t);
4415 if (ws.kind == TARGET_WAITKIND_STOPPED
4416 && ws.value.sig == GDB_SIGNAL_0)
4418 /* We caught the event that we intended to catch, so
4419 there's no event pending. */
4420 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4421 t->suspend.waitstatus_pending_p = 0;
4423 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4425 /* Add it back to the step-over queue. */
4428 fprintf_unfiltered (gdb_stdlog,
4429 "infrun: displaced-step of %s "
4430 "canceled: adding back to the "
4431 "step-over queue\n",
4432 target_pid_to_str (t->ptid));
4434 t->control.trap_expected = 0;
4435 thread_step_over_chain_enqueue (t);
4440 enum gdb_signal sig;
4441 struct regcache *regcache;
4445 std::string statstr = target_waitstatus_to_string (&ws);
4447 fprintf_unfiltered (gdb_stdlog,
4448 "infrun: target_wait %s, saving "
4449 "status for %d.%ld.%ld\n",
4456 /* Record for later. */
4457 save_waitstatus (t, &ws);
4459 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4460 ? ws.value.sig : GDB_SIGNAL_0);
4462 if (displaced_step_fixup (t, sig) < 0)
4464 /* Add it back to the step-over queue. */
4465 t->control.trap_expected = 0;
4466 thread_step_over_chain_enqueue (t);
4469 regcache = get_thread_regcache (t);
4470 t->suspend.stop_pc = regcache_read_pc (regcache);
4474 fprintf_unfiltered (gdb_stdlog,
4475 "infrun: saved stop_pc=%s for %s "
4476 "(currently_stepping=%d)\n",
4477 paddress (target_gdbarch (),
4478 t->suspend.stop_pc),
4479 target_pid_to_str (t->ptid),
4480 currently_stepping (t));
4487 do_cleanups (old_chain);
4490 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4493 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4496 handle_no_resumed (struct execution_control_state *ecs)
4498 if (target_can_async_p ())
4505 if (ui->prompt_state == PROMPT_BLOCKED)
4513 /* There were no unwaited-for children left in the target, but,
4514 we're not synchronously waiting for events either. Just
4518 fprintf_unfiltered (gdb_stdlog,
4519 "infrun: TARGET_WAITKIND_NO_RESUMED "
4520 "(ignoring: bg)\n");
4521 prepare_to_wait (ecs);
4526 /* Otherwise, if we were running a synchronous execution command, we
4527 may need to cancel it and give the user back the terminal.
4529 In non-stop mode, the target can't tell whether we've already
4530 consumed previous stop events, so it can end up sending us a
4531 no-resumed event like so:
4533 #0 - thread 1 is left stopped
4535 #1 - thread 2 is resumed and hits breakpoint
4536 -> TARGET_WAITKIND_STOPPED
4538 #2 - thread 3 is resumed and exits
4539 this is the last resumed thread, so
4540 -> TARGET_WAITKIND_NO_RESUMED
4542 #3 - gdb processes stop for thread 2 and decides to re-resume
4545 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4546 thread 2 is now resumed, so the event should be ignored.
4548 IOW, if the stop for thread 2 doesn't end a foreground command,
4549 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4550 event. But it could be that the event meant that thread 2 itself
4551 (or whatever other thread was the last resumed thread) exited.
4553 To address this we refresh the thread list and check whether we
4554 have resumed threads _now_. In the example above, this removes
4555 thread 3 from the thread list. If thread 2 was re-resumed, we
4556 ignore this event. If we find no thread resumed, then we cancel
4557 the synchronous command show "no unwaited-for " to the user. */
4558 update_thread_list ();
4560 for (thread_info *thread : all_non_exited_threads ())
4562 if (thread->executing
4563 || thread->suspend.waitstatus_pending_p)
4565 /* There were no unwaited-for children left in the target at
4566 some point, but there are now. Just ignore. */
4568 fprintf_unfiltered (gdb_stdlog,
4569 "infrun: TARGET_WAITKIND_NO_RESUMED "
4570 "(ignoring: found resumed)\n");
4571 prepare_to_wait (ecs);
4576 /* Note however that we may find no resumed thread because the whole
4577 process exited meanwhile (thus updating the thread list results
4578 in an empty thread list). In this case we know we'll be getting
4579 a process exit event shortly. */
4580 for (inferior *inf : all_inferiors ())
4585 thread_info *thread = any_live_thread_of_inferior (inf);
4589 fprintf_unfiltered (gdb_stdlog,
4590 "infrun: TARGET_WAITKIND_NO_RESUMED "
4591 "(expect process exit)\n");
4592 prepare_to_wait (ecs);
4597 /* Go ahead and report the event. */
4601 /* Given an execution control state that has been freshly filled in by
4602 an event from the inferior, figure out what it means and take
4605 The alternatives are:
4607 1) stop_waiting and return; to really stop and return to the
4610 2) keep_going and return; to wait for the next event (set
4611 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4615 handle_inferior_event_1 (struct execution_control_state *ecs)
4617 enum stop_kind stop_soon;
4619 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4621 /* We had an event in the inferior, but we are not interested in
4622 handling it at this level. The lower layers have already
4623 done what needs to be done, if anything.
4625 One of the possible circumstances for this is when the
4626 inferior produces output for the console. The inferior has
4627 not stopped, and we are ignoring the event. Another possible
4628 circumstance is any event which the lower level knows will be
4629 reported multiple times without an intervening resume. */
4631 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4632 prepare_to_wait (ecs);
4636 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4639 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4640 prepare_to_wait (ecs);
4644 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4645 && handle_no_resumed (ecs))
4648 /* Cache the last pid/waitstatus. */
4649 set_last_target_status (ecs->ptid, ecs->ws);
4651 /* Always clear state belonging to the previous time we stopped. */
4652 stop_stack_dummy = STOP_NONE;
4654 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4656 /* No unwaited-for children left. IOW, all resumed children
4659 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4661 stop_print_frame = 0;
4666 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4667 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4669 ecs->event_thread = find_thread_ptid (ecs->ptid);
4670 /* If it's a new thread, add it to the thread database. */
4671 if (ecs->event_thread == NULL)
4672 ecs->event_thread = add_thread (ecs->ptid);
4674 /* Disable range stepping. If the next step request could use a
4675 range, this will be end up re-enabled then. */
4676 ecs->event_thread->control.may_range_step = 0;
4679 /* Dependent on valid ECS->EVENT_THREAD. */
4680 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4682 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4683 reinit_frame_cache ();
4685 breakpoint_retire_moribund ();
4687 /* First, distinguish signals caused by the debugger from signals
4688 that have to do with the program's own actions. Note that
4689 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4690 on the operating system version. Here we detect when a SIGILL or
4691 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4692 something similar for SIGSEGV, since a SIGSEGV will be generated
4693 when we're trying to execute a breakpoint instruction on a
4694 non-executable stack. This happens for call dummy breakpoints
4695 for architectures like SPARC that place call dummies on the
4697 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4698 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4699 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4700 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4702 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4704 if (breakpoint_inserted_here_p (regcache->aspace (),
4705 regcache_read_pc (regcache)))
4708 fprintf_unfiltered (gdb_stdlog,
4709 "infrun: Treating signal as SIGTRAP\n");
4710 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4714 /* Mark the non-executing threads accordingly. In all-stop, all
4715 threads of all processes are stopped when we get any event
4716 reported. In non-stop mode, only the event thread stops. */
4720 if (!target_is_non_stop_p ())
4721 mark_ptid = minus_one_ptid;
4722 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4723 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4725 /* If we're handling a process exit in non-stop mode, even
4726 though threads haven't been deleted yet, one would think
4727 that there is nothing to do, as threads of the dead process
4728 will be soon deleted, and threads of any other process were
4729 left running. However, on some targets, threads survive a
4730 process exit event. E.g., for the "checkpoint" command,
4731 when the current checkpoint/fork exits, linux-fork.c
4732 automatically switches to another fork from within
4733 target_mourn_inferior, by associating the same
4734 inferior/thread to another fork. We haven't mourned yet at
4735 this point, but we must mark any threads left in the
4736 process as not-executing so that finish_thread_state marks
4737 them stopped (in the user's perspective) if/when we present
4738 the stop to the user. */
4739 mark_ptid = ptid_t (ecs->ptid.pid ());
4742 mark_ptid = ecs->ptid;
4744 set_executing (mark_ptid, 0);
4746 /* Likewise the resumed flag. */
4747 set_resumed (mark_ptid, 0);
4750 switch (ecs->ws.kind)
4752 case TARGET_WAITKIND_LOADED:
4754 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4755 context_switch (ecs);
4756 /* Ignore gracefully during startup of the inferior, as it might
4757 be the shell which has just loaded some objects, otherwise
4758 add the symbols for the newly loaded objects. Also ignore at
4759 the beginning of an attach or remote session; we will query
4760 the full list of libraries once the connection is
4763 stop_soon = get_inferior_stop_soon (ecs);
4764 if (stop_soon == NO_STOP_QUIETLY)
4766 struct regcache *regcache;
4768 regcache = get_thread_regcache (ecs->event_thread);
4770 handle_solib_event ();
4772 ecs->event_thread->control.stop_bpstat
4773 = bpstat_stop_status (regcache->aspace (),
4774 ecs->event_thread->suspend.stop_pc,
4775 ecs->event_thread, &ecs->ws);
4777 if (handle_stop_requested (ecs))
4780 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4782 /* A catchpoint triggered. */
4783 process_event_stop_test (ecs);
4787 /* If requested, stop when the dynamic linker notifies
4788 gdb of events. This allows the user to get control
4789 and place breakpoints in initializer routines for
4790 dynamically loaded objects (among other things). */
4791 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4792 if (stop_on_solib_events)
4794 /* Make sure we print "Stopped due to solib-event" in
4796 stop_print_frame = 1;
4803 /* If we are skipping through a shell, or through shared library
4804 loading that we aren't interested in, resume the program. If
4805 we're running the program normally, also resume. */
4806 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4808 /* Loading of shared libraries might have changed breakpoint
4809 addresses. Make sure new breakpoints are inserted. */
4810 if (stop_soon == NO_STOP_QUIETLY)
4811 insert_breakpoints ();
4812 resume (GDB_SIGNAL_0);
4813 prepare_to_wait (ecs);
4817 /* But stop if we're attaching or setting up a remote
4819 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4820 || stop_soon == STOP_QUIETLY_REMOTE)
4823 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4828 internal_error (__FILE__, __LINE__,
4829 _("unhandled stop_soon: %d"), (int) stop_soon);
4831 case TARGET_WAITKIND_SPURIOUS:
4833 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4834 if (handle_stop_requested (ecs))
4836 context_switch (ecs);
4837 resume (GDB_SIGNAL_0);
4838 prepare_to_wait (ecs);
4841 case TARGET_WAITKIND_THREAD_CREATED:
4843 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
4844 if (handle_stop_requested (ecs))
4846 context_switch (ecs);
4847 if (!switch_back_to_stepped_thread (ecs))
4851 case TARGET_WAITKIND_EXITED:
4852 case TARGET_WAITKIND_SIGNALLED:
4855 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4856 fprintf_unfiltered (gdb_stdlog,
4857 "infrun: TARGET_WAITKIND_EXITED\n");
4859 fprintf_unfiltered (gdb_stdlog,
4860 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4863 inferior_ptid = ecs->ptid;
4864 set_current_inferior (find_inferior_ptid (ecs->ptid));
4865 set_current_program_space (current_inferior ()->pspace);
4866 handle_vfork_child_exec_or_exit (0);
4867 target_terminal::ours (); /* Must do this before mourn anyway. */
4869 /* Clearing any previous state of convenience variables. */
4870 clear_exit_convenience_vars ();
4872 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4874 /* Record the exit code in the convenience variable $_exitcode, so
4875 that the user can inspect this again later. */
4876 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4877 (LONGEST) ecs->ws.value.integer);
4879 /* Also record this in the inferior itself. */
4880 current_inferior ()->has_exit_code = 1;
4881 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4883 /* Support the --return-child-result option. */
4884 return_child_result_value = ecs->ws.value.integer;
4886 gdb::observers::exited.notify (ecs->ws.value.integer);
4890 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
4892 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4894 /* Set the value of the internal variable $_exitsignal,
4895 which holds the signal uncaught by the inferior. */
4896 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4897 gdbarch_gdb_signal_to_target (gdbarch,
4898 ecs->ws.value.sig));
4902 /* We don't have access to the target's method used for
4903 converting between signal numbers (GDB's internal
4904 representation <-> target's representation).
4905 Therefore, we cannot do a good job at displaying this
4906 information to the user. It's better to just warn
4907 her about it (if infrun debugging is enabled), and
4910 fprintf_filtered (gdb_stdlog, _("\
4911 Cannot fill $_exitsignal with the correct signal number.\n"));
4914 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
4917 gdb_flush (gdb_stdout);
4918 target_mourn_inferior (inferior_ptid);
4919 stop_print_frame = 0;
4923 /* The following are the only cases in which we keep going;
4924 the above cases end in a continue or goto. */
4925 case TARGET_WAITKIND_FORKED:
4926 case TARGET_WAITKIND_VFORKED:
4929 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4930 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4932 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4935 /* Check whether the inferior is displaced stepping. */
4937 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4938 struct gdbarch *gdbarch = regcache->arch ();
4940 /* If checking displaced stepping is supported, and thread
4941 ecs->ptid is displaced stepping. */
4942 if (displaced_step_in_progress_thread (ecs->event_thread))
4944 struct inferior *parent_inf
4945 = find_inferior_ptid (ecs->ptid);
4946 struct regcache *child_regcache;
4947 CORE_ADDR parent_pc;
4949 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4950 indicating that the displaced stepping of syscall instruction
4951 has been done. Perform cleanup for parent process here. Note
4952 that this operation also cleans up the child process for vfork,
4953 because their pages are shared. */
4954 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
4955 /* Start a new step-over in another thread if there's one
4959 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4961 struct displaced_step_inferior_state *displaced
4962 = get_displaced_stepping_state (parent_inf);
4964 /* Restore scratch pad for child process. */
4965 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4968 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4969 the child's PC is also within the scratchpad. Set the child's PC
4970 to the parent's PC value, which has already been fixed up.
4971 FIXME: we use the parent's aspace here, although we're touching
4972 the child, because the child hasn't been added to the inferior
4973 list yet at this point. */
4976 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4978 parent_inf->aspace);
4979 /* Read PC value of parent process. */
4980 parent_pc = regcache_read_pc (regcache);
4982 if (debug_displaced)
4983 fprintf_unfiltered (gdb_stdlog,
4984 "displaced: write child pc from %s to %s\n",
4986 regcache_read_pc (child_regcache)),
4987 paddress (gdbarch, parent_pc));
4989 regcache_write_pc (child_regcache, parent_pc);
4993 context_switch (ecs);
4995 /* Immediately detach breakpoints from the child before there's
4996 any chance of letting the user delete breakpoints from the
4997 breakpoint lists. If we don't do this early, it's easy to
4998 leave left over traps in the child, vis: "break foo; catch
4999 fork; c; <fork>; del; c; <child calls foo>". We only follow
5000 the fork on the last `continue', and by that time the
5001 breakpoint at "foo" is long gone from the breakpoint table.
5002 If we vforked, then we don't need to unpatch here, since both
5003 parent and child are sharing the same memory pages; we'll
5004 need to unpatch at follow/detach time instead to be certain
5005 that new breakpoints added between catchpoint hit time and
5006 vfork follow are detached. */
5007 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5009 /* This won't actually modify the breakpoint list, but will
5010 physically remove the breakpoints from the child. */
5011 detach_breakpoints (ecs->ws.value.related_pid);
5014 delete_just_stopped_threads_single_step_breakpoints ();
5016 /* In case the event is caught by a catchpoint, remember that
5017 the event is to be followed at the next resume of the thread,
5018 and not immediately. */
5019 ecs->event_thread->pending_follow = ecs->ws;
5021 ecs->event_thread->suspend.stop_pc
5022 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5024 ecs->event_thread->control.stop_bpstat
5025 = bpstat_stop_status (get_current_regcache ()->aspace (),
5026 ecs->event_thread->suspend.stop_pc,
5027 ecs->event_thread, &ecs->ws);
5029 if (handle_stop_requested (ecs))
5032 /* If no catchpoint triggered for this, then keep going. Note
5033 that we're interested in knowing the bpstat actually causes a
5034 stop, not just if it may explain the signal. Software
5035 watchpoints, for example, always appear in the bpstat. */
5036 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5040 = (follow_fork_mode_string == follow_fork_mode_child);
5042 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5044 should_resume = follow_fork ();
5046 thread_info *parent = ecs->event_thread;
5047 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5049 /* At this point, the parent is marked running, and the
5050 child is marked stopped. */
5052 /* If not resuming the parent, mark it stopped. */
5053 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5054 parent->set_running (false);
5056 /* If resuming the child, mark it running. */
5057 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5058 child->set_running (true);
5060 /* In non-stop mode, also resume the other branch. */
5061 if (!detach_fork && (non_stop
5062 || (sched_multi && target_is_non_stop_p ())))
5065 switch_to_thread (parent);
5067 switch_to_thread (child);
5069 ecs->event_thread = inferior_thread ();
5070 ecs->ptid = inferior_ptid;
5075 switch_to_thread (child);
5077 switch_to_thread (parent);
5079 ecs->event_thread = inferior_thread ();
5080 ecs->ptid = inferior_ptid;
5088 process_event_stop_test (ecs);
5091 case TARGET_WAITKIND_VFORK_DONE:
5092 /* Done with the shared memory region. Re-insert breakpoints in
5093 the parent, and keep going. */
5096 fprintf_unfiltered (gdb_stdlog,
5097 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5099 context_switch (ecs);
5101 current_inferior ()->waiting_for_vfork_done = 0;
5102 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5104 if (handle_stop_requested (ecs))
5107 /* This also takes care of reinserting breakpoints in the
5108 previously locked inferior. */
5112 case TARGET_WAITKIND_EXECD:
5114 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5116 /* Note we can't read registers yet (the stop_pc), because we
5117 don't yet know the inferior's post-exec architecture.
5118 'stop_pc' is explicitly read below instead. */
5119 switch_to_thread_no_regs (ecs->event_thread);
5121 /* Do whatever is necessary to the parent branch of the vfork. */
5122 handle_vfork_child_exec_or_exit (1);
5124 /* This causes the eventpoints and symbol table to be reset.
5125 Must do this now, before trying to determine whether to
5127 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5129 /* In follow_exec we may have deleted the original thread and
5130 created a new one. Make sure that the event thread is the
5131 execd thread for that case (this is a nop otherwise). */
5132 ecs->event_thread = inferior_thread ();
5134 ecs->event_thread->suspend.stop_pc
5135 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5137 ecs->event_thread->control.stop_bpstat
5138 = bpstat_stop_status (get_current_regcache ()->aspace (),
5139 ecs->event_thread->suspend.stop_pc,
5140 ecs->event_thread, &ecs->ws);
5142 /* Note that this may be referenced from inside
5143 bpstat_stop_status above, through inferior_has_execd. */
5144 xfree (ecs->ws.value.execd_pathname);
5145 ecs->ws.value.execd_pathname = NULL;
5147 if (handle_stop_requested (ecs))
5150 /* If no catchpoint triggered for this, then keep going. */
5151 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5153 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5157 process_event_stop_test (ecs);
5160 /* Be careful not to try to gather much state about a thread
5161 that's in a syscall. It's frequently a losing proposition. */
5162 case TARGET_WAITKIND_SYSCALL_ENTRY:
5164 fprintf_unfiltered (gdb_stdlog,
5165 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5166 /* Getting the current syscall number. */
5167 if (handle_syscall_event (ecs) == 0)
5168 process_event_stop_test (ecs);
5171 /* Before examining the threads further, step this thread to
5172 get it entirely out of the syscall. (We get notice of the
5173 event when the thread is just on the verge of exiting a
5174 syscall. Stepping one instruction seems to get it back
5176 case TARGET_WAITKIND_SYSCALL_RETURN:
5178 fprintf_unfiltered (gdb_stdlog,
5179 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5180 if (handle_syscall_event (ecs) == 0)
5181 process_event_stop_test (ecs);
5184 case TARGET_WAITKIND_STOPPED:
5186 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5187 handle_signal_stop (ecs);
5190 case TARGET_WAITKIND_NO_HISTORY:
5192 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5193 /* Reverse execution: target ran out of history info. */
5195 /* Switch to the stopped thread. */
5196 context_switch (ecs);
5198 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5200 delete_just_stopped_threads_single_step_breakpoints ();
5201 ecs->event_thread->suspend.stop_pc
5202 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5204 if (handle_stop_requested (ecs))
5207 gdb::observers::no_history.notify ();
5213 /* A wrapper around handle_inferior_event_1, which also makes sure
5214 that all temporary struct value objects that were created during
5215 the handling of the event get deleted at the end. */
5218 handle_inferior_event (struct execution_control_state *ecs)
5220 struct value *mark = value_mark ();
5222 handle_inferior_event_1 (ecs);
5223 /* Purge all temporary values created during the event handling,
5224 as it could be a long time before we return to the command level
5225 where such values would otherwise be purged. */
5226 value_free_to_mark (mark);
5229 /* Restart threads back to what they were trying to do back when we
5230 paused them for an in-line step-over. The EVENT_THREAD thread is
5234 restart_threads (struct thread_info *event_thread)
5236 /* In case the instruction just stepped spawned a new thread. */
5237 update_thread_list ();
5239 for (thread_info *tp : all_non_exited_threads ())
5241 if (tp == event_thread)
5244 fprintf_unfiltered (gdb_stdlog,
5245 "infrun: restart threads: "
5246 "[%s] is event thread\n",
5247 target_pid_to_str (tp->ptid));
5251 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5254 fprintf_unfiltered (gdb_stdlog,
5255 "infrun: restart threads: "
5256 "[%s] not meant to be running\n",
5257 target_pid_to_str (tp->ptid));
5264 fprintf_unfiltered (gdb_stdlog,
5265 "infrun: restart threads: [%s] resumed\n",
5266 target_pid_to_str (tp->ptid));
5267 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5271 if (thread_is_in_step_over_chain (tp))
5274 fprintf_unfiltered (gdb_stdlog,
5275 "infrun: restart threads: "
5276 "[%s] needs step-over\n",
5277 target_pid_to_str (tp->ptid));
5278 gdb_assert (!tp->resumed);
5283 if (tp->suspend.waitstatus_pending_p)
5286 fprintf_unfiltered (gdb_stdlog,
5287 "infrun: restart threads: "
5288 "[%s] has pending status\n",
5289 target_pid_to_str (tp->ptid));
5294 gdb_assert (!tp->stop_requested);
5296 /* If some thread needs to start a step-over at this point, it
5297 should still be in the step-over queue, and thus skipped
5299 if (thread_still_needs_step_over (tp))
5301 internal_error (__FILE__, __LINE__,
5302 "thread [%s] needs a step-over, but not in "
5303 "step-over queue\n",
5304 target_pid_to_str (tp->ptid));
5307 if (currently_stepping (tp))
5310 fprintf_unfiltered (gdb_stdlog,
5311 "infrun: restart threads: [%s] was stepping\n",
5312 target_pid_to_str (tp->ptid));
5313 keep_going_stepped_thread (tp);
5317 struct execution_control_state ecss;
5318 struct execution_control_state *ecs = &ecss;
5321 fprintf_unfiltered (gdb_stdlog,
5322 "infrun: restart threads: [%s] continuing\n",
5323 target_pid_to_str (tp->ptid));
5324 reset_ecs (ecs, tp);
5325 switch_to_thread (tp);
5326 keep_going_pass_signal (ecs);
5331 /* Callback for iterate_over_threads. Find a resumed thread that has
5332 a pending waitstatus. */
5335 resumed_thread_with_pending_status (struct thread_info *tp,
5339 && tp->suspend.waitstatus_pending_p);
5342 /* Called when we get an event that may finish an in-line or
5343 out-of-line (displaced stepping) step-over started previously.
5344 Return true if the event is processed and we should go back to the
5345 event loop; false if the caller should continue processing the
5349 finish_step_over (struct execution_control_state *ecs)
5351 int had_step_over_info;
5353 displaced_step_fixup (ecs->event_thread,
5354 ecs->event_thread->suspend.stop_signal);
5356 had_step_over_info = step_over_info_valid_p ();
5358 if (had_step_over_info)
5360 /* If we're stepping over a breakpoint with all threads locked,
5361 then only the thread that was stepped should be reporting
5363 gdb_assert (ecs->event_thread->control.trap_expected);
5365 clear_step_over_info ();
5368 if (!target_is_non_stop_p ())
5371 /* Start a new step-over in another thread if there's one that
5375 /* If we were stepping over a breakpoint before, and haven't started
5376 a new in-line step-over sequence, then restart all other threads
5377 (except the event thread). We can't do this in all-stop, as then
5378 e.g., we wouldn't be able to issue any other remote packet until
5379 these other threads stop. */
5380 if (had_step_over_info && !step_over_info_valid_p ())
5382 struct thread_info *pending;
5384 /* If we only have threads with pending statuses, the restart
5385 below won't restart any thread and so nothing re-inserts the
5386 breakpoint we just stepped over. But we need it inserted
5387 when we later process the pending events, otherwise if
5388 another thread has a pending event for this breakpoint too,
5389 we'd discard its event (because the breakpoint that
5390 originally caused the event was no longer inserted). */
5391 context_switch (ecs);
5392 insert_breakpoints ();
5394 restart_threads (ecs->event_thread);
5396 /* If we have events pending, go through handle_inferior_event
5397 again, picking up a pending event at random. This avoids
5398 thread starvation. */
5400 /* But not if we just stepped over a watchpoint in order to let
5401 the instruction execute so we can evaluate its expression.
5402 The set of watchpoints that triggered is recorded in the
5403 breakpoint objects themselves (see bp->watchpoint_triggered).
5404 If we processed another event first, that other event could
5405 clobber this info. */
5406 if (ecs->event_thread->stepping_over_watchpoint)
5409 pending = iterate_over_threads (resumed_thread_with_pending_status,
5411 if (pending != NULL)
5413 struct thread_info *tp = ecs->event_thread;
5414 struct regcache *regcache;
5418 fprintf_unfiltered (gdb_stdlog,
5419 "infrun: found resumed threads with "
5420 "pending events, saving status\n");
5423 gdb_assert (pending != tp);
5425 /* Record the event thread's event for later. */
5426 save_waitstatus (tp, &ecs->ws);
5427 /* This was cleared early, by handle_inferior_event. Set it
5428 so this pending event is considered by
5432 gdb_assert (!tp->executing);
5434 regcache = get_thread_regcache (tp);
5435 tp->suspend.stop_pc = regcache_read_pc (regcache);
5439 fprintf_unfiltered (gdb_stdlog,
5440 "infrun: saved stop_pc=%s for %s "
5441 "(currently_stepping=%d)\n",
5442 paddress (target_gdbarch (),
5443 tp->suspend.stop_pc),
5444 target_pid_to_str (tp->ptid),
5445 currently_stepping (tp));
5448 /* This in-line step-over finished; clear this so we won't
5449 start a new one. This is what handle_signal_stop would
5450 do, if we returned false. */
5451 tp->stepping_over_breakpoint = 0;
5453 /* Wake up the event loop again. */
5454 mark_async_event_handler (infrun_async_inferior_event_token);
5456 prepare_to_wait (ecs);
5464 /* Come here when the program has stopped with a signal. */
5467 handle_signal_stop (struct execution_control_state *ecs)
5469 struct frame_info *frame;
5470 struct gdbarch *gdbarch;
5471 int stopped_by_watchpoint;
5472 enum stop_kind stop_soon;
5475 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5477 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5479 /* Do we need to clean up the state of a thread that has
5480 completed a displaced single-step? (Doing so usually affects
5481 the PC, so do it here, before we set stop_pc.) */
5482 if (finish_step_over (ecs))
5485 /* If we either finished a single-step or hit a breakpoint, but
5486 the user wanted this thread to be stopped, pretend we got a
5487 SIG0 (generic unsignaled stop). */
5488 if (ecs->event_thread->stop_requested
5489 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5490 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5492 ecs->event_thread->suspend.stop_pc
5493 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5497 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5498 struct gdbarch *reg_gdbarch = regcache->arch ();
5499 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5501 inferior_ptid = ecs->ptid;
5503 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5504 paddress (reg_gdbarch,
5505 ecs->event_thread->suspend.stop_pc));
5506 if (target_stopped_by_watchpoint ())
5510 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5512 if (target_stopped_data_address (current_top_target (), &addr))
5513 fprintf_unfiltered (gdb_stdlog,
5514 "infrun: stopped data address = %s\n",
5515 paddress (reg_gdbarch, addr));
5517 fprintf_unfiltered (gdb_stdlog,
5518 "infrun: (no data address available)\n");
5522 /* This is originated from start_remote(), start_inferior() and
5523 shared libraries hook functions. */
5524 stop_soon = get_inferior_stop_soon (ecs);
5525 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5527 context_switch (ecs);
5529 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5530 stop_print_frame = 1;
5535 /* This originates from attach_command(). We need to overwrite
5536 the stop_signal here, because some kernels don't ignore a
5537 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5538 See more comments in inferior.h. On the other hand, if we
5539 get a non-SIGSTOP, report it to the user - assume the backend
5540 will handle the SIGSTOP if it should show up later.
5542 Also consider that the attach is complete when we see a
5543 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5544 target extended-remote report it instead of a SIGSTOP
5545 (e.g. gdbserver). We already rely on SIGTRAP being our
5546 signal, so this is no exception.
5548 Also consider that the attach is complete when we see a
5549 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5550 the target to stop all threads of the inferior, in case the
5551 low level attach operation doesn't stop them implicitly. If
5552 they weren't stopped implicitly, then the stub will report a
5553 GDB_SIGNAL_0, meaning: stopped for no particular reason
5554 other than GDB's request. */
5555 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5556 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5557 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5558 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5560 stop_print_frame = 1;
5562 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5566 /* See if something interesting happened to the non-current thread. If
5567 so, then switch to that thread. */
5568 if (ecs->ptid != inferior_ptid)
5571 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5573 context_switch (ecs);
5575 if (deprecated_context_hook)
5576 deprecated_context_hook (ecs->event_thread->global_num);
5579 /* At this point, get hold of the now-current thread's frame. */
5580 frame = get_current_frame ();
5581 gdbarch = get_frame_arch (frame);
5583 /* Pull the single step breakpoints out of the target. */
5584 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5586 struct regcache *regcache;
5589 regcache = get_thread_regcache (ecs->event_thread);
5590 const address_space *aspace = regcache->aspace ();
5592 pc = regcache_read_pc (regcache);
5594 /* However, before doing so, if this single-step breakpoint was
5595 actually for another thread, set this thread up for moving
5597 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5600 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5604 fprintf_unfiltered (gdb_stdlog,
5605 "infrun: [%s] hit another thread's "
5606 "single-step breakpoint\n",
5607 target_pid_to_str (ecs->ptid));
5609 ecs->hit_singlestep_breakpoint = 1;
5616 fprintf_unfiltered (gdb_stdlog,
5617 "infrun: [%s] hit its "
5618 "single-step breakpoint\n",
5619 target_pid_to_str (ecs->ptid));
5623 delete_just_stopped_threads_single_step_breakpoints ();
5625 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5626 && ecs->event_thread->control.trap_expected
5627 && ecs->event_thread->stepping_over_watchpoint)
5628 stopped_by_watchpoint = 0;
5630 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5632 /* If necessary, step over this watchpoint. We'll be back to display
5634 if (stopped_by_watchpoint
5635 && (target_have_steppable_watchpoint
5636 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5638 /* At this point, we are stopped at an instruction which has
5639 attempted to write to a piece of memory under control of
5640 a watchpoint. The instruction hasn't actually executed
5641 yet. If we were to evaluate the watchpoint expression
5642 now, we would get the old value, and therefore no change
5643 would seem to have occurred.
5645 In order to make watchpoints work `right', we really need
5646 to complete the memory write, and then evaluate the
5647 watchpoint expression. We do this by single-stepping the
5650 It may not be necessary to disable the watchpoint to step over
5651 it. For example, the PA can (with some kernel cooperation)
5652 single step over a watchpoint without disabling the watchpoint.
5654 It is far more common to need to disable a watchpoint to step
5655 the inferior over it. If we have non-steppable watchpoints,
5656 we must disable the current watchpoint; it's simplest to
5657 disable all watchpoints.
5659 Any breakpoint at PC must also be stepped over -- if there's
5660 one, it will have already triggered before the watchpoint
5661 triggered, and we either already reported it to the user, or
5662 it didn't cause a stop and we called keep_going. In either
5663 case, if there was a breakpoint at PC, we must be trying to
5665 ecs->event_thread->stepping_over_watchpoint = 1;
5670 ecs->event_thread->stepping_over_breakpoint = 0;
5671 ecs->event_thread->stepping_over_watchpoint = 0;
5672 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5673 ecs->event_thread->control.stop_step = 0;
5674 stop_print_frame = 1;
5675 stopped_by_random_signal = 0;
5676 bpstat stop_chain = NULL;
5678 /* Hide inlined functions starting here, unless we just performed stepi or
5679 nexti. After stepi and nexti, always show the innermost frame (not any
5680 inline function call sites). */
5681 if (ecs->event_thread->control.step_range_end != 1)
5683 const address_space *aspace
5684 = get_thread_regcache (ecs->event_thread)->aspace ();
5686 /* skip_inline_frames is expensive, so we avoid it if we can
5687 determine that the address is one where functions cannot have
5688 been inlined. This improves performance with inferiors that
5689 load a lot of shared libraries, because the solib event
5690 breakpoint is defined as the address of a function (i.e. not
5691 inline). Note that we have to check the previous PC as well
5692 as the current one to catch cases when we have just
5693 single-stepped off a breakpoint prior to reinstating it.
5694 Note that we're assuming that the code we single-step to is
5695 not inline, but that's not definitive: there's nothing
5696 preventing the event breakpoint function from containing
5697 inlined code, and the single-step ending up there. If the
5698 user had set a breakpoint on that inlined code, the missing
5699 skip_inline_frames call would break things. Fortunately
5700 that's an extremely unlikely scenario. */
5701 if (!pc_at_non_inline_function (aspace,
5702 ecs->event_thread->suspend.stop_pc,
5704 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5705 && ecs->event_thread->control.trap_expected
5706 && pc_at_non_inline_function (aspace,
5707 ecs->event_thread->prev_pc,
5710 stop_chain = build_bpstat_chain (aspace,
5711 ecs->event_thread->suspend.stop_pc,
5713 skip_inline_frames (ecs->event_thread, stop_chain);
5715 /* Re-fetch current thread's frame in case that invalidated
5717 frame = get_current_frame ();
5718 gdbarch = get_frame_arch (frame);
5722 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5723 && ecs->event_thread->control.trap_expected
5724 && gdbarch_single_step_through_delay_p (gdbarch)
5725 && currently_stepping (ecs->event_thread))
5727 /* We're trying to step off a breakpoint. Turns out that we're
5728 also on an instruction that needs to be stepped multiple
5729 times before it's been fully executing. E.g., architectures
5730 with a delay slot. It needs to be stepped twice, once for
5731 the instruction and once for the delay slot. */
5732 int step_through_delay
5733 = gdbarch_single_step_through_delay (gdbarch, frame);
5735 if (debug_infrun && step_through_delay)
5736 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5737 if (ecs->event_thread->control.step_range_end == 0
5738 && step_through_delay)
5740 /* The user issued a continue when stopped at a breakpoint.
5741 Set up for another trap and get out of here. */
5742 ecs->event_thread->stepping_over_breakpoint = 1;
5746 else if (step_through_delay)
5748 /* The user issued a step when stopped at a breakpoint.
5749 Maybe we should stop, maybe we should not - the delay
5750 slot *might* correspond to a line of source. In any
5751 case, don't decide that here, just set
5752 ecs->stepping_over_breakpoint, making sure we
5753 single-step again before breakpoints are re-inserted. */
5754 ecs->event_thread->stepping_over_breakpoint = 1;
5758 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5759 handles this event. */
5760 ecs->event_thread->control.stop_bpstat
5761 = bpstat_stop_status (get_current_regcache ()->aspace (),
5762 ecs->event_thread->suspend.stop_pc,
5763 ecs->event_thread, &ecs->ws, stop_chain);
5765 /* Following in case break condition called a
5767 stop_print_frame = 1;
5769 /* This is where we handle "moribund" watchpoints. Unlike
5770 software breakpoints traps, hardware watchpoint traps are
5771 always distinguishable from random traps. If no high-level
5772 watchpoint is associated with the reported stop data address
5773 anymore, then the bpstat does not explain the signal ---
5774 simply make sure to ignore it if `stopped_by_watchpoint' is
5778 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5779 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5781 && stopped_by_watchpoint)
5782 fprintf_unfiltered (gdb_stdlog,
5783 "infrun: no user watchpoint explains "
5784 "watchpoint SIGTRAP, ignoring\n");
5786 /* NOTE: cagney/2003-03-29: These checks for a random signal
5787 at one stage in the past included checks for an inferior
5788 function call's call dummy's return breakpoint. The original
5789 comment, that went with the test, read:
5791 ``End of a stack dummy. Some systems (e.g. Sony news) give
5792 another signal besides SIGTRAP, so check here as well as
5795 If someone ever tries to get call dummys on a
5796 non-executable stack to work (where the target would stop
5797 with something like a SIGSEGV), then those tests might need
5798 to be re-instated. Given, however, that the tests were only
5799 enabled when momentary breakpoints were not being used, I
5800 suspect that it won't be the case.
5802 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5803 be necessary for call dummies on a non-executable stack on
5806 /* See if the breakpoints module can explain the signal. */
5808 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5809 ecs->event_thread->suspend.stop_signal);
5811 /* Maybe this was a trap for a software breakpoint that has since
5813 if (random_signal && target_stopped_by_sw_breakpoint ())
5815 if (program_breakpoint_here_p (gdbarch,
5816 ecs->event_thread->suspend.stop_pc))
5818 struct regcache *regcache;
5821 /* Re-adjust PC to what the program would see if GDB was not
5823 regcache = get_thread_regcache (ecs->event_thread);
5824 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5827 gdb::optional<scoped_restore_tmpl<int>>
5828 restore_operation_disable;
5830 if (record_full_is_used ())
5831 restore_operation_disable.emplace
5832 (record_full_gdb_operation_disable_set ());
5834 regcache_write_pc (regcache,
5835 ecs->event_thread->suspend.stop_pc + decr_pc);
5840 /* A delayed software breakpoint event. Ignore the trap. */
5842 fprintf_unfiltered (gdb_stdlog,
5843 "infrun: delayed software breakpoint "
5844 "trap, ignoring\n");
5849 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5850 has since been removed. */
5851 if (random_signal && target_stopped_by_hw_breakpoint ())
5853 /* A delayed hardware breakpoint event. Ignore the trap. */
5855 fprintf_unfiltered (gdb_stdlog,
5856 "infrun: delayed hardware breakpoint/watchpoint "
5857 "trap, ignoring\n");
5861 /* If not, perhaps stepping/nexting can. */
5863 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5864 && currently_stepping (ecs->event_thread));
5866 /* Perhaps the thread hit a single-step breakpoint of _another_
5867 thread. Single-step breakpoints are transparent to the
5868 breakpoints module. */
5870 random_signal = !ecs->hit_singlestep_breakpoint;
5872 /* No? Perhaps we got a moribund watchpoint. */
5874 random_signal = !stopped_by_watchpoint;
5876 /* Always stop if the user explicitly requested this thread to
5878 if (ecs->event_thread->stop_requested)
5882 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
5885 /* For the program's own signals, act according to
5886 the signal handling tables. */
5890 /* Signal not for debugging purposes. */
5891 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5892 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5895 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5896 gdb_signal_to_symbol_string (stop_signal));
5898 stopped_by_random_signal = 1;
5900 /* Always stop on signals if we're either just gaining control
5901 of the program, or the user explicitly requested this thread
5902 to remain stopped. */
5903 if (stop_soon != NO_STOP_QUIETLY
5904 || ecs->event_thread->stop_requested
5906 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5912 /* Notify observers the signal has "handle print" set. Note we
5913 returned early above if stopping; normal_stop handles the
5914 printing in that case. */
5915 if (signal_print[ecs->event_thread->suspend.stop_signal])
5917 /* The signal table tells us to print about this signal. */
5918 target_terminal::ours_for_output ();
5919 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
5920 target_terminal::inferior ();
5923 /* Clear the signal if it should not be passed. */
5924 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5925 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5927 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
5928 && ecs->event_thread->control.trap_expected
5929 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5931 /* We were just starting a new sequence, attempting to
5932 single-step off of a breakpoint and expecting a SIGTRAP.
5933 Instead this signal arrives. This signal will take us out
5934 of the stepping range so GDB needs to remember to, when
5935 the signal handler returns, resume stepping off that
5937 /* To simplify things, "continue" is forced to use the same
5938 code paths as single-step - set a breakpoint at the
5939 signal return address and then, once hit, step off that
5942 fprintf_unfiltered (gdb_stdlog,
5943 "infrun: signal arrived while stepping over "
5946 insert_hp_step_resume_breakpoint_at_frame (frame);
5947 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5948 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5949 ecs->event_thread->control.trap_expected = 0;
5951 /* If we were nexting/stepping some other thread, switch to
5952 it, so that we don't continue it, losing control. */
5953 if (!switch_back_to_stepped_thread (ecs))
5958 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5959 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
5961 || ecs->event_thread->control.step_range_end == 1)
5962 && frame_id_eq (get_stack_frame_id (frame),
5963 ecs->event_thread->control.step_stack_frame_id)
5964 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5966 /* The inferior is about to take a signal that will take it
5967 out of the single step range. Set a breakpoint at the
5968 current PC (which is presumably where the signal handler
5969 will eventually return) and then allow the inferior to
5972 Note that this is only needed for a signal delivered
5973 while in the single-step range. Nested signals aren't a
5974 problem as they eventually all return. */
5976 fprintf_unfiltered (gdb_stdlog,
5977 "infrun: signal may take us out of "
5978 "single-step range\n");
5980 clear_step_over_info ();
5981 insert_hp_step_resume_breakpoint_at_frame (frame);
5982 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5983 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5984 ecs->event_thread->control.trap_expected = 0;
5989 /* Note: step_resume_breakpoint may be non-NULL. This occures
5990 when either there's a nested signal, or when there's a
5991 pending signal enabled just as the signal handler returns
5992 (leaving the inferior at the step-resume-breakpoint without
5993 actually executing it). Either way continue until the
5994 breakpoint is really hit. */
5996 if (!switch_back_to_stepped_thread (ecs))
5999 fprintf_unfiltered (gdb_stdlog,
6000 "infrun: random signal, keep going\n");
6007 process_event_stop_test (ecs);
6010 /* Come here when we've got some debug event / signal we can explain
6011 (IOW, not a random signal), and test whether it should cause a
6012 stop, or whether we should resume the inferior (transparently).
6013 E.g., could be a breakpoint whose condition evaluates false; we
6014 could be still stepping within the line; etc. */
6017 process_event_stop_test (struct execution_control_state *ecs)
6019 struct symtab_and_line stop_pc_sal;
6020 struct frame_info *frame;
6021 struct gdbarch *gdbarch;
6022 CORE_ADDR jmp_buf_pc;
6023 struct bpstat_what what;
6025 /* Handle cases caused by hitting a breakpoint. */
6027 frame = get_current_frame ();
6028 gdbarch = get_frame_arch (frame);
6030 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6032 if (what.call_dummy)
6034 stop_stack_dummy = what.call_dummy;
6037 /* A few breakpoint types have callbacks associated (e.g.,
6038 bp_jit_event). Run them now. */
6039 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6041 /* If we hit an internal event that triggers symbol changes, the
6042 current frame will be invalidated within bpstat_what (e.g., if we
6043 hit an internal solib event). Re-fetch it. */
6044 frame = get_current_frame ();
6045 gdbarch = get_frame_arch (frame);
6047 switch (what.main_action)
6049 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6050 /* If we hit the breakpoint at longjmp while stepping, we
6051 install a momentary breakpoint at the target of the
6055 fprintf_unfiltered (gdb_stdlog,
6056 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6058 ecs->event_thread->stepping_over_breakpoint = 1;
6060 if (what.is_longjmp)
6062 struct value *arg_value;
6064 /* If we set the longjmp breakpoint via a SystemTap probe,
6065 then use it to extract the arguments. The destination PC
6066 is the third argument to the probe. */
6067 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6070 jmp_buf_pc = value_as_address (arg_value);
6071 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6073 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6074 || !gdbarch_get_longjmp_target (gdbarch,
6075 frame, &jmp_buf_pc))
6078 fprintf_unfiltered (gdb_stdlog,
6079 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6080 "(!gdbarch_get_longjmp_target)\n");
6085 /* Insert a breakpoint at resume address. */
6086 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6089 check_exception_resume (ecs, frame);
6093 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6095 struct frame_info *init_frame;
6097 /* There are several cases to consider.
6099 1. The initiating frame no longer exists. In this case we
6100 must stop, because the exception or longjmp has gone too
6103 2. The initiating frame exists, and is the same as the
6104 current frame. We stop, because the exception or longjmp
6107 3. The initiating frame exists and is different from the
6108 current frame. This means the exception or longjmp has
6109 been caught beneath the initiating frame, so keep going.
6111 4. longjmp breakpoint has been placed just to protect
6112 against stale dummy frames and user is not interested in
6113 stopping around longjmps. */
6116 fprintf_unfiltered (gdb_stdlog,
6117 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6119 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6121 delete_exception_resume_breakpoint (ecs->event_thread);
6123 if (what.is_longjmp)
6125 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6127 if (!frame_id_p (ecs->event_thread->initiating_frame))
6135 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6139 struct frame_id current_id
6140 = get_frame_id (get_current_frame ());
6141 if (frame_id_eq (current_id,
6142 ecs->event_thread->initiating_frame))
6144 /* Case 2. Fall through. */
6154 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6156 delete_step_resume_breakpoint (ecs->event_thread);
6158 end_stepping_range (ecs);
6162 case BPSTAT_WHAT_SINGLE:
6164 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6165 ecs->event_thread->stepping_over_breakpoint = 1;
6166 /* Still need to check other stuff, at least the case where we
6167 are stepping and step out of the right range. */
6170 case BPSTAT_WHAT_STEP_RESUME:
6172 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6174 delete_step_resume_breakpoint (ecs->event_thread);
6175 if (ecs->event_thread->control.proceed_to_finish
6176 && execution_direction == EXEC_REVERSE)
6178 struct thread_info *tp = ecs->event_thread;
6180 /* We are finishing a function in reverse, and just hit the
6181 step-resume breakpoint at the start address of the
6182 function, and we're almost there -- just need to back up
6183 by one more single-step, which should take us back to the
6185 tp->control.step_range_start = tp->control.step_range_end = 1;
6189 fill_in_stop_func (gdbarch, ecs);
6190 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6191 && execution_direction == EXEC_REVERSE)
6193 /* We are stepping over a function call in reverse, and just
6194 hit the step-resume breakpoint at the start address of
6195 the function. Go back to single-stepping, which should
6196 take us back to the function call. */
6197 ecs->event_thread->stepping_over_breakpoint = 1;
6203 case BPSTAT_WHAT_STOP_NOISY:
6205 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6206 stop_print_frame = 1;
6208 /* Assume the thread stopped for a breapoint. We'll still check
6209 whether a/the breakpoint is there when the thread is next
6211 ecs->event_thread->stepping_over_breakpoint = 1;
6216 case BPSTAT_WHAT_STOP_SILENT:
6218 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6219 stop_print_frame = 0;
6221 /* Assume the thread stopped for a breapoint. We'll still check
6222 whether a/the breakpoint is there when the thread is next
6224 ecs->event_thread->stepping_over_breakpoint = 1;
6228 case BPSTAT_WHAT_HP_STEP_RESUME:
6230 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6232 delete_step_resume_breakpoint (ecs->event_thread);
6233 if (ecs->event_thread->step_after_step_resume_breakpoint)
6235 /* Back when the step-resume breakpoint was inserted, we
6236 were trying to single-step off a breakpoint. Go back to
6238 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6239 ecs->event_thread->stepping_over_breakpoint = 1;
6245 case BPSTAT_WHAT_KEEP_CHECKING:
6249 /* If we stepped a permanent breakpoint and we had a high priority
6250 step-resume breakpoint for the address we stepped, but we didn't
6251 hit it, then we must have stepped into the signal handler. The
6252 step-resume was only necessary to catch the case of _not_
6253 stepping into the handler, so delete it, and fall through to
6254 checking whether the step finished. */
6255 if (ecs->event_thread->stepped_breakpoint)
6257 struct breakpoint *sr_bp
6258 = ecs->event_thread->control.step_resume_breakpoint;
6261 && sr_bp->loc->permanent
6262 && sr_bp->type == bp_hp_step_resume
6263 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6266 fprintf_unfiltered (gdb_stdlog,
6267 "infrun: stepped permanent breakpoint, stopped in "
6269 delete_step_resume_breakpoint (ecs->event_thread);
6270 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6274 /* We come here if we hit a breakpoint but should not stop for it.
6275 Possibly we also were stepping and should stop for that. So fall
6276 through and test for stepping. But, if not stepping, do not
6279 /* In all-stop mode, if we're currently stepping but have stopped in
6280 some other thread, we need to switch back to the stepped thread. */
6281 if (switch_back_to_stepped_thread (ecs))
6284 if (ecs->event_thread->control.step_resume_breakpoint)
6287 fprintf_unfiltered (gdb_stdlog,
6288 "infrun: step-resume breakpoint is inserted\n");
6290 /* Having a step-resume breakpoint overrides anything
6291 else having to do with stepping commands until
6292 that breakpoint is reached. */
6297 if (ecs->event_thread->control.step_range_end == 0)
6300 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6301 /* Likewise if we aren't even stepping. */
6306 /* Re-fetch current thread's frame in case the code above caused
6307 the frame cache to be re-initialized, making our FRAME variable
6308 a dangling pointer. */
6309 frame = get_current_frame ();
6310 gdbarch = get_frame_arch (frame);
6311 fill_in_stop_func (gdbarch, ecs);
6313 /* If stepping through a line, keep going if still within it.
6315 Note that step_range_end is the address of the first instruction
6316 beyond the step range, and NOT the address of the last instruction
6319 Note also that during reverse execution, we may be stepping
6320 through a function epilogue and therefore must detect when
6321 the current-frame changes in the middle of a line. */
6323 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6325 && (execution_direction != EXEC_REVERSE
6326 || frame_id_eq (get_frame_id (frame),
6327 ecs->event_thread->control.step_frame_id)))
6331 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6332 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6333 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6335 /* Tentatively re-enable range stepping; `resume' disables it if
6336 necessary (e.g., if we're stepping over a breakpoint or we
6337 have software watchpoints). */
6338 ecs->event_thread->control.may_range_step = 1;
6340 /* When stepping backward, stop at beginning of line range
6341 (unless it's the function entry point, in which case
6342 keep going back to the call point). */
6343 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6344 if (stop_pc == ecs->event_thread->control.step_range_start
6345 && stop_pc != ecs->stop_func_start
6346 && execution_direction == EXEC_REVERSE)
6347 end_stepping_range (ecs);
6354 /* We stepped out of the stepping range. */
6356 /* If we are stepping at the source level and entered the runtime
6357 loader dynamic symbol resolution code...
6359 EXEC_FORWARD: we keep on single stepping until we exit the run
6360 time loader code and reach the callee's address.
6362 EXEC_REVERSE: we've already executed the callee (backward), and
6363 the runtime loader code is handled just like any other
6364 undebuggable function call. Now we need only keep stepping
6365 backward through the trampoline code, and that's handled further
6366 down, so there is nothing for us to do here. */
6368 if (execution_direction != EXEC_REVERSE
6369 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6370 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6372 CORE_ADDR pc_after_resolver =
6373 gdbarch_skip_solib_resolver (gdbarch,
6374 ecs->event_thread->suspend.stop_pc);
6377 fprintf_unfiltered (gdb_stdlog,
6378 "infrun: stepped into dynsym resolve code\n");
6380 if (pc_after_resolver)
6382 /* Set up a step-resume breakpoint at the address
6383 indicated by SKIP_SOLIB_RESOLVER. */
6384 symtab_and_line sr_sal;
6385 sr_sal.pc = pc_after_resolver;
6386 sr_sal.pspace = get_frame_program_space (frame);
6388 insert_step_resume_breakpoint_at_sal (gdbarch,
6389 sr_sal, null_frame_id);
6396 /* Step through an indirect branch thunk. */
6397 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6398 && gdbarch_in_indirect_branch_thunk (gdbarch,
6399 ecs->event_thread->suspend.stop_pc))
6402 fprintf_unfiltered (gdb_stdlog,
6403 "infrun: stepped into indirect branch thunk\n");
6408 if (ecs->event_thread->control.step_range_end != 1
6409 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6410 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6411 && get_frame_type (frame) == SIGTRAMP_FRAME)
6414 fprintf_unfiltered (gdb_stdlog,
6415 "infrun: stepped into signal trampoline\n");
6416 /* The inferior, while doing a "step" or "next", has ended up in
6417 a signal trampoline (either by a signal being delivered or by
6418 the signal handler returning). Just single-step until the
6419 inferior leaves the trampoline (either by calling the handler
6425 /* If we're in the return path from a shared library trampoline,
6426 we want to proceed through the trampoline when stepping. */
6427 /* macro/2012-04-25: This needs to come before the subroutine
6428 call check below as on some targets return trampolines look
6429 like subroutine calls (MIPS16 return thunks). */
6430 if (gdbarch_in_solib_return_trampoline (gdbarch,
6431 ecs->event_thread->suspend.stop_pc,
6432 ecs->stop_func_name)
6433 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6435 /* Determine where this trampoline returns. */
6436 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6437 CORE_ADDR real_stop_pc
6438 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6441 fprintf_unfiltered (gdb_stdlog,
6442 "infrun: stepped into solib return tramp\n");
6444 /* Only proceed through if we know where it's going. */
6447 /* And put the step-breakpoint there and go until there. */
6448 symtab_and_line sr_sal;
6449 sr_sal.pc = real_stop_pc;
6450 sr_sal.section = find_pc_overlay (sr_sal.pc);
6451 sr_sal.pspace = get_frame_program_space (frame);
6453 /* Do not specify what the fp should be when we stop since
6454 on some machines the prologue is where the new fp value
6456 insert_step_resume_breakpoint_at_sal (gdbarch,
6457 sr_sal, null_frame_id);
6459 /* Restart without fiddling with the step ranges or
6466 /* Check for subroutine calls. The check for the current frame
6467 equalling the step ID is not necessary - the check of the
6468 previous frame's ID is sufficient - but it is a common case and
6469 cheaper than checking the previous frame's ID.
6471 NOTE: frame_id_eq will never report two invalid frame IDs as
6472 being equal, so to get into this block, both the current and
6473 previous frame must have valid frame IDs. */
6474 /* The outer_frame_id check is a heuristic to detect stepping
6475 through startup code. If we step over an instruction which
6476 sets the stack pointer from an invalid value to a valid value,
6477 we may detect that as a subroutine call from the mythical
6478 "outermost" function. This could be fixed by marking
6479 outermost frames as !stack_p,code_p,special_p. Then the
6480 initial outermost frame, before sp was valid, would
6481 have code_addr == &_start. See the comment in frame_id_eq
6483 if (!frame_id_eq (get_stack_frame_id (frame),
6484 ecs->event_thread->control.step_stack_frame_id)
6485 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6486 ecs->event_thread->control.step_stack_frame_id)
6487 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6489 || (ecs->event_thread->control.step_start_function
6490 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6492 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6493 CORE_ADDR real_stop_pc;
6496 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6498 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6500 /* I presume that step_over_calls is only 0 when we're
6501 supposed to be stepping at the assembly language level
6502 ("stepi"). Just stop. */
6503 /* And this works the same backward as frontward. MVS */
6504 end_stepping_range (ecs);
6508 /* Reverse stepping through solib trampolines. */
6510 if (execution_direction == EXEC_REVERSE
6511 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6512 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6513 || (ecs->stop_func_start == 0
6514 && in_solib_dynsym_resolve_code (stop_pc))))
6516 /* Any solib trampoline code can be handled in reverse
6517 by simply continuing to single-step. We have already
6518 executed the solib function (backwards), and a few
6519 steps will take us back through the trampoline to the
6525 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6527 /* We're doing a "next".
6529 Normal (forward) execution: set a breakpoint at the
6530 callee's return address (the address at which the caller
6533 Reverse (backward) execution. set the step-resume
6534 breakpoint at the start of the function that we just
6535 stepped into (backwards), and continue to there. When we
6536 get there, we'll need to single-step back to the caller. */
6538 if (execution_direction == EXEC_REVERSE)
6540 /* If we're already at the start of the function, we've either
6541 just stepped backward into a single instruction function,
6542 or stepped back out of a signal handler to the first instruction
6543 of the function. Just keep going, which will single-step back
6545 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6547 /* Normal function call return (static or dynamic). */
6548 symtab_and_line sr_sal;
6549 sr_sal.pc = ecs->stop_func_start;
6550 sr_sal.pspace = get_frame_program_space (frame);
6551 insert_step_resume_breakpoint_at_sal (gdbarch,
6552 sr_sal, null_frame_id);
6556 insert_step_resume_breakpoint_at_caller (frame);
6562 /* If we are in a function call trampoline (a stub between the
6563 calling routine and the real function), locate the real
6564 function. That's what tells us (a) whether we want to step
6565 into it at all, and (b) what prologue we want to run to the
6566 end of, if we do step into it. */
6567 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6568 if (real_stop_pc == 0)
6569 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6570 if (real_stop_pc != 0)
6571 ecs->stop_func_start = real_stop_pc;
6573 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6575 symtab_and_line sr_sal;
6576 sr_sal.pc = ecs->stop_func_start;
6577 sr_sal.pspace = get_frame_program_space (frame);
6579 insert_step_resume_breakpoint_at_sal (gdbarch,
6580 sr_sal, null_frame_id);
6585 /* If we have line number information for the function we are
6586 thinking of stepping into and the function isn't on the skip
6589 If there are several symtabs at that PC (e.g. with include
6590 files), just want to know whether *any* of them have line
6591 numbers. find_pc_line handles this. */
6593 struct symtab_and_line tmp_sal;
6595 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6596 if (tmp_sal.line != 0
6597 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6600 if (execution_direction == EXEC_REVERSE)
6601 handle_step_into_function_backward (gdbarch, ecs);
6603 handle_step_into_function (gdbarch, ecs);
6608 /* If we have no line number and the step-stop-if-no-debug is
6609 set, we stop the step so that the user has a chance to switch
6610 in assembly mode. */
6611 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6612 && step_stop_if_no_debug)
6614 end_stepping_range (ecs);
6618 if (execution_direction == EXEC_REVERSE)
6620 /* If we're already at the start of the function, we've either just
6621 stepped backward into a single instruction function without line
6622 number info, or stepped back out of a signal handler to the first
6623 instruction of the function without line number info. Just keep
6624 going, which will single-step back to the caller. */
6625 if (ecs->stop_func_start != stop_pc)
6627 /* Set a breakpoint at callee's start address.
6628 From there we can step once and be back in the caller. */
6629 symtab_and_line sr_sal;
6630 sr_sal.pc = ecs->stop_func_start;
6631 sr_sal.pspace = get_frame_program_space (frame);
6632 insert_step_resume_breakpoint_at_sal (gdbarch,
6633 sr_sal, null_frame_id);
6637 /* Set a breakpoint at callee's return address (the address
6638 at which the caller will resume). */
6639 insert_step_resume_breakpoint_at_caller (frame);
6645 /* Reverse stepping through solib trampolines. */
6647 if (execution_direction == EXEC_REVERSE
6648 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6650 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6652 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6653 || (ecs->stop_func_start == 0
6654 && in_solib_dynsym_resolve_code (stop_pc)))
6656 /* Any solib trampoline code can be handled in reverse
6657 by simply continuing to single-step. We have already
6658 executed the solib function (backwards), and a few
6659 steps will take us back through the trampoline to the
6664 else if (in_solib_dynsym_resolve_code (stop_pc))
6666 /* Stepped backward into the solib dynsym resolver.
6667 Set a breakpoint at its start and continue, then
6668 one more step will take us out. */
6669 symtab_and_line sr_sal;
6670 sr_sal.pc = ecs->stop_func_start;
6671 sr_sal.pspace = get_frame_program_space (frame);
6672 insert_step_resume_breakpoint_at_sal (gdbarch,
6673 sr_sal, null_frame_id);
6679 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6681 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6682 the trampoline processing logic, however, there are some trampolines
6683 that have no names, so we should do trampoline handling first. */
6684 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6685 && ecs->stop_func_name == NULL
6686 && stop_pc_sal.line == 0)
6689 fprintf_unfiltered (gdb_stdlog,
6690 "infrun: stepped into undebuggable function\n");
6692 /* The inferior just stepped into, or returned to, an
6693 undebuggable function (where there is no debugging information
6694 and no line number corresponding to the address where the
6695 inferior stopped). Since we want to skip this kind of code,
6696 we keep going until the inferior returns from this
6697 function - unless the user has asked us not to (via
6698 set step-mode) or we no longer know how to get back
6699 to the call site. */
6700 if (step_stop_if_no_debug
6701 || !frame_id_p (frame_unwind_caller_id (frame)))
6703 /* If we have no line number and the step-stop-if-no-debug
6704 is set, we stop the step so that the user has a chance to
6705 switch in assembly mode. */
6706 end_stepping_range (ecs);
6711 /* Set a breakpoint at callee's return address (the address
6712 at which the caller will resume). */
6713 insert_step_resume_breakpoint_at_caller (frame);
6719 if (ecs->event_thread->control.step_range_end == 1)
6721 /* It is stepi or nexti. We always want to stop stepping after
6724 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6725 end_stepping_range (ecs);
6729 if (stop_pc_sal.line == 0)
6731 /* We have no line number information. That means to stop
6732 stepping (does this always happen right after one instruction,
6733 when we do "s" in a function with no line numbers,
6734 or can this happen as a result of a return or longjmp?). */
6736 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6737 end_stepping_range (ecs);
6741 /* Look for "calls" to inlined functions, part one. If the inline
6742 frame machinery detected some skipped call sites, we have entered
6743 a new inline function. */
6745 if (frame_id_eq (get_frame_id (get_current_frame ()),
6746 ecs->event_thread->control.step_frame_id)
6747 && inline_skipped_frames (ecs->event_thread))
6750 fprintf_unfiltered (gdb_stdlog,
6751 "infrun: stepped into inlined function\n");
6753 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6755 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6757 /* For "step", we're going to stop. But if the call site
6758 for this inlined function is on the same source line as
6759 we were previously stepping, go down into the function
6760 first. Otherwise stop at the call site. */
6762 if (call_sal.line == ecs->event_thread->current_line
6763 && call_sal.symtab == ecs->event_thread->current_symtab)
6764 step_into_inline_frame (ecs->event_thread);
6766 end_stepping_range (ecs);
6771 /* For "next", we should stop at the call site if it is on a
6772 different source line. Otherwise continue through the
6773 inlined function. */
6774 if (call_sal.line == ecs->event_thread->current_line
6775 && call_sal.symtab == ecs->event_thread->current_symtab)
6778 end_stepping_range (ecs);
6783 /* Look for "calls" to inlined functions, part two. If we are still
6784 in the same real function we were stepping through, but we have
6785 to go further up to find the exact frame ID, we are stepping
6786 through a more inlined call beyond its call site. */
6788 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6789 && !frame_id_eq (get_frame_id (get_current_frame ()),
6790 ecs->event_thread->control.step_frame_id)
6791 && stepped_in_from (get_current_frame (),
6792 ecs->event_thread->control.step_frame_id))
6795 fprintf_unfiltered (gdb_stdlog,
6796 "infrun: stepping through inlined function\n");
6798 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6801 end_stepping_range (ecs);
6805 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6806 && (ecs->event_thread->current_line != stop_pc_sal.line
6807 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6809 /* We are at the start of a different line. So stop. Note that
6810 we don't stop if we step into the middle of a different line.
6811 That is said to make things like for (;;) statements work
6814 fprintf_unfiltered (gdb_stdlog,
6815 "infrun: stepped to a different line\n");
6816 end_stepping_range (ecs);
6820 /* We aren't done stepping.
6822 Optimize by setting the stepping range to the line.
6823 (We might not be in the original line, but if we entered a
6824 new line in mid-statement, we continue stepping. This makes
6825 things like for(;;) statements work better.) */
6827 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6828 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6829 ecs->event_thread->control.may_range_step = 1;
6830 set_step_info (frame, stop_pc_sal);
6833 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6837 /* In all-stop mode, if we're currently stepping but have stopped in
6838 some other thread, we may need to switch back to the stepped
6839 thread. Returns true we set the inferior running, false if we left
6840 it stopped (and the event needs further processing). */
6843 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6845 if (!target_is_non_stop_p ())
6847 struct thread_info *stepping_thread;
6849 /* If any thread is blocked on some internal breakpoint, and we
6850 simply need to step over that breakpoint to get it going
6851 again, do that first. */
6853 /* However, if we see an event for the stepping thread, then we
6854 know all other threads have been moved past their breakpoints
6855 already. Let the caller check whether the step is finished,
6856 etc., before deciding to move it past a breakpoint. */
6857 if (ecs->event_thread->control.step_range_end != 0)
6860 /* Check if the current thread is blocked on an incomplete
6861 step-over, interrupted by a random signal. */
6862 if (ecs->event_thread->control.trap_expected
6863 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6867 fprintf_unfiltered (gdb_stdlog,
6868 "infrun: need to finish step-over of [%s]\n",
6869 target_pid_to_str (ecs->event_thread->ptid));
6875 /* Check if the current thread is blocked by a single-step
6876 breakpoint of another thread. */
6877 if (ecs->hit_singlestep_breakpoint)
6881 fprintf_unfiltered (gdb_stdlog,
6882 "infrun: need to step [%s] over single-step "
6884 target_pid_to_str (ecs->ptid));
6890 /* If this thread needs yet another step-over (e.g., stepping
6891 through a delay slot), do it first before moving on to
6893 if (thread_still_needs_step_over (ecs->event_thread))
6897 fprintf_unfiltered (gdb_stdlog,
6898 "infrun: thread [%s] still needs step-over\n",
6899 target_pid_to_str (ecs->event_thread->ptid));
6905 /* If scheduler locking applies even if not stepping, there's no
6906 need to walk over threads. Above we've checked whether the
6907 current thread is stepping. If some other thread not the
6908 event thread is stepping, then it must be that scheduler
6909 locking is not in effect. */
6910 if (schedlock_applies (ecs->event_thread))
6913 /* Otherwise, we no longer expect a trap in the current thread.
6914 Clear the trap_expected flag before switching back -- this is
6915 what keep_going does as well, if we call it. */
6916 ecs->event_thread->control.trap_expected = 0;
6918 /* Likewise, clear the signal if it should not be passed. */
6919 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6920 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6922 /* Do all pending step-overs before actually proceeding with
6924 if (start_step_over ())
6926 prepare_to_wait (ecs);
6930 /* Look for the stepping/nexting thread. */
6931 stepping_thread = NULL;
6933 for (thread_info *tp : all_non_exited_threads ())
6935 /* Ignore threads of processes the caller is not
6938 && tp->ptid.pid () != ecs->ptid.pid ())
6941 /* When stepping over a breakpoint, we lock all threads
6942 except the one that needs to move past the breakpoint.
6943 If a non-event thread has this set, the "incomplete
6944 step-over" check above should have caught it earlier. */
6945 if (tp->control.trap_expected)
6947 internal_error (__FILE__, __LINE__,
6948 "[%s] has inconsistent state: "
6949 "trap_expected=%d\n",
6950 target_pid_to_str (tp->ptid),
6951 tp->control.trap_expected);
6954 /* Did we find the stepping thread? */
6955 if (tp->control.step_range_end)
6957 /* Yep. There should only one though. */
6958 gdb_assert (stepping_thread == NULL);
6960 /* The event thread is handled at the top, before we
6962 gdb_assert (tp != ecs->event_thread);
6964 /* If some thread other than the event thread is
6965 stepping, then scheduler locking can't be in effect,
6966 otherwise we wouldn't have resumed the current event
6967 thread in the first place. */
6968 gdb_assert (!schedlock_applies (tp));
6970 stepping_thread = tp;
6974 if (stepping_thread != NULL)
6977 fprintf_unfiltered (gdb_stdlog,
6978 "infrun: switching back to stepped thread\n");
6980 if (keep_going_stepped_thread (stepping_thread))
6982 prepare_to_wait (ecs);
6991 /* Set a previously stepped thread back to stepping. Returns true on
6992 success, false if the resume is not possible (e.g., the thread
6996 keep_going_stepped_thread (struct thread_info *tp)
6998 struct frame_info *frame;
6999 struct execution_control_state ecss;
7000 struct execution_control_state *ecs = &ecss;
7002 /* If the stepping thread exited, then don't try to switch back and
7003 resume it, which could fail in several different ways depending
7004 on the target. Instead, just keep going.
7006 We can find a stepping dead thread in the thread list in two
7009 - The target supports thread exit events, and when the target
7010 tries to delete the thread from the thread list, inferior_ptid
7011 pointed at the exiting thread. In such case, calling
7012 delete_thread does not really remove the thread from the list;
7013 instead, the thread is left listed, with 'exited' state.
7015 - The target's debug interface does not support thread exit
7016 events, and so we have no idea whatsoever if the previously
7017 stepping thread is still alive. For that reason, we need to
7018 synchronously query the target now. */
7020 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
7023 fprintf_unfiltered (gdb_stdlog,
7024 "infrun: not resuming previously "
7025 "stepped thread, it has vanished\n");
7032 fprintf_unfiltered (gdb_stdlog,
7033 "infrun: resuming previously stepped thread\n");
7035 reset_ecs (ecs, tp);
7036 switch_to_thread (tp);
7038 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7039 frame = get_current_frame ();
7041 /* If the PC of the thread we were trying to single-step has
7042 changed, then that thread has trapped or been signaled, but the
7043 event has not been reported to GDB yet. Re-poll the target
7044 looking for this particular thread's event (i.e. temporarily
7045 enable schedlock) by:
7047 - setting a break at the current PC
7048 - resuming that particular thread, only (by setting trap
7051 This prevents us continuously moving the single-step breakpoint
7052 forward, one instruction at a time, overstepping. */
7054 if (tp->suspend.stop_pc != tp->prev_pc)
7059 fprintf_unfiltered (gdb_stdlog,
7060 "infrun: expected thread advanced also (%s -> %s)\n",
7061 paddress (target_gdbarch (), tp->prev_pc),
7062 paddress (target_gdbarch (), tp->suspend.stop_pc));
7064 /* Clear the info of the previous step-over, as it's no longer
7065 valid (if the thread was trying to step over a breakpoint, it
7066 has already succeeded). It's what keep_going would do too,
7067 if we called it. Do this before trying to insert the sss
7068 breakpoint, otherwise if we were previously trying to step
7069 over this exact address in another thread, the breakpoint is
7071 clear_step_over_info ();
7072 tp->control.trap_expected = 0;
7074 insert_single_step_breakpoint (get_frame_arch (frame),
7075 get_frame_address_space (frame),
7076 tp->suspend.stop_pc);
7079 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7080 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7085 fprintf_unfiltered (gdb_stdlog,
7086 "infrun: expected thread still hasn't advanced\n");
7088 keep_going_pass_signal (ecs);
7093 /* Is thread TP in the middle of (software or hardware)
7094 single-stepping? (Note the result of this function must never be
7095 passed directly as target_resume's STEP parameter.) */
7098 currently_stepping (struct thread_info *tp)
7100 return ((tp->control.step_range_end
7101 && tp->control.step_resume_breakpoint == NULL)
7102 || tp->control.trap_expected
7103 || tp->stepped_breakpoint
7104 || bpstat_should_step ());
7107 /* Inferior has stepped into a subroutine call with source code that
7108 we should not step over. Do step to the first line of code in
7112 handle_step_into_function (struct gdbarch *gdbarch,
7113 struct execution_control_state *ecs)
7115 fill_in_stop_func (gdbarch, ecs);
7117 compunit_symtab *cust
7118 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7119 if (cust != NULL && compunit_language (cust) != language_asm)
7120 ecs->stop_func_start
7121 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7123 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7124 /* Use the step_resume_break to step until the end of the prologue,
7125 even if that involves jumps (as it seems to on the vax under
7127 /* If the prologue ends in the middle of a source line, continue to
7128 the end of that source line (if it is still within the function).
7129 Otherwise, just go to end of prologue. */
7130 if (stop_func_sal.end
7131 && stop_func_sal.pc != ecs->stop_func_start
7132 && stop_func_sal.end < ecs->stop_func_end)
7133 ecs->stop_func_start = stop_func_sal.end;
7135 /* Architectures which require breakpoint adjustment might not be able
7136 to place a breakpoint at the computed address. If so, the test
7137 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7138 ecs->stop_func_start to an address at which a breakpoint may be
7139 legitimately placed.
7141 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7142 made, GDB will enter an infinite loop when stepping through
7143 optimized code consisting of VLIW instructions which contain
7144 subinstructions corresponding to different source lines. On
7145 FR-V, it's not permitted to place a breakpoint on any but the
7146 first subinstruction of a VLIW instruction. When a breakpoint is
7147 set, GDB will adjust the breakpoint address to the beginning of
7148 the VLIW instruction. Thus, we need to make the corresponding
7149 adjustment here when computing the stop address. */
7151 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7153 ecs->stop_func_start
7154 = gdbarch_adjust_breakpoint_address (gdbarch,
7155 ecs->stop_func_start);
7158 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7160 /* We are already there: stop now. */
7161 end_stepping_range (ecs);
7166 /* Put the step-breakpoint there and go until there. */
7167 symtab_and_line sr_sal;
7168 sr_sal.pc = ecs->stop_func_start;
7169 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7170 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7172 /* Do not specify what the fp should be when we stop since on
7173 some machines the prologue is where the new fp value is
7175 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7177 /* And make sure stepping stops right away then. */
7178 ecs->event_thread->control.step_range_end
7179 = ecs->event_thread->control.step_range_start;
7184 /* Inferior has stepped backward into a subroutine call with source
7185 code that we should not step over. Do step to the beginning of the
7186 last line of code in it. */
7189 handle_step_into_function_backward (struct gdbarch *gdbarch,
7190 struct execution_control_state *ecs)
7192 struct compunit_symtab *cust;
7193 struct symtab_and_line stop_func_sal;
7195 fill_in_stop_func (gdbarch, ecs);
7197 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7198 if (cust != NULL && compunit_language (cust) != language_asm)
7199 ecs->stop_func_start
7200 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7202 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7204 /* OK, we're just going to keep stepping here. */
7205 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7207 /* We're there already. Just stop stepping now. */
7208 end_stepping_range (ecs);
7212 /* Else just reset the step range and keep going.
7213 No step-resume breakpoint, they don't work for
7214 epilogues, which can have multiple entry paths. */
7215 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7216 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7222 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7223 This is used to both functions and to skip over code. */
7226 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7227 struct symtab_and_line sr_sal,
7228 struct frame_id sr_id,
7229 enum bptype sr_type)
7231 /* There should never be more than one step-resume or longjmp-resume
7232 breakpoint per thread, so we should never be setting a new
7233 step_resume_breakpoint when one is already active. */
7234 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7235 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7238 fprintf_unfiltered (gdb_stdlog,
7239 "infrun: inserting step-resume breakpoint at %s\n",
7240 paddress (gdbarch, sr_sal.pc));
7242 inferior_thread ()->control.step_resume_breakpoint
7243 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7247 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7248 struct symtab_and_line sr_sal,
7249 struct frame_id sr_id)
7251 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7256 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7257 This is used to skip a potential signal handler.
7259 This is called with the interrupted function's frame. The signal
7260 handler, when it returns, will resume the interrupted function at
7264 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7266 gdb_assert (return_frame != NULL);
7268 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7270 symtab_and_line sr_sal;
7271 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7272 sr_sal.section = find_pc_overlay (sr_sal.pc);
7273 sr_sal.pspace = get_frame_program_space (return_frame);
7275 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7276 get_stack_frame_id (return_frame),
7280 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7281 is used to skip a function after stepping into it (for "next" or if
7282 the called function has no debugging information).
7284 The current function has almost always been reached by single
7285 stepping a call or return instruction. NEXT_FRAME belongs to the
7286 current function, and the breakpoint will be set at the caller's
7289 This is a separate function rather than reusing
7290 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7291 get_prev_frame, which may stop prematurely (see the implementation
7292 of frame_unwind_caller_id for an example). */
7295 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7297 /* We shouldn't have gotten here if we don't know where the call site
7299 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7301 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7303 symtab_and_line sr_sal;
7304 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7305 frame_unwind_caller_pc (next_frame));
7306 sr_sal.section = find_pc_overlay (sr_sal.pc);
7307 sr_sal.pspace = frame_unwind_program_space (next_frame);
7309 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7310 frame_unwind_caller_id (next_frame));
7313 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7314 new breakpoint at the target of a jmp_buf. The handling of
7315 longjmp-resume uses the same mechanisms used for handling
7316 "step-resume" breakpoints. */
7319 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7321 /* There should never be more than one longjmp-resume breakpoint per
7322 thread, so we should never be setting a new
7323 longjmp_resume_breakpoint when one is already active. */
7324 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7327 fprintf_unfiltered (gdb_stdlog,
7328 "infrun: inserting longjmp-resume breakpoint at %s\n",
7329 paddress (gdbarch, pc));
7331 inferior_thread ()->control.exception_resume_breakpoint =
7332 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7335 /* Insert an exception resume breakpoint. TP is the thread throwing
7336 the exception. The block B is the block of the unwinder debug hook
7337 function. FRAME is the frame corresponding to the call to this
7338 function. SYM is the symbol of the function argument holding the
7339 target PC of the exception. */
7342 insert_exception_resume_breakpoint (struct thread_info *tp,
7343 const struct block *b,
7344 struct frame_info *frame,
7349 struct block_symbol vsym;
7350 struct value *value;
7352 struct breakpoint *bp;
7354 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7356 value = read_var_value (vsym.symbol, vsym.block, frame);
7357 /* If the value was optimized out, revert to the old behavior. */
7358 if (! value_optimized_out (value))
7360 handler = value_as_address (value);
7363 fprintf_unfiltered (gdb_stdlog,
7364 "infrun: exception resume at %lx\n",
7365 (unsigned long) handler);
7367 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7369 bp_exception_resume).release ();
7371 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7374 bp->thread = tp->global_num;
7375 inferior_thread ()->control.exception_resume_breakpoint = bp;
7378 CATCH (e, RETURN_MASK_ERROR)
7380 /* We want to ignore errors here. */
7385 /* A helper for check_exception_resume that sets an
7386 exception-breakpoint based on a SystemTap probe. */
7389 insert_exception_resume_from_probe (struct thread_info *tp,
7390 const struct bound_probe *probe,
7391 struct frame_info *frame)
7393 struct value *arg_value;
7395 struct breakpoint *bp;
7397 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7401 handler = value_as_address (arg_value);
7404 fprintf_unfiltered (gdb_stdlog,
7405 "infrun: exception resume at %s\n",
7406 paddress (get_objfile_arch (probe->objfile),
7409 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7410 handler, bp_exception_resume).release ();
7411 bp->thread = tp->global_num;
7412 inferior_thread ()->control.exception_resume_breakpoint = bp;
7415 /* This is called when an exception has been intercepted. Check to
7416 see whether the exception's destination is of interest, and if so,
7417 set an exception resume breakpoint there. */
7420 check_exception_resume (struct execution_control_state *ecs,
7421 struct frame_info *frame)
7423 struct bound_probe probe;
7424 struct symbol *func;
7426 /* First see if this exception unwinding breakpoint was set via a
7427 SystemTap probe point. If so, the probe has two arguments: the
7428 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7429 set a breakpoint there. */
7430 probe = find_probe_by_pc (get_frame_pc (frame));
7433 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7437 func = get_frame_function (frame);
7443 const struct block *b;
7444 struct block_iterator iter;
7448 /* The exception breakpoint is a thread-specific breakpoint on
7449 the unwinder's debug hook, declared as:
7451 void _Unwind_DebugHook (void *cfa, void *handler);
7453 The CFA argument indicates the frame to which control is
7454 about to be transferred. HANDLER is the destination PC.
7456 We ignore the CFA and set a temporary breakpoint at HANDLER.
7457 This is not extremely efficient but it avoids issues in gdb
7458 with computing the DWARF CFA, and it also works even in weird
7459 cases such as throwing an exception from inside a signal
7462 b = SYMBOL_BLOCK_VALUE (func);
7463 ALL_BLOCK_SYMBOLS (b, iter, sym)
7465 if (!SYMBOL_IS_ARGUMENT (sym))
7472 insert_exception_resume_breakpoint (ecs->event_thread,
7478 CATCH (e, RETURN_MASK_ERROR)
7485 stop_waiting (struct execution_control_state *ecs)
7488 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7490 /* Let callers know we don't want to wait for the inferior anymore. */
7491 ecs->wait_some_more = 0;
7493 /* If all-stop, but the target is always in non-stop mode, stop all
7494 threads now that we're presenting the stop to the user. */
7495 if (!non_stop && target_is_non_stop_p ())
7496 stop_all_threads ();
7499 /* Like keep_going, but passes the signal to the inferior, even if the
7500 signal is set to nopass. */
7503 keep_going_pass_signal (struct execution_control_state *ecs)
7505 gdb_assert (ecs->event_thread->ptid == inferior_ptid);
7506 gdb_assert (!ecs->event_thread->resumed);
7508 /* Save the pc before execution, to compare with pc after stop. */
7509 ecs->event_thread->prev_pc
7510 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7512 if (ecs->event_thread->control.trap_expected)
7514 struct thread_info *tp = ecs->event_thread;
7517 fprintf_unfiltered (gdb_stdlog,
7518 "infrun: %s has trap_expected set, "
7519 "resuming to collect trap\n",
7520 target_pid_to_str (tp->ptid));
7522 /* We haven't yet gotten our trap, and either: intercepted a
7523 non-signal event (e.g., a fork); or took a signal which we
7524 are supposed to pass through to the inferior. Simply
7526 resume (ecs->event_thread->suspend.stop_signal);
7528 else if (step_over_info_valid_p ())
7530 /* Another thread is stepping over a breakpoint in-line. If
7531 this thread needs a step-over too, queue the request. In
7532 either case, this resume must be deferred for later. */
7533 struct thread_info *tp = ecs->event_thread;
7535 if (ecs->hit_singlestep_breakpoint
7536 || thread_still_needs_step_over (tp))
7539 fprintf_unfiltered (gdb_stdlog,
7540 "infrun: step-over already in progress: "
7541 "step-over for %s deferred\n",
7542 target_pid_to_str (tp->ptid));
7543 thread_step_over_chain_enqueue (tp);
7548 fprintf_unfiltered (gdb_stdlog,
7549 "infrun: step-over in progress: "
7550 "resume of %s deferred\n",
7551 target_pid_to_str (tp->ptid));
7556 struct regcache *regcache = get_current_regcache ();
7559 step_over_what step_what;
7561 /* Either the trap was not expected, but we are continuing
7562 anyway (if we got a signal, the user asked it be passed to
7565 We got our expected trap, but decided we should resume from
7568 We're going to run this baby now!
7570 Note that insert_breakpoints won't try to re-insert
7571 already inserted breakpoints. Therefore, we don't
7572 care if breakpoints were already inserted, or not. */
7574 /* If we need to step over a breakpoint, and we're not using
7575 displaced stepping to do so, insert all breakpoints
7576 (watchpoints, etc.) but the one we're stepping over, step one
7577 instruction, and then re-insert the breakpoint when that step
7580 step_what = thread_still_needs_step_over (ecs->event_thread);
7582 remove_bp = (ecs->hit_singlestep_breakpoint
7583 || (step_what & STEP_OVER_BREAKPOINT));
7584 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7586 /* We can't use displaced stepping if we need to step past a
7587 watchpoint. The instruction copied to the scratch pad would
7588 still trigger the watchpoint. */
7590 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7592 set_step_over_info (regcache->aspace (),
7593 regcache_read_pc (regcache), remove_wps,
7594 ecs->event_thread->global_num);
7596 else if (remove_wps)
7597 set_step_over_info (NULL, 0, remove_wps, -1);
7599 /* If we now need to do an in-line step-over, we need to stop
7600 all other threads. Note this must be done before
7601 insert_breakpoints below, because that removes the breakpoint
7602 we're about to step over, otherwise other threads could miss
7604 if (step_over_info_valid_p () && target_is_non_stop_p ())
7605 stop_all_threads ();
7607 /* Stop stepping if inserting breakpoints fails. */
7610 insert_breakpoints ();
7612 CATCH (e, RETURN_MASK_ERROR)
7614 exception_print (gdb_stderr, e);
7616 clear_step_over_info ();
7621 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7623 resume (ecs->event_thread->suspend.stop_signal);
7626 prepare_to_wait (ecs);
7629 /* Called when we should continue running the inferior, because the
7630 current event doesn't cause a user visible stop. This does the
7631 resuming part; waiting for the next event is done elsewhere. */
7634 keep_going (struct execution_control_state *ecs)
7636 if (ecs->event_thread->control.trap_expected
7637 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7638 ecs->event_thread->control.trap_expected = 0;
7640 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7641 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7642 keep_going_pass_signal (ecs);
7645 /* This function normally comes after a resume, before
7646 handle_inferior_event exits. It takes care of any last bits of
7647 housekeeping, and sets the all-important wait_some_more flag. */
7650 prepare_to_wait (struct execution_control_state *ecs)
7653 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7655 ecs->wait_some_more = 1;
7657 if (!target_is_async_p ())
7658 mark_infrun_async_event_handler ();
7661 /* We are done with the step range of a step/next/si/ni command.
7662 Called once for each n of a "step n" operation. */
7665 end_stepping_range (struct execution_control_state *ecs)
7667 ecs->event_thread->control.stop_step = 1;
7671 /* Several print_*_reason functions to print why the inferior has stopped.
7672 We always print something when the inferior exits, or receives a signal.
7673 The rest of the cases are dealt with later on in normal_stop and
7674 print_it_typical. Ideally there should be a call to one of these
7675 print_*_reason functions functions from handle_inferior_event each time
7676 stop_waiting is called.
7678 Note that we don't call these directly, instead we delegate that to
7679 the interpreters, through observers. Interpreters then call these
7680 with whatever uiout is right. */
7683 print_end_stepping_range_reason (struct ui_out *uiout)
7685 /* For CLI-like interpreters, print nothing. */
7687 if (uiout->is_mi_like_p ())
7689 uiout->field_string ("reason",
7690 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7695 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7697 annotate_signalled ();
7698 if (uiout->is_mi_like_p ())
7700 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7701 uiout->text ("\nProgram terminated with signal ");
7702 annotate_signal_name ();
7703 uiout->field_string ("signal-name",
7704 gdb_signal_to_name (siggnal));
7705 annotate_signal_name_end ();
7707 annotate_signal_string ();
7708 uiout->field_string ("signal-meaning",
7709 gdb_signal_to_string (siggnal));
7710 annotate_signal_string_end ();
7711 uiout->text (".\n");
7712 uiout->text ("The program no longer exists.\n");
7716 print_exited_reason (struct ui_out *uiout, int exitstatus)
7718 struct inferior *inf = current_inferior ();
7719 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7721 annotate_exited (exitstatus);
7724 if (uiout->is_mi_like_p ())
7725 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7726 uiout->text ("[Inferior ");
7727 uiout->text (plongest (inf->num));
7729 uiout->text (pidstr);
7730 uiout->text (") exited with code ");
7731 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7732 uiout->text ("]\n");
7736 if (uiout->is_mi_like_p ())
7738 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7739 uiout->text ("[Inferior ");
7740 uiout->text (plongest (inf->num));
7742 uiout->text (pidstr);
7743 uiout->text (") exited normally]\n");
7747 /* Some targets/architectures can do extra processing/display of
7748 segmentation faults. E.g., Intel MPX boundary faults.
7749 Call the architecture dependent function to handle the fault. */
7752 handle_segmentation_fault (struct ui_out *uiout)
7754 struct regcache *regcache = get_current_regcache ();
7755 struct gdbarch *gdbarch = regcache->arch ();
7757 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7758 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7762 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7764 struct thread_info *thr = inferior_thread ();
7768 if (uiout->is_mi_like_p ())
7770 else if (show_thread_that_caused_stop ())
7774 uiout->text ("\nThread ");
7775 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7777 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7780 uiout->text (" \"");
7781 uiout->field_fmt ("name", "%s", name);
7786 uiout->text ("\nProgram");
7788 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7789 uiout->text (" stopped");
7792 uiout->text (" received signal ");
7793 annotate_signal_name ();
7794 if (uiout->is_mi_like_p ())
7796 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7797 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7798 annotate_signal_name_end ();
7800 annotate_signal_string ();
7801 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7803 if (siggnal == GDB_SIGNAL_SEGV)
7804 handle_segmentation_fault (uiout);
7806 annotate_signal_string_end ();
7808 uiout->text (".\n");
7812 print_no_history_reason (struct ui_out *uiout)
7814 uiout->text ("\nNo more reverse-execution history.\n");
7817 /* Print current location without a level number, if we have changed
7818 functions or hit a breakpoint. Print source line if we have one.
7819 bpstat_print contains the logic deciding in detail what to print,
7820 based on the event(s) that just occurred. */
7823 print_stop_location (struct target_waitstatus *ws)
7826 enum print_what source_flag;
7827 int do_frame_printing = 1;
7828 struct thread_info *tp = inferior_thread ();
7830 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7834 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7835 should) carry around the function and does (or should) use
7836 that when doing a frame comparison. */
7837 if (tp->control.stop_step
7838 && frame_id_eq (tp->control.step_frame_id,
7839 get_frame_id (get_current_frame ()))
7840 && (tp->control.step_start_function
7841 == find_pc_function (tp->suspend.stop_pc)))
7843 /* Finished step, just print source line. */
7844 source_flag = SRC_LINE;
7848 /* Print location and source line. */
7849 source_flag = SRC_AND_LOC;
7852 case PRINT_SRC_AND_LOC:
7853 /* Print location and source line. */
7854 source_flag = SRC_AND_LOC;
7856 case PRINT_SRC_ONLY:
7857 source_flag = SRC_LINE;
7860 /* Something bogus. */
7861 source_flag = SRC_LINE;
7862 do_frame_printing = 0;
7865 internal_error (__FILE__, __LINE__, _("Unknown value."));
7868 /* The behavior of this routine with respect to the source
7870 SRC_LINE: Print only source line
7871 LOCATION: Print only location
7872 SRC_AND_LOC: Print location and source line. */
7873 if (do_frame_printing)
7874 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7880 print_stop_event (struct ui_out *uiout)
7882 struct target_waitstatus last;
7884 struct thread_info *tp;
7886 get_last_target_status (&last_ptid, &last);
7889 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
7891 print_stop_location (&last);
7893 /* Display the auto-display expressions. */
7897 tp = inferior_thread ();
7898 if (tp->thread_fsm != NULL
7899 && thread_fsm_finished_p (tp->thread_fsm))
7901 struct return_value_info *rv;
7903 rv = thread_fsm_return_value (tp->thread_fsm);
7905 print_return_value (uiout, rv);
7912 maybe_remove_breakpoints (void)
7914 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7916 if (remove_breakpoints ())
7918 target_terminal::ours_for_output ();
7919 printf_filtered (_("Cannot remove breakpoints because "
7920 "program is no longer writable.\nFurther "
7921 "execution is probably impossible.\n"));
7926 /* The execution context that just caused a normal stop. */
7933 DISABLE_COPY_AND_ASSIGN (stop_context);
7935 bool changed () const;
7940 /* The event PTID. */
7944 /* If stopp for a thread event, this is the thread that caused the
7946 struct thread_info *thread;
7948 /* The inferior that caused the stop. */
7952 /* Initializes a new stop context. If stopped for a thread event, this
7953 takes a strong reference to the thread. */
7955 stop_context::stop_context ()
7957 stop_id = get_stop_id ();
7958 ptid = inferior_ptid;
7959 inf_num = current_inferior ()->num;
7961 if (inferior_ptid != null_ptid)
7963 /* Take a strong reference so that the thread can't be deleted
7965 thread = inferior_thread ();
7972 /* Release a stop context previously created with save_stop_context.
7973 Releases the strong reference to the thread as well. */
7975 stop_context::~stop_context ()
7981 /* Return true if the current context no longer matches the saved stop
7985 stop_context::changed () const
7987 if (ptid != inferior_ptid)
7989 if (inf_num != current_inferior ()->num)
7991 if (thread != NULL && thread->state != THREAD_STOPPED)
7993 if (get_stop_id () != stop_id)
8003 struct target_waitstatus last;
8006 get_last_target_status (&last_ptid, &last);
8010 /* If an exception is thrown from this point on, make sure to
8011 propagate GDB's knowledge of the executing state to the
8012 frontend/user running state. A QUIT is an easy exception to see
8013 here, so do this before any filtered output. */
8015 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
8018 maybe_finish_thread_state.emplace (minus_one_ptid);
8019 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8020 || last.kind == TARGET_WAITKIND_EXITED)
8022 /* On some targets, we may still have live threads in the
8023 inferior when we get a process exit event. E.g., for
8024 "checkpoint", when the current checkpoint/fork exits,
8025 linux-fork.c automatically switches to another fork from
8026 within target_mourn_inferior. */
8027 if (inferior_ptid != null_ptid)
8028 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8030 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8031 maybe_finish_thread_state.emplace (inferior_ptid);
8033 /* As we're presenting a stop, and potentially removing breakpoints,
8034 update the thread list so we can tell whether there are threads
8035 running on the target. With target remote, for example, we can
8036 only learn about new threads when we explicitly update the thread
8037 list. Do this before notifying the interpreters about signal
8038 stops, end of stepping ranges, etc., so that the "new thread"
8039 output is emitted before e.g., "Program received signal FOO",
8040 instead of after. */
8041 update_thread_list ();
8043 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8044 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8046 /* As with the notification of thread events, we want to delay
8047 notifying the user that we've switched thread context until
8048 the inferior actually stops.
8050 There's no point in saying anything if the inferior has exited.
8051 Note that SIGNALLED here means "exited with a signal", not
8052 "received a signal".
8054 Also skip saying anything in non-stop mode. In that mode, as we
8055 don't want GDB to switch threads behind the user's back, to avoid
8056 races where the user is typing a command to apply to thread x,
8057 but GDB switches to thread y before the user finishes entering
8058 the command, fetch_inferior_event installs a cleanup to restore
8059 the current thread back to the thread the user had selected right
8060 after this event is handled, so we're not really switching, only
8061 informing of a stop. */
8063 && previous_inferior_ptid != inferior_ptid
8064 && target_has_execution
8065 && last.kind != TARGET_WAITKIND_SIGNALLED
8066 && last.kind != TARGET_WAITKIND_EXITED
8067 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8069 SWITCH_THRU_ALL_UIS ()
8071 target_terminal::ours_for_output ();
8072 printf_filtered (_("[Switching to %s]\n"),
8073 target_pid_to_str (inferior_ptid));
8074 annotate_thread_changed ();
8076 previous_inferior_ptid = inferior_ptid;
8079 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8081 SWITCH_THRU_ALL_UIS ()
8082 if (current_ui->prompt_state == PROMPT_BLOCKED)
8084 target_terminal::ours_for_output ();
8085 printf_filtered (_("No unwaited-for children left.\n"));
8089 /* Note: this depends on the update_thread_list call above. */
8090 maybe_remove_breakpoints ();
8092 /* If an auto-display called a function and that got a signal,
8093 delete that auto-display to avoid an infinite recursion. */
8095 if (stopped_by_random_signal)
8096 disable_current_display ();
8098 SWITCH_THRU_ALL_UIS ()
8100 async_enable_stdin ();
8103 /* Let the user/frontend see the threads as stopped. */
8104 maybe_finish_thread_state.reset ();
8106 /* Select innermost stack frame - i.e., current frame is frame 0,
8107 and current location is based on that. Handle the case where the
8108 dummy call is returning after being stopped. E.g. the dummy call
8109 previously hit a breakpoint. (If the dummy call returns
8110 normally, we won't reach here.) Do this before the stop hook is
8111 run, so that it doesn't get to see the temporary dummy frame,
8112 which is not where we'll present the stop. */
8113 if (has_stack_frames ())
8115 if (stop_stack_dummy == STOP_STACK_DUMMY)
8117 /* Pop the empty frame that contains the stack dummy. This
8118 also restores inferior state prior to the call (struct
8119 infcall_suspend_state). */
8120 struct frame_info *frame = get_current_frame ();
8122 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8124 /* frame_pop calls reinit_frame_cache as the last thing it
8125 does which means there's now no selected frame. */
8128 select_frame (get_current_frame ());
8130 /* Set the current source location. */
8131 set_current_sal_from_frame (get_current_frame ());
8134 /* Look up the hook_stop and run it (CLI internally handles problem
8135 of stop_command's pre-hook not existing). */
8136 if (stop_command != NULL)
8138 stop_context saved_context;
8142 execute_cmd_pre_hook (stop_command);
8144 CATCH (ex, RETURN_MASK_ALL)
8146 exception_fprintf (gdb_stderr, ex,
8147 "Error while running hook_stop:\n");
8151 /* If the stop hook resumes the target, then there's no point in
8152 trying to notify about the previous stop; its context is
8153 gone. Likewise if the command switches thread or inferior --
8154 the observers would print a stop for the wrong
8156 if (saved_context.changed ())
8160 /* Notify observers about the stop. This is where the interpreters
8161 print the stop event. */
8162 if (inferior_ptid != null_ptid)
8163 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8166 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8168 annotate_stopped ();
8170 if (target_has_execution)
8172 if (last.kind != TARGET_WAITKIND_SIGNALLED
8173 && last.kind != TARGET_WAITKIND_EXITED)
8174 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8175 Delete any breakpoint that is to be deleted at the next stop. */
8176 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8179 /* Try to get rid of automatically added inferiors that are no
8180 longer needed. Keeping those around slows down things linearly.
8181 Note that this never removes the current inferior. */
8188 signal_stop_state (int signo)
8190 return signal_stop[signo];
8194 signal_print_state (int signo)
8196 return signal_print[signo];
8200 signal_pass_state (int signo)
8202 return signal_program[signo];
8206 signal_cache_update (int signo)
8210 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8211 signal_cache_update (signo);
8216 signal_pass[signo] = (signal_stop[signo] == 0
8217 && signal_print[signo] == 0
8218 && signal_program[signo] == 1
8219 && signal_catch[signo] == 0);
8223 signal_stop_update (int signo, int state)
8225 int ret = signal_stop[signo];
8227 signal_stop[signo] = state;
8228 signal_cache_update (signo);
8233 signal_print_update (int signo, int state)
8235 int ret = signal_print[signo];
8237 signal_print[signo] = state;
8238 signal_cache_update (signo);
8243 signal_pass_update (int signo, int state)
8245 int ret = signal_program[signo];
8247 signal_program[signo] = state;
8248 signal_cache_update (signo);
8252 /* Update the global 'signal_catch' from INFO and notify the
8256 signal_catch_update (const unsigned int *info)
8260 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8261 signal_catch[i] = info[i] > 0;
8262 signal_cache_update (-1);
8263 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8267 sig_print_header (void)
8269 printf_filtered (_("Signal Stop\tPrint\tPass "
8270 "to program\tDescription\n"));
8274 sig_print_info (enum gdb_signal oursig)
8276 const char *name = gdb_signal_to_name (oursig);
8277 int name_padding = 13 - strlen (name);
8279 if (name_padding <= 0)
8282 printf_filtered ("%s", name);
8283 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8284 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8285 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8286 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8287 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8290 /* Specify how various signals in the inferior should be handled. */
8293 handle_command (const char *args, int from_tty)
8295 int digits, wordlen;
8296 int sigfirst, siglast;
8297 enum gdb_signal oursig;
8300 unsigned char *sigs;
8304 error_no_arg (_("signal to handle"));
8307 /* Allocate and zero an array of flags for which signals to handle. */
8309 nsigs = (int) GDB_SIGNAL_LAST;
8310 sigs = (unsigned char *) alloca (nsigs);
8311 memset (sigs, 0, nsigs);
8313 /* Break the command line up into args. */
8315 gdb_argv built_argv (args);
8317 /* Walk through the args, looking for signal oursigs, signal names, and
8318 actions. Signal numbers and signal names may be interspersed with
8319 actions, with the actions being performed for all signals cumulatively
8320 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8322 for (char *arg : built_argv)
8324 wordlen = strlen (arg);
8325 for (digits = 0; isdigit (arg[digits]); digits++)
8329 sigfirst = siglast = -1;
8331 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8333 /* Apply action to all signals except those used by the
8334 debugger. Silently skip those. */
8337 siglast = nsigs - 1;
8339 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8341 SET_SIGS (nsigs, sigs, signal_stop);
8342 SET_SIGS (nsigs, sigs, signal_print);
8344 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8346 UNSET_SIGS (nsigs, sigs, signal_program);
8348 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8350 SET_SIGS (nsigs, sigs, signal_print);
8352 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8354 SET_SIGS (nsigs, sigs, signal_program);
8356 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8358 UNSET_SIGS (nsigs, sigs, signal_stop);
8360 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8362 SET_SIGS (nsigs, sigs, signal_program);
8364 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8366 UNSET_SIGS (nsigs, sigs, signal_print);
8367 UNSET_SIGS (nsigs, sigs, signal_stop);
8369 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8371 UNSET_SIGS (nsigs, sigs, signal_program);
8373 else if (digits > 0)
8375 /* It is numeric. The numeric signal refers to our own
8376 internal signal numbering from target.h, not to host/target
8377 signal number. This is a feature; users really should be
8378 using symbolic names anyway, and the common ones like
8379 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8381 sigfirst = siglast = (int)
8382 gdb_signal_from_command (atoi (arg));
8383 if (arg[digits] == '-')
8386 gdb_signal_from_command (atoi (arg + digits + 1));
8388 if (sigfirst > siglast)
8390 /* Bet he didn't figure we'd think of this case... */
8391 std::swap (sigfirst, siglast);
8396 oursig = gdb_signal_from_name (arg);
8397 if (oursig != GDB_SIGNAL_UNKNOWN)
8399 sigfirst = siglast = (int) oursig;
8403 /* Not a number and not a recognized flag word => complain. */
8404 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8408 /* If any signal numbers or symbol names were found, set flags for
8409 which signals to apply actions to. */
8411 for (int signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8413 switch ((enum gdb_signal) signum)
8415 case GDB_SIGNAL_TRAP:
8416 case GDB_SIGNAL_INT:
8417 if (!allsigs && !sigs[signum])
8419 if (query (_("%s is used by the debugger.\n\
8420 Are you sure you want to change it? "),
8421 gdb_signal_to_name ((enum gdb_signal) signum)))
8427 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8428 gdb_flush (gdb_stdout);
8433 case GDB_SIGNAL_DEFAULT:
8434 case GDB_SIGNAL_UNKNOWN:
8435 /* Make sure that "all" doesn't print these. */
8444 for (int signum = 0; signum < nsigs; signum++)
8447 signal_cache_update (-1);
8448 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8449 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8453 /* Show the results. */
8454 sig_print_header ();
8455 for (; signum < nsigs; signum++)
8457 sig_print_info ((enum gdb_signal) signum);
8464 /* Complete the "handle" command. */
8467 handle_completer (struct cmd_list_element *ignore,
8468 completion_tracker &tracker,
8469 const char *text, const char *word)
8471 static const char * const keywords[] =
8485 signal_completer (ignore, tracker, text, word);
8486 complete_on_enum (tracker, keywords, word, word);
8490 gdb_signal_from_command (int num)
8492 if (num >= 1 && num <= 15)
8493 return (enum gdb_signal) num;
8494 error (_("Only signals 1-15 are valid as numeric signals.\n\
8495 Use \"info signals\" for a list of symbolic signals."));
8498 /* Print current contents of the tables set by the handle command.
8499 It is possible we should just be printing signals actually used
8500 by the current target (but for things to work right when switching
8501 targets, all signals should be in the signal tables). */
8504 info_signals_command (const char *signum_exp, int from_tty)
8506 enum gdb_signal oursig;
8508 sig_print_header ();
8512 /* First see if this is a symbol name. */
8513 oursig = gdb_signal_from_name (signum_exp);
8514 if (oursig == GDB_SIGNAL_UNKNOWN)
8516 /* No, try numeric. */
8518 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8520 sig_print_info (oursig);
8524 printf_filtered ("\n");
8525 /* These ugly casts brought to you by the native VAX compiler. */
8526 for (oursig = GDB_SIGNAL_FIRST;
8527 (int) oursig < (int) GDB_SIGNAL_LAST;
8528 oursig = (enum gdb_signal) ((int) oursig + 1))
8532 if (oursig != GDB_SIGNAL_UNKNOWN
8533 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8534 sig_print_info (oursig);
8537 printf_filtered (_("\nUse the \"handle\" command "
8538 "to change these tables.\n"));
8541 /* The $_siginfo convenience variable is a bit special. We don't know
8542 for sure the type of the value until we actually have a chance to
8543 fetch the data. The type can change depending on gdbarch, so it is
8544 also dependent on which thread you have selected.
8546 1. making $_siginfo be an internalvar that creates a new value on
8549 2. making the value of $_siginfo be an lval_computed value. */
8551 /* This function implements the lval_computed support for reading a
8555 siginfo_value_read (struct value *v)
8557 LONGEST transferred;
8559 /* If we can access registers, so can we access $_siginfo. Likewise
8561 validate_registers_access ();
8564 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO,
8566 value_contents_all_raw (v),
8568 TYPE_LENGTH (value_type (v)));
8570 if (transferred != TYPE_LENGTH (value_type (v)))
8571 error (_("Unable to read siginfo"));
8574 /* This function implements the lval_computed support for writing a
8578 siginfo_value_write (struct value *v, struct value *fromval)
8580 LONGEST transferred;
8582 /* If we can access registers, so can we access $_siginfo. Likewise
8584 validate_registers_access ();
8586 transferred = target_write (current_top_target (),
8587 TARGET_OBJECT_SIGNAL_INFO,
8589 value_contents_all_raw (fromval),
8591 TYPE_LENGTH (value_type (fromval)));
8593 if (transferred != TYPE_LENGTH (value_type (fromval)))
8594 error (_("Unable to write siginfo"));
8597 static const struct lval_funcs siginfo_value_funcs =
8603 /* Return a new value with the correct type for the siginfo object of
8604 the current thread using architecture GDBARCH. Return a void value
8605 if there's no object available. */
8607 static struct value *
8608 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8611 if (target_has_stack
8612 && inferior_ptid != null_ptid
8613 && gdbarch_get_siginfo_type_p (gdbarch))
8615 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8617 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8620 return allocate_value (builtin_type (gdbarch)->builtin_void);
8624 /* infcall_suspend_state contains state about the program itself like its
8625 registers and any signal it received when it last stopped.
8626 This state must be restored regardless of how the inferior function call
8627 ends (either successfully, or after it hits a breakpoint or signal)
8628 if the program is to properly continue where it left off. */
8630 class infcall_suspend_state
8633 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8634 once the inferior function call has finished. */
8635 infcall_suspend_state (struct gdbarch *gdbarch,
8636 const struct thread_info *tp,
8637 struct regcache *regcache)
8638 : m_thread_suspend (tp->suspend),
8639 m_registers (new readonly_detached_regcache (*regcache))
8641 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8643 if (gdbarch_get_siginfo_type_p (gdbarch))
8645 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8646 size_t len = TYPE_LENGTH (type);
8648 siginfo_data.reset ((gdb_byte *) xmalloc (len));
8650 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8651 siginfo_data.get (), 0, len) != len)
8653 /* Errors ignored. */
8654 siginfo_data.reset (nullptr);
8660 m_siginfo_gdbarch = gdbarch;
8661 m_siginfo_data = std::move (siginfo_data);
8665 /* Return a pointer to the stored register state. */
8667 readonly_detached_regcache *registers () const
8669 return m_registers.get ();
8672 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8674 void restore (struct gdbarch *gdbarch,
8675 struct thread_info *tp,
8676 struct regcache *regcache) const
8678 tp->suspend = m_thread_suspend;
8680 if (m_siginfo_gdbarch == gdbarch)
8682 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8684 /* Errors ignored. */
8685 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8686 m_siginfo_data.get (), 0, TYPE_LENGTH (type));
8689 /* The inferior can be gone if the user types "print exit(0)"
8690 (and perhaps other times). */
8691 if (target_has_execution)
8692 /* NB: The register write goes through to the target. */
8693 regcache->restore (registers ());
8697 /* How the current thread stopped before the inferior function call was
8699 struct thread_suspend_state m_thread_suspend;
8701 /* The registers before the inferior function call was executed. */
8702 std::unique_ptr<readonly_detached_regcache> m_registers;
8704 /* Format of SIGINFO_DATA or NULL if it is not present. */
8705 struct gdbarch *m_siginfo_gdbarch = nullptr;
8707 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8708 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8709 content would be invalid. */
8710 gdb::unique_xmalloc_ptr<gdb_byte> m_siginfo_data;
8713 infcall_suspend_state_up
8714 save_infcall_suspend_state ()
8716 struct thread_info *tp = inferior_thread ();
8717 struct regcache *regcache = get_current_regcache ();
8718 struct gdbarch *gdbarch = regcache->arch ();
8720 infcall_suspend_state_up inf_state
8721 (new struct infcall_suspend_state (gdbarch, tp, regcache));
8723 /* Having saved the current state, adjust the thread state, discarding
8724 any stop signal information. The stop signal is not useful when
8725 starting an inferior function call, and run_inferior_call will not use
8726 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8727 tp->suspend.stop_signal = GDB_SIGNAL_0;
8732 /* Restore inferior session state to INF_STATE. */
8735 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8737 struct thread_info *tp = inferior_thread ();
8738 struct regcache *regcache = get_current_regcache ();
8739 struct gdbarch *gdbarch = regcache->arch ();
8741 inf_state->restore (gdbarch, tp, regcache);
8742 discard_infcall_suspend_state (inf_state);
8746 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8751 readonly_detached_regcache *
8752 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8754 return inf_state->registers ();
8757 /* infcall_control_state contains state regarding gdb's control of the
8758 inferior itself like stepping control. It also contains session state like
8759 the user's currently selected frame. */
8761 struct infcall_control_state
8763 struct thread_control_state thread_control;
8764 struct inferior_control_state inferior_control;
8767 enum stop_stack_kind stop_stack_dummy = STOP_NONE;
8768 int stopped_by_random_signal = 0;
8770 /* ID if the selected frame when the inferior function call was made. */
8771 struct frame_id selected_frame_id {};
8774 /* Save all of the information associated with the inferior<==>gdb
8777 infcall_control_state_up
8778 save_infcall_control_state ()
8780 infcall_control_state_up inf_status (new struct infcall_control_state);
8781 struct thread_info *tp = inferior_thread ();
8782 struct inferior *inf = current_inferior ();
8784 inf_status->thread_control = tp->control;
8785 inf_status->inferior_control = inf->control;
8787 tp->control.step_resume_breakpoint = NULL;
8788 tp->control.exception_resume_breakpoint = NULL;
8790 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8791 chain. If caller's caller is walking the chain, they'll be happier if we
8792 hand them back the original chain when restore_infcall_control_state is
8794 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8797 inf_status->stop_stack_dummy = stop_stack_dummy;
8798 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8800 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8806 restore_selected_frame (const frame_id &fid)
8808 frame_info *frame = frame_find_by_id (fid);
8810 /* If inf_status->selected_frame_id is NULL, there was no previously
8814 warning (_("Unable to restore previously selected frame."));
8818 select_frame (frame);
8821 /* Restore inferior session state to INF_STATUS. */
8824 restore_infcall_control_state (struct infcall_control_state *inf_status)
8826 struct thread_info *tp = inferior_thread ();
8827 struct inferior *inf = current_inferior ();
8829 if (tp->control.step_resume_breakpoint)
8830 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8832 if (tp->control.exception_resume_breakpoint)
8833 tp->control.exception_resume_breakpoint->disposition
8834 = disp_del_at_next_stop;
8836 /* Handle the bpstat_copy of the chain. */
8837 bpstat_clear (&tp->control.stop_bpstat);
8839 tp->control = inf_status->thread_control;
8840 inf->control = inf_status->inferior_control;
8843 stop_stack_dummy = inf_status->stop_stack_dummy;
8844 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8846 if (target_has_stack)
8848 /* The point of the try/catch is that if the stack is clobbered,
8849 walking the stack might encounter a garbage pointer and
8850 error() trying to dereference it. */
8853 restore_selected_frame (inf_status->selected_frame_id);
8855 CATCH (ex, RETURN_MASK_ERROR)
8857 exception_fprintf (gdb_stderr, ex,
8858 "Unable to restore previously selected frame:\n");
8859 /* Error in restoring the selected frame. Select the
8861 select_frame (get_current_frame ());
8870 discard_infcall_control_state (struct infcall_control_state *inf_status)
8872 if (inf_status->thread_control.step_resume_breakpoint)
8873 inf_status->thread_control.step_resume_breakpoint->disposition
8874 = disp_del_at_next_stop;
8876 if (inf_status->thread_control.exception_resume_breakpoint)
8877 inf_status->thread_control.exception_resume_breakpoint->disposition
8878 = disp_del_at_next_stop;
8880 /* See save_infcall_control_state for info on stop_bpstat. */
8881 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8889 clear_exit_convenience_vars (void)
8891 clear_internalvar (lookup_internalvar ("_exitsignal"));
8892 clear_internalvar (lookup_internalvar ("_exitcode"));
8896 /* User interface for reverse debugging:
8897 Set exec-direction / show exec-direction commands
8898 (returns error unless target implements to_set_exec_direction method). */
8900 enum exec_direction_kind execution_direction = EXEC_FORWARD;
8901 static const char exec_forward[] = "forward";
8902 static const char exec_reverse[] = "reverse";
8903 static const char *exec_direction = exec_forward;
8904 static const char *const exec_direction_names[] = {
8911 set_exec_direction_func (const char *args, int from_tty,
8912 struct cmd_list_element *cmd)
8914 if (target_can_execute_reverse)
8916 if (!strcmp (exec_direction, exec_forward))
8917 execution_direction = EXEC_FORWARD;
8918 else if (!strcmp (exec_direction, exec_reverse))
8919 execution_direction = EXEC_REVERSE;
8923 exec_direction = exec_forward;
8924 error (_("Target does not support this operation."));
8929 show_exec_direction_func (struct ui_file *out, int from_tty,
8930 struct cmd_list_element *cmd, const char *value)
8932 switch (execution_direction) {
8934 fprintf_filtered (out, _("Forward.\n"));
8937 fprintf_filtered (out, _("Reverse.\n"));
8940 internal_error (__FILE__, __LINE__,
8941 _("bogus execution_direction value: %d"),
8942 (int) execution_direction);
8947 show_schedule_multiple (struct ui_file *file, int from_tty,
8948 struct cmd_list_element *c, const char *value)
8950 fprintf_filtered (file, _("Resuming the execution of threads "
8951 "of all processes is %s.\n"), value);
8954 /* Implementation of `siginfo' variable. */
8956 static const struct internalvar_funcs siginfo_funcs =
8963 /* Callback for infrun's target events source. This is marked when a
8964 thread has a pending status to process. */
8967 infrun_async_inferior_event_handler (gdb_client_data data)
8969 inferior_event_handler (INF_REG_EVENT, NULL);
8973 _initialize_infrun (void)
8977 struct cmd_list_element *c;
8979 /* Register extra event sources in the event loop. */
8980 infrun_async_inferior_event_token
8981 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8983 add_info ("signals", info_signals_command, _("\
8984 What debugger does when program gets various signals.\n\
8985 Specify a signal as argument to print info on that signal only."));
8986 add_info_alias ("handle", "signals", 0);
8988 c = add_com ("handle", class_run, handle_command, _("\
8989 Specify how to handle signals.\n\
8990 Usage: handle SIGNAL [ACTIONS]\n\
8991 Args are signals and actions to apply to those signals.\n\
8992 If no actions are specified, the current settings for the specified signals\n\
8993 will be displayed instead.\n\
8995 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8996 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8997 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8998 The special arg \"all\" is recognized to mean all signals except those\n\
8999 used by the debugger, typically SIGTRAP and SIGINT.\n\
9001 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9002 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9003 Stop means reenter debugger if this signal happens (implies print).\n\
9004 Print means print a message if this signal happens.\n\
9005 Pass means let program see this signal; otherwise program doesn't know.\n\
9006 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9007 Pass and Stop may be combined.\n\
9009 Multiple signals may be specified. Signal numbers and signal names\n\
9010 may be interspersed with actions, with the actions being performed for\n\
9011 all signals cumulatively specified."));
9012 set_cmd_completer (c, handle_completer);
9015 stop_command = add_cmd ("stop", class_obscure,
9016 not_just_help_class_command, _("\
9017 There is no `stop' command, but you can set a hook on `stop'.\n\
9018 This allows you to set a list of commands to be run each time execution\n\
9019 of the program stops."), &cmdlist);
9021 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9022 Set inferior debugging."), _("\
9023 Show inferior debugging."), _("\
9024 When non-zero, inferior specific debugging is enabled."),
9027 &setdebuglist, &showdebuglist);
9029 add_setshow_boolean_cmd ("displaced", class_maintenance,
9030 &debug_displaced, _("\
9031 Set displaced stepping debugging."), _("\
9032 Show displaced stepping debugging."), _("\
9033 When non-zero, displaced stepping specific debugging is enabled."),
9035 show_debug_displaced,
9036 &setdebuglist, &showdebuglist);
9038 add_setshow_boolean_cmd ("non-stop", no_class,
9040 Set whether gdb controls the inferior in non-stop mode."), _("\
9041 Show whether gdb controls the inferior in non-stop mode."), _("\
9042 When debugging a multi-threaded program and this setting is\n\
9043 off (the default, also called all-stop mode), when one thread stops\n\
9044 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9045 all other threads in the program while you interact with the thread of\n\
9046 interest. When you continue or step a thread, you can allow the other\n\
9047 threads to run, or have them remain stopped, but while you inspect any\n\
9048 thread's state, all threads stop.\n\
9050 In non-stop mode, when one thread stops, other threads can continue\n\
9051 to run freely. You'll be able to step each thread independently,\n\
9052 leave it stopped or free to run as needed."),
9058 numsigs = (int) GDB_SIGNAL_LAST;
9059 signal_stop = XNEWVEC (unsigned char, numsigs);
9060 signal_print = XNEWVEC (unsigned char, numsigs);
9061 signal_program = XNEWVEC (unsigned char, numsigs);
9062 signal_catch = XNEWVEC (unsigned char, numsigs);
9063 signal_pass = XNEWVEC (unsigned char, numsigs);
9064 for (i = 0; i < numsigs; i++)
9067 signal_print[i] = 1;
9068 signal_program[i] = 1;
9069 signal_catch[i] = 0;
9072 /* Signals caused by debugger's own actions should not be given to
9073 the program afterwards.
9075 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9076 explicitly specifies that it should be delivered to the target
9077 program. Typically, that would occur when a user is debugging a
9078 target monitor on a simulator: the target monitor sets a
9079 breakpoint; the simulator encounters this breakpoint and halts
9080 the simulation handing control to GDB; GDB, noting that the stop
9081 address doesn't map to any known breakpoint, returns control back
9082 to the simulator; the simulator then delivers the hardware
9083 equivalent of a GDB_SIGNAL_TRAP to the program being
9085 signal_program[GDB_SIGNAL_TRAP] = 0;
9086 signal_program[GDB_SIGNAL_INT] = 0;
9088 /* Signals that are not errors should not normally enter the debugger. */
9089 signal_stop[GDB_SIGNAL_ALRM] = 0;
9090 signal_print[GDB_SIGNAL_ALRM] = 0;
9091 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9092 signal_print[GDB_SIGNAL_VTALRM] = 0;
9093 signal_stop[GDB_SIGNAL_PROF] = 0;
9094 signal_print[GDB_SIGNAL_PROF] = 0;
9095 signal_stop[GDB_SIGNAL_CHLD] = 0;
9096 signal_print[GDB_SIGNAL_CHLD] = 0;
9097 signal_stop[GDB_SIGNAL_IO] = 0;
9098 signal_print[GDB_SIGNAL_IO] = 0;
9099 signal_stop[GDB_SIGNAL_POLL] = 0;
9100 signal_print[GDB_SIGNAL_POLL] = 0;
9101 signal_stop[GDB_SIGNAL_URG] = 0;
9102 signal_print[GDB_SIGNAL_URG] = 0;
9103 signal_stop[GDB_SIGNAL_WINCH] = 0;
9104 signal_print[GDB_SIGNAL_WINCH] = 0;
9105 signal_stop[GDB_SIGNAL_PRIO] = 0;
9106 signal_print[GDB_SIGNAL_PRIO] = 0;
9108 /* These signals are used internally by user-level thread
9109 implementations. (See signal(5) on Solaris.) Like the above
9110 signals, a healthy program receives and handles them as part of
9111 its normal operation. */
9112 signal_stop[GDB_SIGNAL_LWP] = 0;
9113 signal_print[GDB_SIGNAL_LWP] = 0;
9114 signal_stop[GDB_SIGNAL_WAITING] = 0;
9115 signal_print[GDB_SIGNAL_WAITING] = 0;
9116 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9117 signal_print[GDB_SIGNAL_CANCEL] = 0;
9118 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9119 signal_print[GDB_SIGNAL_LIBRT] = 0;
9121 /* Update cached state. */
9122 signal_cache_update (-1);
9124 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9125 &stop_on_solib_events, _("\
9126 Set stopping for shared library events."), _("\
9127 Show stopping for shared library events."), _("\
9128 If nonzero, gdb will give control to the user when the dynamic linker\n\
9129 notifies gdb of shared library events. The most common event of interest\n\
9130 to the user would be loading/unloading of a new library."),
9131 set_stop_on_solib_events,
9132 show_stop_on_solib_events,
9133 &setlist, &showlist);
9135 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9136 follow_fork_mode_kind_names,
9137 &follow_fork_mode_string, _("\
9138 Set debugger response to a program call of fork or vfork."), _("\
9139 Show debugger response to a program call of fork or vfork."), _("\
9140 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9141 parent - the original process is debugged after a fork\n\
9142 child - the new process is debugged after a fork\n\
9143 The unfollowed process will continue to run.\n\
9144 By default, the debugger will follow the parent process."),
9146 show_follow_fork_mode_string,
9147 &setlist, &showlist);
9149 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9150 follow_exec_mode_names,
9151 &follow_exec_mode_string, _("\
9152 Set debugger response to a program call of exec."), _("\
9153 Show debugger response to a program call of exec."), _("\
9154 An exec call replaces the program image of a process.\n\
9156 follow-exec-mode can be:\n\
9158 new - the debugger creates a new inferior and rebinds the process\n\
9159 to this new inferior. The program the process was running before\n\
9160 the exec call can be restarted afterwards by restarting the original\n\
9163 same - the debugger keeps the process bound to the same inferior.\n\
9164 The new executable image replaces the previous executable loaded in\n\
9165 the inferior. Restarting the inferior after the exec call restarts\n\
9166 the executable the process was running after the exec call.\n\
9168 By default, the debugger will use the same inferior."),
9170 show_follow_exec_mode_string,
9171 &setlist, &showlist);
9173 add_setshow_enum_cmd ("scheduler-locking", class_run,
9174 scheduler_enums, &scheduler_mode, _("\
9175 Set mode for locking scheduler during execution."), _("\
9176 Show mode for locking scheduler during execution."), _("\
9177 off == no locking (threads may preempt at any time)\n\
9178 on == full locking (no thread except the current thread may run)\n\
9179 This applies to both normal execution and replay mode.\n\
9180 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9181 In this mode, other threads may run during other commands.\n\
9182 This applies to both normal execution and replay mode.\n\
9183 replay == scheduler locked in replay mode and unlocked during normal execution."),
9184 set_schedlock_func, /* traps on target vector */
9185 show_scheduler_mode,
9186 &setlist, &showlist);
9188 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9189 Set mode for resuming threads of all processes."), _("\
9190 Show mode for resuming threads of all processes."), _("\
9191 When on, execution commands (such as 'continue' or 'next') resume all\n\
9192 threads of all processes. When off (which is the default), execution\n\
9193 commands only resume the threads of the current process. The set of\n\
9194 threads that are resumed is further refined by the scheduler-locking\n\
9195 mode (see help set scheduler-locking)."),
9197 show_schedule_multiple,
9198 &setlist, &showlist);
9200 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9201 Set mode of the step operation."), _("\
9202 Show mode of the step operation."), _("\
9203 When set, doing a step over a function without debug line information\n\
9204 will stop at the first instruction of that function. Otherwise, the\n\
9205 function is skipped and the step command stops at a different source line."),
9207 show_step_stop_if_no_debug,
9208 &setlist, &showlist);
9210 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9211 &can_use_displaced_stepping, _("\
9212 Set debugger's willingness to use displaced stepping."), _("\
9213 Show debugger's willingness to use displaced stepping."), _("\
9214 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9215 supported by the target architecture. If off, gdb will not use displaced\n\
9216 stepping to step over breakpoints, even if such is supported by the target\n\
9217 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9218 if the target architecture supports it and non-stop mode is active, but will not\n\
9219 use it in all-stop mode (see help set non-stop)."),
9221 show_can_use_displaced_stepping,
9222 &setlist, &showlist);
9224 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9225 &exec_direction, _("Set direction of execution.\n\
9226 Options are 'forward' or 'reverse'."),
9227 _("Show direction of execution (forward/reverse)."),
9228 _("Tells gdb whether to execute forward or backward."),
9229 set_exec_direction_func, show_exec_direction_func,
9230 &setlist, &showlist);
9232 /* Set/show detach-on-fork: user-settable mode. */
9234 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9235 Set whether gdb will detach the child of a fork."), _("\
9236 Show whether gdb will detach the child of a fork."), _("\
9237 Tells gdb whether to detach the child of a fork."),
9238 NULL, NULL, &setlist, &showlist);
9240 /* Set/show disable address space randomization mode. */
9242 add_setshow_boolean_cmd ("disable-randomization", class_support,
9243 &disable_randomization, _("\
9244 Set disabling of debuggee's virtual address space randomization."), _("\
9245 Show disabling of debuggee's virtual address space randomization."), _("\
9246 When this mode is on (which is the default), randomization of the virtual\n\
9247 address space is disabled. Standalone programs run with the randomization\n\
9248 enabled by default on some platforms."),
9249 &set_disable_randomization,
9250 &show_disable_randomization,
9251 &setlist, &showlist);
9253 /* ptid initializations */
9254 inferior_ptid = null_ptid;
9255 target_last_wait_ptid = minus_one_ptid;
9257 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9258 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9259 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9260 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9262 /* Explicitly create without lookup, since that tries to create a
9263 value with a void typed value, and when we get here, gdbarch
9264 isn't initialized yet. At this point, we're quite sure there
9265 isn't another convenience variable of the same name. */
9266 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9268 add_setshow_boolean_cmd ("observer", no_class,
9269 &observer_mode_1, _("\
9270 Set whether gdb controls the inferior in observer mode."), _("\
9271 Show whether gdb controls the inferior in observer mode."), _("\
9272 In observer mode, GDB can get data from the inferior, but not\n\
9273 affect its execution. Registers and memory may not be changed,\n\
9274 breakpoints may not be set, and the program cannot be interrupted\n\