1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2018 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"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal);
75 static void sig_print_header (void);
77 static int follow_fork (void);
79 static int follow_fork_inferior (int follow_child, int detach_fork);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info *tp);
85 void nullify_last_target_wait_ptid (void);
87 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
89 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
91 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
93 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
95 static void resume (gdb_signal sig);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler *infrun_async_inferior_event_token;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async = -1;
108 infrun_async (int enable)
110 if (infrun_is_async != enable)
112 infrun_is_async = enable;
115 fprintf_unfiltered (gdb_stdlog,
116 "infrun: infrun_async(%d)\n",
120 mark_async_event_handler (infrun_async_inferior_event_token);
122 clear_async_event_handler (infrun_async_inferior_event_token);
129 mark_infrun_async_event_handler (void)
131 mark_async_event_handler (infrun_async_inferior_event_token);
134 /* When set, stop the 'step' command if we enter a function which has
135 no line number information. The normal behavior is that we step
136 over such function. */
137 int step_stop_if_no_debug = 0;
139 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
140 struct cmd_list_element *c, const char *value)
142 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
145 /* proceed and normal_stop use this to notify the user when the
146 inferior stopped in a different thread than it had been running
149 static ptid_t previous_inferior_ptid;
151 /* If set (default for legacy reasons), when following a fork, GDB
152 will detach from one of the fork branches, child or parent.
153 Exactly which branch is detached depends on 'set follow-fork-mode'
156 static int detach_fork = 1;
158 int debug_displaced = 0;
160 show_debug_displaced (struct ui_file *file, int from_tty,
161 struct cmd_list_element *c, const char *value)
163 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
166 unsigned int debug_infrun = 0;
168 show_debug_infrun (struct ui_file *file, int from_tty,
169 struct cmd_list_element *c, const char *value)
171 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
175 /* Support for disabling address space randomization. */
177 int disable_randomization = 1;
180 show_disable_randomization (struct ui_file *file, int from_tty,
181 struct cmd_list_element *c, const char *value)
183 if (target_supports_disable_randomization ())
184 fprintf_filtered (file,
185 _("Disabling randomization of debuggee's "
186 "virtual address space is %s.\n"),
189 fputs_filtered (_("Disabling randomization of debuggee's "
190 "virtual address space is unsupported on\n"
191 "this platform.\n"), file);
195 set_disable_randomization (const char *args, int from_tty,
196 struct cmd_list_element *c)
198 if (!target_supports_disable_randomization ())
199 error (_("Disabling randomization of debuggee's "
200 "virtual address space is unsupported on\n"
204 /* User interface for non-stop mode. */
207 static int non_stop_1 = 0;
210 set_non_stop (const char *args, int from_tty,
211 struct cmd_list_element *c)
213 if (target_has_execution)
215 non_stop_1 = non_stop;
216 error (_("Cannot change this setting while the inferior is running."));
219 non_stop = non_stop_1;
223 show_non_stop (struct ui_file *file, int from_tty,
224 struct cmd_list_element *c, const char *value)
226 fprintf_filtered (file,
227 _("Controlling the inferior in non-stop mode is %s.\n"),
231 /* "Observer mode" is somewhat like a more extreme version of
232 non-stop, in which all GDB operations that might affect the
233 target's execution have been disabled. */
235 int observer_mode = 0;
236 static int observer_mode_1 = 0;
239 set_observer_mode (const char *args, int from_tty,
240 struct cmd_list_element *c)
242 if (target_has_execution)
244 observer_mode_1 = observer_mode;
245 error (_("Cannot change this setting while the inferior is running."));
248 observer_mode = observer_mode_1;
250 may_write_registers = !observer_mode;
251 may_write_memory = !observer_mode;
252 may_insert_breakpoints = !observer_mode;
253 may_insert_tracepoints = !observer_mode;
254 /* We can insert fast tracepoints in or out of observer mode,
255 but enable them if we're going into this mode. */
257 may_insert_fast_tracepoints = 1;
258 may_stop = !observer_mode;
259 update_target_permissions ();
261 /* Going *into* observer mode we must force non-stop, then
262 going out we leave it that way. */
265 pagination_enabled = 0;
266 non_stop = non_stop_1 = 1;
270 printf_filtered (_("Observer mode is now %s.\n"),
271 (observer_mode ? "on" : "off"));
275 show_observer_mode (struct ui_file *file, int from_tty,
276 struct cmd_list_element *c, const char *value)
278 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
281 /* This updates the value of observer mode based on changes in
282 permissions. Note that we are deliberately ignoring the values of
283 may-write-registers and may-write-memory, since the user may have
284 reason to enable these during a session, for instance to turn on a
285 debugging-related global. */
288 update_observer_mode (void)
292 newval = (!may_insert_breakpoints
293 && !may_insert_tracepoints
294 && may_insert_fast_tracepoints
298 /* Let the user know if things change. */
299 if (newval != observer_mode)
300 printf_filtered (_("Observer mode is now %s.\n"),
301 (newval ? "on" : "off"));
303 observer_mode = observer_mode_1 = newval;
306 /* Tables of how to react to signals; the user sets them. */
308 static unsigned char *signal_stop;
309 static unsigned char *signal_print;
310 static unsigned char *signal_program;
312 /* Table of signals that are registered with "catch signal". A
313 non-zero entry indicates that the signal is caught by some "catch
314 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
316 static unsigned char *signal_catch;
318 /* Table of signals that the target may silently handle.
319 This is automatically determined from the flags above,
320 and simply cached here. */
321 static unsigned char *signal_pass;
323 #define SET_SIGS(nsigs,sigs,flags) \
325 int signum = (nsigs); \
326 while (signum-- > 0) \
327 if ((sigs)[signum]) \
328 (flags)[signum] = 1; \
331 #define UNSET_SIGS(nsigs,sigs,flags) \
333 int signum = (nsigs); \
334 while (signum-- > 0) \
335 if ((sigs)[signum]) \
336 (flags)[signum] = 0; \
339 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
340 this function is to avoid exporting `signal_program'. */
343 update_signals_program_target (void)
345 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
348 /* Value to pass to target_resume() to cause all threads to resume. */
350 #define RESUME_ALL minus_one_ptid
352 /* Command list pointer for the "stop" placeholder. */
354 static struct cmd_list_element *stop_command;
356 /* Nonzero if we want to give control to the user when we're notified
357 of shared library events by the dynamic linker. */
358 int stop_on_solib_events;
360 /* Enable or disable optional shared library event breakpoints
361 as appropriate when the above flag is changed. */
364 set_stop_on_solib_events (const char *args,
365 int from_tty, struct cmd_list_element *c)
367 update_solib_breakpoints ();
371 show_stop_on_solib_events (struct ui_file *file, int from_tty,
372 struct cmd_list_element *c, const char *value)
374 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
378 /* Nonzero after stop if current stack frame should be printed. */
380 static int stop_print_frame;
382 /* This is a cached copy of the pid/waitstatus of the last event
383 returned by target_wait()/deprecated_target_wait_hook(). This
384 information is returned by get_last_target_status(). */
385 static ptid_t target_last_wait_ptid;
386 static struct target_waitstatus target_last_waitstatus;
388 void init_thread_stepping_state (struct thread_info *tss);
390 static const char follow_fork_mode_child[] = "child";
391 static const char follow_fork_mode_parent[] = "parent";
393 static const char *const follow_fork_mode_kind_names[] = {
394 follow_fork_mode_child,
395 follow_fork_mode_parent,
399 static const char *follow_fork_mode_string = follow_fork_mode_parent;
401 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
402 struct cmd_list_element *c, const char *value)
404 fprintf_filtered (file,
405 _("Debugger response to a program "
406 "call of fork or vfork is \"%s\".\n"),
411 /* Handle changes to the inferior list based on the type of fork,
412 which process is being followed, and whether the other process
413 should be detached. On entry inferior_ptid must be the ptid of
414 the fork parent. At return inferior_ptid is the ptid of the
415 followed inferior. */
418 follow_fork_inferior (int follow_child, int detach_fork)
421 ptid_t parent_ptid, child_ptid;
423 has_vforked = (inferior_thread ()->pending_follow.kind
424 == TARGET_WAITKIND_VFORKED);
425 parent_ptid = inferior_ptid;
426 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
429 && !non_stop /* Non-stop always resumes both branches. */
430 && current_ui->prompt_state == PROMPT_BLOCKED
431 && !(follow_child || detach_fork || sched_multi))
433 /* The parent stays blocked inside the vfork syscall until the
434 child execs or exits. If we don't let the child run, then
435 the parent stays blocked. If we're telling the parent to run
436 in the foreground, the user will not be able to ctrl-c to get
437 back the terminal, effectively hanging the debug session. */
438 fprintf_filtered (gdb_stderr, _("\
439 Can not resume the parent process over vfork in the foreground while\n\
440 holding the child stopped. Try \"set detach-on-fork\" or \
441 \"set schedule-multiple\".\n"));
442 /* FIXME output string > 80 columns. */
448 /* Detach new forked process? */
451 /* Before detaching from the child, remove all breakpoints
452 from it. If we forked, then this has already been taken
453 care of by infrun.c. If we vforked however, any
454 breakpoint inserted in the parent is visible in the
455 child, even those added while stopped in a vfork
456 catchpoint. This will remove the breakpoints from the
457 parent also, but they'll be reinserted below. */
460 /* Keep breakpoints list in sync. */
461 remove_breakpoints_inf (current_inferior ());
464 if (print_inferior_events)
466 /* Ensure that we have a process ptid. */
467 ptid_t process_ptid = ptid_t (child_ptid.pid ());
469 target_terminal::ours_for_output ();
470 fprintf_filtered (gdb_stdlog,
471 _("[Detaching after %s from child %s]\n"),
472 has_vforked ? "vfork" : "fork",
473 target_pid_to_str (process_ptid));
478 struct inferior *parent_inf, *child_inf;
480 /* Add process to GDB's tables. */
481 child_inf = add_inferior (child_ptid.pid ());
483 parent_inf = current_inferior ();
484 child_inf->attach_flag = parent_inf->attach_flag;
485 copy_terminal_info (child_inf, parent_inf);
486 child_inf->gdbarch = parent_inf->gdbarch;
487 copy_inferior_target_desc_info (child_inf, parent_inf);
489 scoped_restore_current_pspace_and_thread restore_pspace_thread;
491 inferior_ptid = child_ptid;
492 add_thread_silent (inferior_ptid);
493 set_current_inferior (child_inf);
494 child_inf->symfile_flags = SYMFILE_NO_READ;
496 /* If this is a vfork child, then the address-space is
497 shared with the parent. */
500 child_inf->pspace = parent_inf->pspace;
501 child_inf->aspace = parent_inf->aspace;
503 /* The parent will be frozen until the child is done
504 with the shared region. Keep track of the
506 child_inf->vfork_parent = parent_inf;
507 child_inf->pending_detach = 0;
508 parent_inf->vfork_child = child_inf;
509 parent_inf->pending_detach = 0;
513 child_inf->aspace = new_address_space ();
514 child_inf->pspace = new program_space (child_inf->aspace);
515 child_inf->removable = 1;
516 set_current_program_space (child_inf->pspace);
517 clone_program_space (child_inf->pspace, parent_inf->pspace);
519 /* Let the shared library layer (e.g., solib-svr4) learn
520 about this new process, relocate the cloned exec, pull
521 in shared libraries, and install the solib event
522 breakpoint. If a "cloned-VM" event was propagated
523 better throughout the core, this wouldn't be
525 solib_create_inferior_hook (0);
531 struct inferior *parent_inf;
533 parent_inf = current_inferior ();
535 /* If we detached from the child, then we have to be careful
536 to not insert breakpoints in the parent until the child
537 is done with the shared memory region. However, if we're
538 staying attached to the child, then we can and should
539 insert breakpoints, so that we can debug it. A
540 subsequent child exec or exit is enough to know when does
541 the child stops using the parent's address space. */
542 parent_inf->waiting_for_vfork_done = detach_fork;
543 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
548 /* Follow the child. */
549 struct inferior *parent_inf, *child_inf;
550 struct program_space *parent_pspace;
552 if (print_inferior_events)
554 std::string parent_pid = target_pid_to_str (parent_ptid);
555 std::string child_pid = target_pid_to_str (child_ptid);
557 target_terminal::ours_for_output ();
558 fprintf_filtered (gdb_stdlog,
559 _("[Attaching after %s %s to child %s]\n"),
561 has_vforked ? "vfork" : "fork",
565 /* Add the new inferior first, so that the target_detach below
566 doesn't unpush the target. */
568 child_inf = add_inferior (child_ptid.pid ());
570 parent_inf = current_inferior ();
571 child_inf->attach_flag = parent_inf->attach_flag;
572 copy_terminal_info (child_inf, parent_inf);
573 child_inf->gdbarch = parent_inf->gdbarch;
574 copy_inferior_target_desc_info (child_inf, parent_inf);
576 parent_pspace = parent_inf->pspace;
578 /* If we're vforking, we want to hold on to the parent until the
579 child exits or execs. At child exec or exit time we can
580 remove the old breakpoints from the parent and detach or
581 resume debugging it. Otherwise, detach the parent now; we'll
582 want to reuse it's program/address spaces, but we can't set
583 them to the child before removing breakpoints from the
584 parent, otherwise, the breakpoints module could decide to
585 remove breakpoints from the wrong process (since they'd be
586 assigned to the same address space). */
590 gdb_assert (child_inf->vfork_parent == NULL);
591 gdb_assert (parent_inf->vfork_child == NULL);
592 child_inf->vfork_parent = parent_inf;
593 child_inf->pending_detach = 0;
594 parent_inf->vfork_child = child_inf;
595 parent_inf->pending_detach = detach_fork;
596 parent_inf->waiting_for_vfork_done = 0;
598 else if (detach_fork)
600 if (print_inferior_events)
602 /* Ensure that we have a process ptid. */
603 ptid_t process_ptid = ptid_t (parent_ptid.pid ());
605 target_terminal::ours_for_output ();
606 fprintf_filtered (gdb_stdlog,
607 _("[Detaching after fork from "
609 target_pid_to_str (process_ptid));
612 target_detach (parent_inf, 0);
615 /* Note that the detach above makes PARENT_INF dangling. */
617 /* Add the child thread to the appropriate lists, and switch to
618 this new thread, before cloning the program space, and
619 informing the solib layer about this new process. */
621 inferior_ptid = child_ptid;
622 add_thread_silent (inferior_ptid);
623 set_current_inferior (child_inf);
625 /* If this is a vfork child, then the address-space is shared
626 with the parent. If we detached from the parent, then we can
627 reuse the parent's program/address spaces. */
628 if (has_vforked || detach_fork)
630 child_inf->pspace = parent_pspace;
631 child_inf->aspace = child_inf->pspace->aspace;
635 child_inf->aspace = new_address_space ();
636 child_inf->pspace = new program_space (child_inf->aspace);
637 child_inf->removable = 1;
638 child_inf->symfile_flags = SYMFILE_NO_READ;
639 set_current_program_space (child_inf->pspace);
640 clone_program_space (child_inf->pspace, parent_pspace);
642 /* Let the shared library layer (e.g., solib-svr4) learn
643 about this new process, relocate the cloned exec, pull in
644 shared libraries, and install the solib event breakpoint.
645 If a "cloned-VM" event was propagated better throughout
646 the core, this wouldn't be required. */
647 solib_create_inferior_hook (0);
651 return target_follow_fork (follow_child, detach_fork);
654 /* Tell the target to follow the fork we're stopped at. Returns true
655 if the inferior should be resumed; false, if the target for some
656 reason decided it's best not to resume. */
661 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
662 int should_resume = 1;
663 struct thread_info *tp;
665 /* Copy user stepping state to the new inferior thread. FIXME: the
666 followed fork child thread should have a copy of most of the
667 parent thread structure's run control related fields, not just these.
668 Initialized to avoid "may be used uninitialized" warnings from gcc. */
669 struct breakpoint *step_resume_breakpoint = NULL;
670 struct breakpoint *exception_resume_breakpoint = NULL;
671 CORE_ADDR step_range_start = 0;
672 CORE_ADDR step_range_end = 0;
673 struct frame_id step_frame_id = { 0 };
674 struct thread_fsm *thread_fsm = NULL;
679 struct target_waitstatus wait_status;
681 /* Get the last target status returned by target_wait(). */
682 get_last_target_status (&wait_ptid, &wait_status);
684 /* If not stopped at a fork event, then there's nothing else to
686 if (wait_status.kind != TARGET_WAITKIND_FORKED
687 && wait_status.kind != TARGET_WAITKIND_VFORKED)
690 /* Check if we switched over from WAIT_PTID, since the event was
692 if (wait_ptid != minus_one_ptid
693 && inferior_ptid != wait_ptid)
695 /* We did. Switch back to WAIT_PTID thread, to tell the
696 target to follow it (in either direction). We'll
697 afterwards refuse to resume, and inform the user what
699 thread_info *wait_thread
700 = find_thread_ptid (wait_ptid);
701 switch_to_thread (wait_thread);
706 tp = inferior_thread ();
708 /* If there were any forks/vforks that were caught and are now to be
709 followed, then do so now. */
710 switch (tp->pending_follow.kind)
712 case TARGET_WAITKIND_FORKED:
713 case TARGET_WAITKIND_VFORKED:
715 ptid_t parent, child;
717 /* If the user did a next/step, etc, over a fork call,
718 preserve the stepping state in the fork child. */
719 if (follow_child && should_resume)
721 step_resume_breakpoint = clone_momentary_breakpoint
722 (tp->control.step_resume_breakpoint);
723 step_range_start = tp->control.step_range_start;
724 step_range_end = tp->control.step_range_end;
725 step_frame_id = tp->control.step_frame_id;
726 exception_resume_breakpoint
727 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
728 thread_fsm = tp->thread_fsm;
730 /* For now, delete the parent's sr breakpoint, otherwise,
731 parent/child sr breakpoints are considered duplicates,
732 and the child version will not be installed. Remove
733 this when the breakpoints module becomes aware of
734 inferiors and address spaces. */
735 delete_step_resume_breakpoint (tp);
736 tp->control.step_range_start = 0;
737 tp->control.step_range_end = 0;
738 tp->control.step_frame_id = null_frame_id;
739 delete_exception_resume_breakpoint (tp);
740 tp->thread_fsm = NULL;
743 parent = inferior_ptid;
744 child = tp->pending_follow.value.related_pid;
746 /* Set up inferior(s) as specified by the caller, and tell the
747 target to do whatever is necessary to follow either parent
749 if (follow_fork_inferior (follow_child, detach_fork))
751 /* Target refused to follow, or there's some other reason
752 we shouldn't resume. */
757 /* This pending follow fork event is now handled, one way
758 or another. The previous selected thread may be gone
759 from the lists by now, but if it is still around, need
760 to clear the pending follow request. */
761 tp = find_thread_ptid (parent);
763 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
765 /* This makes sure we don't try to apply the "Switched
766 over from WAIT_PID" logic above. */
767 nullify_last_target_wait_ptid ();
769 /* If we followed the child, switch to it... */
772 thread_info *child_thr = find_thread_ptid (child);
773 switch_to_thread (child_thr);
775 /* ... and preserve the stepping state, in case the
776 user was stepping over the fork call. */
779 tp = inferior_thread ();
780 tp->control.step_resume_breakpoint
781 = step_resume_breakpoint;
782 tp->control.step_range_start = step_range_start;
783 tp->control.step_range_end = step_range_end;
784 tp->control.step_frame_id = step_frame_id;
785 tp->control.exception_resume_breakpoint
786 = exception_resume_breakpoint;
787 tp->thread_fsm = thread_fsm;
791 /* If we get here, it was because we're trying to
792 resume from a fork catchpoint, but, the user
793 has switched threads away from the thread that
794 forked. In that case, the resume command
795 issued is most likely not applicable to the
796 child, so just warn, and refuse to resume. */
797 warning (_("Not resuming: switched threads "
798 "before following fork child."));
801 /* Reset breakpoints in the child as appropriate. */
802 follow_inferior_reset_breakpoints ();
807 case TARGET_WAITKIND_SPURIOUS:
808 /* Nothing to follow. */
811 internal_error (__FILE__, __LINE__,
812 "Unexpected pending_follow.kind %d\n",
813 tp->pending_follow.kind);
817 return should_resume;
821 follow_inferior_reset_breakpoints (void)
823 struct thread_info *tp = inferior_thread ();
825 /* Was there a step_resume breakpoint? (There was if the user
826 did a "next" at the fork() call.) If so, explicitly reset its
827 thread number. Cloned step_resume breakpoints are disabled on
828 creation, so enable it here now that it is associated with the
831 step_resumes are a form of bp that are made to be per-thread.
832 Since we created the step_resume bp when the parent process
833 was being debugged, and now are switching to the child process,
834 from the breakpoint package's viewpoint, that's a switch of
835 "threads". We must update the bp's notion of which thread
836 it is for, or it'll be ignored when it triggers. */
838 if (tp->control.step_resume_breakpoint)
840 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
841 tp->control.step_resume_breakpoint->loc->enabled = 1;
844 /* Treat exception_resume breakpoints like step_resume breakpoints. */
845 if (tp->control.exception_resume_breakpoint)
847 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
848 tp->control.exception_resume_breakpoint->loc->enabled = 1;
851 /* Reinsert all breakpoints in the child. The user may have set
852 breakpoints after catching the fork, in which case those
853 were never set in the child, but only in the parent. This makes
854 sure the inserted breakpoints match the breakpoint list. */
856 breakpoint_re_set ();
857 insert_breakpoints ();
860 /* The child has exited or execed: resume threads of the parent the
861 user wanted to be executing. */
864 proceed_after_vfork_done (struct thread_info *thread,
867 int pid = * (int *) arg;
869 if (thread->ptid.pid () == pid
870 && thread->state == THREAD_RUNNING
871 && !thread->executing
872 && !thread->stop_requested
873 && thread->suspend.stop_signal == GDB_SIGNAL_0)
876 fprintf_unfiltered (gdb_stdlog,
877 "infrun: resuming vfork parent thread %s\n",
878 target_pid_to_str (thread->ptid));
880 switch_to_thread (thread);
881 clear_proceed_status (0);
882 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
888 /* Save/restore inferior_ptid, current program space and current
889 inferior. Only use this if the current context points at an exited
890 inferior (and therefore there's no current thread to save). */
891 class scoped_restore_exited_inferior
894 scoped_restore_exited_inferior ()
895 : m_saved_ptid (&inferior_ptid)
899 scoped_restore_tmpl<ptid_t> m_saved_ptid;
900 scoped_restore_current_program_space m_pspace;
901 scoped_restore_current_inferior m_inferior;
904 /* Called whenever we notice an exec or exit event, to handle
905 detaching or resuming a vfork parent. */
908 handle_vfork_child_exec_or_exit (int exec)
910 struct inferior *inf = current_inferior ();
912 if (inf->vfork_parent)
914 int resume_parent = -1;
916 /* This exec or exit marks the end of the shared memory region
917 between the parent and the child. If the user wanted to
918 detach from the parent, now is the time. */
920 if (inf->vfork_parent->pending_detach)
922 struct thread_info *tp;
923 struct program_space *pspace;
924 struct address_space *aspace;
926 /* follow-fork child, detach-on-fork on. */
928 inf->vfork_parent->pending_detach = 0;
930 gdb::optional<scoped_restore_exited_inferior>
931 maybe_restore_inferior;
932 gdb::optional<scoped_restore_current_pspace_and_thread>
933 maybe_restore_thread;
935 /* If we're handling a child exit, then inferior_ptid points
936 at the inferior's pid, not to a thread. */
938 maybe_restore_inferior.emplace ();
940 maybe_restore_thread.emplace ();
942 /* We're letting loose of the parent. */
943 tp = any_live_thread_of_inferior (inf->vfork_parent);
944 switch_to_thread (tp);
946 /* We're about to detach from the parent, which implicitly
947 removes breakpoints from its address space. There's a
948 catch here: we want to reuse the spaces for the child,
949 but, parent/child are still sharing the pspace at this
950 point, although the exec in reality makes the kernel give
951 the child a fresh set of new pages. The problem here is
952 that the breakpoints module being unaware of this, would
953 likely chose the child process to write to the parent
954 address space. Swapping the child temporarily away from
955 the spaces has the desired effect. Yes, this is "sort
958 pspace = inf->pspace;
959 aspace = inf->aspace;
963 if (print_inferior_events)
966 = target_pid_to_str (ptid_t (inf->vfork_parent->pid));
968 target_terminal::ours_for_output ();
972 fprintf_filtered (gdb_stdlog,
973 _("[Detaching vfork parent %s "
974 "after child exec]\n"), pidstr);
978 fprintf_filtered (gdb_stdlog,
979 _("[Detaching vfork parent %s "
980 "after child exit]\n"), pidstr);
984 target_detach (inf->vfork_parent, 0);
987 inf->pspace = pspace;
988 inf->aspace = aspace;
992 /* We're staying attached to the parent, so, really give the
993 child a new address space. */
994 inf->pspace = new program_space (maybe_new_address_space ());
995 inf->aspace = inf->pspace->aspace;
997 set_current_program_space (inf->pspace);
999 resume_parent = inf->vfork_parent->pid;
1001 /* Break the bonds. */
1002 inf->vfork_parent->vfork_child = NULL;
1006 struct program_space *pspace;
1008 /* If this is a vfork child exiting, then the pspace and
1009 aspaces were shared with the parent. Since we're
1010 reporting the process exit, we'll be mourning all that is
1011 found in the address space, and switching to null_ptid,
1012 preparing to start a new inferior. But, since we don't
1013 want to clobber the parent's address/program spaces, we
1014 go ahead and create a new one for this exiting
1017 /* Switch to null_ptid while running clone_program_space, so
1018 that clone_program_space doesn't want to read the
1019 selected frame of a dead process. */
1020 scoped_restore restore_ptid
1021 = make_scoped_restore (&inferior_ptid, null_ptid);
1023 /* This inferior is dead, so avoid giving the breakpoints
1024 module the option to write through to it (cloning a
1025 program space resets breakpoints). */
1028 pspace = new program_space (maybe_new_address_space ());
1029 set_current_program_space (pspace);
1031 inf->symfile_flags = SYMFILE_NO_READ;
1032 clone_program_space (pspace, inf->vfork_parent->pspace);
1033 inf->pspace = pspace;
1034 inf->aspace = pspace->aspace;
1036 resume_parent = inf->vfork_parent->pid;
1037 /* Break the bonds. */
1038 inf->vfork_parent->vfork_child = NULL;
1041 inf->vfork_parent = NULL;
1043 gdb_assert (current_program_space == inf->pspace);
1045 if (non_stop && resume_parent != -1)
1047 /* If the user wanted the parent to be running, let it go
1049 scoped_restore_current_thread restore_thread;
1052 fprintf_unfiltered (gdb_stdlog,
1053 "infrun: resuming vfork parent process %d\n",
1056 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1061 /* Enum strings for "set|show follow-exec-mode". */
1063 static const char follow_exec_mode_new[] = "new";
1064 static const char follow_exec_mode_same[] = "same";
1065 static const char *const follow_exec_mode_names[] =
1067 follow_exec_mode_new,
1068 follow_exec_mode_same,
1072 static const char *follow_exec_mode_string = follow_exec_mode_same;
1074 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1075 struct cmd_list_element *c, const char *value)
1077 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1080 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1083 follow_exec (ptid_t ptid, char *exec_file_target)
1085 struct thread_info *th, *tmp;
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 ALL_THREADS_SAFE (th, tmp)
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 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 adding
1193 the new inferior so we don't have two active inferiors with
1194 the same ptid, which can confuse find_inferior_ptid. */
1195 exit_inferior_silent (current_inferior ());
1197 inf = add_inferior_with_spaces ();
1199 target_follow_exec (inf, exec_file_target);
1201 set_current_inferior (inf);
1202 set_current_program_space (inf->pspace);
1206 /* The old description may no longer be fit for the new image.
1207 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1208 old description; we'll read a new one below. No need to do
1209 this on "follow-exec-mode new", as the old inferior stays
1210 around (its description is later cleared/refetched on
1212 target_clear_description ();
1215 gdb_assert (current_program_space == inf->pspace);
1217 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1218 because the proper displacement for a PIE (Position Independent
1219 Executable) main symbol file will only be computed by
1220 solib_create_inferior_hook below. breakpoint_re_set would fail
1221 to insert the breakpoints with the zero displacement. */
1222 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1224 /* If the target can specify a description, read it. Must do this
1225 after flipping to the new executable (because the target supplied
1226 description must be compatible with the executable's
1227 architecture, and the old executable may e.g., be 32-bit, while
1228 the new one 64-bit), and before anything involving memory or
1230 target_find_description ();
1232 /* The add_thread call ends up reading registers, so do it after updating the
1233 target description. */
1234 if (follow_exec_mode_string == follow_exec_mode_new)
1237 solib_create_inferior_hook (0);
1239 jit_inferior_created_hook ();
1241 breakpoint_re_set ();
1243 /* Reinsert all breakpoints. (Those which were symbolic have
1244 been reset to the proper address in the new a.out, thanks
1245 to symbol_file_command...). */
1246 insert_breakpoints ();
1248 /* The next resume of this inferior should bring it to the shlib
1249 startup breakpoints. (If the user had also set bp's on
1250 "main" from the old (parent) process, then they'll auto-
1251 matically get reset there in the new process.). */
1254 /* The queue of threads that need to do a step-over operation to get
1255 past e.g., a breakpoint. What technique is used to step over the
1256 breakpoint/watchpoint does not matter -- all threads end up in the
1257 same queue, to maintain rough temporal order of execution, in order
1258 to avoid starvation, otherwise, we could e.g., find ourselves
1259 constantly stepping the same couple threads past their breakpoints
1260 over and over, if the single-step finish fast enough. */
1261 struct thread_info *step_over_queue_head;
1263 /* Bit flags indicating what the thread needs to step over. */
1265 enum step_over_what_flag
1267 /* Step over a breakpoint. */
1268 STEP_OVER_BREAKPOINT = 1,
1270 /* Step past a non-continuable watchpoint, in order to let the
1271 instruction execute so we can evaluate the watchpoint
1273 STEP_OVER_WATCHPOINT = 2
1275 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1277 /* Info about an instruction that is being stepped over. */
1279 struct step_over_info
1281 /* If we're stepping past a breakpoint, this is the address space
1282 and address of the instruction the breakpoint is set at. We'll
1283 skip inserting all breakpoints here. Valid iff ASPACE is
1285 const address_space *aspace;
1288 /* The instruction being stepped over triggers a nonsteppable
1289 watchpoint. If true, we'll skip inserting watchpoints. */
1290 int nonsteppable_watchpoint_p;
1292 /* The thread's global number. */
1296 /* The step-over info of the location that is being stepped over.
1298 Note that with async/breakpoint always-inserted mode, a user might
1299 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1300 being stepped over. As setting a new breakpoint inserts all
1301 breakpoints, we need to make sure the breakpoint being stepped over
1302 isn't inserted then. We do that by only clearing the step-over
1303 info when the step-over is actually finished (or aborted).
1305 Presently GDB can only step over one breakpoint at any given time.
1306 Given threads that can't run code in the same address space as the
1307 breakpoint's can't really miss the breakpoint, GDB could be taught
1308 to step-over at most one breakpoint per address space (so this info
1309 could move to the address space object if/when GDB is extended).
1310 The set of breakpoints being stepped over will normally be much
1311 smaller than the set of all breakpoints, so a flag in the
1312 breakpoint location structure would be wasteful. A separate list
1313 also saves complexity and run-time, as otherwise we'd have to go
1314 through all breakpoint locations clearing their flag whenever we
1315 start a new sequence. Similar considerations weigh against storing
1316 this info in the thread object. Plus, not all step overs actually
1317 have breakpoint locations -- e.g., stepping past a single-step
1318 breakpoint, or stepping to complete a non-continuable
1320 static struct step_over_info step_over_info;
1322 /* Record the address of the breakpoint/instruction we're currently
1324 N.B. We record the aspace and address now, instead of say just the thread,
1325 because when we need the info later the thread may be running. */
1328 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1329 int nonsteppable_watchpoint_p,
1332 step_over_info.aspace = aspace;
1333 step_over_info.address = address;
1334 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1335 step_over_info.thread = thread;
1338 /* Called when we're not longer stepping over a breakpoint / an
1339 instruction, so all breakpoints are free to be (re)inserted. */
1342 clear_step_over_info (void)
1345 fprintf_unfiltered (gdb_stdlog,
1346 "infrun: clear_step_over_info\n");
1347 step_over_info.aspace = NULL;
1348 step_over_info.address = 0;
1349 step_over_info.nonsteppable_watchpoint_p = 0;
1350 step_over_info.thread = -1;
1356 stepping_past_instruction_at (struct address_space *aspace,
1359 return (step_over_info.aspace != NULL
1360 && breakpoint_address_match (aspace, address,
1361 step_over_info.aspace,
1362 step_over_info.address));
1368 thread_is_stepping_over_breakpoint (int thread)
1370 return (step_over_info.thread != -1
1371 && thread == step_over_info.thread);
1377 stepping_past_nonsteppable_watchpoint (void)
1379 return step_over_info.nonsteppable_watchpoint_p;
1382 /* Returns true if step-over info is valid. */
1385 step_over_info_valid_p (void)
1387 return (step_over_info.aspace != NULL
1388 || stepping_past_nonsteppable_watchpoint ());
1392 /* Displaced stepping. */
1394 /* In non-stop debugging mode, we must take special care to manage
1395 breakpoints properly; in particular, the traditional strategy for
1396 stepping a thread past a breakpoint it has hit is unsuitable.
1397 'Displaced stepping' is a tactic for stepping one thread past a
1398 breakpoint it has hit while ensuring that other threads running
1399 concurrently will hit the breakpoint as they should.
1401 The traditional way to step a thread T off a breakpoint in a
1402 multi-threaded program in all-stop mode is as follows:
1404 a0) Initially, all threads are stopped, and breakpoints are not
1406 a1) We single-step T, leaving breakpoints uninserted.
1407 a2) We insert breakpoints, and resume all threads.
1409 In non-stop debugging, however, this strategy is unsuitable: we
1410 don't want to have to stop all threads in the system in order to
1411 continue or step T past a breakpoint. Instead, we use displaced
1414 n0) Initially, T is stopped, other threads are running, and
1415 breakpoints are inserted.
1416 n1) We copy the instruction "under" the breakpoint to a separate
1417 location, outside the main code stream, making any adjustments
1418 to the instruction, register, and memory state as directed by
1420 n2) We single-step T over the instruction at its new location.
1421 n3) We adjust the resulting register and memory state as directed
1422 by T's architecture. This includes resetting T's PC to point
1423 back into the main instruction stream.
1426 This approach depends on the following gdbarch methods:
1428 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1429 indicate where to copy the instruction, and how much space must
1430 be reserved there. We use these in step n1.
1432 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1433 address, and makes any necessary adjustments to the instruction,
1434 register contents, and memory. We use this in step n1.
1436 - gdbarch_displaced_step_fixup adjusts registers and memory after
1437 we have successfuly single-stepped the instruction, to yield the
1438 same effect the instruction would have had if we had executed it
1439 at its original address. We use this in step n3.
1441 The gdbarch_displaced_step_copy_insn and
1442 gdbarch_displaced_step_fixup functions must be written so that
1443 copying an instruction with gdbarch_displaced_step_copy_insn,
1444 single-stepping across the copied instruction, and then applying
1445 gdbarch_displaced_insn_fixup should have the same effects on the
1446 thread's memory and registers as stepping the instruction in place
1447 would have. Exactly which responsibilities fall to the copy and
1448 which fall to the fixup is up to the author of those functions.
1450 See the comments in gdbarch.sh for details.
1452 Note that displaced stepping and software single-step cannot
1453 currently be used in combination, although with some care I think
1454 they could be made to. Software single-step works by placing
1455 breakpoints on all possible subsequent instructions; if the
1456 displaced instruction is a PC-relative jump, those breakpoints
1457 could fall in very strange places --- on pages that aren't
1458 executable, or at addresses that are not proper instruction
1459 boundaries. (We do generally let other threads run while we wait
1460 to hit the software single-step breakpoint, and they might
1461 encounter such a corrupted instruction.) One way to work around
1462 this would be to have gdbarch_displaced_step_copy_insn fully
1463 simulate the effect of PC-relative instructions (and return NULL)
1464 on architectures that use software single-stepping.
1466 In non-stop mode, we can have independent and simultaneous step
1467 requests, so more than one thread may need to simultaneously step
1468 over a breakpoint. The current implementation assumes there is
1469 only one scratch space per process. In this case, we have to
1470 serialize access to the scratch space. If thread A wants to step
1471 over a breakpoint, but we are currently waiting for some other
1472 thread to complete a displaced step, we leave thread A stopped and
1473 place it in the displaced_step_request_queue. Whenever a displaced
1474 step finishes, we pick the next thread in the queue and start a new
1475 displaced step operation on it. See displaced_step_prepare and
1476 displaced_step_fixup for details. */
1478 /* Default destructor for displaced_step_closure. */
1480 displaced_step_closure::~displaced_step_closure () = default;
1482 /* Per-inferior displaced stepping state. */
1483 struct displaced_step_inferior_state
1485 /* Pointer to next in linked list. */
1486 struct displaced_step_inferior_state *next;
1488 /* The process this displaced step state refers to. */
1491 /* True if preparing a displaced step ever failed. If so, we won't
1492 try displaced stepping for this inferior again. */
1495 /* If this is not nullptr, this is the thread carrying out a
1496 displaced single-step in process PID. This thread's state will
1497 require fixing up once it has completed its step. */
1498 thread_info *step_thread;
1500 /* The architecture the thread had when we stepped it. */
1501 struct gdbarch *step_gdbarch;
1503 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1504 for post-step cleanup. */
1505 struct displaced_step_closure *step_closure;
1507 /* The address of the original instruction, and the copy we
1509 CORE_ADDR step_original, step_copy;
1511 /* Saved contents of copy area. */
1512 gdb_byte *step_saved_copy;
1515 /* The list of states of processes involved in displaced stepping
1517 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1519 /* Get the displaced stepping state of process PID. */
1521 static struct displaced_step_inferior_state *
1522 get_displaced_stepping_state (inferior *inf)
1524 struct displaced_step_inferior_state *state;
1526 for (state = displaced_step_inferior_states;
1528 state = state->next)
1529 if (state->inf == inf)
1535 /* Returns true if any inferior has a thread doing a displaced
1539 displaced_step_in_progress_any_inferior (void)
1541 struct displaced_step_inferior_state *state;
1543 for (state = displaced_step_inferior_states;
1545 state = state->next)
1546 if (state->step_thread != nullptr)
1552 /* Return true if thread represented by PTID is doing a displaced
1556 displaced_step_in_progress_thread (thread_info *thread)
1558 struct displaced_step_inferior_state *displaced;
1560 gdb_assert (thread != NULL);
1562 displaced = get_displaced_stepping_state (thread->inf);
1564 return (displaced != NULL && displaced->step_thread == thread);
1567 /* Return true if process PID has a thread doing a displaced step. */
1570 displaced_step_in_progress (inferior *inf)
1572 struct displaced_step_inferior_state *displaced;
1574 displaced = get_displaced_stepping_state (inf);
1575 if (displaced != NULL && displaced->step_thread != nullptr)
1581 /* Add a new displaced stepping state for process PID to the displaced
1582 stepping state list, or return a pointer to an already existing
1583 entry, if it already exists. Never returns NULL. */
1585 static struct displaced_step_inferior_state *
1586 add_displaced_stepping_state (inferior *inf)
1588 struct displaced_step_inferior_state *state;
1590 for (state = displaced_step_inferior_states;
1592 state = state->next)
1593 if (state->inf == inf)
1596 state = XCNEW (struct displaced_step_inferior_state);
1598 state->next = displaced_step_inferior_states;
1599 displaced_step_inferior_states = state;
1604 /* If inferior is in displaced stepping, and ADDR equals to starting address
1605 of copy area, return corresponding displaced_step_closure. Otherwise,
1608 struct displaced_step_closure*
1609 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1611 struct displaced_step_inferior_state *displaced
1612 = get_displaced_stepping_state (current_inferior ());
1614 /* If checking the mode of displaced instruction in copy area. */
1615 if (displaced != NULL
1616 && displaced->step_thread != nullptr
1617 && displaced->step_copy == addr)
1618 return displaced->step_closure;
1623 /* Remove the displaced stepping state of process PID. */
1626 remove_displaced_stepping_state (inferior *inf)
1628 struct displaced_step_inferior_state *it, **prev_next_p;
1630 gdb_assert (inf != nullptr);
1632 it = displaced_step_inferior_states;
1633 prev_next_p = &displaced_step_inferior_states;
1638 *prev_next_p = it->next;
1643 prev_next_p = &it->next;
1649 infrun_inferior_exit (struct inferior *inf)
1651 remove_displaced_stepping_state (inf);
1654 /* If ON, and the architecture supports it, GDB will use displaced
1655 stepping to step over breakpoints. If OFF, or if the architecture
1656 doesn't support it, GDB will instead use the traditional
1657 hold-and-step approach. If AUTO (which is the default), GDB will
1658 decide which technique to use to step over breakpoints depending on
1659 which of all-stop or non-stop mode is active --- displaced stepping
1660 in non-stop mode; hold-and-step in all-stop mode. */
1662 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1665 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1666 struct cmd_list_element *c,
1669 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1670 fprintf_filtered (file,
1671 _("Debugger's willingness to use displaced stepping "
1672 "to step over breakpoints is %s (currently %s).\n"),
1673 value, target_is_non_stop_p () ? "on" : "off");
1675 fprintf_filtered (file,
1676 _("Debugger's willingness to use displaced stepping "
1677 "to step over breakpoints is %s.\n"), value);
1680 /* Return non-zero if displaced stepping can/should be used to step
1681 over breakpoints of thread TP. */
1684 use_displaced_stepping (struct thread_info *tp)
1686 struct regcache *regcache = get_thread_regcache (tp);
1687 struct gdbarch *gdbarch = regcache->arch ();
1688 struct displaced_step_inferior_state *displaced_state;
1690 displaced_state = get_displaced_stepping_state (tp->inf);
1692 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1693 && target_is_non_stop_p ())
1694 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1695 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1696 && find_record_target () == NULL
1697 && (displaced_state == NULL
1698 || !displaced_state->failed_before));
1701 /* Clean out any stray displaced stepping state. */
1703 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1705 /* Indicate that there is no cleanup pending. */
1706 displaced->step_thread = nullptr;
1708 delete displaced->step_closure;
1709 displaced->step_closure = NULL;
1713 displaced_step_clear_cleanup (void *arg)
1715 struct displaced_step_inferior_state *state
1716 = (struct displaced_step_inferior_state *) arg;
1718 displaced_step_clear (state);
1721 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1723 displaced_step_dump_bytes (struct ui_file *file,
1724 const gdb_byte *buf,
1729 for (i = 0; i < len; i++)
1730 fprintf_unfiltered (file, "%02x ", buf[i]);
1731 fputs_unfiltered ("\n", file);
1734 /* Prepare to single-step, using displaced stepping.
1736 Note that we cannot use displaced stepping when we have a signal to
1737 deliver. If we have a signal to deliver and an instruction to step
1738 over, then after the step, there will be no indication from the
1739 target whether the thread entered a signal handler or ignored the
1740 signal and stepped over the instruction successfully --- both cases
1741 result in a simple SIGTRAP. In the first case we mustn't do a
1742 fixup, and in the second case we must --- but we can't tell which.
1743 Comments in the code for 'random signals' in handle_inferior_event
1744 explain how we handle this case instead.
1746 Returns 1 if preparing was successful -- this thread is going to be
1747 stepped now; 0 if displaced stepping this thread got queued; or -1
1748 if this instruction can't be displaced stepped. */
1751 displaced_step_prepare_throw (thread_info *tp)
1753 struct cleanup *ignore_cleanups;
1754 regcache *regcache = get_thread_regcache (tp);
1755 struct gdbarch *gdbarch = regcache->arch ();
1756 const address_space *aspace = regcache->aspace ();
1757 CORE_ADDR original, copy;
1759 struct displaced_step_closure *closure;
1760 struct displaced_step_inferior_state *displaced;
1763 /* We should never reach this function if the architecture does not
1764 support displaced stepping. */
1765 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1767 /* Nor if the thread isn't meant to step over a breakpoint. */
1768 gdb_assert (tp->control.trap_expected);
1770 /* Disable range stepping while executing in the scratch pad. We
1771 want a single-step even if executing the displaced instruction in
1772 the scratch buffer lands within the stepping range (e.g., a
1774 tp->control.may_range_step = 0;
1776 /* We have to displaced step one thread at a time, as we only have
1777 access to a single scratch space per inferior. */
1779 displaced = add_displaced_stepping_state (tp->inf);
1781 if (displaced->step_thread != nullptr)
1783 /* Already waiting for a displaced step to finish. Defer this
1784 request and place in queue. */
1786 if (debug_displaced)
1787 fprintf_unfiltered (gdb_stdlog,
1788 "displaced: deferring step of %s\n",
1789 target_pid_to_str (tp->ptid));
1791 thread_step_over_chain_enqueue (tp);
1796 if (debug_displaced)
1797 fprintf_unfiltered (gdb_stdlog,
1798 "displaced: stepping %s now\n",
1799 target_pid_to_str (tp->ptid));
1802 displaced_step_clear (displaced);
1804 scoped_restore_current_thread restore_thread;
1806 switch_to_thread (tp);
1808 original = regcache_read_pc (regcache);
1810 copy = gdbarch_displaced_step_location (gdbarch);
1811 len = gdbarch_max_insn_length (gdbarch);
1813 if (breakpoint_in_range_p (aspace, copy, len))
1815 /* There's a breakpoint set in the scratch pad location range
1816 (which is usually around the entry point). We'd either
1817 install it before resuming, which would overwrite/corrupt the
1818 scratch pad, or if it was already inserted, this displaced
1819 step would overwrite it. The latter is OK in the sense that
1820 we already assume that no thread is going to execute the code
1821 in the scratch pad range (after initial startup) anyway, but
1822 the former is unacceptable. Simply punt and fallback to
1823 stepping over this breakpoint in-line. */
1824 if (debug_displaced)
1826 fprintf_unfiltered (gdb_stdlog,
1827 "displaced: breakpoint set in scratch pad. "
1828 "Stepping over breakpoint in-line instead.\n");
1834 /* Save the original contents of the copy area. */
1835 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1836 ignore_cleanups = make_cleanup (free_current_contents,
1837 &displaced->step_saved_copy);
1838 status = target_read_memory (copy, displaced->step_saved_copy, len);
1840 throw_error (MEMORY_ERROR,
1841 _("Error accessing memory address %s (%s) for "
1842 "displaced-stepping scratch space."),
1843 paddress (gdbarch, copy), safe_strerror (status));
1844 if (debug_displaced)
1846 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1847 paddress (gdbarch, copy));
1848 displaced_step_dump_bytes (gdb_stdlog,
1849 displaced->step_saved_copy,
1853 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1854 original, copy, regcache);
1855 if (closure == NULL)
1857 /* The architecture doesn't know how or want to displaced step
1858 this instruction or instruction sequence. Fallback to
1859 stepping over the breakpoint in-line. */
1860 do_cleanups (ignore_cleanups);
1864 /* Save the information we need to fix things up if the step
1866 displaced->step_thread = tp;
1867 displaced->step_gdbarch = gdbarch;
1868 displaced->step_closure = closure;
1869 displaced->step_original = original;
1870 displaced->step_copy = copy;
1872 make_cleanup (displaced_step_clear_cleanup, displaced);
1874 /* Resume execution at the copy. */
1875 regcache_write_pc (regcache, copy);
1877 discard_cleanups (ignore_cleanups);
1879 if (debug_displaced)
1880 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1881 paddress (gdbarch, copy));
1886 /* Wrapper for displaced_step_prepare_throw that disabled further
1887 attempts at displaced stepping if we get a memory error. */
1890 displaced_step_prepare (thread_info *thread)
1896 prepared = displaced_step_prepare_throw (thread);
1898 CATCH (ex, RETURN_MASK_ERROR)
1900 struct displaced_step_inferior_state *displaced_state;
1902 if (ex.error != MEMORY_ERROR
1903 && ex.error != NOT_SUPPORTED_ERROR)
1904 throw_exception (ex);
1908 fprintf_unfiltered (gdb_stdlog,
1909 "infrun: disabling displaced stepping: %s\n",
1913 /* Be verbose if "set displaced-stepping" is "on", silent if
1915 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1917 warning (_("disabling displaced stepping: %s"),
1921 /* Disable further displaced stepping attempts. */
1923 = get_displaced_stepping_state (thread->inf);
1924 displaced_state->failed_before = 1;
1932 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1933 const gdb_byte *myaddr, int len)
1935 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1937 inferior_ptid = ptid;
1938 write_memory (memaddr, myaddr, len);
1941 /* Restore the contents of the copy area for thread PTID. */
1944 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1947 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1949 write_memory_ptid (ptid, displaced->step_copy,
1950 displaced->step_saved_copy, len);
1951 if (debug_displaced)
1952 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1953 target_pid_to_str (ptid),
1954 paddress (displaced->step_gdbarch,
1955 displaced->step_copy));
1958 /* If we displaced stepped an instruction successfully, adjust
1959 registers and memory to yield the same effect the instruction would
1960 have had if we had executed it at its original address, and return
1961 1. If the instruction didn't complete, relocate the PC and return
1962 -1. If the thread wasn't displaced stepping, return 0. */
1965 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1967 struct cleanup *old_cleanups;
1968 struct displaced_step_inferior_state *displaced
1969 = get_displaced_stepping_state (event_thread->inf);
1972 /* Was any thread of this process doing a displaced step? */
1973 if (displaced == NULL)
1976 /* Was this event for the thread we displaced? */
1977 if (displaced->step_thread != event_thread)
1980 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1982 displaced_step_restore (displaced, displaced->step_thread->ptid);
1984 /* Fixup may need to read memory/registers. Switch to the thread
1985 that we're fixing up. Also, target_stopped_by_watchpoint checks
1986 the current thread. */
1987 switch_to_thread (event_thread);
1989 /* Did the instruction complete successfully? */
1990 if (signal == GDB_SIGNAL_TRAP
1991 && !(target_stopped_by_watchpoint ()
1992 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1993 || target_have_steppable_watchpoint)))
1995 /* Fix up the resulting state. */
1996 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1997 displaced->step_closure,
1998 displaced->step_original,
1999 displaced->step_copy,
2000 get_thread_regcache (displaced->step_thread));
2005 /* Since the instruction didn't complete, all we can do is
2007 struct regcache *regcache = get_thread_regcache (event_thread);
2008 CORE_ADDR pc = regcache_read_pc (regcache);
2010 pc = displaced->step_original + (pc - displaced->step_copy);
2011 regcache_write_pc (regcache, pc);
2015 do_cleanups (old_cleanups);
2017 displaced->step_thread = nullptr;
2022 /* Data to be passed around while handling an event. This data is
2023 discarded between events. */
2024 struct execution_control_state
2027 /* The thread that got the event, if this was a thread event; NULL
2029 struct thread_info *event_thread;
2031 struct target_waitstatus ws;
2032 int stop_func_filled_in;
2033 CORE_ADDR stop_func_start;
2034 CORE_ADDR stop_func_end;
2035 const char *stop_func_name;
2038 /* True if the event thread hit the single-step breakpoint of
2039 another thread. Thus the event doesn't cause a stop, the thread
2040 needs to be single-stepped past the single-step breakpoint before
2041 we can switch back to the original stepping thread. */
2042 int hit_singlestep_breakpoint;
2045 /* Clear ECS and set it to point at TP. */
2048 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2050 memset (ecs, 0, sizeof (*ecs));
2051 ecs->event_thread = tp;
2052 ecs->ptid = tp->ptid;
2055 static void keep_going_pass_signal (struct execution_control_state *ecs);
2056 static void prepare_to_wait (struct execution_control_state *ecs);
2057 static int keep_going_stepped_thread (struct thread_info *tp);
2058 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2060 /* Are there any pending step-over requests? If so, run all we can
2061 now and return true. Otherwise, return false. */
2064 start_step_over (void)
2066 struct thread_info *tp, *next;
2068 /* Don't start a new step-over if we already have an in-line
2069 step-over operation ongoing. */
2070 if (step_over_info_valid_p ())
2073 for (tp = step_over_queue_head; tp != NULL; tp = next)
2075 struct execution_control_state ecss;
2076 struct execution_control_state *ecs = &ecss;
2077 step_over_what step_what;
2078 int must_be_in_line;
2080 gdb_assert (!tp->stop_requested);
2082 next = thread_step_over_chain_next (tp);
2084 /* If this inferior already has a displaced step in process,
2085 don't start a new one. */
2086 if (displaced_step_in_progress (tp->inf))
2089 step_what = thread_still_needs_step_over (tp);
2090 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2091 || ((step_what & STEP_OVER_BREAKPOINT)
2092 && !use_displaced_stepping (tp)));
2094 /* We currently stop all threads of all processes to step-over
2095 in-line. If we need to start a new in-line step-over, let
2096 any pending displaced steps finish first. */
2097 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2100 thread_step_over_chain_remove (tp);
2102 if (step_over_queue_head == NULL)
2105 fprintf_unfiltered (gdb_stdlog,
2106 "infrun: step-over queue now empty\n");
2109 if (tp->control.trap_expected
2113 internal_error (__FILE__, __LINE__,
2114 "[%s] has inconsistent state: "
2115 "trap_expected=%d, resumed=%d, executing=%d\n",
2116 target_pid_to_str (tp->ptid),
2117 tp->control.trap_expected,
2123 fprintf_unfiltered (gdb_stdlog,
2124 "infrun: resuming [%s] for step-over\n",
2125 target_pid_to_str (tp->ptid));
2127 /* keep_going_pass_signal skips the step-over if the breakpoint
2128 is no longer inserted. In all-stop, we want to keep looking
2129 for a thread that needs a step-over instead of resuming TP,
2130 because we wouldn't be able to resume anything else until the
2131 target stops again. In non-stop, the resume always resumes
2132 only TP, so it's OK to let the thread resume freely. */
2133 if (!target_is_non_stop_p () && !step_what)
2136 switch_to_thread (tp);
2137 reset_ecs (ecs, tp);
2138 keep_going_pass_signal (ecs);
2140 if (!ecs->wait_some_more)
2141 error (_("Command aborted."));
2143 gdb_assert (tp->resumed);
2145 /* If we started a new in-line step-over, we're done. */
2146 if (step_over_info_valid_p ())
2148 gdb_assert (tp->control.trap_expected);
2152 if (!target_is_non_stop_p ())
2154 /* On all-stop, shouldn't have resumed unless we needed a
2156 gdb_assert (tp->control.trap_expected
2157 || tp->step_after_step_resume_breakpoint);
2159 /* With remote targets (at least), in all-stop, we can't
2160 issue any further remote commands until the program stops
2165 /* Either the thread no longer needed a step-over, or a new
2166 displaced stepping sequence started. Even in the latter
2167 case, continue looking. Maybe we can also start another
2168 displaced step on a thread of other process. */
2174 /* Update global variables holding ptids to hold NEW_PTID if they were
2175 holding OLD_PTID. */
2177 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2179 if (inferior_ptid == old_ptid)
2180 inferior_ptid = new_ptid;
2185 static const char schedlock_off[] = "off";
2186 static const char schedlock_on[] = "on";
2187 static const char schedlock_step[] = "step";
2188 static const char schedlock_replay[] = "replay";
2189 static const char *const scheduler_enums[] = {
2196 static const char *scheduler_mode = schedlock_replay;
2198 show_scheduler_mode (struct ui_file *file, int from_tty,
2199 struct cmd_list_element *c, const char *value)
2201 fprintf_filtered (file,
2202 _("Mode for locking scheduler "
2203 "during execution is \"%s\".\n"),
2208 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2210 if (!target_can_lock_scheduler)
2212 scheduler_mode = schedlock_off;
2213 error (_("Target '%s' cannot support this command."), target_shortname);
2217 /* True if execution commands resume all threads of all processes by
2218 default; otherwise, resume only threads of the current inferior
2220 int sched_multi = 0;
2222 /* Try to setup for software single stepping over the specified location.
2223 Return 1 if target_resume() should use hardware single step.
2225 GDBARCH the current gdbarch.
2226 PC the location to step over. */
2229 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2233 if (execution_direction == EXEC_FORWARD
2234 && gdbarch_software_single_step_p (gdbarch))
2235 hw_step = !insert_single_step_breakpoints (gdbarch);
2243 user_visible_resume_ptid (int step)
2249 /* With non-stop mode on, threads are always handled
2251 resume_ptid = inferior_ptid;
2253 else if ((scheduler_mode == schedlock_on)
2254 || (scheduler_mode == schedlock_step && step))
2256 /* User-settable 'scheduler' mode requires solo thread
2258 resume_ptid = inferior_ptid;
2260 else if ((scheduler_mode == schedlock_replay)
2261 && target_record_will_replay (minus_one_ptid, execution_direction))
2263 /* User-settable 'scheduler' mode requires solo thread resume in replay
2265 resume_ptid = inferior_ptid;
2267 else if (!sched_multi && target_supports_multi_process ())
2269 /* Resume all threads of the current process (and none of other
2271 resume_ptid = ptid_t (inferior_ptid.pid ());
2275 /* Resume all threads of all processes. */
2276 resume_ptid = RESUME_ALL;
2282 /* Return a ptid representing the set of threads that we will resume,
2283 in the perspective of the target, assuming run control handling
2284 does not require leaving some threads stopped (e.g., stepping past
2285 breakpoint). USER_STEP indicates whether we're about to start the
2286 target for a stepping command. */
2289 internal_resume_ptid (int user_step)
2291 /* In non-stop, we always control threads individually. Note that
2292 the target may always work in non-stop mode even with "set
2293 non-stop off", in which case user_visible_resume_ptid could
2294 return a wildcard ptid. */
2295 if (target_is_non_stop_p ())
2296 return inferior_ptid;
2298 return user_visible_resume_ptid (user_step);
2301 /* Wrapper for target_resume, that handles infrun-specific
2305 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2307 struct thread_info *tp = inferior_thread ();
2309 gdb_assert (!tp->stop_requested);
2311 /* Install inferior's terminal modes. */
2312 target_terminal::inferior ();
2314 /* Avoid confusing the next resume, if the next stop/resume
2315 happens to apply to another thread. */
2316 tp->suspend.stop_signal = GDB_SIGNAL_0;
2318 /* Advise target which signals may be handled silently.
2320 If we have removed breakpoints because we are stepping over one
2321 in-line (in any thread), we need to receive all signals to avoid
2322 accidentally skipping a breakpoint during execution of a signal
2325 Likewise if we're displaced stepping, otherwise a trap for a
2326 breakpoint in a signal handler might be confused with the
2327 displaced step finishing. We don't make the displaced_step_fixup
2328 step distinguish the cases instead, because:
2330 - a backtrace while stopped in the signal handler would show the
2331 scratch pad as frame older than the signal handler, instead of
2332 the real mainline code.
2334 - when the thread is later resumed, the signal handler would
2335 return to the scratch pad area, which would no longer be
2337 if (step_over_info_valid_p ()
2338 || displaced_step_in_progress (tp->inf))
2339 target_pass_signals (0, NULL);
2341 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2343 target_resume (resume_ptid, step, sig);
2345 target_commit_resume ();
2348 /* Resume the inferior. SIG is the signal to give the inferior
2349 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2350 call 'resume', which handles exceptions. */
2353 resume_1 (enum gdb_signal sig)
2355 struct regcache *regcache = get_current_regcache ();
2356 struct gdbarch *gdbarch = regcache->arch ();
2357 struct thread_info *tp = inferior_thread ();
2358 CORE_ADDR pc = regcache_read_pc (regcache);
2359 const address_space *aspace = regcache->aspace ();
2361 /* This represents the user's step vs continue request. When
2362 deciding whether "set scheduler-locking step" applies, it's the
2363 user's intention that counts. */
2364 const int user_step = tp->control.stepping_command;
2365 /* This represents what we'll actually request the target to do.
2366 This can decay from a step to a continue, if e.g., we need to
2367 implement single-stepping with breakpoints (software
2371 gdb_assert (!tp->stop_requested);
2372 gdb_assert (!thread_is_in_step_over_chain (tp));
2374 if (tp->suspend.waitstatus_pending_p)
2379 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2381 fprintf_unfiltered (gdb_stdlog,
2382 "infrun: resume: thread %s has pending wait "
2383 "status %s (currently_stepping=%d).\n",
2384 target_pid_to_str (tp->ptid), statstr.c_str (),
2385 currently_stepping (tp));
2390 /* FIXME: What should we do if we are supposed to resume this
2391 thread with a signal? Maybe we should maintain a queue of
2392 pending signals to deliver. */
2393 if (sig != GDB_SIGNAL_0)
2395 warning (_("Couldn't deliver signal %s to %s."),
2396 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2399 tp->suspend.stop_signal = GDB_SIGNAL_0;
2401 if (target_can_async_p ())
2404 /* Tell the event loop we have an event to process. */
2405 mark_async_event_handler (infrun_async_inferior_event_token);
2410 tp->stepped_breakpoint = 0;
2412 /* Depends on stepped_breakpoint. */
2413 step = currently_stepping (tp);
2415 if (current_inferior ()->waiting_for_vfork_done)
2417 /* Don't try to single-step a vfork parent that is waiting for
2418 the child to get out of the shared memory region (by exec'ing
2419 or exiting). This is particularly important on software
2420 single-step archs, as the child process would trip on the
2421 software single step breakpoint inserted for the parent
2422 process. Since the parent will not actually execute any
2423 instruction until the child is out of the shared region (such
2424 are vfork's semantics), it is safe to simply continue it.
2425 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2426 the parent, and tell it to `keep_going', which automatically
2427 re-sets it stepping. */
2429 fprintf_unfiltered (gdb_stdlog,
2430 "infrun: resume : clear step\n");
2435 fprintf_unfiltered (gdb_stdlog,
2436 "infrun: resume (step=%d, signal=%s), "
2437 "trap_expected=%d, current thread [%s] at %s\n",
2438 step, gdb_signal_to_symbol_string (sig),
2439 tp->control.trap_expected,
2440 target_pid_to_str (inferior_ptid),
2441 paddress (gdbarch, pc));
2443 /* Normally, by the time we reach `resume', the breakpoints are either
2444 removed or inserted, as appropriate. The exception is if we're sitting
2445 at a permanent breakpoint; we need to step over it, but permanent
2446 breakpoints can't be removed. So we have to test for it here. */
2447 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2449 if (sig != GDB_SIGNAL_0)
2451 /* We have a signal to pass to the inferior. The resume
2452 may, or may not take us to the signal handler. If this
2453 is a step, we'll need to stop in the signal handler, if
2454 there's one, (if the target supports stepping into
2455 handlers), or in the next mainline instruction, if
2456 there's no handler. If this is a continue, we need to be
2457 sure to run the handler with all breakpoints inserted.
2458 In all cases, set a breakpoint at the current address
2459 (where the handler returns to), and once that breakpoint
2460 is hit, resume skipping the permanent breakpoint. If
2461 that breakpoint isn't hit, then we've stepped into the
2462 signal handler (or hit some other event). We'll delete
2463 the step-resume breakpoint then. */
2466 fprintf_unfiltered (gdb_stdlog,
2467 "infrun: resume: skipping permanent breakpoint, "
2468 "deliver signal first\n");
2470 clear_step_over_info ();
2471 tp->control.trap_expected = 0;
2473 if (tp->control.step_resume_breakpoint == NULL)
2475 /* Set a "high-priority" step-resume, as we don't want
2476 user breakpoints at PC to trigger (again) when this
2478 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2479 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2481 tp->step_after_step_resume_breakpoint = step;
2484 insert_breakpoints ();
2488 /* There's no signal to pass, we can go ahead and skip the
2489 permanent breakpoint manually. */
2491 fprintf_unfiltered (gdb_stdlog,
2492 "infrun: resume: skipping permanent breakpoint\n");
2493 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2494 /* Update pc to reflect the new address from which we will
2495 execute instructions. */
2496 pc = regcache_read_pc (regcache);
2500 /* We've already advanced the PC, so the stepping part
2501 is done. Now we need to arrange for a trap to be
2502 reported to handle_inferior_event. Set a breakpoint
2503 at the current PC, and run to it. Don't update
2504 prev_pc, because if we end in
2505 switch_back_to_stepped_thread, we want the "expected
2506 thread advanced also" branch to be taken. IOW, we
2507 don't want this thread to step further from PC
2509 gdb_assert (!step_over_info_valid_p ());
2510 insert_single_step_breakpoint (gdbarch, aspace, pc);
2511 insert_breakpoints ();
2513 resume_ptid = internal_resume_ptid (user_step);
2514 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2521 /* If we have a breakpoint to step over, make sure to do a single
2522 step only. Same if we have software watchpoints. */
2523 if (tp->control.trap_expected || bpstat_should_step ())
2524 tp->control.may_range_step = 0;
2526 /* If enabled, step over breakpoints by executing a copy of the
2527 instruction at a different address.
2529 We can't use displaced stepping when we have a signal to deliver;
2530 the comments for displaced_step_prepare explain why. The
2531 comments in the handle_inferior event for dealing with 'random
2532 signals' explain what we do instead.
2534 We can't use displaced stepping when we are waiting for vfork_done
2535 event, displaced stepping breaks the vfork child similarly as single
2536 step software breakpoint. */
2537 if (tp->control.trap_expected
2538 && use_displaced_stepping (tp)
2539 && !step_over_info_valid_p ()
2540 && sig == GDB_SIGNAL_0
2541 && !current_inferior ()->waiting_for_vfork_done)
2543 int prepared = displaced_step_prepare (tp);
2548 fprintf_unfiltered (gdb_stdlog,
2549 "Got placed in step-over queue\n");
2551 tp->control.trap_expected = 0;
2554 else if (prepared < 0)
2556 /* Fallback to stepping over the breakpoint in-line. */
2558 if (target_is_non_stop_p ())
2559 stop_all_threads ();
2561 set_step_over_info (regcache->aspace (),
2562 regcache_read_pc (regcache), 0, tp->global_num);
2564 step = maybe_software_singlestep (gdbarch, pc);
2566 insert_breakpoints ();
2568 else if (prepared > 0)
2570 struct displaced_step_inferior_state *displaced;
2572 /* Update pc to reflect the new address from which we will
2573 execute instructions due to displaced stepping. */
2574 pc = regcache_read_pc (get_thread_regcache (tp));
2576 displaced = get_displaced_stepping_state (tp->inf);
2577 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2578 displaced->step_closure);
2582 /* Do we need to do it the hard way, w/temp breakpoints? */
2584 step = maybe_software_singlestep (gdbarch, pc);
2586 /* Currently, our software single-step implementation leads to different
2587 results than hardware single-stepping in one situation: when stepping
2588 into delivering a signal which has an associated signal handler,
2589 hardware single-step will stop at the first instruction of the handler,
2590 while software single-step will simply skip execution of the handler.
2592 For now, this difference in behavior is accepted since there is no
2593 easy way to actually implement single-stepping into a signal handler
2594 without kernel support.
2596 However, there is one scenario where this difference leads to follow-on
2597 problems: if we're stepping off a breakpoint by removing all breakpoints
2598 and then single-stepping. In this case, the software single-step
2599 behavior means that even if there is a *breakpoint* in the signal
2600 handler, GDB still would not stop.
2602 Fortunately, we can at least fix this particular issue. We detect
2603 here the case where we are about to deliver a signal while software
2604 single-stepping with breakpoints removed. In this situation, we
2605 revert the decisions to remove all breakpoints and insert single-
2606 step breakpoints, and instead we install a step-resume breakpoint
2607 at the current address, deliver the signal without stepping, and
2608 once we arrive back at the step-resume breakpoint, actually step
2609 over the breakpoint we originally wanted to step over. */
2610 if (thread_has_single_step_breakpoints_set (tp)
2611 && sig != GDB_SIGNAL_0
2612 && step_over_info_valid_p ())
2614 /* If we have nested signals or a pending signal is delivered
2615 immediately after a handler returns, might might already have
2616 a step-resume breakpoint set on the earlier handler. We cannot
2617 set another step-resume breakpoint; just continue on until the
2618 original breakpoint is hit. */
2619 if (tp->control.step_resume_breakpoint == NULL)
2621 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2622 tp->step_after_step_resume_breakpoint = 1;
2625 delete_single_step_breakpoints (tp);
2627 clear_step_over_info ();
2628 tp->control.trap_expected = 0;
2630 insert_breakpoints ();
2633 /* If STEP is set, it's a request to use hardware stepping
2634 facilities. But in that case, we should never
2635 use singlestep breakpoint. */
2636 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2638 /* Decide the set of threads to ask the target to resume. */
2639 if (tp->control.trap_expected)
2641 /* We're allowing a thread to run past a breakpoint it has
2642 hit, either by single-stepping the thread with the breakpoint
2643 removed, or by displaced stepping, with the breakpoint inserted.
2644 In the former case, we need to single-step only this thread,
2645 and keep others stopped, as they can miss this breakpoint if
2646 allowed to run. That's not really a problem for displaced
2647 stepping, but, we still keep other threads stopped, in case
2648 another thread is also stopped for a breakpoint waiting for
2649 its turn in the displaced stepping queue. */
2650 resume_ptid = inferior_ptid;
2653 resume_ptid = internal_resume_ptid (user_step);
2655 if (execution_direction != EXEC_REVERSE
2656 && step && breakpoint_inserted_here_p (aspace, pc))
2658 /* There are two cases where we currently need to step a
2659 breakpoint instruction when we have a signal to deliver:
2661 - See handle_signal_stop where we handle random signals that
2662 could take out us out of the stepping range. Normally, in
2663 that case we end up continuing (instead of stepping) over the
2664 signal handler with a breakpoint at PC, but there are cases
2665 where we should _always_ single-step, even if we have a
2666 step-resume breakpoint, like when a software watchpoint is
2667 set. Assuming single-stepping and delivering a signal at the
2668 same time would takes us to the signal handler, then we could
2669 have removed the breakpoint at PC to step over it. However,
2670 some hardware step targets (like e.g., Mac OS) can't step
2671 into signal handlers, and for those, we need to leave the
2672 breakpoint at PC inserted, as otherwise if the handler
2673 recurses and executes PC again, it'll miss the breakpoint.
2674 So we leave the breakpoint inserted anyway, but we need to
2675 record that we tried to step a breakpoint instruction, so
2676 that adjust_pc_after_break doesn't end up confused.
2678 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2679 in one thread after another thread that was stepping had been
2680 momentarily paused for a step-over. When we re-resume the
2681 stepping thread, it may be resumed from that address with a
2682 breakpoint that hasn't trapped yet. Seen with
2683 gdb.threads/non-stop-fair-events.exp, on targets that don't
2684 do displaced stepping. */
2687 fprintf_unfiltered (gdb_stdlog,
2688 "infrun: resume: [%s] stepped breakpoint\n",
2689 target_pid_to_str (tp->ptid));
2691 tp->stepped_breakpoint = 1;
2693 /* Most targets can step a breakpoint instruction, thus
2694 executing it normally. But if this one cannot, just
2695 continue and we will hit it anyway. */
2696 if (gdbarch_cannot_step_breakpoint (gdbarch))
2701 && tp->control.trap_expected
2702 && use_displaced_stepping (tp)
2703 && !step_over_info_valid_p ())
2705 struct regcache *resume_regcache = get_thread_regcache (tp);
2706 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2707 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2710 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2711 paddress (resume_gdbarch, actual_pc));
2712 read_memory (actual_pc, buf, sizeof (buf));
2713 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2716 if (tp->control.may_range_step)
2718 /* If we're resuming a thread with the PC out of the step
2719 range, then we're doing some nested/finer run control
2720 operation, like stepping the thread out of the dynamic
2721 linker or the displaced stepping scratch pad. We
2722 shouldn't have allowed a range step then. */
2723 gdb_assert (pc_in_thread_step_range (pc, tp));
2726 do_target_resume (resume_ptid, step, sig);
2730 /* Resume the inferior. SIG is the signal to give the inferior
2731 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2732 rolls back state on error. */
2735 resume (gdb_signal sig)
2741 CATCH (ex, RETURN_MASK_ALL)
2743 /* If resuming is being aborted for any reason, delete any
2744 single-step breakpoint resume_1 may have created, to avoid
2745 confusing the following resumption, and to avoid leaving
2746 single-step breakpoints perturbing other threads, in case
2747 we're running in non-stop mode. */
2748 if (inferior_ptid != null_ptid)
2749 delete_single_step_breakpoints (inferior_thread ());
2750 throw_exception (ex);
2760 /* Counter that tracks number of user visible stops. This can be used
2761 to tell whether a command has proceeded the inferior past the
2762 current location. This allows e.g., inferior function calls in
2763 breakpoint commands to not interrupt the command list. When the
2764 call finishes successfully, the inferior is standing at the same
2765 breakpoint as if nothing happened (and so we don't call
2767 static ULONGEST current_stop_id;
2774 return current_stop_id;
2777 /* Called when we report a user visible stop. */
2785 /* Clear out all variables saying what to do when inferior is continued.
2786 First do this, then set the ones you want, then call `proceed'. */
2789 clear_proceed_status_thread (struct thread_info *tp)
2792 fprintf_unfiltered (gdb_stdlog,
2793 "infrun: clear_proceed_status_thread (%s)\n",
2794 target_pid_to_str (tp->ptid));
2796 /* If we're starting a new sequence, then the previous finished
2797 single-step is no longer relevant. */
2798 if (tp->suspend.waitstatus_pending_p)
2800 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2803 fprintf_unfiltered (gdb_stdlog,
2804 "infrun: clear_proceed_status: pending "
2805 "event of %s was a finished step. "
2807 target_pid_to_str (tp->ptid));
2809 tp->suspend.waitstatus_pending_p = 0;
2810 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2812 else if (debug_infrun)
2815 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2817 fprintf_unfiltered (gdb_stdlog,
2818 "infrun: clear_proceed_status_thread: thread %s "
2819 "has pending wait status %s "
2820 "(currently_stepping=%d).\n",
2821 target_pid_to_str (tp->ptid), statstr.c_str (),
2822 currently_stepping (tp));
2826 /* If this signal should not be seen by program, give it zero.
2827 Used for debugging signals. */
2828 if (!signal_pass_state (tp->suspend.stop_signal))
2829 tp->suspend.stop_signal = GDB_SIGNAL_0;
2831 thread_fsm_delete (tp->thread_fsm);
2832 tp->thread_fsm = NULL;
2834 tp->control.trap_expected = 0;
2835 tp->control.step_range_start = 0;
2836 tp->control.step_range_end = 0;
2837 tp->control.may_range_step = 0;
2838 tp->control.step_frame_id = null_frame_id;
2839 tp->control.step_stack_frame_id = null_frame_id;
2840 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2841 tp->control.step_start_function = NULL;
2842 tp->stop_requested = 0;
2844 tp->control.stop_step = 0;
2846 tp->control.proceed_to_finish = 0;
2848 tp->control.stepping_command = 0;
2850 /* Discard any remaining commands or status from previous stop. */
2851 bpstat_clear (&tp->control.stop_bpstat);
2855 clear_proceed_status (int step)
2857 /* With scheduler-locking replay, stop replaying other threads if we're
2858 not replaying the user-visible resume ptid.
2860 This is a convenience feature to not require the user to explicitly
2861 stop replaying the other threads. We're assuming that the user's
2862 intent is to resume tracing the recorded process. */
2863 if (!non_stop && scheduler_mode == schedlock_replay
2864 && target_record_is_replaying (minus_one_ptid)
2865 && !target_record_will_replay (user_visible_resume_ptid (step),
2866 execution_direction))
2867 target_record_stop_replaying ();
2871 struct thread_info *tp;
2874 resume_ptid = user_visible_resume_ptid (step);
2876 /* In all-stop mode, delete the per-thread status of all threads
2877 we're about to resume, implicitly and explicitly. */
2878 ALL_NON_EXITED_THREADS (tp)
2880 if (!tp->ptid.matches (resume_ptid))
2882 clear_proceed_status_thread (tp);
2886 if (inferior_ptid != null_ptid)
2888 struct inferior *inferior;
2892 /* If in non-stop mode, only delete the per-thread status of
2893 the current thread. */
2894 clear_proceed_status_thread (inferior_thread ());
2897 inferior = current_inferior ();
2898 inferior->control.stop_soon = NO_STOP_QUIETLY;
2901 gdb::observers::about_to_proceed.notify ();
2904 /* Returns true if TP is still stopped at a breakpoint that needs
2905 stepping-over in order to make progress. If the breakpoint is gone
2906 meanwhile, we can skip the whole step-over dance. */
2909 thread_still_needs_step_over_bp (struct thread_info *tp)
2911 if (tp->stepping_over_breakpoint)
2913 struct regcache *regcache = get_thread_regcache (tp);
2915 if (breakpoint_here_p (regcache->aspace (),
2916 regcache_read_pc (regcache))
2917 == ordinary_breakpoint_here)
2920 tp->stepping_over_breakpoint = 0;
2926 /* Check whether thread TP still needs to start a step-over in order
2927 to make progress when resumed. Returns an bitwise or of enum
2928 step_over_what bits, indicating what needs to be stepped over. */
2930 static step_over_what
2931 thread_still_needs_step_over (struct thread_info *tp)
2933 step_over_what what = 0;
2935 if (thread_still_needs_step_over_bp (tp))
2936 what |= STEP_OVER_BREAKPOINT;
2938 if (tp->stepping_over_watchpoint
2939 && !target_have_steppable_watchpoint)
2940 what |= STEP_OVER_WATCHPOINT;
2945 /* Returns true if scheduler locking applies. STEP indicates whether
2946 we're about to do a step/next-like command to a thread. */
2949 schedlock_applies (struct thread_info *tp)
2951 return (scheduler_mode == schedlock_on
2952 || (scheduler_mode == schedlock_step
2953 && tp->control.stepping_command)
2954 || (scheduler_mode == schedlock_replay
2955 && target_record_will_replay (minus_one_ptid,
2956 execution_direction)));
2959 /* Basic routine for continuing the program in various fashions.
2961 ADDR is the address to resume at, or -1 for resume where stopped.
2962 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2963 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2965 You should call clear_proceed_status before calling proceed. */
2968 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2970 struct regcache *regcache;
2971 struct gdbarch *gdbarch;
2972 struct thread_info *tp;
2975 struct execution_control_state ecss;
2976 struct execution_control_state *ecs = &ecss;
2979 /* If we're stopped at a fork/vfork, follow the branch set by the
2980 "set follow-fork-mode" command; otherwise, we'll just proceed
2981 resuming the current thread. */
2982 if (!follow_fork ())
2984 /* The target for some reason decided not to resume. */
2986 if (target_can_async_p ())
2987 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2991 /* We'll update this if & when we switch to a new thread. */
2992 previous_inferior_ptid = inferior_ptid;
2994 regcache = get_current_regcache ();
2995 gdbarch = regcache->arch ();
2996 const address_space *aspace = regcache->aspace ();
2998 pc = regcache_read_pc (regcache);
2999 tp = inferior_thread ();
3001 /* Fill in with reasonable starting values. */
3002 init_thread_stepping_state (tp);
3004 gdb_assert (!thread_is_in_step_over_chain (tp));
3006 if (addr == (CORE_ADDR) -1)
3008 if (pc == tp->suspend.stop_pc
3009 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3010 && execution_direction != EXEC_REVERSE)
3011 /* There is a breakpoint at the address we will resume at,
3012 step one instruction before inserting breakpoints so that
3013 we do not stop right away (and report a second hit at this
3016 Note, we don't do this in reverse, because we won't
3017 actually be executing the breakpoint insn anyway.
3018 We'll be (un-)executing the previous instruction. */
3019 tp->stepping_over_breakpoint = 1;
3020 else if (gdbarch_single_step_through_delay_p (gdbarch)
3021 && gdbarch_single_step_through_delay (gdbarch,
3022 get_current_frame ()))
3023 /* We stepped onto an instruction that needs to be stepped
3024 again before re-inserting the breakpoint, do so. */
3025 tp->stepping_over_breakpoint = 1;
3029 regcache_write_pc (regcache, addr);
3032 if (siggnal != GDB_SIGNAL_DEFAULT)
3033 tp->suspend.stop_signal = siggnal;
3035 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3037 /* If an exception is thrown from this point on, make sure to
3038 propagate GDB's knowledge of the executing state to the
3039 frontend/user running state. */
3040 scoped_finish_thread_state finish_state (resume_ptid);
3042 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3043 threads (e.g., we might need to set threads stepping over
3044 breakpoints first), from the user/frontend's point of view, all
3045 threads in RESUME_PTID are now running. Unless we're calling an
3046 inferior function, as in that case we pretend the inferior
3047 doesn't run at all. */
3048 if (!tp->control.in_infcall)
3049 set_running (resume_ptid, 1);
3052 fprintf_unfiltered (gdb_stdlog,
3053 "infrun: proceed (addr=%s, signal=%s)\n",
3054 paddress (gdbarch, addr),
3055 gdb_signal_to_symbol_string (siggnal));
3057 annotate_starting ();
3059 /* Make sure that output from GDB appears before output from the
3061 gdb_flush (gdb_stdout);
3063 /* Since we've marked the inferior running, give it the terminal. A
3064 QUIT/Ctrl-C from here on is forwarded to the target (which can
3065 still detect attempts to unblock a stuck connection with repeated
3066 Ctrl-C from within target_pass_ctrlc). */
3067 target_terminal::inferior ();
3069 /* In a multi-threaded task we may select another thread and
3070 then continue or step.
3072 But if a thread that we're resuming had stopped at a breakpoint,
3073 it will immediately cause another breakpoint stop without any
3074 execution (i.e. it will report a breakpoint hit incorrectly). So
3075 we must step over it first.
3077 Look for threads other than the current (TP) that reported a
3078 breakpoint hit and haven't been resumed yet since. */
3080 /* If scheduler locking applies, we can avoid iterating over all
3082 if (!non_stop && !schedlock_applies (tp))
3084 struct thread_info *current = tp;
3086 ALL_NON_EXITED_THREADS (tp)
3088 /* Ignore the current thread here. It's handled
3093 /* Ignore threads of processes we're not resuming. */
3094 if (!tp->ptid.matches (resume_ptid))
3097 if (!thread_still_needs_step_over (tp))
3100 gdb_assert (!thread_is_in_step_over_chain (tp));
3103 fprintf_unfiltered (gdb_stdlog,
3104 "infrun: need to step-over [%s] first\n",
3105 target_pid_to_str (tp->ptid));
3107 thread_step_over_chain_enqueue (tp);
3113 /* Enqueue the current thread last, so that we move all other
3114 threads over their breakpoints first. */
3115 if (tp->stepping_over_breakpoint)
3116 thread_step_over_chain_enqueue (tp);
3118 /* If the thread isn't started, we'll still need to set its prev_pc,
3119 so that switch_back_to_stepped_thread knows the thread hasn't
3120 advanced. Must do this before resuming any thread, as in
3121 all-stop/remote, once we resume we can't send any other packet
3122 until the target stops again. */
3123 tp->prev_pc = regcache_read_pc (regcache);
3126 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3128 started = start_step_over ();
3130 if (step_over_info_valid_p ())
3132 /* Either this thread started a new in-line step over, or some
3133 other thread was already doing one. In either case, don't
3134 resume anything else until the step-over is finished. */
3136 else if (started && !target_is_non_stop_p ())
3138 /* A new displaced stepping sequence was started. In all-stop,
3139 we can't talk to the target anymore until it next stops. */
3141 else if (!non_stop && target_is_non_stop_p ())
3143 /* In all-stop, but the target is always in non-stop mode.
3144 Start all other threads that are implicitly resumed too. */
3145 ALL_NON_EXITED_THREADS (tp)
3147 /* Ignore threads of processes we're not resuming. */
3148 if (!tp->ptid.matches (resume_ptid))
3154 fprintf_unfiltered (gdb_stdlog,
3155 "infrun: proceed: [%s] resumed\n",
3156 target_pid_to_str (tp->ptid));
3157 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3161 if (thread_is_in_step_over_chain (tp))
3164 fprintf_unfiltered (gdb_stdlog,
3165 "infrun: proceed: [%s] needs step-over\n",
3166 target_pid_to_str (tp->ptid));
3171 fprintf_unfiltered (gdb_stdlog,
3172 "infrun: proceed: resuming %s\n",
3173 target_pid_to_str (tp->ptid));
3175 reset_ecs (ecs, tp);
3176 switch_to_thread (tp);
3177 keep_going_pass_signal (ecs);
3178 if (!ecs->wait_some_more)
3179 error (_("Command aborted."));
3182 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3184 /* The thread wasn't started, and isn't queued, run it now. */
3185 reset_ecs (ecs, tp);
3186 switch_to_thread (tp);
3187 keep_going_pass_signal (ecs);
3188 if (!ecs->wait_some_more)
3189 error (_("Command aborted."));
3193 target_commit_resume ();
3195 finish_state.release ();
3197 /* Tell the event loop to wait for it to stop. If the target
3198 supports asynchronous execution, it'll do this from within
3200 if (!target_can_async_p ())
3201 mark_async_event_handler (infrun_async_inferior_event_token);
3205 /* Start remote-debugging of a machine over a serial link. */
3208 start_remote (int from_tty)
3210 struct inferior *inferior;
3212 inferior = current_inferior ();
3213 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3215 /* Always go on waiting for the target, regardless of the mode. */
3216 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3217 indicate to wait_for_inferior that a target should timeout if
3218 nothing is returned (instead of just blocking). Because of this,
3219 targets expecting an immediate response need to, internally, set
3220 things up so that the target_wait() is forced to eventually
3222 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3223 differentiate to its caller what the state of the target is after
3224 the initial open has been performed. Here we're assuming that
3225 the target has stopped. It should be possible to eventually have
3226 target_open() return to the caller an indication that the target
3227 is currently running and GDB state should be set to the same as
3228 for an async run. */
3229 wait_for_inferior ();
3231 /* Now that the inferior has stopped, do any bookkeeping like
3232 loading shared libraries. We want to do this before normal_stop,
3233 so that the displayed frame is up to date. */
3234 post_create_inferior (current_top_target (), from_tty);
3239 /* Initialize static vars when a new inferior begins. */
3242 init_wait_for_inferior (void)
3244 /* These are meaningless until the first time through wait_for_inferior. */
3246 breakpoint_init_inferior (inf_starting);
3248 clear_proceed_status (0);
3250 target_last_wait_ptid = minus_one_ptid;
3252 previous_inferior_ptid = inferior_ptid;
3254 /* Discard any skipped inlined frames. */
3255 clear_inline_frame_state (minus_one_ptid);
3260 static void handle_inferior_event (struct execution_control_state *ecs);
3262 static void handle_step_into_function (struct gdbarch *gdbarch,
3263 struct execution_control_state *ecs);
3264 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3265 struct execution_control_state *ecs);
3266 static void handle_signal_stop (struct execution_control_state *ecs);
3267 static void check_exception_resume (struct execution_control_state *,
3268 struct frame_info *);
3270 static void end_stepping_range (struct execution_control_state *ecs);
3271 static void stop_waiting (struct execution_control_state *ecs);
3272 static void keep_going (struct execution_control_state *ecs);
3273 static void process_event_stop_test (struct execution_control_state *ecs);
3274 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3276 /* This function is attached as a "thread_stop_requested" observer.
3277 Cleanup local state that assumed the PTID was to be resumed, and
3278 report the stop to the frontend. */
3281 infrun_thread_stop_requested (ptid_t ptid)
3283 struct thread_info *tp;
3285 /* PTID was requested to stop. If the thread was already stopped,
3286 but the user/frontend doesn't know about that yet (e.g., the
3287 thread had been temporarily paused for some step-over), set up
3288 for reporting the stop now. */
3289 ALL_NON_EXITED_THREADS (tp)
3290 if (tp->ptid.matches (ptid))
3292 if (tp->state != THREAD_RUNNING)
3297 /* Remove matching threads from the step-over queue, so
3298 start_step_over doesn't try to resume them
3300 if (thread_is_in_step_over_chain (tp))
3301 thread_step_over_chain_remove (tp);
3303 /* If the thread is stopped, but the user/frontend doesn't
3304 know about that yet, queue a pending event, as if the
3305 thread had just stopped now. Unless the thread already had
3307 if (!tp->suspend.waitstatus_pending_p)
3309 tp->suspend.waitstatus_pending_p = 1;
3310 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3311 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3314 /* Clear the inline-frame state, since we're re-processing the
3316 clear_inline_frame_state (tp->ptid);
3318 /* If this thread was paused because some other thread was
3319 doing an inline-step over, let that finish first. Once
3320 that happens, we'll restart all threads and consume pending
3321 stop events then. */
3322 if (step_over_info_valid_p ())
3325 /* Otherwise we can process the (new) pending event now. Set
3326 it so this pending event is considered by
3333 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3335 if (target_last_wait_ptid == tp->ptid)
3336 nullify_last_target_wait_ptid ();
3339 /* Delete the step resume, single-step and longjmp/exception resume
3340 breakpoints of TP. */
3343 delete_thread_infrun_breakpoints (struct thread_info *tp)
3345 delete_step_resume_breakpoint (tp);
3346 delete_exception_resume_breakpoint (tp);
3347 delete_single_step_breakpoints (tp);
3350 /* If the target still has execution, call FUNC for each thread that
3351 just stopped. In all-stop, that's all the non-exited threads; in
3352 non-stop, that's the current thread, only. */
3354 typedef void (*for_each_just_stopped_thread_callback_func)
3355 (struct thread_info *tp);
3358 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3360 if (!target_has_execution || inferior_ptid == null_ptid)
3363 if (target_is_non_stop_p ())
3365 /* If in non-stop mode, only the current thread stopped. */
3366 func (inferior_thread ());
3370 struct thread_info *tp;
3372 /* In all-stop mode, all threads have stopped. */
3373 ALL_NON_EXITED_THREADS (tp)
3380 /* Delete the step resume and longjmp/exception resume breakpoints of
3381 the threads that just stopped. */
3384 delete_just_stopped_threads_infrun_breakpoints (void)
3386 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3389 /* Delete the single-step breakpoints of the threads that just
3393 delete_just_stopped_threads_single_step_breakpoints (void)
3395 for_each_just_stopped_thread (delete_single_step_breakpoints);
3398 /* A cleanup wrapper. */
3401 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3403 delete_just_stopped_threads_infrun_breakpoints ();
3409 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3410 const struct target_waitstatus *ws)
3412 std::string status_string = target_waitstatus_to_string (ws);
3415 /* The text is split over several lines because it was getting too long.
3416 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3417 output as a unit; we want only one timestamp printed if debug_timestamp
3420 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3423 waiton_ptid.tid ());
3424 if (waiton_ptid.pid () != -1)
3425 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3426 stb.printf (", status) =\n");
3427 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3431 target_pid_to_str (result_ptid));
3432 stb.printf ("infrun: %s\n", status_string.c_str ());
3434 /* This uses %s in part to handle %'s in the text, but also to avoid
3435 a gcc error: the format attribute requires a string literal. */
3436 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3439 /* Select a thread at random, out of those which are resumed and have
3442 static struct thread_info *
3443 random_pending_event_thread (ptid_t waiton_ptid)
3445 struct thread_info *event_tp;
3447 int random_selector;
3449 /* First see how many events we have. Count only resumed threads
3450 that have an event pending. */
3451 ALL_NON_EXITED_THREADS (event_tp)
3452 if (event_tp->ptid.matches (waiton_ptid)
3453 && event_tp->resumed
3454 && event_tp->suspend.waitstatus_pending_p)
3457 if (num_events == 0)
3460 /* Now randomly pick a thread out of those that have had events. */
3461 random_selector = (int)
3462 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3464 if (debug_infrun && num_events > 1)
3465 fprintf_unfiltered (gdb_stdlog,
3466 "infrun: Found %d events, selecting #%d\n",
3467 num_events, random_selector);
3469 /* Select the Nth thread that has had an event. */
3470 ALL_NON_EXITED_THREADS (event_tp)
3471 if (event_tp->ptid.matches (waiton_ptid)
3472 && event_tp->resumed
3473 && event_tp->suspend.waitstatus_pending_p)
3474 if (random_selector-- == 0)
3480 /* Wrapper for target_wait that first checks whether threads have
3481 pending statuses to report before actually asking the target for
3485 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3488 struct thread_info *tp;
3490 /* First check if there is a resumed thread with a wait status
3492 if (ptid == minus_one_ptid || ptid.is_pid ())
3494 tp = random_pending_event_thread (ptid);
3499 fprintf_unfiltered (gdb_stdlog,
3500 "infrun: Waiting for specific thread %s.\n",
3501 target_pid_to_str (ptid));
3503 /* We have a specific thread to check. */
3504 tp = find_thread_ptid (ptid);
3505 gdb_assert (tp != NULL);
3506 if (!tp->suspend.waitstatus_pending_p)
3511 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3512 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3514 struct regcache *regcache = get_thread_regcache (tp);
3515 struct gdbarch *gdbarch = regcache->arch ();
3519 pc = regcache_read_pc (regcache);
3521 if (pc != tp->suspend.stop_pc)
3524 fprintf_unfiltered (gdb_stdlog,
3525 "infrun: PC of %s changed. was=%s, now=%s\n",
3526 target_pid_to_str (tp->ptid),
3527 paddress (gdbarch, tp->suspend.stop_pc),
3528 paddress (gdbarch, pc));
3531 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3534 fprintf_unfiltered (gdb_stdlog,
3535 "infrun: previous breakpoint of %s, at %s gone\n",
3536 target_pid_to_str (tp->ptid),
3537 paddress (gdbarch, pc));
3545 fprintf_unfiltered (gdb_stdlog,
3546 "infrun: pending event of %s cancelled.\n",
3547 target_pid_to_str (tp->ptid));
3549 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3550 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3559 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3561 fprintf_unfiltered (gdb_stdlog,
3562 "infrun: Using pending wait status %s for %s.\n",
3564 target_pid_to_str (tp->ptid));
3567 /* Now that we've selected our final event LWP, un-adjust its PC
3568 if it was a software breakpoint (and the target doesn't
3569 always adjust the PC itself). */
3570 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3571 && !target_supports_stopped_by_sw_breakpoint ())
3573 struct regcache *regcache;
3574 struct gdbarch *gdbarch;
3577 regcache = get_thread_regcache (tp);
3578 gdbarch = regcache->arch ();
3580 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3585 pc = regcache_read_pc (regcache);
3586 regcache_write_pc (regcache, pc + decr_pc);
3590 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3591 *status = tp->suspend.waitstatus;
3592 tp->suspend.waitstatus_pending_p = 0;
3594 /* Wake up the event loop again, until all pending events are
3596 if (target_is_async_p ())
3597 mark_async_event_handler (infrun_async_inferior_event_token);
3601 /* But if we don't find one, we'll have to wait. */
3603 if (deprecated_target_wait_hook)
3604 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3606 event_ptid = target_wait (ptid, status, options);
3611 /* Prepare and stabilize the inferior for detaching it. E.g.,
3612 detaching while a thread is displaced stepping is a recipe for
3613 crashing it, as nothing would readjust the PC out of the scratch
3617 prepare_for_detach (void)
3619 struct inferior *inf = current_inferior ();
3620 ptid_t pid_ptid = ptid_t (inf->pid);
3622 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3624 /* Is any thread of this process displaced stepping? If not,
3625 there's nothing else to do. */
3626 if (displaced == NULL || displaced->step_thread == nullptr)
3630 fprintf_unfiltered (gdb_stdlog,
3631 "displaced-stepping in-process while detaching");
3633 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3635 while (displaced->step_thread != nullptr)
3637 struct execution_control_state ecss;
3638 struct execution_control_state *ecs;
3641 memset (ecs, 0, sizeof (*ecs));
3643 overlay_cache_invalid = 1;
3644 /* Flush target cache before starting to handle each event.
3645 Target was running and cache could be stale. This is just a
3646 heuristic. Running threads may modify target memory, but we
3647 don't get any event. */
3648 target_dcache_invalidate ();
3650 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3653 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3655 /* If an error happens while handling the event, propagate GDB's
3656 knowledge of the executing state to the frontend/user running
3658 scoped_finish_thread_state finish_state (minus_one_ptid);
3660 /* Now figure out what to do with the result of the result. */
3661 handle_inferior_event (ecs);
3663 /* No error, don't finish the state yet. */
3664 finish_state.release ();
3666 /* Breakpoints and watchpoints are not installed on the target
3667 at this point, and signals are passed directly to the
3668 inferior, so this must mean the process is gone. */
3669 if (!ecs->wait_some_more)
3671 restore_detaching.release ();
3672 error (_("Program exited while detaching"));
3676 restore_detaching.release ();
3679 /* Wait for control to return from inferior to debugger.
3681 If inferior gets a signal, we may decide to start it up again
3682 instead of returning. That is why there is a loop in this function.
3683 When this function actually returns it means the inferior
3684 should be left stopped and GDB should read more commands. */
3687 wait_for_inferior (void)
3689 struct cleanup *old_cleanups;
3693 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3696 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3699 /* If an error happens while handling the event, propagate GDB's
3700 knowledge of the executing state to the frontend/user running
3702 scoped_finish_thread_state finish_state (minus_one_ptid);
3706 struct execution_control_state ecss;
3707 struct execution_control_state *ecs = &ecss;
3708 ptid_t waiton_ptid = minus_one_ptid;
3710 memset (ecs, 0, sizeof (*ecs));
3712 overlay_cache_invalid = 1;
3714 /* Flush target cache before starting to handle each event.
3715 Target was running and cache could be stale. This is just a
3716 heuristic. Running threads may modify target memory, but we
3717 don't get any event. */
3718 target_dcache_invalidate ();
3720 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3723 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3725 /* Now figure out what to do with the result of the result. */
3726 handle_inferior_event (ecs);
3728 if (!ecs->wait_some_more)
3732 /* No error, don't finish the state yet. */
3733 finish_state.release ();
3735 do_cleanups (old_cleanups);
3738 /* Cleanup that reinstalls the readline callback handler, if the
3739 target is running in the background. If while handling the target
3740 event something triggered a secondary prompt, like e.g., a
3741 pagination prompt, we'll have removed the callback handler (see
3742 gdb_readline_wrapper_line). Need to do this as we go back to the
3743 event loop, ready to process further input. Note this has no
3744 effect if the handler hasn't actually been removed, because calling
3745 rl_callback_handler_install resets the line buffer, thus losing
3749 reinstall_readline_callback_handler_cleanup (void *arg)
3751 struct ui *ui = current_ui;
3755 /* We're not going back to the top level event loop yet. Don't
3756 install the readline callback, as it'd prep the terminal,
3757 readline-style (raw, noecho) (e.g., --batch). We'll install
3758 it the next time the prompt is displayed, when we're ready
3763 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3764 gdb_rl_callback_handler_reinstall ();
3767 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3768 that's just the event thread. In all-stop, that's all threads. */
3771 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3773 struct thread_info *thr = ecs->event_thread;
3775 if (thr != NULL && thr->thread_fsm != NULL)
3776 thread_fsm_clean_up (thr->thread_fsm, thr);
3780 ALL_NON_EXITED_THREADS (thr)
3782 if (thr->thread_fsm == NULL)
3784 if (thr == ecs->event_thread)
3787 switch_to_thread (thr);
3788 thread_fsm_clean_up (thr->thread_fsm, thr);
3791 if (ecs->event_thread != NULL)
3792 switch_to_thread (ecs->event_thread);
3796 /* Helper for all_uis_check_sync_execution_done that works on the
3800 check_curr_ui_sync_execution_done (void)
3802 struct ui *ui = current_ui;
3804 if (ui->prompt_state == PROMPT_NEEDED
3806 && !gdb_in_secondary_prompt_p (ui))
3808 target_terminal::ours ();
3809 gdb::observers::sync_execution_done.notify ();
3810 ui_register_input_event_handler (ui);
3817 all_uis_check_sync_execution_done (void)
3819 SWITCH_THRU_ALL_UIS ()
3821 check_curr_ui_sync_execution_done ();
3828 all_uis_on_sync_execution_starting (void)
3830 SWITCH_THRU_ALL_UIS ()
3832 if (current_ui->prompt_state == PROMPT_NEEDED)
3833 async_disable_stdin ();
3837 /* Asynchronous version of wait_for_inferior. It is called by the
3838 event loop whenever a change of state is detected on the file
3839 descriptor corresponding to the target. It can be called more than
3840 once to complete a single execution command. In such cases we need
3841 to keep the state in a global variable ECSS. If it is the last time
3842 that this function is called for a single execution command, then
3843 report to the user that the inferior has stopped, and do the
3844 necessary cleanups. */
3847 fetch_inferior_event (void *client_data)
3849 struct execution_control_state ecss;
3850 struct execution_control_state *ecs = &ecss;
3851 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3853 ptid_t waiton_ptid = minus_one_ptid;
3855 memset (ecs, 0, sizeof (*ecs));
3857 /* Events are always processed with the main UI as current UI. This
3858 way, warnings, debug output, etc. are always consistently sent to
3859 the main console. */
3860 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3862 /* End up with readline processing input, if necessary. */
3863 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3865 /* We're handling a live event, so make sure we're doing live
3866 debugging. If we're looking at traceframes while the target is
3867 running, we're going to need to get back to that mode after
3868 handling the event. */
3869 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3872 maybe_restore_traceframe.emplace ();
3873 set_current_traceframe (-1);
3876 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3879 /* In non-stop mode, the user/frontend should not notice a thread
3880 switch due to internal events. Make sure we reverse to the
3881 user selected thread and frame after handling the event and
3882 running any breakpoint commands. */
3883 maybe_restore_thread.emplace ();
3885 overlay_cache_invalid = 1;
3886 /* Flush target cache before starting to handle each event. Target
3887 was running and cache could be stale. This is just a heuristic.
3888 Running threads may modify target memory, but we don't get any
3890 target_dcache_invalidate ();
3892 scoped_restore save_exec_dir
3893 = make_scoped_restore (&execution_direction, target_execution_direction ());
3895 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3896 target_can_async_p () ? TARGET_WNOHANG : 0);
3899 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3901 /* If an error happens while handling the event, propagate GDB's
3902 knowledge of the executing state to the frontend/user running
3904 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3905 scoped_finish_thread_state finish_state (finish_ptid);
3907 /* Get executed before make_cleanup_restore_current_thread above to apply
3908 still for the thread which has thrown the exception. */
3909 struct cleanup *ts_old_chain = make_bpstat_clear_actions_cleanup ();
3911 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3913 /* Now figure out what to do with the result of the result. */
3914 handle_inferior_event (ecs);
3916 if (!ecs->wait_some_more)
3918 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3919 int should_stop = 1;
3920 struct thread_info *thr = ecs->event_thread;
3922 delete_just_stopped_threads_infrun_breakpoints ();
3926 struct thread_fsm *thread_fsm = thr->thread_fsm;
3928 if (thread_fsm != NULL)
3929 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3938 int should_notify_stop = 1;
3941 clean_up_just_stopped_threads_fsms (ecs);
3943 if (thr != NULL && thr->thread_fsm != NULL)
3946 = thread_fsm_should_notify_stop (thr->thread_fsm);
3949 if (should_notify_stop)
3951 /* We may not find an inferior if this was a process exit. */
3952 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3953 proceeded = normal_stop ();
3958 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3964 discard_cleanups (ts_old_chain);
3966 /* No error, don't finish the thread states yet. */
3967 finish_state.release ();
3969 /* Revert thread and frame. */
3970 do_cleanups (old_chain);
3972 /* If a UI was in sync execution mode, and now isn't, restore its
3973 prompt (a synchronous execution command has finished, and we're
3974 ready for input). */
3975 all_uis_check_sync_execution_done ();
3978 && exec_done_display_p
3979 && (inferior_ptid == null_ptid
3980 || inferior_thread ()->state != THREAD_RUNNING))
3981 printf_unfiltered (_("completed.\n"));
3984 /* Record the frame and location we're currently stepping through. */
3986 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3988 struct thread_info *tp = inferior_thread ();
3990 tp->control.step_frame_id = get_frame_id (frame);
3991 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3993 tp->current_symtab = sal.symtab;
3994 tp->current_line = sal.line;
3997 /* Clear context switchable stepping state. */
4000 init_thread_stepping_state (struct thread_info *tss)
4002 tss->stepped_breakpoint = 0;
4003 tss->stepping_over_breakpoint = 0;
4004 tss->stepping_over_watchpoint = 0;
4005 tss->step_after_step_resume_breakpoint = 0;
4008 /* Set the cached copy of the last ptid/waitstatus. */
4011 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4013 target_last_wait_ptid = ptid;
4014 target_last_waitstatus = status;
4017 /* Return the cached copy of the last pid/waitstatus returned by
4018 target_wait()/deprecated_target_wait_hook(). The data is actually
4019 cached by handle_inferior_event(), which gets called immediately
4020 after target_wait()/deprecated_target_wait_hook(). */
4023 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4025 *ptidp = target_last_wait_ptid;
4026 *status = target_last_waitstatus;
4030 nullify_last_target_wait_ptid (void)
4032 target_last_wait_ptid = minus_one_ptid;
4035 /* Switch thread contexts. */
4038 context_switch (execution_control_state *ecs)
4041 && ecs->ptid != inferior_ptid
4042 && ecs->event_thread != inferior_thread ())
4044 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4045 target_pid_to_str (inferior_ptid));
4046 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4047 target_pid_to_str (ecs->ptid));
4050 switch_to_thread (ecs->event_thread);
4053 /* If the target can't tell whether we've hit breakpoints
4054 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4055 check whether that could have been caused by a breakpoint. If so,
4056 adjust the PC, per gdbarch_decr_pc_after_break. */
4059 adjust_pc_after_break (struct thread_info *thread,
4060 struct target_waitstatus *ws)
4062 struct regcache *regcache;
4063 struct gdbarch *gdbarch;
4064 CORE_ADDR breakpoint_pc, decr_pc;
4066 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4067 we aren't, just return.
4069 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4070 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4071 implemented by software breakpoints should be handled through the normal
4074 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4075 different signals (SIGILL or SIGEMT for instance), but it is less
4076 clear where the PC is pointing afterwards. It may not match
4077 gdbarch_decr_pc_after_break. I don't know any specific target that
4078 generates these signals at breakpoints (the code has been in GDB since at
4079 least 1992) so I can not guess how to handle them here.
4081 In earlier versions of GDB, a target with
4082 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4083 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4084 target with both of these set in GDB history, and it seems unlikely to be
4085 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4087 if (ws->kind != TARGET_WAITKIND_STOPPED)
4090 if (ws->value.sig != GDB_SIGNAL_TRAP)
4093 /* In reverse execution, when a breakpoint is hit, the instruction
4094 under it has already been de-executed. The reported PC always
4095 points at the breakpoint address, so adjusting it further would
4096 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4099 B1 0x08000000 : INSN1
4100 B2 0x08000001 : INSN2
4102 PC -> 0x08000003 : INSN4
4104 Say you're stopped at 0x08000003 as above. Reverse continuing
4105 from that point should hit B2 as below. Reading the PC when the
4106 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4107 been de-executed already.
4109 B1 0x08000000 : INSN1
4110 B2 PC -> 0x08000001 : INSN2
4114 We can't apply the same logic as for forward execution, because
4115 we would wrongly adjust the PC to 0x08000000, since there's a
4116 breakpoint at PC - 1. We'd then report a hit on B1, although
4117 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4119 if (execution_direction == EXEC_REVERSE)
4122 /* If the target can tell whether the thread hit a SW breakpoint,
4123 trust it. Targets that can tell also adjust the PC
4125 if (target_supports_stopped_by_sw_breakpoint ())
4128 /* Note that relying on whether a breakpoint is planted in memory to
4129 determine this can fail. E.g,. the breakpoint could have been
4130 removed since. Or the thread could have been told to step an
4131 instruction the size of a breakpoint instruction, and only
4132 _after_ was a breakpoint inserted at its address. */
4134 /* If this target does not decrement the PC after breakpoints, then
4135 we have nothing to do. */
4136 regcache = get_thread_regcache (thread);
4137 gdbarch = regcache->arch ();
4139 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4143 const address_space *aspace = regcache->aspace ();
4145 /* Find the location where (if we've hit a breakpoint) the
4146 breakpoint would be. */
4147 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4149 /* If the target can't tell whether a software breakpoint triggered,
4150 fallback to figuring it out based on breakpoints we think were
4151 inserted in the target, and on whether the thread was stepped or
4154 /* Check whether there actually is a software breakpoint inserted at
4157 If in non-stop mode, a race condition is possible where we've
4158 removed a breakpoint, but stop events for that breakpoint were
4159 already queued and arrive later. To suppress those spurious
4160 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4161 and retire them after a number of stop events are reported. Note
4162 this is an heuristic and can thus get confused. The real fix is
4163 to get the "stopped by SW BP and needs adjustment" info out of
4164 the target/kernel (and thus never reach here; see above). */
4165 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4166 || (target_is_non_stop_p ()
4167 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4169 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4171 if (record_full_is_used ())
4172 restore_operation_disable.emplace
4173 (record_full_gdb_operation_disable_set ());
4175 /* When using hardware single-step, a SIGTRAP is reported for both
4176 a completed single-step and a software breakpoint. Need to
4177 differentiate between the two, as the latter needs adjusting
4178 but the former does not.
4180 The SIGTRAP can be due to a completed hardware single-step only if
4181 - we didn't insert software single-step breakpoints
4182 - this thread is currently being stepped
4184 If any of these events did not occur, we must have stopped due
4185 to hitting a software breakpoint, and have to back up to the
4188 As a special case, we could have hardware single-stepped a
4189 software breakpoint. In this case (prev_pc == breakpoint_pc),
4190 we also need to back up to the breakpoint address. */
4192 if (thread_has_single_step_breakpoints_set (thread)
4193 || !currently_stepping (thread)
4194 || (thread->stepped_breakpoint
4195 && thread->prev_pc == breakpoint_pc))
4196 regcache_write_pc (regcache, breakpoint_pc);
4201 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4203 for (frame = get_prev_frame (frame);
4205 frame = get_prev_frame (frame))
4207 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4209 if (get_frame_type (frame) != INLINE_FRAME)
4216 /* If the event thread has the stop requested flag set, pretend it
4217 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4221 handle_stop_requested (struct execution_control_state *ecs)
4223 if (ecs->event_thread->stop_requested)
4225 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4226 ecs->ws.value.sig = GDB_SIGNAL_0;
4227 handle_signal_stop (ecs);
4233 /* Auxiliary function that handles syscall entry/return events.
4234 It returns 1 if the inferior should keep going (and GDB
4235 should ignore the event), or 0 if the event deserves to be
4239 handle_syscall_event (struct execution_control_state *ecs)
4241 struct regcache *regcache;
4244 context_switch (ecs);
4246 regcache = get_thread_regcache (ecs->event_thread);
4247 syscall_number = ecs->ws.value.syscall_number;
4248 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4250 if (catch_syscall_enabled () > 0
4251 && catching_syscall_number (syscall_number) > 0)
4254 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4257 ecs->event_thread->control.stop_bpstat
4258 = bpstat_stop_status (regcache->aspace (),
4259 ecs->event_thread->suspend.stop_pc,
4260 ecs->event_thread, &ecs->ws);
4262 if (handle_stop_requested (ecs))
4265 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4267 /* Catchpoint hit. */
4272 if (handle_stop_requested (ecs))
4275 /* If no catchpoint triggered for this, then keep going. */
4280 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4283 fill_in_stop_func (struct gdbarch *gdbarch,
4284 struct execution_control_state *ecs)
4286 if (!ecs->stop_func_filled_in)
4288 /* Don't care about return value; stop_func_start and stop_func_name
4289 will both be 0 if it doesn't work. */
4290 find_function_entry_range_from_pc (ecs->event_thread->suspend.stop_pc,
4291 &ecs->stop_func_name,
4292 &ecs->stop_func_start,
4293 &ecs->stop_func_end);
4294 ecs->stop_func_start
4295 += gdbarch_deprecated_function_start_offset (gdbarch);
4297 if (gdbarch_skip_entrypoint_p (gdbarch))
4298 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4299 ecs->stop_func_start);
4301 ecs->stop_func_filled_in = 1;
4306 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4308 static enum stop_kind
4309 get_inferior_stop_soon (execution_control_state *ecs)
4311 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4313 gdb_assert (inf != NULL);
4314 return inf->control.stop_soon;
4317 /* Wait for one event. Store the resulting waitstatus in WS, and
4318 return the event ptid. */
4321 wait_one (struct target_waitstatus *ws)
4324 ptid_t wait_ptid = minus_one_ptid;
4326 overlay_cache_invalid = 1;
4328 /* Flush target cache before starting to handle each event.
4329 Target was running and cache could be stale. This is just a
4330 heuristic. Running threads may modify target memory, but we
4331 don't get any event. */
4332 target_dcache_invalidate ();
4334 if (deprecated_target_wait_hook)
4335 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4337 event_ptid = target_wait (wait_ptid, ws, 0);
4340 print_target_wait_results (wait_ptid, event_ptid, ws);
4345 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4346 instead of the current thread. */
4347 #define THREAD_STOPPED_BY(REASON) \
4349 thread_stopped_by_ ## REASON (ptid_t ptid) \
4351 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4352 inferior_ptid = ptid; \
4354 return target_stopped_by_ ## REASON (); \
4357 /* Generate thread_stopped_by_watchpoint. */
4358 THREAD_STOPPED_BY (watchpoint)
4359 /* Generate thread_stopped_by_sw_breakpoint. */
4360 THREAD_STOPPED_BY (sw_breakpoint)
4361 /* Generate thread_stopped_by_hw_breakpoint. */
4362 THREAD_STOPPED_BY (hw_breakpoint)
4364 /* Save the thread's event and stop reason to process it later. */
4367 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4371 std::string statstr = target_waitstatus_to_string (ws);
4373 fprintf_unfiltered (gdb_stdlog,
4374 "infrun: saving status %s for %d.%ld.%ld\n",
4381 /* Record for later. */
4382 tp->suspend.waitstatus = *ws;
4383 tp->suspend.waitstatus_pending_p = 1;
4385 struct regcache *regcache = get_thread_regcache (tp);
4386 const address_space *aspace = regcache->aspace ();
4388 if (ws->kind == TARGET_WAITKIND_STOPPED
4389 && ws->value.sig == GDB_SIGNAL_TRAP)
4391 CORE_ADDR pc = regcache_read_pc (regcache);
4393 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4395 if (thread_stopped_by_watchpoint (tp->ptid))
4397 tp->suspend.stop_reason
4398 = TARGET_STOPPED_BY_WATCHPOINT;
4400 else if (target_supports_stopped_by_sw_breakpoint ()
4401 && thread_stopped_by_sw_breakpoint (tp->ptid))
4403 tp->suspend.stop_reason
4404 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4406 else if (target_supports_stopped_by_hw_breakpoint ()
4407 && thread_stopped_by_hw_breakpoint (tp->ptid))
4409 tp->suspend.stop_reason
4410 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4412 else if (!target_supports_stopped_by_hw_breakpoint ()
4413 && hardware_breakpoint_inserted_here_p (aspace,
4416 tp->suspend.stop_reason
4417 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4419 else if (!target_supports_stopped_by_sw_breakpoint ()
4420 && software_breakpoint_inserted_here_p (aspace,
4423 tp->suspend.stop_reason
4424 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4426 else if (!thread_has_single_step_breakpoints_set (tp)
4427 && currently_stepping (tp))
4429 tp->suspend.stop_reason
4430 = TARGET_STOPPED_BY_SINGLE_STEP;
4435 /* A cleanup that disables thread create/exit events. */
4438 disable_thread_events (void *arg)
4440 target_thread_events (0);
4446 stop_all_threads (void)
4448 /* We may need multiple passes to discover all threads. */
4451 struct cleanup *old_chain;
4453 gdb_assert (target_is_non_stop_p ());
4456 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4458 scoped_restore_current_thread restore_thread;
4460 target_thread_events (1);
4461 old_chain = make_cleanup (disable_thread_events, NULL);
4463 /* Request threads to stop, and then wait for the stops. Because
4464 threads we already know about can spawn more threads while we're
4465 trying to stop them, and we only learn about new threads when we
4466 update the thread list, do this in a loop, and keep iterating
4467 until two passes find no threads that need to be stopped. */
4468 for (pass = 0; pass < 2; pass++, iterations++)
4471 fprintf_unfiltered (gdb_stdlog,
4472 "infrun: stop_all_threads, pass=%d, "
4473 "iterations=%d\n", pass, iterations);
4477 struct target_waitstatus ws;
4479 struct thread_info *t;
4481 update_thread_list ();
4483 /* Go through all threads looking for threads that we need
4484 to tell the target to stop. */
4485 ALL_NON_EXITED_THREADS (t)
4489 /* If already stopping, don't request a stop again.
4490 We just haven't seen the notification yet. */
4491 if (!t->stop_requested)
4494 fprintf_unfiltered (gdb_stdlog,
4495 "infrun: %s executing, "
4497 target_pid_to_str (t->ptid));
4498 target_stop (t->ptid);
4499 t->stop_requested = 1;
4504 fprintf_unfiltered (gdb_stdlog,
4505 "infrun: %s executing, "
4506 "already stopping\n",
4507 target_pid_to_str (t->ptid));
4510 if (t->stop_requested)
4516 fprintf_unfiltered (gdb_stdlog,
4517 "infrun: %s not executing\n",
4518 target_pid_to_str (t->ptid));
4520 /* The thread may be not executing, but still be
4521 resumed with a pending status to process. */
4529 /* If we find new threads on the second iteration, restart
4530 over. We want to see two iterations in a row with all
4535 event_ptid = wait_one (&ws);
4537 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4539 /* All resumed threads exited. */
4541 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4542 || ws.kind == TARGET_WAITKIND_EXITED
4543 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4547 ptid_t ptid = ptid_t (ws.value.integer);
4549 fprintf_unfiltered (gdb_stdlog,
4550 "infrun: %s exited while "
4551 "stopping threads\n",
4552 target_pid_to_str (ptid));
4559 t = find_thread_ptid (event_ptid);
4561 t = add_thread (event_ptid);
4563 t->stop_requested = 0;
4566 t->control.may_range_step = 0;
4568 /* This may be the first time we see the inferior report
4570 inf = find_inferior_ptid (event_ptid);
4571 if (inf->needs_setup)
4573 switch_to_thread_no_regs (t);
4577 if (ws.kind == TARGET_WAITKIND_STOPPED
4578 && ws.value.sig == GDB_SIGNAL_0)
4580 /* We caught the event that we intended to catch, so
4581 there's no event pending. */
4582 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4583 t->suspend.waitstatus_pending_p = 0;
4585 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4587 /* Add it back to the step-over queue. */
4590 fprintf_unfiltered (gdb_stdlog,
4591 "infrun: displaced-step of %s "
4592 "canceled: adding back to the "
4593 "step-over queue\n",
4594 target_pid_to_str (t->ptid));
4596 t->control.trap_expected = 0;
4597 thread_step_over_chain_enqueue (t);
4602 enum gdb_signal sig;
4603 struct regcache *regcache;
4607 std::string statstr = target_waitstatus_to_string (&ws);
4609 fprintf_unfiltered (gdb_stdlog,
4610 "infrun: target_wait %s, saving "
4611 "status for %d.%ld.%ld\n",
4618 /* Record for later. */
4619 save_waitstatus (t, &ws);
4621 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4622 ? ws.value.sig : GDB_SIGNAL_0);
4624 if (displaced_step_fixup (t, sig) < 0)
4626 /* Add it back to the step-over queue. */
4627 t->control.trap_expected = 0;
4628 thread_step_over_chain_enqueue (t);
4631 regcache = get_thread_regcache (t);
4632 t->suspend.stop_pc = regcache_read_pc (regcache);
4636 fprintf_unfiltered (gdb_stdlog,
4637 "infrun: saved stop_pc=%s for %s "
4638 "(currently_stepping=%d)\n",
4639 paddress (target_gdbarch (),
4640 t->suspend.stop_pc),
4641 target_pid_to_str (t->ptid),
4642 currently_stepping (t));
4649 do_cleanups (old_chain);
4652 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4655 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4658 handle_no_resumed (struct execution_control_state *ecs)
4660 struct inferior *inf;
4661 struct thread_info *thread;
4663 if (target_can_async_p ())
4670 if (ui->prompt_state == PROMPT_BLOCKED)
4678 /* There were no unwaited-for children left in the target, but,
4679 we're not synchronously waiting for events either. Just
4683 fprintf_unfiltered (gdb_stdlog,
4684 "infrun: TARGET_WAITKIND_NO_RESUMED "
4685 "(ignoring: bg)\n");
4686 prepare_to_wait (ecs);
4691 /* Otherwise, if we were running a synchronous execution command, we
4692 may need to cancel it and give the user back the terminal.
4694 In non-stop mode, the target can't tell whether we've already
4695 consumed previous stop events, so it can end up sending us a
4696 no-resumed event like so:
4698 #0 - thread 1 is left stopped
4700 #1 - thread 2 is resumed and hits breakpoint
4701 -> TARGET_WAITKIND_STOPPED
4703 #2 - thread 3 is resumed and exits
4704 this is the last resumed thread, so
4705 -> TARGET_WAITKIND_NO_RESUMED
4707 #3 - gdb processes stop for thread 2 and decides to re-resume
4710 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4711 thread 2 is now resumed, so the event should be ignored.
4713 IOW, if the stop for thread 2 doesn't end a foreground command,
4714 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4715 event. But it could be that the event meant that thread 2 itself
4716 (or whatever other thread was the last resumed thread) exited.
4718 To address this we refresh the thread list and check whether we
4719 have resumed threads _now_. In the example above, this removes
4720 thread 3 from the thread list. If thread 2 was re-resumed, we
4721 ignore this event. If we find no thread resumed, then we cancel
4722 the synchronous command show "no unwaited-for " to the user. */
4723 update_thread_list ();
4725 ALL_NON_EXITED_THREADS (thread)
4727 if (thread->executing
4728 || thread->suspend.waitstatus_pending_p)
4730 /* There were no unwaited-for children left in the target at
4731 some point, but there are now. Just ignore. */
4733 fprintf_unfiltered (gdb_stdlog,
4734 "infrun: TARGET_WAITKIND_NO_RESUMED "
4735 "(ignoring: found resumed)\n");
4736 prepare_to_wait (ecs);
4741 /* Note however that we may find no resumed thread because the whole
4742 process exited meanwhile (thus updating the thread list results
4743 in an empty thread list). In this case we know we'll be getting
4744 a process exit event shortly. */
4750 thread_info *thread = any_live_thread_of_inferior (inf);
4754 fprintf_unfiltered (gdb_stdlog,
4755 "infrun: TARGET_WAITKIND_NO_RESUMED "
4756 "(expect process exit)\n");
4757 prepare_to_wait (ecs);
4762 /* Go ahead and report the event. */
4766 /* Given an execution control state that has been freshly filled in by
4767 an event from the inferior, figure out what it means and take
4770 The alternatives are:
4772 1) stop_waiting and return; to really stop and return to the
4775 2) keep_going and return; to wait for the next event (set
4776 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4780 handle_inferior_event_1 (struct execution_control_state *ecs)
4782 enum stop_kind stop_soon;
4784 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4786 /* We had an event in the inferior, but we are not interested in
4787 handling it at this level. The lower layers have already
4788 done what needs to be done, if anything.
4790 One of the possible circumstances for this is when the
4791 inferior produces output for the console. The inferior has
4792 not stopped, and we are ignoring the event. Another possible
4793 circumstance is any event which the lower level knows will be
4794 reported multiple times without an intervening resume. */
4796 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4797 prepare_to_wait (ecs);
4801 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4804 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4805 prepare_to_wait (ecs);
4809 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4810 && handle_no_resumed (ecs))
4813 /* Cache the last pid/waitstatus. */
4814 set_last_target_status (ecs->ptid, ecs->ws);
4816 /* Always clear state belonging to the previous time we stopped. */
4817 stop_stack_dummy = STOP_NONE;
4819 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4821 /* No unwaited-for children left. IOW, all resumed children
4824 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4826 stop_print_frame = 0;
4831 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4832 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4834 ecs->event_thread = find_thread_ptid (ecs->ptid);
4835 /* If it's a new thread, add it to the thread database. */
4836 if (ecs->event_thread == NULL)
4837 ecs->event_thread = add_thread (ecs->ptid);
4839 /* Disable range stepping. If the next step request could use a
4840 range, this will be end up re-enabled then. */
4841 ecs->event_thread->control.may_range_step = 0;
4844 /* Dependent on valid ECS->EVENT_THREAD. */
4845 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4847 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4848 reinit_frame_cache ();
4850 breakpoint_retire_moribund ();
4852 /* First, distinguish signals caused by the debugger from signals
4853 that have to do with the program's own actions. Note that
4854 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4855 on the operating system version. Here we detect when a SIGILL or
4856 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4857 something similar for SIGSEGV, since a SIGSEGV will be generated
4858 when we're trying to execute a breakpoint instruction on a
4859 non-executable stack. This happens for call dummy breakpoints
4860 for architectures like SPARC that place call dummies on the
4862 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4863 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4864 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4865 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4867 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4869 if (breakpoint_inserted_here_p (regcache->aspace (),
4870 regcache_read_pc (regcache)))
4873 fprintf_unfiltered (gdb_stdlog,
4874 "infrun: Treating signal as SIGTRAP\n");
4875 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4879 /* Mark the non-executing threads accordingly. In all-stop, all
4880 threads of all processes are stopped when we get any event
4881 reported. In non-stop mode, only the event thread stops. */
4885 if (!target_is_non_stop_p ())
4886 mark_ptid = minus_one_ptid;
4887 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4888 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4890 /* If we're handling a process exit in non-stop mode, even
4891 though threads haven't been deleted yet, one would think
4892 that there is nothing to do, as threads of the dead process
4893 will be soon deleted, and threads of any other process were
4894 left running. However, on some targets, threads survive a
4895 process exit event. E.g., for the "checkpoint" command,
4896 when the current checkpoint/fork exits, linux-fork.c
4897 automatically switches to another fork from within
4898 target_mourn_inferior, by associating the same
4899 inferior/thread to another fork. We haven't mourned yet at
4900 this point, but we must mark any threads left in the
4901 process as not-executing so that finish_thread_state marks
4902 them stopped (in the user's perspective) if/when we present
4903 the stop to the user. */
4904 mark_ptid = ptid_t (ecs->ptid.pid ());
4907 mark_ptid = ecs->ptid;
4909 set_executing (mark_ptid, 0);
4911 /* Likewise the resumed flag. */
4912 set_resumed (mark_ptid, 0);
4915 switch (ecs->ws.kind)
4917 case TARGET_WAITKIND_LOADED:
4919 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4920 context_switch (ecs);
4921 /* Ignore gracefully during startup of the inferior, as it might
4922 be the shell which has just loaded some objects, otherwise
4923 add the symbols for the newly loaded objects. Also ignore at
4924 the beginning of an attach or remote session; we will query
4925 the full list of libraries once the connection is
4928 stop_soon = get_inferior_stop_soon (ecs);
4929 if (stop_soon == NO_STOP_QUIETLY)
4931 struct regcache *regcache;
4933 regcache = get_thread_regcache (ecs->event_thread);
4935 handle_solib_event ();
4937 ecs->event_thread->control.stop_bpstat
4938 = bpstat_stop_status (regcache->aspace (),
4939 ecs->event_thread->suspend.stop_pc,
4940 ecs->event_thread, &ecs->ws);
4942 if (handle_stop_requested (ecs))
4945 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4947 /* A catchpoint triggered. */
4948 process_event_stop_test (ecs);
4952 /* If requested, stop when the dynamic linker notifies
4953 gdb of events. This allows the user to get control
4954 and place breakpoints in initializer routines for
4955 dynamically loaded objects (among other things). */
4956 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4957 if (stop_on_solib_events)
4959 /* Make sure we print "Stopped due to solib-event" in
4961 stop_print_frame = 1;
4968 /* If we are skipping through a shell, or through shared library
4969 loading that we aren't interested in, resume the program. If
4970 we're running the program normally, also resume. */
4971 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4973 /* Loading of shared libraries might have changed breakpoint
4974 addresses. Make sure new breakpoints are inserted. */
4975 if (stop_soon == NO_STOP_QUIETLY)
4976 insert_breakpoints ();
4977 resume (GDB_SIGNAL_0);
4978 prepare_to_wait (ecs);
4982 /* But stop if we're attaching or setting up a remote
4984 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4985 || stop_soon == STOP_QUIETLY_REMOTE)
4988 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4993 internal_error (__FILE__, __LINE__,
4994 _("unhandled stop_soon: %d"), (int) stop_soon);
4996 case TARGET_WAITKIND_SPURIOUS:
4998 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4999 if (handle_stop_requested (ecs))
5001 context_switch (ecs);
5002 resume (GDB_SIGNAL_0);
5003 prepare_to_wait (ecs);
5006 case TARGET_WAITKIND_THREAD_CREATED:
5008 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5009 if (handle_stop_requested (ecs))
5011 context_switch (ecs);
5012 if (!switch_back_to_stepped_thread (ecs))
5016 case TARGET_WAITKIND_EXITED:
5017 case TARGET_WAITKIND_SIGNALLED:
5020 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5021 fprintf_unfiltered (gdb_stdlog,
5022 "infrun: TARGET_WAITKIND_EXITED\n");
5024 fprintf_unfiltered (gdb_stdlog,
5025 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5028 inferior_ptid = ecs->ptid;
5029 set_current_inferior (find_inferior_ptid (ecs->ptid));
5030 set_current_program_space (current_inferior ()->pspace);
5031 handle_vfork_child_exec_or_exit (0);
5032 target_terminal::ours (); /* Must do this before mourn anyway. */
5034 /* Clearing any previous state of convenience variables. */
5035 clear_exit_convenience_vars ();
5037 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5039 /* Record the exit code in the convenience variable $_exitcode, so
5040 that the user can inspect this again later. */
5041 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5042 (LONGEST) ecs->ws.value.integer);
5044 /* Also record this in the inferior itself. */
5045 current_inferior ()->has_exit_code = 1;
5046 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5048 /* Support the --return-child-result option. */
5049 return_child_result_value = ecs->ws.value.integer;
5051 gdb::observers::exited.notify (ecs->ws.value.integer);
5055 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
5057 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5059 /* Set the value of the internal variable $_exitsignal,
5060 which holds the signal uncaught by the inferior. */
5061 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5062 gdbarch_gdb_signal_to_target (gdbarch,
5063 ecs->ws.value.sig));
5067 /* We don't have access to the target's method used for
5068 converting between signal numbers (GDB's internal
5069 representation <-> target's representation).
5070 Therefore, we cannot do a good job at displaying this
5071 information to the user. It's better to just warn
5072 her about it (if infrun debugging is enabled), and
5075 fprintf_filtered (gdb_stdlog, _("\
5076 Cannot fill $_exitsignal with the correct signal number.\n"));
5079 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
5082 gdb_flush (gdb_stdout);
5083 target_mourn_inferior (inferior_ptid);
5084 stop_print_frame = 0;
5088 /* The following are the only cases in which we keep going;
5089 the above cases end in a continue or goto. */
5090 case TARGET_WAITKIND_FORKED:
5091 case TARGET_WAITKIND_VFORKED:
5094 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5095 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5097 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5100 /* Check whether the inferior is displaced stepping. */
5102 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5103 struct gdbarch *gdbarch = regcache->arch ();
5105 /* If checking displaced stepping is supported, and thread
5106 ecs->ptid is displaced stepping. */
5107 if (displaced_step_in_progress_thread (ecs->event_thread))
5109 struct inferior *parent_inf
5110 = find_inferior_ptid (ecs->ptid);
5111 struct regcache *child_regcache;
5112 CORE_ADDR parent_pc;
5114 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5115 indicating that the displaced stepping of syscall instruction
5116 has been done. Perform cleanup for parent process here. Note
5117 that this operation also cleans up the child process for vfork,
5118 because their pages are shared. */
5119 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
5120 /* Start a new step-over in another thread if there's one
5124 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5126 struct displaced_step_inferior_state *displaced
5127 = get_displaced_stepping_state (parent_inf);
5129 /* Restore scratch pad for child process. */
5130 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5133 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5134 the child's PC is also within the scratchpad. Set the child's PC
5135 to the parent's PC value, which has already been fixed up.
5136 FIXME: we use the parent's aspace here, although we're touching
5137 the child, because the child hasn't been added to the inferior
5138 list yet at this point. */
5141 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5143 parent_inf->aspace);
5144 /* Read PC value of parent process. */
5145 parent_pc = regcache_read_pc (regcache);
5147 if (debug_displaced)
5148 fprintf_unfiltered (gdb_stdlog,
5149 "displaced: write child pc from %s to %s\n",
5151 regcache_read_pc (child_regcache)),
5152 paddress (gdbarch, parent_pc));
5154 regcache_write_pc (child_regcache, parent_pc);
5158 context_switch (ecs);
5160 /* Immediately detach breakpoints from the child before there's
5161 any chance of letting the user delete breakpoints from the
5162 breakpoint lists. If we don't do this early, it's easy to
5163 leave left over traps in the child, vis: "break foo; catch
5164 fork; c; <fork>; del; c; <child calls foo>". We only follow
5165 the fork on the last `continue', and by that time the
5166 breakpoint at "foo" is long gone from the breakpoint table.
5167 If we vforked, then we don't need to unpatch here, since both
5168 parent and child are sharing the same memory pages; we'll
5169 need to unpatch at follow/detach time instead to be certain
5170 that new breakpoints added between catchpoint hit time and
5171 vfork follow are detached. */
5172 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5174 /* This won't actually modify the breakpoint list, but will
5175 physically remove the breakpoints from the child. */
5176 detach_breakpoints (ecs->ws.value.related_pid);
5179 delete_just_stopped_threads_single_step_breakpoints ();
5181 /* In case the event is caught by a catchpoint, remember that
5182 the event is to be followed at the next resume of the thread,
5183 and not immediately. */
5184 ecs->event_thread->pending_follow = ecs->ws;
5186 ecs->event_thread->suspend.stop_pc
5187 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5189 ecs->event_thread->control.stop_bpstat
5190 = bpstat_stop_status (get_current_regcache ()->aspace (),
5191 ecs->event_thread->suspend.stop_pc,
5192 ecs->event_thread, &ecs->ws);
5194 if (handle_stop_requested (ecs))
5197 /* If no catchpoint triggered for this, then keep going. Note
5198 that we're interested in knowing the bpstat actually causes a
5199 stop, not just if it may explain the signal. Software
5200 watchpoints, for example, always appear in the bpstat. */
5201 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5205 = (follow_fork_mode_string == follow_fork_mode_child);
5207 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5209 should_resume = follow_fork ();
5211 thread_info *parent = ecs->event_thread;
5212 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5214 /* At this point, the parent is marked running, and the
5215 child is marked stopped. */
5217 /* If not resuming the parent, mark it stopped. */
5218 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5219 parent->set_running (false);
5221 /* If resuming the child, mark it running. */
5222 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5223 child->set_running (true);
5225 /* In non-stop mode, also resume the other branch. */
5226 if (!detach_fork && (non_stop
5227 || (sched_multi && target_is_non_stop_p ())))
5230 switch_to_thread (parent);
5232 switch_to_thread (child);
5234 ecs->event_thread = inferior_thread ();
5235 ecs->ptid = inferior_ptid;
5240 switch_to_thread (child);
5242 switch_to_thread (parent);
5244 ecs->event_thread = inferior_thread ();
5245 ecs->ptid = inferior_ptid;
5253 process_event_stop_test (ecs);
5256 case TARGET_WAITKIND_VFORK_DONE:
5257 /* Done with the shared memory region. Re-insert breakpoints in
5258 the parent, and keep going. */
5261 fprintf_unfiltered (gdb_stdlog,
5262 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5264 context_switch (ecs);
5266 current_inferior ()->waiting_for_vfork_done = 0;
5267 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5269 if (handle_stop_requested (ecs))
5272 /* This also takes care of reinserting breakpoints in the
5273 previously locked inferior. */
5277 case TARGET_WAITKIND_EXECD:
5279 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5281 /* Note we can't read registers yet (the stop_pc), because we
5282 don't yet know the inferior's post-exec architecture.
5283 'stop_pc' is explicitly read below instead. */
5284 switch_to_thread_no_regs (ecs->event_thread);
5286 /* Do whatever is necessary to the parent branch of the vfork. */
5287 handle_vfork_child_exec_or_exit (1);
5289 /* This causes the eventpoints and symbol table to be reset.
5290 Must do this now, before trying to determine whether to
5292 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5294 /* In follow_exec we may have deleted the original thread and
5295 created a new one. Make sure that the event thread is the
5296 execd thread for that case (this is a nop otherwise). */
5297 ecs->event_thread = inferior_thread ();
5299 ecs->event_thread->suspend.stop_pc
5300 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5302 ecs->event_thread->control.stop_bpstat
5303 = bpstat_stop_status (get_current_regcache ()->aspace (),
5304 ecs->event_thread->suspend.stop_pc,
5305 ecs->event_thread, &ecs->ws);
5307 /* Note that this may be referenced from inside
5308 bpstat_stop_status above, through inferior_has_execd. */
5309 xfree (ecs->ws.value.execd_pathname);
5310 ecs->ws.value.execd_pathname = NULL;
5312 if (handle_stop_requested (ecs))
5315 /* If no catchpoint triggered for this, then keep going. */
5316 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5318 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5322 process_event_stop_test (ecs);
5325 /* Be careful not to try to gather much state about a thread
5326 that's in a syscall. It's frequently a losing proposition. */
5327 case TARGET_WAITKIND_SYSCALL_ENTRY:
5329 fprintf_unfiltered (gdb_stdlog,
5330 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5331 /* Getting the current syscall number. */
5332 if (handle_syscall_event (ecs) == 0)
5333 process_event_stop_test (ecs);
5336 /* Before examining the threads further, step this thread to
5337 get it entirely out of the syscall. (We get notice of the
5338 event when the thread is just on the verge of exiting a
5339 syscall. Stepping one instruction seems to get it back
5341 case TARGET_WAITKIND_SYSCALL_RETURN:
5343 fprintf_unfiltered (gdb_stdlog,
5344 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5345 if (handle_syscall_event (ecs) == 0)
5346 process_event_stop_test (ecs);
5349 case TARGET_WAITKIND_STOPPED:
5351 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5352 handle_signal_stop (ecs);
5355 case TARGET_WAITKIND_NO_HISTORY:
5357 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5358 /* Reverse execution: target ran out of history info. */
5360 /* Switch to the stopped thread. */
5361 context_switch (ecs);
5363 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5365 delete_just_stopped_threads_single_step_breakpoints ();
5366 ecs->event_thread->suspend.stop_pc
5367 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5369 if (handle_stop_requested (ecs))
5372 gdb::observers::no_history.notify ();
5378 /* A wrapper around handle_inferior_event_1, which also makes sure
5379 that all temporary struct value objects that were created during
5380 the handling of the event get deleted at the end. */
5383 handle_inferior_event (struct execution_control_state *ecs)
5385 struct value *mark = value_mark ();
5387 handle_inferior_event_1 (ecs);
5388 /* Purge all temporary values created during the event handling,
5389 as it could be a long time before we return to the command level
5390 where such values would otherwise be purged. */
5391 value_free_to_mark (mark);
5394 /* Restart threads back to what they were trying to do back when we
5395 paused them for an in-line step-over. The EVENT_THREAD thread is
5399 restart_threads (struct thread_info *event_thread)
5401 struct thread_info *tp;
5403 /* In case the instruction just stepped spawned a new thread. */
5404 update_thread_list ();
5406 ALL_NON_EXITED_THREADS (tp)
5408 if (tp == event_thread)
5411 fprintf_unfiltered (gdb_stdlog,
5412 "infrun: restart threads: "
5413 "[%s] is event thread\n",
5414 target_pid_to_str (tp->ptid));
5418 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5421 fprintf_unfiltered (gdb_stdlog,
5422 "infrun: restart threads: "
5423 "[%s] not meant to be running\n",
5424 target_pid_to_str (tp->ptid));
5431 fprintf_unfiltered (gdb_stdlog,
5432 "infrun: restart threads: [%s] resumed\n",
5433 target_pid_to_str (tp->ptid));
5434 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5438 if (thread_is_in_step_over_chain (tp))
5441 fprintf_unfiltered (gdb_stdlog,
5442 "infrun: restart threads: "
5443 "[%s] needs step-over\n",
5444 target_pid_to_str (tp->ptid));
5445 gdb_assert (!tp->resumed);
5450 if (tp->suspend.waitstatus_pending_p)
5453 fprintf_unfiltered (gdb_stdlog,
5454 "infrun: restart threads: "
5455 "[%s] has pending status\n",
5456 target_pid_to_str (tp->ptid));
5461 gdb_assert (!tp->stop_requested);
5463 /* If some thread needs to start a step-over at this point, it
5464 should still be in the step-over queue, and thus skipped
5466 if (thread_still_needs_step_over (tp))
5468 internal_error (__FILE__, __LINE__,
5469 "thread [%s] needs a step-over, but not in "
5470 "step-over queue\n",
5471 target_pid_to_str (tp->ptid));
5474 if (currently_stepping (tp))
5477 fprintf_unfiltered (gdb_stdlog,
5478 "infrun: restart threads: [%s] was stepping\n",
5479 target_pid_to_str (tp->ptid));
5480 keep_going_stepped_thread (tp);
5484 struct execution_control_state ecss;
5485 struct execution_control_state *ecs = &ecss;
5488 fprintf_unfiltered (gdb_stdlog,
5489 "infrun: restart threads: [%s] continuing\n",
5490 target_pid_to_str (tp->ptid));
5491 reset_ecs (ecs, tp);
5492 switch_to_thread (tp);
5493 keep_going_pass_signal (ecs);
5498 /* Callback for iterate_over_threads. Find a resumed thread that has
5499 a pending waitstatus. */
5502 resumed_thread_with_pending_status (struct thread_info *tp,
5506 && tp->suspend.waitstatus_pending_p);
5509 /* Called when we get an event that may finish an in-line or
5510 out-of-line (displaced stepping) step-over started previously.
5511 Return true if the event is processed and we should go back to the
5512 event loop; false if the caller should continue processing the
5516 finish_step_over (struct execution_control_state *ecs)
5518 int had_step_over_info;
5520 displaced_step_fixup (ecs->event_thread,
5521 ecs->event_thread->suspend.stop_signal);
5523 had_step_over_info = step_over_info_valid_p ();
5525 if (had_step_over_info)
5527 /* If we're stepping over a breakpoint with all threads locked,
5528 then only the thread that was stepped should be reporting
5530 gdb_assert (ecs->event_thread->control.trap_expected);
5532 clear_step_over_info ();
5535 if (!target_is_non_stop_p ())
5538 /* Start a new step-over in another thread if there's one that
5542 /* If we were stepping over a breakpoint before, and haven't started
5543 a new in-line step-over sequence, then restart all other threads
5544 (except the event thread). We can't do this in all-stop, as then
5545 e.g., we wouldn't be able to issue any other remote packet until
5546 these other threads stop. */
5547 if (had_step_over_info && !step_over_info_valid_p ())
5549 struct thread_info *pending;
5551 /* If we only have threads with pending statuses, the restart
5552 below won't restart any thread and so nothing re-inserts the
5553 breakpoint we just stepped over. But we need it inserted
5554 when we later process the pending events, otherwise if
5555 another thread has a pending event for this breakpoint too,
5556 we'd discard its event (because the breakpoint that
5557 originally caused the event was no longer inserted). */
5558 context_switch (ecs);
5559 insert_breakpoints ();
5561 restart_threads (ecs->event_thread);
5563 /* If we have events pending, go through handle_inferior_event
5564 again, picking up a pending event at random. This avoids
5565 thread starvation. */
5567 /* But not if we just stepped over a watchpoint in order to let
5568 the instruction execute so we can evaluate its expression.
5569 The set of watchpoints that triggered is recorded in the
5570 breakpoint objects themselves (see bp->watchpoint_triggered).
5571 If we processed another event first, that other event could
5572 clobber this info. */
5573 if (ecs->event_thread->stepping_over_watchpoint)
5576 pending = iterate_over_threads (resumed_thread_with_pending_status,
5578 if (pending != NULL)
5580 struct thread_info *tp = ecs->event_thread;
5581 struct regcache *regcache;
5585 fprintf_unfiltered (gdb_stdlog,
5586 "infrun: found resumed threads with "
5587 "pending events, saving status\n");
5590 gdb_assert (pending != tp);
5592 /* Record the event thread's event for later. */
5593 save_waitstatus (tp, &ecs->ws);
5594 /* This was cleared early, by handle_inferior_event. Set it
5595 so this pending event is considered by
5599 gdb_assert (!tp->executing);
5601 regcache = get_thread_regcache (tp);
5602 tp->suspend.stop_pc = regcache_read_pc (regcache);
5606 fprintf_unfiltered (gdb_stdlog,
5607 "infrun: saved stop_pc=%s for %s "
5608 "(currently_stepping=%d)\n",
5609 paddress (target_gdbarch (),
5610 tp->suspend.stop_pc),
5611 target_pid_to_str (tp->ptid),
5612 currently_stepping (tp));
5615 /* This in-line step-over finished; clear this so we won't
5616 start a new one. This is what handle_signal_stop would
5617 do, if we returned false. */
5618 tp->stepping_over_breakpoint = 0;
5620 /* Wake up the event loop again. */
5621 mark_async_event_handler (infrun_async_inferior_event_token);
5623 prepare_to_wait (ecs);
5631 /* Come here when the program has stopped with a signal. */
5634 handle_signal_stop (struct execution_control_state *ecs)
5636 struct frame_info *frame;
5637 struct gdbarch *gdbarch;
5638 int stopped_by_watchpoint;
5639 enum stop_kind stop_soon;
5642 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5644 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5646 /* Do we need to clean up the state of a thread that has
5647 completed a displaced single-step? (Doing so usually affects
5648 the PC, so do it here, before we set stop_pc.) */
5649 if (finish_step_over (ecs))
5652 /* If we either finished a single-step or hit a breakpoint, but
5653 the user wanted this thread to be stopped, pretend we got a
5654 SIG0 (generic unsignaled stop). */
5655 if (ecs->event_thread->stop_requested
5656 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5657 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5659 ecs->event_thread->suspend.stop_pc
5660 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5664 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5665 struct gdbarch *gdbarch = regcache->arch ();
5666 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5668 inferior_ptid = ecs->ptid;
5670 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5672 ecs->event_thread->suspend.stop_pc));
5673 if (target_stopped_by_watchpoint ())
5677 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5679 if (target_stopped_data_address (current_top_target (), &addr))
5680 fprintf_unfiltered (gdb_stdlog,
5681 "infrun: stopped data address = %s\n",
5682 paddress (gdbarch, addr));
5684 fprintf_unfiltered (gdb_stdlog,
5685 "infrun: (no data address available)\n");
5689 /* This is originated from start_remote(), start_inferior() and
5690 shared libraries hook functions. */
5691 stop_soon = get_inferior_stop_soon (ecs);
5692 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5694 context_switch (ecs);
5696 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5697 stop_print_frame = 1;
5702 /* This originates from attach_command(). We need to overwrite
5703 the stop_signal here, because some kernels don't ignore a
5704 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5705 See more comments in inferior.h. On the other hand, if we
5706 get a non-SIGSTOP, report it to the user - assume the backend
5707 will handle the SIGSTOP if it should show up later.
5709 Also consider that the attach is complete when we see a
5710 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5711 target extended-remote report it instead of a SIGSTOP
5712 (e.g. gdbserver). We already rely on SIGTRAP being our
5713 signal, so this is no exception.
5715 Also consider that the attach is complete when we see a
5716 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5717 the target to stop all threads of the inferior, in case the
5718 low level attach operation doesn't stop them implicitly. If
5719 they weren't stopped implicitly, then the stub will report a
5720 GDB_SIGNAL_0, meaning: stopped for no particular reason
5721 other than GDB's request. */
5722 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5723 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5724 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5725 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5727 stop_print_frame = 1;
5729 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5733 /* See if something interesting happened to the non-current thread. If
5734 so, then switch to that thread. */
5735 if (ecs->ptid != inferior_ptid)
5738 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5740 context_switch (ecs);
5742 if (deprecated_context_hook)
5743 deprecated_context_hook (ecs->event_thread->global_num);
5746 /* At this point, get hold of the now-current thread's frame. */
5747 frame = get_current_frame ();
5748 gdbarch = get_frame_arch (frame);
5750 /* Pull the single step breakpoints out of the target. */
5751 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5753 struct regcache *regcache;
5756 regcache = get_thread_regcache (ecs->event_thread);
5757 const address_space *aspace = regcache->aspace ();
5759 pc = regcache_read_pc (regcache);
5761 /* However, before doing so, if this single-step breakpoint was
5762 actually for another thread, set this thread up for moving
5764 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5767 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5771 fprintf_unfiltered (gdb_stdlog,
5772 "infrun: [%s] hit another thread's "
5773 "single-step breakpoint\n",
5774 target_pid_to_str (ecs->ptid));
5776 ecs->hit_singlestep_breakpoint = 1;
5783 fprintf_unfiltered (gdb_stdlog,
5784 "infrun: [%s] hit its "
5785 "single-step breakpoint\n",
5786 target_pid_to_str (ecs->ptid));
5790 delete_just_stopped_threads_single_step_breakpoints ();
5792 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5793 && ecs->event_thread->control.trap_expected
5794 && ecs->event_thread->stepping_over_watchpoint)
5795 stopped_by_watchpoint = 0;
5797 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5799 /* If necessary, step over this watchpoint. We'll be back to display
5801 if (stopped_by_watchpoint
5802 && (target_have_steppable_watchpoint
5803 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5805 /* At this point, we are stopped at an instruction which has
5806 attempted to write to a piece of memory under control of
5807 a watchpoint. The instruction hasn't actually executed
5808 yet. If we were to evaluate the watchpoint expression
5809 now, we would get the old value, and therefore no change
5810 would seem to have occurred.
5812 In order to make watchpoints work `right', we really need
5813 to complete the memory write, and then evaluate the
5814 watchpoint expression. We do this by single-stepping the
5817 It may not be necessary to disable the watchpoint to step over
5818 it. For example, the PA can (with some kernel cooperation)
5819 single step over a watchpoint without disabling the watchpoint.
5821 It is far more common to need to disable a watchpoint to step
5822 the inferior over it. If we have non-steppable watchpoints,
5823 we must disable the current watchpoint; it's simplest to
5824 disable all watchpoints.
5826 Any breakpoint at PC must also be stepped over -- if there's
5827 one, it will have already triggered before the watchpoint
5828 triggered, and we either already reported it to the user, or
5829 it didn't cause a stop and we called keep_going. In either
5830 case, if there was a breakpoint at PC, we must be trying to
5832 ecs->event_thread->stepping_over_watchpoint = 1;
5837 ecs->event_thread->stepping_over_breakpoint = 0;
5838 ecs->event_thread->stepping_over_watchpoint = 0;
5839 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5840 ecs->event_thread->control.stop_step = 0;
5841 stop_print_frame = 1;
5842 stopped_by_random_signal = 0;
5843 bpstat stop_chain = NULL;
5845 /* Hide inlined functions starting here, unless we just performed stepi or
5846 nexti. After stepi and nexti, always show the innermost frame (not any
5847 inline function call sites). */
5848 if (ecs->event_thread->control.step_range_end != 1)
5850 const address_space *aspace
5851 = get_thread_regcache (ecs->event_thread)->aspace ();
5853 /* skip_inline_frames is expensive, so we avoid it if we can
5854 determine that the address is one where functions cannot have
5855 been inlined. This improves performance with inferiors that
5856 load a lot of shared libraries, because the solib event
5857 breakpoint is defined as the address of a function (i.e. not
5858 inline). Note that we have to check the previous PC as well
5859 as the current one to catch cases when we have just
5860 single-stepped off a breakpoint prior to reinstating it.
5861 Note that we're assuming that the code we single-step to is
5862 not inline, but that's not definitive: there's nothing
5863 preventing the event breakpoint function from containing
5864 inlined code, and the single-step ending up there. If the
5865 user had set a breakpoint on that inlined code, the missing
5866 skip_inline_frames call would break things. Fortunately
5867 that's an extremely unlikely scenario. */
5868 if (!pc_at_non_inline_function (aspace,
5869 ecs->event_thread->suspend.stop_pc,
5871 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5872 && ecs->event_thread->control.trap_expected
5873 && pc_at_non_inline_function (aspace,
5874 ecs->event_thread->prev_pc,
5877 stop_chain = build_bpstat_chain (aspace,
5878 ecs->event_thread->suspend.stop_pc,
5880 skip_inline_frames (ecs->event_thread, stop_chain);
5882 /* Re-fetch current thread's frame in case that invalidated
5884 frame = get_current_frame ();
5885 gdbarch = get_frame_arch (frame);
5889 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5890 && ecs->event_thread->control.trap_expected
5891 && gdbarch_single_step_through_delay_p (gdbarch)
5892 && currently_stepping (ecs->event_thread))
5894 /* We're trying to step off a breakpoint. Turns out that we're
5895 also on an instruction that needs to be stepped multiple
5896 times before it's been fully executing. E.g., architectures
5897 with a delay slot. It needs to be stepped twice, once for
5898 the instruction and once for the delay slot. */
5899 int step_through_delay
5900 = gdbarch_single_step_through_delay (gdbarch, frame);
5902 if (debug_infrun && step_through_delay)
5903 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5904 if (ecs->event_thread->control.step_range_end == 0
5905 && step_through_delay)
5907 /* The user issued a continue when stopped at a breakpoint.
5908 Set up for another trap and get out of here. */
5909 ecs->event_thread->stepping_over_breakpoint = 1;
5913 else if (step_through_delay)
5915 /* The user issued a step when stopped at a breakpoint.
5916 Maybe we should stop, maybe we should not - the delay
5917 slot *might* correspond to a line of source. In any
5918 case, don't decide that here, just set
5919 ecs->stepping_over_breakpoint, making sure we
5920 single-step again before breakpoints are re-inserted. */
5921 ecs->event_thread->stepping_over_breakpoint = 1;
5925 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5926 handles this event. */
5927 ecs->event_thread->control.stop_bpstat
5928 = bpstat_stop_status (get_current_regcache ()->aspace (),
5929 ecs->event_thread->suspend.stop_pc,
5930 ecs->event_thread, &ecs->ws, stop_chain);
5932 /* Following in case break condition called a
5934 stop_print_frame = 1;
5936 /* This is where we handle "moribund" watchpoints. Unlike
5937 software breakpoints traps, hardware watchpoint traps are
5938 always distinguishable from random traps. If no high-level
5939 watchpoint is associated with the reported stop data address
5940 anymore, then the bpstat does not explain the signal ---
5941 simply make sure to ignore it if `stopped_by_watchpoint' is
5945 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5946 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5948 && stopped_by_watchpoint)
5949 fprintf_unfiltered (gdb_stdlog,
5950 "infrun: no user watchpoint explains "
5951 "watchpoint SIGTRAP, ignoring\n");
5953 /* NOTE: cagney/2003-03-29: These checks for a random signal
5954 at one stage in the past included checks for an inferior
5955 function call's call dummy's return breakpoint. The original
5956 comment, that went with the test, read:
5958 ``End of a stack dummy. Some systems (e.g. Sony news) give
5959 another signal besides SIGTRAP, so check here as well as
5962 If someone ever tries to get call dummys on a
5963 non-executable stack to work (where the target would stop
5964 with something like a SIGSEGV), then those tests might need
5965 to be re-instated. Given, however, that the tests were only
5966 enabled when momentary breakpoints were not being used, I
5967 suspect that it won't be the case.
5969 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5970 be necessary for call dummies on a non-executable stack on
5973 /* See if the breakpoints module can explain the signal. */
5975 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5976 ecs->event_thread->suspend.stop_signal);
5978 /* Maybe this was a trap for a software breakpoint that has since
5980 if (random_signal && target_stopped_by_sw_breakpoint ())
5982 if (program_breakpoint_here_p (gdbarch,
5983 ecs->event_thread->suspend.stop_pc))
5985 struct regcache *regcache;
5988 /* Re-adjust PC to what the program would see if GDB was not
5990 regcache = get_thread_regcache (ecs->event_thread);
5991 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5994 gdb::optional<scoped_restore_tmpl<int>>
5995 restore_operation_disable;
5997 if (record_full_is_used ())
5998 restore_operation_disable.emplace
5999 (record_full_gdb_operation_disable_set ());
6001 regcache_write_pc (regcache,
6002 ecs->event_thread->suspend.stop_pc + decr_pc);
6007 /* A delayed software breakpoint event. Ignore the trap. */
6009 fprintf_unfiltered (gdb_stdlog,
6010 "infrun: delayed software breakpoint "
6011 "trap, ignoring\n");
6016 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6017 has since been removed. */
6018 if (random_signal && target_stopped_by_hw_breakpoint ())
6020 /* A delayed hardware breakpoint event. Ignore the trap. */
6022 fprintf_unfiltered (gdb_stdlog,
6023 "infrun: delayed hardware breakpoint/watchpoint "
6024 "trap, ignoring\n");
6028 /* If not, perhaps stepping/nexting can. */
6030 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6031 && currently_stepping (ecs->event_thread));
6033 /* Perhaps the thread hit a single-step breakpoint of _another_
6034 thread. Single-step breakpoints are transparent to the
6035 breakpoints module. */
6037 random_signal = !ecs->hit_singlestep_breakpoint;
6039 /* No? Perhaps we got a moribund watchpoint. */
6041 random_signal = !stopped_by_watchpoint;
6043 /* Always stop if the user explicitly requested this thread to
6045 if (ecs->event_thread->stop_requested)
6049 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6052 /* For the program's own signals, act according to
6053 the signal handling tables. */
6057 /* Signal not for debugging purposes. */
6058 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6059 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6062 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6063 gdb_signal_to_symbol_string (stop_signal));
6065 stopped_by_random_signal = 1;
6067 /* Always stop on signals if we're either just gaining control
6068 of the program, or the user explicitly requested this thread
6069 to remain stopped. */
6070 if (stop_soon != NO_STOP_QUIETLY
6071 || ecs->event_thread->stop_requested
6073 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6079 /* Notify observers the signal has "handle print" set. Note we
6080 returned early above if stopping; normal_stop handles the
6081 printing in that case. */
6082 if (signal_print[ecs->event_thread->suspend.stop_signal])
6084 /* The signal table tells us to print about this signal. */
6085 target_terminal::ours_for_output ();
6086 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
6087 target_terminal::inferior ();
6090 /* Clear the signal if it should not be passed. */
6091 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6092 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6094 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
6095 && ecs->event_thread->control.trap_expected
6096 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6098 /* We were just starting a new sequence, attempting to
6099 single-step off of a breakpoint and expecting a SIGTRAP.
6100 Instead this signal arrives. This signal will take us out
6101 of the stepping range so GDB needs to remember to, when
6102 the signal handler returns, resume stepping off that
6104 /* To simplify things, "continue" is forced to use the same
6105 code paths as single-step - set a breakpoint at the
6106 signal return address and then, once hit, step off that
6109 fprintf_unfiltered (gdb_stdlog,
6110 "infrun: signal arrived while stepping over "
6113 insert_hp_step_resume_breakpoint_at_frame (frame);
6114 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6115 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6116 ecs->event_thread->control.trap_expected = 0;
6118 /* If we were nexting/stepping some other thread, switch to
6119 it, so that we don't continue it, losing control. */
6120 if (!switch_back_to_stepped_thread (ecs))
6125 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6126 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6128 || ecs->event_thread->control.step_range_end == 1)
6129 && frame_id_eq (get_stack_frame_id (frame),
6130 ecs->event_thread->control.step_stack_frame_id)
6131 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6133 /* The inferior is about to take a signal that will take it
6134 out of the single step range. Set a breakpoint at the
6135 current PC (which is presumably where the signal handler
6136 will eventually return) and then allow the inferior to
6139 Note that this is only needed for a signal delivered
6140 while in the single-step range. Nested signals aren't a
6141 problem as they eventually all return. */
6143 fprintf_unfiltered (gdb_stdlog,
6144 "infrun: signal may take us out of "
6145 "single-step range\n");
6147 clear_step_over_info ();
6148 insert_hp_step_resume_breakpoint_at_frame (frame);
6149 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6150 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6151 ecs->event_thread->control.trap_expected = 0;
6156 /* Note: step_resume_breakpoint may be non-NULL. This occures
6157 when either there's a nested signal, or when there's a
6158 pending signal enabled just as the signal handler returns
6159 (leaving the inferior at the step-resume-breakpoint without
6160 actually executing it). Either way continue until the
6161 breakpoint is really hit. */
6163 if (!switch_back_to_stepped_thread (ecs))
6166 fprintf_unfiltered (gdb_stdlog,
6167 "infrun: random signal, keep going\n");
6174 process_event_stop_test (ecs);
6177 /* Come here when we've got some debug event / signal we can explain
6178 (IOW, not a random signal), and test whether it should cause a
6179 stop, or whether we should resume the inferior (transparently).
6180 E.g., could be a breakpoint whose condition evaluates false; we
6181 could be still stepping within the line; etc. */
6184 process_event_stop_test (struct execution_control_state *ecs)
6186 struct symtab_and_line stop_pc_sal;
6187 struct frame_info *frame;
6188 struct gdbarch *gdbarch;
6189 CORE_ADDR jmp_buf_pc;
6190 struct bpstat_what what;
6192 /* Handle cases caused by hitting a breakpoint. */
6194 frame = get_current_frame ();
6195 gdbarch = get_frame_arch (frame);
6197 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6199 if (what.call_dummy)
6201 stop_stack_dummy = what.call_dummy;
6204 /* A few breakpoint types have callbacks associated (e.g.,
6205 bp_jit_event). Run them now. */
6206 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6208 /* If we hit an internal event that triggers symbol changes, the
6209 current frame will be invalidated within bpstat_what (e.g., if we
6210 hit an internal solib event). Re-fetch it. */
6211 frame = get_current_frame ();
6212 gdbarch = get_frame_arch (frame);
6214 switch (what.main_action)
6216 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6217 /* If we hit the breakpoint at longjmp while stepping, we
6218 install a momentary breakpoint at the target of the
6222 fprintf_unfiltered (gdb_stdlog,
6223 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6225 ecs->event_thread->stepping_over_breakpoint = 1;
6227 if (what.is_longjmp)
6229 struct value *arg_value;
6231 /* If we set the longjmp breakpoint via a SystemTap probe,
6232 then use it to extract the arguments. The destination PC
6233 is the third argument to the probe. */
6234 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6237 jmp_buf_pc = value_as_address (arg_value);
6238 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6240 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6241 || !gdbarch_get_longjmp_target (gdbarch,
6242 frame, &jmp_buf_pc))
6245 fprintf_unfiltered (gdb_stdlog,
6246 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6247 "(!gdbarch_get_longjmp_target)\n");
6252 /* Insert a breakpoint at resume address. */
6253 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6256 check_exception_resume (ecs, frame);
6260 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6262 struct frame_info *init_frame;
6264 /* There are several cases to consider.
6266 1. The initiating frame no longer exists. In this case we
6267 must stop, because the exception or longjmp has gone too
6270 2. The initiating frame exists, and is the same as the
6271 current frame. We stop, because the exception or longjmp
6274 3. The initiating frame exists and is different from the
6275 current frame. This means the exception or longjmp has
6276 been caught beneath the initiating frame, so keep going.
6278 4. longjmp breakpoint has been placed just to protect
6279 against stale dummy frames and user is not interested in
6280 stopping around longjmps. */
6283 fprintf_unfiltered (gdb_stdlog,
6284 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6286 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6288 delete_exception_resume_breakpoint (ecs->event_thread);
6290 if (what.is_longjmp)
6292 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6294 if (!frame_id_p (ecs->event_thread->initiating_frame))
6302 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6306 struct frame_id current_id
6307 = get_frame_id (get_current_frame ());
6308 if (frame_id_eq (current_id,
6309 ecs->event_thread->initiating_frame))
6311 /* Case 2. Fall through. */
6321 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6323 delete_step_resume_breakpoint (ecs->event_thread);
6325 end_stepping_range (ecs);
6329 case BPSTAT_WHAT_SINGLE:
6331 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6332 ecs->event_thread->stepping_over_breakpoint = 1;
6333 /* Still need to check other stuff, at least the case where we
6334 are stepping and step out of the right range. */
6337 case BPSTAT_WHAT_STEP_RESUME:
6339 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6341 delete_step_resume_breakpoint (ecs->event_thread);
6342 if (ecs->event_thread->control.proceed_to_finish
6343 && execution_direction == EXEC_REVERSE)
6345 struct thread_info *tp = ecs->event_thread;
6347 /* We are finishing a function in reverse, and just hit the
6348 step-resume breakpoint at the start address of the
6349 function, and we're almost there -- just need to back up
6350 by one more single-step, which should take us back to the
6352 tp->control.step_range_start = tp->control.step_range_end = 1;
6356 fill_in_stop_func (gdbarch, ecs);
6357 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6358 && execution_direction == EXEC_REVERSE)
6360 /* We are stepping over a function call in reverse, and just
6361 hit the step-resume breakpoint at the start address of
6362 the function. Go back to single-stepping, which should
6363 take us back to the function call. */
6364 ecs->event_thread->stepping_over_breakpoint = 1;
6370 case BPSTAT_WHAT_STOP_NOISY:
6372 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6373 stop_print_frame = 1;
6375 /* Assume the thread stopped for a breapoint. We'll still check
6376 whether a/the breakpoint is there when the thread is next
6378 ecs->event_thread->stepping_over_breakpoint = 1;
6383 case BPSTAT_WHAT_STOP_SILENT:
6385 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6386 stop_print_frame = 0;
6388 /* Assume the thread stopped for a breapoint. We'll still check
6389 whether a/the breakpoint is there when the thread is next
6391 ecs->event_thread->stepping_over_breakpoint = 1;
6395 case BPSTAT_WHAT_HP_STEP_RESUME:
6397 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6399 delete_step_resume_breakpoint (ecs->event_thread);
6400 if (ecs->event_thread->step_after_step_resume_breakpoint)
6402 /* Back when the step-resume breakpoint was inserted, we
6403 were trying to single-step off a breakpoint. Go back to
6405 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6406 ecs->event_thread->stepping_over_breakpoint = 1;
6412 case BPSTAT_WHAT_KEEP_CHECKING:
6416 /* If we stepped a permanent breakpoint and we had a high priority
6417 step-resume breakpoint for the address we stepped, but we didn't
6418 hit it, then we must have stepped into the signal handler. The
6419 step-resume was only necessary to catch the case of _not_
6420 stepping into the handler, so delete it, and fall through to
6421 checking whether the step finished. */
6422 if (ecs->event_thread->stepped_breakpoint)
6424 struct breakpoint *sr_bp
6425 = ecs->event_thread->control.step_resume_breakpoint;
6428 && sr_bp->loc->permanent
6429 && sr_bp->type == bp_hp_step_resume
6430 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6433 fprintf_unfiltered (gdb_stdlog,
6434 "infrun: stepped permanent breakpoint, stopped in "
6436 delete_step_resume_breakpoint (ecs->event_thread);
6437 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6441 /* We come here if we hit a breakpoint but should not stop for it.
6442 Possibly we also were stepping and should stop for that. So fall
6443 through and test for stepping. But, if not stepping, do not
6446 /* In all-stop mode, if we're currently stepping but have stopped in
6447 some other thread, we need to switch back to the stepped thread. */
6448 if (switch_back_to_stepped_thread (ecs))
6451 if (ecs->event_thread->control.step_resume_breakpoint)
6454 fprintf_unfiltered (gdb_stdlog,
6455 "infrun: step-resume breakpoint is inserted\n");
6457 /* Having a step-resume breakpoint overrides anything
6458 else having to do with stepping commands until
6459 that breakpoint is reached. */
6464 if (ecs->event_thread->control.step_range_end == 0)
6467 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6468 /* Likewise if we aren't even stepping. */
6473 /* Re-fetch current thread's frame in case the code above caused
6474 the frame cache to be re-initialized, making our FRAME variable
6475 a dangling pointer. */
6476 frame = get_current_frame ();
6477 gdbarch = get_frame_arch (frame);
6478 fill_in_stop_func (gdbarch, ecs);
6480 /* If stepping through a line, keep going if still within it.
6482 Note that step_range_end is the address of the first instruction
6483 beyond the step range, and NOT the address of the last instruction
6486 Note also that during reverse execution, we may be stepping
6487 through a function epilogue and therefore must detect when
6488 the current-frame changes in the middle of a line. */
6490 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6492 && (execution_direction != EXEC_REVERSE
6493 || frame_id_eq (get_frame_id (frame),
6494 ecs->event_thread->control.step_frame_id)))
6498 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6499 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6500 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6502 /* Tentatively re-enable range stepping; `resume' disables it if
6503 necessary (e.g., if we're stepping over a breakpoint or we
6504 have software watchpoints). */
6505 ecs->event_thread->control.may_range_step = 1;
6507 /* When stepping backward, stop at beginning of line range
6508 (unless it's the function entry point, in which case
6509 keep going back to the call point). */
6510 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6511 if (stop_pc == ecs->event_thread->control.step_range_start
6512 && stop_pc != ecs->stop_func_start
6513 && execution_direction == EXEC_REVERSE)
6514 end_stepping_range (ecs);
6521 /* We stepped out of the stepping range. */
6523 /* If we are stepping at the source level and entered the runtime
6524 loader dynamic symbol resolution code...
6526 EXEC_FORWARD: we keep on single stepping until we exit the run
6527 time loader code and reach the callee's address.
6529 EXEC_REVERSE: we've already executed the callee (backward), and
6530 the runtime loader code is handled just like any other
6531 undebuggable function call. Now we need only keep stepping
6532 backward through the trampoline code, and that's handled further
6533 down, so there is nothing for us to do here. */
6535 if (execution_direction != EXEC_REVERSE
6536 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6537 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6539 CORE_ADDR pc_after_resolver =
6540 gdbarch_skip_solib_resolver (gdbarch,
6541 ecs->event_thread->suspend.stop_pc);
6544 fprintf_unfiltered (gdb_stdlog,
6545 "infrun: stepped into dynsym resolve code\n");
6547 if (pc_after_resolver)
6549 /* Set up a step-resume breakpoint at the address
6550 indicated by SKIP_SOLIB_RESOLVER. */
6551 symtab_and_line sr_sal;
6552 sr_sal.pc = pc_after_resolver;
6553 sr_sal.pspace = get_frame_program_space (frame);
6555 insert_step_resume_breakpoint_at_sal (gdbarch,
6556 sr_sal, null_frame_id);
6563 /* Step through an indirect branch thunk. */
6564 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6565 && gdbarch_in_indirect_branch_thunk (gdbarch,
6566 ecs->event_thread->suspend.stop_pc))
6569 fprintf_unfiltered (gdb_stdlog,
6570 "infrun: stepped into indirect branch thunk\n");
6575 if (ecs->event_thread->control.step_range_end != 1
6576 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6577 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6578 && get_frame_type (frame) == SIGTRAMP_FRAME)
6581 fprintf_unfiltered (gdb_stdlog,
6582 "infrun: stepped into signal trampoline\n");
6583 /* The inferior, while doing a "step" or "next", has ended up in
6584 a signal trampoline (either by a signal being delivered or by
6585 the signal handler returning). Just single-step until the
6586 inferior leaves the trampoline (either by calling the handler
6592 /* If we're in the return path from a shared library trampoline,
6593 we want to proceed through the trampoline when stepping. */
6594 /* macro/2012-04-25: This needs to come before the subroutine
6595 call check below as on some targets return trampolines look
6596 like subroutine calls (MIPS16 return thunks). */
6597 if (gdbarch_in_solib_return_trampoline (gdbarch,
6598 ecs->event_thread->suspend.stop_pc,
6599 ecs->stop_func_name)
6600 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6602 /* Determine where this trampoline returns. */
6603 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6604 CORE_ADDR real_stop_pc
6605 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6608 fprintf_unfiltered (gdb_stdlog,
6609 "infrun: stepped into solib return tramp\n");
6611 /* Only proceed through if we know where it's going. */
6614 /* And put the step-breakpoint there and go until there. */
6615 symtab_and_line sr_sal;
6616 sr_sal.pc = real_stop_pc;
6617 sr_sal.section = find_pc_overlay (sr_sal.pc);
6618 sr_sal.pspace = get_frame_program_space (frame);
6620 /* Do not specify what the fp should be when we stop since
6621 on some machines the prologue is where the new fp value
6623 insert_step_resume_breakpoint_at_sal (gdbarch,
6624 sr_sal, null_frame_id);
6626 /* Restart without fiddling with the step ranges or
6633 /* Check for subroutine calls. The check for the current frame
6634 equalling the step ID is not necessary - the check of the
6635 previous frame's ID is sufficient - but it is a common case and
6636 cheaper than checking the previous frame's ID.
6638 NOTE: frame_id_eq will never report two invalid frame IDs as
6639 being equal, so to get into this block, both the current and
6640 previous frame must have valid frame IDs. */
6641 /* The outer_frame_id check is a heuristic to detect stepping
6642 through startup code. If we step over an instruction which
6643 sets the stack pointer from an invalid value to a valid value,
6644 we may detect that as a subroutine call from the mythical
6645 "outermost" function. This could be fixed by marking
6646 outermost frames as !stack_p,code_p,special_p. Then the
6647 initial outermost frame, before sp was valid, would
6648 have code_addr == &_start. See the comment in frame_id_eq
6650 if (!frame_id_eq (get_stack_frame_id (frame),
6651 ecs->event_thread->control.step_stack_frame_id)
6652 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6653 ecs->event_thread->control.step_stack_frame_id)
6654 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6656 || (ecs->event_thread->control.step_start_function
6657 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6659 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6660 CORE_ADDR real_stop_pc;
6663 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6665 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6667 /* I presume that step_over_calls is only 0 when we're
6668 supposed to be stepping at the assembly language level
6669 ("stepi"). Just stop. */
6670 /* And this works the same backward as frontward. MVS */
6671 end_stepping_range (ecs);
6675 /* Reverse stepping through solib trampolines. */
6677 if (execution_direction == EXEC_REVERSE
6678 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6679 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6680 || (ecs->stop_func_start == 0
6681 && in_solib_dynsym_resolve_code (stop_pc))))
6683 /* Any solib trampoline code can be handled in reverse
6684 by simply continuing to single-step. We have already
6685 executed the solib function (backwards), and a few
6686 steps will take us back through the trampoline to the
6692 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6694 /* We're doing a "next".
6696 Normal (forward) execution: set a breakpoint at the
6697 callee's return address (the address at which the caller
6700 Reverse (backward) execution. set the step-resume
6701 breakpoint at the start of the function that we just
6702 stepped into (backwards), and continue to there. When we
6703 get there, we'll need to single-step back to the caller. */
6705 if (execution_direction == EXEC_REVERSE)
6707 /* If we're already at the start of the function, we've either
6708 just stepped backward into a single instruction function,
6709 or stepped back out of a signal handler to the first instruction
6710 of the function. Just keep going, which will single-step back
6712 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6714 /* Normal function call return (static or dynamic). */
6715 symtab_and_line sr_sal;
6716 sr_sal.pc = ecs->stop_func_start;
6717 sr_sal.pspace = get_frame_program_space (frame);
6718 insert_step_resume_breakpoint_at_sal (gdbarch,
6719 sr_sal, null_frame_id);
6723 insert_step_resume_breakpoint_at_caller (frame);
6729 /* If we are in a function call trampoline (a stub between the
6730 calling routine and the real function), locate the real
6731 function. That's what tells us (a) whether we want to step
6732 into it at all, and (b) what prologue we want to run to the
6733 end of, if we do step into it. */
6734 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6735 if (real_stop_pc == 0)
6736 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6737 if (real_stop_pc != 0)
6738 ecs->stop_func_start = real_stop_pc;
6740 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6742 symtab_and_line sr_sal;
6743 sr_sal.pc = ecs->stop_func_start;
6744 sr_sal.pspace = get_frame_program_space (frame);
6746 insert_step_resume_breakpoint_at_sal (gdbarch,
6747 sr_sal, null_frame_id);
6752 /* If we have line number information for the function we are
6753 thinking of stepping into and the function isn't on the skip
6756 If there are several symtabs at that PC (e.g. with include
6757 files), just want to know whether *any* of them have line
6758 numbers. find_pc_line handles this. */
6760 struct symtab_and_line tmp_sal;
6762 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6763 if (tmp_sal.line != 0
6764 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6767 if (execution_direction == EXEC_REVERSE)
6768 handle_step_into_function_backward (gdbarch, ecs);
6770 handle_step_into_function (gdbarch, ecs);
6775 /* If we have no line number and the step-stop-if-no-debug is
6776 set, we stop the step so that the user has a chance to switch
6777 in assembly mode. */
6778 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6779 && step_stop_if_no_debug)
6781 end_stepping_range (ecs);
6785 if (execution_direction == EXEC_REVERSE)
6787 /* If we're already at the start of the function, we've either just
6788 stepped backward into a single instruction function without line
6789 number info, or stepped back out of a signal handler to the first
6790 instruction of the function without line number info. Just keep
6791 going, which will single-step back to the caller. */
6792 if (ecs->stop_func_start != stop_pc)
6794 /* Set a breakpoint at callee's start address.
6795 From there we can step once and be back in the caller. */
6796 symtab_and_line sr_sal;
6797 sr_sal.pc = ecs->stop_func_start;
6798 sr_sal.pspace = get_frame_program_space (frame);
6799 insert_step_resume_breakpoint_at_sal (gdbarch,
6800 sr_sal, null_frame_id);
6804 /* Set a breakpoint at callee's return address (the address
6805 at which the caller will resume). */
6806 insert_step_resume_breakpoint_at_caller (frame);
6812 /* Reverse stepping through solib trampolines. */
6814 if (execution_direction == EXEC_REVERSE
6815 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6817 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6819 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6820 || (ecs->stop_func_start == 0
6821 && in_solib_dynsym_resolve_code (stop_pc)))
6823 /* Any solib trampoline code can be handled in reverse
6824 by simply continuing to single-step. We have already
6825 executed the solib function (backwards), and a few
6826 steps will take us back through the trampoline to the
6831 else if (in_solib_dynsym_resolve_code (stop_pc))
6833 /* Stepped backward into the solib dynsym resolver.
6834 Set a breakpoint at its start and continue, then
6835 one more step will take us out. */
6836 symtab_and_line sr_sal;
6837 sr_sal.pc = ecs->stop_func_start;
6838 sr_sal.pspace = get_frame_program_space (frame);
6839 insert_step_resume_breakpoint_at_sal (gdbarch,
6840 sr_sal, null_frame_id);
6846 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6848 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6849 the trampoline processing logic, however, there are some trampolines
6850 that have no names, so we should do trampoline handling first. */
6851 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6852 && ecs->stop_func_name == NULL
6853 && stop_pc_sal.line == 0)
6856 fprintf_unfiltered (gdb_stdlog,
6857 "infrun: stepped into undebuggable function\n");
6859 /* The inferior just stepped into, or returned to, an
6860 undebuggable function (where there is no debugging information
6861 and no line number corresponding to the address where the
6862 inferior stopped). Since we want to skip this kind of code,
6863 we keep going until the inferior returns from this
6864 function - unless the user has asked us not to (via
6865 set step-mode) or we no longer know how to get back
6866 to the call site. */
6867 if (step_stop_if_no_debug
6868 || !frame_id_p (frame_unwind_caller_id (frame)))
6870 /* If we have no line number and the step-stop-if-no-debug
6871 is set, we stop the step so that the user has a chance to
6872 switch in assembly mode. */
6873 end_stepping_range (ecs);
6878 /* Set a breakpoint at callee's return address (the address
6879 at which the caller will resume). */
6880 insert_step_resume_breakpoint_at_caller (frame);
6886 if (ecs->event_thread->control.step_range_end == 1)
6888 /* It is stepi or nexti. We always want to stop stepping after
6891 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6892 end_stepping_range (ecs);
6896 if (stop_pc_sal.line == 0)
6898 /* We have no line number information. That means to stop
6899 stepping (does this always happen right after one instruction,
6900 when we do "s" in a function with no line numbers,
6901 or can this happen as a result of a return or longjmp?). */
6903 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6904 end_stepping_range (ecs);
6908 /* Look for "calls" to inlined functions, part one. If the inline
6909 frame machinery detected some skipped call sites, we have entered
6910 a new inline function. */
6912 if (frame_id_eq (get_frame_id (get_current_frame ()),
6913 ecs->event_thread->control.step_frame_id)
6914 && inline_skipped_frames (ecs->event_thread))
6917 fprintf_unfiltered (gdb_stdlog,
6918 "infrun: stepped into inlined function\n");
6920 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6922 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6924 /* For "step", we're going to stop. But if the call site
6925 for this inlined function is on the same source line as
6926 we were previously stepping, go down into the function
6927 first. Otherwise stop at the call site. */
6929 if (call_sal.line == ecs->event_thread->current_line
6930 && call_sal.symtab == ecs->event_thread->current_symtab)
6931 step_into_inline_frame (ecs->event_thread);
6933 end_stepping_range (ecs);
6938 /* For "next", we should stop at the call site if it is on a
6939 different source line. Otherwise continue through the
6940 inlined function. */
6941 if (call_sal.line == ecs->event_thread->current_line
6942 && call_sal.symtab == ecs->event_thread->current_symtab)
6945 end_stepping_range (ecs);
6950 /* Look for "calls" to inlined functions, part two. If we are still
6951 in the same real function we were stepping through, but we have
6952 to go further up to find the exact frame ID, we are stepping
6953 through a more inlined call beyond its call site. */
6955 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6956 && !frame_id_eq (get_frame_id (get_current_frame ()),
6957 ecs->event_thread->control.step_frame_id)
6958 && stepped_in_from (get_current_frame (),
6959 ecs->event_thread->control.step_frame_id))
6962 fprintf_unfiltered (gdb_stdlog,
6963 "infrun: stepping through inlined function\n");
6965 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6968 end_stepping_range (ecs);
6972 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6973 && (ecs->event_thread->current_line != stop_pc_sal.line
6974 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6976 /* We are at the start of a different line. So stop. Note that
6977 we don't stop if we step into the middle of a different line.
6978 That is said to make things like for (;;) statements work
6981 fprintf_unfiltered (gdb_stdlog,
6982 "infrun: stepped to a different line\n");
6983 end_stepping_range (ecs);
6987 /* We aren't done stepping.
6989 Optimize by setting the stepping range to the line.
6990 (We might not be in the original line, but if we entered a
6991 new line in mid-statement, we continue stepping. This makes
6992 things like for(;;) statements work better.) */
6994 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6995 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6996 ecs->event_thread->control.may_range_step = 1;
6997 set_step_info (frame, stop_pc_sal);
7000 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
7004 /* In all-stop mode, if we're currently stepping but have stopped in
7005 some other thread, we may need to switch back to the stepped
7006 thread. Returns true we set the inferior running, false if we left
7007 it stopped (and the event needs further processing). */
7010 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7012 if (!target_is_non_stop_p ())
7014 struct thread_info *tp;
7015 struct thread_info *stepping_thread;
7017 /* If any thread is blocked on some internal breakpoint, and we
7018 simply need to step over that breakpoint to get it going
7019 again, do that first. */
7021 /* However, if we see an event for the stepping thread, then we
7022 know all other threads have been moved past their breakpoints
7023 already. Let the caller check whether the step is finished,
7024 etc., before deciding to move it past a breakpoint. */
7025 if (ecs->event_thread->control.step_range_end != 0)
7028 /* Check if the current thread is blocked on an incomplete
7029 step-over, interrupted by a random signal. */
7030 if (ecs->event_thread->control.trap_expected
7031 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7035 fprintf_unfiltered (gdb_stdlog,
7036 "infrun: need to finish step-over of [%s]\n",
7037 target_pid_to_str (ecs->event_thread->ptid));
7043 /* Check if the current thread is blocked by a single-step
7044 breakpoint of another thread. */
7045 if (ecs->hit_singlestep_breakpoint)
7049 fprintf_unfiltered (gdb_stdlog,
7050 "infrun: need to step [%s] over single-step "
7052 target_pid_to_str (ecs->ptid));
7058 /* If this thread needs yet another step-over (e.g., stepping
7059 through a delay slot), do it first before moving on to
7061 if (thread_still_needs_step_over (ecs->event_thread))
7065 fprintf_unfiltered (gdb_stdlog,
7066 "infrun: thread [%s] still needs step-over\n",
7067 target_pid_to_str (ecs->event_thread->ptid));
7073 /* If scheduler locking applies even if not stepping, there's no
7074 need to walk over threads. Above we've checked whether the
7075 current thread is stepping. If some other thread not the
7076 event thread is stepping, then it must be that scheduler
7077 locking is not in effect. */
7078 if (schedlock_applies (ecs->event_thread))
7081 /* Otherwise, we no longer expect a trap in the current thread.
7082 Clear the trap_expected flag before switching back -- this is
7083 what keep_going does as well, if we call it. */
7084 ecs->event_thread->control.trap_expected = 0;
7086 /* Likewise, clear the signal if it should not be passed. */
7087 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7088 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7090 /* Do all pending step-overs before actually proceeding with
7092 if (start_step_over ())
7094 prepare_to_wait (ecs);
7098 /* Look for the stepping/nexting thread. */
7099 stepping_thread = NULL;
7101 ALL_NON_EXITED_THREADS (tp)
7103 /* Ignore threads of processes the caller is not
7106 && tp->ptid.pid () != ecs->ptid.pid ())
7109 /* When stepping over a breakpoint, we lock all threads
7110 except the one that needs to move past the breakpoint.
7111 If a non-event thread has this set, the "incomplete
7112 step-over" check above should have caught it earlier. */
7113 if (tp->control.trap_expected)
7115 internal_error (__FILE__, __LINE__,
7116 "[%s] has inconsistent state: "
7117 "trap_expected=%d\n",
7118 target_pid_to_str (tp->ptid),
7119 tp->control.trap_expected);
7122 /* Did we find the stepping thread? */
7123 if (tp->control.step_range_end)
7125 /* Yep. There should only one though. */
7126 gdb_assert (stepping_thread == NULL);
7128 /* The event thread is handled at the top, before we
7130 gdb_assert (tp != ecs->event_thread);
7132 /* If some thread other than the event thread is
7133 stepping, then scheduler locking can't be in effect,
7134 otherwise we wouldn't have resumed the current event
7135 thread in the first place. */
7136 gdb_assert (!schedlock_applies (tp));
7138 stepping_thread = tp;
7142 if (stepping_thread != NULL)
7145 fprintf_unfiltered (gdb_stdlog,
7146 "infrun: switching back to stepped thread\n");
7148 if (keep_going_stepped_thread (stepping_thread))
7150 prepare_to_wait (ecs);
7159 /* Set a previously stepped thread back to stepping. Returns true on
7160 success, false if the resume is not possible (e.g., the thread
7164 keep_going_stepped_thread (struct thread_info *tp)
7166 struct frame_info *frame;
7167 struct execution_control_state ecss;
7168 struct execution_control_state *ecs = &ecss;
7170 /* If the stepping thread exited, then don't try to switch back and
7171 resume it, which could fail in several different ways depending
7172 on the target. Instead, just keep going.
7174 We can find a stepping dead thread in the thread list in two
7177 - The target supports thread exit events, and when the target
7178 tries to delete the thread from the thread list, inferior_ptid
7179 pointed at the exiting thread. In such case, calling
7180 delete_thread does not really remove the thread from the list;
7181 instead, the thread is left listed, with 'exited' state.
7183 - The target's debug interface does not support thread exit
7184 events, and so we have no idea whatsoever if the previously
7185 stepping thread is still alive. For that reason, we need to
7186 synchronously query the target now. */
7188 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
7191 fprintf_unfiltered (gdb_stdlog,
7192 "infrun: not resuming previously "
7193 "stepped thread, it has vanished\n");
7200 fprintf_unfiltered (gdb_stdlog,
7201 "infrun: resuming previously stepped thread\n");
7203 reset_ecs (ecs, tp);
7204 switch_to_thread (tp);
7206 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7207 frame = get_current_frame ();
7209 /* If the PC of the thread we were trying to single-step has
7210 changed, then that thread has trapped or been signaled, but the
7211 event has not been reported to GDB yet. Re-poll the target
7212 looking for this particular thread's event (i.e. temporarily
7213 enable schedlock) by:
7215 - setting a break at the current PC
7216 - resuming that particular thread, only (by setting trap
7219 This prevents us continuously moving the single-step breakpoint
7220 forward, one instruction at a time, overstepping. */
7222 if (tp->suspend.stop_pc != tp->prev_pc)
7227 fprintf_unfiltered (gdb_stdlog,
7228 "infrun: expected thread advanced also (%s -> %s)\n",
7229 paddress (target_gdbarch (), tp->prev_pc),
7230 paddress (target_gdbarch (), tp->suspend.stop_pc));
7232 /* Clear the info of the previous step-over, as it's no longer
7233 valid (if the thread was trying to step over a breakpoint, it
7234 has already succeeded). It's what keep_going would do too,
7235 if we called it. Do this before trying to insert the sss
7236 breakpoint, otherwise if we were previously trying to step
7237 over this exact address in another thread, the breakpoint is
7239 clear_step_over_info ();
7240 tp->control.trap_expected = 0;
7242 insert_single_step_breakpoint (get_frame_arch (frame),
7243 get_frame_address_space (frame),
7244 tp->suspend.stop_pc);
7247 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7248 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7253 fprintf_unfiltered (gdb_stdlog,
7254 "infrun: expected thread still hasn't advanced\n");
7256 keep_going_pass_signal (ecs);
7261 /* Is thread TP in the middle of (software or hardware)
7262 single-stepping? (Note the result of this function must never be
7263 passed directly as target_resume's STEP parameter.) */
7266 currently_stepping (struct thread_info *tp)
7268 return ((tp->control.step_range_end
7269 && tp->control.step_resume_breakpoint == NULL)
7270 || tp->control.trap_expected
7271 || tp->stepped_breakpoint
7272 || bpstat_should_step ());
7275 /* Inferior has stepped into a subroutine call with source code that
7276 we should not step over. Do step to the first line of code in
7280 handle_step_into_function (struct gdbarch *gdbarch,
7281 struct execution_control_state *ecs)
7283 fill_in_stop_func (gdbarch, ecs);
7285 compunit_symtab *cust
7286 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7287 if (cust != NULL && compunit_language (cust) != language_asm)
7288 ecs->stop_func_start
7289 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7291 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7292 /* Use the step_resume_break to step until the end of the prologue,
7293 even if that involves jumps (as it seems to on the vax under
7295 /* If the prologue ends in the middle of a source line, continue to
7296 the end of that source line (if it is still within the function).
7297 Otherwise, just go to end of prologue. */
7298 if (stop_func_sal.end
7299 && stop_func_sal.pc != ecs->stop_func_start
7300 && stop_func_sal.end < ecs->stop_func_end)
7301 ecs->stop_func_start = stop_func_sal.end;
7303 /* Architectures which require breakpoint adjustment might not be able
7304 to place a breakpoint at the computed address. If so, the test
7305 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7306 ecs->stop_func_start to an address at which a breakpoint may be
7307 legitimately placed.
7309 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7310 made, GDB will enter an infinite loop when stepping through
7311 optimized code consisting of VLIW instructions which contain
7312 subinstructions corresponding to different source lines. On
7313 FR-V, it's not permitted to place a breakpoint on any but the
7314 first subinstruction of a VLIW instruction. When a breakpoint is
7315 set, GDB will adjust the breakpoint address to the beginning of
7316 the VLIW instruction. Thus, we need to make the corresponding
7317 adjustment here when computing the stop address. */
7319 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7321 ecs->stop_func_start
7322 = gdbarch_adjust_breakpoint_address (gdbarch,
7323 ecs->stop_func_start);
7326 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7328 /* We are already there: stop now. */
7329 end_stepping_range (ecs);
7334 /* Put the step-breakpoint there and go until there. */
7335 symtab_and_line sr_sal;
7336 sr_sal.pc = ecs->stop_func_start;
7337 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7338 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7340 /* Do not specify what the fp should be when we stop since on
7341 some machines the prologue is where the new fp value is
7343 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7345 /* And make sure stepping stops right away then. */
7346 ecs->event_thread->control.step_range_end
7347 = ecs->event_thread->control.step_range_start;
7352 /* Inferior has stepped backward into a subroutine call with source
7353 code that we should not step over. Do step to the beginning of the
7354 last line of code in it. */
7357 handle_step_into_function_backward (struct gdbarch *gdbarch,
7358 struct execution_control_state *ecs)
7360 struct compunit_symtab *cust;
7361 struct symtab_and_line stop_func_sal;
7363 fill_in_stop_func (gdbarch, ecs);
7365 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7366 if (cust != NULL && compunit_language (cust) != language_asm)
7367 ecs->stop_func_start
7368 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7370 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7372 /* OK, we're just going to keep stepping here. */
7373 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7375 /* We're there already. Just stop stepping now. */
7376 end_stepping_range (ecs);
7380 /* Else just reset the step range and keep going.
7381 No step-resume breakpoint, they don't work for
7382 epilogues, which can have multiple entry paths. */
7383 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7384 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7390 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7391 This is used to both functions and to skip over code. */
7394 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7395 struct symtab_and_line sr_sal,
7396 struct frame_id sr_id,
7397 enum bptype sr_type)
7399 /* There should never be more than one step-resume or longjmp-resume
7400 breakpoint per thread, so we should never be setting a new
7401 step_resume_breakpoint when one is already active. */
7402 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7403 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7406 fprintf_unfiltered (gdb_stdlog,
7407 "infrun: inserting step-resume breakpoint at %s\n",
7408 paddress (gdbarch, sr_sal.pc));
7410 inferior_thread ()->control.step_resume_breakpoint
7411 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7415 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7416 struct symtab_and_line sr_sal,
7417 struct frame_id sr_id)
7419 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7424 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7425 This is used to skip a potential signal handler.
7427 This is called with the interrupted function's frame. The signal
7428 handler, when it returns, will resume the interrupted function at
7432 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7434 gdb_assert (return_frame != NULL);
7436 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7438 symtab_and_line sr_sal;
7439 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7440 sr_sal.section = find_pc_overlay (sr_sal.pc);
7441 sr_sal.pspace = get_frame_program_space (return_frame);
7443 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7444 get_stack_frame_id (return_frame),
7448 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7449 is used to skip a function after stepping into it (for "next" or if
7450 the called function has no debugging information).
7452 The current function has almost always been reached by single
7453 stepping a call or return instruction. NEXT_FRAME belongs to the
7454 current function, and the breakpoint will be set at the caller's
7457 This is a separate function rather than reusing
7458 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7459 get_prev_frame, which may stop prematurely (see the implementation
7460 of frame_unwind_caller_id for an example). */
7463 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7465 /* We shouldn't have gotten here if we don't know where the call site
7467 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7469 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7471 symtab_and_line sr_sal;
7472 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7473 frame_unwind_caller_pc (next_frame));
7474 sr_sal.section = find_pc_overlay (sr_sal.pc);
7475 sr_sal.pspace = frame_unwind_program_space (next_frame);
7477 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7478 frame_unwind_caller_id (next_frame));
7481 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7482 new breakpoint at the target of a jmp_buf. The handling of
7483 longjmp-resume uses the same mechanisms used for handling
7484 "step-resume" breakpoints. */
7487 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7489 /* There should never be more than one longjmp-resume breakpoint per
7490 thread, so we should never be setting a new
7491 longjmp_resume_breakpoint when one is already active. */
7492 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7495 fprintf_unfiltered (gdb_stdlog,
7496 "infrun: inserting longjmp-resume breakpoint at %s\n",
7497 paddress (gdbarch, pc));
7499 inferior_thread ()->control.exception_resume_breakpoint =
7500 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7503 /* Insert an exception resume breakpoint. TP is the thread throwing
7504 the exception. The block B is the block of the unwinder debug hook
7505 function. FRAME is the frame corresponding to the call to this
7506 function. SYM is the symbol of the function argument holding the
7507 target PC of the exception. */
7510 insert_exception_resume_breakpoint (struct thread_info *tp,
7511 const struct block *b,
7512 struct frame_info *frame,
7517 struct block_symbol vsym;
7518 struct value *value;
7520 struct breakpoint *bp;
7522 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7524 value = read_var_value (vsym.symbol, vsym.block, frame);
7525 /* If the value was optimized out, revert to the old behavior. */
7526 if (! value_optimized_out (value))
7528 handler = value_as_address (value);
7531 fprintf_unfiltered (gdb_stdlog,
7532 "infrun: exception resume at %lx\n",
7533 (unsigned long) handler);
7535 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7537 bp_exception_resume).release ();
7539 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7542 bp->thread = tp->global_num;
7543 inferior_thread ()->control.exception_resume_breakpoint = bp;
7546 CATCH (e, RETURN_MASK_ERROR)
7548 /* We want to ignore errors here. */
7553 /* A helper for check_exception_resume that sets an
7554 exception-breakpoint based on a SystemTap probe. */
7557 insert_exception_resume_from_probe (struct thread_info *tp,
7558 const struct bound_probe *probe,
7559 struct frame_info *frame)
7561 struct value *arg_value;
7563 struct breakpoint *bp;
7565 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7569 handler = value_as_address (arg_value);
7572 fprintf_unfiltered (gdb_stdlog,
7573 "infrun: exception resume at %s\n",
7574 paddress (get_objfile_arch (probe->objfile),
7577 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7578 handler, bp_exception_resume).release ();
7579 bp->thread = tp->global_num;
7580 inferior_thread ()->control.exception_resume_breakpoint = bp;
7583 /* This is called when an exception has been intercepted. Check to
7584 see whether the exception's destination is of interest, and if so,
7585 set an exception resume breakpoint there. */
7588 check_exception_resume (struct execution_control_state *ecs,
7589 struct frame_info *frame)
7591 struct bound_probe probe;
7592 struct symbol *func;
7594 /* First see if this exception unwinding breakpoint was set via a
7595 SystemTap probe point. If so, the probe has two arguments: the
7596 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7597 set a breakpoint there. */
7598 probe = find_probe_by_pc (get_frame_pc (frame));
7601 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7605 func = get_frame_function (frame);
7611 const struct block *b;
7612 struct block_iterator iter;
7616 /* The exception breakpoint is a thread-specific breakpoint on
7617 the unwinder's debug hook, declared as:
7619 void _Unwind_DebugHook (void *cfa, void *handler);
7621 The CFA argument indicates the frame to which control is
7622 about to be transferred. HANDLER is the destination PC.
7624 We ignore the CFA and set a temporary breakpoint at HANDLER.
7625 This is not extremely efficient but it avoids issues in gdb
7626 with computing the DWARF CFA, and it also works even in weird
7627 cases such as throwing an exception from inside a signal
7630 b = SYMBOL_BLOCK_VALUE (func);
7631 ALL_BLOCK_SYMBOLS (b, iter, sym)
7633 if (!SYMBOL_IS_ARGUMENT (sym))
7640 insert_exception_resume_breakpoint (ecs->event_thread,
7646 CATCH (e, RETURN_MASK_ERROR)
7653 stop_waiting (struct execution_control_state *ecs)
7656 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7658 /* Let callers know we don't want to wait for the inferior anymore. */
7659 ecs->wait_some_more = 0;
7661 /* If all-stop, but the target is always in non-stop mode, stop all
7662 threads now that we're presenting the stop to the user. */
7663 if (!non_stop && target_is_non_stop_p ())
7664 stop_all_threads ();
7667 /* Like keep_going, but passes the signal to the inferior, even if the
7668 signal is set to nopass. */
7671 keep_going_pass_signal (struct execution_control_state *ecs)
7673 gdb_assert (ecs->event_thread->ptid == inferior_ptid);
7674 gdb_assert (!ecs->event_thread->resumed);
7676 /* Save the pc before execution, to compare with pc after stop. */
7677 ecs->event_thread->prev_pc
7678 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7680 if (ecs->event_thread->control.trap_expected)
7682 struct thread_info *tp = ecs->event_thread;
7685 fprintf_unfiltered (gdb_stdlog,
7686 "infrun: %s has trap_expected set, "
7687 "resuming to collect trap\n",
7688 target_pid_to_str (tp->ptid));
7690 /* We haven't yet gotten our trap, and either: intercepted a
7691 non-signal event (e.g., a fork); or took a signal which we
7692 are supposed to pass through to the inferior. Simply
7694 resume (ecs->event_thread->suspend.stop_signal);
7696 else if (step_over_info_valid_p ())
7698 /* Another thread is stepping over a breakpoint in-line. If
7699 this thread needs a step-over too, queue the request. In
7700 either case, this resume must be deferred for later. */
7701 struct thread_info *tp = ecs->event_thread;
7703 if (ecs->hit_singlestep_breakpoint
7704 || thread_still_needs_step_over (tp))
7707 fprintf_unfiltered (gdb_stdlog,
7708 "infrun: step-over already in progress: "
7709 "step-over for %s deferred\n",
7710 target_pid_to_str (tp->ptid));
7711 thread_step_over_chain_enqueue (tp);
7716 fprintf_unfiltered (gdb_stdlog,
7717 "infrun: step-over in progress: "
7718 "resume of %s deferred\n",
7719 target_pid_to_str (tp->ptid));
7724 struct regcache *regcache = get_current_regcache ();
7727 step_over_what step_what;
7729 /* Either the trap was not expected, but we are continuing
7730 anyway (if we got a signal, the user asked it be passed to
7733 We got our expected trap, but decided we should resume from
7736 We're going to run this baby now!
7738 Note that insert_breakpoints won't try to re-insert
7739 already inserted breakpoints. Therefore, we don't
7740 care if breakpoints were already inserted, or not. */
7742 /* If we need to step over a breakpoint, and we're not using
7743 displaced stepping to do so, insert all breakpoints
7744 (watchpoints, etc.) but the one we're stepping over, step one
7745 instruction, and then re-insert the breakpoint when that step
7748 step_what = thread_still_needs_step_over (ecs->event_thread);
7750 remove_bp = (ecs->hit_singlestep_breakpoint
7751 || (step_what & STEP_OVER_BREAKPOINT));
7752 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7754 /* We can't use displaced stepping if we need to step past a
7755 watchpoint. The instruction copied to the scratch pad would
7756 still trigger the watchpoint. */
7758 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7760 set_step_over_info (regcache->aspace (),
7761 regcache_read_pc (regcache), remove_wps,
7762 ecs->event_thread->global_num);
7764 else if (remove_wps)
7765 set_step_over_info (NULL, 0, remove_wps, -1);
7767 /* If we now need to do an in-line step-over, we need to stop
7768 all other threads. Note this must be done before
7769 insert_breakpoints below, because that removes the breakpoint
7770 we're about to step over, otherwise other threads could miss
7772 if (step_over_info_valid_p () && target_is_non_stop_p ())
7773 stop_all_threads ();
7775 /* Stop stepping if inserting breakpoints fails. */
7778 insert_breakpoints ();
7780 CATCH (e, RETURN_MASK_ERROR)
7782 exception_print (gdb_stderr, e);
7784 clear_step_over_info ();
7789 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7791 resume (ecs->event_thread->suspend.stop_signal);
7794 prepare_to_wait (ecs);
7797 /* Called when we should continue running the inferior, because the
7798 current event doesn't cause a user visible stop. This does the
7799 resuming part; waiting for the next event is done elsewhere. */
7802 keep_going (struct execution_control_state *ecs)
7804 if (ecs->event_thread->control.trap_expected
7805 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7806 ecs->event_thread->control.trap_expected = 0;
7808 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7809 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7810 keep_going_pass_signal (ecs);
7813 /* This function normally comes after a resume, before
7814 handle_inferior_event exits. It takes care of any last bits of
7815 housekeeping, and sets the all-important wait_some_more flag. */
7818 prepare_to_wait (struct execution_control_state *ecs)
7821 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7823 ecs->wait_some_more = 1;
7825 if (!target_is_async_p ())
7826 mark_infrun_async_event_handler ();
7829 /* We are done with the step range of a step/next/si/ni command.
7830 Called once for each n of a "step n" operation. */
7833 end_stepping_range (struct execution_control_state *ecs)
7835 ecs->event_thread->control.stop_step = 1;
7839 /* Several print_*_reason functions to print why the inferior has stopped.
7840 We always print something when the inferior exits, or receives a signal.
7841 The rest of the cases are dealt with later on in normal_stop and
7842 print_it_typical. Ideally there should be a call to one of these
7843 print_*_reason functions functions from handle_inferior_event each time
7844 stop_waiting is called.
7846 Note that we don't call these directly, instead we delegate that to
7847 the interpreters, through observers. Interpreters then call these
7848 with whatever uiout is right. */
7851 print_end_stepping_range_reason (struct ui_out *uiout)
7853 /* For CLI-like interpreters, print nothing. */
7855 if (uiout->is_mi_like_p ())
7857 uiout->field_string ("reason",
7858 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7863 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7865 annotate_signalled ();
7866 if (uiout->is_mi_like_p ())
7868 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7869 uiout->text ("\nProgram terminated with signal ");
7870 annotate_signal_name ();
7871 uiout->field_string ("signal-name",
7872 gdb_signal_to_name (siggnal));
7873 annotate_signal_name_end ();
7875 annotate_signal_string ();
7876 uiout->field_string ("signal-meaning",
7877 gdb_signal_to_string (siggnal));
7878 annotate_signal_string_end ();
7879 uiout->text (".\n");
7880 uiout->text ("The program no longer exists.\n");
7884 print_exited_reason (struct ui_out *uiout, int exitstatus)
7886 struct inferior *inf = current_inferior ();
7887 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7889 annotate_exited (exitstatus);
7892 if (uiout->is_mi_like_p ())
7893 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7894 uiout->text ("[Inferior ");
7895 uiout->text (plongest (inf->num));
7897 uiout->text (pidstr);
7898 uiout->text (") exited with code ");
7899 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7900 uiout->text ("]\n");
7904 if (uiout->is_mi_like_p ())
7906 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7907 uiout->text ("[Inferior ");
7908 uiout->text (plongest (inf->num));
7910 uiout->text (pidstr);
7911 uiout->text (") exited normally]\n");
7915 /* Some targets/architectures can do extra processing/display of
7916 segmentation faults. E.g., Intel MPX boundary faults.
7917 Call the architecture dependent function to handle the fault. */
7920 handle_segmentation_fault (struct ui_out *uiout)
7922 struct regcache *regcache = get_current_regcache ();
7923 struct gdbarch *gdbarch = regcache->arch ();
7925 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7926 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7930 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7932 struct thread_info *thr = inferior_thread ();
7936 if (uiout->is_mi_like_p ())
7938 else if (show_thread_that_caused_stop ())
7942 uiout->text ("\nThread ");
7943 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7945 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7948 uiout->text (" \"");
7949 uiout->field_fmt ("name", "%s", name);
7954 uiout->text ("\nProgram");
7956 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7957 uiout->text (" stopped");
7960 uiout->text (" received signal ");
7961 annotate_signal_name ();
7962 if (uiout->is_mi_like_p ())
7964 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7965 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7966 annotate_signal_name_end ();
7968 annotate_signal_string ();
7969 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7971 if (siggnal == GDB_SIGNAL_SEGV)
7972 handle_segmentation_fault (uiout);
7974 annotate_signal_string_end ();
7976 uiout->text (".\n");
7980 print_no_history_reason (struct ui_out *uiout)
7982 uiout->text ("\nNo more reverse-execution history.\n");
7985 /* Print current location without a level number, if we have changed
7986 functions or hit a breakpoint. Print source line if we have one.
7987 bpstat_print contains the logic deciding in detail what to print,
7988 based on the event(s) that just occurred. */
7991 print_stop_location (struct target_waitstatus *ws)
7994 enum print_what source_flag;
7995 int do_frame_printing = 1;
7996 struct thread_info *tp = inferior_thread ();
7998 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8002 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8003 should) carry around the function and does (or should) use
8004 that when doing a frame comparison. */
8005 if (tp->control.stop_step
8006 && frame_id_eq (tp->control.step_frame_id,
8007 get_frame_id (get_current_frame ()))
8008 && (tp->control.step_start_function
8009 == find_pc_function (tp->suspend.stop_pc)))
8011 /* Finished step, just print source line. */
8012 source_flag = SRC_LINE;
8016 /* Print location and source line. */
8017 source_flag = SRC_AND_LOC;
8020 case PRINT_SRC_AND_LOC:
8021 /* Print location and source line. */
8022 source_flag = SRC_AND_LOC;
8024 case PRINT_SRC_ONLY:
8025 source_flag = SRC_LINE;
8028 /* Something bogus. */
8029 source_flag = SRC_LINE;
8030 do_frame_printing = 0;
8033 internal_error (__FILE__, __LINE__, _("Unknown value."));
8036 /* The behavior of this routine with respect to the source
8038 SRC_LINE: Print only source line
8039 LOCATION: Print only location
8040 SRC_AND_LOC: Print location and source line. */
8041 if (do_frame_printing)
8042 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8048 print_stop_event (struct ui_out *uiout)
8050 struct target_waitstatus last;
8052 struct thread_info *tp;
8054 get_last_target_status (&last_ptid, &last);
8057 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8059 print_stop_location (&last);
8061 /* Display the auto-display expressions. */
8065 tp = inferior_thread ();
8066 if (tp->thread_fsm != NULL
8067 && thread_fsm_finished_p (tp->thread_fsm))
8069 struct return_value_info *rv;
8071 rv = thread_fsm_return_value (tp->thread_fsm);
8073 print_return_value (uiout, rv);
8080 maybe_remove_breakpoints (void)
8082 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8084 if (remove_breakpoints ())
8086 target_terminal::ours_for_output ();
8087 printf_filtered (_("Cannot remove breakpoints because "
8088 "program is no longer writable.\nFurther "
8089 "execution is probably impossible.\n"));
8094 /* The execution context that just caused a normal stop. */
8101 /* The event PTID. */
8105 /* If stopp for a thread event, this is the thread that caused the
8107 struct thread_info *thread;
8109 /* The inferior that caused the stop. */
8113 /* Returns a new stop context. If stopped for a thread event, this
8114 takes a strong reference to the thread. */
8116 static struct stop_context *
8117 save_stop_context (void)
8119 struct stop_context *sc = XNEW (struct stop_context);
8121 sc->stop_id = get_stop_id ();
8122 sc->ptid = inferior_ptid;
8123 sc->inf_num = current_inferior ()->num;
8125 if (inferior_ptid != null_ptid)
8127 /* Take a strong reference so that the thread can't be deleted
8129 sc->thread = inferior_thread ();
8130 sc->thread->incref ();
8138 /* Release a stop context previously created with save_stop_context.
8139 Releases the strong reference to the thread as well. */
8142 release_stop_context_cleanup (void *arg)
8144 struct stop_context *sc = (struct stop_context *) arg;
8146 if (sc->thread != NULL)
8147 sc->thread->decref ();
8151 /* Return true if the current context no longer matches the saved stop
8155 stop_context_changed (struct stop_context *prev)
8157 if (prev->ptid != inferior_ptid)
8159 if (prev->inf_num != current_inferior ()->num)
8161 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8163 if (get_stop_id () != prev->stop_id)
8173 struct target_waitstatus last;
8176 get_last_target_status (&last_ptid, &last);
8180 /* If an exception is thrown from this point on, make sure to
8181 propagate GDB's knowledge of the executing state to the
8182 frontend/user running state. A QUIT is an easy exception to see
8183 here, so do this before any filtered output. */
8185 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
8188 maybe_finish_thread_state.emplace (minus_one_ptid);
8189 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8190 || last.kind == TARGET_WAITKIND_EXITED)
8192 /* On some targets, we may still have live threads in the
8193 inferior when we get a process exit event. E.g., for
8194 "checkpoint", when the current checkpoint/fork exits,
8195 linux-fork.c automatically switches to another fork from
8196 within target_mourn_inferior. */
8197 if (inferior_ptid != null_ptid)
8198 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8200 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8201 maybe_finish_thread_state.emplace (inferior_ptid);
8203 /* As we're presenting a stop, and potentially removing breakpoints,
8204 update the thread list so we can tell whether there are threads
8205 running on the target. With target remote, for example, we can
8206 only learn about new threads when we explicitly update the thread
8207 list. Do this before notifying the interpreters about signal
8208 stops, end of stepping ranges, etc., so that the "new thread"
8209 output is emitted before e.g., "Program received signal FOO",
8210 instead of after. */
8211 update_thread_list ();
8213 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8214 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8216 /* As with the notification of thread events, we want to delay
8217 notifying the user that we've switched thread context until
8218 the inferior actually stops.
8220 There's no point in saying anything if the inferior has exited.
8221 Note that SIGNALLED here means "exited with a signal", not
8222 "received a signal".
8224 Also skip saying anything in non-stop mode. In that mode, as we
8225 don't want GDB to switch threads behind the user's back, to avoid
8226 races where the user is typing a command to apply to thread x,
8227 but GDB switches to thread y before the user finishes entering
8228 the command, fetch_inferior_event installs a cleanup to restore
8229 the current thread back to the thread the user had selected right
8230 after this event is handled, so we're not really switching, only
8231 informing of a stop. */
8233 && previous_inferior_ptid != inferior_ptid
8234 && target_has_execution
8235 && last.kind != TARGET_WAITKIND_SIGNALLED
8236 && last.kind != TARGET_WAITKIND_EXITED
8237 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8239 SWITCH_THRU_ALL_UIS ()
8241 target_terminal::ours_for_output ();
8242 printf_filtered (_("[Switching to %s]\n"),
8243 target_pid_to_str (inferior_ptid));
8244 annotate_thread_changed ();
8246 previous_inferior_ptid = inferior_ptid;
8249 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8251 SWITCH_THRU_ALL_UIS ()
8252 if (current_ui->prompt_state == PROMPT_BLOCKED)
8254 target_terminal::ours_for_output ();
8255 printf_filtered (_("No unwaited-for children left.\n"));
8259 /* Note: this depends on the update_thread_list call above. */
8260 maybe_remove_breakpoints ();
8262 /* If an auto-display called a function and that got a signal,
8263 delete that auto-display to avoid an infinite recursion. */
8265 if (stopped_by_random_signal)
8266 disable_current_display ();
8268 SWITCH_THRU_ALL_UIS ()
8270 async_enable_stdin ();
8273 /* Let the user/frontend see the threads as stopped. */
8274 maybe_finish_thread_state.reset ();
8276 /* Select innermost stack frame - i.e., current frame is frame 0,
8277 and current location is based on that. Handle the case where the
8278 dummy call is returning after being stopped. E.g. the dummy call
8279 previously hit a breakpoint. (If the dummy call returns
8280 normally, we won't reach here.) Do this before the stop hook is
8281 run, so that it doesn't get to see the temporary dummy frame,
8282 which is not where we'll present the stop. */
8283 if (has_stack_frames ())
8285 if (stop_stack_dummy == STOP_STACK_DUMMY)
8287 /* Pop the empty frame that contains the stack dummy. This
8288 also restores inferior state prior to the call (struct
8289 infcall_suspend_state). */
8290 struct frame_info *frame = get_current_frame ();
8292 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8294 /* frame_pop calls reinit_frame_cache as the last thing it
8295 does which means there's now no selected frame. */
8298 select_frame (get_current_frame ());
8300 /* Set the current source location. */
8301 set_current_sal_from_frame (get_current_frame ());
8304 /* Look up the hook_stop and run it (CLI internally handles problem
8305 of stop_command's pre-hook not existing). */
8306 if (stop_command != NULL)
8308 struct stop_context *saved_context = save_stop_context ();
8309 struct cleanup *old_chain
8310 = make_cleanup (release_stop_context_cleanup, saved_context);
8314 execute_cmd_pre_hook (stop_command);
8316 CATCH (ex, RETURN_MASK_ALL)
8318 exception_fprintf (gdb_stderr, ex,
8319 "Error while running hook_stop:\n");
8323 /* If the stop hook resumes the target, then there's no point in
8324 trying to notify about the previous stop; its context is
8325 gone. Likewise if the command switches thread or inferior --
8326 the observers would print a stop for the wrong
8328 if (stop_context_changed (saved_context))
8330 do_cleanups (old_chain);
8333 do_cleanups (old_chain);
8336 /* Notify observers about the stop. This is where the interpreters
8337 print the stop event. */
8338 if (inferior_ptid != null_ptid)
8339 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8342 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8344 annotate_stopped ();
8346 if (target_has_execution)
8348 if (last.kind != TARGET_WAITKIND_SIGNALLED
8349 && last.kind != TARGET_WAITKIND_EXITED)
8350 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8351 Delete any breakpoint that is to be deleted at the next stop. */
8352 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8355 /* Try to get rid of automatically added inferiors that are no
8356 longer needed. Keeping those around slows down things linearly.
8357 Note that this never removes the current inferior. */
8364 signal_stop_state (int signo)
8366 return signal_stop[signo];
8370 signal_print_state (int signo)
8372 return signal_print[signo];
8376 signal_pass_state (int signo)
8378 return signal_program[signo];
8382 signal_cache_update (int signo)
8386 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8387 signal_cache_update (signo);
8392 signal_pass[signo] = (signal_stop[signo] == 0
8393 && signal_print[signo] == 0
8394 && signal_program[signo] == 1
8395 && signal_catch[signo] == 0);
8399 signal_stop_update (int signo, int state)
8401 int ret = signal_stop[signo];
8403 signal_stop[signo] = state;
8404 signal_cache_update (signo);
8409 signal_print_update (int signo, int state)
8411 int ret = signal_print[signo];
8413 signal_print[signo] = state;
8414 signal_cache_update (signo);
8419 signal_pass_update (int signo, int state)
8421 int ret = signal_program[signo];
8423 signal_program[signo] = state;
8424 signal_cache_update (signo);
8428 /* Update the global 'signal_catch' from INFO and notify the
8432 signal_catch_update (const unsigned int *info)
8436 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8437 signal_catch[i] = info[i] > 0;
8438 signal_cache_update (-1);
8439 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8443 sig_print_header (void)
8445 printf_filtered (_("Signal Stop\tPrint\tPass "
8446 "to program\tDescription\n"));
8450 sig_print_info (enum gdb_signal oursig)
8452 const char *name = gdb_signal_to_name (oursig);
8453 int name_padding = 13 - strlen (name);
8455 if (name_padding <= 0)
8458 printf_filtered ("%s", name);
8459 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8460 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8461 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8462 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8463 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8466 /* Specify how various signals in the inferior should be handled. */
8469 handle_command (const char *args, int from_tty)
8471 int digits, wordlen;
8472 int sigfirst, signum, siglast;
8473 enum gdb_signal oursig;
8476 unsigned char *sigs;
8480 error_no_arg (_("signal to handle"));
8483 /* Allocate and zero an array of flags for which signals to handle. */
8485 nsigs = (int) GDB_SIGNAL_LAST;
8486 sigs = (unsigned char *) alloca (nsigs);
8487 memset (sigs, 0, nsigs);
8489 /* Break the command line up into args. */
8491 gdb_argv built_argv (args);
8493 /* Walk through the args, looking for signal oursigs, signal names, and
8494 actions. Signal numbers and signal names may be interspersed with
8495 actions, with the actions being performed for all signals cumulatively
8496 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8498 for (char *arg : built_argv)
8500 wordlen = strlen (arg);
8501 for (digits = 0; isdigit (arg[digits]); digits++)
8505 sigfirst = siglast = -1;
8507 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8509 /* Apply action to all signals except those used by the
8510 debugger. Silently skip those. */
8513 siglast = nsigs - 1;
8515 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8517 SET_SIGS (nsigs, sigs, signal_stop);
8518 SET_SIGS (nsigs, sigs, signal_print);
8520 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8522 UNSET_SIGS (nsigs, sigs, signal_program);
8524 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8526 SET_SIGS (nsigs, sigs, signal_print);
8528 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8530 SET_SIGS (nsigs, sigs, signal_program);
8532 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8534 UNSET_SIGS (nsigs, sigs, signal_stop);
8536 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8538 SET_SIGS (nsigs, sigs, signal_program);
8540 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8542 UNSET_SIGS (nsigs, sigs, signal_print);
8543 UNSET_SIGS (nsigs, sigs, signal_stop);
8545 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8547 UNSET_SIGS (nsigs, sigs, signal_program);
8549 else if (digits > 0)
8551 /* It is numeric. The numeric signal refers to our own
8552 internal signal numbering from target.h, not to host/target
8553 signal number. This is a feature; users really should be
8554 using symbolic names anyway, and the common ones like
8555 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8557 sigfirst = siglast = (int)
8558 gdb_signal_from_command (atoi (arg));
8559 if (arg[digits] == '-')
8562 gdb_signal_from_command (atoi (arg + digits + 1));
8564 if (sigfirst > siglast)
8566 /* Bet he didn't figure we'd think of this case... */
8574 oursig = gdb_signal_from_name (arg);
8575 if (oursig != GDB_SIGNAL_UNKNOWN)
8577 sigfirst = siglast = (int) oursig;
8581 /* Not a number and not a recognized flag word => complain. */
8582 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8586 /* If any signal numbers or symbol names were found, set flags for
8587 which signals to apply actions to. */
8589 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8591 switch ((enum gdb_signal) signum)
8593 case GDB_SIGNAL_TRAP:
8594 case GDB_SIGNAL_INT:
8595 if (!allsigs && !sigs[signum])
8597 if (query (_("%s is used by the debugger.\n\
8598 Are you sure you want to change it? "),
8599 gdb_signal_to_name ((enum gdb_signal) signum)))
8605 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8606 gdb_flush (gdb_stdout);
8611 case GDB_SIGNAL_DEFAULT:
8612 case GDB_SIGNAL_UNKNOWN:
8613 /* Make sure that "all" doesn't print these. */
8622 for (signum = 0; signum < nsigs; signum++)
8625 signal_cache_update (-1);
8626 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8627 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8631 /* Show the results. */
8632 sig_print_header ();
8633 for (; signum < nsigs; signum++)
8635 sig_print_info ((enum gdb_signal) signum);
8642 /* Complete the "handle" command. */
8645 handle_completer (struct cmd_list_element *ignore,
8646 completion_tracker &tracker,
8647 const char *text, const char *word)
8649 static const char * const keywords[] =
8663 signal_completer (ignore, tracker, text, word);
8664 complete_on_enum (tracker, keywords, word, word);
8668 gdb_signal_from_command (int num)
8670 if (num >= 1 && num <= 15)
8671 return (enum gdb_signal) num;
8672 error (_("Only signals 1-15 are valid as numeric signals.\n\
8673 Use \"info signals\" for a list of symbolic signals."));
8676 /* Print current contents of the tables set by the handle command.
8677 It is possible we should just be printing signals actually used
8678 by the current target (but for things to work right when switching
8679 targets, all signals should be in the signal tables). */
8682 info_signals_command (const char *signum_exp, int from_tty)
8684 enum gdb_signal oursig;
8686 sig_print_header ();
8690 /* First see if this is a symbol name. */
8691 oursig = gdb_signal_from_name (signum_exp);
8692 if (oursig == GDB_SIGNAL_UNKNOWN)
8694 /* No, try numeric. */
8696 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8698 sig_print_info (oursig);
8702 printf_filtered ("\n");
8703 /* These ugly casts brought to you by the native VAX compiler. */
8704 for (oursig = GDB_SIGNAL_FIRST;
8705 (int) oursig < (int) GDB_SIGNAL_LAST;
8706 oursig = (enum gdb_signal) ((int) oursig + 1))
8710 if (oursig != GDB_SIGNAL_UNKNOWN
8711 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8712 sig_print_info (oursig);
8715 printf_filtered (_("\nUse the \"handle\" command "
8716 "to change these tables.\n"));
8719 /* The $_siginfo convenience variable is a bit special. We don't know
8720 for sure the type of the value until we actually have a chance to
8721 fetch the data. The type can change depending on gdbarch, so it is
8722 also dependent on which thread you have selected.
8724 1. making $_siginfo be an internalvar that creates a new value on
8727 2. making the value of $_siginfo be an lval_computed value. */
8729 /* This function implements the lval_computed support for reading a
8733 siginfo_value_read (struct value *v)
8735 LONGEST transferred;
8737 /* If we can access registers, so can we access $_siginfo. Likewise
8739 validate_registers_access ();
8742 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO,
8744 value_contents_all_raw (v),
8746 TYPE_LENGTH (value_type (v)));
8748 if (transferred != TYPE_LENGTH (value_type (v)))
8749 error (_("Unable to read siginfo"));
8752 /* This function implements the lval_computed support for writing a
8756 siginfo_value_write (struct value *v, struct value *fromval)
8758 LONGEST transferred;
8760 /* If we can access registers, so can we access $_siginfo. Likewise
8762 validate_registers_access ();
8764 transferred = target_write (current_top_target (),
8765 TARGET_OBJECT_SIGNAL_INFO,
8767 value_contents_all_raw (fromval),
8769 TYPE_LENGTH (value_type (fromval)));
8771 if (transferred != TYPE_LENGTH (value_type (fromval)))
8772 error (_("Unable to write siginfo"));
8775 static const struct lval_funcs siginfo_value_funcs =
8781 /* Return a new value with the correct type for the siginfo object of
8782 the current thread using architecture GDBARCH. Return a void value
8783 if there's no object available. */
8785 static struct value *
8786 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8789 if (target_has_stack
8790 && inferior_ptid != null_ptid
8791 && gdbarch_get_siginfo_type_p (gdbarch))
8793 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8795 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8798 return allocate_value (builtin_type (gdbarch)->builtin_void);
8802 /* infcall_suspend_state contains state about the program itself like its
8803 registers and any signal it received when it last stopped.
8804 This state must be restored regardless of how the inferior function call
8805 ends (either successfully, or after it hits a breakpoint or signal)
8806 if the program is to properly continue where it left off. */
8808 struct infcall_suspend_state
8810 struct thread_suspend_state thread_suspend;
8813 std::unique_ptr<readonly_detached_regcache> registers;
8815 /* Format of SIGINFO_DATA or NULL if it is not present. */
8816 struct gdbarch *siginfo_gdbarch = nullptr;
8818 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8819 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8820 content would be invalid. */
8821 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8824 struct infcall_suspend_state *
8825 save_infcall_suspend_state (void)
8827 struct infcall_suspend_state *inf_state;
8828 struct thread_info *tp = inferior_thread ();
8829 struct regcache *regcache = get_current_regcache ();
8830 struct gdbarch *gdbarch = regcache->arch ();
8831 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8833 if (gdbarch_get_siginfo_type_p (gdbarch))
8835 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8836 size_t len = TYPE_LENGTH (type);
8838 siginfo_data.reset ((gdb_byte *) xmalloc (len));
8840 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8841 siginfo_data.get (), 0, len) != len)
8843 /* Errors ignored. */
8844 siginfo_data.reset (nullptr);
8848 inf_state = new struct infcall_suspend_state;
8852 inf_state->siginfo_gdbarch = gdbarch;
8853 inf_state->siginfo_data = std::move (siginfo_data);
8856 inf_state->thread_suspend = tp->suspend;
8858 /* run_inferior_call will not use the signal due to its `proceed' call with
8859 GDB_SIGNAL_0 anyway. */
8860 tp->suspend.stop_signal = GDB_SIGNAL_0;
8862 inf_state->registers.reset (new readonly_detached_regcache (*regcache));
8867 /* Restore inferior session state to INF_STATE. */
8870 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8872 struct thread_info *tp = inferior_thread ();
8873 struct regcache *regcache = get_current_regcache ();
8874 struct gdbarch *gdbarch = regcache->arch ();
8876 tp->suspend = inf_state->thread_suspend;
8878 if (inf_state->siginfo_gdbarch == gdbarch)
8880 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8882 /* Errors ignored. */
8883 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8884 inf_state->siginfo_data.get (), 0, TYPE_LENGTH (type));
8887 /* The inferior can be gone if the user types "print exit(0)"
8888 (and perhaps other times). */
8889 if (target_has_execution)
8890 /* NB: The register write goes through to the target. */
8891 regcache->restore (inf_state->registers.get ());
8893 discard_infcall_suspend_state (inf_state);
8897 do_restore_infcall_suspend_state_cleanup (void *state)
8899 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8903 make_cleanup_restore_infcall_suspend_state
8904 (struct infcall_suspend_state *inf_state)
8906 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8910 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8915 readonly_detached_regcache *
8916 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8918 return inf_state->registers.get ();
8921 /* infcall_control_state contains state regarding gdb's control of the
8922 inferior itself like stepping control. It also contains session state like
8923 the user's currently selected frame. */
8925 struct infcall_control_state
8927 struct thread_control_state thread_control;
8928 struct inferior_control_state inferior_control;
8931 enum stop_stack_kind stop_stack_dummy;
8932 int stopped_by_random_signal;
8934 /* ID if the selected frame when the inferior function call was made. */
8935 struct frame_id selected_frame_id;
8938 /* Save all of the information associated with the inferior<==>gdb
8941 struct infcall_control_state *
8942 save_infcall_control_state (void)
8944 struct infcall_control_state *inf_status =
8945 XNEW (struct infcall_control_state);
8946 struct thread_info *tp = inferior_thread ();
8947 struct inferior *inf = current_inferior ();
8949 inf_status->thread_control = tp->control;
8950 inf_status->inferior_control = inf->control;
8952 tp->control.step_resume_breakpoint = NULL;
8953 tp->control.exception_resume_breakpoint = NULL;
8955 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8956 chain. If caller's caller is walking the chain, they'll be happier if we
8957 hand them back the original chain when restore_infcall_control_state is
8959 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8962 inf_status->stop_stack_dummy = stop_stack_dummy;
8963 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8965 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8971 restore_selected_frame (const frame_id &fid)
8973 frame_info *frame = frame_find_by_id (fid);
8975 /* If inf_status->selected_frame_id is NULL, there was no previously
8979 warning (_("Unable to restore previously selected frame."));
8983 select_frame (frame);
8986 /* Restore inferior session state to INF_STATUS. */
8989 restore_infcall_control_state (struct infcall_control_state *inf_status)
8991 struct thread_info *tp = inferior_thread ();
8992 struct inferior *inf = current_inferior ();
8994 if (tp->control.step_resume_breakpoint)
8995 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8997 if (tp->control.exception_resume_breakpoint)
8998 tp->control.exception_resume_breakpoint->disposition
8999 = disp_del_at_next_stop;
9001 /* Handle the bpstat_copy of the chain. */
9002 bpstat_clear (&tp->control.stop_bpstat);
9004 tp->control = inf_status->thread_control;
9005 inf->control = inf_status->inferior_control;
9008 stop_stack_dummy = inf_status->stop_stack_dummy;
9009 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9011 if (target_has_stack)
9013 /* The point of the try/catch is that if the stack is clobbered,
9014 walking the stack might encounter a garbage pointer and
9015 error() trying to dereference it. */
9018 restore_selected_frame (inf_status->selected_frame_id);
9020 CATCH (ex, RETURN_MASK_ERROR)
9022 exception_fprintf (gdb_stderr, ex,
9023 "Unable to restore previously selected frame:\n");
9024 /* Error in restoring the selected frame. Select the
9026 select_frame (get_current_frame ());
9035 do_restore_infcall_control_state_cleanup (void *sts)
9037 restore_infcall_control_state ((struct infcall_control_state *) sts);
9041 make_cleanup_restore_infcall_control_state
9042 (struct infcall_control_state *inf_status)
9044 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9048 discard_infcall_control_state (struct infcall_control_state *inf_status)
9050 if (inf_status->thread_control.step_resume_breakpoint)
9051 inf_status->thread_control.step_resume_breakpoint->disposition
9052 = disp_del_at_next_stop;
9054 if (inf_status->thread_control.exception_resume_breakpoint)
9055 inf_status->thread_control.exception_resume_breakpoint->disposition
9056 = disp_del_at_next_stop;
9058 /* See save_infcall_control_state for info on stop_bpstat. */
9059 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9067 clear_exit_convenience_vars (void)
9069 clear_internalvar (lookup_internalvar ("_exitsignal"));
9070 clear_internalvar (lookup_internalvar ("_exitcode"));
9074 /* User interface for reverse debugging:
9075 Set exec-direction / show exec-direction commands
9076 (returns error unless target implements to_set_exec_direction method). */
9078 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9079 static const char exec_forward[] = "forward";
9080 static const char exec_reverse[] = "reverse";
9081 static const char *exec_direction = exec_forward;
9082 static const char *const exec_direction_names[] = {
9089 set_exec_direction_func (const char *args, int from_tty,
9090 struct cmd_list_element *cmd)
9092 if (target_can_execute_reverse)
9094 if (!strcmp (exec_direction, exec_forward))
9095 execution_direction = EXEC_FORWARD;
9096 else if (!strcmp (exec_direction, exec_reverse))
9097 execution_direction = EXEC_REVERSE;
9101 exec_direction = exec_forward;
9102 error (_("Target does not support this operation."));
9107 show_exec_direction_func (struct ui_file *out, int from_tty,
9108 struct cmd_list_element *cmd, const char *value)
9110 switch (execution_direction) {
9112 fprintf_filtered (out, _("Forward.\n"));
9115 fprintf_filtered (out, _("Reverse.\n"));
9118 internal_error (__FILE__, __LINE__,
9119 _("bogus execution_direction value: %d"),
9120 (int) execution_direction);
9125 show_schedule_multiple (struct ui_file *file, int from_tty,
9126 struct cmd_list_element *c, const char *value)
9128 fprintf_filtered (file, _("Resuming the execution of threads "
9129 "of all processes is %s.\n"), value);
9132 /* Implementation of `siginfo' variable. */
9134 static const struct internalvar_funcs siginfo_funcs =
9141 /* Callback for infrun's target events source. This is marked when a
9142 thread has a pending status to process. */
9145 infrun_async_inferior_event_handler (gdb_client_data data)
9147 inferior_event_handler (INF_REG_EVENT, NULL);
9151 _initialize_infrun (void)
9155 struct cmd_list_element *c;
9157 /* Register extra event sources in the event loop. */
9158 infrun_async_inferior_event_token
9159 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9161 add_info ("signals", info_signals_command, _("\
9162 What debugger does when program gets various signals.\n\
9163 Specify a signal as argument to print info on that signal only."));
9164 add_info_alias ("handle", "signals", 0);
9166 c = add_com ("handle", class_run, handle_command, _("\
9167 Specify how to handle signals.\n\
9168 Usage: handle SIGNAL [ACTIONS]\n\
9169 Args are signals and actions to apply to those signals.\n\
9170 If no actions are specified, the current settings for the specified signals\n\
9171 will be displayed instead.\n\
9173 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9174 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9175 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9176 The special arg \"all\" is recognized to mean all signals except those\n\
9177 used by the debugger, typically SIGTRAP and SIGINT.\n\
9179 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9180 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9181 Stop means reenter debugger if this signal happens (implies print).\n\
9182 Print means print a message if this signal happens.\n\
9183 Pass means let program see this signal; otherwise program doesn't know.\n\
9184 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9185 Pass and Stop may be combined.\n\
9187 Multiple signals may be specified. Signal numbers and signal names\n\
9188 may be interspersed with actions, with the actions being performed for\n\
9189 all signals cumulatively specified."));
9190 set_cmd_completer (c, handle_completer);
9193 stop_command = add_cmd ("stop", class_obscure,
9194 not_just_help_class_command, _("\
9195 There is no `stop' command, but you can set a hook on `stop'.\n\
9196 This allows you to set a list of commands to be run each time execution\n\
9197 of the program stops."), &cmdlist);
9199 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9200 Set inferior debugging."), _("\
9201 Show inferior debugging."), _("\
9202 When non-zero, inferior specific debugging is enabled."),
9205 &setdebuglist, &showdebuglist);
9207 add_setshow_boolean_cmd ("displaced", class_maintenance,
9208 &debug_displaced, _("\
9209 Set displaced stepping debugging."), _("\
9210 Show displaced stepping debugging."), _("\
9211 When non-zero, displaced stepping specific debugging is enabled."),
9213 show_debug_displaced,
9214 &setdebuglist, &showdebuglist);
9216 add_setshow_boolean_cmd ("non-stop", no_class,
9218 Set whether gdb controls the inferior in non-stop mode."), _("\
9219 Show whether gdb controls the inferior in non-stop mode."), _("\
9220 When debugging a multi-threaded program and this setting is\n\
9221 off (the default, also called all-stop mode), when one thread stops\n\
9222 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9223 all other threads in the program while you interact with the thread of\n\
9224 interest. When you continue or step a thread, you can allow the other\n\
9225 threads to run, or have them remain stopped, but while you inspect any\n\
9226 thread's state, all threads stop.\n\
9228 In non-stop mode, when one thread stops, other threads can continue\n\
9229 to run freely. You'll be able to step each thread independently,\n\
9230 leave it stopped or free to run as needed."),
9236 numsigs = (int) GDB_SIGNAL_LAST;
9237 signal_stop = XNEWVEC (unsigned char, numsigs);
9238 signal_print = XNEWVEC (unsigned char, numsigs);
9239 signal_program = XNEWVEC (unsigned char, numsigs);
9240 signal_catch = XNEWVEC (unsigned char, numsigs);
9241 signal_pass = XNEWVEC (unsigned char, numsigs);
9242 for (i = 0; i < numsigs; i++)
9245 signal_print[i] = 1;
9246 signal_program[i] = 1;
9247 signal_catch[i] = 0;
9250 /* Signals caused by debugger's own actions should not be given to
9251 the program afterwards.
9253 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9254 explicitly specifies that it should be delivered to the target
9255 program. Typically, that would occur when a user is debugging a
9256 target monitor on a simulator: the target monitor sets a
9257 breakpoint; the simulator encounters this breakpoint and halts
9258 the simulation handing control to GDB; GDB, noting that the stop
9259 address doesn't map to any known breakpoint, returns control back
9260 to the simulator; the simulator then delivers the hardware
9261 equivalent of a GDB_SIGNAL_TRAP to the program being
9263 signal_program[GDB_SIGNAL_TRAP] = 0;
9264 signal_program[GDB_SIGNAL_INT] = 0;
9266 /* Signals that are not errors should not normally enter the debugger. */
9267 signal_stop[GDB_SIGNAL_ALRM] = 0;
9268 signal_print[GDB_SIGNAL_ALRM] = 0;
9269 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9270 signal_print[GDB_SIGNAL_VTALRM] = 0;
9271 signal_stop[GDB_SIGNAL_PROF] = 0;
9272 signal_print[GDB_SIGNAL_PROF] = 0;
9273 signal_stop[GDB_SIGNAL_CHLD] = 0;
9274 signal_print[GDB_SIGNAL_CHLD] = 0;
9275 signal_stop[GDB_SIGNAL_IO] = 0;
9276 signal_print[GDB_SIGNAL_IO] = 0;
9277 signal_stop[GDB_SIGNAL_POLL] = 0;
9278 signal_print[GDB_SIGNAL_POLL] = 0;
9279 signal_stop[GDB_SIGNAL_URG] = 0;
9280 signal_print[GDB_SIGNAL_URG] = 0;
9281 signal_stop[GDB_SIGNAL_WINCH] = 0;
9282 signal_print[GDB_SIGNAL_WINCH] = 0;
9283 signal_stop[GDB_SIGNAL_PRIO] = 0;
9284 signal_print[GDB_SIGNAL_PRIO] = 0;
9286 /* These signals are used internally by user-level thread
9287 implementations. (See signal(5) on Solaris.) Like the above
9288 signals, a healthy program receives and handles them as part of
9289 its normal operation. */
9290 signal_stop[GDB_SIGNAL_LWP] = 0;
9291 signal_print[GDB_SIGNAL_LWP] = 0;
9292 signal_stop[GDB_SIGNAL_WAITING] = 0;
9293 signal_print[GDB_SIGNAL_WAITING] = 0;
9294 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9295 signal_print[GDB_SIGNAL_CANCEL] = 0;
9296 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9297 signal_print[GDB_SIGNAL_LIBRT] = 0;
9299 /* Update cached state. */
9300 signal_cache_update (-1);
9302 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9303 &stop_on_solib_events, _("\
9304 Set stopping for shared library events."), _("\
9305 Show stopping for shared library events."), _("\
9306 If nonzero, gdb will give control to the user when the dynamic linker\n\
9307 notifies gdb of shared library events. The most common event of interest\n\
9308 to the user would be loading/unloading of a new library."),
9309 set_stop_on_solib_events,
9310 show_stop_on_solib_events,
9311 &setlist, &showlist);
9313 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9314 follow_fork_mode_kind_names,
9315 &follow_fork_mode_string, _("\
9316 Set debugger response to a program call of fork or vfork."), _("\
9317 Show debugger response to a program call of fork or vfork."), _("\
9318 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9319 parent - the original process is debugged after a fork\n\
9320 child - the new process is debugged after a fork\n\
9321 The unfollowed process will continue to run.\n\
9322 By default, the debugger will follow the parent process."),
9324 show_follow_fork_mode_string,
9325 &setlist, &showlist);
9327 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9328 follow_exec_mode_names,
9329 &follow_exec_mode_string, _("\
9330 Set debugger response to a program call of exec."), _("\
9331 Show debugger response to a program call of exec."), _("\
9332 An exec call replaces the program image of a process.\n\
9334 follow-exec-mode can be:\n\
9336 new - the debugger creates a new inferior and rebinds the process\n\
9337 to this new inferior. The program the process was running before\n\
9338 the exec call can be restarted afterwards by restarting the original\n\
9341 same - the debugger keeps the process bound to the same inferior.\n\
9342 The new executable image replaces the previous executable loaded in\n\
9343 the inferior. Restarting the inferior after the exec call restarts\n\
9344 the executable the process was running after the exec call.\n\
9346 By default, the debugger will use the same inferior."),
9348 show_follow_exec_mode_string,
9349 &setlist, &showlist);
9351 add_setshow_enum_cmd ("scheduler-locking", class_run,
9352 scheduler_enums, &scheduler_mode, _("\
9353 Set mode for locking scheduler during execution."), _("\
9354 Show mode for locking scheduler during execution."), _("\
9355 off == no locking (threads may preempt at any time)\n\
9356 on == full locking (no thread except the current thread may run)\n\
9357 This applies to both normal execution and replay mode.\n\
9358 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9359 In this mode, other threads may run during other commands.\n\
9360 This applies to both normal execution and replay mode.\n\
9361 replay == scheduler locked in replay mode and unlocked during normal execution."),
9362 set_schedlock_func, /* traps on target vector */
9363 show_scheduler_mode,
9364 &setlist, &showlist);
9366 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9367 Set mode for resuming threads of all processes."), _("\
9368 Show mode for resuming threads of all processes."), _("\
9369 When on, execution commands (such as 'continue' or 'next') resume all\n\
9370 threads of all processes. When off (which is the default), execution\n\
9371 commands only resume the threads of the current process. The set of\n\
9372 threads that are resumed is further refined by the scheduler-locking\n\
9373 mode (see help set scheduler-locking)."),
9375 show_schedule_multiple,
9376 &setlist, &showlist);
9378 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9379 Set mode of the step operation."), _("\
9380 Show mode of the step operation."), _("\
9381 When set, doing a step over a function without debug line information\n\
9382 will stop at the first instruction of that function. Otherwise, the\n\
9383 function is skipped and the step command stops at a different source line."),
9385 show_step_stop_if_no_debug,
9386 &setlist, &showlist);
9388 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9389 &can_use_displaced_stepping, _("\
9390 Set debugger's willingness to use displaced stepping."), _("\
9391 Show debugger's willingness to use displaced stepping."), _("\
9392 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9393 supported by the target architecture. If off, gdb will not use displaced\n\
9394 stepping to step over breakpoints, even if such is supported by the target\n\
9395 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9396 if the target architecture supports it and non-stop mode is active, but will not\n\
9397 use it in all-stop mode (see help set non-stop)."),
9399 show_can_use_displaced_stepping,
9400 &setlist, &showlist);
9402 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9403 &exec_direction, _("Set direction of execution.\n\
9404 Options are 'forward' or 'reverse'."),
9405 _("Show direction of execution (forward/reverse)."),
9406 _("Tells gdb whether to execute forward or backward."),
9407 set_exec_direction_func, show_exec_direction_func,
9408 &setlist, &showlist);
9410 /* Set/show detach-on-fork: user-settable mode. */
9412 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9413 Set whether gdb will detach the child of a fork."), _("\
9414 Show whether gdb will detach the child of a fork."), _("\
9415 Tells gdb whether to detach the child of a fork."),
9416 NULL, NULL, &setlist, &showlist);
9418 /* Set/show disable address space randomization mode. */
9420 add_setshow_boolean_cmd ("disable-randomization", class_support,
9421 &disable_randomization, _("\
9422 Set disabling of debuggee's virtual address space randomization."), _("\
9423 Show disabling of debuggee's virtual address space randomization."), _("\
9424 When this mode is on (which is the default), randomization of the virtual\n\
9425 address space is disabled. Standalone programs run with the randomization\n\
9426 enabled by default on some platforms."),
9427 &set_disable_randomization,
9428 &show_disable_randomization,
9429 &setlist, &showlist);
9431 /* ptid initializations */
9432 inferior_ptid = null_ptid;
9433 target_last_wait_ptid = minus_one_ptid;
9435 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9436 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9437 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9438 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9440 /* Explicitly create without lookup, since that tries to create a
9441 value with a void typed value, and when we get here, gdbarch
9442 isn't initialized yet. At this point, we're quite sure there
9443 isn't another convenience variable of the same name. */
9444 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9446 add_setshow_boolean_cmd ("observer", no_class,
9447 &observer_mode_1, _("\
9448 Set whether gdb controls the inferior in observer mode."), _("\
9449 Show whether gdb controls the inferior in observer mode."), _("\
9450 In observer mode, GDB can get data from the inferior, but not\n\
9451 affect its execution. Registers and memory may not be changed,\n\
9452 breakpoints may not be set, and the program cannot be interrupted\n\