1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2017 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"
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 info_signals_command (char *, int);
75 static void handle_command (char *, int);
77 static void sig_print_info (enum gdb_signal);
79 static void sig_print_header (void);
81 static void resume_cleanups (void *);
83 static int follow_fork (void);
85 static int follow_fork_inferior (int follow_child, int detach_fork);
87 static void follow_inferior_reset_breakpoints (void);
89 static void set_schedlock_func (char *args, int from_tty,
90 struct cmd_list_element *c);
92 static int currently_stepping (struct thread_info *tp);
94 void nullify_last_target_wait_ptid (void);
96 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
98 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
100 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
102 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
104 /* Asynchronous signal handler registered as event loop source for
105 when we have pending events ready to be passed to the core. */
106 static struct async_event_handler *infrun_async_inferior_event_token;
108 /* Stores whether infrun_async was previously enabled or disabled.
109 Starts off as -1, indicating "never enabled/disabled". */
110 static int infrun_is_async = -1;
115 infrun_async (int enable)
117 if (infrun_is_async != enable)
119 infrun_is_async = enable;
122 fprintf_unfiltered (gdb_stdlog,
123 "infrun: infrun_async(%d)\n",
127 mark_async_event_handler (infrun_async_inferior_event_token);
129 clear_async_event_handler (infrun_async_inferior_event_token);
136 mark_infrun_async_event_handler (void)
138 mark_async_event_handler (infrun_async_inferior_event_token);
141 /* When set, stop the 'step' command if we enter a function which has
142 no line number information. The normal behavior is that we step
143 over such function. */
144 int step_stop_if_no_debug = 0;
146 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
147 struct cmd_list_element *c, const char *value)
149 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
152 /* proceed and normal_stop use this to notify the user when the
153 inferior stopped in a different thread than it had been running
156 static ptid_t previous_inferior_ptid;
158 /* If set (default for legacy reasons), when following a fork, GDB
159 will detach from one of the fork branches, child or parent.
160 Exactly which branch is detached depends on 'set follow-fork-mode'
163 static int detach_fork = 1;
165 int debug_displaced = 0;
167 show_debug_displaced (struct ui_file *file, int from_tty,
168 struct cmd_list_element *c, const char *value)
170 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
173 unsigned int debug_infrun = 0;
175 show_debug_infrun (struct ui_file *file, int from_tty,
176 struct cmd_list_element *c, const char *value)
178 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
182 /* Support for disabling address space randomization. */
184 int disable_randomization = 1;
187 show_disable_randomization (struct ui_file *file, int from_tty,
188 struct cmd_list_element *c, const char *value)
190 if (target_supports_disable_randomization ())
191 fprintf_filtered (file,
192 _("Disabling randomization of debuggee's "
193 "virtual address space is %s.\n"),
196 fputs_filtered (_("Disabling randomization of debuggee's "
197 "virtual address space is unsupported on\n"
198 "this platform.\n"), file);
202 set_disable_randomization (char *args, int from_tty,
203 struct cmd_list_element *c)
205 if (!target_supports_disable_randomization ())
206 error (_("Disabling randomization of debuggee's "
207 "virtual address space is unsupported on\n"
211 /* User interface for non-stop mode. */
214 static int non_stop_1 = 0;
217 set_non_stop (char *args, int from_tty,
218 struct cmd_list_element *c)
220 if (target_has_execution)
222 non_stop_1 = non_stop;
223 error (_("Cannot change this setting while the inferior is running."));
226 non_stop = non_stop_1;
230 show_non_stop (struct ui_file *file, int from_tty,
231 struct cmd_list_element *c, const char *value)
233 fprintf_filtered (file,
234 _("Controlling the inferior in non-stop mode is %s.\n"),
238 /* "Observer mode" is somewhat like a more extreme version of
239 non-stop, in which all GDB operations that might affect the
240 target's execution have been disabled. */
242 int observer_mode = 0;
243 static int observer_mode_1 = 0;
246 set_observer_mode (char *args, int from_tty,
247 struct cmd_list_element *c)
249 if (target_has_execution)
251 observer_mode_1 = observer_mode;
252 error (_("Cannot change this setting while the inferior is running."));
255 observer_mode = observer_mode_1;
257 may_write_registers = !observer_mode;
258 may_write_memory = !observer_mode;
259 may_insert_breakpoints = !observer_mode;
260 may_insert_tracepoints = !observer_mode;
261 /* We can insert fast tracepoints in or out of observer mode,
262 but enable them if we're going into this mode. */
264 may_insert_fast_tracepoints = 1;
265 may_stop = !observer_mode;
266 update_target_permissions ();
268 /* Going *into* observer mode we must force non-stop, then
269 going out we leave it that way. */
272 pagination_enabled = 0;
273 non_stop = non_stop_1 = 1;
277 printf_filtered (_("Observer mode is now %s.\n"),
278 (observer_mode ? "on" : "off"));
282 show_observer_mode (struct ui_file *file, int from_tty,
283 struct cmd_list_element *c, const char *value)
285 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
288 /* This updates the value of observer mode based on changes in
289 permissions. Note that we are deliberately ignoring the values of
290 may-write-registers and may-write-memory, since the user may have
291 reason to enable these during a session, for instance to turn on a
292 debugging-related global. */
295 update_observer_mode (void)
299 newval = (!may_insert_breakpoints
300 && !may_insert_tracepoints
301 && may_insert_fast_tracepoints
305 /* Let the user know if things change. */
306 if (newval != observer_mode)
307 printf_filtered (_("Observer mode is now %s.\n"),
308 (newval ? "on" : "off"));
310 observer_mode = observer_mode_1 = newval;
313 /* Tables of how to react to signals; the user sets them. */
315 static unsigned char *signal_stop;
316 static unsigned char *signal_print;
317 static unsigned char *signal_program;
319 /* Table of signals that are registered with "catch signal". A
320 non-zero entry indicates that the signal is caught by some "catch
321 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
323 static unsigned char *signal_catch;
325 /* Table of signals that the target may silently handle.
326 This is automatically determined from the flags above,
327 and simply cached here. */
328 static unsigned char *signal_pass;
330 #define SET_SIGS(nsigs,sigs,flags) \
332 int signum = (nsigs); \
333 while (signum-- > 0) \
334 if ((sigs)[signum]) \
335 (flags)[signum] = 1; \
338 #define UNSET_SIGS(nsigs,sigs,flags) \
340 int signum = (nsigs); \
341 while (signum-- > 0) \
342 if ((sigs)[signum]) \
343 (flags)[signum] = 0; \
346 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
347 this function is to avoid exporting `signal_program'. */
350 update_signals_program_target (void)
352 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
355 /* Value to pass to target_resume() to cause all threads to resume. */
357 #define RESUME_ALL minus_one_ptid
359 /* Command list pointer for the "stop" placeholder. */
361 static struct cmd_list_element *stop_command;
363 /* Nonzero if we want to give control to the user when we're notified
364 of shared library events by the dynamic linker. */
365 int stop_on_solib_events;
367 /* Enable or disable optional shared library event breakpoints
368 as appropriate when the above flag is changed. */
371 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
373 update_solib_breakpoints ();
377 show_stop_on_solib_events (struct ui_file *file, int from_tty,
378 struct cmd_list_element *c, const char *value)
380 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
384 /* Nonzero after stop if current stack frame should be printed. */
386 static int stop_print_frame;
388 /* This is a cached copy of the pid/waitstatus of the last event
389 returned by target_wait()/deprecated_target_wait_hook(). This
390 information is returned by get_last_target_status(). */
391 static ptid_t target_last_wait_ptid;
392 static struct target_waitstatus target_last_waitstatus;
394 static void context_switch (ptid_t ptid);
396 void init_thread_stepping_state (struct thread_info *tss);
398 static const char follow_fork_mode_child[] = "child";
399 static const char follow_fork_mode_parent[] = "parent";
401 static const char *const follow_fork_mode_kind_names[] = {
402 follow_fork_mode_child,
403 follow_fork_mode_parent,
407 static const char *follow_fork_mode_string = follow_fork_mode_parent;
409 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
410 struct cmd_list_element *c, const char *value)
412 fprintf_filtered (file,
413 _("Debugger response to a program "
414 "call of fork or vfork is \"%s\".\n"),
419 /* Handle changes to the inferior list based on the type of fork,
420 which process is being followed, and whether the other process
421 should be detached. On entry inferior_ptid must be the ptid of
422 the fork parent. At return inferior_ptid is the ptid of the
423 followed inferior. */
426 follow_fork_inferior (int follow_child, int detach_fork)
429 ptid_t parent_ptid, child_ptid;
431 has_vforked = (inferior_thread ()->pending_follow.kind
432 == TARGET_WAITKIND_VFORKED);
433 parent_ptid = inferior_ptid;
434 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
437 && !non_stop /* Non-stop always resumes both branches. */
438 && current_ui->prompt_state == PROMPT_BLOCKED
439 && !(follow_child || detach_fork || sched_multi))
441 /* The parent stays blocked inside the vfork syscall until the
442 child execs or exits. If we don't let the child run, then
443 the parent stays blocked. If we're telling the parent to run
444 in the foreground, the user will not be able to ctrl-c to get
445 back the terminal, effectively hanging the debug session. */
446 fprintf_filtered (gdb_stderr, _("\
447 Can not resume the parent process over vfork in the foreground while\n\
448 holding the child stopped. Try \"set detach-on-fork\" or \
449 \"set schedule-multiple\".\n"));
450 /* FIXME output string > 80 columns. */
456 /* Detach new forked process? */
459 /* Before detaching from the child, remove all breakpoints
460 from it. If we forked, then this has already been taken
461 care of by infrun.c. If we vforked however, any
462 breakpoint inserted in the parent is visible in the
463 child, even those added while stopped in a vfork
464 catchpoint. This will remove the breakpoints from the
465 parent also, but they'll be reinserted below. */
468 /* Keep breakpoints list in sync. */
469 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
472 if (info_verbose || debug_infrun)
474 /* Ensure that we have a process ptid. */
475 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
477 target_terminal::ours_for_output ();
478 fprintf_filtered (gdb_stdlog,
479 _("Detaching after %s from child %s.\n"),
480 has_vforked ? "vfork" : "fork",
481 target_pid_to_str (process_ptid));
486 struct inferior *parent_inf, *child_inf;
488 /* Add process to GDB's tables. */
489 child_inf = add_inferior (ptid_get_pid (child_ptid));
491 parent_inf = current_inferior ();
492 child_inf->attach_flag = parent_inf->attach_flag;
493 copy_terminal_info (child_inf, parent_inf);
494 child_inf->gdbarch = parent_inf->gdbarch;
495 copy_inferior_target_desc_info (child_inf, parent_inf);
497 scoped_restore_current_pspace_and_thread restore_pspace_thread;
499 inferior_ptid = child_ptid;
500 add_thread (inferior_ptid);
501 set_current_inferior (child_inf);
502 child_inf->symfile_flags = SYMFILE_NO_READ;
504 /* If this is a vfork child, then the address-space is
505 shared with the parent. */
508 child_inf->pspace = parent_inf->pspace;
509 child_inf->aspace = parent_inf->aspace;
511 /* The parent will be frozen until the child is done
512 with the shared region. Keep track of the
514 child_inf->vfork_parent = parent_inf;
515 child_inf->pending_detach = 0;
516 parent_inf->vfork_child = child_inf;
517 parent_inf->pending_detach = 0;
521 child_inf->aspace = new_address_space ();
522 child_inf->pspace = add_program_space (child_inf->aspace);
523 child_inf->removable = 1;
524 set_current_program_space (child_inf->pspace);
525 clone_program_space (child_inf->pspace, parent_inf->pspace);
527 /* Let the shared library layer (e.g., solib-svr4) learn
528 about this new process, relocate the cloned exec, pull
529 in shared libraries, and install the solib event
530 breakpoint. If a "cloned-VM" event was propagated
531 better throughout the core, this wouldn't be
533 solib_create_inferior_hook (0);
539 struct inferior *parent_inf;
541 parent_inf = current_inferior ();
543 /* If we detached from the child, then we have to be careful
544 to not insert breakpoints in the parent until the child
545 is done with the shared memory region. However, if we're
546 staying attached to the child, then we can and should
547 insert breakpoints, so that we can debug it. A
548 subsequent child exec or exit is enough to know when does
549 the child stops using the parent's address space. */
550 parent_inf->waiting_for_vfork_done = detach_fork;
551 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
556 /* Follow the child. */
557 struct inferior *parent_inf, *child_inf;
558 struct program_space *parent_pspace;
560 if (info_verbose || debug_infrun)
562 target_terminal::ours_for_output ();
563 fprintf_filtered (gdb_stdlog,
564 _("Attaching after %s %s to child %s.\n"),
565 target_pid_to_str (parent_ptid),
566 has_vforked ? "vfork" : "fork",
567 target_pid_to_str (child_ptid));
570 /* Add the new inferior first, so that the target_detach below
571 doesn't unpush the target. */
573 child_inf = add_inferior (ptid_get_pid (child_ptid));
575 parent_inf = current_inferior ();
576 child_inf->attach_flag = parent_inf->attach_flag;
577 copy_terminal_info (child_inf, parent_inf);
578 child_inf->gdbarch = parent_inf->gdbarch;
579 copy_inferior_target_desc_info (child_inf, parent_inf);
581 parent_pspace = parent_inf->pspace;
583 /* If we're vforking, we want to hold on to the parent until the
584 child exits or execs. At child exec or exit time we can
585 remove the old breakpoints from the parent and detach or
586 resume debugging it. Otherwise, detach the parent now; we'll
587 want to reuse it's program/address spaces, but we can't set
588 them to the child before removing breakpoints from the
589 parent, otherwise, the breakpoints module could decide to
590 remove breakpoints from the wrong process (since they'd be
591 assigned to the same address space). */
595 gdb_assert (child_inf->vfork_parent == NULL);
596 gdb_assert (parent_inf->vfork_child == NULL);
597 child_inf->vfork_parent = parent_inf;
598 child_inf->pending_detach = 0;
599 parent_inf->vfork_child = child_inf;
600 parent_inf->pending_detach = detach_fork;
601 parent_inf->waiting_for_vfork_done = 0;
603 else if (detach_fork)
605 if (info_verbose || debug_infrun)
607 /* Ensure that we have a process ptid. */
608 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
610 target_terminal::ours_for_output ();
611 fprintf_filtered (gdb_stdlog,
612 _("Detaching after fork from "
614 target_pid_to_str (process_ptid));
617 target_detach (NULL, 0);
620 /* Note that the detach above makes PARENT_INF dangling. */
622 /* Add the child thread to the appropriate lists, and switch to
623 this new thread, before cloning the program space, and
624 informing the solib layer about this new process. */
626 inferior_ptid = child_ptid;
627 add_thread (inferior_ptid);
628 set_current_inferior (child_inf);
630 /* If this is a vfork child, then the address-space is shared
631 with the parent. If we detached from the parent, then we can
632 reuse the parent's program/address spaces. */
633 if (has_vforked || detach_fork)
635 child_inf->pspace = parent_pspace;
636 child_inf->aspace = child_inf->pspace->aspace;
640 child_inf->aspace = new_address_space ();
641 child_inf->pspace = add_program_space (child_inf->aspace);
642 child_inf->removable = 1;
643 child_inf->symfile_flags = SYMFILE_NO_READ;
644 set_current_program_space (child_inf->pspace);
645 clone_program_space (child_inf->pspace, parent_pspace);
647 /* Let the shared library layer (e.g., solib-svr4) learn
648 about this new process, relocate the cloned exec, pull in
649 shared libraries, and install the solib event breakpoint.
650 If a "cloned-VM" event was propagated better throughout
651 the core, this wouldn't be required. */
652 solib_create_inferior_hook (0);
656 return target_follow_fork (follow_child, detach_fork);
659 /* Tell the target to follow the fork we're stopped at. Returns true
660 if the inferior should be resumed; false, if the target for some
661 reason decided it's best not to resume. */
666 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
667 int should_resume = 1;
668 struct thread_info *tp;
670 /* Copy user stepping state to the new inferior thread. FIXME: the
671 followed fork child thread should have a copy of most of the
672 parent thread structure's run control related fields, not just these.
673 Initialized to avoid "may be used uninitialized" warnings from gcc. */
674 struct breakpoint *step_resume_breakpoint = NULL;
675 struct breakpoint *exception_resume_breakpoint = NULL;
676 CORE_ADDR step_range_start = 0;
677 CORE_ADDR step_range_end = 0;
678 struct frame_id step_frame_id = { 0 };
679 struct thread_fsm *thread_fsm = NULL;
684 struct target_waitstatus wait_status;
686 /* Get the last target status returned by target_wait(). */
687 get_last_target_status (&wait_ptid, &wait_status);
689 /* If not stopped at a fork event, then there's nothing else to
691 if (wait_status.kind != TARGET_WAITKIND_FORKED
692 && wait_status.kind != TARGET_WAITKIND_VFORKED)
695 /* Check if we switched over from WAIT_PTID, since the event was
697 if (!ptid_equal (wait_ptid, minus_one_ptid)
698 && !ptid_equal (inferior_ptid, wait_ptid))
700 /* We did. Switch back to WAIT_PTID thread, to tell the
701 target to follow it (in either direction). We'll
702 afterwards refuse to resume, and inform the user what
704 switch_to_thread (wait_ptid);
709 tp = inferior_thread ();
711 /* If there were any forks/vforks that were caught and are now to be
712 followed, then do so now. */
713 switch (tp->pending_follow.kind)
715 case TARGET_WAITKIND_FORKED:
716 case TARGET_WAITKIND_VFORKED:
718 ptid_t parent, child;
720 /* If the user did a next/step, etc, over a fork call,
721 preserve the stepping state in the fork child. */
722 if (follow_child && should_resume)
724 step_resume_breakpoint = clone_momentary_breakpoint
725 (tp->control.step_resume_breakpoint);
726 step_range_start = tp->control.step_range_start;
727 step_range_end = tp->control.step_range_end;
728 step_frame_id = tp->control.step_frame_id;
729 exception_resume_breakpoint
730 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
731 thread_fsm = tp->thread_fsm;
733 /* For now, delete the parent's sr breakpoint, otherwise,
734 parent/child sr breakpoints are considered duplicates,
735 and the child version will not be installed. Remove
736 this when the breakpoints module becomes aware of
737 inferiors and address spaces. */
738 delete_step_resume_breakpoint (tp);
739 tp->control.step_range_start = 0;
740 tp->control.step_range_end = 0;
741 tp->control.step_frame_id = null_frame_id;
742 delete_exception_resume_breakpoint (tp);
743 tp->thread_fsm = NULL;
746 parent = inferior_ptid;
747 child = tp->pending_follow.value.related_pid;
749 /* Set up inferior(s) as specified by the caller, and tell the
750 target to do whatever is necessary to follow either parent
752 if (follow_fork_inferior (follow_child, detach_fork))
754 /* Target refused to follow, or there's some other reason
755 we shouldn't resume. */
760 /* This pending follow fork event is now handled, one way
761 or another. The previous selected thread may be gone
762 from the lists by now, but if it is still around, need
763 to clear the pending follow request. */
764 tp = find_thread_ptid (parent);
766 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
768 /* This makes sure we don't try to apply the "Switched
769 over from WAIT_PID" logic above. */
770 nullify_last_target_wait_ptid ();
772 /* If we followed the child, switch to it... */
775 switch_to_thread (child);
777 /* ... and preserve the stepping state, in case the
778 user was stepping over the fork call. */
781 tp = inferior_thread ();
782 tp->control.step_resume_breakpoint
783 = step_resume_breakpoint;
784 tp->control.step_range_start = step_range_start;
785 tp->control.step_range_end = step_range_end;
786 tp->control.step_frame_id = step_frame_id;
787 tp->control.exception_resume_breakpoint
788 = exception_resume_breakpoint;
789 tp->thread_fsm = thread_fsm;
793 /* If we get here, it was because we're trying to
794 resume from a fork catchpoint, but, the user
795 has switched threads away from the thread that
796 forked. In that case, the resume command
797 issued is most likely not applicable to the
798 child, so just warn, and refuse to resume. */
799 warning (_("Not resuming: switched threads "
800 "before following fork child."));
803 /* Reset breakpoints in the child as appropriate. */
804 follow_inferior_reset_breakpoints ();
807 switch_to_thread (parent);
811 case TARGET_WAITKIND_SPURIOUS:
812 /* Nothing to follow. */
815 internal_error (__FILE__, __LINE__,
816 "Unexpected pending_follow.kind %d\n",
817 tp->pending_follow.kind);
821 return should_resume;
825 follow_inferior_reset_breakpoints (void)
827 struct thread_info *tp = inferior_thread ();
829 /* Was there a step_resume breakpoint? (There was if the user
830 did a "next" at the fork() call.) If so, explicitly reset its
831 thread number. Cloned step_resume breakpoints are disabled on
832 creation, so enable it here now that it is associated with the
835 step_resumes are a form of bp that are made to be per-thread.
836 Since we created the step_resume bp when the parent process
837 was being debugged, and now are switching to the child process,
838 from the breakpoint package's viewpoint, that's a switch of
839 "threads". We must update the bp's notion of which thread
840 it is for, or it'll be ignored when it triggers. */
842 if (tp->control.step_resume_breakpoint)
844 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
845 tp->control.step_resume_breakpoint->loc->enabled = 1;
848 /* Treat exception_resume breakpoints like step_resume breakpoints. */
849 if (tp->control.exception_resume_breakpoint)
851 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
852 tp->control.exception_resume_breakpoint->loc->enabled = 1;
855 /* Reinsert all breakpoints in the child. The user may have set
856 breakpoints after catching the fork, in which case those
857 were never set in the child, but only in the parent. This makes
858 sure the inserted breakpoints match the breakpoint list. */
860 breakpoint_re_set ();
861 insert_breakpoints ();
864 /* The child has exited or execed: resume threads of the parent the
865 user wanted to be executing. */
868 proceed_after_vfork_done (struct thread_info *thread,
871 int pid = * (int *) arg;
873 if (ptid_get_pid (thread->ptid) == pid
874 && is_running (thread->ptid)
875 && !is_executing (thread->ptid)
876 && !thread->stop_requested
877 && thread->suspend.stop_signal == GDB_SIGNAL_0)
880 fprintf_unfiltered (gdb_stdlog,
881 "infrun: resuming vfork parent thread %s\n",
882 target_pid_to_str (thread->ptid));
884 switch_to_thread (thread->ptid);
885 clear_proceed_status (0);
886 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
892 /* Save/restore inferior_ptid, current program space and current
893 inferior. Only use this if the current context points at an exited
894 inferior (and therefore there's no current thread to save). */
895 class scoped_restore_exited_inferior
898 scoped_restore_exited_inferior ()
899 : m_saved_ptid (&inferior_ptid)
903 scoped_restore_tmpl<ptid_t> m_saved_ptid;
904 scoped_restore_current_program_space m_pspace;
905 scoped_restore_current_inferior m_inferior;
908 /* Called whenever we notice an exec or exit event, to handle
909 detaching or resuming a vfork parent. */
912 handle_vfork_child_exec_or_exit (int exec)
914 struct inferior *inf = current_inferior ();
916 if (inf->vfork_parent)
918 int resume_parent = -1;
920 /* This exec or exit marks the end of the shared memory region
921 between the parent and the child. If the user wanted to
922 detach from the parent, now is the time. */
924 if (inf->vfork_parent->pending_detach)
926 struct thread_info *tp;
927 struct program_space *pspace;
928 struct address_space *aspace;
930 /* follow-fork child, detach-on-fork on. */
932 inf->vfork_parent->pending_detach = 0;
934 gdb::optional<scoped_restore_exited_inferior>
935 maybe_restore_inferior;
936 gdb::optional<scoped_restore_current_pspace_and_thread>
937 maybe_restore_thread;
939 /* If we're handling a child exit, then inferior_ptid points
940 at the inferior's pid, not to a thread. */
942 maybe_restore_inferior.emplace ();
944 maybe_restore_thread.emplace ();
946 /* We're letting loose of the parent. */
947 tp = any_live_thread_of_process (inf->vfork_parent->pid);
948 switch_to_thread (tp->ptid);
950 /* We're about to detach from the parent, which implicitly
951 removes breakpoints from its address space. There's a
952 catch here: we want to reuse the spaces for the child,
953 but, parent/child are still sharing the pspace at this
954 point, although the exec in reality makes the kernel give
955 the child a fresh set of new pages. The problem here is
956 that the breakpoints module being unaware of this, would
957 likely chose the child process to write to the parent
958 address space. Swapping the child temporarily away from
959 the spaces has the desired effect. Yes, this is "sort
962 pspace = inf->pspace;
963 aspace = inf->aspace;
967 if (debug_infrun || info_verbose)
969 target_terminal::ours_for_output ();
973 fprintf_filtered (gdb_stdlog,
974 _("Detaching vfork parent process "
975 "%d after child exec.\n"),
976 inf->vfork_parent->pid);
980 fprintf_filtered (gdb_stdlog,
981 _("Detaching vfork parent process "
982 "%d after child exit.\n"),
983 inf->vfork_parent->pid);
987 target_detach (NULL, 0);
990 inf->pspace = pspace;
991 inf->aspace = aspace;
995 /* We're staying attached to the parent, so, really give the
996 child a new address space. */
997 inf->pspace = add_program_space (maybe_new_address_space ());
998 inf->aspace = inf->pspace->aspace;
1000 set_current_program_space (inf->pspace);
1002 resume_parent = inf->vfork_parent->pid;
1004 /* Break the bonds. */
1005 inf->vfork_parent->vfork_child = NULL;
1009 struct program_space *pspace;
1011 /* If this is a vfork child exiting, then the pspace and
1012 aspaces were shared with the parent. Since we're
1013 reporting the process exit, we'll be mourning all that is
1014 found in the address space, and switching to null_ptid,
1015 preparing to start a new inferior. But, since we don't
1016 want to clobber the parent's address/program spaces, we
1017 go ahead and create a new one for this exiting
1020 /* Switch to null_ptid while running clone_program_space, so
1021 that clone_program_space doesn't want to read the
1022 selected frame of a dead process. */
1023 scoped_restore restore_ptid
1024 = make_scoped_restore (&inferior_ptid, null_ptid);
1026 /* This inferior is dead, so avoid giving the breakpoints
1027 module the option to write through to it (cloning a
1028 program space resets breakpoints). */
1031 pspace = add_program_space (maybe_new_address_space ());
1032 set_current_program_space (pspace);
1034 inf->symfile_flags = SYMFILE_NO_READ;
1035 clone_program_space (pspace, inf->vfork_parent->pspace);
1036 inf->pspace = pspace;
1037 inf->aspace = pspace->aspace;
1039 resume_parent = inf->vfork_parent->pid;
1040 /* Break the bonds. */
1041 inf->vfork_parent->vfork_child = NULL;
1044 inf->vfork_parent = NULL;
1046 gdb_assert (current_program_space == inf->pspace);
1048 if (non_stop && resume_parent != -1)
1050 /* If the user wanted the parent to be running, let it go
1052 scoped_restore_current_thread restore_thread;
1055 fprintf_unfiltered (gdb_stdlog,
1056 "infrun: resuming vfork parent process %d\n",
1059 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1064 /* Enum strings for "set|show follow-exec-mode". */
1066 static const char follow_exec_mode_new[] = "new";
1067 static const char follow_exec_mode_same[] = "same";
1068 static const char *const follow_exec_mode_names[] =
1070 follow_exec_mode_new,
1071 follow_exec_mode_same,
1075 static const char *follow_exec_mode_string = follow_exec_mode_same;
1077 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1078 struct cmd_list_element *c, const char *value)
1080 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1083 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1086 follow_exec (ptid_t ptid, char *exec_file_target)
1088 struct thread_info *th, *tmp;
1089 struct inferior *inf = current_inferior ();
1090 int pid = ptid_get_pid (ptid);
1091 ptid_t process_ptid;
1092 char *exec_file_host;
1093 struct cleanup *old_chain;
1095 /* This is an exec event that we actually wish to pay attention to.
1096 Refresh our symbol table to the newly exec'd program, remove any
1097 momentary bp's, etc.
1099 If there are breakpoints, they aren't really inserted now,
1100 since the exec() transformed our inferior into a fresh set
1103 We want to preserve symbolic breakpoints on the list, since
1104 we have hopes that they can be reset after the new a.out's
1105 symbol table is read.
1107 However, any "raw" breakpoints must be removed from the list
1108 (e.g., the solib bp's), since their address is probably invalid
1111 And, we DON'T want to call delete_breakpoints() here, since
1112 that may write the bp's "shadow contents" (the instruction
1113 value that was overwritten witha TRAP instruction). Since
1114 we now have a new a.out, those shadow contents aren't valid. */
1116 mark_breakpoints_out ();
1118 /* The target reports the exec event to the main thread, even if
1119 some other thread does the exec, and even if the main thread was
1120 stopped or already gone. We may still have non-leader threads of
1121 the process on our list. E.g., on targets that don't have thread
1122 exit events (like remote); or on native Linux in non-stop mode if
1123 there were only two threads in the inferior and the non-leader
1124 one is the one that execs (and nothing forces an update of the
1125 thread list up to here). When debugging remotely, it's best to
1126 avoid extra traffic, when possible, so avoid syncing the thread
1127 list with the target, and instead go ahead and delete all threads
1128 of the process but one that reported the event. Note this must
1129 be done before calling update_breakpoints_after_exec, as
1130 otherwise clearing the threads' resources would reference stale
1131 thread breakpoints -- it may have been one of these threads that
1132 stepped across the exec. We could just clear their stepping
1133 states, but as long as we're iterating, might as well delete
1134 them. Deleting them now rather than at the next user-visible
1135 stop provides a nicer sequence of events for user and MI
1137 ALL_THREADS_SAFE (th, tmp)
1138 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1139 delete_thread (th->ptid);
1141 /* We also need to clear any left over stale state for the
1142 leader/event thread. E.g., if there was any step-resume
1143 breakpoint or similar, it's gone now. We cannot truly
1144 step-to-next statement through an exec(). */
1145 th = inferior_thread ();
1146 th->control.step_resume_breakpoint = NULL;
1147 th->control.exception_resume_breakpoint = NULL;
1148 th->control.single_step_breakpoints = NULL;
1149 th->control.step_range_start = 0;
1150 th->control.step_range_end = 0;
1152 /* The user may have had the main thread held stopped in the
1153 previous image (e.g., schedlock on, or non-stop). Release
1155 th->stop_requested = 0;
1157 update_breakpoints_after_exec ();
1159 /* What is this a.out's name? */
1160 process_ptid = pid_to_ptid (pid);
1161 printf_unfiltered (_("%s is executing new program: %s\n"),
1162 target_pid_to_str (process_ptid),
1165 /* We've followed the inferior through an exec. Therefore, the
1166 inferior has essentially been killed & reborn. */
1168 gdb_flush (gdb_stdout);
1170 breakpoint_init_inferior (inf_execd);
1172 exec_file_host = exec_file_find (exec_file_target, NULL);
1173 old_chain = make_cleanup (xfree, exec_file_host);
1175 /* If we were unable to map the executable target pathname onto a host
1176 pathname, tell the user that. Otherwise GDB's subsequent behavior
1177 is confusing. Maybe it would even be better to stop at this point
1178 so that the user can specify a file manually before continuing. */
1179 if (exec_file_host == NULL)
1180 warning (_("Could not load symbols for executable %s.\n"
1181 "Do you need \"set sysroot\"?"),
1184 /* Reset the shared library package. This ensures that we get a
1185 shlib event when the child reaches "_start", at which point the
1186 dld will have had a chance to initialize the child. */
1187 /* Also, loading a symbol file below may trigger symbol lookups, and
1188 we don't want those to be satisfied by the libraries of the
1189 previous incarnation of this process. */
1190 no_shared_libraries (NULL, 0);
1192 if (follow_exec_mode_string == follow_exec_mode_new)
1194 /* The user wants to keep the old inferior and program spaces
1195 around. Create a new fresh one, and switch to it. */
1197 /* Do exit processing for the original inferior before adding
1198 the new inferior so we don't have two active inferiors with
1199 the same ptid, which can confuse find_inferior_ptid. */
1200 exit_inferior_num_silent (current_inferior ()->num);
1202 inf = add_inferior_with_spaces ();
1204 target_follow_exec (inf, exec_file_target);
1206 set_current_inferior (inf);
1207 set_current_program_space (inf->pspace);
1211 /* The old description may no longer be fit for the new image.
1212 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1213 old description; we'll read a new one below. No need to do
1214 this on "follow-exec-mode new", as the old inferior stays
1215 around (its description is later cleared/refetched on
1217 target_clear_description ();
1220 gdb_assert (current_program_space == inf->pspace);
1222 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1223 because the proper displacement for a PIE (Position Independent
1224 Executable) main symbol file will only be computed by
1225 solib_create_inferior_hook below. breakpoint_re_set would fail
1226 to insert the breakpoints with the zero displacement. */
1227 try_open_exec_file (exec_file_host, inf, SYMFILE_DEFER_BP_RESET);
1229 do_cleanups (old_chain);
1231 /* If the target can specify a description, read it. Must do this
1232 after flipping to the new executable (because the target supplied
1233 description must be compatible with the executable's
1234 architecture, and the old executable may e.g., be 32-bit, while
1235 the new one 64-bit), and before anything involving memory or
1237 target_find_description ();
1239 /* The add_thread call ends up reading registers, so do it after updating the
1240 target description. */
1241 if (follow_exec_mode_string == follow_exec_mode_new)
1244 solib_create_inferior_hook (0);
1246 jit_inferior_created_hook ();
1248 breakpoint_re_set ();
1250 /* Reinsert all breakpoints. (Those which were symbolic have
1251 been reset to the proper address in the new a.out, thanks
1252 to symbol_file_command...). */
1253 insert_breakpoints ();
1255 /* The next resume of this inferior should bring it to the shlib
1256 startup breakpoints. (If the user had also set bp's on
1257 "main" from the old (parent) process, then they'll auto-
1258 matically get reset there in the new process.). */
1261 /* The queue of threads that need to do a step-over operation to get
1262 past e.g., a breakpoint. What technique is used to step over the
1263 breakpoint/watchpoint does not matter -- all threads end up in the
1264 same queue, to maintain rough temporal order of execution, in order
1265 to avoid starvation, otherwise, we could e.g., find ourselves
1266 constantly stepping the same couple threads past their breakpoints
1267 over and over, if the single-step finish fast enough. */
1268 struct thread_info *step_over_queue_head;
1270 /* Bit flags indicating what the thread needs to step over. */
1272 enum step_over_what_flag
1274 /* Step over a breakpoint. */
1275 STEP_OVER_BREAKPOINT = 1,
1277 /* Step past a non-continuable watchpoint, in order to let the
1278 instruction execute so we can evaluate the watchpoint
1280 STEP_OVER_WATCHPOINT = 2
1282 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1284 /* Info about an instruction that is being stepped over. */
1286 struct step_over_info
1288 /* If we're stepping past a breakpoint, this is the address space
1289 and address of the instruction the breakpoint is set at. We'll
1290 skip inserting all breakpoints here. Valid iff ASPACE is
1292 struct address_space *aspace;
1295 /* The instruction being stepped over triggers a nonsteppable
1296 watchpoint. If true, we'll skip inserting watchpoints. */
1297 int nonsteppable_watchpoint_p;
1299 /* The thread's global number. */
1303 /* The step-over info of the location that is being stepped over.
1305 Note that with async/breakpoint always-inserted mode, a user might
1306 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1307 being stepped over. As setting a new breakpoint inserts all
1308 breakpoints, we need to make sure the breakpoint being stepped over
1309 isn't inserted then. We do that by only clearing the step-over
1310 info when the step-over is actually finished (or aborted).
1312 Presently GDB can only step over one breakpoint at any given time.
1313 Given threads that can't run code in the same address space as the
1314 breakpoint's can't really miss the breakpoint, GDB could be taught
1315 to step-over at most one breakpoint per address space (so this info
1316 could move to the address space object if/when GDB is extended).
1317 The set of breakpoints being stepped over will normally be much
1318 smaller than the set of all breakpoints, so a flag in the
1319 breakpoint location structure would be wasteful. A separate list
1320 also saves complexity and run-time, as otherwise we'd have to go
1321 through all breakpoint locations clearing their flag whenever we
1322 start a new sequence. Similar considerations weigh against storing
1323 this info in the thread object. Plus, not all step overs actually
1324 have breakpoint locations -- e.g., stepping past a single-step
1325 breakpoint, or stepping to complete a non-continuable
1327 static struct step_over_info step_over_info;
1329 /* Record the address of the breakpoint/instruction we're currently
1331 N.B. We record the aspace and address now, instead of say just the thread,
1332 because when we need the info later the thread may be running. */
1335 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1336 int nonsteppable_watchpoint_p,
1339 step_over_info.aspace = aspace;
1340 step_over_info.address = address;
1341 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1342 step_over_info.thread = thread;
1345 /* Called when we're not longer stepping over a breakpoint / an
1346 instruction, so all breakpoints are free to be (re)inserted. */
1349 clear_step_over_info (void)
1352 fprintf_unfiltered (gdb_stdlog,
1353 "infrun: clear_step_over_info\n");
1354 step_over_info.aspace = NULL;
1355 step_over_info.address = 0;
1356 step_over_info.nonsteppable_watchpoint_p = 0;
1357 step_over_info.thread = -1;
1363 stepping_past_instruction_at (struct address_space *aspace,
1366 return (step_over_info.aspace != NULL
1367 && breakpoint_address_match (aspace, address,
1368 step_over_info.aspace,
1369 step_over_info.address));
1375 thread_is_stepping_over_breakpoint (int thread)
1377 return (step_over_info.thread != -1
1378 && thread == step_over_info.thread);
1384 stepping_past_nonsteppable_watchpoint (void)
1386 return step_over_info.nonsteppable_watchpoint_p;
1389 /* Returns true if step-over info is valid. */
1392 step_over_info_valid_p (void)
1394 return (step_over_info.aspace != NULL
1395 || stepping_past_nonsteppable_watchpoint ());
1399 /* Displaced stepping. */
1401 /* In non-stop debugging mode, we must take special care to manage
1402 breakpoints properly; in particular, the traditional strategy for
1403 stepping a thread past a breakpoint it has hit is unsuitable.
1404 'Displaced stepping' is a tactic for stepping one thread past a
1405 breakpoint it has hit while ensuring that other threads running
1406 concurrently will hit the breakpoint as they should.
1408 The traditional way to step a thread T off a breakpoint in a
1409 multi-threaded program in all-stop mode is as follows:
1411 a0) Initially, all threads are stopped, and breakpoints are not
1413 a1) We single-step T, leaving breakpoints uninserted.
1414 a2) We insert breakpoints, and resume all threads.
1416 In non-stop debugging, however, this strategy is unsuitable: we
1417 don't want to have to stop all threads in the system in order to
1418 continue or step T past a breakpoint. Instead, we use displaced
1421 n0) Initially, T is stopped, other threads are running, and
1422 breakpoints are inserted.
1423 n1) We copy the instruction "under" the breakpoint to a separate
1424 location, outside the main code stream, making any adjustments
1425 to the instruction, register, and memory state as directed by
1427 n2) We single-step T over the instruction at its new location.
1428 n3) We adjust the resulting register and memory state as directed
1429 by T's architecture. This includes resetting T's PC to point
1430 back into the main instruction stream.
1433 This approach depends on the following gdbarch methods:
1435 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1436 indicate where to copy the instruction, and how much space must
1437 be reserved there. We use these in step n1.
1439 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1440 address, and makes any necessary adjustments to the instruction,
1441 register contents, and memory. We use this in step n1.
1443 - gdbarch_displaced_step_fixup adjusts registers and memory after
1444 we have successfuly single-stepped the instruction, to yield the
1445 same effect the instruction would have had if we had executed it
1446 at its original address. We use this in step n3.
1448 The gdbarch_displaced_step_copy_insn and
1449 gdbarch_displaced_step_fixup functions must be written so that
1450 copying an instruction with gdbarch_displaced_step_copy_insn,
1451 single-stepping across the copied instruction, and then applying
1452 gdbarch_displaced_insn_fixup should have the same effects on the
1453 thread's memory and registers as stepping the instruction in place
1454 would have. Exactly which responsibilities fall to the copy and
1455 which fall to the fixup is up to the author of those functions.
1457 See the comments in gdbarch.sh for details.
1459 Note that displaced stepping and software single-step cannot
1460 currently be used in combination, although with some care I think
1461 they could be made to. Software single-step works by placing
1462 breakpoints on all possible subsequent instructions; if the
1463 displaced instruction is a PC-relative jump, those breakpoints
1464 could fall in very strange places --- on pages that aren't
1465 executable, or at addresses that are not proper instruction
1466 boundaries. (We do generally let other threads run while we wait
1467 to hit the software single-step breakpoint, and they might
1468 encounter such a corrupted instruction.) One way to work around
1469 this would be to have gdbarch_displaced_step_copy_insn fully
1470 simulate the effect of PC-relative instructions (and return NULL)
1471 on architectures that use software single-stepping.
1473 In non-stop mode, we can have independent and simultaneous step
1474 requests, so more than one thread may need to simultaneously step
1475 over a breakpoint. The current implementation assumes there is
1476 only one scratch space per process. In this case, we have to
1477 serialize access to the scratch space. If thread A wants to step
1478 over a breakpoint, but we are currently waiting for some other
1479 thread to complete a displaced step, we leave thread A stopped and
1480 place it in the displaced_step_request_queue. Whenever a displaced
1481 step finishes, we pick the next thread in the queue and start a new
1482 displaced step operation on it. See displaced_step_prepare and
1483 displaced_step_fixup for details. */
1485 /* Default destructor for displaced_step_closure. */
1487 displaced_step_closure::~displaced_step_closure () = default;
1489 /* Per-inferior displaced stepping state. */
1490 struct displaced_step_inferior_state
1492 /* Pointer to next in linked list. */
1493 struct displaced_step_inferior_state *next;
1495 /* The process this displaced step state refers to. */
1498 /* True if preparing a displaced step ever failed. If so, we won't
1499 try displaced stepping for this inferior again. */
1502 /* If this is not null_ptid, this is the thread carrying out a
1503 displaced single-step in process PID. This thread's state will
1504 require fixing up once it has completed its step. */
1507 /* The architecture the thread had when we stepped it. */
1508 struct gdbarch *step_gdbarch;
1510 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1511 for post-step cleanup. */
1512 struct displaced_step_closure *step_closure;
1514 /* The address of the original instruction, and the copy we
1516 CORE_ADDR step_original, step_copy;
1518 /* Saved contents of copy area. */
1519 gdb_byte *step_saved_copy;
1522 /* The list of states of processes involved in displaced stepping
1524 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1526 /* Get the displaced stepping state of process PID. */
1528 static struct displaced_step_inferior_state *
1529 get_displaced_stepping_state (int pid)
1531 struct displaced_step_inferior_state *state;
1533 for (state = displaced_step_inferior_states;
1535 state = state->next)
1536 if (state->pid == pid)
1542 /* Returns true if any inferior has a thread doing a displaced
1546 displaced_step_in_progress_any_inferior (void)
1548 struct displaced_step_inferior_state *state;
1550 for (state = displaced_step_inferior_states;
1552 state = state->next)
1553 if (!ptid_equal (state->step_ptid, null_ptid))
1559 /* Return true if thread represented by PTID is doing a displaced
1563 displaced_step_in_progress_thread (ptid_t ptid)
1565 struct displaced_step_inferior_state *displaced;
1567 gdb_assert (!ptid_equal (ptid, null_ptid));
1569 displaced = get_displaced_stepping_state (ptid_get_pid (ptid));
1571 return (displaced != NULL && ptid_equal (displaced->step_ptid, ptid));
1574 /* Return true if process PID has a thread doing a displaced step. */
1577 displaced_step_in_progress (int pid)
1579 struct displaced_step_inferior_state *displaced;
1581 displaced = get_displaced_stepping_state (pid);
1582 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1588 /* Add a new displaced stepping state for process PID to the displaced
1589 stepping state list, or return a pointer to an already existing
1590 entry, if it already exists. Never returns NULL. */
1592 static struct displaced_step_inferior_state *
1593 add_displaced_stepping_state (int pid)
1595 struct displaced_step_inferior_state *state;
1597 for (state = displaced_step_inferior_states;
1599 state = state->next)
1600 if (state->pid == pid)
1603 state = XCNEW (struct displaced_step_inferior_state);
1605 state->next = displaced_step_inferior_states;
1606 displaced_step_inferior_states = state;
1611 /* If inferior is in displaced stepping, and ADDR equals to starting address
1612 of copy area, return corresponding displaced_step_closure. Otherwise,
1615 struct displaced_step_closure*
1616 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1618 struct displaced_step_inferior_state *displaced
1619 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1621 /* If checking the mode of displaced instruction in copy area. */
1622 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1623 && (displaced->step_copy == addr))
1624 return displaced->step_closure;
1629 /* Remove the displaced stepping state of process PID. */
1632 remove_displaced_stepping_state (int pid)
1634 struct displaced_step_inferior_state *it, **prev_next_p;
1636 gdb_assert (pid != 0);
1638 it = displaced_step_inferior_states;
1639 prev_next_p = &displaced_step_inferior_states;
1644 *prev_next_p = it->next;
1649 prev_next_p = &it->next;
1655 infrun_inferior_exit (struct inferior *inf)
1657 remove_displaced_stepping_state (inf->pid);
1660 /* If ON, and the architecture supports it, GDB will use displaced
1661 stepping to step over breakpoints. If OFF, or if the architecture
1662 doesn't support it, GDB will instead use the traditional
1663 hold-and-step approach. If AUTO (which is the default), GDB will
1664 decide which technique to use to step over breakpoints depending on
1665 which of all-stop or non-stop mode is active --- displaced stepping
1666 in non-stop mode; hold-and-step in all-stop mode. */
1668 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1671 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1672 struct cmd_list_element *c,
1675 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1676 fprintf_filtered (file,
1677 _("Debugger's willingness to use displaced stepping "
1678 "to step over breakpoints is %s (currently %s).\n"),
1679 value, target_is_non_stop_p () ? "on" : "off");
1681 fprintf_filtered (file,
1682 _("Debugger's willingness to use displaced stepping "
1683 "to step over breakpoints is %s.\n"), value);
1686 /* Return non-zero if displaced stepping can/should be used to step
1687 over breakpoints of thread TP. */
1690 use_displaced_stepping (struct thread_info *tp)
1692 struct regcache *regcache = get_thread_regcache (tp->ptid);
1693 struct gdbarch *gdbarch = regcache->arch ();
1694 struct displaced_step_inferior_state *displaced_state;
1696 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1698 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1699 && target_is_non_stop_p ())
1700 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1701 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1702 && find_record_target () == NULL
1703 && (displaced_state == NULL
1704 || !displaced_state->failed_before));
1707 /* Clean out any stray displaced stepping state. */
1709 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1711 /* Indicate that there is no cleanup pending. */
1712 displaced->step_ptid = null_ptid;
1714 delete displaced->step_closure;
1715 displaced->step_closure = NULL;
1719 displaced_step_clear_cleanup (void *arg)
1721 struct displaced_step_inferior_state *state
1722 = (struct displaced_step_inferior_state *) arg;
1724 displaced_step_clear (state);
1727 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1729 displaced_step_dump_bytes (struct ui_file *file,
1730 const gdb_byte *buf,
1735 for (i = 0; i < len; i++)
1736 fprintf_unfiltered (file, "%02x ", buf[i]);
1737 fputs_unfiltered ("\n", file);
1740 /* Prepare to single-step, using displaced stepping.
1742 Note that we cannot use displaced stepping when we have a signal to
1743 deliver. If we have a signal to deliver and an instruction to step
1744 over, then after the step, there will be no indication from the
1745 target whether the thread entered a signal handler or ignored the
1746 signal and stepped over the instruction successfully --- both cases
1747 result in a simple SIGTRAP. In the first case we mustn't do a
1748 fixup, and in the second case we must --- but we can't tell which.
1749 Comments in the code for 'random signals' in handle_inferior_event
1750 explain how we handle this case instead.
1752 Returns 1 if preparing was successful -- this thread is going to be
1753 stepped now; 0 if displaced stepping this thread got queued; or -1
1754 if this instruction can't be displaced stepped. */
1757 displaced_step_prepare_throw (ptid_t ptid)
1759 struct cleanup *ignore_cleanups;
1760 struct thread_info *tp = find_thread_ptid (ptid);
1761 struct regcache *regcache = get_thread_regcache (ptid);
1762 struct gdbarch *gdbarch = regcache->arch ();
1763 struct address_space *aspace = regcache->aspace ();
1764 CORE_ADDR original, copy;
1766 struct displaced_step_closure *closure;
1767 struct displaced_step_inferior_state *displaced;
1770 /* We should never reach this function if the architecture does not
1771 support displaced stepping. */
1772 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1774 /* Nor if the thread isn't meant to step over a breakpoint. */
1775 gdb_assert (tp->control.trap_expected);
1777 /* Disable range stepping while executing in the scratch pad. We
1778 want a single-step even if executing the displaced instruction in
1779 the scratch buffer lands within the stepping range (e.g., a
1781 tp->control.may_range_step = 0;
1783 /* We have to displaced step one thread at a time, as we only have
1784 access to a single scratch space per inferior. */
1786 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1788 if (!ptid_equal (displaced->step_ptid, null_ptid))
1790 /* Already waiting for a displaced step to finish. Defer this
1791 request and place in queue. */
1793 if (debug_displaced)
1794 fprintf_unfiltered (gdb_stdlog,
1795 "displaced: deferring step of %s\n",
1796 target_pid_to_str (ptid));
1798 thread_step_over_chain_enqueue (tp);
1803 if (debug_displaced)
1804 fprintf_unfiltered (gdb_stdlog,
1805 "displaced: stepping %s now\n",
1806 target_pid_to_str (ptid));
1809 displaced_step_clear (displaced);
1811 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1812 inferior_ptid = ptid;
1814 original = regcache_read_pc (regcache);
1816 copy = gdbarch_displaced_step_location (gdbarch);
1817 len = gdbarch_max_insn_length (gdbarch);
1819 if (breakpoint_in_range_p (aspace, copy, len))
1821 /* There's a breakpoint set in the scratch pad location range
1822 (which is usually around the entry point). We'd either
1823 install it before resuming, which would overwrite/corrupt the
1824 scratch pad, or if it was already inserted, this displaced
1825 step would overwrite it. The latter is OK in the sense that
1826 we already assume that no thread is going to execute the code
1827 in the scratch pad range (after initial startup) anyway, but
1828 the former is unacceptable. Simply punt and fallback to
1829 stepping over this breakpoint in-line. */
1830 if (debug_displaced)
1832 fprintf_unfiltered (gdb_stdlog,
1833 "displaced: breakpoint set in scratch pad. "
1834 "Stepping over breakpoint in-line instead.\n");
1840 /* Save the original contents of the copy area. */
1841 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1842 ignore_cleanups = make_cleanup (free_current_contents,
1843 &displaced->step_saved_copy);
1844 status = target_read_memory (copy, displaced->step_saved_copy, len);
1846 throw_error (MEMORY_ERROR,
1847 _("Error accessing memory address %s (%s) for "
1848 "displaced-stepping scratch space."),
1849 paddress (gdbarch, copy), safe_strerror (status));
1850 if (debug_displaced)
1852 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1853 paddress (gdbarch, copy));
1854 displaced_step_dump_bytes (gdb_stdlog,
1855 displaced->step_saved_copy,
1859 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1860 original, copy, regcache);
1861 if (closure == NULL)
1863 /* The architecture doesn't know how or want to displaced step
1864 this instruction or instruction sequence. Fallback to
1865 stepping over the breakpoint in-line. */
1866 do_cleanups (ignore_cleanups);
1870 /* Save the information we need to fix things up if the step
1872 displaced->step_ptid = ptid;
1873 displaced->step_gdbarch = gdbarch;
1874 displaced->step_closure = closure;
1875 displaced->step_original = original;
1876 displaced->step_copy = copy;
1878 make_cleanup (displaced_step_clear_cleanup, displaced);
1880 /* Resume execution at the copy. */
1881 regcache_write_pc (regcache, copy);
1883 discard_cleanups (ignore_cleanups);
1885 if (debug_displaced)
1886 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1887 paddress (gdbarch, copy));
1892 /* Wrapper for displaced_step_prepare_throw that disabled further
1893 attempts at displaced stepping if we get a memory error. */
1896 displaced_step_prepare (ptid_t ptid)
1902 prepared = displaced_step_prepare_throw (ptid);
1904 CATCH (ex, RETURN_MASK_ERROR)
1906 struct displaced_step_inferior_state *displaced_state;
1908 if (ex.error != MEMORY_ERROR
1909 && ex.error != NOT_SUPPORTED_ERROR)
1910 throw_exception (ex);
1914 fprintf_unfiltered (gdb_stdlog,
1915 "infrun: disabling displaced stepping: %s\n",
1919 /* Be verbose if "set displaced-stepping" is "on", silent if
1921 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1923 warning (_("disabling displaced stepping: %s"),
1927 /* Disable further displaced stepping attempts. */
1929 = get_displaced_stepping_state (ptid_get_pid (ptid));
1930 displaced_state->failed_before = 1;
1938 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1939 const gdb_byte *myaddr, int len)
1941 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1943 inferior_ptid = ptid;
1944 write_memory (memaddr, myaddr, len);
1947 /* Restore the contents of the copy area for thread PTID. */
1950 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1953 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1955 write_memory_ptid (ptid, displaced->step_copy,
1956 displaced->step_saved_copy, len);
1957 if (debug_displaced)
1958 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1959 target_pid_to_str (ptid),
1960 paddress (displaced->step_gdbarch,
1961 displaced->step_copy));
1964 /* If we displaced stepped an instruction successfully, adjust
1965 registers and memory to yield the same effect the instruction would
1966 have had if we had executed it at its original address, and return
1967 1. If the instruction didn't complete, relocate the PC and return
1968 -1. If the thread wasn't displaced stepping, return 0. */
1971 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1973 struct cleanup *old_cleanups;
1974 struct displaced_step_inferior_state *displaced
1975 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1978 /* Was any thread of this process doing a displaced step? */
1979 if (displaced == NULL)
1982 /* Was this event for the pid we displaced? */
1983 if (ptid_equal (displaced->step_ptid, null_ptid)
1984 || ! ptid_equal (displaced->step_ptid, event_ptid))
1987 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1989 displaced_step_restore (displaced, displaced->step_ptid);
1991 /* Fixup may need to read memory/registers. Switch to the thread
1992 that we're fixing up. Also, target_stopped_by_watchpoint checks
1993 the current thread. */
1994 switch_to_thread (event_ptid);
1996 /* Did the instruction complete successfully? */
1997 if (signal == GDB_SIGNAL_TRAP
1998 && !(target_stopped_by_watchpoint ()
1999 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
2000 || target_have_steppable_watchpoint)))
2002 /* Fix up the resulting state. */
2003 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
2004 displaced->step_closure,
2005 displaced->step_original,
2006 displaced->step_copy,
2007 get_thread_regcache (displaced->step_ptid));
2012 /* Since the instruction didn't complete, all we can do is
2014 struct regcache *regcache = get_thread_regcache (event_ptid);
2015 CORE_ADDR pc = regcache_read_pc (regcache);
2017 pc = displaced->step_original + (pc - displaced->step_copy);
2018 regcache_write_pc (regcache, pc);
2022 do_cleanups (old_cleanups);
2024 displaced->step_ptid = null_ptid;
2029 /* Data to be passed around while handling an event. This data is
2030 discarded between events. */
2031 struct execution_control_state
2034 /* The thread that got the event, if this was a thread event; NULL
2036 struct thread_info *event_thread;
2038 struct target_waitstatus ws;
2039 int stop_func_filled_in;
2040 CORE_ADDR stop_func_start;
2041 CORE_ADDR stop_func_end;
2042 const char *stop_func_name;
2045 /* True if the event thread hit the single-step breakpoint of
2046 another thread. Thus the event doesn't cause a stop, the thread
2047 needs to be single-stepped past the single-step breakpoint before
2048 we can switch back to the original stepping thread. */
2049 int hit_singlestep_breakpoint;
2052 /* Clear ECS and set it to point at TP. */
2055 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2057 memset (ecs, 0, sizeof (*ecs));
2058 ecs->event_thread = tp;
2059 ecs->ptid = tp->ptid;
2062 static void keep_going_pass_signal (struct execution_control_state *ecs);
2063 static void prepare_to_wait (struct execution_control_state *ecs);
2064 static int keep_going_stepped_thread (struct thread_info *tp);
2065 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2067 /* Are there any pending step-over requests? If so, run all we can
2068 now and return true. Otherwise, return false. */
2071 start_step_over (void)
2073 struct thread_info *tp, *next;
2075 /* Don't start a new step-over if we already have an in-line
2076 step-over operation ongoing. */
2077 if (step_over_info_valid_p ())
2080 for (tp = step_over_queue_head; tp != NULL; tp = next)
2082 struct execution_control_state ecss;
2083 struct execution_control_state *ecs = &ecss;
2084 step_over_what step_what;
2085 int must_be_in_line;
2087 gdb_assert (!tp->stop_requested);
2089 next = thread_step_over_chain_next (tp);
2091 /* If this inferior already has a displaced step in process,
2092 don't start a new one. */
2093 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2096 step_what = thread_still_needs_step_over (tp);
2097 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2098 || ((step_what & STEP_OVER_BREAKPOINT)
2099 && !use_displaced_stepping (tp)));
2101 /* We currently stop all threads of all processes to step-over
2102 in-line. If we need to start a new in-line step-over, let
2103 any pending displaced steps finish first. */
2104 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2107 thread_step_over_chain_remove (tp);
2109 if (step_over_queue_head == NULL)
2112 fprintf_unfiltered (gdb_stdlog,
2113 "infrun: step-over queue now empty\n");
2116 if (tp->control.trap_expected
2120 internal_error (__FILE__, __LINE__,
2121 "[%s] has inconsistent state: "
2122 "trap_expected=%d, resumed=%d, executing=%d\n",
2123 target_pid_to_str (tp->ptid),
2124 tp->control.trap_expected,
2130 fprintf_unfiltered (gdb_stdlog,
2131 "infrun: resuming [%s] for step-over\n",
2132 target_pid_to_str (tp->ptid));
2134 /* keep_going_pass_signal skips the step-over if the breakpoint
2135 is no longer inserted. In all-stop, we want to keep looking
2136 for a thread that needs a step-over instead of resuming TP,
2137 because we wouldn't be able to resume anything else until the
2138 target stops again. In non-stop, the resume always resumes
2139 only TP, so it's OK to let the thread resume freely. */
2140 if (!target_is_non_stop_p () && !step_what)
2143 switch_to_thread (tp->ptid);
2144 reset_ecs (ecs, tp);
2145 keep_going_pass_signal (ecs);
2147 if (!ecs->wait_some_more)
2148 error (_("Command aborted."));
2150 gdb_assert (tp->resumed);
2152 /* If we started a new in-line step-over, we're done. */
2153 if (step_over_info_valid_p ())
2155 gdb_assert (tp->control.trap_expected);
2159 if (!target_is_non_stop_p ())
2161 /* On all-stop, shouldn't have resumed unless we needed a
2163 gdb_assert (tp->control.trap_expected
2164 || tp->step_after_step_resume_breakpoint);
2166 /* With remote targets (at least), in all-stop, we can't
2167 issue any further remote commands until the program stops
2172 /* Either the thread no longer needed a step-over, or a new
2173 displaced stepping sequence started. Even in the latter
2174 case, continue looking. Maybe we can also start another
2175 displaced step on a thread of other process. */
2181 /* Update global variables holding ptids to hold NEW_PTID if they were
2182 holding OLD_PTID. */
2184 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2186 struct displaced_step_inferior_state *displaced;
2188 if (ptid_equal (inferior_ptid, old_ptid))
2189 inferior_ptid = new_ptid;
2191 for (displaced = displaced_step_inferior_states;
2193 displaced = displaced->next)
2195 if (ptid_equal (displaced->step_ptid, old_ptid))
2196 displaced->step_ptid = new_ptid;
2203 /* Things to clean up if we QUIT out of resume (). */
2205 resume_cleanups (void *ignore)
2207 if (!ptid_equal (inferior_ptid, null_ptid))
2208 delete_single_step_breakpoints (inferior_thread ());
2213 static const char schedlock_off[] = "off";
2214 static const char schedlock_on[] = "on";
2215 static const char schedlock_step[] = "step";
2216 static const char schedlock_replay[] = "replay";
2217 static const char *const scheduler_enums[] = {
2224 static const char *scheduler_mode = schedlock_replay;
2226 show_scheduler_mode (struct ui_file *file, int from_tty,
2227 struct cmd_list_element *c, const char *value)
2229 fprintf_filtered (file,
2230 _("Mode for locking scheduler "
2231 "during execution is \"%s\".\n"),
2236 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2238 if (!target_can_lock_scheduler)
2240 scheduler_mode = schedlock_off;
2241 error (_("Target '%s' cannot support this command."), target_shortname);
2245 /* True if execution commands resume all threads of all processes by
2246 default; otherwise, resume only threads of the current inferior
2248 int sched_multi = 0;
2250 /* Try to setup for software single stepping over the specified location.
2251 Return 1 if target_resume() should use hardware single step.
2253 GDBARCH the current gdbarch.
2254 PC the location to step over. */
2257 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2261 if (execution_direction == EXEC_FORWARD
2262 && gdbarch_software_single_step_p (gdbarch))
2263 hw_step = !insert_single_step_breakpoints (gdbarch);
2271 user_visible_resume_ptid (int step)
2277 /* With non-stop mode on, threads are always handled
2279 resume_ptid = inferior_ptid;
2281 else if ((scheduler_mode == schedlock_on)
2282 || (scheduler_mode == schedlock_step && step))
2284 /* User-settable 'scheduler' mode requires solo thread
2286 resume_ptid = inferior_ptid;
2288 else if ((scheduler_mode == schedlock_replay)
2289 && target_record_will_replay (minus_one_ptid, execution_direction))
2291 /* User-settable 'scheduler' mode requires solo thread resume in replay
2293 resume_ptid = inferior_ptid;
2295 else if (!sched_multi && target_supports_multi_process ())
2297 /* Resume all threads of the current process (and none of other
2299 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2303 /* Resume all threads of all processes. */
2304 resume_ptid = RESUME_ALL;
2310 /* Return a ptid representing the set of threads that we will resume,
2311 in the perspective of the target, assuming run control handling
2312 does not require leaving some threads stopped (e.g., stepping past
2313 breakpoint). USER_STEP indicates whether we're about to start the
2314 target for a stepping command. */
2317 internal_resume_ptid (int user_step)
2319 /* In non-stop, we always control threads individually. Note that
2320 the target may always work in non-stop mode even with "set
2321 non-stop off", in which case user_visible_resume_ptid could
2322 return a wildcard ptid. */
2323 if (target_is_non_stop_p ())
2324 return inferior_ptid;
2326 return user_visible_resume_ptid (user_step);
2329 /* Wrapper for target_resume, that handles infrun-specific
2333 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2335 struct thread_info *tp = inferior_thread ();
2337 gdb_assert (!tp->stop_requested);
2339 /* Install inferior's terminal modes. */
2340 target_terminal::inferior ();
2342 /* Avoid confusing the next resume, if the next stop/resume
2343 happens to apply to another thread. */
2344 tp->suspend.stop_signal = GDB_SIGNAL_0;
2346 /* Advise target which signals may be handled silently.
2348 If we have removed breakpoints because we are stepping over one
2349 in-line (in any thread), we need to receive all signals to avoid
2350 accidentally skipping a breakpoint during execution of a signal
2353 Likewise if we're displaced stepping, otherwise a trap for a
2354 breakpoint in a signal handler might be confused with the
2355 displaced step finishing. We don't make the displaced_step_fixup
2356 step distinguish the cases instead, because:
2358 - a backtrace while stopped in the signal handler would show the
2359 scratch pad as frame older than the signal handler, instead of
2360 the real mainline code.
2362 - when the thread is later resumed, the signal handler would
2363 return to the scratch pad area, which would no longer be
2365 if (step_over_info_valid_p ()
2366 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2367 target_pass_signals (0, NULL);
2369 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2371 target_resume (resume_ptid, step, sig);
2373 target_commit_resume ();
2376 /* Resume the inferior, but allow a QUIT. This is useful if the user
2377 wants to interrupt some lengthy single-stepping operation
2378 (for child processes, the SIGINT goes to the inferior, and so
2379 we get a SIGINT random_signal, but for remote debugging and perhaps
2380 other targets, that's not true).
2382 SIG is the signal to give the inferior (zero for none). */
2384 resume (enum gdb_signal sig)
2386 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2387 struct regcache *regcache = get_current_regcache ();
2388 struct gdbarch *gdbarch = regcache->arch ();
2389 struct thread_info *tp = inferior_thread ();
2390 CORE_ADDR pc = regcache_read_pc (regcache);
2391 struct address_space *aspace = regcache->aspace ();
2393 /* This represents the user's step vs continue request. When
2394 deciding whether "set scheduler-locking step" applies, it's the
2395 user's intention that counts. */
2396 const int user_step = tp->control.stepping_command;
2397 /* This represents what we'll actually request the target to do.
2398 This can decay from a step to a continue, if e.g., we need to
2399 implement single-stepping with breakpoints (software
2403 gdb_assert (!tp->stop_requested);
2404 gdb_assert (!thread_is_in_step_over_chain (tp));
2408 if (tp->suspend.waitstatus_pending_p)
2413 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2415 fprintf_unfiltered (gdb_stdlog,
2416 "infrun: resume: thread %s has pending wait "
2417 "status %s (currently_stepping=%d).\n",
2418 target_pid_to_str (tp->ptid), statstr.c_str (),
2419 currently_stepping (tp));
2424 /* FIXME: What should we do if we are supposed to resume this
2425 thread with a signal? Maybe we should maintain a queue of
2426 pending signals to deliver. */
2427 if (sig != GDB_SIGNAL_0)
2429 warning (_("Couldn't deliver signal %s to %s."),
2430 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2433 tp->suspend.stop_signal = GDB_SIGNAL_0;
2434 discard_cleanups (old_cleanups);
2436 if (target_can_async_p ())
2441 tp->stepped_breakpoint = 0;
2443 /* Depends on stepped_breakpoint. */
2444 step = currently_stepping (tp);
2446 if (current_inferior ()->waiting_for_vfork_done)
2448 /* Don't try to single-step a vfork parent that is waiting for
2449 the child to get out of the shared memory region (by exec'ing
2450 or exiting). This is particularly important on software
2451 single-step archs, as the child process would trip on the
2452 software single step breakpoint inserted for the parent
2453 process. Since the parent will not actually execute any
2454 instruction until the child is out of the shared region (such
2455 are vfork's semantics), it is safe to simply continue it.
2456 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2457 the parent, and tell it to `keep_going', which automatically
2458 re-sets it stepping. */
2460 fprintf_unfiltered (gdb_stdlog,
2461 "infrun: resume : clear step\n");
2466 fprintf_unfiltered (gdb_stdlog,
2467 "infrun: resume (step=%d, signal=%s), "
2468 "trap_expected=%d, current thread [%s] at %s\n",
2469 step, gdb_signal_to_symbol_string (sig),
2470 tp->control.trap_expected,
2471 target_pid_to_str (inferior_ptid),
2472 paddress (gdbarch, pc));
2474 /* Normally, by the time we reach `resume', the breakpoints are either
2475 removed or inserted, as appropriate. The exception is if we're sitting
2476 at a permanent breakpoint; we need to step over it, but permanent
2477 breakpoints can't be removed. So we have to test for it here. */
2478 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2480 if (sig != GDB_SIGNAL_0)
2482 /* We have a signal to pass to the inferior. The resume
2483 may, or may not take us to the signal handler. If this
2484 is a step, we'll need to stop in the signal handler, if
2485 there's one, (if the target supports stepping into
2486 handlers), or in the next mainline instruction, if
2487 there's no handler. If this is a continue, we need to be
2488 sure to run the handler with all breakpoints inserted.
2489 In all cases, set a breakpoint at the current address
2490 (where the handler returns to), and once that breakpoint
2491 is hit, resume skipping the permanent breakpoint. If
2492 that breakpoint isn't hit, then we've stepped into the
2493 signal handler (or hit some other event). We'll delete
2494 the step-resume breakpoint then. */
2497 fprintf_unfiltered (gdb_stdlog,
2498 "infrun: resume: skipping permanent breakpoint, "
2499 "deliver signal first\n");
2501 clear_step_over_info ();
2502 tp->control.trap_expected = 0;
2504 if (tp->control.step_resume_breakpoint == NULL)
2506 /* Set a "high-priority" step-resume, as we don't want
2507 user breakpoints at PC to trigger (again) when this
2509 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2510 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2512 tp->step_after_step_resume_breakpoint = step;
2515 insert_breakpoints ();
2519 /* There's no signal to pass, we can go ahead and skip the
2520 permanent breakpoint manually. */
2522 fprintf_unfiltered (gdb_stdlog,
2523 "infrun: resume: skipping permanent breakpoint\n");
2524 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2525 /* Update pc to reflect the new address from which we will
2526 execute instructions. */
2527 pc = regcache_read_pc (regcache);
2531 /* We've already advanced the PC, so the stepping part
2532 is done. Now we need to arrange for a trap to be
2533 reported to handle_inferior_event. Set a breakpoint
2534 at the current PC, and run to it. Don't update
2535 prev_pc, because if we end in
2536 switch_back_to_stepped_thread, we want the "expected
2537 thread advanced also" branch to be taken. IOW, we
2538 don't want this thread to step further from PC
2540 gdb_assert (!step_over_info_valid_p ());
2541 insert_single_step_breakpoint (gdbarch, aspace, pc);
2542 insert_breakpoints ();
2544 resume_ptid = internal_resume_ptid (user_step);
2545 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2546 discard_cleanups (old_cleanups);
2553 /* If we have a breakpoint to step over, make sure to do a single
2554 step only. Same if we have software watchpoints. */
2555 if (tp->control.trap_expected || bpstat_should_step ())
2556 tp->control.may_range_step = 0;
2558 /* If enabled, step over breakpoints by executing a copy of the
2559 instruction at a different address.
2561 We can't use displaced stepping when we have a signal to deliver;
2562 the comments for displaced_step_prepare explain why. The
2563 comments in the handle_inferior event for dealing with 'random
2564 signals' explain what we do instead.
2566 We can't use displaced stepping when we are waiting for vfork_done
2567 event, displaced stepping breaks the vfork child similarly as single
2568 step software breakpoint. */
2569 if (tp->control.trap_expected
2570 && use_displaced_stepping (tp)
2571 && !step_over_info_valid_p ()
2572 && sig == GDB_SIGNAL_0
2573 && !current_inferior ()->waiting_for_vfork_done)
2575 int prepared = displaced_step_prepare (inferior_ptid);
2580 fprintf_unfiltered (gdb_stdlog,
2581 "Got placed in step-over queue\n");
2583 tp->control.trap_expected = 0;
2584 discard_cleanups (old_cleanups);
2587 else if (prepared < 0)
2589 /* Fallback to stepping over the breakpoint in-line. */
2591 if (target_is_non_stop_p ())
2592 stop_all_threads ();
2594 set_step_over_info (regcache->aspace (),
2595 regcache_read_pc (regcache), 0, tp->global_num);
2597 step = maybe_software_singlestep (gdbarch, pc);
2599 insert_breakpoints ();
2601 else if (prepared > 0)
2603 struct displaced_step_inferior_state *displaced;
2605 /* Update pc to reflect the new address from which we will
2606 execute instructions due to displaced stepping. */
2607 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2609 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2610 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2611 displaced->step_closure);
2615 /* Do we need to do it the hard way, w/temp breakpoints? */
2617 step = maybe_software_singlestep (gdbarch, pc);
2619 /* Currently, our software single-step implementation leads to different
2620 results than hardware single-stepping in one situation: when stepping
2621 into delivering a signal which has an associated signal handler,
2622 hardware single-step will stop at the first instruction of the handler,
2623 while software single-step will simply skip execution of the handler.
2625 For now, this difference in behavior is accepted since there is no
2626 easy way to actually implement single-stepping into a signal handler
2627 without kernel support.
2629 However, there is one scenario where this difference leads to follow-on
2630 problems: if we're stepping off a breakpoint by removing all breakpoints
2631 and then single-stepping. In this case, the software single-step
2632 behavior means that even if there is a *breakpoint* in the signal
2633 handler, GDB still would not stop.
2635 Fortunately, we can at least fix this particular issue. We detect
2636 here the case where we are about to deliver a signal while software
2637 single-stepping with breakpoints removed. In this situation, we
2638 revert the decisions to remove all breakpoints and insert single-
2639 step breakpoints, and instead we install a step-resume breakpoint
2640 at the current address, deliver the signal without stepping, and
2641 once we arrive back at the step-resume breakpoint, actually step
2642 over the breakpoint we originally wanted to step over. */
2643 if (thread_has_single_step_breakpoints_set (tp)
2644 && sig != GDB_SIGNAL_0
2645 && step_over_info_valid_p ())
2647 /* If we have nested signals or a pending signal is delivered
2648 immediately after a handler returns, might might already have
2649 a step-resume breakpoint set on the earlier handler. We cannot
2650 set another step-resume breakpoint; just continue on until the
2651 original breakpoint is hit. */
2652 if (tp->control.step_resume_breakpoint == NULL)
2654 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2655 tp->step_after_step_resume_breakpoint = 1;
2658 delete_single_step_breakpoints (tp);
2660 clear_step_over_info ();
2661 tp->control.trap_expected = 0;
2663 insert_breakpoints ();
2666 /* If STEP is set, it's a request to use hardware stepping
2667 facilities. But in that case, we should never
2668 use singlestep breakpoint. */
2669 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2671 /* Decide the set of threads to ask the target to resume. */
2672 if (tp->control.trap_expected)
2674 /* We're allowing a thread to run past a breakpoint it has
2675 hit, either by single-stepping the thread with the breakpoint
2676 removed, or by displaced stepping, with the breakpoint inserted.
2677 In the former case, we need to single-step only this thread,
2678 and keep others stopped, as they can miss this breakpoint if
2679 allowed to run. That's not really a problem for displaced
2680 stepping, but, we still keep other threads stopped, in case
2681 another thread is also stopped for a breakpoint waiting for
2682 its turn in the displaced stepping queue. */
2683 resume_ptid = inferior_ptid;
2686 resume_ptid = internal_resume_ptid (user_step);
2688 if (execution_direction != EXEC_REVERSE
2689 && step && breakpoint_inserted_here_p (aspace, pc))
2691 /* There are two cases where we currently need to step a
2692 breakpoint instruction when we have a signal to deliver:
2694 - See handle_signal_stop where we handle random signals that
2695 could take out us out of the stepping range. Normally, in
2696 that case we end up continuing (instead of stepping) over the
2697 signal handler with a breakpoint at PC, but there are cases
2698 where we should _always_ single-step, even if we have a
2699 step-resume breakpoint, like when a software watchpoint is
2700 set. Assuming single-stepping and delivering a signal at the
2701 same time would takes us to the signal handler, then we could
2702 have removed the breakpoint at PC to step over it. However,
2703 some hardware step targets (like e.g., Mac OS) can't step
2704 into signal handlers, and for those, we need to leave the
2705 breakpoint at PC inserted, as otherwise if the handler
2706 recurses and executes PC again, it'll miss the breakpoint.
2707 So we leave the breakpoint inserted anyway, but we need to
2708 record that we tried to step a breakpoint instruction, so
2709 that adjust_pc_after_break doesn't end up confused.
2711 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2712 in one thread after another thread that was stepping had been
2713 momentarily paused for a step-over. When we re-resume the
2714 stepping thread, it may be resumed from that address with a
2715 breakpoint that hasn't trapped yet. Seen with
2716 gdb.threads/non-stop-fair-events.exp, on targets that don't
2717 do displaced stepping. */
2720 fprintf_unfiltered (gdb_stdlog,
2721 "infrun: resume: [%s] stepped breakpoint\n",
2722 target_pid_to_str (tp->ptid));
2724 tp->stepped_breakpoint = 1;
2726 /* Most targets can step a breakpoint instruction, thus
2727 executing it normally. But if this one cannot, just
2728 continue and we will hit it anyway. */
2729 if (gdbarch_cannot_step_breakpoint (gdbarch))
2734 && tp->control.trap_expected
2735 && use_displaced_stepping (tp)
2736 && !step_over_info_valid_p ())
2738 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2739 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2740 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2743 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2744 paddress (resume_gdbarch, actual_pc));
2745 read_memory (actual_pc, buf, sizeof (buf));
2746 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2749 if (tp->control.may_range_step)
2751 /* If we're resuming a thread with the PC out of the step
2752 range, then we're doing some nested/finer run control
2753 operation, like stepping the thread out of the dynamic
2754 linker or the displaced stepping scratch pad. We
2755 shouldn't have allowed a range step then. */
2756 gdb_assert (pc_in_thread_step_range (pc, tp));
2759 do_target_resume (resume_ptid, step, sig);
2761 discard_cleanups (old_cleanups);
2768 /* Counter that tracks number of user visible stops. This can be used
2769 to tell whether a command has proceeded the inferior past the
2770 current location. This allows e.g., inferior function calls in
2771 breakpoint commands to not interrupt the command list. When the
2772 call finishes successfully, the inferior is standing at the same
2773 breakpoint as if nothing happened (and so we don't call
2775 static ULONGEST current_stop_id;
2782 return current_stop_id;
2785 /* Called when we report a user visible stop. */
2793 /* Clear out all variables saying what to do when inferior is continued.
2794 First do this, then set the ones you want, then call `proceed'. */
2797 clear_proceed_status_thread (struct thread_info *tp)
2800 fprintf_unfiltered (gdb_stdlog,
2801 "infrun: clear_proceed_status_thread (%s)\n",
2802 target_pid_to_str (tp->ptid));
2804 /* If we're starting a new sequence, then the previous finished
2805 single-step is no longer relevant. */
2806 if (tp->suspend.waitstatus_pending_p)
2808 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2811 fprintf_unfiltered (gdb_stdlog,
2812 "infrun: clear_proceed_status: pending "
2813 "event of %s was a finished step. "
2815 target_pid_to_str (tp->ptid));
2817 tp->suspend.waitstatus_pending_p = 0;
2818 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2820 else if (debug_infrun)
2823 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2825 fprintf_unfiltered (gdb_stdlog,
2826 "infrun: clear_proceed_status_thread: thread %s "
2827 "has pending wait status %s "
2828 "(currently_stepping=%d).\n",
2829 target_pid_to_str (tp->ptid), statstr.c_str (),
2830 currently_stepping (tp));
2834 /* If this signal should not be seen by program, give it zero.
2835 Used for debugging signals. */
2836 if (!signal_pass_state (tp->suspend.stop_signal))
2837 tp->suspend.stop_signal = GDB_SIGNAL_0;
2839 thread_fsm_delete (tp->thread_fsm);
2840 tp->thread_fsm = NULL;
2842 tp->control.trap_expected = 0;
2843 tp->control.step_range_start = 0;
2844 tp->control.step_range_end = 0;
2845 tp->control.may_range_step = 0;
2846 tp->control.step_frame_id = null_frame_id;
2847 tp->control.step_stack_frame_id = null_frame_id;
2848 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2849 tp->control.step_start_function = NULL;
2850 tp->stop_requested = 0;
2852 tp->control.stop_step = 0;
2854 tp->control.proceed_to_finish = 0;
2856 tp->control.stepping_command = 0;
2858 /* Discard any remaining commands or status from previous stop. */
2859 bpstat_clear (&tp->control.stop_bpstat);
2863 clear_proceed_status (int step)
2865 /* With scheduler-locking replay, stop replaying other threads if we're
2866 not replaying the user-visible resume ptid.
2868 This is a convenience feature to not require the user to explicitly
2869 stop replaying the other threads. We're assuming that the user's
2870 intent is to resume tracing the recorded process. */
2871 if (!non_stop && scheduler_mode == schedlock_replay
2872 && target_record_is_replaying (minus_one_ptid)
2873 && !target_record_will_replay (user_visible_resume_ptid (step),
2874 execution_direction))
2875 target_record_stop_replaying ();
2879 struct thread_info *tp;
2882 resume_ptid = user_visible_resume_ptid (step);
2884 /* In all-stop mode, delete the per-thread status of all threads
2885 we're about to resume, implicitly and explicitly. */
2886 ALL_NON_EXITED_THREADS (tp)
2888 if (!ptid_match (tp->ptid, resume_ptid))
2890 clear_proceed_status_thread (tp);
2894 if (!ptid_equal (inferior_ptid, null_ptid))
2896 struct inferior *inferior;
2900 /* If in non-stop mode, only delete the per-thread status of
2901 the current thread. */
2902 clear_proceed_status_thread (inferior_thread ());
2905 inferior = current_inferior ();
2906 inferior->control.stop_soon = NO_STOP_QUIETLY;
2909 observer_notify_about_to_proceed ();
2912 /* Returns true if TP is still stopped at a breakpoint that needs
2913 stepping-over in order to make progress. If the breakpoint is gone
2914 meanwhile, we can skip the whole step-over dance. */
2917 thread_still_needs_step_over_bp (struct thread_info *tp)
2919 if (tp->stepping_over_breakpoint)
2921 struct regcache *regcache = get_thread_regcache (tp->ptid);
2923 if (breakpoint_here_p (regcache->aspace (),
2924 regcache_read_pc (regcache))
2925 == ordinary_breakpoint_here)
2928 tp->stepping_over_breakpoint = 0;
2934 /* Check whether thread TP still needs to start a step-over in order
2935 to make progress when resumed. Returns an bitwise or of enum
2936 step_over_what bits, indicating what needs to be stepped over. */
2938 static step_over_what
2939 thread_still_needs_step_over (struct thread_info *tp)
2941 step_over_what what = 0;
2943 if (thread_still_needs_step_over_bp (tp))
2944 what |= STEP_OVER_BREAKPOINT;
2946 if (tp->stepping_over_watchpoint
2947 && !target_have_steppable_watchpoint)
2948 what |= STEP_OVER_WATCHPOINT;
2953 /* Returns true if scheduler locking applies. STEP indicates whether
2954 we're about to do a step/next-like command to a thread. */
2957 schedlock_applies (struct thread_info *tp)
2959 return (scheduler_mode == schedlock_on
2960 || (scheduler_mode == schedlock_step
2961 && tp->control.stepping_command)
2962 || (scheduler_mode == schedlock_replay
2963 && target_record_will_replay (minus_one_ptid,
2964 execution_direction)));
2967 /* Basic routine for continuing the program in various fashions.
2969 ADDR is the address to resume at, or -1 for resume where stopped.
2970 SIGGNAL is the signal to give it, or 0 for none,
2971 or -1 for act according to how it stopped.
2972 STEP is nonzero if should trap after one instruction.
2973 -1 means return after that and print nothing.
2974 You should probably set various step_... variables
2975 before calling here, if you are stepping.
2977 You should call clear_proceed_status before calling proceed. */
2980 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2982 struct regcache *regcache;
2983 struct gdbarch *gdbarch;
2984 struct thread_info *tp;
2986 struct address_space *aspace;
2988 struct execution_control_state ecss;
2989 struct execution_control_state *ecs = &ecss;
2990 struct cleanup *old_chain;
2993 /* If we're stopped at a fork/vfork, follow the branch set by the
2994 "set follow-fork-mode" command; otherwise, we'll just proceed
2995 resuming the current thread. */
2996 if (!follow_fork ())
2998 /* The target for some reason decided not to resume. */
3000 if (target_can_async_p ())
3001 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3005 /* We'll update this if & when we switch to a new thread. */
3006 previous_inferior_ptid = inferior_ptid;
3008 regcache = get_current_regcache ();
3009 gdbarch = regcache->arch ();
3010 aspace = regcache->aspace ();
3011 pc = regcache_read_pc (regcache);
3012 tp = inferior_thread ();
3014 /* Fill in with reasonable starting values. */
3015 init_thread_stepping_state (tp);
3017 gdb_assert (!thread_is_in_step_over_chain (tp));
3019 if (addr == (CORE_ADDR) -1)
3022 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3023 && execution_direction != EXEC_REVERSE)
3024 /* There is a breakpoint at the address we will resume at,
3025 step one instruction before inserting breakpoints so that
3026 we do not stop right away (and report a second hit at this
3029 Note, we don't do this in reverse, because we won't
3030 actually be executing the breakpoint insn anyway.
3031 We'll be (un-)executing the previous instruction. */
3032 tp->stepping_over_breakpoint = 1;
3033 else if (gdbarch_single_step_through_delay_p (gdbarch)
3034 && gdbarch_single_step_through_delay (gdbarch,
3035 get_current_frame ()))
3036 /* We stepped onto an instruction that needs to be stepped
3037 again before re-inserting the breakpoint, do so. */
3038 tp->stepping_over_breakpoint = 1;
3042 regcache_write_pc (regcache, addr);
3045 if (siggnal != GDB_SIGNAL_DEFAULT)
3046 tp->suspend.stop_signal = siggnal;
3048 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3050 /* If an exception is thrown from this point on, make sure to
3051 propagate GDB's knowledge of the executing state to the
3052 frontend/user running state. */
3053 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3055 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3056 threads (e.g., we might need to set threads stepping over
3057 breakpoints first), from the user/frontend's point of view, all
3058 threads in RESUME_PTID are now running. Unless we're calling an
3059 inferior function, as in that case we pretend the inferior
3060 doesn't run at all. */
3061 if (!tp->control.in_infcall)
3062 set_running (resume_ptid, 1);
3065 fprintf_unfiltered (gdb_stdlog,
3066 "infrun: proceed (addr=%s, signal=%s)\n",
3067 paddress (gdbarch, addr),
3068 gdb_signal_to_symbol_string (siggnal));
3070 annotate_starting ();
3072 /* Make sure that output from GDB appears before output from the
3074 gdb_flush (gdb_stdout);
3076 /* In a multi-threaded task we may select another thread and
3077 then continue or step.
3079 But if a thread that we're resuming had stopped at a breakpoint,
3080 it will immediately cause another breakpoint stop without any
3081 execution (i.e. it will report a breakpoint hit incorrectly). So
3082 we must step over it first.
3084 Look for threads other than the current (TP) that reported a
3085 breakpoint hit and haven't been resumed yet since. */
3087 /* If scheduler locking applies, we can avoid iterating over all
3089 if (!non_stop && !schedlock_applies (tp))
3091 struct thread_info *current = tp;
3093 ALL_NON_EXITED_THREADS (tp)
3095 /* Ignore the current thread here. It's handled
3100 /* Ignore threads of processes we're not resuming. */
3101 if (!ptid_match (tp->ptid, resume_ptid))
3104 if (!thread_still_needs_step_over (tp))
3107 gdb_assert (!thread_is_in_step_over_chain (tp));
3110 fprintf_unfiltered (gdb_stdlog,
3111 "infrun: need to step-over [%s] first\n",
3112 target_pid_to_str (tp->ptid));
3114 thread_step_over_chain_enqueue (tp);
3120 /* Enqueue the current thread last, so that we move all other
3121 threads over their breakpoints first. */
3122 if (tp->stepping_over_breakpoint)
3123 thread_step_over_chain_enqueue (tp);
3125 /* If the thread isn't started, we'll still need to set its prev_pc,
3126 so that switch_back_to_stepped_thread knows the thread hasn't
3127 advanced. Must do this before resuming any thread, as in
3128 all-stop/remote, once we resume we can't send any other packet
3129 until the target stops again. */
3130 tp->prev_pc = regcache_read_pc (regcache);
3133 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3135 started = start_step_over ();
3137 if (step_over_info_valid_p ())
3139 /* Either this thread started a new in-line step over, or some
3140 other thread was already doing one. In either case, don't
3141 resume anything else until the step-over is finished. */
3143 else if (started && !target_is_non_stop_p ())
3145 /* A new displaced stepping sequence was started. In all-stop,
3146 we can't talk to the target anymore until it next stops. */
3148 else if (!non_stop && target_is_non_stop_p ())
3150 /* In all-stop, but the target is always in non-stop mode.
3151 Start all other threads that are implicitly resumed too. */
3152 ALL_NON_EXITED_THREADS (tp)
3154 /* Ignore threads of processes we're not resuming. */
3155 if (!ptid_match (tp->ptid, resume_ptid))
3161 fprintf_unfiltered (gdb_stdlog,
3162 "infrun: proceed: [%s] resumed\n",
3163 target_pid_to_str (tp->ptid));
3164 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3168 if (thread_is_in_step_over_chain (tp))
3171 fprintf_unfiltered (gdb_stdlog,
3172 "infrun: proceed: [%s] needs step-over\n",
3173 target_pid_to_str (tp->ptid));
3178 fprintf_unfiltered (gdb_stdlog,
3179 "infrun: proceed: resuming %s\n",
3180 target_pid_to_str (tp->ptid));
3182 reset_ecs (ecs, tp);
3183 switch_to_thread (tp->ptid);
3184 keep_going_pass_signal (ecs);
3185 if (!ecs->wait_some_more)
3186 error (_("Command aborted."));
3189 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3191 /* The thread wasn't started, and isn't queued, run it now. */
3192 reset_ecs (ecs, tp);
3193 switch_to_thread (tp->ptid);
3194 keep_going_pass_signal (ecs);
3195 if (!ecs->wait_some_more)
3196 error (_("Command aborted."));
3200 target_commit_resume ();
3202 discard_cleanups (old_chain);
3204 /* Tell the event loop to wait for it to stop. If the target
3205 supports asynchronous execution, it'll do this from within
3207 if (!target_can_async_p ())
3208 mark_async_event_handler (infrun_async_inferior_event_token);
3212 /* Start remote-debugging of a machine over a serial link. */
3215 start_remote (int from_tty)
3217 struct inferior *inferior;
3219 inferior = current_inferior ();
3220 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3222 /* Always go on waiting for the target, regardless of the mode. */
3223 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3224 indicate to wait_for_inferior that a target should timeout if
3225 nothing is returned (instead of just blocking). Because of this,
3226 targets expecting an immediate response need to, internally, set
3227 things up so that the target_wait() is forced to eventually
3229 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3230 differentiate to its caller what the state of the target is after
3231 the initial open has been performed. Here we're assuming that
3232 the target has stopped. It should be possible to eventually have
3233 target_open() return to the caller an indication that the target
3234 is currently running and GDB state should be set to the same as
3235 for an async run. */
3236 wait_for_inferior ();
3238 /* Now that the inferior has stopped, do any bookkeeping like
3239 loading shared libraries. We want to do this before normal_stop,
3240 so that the displayed frame is up to date. */
3241 post_create_inferior (¤t_target, from_tty);
3246 /* Initialize static vars when a new inferior begins. */
3249 init_wait_for_inferior (void)
3251 /* These are meaningless until the first time through wait_for_inferior. */
3253 breakpoint_init_inferior (inf_starting);
3255 clear_proceed_status (0);
3257 target_last_wait_ptid = minus_one_ptid;
3259 previous_inferior_ptid = inferior_ptid;
3261 /* Discard any skipped inlined frames. */
3262 clear_inline_frame_state (minus_one_ptid);
3267 static void handle_inferior_event (struct execution_control_state *ecs);
3269 static void handle_step_into_function (struct gdbarch *gdbarch,
3270 struct execution_control_state *ecs);
3271 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3272 struct execution_control_state *ecs);
3273 static void handle_signal_stop (struct execution_control_state *ecs);
3274 static void check_exception_resume (struct execution_control_state *,
3275 struct frame_info *);
3277 static void end_stepping_range (struct execution_control_state *ecs);
3278 static void stop_waiting (struct execution_control_state *ecs);
3279 static void keep_going (struct execution_control_state *ecs);
3280 static void process_event_stop_test (struct execution_control_state *ecs);
3281 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3283 /* This function is attached as a "thread_stop_requested" observer.
3284 Cleanup local state that assumed the PTID was to be resumed, and
3285 report the stop to the frontend. */
3288 infrun_thread_stop_requested (ptid_t ptid)
3290 struct thread_info *tp;
3292 /* PTID was requested to stop. If the thread was already stopped,
3293 but the user/frontend doesn't know about that yet (e.g., the
3294 thread had been temporarily paused for some step-over), set up
3295 for reporting the stop now. */
3296 ALL_NON_EXITED_THREADS (tp)
3297 if (ptid_match (tp->ptid, ptid))
3299 if (tp->state != THREAD_RUNNING)
3304 /* Remove matching threads from the step-over queue, so
3305 start_step_over doesn't try to resume them
3307 if (thread_is_in_step_over_chain (tp))
3308 thread_step_over_chain_remove (tp);
3310 /* If the thread is stopped, but the user/frontend doesn't
3311 know about that yet, queue a pending event, as if the
3312 thread had just stopped now. Unless the thread already had
3314 if (!tp->suspend.waitstatus_pending_p)
3316 tp->suspend.waitstatus_pending_p = 1;
3317 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3318 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3321 /* Clear the inline-frame state, since we're re-processing the
3323 clear_inline_frame_state (tp->ptid);
3325 /* If this thread was paused because some other thread was
3326 doing an inline-step over, let that finish first. Once
3327 that happens, we'll restart all threads and consume pending
3328 stop events then. */
3329 if (step_over_info_valid_p ())
3332 /* Otherwise we can process the (new) pending event now. Set
3333 it so this pending event is considered by
3340 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3342 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3343 nullify_last_target_wait_ptid ();
3346 /* Delete the step resume, single-step and longjmp/exception resume
3347 breakpoints of TP. */
3350 delete_thread_infrun_breakpoints (struct thread_info *tp)
3352 delete_step_resume_breakpoint (tp);
3353 delete_exception_resume_breakpoint (tp);
3354 delete_single_step_breakpoints (tp);
3357 /* If the target still has execution, call FUNC for each thread that
3358 just stopped. In all-stop, that's all the non-exited threads; in
3359 non-stop, that's the current thread, only. */
3361 typedef void (*for_each_just_stopped_thread_callback_func)
3362 (struct thread_info *tp);
3365 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3367 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3370 if (target_is_non_stop_p ())
3372 /* If in non-stop mode, only the current thread stopped. */
3373 func (inferior_thread ());
3377 struct thread_info *tp;
3379 /* In all-stop mode, all threads have stopped. */
3380 ALL_NON_EXITED_THREADS (tp)
3387 /* Delete the step resume and longjmp/exception resume breakpoints of
3388 the threads that just stopped. */
3391 delete_just_stopped_threads_infrun_breakpoints (void)
3393 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3396 /* Delete the single-step breakpoints of the threads that just
3400 delete_just_stopped_threads_single_step_breakpoints (void)
3402 for_each_just_stopped_thread (delete_single_step_breakpoints);
3405 /* A cleanup wrapper. */
3408 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3410 delete_just_stopped_threads_infrun_breakpoints ();
3416 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3417 const struct target_waitstatus *ws)
3419 std::string status_string = target_waitstatus_to_string (ws);
3422 /* The text is split over several lines because it was getting too long.
3423 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3424 output as a unit; we want only one timestamp printed if debug_timestamp
3427 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3428 ptid_get_pid (waiton_ptid),
3429 ptid_get_lwp (waiton_ptid),
3430 ptid_get_tid (waiton_ptid));
3431 if (ptid_get_pid (waiton_ptid) != -1)
3432 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3433 stb.printf (", status) =\n");
3434 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3435 ptid_get_pid (result_ptid),
3436 ptid_get_lwp (result_ptid),
3437 ptid_get_tid (result_ptid),
3438 target_pid_to_str (result_ptid));
3439 stb.printf ("infrun: %s\n", status_string.c_str ());
3441 /* This uses %s in part to handle %'s in the text, but also to avoid
3442 a gcc error: the format attribute requires a string literal. */
3443 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3446 /* Select a thread at random, out of those which are resumed and have
3449 static struct thread_info *
3450 random_pending_event_thread (ptid_t waiton_ptid)
3452 struct thread_info *event_tp;
3454 int random_selector;
3456 /* First see how many events we have. Count only resumed threads
3457 that have an event pending. */
3458 ALL_NON_EXITED_THREADS (event_tp)
3459 if (ptid_match (event_tp->ptid, waiton_ptid)
3460 && event_tp->resumed
3461 && event_tp->suspend.waitstatus_pending_p)
3464 if (num_events == 0)
3467 /* Now randomly pick a thread out of those that have had events. */
3468 random_selector = (int)
3469 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3471 if (debug_infrun && num_events > 1)
3472 fprintf_unfiltered (gdb_stdlog,
3473 "infrun: Found %d events, selecting #%d\n",
3474 num_events, random_selector);
3476 /* Select the Nth thread that has had an event. */
3477 ALL_NON_EXITED_THREADS (event_tp)
3478 if (ptid_match (event_tp->ptid, waiton_ptid)
3479 && event_tp->resumed
3480 && event_tp->suspend.waitstatus_pending_p)
3481 if (random_selector-- == 0)
3487 /* Wrapper for target_wait that first checks whether threads have
3488 pending statuses to report before actually asking the target for
3492 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3495 struct thread_info *tp;
3497 /* First check if there is a resumed thread with a wait status
3499 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3501 tp = random_pending_event_thread (ptid);
3506 fprintf_unfiltered (gdb_stdlog,
3507 "infrun: Waiting for specific thread %s.\n",
3508 target_pid_to_str (ptid));
3510 /* We have a specific thread to check. */
3511 tp = find_thread_ptid (ptid);
3512 gdb_assert (tp != NULL);
3513 if (!tp->suspend.waitstatus_pending_p)
3518 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3519 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3521 struct regcache *regcache = get_thread_regcache (tp->ptid);
3522 struct gdbarch *gdbarch = regcache->arch ();
3526 pc = regcache_read_pc (regcache);
3528 if (pc != tp->suspend.stop_pc)
3531 fprintf_unfiltered (gdb_stdlog,
3532 "infrun: PC of %s changed. was=%s, now=%s\n",
3533 target_pid_to_str (tp->ptid),
3534 paddress (gdbarch, tp->prev_pc),
3535 paddress (gdbarch, pc));
3538 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3541 fprintf_unfiltered (gdb_stdlog,
3542 "infrun: previous breakpoint of %s, at %s gone\n",
3543 target_pid_to_str (tp->ptid),
3544 paddress (gdbarch, pc));
3552 fprintf_unfiltered (gdb_stdlog,
3553 "infrun: pending event of %s cancelled.\n",
3554 target_pid_to_str (tp->ptid));
3556 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3557 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3566 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3568 fprintf_unfiltered (gdb_stdlog,
3569 "infrun: Using pending wait status %s for %s.\n",
3571 target_pid_to_str (tp->ptid));
3574 /* Now that we've selected our final event LWP, un-adjust its PC
3575 if it was a software breakpoint (and the target doesn't
3576 always adjust the PC itself). */
3577 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3578 && !target_supports_stopped_by_sw_breakpoint ())
3580 struct regcache *regcache;
3581 struct gdbarch *gdbarch;
3584 regcache = get_thread_regcache (tp->ptid);
3585 gdbarch = regcache->arch ();
3587 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3592 pc = regcache_read_pc (regcache);
3593 regcache_write_pc (regcache, pc + decr_pc);
3597 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3598 *status = tp->suspend.waitstatus;
3599 tp->suspend.waitstatus_pending_p = 0;
3601 /* Wake up the event loop again, until all pending events are
3603 if (target_is_async_p ())
3604 mark_async_event_handler (infrun_async_inferior_event_token);
3608 /* But if we don't find one, we'll have to wait. */
3610 if (deprecated_target_wait_hook)
3611 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3613 event_ptid = target_wait (ptid, status, options);
3618 /* Prepare and stabilize the inferior for detaching it. E.g.,
3619 detaching while a thread is displaced stepping is a recipe for
3620 crashing it, as nothing would readjust the PC out of the scratch
3624 prepare_for_detach (void)
3626 struct inferior *inf = current_inferior ();
3627 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3628 struct displaced_step_inferior_state *displaced;
3630 displaced = get_displaced_stepping_state (inf->pid);
3632 /* Is any thread of this process displaced stepping? If not,
3633 there's nothing else to do. */
3634 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3638 fprintf_unfiltered (gdb_stdlog,
3639 "displaced-stepping in-process while detaching");
3641 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3643 while (!ptid_equal (displaced->step_ptid, null_ptid))
3645 struct cleanup *old_chain_2;
3646 struct execution_control_state ecss;
3647 struct execution_control_state *ecs;
3650 memset (ecs, 0, sizeof (*ecs));
3652 overlay_cache_invalid = 1;
3653 /* Flush target cache before starting to handle each event.
3654 Target was running and cache could be stale. This is just a
3655 heuristic. Running threads may modify target memory, but we
3656 don't get any event. */
3657 target_dcache_invalidate ();
3659 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3662 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3664 /* If an error happens while handling the event, propagate GDB's
3665 knowledge of the executing state to the frontend/user running
3667 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3670 /* Now figure out what to do with the result of the result. */
3671 handle_inferior_event (ecs);
3673 /* No error, don't finish the state yet. */
3674 discard_cleanups (old_chain_2);
3676 /* Breakpoints and watchpoints are not installed on the target
3677 at this point, and signals are passed directly to the
3678 inferior, so this must mean the process is gone. */
3679 if (!ecs->wait_some_more)
3681 restore_detaching.release ();
3682 error (_("Program exited while detaching"));
3686 restore_detaching.release ();
3689 /* Wait for control to return from inferior to debugger.
3691 If inferior gets a signal, we may decide to start it up again
3692 instead of returning. That is why there is a loop in this function.
3693 When this function actually returns it means the inferior
3694 should be left stopped and GDB should read more commands. */
3697 wait_for_inferior (void)
3699 struct cleanup *old_cleanups;
3700 struct cleanup *thread_state_chain;
3704 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3707 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3710 /* If an error happens while handling the event, propagate GDB's
3711 knowledge of the executing state to the frontend/user running
3713 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3717 struct execution_control_state ecss;
3718 struct execution_control_state *ecs = &ecss;
3719 ptid_t waiton_ptid = minus_one_ptid;
3721 memset (ecs, 0, sizeof (*ecs));
3723 overlay_cache_invalid = 1;
3725 /* Flush target cache before starting to handle each event.
3726 Target was running and cache could be stale. This is just a
3727 heuristic. Running threads may modify target memory, but we
3728 don't get any event. */
3729 target_dcache_invalidate ();
3731 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3734 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3736 /* Now figure out what to do with the result of the result. */
3737 handle_inferior_event (ecs);
3739 if (!ecs->wait_some_more)
3743 /* No error, don't finish the state yet. */
3744 discard_cleanups (thread_state_chain);
3746 do_cleanups (old_cleanups);
3749 /* Cleanup that reinstalls the readline callback handler, if the
3750 target is running in the background. If while handling the target
3751 event something triggered a secondary prompt, like e.g., a
3752 pagination prompt, we'll have removed the callback handler (see
3753 gdb_readline_wrapper_line). Need to do this as we go back to the
3754 event loop, ready to process further input. Note this has no
3755 effect if the handler hasn't actually been removed, because calling
3756 rl_callback_handler_install resets the line buffer, thus losing
3760 reinstall_readline_callback_handler_cleanup (void *arg)
3762 struct ui *ui = current_ui;
3766 /* We're not going back to the top level event loop yet. Don't
3767 install the readline callback, as it'd prep the terminal,
3768 readline-style (raw, noecho) (e.g., --batch). We'll install
3769 it the next time the prompt is displayed, when we're ready
3774 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3775 gdb_rl_callback_handler_reinstall ();
3778 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3779 that's just the event thread. In all-stop, that's all threads. */
3782 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3784 struct thread_info *thr = ecs->event_thread;
3786 if (thr != NULL && thr->thread_fsm != NULL)
3787 thread_fsm_clean_up (thr->thread_fsm, thr);
3791 ALL_NON_EXITED_THREADS (thr)
3793 if (thr->thread_fsm == NULL)
3795 if (thr == ecs->event_thread)
3798 switch_to_thread (thr->ptid);
3799 thread_fsm_clean_up (thr->thread_fsm, thr);
3802 if (ecs->event_thread != NULL)
3803 switch_to_thread (ecs->event_thread->ptid);
3807 /* Helper for all_uis_check_sync_execution_done that works on the
3811 check_curr_ui_sync_execution_done (void)
3813 struct ui *ui = current_ui;
3815 if (ui->prompt_state == PROMPT_NEEDED
3817 && !gdb_in_secondary_prompt_p (ui))
3819 target_terminal::ours ();
3820 observer_notify_sync_execution_done ();
3821 ui_register_input_event_handler (ui);
3828 all_uis_check_sync_execution_done (void)
3830 SWITCH_THRU_ALL_UIS ()
3832 check_curr_ui_sync_execution_done ();
3839 all_uis_on_sync_execution_starting (void)
3841 SWITCH_THRU_ALL_UIS ()
3843 if (current_ui->prompt_state == PROMPT_NEEDED)
3844 async_disable_stdin ();
3848 /* Asynchronous version of wait_for_inferior. It is called by the
3849 event loop whenever a change of state is detected on the file
3850 descriptor corresponding to the target. It can be called more than
3851 once to complete a single execution command. In such cases we need
3852 to keep the state in a global variable ECSS. If it is the last time
3853 that this function is called for a single execution command, then
3854 report to the user that the inferior has stopped, and do the
3855 necessary cleanups. */
3858 fetch_inferior_event (void *client_data)
3860 struct execution_control_state ecss;
3861 struct execution_control_state *ecs = &ecss;
3862 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3863 struct cleanup *ts_old_chain;
3865 ptid_t waiton_ptid = minus_one_ptid;
3867 memset (ecs, 0, sizeof (*ecs));
3869 /* Events are always processed with the main UI as current UI. This
3870 way, warnings, debug output, etc. are always consistently sent to
3871 the main console. */
3872 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3874 /* End up with readline processing input, if necessary. */
3875 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3877 /* We're handling a live event, so make sure we're doing live
3878 debugging. If we're looking at traceframes while the target is
3879 running, we're going to need to get back to that mode after
3880 handling the event. */
3883 make_cleanup_restore_current_traceframe ();
3884 set_current_traceframe (-1);
3887 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3890 /* In non-stop mode, the user/frontend should not notice a thread
3891 switch due to internal events. Make sure we reverse to the
3892 user selected thread and frame after handling the event and
3893 running any breakpoint commands. */
3894 maybe_restore_thread.emplace ();
3896 overlay_cache_invalid = 1;
3897 /* Flush target cache before starting to handle each event. Target
3898 was running and cache could be stale. This is just a heuristic.
3899 Running threads may modify target memory, but we don't get any
3901 target_dcache_invalidate ();
3903 scoped_restore save_exec_dir
3904 = make_scoped_restore (&execution_direction, target_execution_direction ());
3906 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3907 target_can_async_p () ? TARGET_WNOHANG : 0);
3910 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3912 /* If an error happens while handling the event, propagate GDB's
3913 knowledge of the executing state to the frontend/user running
3915 if (!target_is_non_stop_p ())
3916 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3918 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3920 /* Get executed before make_cleanup_restore_current_thread above to apply
3921 still for the thread which has thrown the exception. */
3922 make_bpstat_clear_actions_cleanup ();
3924 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3926 /* Now figure out what to do with the result of the result. */
3927 handle_inferior_event (ecs);
3929 if (!ecs->wait_some_more)
3931 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3932 int should_stop = 1;
3933 struct thread_info *thr = ecs->event_thread;
3934 int should_notify_stop = 1;
3936 delete_just_stopped_threads_infrun_breakpoints ();
3940 struct thread_fsm *thread_fsm = thr->thread_fsm;
3942 if (thread_fsm != NULL)
3943 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3952 clean_up_just_stopped_threads_fsms (ecs);
3954 if (thr != NULL && thr->thread_fsm != NULL)
3957 = thread_fsm_should_notify_stop (thr->thread_fsm);
3960 if (should_notify_stop)
3964 /* We may not find an inferior if this was a process exit. */
3965 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3966 proceeded = normal_stop ();
3970 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3977 /* No error, don't finish the thread states yet. */
3978 discard_cleanups (ts_old_chain);
3980 /* Revert thread and frame. */
3981 do_cleanups (old_chain);
3983 /* If a UI was in sync execution mode, and now isn't, restore its
3984 prompt (a synchronous execution command has finished, and we're
3985 ready for input). */
3986 all_uis_check_sync_execution_done ();
3989 && exec_done_display_p
3990 && (ptid_equal (inferior_ptid, null_ptid)
3991 || !is_running (inferior_ptid)))
3992 printf_unfiltered (_("completed.\n"));
3995 /* Record the frame and location we're currently stepping through. */
3997 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3999 struct thread_info *tp = inferior_thread ();
4001 tp->control.step_frame_id = get_frame_id (frame);
4002 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
4004 tp->current_symtab = sal.symtab;
4005 tp->current_line = sal.line;
4008 /* Clear context switchable stepping state. */
4011 init_thread_stepping_state (struct thread_info *tss)
4013 tss->stepped_breakpoint = 0;
4014 tss->stepping_over_breakpoint = 0;
4015 tss->stepping_over_watchpoint = 0;
4016 tss->step_after_step_resume_breakpoint = 0;
4019 /* Set the cached copy of the last ptid/waitstatus. */
4022 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4024 target_last_wait_ptid = ptid;
4025 target_last_waitstatus = status;
4028 /* Return the cached copy of the last pid/waitstatus returned by
4029 target_wait()/deprecated_target_wait_hook(). The data is actually
4030 cached by handle_inferior_event(), which gets called immediately
4031 after target_wait()/deprecated_target_wait_hook(). */
4034 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4036 *ptidp = target_last_wait_ptid;
4037 *status = target_last_waitstatus;
4041 nullify_last_target_wait_ptid (void)
4043 target_last_wait_ptid = minus_one_ptid;
4046 /* Switch thread contexts. */
4049 context_switch (ptid_t ptid)
4051 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4053 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4054 target_pid_to_str (inferior_ptid));
4055 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4056 target_pid_to_str (ptid));
4059 switch_to_thread (ptid);
4062 /* If the target can't tell whether we've hit breakpoints
4063 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4064 check whether that could have been caused by a breakpoint. If so,
4065 adjust the PC, per gdbarch_decr_pc_after_break. */
4068 adjust_pc_after_break (struct thread_info *thread,
4069 struct target_waitstatus *ws)
4071 struct regcache *regcache;
4072 struct gdbarch *gdbarch;
4073 struct address_space *aspace;
4074 CORE_ADDR breakpoint_pc, decr_pc;
4076 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4077 we aren't, just return.
4079 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4080 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4081 implemented by software breakpoints should be handled through the normal
4084 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4085 different signals (SIGILL or SIGEMT for instance), but it is less
4086 clear where the PC is pointing afterwards. It may not match
4087 gdbarch_decr_pc_after_break. I don't know any specific target that
4088 generates these signals at breakpoints (the code has been in GDB since at
4089 least 1992) so I can not guess how to handle them here.
4091 In earlier versions of GDB, a target with
4092 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4093 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4094 target with both of these set in GDB history, and it seems unlikely to be
4095 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4097 if (ws->kind != TARGET_WAITKIND_STOPPED)
4100 if (ws->value.sig != GDB_SIGNAL_TRAP)
4103 /* In reverse execution, when a breakpoint is hit, the instruction
4104 under it has already been de-executed. The reported PC always
4105 points at the breakpoint address, so adjusting it further would
4106 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4109 B1 0x08000000 : INSN1
4110 B2 0x08000001 : INSN2
4112 PC -> 0x08000003 : INSN4
4114 Say you're stopped at 0x08000003 as above. Reverse continuing
4115 from that point should hit B2 as below. Reading the PC when the
4116 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4117 been de-executed already.
4119 B1 0x08000000 : INSN1
4120 B2 PC -> 0x08000001 : INSN2
4124 We can't apply the same logic as for forward execution, because
4125 we would wrongly adjust the PC to 0x08000000, since there's a
4126 breakpoint at PC - 1. We'd then report a hit on B1, although
4127 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4129 if (execution_direction == EXEC_REVERSE)
4132 /* If the target can tell whether the thread hit a SW breakpoint,
4133 trust it. Targets that can tell also adjust the PC
4135 if (target_supports_stopped_by_sw_breakpoint ())
4138 /* Note that relying on whether a breakpoint is planted in memory to
4139 determine this can fail. E.g,. the breakpoint could have been
4140 removed since. Or the thread could have been told to step an
4141 instruction the size of a breakpoint instruction, and only
4142 _after_ was a breakpoint inserted at its address. */
4144 /* If this target does not decrement the PC after breakpoints, then
4145 we have nothing to do. */
4146 regcache = get_thread_regcache (thread->ptid);
4147 gdbarch = regcache->arch ();
4149 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4153 aspace = regcache->aspace ();
4155 /* Find the location where (if we've hit a breakpoint) the
4156 breakpoint would be. */
4157 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4159 /* If the target can't tell whether a software breakpoint triggered,
4160 fallback to figuring it out based on breakpoints we think were
4161 inserted in the target, and on whether the thread was stepped or
4164 /* Check whether there actually is a software breakpoint inserted at
4167 If in non-stop mode, a race condition is possible where we've
4168 removed a breakpoint, but stop events for that breakpoint were
4169 already queued and arrive later. To suppress those spurious
4170 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4171 and retire them after a number of stop events are reported. Note
4172 this is an heuristic and can thus get confused. The real fix is
4173 to get the "stopped by SW BP and needs adjustment" info out of
4174 the target/kernel (and thus never reach here; see above). */
4175 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4176 || (target_is_non_stop_p ()
4177 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4179 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4181 if (record_full_is_used ())
4182 restore_operation_disable.emplace
4183 (record_full_gdb_operation_disable_set ());
4185 /* When using hardware single-step, a SIGTRAP is reported for both
4186 a completed single-step and a software breakpoint. Need to
4187 differentiate between the two, as the latter needs adjusting
4188 but the former does not.
4190 The SIGTRAP can be due to a completed hardware single-step only if
4191 - we didn't insert software single-step breakpoints
4192 - this thread is currently being stepped
4194 If any of these events did not occur, we must have stopped due
4195 to hitting a software breakpoint, and have to back up to the
4198 As a special case, we could have hardware single-stepped a
4199 software breakpoint. In this case (prev_pc == breakpoint_pc),
4200 we also need to back up to the breakpoint address. */
4202 if (thread_has_single_step_breakpoints_set (thread)
4203 || !currently_stepping (thread)
4204 || (thread->stepped_breakpoint
4205 && thread->prev_pc == breakpoint_pc))
4206 regcache_write_pc (regcache, breakpoint_pc);
4211 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4213 for (frame = get_prev_frame (frame);
4215 frame = get_prev_frame (frame))
4217 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4219 if (get_frame_type (frame) != INLINE_FRAME)
4226 /* If the event thread has the stop requested flag set, pretend it
4227 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4231 handle_stop_requested (struct execution_control_state *ecs)
4233 if (ecs->event_thread->stop_requested)
4235 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4236 ecs->ws.value.sig = GDB_SIGNAL_0;
4237 handle_signal_stop (ecs);
4243 /* Auxiliary function that handles syscall entry/return events.
4244 It returns 1 if the inferior should keep going (and GDB
4245 should ignore the event), or 0 if the event deserves to be
4249 handle_syscall_event (struct execution_control_state *ecs)
4251 struct regcache *regcache;
4254 if (!ptid_equal (ecs->ptid, inferior_ptid))
4255 context_switch (ecs->ptid);
4257 regcache = get_thread_regcache (ecs->ptid);
4258 syscall_number = ecs->ws.value.syscall_number;
4259 stop_pc = regcache_read_pc (regcache);
4261 if (catch_syscall_enabled () > 0
4262 && catching_syscall_number (syscall_number) > 0)
4265 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4268 ecs->event_thread->control.stop_bpstat
4269 = bpstat_stop_status (regcache->aspace (),
4270 stop_pc, ecs->ptid, &ecs->ws);
4272 if (handle_stop_requested (ecs))
4275 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4277 /* Catchpoint hit. */
4282 if (handle_stop_requested (ecs))
4285 /* If no catchpoint triggered for this, then keep going. */
4290 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4293 fill_in_stop_func (struct gdbarch *gdbarch,
4294 struct execution_control_state *ecs)
4296 if (!ecs->stop_func_filled_in)
4298 /* Don't care about return value; stop_func_start and stop_func_name
4299 will both be 0 if it doesn't work. */
4300 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4301 &ecs->stop_func_start, &ecs->stop_func_end);
4302 ecs->stop_func_start
4303 += gdbarch_deprecated_function_start_offset (gdbarch);
4305 if (gdbarch_skip_entrypoint_p (gdbarch))
4306 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4307 ecs->stop_func_start);
4309 ecs->stop_func_filled_in = 1;
4314 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4316 static enum stop_kind
4317 get_inferior_stop_soon (ptid_t ptid)
4319 struct inferior *inf = find_inferior_ptid (ptid);
4321 gdb_assert (inf != NULL);
4322 return inf->control.stop_soon;
4325 /* Wait for one event. Store the resulting waitstatus in WS, and
4326 return the event ptid. */
4329 wait_one (struct target_waitstatus *ws)
4332 ptid_t wait_ptid = minus_one_ptid;
4334 overlay_cache_invalid = 1;
4336 /* Flush target cache before starting to handle each event.
4337 Target was running and cache could be stale. This is just a
4338 heuristic. Running threads may modify target memory, but we
4339 don't get any event. */
4340 target_dcache_invalidate ();
4342 if (deprecated_target_wait_hook)
4343 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4345 event_ptid = target_wait (wait_ptid, ws, 0);
4348 print_target_wait_results (wait_ptid, event_ptid, ws);
4353 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4354 instead of the current thread. */
4355 #define THREAD_STOPPED_BY(REASON) \
4357 thread_stopped_by_ ## REASON (ptid_t ptid) \
4359 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4360 inferior_ptid = ptid; \
4362 return target_stopped_by_ ## REASON (); \
4365 /* Generate thread_stopped_by_watchpoint. */
4366 THREAD_STOPPED_BY (watchpoint)
4367 /* Generate thread_stopped_by_sw_breakpoint. */
4368 THREAD_STOPPED_BY (sw_breakpoint)
4369 /* Generate thread_stopped_by_hw_breakpoint. */
4370 THREAD_STOPPED_BY (hw_breakpoint)
4372 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4375 switch_to_thread_cleanup (void *ptid_p)
4377 ptid_t ptid = *(ptid_t *) ptid_p;
4379 switch_to_thread (ptid);
4382 /* Save the thread's event and stop reason to process it later. */
4385 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4387 struct regcache *regcache;
4388 struct address_space *aspace;
4392 std::string statstr = target_waitstatus_to_string (ws);
4394 fprintf_unfiltered (gdb_stdlog,
4395 "infrun: saving status %s for %d.%ld.%ld\n",
4397 ptid_get_pid (tp->ptid),
4398 ptid_get_lwp (tp->ptid),
4399 ptid_get_tid (tp->ptid));
4402 /* Record for later. */
4403 tp->suspend.waitstatus = *ws;
4404 tp->suspend.waitstatus_pending_p = 1;
4406 regcache = get_thread_regcache (tp->ptid);
4407 aspace = regcache->aspace ();
4409 if (ws->kind == TARGET_WAITKIND_STOPPED
4410 && ws->value.sig == GDB_SIGNAL_TRAP)
4412 CORE_ADDR pc = regcache_read_pc (regcache);
4414 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4416 if (thread_stopped_by_watchpoint (tp->ptid))
4418 tp->suspend.stop_reason
4419 = TARGET_STOPPED_BY_WATCHPOINT;
4421 else if (target_supports_stopped_by_sw_breakpoint ()
4422 && thread_stopped_by_sw_breakpoint (tp->ptid))
4424 tp->suspend.stop_reason
4425 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4427 else if (target_supports_stopped_by_hw_breakpoint ()
4428 && thread_stopped_by_hw_breakpoint (tp->ptid))
4430 tp->suspend.stop_reason
4431 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4433 else if (!target_supports_stopped_by_hw_breakpoint ()
4434 && hardware_breakpoint_inserted_here_p (aspace,
4437 tp->suspend.stop_reason
4438 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4440 else if (!target_supports_stopped_by_sw_breakpoint ()
4441 && software_breakpoint_inserted_here_p (aspace,
4444 tp->suspend.stop_reason
4445 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4447 else if (!thread_has_single_step_breakpoints_set (tp)
4448 && currently_stepping (tp))
4450 tp->suspend.stop_reason
4451 = TARGET_STOPPED_BY_SINGLE_STEP;
4456 /* A cleanup that disables thread create/exit events. */
4459 disable_thread_events (void *arg)
4461 target_thread_events (0);
4467 stop_all_threads (void)
4469 /* We may need multiple passes to discover all threads. */
4473 struct cleanup *old_chain;
4475 gdb_assert (target_is_non_stop_p ());
4478 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4480 entry_ptid = inferior_ptid;
4481 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4483 target_thread_events (1);
4484 make_cleanup (disable_thread_events, NULL);
4486 /* Request threads to stop, and then wait for the stops. Because
4487 threads we already know about can spawn more threads while we're
4488 trying to stop them, and we only learn about new threads when we
4489 update the thread list, do this in a loop, and keep iterating
4490 until two passes find no threads that need to be stopped. */
4491 for (pass = 0; pass < 2; pass++, iterations++)
4494 fprintf_unfiltered (gdb_stdlog,
4495 "infrun: stop_all_threads, pass=%d, "
4496 "iterations=%d\n", pass, iterations);
4500 struct target_waitstatus ws;
4502 struct thread_info *t;
4504 update_thread_list ();
4506 /* Go through all threads looking for threads that we need
4507 to tell the target to stop. */
4508 ALL_NON_EXITED_THREADS (t)
4512 /* If already stopping, don't request a stop again.
4513 We just haven't seen the notification yet. */
4514 if (!t->stop_requested)
4517 fprintf_unfiltered (gdb_stdlog,
4518 "infrun: %s executing, "
4520 target_pid_to_str (t->ptid));
4521 target_stop (t->ptid);
4522 t->stop_requested = 1;
4527 fprintf_unfiltered (gdb_stdlog,
4528 "infrun: %s executing, "
4529 "already stopping\n",
4530 target_pid_to_str (t->ptid));
4533 if (t->stop_requested)
4539 fprintf_unfiltered (gdb_stdlog,
4540 "infrun: %s not executing\n",
4541 target_pid_to_str (t->ptid));
4543 /* The thread may be not executing, but still be
4544 resumed with a pending status to process. */
4552 /* If we find new threads on the second iteration, restart
4553 over. We want to see two iterations in a row with all
4558 event_ptid = wait_one (&ws);
4559 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4561 /* All resumed threads exited. */
4563 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4564 || ws.kind == TARGET_WAITKIND_EXITED
4565 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4569 ptid_t ptid = pid_to_ptid (ws.value.integer);
4571 fprintf_unfiltered (gdb_stdlog,
4572 "infrun: %s exited while "
4573 "stopping threads\n",
4574 target_pid_to_str (ptid));
4579 struct inferior *inf;
4581 t = find_thread_ptid (event_ptid);
4583 t = add_thread (event_ptid);
4585 t->stop_requested = 0;
4588 t->control.may_range_step = 0;
4590 /* This may be the first time we see the inferior report
4592 inf = find_inferior_ptid (event_ptid);
4593 if (inf->needs_setup)
4595 switch_to_thread_no_regs (t);
4599 if (ws.kind == TARGET_WAITKIND_STOPPED
4600 && ws.value.sig == GDB_SIGNAL_0)
4602 /* We caught the event that we intended to catch, so
4603 there's no event pending. */
4604 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4605 t->suspend.waitstatus_pending_p = 0;
4607 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4609 /* Add it back to the step-over queue. */
4612 fprintf_unfiltered (gdb_stdlog,
4613 "infrun: displaced-step of %s "
4614 "canceled: adding back to the "
4615 "step-over queue\n",
4616 target_pid_to_str (t->ptid));
4618 t->control.trap_expected = 0;
4619 thread_step_over_chain_enqueue (t);
4624 enum gdb_signal sig;
4625 struct regcache *regcache;
4629 std::string statstr = target_waitstatus_to_string (&ws);
4631 fprintf_unfiltered (gdb_stdlog,
4632 "infrun: target_wait %s, saving "
4633 "status for %d.%ld.%ld\n",
4635 ptid_get_pid (t->ptid),
4636 ptid_get_lwp (t->ptid),
4637 ptid_get_tid (t->ptid));
4640 /* Record for later. */
4641 save_waitstatus (t, &ws);
4643 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4644 ? ws.value.sig : GDB_SIGNAL_0);
4646 if (displaced_step_fixup (t->ptid, sig) < 0)
4648 /* Add it back to the step-over queue. */
4649 t->control.trap_expected = 0;
4650 thread_step_over_chain_enqueue (t);
4653 regcache = get_thread_regcache (t->ptid);
4654 t->suspend.stop_pc = regcache_read_pc (regcache);
4658 fprintf_unfiltered (gdb_stdlog,
4659 "infrun: saved stop_pc=%s for %s "
4660 "(currently_stepping=%d)\n",
4661 paddress (target_gdbarch (),
4662 t->suspend.stop_pc),
4663 target_pid_to_str (t->ptid),
4664 currently_stepping (t));
4671 do_cleanups (old_chain);
4674 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4677 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4680 handle_no_resumed (struct execution_control_state *ecs)
4682 struct inferior *inf;
4683 struct thread_info *thread;
4685 if (target_can_async_p ())
4692 if (ui->prompt_state == PROMPT_BLOCKED)
4700 /* There were no unwaited-for children left in the target, but,
4701 we're not synchronously waiting for events either. Just
4705 fprintf_unfiltered (gdb_stdlog,
4706 "infrun: TARGET_WAITKIND_NO_RESUMED "
4707 "(ignoring: bg)\n");
4708 prepare_to_wait (ecs);
4713 /* Otherwise, if we were running a synchronous execution command, we
4714 may need to cancel it and give the user back the terminal.
4716 In non-stop mode, the target can't tell whether we've already
4717 consumed previous stop events, so it can end up sending us a
4718 no-resumed event like so:
4720 #0 - thread 1 is left stopped
4722 #1 - thread 2 is resumed and hits breakpoint
4723 -> TARGET_WAITKIND_STOPPED
4725 #2 - thread 3 is resumed and exits
4726 this is the last resumed thread, so
4727 -> TARGET_WAITKIND_NO_RESUMED
4729 #3 - gdb processes stop for thread 2 and decides to re-resume
4732 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4733 thread 2 is now resumed, so the event should be ignored.
4735 IOW, if the stop for thread 2 doesn't end a foreground command,
4736 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4737 event. But it could be that the event meant that thread 2 itself
4738 (or whatever other thread was the last resumed thread) exited.
4740 To address this we refresh the thread list and check whether we
4741 have resumed threads _now_. In the example above, this removes
4742 thread 3 from the thread list. If thread 2 was re-resumed, we
4743 ignore this event. If we find no thread resumed, then we cancel
4744 the synchronous command show "no unwaited-for " to the user. */
4745 update_thread_list ();
4747 ALL_NON_EXITED_THREADS (thread)
4749 if (thread->executing
4750 || thread->suspend.waitstatus_pending_p)
4752 /* There were no unwaited-for children left in the target at
4753 some point, but there are now. Just ignore. */
4755 fprintf_unfiltered (gdb_stdlog,
4756 "infrun: TARGET_WAITKIND_NO_RESUMED "
4757 "(ignoring: found resumed)\n");
4758 prepare_to_wait (ecs);
4763 /* Note however that we may find no resumed thread because the whole
4764 process exited meanwhile (thus updating the thread list results
4765 in an empty thread list). In this case we know we'll be getting
4766 a process exit event shortly. */
4772 thread = any_live_thread_of_process (inf->pid);
4776 fprintf_unfiltered (gdb_stdlog,
4777 "infrun: TARGET_WAITKIND_NO_RESUMED "
4778 "(expect process exit)\n");
4779 prepare_to_wait (ecs);
4784 /* Go ahead and report the event. */
4788 /* Given an execution control state that has been freshly filled in by
4789 an event from the inferior, figure out what it means and take
4792 The alternatives are:
4794 1) stop_waiting and return; to really stop and return to the
4797 2) keep_going and return; to wait for the next event (set
4798 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4802 handle_inferior_event_1 (struct execution_control_state *ecs)
4804 enum stop_kind stop_soon;
4806 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4808 /* We had an event in the inferior, but we are not interested in
4809 handling it at this level. The lower layers have already
4810 done what needs to be done, if anything.
4812 One of the possible circumstances for this is when the
4813 inferior produces output for the console. The inferior has
4814 not stopped, and we are ignoring the event. Another possible
4815 circumstance is any event which the lower level knows will be
4816 reported multiple times without an intervening resume. */
4818 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4819 prepare_to_wait (ecs);
4823 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4826 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4827 prepare_to_wait (ecs);
4831 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4832 && handle_no_resumed (ecs))
4835 /* Cache the last pid/waitstatus. */
4836 set_last_target_status (ecs->ptid, ecs->ws);
4838 /* Always clear state belonging to the previous time we stopped. */
4839 stop_stack_dummy = STOP_NONE;
4841 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4843 /* No unwaited-for children left. IOW, all resumed children
4846 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4848 stop_print_frame = 0;
4853 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4854 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4856 ecs->event_thread = find_thread_ptid (ecs->ptid);
4857 /* If it's a new thread, add it to the thread database. */
4858 if (ecs->event_thread == NULL)
4859 ecs->event_thread = add_thread (ecs->ptid);
4861 /* Disable range stepping. If the next step request could use a
4862 range, this will be end up re-enabled then. */
4863 ecs->event_thread->control.may_range_step = 0;
4866 /* Dependent on valid ECS->EVENT_THREAD. */
4867 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4869 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4870 reinit_frame_cache ();
4872 breakpoint_retire_moribund ();
4874 /* First, distinguish signals caused by the debugger from signals
4875 that have to do with the program's own actions. Note that
4876 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4877 on the operating system version. Here we detect when a SIGILL or
4878 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4879 something similar for SIGSEGV, since a SIGSEGV will be generated
4880 when we're trying to execute a breakpoint instruction on a
4881 non-executable stack. This happens for call dummy breakpoints
4882 for architectures like SPARC that place call dummies on the
4884 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4885 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4886 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4887 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4889 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4891 if (breakpoint_inserted_here_p (regcache->aspace (),
4892 regcache_read_pc (regcache)))
4895 fprintf_unfiltered (gdb_stdlog,
4896 "infrun: Treating signal as SIGTRAP\n");
4897 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4901 /* Mark the non-executing threads accordingly. In all-stop, all
4902 threads of all processes are stopped when we get any event
4903 reported. In non-stop mode, only the event thread stops. */
4907 if (!target_is_non_stop_p ())
4908 mark_ptid = minus_one_ptid;
4909 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4910 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4912 /* If we're handling a process exit in non-stop mode, even
4913 though threads haven't been deleted yet, one would think
4914 that there is nothing to do, as threads of the dead process
4915 will be soon deleted, and threads of any other process were
4916 left running. However, on some targets, threads survive a
4917 process exit event. E.g., for the "checkpoint" command,
4918 when the current checkpoint/fork exits, linux-fork.c
4919 automatically switches to another fork from within
4920 target_mourn_inferior, by associating the same
4921 inferior/thread to another fork. We haven't mourned yet at
4922 this point, but we must mark any threads left in the
4923 process as not-executing so that finish_thread_state marks
4924 them stopped (in the user's perspective) if/when we present
4925 the stop to the user. */
4926 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4929 mark_ptid = ecs->ptid;
4931 set_executing (mark_ptid, 0);
4933 /* Likewise the resumed flag. */
4934 set_resumed (mark_ptid, 0);
4937 switch (ecs->ws.kind)
4939 case TARGET_WAITKIND_LOADED:
4941 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4942 if (!ptid_equal (ecs->ptid, inferior_ptid))
4943 context_switch (ecs->ptid);
4944 /* Ignore gracefully during startup of the inferior, as it might
4945 be the shell which has just loaded some objects, otherwise
4946 add the symbols for the newly loaded objects. Also ignore at
4947 the beginning of an attach or remote session; we will query
4948 the full list of libraries once the connection is
4951 stop_soon = get_inferior_stop_soon (ecs->ptid);
4952 if (stop_soon == NO_STOP_QUIETLY)
4954 struct regcache *regcache;
4956 regcache = get_thread_regcache (ecs->ptid);
4958 handle_solib_event ();
4960 ecs->event_thread->control.stop_bpstat
4961 = bpstat_stop_status (regcache->aspace (),
4962 stop_pc, ecs->ptid, &ecs->ws);
4964 if (handle_stop_requested (ecs))
4967 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4969 /* A catchpoint triggered. */
4970 process_event_stop_test (ecs);
4974 /* If requested, stop when the dynamic linker notifies
4975 gdb of events. This allows the user to get control
4976 and place breakpoints in initializer routines for
4977 dynamically loaded objects (among other things). */
4978 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4979 if (stop_on_solib_events)
4981 /* Make sure we print "Stopped due to solib-event" in
4983 stop_print_frame = 1;
4990 /* If we are skipping through a shell, or through shared library
4991 loading that we aren't interested in, resume the program. If
4992 we're running the program normally, also resume. */
4993 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4995 /* Loading of shared libraries might have changed breakpoint
4996 addresses. Make sure new breakpoints are inserted. */
4997 if (stop_soon == NO_STOP_QUIETLY)
4998 insert_breakpoints ();
4999 resume (GDB_SIGNAL_0);
5000 prepare_to_wait (ecs);
5004 /* But stop if we're attaching or setting up a remote
5006 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5007 || stop_soon == STOP_QUIETLY_REMOTE)
5010 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5015 internal_error (__FILE__, __LINE__,
5016 _("unhandled stop_soon: %d"), (int) stop_soon);
5018 case TARGET_WAITKIND_SPURIOUS:
5020 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5021 if (handle_stop_requested (ecs))
5023 if (!ptid_equal (ecs->ptid, inferior_ptid))
5024 context_switch (ecs->ptid);
5025 resume (GDB_SIGNAL_0);
5026 prepare_to_wait (ecs);
5029 case TARGET_WAITKIND_THREAD_CREATED:
5031 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5032 if (handle_stop_requested (ecs))
5034 if (!ptid_equal (ecs->ptid, inferior_ptid))
5035 context_switch (ecs->ptid);
5036 if (!switch_back_to_stepped_thread (ecs))
5040 case TARGET_WAITKIND_EXITED:
5041 case TARGET_WAITKIND_SIGNALLED:
5044 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5045 fprintf_unfiltered (gdb_stdlog,
5046 "infrun: TARGET_WAITKIND_EXITED\n");
5048 fprintf_unfiltered (gdb_stdlog,
5049 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5052 inferior_ptid = ecs->ptid;
5053 set_current_inferior (find_inferior_ptid (ecs->ptid));
5054 set_current_program_space (current_inferior ()->pspace);
5055 handle_vfork_child_exec_or_exit (0);
5056 target_terminal::ours (); /* Must do this before mourn anyway. */
5058 /* Clearing any previous state of convenience variables. */
5059 clear_exit_convenience_vars ();
5061 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5063 /* Record the exit code in the convenience variable $_exitcode, so
5064 that the user can inspect this again later. */
5065 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5066 (LONGEST) ecs->ws.value.integer);
5068 /* Also record this in the inferior itself. */
5069 current_inferior ()->has_exit_code = 1;
5070 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5072 /* Support the --return-child-result option. */
5073 return_child_result_value = ecs->ws.value.integer;
5075 observer_notify_exited (ecs->ws.value.integer);
5079 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5080 struct gdbarch *gdbarch = regcache->arch ();
5082 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5084 /* Set the value of the internal variable $_exitsignal,
5085 which holds the signal uncaught by the inferior. */
5086 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5087 gdbarch_gdb_signal_to_target (gdbarch,
5088 ecs->ws.value.sig));
5092 /* We don't have access to the target's method used for
5093 converting between signal numbers (GDB's internal
5094 representation <-> target's representation).
5095 Therefore, we cannot do a good job at displaying this
5096 information to the user. It's better to just warn
5097 her about it (if infrun debugging is enabled), and
5100 fprintf_filtered (gdb_stdlog, _("\
5101 Cannot fill $_exitsignal with the correct signal number.\n"));
5104 observer_notify_signal_exited (ecs->ws.value.sig);
5107 gdb_flush (gdb_stdout);
5108 target_mourn_inferior (inferior_ptid);
5109 stop_print_frame = 0;
5113 /* The following are the only cases in which we keep going;
5114 the above cases end in a continue or goto. */
5115 case TARGET_WAITKIND_FORKED:
5116 case TARGET_WAITKIND_VFORKED:
5119 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5120 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5122 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5125 /* Check whether the inferior is displaced stepping. */
5127 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5128 struct gdbarch *gdbarch = regcache->arch ();
5130 /* If checking displaced stepping is supported, and thread
5131 ecs->ptid is displaced stepping. */
5132 if (displaced_step_in_progress_thread (ecs->ptid))
5134 struct inferior *parent_inf
5135 = find_inferior_ptid (ecs->ptid);
5136 struct regcache *child_regcache;
5137 CORE_ADDR parent_pc;
5139 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5140 indicating that the displaced stepping of syscall instruction
5141 has been done. Perform cleanup for parent process here. Note
5142 that this operation also cleans up the child process for vfork,
5143 because their pages are shared. */
5144 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
5145 /* Start a new step-over in another thread if there's one
5149 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5151 struct displaced_step_inferior_state *displaced
5152 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
5154 /* Restore scratch pad for child process. */
5155 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5158 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5159 the child's PC is also within the scratchpad. Set the child's PC
5160 to the parent's PC value, which has already been fixed up.
5161 FIXME: we use the parent's aspace here, although we're touching
5162 the child, because the child hasn't been added to the inferior
5163 list yet at this point. */
5166 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5168 parent_inf->aspace);
5169 /* Read PC value of parent process. */
5170 parent_pc = regcache_read_pc (regcache);
5172 if (debug_displaced)
5173 fprintf_unfiltered (gdb_stdlog,
5174 "displaced: write child pc from %s to %s\n",
5176 regcache_read_pc (child_regcache)),
5177 paddress (gdbarch, parent_pc));
5179 regcache_write_pc (child_regcache, parent_pc);
5183 if (!ptid_equal (ecs->ptid, inferior_ptid))
5184 context_switch (ecs->ptid);
5186 /* Immediately detach breakpoints from the child before there's
5187 any chance of letting the user delete breakpoints from the
5188 breakpoint lists. If we don't do this early, it's easy to
5189 leave left over traps in the child, vis: "break foo; catch
5190 fork; c; <fork>; del; c; <child calls foo>". We only follow
5191 the fork on the last `continue', and by that time the
5192 breakpoint at "foo" is long gone from the breakpoint table.
5193 If we vforked, then we don't need to unpatch here, since both
5194 parent and child are sharing the same memory pages; we'll
5195 need to unpatch at follow/detach time instead to be certain
5196 that new breakpoints added between catchpoint hit time and
5197 vfork follow are detached. */
5198 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5200 /* This won't actually modify the breakpoint list, but will
5201 physically remove the breakpoints from the child. */
5202 detach_breakpoints (ecs->ws.value.related_pid);
5205 delete_just_stopped_threads_single_step_breakpoints ();
5207 /* In case the event is caught by a catchpoint, remember that
5208 the event is to be followed at the next resume of the thread,
5209 and not immediately. */
5210 ecs->event_thread->pending_follow = ecs->ws;
5212 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5214 ecs->event_thread->control.stop_bpstat
5215 = bpstat_stop_status (get_current_regcache ()->aspace (),
5216 stop_pc, ecs->ptid, &ecs->ws);
5218 if (handle_stop_requested (ecs))
5221 /* If no catchpoint triggered for this, then keep going. Note
5222 that we're interested in knowing the bpstat actually causes a
5223 stop, not just if it may explain the signal. Software
5224 watchpoints, for example, always appear in the bpstat. */
5225 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5231 = (follow_fork_mode_string == follow_fork_mode_child);
5233 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5235 should_resume = follow_fork ();
5238 child = ecs->ws.value.related_pid;
5240 /* At this point, the parent is marked running, and the
5241 child is marked stopped. */
5243 /* If not resuming the parent, mark it stopped. */
5244 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5245 set_running (parent, 0);
5247 /* If resuming the child, mark it running. */
5248 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5249 set_running (child, 1);
5251 /* In non-stop mode, also resume the other branch. */
5252 if (!detach_fork && (non_stop
5253 || (sched_multi && target_is_non_stop_p ())))
5256 switch_to_thread (parent);
5258 switch_to_thread (child);
5260 ecs->event_thread = inferior_thread ();
5261 ecs->ptid = inferior_ptid;
5266 switch_to_thread (child);
5268 switch_to_thread (parent);
5270 ecs->event_thread = inferior_thread ();
5271 ecs->ptid = inferior_ptid;
5279 process_event_stop_test (ecs);
5282 case TARGET_WAITKIND_VFORK_DONE:
5283 /* Done with the shared memory region. Re-insert breakpoints in
5284 the parent, and keep going. */
5287 fprintf_unfiltered (gdb_stdlog,
5288 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5290 if (!ptid_equal (ecs->ptid, inferior_ptid))
5291 context_switch (ecs->ptid);
5293 current_inferior ()->waiting_for_vfork_done = 0;
5294 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5296 if (handle_stop_requested (ecs))
5299 /* This also takes care of reinserting breakpoints in the
5300 previously locked inferior. */
5304 case TARGET_WAITKIND_EXECD:
5306 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5308 /* Note we can't read registers yet (the stop_pc), because we
5309 don't yet know the inferior's post-exec architecture.
5310 'stop_pc' is explicitly read below instead. */
5311 if (!ptid_equal (ecs->ptid, inferior_ptid))
5312 switch_to_thread_no_regs (ecs->event_thread);
5314 /* Do whatever is necessary to the parent branch of the vfork. */
5315 handle_vfork_child_exec_or_exit (1);
5317 /* This causes the eventpoints and symbol table to be reset.
5318 Must do this now, before trying to determine whether to
5320 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5322 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5324 /* In follow_exec we may have deleted the original thread and
5325 created a new one. Make sure that the event thread is the
5326 execd thread for that case (this is a nop otherwise). */
5327 ecs->event_thread = inferior_thread ();
5329 ecs->event_thread->control.stop_bpstat
5330 = bpstat_stop_status (get_current_regcache ()->aspace (),
5331 stop_pc, ecs->ptid, &ecs->ws);
5333 /* Note that this may be referenced from inside
5334 bpstat_stop_status above, through inferior_has_execd. */
5335 xfree (ecs->ws.value.execd_pathname);
5336 ecs->ws.value.execd_pathname = NULL;
5338 if (handle_stop_requested (ecs))
5341 /* If no catchpoint triggered for this, then keep going. */
5342 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5344 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5348 process_event_stop_test (ecs);
5351 /* Be careful not to try to gather much state about a thread
5352 that's in a syscall. It's frequently a losing proposition. */
5353 case TARGET_WAITKIND_SYSCALL_ENTRY:
5355 fprintf_unfiltered (gdb_stdlog,
5356 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5357 /* Getting the current syscall number. */
5358 if (handle_syscall_event (ecs) == 0)
5359 process_event_stop_test (ecs);
5362 /* Before examining the threads further, step this thread to
5363 get it entirely out of the syscall. (We get notice of the
5364 event when the thread is just on the verge of exiting a
5365 syscall. Stepping one instruction seems to get it back
5367 case TARGET_WAITKIND_SYSCALL_RETURN:
5369 fprintf_unfiltered (gdb_stdlog,
5370 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5371 if (handle_syscall_event (ecs) == 0)
5372 process_event_stop_test (ecs);
5375 case TARGET_WAITKIND_STOPPED:
5377 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5378 handle_signal_stop (ecs);
5381 case TARGET_WAITKIND_NO_HISTORY:
5383 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5384 /* Reverse execution: target ran out of history info. */
5386 /* Switch to the stopped thread. */
5387 if (!ptid_equal (ecs->ptid, inferior_ptid))
5388 context_switch (ecs->ptid);
5390 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5392 delete_just_stopped_threads_single_step_breakpoints ();
5393 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5395 if (handle_stop_requested (ecs))
5398 observer_notify_no_history ();
5404 /* A wrapper around handle_inferior_event_1, which also makes sure
5405 that all temporary struct value objects that were created during
5406 the handling of the event get deleted at the end. */
5409 handle_inferior_event (struct execution_control_state *ecs)
5411 struct value *mark = value_mark ();
5413 handle_inferior_event_1 (ecs);
5414 /* Purge all temporary values created during the event handling,
5415 as it could be a long time before we return to the command level
5416 where such values would otherwise be purged. */
5417 value_free_to_mark (mark);
5420 /* Restart threads back to what they were trying to do back when we
5421 paused them for an in-line step-over. The EVENT_THREAD thread is
5425 restart_threads (struct thread_info *event_thread)
5427 struct thread_info *tp;
5429 /* In case the instruction just stepped spawned a new thread. */
5430 update_thread_list ();
5432 ALL_NON_EXITED_THREADS (tp)
5434 if (tp == event_thread)
5437 fprintf_unfiltered (gdb_stdlog,
5438 "infrun: restart threads: "
5439 "[%s] is event thread\n",
5440 target_pid_to_str (tp->ptid));
5444 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5447 fprintf_unfiltered (gdb_stdlog,
5448 "infrun: restart threads: "
5449 "[%s] not meant to be running\n",
5450 target_pid_to_str (tp->ptid));
5457 fprintf_unfiltered (gdb_stdlog,
5458 "infrun: restart threads: [%s] resumed\n",
5459 target_pid_to_str (tp->ptid));
5460 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5464 if (thread_is_in_step_over_chain (tp))
5467 fprintf_unfiltered (gdb_stdlog,
5468 "infrun: restart threads: "
5469 "[%s] needs step-over\n",
5470 target_pid_to_str (tp->ptid));
5471 gdb_assert (!tp->resumed);
5476 if (tp->suspend.waitstatus_pending_p)
5479 fprintf_unfiltered (gdb_stdlog,
5480 "infrun: restart threads: "
5481 "[%s] has pending status\n",
5482 target_pid_to_str (tp->ptid));
5487 gdb_assert (!tp->stop_requested);
5489 /* If some thread needs to start a step-over at this point, it
5490 should still be in the step-over queue, and thus skipped
5492 if (thread_still_needs_step_over (tp))
5494 internal_error (__FILE__, __LINE__,
5495 "thread [%s] needs a step-over, but not in "
5496 "step-over queue\n",
5497 target_pid_to_str (tp->ptid));
5500 if (currently_stepping (tp))
5503 fprintf_unfiltered (gdb_stdlog,
5504 "infrun: restart threads: [%s] was stepping\n",
5505 target_pid_to_str (tp->ptid));
5506 keep_going_stepped_thread (tp);
5510 struct execution_control_state ecss;
5511 struct execution_control_state *ecs = &ecss;
5514 fprintf_unfiltered (gdb_stdlog,
5515 "infrun: restart threads: [%s] continuing\n",
5516 target_pid_to_str (tp->ptid));
5517 reset_ecs (ecs, tp);
5518 switch_to_thread (tp->ptid);
5519 keep_going_pass_signal (ecs);
5524 /* Callback for iterate_over_threads. Find a resumed thread that has
5525 a pending waitstatus. */
5528 resumed_thread_with_pending_status (struct thread_info *tp,
5532 && tp->suspend.waitstatus_pending_p);
5535 /* Called when we get an event that may finish an in-line or
5536 out-of-line (displaced stepping) step-over started previously.
5537 Return true if the event is processed and we should go back to the
5538 event loop; false if the caller should continue processing the
5542 finish_step_over (struct execution_control_state *ecs)
5544 int had_step_over_info;
5546 displaced_step_fixup (ecs->ptid,
5547 ecs->event_thread->suspend.stop_signal);
5549 had_step_over_info = step_over_info_valid_p ();
5551 if (had_step_over_info)
5553 /* If we're stepping over a breakpoint with all threads locked,
5554 then only the thread that was stepped should be reporting
5556 gdb_assert (ecs->event_thread->control.trap_expected);
5558 clear_step_over_info ();
5561 if (!target_is_non_stop_p ())
5564 /* Start a new step-over in another thread if there's one that
5568 /* If we were stepping over a breakpoint before, and haven't started
5569 a new in-line step-over sequence, then restart all other threads
5570 (except the event thread). We can't do this in all-stop, as then
5571 e.g., we wouldn't be able to issue any other remote packet until
5572 these other threads stop. */
5573 if (had_step_over_info && !step_over_info_valid_p ())
5575 struct thread_info *pending;
5577 /* If we only have threads with pending statuses, the restart
5578 below won't restart any thread and so nothing re-inserts the
5579 breakpoint we just stepped over. But we need it inserted
5580 when we later process the pending events, otherwise if
5581 another thread has a pending event for this breakpoint too,
5582 we'd discard its event (because the breakpoint that
5583 originally caused the event was no longer inserted). */
5584 context_switch (ecs->ptid);
5585 insert_breakpoints ();
5587 restart_threads (ecs->event_thread);
5589 /* If we have events pending, go through handle_inferior_event
5590 again, picking up a pending event at random. This avoids
5591 thread starvation. */
5593 /* But not if we just stepped over a watchpoint in order to let
5594 the instruction execute so we can evaluate its expression.
5595 The set of watchpoints that triggered is recorded in the
5596 breakpoint objects themselves (see bp->watchpoint_triggered).
5597 If we processed another event first, that other event could
5598 clobber this info. */
5599 if (ecs->event_thread->stepping_over_watchpoint)
5602 pending = iterate_over_threads (resumed_thread_with_pending_status,
5604 if (pending != NULL)
5606 struct thread_info *tp = ecs->event_thread;
5607 struct regcache *regcache;
5611 fprintf_unfiltered (gdb_stdlog,
5612 "infrun: found resumed threads with "
5613 "pending events, saving status\n");
5616 gdb_assert (pending != tp);
5618 /* Record the event thread's event for later. */
5619 save_waitstatus (tp, &ecs->ws);
5620 /* This was cleared early, by handle_inferior_event. Set it
5621 so this pending event is considered by
5625 gdb_assert (!tp->executing);
5627 regcache = get_thread_regcache (tp->ptid);
5628 tp->suspend.stop_pc = regcache_read_pc (regcache);
5632 fprintf_unfiltered (gdb_stdlog,
5633 "infrun: saved stop_pc=%s for %s "
5634 "(currently_stepping=%d)\n",
5635 paddress (target_gdbarch (),
5636 tp->suspend.stop_pc),
5637 target_pid_to_str (tp->ptid),
5638 currently_stepping (tp));
5641 /* This in-line step-over finished; clear this so we won't
5642 start a new one. This is what handle_signal_stop would
5643 do, if we returned false. */
5644 tp->stepping_over_breakpoint = 0;
5646 /* Wake up the event loop again. */
5647 mark_async_event_handler (infrun_async_inferior_event_token);
5649 prepare_to_wait (ecs);
5657 /* Come here when the program has stopped with a signal. */
5660 handle_signal_stop (struct execution_control_state *ecs)
5662 struct frame_info *frame;
5663 struct gdbarch *gdbarch;
5664 int stopped_by_watchpoint;
5665 enum stop_kind stop_soon;
5668 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5670 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5672 /* Do we need to clean up the state of a thread that has
5673 completed a displaced single-step? (Doing so usually affects
5674 the PC, so do it here, before we set stop_pc.) */
5675 if (finish_step_over (ecs))
5678 /* If we either finished a single-step or hit a breakpoint, but
5679 the user wanted this thread to be stopped, pretend we got a
5680 SIG0 (generic unsignaled stop). */
5681 if (ecs->event_thread->stop_requested
5682 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5683 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5685 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5689 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5690 struct gdbarch *gdbarch = regcache->arch ();
5691 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5693 inferior_ptid = ecs->ptid;
5695 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5696 paddress (gdbarch, stop_pc));
5697 if (target_stopped_by_watchpoint ())
5701 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5703 if (target_stopped_data_address (¤t_target, &addr))
5704 fprintf_unfiltered (gdb_stdlog,
5705 "infrun: stopped data address = %s\n",
5706 paddress (gdbarch, addr));
5708 fprintf_unfiltered (gdb_stdlog,
5709 "infrun: (no data address available)\n");
5713 /* This is originated from start_remote(), start_inferior() and
5714 shared libraries hook functions. */
5715 stop_soon = get_inferior_stop_soon (ecs->ptid);
5716 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5718 if (!ptid_equal (ecs->ptid, inferior_ptid))
5719 context_switch (ecs->ptid);
5721 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5722 stop_print_frame = 1;
5727 /* This originates from attach_command(). We need to overwrite
5728 the stop_signal here, because some kernels don't ignore a
5729 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5730 See more comments in inferior.h. On the other hand, if we
5731 get a non-SIGSTOP, report it to the user - assume the backend
5732 will handle the SIGSTOP if it should show up later.
5734 Also consider that the attach is complete when we see a
5735 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5736 target extended-remote report it instead of a SIGSTOP
5737 (e.g. gdbserver). We already rely on SIGTRAP being our
5738 signal, so this is no exception.
5740 Also consider that the attach is complete when we see a
5741 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5742 the target to stop all threads of the inferior, in case the
5743 low level attach operation doesn't stop them implicitly. If
5744 they weren't stopped implicitly, then the stub will report a
5745 GDB_SIGNAL_0, meaning: stopped for no particular reason
5746 other than GDB's request. */
5747 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5748 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5749 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5750 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5752 stop_print_frame = 1;
5754 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5758 /* See if something interesting happened to the non-current thread. If
5759 so, then switch to that thread. */
5760 if (!ptid_equal (ecs->ptid, inferior_ptid))
5763 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5765 context_switch (ecs->ptid);
5767 if (deprecated_context_hook)
5768 deprecated_context_hook (ptid_to_global_thread_id (ecs->ptid));
5771 /* At this point, get hold of the now-current thread's frame. */
5772 frame = get_current_frame ();
5773 gdbarch = get_frame_arch (frame);
5775 /* Pull the single step breakpoints out of the target. */
5776 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5778 struct regcache *regcache;
5779 struct address_space *aspace;
5782 regcache = get_thread_regcache (ecs->ptid);
5783 aspace = regcache->aspace ();
5784 pc = regcache_read_pc (regcache);
5786 /* However, before doing so, if this single-step breakpoint was
5787 actually for another thread, set this thread up for moving
5789 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5792 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5796 fprintf_unfiltered (gdb_stdlog,
5797 "infrun: [%s] hit another thread's "
5798 "single-step breakpoint\n",
5799 target_pid_to_str (ecs->ptid));
5801 ecs->hit_singlestep_breakpoint = 1;
5808 fprintf_unfiltered (gdb_stdlog,
5809 "infrun: [%s] hit its "
5810 "single-step breakpoint\n",
5811 target_pid_to_str (ecs->ptid));
5815 delete_just_stopped_threads_single_step_breakpoints ();
5817 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5818 && ecs->event_thread->control.trap_expected
5819 && ecs->event_thread->stepping_over_watchpoint)
5820 stopped_by_watchpoint = 0;
5822 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5824 /* If necessary, step over this watchpoint. We'll be back to display
5826 if (stopped_by_watchpoint
5827 && (target_have_steppable_watchpoint
5828 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5830 /* At this point, we are stopped at an instruction which has
5831 attempted to write to a piece of memory under control of
5832 a watchpoint. The instruction hasn't actually executed
5833 yet. If we were to evaluate the watchpoint expression
5834 now, we would get the old value, and therefore no change
5835 would seem to have occurred.
5837 In order to make watchpoints work `right', we really need
5838 to complete the memory write, and then evaluate the
5839 watchpoint expression. We do this by single-stepping the
5842 It may not be necessary to disable the watchpoint to step over
5843 it. For example, the PA can (with some kernel cooperation)
5844 single step over a watchpoint without disabling the watchpoint.
5846 It is far more common to need to disable a watchpoint to step
5847 the inferior over it. If we have non-steppable watchpoints,
5848 we must disable the current watchpoint; it's simplest to
5849 disable all watchpoints.
5851 Any breakpoint at PC must also be stepped over -- if there's
5852 one, it will have already triggered before the watchpoint
5853 triggered, and we either already reported it to the user, or
5854 it didn't cause a stop and we called keep_going. In either
5855 case, if there was a breakpoint at PC, we must be trying to
5857 ecs->event_thread->stepping_over_watchpoint = 1;
5862 ecs->event_thread->stepping_over_breakpoint = 0;
5863 ecs->event_thread->stepping_over_watchpoint = 0;
5864 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5865 ecs->event_thread->control.stop_step = 0;
5866 stop_print_frame = 1;
5867 stopped_by_random_signal = 0;
5869 /* Hide inlined functions starting here, unless we just performed stepi or
5870 nexti. After stepi and nexti, always show the innermost frame (not any
5871 inline function call sites). */
5872 if (ecs->event_thread->control.step_range_end != 1)
5874 struct address_space *aspace =
5875 get_thread_regcache (ecs->ptid)->aspace ();
5877 /* skip_inline_frames is expensive, so we avoid it if we can
5878 determine that the address is one where functions cannot have
5879 been inlined. This improves performance with inferiors that
5880 load a lot of shared libraries, because the solib event
5881 breakpoint is defined as the address of a function (i.e. not
5882 inline). Note that we have to check the previous PC as well
5883 as the current one to catch cases when we have just
5884 single-stepped off a breakpoint prior to reinstating it.
5885 Note that we're assuming that the code we single-step to is
5886 not inline, but that's not definitive: there's nothing
5887 preventing the event breakpoint function from containing
5888 inlined code, and the single-step ending up there. If the
5889 user had set a breakpoint on that inlined code, the missing
5890 skip_inline_frames call would break things. Fortunately
5891 that's an extremely unlikely scenario. */
5892 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5893 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5894 && ecs->event_thread->control.trap_expected
5895 && pc_at_non_inline_function (aspace,
5896 ecs->event_thread->prev_pc,
5899 skip_inline_frames (ecs->ptid);
5901 /* Re-fetch current thread's frame in case that invalidated
5903 frame = get_current_frame ();
5904 gdbarch = get_frame_arch (frame);
5908 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5909 && ecs->event_thread->control.trap_expected
5910 && gdbarch_single_step_through_delay_p (gdbarch)
5911 && currently_stepping (ecs->event_thread))
5913 /* We're trying to step off a breakpoint. Turns out that we're
5914 also on an instruction that needs to be stepped multiple
5915 times before it's been fully executing. E.g., architectures
5916 with a delay slot. It needs to be stepped twice, once for
5917 the instruction and once for the delay slot. */
5918 int step_through_delay
5919 = gdbarch_single_step_through_delay (gdbarch, frame);
5921 if (debug_infrun && step_through_delay)
5922 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5923 if (ecs->event_thread->control.step_range_end == 0
5924 && step_through_delay)
5926 /* The user issued a continue when stopped at a breakpoint.
5927 Set up for another trap and get out of here. */
5928 ecs->event_thread->stepping_over_breakpoint = 1;
5932 else if (step_through_delay)
5934 /* The user issued a step when stopped at a breakpoint.
5935 Maybe we should stop, maybe we should not - the delay
5936 slot *might* correspond to a line of source. In any
5937 case, don't decide that here, just set
5938 ecs->stepping_over_breakpoint, making sure we
5939 single-step again before breakpoints are re-inserted. */
5940 ecs->event_thread->stepping_over_breakpoint = 1;
5944 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5945 handles this event. */
5946 ecs->event_thread->control.stop_bpstat
5947 = bpstat_stop_status (get_current_regcache ()->aspace (),
5948 stop_pc, ecs->ptid, &ecs->ws);
5950 /* Following in case break condition called a
5952 stop_print_frame = 1;
5954 /* This is where we handle "moribund" watchpoints. Unlike
5955 software breakpoints traps, hardware watchpoint traps are
5956 always distinguishable from random traps. If no high-level
5957 watchpoint is associated with the reported stop data address
5958 anymore, then the bpstat does not explain the signal ---
5959 simply make sure to ignore it if `stopped_by_watchpoint' is
5963 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5964 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5966 && stopped_by_watchpoint)
5967 fprintf_unfiltered (gdb_stdlog,
5968 "infrun: no user watchpoint explains "
5969 "watchpoint SIGTRAP, ignoring\n");
5971 /* NOTE: cagney/2003-03-29: These checks for a random signal
5972 at one stage in the past included checks for an inferior
5973 function call's call dummy's return breakpoint. The original
5974 comment, that went with the test, read:
5976 ``End of a stack dummy. Some systems (e.g. Sony news) give
5977 another signal besides SIGTRAP, so check here as well as
5980 If someone ever tries to get call dummys on a
5981 non-executable stack to work (where the target would stop
5982 with something like a SIGSEGV), then those tests might need
5983 to be re-instated. Given, however, that the tests were only
5984 enabled when momentary breakpoints were not being used, I
5985 suspect that it won't be the case.
5987 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5988 be necessary for call dummies on a non-executable stack on
5991 /* See if the breakpoints module can explain the signal. */
5993 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5994 ecs->event_thread->suspend.stop_signal);
5996 /* Maybe this was a trap for a software breakpoint that has since
5998 if (random_signal && target_stopped_by_sw_breakpoint ())
6000 if (program_breakpoint_here_p (gdbarch, stop_pc))
6002 struct regcache *regcache;
6005 /* Re-adjust PC to what the program would see if GDB was not
6007 regcache = get_thread_regcache (ecs->event_thread->ptid);
6008 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
6011 gdb::optional<scoped_restore_tmpl<int>>
6012 restore_operation_disable;
6014 if (record_full_is_used ())
6015 restore_operation_disable.emplace
6016 (record_full_gdb_operation_disable_set ());
6018 regcache_write_pc (regcache, stop_pc + decr_pc);
6023 /* A delayed software breakpoint event. Ignore the trap. */
6025 fprintf_unfiltered (gdb_stdlog,
6026 "infrun: delayed software breakpoint "
6027 "trap, ignoring\n");
6032 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6033 has since been removed. */
6034 if (random_signal && target_stopped_by_hw_breakpoint ())
6036 /* A delayed hardware breakpoint event. Ignore the trap. */
6038 fprintf_unfiltered (gdb_stdlog,
6039 "infrun: delayed hardware breakpoint/watchpoint "
6040 "trap, ignoring\n");
6044 /* If not, perhaps stepping/nexting can. */
6046 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6047 && currently_stepping (ecs->event_thread));
6049 /* Perhaps the thread hit a single-step breakpoint of _another_
6050 thread. Single-step breakpoints are transparent to the
6051 breakpoints module. */
6053 random_signal = !ecs->hit_singlestep_breakpoint;
6055 /* No? Perhaps we got a moribund watchpoint. */
6057 random_signal = !stopped_by_watchpoint;
6059 /* Always stop if the user explicitly requested this thread to
6061 if (ecs->event_thread->stop_requested)
6065 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6068 /* For the program's own signals, act according to
6069 the signal handling tables. */
6073 /* Signal not for debugging purposes. */
6074 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6075 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6078 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6079 gdb_signal_to_symbol_string (stop_signal));
6081 stopped_by_random_signal = 1;
6083 /* Always stop on signals if we're either just gaining control
6084 of the program, or the user explicitly requested this thread
6085 to remain stopped. */
6086 if (stop_soon != NO_STOP_QUIETLY
6087 || ecs->event_thread->stop_requested
6089 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6095 /* Notify observers the signal has "handle print" set. Note we
6096 returned early above if stopping; normal_stop handles the
6097 printing in that case. */
6098 if (signal_print[ecs->event_thread->suspend.stop_signal])
6100 /* The signal table tells us to print about this signal. */
6101 target_terminal::ours_for_output ();
6102 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
6103 target_terminal::inferior ();
6106 /* Clear the signal if it should not be passed. */
6107 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6108 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6110 if (ecs->event_thread->prev_pc == stop_pc
6111 && ecs->event_thread->control.trap_expected
6112 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6114 /* We were just starting a new sequence, attempting to
6115 single-step off of a breakpoint and expecting a SIGTRAP.
6116 Instead this signal arrives. This signal will take us out
6117 of the stepping range so GDB needs to remember to, when
6118 the signal handler returns, resume stepping off that
6120 /* To simplify things, "continue" is forced to use the same
6121 code paths as single-step - set a breakpoint at the
6122 signal return address and then, once hit, step off that
6125 fprintf_unfiltered (gdb_stdlog,
6126 "infrun: signal arrived while stepping over "
6129 insert_hp_step_resume_breakpoint_at_frame (frame);
6130 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6131 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6132 ecs->event_thread->control.trap_expected = 0;
6134 /* If we were nexting/stepping some other thread, switch to
6135 it, so that we don't continue it, losing control. */
6136 if (!switch_back_to_stepped_thread (ecs))
6141 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6142 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6143 || ecs->event_thread->control.step_range_end == 1)
6144 && frame_id_eq (get_stack_frame_id (frame),
6145 ecs->event_thread->control.step_stack_frame_id)
6146 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6148 /* The inferior is about to take a signal that will take it
6149 out of the single step range. Set a breakpoint at the
6150 current PC (which is presumably where the signal handler
6151 will eventually return) and then allow the inferior to
6154 Note that this is only needed for a signal delivered
6155 while in the single-step range. Nested signals aren't a
6156 problem as they eventually all return. */
6158 fprintf_unfiltered (gdb_stdlog,
6159 "infrun: signal may take us out of "
6160 "single-step range\n");
6162 clear_step_over_info ();
6163 insert_hp_step_resume_breakpoint_at_frame (frame);
6164 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6165 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6166 ecs->event_thread->control.trap_expected = 0;
6171 /* Note: step_resume_breakpoint may be non-NULL. This occures
6172 when either there's a nested signal, or when there's a
6173 pending signal enabled just as the signal handler returns
6174 (leaving the inferior at the step-resume-breakpoint without
6175 actually executing it). Either way continue until the
6176 breakpoint is really hit. */
6178 if (!switch_back_to_stepped_thread (ecs))
6181 fprintf_unfiltered (gdb_stdlog,
6182 "infrun: random signal, keep going\n");
6189 process_event_stop_test (ecs);
6192 /* Come here when we've got some debug event / signal we can explain
6193 (IOW, not a random signal), and test whether it should cause a
6194 stop, or whether we should resume the inferior (transparently).
6195 E.g., could be a breakpoint whose condition evaluates false; we
6196 could be still stepping within the line; etc. */
6199 process_event_stop_test (struct execution_control_state *ecs)
6201 struct symtab_and_line stop_pc_sal;
6202 struct frame_info *frame;
6203 struct gdbarch *gdbarch;
6204 CORE_ADDR jmp_buf_pc;
6205 struct bpstat_what what;
6207 /* Handle cases caused by hitting a breakpoint. */
6209 frame = get_current_frame ();
6210 gdbarch = get_frame_arch (frame);
6212 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6214 if (what.call_dummy)
6216 stop_stack_dummy = what.call_dummy;
6219 /* A few breakpoint types have callbacks associated (e.g.,
6220 bp_jit_event). Run them now. */
6221 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6223 /* If we hit an internal event that triggers symbol changes, the
6224 current frame will be invalidated within bpstat_what (e.g., if we
6225 hit an internal solib event). Re-fetch it. */
6226 frame = get_current_frame ();
6227 gdbarch = get_frame_arch (frame);
6229 switch (what.main_action)
6231 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6232 /* If we hit the breakpoint at longjmp while stepping, we
6233 install a momentary breakpoint at the target of the
6237 fprintf_unfiltered (gdb_stdlog,
6238 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6240 ecs->event_thread->stepping_over_breakpoint = 1;
6242 if (what.is_longjmp)
6244 struct value *arg_value;
6246 /* If we set the longjmp breakpoint via a SystemTap probe,
6247 then use it to extract the arguments. The destination PC
6248 is the third argument to the probe. */
6249 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6252 jmp_buf_pc = value_as_address (arg_value);
6253 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6255 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6256 || !gdbarch_get_longjmp_target (gdbarch,
6257 frame, &jmp_buf_pc))
6260 fprintf_unfiltered (gdb_stdlog,
6261 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6262 "(!gdbarch_get_longjmp_target)\n");
6267 /* Insert a breakpoint at resume address. */
6268 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6271 check_exception_resume (ecs, frame);
6275 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6277 struct frame_info *init_frame;
6279 /* There are several cases to consider.
6281 1. The initiating frame no longer exists. In this case we
6282 must stop, because the exception or longjmp has gone too
6285 2. The initiating frame exists, and is the same as the
6286 current frame. We stop, because the exception or longjmp
6289 3. The initiating frame exists and is different from the
6290 current frame. This means the exception or longjmp has
6291 been caught beneath the initiating frame, so keep going.
6293 4. longjmp breakpoint has been placed just to protect
6294 against stale dummy frames and user is not interested in
6295 stopping around longjmps. */
6298 fprintf_unfiltered (gdb_stdlog,
6299 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6301 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6303 delete_exception_resume_breakpoint (ecs->event_thread);
6305 if (what.is_longjmp)
6307 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6309 if (!frame_id_p (ecs->event_thread->initiating_frame))
6317 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6321 struct frame_id current_id
6322 = get_frame_id (get_current_frame ());
6323 if (frame_id_eq (current_id,
6324 ecs->event_thread->initiating_frame))
6326 /* Case 2. Fall through. */
6336 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6338 delete_step_resume_breakpoint (ecs->event_thread);
6340 end_stepping_range (ecs);
6344 case BPSTAT_WHAT_SINGLE:
6346 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6347 ecs->event_thread->stepping_over_breakpoint = 1;
6348 /* Still need to check other stuff, at least the case where we
6349 are stepping and step out of the right range. */
6352 case BPSTAT_WHAT_STEP_RESUME:
6354 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6356 delete_step_resume_breakpoint (ecs->event_thread);
6357 if (ecs->event_thread->control.proceed_to_finish
6358 && execution_direction == EXEC_REVERSE)
6360 struct thread_info *tp = ecs->event_thread;
6362 /* We are finishing a function in reverse, and just hit the
6363 step-resume breakpoint at the start address of the
6364 function, and we're almost there -- just need to back up
6365 by one more single-step, which should take us back to the
6367 tp->control.step_range_start = tp->control.step_range_end = 1;
6371 fill_in_stop_func (gdbarch, ecs);
6372 if (stop_pc == ecs->stop_func_start
6373 && execution_direction == EXEC_REVERSE)
6375 /* We are stepping over a function call in reverse, and just
6376 hit the step-resume breakpoint at the start address of
6377 the function. Go back to single-stepping, which should
6378 take us back to the function call. */
6379 ecs->event_thread->stepping_over_breakpoint = 1;
6385 case BPSTAT_WHAT_STOP_NOISY:
6387 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6388 stop_print_frame = 1;
6390 /* Assume the thread stopped for a breapoint. We'll still check
6391 whether a/the breakpoint is there when the thread is next
6393 ecs->event_thread->stepping_over_breakpoint = 1;
6398 case BPSTAT_WHAT_STOP_SILENT:
6400 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6401 stop_print_frame = 0;
6403 /* Assume the thread stopped for a breapoint. We'll still check
6404 whether a/the breakpoint is there when the thread is next
6406 ecs->event_thread->stepping_over_breakpoint = 1;
6410 case BPSTAT_WHAT_HP_STEP_RESUME:
6412 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6414 delete_step_resume_breakpoint (ecs->event_thread);
6415 if (ecs->event_thread->step_after_step_resume_breakpoint)
6417 /* Back when the step-resume breakpoint was inserted, we
6418 were trying to single-step off a breakpoint. Go back to
6420 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6421 ecs->event_thread->stepping_over_breakpoint = 1;
6427 case BPSTAT_WHAT_KEEP_CHECKING:
6431 /* If we stepped a permanent breakpoint and we had a high priority
6432 step-resume breakpoint for the address we stepped, but we didn't
6433 hit it, then we must have stepped into the signal handler. The
6434 step-resume was only necessary to catch the case of _not_
6435 stepping into the handler, so delete it, and fall through to
6436 checking whether the step finished. */
6437 if (ecs->event_thread->stepped_breakpoint)
6439 struct breakpoint *sr_bp
6440 = ecs->event_thread->control.step_resume_breakpoint;
6443 && sr_bp->loc->permanent
6444 && sr_bp->type == bp_hp_step_resume
6445 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6448 fprintf_unfiltered (gdb_stdlog,
6449 "infrun: stepped permanent breakpoint, stopped in "
6451 delete_step_resume_breakpoint (ecs->event_thread);
6452 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6456 /* We come here if we hit a breakpoint but should not stop for it.
6457 Possibly we also were stepping and should stop for that. So fall
6458 through and test for stepping. But, if not stepping, do not
6461 /* In all-stop mode, if we're currently stepping but have stopped in
6462 some other thread, we need to switch back to the stepped thread. */
6463 if (switch_back_to_stepped_thread (ecs))
6466 if (ecs->event_thread->control.step_resume_breakpoint)
6469 fprintf_unfiltered (gdb_stdlog,
6470 "infrun: step-resume breakpoint is inserted\n");
6472 /* Having a step-resume breakpoint overrides anything
6473 else having to do with stepping commands until
6474 that breakpoint is reached. */
6479 if (ecs->event_thread->control.step_range_end == 0)
6482 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6483 /* Likewise if we aren't even stepping. */
6488 /* Re-fetch current thread's frame in case the code above caused
6489 the frame cache to be re-initialized, making our FRAME variable
6490 a dangling pointer. */
6491 frame = get_current_frame ();
6492 gdbarch = get_frame_arch (frame);
6493 fill_in_stop_func (gdbarch, ecs);
6495 /* If stepping through a line, keep going if still within it.
6497 Note that step_range_end is the address of the first instruction
6498 beyond the step range, and NOT the address of the last instruction
6501 Note also that during reverse execution, we may be stepping
6502 through a function epilogue and therefore must detect when
6503 the current-frame changes in the middle of a line. */
6505 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6506 && (execution_direction != EXEC_REVERSE
6507 || frame_id_eq (get_frame_id (frame),
6508 ecs->event_thread->control.step_frame_id)))
6512 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6513 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6514 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6516 /* Tentatively re-enable range stepping; `resume' disables it if
6517 necessary (e.g., if we're stepping over a breakpoint or we
6518 have software watchpoints). */
6519 ecs->event_thread->control.may_range_step = 1;
6521 /* When stepping backward, stop at beginning of line range
6522 (unless it's the function entry point, in which case
6523 keep going back to the call point). */
6524 if (stop_pc == ecs->event_thread->control.step_range_start
6525 && stop_pc != ecs->stop_func_start
6526 && execution_direction == EXEC_REVERSE)
6527 end_stepping_range (ecs);
6534 /* We stepped out of the stepping range. */
6536 /* If we are stepping at the source level and entered the runtime
6537 loader dynamic symbol resolution code...
6539 EXEC_FORWARD: we keep on single stepping until we exit the run
6540 time loader code and reach the callee's address.
6542 EXEC_REVERSE: we've already executed the callee (backward), and
6543 the runtime loader code is handled just like any other
6544 undebuggable function call. Now we need only keep stepping
6545 backward through the trampoline code, and that's handled further
6546 down, so there is nothing for us to do here. */
6548 if (execution_direction != EXEC_REVERSE
6549 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6550 && in_solib_dynsym_resolve_code (stop_pc))
6552 CORE_ADDR pc_after_resolver =
6553 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6556 fprintf_unfiltered (gdb_stdlog,
6557 "infrun: stepped into dynsym resolve code\n");
6559 if (pc_after_resolver)
6561 /* Set up a step-resume breakpoint at the address
6562 indicated by SKIP_SOLIB_RESOLVER. */
6563 symtab_and_line sr_sal;
6564 sr_sal.pc = pc_after_resolver;
6565 sr_sal.pspace = get_frame_program_space (frame);
6567 insert_step_resume_breakpoint_at_sal (gdbarch,
6568 sr_sal, null_frame_id);
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 stop_pc, ecs->stop_func_name)
6599 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6601 /* Determine where this trampoline returns. */
6602 CORE_ADDR real_stop_pc;
6604 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6607 fprintf_unfiltered (gdb_stdlog,
6608 "infrun: stepped into solib return tramp\n");
6610 /* Only proceed through if we know where it's going. */
6613 /* And put the step-breakpoint there and go until there. */
6614 symtab_and_line sr_sal;
6615 sr_sal.pc = real_stop_pc;
6616 sr_sal.section = find_pc_overlay (sr_sal.pc);
6617 sr_sal.pspace = get_frame_program_space (frame);
6619 /* Do not specify what the fp should be when we stop since
6620 on some machines the prologue is where the new fp value
6622 insert_step_resume_breakpoint_at_sal (gdbarch,
6623 sr_sal, null_frame_id);
6625 /* Restart without fiddling with the step ranges or
6632 /* Check for subroutine calls. The check for the current frame
6633 equalling the step ID is not necessary - the check of the
6634 previous frame's ID is sufficient - but it is a common case and
6635 cheaper than checking the previous frame's ID.
6637 NOTE: frame_id_eq will never report two invalid frame IDs as
6638 being equal, so to get into this block, both the current and
6639 previous frame must have valid frame IDs. */
6640 /* The outer_frame_id check is a heuristic to detect stepping
6641 through startup code. If we step over an instruction which
6642 sets the stack pointer from an invalid value to a valid value,
6643 we may detect that as a subroutine call from the mythical
6644 "outermost" function. This could be fixed by marking
6645 outermost frames as !stack_p,code_p,special_p. Then the
6646 initial outermost frame, before sp was valid, would
6647 have code_addr == &_start. See the comment in frame_id_eq
6649 if (!frame_id_eq (get_stack_frame_id (frame),
6650 ecs->event_thread->control.step_stack_frame_id)
6651 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6652 ecs->event_thread->control.step_stack_frame_id)
6653 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6655 || (ecs->event_thread->control.step_start_function
6656 != find_pc_function (stop_pc)))))
6658 CORE_ADDR real_stop_pc;
6661 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6663 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6665 /* I presume that step_over_calls is only 0 when we're
6666 supposed to be stepping at the assembly language level
6667 ("stepi"). Just stop. */
6668 /* And this works the same backward as frontward. MVS */
6669 end_stepping_range (ecs);
6673 /* Reverse stepping through solib trampolines. */
6675 if (execution_direction == EXEC_REVERSE
6676 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6677 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6678 || (ecs->stop_func_start == 0
6679 && in_solib_dynsym_resolve_code (stop_pc))))
6681 /* Any solib trampoline code can be handled in reverse
6682 by simply continuing to single-step. We have already
6683 executed the solib function (backwards), and a few
6684 steps will take us back through the trampoline to the
6690 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6692 /* We're doing a "next".
6694 Normal (forward) execution: set a breakpoint at the
6695 callee's return address (the address at which the caller
6698 Reverse (backward) execution. set the step-resume
6699 breakpoint at the start of the function that we just
6700 stepped into (backwards), and continue to there. When we
6701 get there, we'll need to single-step back to the caller. */
6703 if (execution_direction == EXEC_REVERSE)
6705 /* If we're already at the start of the function, we've either
6706 just stepped backward into a single instruction function,
6707 or stepped back out of a signal handler to the first instruction
6708 of the function. Just keep going, which will single-step back
6710 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6712 /* Normal function call return (static or dynamic). */
6713 symtab_and_line sr_sal;
6714 sr_sal.pc = ecs->stop_func_start;
6715 sr_sal.pspace = get_frame_program_space (frame);
6716 insert_step_resume_breakpoint_at_sal (gdbarch,
6717 sr_sal, null_frame_id);
6721 insert_step_resume_breakpoint_at_caller (frame);
6727 /* If we are in a function call trampoline (a stub between the
6728 calling routine and the real function), locate the real
6729 function. That's what tells us (a) whether we want to step
6730 into it at all, and (b) what prologue we want to run to the
6731 end of, if we do step into it. */
6732 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6733 if (real_stop_pc == 0)
6734 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6735 if (real_stop_pc != 0)
6736 ecs->stop_func_start = real_stop_pc;
6738 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6740 symtab_and_line sr_sal;
6741 sr_sal.pc = ecs->stop_func_start;
6742 sr_sal.pspace = get_frame_program_space (frame);
6744 insert_step_resume_breakpoint_at_sal (gdbarch,
6745 sr_sal, null_frame_id);
6750 /* If we have line number information for the function we are
6751 thinking of stepping into and the function isn't on the skip
6754 If there are several symtabs at that PC (e.g. with include
6755 files), just want to know whether *any* of them have line
6756 numbers. find_pc_line handles this. */
6758 struct symtab_and_line tmp_sal;
6760 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6761 if (tmp_sal.line != 0
6762 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6765 if (execution_direction == EXEC_REVERSE)
6766 handle_step_into_function_backward (gdbarch, ecs);
6768 handle_step_into_function (gdbarch, ecs);
6773 /* If we have no line number and the step-stop-if-no-debug is
6774 set, we stop the step so that the user has a chance to switch
6775 in assembly mode. */
6776 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6777 && step_stop_if_no_debug)
6779 end_stepping_range (ecs);
6783 if (execution_direction == EXEC_REVERSE)
6785 /* If we're already at the start of the function, we've either just
6786 stepped backward into a single instruction function without line
6787 number info, or stepped back out of a signal handler to the first
6788 instruction of the function without line number info. Just keep
6789 going, which will single-step back to the caller. */
6790 if (ecs->stop_func_start != stop_pc)
6792 /* Set a breakpoint at callee's start address.
6793 From there we can step once and be back in the caller. */
6794 symtab_and_line sr_sal;
6795 sr_sal.pc = ecs->stop_func_start;
6796 sr_sal.pspace = get_frame_program_space (frame);
6797 insert_step_resume_breakpoint_at_sal (gdbarch,
6798 sr_sal, null_frame_id);
6802 /* Set a breakpoint at callee's return address (the address
6803 at which the caller will resume). */
6804 insert_step_resume_breakpoint_at_caller (frame);
6810 /* Reverse stepping through solib trampolines. */
6812 if (execution_direction == EXEC_REVERSE
6813 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6815 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6816 || (ecs->stop_func_start == 0
6817 && in_solib_dynsym_resolve_code (stop_pc)))
6819 /* Any solib trampoline code can be handled in reverse
6820 by simply continuing to single-step. We have already
6821 executed the solib function (backwards), and a few
6822 steps will take us back through the trampoline to the
6827 else if (in_solib_dynsym_resolve_code (stop_pc))
6829 /* Stepped backward into the solib dynsym resolver.
6830 Set a breakpoint at its start and continue, then
6831 one more step will take us out. */
6832 symtab_and_line sr_sal;
6833 sr_sal.pc = ecs->stop_func_start;
6834 sr_sal.pspace = get_frame_program_space (frame);
6835 insert_step_resume_breakpoint_at_sal (gdbarch,
6836 sr_sal, null_frame_id);
6842 stop_pc_sal = find_pc_line (stop_pc, 0);
6844 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6845 the trampoline processing logic, however, there are some trampolines
6846 that have no names, so we should do trampoline handling first. */
6847 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6848 && ecs->stop_func_name == NULL
6849 && stop_pc_sal.line == 0)
6852 fprintf_unfiltered (gdb_stdlog,
6853 "infrun: stepped into undebuggable function\n");
6855 /* The inferior just stepped into, or returned to, an
6856 undebuggable function (where there is no debugging information
6857 and no line number corresponding to the address where the
6858 inferior stopped). Since we want to skip this kind of code,
6859 we keep going until the inferior returns from this
6860 function - unless the user has asked us not to (via
6861 set step-mode) or we no longer know how to get back
6862 to the call site. */
6863 if (step_stop_if_no_debug
6864 || !frame_id_p (frame_unwind_caller_id (frame)))
6866 /* If we have no line number and the step-stop-if-no-debug
6867 is set, we stop the step so that the user has a chance to
6868 switch in assembly mode. */
6869 end_stepping_range (ecs);
6874 /* Set a breakpoint at callee's return address (the address
6875 at which the caller will resume). */
6876 insert_step_resume_breakpoint_at_caller (frame);
6882 if (ecs->event_thread->control.step_range_end == 1)
6884 /* It is stepi or nexti. We always want to stop stepping after
6887 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6888 end_stepping_range (ecs);
6892 if (stop_pc_sal.line == 0)
6894 /* We have no line number information. That means to stop
6895 stepping (does this always happen right after one instruction,
6896 when we do "s" in a function with no line numbers,
6897 or can this happen as a result of a return or longjmp?). */
6899 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6900 end_stepping_range (ecs);
6904 /* Look for "calls" to inlined functions, part one. If the inline
6905 frame machinery detected some skipped call sites, we have entered
6906 a new inline function. */
6908 if (frame_id_eq (get_frame_id (get_current_frame ()),
6909 ecs->event_thread->control.step_frame_id)
6910 && inline_skipped_frames (ecs->ptid))
6913 fprintf_unfiltered (gdb_stdlog,
6914 "infrun: stepped into inlined function\n");
6916 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6918 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6920 /* For "step", we're going to stop. But if the call site
6921 for this inlined function is on the same source line as
6922 we were previously stepping, go down into the function
6923 first. Otherwise stop at the call site. */
6925 if (call_sal.line == ecs->event_thread->current_line
6926 && call_sal.symtab == ecs->event_thread->current_symtab)
6927 step_into_inline_frame (ecs->ptid);
6929 end_stepping_range (ecs);
6934 /* For "next", we should stop at the call site if it is on a
6935 different source line. Otherwise continue through the
6936 inlined function. */
6937 if (call_sal.line == ecs->event_thread->current_line
6938 && call_sal.symtab == ecs->event_thread->current_symtab)
6941 end_stepping_range (ecs);
6946 /* Look for "calls" to inlined functions, part two. If we are still
6947 in the same real function we were stepping through, but we have
6948 to go further up to find the exact frame ID, we are stepping
6949 through a more inlined call beyond its call site. */
6951 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6952 && !frame_id_eq (get_frame_id (get_current_frame ()),
6953 ecs->event_thread->control.step_frame_id)
6954 && stepped_in_from (get_current_frame (),
6955 ecs->event_thread->control.step_frame_id))
6958 fprintf_unfiltered (gdb_stdlog,
6959 "infrun: stepping through inlined function\n");
6961 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6964 end_stepping_range (ecs);
6968 if ((stop_pc == stop_pc_sal.pc)
6969 && (ecs->event_thread->current_line != stop_pc_sal.line
6970 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6972 /* We are at the start of a different line. So stop. Note that
6973 we don't stop if we step into the middle of a different line.
6974 That is said to make things like for (;;) statements work
6977 fprintf_unfiltered (gdb_stdlog,
6978 "infrun: stepped to a different line\n");
6979 end_stepping_range (ecs);
6983 /* We aren't done stepping.
6985 Optimize by setting the stepping range to the line.
6986 (We might not be in the original line, but if we entered a
6987 new line in mid-statement, we continue stepping. This makes
6988 things like for(;;) statements work better.) */
6990 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6991 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6992 ecs->event_thread->control.may_range_step = 1;
6993 set_step_info (frame, stop_pc_sal);
6996 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
7000 /* In all-stop mode, if we're currently stepping but have stopped in
7001 some other thread, we may need to switch back to the stepped
7002 thread. Returns true we set the inferior running, false if we left
7003 it stopped (and the event needs further processing). */
7006 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7008 if (!target_is_non_stop_p ())
7010 struct thread_info *tp;
7011 struct thread_info *stepping_thread;
7013 /* If any thread is blocked on some internal breakpoint, and we
7014 simply need to step over that breakpoint to get it going
7015 again, do that first. */
7017 /* However, if we see an event for the stepping thread, then we
7018 know all other threads have been moved past their breakpoints
7019 already. Let the caller check whether the step is finished,
7020 etc., before deciding to move it past a breakpoint. */
7021 if (ecs->event_thread->control.step_range_end != 0)
7024 /* Check if the current thread is blocked on an incomplete
7025 step-over, interrupted by a random signal. */
7026 if (ecs->event_thread->control.trap_expected
7027 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7031 fprintf_unfiltered (gdb_stdlog,
7032 "infrun: need to finish step-over of [%s]\n",
7033 target_pid_to_str (ecs->event_thread->ptid));
7039 /* Check if the current thread is blocked by a single-step
7040 breakpoint of another thread. */
7041 if (ecs->hit_singlestep_breakpoint)
7045 fprintf_unfiltered (gdb_stdlog,
7046 "infrun: need to step [%s] over single-step "
7048 target_pid_to_str (ecs->ptid));
7054 /* If this thread needs yet another step-over (e.g., stepping
7055 through a delay slot), do it first before moving on to
7057 if (thread_still_needs_step_over (ecs->event_thread))
7061 fprintf_unfiltered (gdb_stdlog,
7062 "infrun: thread [%s] still needs step-over\n",
7063 target_pid_to_str (ecs->event_thread->ptid));
7069 /* If scheduler locking applies even if not stepping, there's no
7070 need to walk over threads. Above we've checked whether the
7071 current thread is stepping. If some other thread not the
7072 event thread is stepping, then it must be that scheduler
7073 locking is not in effect. */
7074 if (schedlock_applies (ecs->event_thread))
7077 /* Otherwise, we no longer expect a trap in the current thread.
7078 Clear the trap_expected flag before switching back -- this is
7079 what keep_going does as well, if we call it. */
7080 ecs->event_thread->control.trap_expected = 0;
7082 /* Likewise, clear the signal if it should not be passed. */
7083 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7084 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7086 /* Do all pending step-overs before actually proceeding with
7088 if (start_step_over ())
7090 prepare_to_wait (ecs);
7094 /* Look for the stepping/nexting thread. */
7095 stepping_thread = NULL;
7097 ALL_NON_EXITED_THREADS (tp)
7099 /* Ignore threads of processes the caller is not
7102 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7105 /* When stepping over a breakpoint, we lock all threads
7106 except the one that needs to move past the breakpoint.
7107 If a non-event thread has this set, the "incomplete
7108 step-over" check above should have caught it earlier. */
7109 if (tp->control.trap_expected)
7111 internal_error (__FILE__, __LINE__,
7112 "[%s] has inconsistent state: "
7113 "trap_expected=%d\n",
7114 target_pid_to_str (tp->ptid),
7115 tp->control.trap_expected);
7118 /* Did we find the stepping thread? */
7119 if (tp->control.step_range_end)
7121 /* Yep. There should only one though. */
7122 gdb_assert (stepping_thread == NULL);
7124 /* The event thread is handled at the top, before we
7126 gdb_assert (tp != ecs->event_thread);
7128 /* If some thread other than the event thread is
7129 stepping, then scheduler locking can't be in effect,
7130 otherwise we wouldn't have resumed the current event
7131 thread in the first place. */
7132 gdb_assert (!schedlock_applies (tp));
7134 stepping_thread = tp;
7138 if (stepping_thread != NULL)
7141 fprintf_unfiltered (gdb_stdlog,
7142 "infrun: switching back to stepped thread\n");
7144 if (keep_going_stepped_thread (stepping_thread))
7146 prepare_to_wait (ecs);
7155 /* Set a previously stepped thread back to stepping. Returns true on
7156 success, false if the resume is not possible (e.g., the thread
7160 keep_going_stepped_thread (struct thread_info *tp)
7162 struct frame_info *frame;
7163 struct execution_control_state ecss;
7164 struct execution_control_state *ecs = &ecss;
7166 /* If the stepping thread exited, then don't try to switch back and
7167 resume it, which could fail in several different ways depending
7168 on the target. Instead, just keep going.
7170 We can find a stepping dead thread in the thread list in two
7173 - The target supports thread exit events, and when the target
7174 tries to delete the thread from the thread list, inferior_ptid
7175 pointed at the exiting thread. In such case, calling
7176 delete_thread does not really remove the thread from the list;
7177 instead, the thread is left listed, with 'exited' state.
7179 - The target's debug interface does not support thread exit
7180 events, and so we have no idea whatsoever if the previously
7181 stepping thread is still alive. For that reason, we need to
7182 synchronously query the target now. */
7184 if (is_exited (tp->ptid)
7185 || !target_thread_alive (tp->ptid))
7188 fprintf_unfiltered (gdb_stdlog,
7189 "infrun: not resuming previously "
7190 "stepped thread, it has vanished\n");
7192 delete_thread (tp->ptid);
7197 fprintf_unfiltered (gdb_stdlog,
7198 "infrun: resuming previously stepped thread\n");
7200 reset_ecs (ecs, tp);
7201 switch_to_thread (tp->ptid);
7203 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7204 frame = get_current_frame ();
7206 /* If the PC of the thread we were trying to single-step has
7207 changed, then that thread has trapped or been signaled, but the
7208 event has not been reported to GDB yet. Re-poll the target
7209 looking for this particular thread's event (i.e. temporarily
7210 enable schedlock) by:
7212 - setting a break at the current PC
7213 - resuming that particular thread, only (by setting trap
7216 This prevents us continuously moving the single-step breakpoint
7217 forward, one instruction at a time, overstepping. */
7219 if (stop_pc != tp->prev_pc)
7224 fprintf_unfiltered (gdb_stdlog,
7225 "infrun: expected thread advanced also (%s -> %s)\n",
7226 paddress (target_gdbarch (), tp->prev_pc),
7227 paddress (target_gdbarch (), stop_pc));
7229 /* Clear the info of the previous step-over, as it's no longer
7230 valid (if the thread was trying to step over a breakpoint, it
7231 has already succeeded). It's what keep_going would do too,
7232 if we called it. Do this before trying to insert the sss
7233 breakpoint, otherwise if we were previously trying to step
7234 over this exact address in another thread, the breakpoint is
7236 clear_step_over_info ();
7237 tp->control.trap_expected = 0;
7239 insert_single_step_breakpoint (get_frame_arch (frame),
7240 get_frame_address_space (frame),
7244 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7245 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7250 fprintf_unfiltered (gdb_stdlog,
7251 "infrun: expected thread still hasn't advanced\n");
7253 keep_going_pass_signal (ecs);
7258 /* Is thread TP in the middle of (software or hardware)
7259 single-stepping? (Note the result of this function must never be
7260 passed directly as target_resume's STEP parameter.) */
7263 currently_stepping (struct thread_info *tp)
7265 return ((tp->control.step_range_end
7266 && tp->control.step_resume_breakpoint == NULL)
7267 || tp->control.trap_expected
7268 || tp->stepped_breakpoint
7269 || bpstat_should_step ());
7272 /* Inferior has stepped into a subroutine call with source code that
7273 we should not step over. Do step to the first line of code in
7277 handle_step_into_function (struct gdbarch *gdbarch,
7278 struct execution_control_state *ecs)
7280 fill_in_stop_func (gdbarch, ecs);
7282 compunit_symtab *cust = find_pc_compunit_symtab (stop_pc);
7283 if (cust != NULL && compunit_language (cust) != language_asm)
7284 ecs->stop_func_start
7285 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7287 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7288 /* Use the step_resume_break to step until the end of the prologue,
7289 even if that involves jumps (as it seems to on the vax under
7291 /* If the prologue ends in the middle of a source line, continue to
7292 the end of that source line (if it is still within the function).
7293 Otherwise, just go to end of prologue. */
7294 if (stop_func_sal.end
7295 && stop_func_sal.pc != ecs->stop_func_start
7296 && stop_func_sal.end < ecs->stop_func_end)
7297 ecs->stop_func_start = stop_func_sal.end;
7299 /* Architectures which require breakpoint adjustment might not be able
7300 to place a breakpoint at the computed address. If so, the test
7301 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7302 ecs->stop_func_start to an address at which a breakpoint may be
7303 legitimately placed.
7305 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7306 made, GDB will enter an infinite loop when stepping through
7307 optimized code consisting of VLIW instructions which contain
7308 subinstructions corresponding to different source lines. On
7309 FR-V, it's not permitted to place a breakpoint on any but the
7310 first subinstruction of a VLIW instruction. When a breakpoint is
7311 set, GDB will adjust the breakpoint address to the beginning of
7312 the VLIW instruction. Thus, we need to make the corresponding
7313 adjustment here when computing the stop address. */
7315 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7317 ecs->stop_func_start
7318 = gdbarch_adjust_breakpoint_address (gdbarch,
7319 ecs->stop_func_start);
7322 if (ecs->stop_func_start == stop_pc)
7324 /* We are already there: stop now. */
7325 end_stepping_range (ecs);
7330 /* Put the step-breakpoint there and go until there. */
7331 symtab_and_line sr_sal;
7332 sr_sal.pc = ecs->stop_func_start;
7333 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7334 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7336 /* Do not specify what the fp should be when we stop since on
7337 some machines the prologue is where the new fp value is
7339 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7341 /* And make sure stepping stops right away then. */
7342 ecs->event_thread->control.step_range_end
7343 = ecs->event_thread->control.step_range_start;
7348 /* Inferior has stepped backward into a subroutine call with source
7349 code that we should not step over. Do step to the beginning of the
7350 last line of code in it. */
7353 handle_step_into_function_backward (struct gdbarch *gdbarch,
7354 struct execution_control_state *ecs)
7356 struct compunit_symtab *cust;
7357 struct symtab_and_line stop_func_sal;
7359 fill_in_stop_func (gdbarch, ecs);
7361 cust = find_pc_compunit_symtab (stop_pc);
7362 if (cust != NULL && compunit_language (cust) != language_asm)
7363 ecs->stop_func_start
7364 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7366 stop_func_sal = find_pc_line (stop_pc, 0);
7368 /* OK, we're just going to keep stepping here. */
7369 if (stop_func_sal.pc == stop_pc)
7371 /* We're there already. Just stop stepping now. */
7372 end_stepping_range (ecs);
7376 /* Else just reset the step range and keep going.
7377 No step-resume breakpoint, they don't work for
7378 epilogues, which can have multiple entry paths. */
7379 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7380 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7386 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7387 This is used to both functions and to skip over code. */
7390 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7391 struct symtab_and_line sr_sal,
7392 struct frame_id sr_id,
7393 enum bptype sr_type)
7395 /* There should never be more than one step-resume or longjmp-resume
7396 breakpoint per thread, so we should never be setting a new
7397 step_resume_breakpoint when one is already active. */
7398 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7399 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7402 fprintf_unfiltered (gdb_stdlog,
7403 "infrun: inserting step-resume breakpoint at %s\n",
7404 paddress (gdbarch, sr_sal.pc));
7406 inferior_thread ()->control.step_resume_breakpoint
7407 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7411 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7412 struct symtab_and_line sr_sal,
7413 struct frame_id sr_id)
7415 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7420 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7421 This is used to skip a potential signal handler.
7423 This is called with the interrupted function's frame. The signal
7424 handler, when it returns, will resume the interrupted function at
7428 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7430 gdb_assert (return_frame != NULL);
7432 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7434 symtab_and_line sr_sal;
7435 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7436 sr_sal.section = find_pc_overlay (sr_sal.pc);
7437 sr_sal.pspace = get_frame_program_space (return_frame);
7439 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7440 get_stack_frame_id (return_frame),
7444 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7445 is used to skip a function after stepping into it (for "next" or if
7446 the called function has no debugging information).
7448 The current function has almost always been reached by single
7449 stepping a call or return instruction. NEXT_FRAME belongs to the
7450 current function, and the breakpoint will be set at the caller's
7453 This is a separate function rather than reusing
7454 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7455 get_prev_frame, which may stop prematurely (see the implementation
7456 of frame_unwind_caller_id for an example). */
7459 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7461 /* We shouldn't have gotten here if we don't know where the call site
7463 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7465 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7467 symtab_and_line sr_sal;
7468 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7469 frame_unwind_caller_pc (next_frame));
7470 sr_sal.section = find_pc_overlay (sr_sal.pc);
7471 sr_sal.pspace = frame_unwind_program_space (next_frame);
7473 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7474 frame_unwind_caller_id (next_frame));
7477 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7478 new breakpoint at the target of a jmp_buf. The handling of
7479 longjmp-resume uses the same mechanisms used for handling
7480 "step-resume" breakpoints. */
7483 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7485 /* There should never be more than one longjmp-resume breakpoint per
7486 thread, so we should never be setting a new
7487 longjmp_resume_breakpoint when one is already active. */
7488 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7491 fprintf_unfiltered (gdb_stdlog,
7492 "infrun: inserting longjmp-resume breakpoint at %s\n",
7493 paddress (gdbarch, pc));
7495 inferior_thread ()->control.exception_resume_breakpoint =
7496 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7499 /* Insert an exception resume breakpoint. TP is the thread throwing
7500 the exception. The block B is the block of the unwinder debug hook
7501 function. FRAME is the frame corresponding to the call to this
7502 function. SYM is the symbol of the function argument holding the
7503 target PC of the exception. */
7506 insert_exception_resume_breakpoint (struct thread_info *tp,
7507 const struct block *b,
7508 struct frame_info *frame,
7513 struct block_symbol vsym;
7514 struct value *value;
7516 struct breakpoint *bp;
7518 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7519 value = read_var_value (vsym.symbol, vsym.block, frame);
7520 /* If the value was optimized out, revert to the old behavior. */
7521 if (! value_optimized_out (value))
7523 handler = value_as_address (value);
7526 fprintf_unfiltered (gdb_stdlog,
7527 "infrun: exception resume at %lx\n",
7528 (unsigned long) handler);
7530 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7531 handler, bp_exception_resume);
7533 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7536 bp->thread = tp->global_num;
7537 inferior_thread ()->control.exception_resume_breakpoint = bp;
7540 CATCH (e, RETURN_MASK_ERROR)
7542 /* We want to ignore errors here. */
7547 /* A helper for check_exception_resume that sets an
7548 exception-breakpoint based on a SystemTap probe. */
7551 insert_exception_resume_from_probe (struct thread_info *tp,
7552 const struct bound_probe *probe,
7553 struct frame_info *frame)
7555 struct value *arg_value;
7557 struct breakpoint *bp;
7559 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7563 handler = value_as_address (arg_value);
7566 fprintf_unfiltered (gdb_stdlog,
7567 "infrun: exception resume at %s\n",
7568 paddress (get_objfile_arch (probe->objfile),
7571 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7572 handler, bp_exception_resume);
7573 bp->thread = tp->global_num;
7574 inferior_thread ()->control.exception_resume_breakpoint = bp;
7577 /* This is called when an exception has been intercepted. Check to
7578 see whether the exception's destination is of interest, and if so,
7579 set an exception resume breakpoint there. */
7582 check_exception_resume (struct execution_control_state *ecs,
7583 struct frame_info *frame)
7585 struct bound_probe probe;
7586 struct symbol *func;
7588 /* First see if this exception unwinding breakpoint was set via a
7589 SystemTap probe point. If so, the probe has two arguments: the
7590 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7591 set a breakpoint there. */
7592 probe = find_probe_by_pc (get_frame_pc (frame));
7595 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7599 func = get_frame_function (frame);
7605 const struct block *b;
7606 struct block_iterator iter;
7610 /* The exception breakpoint is a thread-specific breakpoint on
7611 the unwinder's debug hook, declared as:
7613 void _Unwind_DebugHook (void *cfa, void *handler);
7615 The CFA argument indicates the frame to which control is
7616 about to be transferred. HANDLER is the destination PC.
7618 We ignore the CFA and set a temporary breakpoint at HANDLER.
7619 This is not extremely efficient but it avoids issues in gdb
7620 with computing the DWARF CFA, and it also works even in weird
7621 cases such as throwing an exception from inside a signal
7624 b = SYMBOL_BLOCK_VALUE (func);
7625 ALL_BLOCK_SYMBOLS (b, iter, sym)
7627 if (!SYMBOL_IS_ARGUMENT (sym))
7634 insert_exception_resume_breakpoint (ecs->event_thread,
7640 CATCH (e, RETURN_MASK_ERROR)
7647 stop_waiting (struct execution_control_state *ecs)
7650 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7652 /* Let callers know we don't want to wait for the inferior anymore. */
7653 ecs->wait_some_more = 0;
7655 /* If all-stop, but the target is always in non-stop mode, stop all
7656 threads now that we're presenting the stop to the user. */
7657 if (!non_stop && target_is_non_stop_p ())
7658 stop_all_threads ();
7661 /* Like keep_going, but passes the signal to the inferior, even if the
7662 signal is set to nopass. */
7665 keep_going_pass_signal (struct execution_control_state *ecs)
7667 /* Make sure normal_stop is called if we get a QUIT handled before
7669 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7671 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7672 gdb_assert (!ecs->event_thread->resumed);
7674 /* Save the pc before execution, to compare with pc after stop. */
7675 ecs->event_thread->prev_pc
7676 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7678 if (ecs->event_thread->control.trap_expected)
7680 struct thread_info *tp = ecs->event_thread;
7683 fprintf_unfiltered (gdb_stdlog,
7684 "infrun: %s has trap_expected set, "
7685 "resuming to collect trap\n",
7686 target_pid_to_str (tp->ptid));
7688 /* We haven't yet gotten our trap, and either: intercepted a
7689 non-signal event (e.g., a fork); or took a signal which we
7690 are supposed to pass through to the inferior. Simply
7692 discard_cleanups (old_cleanups);
7693 resume (ecs->event_thread->suspend.stop_signal);
7695 else if (step_over_info_valid_p ())
7697 /* Another thread is stepping over a breakpoint in-line. If
7698 this thread needs a step-over too, queue the request. In
7699 either case, this resume must be deferred for later. */
7700 struct thread_info *tp = ecs->event_thread;
7702 if (ecs->hit_singlestep_breakpoint
7703 || thread_still_needs_step_over (tp))
7706 fprintf_unfiltered (gdb_stdlog,
7707 "infrun: step-over already in progress: "
7708 "step-over for %s deferred\n",
7709 target_pid_to_str (tp->ptid));
7710 thread_step_over_chain_enqueue (tp);
7715 fprintf_unfiltered (gdb_stdlog,
7716 "infrun: step-over in progress: "
7717 "resume of %s deferred\n",
7718 target_pid_to_str (tp->ptid));
7721 discard_cleanups (old_cleanups);
7725 struct regcache *regcache = get_current_regcache ();
7728 step_over_what step_what;
7730 /* Either the trap was not expected, but we are continuing
7731 anyway (if we got a signal, the user asked it be passed to
7734 We got our expected trap, but decided we should resume from
7737 We're going to run this baby now!
7739 Note that insert_breakpoints won't try to re-insert
7740 already inserted breakpoints. Therefore, we don't
7741 care if breakpoints were already inserted, or not. */
7743 /* If we need to step over a breakpoint, and we're not using
7744 displaced stepping to do so, insert all breakpoints
7745 (watchpoints, etc.) but the one we're stepping over, step one
7746 instruction, and then re-insert the breakpoint when that step
7749 step_what = thread_still_needs_step_over (ecs->event_thread);
7751 remove_bp = (ecs->hit_singlestep_breakpoint
7752 || (step_what & STEP_OVER_BREAKPOINT));
7753 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7755 /* We can't use displaced stepping if we need to step past a
7756 watchpoint. The instruction copied to the scratch pad would
7757 still trigger the watchpoint. */
7759 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7761 set_step_over_info (regcache->aspace (),
7762 regcache_read_pc (regcache), remove_wps,
7763 ecs->event_thread->global_num);
7765 else if (remove_wps)
7766 set_step_over_info (NULL, 0, remove_wps, -1);
7768 /* If we now need to do an in-line step-over, we need to stop
7769 all other threads. Note this must be done before
7770 insert_breakpoints below, because that removes the breakpoint
7771 we're about to step over, otherwise other threads could miss
7773 if (step_over_info_valid_p () && target_is_non_stop_p ())
7774 stop_all_threads ();
7776 /* Stop stepping if inserting breakpoints fails. */
7779 insert_breakpoints ();
7781 CATCH (e, RETURN_MASK_ERROR)
7783 exception_print (gdb_stderr, e);
7785 discard_cleanups (old_cleanups);
7790 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7792 discard_cleanups (old_cleanups);
7793 resume (ecs->event_thread->suspend.stop_signal);
7796 prepare_to_wait (ecs);
7799 /* Called when we should continue running the inferior, because the
7800 current event doesn't cause a user visible stop. This does the
7801 resuming part; waiting for the next event is done elsewhere. */
7804 keep_going (struct execution_control_state *ecs)
7806 if (ecs->event_thread->control.trap_expected
7807 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7808 ecs->event_thread->control.trap_expected = 0;
7810 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7811 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7812 keep_going_pass_signal (ecs);
7815 /* This function normally comes after a resume, before
7816 handle_inferior_event exits. It takes care of any last bits of
7817 housekeeping, and sets the all-important wait_some_more flag. */
7820 prepare_to_wait (struct execution_control_state *ecs)
7823 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7825 ecs->wait_some_more = 1;
7827 if (!target_is_async_p ())
7828 mark_infrun_async_event_handler ();
7831 /* We are done with the step range of a step/next/si/ni command.
7832 Called once for each n of a "step n" operation. */
7835 end_stepping_range (struct execution_control_state *ecs)
7837 ecs->event_thread->control.stop_step = 1;
7841 /* Several print_*_reason functions to print why the inferior has stopped.
7842 We always print something when the inferior exits, or receives a signal.
7843 The rest of the cases are dealt with later on in normal_stop and
7844 print_it_typical. Ideally there should be a call to one of these
7845 print_*_reason functions functions from handle_inferior_event each time
7846 stop_waiting is called.
7848 Note that we don't call these directly, instead we delegate that to
7849 the interpreters, through observers. Interpreters then call these
7850 with whatever uiout is right. */
7853 print_end_stepping_range_reason (struct ui_out *uiout)
7855 /* For CLI-like interpreters, print nothing. */
7857 if (uiout->is_mi_like_p ())
7859 uiout->field_string ("reason",
7860 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7865 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7867 annotate_signalled ();
7868 if (uiout->is_mi_like_p ())
7870 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7871 uiout->text ("\nProgram terminated with signal ");
7872 annotate_signal_name ();
7873 uiout->field_string ("signal-name",
7874 gdb_signal_to_name (siggnal));
7875 annotate_signal_name_end ();
7877 annotate_signal_string ();
7878 uiout->field_string ("signal-meaning",
7879 gdb_signal_to_string (siggnal));
7880 annotate_signal_string_end ();
7881 uiout->text (".\n");
7882 uiout->text ("The program no longer exists.\n");
7886 print_exited_reason (struct ui_out *uiout, int exitstatus)
7888 struct inferior *inf = current_inferior ();
7889 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7891 annotate_exited (exitstatus);
7894 if (uiout->is_mi_like_p ())
7895 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7896 uiout->text ("[Inferior ");
7897 uiout->text (plongest (inf->num));
7899 uiout->text (pidstr);
7900 uiout->text (") exited with code ");
7901 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7902 uiout->text ("]\n");
7906 if (uiout->is_mi_like_p ())
7908 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7909 uiout->text ("[Inferior ");
7910 uiout->text (plongest (inf->num));
7912 uiout->text (pidstr);
7913 uiout->text (") exited normally]\n");
7917 /* Some targets/architectures can do extra processing/display of
7918 segmentation faults. E.g., Intel MPX boundary faults.
7919 Call the architecture dependent function to handle the fault. */
7922 handle_segmentation_fault (struct ui_out *uiout)
7924 struct regcache *regcache = get_current_regcache ();
7925 struct gdbarch *gdbarch = regcache->arch ();
7927 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7928 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7932 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7934 struct thread_info *thr = inferior_thread ();
7938 if (uiout->is_mi_like_p ())
7940 else if (show_thread_that_caused_stop ())
7944 uiout->text ("\nThread ");
7945 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7947 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7950 uiout->text (" \"");
7951 uiout->field_fmt ("name", "%s", name);
7956 uiout->text ("\nProgram");
7958 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7959 uiout->text (" stopped");
7962 uiout->text (" received signal ");
7963 annotate_signal_name ();
7964 if (uiout->is_mi_like_p ())
7966 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7967 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7968 annotate_signal_name_end ();
7970 annotate_signal_string ();
7971 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7973 if (siggnal == GDB_SIGNAL_SEGV)
7974 handle_segmentation_fault (uiout);
7976 annotate_signal_string_end ();
7978 uiout->text (".\n");
7982 print_no_history_reason (struct ui_out *uiout)
7984 uiout->text ("\nNo more reverse-execution history.\n");
7987 /* Print current location without a level number, if we have changed
7988 functions or hit a breakpoint. Print source line if we have one.
7989 bpstat_print contains the logic deciding in detail what to print,
7990 based on the event(s) that just occurred. */
7993 print_stop_location (struct target_waitstatus *ws)
7996 enum print_what source_flag;
7997 int do_frame_printing = 1;
7998 struct thread_info *tp = inferior_thread ();
8000 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8004 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8005 should) carry around the function and does (or should) use
8006 that when doing a frame comparison. */
8007 if (tp->control.stop_step
8008 && frame_id_eq (tp->control.step_frame_id,
8009 get_frame_id (get_current_frame ()))
8010 && tp->control.step_start_function == find_pc_function (stop_pc))
8012 /* Finished step, just print source line. */
8013 source_flag = SRC_LINE;
8017 /* Print location and source line. */
8018 source_flag = SRC_AND_LOC;
8021 case PRINT_SRC_AND_LOC:
8022 /* Print location and source line. */
8023 source_flag = SRC_AND_LOC;
8025 case PRINT_SRC_ONLY:
8026 source_flag = SRC_LINE;
8029 /* Something bogus. */
8030 source_flag = SRC_LINE;
8031 do_frame_printing = 0;
8034 internal_error (__FILE__, __LINE__, _("Unknown value."));
8037 /* The behavior of this routine with respect to the source
8039 SRC_LINE: Print only source line
8040 LOCATION: Print only location
8041 SRC_AND_LOC: Print location and source line. */
8042 if (do_frame_printing)
8043 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8049 print_stop_event (struct ui_out *uiout)
8051 struct target_waitstatus last;
8053 struct thread_info *tp;
8055 get_last_target_status (&last_ptid, &last);
8058 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8060 print_stop_location (&last);
8062 /* Display the auto-display expressions. */
8066 tp = inferior_thread ();
8067 if (tp->thread_fsm != NULL
8068 && thread_fsm_finished_p (tp->thread_fsm))
8070 struct return_value_info *rv;
8072 rv = thread_fsm_return_value (tp->thread_fsm);
8074 print_return_value (uiout, rv);
8081 maybe_remove_breakpoints (void)
8083 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8085 if (remove_breakpoints ())
8087 target_terminal::ours_for_output ();
8088 printf_filtered (_("Cannot remove breakpoints because "
8089 "program is no longer writable.\nFurther "
8090 "execution is probably impossible.\n"));
8095 /* The execution context that just caused a normal stop. */
8102 /* The event PTID. */
8106 /* If stopp for a thread event, this is the thread that caused the
8108 struct thread_info *thread;
8110 /* The inferior that caused the stop. */
8114 /* Returns a new stop context. If stopped for a thread event, this
8115 takes a strong reference to the thread. */
8117 static struct stop_context *
8118 save_stop_context (void)
8120 struct stop_context *sc = XNEW (struct stop_context);
8122 sc->stop_id = get_stop_id ();
8123 sc->ptid = inferior_ptid;
8124 sc->inf_num = current_inferior ()->num;
8126 if (!ptid_equal (inferior_ptid, null_ptid))
8128 /* Take a strong reference so that the thread can't be deleted
8130 sc->thread = inferior_thread ();
8131 sc->thread->incref ();
8139 /* Release a stop context previously created with save_stop_context.
8140 Releases the strong reference to the thread as well. */
8143 release_stop_context_cleanup (void *arg)
8145 struct stop_context *sc = (struct stop_context *) arg;
8147 if (sc->thread != NULL)
8148 sc->thread->decref ();
8152 /* Return true if the current context no longer matches the saved stop
8156 stop_context_changed (struct stop_context *prev)
8158 if (!ptid_equal (prev->ptid, inferior_ptid))
8160 if (prev->inf_num != current_inferior ()->num)
8162 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8164 if (get_stop_id () != prev->stop_id)
8174 struct target_waitstatus last;
8176 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
8179 get_last_target_status (&last_ptid, &last);
8183 /* If an exception is thrown from this point on, make sure to
8184 propagate GDB's knowledge of the executing state to the
8185 frontend/user running state. A QUIT is an easy exception to see
8186 here, so do this before any filtered output. */
8188 make_cleanup (finish_thread_state_cleanup, &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 (!ptid_equal (inferior_ptid, null_ptid))
8199 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
8200 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8203 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8204 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8206 /* As we're presenting a stop, and potentially removing breakpoints,
8207 update the thread list so we can tell whether there are threads
8208 running on the target. With target remote, for example, we can
8209 only learn about new threads when we explicitly update the thread
8210 list. Do this before notifying the interpreters about signal
8211 stops, end of stepping ranges, etc., so that the "new thread"
8212 output is emitted before e.g., "Program received signal FOO",
8213 instead of after. */
8214 update_thread_list ();
8216 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8217 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8219 /* As with the notification of thread events, we want to delay
8220 notifying the user that we've switched thread context until
8221 the inferior actually stops.
8223 There's no point in saying anything if the inferior has exited.
8224 Note that SIGNALLED here means "exited with a signal", not
8225 "received a signal".
8227 Also skip saying anything in non-stop mode. In that mode, as we
8228 don't want GDB to switch threads behind the user's back, to avoid
8229 races where the user is typing a command to apply to thread x,
8230 but GDB switches to thread y before the user finishes entering
8231 the command, fetch_inferior_event installs a cleanup to restore
8232 the current thread back to the thread the user had selected right
8233 after this event is handled, so we're not really switching, only
8234 informing of a stop. */
8236 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8237 && target_has_execution
8238 && last.kind != TARGET_WAITKIND_SIGNALLED
8239 && last.kind != TARGET_WAITKIND_EXITED
8240 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8242 SWITCH_THRU_ALL_UIS ()
8244 target_terminal::ours_for_output ();
8245 printf_filtered (_("[Switching to %s]\n"),
8246 target_pid_to_str (inferior_ptid));
8247 annotate_thread_changed ();
8249 previous_inferior_ptid = inferior_ptid;
8252 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8254 SWITCH_THRU_ALL_UIS ()
8255 if (current_ui->prompt_state == PROMPT_BLOCKED)
8257 target_terminal::ours_for_output ();
8258 printf_filtered (_("No unwaited-for children left.\n"));
8262 /* Note: this depends on the update_thread_list call above. */
8263 maybe_remove_breakpoints ();
8265 /* If an auto-display called a function and that got a signal,
8266 delete that auto-display to avoid an infinite recursion. */
8268 if (stopped_by_random_signal)
8269 disable_current_display ();
8271 SWITCH_THRU_ALL_UIS ()
8273 async_enable_stdin ();
8276 /* Let the user/frontend see the threads as stopped. */
8277 do_cleanups (old_chain);
8279 /* Select innermost stack frame - i.e., current frame is frame 0,
8280 and current location is based on that. Handle the case where the
8281 dummy call is returning after being stopped. E.g. the dummy call
8282 previously hit a breakpoint. (If the dummy call returns
8283 normally, we won't reach here.) Do this before the stop hook is
8284 run, so that it doesn't get to see the temporary dummy frame,
8285 which is not where we'll present the stop. */
8286 if (has_stack_frames ())
8288 if (stop_stack_dummy == STOP_STACK_DUMMY)
8290 /* Pop the empty frame that contains the stack dummy. This
8291 also restores inferior state prior to the call (struct
8292 infcall_suspend_state). */
8293 struct frame_info *frame = get_current_frame ();
8295 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8297 /* frame_pop calls reinit_frame_cache as the last thing it
8298 does which means there's now no selected frame. */
8301 select_frame (get_current_frame ());
8303 /* Set the current source location. */
8304 set_current_sal_from_frame (get_current_frame ());
8307 /* Look up the hook_stop and run it (CLI internally handles problem
8308 of stop_command's pre-hook not existing). */
8309 if (stop_command != NULL)
8311 struct stop_context *saved_context = save_stop_context ();
8312 struct cleanup *old_chain
8313 = make_cleanup (release_stop_context_cleanup, saved_context);
8317 execute_cmd_pre_hook (stop_command);
8319 CATCH (ex, RETURN_MASK_ALL)
8321 exception_fprintf (gdb_stderr, ex,
8322 "Error while running hook_stop:\n");
8326 /* If the stop hook resumes the target, then there's no point in
8327 trying to notify about the previous stop; its context is
8328 gone. Likewise if the command switches thread or inferior --
8329 the observers would print a stop for the wrong
8331 if (stop_context_changed (saved_context))
8333 do_cleanups (old_chain);
8336 do_cleanups (old_chain);
8339 /* Notify observers about the stop. This is where the interpreters
8340 print the stop event. */
8341 if (!ptid_equal (inferior_ptid, null_ptid))
8342 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8345 observer_notify_normal_stop (NULL, stop_print_frame);
8347 annotate_stopped ();
8349 if (target_has_execution)
8351 if (last.kind != TARGET_WAITKIND_SIGNALLED
8352 && last.kind != TARGET_WAITKIND_EXITED)
8353 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8354 Delete any breakpoint that is to be deleted at the next stop. */
8355 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8358 /* Try to get rid of automatically added inferiors that are no
8359 longer needed. Keeping those around slows down things linearly.
8360 Note that this never removes the current inferior. */
8367 signal_stop_state (int signo)
8369 return signal_stop[signo];
8373 signal_print_state (int signo)
8375 return signal_print[signo];
8379 signal_pass_state (int signo)
8381 return signal_program[signo];
8385 signal_cache_update (int signo)
8389 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8390 signal_cache_update (signo);
8395 signal_pass[signo] = (signal_stop[signo] == 0
8396 && signal_print[signo] == 0
8397 && signal_program[signo] == 1
8398 && signal_catch[signo] == 0);
8402 signal_stop_update (int signo, int state)
8404 int ret = signal_stop[signo];
8406 signal_stop[signo] = state;
8407 signal_cache_update (signo);
8412 signal_print_update (int signo, int state)
8414 int ret = signal_print[signo];
8416 signal_print[signo] = state;
8417 signal_cache_update (signo);
8422 signal_pass_update (int signo, int state)
8424 int ret = signal_program[signo];
8426 signal_program[signo] = state;
8427 signal_cache_update (signo);
8431 /* Update the global 'signal_catch' from INFO and notify the
8435 signal_catch_update (const unsigned int *info)
8439 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8440 signal_catch[i] = info[i] > 0;
8441 signal_cache_update (-1);
8442 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8446 sig_print_header (void)
8448 printf_filtered (_("Signal Stop\tPrint\tPass "
8449 "to program\tDescription\n"));
8453 sig_print_info (enum gdb_signal oursig)
8455 const char *name = gdb_signal_to_name (oursig);
8456 int name_padding = 13 - strlen (name);
8458 if (name_padding <= 0)
8461 printf_filtered ("%s", name);
8462 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8463 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8464 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8465 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8466 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8469 /* Specify how various signals in the inferior should be handled. */
8472 handle_command (char *args, int from_tty)
8474 int digits, wordlen;
8475 int sigfirst, signum, siglast;
8476 enum gdb_signal oursig;
8479 unsigned char *sigs;
8483 error_no_arg (_("signal to handle"));
8486 /* Allocate and zero an array of flags for which signals to handle. */
8488 nsigs = (int) GDB_SIGNAL_LAST;
8489 sigs = (unsigned char *) alloca (nsigs);
8490 memset (sigs, 0, nsigs);
8492 /* Break the command line up into args. */
8494 gdb_argv built_argv (args);
8496 /* Walk through the args, looking for signal oursigs, signal names, and
8497 actions. Signal numbers and signal names may be interspersed with
8498 actions, with the actions being performed for all signals cumulatively
8499 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8501 for (char *arg : built_argv)
8503 wordlen = strlen (arg);
8504 for (digits = 0; isdigit (arg[digits]); digits++)
8508 sigfirst = siglast = -1;
8510 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8512 /* Apply action to all signals except those used by the
8513 debugger. Silently skip those. */
8516 siglast = nsigs - 1;
8518 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8520 SET_SIGS (nsigs, sigs, signal_stop);
8521 SET_SIGS (nsigs, sigs, signal_print);
8523 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8525 UNSET_SIGS (nsigs, sigs, signal_program);
8527 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8529 SET_SIGS (nsigs, sigs, signal_print);
8531 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8533 SET_SIGS (nsigs, sigs, signal_program);
8535 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8537 UNSET_SIGS (nsigs, sigs, signal_stop);
8539 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8541 SET_SIGS (nsigs, sigs, signal_program);
8543 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8545 UNSET_SIGS (nsigs, sigs, signal_print);
8546 UNSET_SIGS (nsigs, sigs, signal_stop);
8548 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8550 UNSET_SIGS (nsigs, sigs, signal_program);
8552 else if (digits > 0)
8554 /* It is numeric. The numeric signal refers to our own
8555 internal signal numbering from target.h, not to host/target
8556 signal number. This is a feature; users really should be
8557 using symbolic names anyway, and the common ones like
8558 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8560 sigfirst = siglast = (int)
8561 gdb_signal_from_command (atoi (arg));
8562 if (arg[digits] == '-')
8565 gdb_signal_from_command (atoi (arg + digits + 1));
8567 if (sigfirst > siglast)
8569 /* Bet he didn't figure we'd think of this case... */
8577 oursig = gdb_signal_from_name (arg);
8578 if (oursig != GDB_SIGNAL_UNKNOWN)
8580 sigfirst = siglast = (int) oursig;
8584 /* Not a number and not a recognized flag word => complain. */
8585 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8589 /* If any signal numbers or symbol names were found, set flags for
8590 which signals to apply actions to. */
8592 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8594 switch ((enum gdb_signal) signum)
8596 case GDB_SIGNAL_TRAP:
8597 case GDB_SIGNAL_INT:
8598 if (!allsigs && !sigs[signum])
8600 if (query (_("%s is used by the debugger.\n\
8601 Are you sure you want to change it? "),
8602 gdb_signal_to_name ((enum gdb_signal) signum)))
8608 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8609 gdb_flush (gdb_stdout);
8614 case GDB_SIGNAL_DEFAULT:
8615 case GDB_SIGNAL_UNKNOWN:
8616 /* Make sure that "all" doesn't print these. */
8625 for (signum = 0; signum < nsigs; signum++)
8628 signal_cache_update (-1);
8629 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8630 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8634 /* Show the results. */
8635 sig_print_header ();
8636 for (; signum < nsigs; signum++)
8638 sig_print_info ((enum gdb_signal) signum);
8645 /* Complete the "handle" command. */
8648 handle_completer (struct cmd_list_element *ignore,
8649 completion_tracker &tracker,
8650 const char *text, const char *word)
8652 static const char * const keywords[] =
8666 signal_completer (ignore, tracker, text, word);
8667 complete_on_enum (tracker, keywords, word, word);
8671 gdb_signal_from_command (int num)
8673 if (num >= 1 && num <= 15)
8674 return (enum gdb_signal) num;
8675 error (_("Only signals 1-15 are valid as numeric signals.\n\
8676 Use \"info signals\" for a list of symbolic signals."));
8679 /* Print current contents of the tables set by the handle command.
8680 It is possible we should just be printing signals actually used
8681 by the current target (but for things to work right when switching
8682 targets, all signals should be in the signal tables). */
8685 info_signals_command (char *signum_exp, int from_tty)
8687 enum gdb_signal oursig;
8689 sig_print_header ();
8693 /* First see if this is a symbol name. */
8694 oursig = gdb_signal_from_name (signum_exp);
8695 if (oursig == GDB_SIGNAL_UNKNOWN)
8697 /* No, try numeric. */
8699 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8701 sig_print_info (oursig);
8705 printf_filtered ("\n");
8706 /* These ugly casts brought to you by the native VAX compiler. */
8707 for (oursig = GDB_SIGNAL_FIRST;
8708 (int) oursig < (int) GDB_SIGNAL_LAST;
8709 oursig = (enum gdb_signal) ((int) oursig + 1))
8713 if (oursig != GDB_SIGNAL_UNKNOWN
8714 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8715 sig_print_info (oursig);
8718 printf_filtered (_("\nUse the \"handle\" command "
8719 "to change these tables.\n"));
8722 /* The $_siginfo convenience variable is a bit special. We don't know
8723 for sure the type of the value until we actually have a chance to
8724 fetch the data. The type can change depending on gdbarch, so it is
8725 also dependent on which thread you have selected.
8727 1. making $_siginfo be an internalvar that creates a new value on
8730 2. making the value of $_siginfo be an lval_computed value. */
8732 /* This function implements the lval_computed support for reading a
8736 siginfo_value_read (struct value *v)
8738 LONGEST transferred;
8740 /* If we can access registers, so can we access $_siginfo. Likewise
8742 validate_registers_access ();
8745 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8747 value_contents_all_raw (v),
8749 TYPE_LENGTH (value_type (v)));
8751 if (transferred != TYPE_LENGTH (value_type (v)))
8752 error (_("Unable to read siginfo"));
8755 /* This function implements the lval_computed support for writing a
8759 siginfo_value_write (struct value *v, struct value *fromval)
8761 LONGEST transferred;
8763 /* If we can access registers, so can we access $_siginfo. Likewise
8765 validate_registers_access ();
8767 transferred = target_write (¤t_target,
8768 TARGET_OBJECT_SIGNAL_INFO,
8770 value_contents_all_raw (fromval),
8772 TYPE_LENGTH (value_type (fromval)));
8774 if (transferred != TYPE_LENGTH (value_type (fromval)))
8775 error (_("Unable to write siginfo"));
8778 static const struct lval_funcs siginfo_value_funcs =
8784 /* Return a new value with the correct type for the siginfo object of
8785 the current thread using architecture GDBARCH. Return a void value
8786 if there's no object available. */
8788 static struct value *
8789 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8792 if (target_has_stack
8793 && !ptid_equal (inferior_ptid, null_ptid)
8794 && gdbarch_get_siginfo_type_p (gdbarch))
8796 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8798 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8801 return allocate_value (builtin_type (gdbarch)->builtin_void);
8805 /* infcall_suspend_state contains state about the program itself like its
8806 registers and any signal it received when it last stopped.
8807 This state must be restored regardless of how the inferior function call
8808 ends (either successfully, or after it hits a breakpoint or signal)
8809 if the program is to properly continue where it left off. */
8811 struct infcall_suspend_state
8813 struct thread_suspend_state thread_suspend;
8817 struct regcache *registers;
8819 /* Format of SIGINFO_DATA or NULL if it is not present. */
8820 struct gdbarch *siginfo_gdbarch;
8822 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8823 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8824 content would be invalid. */
8825 gdb_byte *siginfo_data;
8828 struct infcall_suspend_state *
8829 save_infcall_suspend_state (void)
8831 struct infcall_suspend_state *inf_state;
8832 struct thread_info *tp = inferior_thread ();
8833 struct regcache *regcache = get_current_regcache ();
8834 struct gdbarch *gdbarch = regcache->arch ();
8835 gdb_byte *siginfo_data = NULL;
8837 if (gdbarch_get_siginfo_type_p (gdbarch))
8839 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8840 size_t len = TYPE_LENGTH (type);
8841 struct cleanup *back_to;
8843 siginfo_data = (gdb_byte *) xmalloc (len);
8844 back_to = make_cleanup (xfree, siginfo_data);
8846 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8847 siginfo_data, 0, len) == len)
8848 discard_cleanups (back_to);
8851 /* Errors ignored. */
8852 do_cleanups (back_to);
8853 siginfo_data = NULL;
8857 inf_state = XCNEW (struct infcall_suspend_state);
8861 inf_state->siginfo_gdbarch = gdbarch;
8862 inf_state->siginfo_data = siginfo_data;
8865 inf_state->thread_suspend = tp->suspend;
8867 /* run_inferior_call will not use the signal due to its `proceed' call with
8868 GDB_SIGNAL_0 anyway. */
8869 tp->suspend.stop_signal = GDB_SIGNAL_0;
8871 inf_state->stop_pc = stop_pc;
8873 inf_state->registers = regcache_dup (regcache);
8878 /* Restore inferior session state to INF_STATE. */
8881 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8883 struct thread_info *tp = inferior_thread ();
8884 struct regcache *regcache = get_current_regcache ();
8885 struct gdbarch *gdbarch = regcache->arch ();
8887 tp->suspend = inf_state->thread_suspend;
8889 stop_pc = inf_state->stop_pc;
8891 if (inf_state->siginfo_gdbarch == gdbarch)
8893 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8895 /* Errors ignored. */
8896 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8897 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8900 /* The inferior can be gone if the user types "print exit(0)"
8901 (and perhaps other times). */
8902 if (target_has_execution)
8903 /* NB: The register write goes through to the target. */
8904 regcache_cpy (regcache, inf_state->registers);
8906 discard_infcall_suspend_state (inf_state);
8910 do_restore_infcall_suspend_state_cleanup (void *state)
8912 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8916 make_cleanup_restore_infcall_suspend_state
8917 (struct infcall_suspend_state *inf_state)
8919 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8923 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8925 delete inf_state->registers;
8926 xfree (inf_state->siginfo_data);
8931 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8933 return inf_state->registers;
8936 /* infcall_control_state contains state regarding gdb's control of the
8937 inferior itself like stepping control. It also contains session state like
8938 the user's currently selected frame. */
8940 struct infcall_control_state
8942 struct thread_control_state thread_control;
8943 struct inferior_control_state inferior_control;
8946 enum stop_stack_kind stop_stack_dummy;
8947 int stopped_by_random_signal;
8949 /* ID if the selected frame when the inferior function call was made. */
8950 struct frame_id selected_frame_id;
8953 /* Save all of the information associated with the inferior<==>gdb
8956 struct infcall_control_state *
8957 save_infcall_control_state (void)
8959 struct infcall_control_state *inf_status =
8960 XNEW (struct infcall_control_state);
8961 struct thread_info *tp = inferior_thread ();
8962 struct inferior *inf = current_inferior ();
8964 inf_status->thread_control = tp->control;
8965 inf_status->inferior_control = inf->control;
8967 tp->control.step_resume_breakpoint = NULL;
8968 tp->control.exception_resume_breakpoint = NULL;
8970 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8971 chain. If caller's caller is walking the chain, they'll be happier if we
8972 hand them back the original chain when restore_infcall_control_state is
8974 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8977 inf_status->stop_stack_dummy = stop_stack_dummy;
8978 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8980 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8986 restore_selected_frame (const frame_id &fid)
8988 frame_info *frame = frame_find_by_id (fid);
8990 /* If inf_status->selected_frame_id is NULL, there was no previously
8994 warning (_("Unable to restore previously selected frame."));
8998 select_frame (frame);
9001 /* Restore inferior session state to INF_STATUS. */
9004 restore_infcall_control_state (struct infcall_control_state *inf_status)
9006 struct thread_info *tp = inferior_thread ();
9007 struct inferior *inf = current_inferior ();
9009 if (tp->control.step_resume_breakpoint)
9010 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
9012 if (tp->control.exception_resume_breakpoint)
9013 tp->control.exception_resume_breakpoint->disposition
9014 = disp_del_at_next_stop;
9016 /* Handle the bpstat_copy of the chain. */
9017 bpstat_clear (&tp->control.stop_bpstat);
9019 tp->control = inf_status->thread_control;
9020 inf->control = inf_status->inferior_control;
9023 stop_stack_dummy = inf_status->stop_stack_dummy;
9024 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9026 if (target_has_stack)
9028 /* The point of the try/catch is that if the stack is clobbered,
9029 walking the stack might encounter a garbage pointer and
9030 error() trying to dereference it. */
9033 restore_selected_frame (inf_status->selected_frame_id);
9035 CATCH (ex, RETURN_MASK_ERROR)
9037 exception_fprintf (gdb_stderr, ex,
9038 "Unable to restore previously selected frame:\n");
9039 /* Error in restoring the selected frame. Select the
9041 select_frame (get_current_frame ());
9050 do_restore_infcall_control_state_cleanup (void *sts)
9052 restore_infcall_control_state ((struct infcall_control_state *) sts);
9056 make_cleanup_restore_infcall_control_state
9057 (struct infcall_control_state *inf_status)
9059 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9063 discard_infcall_control_state (struct infcall_control_state *inf_status)
9065 if (inf_status->thread_control.step_resume_breakpoint)
9066 inf_status->thread_control.step_resume_breakpoint->disposition
9067 = disp_del_at_next_stop;
9069 if (inf_status->thread_control.exception_resume_breakpoint)
9070 inf_status->thread_control.exception_resume_breakpoint->disposition
9071 = disp_del_at_next_stop;
9073 /* See save_infcall_control_state for info on stop_bpstat. */
9074 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9082 clear_exit_convenience_vars (void)
9084 clear_internalvar (lookup_internalvar ("_exitsignal"));
9085 clear_internalvar (lookup_internalvar ("_exitcode"));
9089 /* User interface for reverse debugging:
9090 Set exec-direction / show exec-direction commands
9091 (returns error unless target implements to_set_exec_direction method). */
9093 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9094 static const char exec_forward[] = "forward";
9095 static const char exec_reverse[] = "reverse";
9096 static const char *exec_direction = exec_forward;
9097 static const char *const exec_direction_names[] = {
9104 set_exec_direction_func (char *args, int from_tty,
9105 struct cmd_list_element *cmd)
9107 if (target_can_execute_reverse)
9109 if (!strcmp (exec_direction, exec_forward))
9110 execution_direction = EXEC_FORWARD;
9111 else if (!strcmp (exec_direction, exec_reverse))
9112 execution_direction = EXEC_REVERSE;
9116 exec_direction = exec_forward;
9117 error (_("Target does not support this operation."));
9122 show_exec_direction_func (struct ui_file *out, int from_tty,
9123 struct cmd_list_element *cmd, const char *value)
9125 switch (execution_direction) {
9127 fprintf_filtered (out, _("Forward.\n"));
9130 fprintf_filtered (out, _("Reverse.\n"));
9133 internal_error (__FILE__, __LINE__,
9134 _("bogus execution_direction value: %d"),
9135 (int) execution_direction);
9140 show_schedule_multiple (struct ui_file *file, int from_tty,
9141 struct cmd_list_element *c, const char *value)
9143 fprintf_filtered (file, _("Resuming the execution of threads "
9144 "of all processes is %s.\n"), value);
9147 /* Implementation of `siginfo' variable. */
9149 static const struct internalvar_funcs siginfo_funcs =
9156 /* Callback for infrun's target events source. This is marked when a
9157 thread has a pending status to process. */
9160 infrun_async_inferior_event_handler (gdb_client_data data)
9162 inferior_event_handler (INF_REG_EVENT, NULL);
9166 _initialize_infrun (void)
9170 struct cmd_list_element *c;
9172 /* Register extra event sources in the event loop. */
9173 infrun_async_inferior_event_token
9174 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9176 add_info ("signals", info_signals_command, _("\
9177 What debugger does when program gets various signals.\n\
9178 Specify a signal as argument to print info on that signal only."));
9179 add_info_alias ("handle", "signals", 0);
9181 c = add_com ("handle", class_run, handle_command, _("\
9182 Specify how to handle signals.\n\
9183 Usage: handle SIGNAL [ACTIONS]\n\
9184 Args are signals and actions to apply to those signals.\n\
9185 If no actions are specified, the current settings for the specified signals\n\
9186 will be displayed instead.\n\
9188 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9189 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9190 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9191 The special arg \"all\" is recognized to mean all signals except those\n\
9192 used by the debugger, typically SIGTRAP and SIGINT.\n\
9194 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9195 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9196 Stop means reenter debugger if this signal happens (implies print).\n\
9197 Print means print a message if this signal happens.\n\
9198 Pass means let program see this signal; otherwise program doesn't know.\n\
9199 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9200 Pass and Stop may be combined.\n\
9202 Multiple signals may be specified. Signal numbers and signal names\n\
9203 may be interspersed with actions, with the actions being performed for\n\
9204 all signals cumulatively specified."));
9205 set_cmd_completer (c, handle_completer);
9208 stop_command = add_cmd ("stop", class_obscure,
9209 not_just_help_class_command, _("\
9210 There is no `stop' command, but you can set a hook on `stop'.\n\
9211 This allows you to set a list of commands to be run each time execution\n\
9212 of the program stops."), &cmdlist);
9214 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9215 Set inferior debugging."), _("\
9216 Show inferior debugging."), _("\
9217 When non-zero, inferior specific debugging is enabled."),
9220 &setdebuglist, &showdebuglist);
9222 add_setshow_boolean_cmd ("displaced", class_maintenance,
9223 &debug_displaced, _("\
9224 Set displaced stepping debugging."), _("\
9225 Show displaced stepping debugging."), _("\
9226 When non-zero, displaced stepping specific debugging is enabled."),
9228 show_debug_displaced,
9229 &setdebuglist, &showdebuglist);
9231 add_setshow_boolean_cmd ("non-stop", no_class,
9233 Set whether gdb controls the inferior in non-stop mode."), _("\
9234 Show whether gdb controls the inferior in non-stop mode."), _("\
9235 When debugging a multi-threaded program and this setting is\n\
9236 off (the default, also called all-stop mode), when one thread stops\n\
9237 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9238 all other threads in the program while you interact with the thread of\n\
9239 interest. When you continue or step a thread, you can allow the other\n\
9240 threads to run, or have them remain stopped, but while you inspect any\n\
9241 thread's state, all threads stop.\n\
9243 In non-stop mode, when one thread stops, other threads can continue\n\
9244 to run freely. You'll be able to step each thread independently,\n\
9245 leave it stopped or free to run as needed."),
9251 numsigs = (int) GDB_SIGNAL_LAST;
9252 signal_stop = XNEWVEC (unsigned char, numsigs);
9253 signal_print = XNEWVEC (unsigned char, numsigs);
9254 signal_program = XNEWVEC (unsigned char, numsigs);
9255 signal_catch = XNEWVEC (unsigned char, numsigs);
9256 signal_pass = XNEWVEC (unsigned char, numsigs);
9257 for (i = 0; i < numsigs; i++)
9260 signal_print[i] = 1;
9261 signal_program[i] = 1;
9262 signal_catch[i] = 0;
9265 /* Signals caused by debugger's own actions should not be given to
9266 the program afterwards.
9268 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9269 explicitly specifies that it should be delivered to the target
9270 program. Typically, that would occur when a user is debugging a
9271 target monitor on a simulator: the target monitor sets a
9272 breakpoint; the simulator encounters this breakpoint and halts
9273 the simulation handing control to GDB; GDB, noting that the stop
9274 address doesn't map to any known breakpoint, returns control back
9275 to the simulator; the simulator then delivers the hardware
9276 equivalent of a GDB_SIGNAL_TRAP to the program being
9278 signal_program[GDB_SIGNAL_TRAP] = 0;
9279 signal_program[GDB_SIGNAL_INT] = 0;
9281 /* Signals that are not errors should not normally enter the debugger. */
9282 signal_stop[GDB_SIGNAL_ALRM] = 0;
9283 signal_print[GDB_SIGNAL_ALRM] = 0;
9284 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9285 signal_print[GDB_SIGNAL_VTALRM] = 0;
9286 signal_stop[GDB_SIGNAL_PROF] = 0;
9287 signal_print[GDB_SIGNAL_PROF] = 0;
9288 signal_stop[GDB_SIGNAL_CHLD] = 0;
9289 signal_print[GDB_SIGNAL_CHLD] = 0;
9290 signal_stop[GDB_SIGNAL_IO] = 0;
9291 signal_print[GDB_SIGNAL_IO] = 0;
9292 signal_stop[GDB_SIGNAL_POLL] = 0;
9293 signal_print[GDB_SIGNAL_POLL] = 0;
9294 signal_stop[GDB_SIGNAL_URG] = 0;
9295 signal_print[GDB_SIGNAL_URG] = 0;
9296 signal_stop[GDB_SIGNAL_WINCH] = 0;
9297 signal_print[GDB_SIGNAL_WINCH] = 0;
9298 signal_stop[GDB_SIGNAL_PRIO] = 0;
9299 signal_print[GDB_SIGNAL_PRIO] = 0;
9301 /* These signals are used internally by user-level thread
9302 implementations. (See signal(5) on Solaris.) Like the above
9303 signals, a healthy program receives and handles them as part of
9304 its normal operation. */
9305 signal_stop[GDB_SIGNAL_LWP] = 0;
9306 signal_print[GDB_SIGNAL_LWP] = 0;
9307 signal_stop[GDB_SIGNAL_WAITING] = 0;
9308 signal_print[GDB_SIGNAL_WAITING] = 0;
9309 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9310 signal_print[GDB_SIGNAL_CANCEL] = 0;
9311 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9312 signal_print[GDB_SIGNAL_LIBRT] = 0;
9314 /* Update cached state. */
9315 signal_cache_update (-1);
9317 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9318 &stop_on_solib_events, _("\
9319 Set stopping for shared library events."), _("\
9320 Show stopping for shared library events."), _("\
9321 If nonzero, gdb will give control to the user when the dynamic linker\n\
9322 notifies gdb of shared library events. The most common event of interest\n\
9323 to the user would be loading/unloading of a new library."),
9324 set_stop_on_solib_events,
9325 show_stop_on_solib_events,
9326 &setlist, &showlist);
9328 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9329 follow_fork_mode_kind_names,
9330 &follow_fork_mode_string, _("\
9331 Set debugger response to a program call of fork or vfork."), _("\
9332 Show debugger response to a program call of fork or vfork."), _("\
9333 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9334 parent - the original process is debugged after a fork\n\
9335 child - the new process is debugged after a fork\n\
9336 The unfollowed process will continue to run.\n\
9337 By default, the debugger will follow the parent process."),
9339 show_follow_fork_mode_string,
9340 &setlist, &showlist);
9342 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9343 follow_exec_mode_names,
9344 &follow_exec_mode_string, _("\
9345 Set debugger response to a program call of exec."), _("\
9346 Show debugger response to a program call of exec."), _("\
9347 An exec call replaces the program image of a process.\n\
9349 follow-exec-mode can be:\n\
9351 new - the debugger creates a new inferior and rebinds the process\n\
9352 to this new inferior. The program the process was running before\n\
9353 the exec call can be restarted afterwards by restarting the original\n\
9356 same - the debugger keeps the process bound to the same inferior.\n\
9357 The new executable image replaces the previous executable loaded in\n\
9358 the inferior. Restarting the inferior after the exec call restarts\n\
9359 the executable the process was running after the exec call.\n\
9361 By default, the debugger will use the same inferior."),
9363 show_follow_exec_mode_string,
9364 &setlist, &showlist);
9366 add_setshow_enum_cmd ("scheduler-locking", class_run,
9367 scheduler_enums, &scheduler_mode, _("\
9368 Set mode for locking scheduler during execution."), _("\
9369 Show mode for locking scheduler during execution."), _("\
9370 off == no locking (threads may preempt at any time)\n\
9371 on == full locking (no thread except the current thread may run)\n\
9372 This applies to both normal execution and replay mode.\n\
9373 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9374 In this mode, other threads may run during other commands.\n\
9375 This applies to both normal execution and replay mode.\n\
9376 replay == scheduler locked in replay mode and unlocked during normal execution."),
9377 set_schedlock_func, /* traps on target vector */
9378 show_scheduler_mode,
9379 &setlist, &showlist);
9381 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9382 Set mode for resuming threads of all processes."), _("\
9383 Show mode for resuming threads of all processes."), _("\
9384 When on, execution commands (such as 'continue' or 'next') resume all\n\
9385 threads of all processes. When off (which is the default), execution\n\
9386 commands only resume the threads of the current process. The set of\n\
9387 threads that are resumed is further refined by the scheduler-locking\n\
9388 mode (see help set scheduler-locking)."),
9390 show_schedule_multiple,
9391 &setlist, &showlist);
9393 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9394 Set mode of the step operation."), _("\
9395 Show mode of the step operation."), _("\
9396 When set, doing a step over a function without debug line information\n\
9397 will stop at the first instruction of that function. Otherwise, the\n\
9398 function is skipped and the step command stops at a different source line."),
9400 show_step_stop_if_no_debug,
9401 &setlist, &showlist);
9403 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9404 &can_use_displaced_stepping, _("\
9405 Set debugger's willingness to use displaced stepping."), _("\
9406 Show debugger's willingness to use displaced stepping."), _("\
9407 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9408 supported by the target architecture. If off, gdb will not use displaced\n\
9409 stepping to step over breakpoints, even if such is supported by the target\n\
9410 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9411 if the target architecture supports it and non-stop mode is active, but will not\n\
9412 use it in all-stop mode (see help set non-stop)."),
9414 show_can_use_displaced_stepping,
9415 &setlist, &showlist);
9417 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9418 &exec_direction, _("Set direction of execution.\n\
9419 Options are 'forward' or 'reverse'."),
9420 _("Show direction of execution (forward/reverse)."),
9421 _("Tells gdb whether to execute forward or backward."),
9422 set_exec_direction_func, show_exec_direction_func,
9423 &setlist, &showlist);
9425 /* Set/show detach-on-fork: user-settable mode. */
9427 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9428 Set whether gdb will detach the child of a fork."), _("\
9429 Show whether gdb will detach the child of a fork."), _("\
9430 Tells gdb whether to detach the child of a fork."),
9431 NULL, NULL, &setlist, &showlist);
9433 /* Set/show disable address space randomization mode. */
9435 add_setshow_boolean_cmd ("disable-randomization", class_support,
9436 &disable_randomization, _("\
9437 Set disabling of debuggee's virtual address space randomization."), _("\
9438 Show disabling of debuggee's virtual address space randomization."), _("\
9439 When this mode is on (which is the default), randomization of the virtual\n\
9440 address space is disabled. Standalone programs run with the randomization\n\
9441 enabled by default on some platforms."),
9442 &set_disable_randomization,
9443 &show_disable_randomization,
9444 &setlist, &showlist);
9446 /* ptid initializations */
9447 inferior_ptid = null_ptid;
9448 target_last_wait_ptid = minus_one_ptid;
9450 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9451 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9452 observer_attach_thread_exit (infrun_thread_thread_exit);
9453 observer_attach_inferior_exit (infrun_inferior_exit);
9455 /* Explicitly create without lookup, since that tries to create a
9456 value with a void typed value, and when we get here, gdbarch
9457 isn't initialized yet. At this point, we're quite sure there
9458 isn't another convenience variable of the same name. */
9459 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9461 add_setshow_boolean_cmd ("observer", no_class,
9462 &observer_mode_1, _("\
9463 Set whether gdb controls the inferior in observer mode."), _("\
9464 Show whether gdb controls the inferior in observer mode."), _("\
9465 In observer mode, GDB can get data from the inferior, but not\n\
9466 affect its execution. Registers and memory may not be changed,\n\
9467 breakpoints may not be set, and the program cannot be interrupted\n\