1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2018 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
41 #include "observable.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
67 #include "progspace-and-thread.h"
68 #include "common/gdb_optional.h"
69 #include "arch-utils.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal);
75 static void sig_print_header (void);
77 static int follow_fork (void);
79 static int follow_fork_inferior (int follow_child, int detach_fork);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info *tp);
85 void nullify_last_target_wait_ptid (void);
87 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
89 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
91 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
93 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
95 /* Asynchronous signal handler registered as event loop source for
96 when we have pending events ready to be passed to the core. */
97 static struct async_event_handler *infrun_async_inferior_event_token;
99 /* Stores whether infrun_async was previously enabled or disabled.
100 Starts off as -1, indicating "never enabled/disabled". */
101 static int infrun_is_async = -1;
106 infrun_async (int enable)
108 if (infrun_is_async != enable)
110 infrun_is_async = enable;
113 fprintf_unfiltered (gdb_stdlog,
114 "infrun: infrun_async(%d)\n",
118 mark_async_event_handler (infrun_async_inferior_event_token);
120 clear_async_event_handler (infrun_async_inferior_event_token);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 int step_stop_if_no_debug = 0;
137 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
138 struct cmd_list_element *c, const char *value)
140 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static int detach_fork = 1;
156 int debug_displaced = 0;
158 show_debug_displaced (struct ui_file *file, int from_tty,
159 struct cmd_list_element *c, const char *value)
161 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
164 unsigned int debug_infrun = 0;
166 show_debug_infrun (struct ui_file *file, int from_tty,
167 struct cmd_list_element *c, const char *value)
169 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
173 /* Support for disabling address space randomization. */
175 int disable_randomization = 1;
178 show_disable_randomization (struct ui_file *file, int from_tty,
179 struct cmd_list_element *c, const char *value)
181 if (target_supports_disable_randomization ())
182 fprintf_filtered (file,
183 _("Disabling randomization of debuggee's "
184 "virtual address space is %s.\n"),
187 fputs_filtered (_("Disabling randomization of debuggee's "
188 "virtual address space is unsupported on\n"
189 "this platform.\n"), file);
193 set_disable_randomization (const char *args, int from_tty,
194 struct cmd_list_element *c)
196 if (!target_supports_disable_randomization ())
197 error (_("Disabling randomization of debuggee's "
198 "virtual address space is unsupported on\n"
202 /* User interface for non-stop mode. */
205 static int non_stop_1 = 0;
208 set_non_stop (const char *args, int from_tty,
209 struct cmd_list_element *c)
211 if (target_has_execution)
213 non_stop_1 = non_stop;
214 error (_("Cannot change this setting while the inferior is running."));
217 non_stop = non_stop_1;
221 show_non_stop (struct ui_file *file, int from_tty,
222 struct cmd_list_element *c, const char *value)
224 fprintf_filtered (file,
225 _("Controlling the inferior in non-stop mode is %s.\n"),
229 /* "Observer mode" is somewhat like a more extreme version of
230 non-stop, in which all GDB operations that might affect the
231 target's execution have been disabled. */
233 int observer_mode = 0;
234 static int observer_mode_1 = 0;
237 set_observer_mode (const char *args, int from_tty,
238 struct cmd_list_element *c)
240 if (target_has_execution)
242 observer_mode_1 = observer_mode;
243 error (_("Cannot change this setting while the inferior is running."));
246 observer_mode = observer_mode_1;
248 may_write_registers = !observer_mode;
249 may_write_memory = !observer_mode;
250 may_insert_breakpoints = !observer_mode;
251 may_insert_tracepoints = !observer_mode;
252 /* We can insert fast tracepoints in or out of observer mode,
253 but enable them if we're going into this mode. */
255 may_insert_fast_tracepoints = 1;
256 may_stop = !observer_mode;
257 update_target_permissions ();
259 /* Going *into* observer mode we must force non-stop, then
260 going out we leave it that way. */
263 pagination_enabled = 0;
264 non_stop = non_stop_1 = 1;
268 printf_filtered (_("Observer mode is now %s.\n"),
269 (observer_mode ? "on" : "off"));
273 show_observer_mode (struct ui_file *file, int from_tty,
274 struct cmd_list_element *c, const char *value)
276 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
279 /* This updates the value of observer mode based on changes in
280 permissions. Note that we are deliberately ignoring the values of
281 may-write-registers and may-write-memory, since the user may have
282 reason to enable these during a session, for instance to turn on a
283 debugging-related global. */
286 update_observer_mode (void)
290 newval = (!may_insert_breakpoints
291 && !may_insert_tracepoints
292 && may_insert_fast_tracepoints
296 /* Let the user know if things change. */
297 if (newval != observer_mode)
298 printf_filtered (_("Observer mode is now %s.\n"),
299 (newval ? "on" : "off"));
301 observer_mode = observer_mode_1 = newval;
304 /* Tables of how to react to signals; the user sets them. */
306 static unsigned char *signal_stop;
307 static unsigned char *signal_print;
308 static unsigned char *signal_program;
310 /* Table of signals that are registered with "catch signal". A
311 non-zero entry indicates that the signal is caught by some "catch
312 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
314 static unsigned char *signal_catch;
316 /* Table of signals that the target may silently handle.
317 This is automatically determined from the flags above,
318 and simply cached here. */
319 static unsigned char *signal_pass;
321 #define SET_SIGS(nsigs,sigs,flags) \
323 int signum = (nsigs); \
324 while (signum-- > 0) \
325 if ((sigs)[signum]) \
326 (flags)[signum] = 1; \
329 #define UNSET_SIGS(nsigs,sigs,flags) \
331 int signum = (nsigs); \
332 while (signum-- > 0) \
333 if ((sigs)[signum]) \
334 (flags)[signum] = 0; \
337 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
338 this function is to avoid exporting `signal_program'. */
341 update_signals_program_target (void)
343 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
346 /* Value to pass to target_resume() to cause all threads to resume. */
348 #define RESUME_ALL minus_one_ptid
350 /* Command list pointer for the "stop" placeholder. */
352 static struct cmd_list_element *stop_command;
354 /* Nonzero if we want to give control to the user when we're notified
355 of shared library events by the dynamic linker. */
356 int stop_on_solib_events;
358 /* Enable or disable optional shared library event breakpoints
359 as appropriate when the above flag is changed. */
362 set_stop_on_solib_events (const char *args,
363 int from_tty, struct cmd_list_element *c)
365 update_solib_breakpoints ();
369 show_stop_on_solib_events (struct ui_file *file, int from_tty,
370 struct cmd_list_element *c, const char *value)
372 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
376 /* Nonzero after stop if current stack frame should be printed. */
378 static int stop_print_frame;
380 /* This is a cached copy of the pid/waitstatus of the last event
381 returned by target_wait()/deprecated_target_wait_hook(). This
382 information is returned by get_last_target_status(). */
383 static ptid_t target_last_wait_ptid;
384 static struct target_waitstatus target_last_waitstatus;
386 void init_thread_stepping_state (struct thread_info *tss);
388 static const char follow_fork_mode_child[] = "child";
389 static const char follow_fork_mode_parent[] = "parent";
391 static const char *const follow_fork_mode_kind_names[] = {
392 follow_fork_mode_child,
393 follow_fork_mode_parent,
397 static const char *follow_fork_mode_string = follow_fork_mode_parent;
399 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
400 struct cmd_list_element *c, const char *value)
402 fprintf_filtered (file,
403 _("Debugger response to a program "
404 "call of fork or vfork is \"%s\".\n"),
409 /* Handle changes to the inferior list based on the type of fork,
410 which process is being followed, and whether the other process
411 should be detached. On entry inferior_ptid must be the ptid of
412 the fork parent. At return inferior_ptid is the ptid of the
413 followed inferior. */
416 follow_fork_inferior (int follow_child, int detach_fork)
419 ptid_t parent_ptid, child_ptid;
421 has_vforked = (inferior_thread ()->pending_follow.kind
422 == TARGET_WAITKIND_VFORKED);
423 parent_ptid = inferior_ptid;
424 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
427 && !non_stop /* Non-stop always resumes both branches. */
428 && current_ui->prompt_state == PROMPT_BLOCKED
429 && !(follow_child || detach_fork || sched_multi))
431 /* The parent stays blocked inside the vfork syscall until the
432 child execs or exits. If we don't let the child run, then
433 the parent stays blocked. If we're telling the parent to run
434 in the foreground, the user will not be able to ctrl-c to get
435 back the terminal, effectively hanging the debug session. */
436 fprintf_filtered (gdb_stderr, _("\
437 Can not resume the parent process over vfork in the foreground while\n\
438 holding the child stopped. Try \"set detach-on-fork\" or \
439 \"set schedule-multiple\".\n"));
440 /* FIXME output string > 80 columns. */
446 /* Detach new forked process? */
449 /* Before detaching from the child, remove all breakpoints
450 from it. If we forked, then this has already been taken
451 care of by infrun.c. If we vforked however, any
452 breakpoint inserted in the parent is visible in the
453 child, even those added while stopped in a vfork
454 catchpoint. This will remove the breakpoints from the
455 parent also, but they'll be reinserted below. */
458 /* Keep breakpoints list in sync. */
459 remove_breakpoints_inf (current_inferior ());
462 if (print_inferior_events)
464 /* Ensure that we have a process ptid. */
465 ptid_t process_ptid = ptid_t (ptid_get_pid (child_ptid));
467 target_terminal::ours_for_output ();
468 fprintf_filtered (gdb_stdlog,
469 _("[Detaching after %s from child %s]\n"),
470 has_vforked ? "vfork" : "fork",
471 target_pid_to_str (process_ptid));
476 struct inferior *parent_inf, *child_inf;
478 /* Add process to GDB's tables. */
479 child_inf = add_inferior (ptid_get_pid (child_ptid));
481 parent_inf = current_inferior ();
482 child_inf->attach_flag = parent_inf->attach_flag;
483 copy_terminal_info (child_inf, parent_inf);
484 child_inf->gdbarch = parent_inf->gdbarch;
485 copy_inferior_target_desc_info (child_inf, parent_inf);
487 scoped_restore_current_pspace_and_thread restore_pspace_thread;
489 inferior_ptid = child_ptid;
490 add_thread_silent (inferior_ptid);
491 set_current_inferior (child_inf);
492 child_inf->symfile_flags = SYMFILE_NO_READ;
494 /* If this is a vfork child, then the address-space is
495 shared with the parent. */
498 child_inf->pspace = parent_inf->pspace;
499 child_inf->aspace = parent_inf->aspace;
501 /* The parent will be frozen until the child is done
502 with the shared region. Keep track of the
504 child_inf->vfork_parent = parent_inf;
505 child_inf->pending_detach = 0;
506 parent_inf->vfork_child = child_inf;
507 parent_inf->pending_detach = 0;
511 child_inf->aspace = new_address_space ();
512 child_inf->pspace = new program_space (child_inf->aspace);
513 child_inf->removable = 1;
514 set_current_program_space (child_inf->pspace);
515 clone_program_space (child_inf->pspace, parent_inf->pspace);
517 /* Let the shared library layer (e.g., solib-svr4) learn
518 about this new process, relocate the cloned exec, pull
519 in shared libraries, and install the solib event
520 breakpoint. If a "cloned-VM" event was propagated
521 better throughout the core, this wouldn't be
523 solib_create_inferior_hook (0);
529 struct inferior *parent_inf;
531 parent_inf = current_inferior ();
533 /* If we detached from the child, then we have to be careful
534 to not insert breakpoints in the parent until the child
535 is done with the shared memory region. However, if we're
536 staying attached to the child, then we can and should
537 insert breakpoints, so that we can debug it. A
538 subsequent child exec or exit is enough to know when does
539 the child stops using the parent's address space. */
540 parent_inf->waiting_for_vfork_done = detach_fork;
541 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
546 /* Follow the child. */
547 struct inferior *parent_inf, *child_inf;
548 struct program_space *parent_pspace;
550 if (print_inferior_events)
552 std::string parent_pid = target_pid_to_str (parent_ptid);
553 std::string child_pid = target_pid_to_str (child_ptid);
555 target_terminal::ours_for_output ();
556 fprintf_filtered (gdb_stdlog,
557 _("[Attaching after %s %s to child %s]\n"),
559 has_vforked ? "vfork" : "fork",
563 /* Add the new inferior first, so that the target_detach below
564 doesn't unpush the target. */
566 child_inf = add_inferior (ptid_get_pid (child_ptid));
568 parent_inf = current_inferior ();
569 child_inf->attach_flag = parent_inf->attach_flag;
570 copy_terminal_info (child_inf, parent_inf);
571 child_inf->gdbarch = parent_inf->gdbarch;
572 copy_inferior_target_desc_info (child_inf, parent_inf);
574 parent_pspace = parent_inf->pspace;
576 /* If we're vforking, we want to hold on to the parent until the
577 child exits or execs. At child exec or exit time we can
578 remove the old breakpoints from the parent and detach or
579 resume debugging it. Otherwise, detach the parent now; we'll
580 want to reuse it's program/address spaces, but we can't set
581 them to the child before removing breakpoints from the
582 parent, otherwise, the breakpoints module could decide to
583 remove breakpoints from the wrong process (since they'd be
584 assigned to the same address space). */
588 gdb_assert (child_inf->vfork_parent == NULL);
589 gdb_assert (parent_inf->vfork_child == NULL);
590 child_inf->vfork_parent = parent_inf;
591 child_inf->pending_detach = 0;
592 parent_inf->vfork_child = child_inf;
593 parent_inf->pending_detach = detach_fork;
594 parent_inf->waiting_for_vfork_done = 0;
596 else if (detach_fork)
598 if (print_inferior_events)
600 /* Ensure that we have a process ptid. */
601 ptid_t process_ptid = ptid_t (ptid_get_pid (parent_ptid));
603 target_terminal::ours_for_output ();
604 fprintf_filtered (gdb_stdlog,
605 _("[Detaching after fork from "
607 target_pid_to_str (process_ptid));
610 target_detach (parent_inf, 0);
613 /* Note that the detach above makes PARENT_INF dangling. */
615 /* Add the child thread to the appropriate lists, and switch to
616 this new thread, before cloning the program space, and
617 informing the solib layer about this new process. */
619 inferior_ptid = child_ptid;
620 add_thread_silent (inferior_ptid);
621 set_current_inferior (child_inf);
623 /* If this is a vfork child, then the address-space is shared
624 with the parent. If we detached from the parent, then we can
625 reuse the parent's program/address spaces. */
626 if (has_vforked || detach_fork)
628 child_inf->pspace = parent_pspace;
629 child_inf->aspace = child_inf->pspace->aspace;
633 child_inf->aspace = new_address_space ();
634 child_inf->pspace = new program_space (child_inf->aspace);
635 child_inf->removable = 1;
636 child_inf->symfile_flags = SYMFILE_NO_READ;
637 set_current_program_space (child_inf->pspace);
638 clone_program_space (child_inf->pspace, parent_pspace);
640 /* Let the shared library layer (e.g., solib-svr4) learn
641 about this new process, relocate the cloned exec, pull in
642 shared libraries, and install the solib event breakpoint.
643 If a "cloned-VM" event was propagated better throughout
644 the core, this wouldn't be required. */
645 solib_create_inferior_hook (0);
649 return target_follow_fork (follow_child, detach_fork);
652 /* Tell the target to follow the fork we're stopped at. Returns true
653 if the inferior should be resumed; false, if the target for some
654 reason decided it's best not to resume. */
659 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
660 int should_resume = 1;
661 struct thread_info *tp;
663 /* Copy user stepping state to the new inferior thread. FIXME: the
664 followed fork child thread should have a copy of most of the
665 parent thread structure's run control related fields, not just these.
666 Initialized to avoid "may be used uninitialized" warnings from gcc. */
667 struct breakpoint *step_resume_breakpoint = NULL;
668 struct breakpoint *exception_resume_breakpoint = NULL;
669 CORE_ADDR step_range_start = 0;
670 CORE_ADDR step_range_end = 0;
671 struct frame_id step_frame_id = { 0 };
672 struct thread_fsm *thread_fsm = NULL;
677 struct target_waitstatus wait_status;
679 /* Get the last target status returned by target_wait(). */
680 get_last_target_status (&wait_ptid, &wait_status);
682 /* If not stopped at a fork event, then there's nothing else to
684 if (wait_status.kind != TARGET_WAITKIND_FORKED
685 && wait_status.kind != TARGET_WAITKIND_VFORKED)
688 /* Check if we switched over from WAIT_PTID, since the event was
690 if (wait_ptid != minus_one_ptid
691 && inferior_ptid != wait_ptid)
693 /* We did. Switch back to WAIT_PTID thread, to tell the
694 target to follow it (in either direction). We'll
695 afterwards refuse to resume, and inform the user what
697 thread_info *wait_thread
698 = find_thread_ptid (wait_ptid);
699 switch_to_thread (wait_thread);
704 tp = inferior_thread ();
706 /* If there were any forks/vforks that were caught and are now to be
707 followed, then do so now. */
708 switch (tp->pending_follow.kind)
710 case TARGET_WAITKIND_FORKED:
711 case TARGET_WAITKIND_VFORKED:
713 ptid_t parent, child;
715 /* If the user did a next/step, etc, over a fork call,
716 preserve the stepping state in the fork child. */
717 if (follow_child && should_resume)
719 step_resume_breakpoint = clone_momentary_breakpoint
720 (tp->control.step_resume_breakpoint);
721 step_range_start = tp->control.step_range_start;
722 step_range_end = tp->control.step_range_end;
723 step_frame_id = tp->control.step_frame_id;
724 exception_resume_breakpoint
725 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
726 thread_fsm = tp->thread_fsm;
728 /* For now, delete the parent's sr breakpoint, otherwise,
729 parent/child sr breakpoints are considered duplicates,
730 and the child version will not be installed. Remove
731 this when the breakpoints module becomes aware of
732 inferiors and address spaces. */
733 delete_step_resume_breakpoint (tp);
734 tp->control.step_range_start = 0;
735 tp->control.step_range_end = 0;
736 tp->control.step_frame_id = null_frame_id;
737 delete_exception_resume_breakpoint (tp);
738 tp->thread_fsm = NULL;
741 parent = inferior_ptid;
742 child = tp->pending_follow.value.related_pid;
744 /* Set up inferior(s) as specified by the caller, and tell the
745 target to do whatever is necessary to follow either parent
747 if (follow_fork_inferior (follow_child, detach_fork))
749 /* Target refused to follow, or there's some other reason
750 we shouldn't resume. */
755 /* This pending follow fork event is now handled, one way
756 or another. The previous selected thread may be gone
757 from the lists by now, but if it is still around, need
758 to clear the pending follow request. */
759 tp = find_thread_ptid (parent);
761 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
763 /* This makes sure we don't try to apply the "Switched
764 over from WAIT_PID" logic above. */
765 nullify_last_target_wait_ptid ();
767 /* If we followed the child, switch to it... */
770 thread_info *child_thr = find_thread_ptid (child);
771 switch_to_thread (child_thr);
773 /* ... and preserve the stepping state, in case the
774 user was stepping over the fork call. */
777 tp = inferior_thread ();
778 tp->control.step_resume_breakpoint
779 = step_resume_breakpoint;
780 tp->control.step_range_start = step_range_start;
781 tp->control.step_range_end = step_range_end;
782 tp->control.step_frame_id = step_frame_id;
783 tp->control.exception_resume_breakpoint
784 = exception_resume_breakpoint;
785 tp->thread_fsm = thread_fsm;
789 /* If we get here, it was because we're trying to
790 resume from a fork catchpoint, but, the user
791 has switched threads away from the thread that
792 forked. In that case, the resume command
793 issued is most likely not applicable to the
794 child, so just warn, and refuse to resume. */
795 warning (_("Not resuming: switched threads "
796 "before following fork child."));
799 /* Reset breakpoints in the child as appropriate. */
800 follow_inferior_reset_breakpoints ();
805 case TARGET_WAITKIND_SPURIOUS:
806 /* Nothing to follow. */
809 internal_error (__FILE__, __LINE__,
810 "Unexpected pending_follow.kind %d\n",
811 tp->pending_follow.kind);
815 return should_resume;
819 follow_inferior_reset_breakpoints (void)
821 struct thread_info *tp = inferior_thread ();
823 /* Was there a step_resume breakpoint? (There was if the user
824 did a "next" at the fork() call.) If so, explicitly reset its
825 thread number. Cloned step_resume breakpoints are disabled on
826 creation, so enable it here now that it is associated with the
829 step_resumes are a form of bp that are made to be per-thread.
830 Since we created the step_resume bp when the parent process
831 was being debugged, and now are switching to the child process,
832 from the breakpoint package's viewpoint, that's a switch of
833 "threads". We must update the bp's notion of which thread
834 it is for, or it'll be ignored when it triggers. */
836 if (tp->control.step_resume_breakpoint)
838 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
839 tp->control.step_resume_breakpoint->loc->enabled = 1;
842 /* Treat exception_resume breakpoints like step_resume breakpoints. */
843 if (tp->control.exception_resume_breakpoint)
845 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
846 tp->control.exception_resume_breakpoint->loc->enabled = 1;
849 /* Reinsert all breakpoints in the child. The user may have set
850 breakpoints after catching the fork, in which case those
851 were never set in the child, but only in the parent. This makes
852 sure the inserted breakpoints match the breakpoint list. */
854 breakpoint_re_set ();
855 insert_breakpoints ();
858 /* The child has exited or execed: resume threads of the parent the
859 user wanted to be executing. */
862 proceed_after_vfork_done (struct thread_info *thread,
865 int pid = * (int *) arg;
867 if (thread->ptid.pid () == pid
868 && thread->state == THREAD_RUNNING
869 && !thread->executing
870 && !thread->stop_requested
871 && thread->suspend.stop_signal == GDB_SIGNAL_0)
874 fprintf_unfiltered (gdb_stdlog,
875 "infrun: resuming vfork parent thread %s\n",
876 target_pid_to_str (thread->ptid));
878 switch_to_thread (thread);
879 clear_proceed_status (0);
880 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
886 /* Save/restore inferior_ptid, current program space and current
887 inferior. Only use this if the current context points at an exited
888 inferior (and therefore there's no current thread to save). */
889 class scoped_restore_exited_inferior
892 scoped_restore_exited_inferior ()
893 : m_saved_ptid (&inferior_ptid)
897 scoped_restore_tmpl<ptid_t> m_saved_ptid;
898 scoped_restore_current_program_space m_pspace;
899 scoped_restore_current_inferior m_inferior;
902 /* Called whenever we notice an exec or exit event, to handle
903 detaching or resuming a vfork parent. */
906 handle_vfork_child_exec_or_exit (int exec)
908 struct inferior *inf = current_inferior ();
910 if (inf->vfork_parent)
912 int resume_parent = -1;
914 /* This exec or exit marks the end of the shared memory region
915 between the parent and the child. If the user wanted to
916 detach from the parent, now is the time. */
918 if (inf->vfork_parent->pending_detach)
920 struct thread_info *tp;
921 struct program_space *pspace;
922 struct address_space *aspace;
924 /* follow-fork child, detach-on-fork on. */
926 inf->vfork_parent->pending_detach = 0;
928 gdb::optional<scoped_restore_exited_inferior>
929 maybe_restore_inferior;
930 gdb::optional<scoped_restore_current_pspace_and_thread>
931 maybe_restore_thread;
933 /* If we're handling a child exit, then inferior_ptid points
934 at the inferior's pid, not to a thread. */
936 maybe_restore_inferior.emplace ();
938 maybe_restore_thread.emplace ();
940 /* We're letting loose of the parent. */
941 tp = any_live_thread_of_inferior (inf->vfork_parent);
942 switch_to_thread (tp);
944 /* We're about to detach from the parent, which implicitly
945 removes breakpoints from its address space. There's a
946 catch here: we want to reuse the spaces for the child,
947 but, parent/child are still sharing the pspace at this
948 point, although the exec in reality makes the kernel give
949 the child a fresh set of new pages. The problem here is
950 that the breakpoints module being unaware of this, would
951 likely chose the child process to write to the parent
952 address space. Swapping the child temporarily away from
953 the spaces has the desired effect. Yes, this is "sort
956 pspace = inf->pspace;
957 aspace = inf->aspace;
961 if (print_inferior_events)
964 = target_pid_to_str (ptid_t (inf->vfork_parent->pid));
966 target_terminal::ours_for_output ();
970 fprintf_filtered (gdb_stdlog,
971 _("[Detaching vfork parent %s "
972 "after child exec]\n"), pidstr);
976 fprintf_filtered (gdb_stdlog,
977 _("[Detaching vfork parent %s "
978 "after child exit]\n"), pidstr);
982 target_detach (inf->vfork_parent, 0);
985 inf->pspace = pspace;
986 inf->aspace = aspace;
990 /* We're staying attached to the parent, so, really give the
991 child a new address space. */
992 inf->pspace = new program_space (maybe_new_address_space ());
993 inf->aspace = inf->pspace->aspace;
995 set_current_program_space (inf->pspace);
997 resume_parent = inf->vfork_parent->pid;
999 /* Break the bonds. */
1000 inf->vfork_parent->vfork_child = NULL;
1004 struct program_space *pspace;
1006 /* If this is a vfork child exiting, then the pspace and
1007 aspaces were shared with the parent. Since we're
1008 reporting the process exit, we'll be mourning all that is
1009 found in the address space, and switching to null_ptid,
1010 preparing to start a new inferior. But, since we don't
1011 want to clobber the parent's address/program spaces, we
1012 go ahead and create a new one for this exiting
1015 /* Switch to null_ptid while running clone_program_space, so
1016 that clone_program_space doesn't want to read the
1017 selected frame of a dead process. */
1018 scoped_restore restore_ptid
1019 = make_scoped_restore (&inferior_ptid, null_ptid);
1021 /* This inferior is dead, so avoid giving the breakpoints
1022 module the option to write through to it (cloning a
1023 program space resets breakpoints). */
1026 pspace = new program_space (maybe_new_address_space ());
1027 set_current_program_space (pspace);
1029 inf->symfile_flags = SYMFILE_NO_READ;
1030 clone_program_space (pspace, inf->vfork_parent->pspace);
1031 inf->pspace = pspace;
1032 inf->aspace = pspace->aspace;
1034 resume_parent = inf->vfork_parent->pid;
1035 /* Break the bonds. */
1036 inf->vfork_parent->vfork_child = NULL;
1039 inf->vfork_parent = NULL;
1041 gdb_assert (current_program_space == inf->pspace);
1043 if (non_stop && resume_parent != -1)
1045 /* If the user wanted the parent to be running, let it go
1047 scoped_restore_current_thread restore_thread;
1050 fprintf_unfiltered (gdb_stdlog,
1051 "infrun: resuming vfork parent process %d\n",
1054 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1059 /* Enum strings for "set|show follow-exec-mode". */
1061 static const char follow_exec_mode_new[] = "new";
1062 static const char follow_exec_mode_same[] = "same";
1063 static const char *const follow_exec_mode_names[] =
1065 follow_exec_mode_new,
1066 follow_exec_mode_same,
1070 static const char *follow_exec_mode_string = follow_exec_mode_same;
1072 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1073 struct cmd_list_element *c, const char *value)
1075 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1078 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1081 follow_exec (ptid_t ptid, char *exec_file_target)
1083 struct thread_info *th, *tmp;
1084 struct inferior *inf = current_inferior ();
1085 int pid = ptid_get_pid (ptid);
1086 ptid_t process_ptid;
1088 /* This is an exec event that we actually wish to pay attention to.
1089 Refresh our symbol table to the newly exec'd program, remove any
1090 momentary bp's, etc.
1092 If there are breakpoints, they aren't really inserted now,
1093 since the exec() transformed our inferior into a fresh set
1096 We want to preserve symbolic breakpoints on the list, since
1097 we have hopes that they can be reset after the new a.out's
1098 symbol table is read.
1100 However, any "raw" breakpoints must be removed from the list
1101 (e.g., the solib bp's), since their address is probably invalid
1104 And, we DON'T want to call delete_breakpoints() here, since
1105 that may write the bp's "shadow contents" (the instruction
1106 value that was overwritten witha TRAP instruction). Since
1107 we now have a new a.out, those shadow contents aren't valid. */
1109 mark_breakpoints_out ();
1111 /* The target reports the exec event to the main thread, even if
1112 some other thread does the exec, and even if the main thread was
1113 stopped or already gone. We may still have non-leader threads of
1114 the process on our list. E.g., on targets that don't have thread
1115 exit events (like remote); or on native Linux in non-stop mode if
1116 there were only two threads in the inferior and the non-leader
1117 one is the one that execs (and nothing forces an update of the
1118 thread list up to here). When debugging remotely, it's best to
1119 avoid extra traffic, when possible, so avoid syncing the thread
1120 list with the target, and instead go ahead and delete all threads
1121 of the process but one that reported the event. Note this must
1122 be done before calling update_breakpoints_after_exec, as
1123 otherwise clearing the threads' resources would reference stale
1124 thread breakpoints -- it may have been one of these threads that
1125 stepped across the exec. We could just clear their stepping
1126 states, but as long as we're iterating, might as well delete
1127 them. Deleting them now rather than at the next user-visible
1128 stop provides a nicer sequence of events for user and MI
1130 ALL_THREADS_SAFE (th, tmp)
1131 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1134 /* We also need to clear any left over stale state for the
1135 leader/event thread. E.g., if there was any step-resume
1136 breakpoint or similar, it's gone now. We cannot truly
1137 step-to-next statement through an exec(). */
1138 th = inferior_thread ();
1139 th->control.step_resume_breakpoint = NULL;
1140 th->control.exception_resume_breakpoint = NULL;
1141 th->control.single_step_breakpoints = NULL;
1142 th->control.step_range_start = 0;
1143 th->control.step_range_end = 0;
1145 /* The user may have had the main thread held stopped in the
1146 previous image (e.g., schedlock on, or non-stop). Release
1148 th->stop_requested = 0;
1150 update_breakpoints_after_exec ();
1152 /* What is this a.out's name? */
1153 process_ptid = ptid_t (pid);
1154 printf_unfiltered (_("%s is executing new program: %s\n"),
1155 target_pid_to_str (process_ptid),
1158 /* We've followed the inferior through an exec. Therefore, the
1159 inferior has essentially been killed & reborn. */
1161 gdb_flush (gdb_stdout);
1163 breakpoint_init_inferior (inf_execd);
1165 gdb::unique_xmalloc_ptr<char> exec_file_host
1166 = exec_file_find (exec_file_target, NULL);
1168 /* If we were unable to map the executable target pathname onto a host
1169 pathname, tell the user that. Otherwise GDB's subsequent behavior
1170 is confusing. Maybe it would even be better to stop at this point
1171 so that the user can specify a file manually before continuing. */
1172 if (exec_file_host == NULL)
1173 warning (_("Could not load symbols for executable %s.\n"
1174 "Do you need \"set sysroot\"?"),
1177 /* Reset the shared library package. This ensures that we get a
1178 shlib event when the child reaches "_start", at which point the
1179 dld will have had a chance to initialize the child. */
1180 /* Also, loading a symbol file below may trigger symbol lookups, and
1181 we don't want those to be satisfied by the libraries of the
1182 previous incarnation of this process. */
1183 no_shared_libraries (NULL, 0);
1185 if (follow_exec_mode_string == follow_exec_mode_new)
1187 /* The user wants to keep the old inferior and program spaces
1188 around. Create a new fresh one, and switch to it. */
1190 /* Do exit processing for the original inferior before adding
1191 the new inferior so we don't have two active inferiors with
1192 the same ptid, which can confuse find_inferior_ptid. */
1193 exit_inferior_silent (current_inferior ());
1195 inf = add_inferior_with_spaces ();
1197 target_follow_exec (inf, exec_file_target);
1199 set_current_inferior (inf);
1200 set_current_program_space (inf->pspace);
1204 /* The old description may no longer be fit for the new image.
1205 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1206 old description; we'll read a new one below. No need to do
1207 this on "follow-exec-mode new", as the old inferior stays
1208 around (its description is later cleared/refetched on
1210 target_clear_description ();
1213 gdb_assert (current_program_space == inf->pspace);
1215 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1216 because the proper displacement for a PIE (Position Independent
1217 Executable) main symbol file will only be computed by
1218 solib_create_inferior_hook below. breakpoint_re_set would fail
1219 to insert the breakpoints with the zero displacement. */
1220 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1222 /* If the target can specify a description, read it. Must do this
1223 after flipping to the new executable (because the target supplied
1224 description must be compatible with the executable's
1225 architecture, and the old executable may e.g., be 32-bit, while
1226 the new one 64-bit), and before anything involving memory or
1228 target_find_description ();
1230 /* The add_thread call ends up reading registers, so do it after updating the
1231 target description. */
1232 if (follow_exec_mode_string == follow_exec_mode_new)
1235 solib_create_inferior_hook (0);
1237 jit_inferior_created_hook ();
1239 breakpoint_re_set ();
1241 /* Reinsert all breakpoints. (Those which were symbolic have
1242 been reset to the proper address in the new a.out, thanks
1243 to symbol_file_command...). */
1244 insert_breakpoints ();
1246 /* The next resume of this inferior should bring it to the shlib
1247 startup breakpoints. (If the user had also set bp's on
1248 "main" from the old (parent) process, then they'll auto-
1249 matically get reset there in the new process.). */
1252 /* The queue of threads that need to do a step-over operation to get
1253 past e.g., a breakpoint. What technique is used to step over the
1254 breakpoint/watchpoint does not matter -- all threads end up in the
1255 same queue, to maintain rough temporal order of execution, in order
1256 to avoid starvation, otherwise, we could e.g., find ourselves
1257 constantly stepping the same couple threads past their breakpoints
1258 over and over, if the single-step finish fast enough. */
1259 struct thread_info *step_over_queue_head;
1261 /* Bit flags indicating what the thread needs to step over. */
1263 enum step_over_what_flag
1265 /* Step over a breakpoint. */
1266 STEP_OVER_BREAKPOINT = 1,
1268 /* Step past a non-continuable watchpoint, in order to let the
1269 instruction execute so we can evaluate the watchpoint
1271 STEP_OVER_WATCHPOINT = 2
1273 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1275 /* Info about an instruction that is being stepped over. */
1277 struct step_over_info
1279 /* If we're stepping past a breakpoint, this is the address space
1280 and address of the instruction the breakpoint is set at. We'll
1281 skip inserting all breakpoints here. Valid iff ASPACE is
1283 const address_space *aspace;
1286 /* The instruction being stepped over triggers a nonsteppable
1287 watchpoint. If true, we'll skip inserting watchpoints. */
1288 int nonsteppable_watchpoint_p;
1290 /* The thread's global number. */
1294 /* The step-over info of the location that is being stepped over.
1296 Note that with async/breakpoint always-inserted mode, a user might
1297 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1298 being stepped over. As setting a new breakpoint inserts all
1299 breakpoints, we need to make sure the breakpoint being stepped over
1300 isn't inserted then. We do that by only clearing the step-over
1301 info when the step-over is actually finished (or aborted).
1303 Presently GDB can only step over one breakpoint at any given time.
1304 Given threads that can't run code in the same address space as the
1305 breakpoint's can't really miss the breakpoint, GDB could be taught
1306 to step-over at most one breakpoint per address space (so this info
1307 could move to the address space object if/when GDB is extended).
1308 The set of breakpoints being stepped over will normally be much
1309 smaller than the set of all breakpoints, so a flag in the
1310 breakpoint location structure would be wasteful. A separate list
1311 also saves complexity and run-time, as otherwise we'd have to go
1312 through all breakpoint locations clearing their flag whenever we
1313 start a new sequence. Similar considerations weigh against storing
1314 this info in the thread object. Plus, not all step overs actually
1315 have breakpoint locations -- e.g., stepping past a single-step
1316 breakpoint, or stepping to complete a non-continuable
1318 static struct step_over_info step_over_info;
1320 /* Record the address of the breakpoint/instruction we're currently
1322 N.B. We record the aspace and address now, instead of say just the thread,
1323 because when we need the info later the thread may be running. */
1326 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1327 int nonsteppable_watchpoint_p,
1330 step_over_info.aspace = aspace;
1331 step_over_info.address = address;
1332 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1333 step_over_info.thread = thread;
1336 /* Called when we're not longer stepping over a breakpoint / an
1337 instruction, so all breakpoints are free to be (re)inserted. */
1340 clear_step_over_info (void)
1343 fprintf_unfiltered (gdb_stdlog,
1344 "infrun: clear_step_over_info\n");
1345 step_over_info.aspace = NULL;
1346 step_over_info.address = 0;
1347 step_over_info.nonsteppable_watchpoint_p = 0;
1348 step_over_info.thread = -1;
1354 stepping_past_instruction_at (struct address_space *aspace,
1357 return (step_over_info.aspace != NULL
1358 && breakpoint_address_match (aspace, address,
1359 step_over_info.aspace,
1360 step_over_info.address));
1366 thread_is_stepping_over_breakpoint (int thread)
1368 return (step_over_info.thread != -1
1369 && thread == step_over_info.thread);
1375 stepping_past_nonsteppable_watchpoint (void)
1377 return step_over_info.nonsteppable_watchpoint_p;
1380 /* Returns true if step-over info is valid. */
1383 step_over_info_valid_p (void)
1385 return (step_over_info.aspace != NULL
1386 || stepping_past_nonsteppable_watchpoint ());
1390 /* Displaced stepping. */
1392 /* In non-stop debugging mode, we must take special care to manage
1393 breakpoints properly; in particular, the traditional strategy for
1394 stepping a thread past a breakpoint it has hit is unsuitable.
1395 'Displaced stepping' is a tactic for stepping one thread past a
1396 breakpoint it has hit while ensuring that other threads running
1397 concurrently will hit the breakpoint as they should.
1399 The traditional way to step a thread T off a breakpoint in a
1400 multi-threaded program in all-stop mode is as follows:
1402 a0) Initially, all threads are stopped, and breakpoints are not
1404 a1) We single-step T, leaving breakpoints uninserted.
1405 a2) We insert breakpoints, and resume all threads.
1407 In non-stop debugging, however, this strategy is unsuitable: we
1408 don't want to have to stop all threads in the system in order to
1409 continue or step T past a breakpoint. Instead, we use displaced
1412 n0) Initially, T is stopped, other threads are running, and
1413 breakpoints are inserted.
1414 n1) We copy the instruction "under" the breakpoint to a separate
1415 location, outside the main code stream, making any adjustments
1416 to the instruction, register, and memory state as directed by
1418 n2) We single-step T over the instruction at its new location.
1419 n3) We adjust the resulting register and memory state as directed
1420 by T's architecture. This includes resetting T's PC to point
1421 back into the main instruction stream.
1424 This approach depends on the following gdbarch methods:
1426 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1427 indicate where to copy the instruction, and how much space must
1428 be reserved there. We use these in step n1.
1430 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1431 address, and makes any necessary adjustments to the instruction,
1432 register contents, and memory. We use this in step n1.
1434 - gdbarch_displaced_step_fixup adjusts registers and memory after
1435 we have successfuly single-stepped the instruction, to yield the
1436 same effect the instruction would have had if we had executed it
1437 at its original address. We use this in step n3.
1439 The gdbarch_displaced_step_copy_insn and
1440 gdbarch_displaced_step_fixup functions must be written so that
1441 copying an instruction with gdbarch_displaced_step_copy_insn,
1442 single-stepping across the copied instruction, and then applying
1443 gdbarch_displaced_insn_fixup should have the same effects on the
1444 thread's memory and registers as stepping the instruction in place
1445 would have. Exactly which responsibilities fall to the copy and
1446 which fall to the fixup is up to the author of those functions.
1448 See the comments in gdbarch.sh for details.
1450 Note that displaced stepping and software single-step cannot
1451 currently be used in combination, although with some care I think
1452 they could be made to. Software single-step works by placing
1453 breakpoints on all possible subsequent instructions; if the
1454 displaced instruction is a PC-relative jump, those breakpoints
1455 could fall in very strange places --- on pages that aren't
1456 executable, or at addresses that are not proper instruction
1457 boundaries. (We do generally let other threads run while we wait
1458 to hit the software single-step breakpoint, and they might
1459 encounter such a corrupted instruction.) One way to work around
1460 this would be to have gdbarch_displaced_step_copy_insn fully
1461 simulate the effect of PC-relative instructions (and return NULL)
1462 on architectures that use software single-stepping.
1464 In non-stop mode, we can have independent and simultaneous step
1465 requests, so more than one thread may need to simultaneously step
1466 over a breakpoint. The current implementation assumes there is
1467 only one scratch space per process. In this case, we have to
1468 serialize access to the scratch space. If thread A wants to step
1469 over a breakpoint, but we are currently waiting for some other
1470 thread to complete a displaced step, we leave thread A stopped and
1471 place it in the displaced_step_request_queue. Whenever a displaced
1472 step finishes, we pick the next thread in the queue and start a new
1473 displaced step operation on it. See displaced_step_prepare and
1474 displaced_step_fixup for details. */
1476 /* Default destructor for displaced_step_closure. */
1478 displaced_step_closure::~displaced_step_closure () = default;
1480 /* Per-inferior displaced stepping state. */
1481 struct displaced_step_inferior_state
1483 /* Pointer to next in linked list. */
1484 struct displaced_step_inferior_state *next;
1486 /* The process this displaced step state refers to. */
1489 /* True if preparing a displaced step ever failed. If so, we won't
1490 try displaced stepping for this inferior again. */
1493 /* If this is not nullptr, this is the thread carrying out a
1494 displaced single-step in process PID. This thread's state will
1495 require fixing up once it has completed its step. */
1496 thread_info *step_thread;
1498 /* The architecture the thread had when we stepped it. */
1499 struct gdbarch *step_gdbarch;
1501 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1502 for post-step cleanup. */
1503 struct displaced_step_closure *step_closure;
1505 /* The address of the original instruction, and the copy we
1507 CORE_ADDR step_original, step_copy;
1509 /* Saved contents of copy area. */
1510 gdb_byte *step_saved_copy;
1513 /* The list of states of processes involved in displaced stepping
1515 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1517 /* Get the displaced stepping state of process PID. */
1519 static struct displaced_step_inferior_state *
1520 get_displaced_stepping_state (inferior *inf)
1522 struct displaced_step_inferior_state *state;
1524 for (state = displaced_step_inferior_states;
1526 state = state->next)
1527 if (state->inf == inf)
1533 /* Returns true if any inferior has a thread doing a displaced
1537 displaced_step_in_progress_any_inferior (void)
1539 struct displaced_step_inferior_state *state;
1541 for (state = displaced_step_inferior_states;
1543 state = state->next)
1544 if (state->step_thread != nullptr)
1550 /* Return true if thread represented by PTID is doing a displaced
1554 displaced_step_in_progress_thread (thread_info *thread)
1556 struct displaced_step_inferior_state *displaced;
1558 gdb_assert (thread != NULL);
1560 displaced = get_displaced_stepping_state (thread->inf);
1562 return (displaced != NULL && displaced->step_thread == thread);
1565 /* Return true if process PID has a thread doing a displaced step. */
1568 displaced_step_in_progress (inferior *inf)
1570 struct displaced_step_inferior_state *displaced;
1572 displaced = get_displaced_stepping_state (inf);
1573 if (displaced != NULL && displaced->step_thread != nullptr)
1579 /* Add a new displaced stepping state for process PID to the displaced
1580 stepping state list, or return a pointer to an already existing
1581 entry, if it already exists. Never returns NULL. */
1583 static struct displaced_step_inferior_state *
1584 add_displaced_stepping_state (inferior *inf)
1586 struct displaced_step_inferior_state *state;
1588 for (state = displaced_step_inferior_states;
1590 state = state->next)
1591 if (state->inf == inf)
1594 state = XCNEW (struct displaced_step_inferior_state);
1596 state->next = displaced_step_inferior_states;
1597 displaced_step_inferior_states = state;
1602 /* If inferior is in displaced stepping, and ADDR equals to starting address
1603 of copy area, return corresponding displaced_step_closure. Otherwise,
1606 struct displaced_step_closure*
1607 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1609 struct displaced_step_inferior_state *displaced
1610 = get_displaced_stepping_state (current_inferior ());
1612 /* If checking the mode of displaced instruction in copy area. */
1613 if (displaced != NULL
1614 && displaced->step_thread != nullptr
1615 && displaced->step_copy == addr)
1616 return displaced->step_closure;
1621 /* Remove the displaced stepping state of process PID. */
1624 remove_displaced_stepping_state (inferior *inf)
1626 struct displaced_step_inferior_state *it, **prev_next_p;
1628 gdb_assert (inf != nullptr);
1630 it = displaced_step_inferior_states;
1631 prev_next_p = &displaced_step_inferior_states;
1636 *prev_next_p = it->next;
1641 prev_next_p = &it->next;
1647 infrun_inferior_exit (struct inferior *inf)
1649 remove_displaced_stepping_state (inf);
1652 /* If ON, and the architecture supports it, GDB will use displaced
1653 stepping to step over breakpoints. If OFF, or if the architecture
1654 doesn't support it, GDB will instead use the traditional
1655 hold-and-step approach. If AUTO (which is the default), GDB will
1656 decide which technique to use to step over breakpoints depending on
1657 which of all-stop or non-stop mode is active --- displaced stepping
1658 in non-stop mode; hold-and-step in all-stop mode. */
1660 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1663 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1664 struct cmd_list_element *c,
1667 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1668 fprintf_filtered (file,
1669 _("Debugger's willingness to use displaced stepping "
1670 "to step over breakpoints is %s (currently %s).\n"),
1671 value, target_is_non_stop_p () ? "on" : "off");
1673 fprintf_filtered (file,
1674 _("Debugger's willingness to use displaced stepping "
1675 "to step over breakpoints is %s.\n"), value);
1678 /* Return non-zero if displaced stepping can/should be used to step
1679 over breakpoints of thread TP. */
1682 use_displaced_stepping (struct thread_info *tp)
1684 struct regcache *regcache = get_thread_regcache (tp);
1685 struct gdbarch *gdbarch = regcache->arch ();
1686 struct displaced_step_inferior_state *displaced_state;
1688 displaced_state = get_displaced_stepping_state (tp->inf);
1690 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1691 && target_is_non_stop_p ())
1692 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1693 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1694 && find_record_target () == NULL
1695 && (displaced_state == NULL
1696 || !displaced_state->failed_before));
1699 /* Clean out any stray displaced stepping state. */
1701 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1703 /* Indicate that there is no cleanup pending. */
1704 displaced->step_thread = nullptr;
1706 delete displaced->step_closure;
1707 displaced->step_closure = NULL;
1711 displaced_step_clear_cleanup (void *arg)
1713 struct displaced_step_inferior_state *state
1714 = (struct displaced_step_inferior_state *) arg;
1716 displaced_step_clear (state);
1719 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1721 displaced_step_dump_bytes (struct ui_file *file,
1722 const gdb_byte *buf,
1727 for (i = 0; i < len; i++)
1728 fprintf_unfiltered (file, "%02x ", buf[i]);
1729 fputs_unfiltered ("\n", file);
1732 /* Prepare to single-step, using displaced stepping.
1734 Note that we cannot use displaced stepping when we have a signal to
1735 deliver. If we have a signal to deliver and an instruction to step
1736 over, then after the step, there will be no indication from the
1737 target whether the thread entered a signal handler or ignored the
1738 signal and stepped over the instruction successfully --- both cases
1739 result in a simple SIGTRAP. In the first case we mustn't do a
1740 fixup, and in the second case we must --- but we can't tell which.
1741 Comments in the code for 'random signals' in handle_inferior_event
1742 explain how we handle this case instead.
1744 Returns 1 if preparing was successful -- this thread is going to be
1745 stepped now; 0 if displaced stepping this thread got queued; or -1
1746 if this instruction can't be displaced stepped. */
1749 displaced_step_prepare_throw (thread_info *tp)
1751 struct cleanup *ignore_cleanups;
1752 regcache *regcache = get_thread_regcache (tp);
1753 struct gdbarch *gdbarch = regcache->arch ();
1754 const address_space *aspace = regcache->aspace ();
1755 CORE_ADDR original, copy;
1757 struct displaced_step_closure *closure;
1758 struct displaced_step_inferior_state *displaced;
1761 /* We should never reach this function if the architecture does not
1762 support displaced stepping. */
1763 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1765 /* Nor if the thread isn't meant to step over a breakpoint. */
1766 gdb_assert (tp->control.trap_expected);
1768 /* Disable range stepping while executing in the scratch pad. We
1769 want a single-step even if executing the displaced instruction in
1770 the scratch buffer lands within the stepping range (e.g., a
1772 tp->control.may_range_step = 0;
1774 /* We have to displaced step one thread at a time, as we only have
1775 access to a single scratch space per inferior. */
1777 displaced = add_displaced_stepping_state (tp->inf);
1779 if (displaced->step_thread != nullptr)
1781 /* Already waiting for a displaced step to finish. Defer this
1782 request and place in queue. */
1784 if (debug_displaced)
1785 fprintf_unfiltered (gdb_stdlog,
1786 "displaced: deferring step of %s\n",
1787 target_pid_to_str (tp->ptid));
1789 thread_step_over_chain_enqueue (tp);
1794 if (debug_displaced)
1795 fprintf_unfiltered (gdb_stdlog,
1796 "displaced: stepping %s now\n",
1797 target_pid_to_str (tp->ptid));
1800 displaced_step_clear (displaced);
1802 scoped_restore_current_thread restore_thread;
1804 switch_to_thread (tp);
1806 original = regcache_read_pc (regcache);
1808 copy = gdbarch_displaced_step_location (gdbarch);
1809 len = gdbarch_max_insn_length (gdbarch);
1811 if (breakpoint_in_range_p (aspace, copy, len))
1813 /* There's a breakpoint set in the scratch pad location range
1814 (which is usually around the entry point). We'd either
1815 install it before resuming, which would overwrite/corrupt the
1816 scratch pad, or if it was already inserted, this displaced
1817 step would overwrite it. The latter is OK in the sense that
1818 we already assume that no thread is going to execute the code
1819 in the scratch pad range (after initial startup) anyway, but
1820 the former is unacceptable. Simply punt and fallback to
1821 stepping over this breakpoint in-line. */
1822 if (debug_displaced)
1824 fprintf_unfiltered (gdb_stdlog,
1825 "displaced: breakpoint set in scratch pad. "
1826 "Stepping over breakpoint in-line instead.\n");
1832 /* Save the original contents of the copy area. */
1833 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1834 ignore_cleanups = make_cleanup (free_current_contents,
1835 &displaced->step_saved_copy);
1836 status = target_read_memory (copy, displaced->step_saved_copy, len);
1838 throw_error (MEMORY_ERROR,
1839 _("Error accessing memory address %s (%s) for "
1840 "displaced-stepping scratch space."),
1841 paddress (gdbarch, copy), safe_strerror (status));
1842 if (debug_displaced)
1844 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1845 paddress (gdbarch, copy));
1846 displaced_step_dump_bytes (gdb_stdlog,
1847 displaced->step_saved_copy,
1851 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1852 original, copy, regcache);
1853 if (closure == NULL)
1855 /* The architecture doesn't know how or want to displaced step
1856 this instruction or instruction sequence. Fallback to
1857 stepping over the breakpoint in-line. */
1858 do_cleanups (ignore_cleanups);
1862 /* Save the information we need to fix things up if the step
1864 displaced->step_thread = tp;
1865 displaced->step_gdbarch = gdbarch;
1866 displaced->step_closure = closure;
1867 displaced->step_original = original;
1868 displaced->step_copy = copy;
1870 make_cleanup (displaced_step_clear_cleanup, displaced);
1872 /* Resume execution at the copy. */
1873 regcache_write_pc (regcache, copy);
1875 discard_cleanups (ignore_cleanups);
1877 if (debug_displaced)
1878 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1879 paddress (gdbarch, copy));
1884 /* Wrapper for displaced_step_prepare_throw that disabled further
1885 attempts at displaced stepping if we get a memory error. */
1888 displaced_step_prepare (thread_info *thread)
1894 prepared = displaced_step_prepare_throw (thread);
1896 CATCH (ex, RETURN_MASK_ERROR)
1898 struct displaced_step_inferior_state *displaced_state;
1900 if (ex.error != MEMORY_ERROR
1901 && ex.error != NOT_SUPPORTED_ERROR)
1902 throw_exception (ex);
1906 fprintf_unfiltered (gdb_stdlog,
1907 "infrun: disabling displaced stepping: %s\n",
1911 /* Be verbose if "set displaced-stepping" is "on", silent if
1913 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1915 warning (_("disabling displaced stepping: %s"),
1919 /* Disable further displaced stepping attempts. */
1921 = get_displaced_stepping_state (thread->inf);
1922 displaced_state->failed_before = 1;
1930 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1931 const gdb_byte *myaddr, int len)
1933 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1935 inferior_ptid = ptid;
1936 write_memory (memaddr, myaddr, len);
1939 /* Restore the contents of the copy area for thread PTID. */
1942 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1945 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1947 write_memory_ptid (ptid, displaced->step_copy,
1948 displaced->step_saved_copy, len);
1949 if (debug_displaced)
1950 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1951 target_pid_to_str (ptid),
1952 paddress (displaced->step_gdbarch,
1953 displaced->step_copy));
1956 /* If we displaced stepped an instruction successfully, adjust
1957 registers and memory to yield the same effect the instruction would
1958 have had if we had executed it at its original address, and return
1959 1. If the instruction didn't complete, relocate the PC and return
1960 -1. If the thread wasn't displaced stepping, return 0. */
1963 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1965 struct cleanup *old_cleanups;
1966 struct displaced_step_inferior_state *displaced
1967 = get_displaced_stepping_state (event_thread->inf);
1970 /* Was any thread of this process doing a displaced step? */
1971 if (displaced == NULL)
1974 /* Was this event for the thread we displaced? */
1975 if (displaced->step_thread != event_thread)
1978 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1980 displaced_step_restore (displaced, displaced->step_thread->ptid);
1982 /* Fixup may need to read memory/registers. Switch to the thread
1983 that we're fixing up. Also, target_stopped_by_watchpoint checks
1984 the current thread. */
1985 switch_to_thread (event_thread);
1987 /* Did the instruction complete successfully? */
1988 if (signal == GDB_SIGNAL_TRAP
1989 && !(target_stopped_by_watchpoint ()
1990 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1991 || target_have_steppable_watchpoint)))
1993 /* Fix up the resulting state. */
1994 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1995 displaced->step_closure,
1996 displaced->step_original,
1997 displaced->step_copy,
1998 get_thread_regcache (displaced->step_thread));
2003 /* Since the instruction didn't complete, all we can do is
2005 struct regcache *regcache = get_thread_regcache (event_thread);
2006 CORE_ADDR pc = regcache_read_pc (regcache);
2008 pc = displaced->step_original + (pc - displaced->step_copy);
2009 regcache_write_pc (regcache, pc);
2013 do_cleanups (old_cleanups);
2015 displaced->step_thread = nullptr;
2020 /* Data to be passed around while handling an event. This data is
2021 discarded between events. */
2022 struct execution_control_state
2025 /* The thread that got the event, if this was a thread event; NULL
2027 struct thread_info *event_thread;
2029 struct target_waitstatus ws;
2030 int stop_func_filled_in;
2031 CORE_ADDR stop_func_start;
2032 CORE_ADDR stop_func_end;
2033 const char *stop_func_name;
2036 /* True if the event thread hit the single-step breakpoint of
2037 another thread. Thus the event doesn't cause a stop, the thread
2038 needs to be single-stepped past the single-step breakpoint before
2039 we can switch back to the original stepping thread. */
2040 int hit_singlestep_breakpoint;
2043 /* Clear ECS and set it to point at TP. */
2046 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2048 memset (ecs, 0, sizeof (*ecs));
2049 ecs->event_thread = tp;
2050 ecs->ptid = tp->ptid;
2053 static void keep_going_pass_signal (struct execution_control_state *ecs);
2054 static void prepare_to_wait (struct execution_control_state *ecs);
2055 static int keep_going_stepped_thread (struct thread_info *tp);
2056 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2058 /* Are there any pending step-over requests? If so, run all we can
2059 now and return true. Otherwise, return false. */
2062 start_step_over (void)
2064 struct thread_info *tp, *next;
2066 /* Don't start a new step-over if we already have an in-line
2067 step-over operation ongoing. */
2068 if (step_over_info_valid_p ())
2071 for (tp = step_over_queue_head; tp != NULL; tp = next)
2073 struct execution_control_state ecss;
2074 struct execution_control_state *ecs = &ecss;
2075 step_over_what step_what;
2076 int must_be_in_line;
2078 gdb_assert (!tp->stop_requested);
2080 next = thread_step_over_chain_next (tp);
2082 /* If this inferior already has a displaced step in process,
2083 don't start a new one. */
2084 if (displaced_step_in_progress (tp->inf))
2087 step_what = thread_still_needs_step_over (tp);
2088 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2089 || ((step_what & STEP_OVER_BREAKPOINT)
2090 && !use_displaced_stepping (tp)));
2092 /* We currently stop all threads of all processes to step-over
2093 in-line. If we need to start a new in-line step-over, let
2094 any pending displaced steps finish first. */
2095 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2098 thread_step_over_chain_remove (tp);
2100 if (step_over_queue_head == NULL)
2103 fprintf_unfiltered (gdb_stdlog,
2104 "infrun: step-over queue now empty\n");
2107 if (tp->control.trap_expected
2111 internal_error (__FILE__, __LINE__,
2112 "[%s] has inconsistent state: "
2113 "trap_expected=%d, resumed=%d, executing=%d\n",
2114 target_pid_to_str (tp->ptid),
2115 tp->control.trap_expected,
2121 fprintf_unfiltered (gdb_stdlog,
2122 "infrun: resuming [%s] for step-over\n",
2123 target_pid_to_str (tp->ptid));
2125 /* keep_going_pass_signal skips the step-over if the breakpoint
2126 is no longer inserted. In all-stop, we want to keep looking
2127 for a thread that needs a step-over instead of resuming TP,
2128 because we wouldn't be able to resume anything else until the
2129 target stops again. In non-stop, the resume always resumes
2130 only TP, so it's OK to let the thread resume freely. */
2131 if (!target_is_non_stop_p () && !step_what)
2134 switch_to_thread (tp);
2135 reset_ecs (ecs, tp);
2136 keep_going_pass_signal (ecs);
2138 if (!ecs->wait_some_more)
2139 error (_("Command aborted."));
2141 gdb_assert (tp->resumed);
2143 /* If we started a new in-line step-over, we're done. */
2144 if (step_over_info_valid_p ())
2146 gdb_assert (tp->control.trap_expected);
2150 if (!target_is_non_stop_p ())
2152 /* On all-stop, shouldn't have resumed unless we needed a
2154 gdb_assert (tp->control.trap_expected
2155 || tp->step_after_step_resume_breakpoint);
2157 /* With remote targets (at least), in all-stop, we can't
2158 issue any further remote commands until the program stops
2163 /* Either the thread no longer needed a step-over, or a new
2164 displaced stepping sequence started. Even in the latter
2165 case, continue looking. Maybe we can also start another
2166 displaced step on a thread of other process. */
2172 /* Update global variables holding ptids to hold NEW_PTID if they were
2173 holding OLD_PTID. */
2175 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2177 struct displaced_step_inferior_state *displaced;
2179 if (ptid_equal (inferior_ptid, old_ptid))
2180 inferior_ptid = new_ptid;
2185 static const char schedlock_off[] = "off";
2186 static const char schedlock_on[] = "on";
2187 static const char schedlock_step[] = "step";
2188 static const char schedlock_replay[] = "replay";
2189 static const char *const scheduler_enums[] = {
2196 static const char *scheduler_mode = schedlock_replay;
2198 show_scheduler_mode (struct ui_file *file, int from_tty,
2199 struct cmd_list_element *c, const char *value)
2201 fprintf_filtered (file,
2202 _("Mode for locking scheduler "
2203 "during execution is \"%s\".\n"),
2208 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2210 if (!target_can_lock_scheduler)
2212 scheduler_mode = schedlock_off;
2213 error (_("Target '%s' cannot support this command."), target_shortname);
2217 /* True if execution commands resume all threads of all processes by
2218 default; otherwise, resume only threads of the current inferior
2220 int sched_multi = 0;
2222 /* Try to setup for software single stepping over the specified location.
2223 Return 1 if target_resume() should use hardware single step.
2225 GDBARCH the current gdbarch.
2226 PC the location to step over. */
2229 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2233 if (execution_direction == EXEC_FORWARD
2234 && gdbarch_software_single_step_p (gdbarch))
2235 hw_step = !insert_single_step_breakpoints (gdbarch);
2243 user_visible_resume_ptid (int step)
2249 /* With non-stop mode on, threads are always handled
2251 resume_ptid = inferior_ptid;
2253 else if ((scheduler_mode == schedlock_on)
2254 || (scheduler_mode == schedlock_step && step))
2256 /* User-settable 'scheduler' mode requires solo thread
2258 resume_ptid = inferior_ptid;
2260 else if ((scheduler_mode == schedlock_replay)
2261 && target_record_will_replay (minus_one_ptid, execution_direction))
2263 /* User-settable 'scheduler' mode requires solo thread resume in replay
2265 resume_ptid = inferior_ptid;
2267 else if (!sched_multi && target_supports_multi_process ())
2269 /* Resume all threads of the current process (and none of other
2271 resume_ptid = ptid_t (ptid_get_pid (inferior_ptid));
2275 /* Resume all threads of all processes. */
2276 resume_ptid = RESUME_ALL;
2282 /* Return a ptid representing the set of threads that we will resume,
2283 in the perspective of the target, assuming run control handling
2284 does not require leaving some threads stopped (e.g., stepping past
2285 breakpoint). USER_STEP indicates whether we're about to start the
2286 target for a stepping command. */
2289 internal_resume_ptid (int user_step)
2291 /* In non-stop, we always control threads individually. Note that
2292 the target may always work in non-stop mode even with "set
2293 non-stop off", in which case user_visible_resume_ptid could
2294 return a wildcard ptid. */
2295 if (target_is_non_stop_p ())
2296 return inferior_ptid;
2298 return user_visible_resume_ptid (user_step);
2301 /* Wrapper for target_resume, that handles infrun-specific
2305 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2307 struct thread_info *tp = inferior_thread ();
2309 gdb_assert (!tp->stop_requested);
2311 /* Install inferior's terminal modes. */
2312 target_terminal::inferior ();
2314 /* Avoid confusing the next resume, if the next stop/resume
2315 happens to apply to another thread. */
2316 tp->suspend.stop_signal = GDB_SIGNAL_0;
2318 /* Advise target which signals may be handled silently.
2320 If we have removed breakpoints because we are stepping over one
2321 in-line (in any thread), we need to receive all signals to avoid
2322 accidentally skipping a breakpoint during execution of a signal
2325 Likewise if we're displaced stepping, otherwise a trap for a
2326 breakpoint in a signal handler might be confused with the
2327 displaced step finishing. We don't make the displaced_step_fixup
2328 step distinguish the cases instead, because:
2330 - a backtrace while stopped in the signal handler would show the
2331 scratch pad as frame older than the signal handler, instead of
2332 the real mainline code.
2334 - when the thread is later resumed, the signal handler would
2335 return to the scratch pad area, which would no longer be
2337 if (step_over_info_valid_p ()
2338 || displaced_step_in_progress (tp->inf))
2339 target_pass_signals (0, NULL);
2341 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2343 target_resume (resume_ptid, step, sig);
2345 target_commit_resume ();
2348 /* Resume the inferior. SIG is the signal to give the inferior
2349 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2350 call 'resume', which handles exceptions. */
2353 resume_1 (enum gdb_signal sig)
2355 struct regcache *regcache = get_current_regcache ();
2356 struct gdbarch *gdbarch = regcache->arch ();
2357 struct thread_info *tp = inferior_thread ();
2358 CORE_ADDR pc = regcache_read_pc (regcache);
2359 const address_space *aspace = regcache->aspace ();
2361 /* This represents the user's step vs continue request. When
2362 deciding whether "set scheduler-locking step" applies, it's the
2363 user's intention that counts. */
2364 const int user_step = tp->control.stepping_command;
2365 /* This represents what we'll actually request the target to do.
2366 This can decay from a step to a continue, if e.g., we need to
2367 implement single-stepping with breakpoints (software
2371 gdb_assert (!tp->stop_requested);
2372 gdb_assert (!thread_is_in_step_over_chain (tp));
2374 if (tp->suspend.waitstatus_pending_p)
2379 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2381 fprintf_unfiltered (gdb_stdlog,
2382 "infrun: resume: thread %s has pending wait "
2383 "status %s (currently_stepping=%d).\n",
2384 target_pid_to_str (tp->ptid), statstr.c_str (),
2385 currently_stepping (tp));
2390 /* FIXME: What should we do if we are supposed to resume this
2391 thread with a signal? Maybe we should maintain a queue of
2392 pending signals to deliver. */
2393 if (sig != GDB_SIGNAL_0)
2395 warning (_("Couldn't deliver signal %s to %s."),
2396 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2399 tp->suspend.stop_signal = GDB_SIGNAL_0;
2401 if (target_can_async_p ())
2404 /* Tell the event loop we have an event to process. */
2405 mark_async_event_handler (infrun_async_inferior_event_token);
2410 tp->stepped_breakpoint = 0;
2412 /* Depends on stepped_breakpoint. */
2413 step = currently_stepping (tp);
2415 if (current_inferior ()->waiting_for_vfork_done)
2417 /* Don't try to single-step a vfork parent that is waiting for
2418 the child to get out of the shared memory region (by exec'ing
2419 or exiting). This is particularly important on software
2420 single-step archs, as the child process would trip on the
2421 software single step breakpoint inserted for the parent
2422 process. Since the parent will not actually execute any
2423 instruction until the child is out of the shared region (such
2424 are vfork's semantics), it is safe to simply continue it.
2425 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2426 the parent, and tell it to `keep_going', which automatically
2427 re-sets it stepping. */
2429 fprintf_unfiltered (gdb_stdlog,
2430 "infrun: resume : clear step\n");
2435 fprintf_unfiltered (gdb_stdlog,
2436 "infrun: resume (step=%d, signal=%s), "
2437 "trap_expected=%d, current thread [%s] at %s\n",
2438 step, gdb_signal_to_symbol_string (sig),
2439 tp->control.trap_expected,
2440 target_pid_to_str (inferior_ptid),
2441 paddress (gdbarch, pc));
2443 /* Normally, by the time we reach `resume', the breakpoints are either
2444 removed or inserted, as appropriate. The exception is if we're sitting
2445 at a permanent breakpoint; we need to step over it, but permanent
2446 breakpoints can't be removed. So we have to test for it here. */
2447 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2449 if (sig != GDB_SIGNAL_0)
2451 /* We have a signal to pass to the inferior. The resume
2452 may, or may not take us to the signal handler. If this
2453 is a step, we'll need to stop in the signal handler, if
2454 there's one, (if the target supports stepping into
2455 handlers), or in the next mainline instruction, if
2456 there's no handler. If this is a continue, we need to be
2457 sure to run the handler with all breakpoints inserted.
2458 In all cases, set a breakpoint at the current address
2459 (where the handler returns to), and once that breakpoint
2460 is hit, resume skipping the permanent breakpoint. If
2461 that breakpoint isn't hit, then we've stepped into the
2462 signal handler (or hit some other event). We'll delete
2463 the step-resume breakpoint then. */
2466 fprintf_unfiltered (gdb_stdlog,
2467 "infrun: resume: skipping permanent breakpoint, "
2468 "deliver signal first\n");
2470 clear_step_over_info ();
2471 tp->control.trap_expected = 0;
2473 if (tp->control.step_resume_breakpoint == NULL)
2475 /* Set a "high-priority" step-resume, as we don't want
2476 user breakpoints at PC to trigger (again) when this
2478 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2479 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2481 tp->step_after_step_resume_breakpoint = step;
2484 insert_breakpoints ();
2488 /* There's no signal to pass, we can go ahead and skip the
2489 permanent breakpoint manually. */
2491 fprintf_unfiltered (gdb_stdlog,
2492 "infrun: resume: skipping permanent breakpoint\n");
2493 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2494 /* Update pc to reflect the new address from which we will
2495 execute instructions. */
2496 pc = regcache_read_pc (regcache);
2500 /* We've already advanced the PC, so the stepping part
2501 is done. Now we need to arrange for a trap to be
2502 reported to handle_inferior_event. Set a breakpoint
2503 at the current PC, and run to it. Don't update
2504 prev_pc, because if we end in
2505 switch_back_to_stepped_thread, we want the "expected
2506 thread advanced also" branch to be taken. IOW, we
2507 don't want this thread to step further from PC
2509 gdb_assert (!step_over_info_valid_p ());
2510 insert_single_step_breakpoint (gdbarch, aspace, pc);
2511 insert_breakpoints ();
2513 resume_ptid = internal_resume_ptid (user_step);
2514 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2521 /* If we have a breakpoint to step over, make sure to do a single
2522 step only. Same if we have software watchpoints. */
2523 if (tp->control.trap_expected || bpstat_should_step ())
2524 tp->control.may_range_step = 0;
2526 /* If enabled, step over breakpoints by executing a copy of the
2527 instruction at a different address.
2529 We can't use displaced stepping when we have a signal to deliver;
2530 the comments for displaced_step_prepare explain why. The
2531 comments in the handle_inferior event for dealing with 'random
2532 signals' explain what we do instead.
2534 We can't use displaced stepping when we are waiting for vfork_done
2535 event, displaced stepping breaks the vfork child similarly as single
2536 step software breakpoint. */
2537 if (tp->control.trap_expected
2538 && use_displaced_stepping (tp)
2539 && !step_over_info_valid_p ()
2540 && sig == GDB_SIGNAL_0
2541 && !current_inferior ()->waiting_for_vfork_done)
2543 int prepared = displaced_step_prepare (tp);
2548 fprintf_unfiltered (gdb_stdlog,
2549 "Got placed in step-over queue\n");
2551 tp->control.trap_expected = 0;
2554 else if (prepared < 0)
2556 /* Fallback to stepping over the breakpoint in-line. */
2558 if (target_is_non_stop_p ())
2559 stop_all_threads ();
2561 set_step_over_info (regcache->aspace (),
2562 regcache_read_pc (regcache), 0, tp->global_num);
2564 step = maybe_software_singlestep (gdbarch, pc);
2566 insert_breakpoints ();
2568 else if (prepared > 0)
2570 struct displaced_step_inferior_state *displaced;
2572 /* Update pc to reflect the new address from which we will
2573 execute instructions due to displaced stepping. */
2574 pc = regcache_read_pc (get_thread_regcache (tp));
2576 displaced = get_displaced_stepping_state (tp->inf);
2577 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2578 displaced->step_closure);
2582 /* Do we need to do it the hard way, w/temp breakpoints? */
2584 step = maybe_software_singlestep (gdbarch, pc);
2586 /* Currently, our software single-step implementation leads to different
2587 results than hardware single-stepping in one situation: when stepping
2588 into delivering a signal which has an associated signal handler,
2589 hardware single-step will stop at the first instruction of the handler,
2590 while software single-step will simply skip execution of the handler.
2592 For now, this difference in behavior is accepted since there is no
2593 easy way to actually implement single-stepping into a signal handler
2594 without kernel support.
2596 However, there is one scenario where this difference leads to follow-on
2597 problems: if we're stepping off a breakpoint by removing all breakpoints
2598 and then single-stepping. In this case, the software single-step
2599 behavior means that even if there is a *breakpoint* in the signal
2600 handler, GDB still would not stop.
2602 Fortunately, we can at least fix this particular issue. We detect
2603 here the case where we are about to deliver a signal while software
2604 single-stepping with breakpoints removed. In this situation, we
2605 revert the decisions to remove all breakpoints and insert single-
2606 step breakpoints, and instead we install a step-resume breakpoint
2607 at the current address, deliver the signal without stepping, and
2608 once we arrive back at the step-resume breakpoint, actually step
2609 over the breakpoint we originally wanted to step over. */
2610 if (thread_has_single_step_breakpoints_set (tp)
2611 && sig != GDB_SIGNAL_0
2612 && step_over_info_valid_p ())
2614 /* If we have nested signals or a pending signal is delivered
2615 immediately after a handler returns, might might already have
2616 a step-resume breakpoint set on the earlier handler. We cannot
2617 set another step-resume breakpoint; just continue on until the
2618 original breakpoint is hit. */
2619 if (tp->control.step_resume_breakpoint == NULL)
2621 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2622 tp->step_after_step_resume_breakpoint = 1;
2625 delete_single_step_breakpoints (tp);
2627 clear_step_over_info ();
2628 tp->control.trap_expected = 0;
2630 insert_breakpoints ();
2633 /* If STEP is set, it's a request to use hardware stepping
2634 facilities. But in that case, we should never
2635 use singlestep breakpoint. */
2636 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2638 /* Decide the set of threads to ask the target to resume. */
2639 if (tp->control.trap_expected)
2641 /* We're allowing a thread to run past a breakpoint it has
2642 hit, either by single-stepping the thread with the breakpoint
2643 removed, or by displaced stepping, with the breakpoint inserted.
2644 In the former case, we need to single-step only this thread,
2645 and keep others stopped, as they can miss this breakpoint if
2646 allowed to run. That's not really a problem for displaced
2647 stepping, but, we still keep other threads stopped, in case
2648 another thread is also stopped for a breakpoint waiting for
2649 its turn in the displaced stepping queue. */
2650 resume_ptid = inferior_ptid;
2653 resume_ptid = internal_resume_ptid (user_step);
2655 if (execution_direction != EXEC_REVERSE
2656 && step && breakpoint_inserted_here_p (aspace, pc))
2658 /* There are two cases where we currently need to step a
2659 breakpoint instruction when we have a signal to deliver:
2661 - See handle_signal_stop where we handle random signals that
2662 could take out us out of the stepping range. Normally, in
2663 that case we end up continuing (instead of stepping) over the
2664 signal handler with a breakpoint at PC, but there are cases
2665 where we should _always_ single-step, even if we have a
2666 step-resume breakpoint, like when a software watchpoint is
2667 set. Assuming single-stepping and delivering a signal at the
2668 same time would takes us to the signal handler, then we could
2669 have removed the breakpoint at PC to step over it. However,
2670 some hardware step targets (like e.g., Mac OS) can't step
2671 into signal handlers, and for those, we need to leave the
2672 breakpoint at PC inserted, as otherwise if the handler
2673 recurses and executes PC again, it'll miss the breakpoint.
2674 So we leave the breakpoint inserted anyway, but we need to
2675 record that we tried to step a breakpoint instruction, so
2676 that adjust_pc_after_break doesn't end up confused.
2678 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2679 in one thread after another thread that was stepping had been
2680 momentarily paused for a step-over. When we re-resume the
2681 stepping thread, it may be resumed from that address with a
2682 breakpoint that hasn't trapped yet. Seen with
2683 gdb.threads/non-stop-fair-events.exp, on targets that don't
2684 do displaced stepping. */
2687 fprintf_unfiltered (gdb_stdlog,
2688 "infrun: resume: [%s] stepped breakpoint\n",
2689 target_pid_to_str (tp->ptid));
2691 tp->stepped_breakpoint = 1;
2693 /* Most targets can step a breakpoint instruction, thus
2694 executing it normally. But if this one cannot, just
2695 continue and we will hit it anyway. */
2696 if (gdbarch_cannot_step_breakpoint (gdbarch))
2701 && tp->control.trap_expected
2702 && use_displaced_stepping (tp)
2703 && !step_over_info_valid_p ())
2705 struct regcache *resume_regcache = get_thread_regcache (tp);
2706 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2707 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2710 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2711 paddress (resume_gdbarch, actual_pc));
2712 read_memory (actual_pc, buf, sizeof (buf));
2713 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2716 if (tp->control.may_range_step)
2718 /* If we're resuming a thread with the PC out of the step
2719 range, then we're doing some nested/finer run control
2720 operation, like stepping the thread out of the dynamic
2721 linker or the displaced stepping scratch pad. We
2722 shouldn't have allowed a range step then. */
2723 gdb_assert (pc_in_thread_step_range (pc, tp));
2726 do_target_resume (resume_ptid, step, sig);
2730 /* Resume the inferior. SIG is the signal to give the inferior
2731 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2732 rolls back state on error. */
2735 resume (gdb_signal sig)
2741 CATCH (ex, RETURN_MASK_ALL)
2743 /* If resuming is being aborted for any reason, delete any
2744 single-step breakpoint resume_1 may have created, to avoid
2745 confusing the following resumption, and to avoid leaving
2746 single-step breakpoints perturbing other threads, in case
2747 we're running in non-stop mode. */
2748 if (inferior_ptid != null_ptid)
2749 delete_single_step_breakpoints (inferior_thread ());
2750 throw_exception (ex);
2760 /* Counter that tracks number of user visible stops. This can be used
2761 to tell whether a command has proceeded the inferior past the
2762 current location. This allows e.g., inferior function calls in
2763 breakpoint commands to not interrupt the command list. When the
2764 call finishes successfully, the inferior is standing at the same
2765 breakpoint as if nothing happened (and so we don't call
2767 static ULONGEST current_stop_id;
2774 return current_stop_id;
2777 /* Called when we report a user visible stop. */
2785 /* Clear out all variables saying what to do when inferior is continued.
2786 First do this, then set the ones you want, then call `proceed'. */
2789 clear_proceed_status_thread (struct thread_info *tp)
2792 fprintf_unfiltered (gdb_stdlog,
2793 "infrun: clear_proceed_status_thread (%s)\n",
2794 target_pid_to_str (tp->ptid));
2796 /* If we're starting a new sequence, then the previous finished
2797 single-step is no longer relevant. */
2798 if (tp->suspend.waitstatus_pending_p)
2800 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2803 fprintf_unfiltered (gdb_stdlog,
2804 "infrun: clear_proceed_status: pending "
2805 "event of %s was a finished step. "
2807 target_pid_to_str (tp->ptid));
2809 tp->suspend.waitstatus_pending_p = 0;
2810 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2812 else if (debug_infrun)
2815 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2817 fprintf_unfiltered (gdb_stdlog,
2818 "infrun: clear_proceed_status_thread: thread %s "
2819 "has pending wait status %s "
2820 "(currently_stepping=%d).\n",
2821 target_pid_to_str (tp->ptid), statstr.c_str (),
2822 currently_stepping (tp));
2826 /* If this signal should not be seen by program, give it zero.
2827 Used for debugging signals. */
2828 if (!signal_pass_state (tp->suspend.stop_signal))
2829 tp->suspend.stop_signal = GDB_SIGNAL_0;
2831 thread_fsm_delete (tp->thread_fsm);
2832 tp->thread_fsm = NULL;
2834 tp->control.trap_expected = 0;
2835 tp->control.step_range_start = 0;
2836 tp->control.step_range_end = 0;
2837 tp->control.may_range_step = 0;
2838 tp->control.step_frame_id = null_frame_id;
2839 tp->control.step_stack_frame_id = null_frame_id;
2840 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2841 tp->control.step_start_function = NULL;
2842 tp->stop_requested = 0;
2844 tp->control.stop_step = 0;
2846 tp->control.proceed_to_finish = 0;
2848 tp->control.stepping_command = 0;
2850 /* Discard any remaining commands or status from previous stop. */
2851 bpstat_clear (&tp->control.stop_bpstat);
2855 clear_proceed_status (int step)
2857 /* With scheduler-locking replay, stop replaying other threads if we're
2858 not replaying the user-visible resume ptid.
2860 This is a convenience feature to not require the user to explicitly
2861 stop replaying the other threads. We're assuming that the user's
2862 intent is to resume tracing the recorded process. */
2863 if (!non_stop && scheduler_mode == schedlock_replay
2864 && target_record_is_replaying (minus_one_ptid)
2865 && !target_record_will_replay (user_visible_resume_ptid (step),
2866 execution_direction))
2867 target_record_stop_replaying ();
2871 struct thread_info *tp;
2874 resume_ptid = user_visible_resume_ptid (step);
2876 /* In all-stop mode, delete the per-thread status of all threads
2877 we're about to resume, implicitly and explicitly. */
2878 ALL_NON_EXITED_THREADS (tp)
2880 if (!ptid_match (tp->ptid, resume_ptid))
2882 clear_proceed_status_thread (tp);
2886 if (!ptid_equal (inferior_ptid, null_ptid))
2888 struct inferior *inferior;
2892 /* If in non-stop mode, only delete the per-thread status of
2893 the current thread. */
2894 clear_proceed_status_thread (inferior_thread ());
2897 inferior = current_inferior ();
2898 inferior->control.stop_soon = NO_STOP_QUIETLY;
2901 gdb::observers::about_to_proceed.notify ();
2904 /* Returns true if TP is still stopped at a breakpoint that needs
2905 stepping-over in order to make progress. If the breakpoint is gone
2906 meanwhile, we can skip the whole step-over dance. */
2909 thread_still_needs_step_over_bp (struct thread_info *tp)
2911 if (tp->stepping_over_breakpoint)
2913 struct regcache *regcache = get_thread_regcache (tp);
2915 if (breakpoint_here_p (regcache->aspace (),
2916 regcache_read_pc (regcache))
2917 == ordinary_breakpoint_here)
2920 tp->stepping_over_breakpoint = 0;
2926 /* Check whether thread TP still needs to start a step-over in order
2927 to make progress when resumed. Returns an bitwise or of enum
2928 step_over_what bits, indicating what needs to be stepped over. */
2930 static step_over_what
2931 thread_still_needs_step_over (struct thread_info *tp)
2933 step_over_what what = 0;
2935 if (thread_still_needs_step_over_bp (tp))
2936 what |= STEP_OVER_BREAKPOINT;
2938 if (tp->stepping_over_watchpoint
2939 && !target_have_steppable_watchpoint)
2940 what |= STEP_OVER_WATCHPOINT;
2945 /* Returns true if scheduler locking applies. STEP indicates whether
2946 we're about to do a step/next-like command to a thread. */
2949 schedlock_applies (struct thread_info *tp)
2951 return (scheduler_mode == schedlock_on
2952 || (scheduler_mode == schedlock_step
2953 && tp->control.stepping_command)
2954 || (scheduler_mode == schedlock_replay
2955 && target_record_will_replay (minus_one_ptid,
2956 execution_direction)));
2959 /* Basic routine for continuing the program in various fashions.
2961 ADDR is the address to resume at, or -1 for resume where stopped.
2962 SIGGNAL is the signal to give it, or 0 for none,
2963 or -1 for act according to how it stopped.
2964 STEP is nonzero if should trap after one instruction.
2965 -1 means return after that and print nothing.
2966 You should probably set various step_... variables
2967 before calling here, if you are stepping.
2969 You should call clear_proceed_status before calling proceed. */
2972 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2974 struct regcache *regcache;
2975 struct gdbarch *gdbarch;
2976 struct thread_info *tp;
2979 struct execution_control_state ecss;
2980 struct execution_control_state *ecs = &ecss;
2983 /* If we're stopped at a fork/vfork, follow the branch set by the
2984 "set follow-fork-mode" command; otherwise, we'll just proceed
2985 resuming the current thread. */
2986 if (!follow_fork ())
2988 /* The target for some reason decided not to resume. */
2990 if (target_can_async_p ())
2991 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2995 /* We'll update this if & when we switch to a new thread. */
2996 previous_inferior_ptid = inferior_ptid;
2998 regcache = get_current_regcache ();
2999 gdbarch = regcache->arch ();
3000 const address_space *aspace = regcache->aspace ();
3002 pc = regcache_read_pc (regcache);
3003 tp = inferior_thread ();
3005 /* Fill in with reasonable starting values. */
3006 init_thread_stepping_state (tp);
3008 gdb_assert (!thread_is_in_step_over_chain (tp));
3010 if (addr == (CORE_ADDR) -1)
3012 if (pc == tp->suspend.stop_pc
3013 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3014 && execution_direction != EXEC_REVERSE)
3015 /* There is a breakpoint at the address we will resume at,
3016 step one instruction before inserting breakpoints so that
3017 we do not stop right away (and report a second hit at this
3020 Note, we don't do this in reverse, because we won't
3021 actually be executing the breakpoint insn anyway.
3022 We'll be (un-)executing the previous instruction. */
3023 tp->stepping_over_breakpoint = 1;
3024 else if (gdbarch_single_step_through_delay_p (gdbarch)
3025 && gdbarch_single_step_through_delay (gdbarch,
3026 get_current_frame ()))
3027 /* We stepped onto an instruction that needs to be stepped
3028 again before re-inserting the breakpoint, do so. */
3029 tp->stepping_over_breakpoint = 1;
3033 regcache_write_pc (regcache, addr);
3036 if (siggnal != GDB_SIGNAL_DEFAULT)
3037 tp->suspend.stop_signal = siggnal;
3039 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3041 /* If an exception is thrown from this point on, make sure to
3042 propagate GDB's knowledge of the executing state to the
3043 frontend/user running state. */
3044 scoped_finish_thread_state finish_state (resume_ptid);
3046 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3047 threads (e.g., we might need to set threads stepping over
3048 breakpoints first), from the user/frontend's point of view, all
3049 threads in RESUME_PTID are now running. Unless we're calling an
3050 inferior function, as in that case we pretend the inferior
3051 doesn't run at all. */
3052 if (!tp->control.in_infcall)
3053 set_running (resume_ptid, 1);
3056 fprintf_unfiltered (gdb_stdlog,
3057 "infrun: proceed (addr=%s, signal=%s)\n",
3058 paddress (gdbarch, addr),
3059 gdb_signal_to_symbol_string (siggnal));
3061 annotate_starting ();
3063 /* Make sure that output from GDB appears before output from the
3065 gdb_flush (gdb_stdout);
3067 /* Since we've marked the inferior running, give it the terminal. A
3068 QUIT/Ctrl-C from here on is forwarded to the target (which can
3069 still detect attempts to unblock a stuck connection with repeated
3070 Ctrl-C from within target_pass_ctrlc). */
3071 target_terminal::inferior ();
3073 /* In a multi-threaded task we may select another thread and
3074 then continue or step.
3076 But if a thread that we're resuming had stopped at a breakpoint,
3077 it will immediately cause another breakpoint stop without any
3078 execution (i.e. it will report a breakpoint hit incorrectly). So
3079 we must step over it first.
3081 Look for threads other than the current (TP) that reported a
3082 breakpoint hit and haven't been resumed yet since. */
3084 /* If scheduler locking applies, we can avoid iterating over all
3086 if (!non_stop && !schedlock_applies (tp))
3088 struct thread_info *current = tp;
3090 ALL_NON_EXITED_THREADS (tp)
3092 /* Ignore the current thread here. It's handled
3097 /* Ignore threads of processes we're not resuming. */
3098 if (!ptid_match (tp->ptid, resume_ptid))
3101 if (!thread_still_needs_step_over (tp))
3104 gdb_assert (!thread_is_in_step_over_chain (tp));
3107 fprintf_unfiltered (gdb_stdlog,
3108 "infrun: need to step-over [%s] first\n",
3109 target_pid_to_str (tp->ptid));
3111 thread_step_over_chain_enqueue (tp);
3117 /* Enqueue the current thread last, so that we move all other
3118 threads over their breakpoints first. */
3119 if (tp->stepping_over_breakpoint)
3120 thread_step_over_chain_enqueue (tp);
3122 /* If the thread isn't started, we'll still need to set its prev_pc,
3123 so that switch_back_to_stepped_thread knows the thread hasn't
3124 advanced. Must do this before resuming any thread, as in
3125 all-stop/remote, once we resume we can't send any other packet
3126 until the target stops again. */
3127 tp->prev_pc = regcache_read_pc (regcache);
3130 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3132 started = start_step_over ();
3134 if (step_over_info_valid_p ())
3136 /* Either this thread started a new in-line step over, or some
3137 other thread was already doing one. In either case, don't
3138 resume anything else until the step-over is finished. */
3140 else if (started && !target_is_non_stop_p ())
3142 /* A new displaced stepping sequence was started. In all-stop,
3143 we can't talk to the target anymore until it next stops. */
3145 else if (!non_stop && target_is_non_stop_p ())
3147 /* In all-stop, but the target is always in non-stop mode.
3148 Start all other threads that are implicitly resumed too. */
3149 ALL_NON_EXITED_THREADS (tp)
3151 /* Ignore threads of processes we're not resuming. */
3152 if (!ptid_match (tp->ptid, resume_ptid))
3158 fprintf_unfiltered (gdb_stdlog,
3159 "infrun: proceed: [%s] resumed\n",
3160 target_pid_to_str (tp->ptid));
3161 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3165 if (thread_is_in_step_over_chain (tp))
3168 fprintf_unfiltered (gdb_stdlog,
3169 "infrun: proceed: [%s] needs step-over\n",
3170 target_pid_to_str (tp->ptid));
3175 fprintf_unfiltered (gdb_stdlog,
3176 "infrun: proceed: resuming %s\n",
3177 target_pid_to_str (tp->ptid));
3179 reset_ecs (ecs, tp);
3180 switch_to_thread (tp);
3181 keep_going_pass_signal (ecs);
3182 if (!ecs->wait_some_more)
3183 error (_("Command aborted."));
3186 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3188 /* The thread wasn't started, and isn't queued, run it now. */
3189 reset_ecs (ecs, tp);
3190 switch_to_thread (tp);
3191 keep_going_pass_signal (ecs);
3192 if (!ecs->wait_some_more)
3193 error (_("Command aborted."));
3197 target_commit_resume ();
3199 finish_state.release ();
3201 /* Tell the event loop to wait for it to stop. If the target
3202 supports asynchronous execution, it'll do this from within
3204 if (!target_can_async_p ())
3205 mark_async_event_handler (infrun_async_inferior_event_token);
3209 /* Start remote-debugging of a machine over a serial link. */
3212 start_remote (int from_tty)
3214 struct inferior *inferior;
3216 inferior = current_inferior ();
3217 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3219 /* Always go on waiting for the target, regardless of the mode. */
3220 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3221 indicate to wait_for_inferior that a target should timeout if
3222 nothing is returned (instead of just blocking). Because of this,
3223 targets expecting an immediate response need to, internally, set
3224 things up so that the target_wait() is forced to eventually
3226 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3227 differentiate to its caller what the state of the target is after
3228 the initial open has been performed. Here we're assuming that
3229 the target has stopped. It should be possible to eventually have
3230 target_open() return to the caller an indication that the target
3231 is currently running and GDB state should be set to the same as
3232 for an async run. */
3233 wait_for_inferior ();
3235 /* Now that the inferior has stopped, do any bookkeeping like
3236 loading shared libraries. We want to do this before normal_stop,
3237 so that the displayed frame is up to date. */
3238 post_create_inferior (current_top_target (), from_tty);
3243 /* Initialize static vars when a new inferior begins. */
3246 init_wait_for_inferior (void)
3248 /* These are meaningless until the first time through wait_for_inferior. */
3250 breakpoint_init_inferior (inf_starting);
3252 clear_proceed_status (0);
3254 target_last_wait_ptid = minus_one_ptid;
3256 previous_inferior_ptid = inferior_ptid;
3258 /* Discard any skipped inlined frames. */
3259 clear_inline_frame_state (minus_one_ptid);
3264 static void handle_inferior_event (struct execution_control_state *ecs);
3266 static void handle_step_into_function (struct gdbarch *gdbarch,
3267 struct execution_control_state *ecs);
3268 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3269 struct execution_control_state *ecs);
3270 static void handle_signal_stop (struct execution_control_state *ecs);
3271 static void check_exception_resume (struct execution_control_state *,
3272 struct frame_info *);
3274 static void end_stepping_range (struct execution_control_state *ecs);
3275 static void stop_waiting (struct execution_control_state *ecs);
3276 static void keep_going (struct execution_control_state *ecs);
3277 static void process_event_stop_test (struct execution_control_state *ecs);
3278 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3280 /* This function is attached as a "thread_stop_requested" observer.
3281 Cleanup local state that assumed the PTID was to be resumed, and
3282 report the stop to the frontend. */
3285 infrun_thread_stop_requested (ptid_t ptid)
3287 struct thread_info *tp;
3289 /* PTID was requested to stop. If the thread was already stopped,
3290 but the user/frontend doesn't know about that yet (e.g., the
3291 thread had been temporarily paused for some step-over), set up
3292 for reporting the stop now. */
3293 ALL_NON_EXITED_THREADS (tp)
3294 if (ptid_match (tp->ptid, ptid))
3296 if (tp->state != THREAD_RUNNING)
3301 /* Remove matching threads from the step-over queue, so
3302 start_step_over doesn't try to resume them
3304 if (thread_is_in_step_over_chain (tp))
3305 thread_step_over_chain_remove (tp);
3307 /* If the thread is stopped, but the user/frontend doesn't
3308 know about that yet, queue a pending event, as if the
3309 thread had just stopped now. Unless the thread already had
3311 if (!tp->suspend.waitstatus_pending_p)
3313 tp->suspend.waitstatus_pending_p = 1;
3314 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3315 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3318 /* Clear the inline-frame state, since we're re-processing the
3320 clear_inline_frame_state (tp->ptid);
3322 /* If this thread was paused because some other thread was
3323 doing an inline-step over, let that finish first. Once
3324 that happens, we'll restart all threads and consume pending
3325 stop events then. */
3326 if (step_over_info_valid_p ())
3329 /* Otherwise we can process the (new) pending event now. Set
3330 it so this pending event is considered by
3337 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3339 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3340 nullify_last_target_wait_ptid ();
3343 /* Delete the step resume, single-step and longjmp/exception resume
3344 breakpoints of TP. */
3347 delete_thread_infrun_breakpoints (struct thread_info *tp)
3349 delete_step_resume_breakpoint (tp);
3350 delete_exception_resume_breakpoint (tp);
3351 delete_single_step_breakpoints (tp);
3354 /* If the target still has execution, call FUNC for each thread that
3355 just stopped. In all-stop, that's all the non-exited threads; in
3356 non-stop, that's the current thread, only. */
3358 typedef void (*for_each_just_stopped_thread_callback_func)
3359 (struct thread_info *tp);
3362 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3364 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3367 if (target_is_non_stop_p ())
3369 /* If in non-stop mode, only the current thread stopped. */
3370 func (inferior_thread ());
3374 struct thread_info *tp;
3376 /* In all-stop mode, all threads have stopped. */
3377 ALL_NON_EXITED_THREADS (tp)
3384 /* Delete the step resume and longjmp/exception resume breakpoints of
3385 the threads that just stopped. */
3388 delete_just_stopped_threads_infrun_breakpoints (void)
3390 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3393 /* Delete the single-step breakpoints of the threads that just
3397 delete_just_stopped_threads_single_step_breakpoints (void)
3399 for_each_just_stopped_thread (delete_single_step_breakpoints);
3402 /* A cleanup wrapper. */
3405 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3407 delete_just_stopped_threads_infrun_breakpoints ();
3413 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3414 const struct target_waitstatus *ws)
3416 std::string status_string = target_waitstatus_to_string (ws);
3419 /* The text is split over several lines because it was getting too long.
3420 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3421 output as a unit; we want only one timestamp printed if debug_timestamp
3424 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3425 ptid_get_pid (waiton_ptid),
3426 ptid_get_lwp (waiton_ptid),
3427 ptid_get_tid (waiton_ptid));
3428 if (ptid_get_pid (waiton_ptid) != -1)
3429 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3430 stb.printf (", status) =\n");
3431 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3432 ptid_get_pid (result_ptid),
3433 ptid_get_lwp (result_ptid),
3434 ptid_get_tid (result_ptid),
3435 target_pid_to_str (result_ptid));
3436 stb.printf ("infrun: %s\n", status_string.c_str ());
3438 /* This uses %s in part to handle %'s in the text, but also to avoid
3439 a gcc error: the format attribute requires a string literal. */
3440 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3443 /* Select a thread at random, out of those which are resumed and have
3446 static struct thread_info *
3447 random_pending_event_thread (ptid_t waiton_ptid)
3449 struct thread_info *event_tp;
3451 int random_selector;
3453 /* First see how many events we have. Count only resumed threads
3454 that have an event pending. */
3455 ALL_NON_EXITED_THREADS (event_tp)
3456 if (ptid_match (event_tp->ptid, waiton_ptid)
3457 && event_tp->resumed
3458 && event_tp->suspend.waitstatus_pending_p)
3461 if (num_events == 0)
3464 /* Now randomly pick a thread out of those that have had events. */
3465 random_selector = (int)
3466 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3468 if (debug_infrun && num_events > 1)
3469 fprintf_unfiltered (gdb_stdlog,
3470 "infrun: Found %d events, selecting #%d\n",
3471 num_events, random_selector);
3473 /* Select the Nth thread that has had an event. */
3474 ALL_NON_EXITED_THREADS (event_tp)
3475 if (ptid_match (event_tp->ptid, waiton_ptid)
3476 && event_tp->resumed
3477 && event_tp->suspend.waitstatus_pending_p)
3478 if (random_selector-- == 0)
3484 /* Wrapper for target_wait that first checks whether threads have
3485 pending statuses to report before actually asking the target for
3489 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3492 struct thread_info *tp;
3494 /* First check if there is a resumed thread with a wait status
3496 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3498 tp = random_pending_event_thread (ptid);
3503 fprintf_unfiltered (gdb_stdlog,
3504 "infrun: Waiting for specific thread %s.\n",
3505 target_pid_to_str (ptid));
3507 /* We have a specific thread to check. */
3508 tp = find_thread_ptid (ptid);
3509 gdb_assert (tp != NULL);
3510 if (!tp->suspend.waitstatus_pending_p)
3515 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3516 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3518 struct regcache *regcache = get_thread_regcache (tp);
3519 struct gdbarch *gdbarch = regcache->arch ();
3523 pc = regcache_read_pc (regcache);
3525 if (pc != tp->suspend.stop_pc)
3528 fprintf_unfiltered (gdb_stdlog,
3529 "infrun: PC of %s changed. was=%s, now=%s\n",
3530 target_pid_to_str (tp->ptid),
3531 paddress (gdbarch, tp->suspend.stop_pc),
3532 paddress (gdbarch, pc));
3535 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3538 fprintf_unfiltered (gdb_stdlog,
3539 "infrun: previous breakpoint of %s, at %s gone\n",
3540 target_pid_to_str (tp->ptid),
3541 paddress (gdbarch, pc));
3549 fprintf_unfiltered (gdb_stdlog,
3550 "infrun: pending event of %s cancelled.\n",
3551 target_pid_to_str (tp->ptid));
3553 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3554 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3563 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3565 fprintf_unfiltered (gdb_stdlog,
3566 "infrun: Using pending wait status %s for %s.\n",
3568 target_pid_to_str (tp->ptid));
3571 /* Now that we've selected our final event LWP, un-adjust its PC
3572 if it was a software breakpoint (and the target doesn't
3573 always adjust the PC itself). */
3574 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3575 && !target_supports_stopped_by_sw_breakpoint ())
3577 struct regcache *regcache;
3578 struct gdbarch *gdbarch;
3581 regcache = get_thread_regcache (tp);
3582 gdbarch = regcache->arch ();
3584 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3589 pc = regcache_read_pc (regcache);
3590 regcache_write_pc (regcache, pc + decr_pc);
3594 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3595 *status = tp->suspend.waitstatus;
3596 tp->suspend.waitstatus_pending_p = 0;
3598 /* Wake up the event loop again, until all pending events are
3600 if (target_is_async_p ())
3601 mark_async_event_handler (infrun_async_inferior_event_token);
3605 /* But if we don't find one, we'll have to wait. */
3607 if (deprecated_target_wait_hook)
3608 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3610 event_ptid = target_wait (ptid, status, options);
3615 /* Prepare and stabilize the inferior for detaching it. E.g.,
3616 detaching while a thread is displaced stepping is a recipe for
3617 crashing it, as nothing would readjust the PC out of the scratch
3621 prepare_for_detach (void)
3623 struct inferior *inf = current_inferior ();
3624 ptid_t pid_ptid = ptid_t (inf->pid);
3626 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3628 /* Is any thread of this process displaced stepping? If not,
3629 there's nothing else to do. */
3630 if (displaced == NULL || displaced->step_thread == nullptr)
3634 fprintf_unfiltered (gdb_stdlog,
3635 "displaced-stepping in-process while detaching");
3637 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3639 while (displaced->step_thread != nullptr)
3641 struct execution_control_state ecss;
3642 struct execution_control_state *ecs;
3645 memset (ecs, 0, sizeof (*ecs));
3647 overlay_cache_invalid = 1;
3648 /* Flush target cache before starting to handle each event.
3649 Target was running and cache could be stale. This is just a
3650 heuristic. Running threads may modify target memory, but we
3651 don't get any event. */
3652 target_dcache_invalidate ();
3654 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3657 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3659 /* If an error happens while handling the event, propagate GDB's
3660 knowledge of the executing state to the frontend/user running
3662 scoped_finish_thread_state finish_state (minus_one_ptid);
3664 /* Now figure out what to do with the result of the result. */
3665 handle_inferior_event (ecs);
3667 /* No error, don't finish the state yet. */
3668 finish_state.release ();
3670 /* Breakpoints and watchpoints are not installed on the target
3671 at this point, and signals are passed directly to the
3672 inferior, so this must mean the process is gone. */
3673 if (!ecs->wait_some_more)
3675 restore_detaching.release ();
3676 error (_("Program exited while detaching"));
3680 restore_detaching.release ();
3683 /* Wait for control to return from inferior to debugger.
3685 If inferior gets a signal, we may decide to start it up again
3686 instead of returning. That is why there is a loop in this function.
3687 When this function actually returns it means the inferior
3688 should be left stopped and GDB should read more commands. */
3691 wait_for_inferior (void)
3693 struct cleanup *old_cleanups;
3697 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3700 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3703 /* If an error happens while handling the event, propagate GDB's
3704 knowledge of the executing state to the frontend/user running
3706 scoped_finish_thread_state finish_state (minus_one_ptid);
3710 struct execution_control_state ecss;
3711 struct execution_control_state *ecs = &ecss;
3712 ptid_t waiton_ptid = minus_one_ptid;
3714 memset (ecs, 0, sizeof (*ecs));
3716 overlay_cache_invalid = 1;
3718 /* Flush target cache before starting to handle each event.
3719 Target was running and cache could be stale. This is just a
3720 heuristic. Running threads may modify target memory, but we
3721 don't get any event. */
3722 target_dcache_invalidate ();
3724 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3727 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3729 /* Now figure out what to do with the result of the result. */
3730 handle_inferior_event (ecs);
3732 if (!ecs->wait_some_more)
3736 /* No error, don't finish the state yet. */
3737 finish_state.release ();
3739 do_cleanups (old_cleanups);
3742 /* Cleanup that reinstalls the readline callback handler, if the
3743 target is running in the background. If while handling the target
3744 event something triggered a secondary prompt, like e.g., a
3745 pagination prompt, we'll have removed the callback handler (see
3746 gdb_readline_wrapper_line). Need to do this as we go back to the
3747 event loop, ready to process further input. Note this has no
3748 effect if the handler hasn't actually been removed, because calling
3749 rl_callback_handler_install resets the line buffer, thus losing
3753 reinstall_readline_callback_handler_cleanup (void *arg)
3755 struct ui *ui = current_ui;
3759 /* We're not going back to the top level event loop yet. Don't
3760 install the readline callback, as it'd prep the terminal,
3761 readline-style (raw, noecho) (e.g., --batch). We'll install
3762 it the next time the prompt is displayed, when we're ready
3767 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3768 gdb_rl_callback_handler_reinstall ();
3771 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3772 that's just the event thread. In all-stop, that's all threads. */
3775 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3777 struct thread_info *thr = ecs->event_thread;
3779 if (thr != NULL && thr->thread_fsm != NULL)
3780 thread_fsm_clean_up (thr->thread_fsm, thr);
3784 ALL_NON_EXITED_THREADS (thr)
3786 if (thr->thread_fsm == NULL)
3788 if (thr == ecs->event_thread)
3791 switch_to_thread (thr);
3792 thread_fsm_clean_up (thr->thread_fsm, thr);
3795 if (ecs->event_thread != NULL)
3796 switch_to_thread (ecs->event_thread);
3800 /* Helper for all_uis_check_sync_execution_done that works on the
3804 check_curr_ui_sync_execution_done (void)
3806 struct ui *ui = current_ui;
3808 if (ui->prompt_state == PROMPT_NEEDED
3810 && !gdb_in_secondary_prompt_p (ui))
3812 target_terminal::ours ();
3813 gdb::observers::sync_execution_done.notify ();
3814 ui_register_input_event_handler (ui);
3821 all_uis_check_sync_execution_done (void)
3823 SWITCH_THRU_ALL_UIS ()
3825 check_curr_ui_sync_execution_done ();
3832 all_uis_on_sync_execution_starting (void)
3834 SWITCH_THRU_ALL_UIS ()
3836 if (current_ui->prompt_state == PROMPT_NEEDED)
3837 async_disable_stdin ();
3841 /* Asynchronous version of wait_for_inferior. It is called by the
3842 event loop whenever a change of state is detected on the file
3843 descriptor corresponding to the target. It can be called more than
3844 once to complete a single execution command. In such cases we need
3845 to keep the state in a global variable ECSS. If it is the last time
3846 that this function is called for a single execution command, then
3847 report to the user that the inferior has stopped, and do the
3848 necessary cleanups. */
3851 fetch_inferior_event (void *client_data)
3853 struct execution_control_state ecss;
3854 struct execution_control_state *ecs = &ecss;
3855 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3857 ptid_t waiton_ptid = minus_one_ptid;
3859 memset (ecs, 0, sizeof (*ecs));
3861 /* Events are always processed with the main UI as current UI. This
3862 way, warnings, debug output, etc. are always consistently sent to
3863 the main console. */
3864 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3866 /* End up with readline processing input, if necessary. */
3867 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3869 /* We're handling a live event, so make sure we're doing live
3870 debugging. If we're looking at traceframes while the target is
3871 running, we're going to need to get back to that mode after
3872 handling the event. */
3873 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3876 maybe_restore_traceframe.emplace ();
3877 set_current_traceframe (-1);
3880 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3883 /* In non-stop mode, the user/frontend should not notice a thread
3884 switch due to internal events. Make sure we reverse to the
3885 user selected thread and frame after handling the event and
3886 running any breakpoint commands. */
3887 maybe_restore_thread.emplace ();
3889 overlay_cache_invalid = 1;
3890 /* Flush target cache before starting to handle each event. Target
3891 was running and cache could be stale. This is just a heuristic.
3892 Running threads may modify target memory, but we don't get any
3894 target_dcache_invalidate ();
3896 scoped_restore save_exec_dir
3897 = make_scoped_restore (&execution_direction, target_execution_direction ());
3899 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3900 target_can_async_p () ? TARGET_WNOHANG : 0);
3903 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3905 /* If an error happens while handling the event, propagate GDB's
3906 knowledge of the executing state to the frontend/user running
3908 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3909 scoped_finish_thread_state finish_state (finish_ptid);
3911 /* Get executed before make_cleanup_restore_current_thread above to apply
3912 still for the thread which has thrown the exception. */
3913 struct cleanup *ts_old_chain = make_bpstat_clear_actions_cleanup ();
3915 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3917 /* Now figure out what to do with the result of the result. */
3918 handle_inferior_event (ecs);
3920 if (!ecs->wait_some_more)
3922 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3923 int should_stop = 1;
3924 struct thread_info *thr = ecs->event_thread;
3926 delete_just_stopped_threads_infrun_breakpoints ();
3930 struct thread_fsm *thread_fsm = thr->thread_fsm;
3932 if (thread_fsm != NULL)
3933 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3942 int should_notify_stop = 1;
3945 clean_up_just_stopped_threads_fsms (ecs);
3947 if (thr != NULL && thr->thread_fsm != NULL)
3950 = thread_fsm_should_notify_stop (thr->thread_fsm);
3953 if (should_notify_stop)
3955 /* We may not find an inferior if this was a process exit. */
3956 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3957 proceeded = normal_stop ();
3962 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3968 discard_cleanups (ts_old_chain);
3970 /* No error, don't finish the thread states yet. */
3971 finish_state.release ();
3973 /* Revert thread and frame. */
3974 do_cleanups (old_chain);
3976 /* If a UI was in sync execution mode, and now isn't, restore its
3977 prompt (a synchronous execution command has finished, and we're
3978 ready for input). */
3979 all_uis_check_sync_execution_done ();
3982 && exec_done_display_p
3983 && (inferior_ptid == null_ptid
3984 || inferior_thread ()->state != THREAD_RUNNING))
3985 printf_unfiltered (_("completed.\n"));
3988 /* Record the frame and location we're currently stepping through. */
3990 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3992 struct thread_info *tp = inferior_thread ();
3994 tp->control.step_frame_id = get_frame_id (frame);
3995 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3997 tp->current_symtab = sal.symtab;
3998 tp->current_line = sal.line;
4001 /* Clear context switchable stepping state. */
4004 init_thread_stepping_state (struct thread_info *tss)
4006 tss->stepped_breakpoint = 0;
4007 tss->stepping_over_breakpoint = 0;
4008 tss->stepping_over_watchpoint = 0;
4009 tss->step_after_step_resume_breakpoint = 0;
4012 /* Set the cached copy of the last ptid/waitstatus. */
4015 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4017 target_last_wait_ptid = ptid;
4018 target_last_waitstatus = status;
4021 /* Return the cached copy of the last pid/waitstatus returned by
4022 target_wait()/deprecated_target_wait_hook(). The data is actually
4023 cached by handle_inferior_event(), which gets called immediately
4024 after target_wait()/deprecated_target_wait_hook(). */
4027 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4029 *ptidp = target_last_wait_ptid;
4030 *status = target_last_waitstatus;
4034 nullify_last_target_wait_ptid (void)
4036 target_last_wait_ptid = minus_one_ptid;
4039 /* Switch thread contexts. */
4042 context_switch (execution_control_state *ecs)
4045 && ecs->ptid != inferior_ptid
4046 && ecs->event_thread != inferior_thread ())
4048 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4049 target_pid_to_str (inferior_ptid));
4050 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4051 target_pid_to_str (ecs->ptid));
4054 switch_to_thread (ecs->event_thread);
4057 /* If the target can't tell whether we've hit breakpoints
4058 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4059 check whether that could have been caused by a breakpoint. If so,
4060 adjust the PC, per gdbarch_decr_pc_after_break. */
4063 adjust_pc_after_break (struct thread_info *thread,
4064 struct target_waitstatus *ws)
4066 struct regcache *regcache;
4067 struct gdbarch *gdbarch;
4068 CORE_ADDR breakpoint_pc, decr_pc;
4070 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4071 we aren't, just return.
4073 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4074 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4075 implemented by software breakpoints should be handled through the normal
4078 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4079 different signals (SIGILL or SIGEMT for instance), but it is less
4080 clear where the PC is pointing afterwards. It may not match
4081 gdbarch_decr_pc_after_break. I don't know any specific target that
4082 generates these signals at breakpoints (the code has been in GDB since at
4083 least 1992) so I can not guess how to handle them here.
4085 In earlier versions of GDB, a target with
4086 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4087 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4088 target with both of these set in GDB history, and it seems unlikely to be
4089 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4091 if (ws->kind != TARGET_WAITKIND_STOPPED)
4094 if (ws->value.sig != GDB_SIGNAL_TRAP)
4097 /* In reverse execution, when a breakpoint is hit, the instruction
4098 under it has already been de-executed. The reported PC always
4099 points at the breakpoint address, so adjusting it further would
4100 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4103 B1 0x08000000 : INSN1
4104 B2 0x08000001 : INSN2
4106 PC -> 0x08000003 : INSN4
4108 Say you're stopped at 0x08000003 as above. Reverse continuing
4109 from that point should hit B2 as below. Reading the PC when the
4110 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4111 been de-executed already.
4113 B1 0x08000000 : INSN1
4114 B2 PC -> 0x08000001 : INSN2
4118 We can't apply the same logic as for forward execution, because
4119 we would wrongly adjust the PC to 0x08000000, since there's a
4120 breakpoint at PC - 1. We'd then report a hit on B1, although
4121 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4123 if (execution_direction == EXEC_REVERSE)
4126 /* If the target can tell whether the thread hit a SW breakpoint,
4127 trust it. Targets that can tell also adjust the PC
4129 if (target_supports_stopped_by_sw_breakpoint ())
4132 /* Note that relying on whether a breakpoint is planted in memory to
4133 determine this can fail. E.g,. the breakpoint could have been
4134 removed since. Or the thread could have been told to step an
4135 instruction the size of a breakpoint instruction, and only
4136 _after_ was a breakpoint inserted at its address. */
4138 /* If this target does not decrement the PC after breakpoints, then
4139 we have nothing to do. */
4140 regcache = get_thread_regcache (thread);
4141 gdbarch = regcache->arch ();
4143 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4147 const address_space *aspace = regcache->aspace ();
4149 /* Find the location where (if we've hit a breakpoint) the
4150 breakpoint would be. */
4151 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4153 /* If the target can't tell whether a software breakpoint triggered,
4154 fallback to figuring it out based on breakpoints we think were
4155 inserted in the target, and on whether the thread was stepped or
4158 /* Check whether there actually is a software breakpoint inserted at
4161 If in non-stop mode, a race condition is possible where we've
4162 removed a breakpoint, but stop events for that breakpoint were
4163 already queued and arrive later. To suppress those spurious
4164 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4165 and retire them after a number of stop events are reported. Note
4166 this is an heuristic and can thus get confused. The real fix is
4167 to get the "stopped by SW BP and needs adjustment" info out of
4168 the target/kernel (and thus never reach here; see above). */
4169 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4170 || (target_is_non_stop_p ()
4171 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4173 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4175 if (record_full_is_used ())
4176 restore_operation_disable.emplace
4177 (record_full_gdb_operation_disable_set ());
4179 /* When using hardware single-step, a SIGTRAP is reported for both
4180 a completed single-step and a software breakpoint. Need to
4181 differentiate between the two, as the latter needs adjusting
4182 but the former does not.
4184 The SIGTRAP can be due to a completed hardware single-step only if
4185 - we didn't insert software single-step breakpoints
4186 - this thread is currently being stepped
4188 If any of these events did not occur, we must have stopped due
4189 to hitting a software breakpoint, and have to back up to the
4192 As a special case, we could have hardware single-stepped a
4193 software breakpoint. In this case (prev_pc == breakpoint_pc),
4194 we also need to back up to the breakpoint address. */
4196 if (thread_has_single_step_breakpoints_set (thread)
4197 || !currently_stepping (thread)
4198 || (thread->stepped_breakpoint
4199 && thread->prev_pc == breakpoint_pc))
4200 regcache_write_pc (regcache, breakpoint_pc);
4205 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4207 for (frame = get_prev_frame (frame);
4209 frame = get_prev_frame (frame))
4211 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4213 if (get_frame_type (frame) != INLINE_FRAME)
4220 /* If the event thread has the stop requested flag set, pretend it
4221 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4225 handle_stop_requested (struct execution_control_state *ecs)
4227 if (ecs->event_thread->stop_requested)
4229 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4230 ecs->ws.value.sig = GDB_SIGNAL_0;
4231 handle_signal_stop (ecs);
4237 /* Auxiliary function that handles syscall entry/return events.
4238 It returns 1 if the inferior should keep going (and GDB
4239 should ignore the event), or 0 if the event deserves to be
4243 handle_syscall_event (struct execution_control_state *ecs)
4245 struct regcache *regcache;
4248 context_switch (ecs);
4250 regcache = get_thread_regcache (ecs->event_thread);
4251 syscall_number = ecs->ws.value.syscall_number;
4252 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4254 if (catch_syscall_enabled () > 0
4255 && catching_syscall_number (syscall_number) > 0)
4258 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4261 ecs->event_thread->control.stop_bpstat
4262 = bpstat_stop_status (regcache->aspace (),
4263 ecs->event_thread->suspend.stop_pc,
4264 ecs->event_thread, &ecs->ws);
4266 if (handle_stop_requested (ecs))
4269 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4271 /* Catchpoint hit. */
4276 if (handle_stop_requested (ecs))
4279 /* If no catchpoint triggered for this, then keep going. */
4284 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4287 fill_in_stop_func (struct gdbarch *gdbarch,
4288 struct execution_control_state *ecs)
4290 if (!ecs->stop_func_filled_in)
4292 /* Don't care about return value; stop_func_start and stop_func_name
4293 will both be 0 if it doesn't work. */
4294 find_pc_partial_function (ecs->event_thread->suspend.stop_pc,
4295 &ecs->stop_func_name,
4296 &ecs->stop_func_start, &ecs->stop_func_end);
4297 ecs->stop_func_start
4298 += gdbarch_deprecated_function_start_offset (gdbarch);
4300 if (gdbarch_skip_entrypoint_p (gdbarch))
4301 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4302 ecs->stop_func_start);
4304 ecs->stop_func_filled_in = 1;
4309 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4311 static enum stop_kind
4312 get_inferior_stop_soon (execution_control_state *ecs)
4314 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4316 gdb_assert (inf != NULL);
4317 return inf->control.stop_soon;
4320 /* Wait for one event. Store the resulting waitstatus in WS, and
4321 return the event ptid. */
4324 wait_one (struct target_waitstatus *ws)
4327 ptid_t wait_ptid = minus_one_ptid;
4329 overlay_cache_invalid = 1;
4331 /* Flush target cache before starting to handle each event.
4332 Target was running and cache could be stale. This is just a
4333 heuristic. Running threads may modify target memory, but we
4334 don't get any event. */
4335 target_dcache_invalidate ();
4337 if (deprecated_target_wait_hook)
4338 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4340 event_ptid = target_wait (wait_ptid, ws, 0);
4343 print_target_wait_results (wait_ptid, event_ptid, ws);
4348 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4349 instead of the current thread. */
4350 #define THREAD_STOPPED_BY(REASON) \
4352 thread_stopped_by_ ## REASON (ptid_t ptid) \
4354 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4355 inferior_ptid = ptid; \
4357 return target_stopped_by_ ## REASON (); \
4360 /* Generate thread_stopped_by_watchpoint. */
4361 THREAD_STOPPED_BY (watchpoint)
4362 /* Generate thread_stopped_by_sw_breakpoint. */
4363 THREAD_STOPPED_BY (sw_breakpoint)
4364 /* Generate thread_stopped_by_hw_breakpoint. */
4365 THREAD_STOPPED_BY (hw_breakpoint)
4367 /* Save the thread's event and stop reason to process it later. */
4370 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4374 std::string statstr = target_waitstatus_to_string (ws);
4376 fprintf_unfiltered (gdb_stdlog,
4377 "infrun: saving status %s for %d.%ld.%ld\n",
4379 ptid_get_pid (tp->ptid),
4380 ptid_get_lwp (tp->ptid),
4381 ptid_get_tid (tp->ptid));
4384 /* Record for later. */
4385 tp->suspend.waitstatus = *ws;
4386 tp->suspend.waitstatus_pending_p = 1;
4388 struct regcache *regcache = get_thread_regcache (tp);
4389 const address_space *aspace = regcache->aspace ();
4391 if (ws->kind == TARGET_WAITKIND_STOPPED
4392 && ws->value.sig == GDB_SIGNAL_TRAP)
4394 CORE_ADDR pc = regcache_read_pc (regcache);
4396 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4398 if (thread_stopped_by_watchpoint (tp->ptid))
4400 tp->suspend.stop_reason
4401 = TARGET_STOPPED_BY_WATCHPOINT;
4403 else if (target_supports_stopped_by_sw_breakpoint ()
4404 && thread_stopped_by_sw_breakpoint (tp->ptid))
4406 tp->suspend.stop_reason
4407 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4409 else if (target_supports_stopped_by_hw_breakpoint ()
4410 && thread_stopped_by_hw_breakpoint (tp->ptid))
4412 tp->suspend.stop_reason
4413 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4415 else if (!target_supports_stopped_by_hw_breakpoint ()
4416 && hardware_breakpoint_inserted_here_p (aspace,
4419 tp->suspend.stop_reason
4420 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4422 else if (!target_supports_stopped_by_sw_breakpoint ()
4423 && software_breakpoint_inserted_here_p (aspace,
4426 tp->suspend.stop_reason
4427 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4429 else if (!thread_has_single_step_breakpoints_set (tp)
4430 && currently_stepping (tp))
4432 tp->suspend.stop_reason
4433 = TARGET_STOPPED_BY_SINGLE_STEP;
4438 /* A cleanup that disables thread create/exit events. */
4441 disable_thread_events (void *arg)
4443 target_thread_events (0);
4449 stop_all_threads (void)
4451 /* We may need multiple passes to discover all threads. */
4454 struct cleanup *old_chain;
4456 gdb_assert (target_is_non_stop_p ());
4459 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4461 scoped_restore_current_thread restore_thread;
4463 target_thread_events (1);
4464 old_chain = make_cleanup (disable_thread_events, NULL);
4466 /* Request threads to stop, and then wait for the stops. Because
4467 threads we already know about can spawn more threads while we're
4468 trying to stop them, and we only learn about new threads when we
4469 update the thread list, do this in a loop, and keep iterating
4470 until two passes find no threads that need to be stopped. */
4471 for (pass = 0; pass < 2; pass++, iterations++)
4474 fprintf_unfiltered (gdb_stdlog,
4475 "infrun: stop_all_threads, pass=%d, "
4476 "iterations=%d\n", pass, iterations);
4480 struct target_waitstatus ws;
4482 struct thread_info *t;
4484 update_thread_list ();
4486 /* Go through all threads looking for threads that we need
4487 to tell the target to stop. */
4488 ALL_NON_EXITED_THREADS (t)
4492 /* If already stopping, don't request a stop again.
4493 We just haven't seen the notification yet. */
4494 if (!t->stop_requested)
4497 fprintf_unfiltered (gdb_stdlog,
4498 "infrun: %s executing, "
4500 target_pid_to_str (t->ptid));
4501 target_stop (t->ptid);
4502 t->stop_requested = 1;
4507 fprintf_unfiltered (gdb_stdlog,
4508 "infrun: %s executing, "
4509 "already stopping\n",
4510 target_pid_to_str (t->ptid));
4513 if (t->stop_requested)
4519 fprintf_unfiltered (gdb_stdlog,
4520 "infrun: %s not executing\n",
4521 target_pid_to_str (t->ptid));
4523 /* The thread may be not executing, but still be
4524 resumed with a pending status to process. */
4532 /* If we find new threads on the second iteration, restart
4533 over. We want to see two iterations in a row with all
4538 event_ptid = wait_one (&ws);
4540 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4542 /* All resumed threads exited. */
4544 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4545 || ws.kind == TARGET_WAITKIND_EXITED
4546 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4550 ptid_t ptid = ptid_t (ws.value.integer);
4552 fprintf_unfiltered (gdb_stdlog,
4553 "infrun: %s exited while "
4554 "stopping threads\n",
4555 target_pid_to_str (ptid));
4562 t = find_thread_ptid (event_ptid);
4564 t = add_thread (event_ptid);
4566 t->stop_requested = 0;
4569 t->control.may_range_step = 0;
4571 /* This may be the first time we see the inferior report
4573 inf = find_inferior_ptid (event_ptid);
4574 if (inf->needs_setup)
4576 switch_to_thread_no_regs (t);
4580 if (ws.kind == TARGET_WAITKIND_STOPPED
4581 && ws.value.sig == GDB_SIGNAL_0)
4583 /* We caught the event that we intended to catch, so
4584 there's no event pending. */
4585 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4586 t->suspend.waitstatus_pending_p = 0;
4588 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4590 /* Add it back to the step-over queue. */
4593 fprintf_unfiltered (gdb_stdlog,
4594 "infrun: displaced-step of %s "
4595 "canceled: adding back to the "
4596 "step-over queue\n",
4597 target_pid_to_str (t->ptid));
4599 t->control.trap_expected = 0;
4600 thread_step_over_chain_enqueue (t);
4605 enum gdb_signal sig;
4606 struct regcache *regcache;
4610 std::string statstr = target_waitstatus_to_string (&ws);
4612 fprintf_unfiltered (gdb_stdlog,
4613 "infrun: target_wait %s, saving "
4614 "status for %d.%ld.%ld\n",
4616 ptid_get_pid (t->ptid),
4617 ptid_get_lwp (t->ptid),
4618 ptid_get_tid (t->ptid));
4621 /* Record for later. */
4622 save_waitstatus (t, &ws);
4624 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4625 ? ws.value.sig : GDB_SIGNAL_0);
4627 if (displaced_step_fixup (t, sig) < 0)
4629 /* Add it back to the step-over queue. */
4630 t->control.trap_expected = 0;
4631 thread_step_over_chain_enqueue (t);
4634 regcache = get_thread_regcache (t);
4635 t->suspend.stop_pc = regcache_read_pc (regcache);
4639 fprintf_unfiltered (gdb_stdlog,
4640 "infrun: saved stop_pc=%s for %s "
4641 "(currently_stepping=%d)\n",
4642 paddress (target_gdbarch (),
4643 t->suspend.stop_pc),
4644 target_pid_to_str (t->ptid),
4645 currently_stepping (t));
4652 do_cleanups (old_chain);
4655 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4658 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4661 handle_no_resumed (struct execution_control_state *ecs)
4663 struct inferior *inf;
4664 struct thread_info *thread;
4666 if (target_can_async_p ())
4673 if (ui->prompt_state == PROMPT_BLOCKED)
4681 /* There were no unwaited-for children left in the target, but,
4682 we're not synchronously waiting for events either. Just
4686 fprintf_unfiltered (gdb_stdlog,
4687 "infrun: TARGET_WAITKIND_NO_RESUMED "
4688 "(ignoring: bg)\n");
4689 prepare_to_wait (ecs);
4694 /* Otherwise, if we were running a synchronous execution command, we
4695 may need to cancel it and give the user back the terminal.
4697 In non-stop mode, the target can't tell whether we've already
4698 consumed previous stop events, so it can end up sending us a
4699 no-resumed event like so:
4701 #0 - thread 1 is left stopped
4703 #1 - thread 2 is resumed and hits breakpoint
4704 -> TARGET_WAITKIND_STOPPED
4706 #2 - thread 3 is resumed and exits
4707 this is the last resumed thread, so
4708 -> TARGET_WAITKIND_NO_RESUMED
4710 #3 - gdb processes stop for thread 2 and decides to re-resume
4713 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4714 thread 2 is now resumed, so the event should be ignored.
4716 IOW, if the stop for thread 2 doesn't end a foreground command,
4717 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4718 event. But it could be that the event meant that thread 2 itself
4719 (or whatever other thread was the last resumed thread) exited.
4721 To address this we refresh the thread list and check whether we
4722 have resumed threads _now_. In the example above, this removes
4723 thread 3 from the thread list. If thread 2 was re-resumed, we
4724 ignore this event. If we find no thread resumed, then we cancel
4725 the synchronous command show "no unwaited-for " to the user. */
4726 update_thread_list ();
4728 ALL_NON_EXITED_THREADS (thread)
4730 if (thread->executing
4731 || thread->suspend.waitstatus_pending_p)
4733 /* There were no unwaited-for children left in the target at
4734 some point, but there are now. Just ignore. */
4736 fprintf_unfiltered (gdb_stdlog,
4737 "infrun: TARGET_WAITKIND_NO_RESUMED "
4738 "(ignoring: found resumed)\n");
4739 prepare_to_wait (ecs);
4744 /* Note however that we may find no resumed thread because the whole
4745 process exited meanwhile (thus updating the thread list results
4746 in an empty thread list). In this case we know we'll be getting
4747 a process exit event shortly. */
4753 thread_info *thread = any_live_thread_of_inferior (inf);
4757 fprintf_unfiltered (gdb_stdlog,
4758 "infrun: TARGET_WAITKIND_NO_RESUMED "
4759 "(expect process exit)\n");
4760 prepare_to_wait (ecs);
4765 /* Go ahead and report the event. */
4769 /* Given an execution control state that has been freshly filled in by
4770 an event from the inferior, figure out what it means and take
4773 The alternatives are:
4775 1) stop_waiting and return; to really stop and return to the
4778 2) keep_going and return; to wait for the next event (set
4779 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4783 handle_inferior_event_1 (struct execution_control_state *ecs)
4785 enum stop_kind stop_soon;
4787 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4789 /* We had an event in the inferior, but we are not interested in
4790 handling it at this level. The lower layers have already
4791 done what needs to be done, if anything.
4793 One of the possible circumstances for this is when the
4794 inferior produces output for the console. The inferior has
4795 not stopped, and we are ignoring the event. Another possible
4796 circumstance is any event which the lower level knows will be
4797 reported multiple times without an intervening resume. */
4799 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4800 prepare_to_wait (ecs);
4804 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4807 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4808 prepare_to_wait (ecs);
4812 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4813 && handle_no_resumed (ecs))
4816 /* Cache the last pid/waitstatus. */
4817 set_last_target_status (ecs->ptid, ecs->ws);
4819 /* Always clear state belonging to the previous time we stopped. */
4820 stop_stack_dummy = STOP_NONE;
4822 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4824 /* No unwaited-for children left. IOW, all resumed children
4827 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4829 stop_print_frame = 0;
4834 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4835 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4837 ecs->event_thread = find_thread_ptid (ecs->ptid);
4838 /* If it's a new thread, add it to the thread database. */
4839 if (ecs->event_thread == NULL)
4840 ecs->event_thread = add_thread (ecs->ptid);
4842 /* Disable range stepping. If the next step request could use a
4843 range, this will be end up re-enabled then. */
4844 ecs->event_thread->control.may_range_step = 0;
4847 /* Dependent on valid ECS->EVENT_THREAD. */
4848 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4850 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4851 reinit_frame_cache ();
4853 breakpoint_retire_moribund ();
4855 /* First, distinguish signals caused by the debugger from signals
4856 that have to do with the program's own actions. Note that
4857 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4858 on the operating system version. Here we detect when a SIGILL or
4859 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4860 something similar for SIGSEGV, since a SIGSEGV will be generated
4861 when we're trying to execute a breakpoint instruction on a
4862 non-executable stack. This happens for call dummy breakpoints
4863 for architectures like SPARC that place call dummies on the
4865 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4866 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4867 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4868 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4870 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4872 if (breakpoint_inserted_here_p (regcache->aspace (),
4873 regcache_read_pc (regcache)))
4876 fprintf_unfiltered (gdb_stdlog,
4877 "infrun: Treating signal as SIGTRAP\n");
4878 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4882 /* Mark the non-executing threads accordingly. In all-stop, all
4883 threads of all processes are stopped when we get any event
4884 reported. In non-stop mode, only the event thread stops. */
4888 if (!target_is_non_stop_p ())
4889 mark_ptid = minus_one_ptid;
4890 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4891 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4893 /* If we're handling a process exit in non-stop mode, even
4894 though threads haven't been deleted yet, one would think
4895 that there is nothing to do, as threads of the dead process
4896 will be soon deleted, and threads of any other process were
4897 left running. However, on some targets, threads survive a
4898 process exit event. E.g., for the "checkpoint" command,
4899 when the current checkpoint/fork exits, linux-fork.c
4900 automatically switches to another fork from within
4901 target_mourn_inferior, by associating the same
4902 inferior/thread to another fork. We haven't mourned yet at
4903 this point, but we must mark any threads left in the
4904 process as not-executing so that finish_thread_state marks
4905 them stopped (in the user's perspective) if/when we present
4906 the stop to the user. */
4907 mark_ptid = ptid_t (ptid_get_pid (ecs->ptid));
4910 mark_ptid = ecs->ptid;
4912 set_executing (mark_ptid, 0);
4914 /* Likewise the resumed flag. */
4915 set_resumed (mark_ptid, 0);
4918 switch (ecs->ws.kind)
4920 case TARGET_WAITKIND_LOADED:
4922 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4923 context_switch (ecs);
4924 /* Ignore gracefully during startup of the inferior, as it might
4925 be the shell which has just loaded some objects, otherwise
4926 add the symbols for the newly loaded objects. Also ignore at
4927 the beginning of an attach or remote session; we will query
4928 the full list of libraries once the connection is
4931 stop_soon = get_inferior_stop_soon (ecs);
4932 if (stop_soon == NO_STOP_QUIETLY)
4934 struct regcache *regcache;
4936 regcache = get_thread_regcache (ecs->event_thread);
4938 handle_solib_event ();
4940 ecs->event_thread->control.stop_bpstat
4941 = bpstat_stop_status (regcache->aspace (),
4942 ecs->event_thread->suspend.stop_pc,
4943 ecs->event_thread, &ecs->ws);
4945 if (handle_stop_requested (ecs))
4948 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4950 /* A catchpoint triggered. */
4951 process_event_stop_test (ecs);
4955 /* If requested, stop when the dynamic linker notifies
4956 gdb of events. This allows the user to get control
4957 and place breakpoints in initializer routines for
4958 dynamically loaded objects (among other things). */
4959 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4960 if (stop_on_solib_events)
4962 /* Make sure we print "Stopped due to solib-event" in
4964 stop_print_frame = 1;
4971 /* If we are skipping through a shell, or through shared library
4972 loading that we aren't interested in, resume the program. If
4973 we're running the program normally, also resume. */
4974 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4976 /* Loading of shared libraries might have changed breakpoint
4977 addresses. Make sure new breakpoints are inserted. */
4978 if (stop_soon == NO_STOP_QUIETLY)
4979 insert_breakpoints ();
4980 resume (GDB_SIGNAL_0);
4981 prepare_to_wait (ecs);
4985 /* But stop if we're attaching or setting up a remote
4987 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4988 || stop_soon == STOP_QUIETLY_REMOTE)
4991 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4996 internal_error (__FILE__, __LINE__,
4997 _("unhandled stop_soon: %d"), (int) stop_soon);
4999 case TARGET_WAITKIND_SPURIOUS:
5001 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5002 if (handle_stop_requested (ecs))
5004 context_switch (ecs);
5005 resume (GDB_SIGNAL_0);
5006 prepare_to_wait (ecs);
5009 case TARGET_WAITKIND_THREAD_CREATED:
5011 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5012 if (handle_stop_requested (ecs))
5014 context_switch (ecs);
5015 if (!switch_back_to_stepped_thread (ecs))
5019 case TARGET_WAITKIND_EXITED:
5020 case TARGET_WAITKIND_SIGNALLED:
5023 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5024 fprintf_unfiltered (gdb_stdlog,
5025 "infrun: TARGET_WAITKIND_EXITED\n");
5027 fprintf_unfiltered (gdb_stdlog,
5028 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5031 inferior_ptid = ecs->ptid;
5032 set_current_inferior (find_inferior_ptid (ecs->ptid));
5033 set_current_program_space (current_inferior ()->pspace);
5034 handle_vfork_child_exec_or_exit (0);
5035 target_terminal::ours (); /* Must do this before mourn anyway. */
5037 /* Clearing any previous state of convenience variables. */
5038 clear_exit_convenience_vars ();
5040 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5042 /* Record the exit code in the convenience variable $_exitcode, so
5043 that the user can inspect this again later. */
5044 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5045 (LONGEST) ecs->ws.value.integer);
5047 /* Also record this in the inferior itself. */
5048 current_inferior ()->has_exit_code = 1;
5049 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5051 /* Support the --return-child-result option. */
5052 return_child_result_value = ecs->ws.value.integer;
5054 gdb::observers::exited.notify (ecs->ws.value.integer);
5058 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
5060 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5062 /* Set the value of the internal variable $_exitsignal,
5063 which holds the signal uncaught by the inferior. */
5064 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5065 gdbarch_gdb_signal_to_target (gdbarch,
5066 ecs->ws.value.sig));
5070 /* We don't have access to the target's method used for
5071 converting between signal numbers (GDB's internal
5072 representation <-> target's representation).
5073 Therefore, we cannot do a good job at displaying this
5074 information to the user. It's better to just warn
5075 her about it (if infrun debugging is enabled), and
5078 fprintf_filtered (gdb_stdlog, _("\
5079 Cannot fill $_exitsignal with the correct signal number.\n"));
5082 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
5085 gdb_flush (gdb_stdout);
5086 target_mourn_inferior (inferior_ptid);
5087 stop_print_frame = 0;
5091 /* The following are the only cases in which we keep going;
5092 the above cases end in a continue or goto. */
5093 case TARGET_WAITKIND_FORKED:
5094 case TARGET_WAITKIND_VFORKED:
5097 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5098 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5100 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5103 /* Check whether the inferior is displaced stepping. */
5105 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5106 struct gdbarch *gdbarch = regcache->arch ();
5108 /* If checking displaced stepping is supported, and thread
5109 ecs->ptid is displaced stepping. */
5110 if (displaced_step_in_progress_thread (ecs->event_thread))
5112 struct inferior *parent_inf
5113 = find_inferior_ptid (ecs->ptid);
5114 struct regcache *child_regcache;
5115 CORE_ADDR parent_pc;
5117 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5118 indicating that the displaced stepping of syscall instruction
5119 has been done. Perform cleanup for parent process here. Note
5120 that this operation also cleans up the child process for vfork,
5121 because their pages are shared. */
5122 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
5123 /* Start a new step-over in another thread if there's one
5127 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5129 struct displaced_step_inferior_state *displaced
5130 = get_displaced_stepping_state (parent_inf);
5132 /* Restore scratch pad for child process. */
5133 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5136 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5137 the child's PC is also within the scratchpad. Set the child's PC
5138 to the parent's PC value, which has already been fixed up.
5139 FIXME: we use the parent's aspace here, although we're touching
5140 the child, because the child hasn't been added to the inferior
5141 list yet at this point. */
5144 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5146 parent_inf->aspace);
5147 /* Read PC value of parent process. */
5148 parent_pc = regcache_read_pc (regcache);
5150 if (debug_displaced)
5151 fprintf_unfiltered (gdb_stdlog,
5152 "displaced: write child pc from %s to %s\n",
5154 regcache_read_pc (child_regcache)),
5155 paddress (gdbarch, parent_pc));
5157 regcache_write_pc (child_regcache, parent_pc);
5161 context_switch (ecs);
5163 /* Immediately detach breakpoints from the child before there's
5164 any chance of letting the user delete breakpoints from the
5165 breakpoint lists. If we don't do this early, it's easy to
5166 leave left over traps in the child, vis: "break foo; catch
5167 fork; c; <fork>; del; c; <child calls foo>". We only follow
5168 the fork on the last `continue', and by that time the
5169 breakpoint at "foo" is long gone from the breakpoint table.
5170 If we vforked, then we don't need to unpatch here, since both
5171 parent and child are sharing the same memory pages; we'll
5172 need to unpatch at follow/detach time instead to be certain
5173 that new breakpoints added between catchpoint hit time and
5174 vfork follow are detached. */
5175 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5177 /* This won't actually modify the breakpoint list, but will
5178 physically remove the breakpoints from the child. */
5179 detach_breakpoints (ecs->ws.value.related_pid);
5182 delete_just_stopped_threads_single_step_breakpoints ();
5184 /* In case the event is caught by a catchpoint, remember that
5185 the event is to be followed at the next resume of the thread,
5186 and not immediately. */
5187 ecs->event_thread->pending_follow = ecs->ws;
5189 ecs->event_thread->suspend.stop_pc
5190 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5192 ecs->event_thread->control.stop_bpstat
5193 = bpstat_stop_status (get_current_regcache ()->aspace (),
5194 ecs->event_thread->suspend.stop_pc,
5195 ecs->event_thread, &ecs->ws);
5197 if (handle_stop_requested (ecs))
5200 /* If no catchpoint triggered for this, then keep going. Note
5201 that we're interested in knowing the bpstat actually causes a
5202 stop, not just if it may explain the signal. Software
5203 watchpoints, for example, always appear in the bpstat. */
5204 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5208 = (follow_fork_mode_string == follow_fork_mode_child);
5210 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5212 should_resume = follow_fork ();
5214 thread_info *parent = ecs->event_thread;
5215 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5217 /* At this point, the parent is marked running, and the
5218 child is marked stopped. */
5220 /* If not resuming the parent, mark it stopped. */
5221 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5222 parent->set_running (false);
5224 /* If resuming the child, mark it running. */
5225 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5226 child->set_running (true);
5228 /* In non-stop mode, also resume the other branch. */
5229 if (!detach_fork && (non_stop
5230 || (sched_multi && target_is_non_stop_p ())))
5233 switch_to_thread (parent);
5235 switch_to_thread (child);
5237 ecs->event_thread = inferior_thread ();
5238 ecs->ptid = inferior_ptid;
5243 switch_to_thread (child);
5245 switch_to_thread (parent);
5247 ecs->event_thread = inferior_thread ();
5248 ecs->ptid = inferior_ptid;
5256 process_event_stop_test (ecs);
5259 case TARGET_WAITKIND_VFORK_DONE:
5260 /* Done with the shared memory region. Re-insert breakpoints in
5261 the parent, and keep going. */
5264 fprintf_unfiltered (gdb_stdlog,
5265 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5267 context_switch (ecs);
5269 current_inferior ()->waiting_for_vfork_done = 0;
5270 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5272 if (handle_stop_requested (ecs))
5275 /* This also takes care of reinserting breakpoints in the
5276 previously locked inferior. */
5280 case TARGET_WAITKIND_EXECD:
5282 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5284 /* Note we can't read registers yet (the stop_pc), because we
5285 don't yet know the inferior's post-exec architecture.
5286 'stop_pc' is explicitly read below instead. */
5287 switch_to_thread_no_regs (ecs->event_thread);
5289 /* Do whatever is necessary to the parent branch of the vfork. */
5290 handle_vfork_child_exec_or_exit (1);
5292 /* This causes the eventpoints and symbol table to be reset.
5293 Must do this now, before trying to determine whether to
5295 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5297 /* In follow_exec we may have deleted the original thread and
5298 created a new one. Make sure that the event thread is the
5299 execd thread for that case (this is a nop otherwise). */
5300 ecs->event_thread = inferior_thread ();
5302 ecs->event_thread->suspend.stop_pc
5303 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5305 ecs->event_thread->control.stop_bpstat
5306 = bpstat_stop_status (get_current_regcache ()->aspace (),
5307 ecs->event_thread->suspend.stop_pc,
5308 ecs->event_thread, &ecs->ws);
5310 /* Note that this may be referenced from inside
5311 bpstat_stop_status above, through inferior_has_execd. */
5312 xfree (ecs->ws.value.execd_pathname);
5313 ecs->ws.value.execd_pathname = NULL;
5315 if (handle_stop_requested (ecs))
5318 /* If no catchpoint triggered for this, then keep going. */
5319 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5321 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5325 process_event_stop_test (ecs);
5328 /* Be careful not to try to gather much state about a thread
5329 that's in a syscall. It's frequently a losing proposition. */
5330 case TARGET_WAITKIND_SYSCALL_ENTRY:
5332 fprintf_unfiltered (gdb_stdlog,
5333 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5334 /* Getting the current syscall number. */
5335 if (handle_syscall_event (ecs) == 0)
5336 process_event_stop_test (ecs);
5339 /* Before examining the threads further, step this thread to
5340 get it entirely out of the syscall. (We get notice of the
5341 event when the thread is just on the verge of exiting a
5342 syscall. Stepping one instruction seems to get it back
5344 case TARGET_WAITKIND_SYSCALL_RETURN:
5346 fprintf_unfiltered (gdb_stdlog,
5347 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5348 if (handle_syscall_event (ecs) == 0)
5349 process_event_stop_test (ecs);
5352 case TARGET_WAITKIND_STOPPED:
5354 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5355 handle_signal_stop (ecs);
5358 case TARGET_WAITKIND_NO_HISTORY:
5360 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5361 /* Reverse execution: target ran out of history info. */
5363 /* Switch to the stopped thread. */
5364 context_switch (ecs);
5366 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5368 delete_just_stopped_threads_single_step_breakpoints ();
5369 ecs->event_thread->suspend.stop_pc
5370 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5372 if (handle_stop_requested (ecs))
5375 gdb::observers::no_history.notify ();
5381 /* A wrapper around handle_inferior_event_1, which also makes sure
5382 that all temporary struct value objects that were created during
5383 the handling of the event get deleted at the end. */
5386 handle_inferior_event (struct execution_control_state *ecs)
5388 struct value *mark = value_mark ();
5390 handle_inferior_event_1 (ecs);
5391 /* Purge all temporary values created during the event handling,
5392 as it could be a long time before we return to the command level
5393 where such values would otherwise be purged. */
5394 value_free_to_mark (mark);
5397 /* Restart threads back to what they were trying to do back when we
5398 paused them for an in-line step-over. The EVENT_THREAD thread is
5402 restart_threads (struct thread_info *event_thread)
5404 struct thread_info *tp;
5406 /* In case the instruction just stepped spawned a new thread. */
5407 update_thread_list ();
5409 ALL_NON_EXITED_THREADS (tp)
5411 if (tp == event_thread)
5414 fprintf_unfiltered (gdb_stdlog,
5415 "infrun: restart threads: "
5416 "[%s] is event thread\n",
5417 target_pid_to_str (tp->ptid));
5421 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5424 fprintf_unfiltered (gdb_stdlog,
5425 "infrun: restart threads: "
5426 "[%s] not meant to be running\n",
5427 target_pid_to_str (tp->ptid));
5434 fprintf_unfiltered (gdb_stdlog,
5435 "infrun: restart threads: [%s] resumed\n",
5436 target_pid_to_str (tp->ptid));
5437 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5441 if (thread_is_in_step_over_chain (tp))
5444 fprintf_unfiltered (gdb_stdlog,
5445 "infrun: restart threads: "
5446 "[%s] needs step-over\n",
5447 target_pid_to_str (tp->ptid));
5448 gdb_assert (!tp->resumed);
5453 if (tp->suspend.waitstatus_pending_p)
5456 fprintf_unfiltered (gdb_stdlog,
5457 "infrun: restart threads: "
5458 "[%s] has pending status\n",
5459 target_pid_to_str (tp->ptid));
5464 gdb_assert (!tp->stop_requested);
5466 /* If some thread needs to start a step-over at this point, it
5467 should still be in the step-over queue, and thus skipped
5469 if (thread_still_needs_step_over (tp))
5471 internal_error (__FILE__, __LINE__,
5472 "thread [%s] needs a step-over, but not in "
5473 "step-over queue\n",
5474 target_pid_to_str (tp->ptid));
5477 if (currently_stepping (tp))
5480 fprintf_unfiltered (gdb_stdlog,
5481 "infrun: restart threads: [%s] was stepping\n",
5482 target_pid_to_str (tp->ptid));
5483 keep_going_stepped_thread (tp);
5487 struct execution_control_state ecss;
5488 struct execution_control_state *ecs = &ecss;
5491 fprintf_unfiltered (gdb_stdlog,
5492 "infrun: restart threads: [%s] continuing\n",
5493 target_pid_to_str (tp->ptid));
5494 reset_ecs (ecs, tp);
5495 switch_to_thread (tp);
5496 keep_going_pass_signal (ecs);
5501 /* Callback for iterate_over_threads. Find a resumed thread that has
5502 a pending waitstatus. */
5505 resumed_thread_with_pending_status (struct thread_info *tp,
5509 && tp->suspend.waitstatus_pending_p);
5512 /* Called when we get an event that may finish an in-line or
5513 out-of-line (displaced stepping) step-over started previously.
5514 Return true if the event is processed and we should go back to the
5515 event loop; false if the caller should continue processing the
5519 finish_step_over (struct execution_control_state *ecs)
5521 int had_step_over_info;
5523 displaced_step_fixup (ecs->event_thread,
5524 ecs->event_thread->suspend.stop_signal);
5526 had_step_over_info = step_over_info_valid_p ();
5528 if (had_step_over_info)
5530 /* If we're stepping over a breakpoint with all threads locked,
5531 then only the thread that was stepped should be reporting
5533 gdb_assert (ecs->event_thread->control.trap_expected);
5535 clear_step_over_info ();
5538 if (!target_is_non_stop_p ())
5541 /* Start a new step-over in another thread if there's one that
5545 /* If we were stepping over a breakpoint before, and haven't started
5546 a new in-line step-over sequence, then restart all other threads
5547 (except the event thread). We can't do this in all-stop, as then
5548 e.g., we wouldn't be able to issue any other remote packet until
5549 these other threads stop. */
5550 if (had_step_over_info && !step_over_info_valid_p ())
5552 struct thread_info *pending;
5554 /* If we only have threads with pending statuses, the restart
5555 below won't restart any thread and so nothing re-inserts the
5556 breakpoint we just stepped over. But we need it inserted
5557 when we later process the pending events, otherwise if
5558 another thread has a pending event for this breakpoint too,
5559 we'd discard its event (because the breakpoint that
5560 originally caused the event was no longer inserted). */
5561 context_switch (ecs);
5562 insert_breakpoints ();
5564 restart_threads (ecs->event_thread);
5566 /* If we have events pending, go through handle_inferior_event
5567 again, picking up a pending event at random. This avoids
5568 thread starvation. */
5570 /* But not if we just stepped over a watchpoint in order to let
5571 the instruction execute so we can evaluate its expression.
5572 The set of watchpoints that triggered is recorded in the
5573 breakpoint objects themselves (see bp->watchpoint_triggered).
5574 If we processed another event first, that other event could
5575 clobber this info. */
5576 if (ecs->event_thread->stepping_over_watchpoint)
5579 pending = iterate_over_threads (resumed_thread_with_pending_status,
5581 if (pending != NULL)
5583 struct thread_info *tp = ecs->event_thread;
5584 struct regcache *regcache;
5588 fprintf_unfiltered (gdb_stdlog,
5589 "infrun: found resumed threads with "
5590 "pending events, saving status\n");
5593 gdb_assert (pending != tp);
5595 /* Record the event thread's event for later. */
5596 save_waitstatus (tp, &ecs->ws);
5597 /* This was cleared early, by handle_inferior_event. Set it
5598 so this pending event is considered by
5602 gdb_assert (!tp->executing);
5604 regcache = get_thread_regcache (tp);
5605 tp->suspend.stop_pc = regcache_read_pc (regcache);
5609 fprintf_unfiltered (gdb_stdlog,
5610 "infrun: saved stop_pc=%s for %s "
5611 "(currently_stepping=%d)\n",
5612 paddress (target_gdbarch (),
5613 tp->suspend.stop_pc),
5614 target_pid_to_str (tp->ptid),
5615 currently_stepping (tp));
5618 /* This in-line step-over finished; clear this so we won't
5619 start a new one. This is what handle_signal_stop would
5620 do, if we returned false. */
5621 tp->stepping_over_breakpoint = 0;
5623 /* Wake up the event loop again. */
5624 mark_async_event_handler (infrun_async_inferior_event_token);
5626 prepare_to_wait (ecs);
5634 /* Come here when the program has stopped with a signal. */
5637 handle_signal_stop (struct execution_control_state *ecs)
5639 struct frame_info *frame;
5640 struct gdbarch *gdbarch;
5641 int stopped_by_watchpoint;
5642 enum stop_kind stop_soon;
5645 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5647 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5649 /* Do we need to clean up the state of a thread that has
5650 completed a displaced single-step? (Doing so usually affects
5651 the PC, so do it here, before we set stop_pc.) */
5652 if (finish_step_over (ecs))
5655 /* If we either finished a single-step or hit a breakpoint, but
5656 the user wanted this thread to be stopped, pretend we got a
5657 SIG0 (generic unsignaled stop). */
5658 if (ecs->event_thread->stop_requested
5659 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5660 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5662 ecs->event_thread->suspend.stop_pc
5663 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5667 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5668 struct gdbarch *gdbarch = regcache->arch ();
5669 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5671 inferior_ptid = ecs->ptid;
5673 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5675 ecs->event_thread->suspend.stop_pc));
5676 if (target_stopped_by_watchpoint ())
5680 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5682 if (target_stopped_data_address (current_top_target (), &addr))
5683 fprintf_unfiltered (gdb_stdlog,
5684 "infrun: stopped data address = %s\n",
5685 paddress (gdbarch, addr));
5687 fprintf_unfiltered (gdb_stdlog,
5688 "infrun: (no data address available)\n");
5692 /* This is originated from start_remote(), start_inferior() and
5693 shared libraries hook functions. */
5694 stop_soon = get_inferior_stop_soon (ecs);
5695 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5697 context_switch (ecs);
5699 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5700 stop_print_frame = 1;
5705 /* This originates from attach_command(). We need to overwrite
5706 the stop_signal here, because some kernels don't ignore a
5707 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5708 See more comments in inferior.h. On the other hand, if we
5709 get a non-SIGSTOP, report it to the user - assume the backend
5710 will handle the SIGSTOP if it should show up later.
5712 Also consider that the attach is complete when we see a
5713 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5714 target extended-remote report it instead of a SIGSTOP
5715 (e.g. gdbserver). We already rely on SIGTRAP being our
5716 signal, so this is no exception.
5718 Also consider that the attach is complete when we see a
5719 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5720 the target to stop all threads of the inferior, in case the
5721 low level attach operation doesn't stop them implicitly. If
5722 they weren't stopped implicitly, then the stub will report a
5723 GDB_SIGNAL_0, meaning: stopped for no particular reason
5724 other than GDB's request. */
5725 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5726 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5727 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5728 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5730 stop_print_frame = 1;
5732 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5736 /* See if something interesting happened to the non-current thread. If
5737 so, then switch to that thread. */
5738 if (!ptid_equal (ecs->ptid, inferior_ptid))
5741 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5743 context_switch (ecs);
5745 if (deprecated_context_hook)
5746 deprecated_context_hook (ecs->event_thread->global_num);
5749 /* At this point, get hold of the now-current thread's frame. */
5750 frame = get_current_frame ();
5751 gdbarch = get_frame_arch (frame);
5753 /* Pull the single step breakpoints out of the target. */
5754 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5756 struct regcache *regcache;
5759 regcache = get_thread_regcache (ecs->event_thread);
5760 const address_space *aspace = regcache->aspace ();
5762 pc = regcache_read_pc (regcache);
5764 /* However, before doing so, if this single-step breakpoint was
5765 actually for another thread, set this thread up for moving
5767 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5770 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5774 fprintf_unfiltered (gdb_stdlog,
5775 "infrun: [%s] hit another thread's "
5776 "single-step breakpoint\n",
5777 target_pid_to_str (ecs->ptid));
5779 ecs->hit_singlestep_breakpoint = 1;
5786 fprintf_unfiltered (gdb_stdlog,
5787 "infrun: [%s] hit its "
5788 "single-step breakpoint\n",
5789 target_pid_to_str (ecs->ptid));
5793 delete_just_stopped_threads_single_step_breakpoints ();
5795 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5796 && ecs->event_thread->control.trap_expected
5797 && ecs->event_thread->stepping_over_watchpoint)
5798 stopped_by_watchpoint = 0;
5800 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5802 /* If necessary, step over this watchpoint. We'll be back to display
5804 if (stopped_by_watchpoint
5805 && (target_have_steppable_watchpoint
5806 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5808 /* At this point, we are stopped at an instruction which has
5809 attempted to write to a piece of memory under control of
5810 a watchpoint. The instruction hasn't actually executed
5811 yet. If we were to evaluate the watchpoint expression
5812 now, we would get the old value, and therefore no change
5813 would seem to have occurred.
5815 In order to make watchpoints work `right', we really need
5816 to complete the memory write, and then evaluate the
5817 watchpoint expression. We do this by single-stepping the
5820 It may not be necessary to disable the watchpoint to step over
5821 it. For example, the PA can (with some kernel cooperation)
5822 single step over a watchpoint without disabling the watchpoint.
5824 It is far more common to need to disable a watchpoint to step
5825 the inferior over it. If we have non-steppable watchpoints,
5826 we must disable the current watchpoint; it's simplest to
5827 disable all watchpoints.
5829 Any breakpoint at PC must also be stepped over -- if there's
5830 one, it will have already triggered before the watchpoint
5831 triggered, and we either already reported it to the user, or
5832 it didn't cause a stop and we called keep_going. In either
5833 case, if there was a breakpoint at PC, we must be trying to
5835 ecs->event_thread->stepping_over_watchpoint = 1;
5840 ecs->event_thread->stepping_over_breakpoint = 0;
5841 ecs->event_thread->stepping_over_watchpoint = 0;
5842 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5843 ecs->event_thread->control.stop_step = 0;
5844 stop_print_frame = 1;
5845 stopped_by_random_signal = 0;
5846 bpstat stop_chain = NULL;
5848 /* Hide inlined functions starting here, unless we just performed stepi or
5849 nexti. After stepi and nexti, always show the innermost frame (not any
5850 inline function call sites). */
5851 if (ecs->event_thread->control.step_range_end != 1)
5853 const address_space *aspace
5854 = get_thread_regcache (ecs->event_thread)->aspace ();
5856 /* skip_inline_frames is expensive, so we avoid it if we can
5857 determine that the address is one where functions cannot have
5858 been inlined. This improves performance with inferiors that
5859 load a lot of shared libraries, because the solib event
5860 breakpoint is defined as the address of a function (i.e. not
5861 inline). Note that we have to check the previous PC as well
5862 as the current one to catch cases when we have just
5863 single-stepped off a breakpoint prior to reinstating it.
5864 Note that we're assuming that the code we single-step to is
5865 not inline, but that's not definitive: there's nothing
5866 preventing the event breakpoint function from containing
5867 inlined code, and the single-step ending up there. If the
5868 user had set a breakpoint on that inlined code, the missing
5869 skip_inline_frames call would break things. Fortunately
5870 that's an extremely unlikely scenario. */
5871 if (!pc_at_non_inline_function (aspace,
5872 ecs->event_thread->suspend.stop_pc,
5874 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5875 && ecs->event_thread->control.trap_expected
5876 && pc_at_non_inline_function (aspace,
5877 ecs->event_thread->prev_pc,
5880 stop_chain = build_bpstat_chain (aspace,
5881 ecs->event_thread->suspend.stop_pc,
5883 skip_inline_frames (ecs->event_thread, stop_chain);
5885 /* Re-fetch current thread's frame in case that invalidated
5887 frame = get_current_frame ();
5888 gdbarch = get_frame_arch (frame);
5892 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5893 && ecs->event_thread->control.trap_expected
5894 && gdbarch_single_step_through_delay_p (gdbarch)
5895 && currently_stepping (ecs->event_thread))
5897 /* We're trying to step off a breakpoint. Turns out that we're
5898 also on an instruction that needs to be stepped multiple
5899 times before it's been fully executing. E.g., architectures
5900 with a delay slot. It needs to be stepped twice, once for
5901 the instruction and once for the delay slot. */
5902 int step_through_delay
5903 = gdbarch_single_step_through_delay (gdbarch, frame);
5905 if (debug_infrun && step_through_delay)
5906 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5907 if (ecs->event_thread->control.step_range_end == 0
5908 && step_through_delay)
5910 /* The user issued a continue when stopped at a breakpoint.
5911 Set up for another trap and get out of here. */
5912 ecs->event_thread->stepping_over_breakpoint = 1;
5916 else if (step_through_delay)
5918 /* The user issued a step when stopped at a breakpoint.
5919 Maybe we should stop, maybe we should not - the delay
5920 slot *might* correspond to a line of source. In any
5921 case, don't decide that here, just set
5922 ecs->stepping_over_breakpoint, making sure we
5923 single-step again before breakpoints are re-inserted. */
5924 ecs->event_thread->stepping_over_breakpoint = 1;
5928 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5929 handles this event. */
5930 ecs->event_thread->control.stop_bpstat
5931 = bpstat_stop_status (get_current_regcache ()->aspace (),
5932 ecs->event_thread->suspend.stop_pc,
5933 ecs->event_thread, &ecs->ws, stop_chain);
5935 /* Following in case break condition called a
5937 stop_print_frame = 1;
5939 /* This is where we handle "moribund" watchpoints. Unlike
5940 software breakpoints traps, hardware watchpoint traps are
5941 always distinguishable from random traps. If no high-level
5942 watchpoint is associated with the reported stop data address
5943 anymore, then the bpstat does not explain the signal ---
5944 simply make sure to ignore it if `stopped_by_watchpoint' is
5948 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5949 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5951 && stopped_by_watchpoint)
5952 fprintf_unfiltered (gdb_stdlog,
5953 "infrun: no user watchpoint explains "
5954 "watchpoint SIGTRAP, ignoring\n");
5956 /* NOTE: cagney/2003-03-29: These checks for a random signal
5957 at one stage in the past included checks for an inferior
5958 function call's call dummy's return breakpoint. The original
5959 comment, that went with the test, read:
5961 ``End of a stack dummy. Some systems (e.g. Sony news) give
5962 another signal besides SIGTRAP, so check here as well as
5965 If someone ever tries to get call dummys on a
5966 non-executable stack to work (where the target would stop
5967 with something like a SIGSEGV), then those tests might need
5968 to be re-instated. Given, however, that the tests were only
5969 enabled when momentary breakpoints were not being used, I
5970 suspect that it won't be the case.
5972 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5973 be necessary for call dummies on a non-executable stack on
5976 /* See if the breakpoints module can explain the signal. */
5978 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5979 ecs->event_thread->suspend.stop_signal);
5981 /* Maybe this was a trap for a software breakpoint that has since
5983 if (random_signal && target_stopped_by_sw_breakpoint ())
5985 if (program_breakpoint_here_p (gdbarch,
5986 ecs->event_thread->suspend.stop_pc))
5988 struct regcache *regcache;
5991 /* Re-adjust PC to what the program would see if GDB was not
5993 regcache = get_thread_regcache (ecs->event_thread);
5994 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5997 gdb::optional<scoped_restore_tmpl<int>>
5998 restore_operation_disable;
6000 if (record_full_is_used ())
6001 restore_operation_disable.emplace
6002 (record_full_gdb_operation_disable_set ());
6004 regcache_write_pc (regcache,
6005 ecs->event_thread->suspend.stop_pc + decr_pc);
6010 /* A delayed software breakpoint event. Ignore the trap. */
6012 fprintf_unfiltered (gdb_stdlog,
6013 "infrun: delayed software breakpoint "
6014 "trap, ignoring\n");
6019 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6020 has since been removed. */
6021 if (random_signal && target_stopped_by_hw_breakpoint ())
6023 /* A delayed hardware breakpoint event. Ignore the trap. */
6025 fprintf_unfiltered (gdb_stdlog,
6026 "infrun: delayed hardware breakpoint/watchpoint "
6027 "trap, ignoring\n");
6031 /* If not, perhaps stepping/nexting can. */
6033 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6034 && currently_stepping (ecs->event_thread));
6036 /* Perhaps the thread hit a single-step breakpoint of _another_
6037 thread. Single-step breakpoints are transparent to the
6038 breakpoints module. */
6040 random_signal = !ecs->hit_singlestep_breakpoint;
6042 /* No? Perhaps we got a moribund watchpoint. */
6044 random_signal = !stopped_by_watchpoint;
6046 /* Always stop if the user explicitly requested this thread to
6048 if (ecs->event_thread->stop_requested)
6052 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6055 /* For the program's own signals, act according to
6056 the signal handling tables. */
6060 /* Signal not for debugging purposes. */
6061 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6062 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6065 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6066 gdb_signal_to_symbol_string (stop_signal));
6068 stopped_by_random_signal = 1;
6070 /* Always stop on signals if we're either just gaining control
6071 of the program, or the user explicitly requested this thread
6072 to remain stopped. */
6073 if (stop_soon != NO_STOP_QUIETLY
6074 || ecs->event_thread->stop_requested
6076 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6082 /* Notify observers the signal has "handle print" set. Note we
6083 returned early above if stopping; normal_stop handles the
6084 printing in that case. */
6085 if (signal_print[ecs->event_thread->suspend.stop_signal])
6087 /* The signal table tells us to print about this signal. */
6088 target_terminal::ours_for_output ();
6089 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
6090 target_terminal::inferior ();
6093 /* Clear the signal if it should not be passed. */
6094 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6095 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6097 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
6098 && ecs->event_thread->control.trap_expected
6099 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6101 /* We were just starting a new sequence, attempting to
6102 single-step off of a breakpoint and expecting a SIGTRAP.
6103 Instead this signal arrives. This signal will take us out
6104 of the stepping range so GDB needs to remember to, when
6105 the signal handler returns, resume stepping off that
6107 /* To simplify things, "continue" is forced to use the same
6108 code paths as single-step - set a breakpoint at the
6109 signal return address and then, once hit, step off that
6112 fprintf_unfiltered (gdb_stdlog,
6113 "infrun: signal arrived while stepping over "
6116 insert_hp_step_resume_breakpoint_at_frame (frame);
6117 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6118 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6119 ecs->event_thread->control.trap_expected = 0;
6121 /* If we were nexting/stepping some other thread, switch to
6122 it, so that we don't continue it, losing control. */
6123 if (!switch_back_to_stepped_thread (ecs))
6128 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6129 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6131 || ecs->event_thread->control.step_range_end == 1)
6132 && frame_id_eq (get_stack_frame_id (frame),
6133 ecs->event_thread->control.step_stack_frame_id)
6134 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6136 /* The inferior is about to take a signal that will take it
6137 out of the single step range. Set a breakpoint at the
6138 current PC (which is presumably where the signal handler
6139 will eventually return) and then allow the inferior to
6142 Note that this is only needed for a signal delivered
6143 while in the single-step range. Nested signals aren't a
6144 problem as they eventually all return. */
6146 fprintf_unfiltered (gdb_stdlog,
6147 "infrun: signal may take us out of "
6148 "single-step range\n");
6150 clear_step_over_info ();
6151 insert_hp_step_resume_breakpoint_at_frame (frame);
6152 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6153 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6154 ecs->event_thread->control.trap_expected = 0;
6159 /* Note: step_resume_breakpoint may be non-NULL. This occures
6160 when either there's a nested signal, or when there's a
6161 pending signal enabled just as the signal handler returns
6162 (leaving the inferior at the step-resume-breakpoint without
6163 actually executing it). Either way continue until the
6164 breakpoint is really hit. */
6166 if (!switch_back_to_stepped_thread (ecs))
6169 fprintf_unfiltered (gdb_stdlog,
6170 "infrun: random signal, keep going\n");
6177 process_event_stop_test (ecs);
6180 /* Come here when we've got some debug event / signal we can explain
6181 (IOW, not a random signal), and test whether it should cause a
6182 stop, or whether we should resume the inferior (transparently).
6183 E.g., could be a breakpoint whose condition evaluates false; we
6184 could be still stepping within the line; etc. */
6187 process_event_stop_test (struct execution_control_state *ecs)
6189 struct symtab_and_line stop_pc_sal;
6190 struct frame_info *frame;
6191 struct gdbarch *gdbarch;
6192 CORE_ADDR jmp_buf_pc;
6193 struct bpstat_what what;
6195 /* Handle cases caused by hitting a breakpoint. */
6197 frame = get_current_frame ();
6198 gdbarch = get_frame_arch (frame);
6200 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6202 if (what.call_dummy)
6204 stop_stack_dummy = what.call_dummy;
6207 /* A few breakpoint types have callbacks associated (e.g.,
6208 bp_jit_event). Run them now. */
6209 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6211 /* If we hit an internal event that triggers symbol changes, the
6212 current frame will be invalidated within bpstat_what (e.g., if we
6213 hit an internal solib event). Re-fetch it. */
6214 frame = get_current_frame ();
6215 gdbarch = get_frame_arch (frame);
6217 switch (what.main_action)
6219 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6220 /* If we hit the breakpoint at longjmp while stepping, we
6221 install a momentary breakpoint at the target of the
6225 fprintf_unfiltered (gdb_stdlog,
6226 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6228 ecs->event_thread->stepping_over_breakpoint = 1;
6230 if (what.is_longjmp)
6232 struct value *arg_value;
6234 /* If we set the longjmp breakpoint via a SystemTap probe,
6235 then use it to extract the arguments. The destination PC
6236 is the third argument to the probe. */
6237 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6240 jmp_buf_pc = value_as_address (arg_value);
6241 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6243 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6244 || !gdbarch_get_longjmp_target (gdbarch,
6245 frame, &jmp_buf_pc))
6248 fprintf_unfiltered (gdb_stdlog,
6249 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6250 "(!gdbarch_get_longjmp_target)\n");
6255 /* Insert a breakpoint at resume address. */
6256 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6259 check_exception_resume (ecs, frame);
6263 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6265 struct frame_info *init_frame;
6267 /* There are several cases to consider.
6269 1. The initiating frame no longer exists. In this case we
6270 must stop, because the exception or longjmp has gone too
6273 2. The initiating frame exists, and is the same as the
6274 current frame. We stop, because the exception or longjmp
6277 3. The initiating frame exists and is different from the
6278 current frame. This means the exception or longjmp has
6279 been caught beneath the initiating frame, so keep going.
6281 4. longjmp breakpoint has been placed just to protect
6282 against stale dummy frames and user is not interested in
6283 stopping around longjmps. */
6286 fprintf_unfiltered (gdb_stdlog,
6287 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6289 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6291 delete_exception_resume_breakpoint (ecs->event_thread);
6293 if (what.is_longjmp)
6295 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6297 if (!frame_id_p (ecs->event_thread->initiating_frame))
6305 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6309 struct frame_id current_id
6310 = get_frame_id (get_current_frame ());
6311 if (frame_id_eq (current_id,
6312 ecs->event_thread->initiating_frame))
6314 /* Case 2. Fall through. */
6324 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6326 delete_step_resume_breakpoint (ecs->event_thread);
6328 end_stepping_range (ecs);
6332 case BPSTAT_WHAT_SINGLE:
6334 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6335 ecs->event_thread->stepping_over_breakpoint = 1;
6336 /* Still need to check other stuff, at least the case where we
6337 are stepping and step out of the right range. */
6340 case BPSTAT_WHAT_STEP_RESUME:
6342 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6344 delete_step_resume_breakpoint (ecs->event_thread);
6345 if (ecs->event_thread->control.proceed_to_finish
6346 && execution_direction == EXEC_REVERSE)
6348 struct thread_info *tp = ecs->event_thread;
6350 /* We are finishing a function in reverse, and just hit the
6351 step-resume breakpoint at the start address of the
6352 function, and we're almost there -- just need to back up
6353 by one more single-step, which should take us back to the
6355 tp->control.step_range_start = tp->control.step_range_end = 1;
6359 fill_in_stop_func (gdbarch, ecs);
6360 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6361 && execution_direction == EXEC_REVERSE)
6363 /* We are stepping over a function call in reverse, and just
6364 hit the step-resume breakpoint at the start address of
6365 the function. Go back to single-stepping, which should
6366 take us back to the function call. */
6367 ecs->event_thread->stepping_over_breakpoint = 1;
6373 case BPSTAT_WHAT_STOP_NOISY:
6375 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6376 stop_print_frame = 1;
6378 /* Assume the thread stopped for a breapoint. We'll still check
6379 whether a/the breakpoint is there when the thread is next
6381 ecs->event_thread->stepping_over_breakpoint = 1;
6386 case BPSTAT_WHAT_STOP_SILENT:
6388 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6389 stop_print_frame = 0;
6391 /* Assume the thread stopped for a breapoint. We'll still check
6392 whether a/the breakpoint is there when the thread is next
6394 ecs->event_thread->stepping_over_breakpoint = 1;
6398 case BPSTAT_WHAT_HP_STEP_RESUME:
6400 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6402 delete_step_resume_breakpoint (ecs->event_thread);
6403 if (ecs->event_thread->step_after_step_resume_breakpoint)
6405 /* Back when the step-resume breakpoint was inserted, we
6406 were trying to single-step off a breakpoint. Go back to
6408 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6409 ecs->event_thread->stepping_over_breakpoint = 1;
6415 case BPSTAT_WHAT_KEEP_CHECKING:
6419 /* If we stepped a permanent breakpoint and we had a high priority
6420 step-resume breakpoint for the address we stepped, but we didn't
6421 hit it, then we must have stepped into the signal handler. The
6422 step-resume was only necessary to catch the case of _not_
6423 stepping into the handler, so delete it, and fall through to
6424 checking whether the step finished. */
6425 if (ecs->event_thread->stepped_breakpoint)
6427 struct breakpoint *sr_bp
6428 = ecs->event_thread->control.step_resume_breakpoint;
6431 && sr_bp->loc->permanent
6432 && sr_bp->type == bp_hp_step_resume
6433 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6436 fprintf_unfiltered (gdb_stdlog,
6437 "infrun: stepped permanent breakpoint, stopped in "
6439 delete_step_resume_breakpoint (ecs->event_thread);
6440 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6444 /* We come here if we hit a breakpoint but should not stop for it.
6445 Possibly we also were stepping and should stop for that. So fall
6446 through and test for stepping. But, if not stepping, do not
6449 /* In all-stop mode, if we're currently stepping but have stopped in
6450 some other thread, we need to switch back to the stepped thread. */
6451 if (switch_back_to_stepped_thread (ecs))
6454 if (ecs->event_thread->control.step_resume_breakpoint)
6457 fprintf_unfiltered (gdb_stdlog,
6458 "infrun: step-resume breakpoint is inserted\n");
6460 /* Having a step-resume breakpoint overrides anything
6461 else having to do with stepping commands until
6462 that breakpoint is reached. */
6467 if (ecs->event_thread->control.step_range_end == 0)
6470 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6471 /* Likewise if we aren't even stepping. */
6476 /* Re-fetch current thread's frame in case the code above caused
6477 the frame cache to be re-initialized, making our FRAME variable
6478 a dangling pointer. */
6479 frame = get_current_frame ();
6480 gdbarch = get_frame_arch (frame);
6481 fill_in_stop_func (gdbarch, ecs);
6483 /* If stepping through a line, keep going if still within it.
6485 Note that step_range_end is the address of the first instruction
6486 beyond the step range, and NOT the address of the last instruction
6489 Note also that during reverse execution, we may be stepping
6490 through a function epilogue and therefore must detect when
6491 the current-frame changes in the middle of a line. */
6493 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6495 && (execution_direction != EXEC_REVERSE
6496 || frame_id_eq (get_frame_id (frame),
6497 ecs->event_thread->control.step_frame_id)))
6501 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6502 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6503 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6505 /* Tentatively re-enable range stepping; `resume' disables it if
6506 necessary (e.g., if we're stepping over a breakpoint or we
6507 have software watchpoints). */
6508 ecs->event_thread->control.may_range_step = 1;
6510 /* When stepping backward, stop at beginning of line range
6511 (unless it's the function entry point, in which case
6512 keep going back to the call point). */
6513 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6514 if (stop_pc == ecs->event_thread->control.step_range_start
6515 && stop_pc != ecs->stop_func_start
6516 && execution_direction == EXEC_REVERSE)
6517 end_stepping_range (ecs);
6524 /* We stepped out of the stepping range. */
6526 /* If we are stepping at the source level and entered the runtime
6527 loader dynamic symbol resolution code...
6529 EXEC_FORWARD: we keep on single stepping until we exit the run
6530 time loader code and reach the callee's address.
6532 EXEC_REVERSE: we've already executed the callee (backward), and
6533 the runtime loader code is handled just like any other
6534 undebuggable function call. Now we need only keep stepping
6535 backward through the trampoline code, and that's handled further
6536 down, so there is nothing for us to do here. */
6538 if (execution_direction != EXEC_REVERSE
6539 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6540 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6542 CORE_ADDR pc_after_resolver =
6543 gdbarch_skip_solib_resolver (gdbarch,
6544 ecs->event_thread->suspend.stop_pc);
6547 fprintf_unfiltered (gdb_stdlog,
6548 "infrun: stepped into dynsym resolve code\n");
6550 if (pc_after_resolver)
6552 /* Set up a step-resume breakpoint at the address
6553 indicated by SKIP_SOLIB_RESOLVER. */
6554 symtab_and_line sr_sal;
6555 sr_sal.pc = pc_after_resolver;
6556 sr_sal.pspace = get_frame_program_space (frame);
6558 insert_step_resume_breakpoint_at_sal (gdbarch,
6559 sr_sal, null_frame_id);
6566 /* Step through an indirect branch thunk. */
6567 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6568 && gdbarch_in_indirect_branch_thunk (gdbarch,
6569 ecs->event_thread->suspend.stop_pc))
6572 fprintf_unfiltered (gdb_stdlog,
6573 "infrun: stepped into indirect branch thunk\n");
6578 if (ecs->event_thread->control.step_range_end != 1
6579 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6580 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6581 && get_frame_type (frame) == SIGTRAMP_FRAME)
6584 fprintf_unfiltered (gdb_stdlog,
6585 "infrun: stepped into signal trampoline\n");
6586 /* The inferior, while doing a "step" or "next", has ended up in
6587 a signal trampoline (either by a signal being delivered or by
6588 the signal handler returning). Just single-step until the
6589 inferior leaves the trampoline (either by calling the handler
6595 /* If we're in the return path from a shared library trampoline,
6596 we want to proceed through the trampoline when stepping. */
6597 /* macro/2012-04-25: This needs to come before the subroutine
6598 call check below as on some targets return trampolines look
6599 like subroutine calls (MIPS16 return thunks). */
6600 if (gdbarch_in_solib_return_trampoline (gdbarch,
6601 ecs->event_thread->suspend.stop_pc,
6602 ecs->stop_func_name)
6603 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6605 /* Determine where this trampoline returns. */
6606 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6607 CORE_ADDR real_stop_pc
6608 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6611 fprintf_unfiltered (gdb_stdlog,
6612 "infrun: stepped into solib return tramp\n");
6614 /* Only proceed through if we know where it's going. */
6617 /* And put the step-breakpoint there and go until there. */
6618 symtab_and_line sr_sal;
6619 sr_sal.pc = real_stop_pc;
6620 sr_sal.section = find_pc_overlay (sr_sal.pc);
6621 sr_sal.pspace = get_frame_program_space (frame);
6623 /* Do not specify what the fp should be when we stop since
6624 on some machines the prologue is where the new fp value
6626 insert_step_resume_breakpoint_at_sal (gdbarch,
6627 sr_sal, null_frame_id);
6629 /* Restart without fiddling with the step ranges or
6636 /* Check for subroutine calls. The check for the current frame
6637 equalling the step ID is not necessary - the check of the
6638 previous frame's ID is sufficient - but it is a common case and
6639 cheaper than checking the previous frame's ID.
6641 NOTE: frame_id_eq will never report two invalid frame IDs as
6642 being equal, so to get into this block, both the current and
6643 previous frame must have valid frame IDs. */
6644 /* The outer_frame_id check is a heuristic to detect stepping
6645 through startup code. If we step over an instruction which
6646 sets the stack pointer from an invalid value to a valid value,
6647 we may detect that as a subroutine call from the mythical
6648 "outermost" function. This could be fixed by marking
6649 outermost frames as !stack_p,code_p,special_p. Then the
6650 initial outermost frame, before sp was valid, would
6651 have code_addr == &_start. See the comment in frame_id_eq
6653 if (!frame_id_eq (get_stack_frame_id (frame),
6654 ecs->event_thread->control.step_stack_frame_id)
6655 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6656 ecs->event_thread->control.step_stack_frame_id)
6657 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6659 || (ecs->event_thread->control.step_start_function
6660 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6662 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6663 CORE_ADDR real_stop_pc;
6666 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6668 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6670 /* I presume that step_over_calls is only 0 when we're
6671 supposed to be stepping at the assembly language level
6672 ("stepi"). Just stop. */
6673 /* And this works the same backward as frontward. MVS */
6674 end_stepping_range (ecs);
6678 /* Reverse stepping through solib trampolines. */
6680 if (execution_direction == EXEC_REVERSE
6681 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6682 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6683 || (ecs->stop_func_start == 0
6684 && in_solib_dynsym_resolve_code (stop_pc))))
6686 /* Any solib trampoline code can be handled in reverse
6687 by simply continuing to single-step. We have already
6688 executed the solib function (backwards), and a few
6689 steps will take us back through the trampoline to the
6695 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6697 /* We're doing a "next".
6699 Normal (forward) execution: set a breakpoint at the
6700 callee's return address (the address at which the caller
6703 Reverse (backward) execution. set the step-resume
6704 breakpoint at the start of the function that we just
6705 stepped into (backwards), and continue to there. When we
6706 get there, we'll need to single-step back to the caller. */
6708 if (execution_direction == EXEC_REVERSE)
6710 /* If we're already at the start of the function, we've either
6711 just stepped backward into a single instruction function,
6712 or stepped back out of a signal handler to the first instruction
6713 of the function. Just keep going, which will single-step back
6715 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6717 /* Normal function call return (static or dynamic). */
6718 symtab_and_line sr_sal;
6719 sr_sal.pc = ecs->stop_func_start;
6720 sr_sal.pspace = get_frame_program_space (frame);
6721 insert_step_resume_breakpoint_at_sal (gdbarch,
6722 sr_sal, null_frame_id);
6726 insert_step_resume_breakpoint_at_caller (frame);
6732 /* If we are in a function call trampoline (a stub between the
6733 calling routine and the real function), locate the real
6734 function. That's what tells us (a) whether we want to step
6735 into it at all, and (b) what prologue we want to run to the
6736 end of, if we do step into it. */
6737 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6738 if (real_stop_pc == 0)
6739 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6740 if (real_stop_pc != 0)
6741 ecs->stop_func_start = real_stop_pc;
6743 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6745 symtab_and_line sr_sal;
6746 sr_sal.pc = ecs->stop_func_start;
6747 sr_sal.pspace = get_frame_program_space (frame);
6749 insert_step_resume_breakpoint_at_sal (gdbarch,
6750 sr_sal, null_frame_id);
6755 /* If we have line number information for the function we are
6756 thinking of stepping into and the function isn't on the skip
6759 If there are several symtabs at that PC (e.g. with include
6760 files), just want to know whether *any* of them have line
6761 numbers. find_pc_line handles this. */
6763 struct symtab_and_line tmp_sal;
6765 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6766 if (tmp_sal.line != 0
6767 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6770 if (execution_direction == EXEC_REVERSE)
6771 handle_step_into_function_backward (gdbarch, ecs);
6773 handle_step_into_function (gdbarch, ecs);
6778 /* If we have no line number and the step-stop-if-no-debug is
6779 set, we stop the step so that the user has a chance to switch
6780 in assembly mode. */
6781 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6782 && step_stop_if_no_debug)
6784 end_stepping_range (ecs);
6788 if (execution_direction == EXEC_REVERSE)
6790 /* If we're already at the start of the function, we've either just
6791 stepped backward into a single instruction function without line
6792 number info, or stepped back out of a signal handler to the first
6793 instruction of the function without line number info. Just keep
6794 going, which will single-step back to the caller. */
6795 if (ecs->stop_func_start != stop_pc)
6797 /* Set a breakpoint at callee's start address.
6798 From there we can step once and be back in the caller. */
6799 symtab_and_line sr_sal;
6800 sr_sal.pc = ecs->stop_func_start;
6801 sr_sal.pspace = get_frame_program_space (frame);
6802 insert_step_resume_breakpoint_at_sal (gdbarch,
6803 sr_sal, null_frame_id);
6807 /* Set a breakpoint at callee's return address (the address
6808 at which the caller will resume). */
6809 insert_step_resume_breakpoint_at_caller (frame);
6815 /* Reverse stepping through solib trampolines. */
6817 if (execution_direction == EXEC_REVERSE
6818 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6820 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6822 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6823 || (ecs->stop_func_start == 0
6824 && in_solib_dynsym_resolve_code (stop_pc)))
6826 /* Any solib trampoline code can be handled in reverse
6827 by simply continuing to single-step. We have already
6828 executed the solib function (backwards), and a few
6829 steps will take us back through the trampoline to the
6834 else if (in_solib_dynsym_resolve_code (stop_pc))
6836 /* Stepped backward into the solib dynsym resolver.
6837 Set a breakpoint at its start and continue, then
6838 one more step will take us out. */
6839 symtab_and_line sr_sal;
6840 sr_sal.pc = ecs->stop_func_start;
6841 sr_sal.pspace = get_frame_program_space (frame);
6842 insert_step_resume_breakpoint_at_sal (gdbarch,
6843 sr_sal, null_frame_id);
6849 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6851 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6852 the trampoline processing logic, however, there are some trampolines
6853 that have no names, so we should do trampoline handling first. */
6854 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6855 && ecs->stop_func_name == NULL
6856 && stop_pc_sal.line == 0)
6859 fprintf_unfiltered (gdb_stdlog,
6860 "infrun: stepped into undebuggable function\n");
6862 /* The inferior just stepped into, or returned to, an
6863 undebuggable function (where there is no debugging information
6864 and no line number corresponding to the address where the
6865 inferior stopped). Since we want to skip this kind of code,
6866 we keep going until the inferior returns from this
6867 function - unless the user has asked us not to (via
6868 set step-mode) or we no longer know how to get back
6869 to the call site. */
6870 if (step_stop_if_no_debug
6871 || !frame_id_p (frame_unwind_caller_id (frame)))
6873 /* If we have no line number and the step-stop-if-no-debug
6874 is set, we stop the step so that the user has a chance to
6875 switch in assembly mode. */
6876 end_stepping_range (ecs);
6881 /* Set a breakpoint at callee's return address (the address
6882 at which the caller will resume). */
6883 insert_step_resume_breakpoint_at_caller (frame);
6889 if (ecs->event_thread->control.step_range_end == 1)
6891 /* It is stepi or nexti. We always want to stop stepping after
6894 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6895 end_stepping_range (ecs);
6899 if (stop_pc_sal.line == 0)
6901 /* We have no line number information. That means to stop
6902 stepping (does this always happen right after one instruction,
6903 when we do "s" in a function with no line numbers,
6904 or can this happen as a result of a return or longjmp?). */
6906 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6907 end_stepping_range (ecs);
6911 /* Look for "calls" to inlined functions, part one. If the inline
6912 frame machinery detected some skipped call sites, we have entered
6913 a new inline function. */
6915 if (frame_id_eq (get_frame_id (get_current_frame ()),
6916 ecs->event_thread->control.step_frame_id)
6917 && inline_skipped_frames (ecs->event_thread))
6920 fprintf_unfiltered (gdb_stdlog,
6921 "infrun: stepped into inlined function\n");
6923 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6925 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6927 /* For "step", we're going to stop. But if the call site
6928 for this inlined function is on the same source line as
6929 we were previously stepping, go down into the function
6930 first. Otherwise stop at the call site. */
6932 if (call_sal.line == ecs->event_thread->current_line
6933 && call_sal.symtab == ecs->event_thread->current_symtab)
6934 step_into_inline_frame (ecs->event_thread);
6936 end_stepping_range (ecs);
6941 /* For "next", we should stop at the call site if it is on a
6942 different source line. Otherwise continue through the
6943 inlined function. */
6944 if (call_sal.line == ecs->event_thread->current_line
6945 && call_sal.symtab == ecs->event_thread->current_symtab)
6948 end_stepping_range (ecs);
6953 /* Look for "calls" to inlined functions, part two. If we are still
6954 in the same real function we were stepping through, but we have
6955 to go further up to find the exact frame ID, we are stepping
6956 through a more inlined call beyond its call site. */
6958 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6959 && !frame_id_eq (get_frame_id (get_current_frame ()),
6960 ecs->event_thread->control.step_frame_id)
6961 && stepped_in_from (get_current_frame (),
6962 ecs->event_thread->control.step_frame_id))
6965 fprintf_unfiltered (gdb_stdlog,
6966 "infrun: stepping through inlined function\n");
6968 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6971 end_stepping_range (ecs);
6975 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6976 && (ecs->event_thread->current_line != stop_pc_sal.line
6977 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6979 /* We are at the start of a different line. So stop. Note that
6980 we don't stop if we step into the middle of a different line.
6981 That is said to make things like for (;;) statements work
6984 fprintf_unfiltered (gdb_stdlog,
6985 "infrun: stepped to a different line\n");
6986 end_stepping_range (ecs);
6990 /* We aren't done stepping.
6992 Optimize by setting the stepping range to the line.
6993 (We might not be in the original line, but if we entered a
6994 new line in mid-statement, we continue stepping. This makes
6995 things like for(;;) statements work better.) */
6997 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6998 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6999 ecs->event_thread->control.may_range_step = 1;
7000 set_step_info (frame, stop_pc_sal);
7003 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
7007 /* In all-stop mode, if we're currently stepping but have stopped in
7008 some other thread, we may need to switch back to the stepped
7009 thread. Returns true we set the inferior running, false if we left
7010 it stopped (and the event needs further processing). */
7013 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7015 if (!target_is_non_stop_p ())
7017 struct thread_info *tp;
7018 struct thread_info *stepping_thread;
7020 /* If any thread is blocked on some internal breakpoint, and we
7021 simply need to step over that breakpoint to get it going
7022 again, do that first. */
7024 /* However, if we see an event for the stepping thread, then we
7025 know all other threads have been moved past their breakpoints
7026 already. Let the caller check whether the step is finished,
7027 etc., before deciding to move it past a breakpoint. */
7028 if (ecs->event_thread->control.step_range_end != 0)
7031 /* Check if the current thread is blocked on an incomplete
7032 step-over, interrupted by a random signal. */
7033 if (ecs->event_thread->control.trap_expected
7034 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7038 fprintf_unfiltered (gdb_stdlog,
7039 "infrun: need to finish step-over of [%s]\n",
7040 target_pid_to_str (ecs->event_thread->ptid));
7046 /* Check if the current thread is blocked by a single-step
7047 breakpoint of another thread. */
7048 if (ecs->hit_singlestep_breakpoint)
7052 fprintf_unfiltered (gdb_stdlog,
7053 "infrun: need to step [%s] over single-step "
7055 target_pid_to_str (ecs->ptid));
7061 /* If this thread needs yet another step-over (e.g., stepping
7062 through a delay slot), do it first before moving on to
7064 if (thread_still_needs_step_over (ecs->event_thread))
7068 fprintf_unfiltered (gdb_stdlog,
7069 "infrun: thread [%s] still needs step-over\n",
7070 target_pid_to_str (ecs->event_thread->ptid));
7076 /* If scheduler locking applies even if not stepping, there's no
7077 need to walk over threads. Above we've checked whether the
7078 current thread is stepping. If some other thread not the
7079 event thread is stepping, then it must be that scheduler
7080 locking is not in effect. */
7081 if (schedlock_applies (ecs->event_thread))
7084 /* Otherwise, we no longer expect a trap in the current thread.
7085 Clear the trap_expected flag before switching back -- this is
7086 what keep_going does as well, if we call it. */
7087 ecs->event_thread->control.trap_expected = 0;
7089 /* Likewise, clear the signal if it should not be passed. */
7090 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7091 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7093 /* Do all pending step-overs before actually proceeding with
7095 if (start_step_over ())
7097 prepare_to_wait (ecs);
7101 /* Look for the stepping/nexting thread. */
7102 stepping_thread = NULL;
7104 ALL_NON_EXITED_THREADS (tp)
7106 /* Ignore threads of processes the caller is not
7109 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7112 /* When stepping over a breakpoint, we lock all threads
7113 except the one that needs to move past the breakpoint.
7114 If a non-event thread has this set, the "incomplete
7115 step-over" check above should have caught it earlier. */
7116 if (tp->control.trap_expected)
7118 internal_error (__FILE__, __LINE__,
7119 "[%s] has inconsistent state: "
7120 "trap_expected=%d\n",
7121 target_pid_to_str (tp->ptid),
7122 tp->control.trap_expected);
7125 /* Did we find the stepping thread? */
7126 if (tp->control.step_range_end)
7128 /* Yep. There should only one though. */
7129 gdb_assert (stepping_thread == NULL);
7131 /* The event thread is handled at the top, before we
7133 gdb_assert (tp != ecs->event_thread);
7135 /* If some thread other than the event thread is
7136 stepping, then scheduler locking can't be in effect,
7137 otherwise we wouldn't have resumed the current event
7138 thread in the first place. */
7139 gdb_assert (!schedlock_applies (tp));
7141 stepping_thread = tp;
7145 if (stepping_thread != NULL)
7148 fprintf_unfiltered (gdb_stdlog,
7149 "infrun: switching back to stepped thread\n");
7151 if (keep_going_stepped_thread (stepping_thread))
7153 prepare_to_wait (ecs);
7162 /* Set a previously stepped thread back to stepping. Returns true on
7163 success, false if the resume is not possible (e.g., the thread
7167 keep_going_stepped_thread (struct thread_info *tp)
7169 struct frame_info *frame;
7170 struct execution_control_state ecss;
7171 struct execution_control_state *ecs = &ecss;
7173 /* If the stepping thread exited, then don't try to switch back and
7174 resume it, which could fail in several different ways depending
7175 on the target. Instead, just keep going.
7177 We can find a stepping dead thread in the thread list in two
7180 - The target supports thread exit events, and when the target
7181 tries to delete the thread from the thread list, inferior_ptid
7182 pointed at the exiting thread. In such case, calling
7183 delete_thread does not really remove the thread from the list;
7184 instead, the thread is left listed, with 'exited' state.
7186 - The target's debug interface does not support thread exit
7187 events, and so we have no idea whatsoever if the previously
7188 stepping thread is still alive. For that reason, we need to
7189 synchronously query the target now. */
7191 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
7194 fprintf_unfiltered (gdb_stdlog,
7195 "infrun: not resuming previously "
7196 "stepped thread, it has vanished\n");
7203 fprintf_unfiltered (gdb_stdlog,
7204 "infrun: resuming previously stepped thread\n");
7206 reset_ecs (ecs, tp);
7207 switch_to_thread (tp);
7209 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7210 frame = get_current_frame ();
7212 /* If the PC of the thread we were trying to single-step has
7213 changed, then that thread has trapped or been signaled, but the
7214 event has not been reported to GDB yet. Re-poll the target
7215 looking for this particular thread's event (i.e. temporarily
7216 enable schedlock) by:
7218 - setting a break at the current PC
7219 - resuming that particular thread, only (by setting trap
7222 This prevents us continuously moving the single-step breakpoint
7223 forward, one instruction at a time, overstepping. */
7225 if (tp->suspend.stop_pc != tp->prev_pc)
7230 fprintf_unfiltered (gdb_stdlog,
7231 "infrun: expected thread advanced also (%s -> %s)\n",
7232 paddress (target_gdbarch (), tp->prev_pc),
7233 paddress (target_gdbarch (), tp->suspend.stop_pc));
7235 /* Clear the info of the previous step-over, as it's no longer
7236 valid (if the thread was trying to step over a breakpoint, it
7237 has already succeeded). It's what keep_going would do too,
7238 if we called it. Do this before trying to insert the sss
7239 breakpoint, otherwise if we were previously trying to step
7240 over this exact address in another thread, the breakpoint is
7242 clear_step_over_info ();
7243 tp->control.trap_expected = 0;
7245 insert_single_step_breakpoint (get_frame_arch (frame),
7246 get_frame_address_space (frame),
7247 tp->suspend.stop_pc);
7250 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7251 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7256 fprintf_unfiltered (gdb_stdlog,
7257 "infrun: expected thread still hasn't advanced\n");
7259 keep_going_pass_signal (ecs);
7264 /* Is thread TP in the middle of (software or hardware)
7265 single-stepping? (Note the result of this function must never be
7266 passed directly as target_resume's STEP parameter.) */
7269 currently_stepping (struct thread_info *tp)
7271 return ((tp->control.step_range_end
7272 && tp->control.step_resume_breakpoint == NULL)
7273 || tp->control.trap_expected
7274 || tp->stepped_breakpoint
7275 || bpstat_should_step ());
7278 /* Inferior has stepped into a subroutine call with source code that
7279 we should not step over. Do step to the first line of code in
7283 handle_step_into_function (struct gdbarch *gdbarch,
7284 struct execution_control_state *ecs)
7286 fill_in_stop_func (gdbarch, ecs);
7288 compunit_symtab *cust
7289 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7290 if (cust != NULL && compunit_language (cust) != language_asm)
7291 ecs->stop_func_start
7292 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7294 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7295 /* Use the step_resume_break to step until the end of the prologue,
7296 even if that involves jumps (as it seems to on the vax under
7298 /* If the prologue ends in the middle of a source line, continue to
7299 the end of that source line (if it is still within the function).
7300 Otherwise, just go to end of prologue. */
7301 if (stop_func_sal.end
7302 && stop_func_sal.pc != ecs->stop_func_start
7303 && stop_func_sal.end < ecs->stop_func_end)
7304 ecs->stop_func_start = stop_func_sal.end;
7306 /* Architectures which require breakpoint adjustment might not be able
7307 to place a breakpoint at the computed address. If so, the test
7308 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7309 ecs->stop_func_start to an address at which a breakpoint may be
7310 legitimately placed.
7312 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7313 made, GDB will enter an infinite loop when stepping through
7314 optimized code consisting of VLIW instructions which contain
7315 subinstructions corresponding to different source lines. On
7316 FR-V, it's not permitted to place a breakpoint on any but the
7317 first subinstruction of a VLIW instruction. When a breakpoint is
7318 set, GDB will adjust the breakpoint address to the beginning of
7319 the VLIW instruction. Thus, we need to make the corresponding
7320 adjustment here when computing the stop address. */
7322 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7324 ecs->stop_func_start
7325 = gdbarch_adjust_breakpoint_address (gdbarch,
7326 ecs->stop_func_start);
7329 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7331 /* We are already there: stop now. */
7332 end_stepping_range (ecs);
7337 /* Put the step-breakpoint there and go until there. */
7338 symtab_and_line sr_sal;
7339 sr_sal.pc = ecs->stop_func_start;
7340 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7341 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7343 /* Do not specify what the fp should be when we stop since on
7344 some machines the prologue is where the new fp value is
7346 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7348 /* And make sure stepping stops right away then. */
7349 ecs->event_thread->control.step_range_end
7350 = ecs->event_thread->control.step_range_start;
7355 /* Inferior has stepped backward into a subroutine call with source
7356 code that we should not step over. Do step to the beginning of the
7357 last line of code in it. */
7360 handle_step_into_function_backward (struct gdbarch *gdbarch,
7361 struct execution_control_state *ecs)
7363 struct compunit_symtab *cust;
7364 struct symtab_and_line stop_func_sal;
7366 fill_in_stop_func (gdbarch, ecs);
7368 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7369 if (cust != NULL && compunit_language (cust) != language_asm)
7370 ecs->stop_func_start
7371 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7373 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7375 /* OK, we're just going to keep stepping here. */
7376 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7378 /* We're there already. Just stop stepping now. */
7379 end_stepping_range (ecs);
7383 /* Else just reset the step range and keep going.
7384 No step-resume breakpoint, they don't work for
7385 epilogues, which can have multiple entry paths. */
7386 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7387 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7393 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7394 This is used to both functions and to skip over code. */
7397 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7398 struct symtab_and_line sr_sal,
7399 struct frame_id sr_id,
7400 enum bptype sr_type)
7402 /* There should never be more than one step-resume or longjmp-resume
7403 breakpoint per thread, so we should never be setting a new
7404 step_resume_breakpoint when one is already active. */
7405 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7406 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7409 fprintf_unfiltered (gdb_stdlog,
7410 "infrun: inserting step-resume breakpoint at %s\n",
7411 paddress (gdbarch, sr_sal.pc));
7413 inferior_thread ()->control.step_resume_breakpoint
7414 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7418 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7419 struct symtab_and_line sr_sal,
7420 struct frame_id sr_id)
7422 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7427 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7428 This is used to skip a potential signal handler.
7430 This is called with the interrupted function's frame. The signal
7431 handler, when it returns, will resume the interrupted function at
7435 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7437 gdb_assert (return_frame != NULL);
7439 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7441 symtab_and_line sr_sal;
7442 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7443 sr_sal.section = find_pc_overlay (sr_sal.pc);
7444 sr_sal.pspace = get_frame_program_space (return_frame);
7446 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7447 get_stack_frame_id (return_frame),
7451 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7452 is used to skip a function after stepping into it (for "next" or if
7453 the called function has no debugging information).
7455 The current function has almost always been reached by single
7456 stepping a call or return instruction. NEXT_FRAME belongs to the
7457 current function, and the breakpoint will be set at the caller's
7460 This is a separate function rather than reusing
7461 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7462 get_prev_frame, which may stop prematurely (see the implementation
7463 of frame_unwind_caller_id for an example). */
7466 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7468 /* We shouldn't have gotten here if we don't know where the call site
7470 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7472 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7474 symtab_and_line sr_sal;
7475 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7476 frame_unwind_caller_pc (next_frame));
7477 sr_sal.section = find_pc_overlay (sr_sal.pc);
7478 sr_sal.pspace = frame_unwind_program_space (next_frame);
7480 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7481 frame_unwind_caller_id (next_frame));
7484 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7485 new breakpoint at the target of a jmp_buf. The handling of
7486 longjmp-resume uses the same mechanisms used for handling
7487 "step-resume" breakpoints. */
7490 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7492 /* There should never be more than one longjmp-resume breakpoint per
7493 thread, so we should never be setting a new
7494 longjmp_resume_breakpoint when one is already active. */
7495 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7498 fprintf_unfiltered (gdb_stdlog,
7499 "infrun: inserting longjmp-resume breakpoint at %s\n",
7500 paddress (gdbarch, pc));
7502 inferior_thread ()->control.exception_resume_breakpoint =
7503 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7506 /* Insert an exception resume breakpoint. TP is the thread throwing
7507 the exception. The block B is the block of the unwinder debug hook
7508 function. FRAME is the frame corresponding to the call to this
7509 function. SYM is the symbol of the function argument holding the
7510 target PC of the exception. */
7513 insert_exception_resume_breakpoint (struct thread_info *tp,
7514 const struct block *b,
7515 struct frame_info *frame,
7520 struct block_symbol vsym;
7521 struct value *value;
7523 struct breakpoint *bp;
7525 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7527 value = read_var_value (vsym.symbol, vsym.block, frame);
7528 /* If the value was optimized out, revert to the old behavior. */
7529 if (! value_optimized_out (value))
7531 handler = value_as_address (value);
7534 fprintf_unfiltered (gdb_stdlog,
7535 "infrun: exception resume at %lx\n",
7536 (unsigned long) handler);
7538 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7540 bp_exception_resume).release ();
7542 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7545 bp->thread = tp->global_num;
7546 inferior_thread ()->control.exception_resume_breakpoint = bp;
7549 CATCH (e, RETURN_MASK_ERROR)
7551 /* We want to ignore errors here. */
7556 /* A helper for check_exception_resume that sets an
7557 exception-breakpoint based on a SystemTap probe. */
7560 insert_exception_resume_from_probe (struct thread_info *tp,
7561 const struct bound_probe *probe,
7562 struct frame_info *frame)
7564 struct value *arg_value;
7566 struct breakpoint *bp;
7568 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7572 handler = value_as_address (arg_value);
7575 fprintf_unfiltered (gdb_stdlog,
7576 "infrun: exception resume at %s\n",
7577 paddress (get_objfile_arch (probe->objfile),
7580 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7581 handler, bp_exception_resume).release ();
7582 bp->thread = tp->global_num;
7583 inferior_thread ()->control.exception_resume_breakpoint = bp;
7586 /* This is called when an exception has been intercepted. Check to
7587 see whether the exception's destination is of interest, and if so,
7588 set an exception resume breakpoint there. */
7591 check_exception_resume (struct execution_control_state *ecs,
7592 struct frame_info *frame)
7594 struct bound_probe probe;
7595 struct symbol *func;
7597 /* First see if this exception unwinding breakpoint was set via a
7598 SystemTap probe point. If so, the probe has two arguments: the
7599 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7600 set a breakpoint there. */
7601 probe = find_probe_by_pc (get_frame_pc (frame));
7604 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7608 func = get_frame_function (frame);
7614 const struct block *b;
7615 struct block_iterator iter;
7619 /* The exception breakpoint is a thread-specific breakpoint on
7620 the unwinder's debug hook, declared as:
7622 void _Unwind_DebugHook (void *cfa, void *handler);
7624 The CFA argument indicates the frame to which control is
7625 about to be transferred. HANDLER is the destination PC.
7627 We ignore the CFA and set a temporary breakpoint at HANDLER.
7628 This is not extremely efficient but it avoids issues in gdb
7629 with computing the DWARF CFA, and it also works even in weird
7630 cases such as throwing an exception from inside a signal
7633 b = SYMBOL_BLOCK_VALUE (func);
7634 ALL_BLOCK_SYMBOLS (b, iter, sym)
7636 if (!SYMBOL_IS_ARGUMENT (sym))
7643 insert_exception_resume_breakpoint (ecs->event_thread,
7649 CATCH (e, RETURN_MASK_ERROR)
7656 stop_waiting (struct execution_control_state *ecs)
7659 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7661 /* Let callers know we don't want to wait for the inferior anymore. */
7662 ecs->wait_some_more = 0;
7664 /* If all-stop, but the target is always in non-stop mode, stop all
7665 threads now that we're presenting the stop to the user. */
7666 if (!non_stop && target_is_non_stop_p ())
7667 stop_all_threads ();
7670 /* Like keep_going, but passes the signal to the inferior, even if the
7671 signal is set to nopass. */
7674 keep_going_pass_signal (struct execution_control_state *ecs)
7676 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7677 gdb_assert (!ecs->event_thread->resumed);
7679 /* Save the pc before execution, to compare with pc after stop. */
7680 ecs->event_thread->prev_pc
7681 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7683 if (ecs->event_thread->control.trap_expected)
7685 struct thread_info *tp = ecs->event_thread;
7688 fprintf_unfiltered (gdb_stdlog,
7689 "infrun: %s has trap_expected set, "
7690 "resuming to collect trap\n",
7691 target_pid_to_str (tp->ptid));
7693 /* We haven't yet gotten our trap, and either: intercepted a
7694 non-signal event (e.g., a fork); or took a signal which we
7695 are supposed to pass through to the inferior. Simply
7697 resume (ecs->event_thread->suspend.stop_signal);
7699 else if (step_over_info_valid_p ())
7701 /* Another thread is stepping over a breakpoint in-line. If
7702 this thread needs a step-over too, queue the request. In
7703 either case, this resume must be deferred for later. */
7704 struct thread_info *tp = ecs->event_thread;
7706 if (ecs->hit_singlestep_breakpoint
7707 || thread_still_needs_step_over (tp))
7710 fprintf_unfiltered (gdb_stdlog,
7711 "infrun: step-over already in progress: "
7712 "step-over for %s deferred\n",
7713 target_pid_to_str (tp->ptid));
7714 thread_step_over_chain_enqueue (tp);
7719 fprintf_unfiltered (gdb_stdlog,
7720 "infrun: step-over in progress: "
7721 "resume of %s deferred\n",
7722 target_pid_to_str (tp->ptid));
7727 struct regcache *regcache = get_current_regcache ();
7730 step_over_what step_what;
7732 /* Either the trap was not expected, but we are continuing
7733 anyway (if we got a signal, the user asked it be passed to
7736 We got our expected trap, but decided we should resume from
7739 We're going to run this baby now!
7741 Note that insert_breakpoints won't try to re-insert
7742 already inserted breakpoints. Therefore, we don't
7743 care if breakpoints were already inserted, or not. */
7745 /* If we need to step over a breakpoint, and we're not using
7746 displaced stepping to do so, insert all breakpoints
7747 (watchpoints, etc.) but the one we're stepping over, step one
7748 instruction, and then re-insert the breakpoint when that step
7751 step_what = thread_still_needs_step_over (ecs->event_thread);
7753 remove_bp = (ecs->hit_singlestep_breakpoint
7754 || (step_what & STEP_OVER_BREAKPOINT));
7755 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7757 /* We can't use displaced stepping if we need to step past a
7758 watchpoint. The instruction copied to the scratch pad would
7759 still trigger the watchpoint. */
7761 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7763 set_step_over_info (regcache->aspace (),
7764 regcache_read_pc (regcache), remove_wps,
7765 ecs->event_thread->global_num);
7767 else if (remove_wps)
7768 set_step_over_info (NULL, 0, remove_wps, -1);
7770 /* If we now need to do an in-line step-over, we need to stop
7771 all other threads. Note this must be done before
7772 insert_breakpoints below, because that removes the breakpoint
7773 we're about to step over, otherwise other threads could miss
7775 if (step_over_info_valid_p () && target_is_non_stop_p ())
7776 stop_all_threads ();
7778 /* Stop stepping if inserting breakpoints fails. */
7781 insert_breakpoints ();
7783 CATCH (e, RETURN_MASK_ERROR)
7785 exception_print (gdb_stderr, e);
7787 clear_step_over_info ();
7792 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7794 resume (ecs->event_thread->suspend.stop_signal);
7797 prepare_to_wait (ecs);
7800 /* Called when we should continue running the inferior, because the
7801 current event doesn't cause a user visible stop. This does the
7802 resuming part; waiting for the next event is done elsewhere. */
7805 keep_going (struct execution_control_state *ecs)
7807 if (ecs->event_thread->control.trap_expected
7808 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7809 ecs->event_thread->control.trap_expected = 0;
7811 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7812 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7813 keep_going_pass_signal (ecs);
7816 /* This function normally comes after a resume, before
7817 handle_inferior_event exits. It takes care of any last bits of
7818 housekeeping, and sets the all-important wait_some_more flag. */
7821 prepare_to_wait (struct execution_control_state *ecs)
7824 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7826 ecs->wait_some_more = 1;
7828 if (!target_is_async_p ())
7829 mark_infrun_async_event_handler ();
7832 /* We are done with the step range of a step/next/si/ni command.
7833 Called once for each n of a "step n" operation. */
7836 end_stepping_range (struct execution_control_state *ecs)
7838 ecs->event_thread->control.stop_step = 1;
7842 /* Several print_*_reason functions to print why the inferior has stopped.
7843 We always print something when the inferior exits, or receives a signal.
7844 The rest of the cases are dealt with later on in normal_stop and
7845 print_it_typical. Ideally there should be a call to one of these
7846 print_*_reason functions functions from handle_inferior_event each time
7847 stop_waiting is called.
7849 Note that we don't call these directly, instead we delegate that to
7850 the interpreters, through observers. Interpreters then call these
7851 with whatever uiout is right. */
7854 print_end_stepping_range_reason (struct ui_out *uiout)
7856 /* For CLI-like interpreters, print nothing. */
7858 if (uiout->is_mi_like_p ())
7860 uiout->field_string ("reason",
7861 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7866 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7868 annotate_signalled ();
7869 if (uiout->is_mi_like_p ())
7871 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7872 uiout->text ("\nProgram terminated with signal ");
7873 annotate_signal_name ();
7874 uiout->field_string ("signal-name",
7875 gdb_signal_to_name (siggnal));
7876 annotate_signal_name_end ();
7878 annotate_signal_string ();
7879 uiout->field_string ("signal-meaning",
7880 gdb_signal_to_string (siggnal));
7881 annotate_signal_string_end ();
7882 uiout->text (".\n");
7883 uiout->text ("The program no longer exists.\n");
7887 print_exited_reason (struct ui_out *uiout, int exitstatus)
7889 struct inferior *inf = current_inferior ();
7890 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7892 annotate_exited (exitstatus);
7895 if (uiout->is_mi_like_p ())
7896 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7897 uiout->text ("[Inferior ");
7898 uiout->text (plongest (inf->num));
7900 uiout->text (pidstr);
7901 uiout->text (") exited with code ");
7902 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7903 uiout->text ("]\n");
7907 if (uiout->is_mi_like_p ())
7909 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7910 uiout->text ("[Inferior ");
7911 uiout->text (plongest (inf->num));
7913 uiout->text (pidstr);
7914 uiout->text (") exited normally]\n");
7918 /* Some targets/architectures can do extra processing/display of
7919 segmentation faults. E.g., Intel MPX boundary faults.
7920 Call the architecture dependent function to handle the fault. */
7923 handle_segmentation_fault (struct ui_out *uiout)
7925 struct regcache *regcache = get_current_regcache ();
7926 struct gdbarch *gdbarch = regcache->arch ();
7928 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7929 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7933 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7935 struct thread_info *thr = inferior_thread ();
7939 if (uiout->is_mi_like_p ())
7941 else if (show_thread_that_caused_stop ())
7945 uiout->text ("\nThread ");
7946 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7948 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7951 uiout->text (" \"");
7952 uiout->field_fmt ("name", "%s", name);
7957 uiout->text ("\nProgram");
7959 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7960 uiout->text (" stopped");
7963 uiout->text (" received signal ");
7964 annotate_signal_name ();
7965 if (uiout->is_mi_like_p ())
7967 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7968 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7969 annotate_signal_name_end ();
7971 annotate_signal_string ();
7972 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7974 if (siggnal == GDB_SIGNAL_SEGV)
7975 handle_segmentation_fault (uiout);
7977 annotate_signal_string_end ();
7979 uiout->text (".\n");
7983 print_no_history_reason (struct ui_out *uiout)
7985 uiout->text ("\nNo more reverse-execution history.\n");
7988 /* Print current location without a level number, if we have changed
7989 functions or hit a breakpoint. Print source line if we have one.
7990 bpstat_print contains the logic deciding in detail what to print,
7991 based on the event(s) that just occurred. */
7994 print_stop_location (struct target_waitstatus *ws)
7997 enum print_what source_flag;
7998 int do_frame_printing = 1;
7999 struct thread_info *tp = inferior_thread ();
8001 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8005 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8006 should) carry around the function and does (or should) use
8007 that when doing a frame comparison. */
8008 if (tp->control.stop_step
8009 && frame_id_eq (tp->control.step_frame_id,
8010 get_frame_id (get_current_frame ()))
8011 && (tp->control.step_start_function
8012 == find_pc_function (tp->suspend.stop_pc)))
8014 /* Finished step, just print source line. */
8015 source_flag = SRC_LINE;
8019 /* Print location and source line. */
8020 source_flag = SRC_AND_LOC;
8023 case PRINT_SRC_AND_LOC:
8024 /* Print location and source line. */
8025 source_flag = SRC_AND_LOC;
8027 case PRINT_SRC_ONLY:
8028 source_flag = SRC_LINE;
8031 /* Something bogus. */
8032 source_flag = SRC_LINE;
8033 do_frame_printing = 0;
8036 internal_error (__FILE__, __LINE__, _("Unknown value."));
8039 /* The behavior of this routine with respect to the source
8041 SRC_LINE: Print only source line
8042 LOCATION: Print only location
8043 SRC_AND_LOC: Print location and source line. */
8044 if (do_frame_printing)
8045 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8051 print_stop_event (struct ui_out *uiout)
8053 struct target_waitstatus last;
8055 struct thread_info *tp;
8057 get_last_target_status (&last_ptid, &last);
8060 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8062 print_stop_location (&last);
8064 /* Display the auto-display expressions. */
8068 tp = inferior_thread ();
8069 if (tp->thread_fsm != NULL
8070 && thread_fsm_finished_p (tp->thread_fsm))
8072 struct return_value_info *rv;
8074 rv = thread_fsm_return_value (tp->thread_fsm);
8076 print_return_value (uiout, rv);
8083 maybe_remove_breakpoints (void)
8085 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8087 if (remove_breakpoints ())
8089 target_terminal::ours_for_output ();
8090 printf_filtered (_("Cannot remove breakpoints because "
8091 "program is no longer writable.\nFurther "
8092 "execution is probably impossible.\n"));
8097 /* The execution context that just caused a normal stop. */
8104 /* The event PTID. */
8108 /* If stopp for a thread event, this is the thread that caused the
8110 struct thread_info *thread;
8112 /* The inferior that caused the stop. */
8116 /* Returns a new stop context. If stopped for a thread event, this
8117 takes a strong reference to the thread. */
8119 static struct stop_context *
8120 save_stop_context (void)
8122 struct stop_context *sc = XNEW (struct stop_context);
8124 sc->stop_id = get_stop_id ();
8125 sc->ptid = inferior_ptid;
8126 sc->inf_num = current_inferior ()->num;
8128 if (!ptid_equal (inferior_ptid, null_ptid))
8130 /* Take a strong reference so that the thread can't be deleted
8132 sc->thread = inferior_thread ();
8133 sc->thread->incref ();
8141 /* Release a stop context previously created with save_stop_context.
8142 Releases the strong reference to the thread as well. */
8145 release_stop_context_cleanup (void *arg)
8147 struct stop_context *sc = (struct stop_context *) arg;
8149 if (sc->thread != NULL)
8150 sc->thread->decref ();
8154 /* Return true if the current context no longer matches the saved stop
8158 stop_context_changed (struct stop_context *prev)
8160 if (!ptid_equal (prev->ptid, inferior_ptid))
8162 if (prev->inf_num != current_inferior ()->num)
8164 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8166 if (get_stop_id () != prev->stop_id)
8176 struct target_waitstatus last;
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 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
8191 maybe_finish_thread_state.emplace (minus_one_ptid);
8192 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8193 || last.kind == TARGET_WAITKIND_EXITED)
8195 /* On some targets, we may still have live threads in the
8196 inferior when we get a process exit event. E.g., for
8197 "checkpoint", when the current checkpoint/fork exits,
8198 linux-fork.c automatically switches to another fork from
8199 within target_mourn_inferior. */
8200 if (inferior_ptid != null_ptid)
8201 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8203 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8204 maybe_finish_thread_state.emplace (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 gdb::observers::signal_received.notify (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 && 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 maybe_finish_thread_state.reset ();
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 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8345 gdb::observers::normal_stop.notify (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 (const 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 (const 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 (current_top_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 (current_top_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;
8816 readonly_detached_regcache *registers;
8818 /* Format of SIGINFO_DATA or NULL if it is not present. */
8819 struct gdbarch *siginfo_gdbarch;
8821 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8822 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8823 content would be invalid. */
8824 gdb_byte *siginfo_data;
8827 struct infcall_suspend_state *
8828 save_infcall_suspend_state (void)
8830 struct infcall_suspend_state *inf_state;
8831 struct thread_info *tp = inferior_thread ();
8832 struct regcache *regcache = get_current_regcache ();
8833 struct gdbarch *gdbarch = regcache->arch ();
8834 gdb_byte *siginfo_data = NULL;
8836 if (gdbarch_get_siginfo_type_p (gdbarch))
8838 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8839 size_t len = TYPE_LENGTH (type);
8840 struct cleanup *back_to;
8842 siginfo_data = (gdb_byte *) xmalloc (len);
8843 back_to = make_cleanup (xfree, siginfo_data);
8845 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8846 siginfo_data, 0, len) == len)
8847 discard_cleanups (back_to);
8850 /* Errors ignored. */
8851 do_cleanups (back_to);
8852 siginfo_data = NULL;
8856 inf_state = XCNEW (struct infcall_suspend_state);
8860 inf_state->siginfo_gdbarch = gdbarch;
8861 inf_state->siginfo_data = siginfo_data;
8864 inf_state->thread_suspend = tp->suspend;
8866 /* run_inferior_call will not use the signal due to its `proceed' call with
8867 GDB_SIGNAL_0 anyway. */
8868 tp->suspend.stop_signal = GDB_SIGNAL_0;
8870 inf_state->registers = new readonly_detached_regcache (*regcache);
8875 /* Restore inferior session state to INF_STATE. */
8878 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8880 struct thread_info *tp = inferior_thread ();
8881 struct regcache *regcache = get_current_regcache ();
8882 struct gdbarch *gdbarch = regcache->arch ();
8884 tp->suspend = inf_state->thread_suspend;
8886 if (inf_state->siginfo_gdbarch == gdbarch)
8888 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8890 /* Errors ignored. */
8891 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8892 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8895 /* The inferior can be gone if the user types "print exit(0)"
8896 (and perhaps other times). */
8897 if (target_has_execution)
8898 /* NB: The register write goes through to the target. */
8899 regcache->restore (inf_state->registers);
8901 discard_infcall_suspend_state (inf_state);
8905 do_restore_infcall_suspend_state_cleanup (void *state)
8907 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8911 make_cleanup_restore_infcall_suspend_state
8912 (struct infcall_suspend_state *inf_state)
8914 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8918 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8920 delete inf_state->registers;
8921 xfree (inf_state->siginfo_data);
8925 readonly_detached_regcache *
8926 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8928 return inf_state->registers;
8931 /* infcall_control_state contains state regarding gdb's control of the
8932 inferior itself like stepping control. It also contains session state like
8933 the user's currently selected frame. */
8935 struct infcall_control_state
8937 struct thread_control_state thread_control;
8938 struct inferior_control_state inferior_control;
8941 enum stop_stack_kind stop_stack_dummy;
8942 int stopped_by_random_signal;
8944 /* ID if the selected frame when the inferior function call was made. */
8945 struct frame_id selected_frame_id;
8948 /* Save all of the information associated with the inferior<==>gdb
8951 struct infcall_control_state *
8952 save_infcall_control_state (void)
8954 struct infcall_control_state *inf_status =
8955 XNEW (struct infcall_control_state);
8956 struct thread_info *tp = inferior_thread ();
8957 struct inferior *inf = current_inferior ();
8959 inf_status->thread_control = tp->control;
8960 inf_status->inferior_control = inf->control;
8962 tp->control.step_resume_breakpoint = NULL;
8963 tp->control.exception_resume_breakpoint = NULL;
8965 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8966 chain. If caller's caller is walking the chain, they'll be happier if we
8967 hand them back the original chain when restore_infcall_control_state is
8969 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8972 inf_status->stop_stack_dummy = stop_stack_dummy;
8973 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8975 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8981 restore_selected_frame (const frame_id &fid)
8983 frame_info *frame = frame_find_by_id (fid);
8985 /* If inf_status->selected_frame_id is NULL, there was no previously
8989 warning (_("Unable to restore previously selected frame."));
8993 select_frame (frame);
8996 /* Restore inferior session state to INF_STATUS. */
8999 restore_infcall_control_state (struct infcall_control_state *inf_status)
9001 struct thread_info *tp = inferior_thread ();
9002 struct inferior *inf = current_inferior ();
9004 if (tp->control.step_resume_breakpoint)
9005 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
9007 if (tp->control.exception_resume_breakpoint)
9008 tp->control.exception_resume_breakpoint->disposition
9009 = disp_del_at_next_stop;
9011 /* Handle the bpstat_copy of the chain. */
9012 bpstat_clear (&tp->control.stop_bpstat);
9014 tp->control = inf_status->thread_control;
9015 inf->control = inf_status->inferior_control;
9018 stop_stack_dummy = inf_status->stop_stack_dummy;
9019 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9021 if (target_has_stack)
9023 /* The point of the try/catch is that if the stack is clobbered,
9024 walking the stack might encounter a garbage pointer and
9025 error() trying to dereference it. */
9028 restore_selected_frame (inf_status->selected_frame_id);
9030 CATCH (ex, RETURN_MASK_ERROR)
9032 exception_fprintf (gdb_stderr, ex,
9033 "Unable to restore previously selected frame:\n");
9034 /* Error in restoring the selected frame. Select the
9036 select_frame (get_current_frame ());
9045 do_restore_infcall_control_state_cleanup (void *sts)
9047 restore_infcall_control_state ((struct infcall_control_state *) sts);
9051 make_cleanup_restore_infcall_control_state
9052 (struct infcall_control_state *inf_status)
9054 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9058 discard_infcall_control_state (struct infcall_control_state *inf_status)
9060 if (inf_status->thread_control.step_resume_breakpoint)
9061 inf_status->thread_control.step_resume_breakpoint->disposition
9062 = disp_del_at_next_stop;
9064 if (inf_status->thread_control.exception_resume_breakpoint)
9065 inf_status->thread_control.exception_resume_breakpoint->disposition
9066 = disp_del_at_next_stop;
9068 /* See save_infcall_control_state for info on stop_bpstat. */
9069 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9077 clear_exit_convenience_vars (void)
9079 clear_internalvar (lookup_internalvar ("_exitsignal"));
9080 clear_internalvar (lookup_internalvar ("_exitcode"));
9084 /* User interface for reverse debugging:
9085 Set exec-direction / show exec-direction commands
9086 (returns error unless target implements to_set_exec_direction method). */
9088 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9089 static const char exec_forward[] = "forward";
9090 static const char exec_reverse[] = "reverse";
9091 static const char *exec_direction = exec_forward;
9092 static const char *const exec_direction_names[] = {
9099 set_exec_direction_func (const char *args, int from_tty,
9100 struct cmd_list_element *cmd)
9102 if (target_can_execute_reverse)
9104 if (!strcmp (exec_direction, exec_forward))
9105 execution_direction = EXEC_FORWARD;
9106 else if (!strcmp (exec_direction, exec_reverse))
9107 execution_direction = EXEC_REVERSE;
9111 exec_direction = exec_forward;
9112 error (_("Target does not support this operation."));
9117 show_exec_direction_func (struct ui_file *out, int from_tty,
9118 struct cmd_list_element *cmd, const char *value)
9120 switch (execution_direction) {
9122 fprintf_filtered (out, _("Forward.\n"));
9125 fprintf_filtered (out, _("Reverse.\n"));
9128 internal_error (__FILE__, __LINE__,
9129 _("bogus execution_direction value: %d"),
9130 (int) execution_direction);
9135 show_schedule_multiple (struct ui_file *file, int from_tty,
9136 struct cmd_list_element *c, const char *value)
9138 fprintf_filtered (file, _("Resuming the execution of threads "
9139 "of all processes is %s.\n"), value);
9142 /* Implementation of `siginfo' variable. */
9144 static const struct internalvar_funcs siginfo_funcs =
9151 /* Callback for infrun's target events source. This is marked when a
9152 thread has a pending status to process. */
9155 infrun_async_inferior_event_handler (gdb_client_data data)
9157 inferior_event_handler (INF_REG_EVENT, NULL);
9161 _initialize_infrun (void)
9165 struct cmd_list_element *c;
9167 /* Register extra event sources in the event loop. */
9168 infrun_async_inferior_event_token
9169 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9171 add_info ("signals", info_signals_command, _("\
9172 What debugger does when program gets various signals.\n\
9173 Specify a signal as argument to print info on that signal only."));
9174 add_info_alias ("handle", "signals", 0);
9176 c = add_com ("handle", class_run, handle_command, _("\
9177 Specify how to handle signals.\n\
9178 Usage: handle SIGNAL [ACTIONS]\n\
9179 Args are signals and actions to apply to those signals.\n\
9180 If no actions are specified, the current settings for the specified signals\n\
9181 will be displayed instead.\n\
9183 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9184 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9185 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9186 The special arg \"all\" is recognized to mean all signals except those\n\
9187 used by the debugger, typically SIGTRAP and SIGINT.\n\
9189 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9190 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9191 Stop means reenter debugger if this signal happens (implies print).\n\
9192 Print means print a message if this signal happens.\n\
9193 Pass means let program see this signal; otherwise program doesn't know.\n\
9194 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9195 Pass and Stop may be combined.\n\
9197 Multiple signals may be specified. Signal numbers and signal names\n\
9198 may be interspersed with actions, with the actions being performed for\n\
9199 all signals cumulatively specified."));
9200 set_cmd_completer (c, handle_completer);
9203 stop_command = add_cmd ("stop", class_obscure,
9204 not_just_help_class_command, _("\
9205 There is no `stop' command, but you can set a hook on `stop'.\n\
9206 This allows you to set a list of commands to be run each time execution\n\
9207 of the program stops."), &cmdlist);
9209 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9210 Set inferior debugging."), _("\
9211 Show inferior debugging."), _("\
9212 When non-zero, inferior specific debugging is enabled."),
9215 &setdebuglist, &showdebuglist);
9217 add_setshow_boolean_cmd ("displaced", class_maintenance,
9218 &debug_displaced, _("\
9219 Set displaced stepping debugging."), _("\
9220 Show displaced stepping debugging."), _("\
9221 When non-zero, displaced stepping specific debugging is enabled."),
9223 show_debug_displaced,
9224 &setdebuglist, &showdebuglist);
9226 add_setshow_boolean_cmd ("non-stop", no_class,
9228 Set whether gdb controls the inferior in non-stop mode."), _("\
9229 Show whether gdb controls the inferior in non-stop mode."), _("\
9230 When debugging a multi-threaded program and this setting is\n\
9231 off (the default, also called all-stop mode), when one thread stops\n\
9232 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9233 all other threads in the program while you interact with the thread of\n\
9234 interest. When you continue or step a thread, you can allow the other\n\
9235 threads to run, or have them remain stopped, but while you inspect any\n\
9236 thread's state, all threads stop.\n\
9238 In non-stop mode, when one thread stops, other threads can continue\n\
9239 to run freely. You'll be able to step each thread independently,\n\
9240 leave it stopped or free to run as needed."),
9246 numsigs = (int) GDB_SIGNAL_LAST;
9247 signal_stop = XNEWVEC (unsigned char, numsigs);
9248 signal_print = XNEWVEC (unsigned char, numsigs);
9249 signal_program = XNEWVEC (unsigned char, numsigs);
9250 signal_catch = XNEWVEC (unsigned char, numsigs);
9251 signal_pass = XNEWVEC (unsigned char, numsigs);
9252 for (i = 0; i < numsigs; i++)
9255 signal_print[i] = 1;
9256 signal_program[i] = 1;
9257 signal_catch[i] = 0;
9260 /* Signals caused by debugger's own actions should not be given to
9261 the program afterwards.
9263 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9264 explicitly specifies that it should be delivered to the target
9265 program. Typically, that would occur when a user is debugging a
9266 target monitor on a simulator: the target monitor sets a
9267 breakpoint; the simulator encounters this breakpoint and halts
9268 the simulation handing control to GDB; GDB, noting that the stop
9269 address doesn't map to any known breakpoint, returns control back
9270 to the simulator; the simulator then delivers the hardware
9271 equivalent of a GDB_SIGNAL_TRAP to the program being
9273 signal_program[GDB_SIGNAL_TRAP] = 0;
9274 signal_program[GDB_SIGNAL_INT] = 0;
9276 /* Signals that are not errors should not normally enter the debugger. */
9277 signal_stop[GDB_SIGNAL_ALRM] = 0;
9278 signal_print[GDB_SIGNAL_ALRM] = 0;
9279 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9280 signal_print[GDB_SIGNAL_VTALRM] = 0;
9281 signal_stop[GDB_SIGNAL_PROF] = 0;
9282 signal_print[GDB_SIGNAL_PROF] = 0;
9283 signal_stop[GDB_SIGNAL_CHLD] = 0;
9284 signal_print[GDB_SIGNAL_CHLD] = 0;
9285 signal_stop[GDB_SIGNAL_IO] = 0;
9286 signal_print[GDB_SIGNAL_IO] = 0;
9287 signal_stop[GDB_SIGNAL_POLL] = 0;
9288 signal_print[GDB_SIGNAL_POLL] = 0;
9289 signal_stop[GDB_SIGNAL_URG] = 0;
9290 signal_print[GDB_SIGNAL_URG] = 0;
9291 signal_stop[GDB_SIGNAL_WINCH] = 0;
9292 signal_print[GDB_SIGNAL_WINCH] = 0;
9293 signal_stop[GDB_SIGNAL_PRIO] = 0;
9294 signal_print[GDB_SIGNAL_PRIO] = 0;
9296 /* These signals are used internally by user-level thread
9297 implementations. (See signal(5) on Solaris.) Like the above
9298 signals, a healthy program receives and handles them as part of
9299 its normal operation. */
9300 signal_stop[GDB_SIGNAL_LWP] = 0;
9301 signal_print[GDB_SIGNAL_LWP] = 0;
9302 signal_stop[GDB_SIGNAL_WAITING] = 0;
9303 signal_print[GDB_SIGNAL_WAITING] = 0;
9304 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9305 signal_print[GDB_SIGNAL_CANCEL] = 0;
9306 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9307 signal_print[GDB_SIGNAL_LIBRT] = 0;
9309 /* Update cached state. */
9310 signal_cache_update (-1);
9312 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9313 &stop_on_solib_events, _("\
9314 Set stopping for shared library events."), _("\
9315 Show stopping for shared library events."), _("\
9316 If nonzero, gdb will give control to the user when the dynamic linker\n\
9317 notifies gdb of shared library events. The most common event of interest\n\
9318 to the user would be loading/unloading of a new library."),
9319 set_stop_on_solib_events,
9320 show_stop_on_solib_events,
9321 &setlist, &showlist);
9323 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9324 follow_fork_mode_kind_names,
9325 &follow_fork_mode_string, _("\
9326 Set debugger response to a program call of fork or vfork."), _("\
9327 Show debugger response to a program call of fork or vfork."), _("\
9328 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9329 parent - the original process is debugged after a fork\n\
9330 child - the new process is debugged after a fork\n\
9331 The unfollowed process will continue to run.\n\
9332 By default, the debugger will follow the parent process."),
9334 show_follow_fork_mode_string,
9335 &setlist, &showlist);
9337 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9338 follow_exec_mode_names,
9339 &follow_exec_mode_string, _("\
9340 Set debugger response to a program call of exec."), _("\
9341 Show debugger response to a program call of exec."), _("\
9342 An exec call replaces the program image of a process.\n\
9344 follow-exec-mode can be:\n\
9346 new - the debugger creates a new inferior and rebinds the process\n\
9347 to this new inferior. The program the process was running before\n\
9348 the exec call can be restarted afterwards by restarting the original\n\
9351 same - the debugger keeps the process bound to the same inferior.\n\
9352 The new executable image replaces the previous executable loaded in\n\
9353 the inferior. Restarting the inferior after the exec call restarts\n\
9354 the executable the process was running after the exec call.\n\
9356 By default, the debugger will use the same inferior."),
9358 show_follow_exec_mode_string,
9359 &setlist, &showlist);
9361 add_setshow_enum_cmd ("scheduler-locking", class_run,
9362 scheduler_enums, &scheduler_mode, _("\
9363 Set mode for locking scheduler during execution."), _("\
9364 Show mode for locking scheduler during execution."), _("\
9365 off == no locking (threads may preempt at any time)\n\
9366 on == full locking (no thread except the current thread may run)\n\
9367 This applies to both normal execution and replay mode.\n\
9368 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9369 In this mode, other threads may run during other commands.\n\
9370 This applies to both normal execution and replay mode.\n\
9371 replay == scheduler locked in replay mode and unlocked during normal execution."),
9372 set_schedlock_func, /* traps on target vector */
9373 show_scheduler_mode,
9374 &setlist, &showlist);
9376 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9377 Set mode for resuming threads of all processes."), _("\
9378 Show mode for resuming threads of all processes."), _("\
9379 When on, execution commands (such as 'continue' or 'next') resume all\n\
9380 threads of all processes. When off (which is the default), execution\n\
9381 commands only resume the threads of the current process. The set of\n\
9382 threads that are resumed is further refined by the scheduler-locking\n\
9383 mode (see help set scheduler-locking)."),
9385 show_schedule_multiple,
9386 &setlist, &showlist);
9388 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9389 Set mode of the step operation."), _("\
9390 Show mode of the step operation."), _("\
9391 When set, doing a step over a function without debug line information\n\
9392 will stop at the first instruction of that function. Otherwise, the\n\
9393 function is skipped and the step command stops at a different source line."),
9395 show_step_stop_if_no_debug,
9396 &setlist, &showlist);
9398 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9399 &can_use_displaced_stepping, _("\
9400 Set debugger's willingness to use displaced stepping."), _("\
9401 Show debugger's willingness to use displaced stepping."), _("\
9402 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9403 supported by the target architecture. If off, gdb will not use displaced\n\
9404 stepping to step over breakpoints, even if such is supported by the target\n\
9405 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9406 if the target architecture supports it and non-stop mode is active, but will not\n\
9407 use it in all-stop mode (see help set non-stop)."),
9409 show_can_use_displaced_stepping,
9410 &setlist, &showlist);
9412 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9413 &exec_direction, _("Set direction of execution.\n\
9414 Options are 'forward' or 'reverse'."),
9415 _("Show direction of execution (forward/reverse)."),
9416 _("Tells gdb whether to execute forward or backward."),
9417 set_exec_direction_func, show_exec_direction_func,
9418 &setlist, &showlist);
9420 /* Set/show detach-on-fork: user-settable mode. */
9422 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9423 Set whether gdb will detach the child of a fork."), _("\
9424 Show whether gdb will detach the child of a fork."), _("\
9425 Tells gdb whether to detach the child of a fork."),
9426 NULL, NULL, &setlist, &showlist);
9428 /* Set/show disable address space randomization mode. */
9430 add_setshow_boolean_cmd ("disable-randomization", class_support,
9431 &disable_randomization, _("\
9432 Set disabling of debuggee's virtual address space randomization."), _("\
9433 Show disabling of debuggee's virtual address space randomization."), _("\
9434 When this mode is on (which is the default), randomization of the virtual\n\
9435 address space is disabled. Standalone programs run with the randomization\n\
9436 enabled by default on some platforms."),
9437 &set_disable_randomization,
9438 &show_disable_randomization,
9439 &setlist, &showlist);
9441 /* ptid initializations */
9442 inferior_ptid = null_ptid;
9443 target_last_wait_ptid = minus_one_ptid;
9445 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9446 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9447 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9448 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9450 /* Explicitly create without lookup, since that tries to create a
9451 value with a void typed value, and when we get here, gdbarch
9452 isn't initialized yet. At this point, we're quite sure there
9453 isn't another convenience variable of the same name. */
9454 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9456 add_setshow_boolean_cmd ("observer", no_class,
9457 &observer_mode_1, _("\
9458 Set whether gdb controls the inferior in observer mode."), _("\
9459 Show whether gdb controls the inferior in observer mode."), _("\
9460 In observer mode, GDB can get data from the inferior, but not\n\
9461 affect its execution. Registers and memory may not be changed,\n\
9462 breakpoints may not be set, and the program cannot be interrupted\n\