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"
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 static void context_switch (ptid_t ptid);
388 void init_thread_stepping_state (struct thread_info *tss);
390 static const char follow_fork_mode_child[] = "child";
391 static const char follow_fork_mode_parent[] = "parent";
393 static const char *const follow_fork_mode_kind_names[] = {
394 follow_fork_mode_child,
395 follow_fork_mode_parent,
399 static const char *follow_fork_mode_string = follow_fork_mode_parent;
401 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
402 struct cmd_list_element *c, const char *value)
404 fprintf_filtered (file,
405 _("Debugger response to a program "
406 "call of fork or vfork is \"%s\".\n"),
411 /* Handle changes to the inferior list based on the type of fork,
412 which process is being followed, and whether the other process
413 should be detached. On entry inferior_ptid must be the ptid of
414 the fork parent. At return inferior_ptid is the ptid of the
415 followed inferior. */
418 follow_fork_inferior (int follow_child, int detach_fork)
421 ptid_t parent_ptid, child_ptid;
423 has_vforked = (inferior_thread ()->pending_follow.kind
424 == TARGET_WAITKIND_VFORKED);
425 parent_ptid = inferior_ptid;
426 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
429 && !non_stop /* Non-stop always resumes both branches. */
430 && current_ui->prompt_state == PROMPT_BLOCKED
431 && !(follow_child || detach_fork || sched_multi))
433 /* The parent stays blocked inside the vfork syscall until the
434 child execs or exits. If we don't let the child run, then
435 the parent stays blocked. If we're telling the parent to run
436 in the foreground, the user will not be able to ctrl-c to get
437 back the terminal, effectively hanging the debug session. */
438 fprintf_filtered (gdb_stderr, _("\
439 Can not resume the parent process over vfork in the foreground while\n\
440 holding the child stopped. Try \"set detach-on-fork\" or \
441 \"set schedule-multiple\".\n"));
442 /* FIXME output string > 80 columns. */
448 /* Detach new forked process? */
451 /* Before detaching from the child, remove all breakpoints
452 from it. If we forked, then this has already been taken
453 care of by infrun.c. If we vforked however, any
454 breakpoint inserted in the parent is visible in the
455 child, even those added while stopped in a vfork
456 catchpoint. This will remove the breakpoints from the
457 parent also, but they'll be reinserted below. */
460 /* Keep breakpoints list in sync. */
461 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
464 if (info_verbose || debug_infrun)
466 /* Ensure that we have a process ptid. */
467 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
469 target_terminal::ours_for_output ();
470 fprintf_filtered (gdb_stdlog,
471 _("Detaching after %s from child %s.\n"),
472 has_vforked ? "vfork" : "fork",
473 target_pid_to_str (process_ptid));
478 struct inferior *parent_inf, *child_inf;
480 /* Add process to GDB's tables. */
481 child_inf = add_inferior (ptid_get_pid (child_ptid));
483 parent_inf = current_inferior ();
484 child_inf->attach_flag = parent_inf->attach_flag;
485 copy_terminal_info (child_inf, parent_inf);
486 child_inf->gdbarch = parent_inf->gdbarch;
487 copy_inferior_target_desc_info (child_inf, parent_inf);
489 scoped_restore_current_pspace_and_thread restore_pspace_thread;
491 inferior_ptid = child_ptid;
492 add_thread (inferior_ptid);
493 set_current_inferior (child_inf);
494 child_inf->symfile_flags = SYMFILE_NO_READ;
496 /* If this is a vfork child, then the address-space is
497 shared with the parent. */
500 child_inf->pspace = parent_inf->pspace;
501 child_inf->aspace = parent_inf->aspace;
503 /* The parent will be frozen until the child is done
504 with the shared region. Keep track of the
506 child_inf->vfork_parent = parent_inf;
507 child_inf->pending_detach = 0;
508 parent_inf->vfork_child = child_inf;
509 parent_inf->pending_detach = 0;
513 child_inf->aspace = new_address_space ();
514 child_inf->pspace = add_program_space (child_inf->aspace);
515 child_inf->removable = 1;
516 set_current_program_space (child_inf->pspace);
517 clone_program_space (child_inf->pspace, parent_inf->pspace);
519 /* Let the shared library layer (e.g., solib-svr4) learn
520 about this new process, relocate the cloned exec, pull
521 in shared libraries, and install the solib event
522 breakpoint. If a "cloned-VM" event was propagated
523 better throughout the core, this wouldn't be
525 solib_create_inferior_hook (0);
531 struct inferior *parent_inf;
533 parent_inf = current_inferior ();
535 /* If we detached from the child, then we have to be careful
536 to not insert breakpoints in the parent until the child
537 is done with the shared memory region. However, if we're
538 staying attached to the child, then we can and should
539 insert breakpoints, so that we can debug it. A
540 subsequent child exec or exit is enough to know when does
541 the child stops using the parent's address space. */
542 parent_inf->waiting_for_vfork_done = detach_fork;
543 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
548 /* Follow the child. */
549 struct inferior *parent_inf, *child_inf;
550 struct program_space *parent_pspace;
552 if (info_verbose || debug_infrun)
554 target_terminal::ours_for_output ();
555 fprintf_filtered (gdb_stdlog,
556 _("Attaching after %s %s to child %s.\n"),
557 target_pid_to_str (parent_ptid),
558 has_vforked ? "vfork" : "fork",
559 target_pid_to_str (child_ptid));
562 /* Add the new inferior first, so that the target_detach below
563 doesn't unpush the target. */
565 child_inf = add_inferior (ptid_get_pid (child_ptid));
567 parent_inf = current_inferior ();
568 child_inf->attach_flag = parent_inf->attach_flag;
569 copy_terminal_info (child_inf, parent_inf);
570 child_inf->gdbarch = parent_inf->gdbarch;
571 copy_inferior_target_desc_info (child_inf, parent_inf);
573 parent_pspace = parent_inf->pspace;
575 /* If we're vforking, we want to hold on to the parent until the
576 child exits or execs. At child exec or exit time we can
577 remove the old breakpoints from the parent and detach or
578 resume debugging it. Otherwise, detach the parent now; we'll
579 want to reuse it's program/address spaces, but we can't set
580 them to the child before removing breakpoints from the
581 parent, otherwise, the breakpoints module could decide to
582 remove breakpoints from the wrong process (since they'd be
583 assigned to the same address space). */
587 gdb_assert (child_inf->vfork_parent == NULL);
588 gdb_assert (parent_inf->vfork_child == NULL);
589 child_inf->vfork_parent = parent_inf;
590 child_inf->pending_detach = 0;
591 parent_inf->vfork_child = child_inf;
592 parent_inf->pending_detach = detach_fork;
593 parent_inf->waiting_for_vfork_done = 0;
595 else if (detach_fork)
597 if (info_verbose || debug_infrun)
599 /* Ensure that we have a process ptid. */
600 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
602 target_terminal::ours_for_output ();
603 fprintf_filtered (gdb_stdlog,
604 _("Detaching after fork from "
606 target_pid_to_str (process_ptid));
609 target_detach (NULL, 0);
612 /* Note that the detach above makes PARENT_INF dangling. */
614 /* Add the child thread to the appropriate lists, and switch to
615 this new thread, before cloning the program space, and
616 informing the solib layer about this new process. */
618 inferior_ptid = child_ptid;
619 add_thread (inferior_ptid);
620 set_current_inferior (child_inf);
622 /* If this is a vfork child, then the address-space is shared
623 with the parent. If we detached from the parent, then we can
624 reuse the parent's program/address spaces. */
625 if (has_vforked || detach_fork)
627 child_inf->pspace = parent_pspace;
628 child_inf->aspace = child_inf->pspace->aspace;
632 child_inf->aspace = new_address_space ();
633 child_inf->pspace = add_program_space (child_inf->aspace);
634 child_inf->removable = 1;
635 child_inf->symfile_flags = SYMFILE_NO_READ;
636 set_current_program_space (child_inf->pspace);
637 clone_program_space (child_inf->pspace, parent_pspace);
639 /* Let the shared library layer (e.g., solib-svr4) learn
640 about this new process, relocate the cloned exec, pull in
641 shared libraries, and install the solib event breakpoint.
642 If a "cloned-VM" event was propagated better throughout
643 the core, this wouldn't be required. */
644 solib_create_inferior_hook (0);
648 return target_follow_fork (follow_child, detach_fork);
651 /* Tell the target to follow the fork we're stopped at. Returns true
652 if the inferior should be resumed; false, if the target for some
653 reason decided it's best not to resume. */
658 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
659 int should_resume = 1;
660 struct thread_info *tp;
662 /* Copy user stepping state to the new inferior thread. FIXME: the
663 followed fork child thread should have a copy of most of the
664 parent thread structure's run control related fields, not just these.
665 Initialized to avoid "may be used uninitialized" warnings from gcc. */
666 struct breakpoint *step_resume_breakpoint = NULL;
667 struct breakpoint *exception_resume_breakpoint = NULL;
668 CORE_ADDR step_range_start = 0;
669 CORE_ADDR step_range_end = 0;
670 struct frame_id step_frame_id = { 0 };
671 struct thread_fsm *thread_fsm = NULL;
676 struct target_waitstatus wait_status;
678 /* Get the last target status returned by target_wait(). */
679 get_last_target_status (&wait_ptid, &wait_status);
681 /* If not stopped at a fork event, then there's nothing else to
683 if (wait_status.kind != TARGET_WAITKIND_FORKED
684 && wait_status.kind != TARGET_WAITKIND_VFORKED)
687 /* Check if we switched over from WAIT_PTID, since the event was
689 if (!ptid_equal (wait_ptid, minus_one_ptid)
690 && !ptid_equal (inferior_ptid, wait_ptid))
692 /* We did. Switch back to WAIT_PTID thread, to tell the
693 target to follow it (in either direction). We'll
694 afterwards refuse to resume, and inform the user what
696 switch_to_thread (wait_ptid);
701 tp = inferior_thread ();
703 /* If there were any forks/vforks that were caught and are now to be
704 followed, then do so now. */
705 switch (tp->pending_follow.kind)
707 case TARGET_WAITKIND_FORKED:
708 case TARGET_WAITKIND_VFORKED:
710 ptid_t parent, child;
712 /* If the user did a next/step, etc, over a fork call,
713 preserve the stepping state in the fork child. */
714 if (follow_child && should_resume)
716 step_resume_breakpoint = clone_momentary_breakpoint
717 (tp->control.step_resume_breakpoint);
718 step_range_start = tp->control.step_range_start;
719 step_range_end = tp->control.step_range_end;
720 step_frame_id = tp->control.step_frame_id;
721 exception_resume_breakpoint
722 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
723 thread_fsm = tp->thread_fsm;
725 /* For now, delete the parent's sr breakpoint, otherwise,
726 parent/child sr breakpoints are considered duplicates,
727 and the child version will not be installed. Remove
728 this when the breakpoints module becomes aware of
729 inferiors and address spaces. */
730 delete_step_resume_breakpoint (tp);
731 tp->control.step_range_start = 0;
732 tp->control.step_range_end = 0;
733 tp->control.step_frame_id = null_frame_id;
734 delete_exception_resume_breakpoint (tp);
735 tp->thread_fsm = NULL;
738 parent = inferior_ptid;
739 child = tp->pending_follow.value.related_pid;
741 /* Set up inferior(s) as specified by the caller, and tell the
742 target to do whatever is necessary to follow either parent
744 if (follow_fork_inferior (follow_child, detach_fork))
746 /* Target refused to follow, or there's some other reason
747 we shouldn't resume. */
752 /* This pending follow fork event is now handled, one way
753 or another. The previous selected thread may be gone
754 from the lists by now, but if it is still around, need
755 to clear the pending follow request. */
756 tp = find_thread_ptid (parent);
758 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
760 /* This makes sure we don't try to apply the "Switched
761 over from WAIT_PID" logic above. */
762 nullify_last_target_wait_ptid ();
764 /* If we followed the child, switch to it... */
767 switch_to_thread (child);
769 /* ... and preserve the stepping state, in case the
770 user was stepping over the fork call. */
773 tp = inferior_thread ();
774 tp->control.step_resume_breakpoint
775 = step_resume_breakpoint;
776 tp->control.step_range_start = step_range_start;
777 tp->control.step_range_end = step_range_end;
778 tp->control.step_frame_id = step_frame_id;
779 tp->control.exception_resume_breakpoint
780 = exception_resume_breakpoint;
781 tp->thread_fsm = thread_fsm;
785 /* If we get here, it was because we're trying to
786 resume from a fork catchpoint, but, the user
787 has switched threads away from the thread that
788 forked. In that case, the resume command
789 issued is most likely not applicable to the
790 child, so just warn, and refuse to resume. */
791 warning (_("Not resuming: switched threads "
792 "before following fork child."));
795 /* Reset breakpoints in the child as appropriate. */
796 follow_inferior_reset_breakpoints ();
799 switch_to_thread (parent);
803 case TARGET_WAITKIND_SPURIOUS:
804 /* Nothing to follow. */
807 internal_error (__FILE__, __LINE__,
808 "Unexpected pending_follow.kind %d\n",
809 tp->pending_follow.kind);
813 return should_resume;
817 follow_inferior_reset_breakpoints (void)
819 struct thread_info *tp = inferior_thread ();
821 /* Was there a step_resume breakpoint? (There was if the user
822 did a "next" at the fork() call.) If so, explicitly reset its
823 thread number. Cloned step_resume breakpoints are disabled on
824 creation, so enable it here now that it is associated with the
827 step_resumes are a form of bp that are made to be per-thread.
828 Since we created the step_resume bp when the parent process
829 was being debugged, and now are switching to the child process,
830 from the breakpoint package's viewpoint, that's a switch of
831 "threads". We must update the bp's notion of which thread
832 it is for, or it'll be ignored when it triggers. */
834 if (tp->control.step_resume_breakpoint)
836 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
837 tp->control.step_resume_breakpoint->loc->enabled = 1;
840 /* Treat exception_resume breakpoints like step_resume breakpoints. */
841 if (tp->control.exception_resume_breakpoint)
843 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
844 tp->control.exception_resume_breakpoint->loc->enabled = 1;
847 /* Reinsert all breakpoints in the child. The user may have set
848 breakpoints after catching the fork, in which case those
849 were never set in the child, but only in the parent. This makes
850 sure the inserted breakpoints match the breakpoint list. */
852 breakpoint_re_set ();
853 insert_breakpoints ();
856 /* The child has exited or execed: resume threads of the parent the
857 user wanted to be executing. */
860 proceed_after_vfork_done (struct thread_info *thread,
863 int pid = * (int *) arg;
865 if (ptid_get_pid (thread->ptid) == pid
866 && is_running (thread->ptid)
867 && !is_executing (thread->ptid)
868 && !thread->stop_requested
869 && thread->suspend.stop_signal == GDB_SIGNAL_0)
872 fprintf_unfiltered (gdb_stdlog,
873 "infrun: resuming vfork parent thread %s\n",
874 target_pid_to_str (thread->ptid));
876 switch_to_thread (thread->ptid);
877 clear_proceed_status (0);
878 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
884 /* Save/restore inferior_ptid, current program space and current
885 inferior. Only use this if the current context points at an exited
886 inferior (and therefore there's no current thread to save). */
887 class scoped_restore_exited_inferior
890 scoped_restore_exited_inferior ()
891 : m_saved_ptid (&inferior_ptid)
895 scoped_restore_tmpl<ptid_t> m_saved_ptid;
896 scoped_restore_current_program_space m_pspace;
897 scoped_restore_current_inferior m_inferior;
900 /* Called whenever we notice an exec or exit event, to handle
901 detaching or resuming a vfork parent. */
904 handle_vfork_child_exec_or_exit (int exec)
906 struct inferior *inf = current_inferior ();
908 if (inf->vfork_parent)
910 int resume_parent = -1;
912 /* This exec or exit marks the end of the shared memory region
913 between the parent and the child. If the user wanted to
914 detach from the parent, now is the time. */
916 if (inf->vfork_parent->pending_detach)
918 struct thread_info *tp;
919 struct program_space *pspace;
920 struct address_space *aspace;
922 /* follow-fork child, detach-on-fork on. */
924 inf->vfork_parent->pending_detach = 0;
926 gdb::optional<scoped_restore_exited_inferior>
927 maybe_restore_inferior;
928 gdb::optional<scoped_restore_current_pspace_and_thread>
929 maybe_restore_thread;
931 /* If we're handling a child exit, then inferior_ptid points
932 at the inferior's pid, not to a thread. */
934 maybe_restore_inferior.emplace ();
936 maybe_restore_thread.emplace ();
938 /* We're letting loose of the parent. */
939 tp = any_live_thread_of_process (inf->vfork_parent->pid);
940 switch_to_thread (tp->ptid);
942 /* We're about to detach from the parent, which implicitly
943 removes breakpoints from its address space. There's a
944 catch here: we want to reuse the spaces for the child,
945 but, parent/child are still sharing the pspace at this
946 point, although the exec in reality makes the kernel give
947 the child a fresh set of new pages. The problem here is
948 that the breakpoints module being unaware of this, would
949 likely chose the child process to write to the parent
950 address space. Swapping the child temporarily away from
951 the spaces has the desired effect. Yes, this is "sort
954 pspace = inf->pspace;
955 aspace = inf->aspace;
959 if (debug_infrun || info_verbose)
961 target_terminal::ours_for_output ();
965 fprintf_filtered (gdb_stdlog,
966 _("Detaching vfork parent process "
967 "%d after child exec.\n"),
968 inf->vfork_parent->pid);
972 fprintf_filtered (gdb_stdlog,
973 _("Detaching vfork parent process "
974 "%d after child exit.\n"),
975 inf->vfork_parent->pid);
979 target_detach (NULL, 0);
982 inf->pspace = pspace;
983 inf->aspace = aspace;
987 /* We're staying attached to the parent, so, really give the
988 child a new address space. */
989 inf->pspace = add_program_space (maybe_new_address_space ());
990 inf->aspace = inf->pspace->aspace;
992 set_current_program_space (inf->pspace);
994 resume_parent = inf->vfork_parent->pid;
996 /* Break the bonds. */
997 inf->vfork_parent->vfork_child = NULL;
1001 struct program_space *pspace;
1003 /* If this is a vfork child exiting, then the pspace and
1004 aspaces were shared with the parent. Since we're
1005 reporting the process exit, we'll be mourning all that is
1006 found in the address space, and switching to null_ptid,
1007 preparing to start a new inferior. But, since we don't
1008 want to clobber the parent's address/program spaces, we
1009 go ahead and create a new one for this exiting
1012 /* Switch to null_ptid while running clone_program_space, so
1013 that clone_program_space doesn't want to read the
1014 selected frame of a dead process. */
1015 scoped_restore restore_ptid
1016 = make_scoped_restore (&inferior_ptid, null_ptid);
1018 /* This inferior is dead, so avoid giving the breakpoints
1019 module the option to write through to it (cloning a
1020 program space resets breakpoints). */
1023 pspace = add_program_space (maybe_new_address_space ());
1024 set_current_program_space (pspace);
1026 inf->symfile_flags = SYMFILE_NO_READ;
1027 clone_program_space (pspace, inf->vfork_parent->pspace);
1028 inf->pspace = pspace;
1029 inf->aspace = pspace->aspace;
1031 resume_parent = inf->vfork_parent->pid;
1032 /* Break the bonds. */
1033 inf->vfork_parent->vfork_child = NULL;
1036 inf->vfork_parent = NULL;
1038 gdb_assert (current_program_space == inf->pspace);
1040 if (non_stop && resume_parent != -1)
1042 /* If the user wanted the parent to be running, let it go
1044 scoped_restore_current_thread restore_thread;
1047 fprintf_unfiltered (gdb_stdlog,
1048 "infrun: resuming vfork parent process %d\n",
1051 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1056 /* Enum strings for "set|show follow-exec-mode". */
1058 static const char follow_exec_mode_new[] = "new";
1059 static const char follow_exec_mode_same[] = "same";
1060 static const char *const follow_exec_mode_names[] =
1062 follow_exec_mode_new,
1063 follow_exec_mode_same,
1067 static const char *follow_exec_mode_string = follow_exec_mode_same;
1069 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1070 struct cmd_list_element *c, const char *value)
1072 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1075 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1078 follow_exec (ptid_t ptid, char *exec_file_target)
1080 struct thread_info *th, *tmp;
1081 struct inferior *inf = current_inferior ();
1082 int pid = ptid_get_pid (ptid);
1083 ptid_t process_ptid;
1084 char *exec_file_host;
1085 struct cleanup *old_chain;
1087 /* This is an exec event that we actually wish to pay attention to.
1088 Refresh our symbol table to the newly exec'd program, remove any
1089 momentary bp's, etc.
1091 If there are breakpoints, they aren't really inserted now,
1092 since the exec() transformed our inferior into a fresh set
1095 We want to preserve symbolic breakpoints on the list, since
1096 we have hopes that they can be reset after the new a.out's
1097 symbol table is read.
1099 However, any "raw" breakpoints must be removed from the list
1100 (e.g., the solib bp's), since their address is probably invalid
1103 And, we DON'T want to call delete_breakpoints() here, since
1104 that may write the bp's "shadow contents" (the instruction
1105 value that was overwritten witha TRAP instruction). Since
1106 we now have a new a.out, those shadow contents aren't valid. */
1108 mark_breakpoints_out ();
1110 /* The target reports the exec event to the main thread, even if
1111 some other thread does the exec, and even if the main thread was
1112 stopped or already gone. We may still have non-leader threads of
1113 the process on our list. E.g., on targets that don't have thread
1114 exit events (like remote); or on native Linux in non-stop mode if
1115 there were only two threads in the inferior and the non-leader
1116 one is the one that execs (and nothing forces an update of the
1117 thread list up to here). When debugging remotely, it's best to
1118 avoid extra traffic, when possible, so avoid syncing the thread
1119 list with the target, and instead go ahead and delete all threads
1120 of the process but one that reported the event. Note this must
1121 be done before calling update_breakpoints_after_exec, as
1122 otherwise clearing the threads' resources would reference stale
1123 thread breakpoints -- it may have been one of these threads that
1124 stepped across the exec. We could just clear their stepping
1125 states, but as long as we're iterating, might as well delete
1126 them. Deleting them now rather than at the next user-visible
1127 stop provides a nicer sequence of events for user and MI
1129 ALL_THREADS_SAFE (th, tmp)
1130 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1131 delete_thread (th->ptid);
1133 /* We also need to clear any left over stale state for the
1134 leader/event thread. E.g., if there was any step-resume
1135 breakpoint or similar, it's gone now. We cannot truly
1136 step-to-next statement through an exec(). */
1137 th = inferior_thread ();
1138 th->control.step_resume_breakpoint = NULL;
1139 th->control.exception_resume_breakpoint = NULL;
1140 th->control.single_step_breakpoints = NULL;
1141 th->control.step_range_start = 0;
1142 th->control.step_range_end = 0;
1144 /* The user may have had the main thread held stopped in the
1145 previous image (e.g., schedlock on, or non-stop). Release
1147 th->stop_requested = 0;
1149 update_breakpoints_after_exec ();
1151 /* What is this a.out's name? */
1152 process_ptid = pid_to_ptid (pid);
1153 printf_unfiltered (_("%s is executing new program: %s\n"),
1154 target_pid_to_str (process_ptid),
1157 /* We've followed the inferior through an exec. Therefore, the
1158 inferior has essentially been killed & reborn. */
1160 gdb_flush (gdb_stdout);
1162 breakpoint_init_inferior (inf_execd);
1164 exec_file_host = exec_file_find (exec_file_target, NULL);
1165 old_chain = make_cleanup (xfree, exec_file_host);
1167 /* If we were unable to map the executable target pathname onto a host
1168 pathname, tell the user that. Otherwise GDB's subsequent behavior
1169 is confusing. Maybe it would even be better to stop at this point
1170 so that the user can specify a file manually before continuing. */
1171 if (exec_file_host == NULL)
1172 warning (_("Could not load symbols for executable %s.\n"
1173 "Do you need \"set sysroot\"?"),
1176 /* Reset the shared library package. This ensures that we get a
1177 shlib event when the child reaches "_start", at which point the
1178 dld will have had a chance to initialize the child. */
1179 /* Also, loading a symbol file below may trigger symbol lookups, and
1180 we don't want those to be satisfied by the libraries of the
1181 previous incarnation of this process. */
1182 no_shared_libraries (NULL, 0);
1184 if (follow_exec_mode_string == follow_exec_mode_new)
1186 /* The user wants to keep the old inferior and program spaces
1187 around. Create a new fresh one, and switch to it. */
1189 /* Do exit processing for the original inferior before adding
1190 the new inferior so we don't have two active inferiors with
1191 the same ptid, which can confuse find_inferior_ptid. */
1192 exit_inferior_num_silent (current_inferior ()->num);
1194 inf = add_inferior_with_spaces ();
1196 target_follow_exec (inf, exec_file_target);
1198 set_current_inferior (inf);
1199 set_current_program_space (inf->pspace);
1203 /* The old description may no longer be fit for the new image.
1204 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1205 old description; we'll read a new one below. No need to do
1206 this on "follow-exec-mode new", as the old inferior stays
1207 around (its description is later cleared/refetched on
1209 target_clear_description ();
1212 gdb_assert (current_program_space == inf->pspace);
1214 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1215 because the proper displacement for a PIE (Position Independent
1216 Executable) main symbol file will only be computed by
1217 solib_create_inferior_hook below. breakpoint_re_set would fail
1218 to insert the breakpoints with the zero displacement. */
1219 try_open_exec_file (exec_file_host, inf, SYMFILE_DEFER_BP_RESET);
1221 do_cleanups (old_chain);
1223 /* If the target can specify a description, read it. Must do this
1224 after flipping to the new executable (because the target supplied
1225 description must be compatible with the executable's
1226 architecture, and the old executable may e.g., be 32-bit, while
1227 the new one 64-bit), and before anything involving memory or
1229 target_find_description ();
1231 /* The add_thread call ends up reading registers, so do it after updating the
1232 target description. */
1233 if (follow_exec_mode_string == follow_exec_mode_new)
1236 solib_create_inferior_hook (0);
1238 jit_inferior_created_hook ();
1240 breakpoint_re_set ();
1242 /* Reinsert all breakpoints. (Those which were symbolic have
1243 been reset to the proper address in the new a.out, thanks
1244 to symbol_file_command...). */
1245 insert_breakpoints ();
1247 /* The next resume of this inferior should bring it to the shlib
1248 startup breakpoints. (If the user had also set bp's on
1249 "main" from the old (parent) process, then they'll auto-
1250 matically get reset there in the new process.). */
1253 /* The queue of threads that need to do a step-over operation to get
1254 past e.g., a breakpoint. What technique is used to step over the
1255 breakpoint/watchpoint does not matter -- all threads end up in the
1256 same queue, to maintain rough temporal order of execution, in order
1257 to avoid starvation, otherwise, we could e.g., find ourselves
1258 constantly stepping the same couple threads past their breakpoints
1259 over and over, if the single-step finish fast enough. */
1260 struct thread_info *step_over_queue_head;
1262 /* Bit flags indicating what the thread needs to step over. */
1264 enum step_over_what_flag
1266 /* Step over a breakpoint. */
1267 STEP_OVER_BREAKPOINT = 1,
1269 /* Step past a non-continuable watchpoint, in order to let the
1270 instruction execute so we can evaluate the watchpoint
1272 STEP_OVER_WATCHPOINT = 2
1274 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1276 /* Info about an instruction that is being stepped over. */
1278 struct step_over_info
1280 /* If we're stepping past a breakpoint, this is the address space
1281 and address of the instruction the breakpoint is set at. We'll
1282 skip inserting all breakpoints here. Valid iff ASPACE is
1284 const address_space *aspace;
1287 /* The instruction being stepped over triggers a nonsteppable
1288 watchpoint. If true, we'll skip inserting watchpoints. */
1289 int nonsteppable_watchpoint_p;
1291 /* The thread's global number. */
1295 /* The step-over info of the location that is being stepped over.
1297 Note that with async/breakpoint always-inserted mode, a user might
1298 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1299 being stepped over. As setting a new breakpoint inserts all
1300 breakpoints, we need to make sure the breakpoint being stepped over
1301 isn't inserted then. We do that by only clearing the step-over
1302 info when the step-over is actually finished (or aborted).
1304 Presently GDB can only step over one breakpoint at any given time.
1305 Given threads that can't run code in the same address space as the
1306 breakpoint's can't really miss the breakpoint, GDB could be taught
1307 to step-over at most one breakpoint per address space (so this info
1308 could move to the address space object if/when GDB is extended).
1309 The set of breakpoints being stepped over will normally be much
1310 smaller than the set of all breakpoints, so a flag in the
1311 breakpoint location structure would be wasteful. A separate list
1312 also saves complexity and run-time, as otherwise we'd have to go
1313 through all breakpoint locations clearing their flag whenever we
1314 start a new sequence. Similar considerations weigh against storing
1315 this info in the thread object. Plus, not all step overs actually
1316 have breakpoint locations -- e.g., stepping past a single-step
1317 breakpoint, or stepping to complete a non-continuable
1319 static struct step_over_info step_over_info;
1321 /* Record the address of the breakpoint/instruction we're currently
1323 N.B. We record the aspace and address now, instead of say just the thread,
1324 because when we need the info later the thread may be running. */
1327 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1328 int nonsteppable_watchpoint_p,
1331 step_over_info.aspace = aspace;
1332 step_over_info.address = address;
1333 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1334 step_over_info.thread = thread;
1337 /* Called when we're not longer stepping over a breakpoint / an
1338 instruction, so all breakpoints are free to be (re)inserted. */
1341 clear_step_over_info (void)
1344 fprintf_unfiltered (gdb_stdlog,
1345 "infrun: clear_step_over_info\n");
1346 step_over_info.aspace = NULL;
1347 step_over_info.address = 0;
1348 step_over_info.nonsteppable_watchpoint_p = 0;
1349 step_over_info.thread = -1;
1355 stepping_past_instruction_at (struct address_space *aspace,
1358 return (step_over_info.aspace != NULL
1359 && breakpoint_address_match (aspace, address,
1360 step_over_info.aspace,
1361 step_over_info.address));
1367 thread_is_stepping_over_breakpoint (int thread)
1369 return (step_over_info.thread != -1
1370 && thread == step_over_info.thread);
1376 stepping_past_nonsteppable_watchpoint (void)
1378 return step_over_info.nonsteppable_watchpoint_p;
1381 /* Returns true if step-over info is valid. */
1384 step_over_info_valid_p (void)
1386 return (step_over_info.aspace != NULL
1387 || stepping_past_nonsteppable_watchpoint ());
1391 /* Displaced stepping. */
1393 /* In non-stop debugging mode, we must take special care to manage
1394 breakpoints properly; in particular, the traditional strategy for
1395 stepping a thread past a breakpoint it has hit is unsuitable.
1396 'Displaced stepping' is a tactic for stepping one thread past a
1397 breakpoint it has hit while ensuring that other threads running
1398 concurrently will hit the breakpoint as they should.
1400 The traditional way to step a thread T off a breakpoint in a
1401 multi-threaded program in all-stop mode is as follows:
1403 a0) Initially, all threads are stopped, and breakpoints are not
1405 a1) We single-step T, leaving breakpoints uninserted.
1406 a2) We insert breakpoints, and resume all threads.
1408 In non-stop debugging, however, this strategy is unsuitable: we
1409 don't want to have to stop all threads in the system in order to
1410 continue or step T past a breakpoint. Instead, we use displaced
1413 n0) Initially, T is stopped, other threads are running, and
1414 breakpoints are inserted.
1415 n1) We copy the instruction "under" the breakpoint to a separate
1416 location, outside the main code stream, making any adjustments
1417 to the instruction, register, and memory state as directed by
1419 n2) We single-step T over the instruction at its new location.
1420 n3) We adjust the resulting register and memory state as directed
1421 by T's architecture. This includes resetting T's PC to point
1422 back into the main instruction stream.
1425 This approach depends on the following gdbarch methods:
1427 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1428 indicate where to copy the instruction, and how much space must
1429 be reserved there. We use these in step n1.
1431 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1432 address, and makes any necessary adjustments to the instruction,
1433 register contents, and memory. We use this in step n1.
1435 - gdbarch_displaced_step_fixup adjusts registers and memory after
1436 we have successfuly single-stepped the instruction, to yield the
1437 same effect the instruction would have had if we had executed it
1438 at its original address. We use this in step n3.
1440 The gdbarch_displaced_step_copy_insn and
1441 gdbarch_displaced_step_fixup functions must be written so that
1442 copying an instruction with gdbarch_displaced_step_copy_insn,
1443 single-stepping across the copied instruction, and then applying
1444 gdbarch_displaced_insn_fixup should have the same effects on the
1445 thread's memory and registers as stepping the instruction in place
1446 would have. Exactly which responsibilities fall to the copy and
1447 which fall to the fixup is up to the author of those functions.
1449 See the comments in gdbarch.sh for details.
1451 Note that displaced stepping and software single-step cannot
1452 currently be used in combination, although with some care I think
1453 they could be made to. Software single-step works by placing
1454 breakpoints on all possible subsequent instructions; if the
1455 displaced instruction is a PC-relative jump, those breakpoints
1456 could fall in very strange places --- on pages that aren't
1457 executable, or at addresses that are not proper instruction
1458 boundaries. (We do generally let other threads run while we wait
1459 to hit the software single-step breakpoint, and they might
1460 encounter such a corrupted instruction.) One way to work around
1461 this would be to have gdbarch_displaced_step_copy_insn fully
1462 simulate the effect of PC-relative instructions (and return NULL)
1463 on architectures that use software single-stepping.
1465 In non-stop mode, we can have independent and simultaneous step
1466 requests, so more than one thread may need to simultaneously step
1467 over a breakpoint. The current implementation assumes there is
1468 only one scratch space per process. In this case, we have to
1469 serialize access to the scratch space. If thread A wants to step
1470 over a breakpoint, but we are currently waiting for some other
1471 thread to complete a displaced step, we leave thread A stopped and
1472 place it in the displaced_step_request_queue. Whenever a displaced
1473 step finishes, we pick the next thread in the queue and start a new
1474 displaced step operation on it. See displaced_step_prepare and
1475 displaced_step_fixup for details. */
1477 /* Default destructor for displaced_step_closure. */
1479 displaced_step_closure::~displaced_step_closure () = default;
1481 /* Per-inferior displaced stepping state. */
1482 struct displaced_step_inferior_state
1484 /* Pointer to next in linked list. */
1485 struct displaced_step_inferior_state *next;
1487 /* The process this displaced step state refers to. */
1490 /* True if preparing a displaced step ever failed. If so, we won't
1491 try displaced stepping for this inferior again. */
1494 /* If this is not null_ptid, this is the thread carrying out a
1495 displaced single-step in process PID. This thread's state will
1496 require fixing up once it has completed its step. */
1499 /* The architecture the thread had when we stepped it. */
1500 struct gdbarch *step_gdbarch;
1502 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1503 for post-step cleanup. */
1504 struct displaced_step_closure *step_closure;
1506 /* The address of the original instruction, and the copy we
1508 CORE_ADDR step_original, step_copy;
1510 /* Saved contents of copy area. */
1511 gdb_byte *step_saved_copy;
1514 /* The list of states of processes involved in displaced stepping
1516 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1518 /* Get the displaced stepping state of process PID. */
1520 static struct displaced_step_inferior_state *
1521 get_displaced_stepping_state (int pid)
1523 struct displaced_step_inferior_state *state;
1525 for (state = displaced_step_inferior_states;
1527 state = state->next)
1528 if (state->pid == pid)
1534 /* Returns true if any inferior has a thread doing a displaced
1538 displaced_step_in_progress_any_inferior (void)
1540 struct displaced_step_inferior_state *state;
1542 for (state = displaced_step_inferior_states;
1544 state = state->next)
1545 if (!ptid_equal (state->step_ptid, null_ptid))
1551 /* Return true if thread represented by PTID is doing a displaced
1555 displaced_step_in_progress_thread (ptid_t ptid)
1557 struct displaced_step_inferior_state *displaced;
1559 gdb_assert (!ptid_equal (ptid, null_ptid));
1561 displaced = get_displaced_stepping_state (ptid_get_pid (ptid));
1563 return (displaced != NULL && ptid_equal (displaced->step_ptid, ptid));
1566 /* Return true if process PID has a thread doing a displaced step. */
1569 displaced_step_in_progress (int pid)
1571 struct displaced_step_inferior_state *displaced;
1573 displaced = get_displaced_stepping_state (pid);
1574 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1580 /* Add a new displaced stepping state for process PID to the displaced
1581 stepping state list, or return a pointer to an already existing
1582 entry, if it already exists. Never returns NULL. */
1584 static struct displaced_step_inferior_state *
1585 add_displaced_stepping_state (int pid)
1587 struct displaced_step_inferior_state *state;
1589 for (state = displaced_step_inferior_states;
1591 state = state->next)
1592 if (state->pid == pid)
1595 state = XCNEW (struct displaced_step_inferior_state);
1597 state->next = displaced_step_inferior_states;
1598 displaced_step_inferior_states = state;
1603 /* If inferior is in displaced stepping, and ADDR equals to starting address
1604 of copy area, return corresponding displaced_step_closure. Otherwise,
1607 struct displaced_step_closure*
1608 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1610 struct displaced_step_inferior_state *displaced
1611 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1613 /* If checking the mode of displaced instruction in copy area. */
1614 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1615 && (displaced->step_copy == addr))
1616 return displaced->step_closure;
1621 /* Remove the displaced stepping state of process PID. */
1624 remove_displaced_stepping_state (int pid)
1626 struct displaced_step_inferior_state *it, **prev_next_p;
1628 gdb_assert (pid != 0);
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->pid);
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->ptid);
1685 struct gdbarch *gdbarch = regcache->arch ();
1686 struct displaced_step_inferior_state *displaced_state;
1688 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
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_ptid = null_ptid;
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 (ptid_t ptid)
1751 struct cleanup *ignore_cleanups;
1752 struct thread_info *tp = find_thread_ptid (ptid);
1753 struct regcache *regcache = get_thread_regcache (ptid);
1754 struct gdbarch *gdbarch = regcache->arch ();
1755 const address_space *aspace = regcache->aspace ();
1756 CORE_ADDR original, copy;
1758 struct displaced_step_closure *closure;
1759 struct displaced_step_inferior_state *displaced;
1762 /* We should never reach this function if the architecture does not
1763 support displaced stepping. */
1764 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1766 /* Nor if the thread isn't meant to step over a breakpoint. */
1767 gdb_assert (tp->control.trap_expected);
1769 /* Disable range stepping while executing in the scratch pad. We
1770 want a single-step even if executing the displaced instruction in
1771 the scratch buffer lands within the stepping range (e.g., a
1773 tp->control.may_range_step = 0;
1775 /* We have to displaced step one thread at a time, as we only have
1776 access to a single scratch space per inferior. */
1778 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1780 if (!ptid_equal (displaced->step_ptid, null_ptid))
1782 /* Already waiting for a displaced step to finish. Defer this
1783 request and place in queue. */
1785 if (debug_displaced)
1786 fprintf_unfiltered (gdb_stdlog,
1787 "displaced: deferring step of %s\n",
1788 target_pid_to_str (ptid));
1790 thread_step_over_chain_enqueue (tp);
1795 if (debug_displaced)
1796 fprintf_unfiltered (gdb_stdlog,
1797 "displaced: stepping %s now\n",
1798 target_pid_to_str (ptid));
1801 displaced_step_clear (displaced);
1803 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1804 inferior_ptid = ptid;
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_ptid = ptid;
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 (ptid_t ptid)
1894 prepared = displaced_step_prepare_throw (ptid);
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 (ptid_get_pid (ptid));
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 (ptid_t event_ptid, enum gdb_signal signal)
1965 struct cleanup *old_cleanups;
1966 struct displaced_step_inferior_state *displaced
1967 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1970 /* Was any thread of this process doing a displaced step? */
1971 if (displaced == NULL)
1974 /* Was this event for the pid we displaced? */
1975 if (ptid_equal (displaced->step_ptid, null_ptid)
1976 || ! ptid_equal (displaced->step_ptid, event_ptid))
1979 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1981 displaced_step_restore (displaced, displaced->step_ptid);
1983 /* Fixup may need to read memory/registers. Switch to the thread
1984 that we're fixing up. Also, target_stopped_by_watchpoint checks
1985 the current thread. */
1986 switch_to_thread (event_ptid);
1988 /* Did the instruction complete successfully? */
1989 if (signal == GDB_SIGNAL_TRAP
1990 && !(target_stopped_by_watchpoint ()
1991 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1992 || target_have_steppable_watchpoint)))
1994 /* Fix up the resulting state. */
1995 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1996 displaced->step_closure,
1997 displaced->step_original,
1998 displaced->step_copy,
1999 get_thread_regcache (displaced->step_ptid));
2004 /* Since the instruction didn't complete, all we can do is
2006 struct regcache *regcache = get_thread_regcache (event_ptid);
2007 CORE_ADDR pc = regcache_read_pc (regcache);
2009 pc = displaced->step_original + (pc - displaced->step_copy);
2010 regcache_write_pc (regcache, pc);
2014 do_cleanups (old_cleanups);
2016 displaced->step_ptid = null_ptid;
2021 /* Data to be passed around while handling an event. This data is
2022 discarded between events. */
2023 struct execution_control_state
2026 /* The thread that got the event, if this was a thread event; NULL
2028 struct thread_info *event_thread;
2030 struct target_waitstatus ws;
2031 int stop_func_filled_in;
2032 CORE_ADDR stop_func_start;
2033 CORE_ADDR stop_func_end;
2034 const char *stop_func_name;
2037 /* True if the event thread hit the single-step breakpoint of
2038 another thread. Thus the event doesn't cause a stop, the thread
2039 needs to be single-stepped past the single-step breakpoint before
2040 we can switch back to the original stepping thread. */
2041 int hit_singlestep_breakpoint;
2044 /* Clear ECS and set it to point at TP. */
2047 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2049 memset (ecs, 0, sizeof (*ecs));
2050 ecs->event_thread = tp;
2051 ecs->ptid = tp->ptid;
2054 static void keep_going_pass_signal (struct execution_control_state *ecs);
2055 static void prepare_to_wait (struct execution_control_state *ecs);
2056 static int keep_going_stepped_thread (struct thread_info *tp);
2057 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2059 /* Are there any pending step-over requests? If so, run all we can
2060 now and return true. Otherwise, return false. */
2063 start_step_over (void)
2065 struct thread_info *tp, *next;
2067 /* Don't start a new step-over if we already have an in-line
2068 step-over operation ongoing. */
2069 if (step_over_info_valid_p ())
2072 for (tp = step_over_queue_head; tp != NULL; tp = next)
2074 struct execution_control_state ecss;
2075 struct execution_control_state *ecs = &ecss;
2076 step_over_what step_what;
2077 int must_be_in_line;
2079 gdb_assert (!tp->stop_requested);
2081 next = thread_step_over_chain_next (tp);
2083 /* If this inferior already has a displaced step in process,
2084 don't start a new one. */
2085 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2088 step_what = thread_still_needs_step_over (tp);
2089 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2090 || ((step_what & STEP_OVER_BREAKPOINT)
2091 && !use_displaced_stepping (tp)));
2093 /* We currently stop all threads of all processes to step-over
2094 in-line. If we need to start a new in-line step-over, let
2095 any pending displaced steps finish first. */
2096 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2099 thread_step_over_chain_remove (tp);
2101 if (step_over_queue_head == NULL)
2104 fprintf_unfiltered (gdb_stdlog,
2105 "infrun: step-over queue now empty\n");
2108 if (tp->control.trap_expected
2112 internal_error (__FILE__, __LINE__,
2113 "[%s] has inconsistent state: "
2114 "trap_expected=%d, resumed=%d, executing=%d\n",
2115 target_pid_to_str (tp->ptid),
2116 tp->control.trap_expected,
2122 fprintf_unfiltered (gdb_stdlog,
2123 "infrun: resuming [%s] for step-over\n",
2124 target_pid_to_str (tp->ptid));
2126 /* keep_going_pass_signal skips the step-over if the breakpoint
2127 is no longer inserted. In all-stop, we want to keep looking
2128 for a thread that needs a step-over instead of resuming TP,
2129 because we wouldn't be able to resume anything else until the
2130 target stops again. In non-stop, the resume always resumes
2131 only TP, so it's OK to let the thread resume freely. */
2132 if (!target_is_non_stop_p () && !step_what)
2135 switch_to_thread (tp->ptid);
2136 reset_ecs (ecs, tp);
2137 keep_going_pass_signal (ecs);
2139 if (!ecs->wait_some_more)
2140 error (_("Command aborted."));
2142 gdb_assert (tp->resumed);
2144 /* If we started a new in-line step-over, we're done. */
2145 if (step_over_info_valid_p ())
2147 gdb_assert (tp->control.trap_expected);
2151 if (!target_is_non_stop_p ())
2153 /* On all-stop, shouldn't have resumed unless we needed a
2155 gdb_assert (tp->control.trap_expected
2156 || tp->step_after_step_resume_breakpoint);
2158 /* With remote targets (at least), in all-stop, we can't
2159 issue any further remote commands until the program stops
2164 /* Either the thread no longer needed a step-over, or a new
2165 displaced stepping sequence started. Even in the latter
2166 case, continue looking. Maybe we can also start another
2167 displaced step on a thread of other process. */
2173 /* Update global variables holding ptids to hold NEW_PTID if they were
2174 holding OLD_PTID. */
2176 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2178 struct displaced_step_inferior_state *displaced;
2180 if (ptid_equal (inferior_ptid, old_ptid))
2181 inferior_ptid = new_ptid;
2183 for (displaced = displaced_step_inferior_states;
2185 displaced = displaced->next)
2187 if (ptid_equal (displaced->step_ptid, old_ptid))
2188 displaced->step_ptid = new_ptid;
2194 static const char schedlock_off[] = "off";
2195 static const char schedlock_on[] = "on";
2196 static const char schedlock_step[] = "step";
2197 static const char schedlock_replay[] = "replay";
2198 static const char *const scheduler_enums[] = {
2205 static const char *scheduler_mode = schedlock_replay;
2207 show_scheduler_mode (struct ui_file *file, int from_tty,
2208 struct cmd_list_element *c, const char *value)
2210 fprintf_filtered (file,
2211 _("Mode for locking scheduler "
2212 "during execution is \"%s\".\n"),
2217 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2219 if (!target_can_lock_scheduler)
2221 scheduler_mode = schedlock_off;
2222 error (_("Target '%s' cannot support this command."), target_shortname);
2226 /* True if execution commands resume all threads of all processes by
2227 default; otherwise, resume only threads of the current inferior
2229 int sched_multi = 0;
2231 /* Try to setup for software single stepping over the specified location.
2232 Return 1 if target_resume() should use hardware single step.
2234 GDBARCH the current gdbarch.
2235 PC the location to step over. */
2238 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2242 if (execution_direction == EXEC_FORWARD
2243 && gdbarch_software_single_step_p (gdbarch))
2244 hw_step = !insert_single_step_breakpoints (gdbarch);
2252 user_visible_resume_ptid (int step)
2258 /* With non-stop mode on, threads are always handled
2260 resume_ptid = inferior_ptid;
2262 else if ((scheduler_mode == schedlock_on)
2263 || (scheduler_mode == schedlock_step && step))
2265 /* User-settable 'scheduler' mode requires solo thread
2267 resume_ptid = inferior_ptid;
2269 else if ((scheduler_mode == schedlock_replay)
2270 && target_record_will_replay (minus_one_ptid, execution_direction))
2272 /* User-settable 'scheduler' mode requires solo thread resume in replay
2274 resume_ptid = inferior_ptid;
2276 else if (!sched_multi && target_supports_multi_process ())
2278 /* Resume all threads of the current process (and none of other
2280 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2284 /* Resume all threads of all processes. */
2285 resume_ptid = RESUME_ALL;
2291 /* Return a ptid representing the set of threads that we will resume,
2292 in the perspective of the target, assuming run control handling
2293 does not require leaving some threads stopped (e.g., stepping past
2294 breakpoint). USER_STEP indicates whether we're about to start the
2295 target for a stepping command. */
2298 internal_resume_ptid (int user_step)
2300 /* In non-stop, we always control threads individually. Note that
2301 the target may always work in non-stop mode even with "set
2302 non-stop off", in which case user_visible_resume_ptid could
2303 return a wildcard ptid. */
2304 if (target_is_non_stop_p ())
2305 return inferior_ptid;
2307 return user_visible_resume_ptid (user_step);
2310 /* Wrapper for target_resume, that handles infrun-specific
2314 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2316 struct thread_info *tp = inferior_thread ();
2318 gdb_assert (!tp->stop_requested);
2320 /* Install inferior's terminal modes. */
2321 target_terminal::inferior ();
2323 /* Avoid confusing the next resume, if the next stop/resume
2324 happens to apply to another thread. */
2325 tp->suspend.stop_signal = GDB_SIGNAL_0;
2327 /* Advise target which signals may be handled silently.
2329 If we have removed breakpoints because we are stepping over one
2330 in-line (in any thread), we need to receive all signals to avoid
2331 accidentally skipping a breakpoint during execution of a signal
2334 Likewise if we're displaced stepping, otherwise a trap for a
2335 breakpoint in a signal handler might be confused with the
2336 displaced step finishing. We don't make the displaced_step_fixup
2337 step distinguish the cases instead, because:
2339 - a backtrace while stopped in the signal handler would show the
2340 scratch pad as frame older than the signal handler, instead of
2341 the real mainline code.
2343 - when the thread is later resumed, the signal handler would
2344 return to the scratch pad area, which would no longer be
2346 if (step_over_info_valid_p ()
2347 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2348 target_pass_signals (0, NULL);
2350 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2352 target_resume (resume_ptid, step, sig);
2354 target_commit_resume ();
2357 /* Resume the inferior. SIG is the signal to give the inferior
2358 (GDB_SIGNAL_0 for none). */
2361 resume (enum gdb_signal sig)
2363 struct regcache *regcache = get_current_regcache ();
2364 struct gdbarch *gdbarch = regcache->arch ();
2365 struct thread_info *tp = inferior_thread ();
2366 CORE_ADDR pc = regcache_read_pc (regcache);
2367 const address_space *aspace = regcache->aspace ();
2369 /* This represents the user's step vs continue request. When
2370 deciding whether "set scheduler-locking step" applies, it's the
2371 user's intention that counts. */
2372 const int user_step = tp->control.stepping_command;
2373 /* This represents what we'll actually request the target to do.
2374 This can decay from a step to a continue, if e.g., we need to
2375 implement single-stepping with breakpoints (software
2379 gdb_assert (!tp->stop_requested);
2380 gdb_assert (!thread_is_in_step_over_chain (tp));
2382 if (tp->suspend.waitstatus_pending_p)
2387 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2389 fprintf_unfiltered (gdb_stdlog,
2390 "infrun: resume: thread %s has pending wait "
2391 "status %s (currently_stepping=%d).\n",
2392 target_pid_to_str (tp->ptid), statstr.c_str (),
2393 currently_stepping (tp));
2398 /* FIXME: What should we do if we are supposed to resume this
2399 thread with a signal? Maybe we should maintain a queue of
2400 pending signals to deliver. */
2401 if (sig != GDB_SIGNAL_0)
2403 warning (_("Couldn't deliver signal %s to %s."),
2404 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2407 tp->suspend.stop_signal = GDB_SIGNAL_0;
2409 if (target_can_async_p ())
2414 tp->stepped_breakpoint = 0;
2416 /* Depends on stepped_breakpoint. */
2417 step = currently_stepping (tp);
2419 if (current_inferior ()->waiting_for_vfork_done)
2421 /* Don't try to single-step a vfork parent that is waiting for
2422 the child to get out of the shared memory region (by exec'ing
2423 or exiting). This is particularly important on software
2424 single-step archs, as the child process would trip on the
2425 software single step breakpoint inserted for the parent
2426 process. Since the parent will not actually execute any
2427 instruction until the child is out of the shared region (such
2428 are vfork's semantics), it is safe to simply continue it.
2429 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2430 the parent, and tell it to `keep_going', which automatically
2431 re-sets it stepping. */
2433 fprintf_unfiltered (gdb_stdlog,
2434 "infrun: resume : clear step\n");
2439 fprintf_unfiltered (gdb_stdlog,
2440 "infrun: resume (step=%d, signal=%s), "
2441 "trap_expected=%d, current thread [%s] at %s\n",
2442 step, gdb_signal_to_symbol_string (sig),
2443 tp->control.trap_expected,
2444 target_pid_to_str (inferior_ptid),
2445 paddress (gdbarch, pc));
2447 /* Normally, by the time we reach `resume', the breakpoints are either
2448 removed or inserted, as appropriate. The exception is if we're sitting
2449 at a permanent breakpoint; we need to step over it, but permanent
2450 breakpoints can't be removed. So we have to test for it here. */
2451 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2453 if (sig != GDB_SIGNAL_0)
2455 /* We have a signal to pass to the inferior. The resume
2456 may, or may not take us to the signal handler. If this
2457 is a step, we'll need to stop in the signal handler, if
2458 there's one, (if the target supports stepping into
2459 handlers), or in the next mainline instruction, if
2460 there's no handler. If this is a continue, we need to be
2461 sure to run the handler with all breakpoints inserted.
2462 In all cases, set a breakpoint at the current address
2463 (where the handler returns to), and once that breakpoint
2464 is hit, resume skipping the permanent breakpoint. If
2465 that breakpoint isn't hit, then we've stepped into the
2466 signal handler (or hit some other event). We'll delete
2467 the step-resume breakpoint then. */
2470 fprintf_unfiltered (gdb_stdlog,
2471 "infrun: resume: skipping permanent breakpoint, "
2472 "deliver signal first\n");
2474 clear_step_over_info ();
2475 tp->control.trap_expected = 0;
2477 if (tp->control.step_resume_breakpoint == NULL)
2479 /* Set a "high-priority" step-resume, as we don't want
2480 user breakpoints at PC to trigger (again) when this
2482 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2483 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2485 tp->step_after_step_resume_breakpoint = step;
2488 insert_breakpoints ();
2492 /* There's no signal to pass, we can go ahead and skip the
2493 permanent breakpoint manually. */
2495 fprintf_unfiltered (gdb_stdlog,
2496 "infrun: resume: skipping permanent breakpoint\n");
2497 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2498 /* Update pc to reflect the new address from which we will
2499 execute instructions. */
2500 pc = regcache_read_pc (regcache);
2504 /* We've already advanced the PC, so the stepping part
2505 is done. Now we need to arrange for a trap to be
2506 reported to handle_inferior_event. Set a breakpoint
2507 at the current PC, and run to it. Don't update
2508 prev_pc, because if we end in
2509 switch_back_to_stepped_thread, we want the "expected
2510 thread advanced also" branch to be taken. IOW, we
2511 don't want this thread to step further from PC
2513 gdb_assert (!step_over_info_valid_p ());
2514 insert_single_step_breakpoint (gdbarch, aspace, pc);
2515 insert_breakpoints ();
2517 resume_ptid = internal_resume_ptid (user_step);
2518 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2525 /* If we have a breakpoint to step over, make sure to do a single
2526 step only. Same if we have software watchpoints. */
2527 if (tp->control.trap_expected || bpstat_should_step ())
2528 tp->control.may_range_step = 0;
2530 /* If enabled, step over breakpoints by executing a copy of the
2531 instruction at a different address.
2533 We can't use displaced stepping when we have a signal to deliver;
2534 the comments for displaced_step_prepare explain why. The
2535 comments in the handle_inferior event for dealing with 'random
2536 signals' explain what we do instead.
2538 We can't use displaced stepping when we are waiting for vfork_done
2539 event, displaced stepping breaks the vfork child similarly as single
2540 step software breakpoint. */
2541 if (tp->control.trap_expected
2542 && use_displaced_stepping (tp)
2543 && !step_over_info_valid_p ()
2544 && sig == GDB_SIGNAL_0
2545 && !current_inferior ()->waiting_for_vfork_done)
2547 int prepared = displaced_step_prepare (inferior_ptid);
2552 fprintf_unfiltered (gdb_stdlog,
2553 "Got placed in step-over queue\n");
2555 tp->control.trap_expected = 0;
2558 else if (prepared < 0)
2560 /* Fallback to stepping over the breakpoint in-line. */
2562 if (target_is_non_stop_p ())
2563 stop_all_threads ();
2565 set_step_over_info (regcache->aspace (),
2566 regcache_read_pc (regcache), 0, tp->global_num);
2568 step = maybe_software_singlestep (gdbarch, pc);
2570 insert_breakpoints ();
2572 else if (prepared > 0)
2574 struct displaced_step_inferior_state *displaced;
2576 /* Update pc to reflect the new address from which we will
2577 execute instructions due to displaced stepping. */
2578 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2580 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2581 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2582 displaced->step_closure);
2586 /* Do we need to do it the hard way, w/temp breakpoints? */
2588 step = maybe_software_singlestep (gdbarch, pc);
2590 /* Currently, our software single-step implementation leads to different
2591 results than hardware single-stepping in one situation: when stepping
2592 into delivering a signal which has an associated signal handler,
2593 hardware single-step will stop at the first instruction of the handler,
2594 while software single-step will simply skip execution of the handler.
2596 For now, this difference in behavior is accepted since there is no
2597 easy way to actually implement single-stepping into a signal handler
2598 without kernel support.
2600 However, there is one scenario where this difference leads to follow-on
2601 problems: if we're stepping off a breakpoint by removing all breakpoints
2602 and then single-stepping. In this case, the software single-step
2603 behavior means that even if there is a *breakpoint* in the signal
2604 handler, GDB still would not stop.
2606 Fortunately, we can at least fix this particular issue. We detect
2607 here the case where we are about to deliver a signal while software
2608 single-stepping with breakpoints removed. In this situation, we
2609 revert the decisions to remove all breakpoints and insert single-
2610 step breakpoints, and instead we install a step-resume breakpoint
2611 at the current address, deliver the signal without stepping, and
2612 once we arrive back at the step-resume breakpoint, actually step
2613 over the breakpoint we originally wanted to step over. */
2614 if (thread_has_single_step_breakpoints_set (tp)
2615 && sig != GDB_SIGNAL_0
2616 && step_over_info_valid_p ())
2618 /* If we have nested signals or a pending signal is delivered
2619 immediately after a handler returns, might might already have
2620 a step-resume breakpoint set on the earlier handler. We cannot
2621 set another step-resume breakpoint; just continue on until the
2622 original breakpoint is hit. */
2623 if (tp->control.step_resume_breakpoint == NULL)
2625 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2626 tp->step_after_step_resume_breakpoint = 1;
2629 delete_single_step_breakpoints (tp);
2631 clear_step_over_info ();
2632 tp->control.trap_expected = 0;
2634 insert_breakpoints ();
2637 /* If STEP is set, it's a request to use hardware stepping
2638 facilities. But in that case, we should never
2639 use singlestep breakpoint. */
2640 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2642 /* Decide the set of threads to ask the target to resume. */
2643 if (tp->control.trap_expected)
2645 /* We're allowing a thread to run past a breakpoint it has
2646 hit, either by single-stepping the thread with the breakpoint
2647 removed, or by displaced stepping, with the breakpoint inserted.
2648 In the former case, we need to single-step only this thread,
2649 and keep others stopped, as they can miss this breakpoint if
2650 allowed to run. That's not really a problem for displaced
2651 stepping, but, we still keep other threads stopped, in case
2652 another thread is also stopped for a breakpoint waiting for
2653 its turn in the displaced stepping queue. */
2654 resume_ptid = inferior_ptid;
2657 resume_ptid = internal_resume_ptid (user_step);
2659 if (execution_direction != EXEC_REVERSE
2660 && step && breakpoint_inserted_here_p (aspace, pc))
2662 /* There are two cases where we currently need to step a
2663 breakpoint instruction when we have a signal to deliver:
2665 - See handle_signal_stop where we handle random signals that
2666 could take out us out of the stepping range. Normally, in
2667 that case we end up continuing (instead of stepping) over the
2668 signal handler with a breakpoint at PC, but there are cases
2669 where we should _always_ single-step, even if we have a
2670 step-resume breakpoint, like when a software watchpoint is
2671 set. Assuming single-stepping and delivering a signal at the
2672 same time would takes us to the signal handler, then we could
2673 have removed the breakpoint at PC to step over it. However,
2674 some hardware step targets (like e.g., Mac OS) can't step
2675 into signal handlers, and for those, we need to leave the
2676 breakpoint at PC inserted, as otherwise if the handler
2677 recurses and executes PC again, it'll miss the breakpoint.
2678 So we leave the breakpoint inserted anyway, but we need to
2679 record that we tried to step a breakpoint instruction, so
2680 that adjust_pc_after_break doesn't end up confused.
2682 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2683 in one thread after another thread that was stepping had been
2684 momentarily paused for a step-over. When we re-resume the
2685 stepping thread, it may be resumed from that address with a
2686 breakpoint that hasn't trapped yet. Seen with
2687 gdb.threads/non-stop-fair-events.exp, on targets that don't
2688 do displaced stepping. */
2691 fprintf_unfiltered (gdb_stdlog,
2692 "infrun: resume: [%s] stepped breakpoint\n",
2693 target_pid_to_str (tp->ptid));
2695 tp->stepped_breakpoint = 1;
2697 /* Most targets can step a breakpoint instruction, thus
2698 executing it normally. But if this one cannot, just
2699 continue and we will hit it anyway. */
2700 if (gdbarch_cannot_step_breakpoint (gdbarch))
2705 && tp->control.trap_expected
2706 && use_displaced_stepping (tp)
2707 && !step_over_info_valid_p ())
2709 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2710 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2711 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2714 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2715 paddress (resume_gdbarch, actual_pc));
2716 read_memory (actual_pc, buf, sizeof (buf));
2717 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2720 if (tp->control.may_range_step)
2722 /* If we're resuming a thread with the PC out of the step
2723 range, then we're doing some nested/finer run control
2724 operation, like stepping the thread out of the dynamic
2725 linker or the displaced stepping scratch pad. We
2726 shouldn't have allowed a range step then. */
2727 gdb_assert (pc_in_thread_step_range (pc, tp));
2730 do_target_resume (resume_ptid, step, sig);
2738 /* Counter that tracks number of user visible stops. This can be used
2739 to tell whether a command has proceeded the inferior past the
2740 current location. This allows e.g., inferior function calls in
2741 breakpoint commands to not interrupt the command list. When the
2742 call finishes successfully, the inferior is standing at the same
2743 breakpoint as if nothing happened (and so we don't call
2745 static ULONGEST current_stop_id;
2752 return current_stop_id;
2755 /* Called when we report a user visible stop. */
2763 /* Clear out all variables saying what to do when inferior is continued.
2764 First do this, then set the ones you want, then call `proceed'. */
2767 clear_proceed_status_thread (struct thread_info *tp)
2770 fprintf_unfiltered (gdb_stdlog,
2771 "infrun: clear_proceed_status_thread (%s)\n",
2772 target_pid_to_str (tp->ptid));
2774 /* If we're starting a new sequence, then the previous finished
2775 single-step is no longer relevant. */
2776 if (tp->suspend.waitstatus_pending_p)
2778 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2781 fprintf_unfiltered (gdb_stdlog,
2782 "infrun: clear_proceed_status: pending "
2783 "event of %s was a finished step. "
2785 target_pid_to_str (tp->ptid));
2787 tp->suspend.waitstatus_pending_p = 0;
2788 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2790 else if (debug_infrun)
2793 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2795 fprintf_unfiltered (gdb_stdlog,
2796 "infrun: clear_proceed_status_thread: thread %s "
2797 "has pending wait status %s "
2798 "(currently_stepping=%d).\n",
2799 target_pid_to_str (tp->ptid), statstr.c_str (),
2800 currently_stepping (tp));
2804 /* If this signal should not be seen by program, give it zero.
2805 Used for debugging signals. */
2806 if (!signal_pass_state (tp->suspend.stop_signal))
2807 tp->suspend.stop_signal = GDB_SIGNAL_0;
2809 thread_fsm_delete (tp->thread_fsm);
2810 tp->thread_fsm = NULL;
2812 tp->control.trap_expected = 0;
2813 tp->control.step_range_start = 0;
2814 tp->control.step_range_end = 0;
2815 tp->control.may_range_step = 0;
2816 tp->control.step_frame_id = null_frame_id;
2817 tp->control.step_stack_frame_id = null_frame_id;
2818 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2819 tp->control.step_start_function = NULL;
2820 tp->stop_requested = 0;
2822 tp->control.stop_step = 0;
2824 tp->control.proceed_to_finish = 0;
2826 tp->control.stepping_command = 0;
2828 /* Discard any remaining commands or status from previous stop. */
2829 bpstat_clear (&tp->control.stop_bpstat);
2833 clear_proceed_status (int step)
2835 /* With scheduler-locking replay, stop replaying other threads if we're
2836 not replaying the user-visible resume ptid.
2838 This is a convenience feature to not require the user to explicitly
2839 stop replaying the other threads. We're assuming that the user's
2840 intent is to resume tracing the recorded process. */
2841 if (!non_stop && scheduler_mode == schedlock_replay
2842 && target_record_is_replaying (minus_one_ptid)
2843 && !target_record_will_replay (user_visible_resume_ptid (step),
2844 execution_direction))
2845 target_record_stop_replaying ();
2849 struct thread_info *tp;
2852 resume_ptid = user_visible_resume_ptid (step);
2854 /* In all-stop mode, delete the per-thread status of all threads
2855 we're about to resume, implicitly and explicitly. */
2856 ALL_NON_EXITED_THREADS (tp)
2858 if (!ptid_match (tp->ptid, resume_ptid))
2860 clear_proceed_status_thread (tp);
2864 if (!ptid_equal (inferior_ptid, null_ptid))
2866 struct inferior *inferior;
2870 /* If in non-stop mode, only delete the per-thread status of
2871 the current thread. */
2872 clear_proceed_status_thread (inferior_thread ());
2875 inferior = current_inferior ();
2876 inferior->control.stop_soon = NO_STOP_QUIETLY;
2879 observer_notify_about_to_proceed ();
2882 /* Returns true if TP is still stopped at a breakpoint that needs
2883 stepping-over in order to make progress. If the breakpoint is gone
2884 meanwhile, we can skip the whole step-over dance. */
2887 thread_still_needs_step_over_bp (struct thread_info *tp)
2889 if (tp->stepping_over_breakpoint)
2891 struct regcache *regcache = get_thread_regcache (tp->ptid);
2893 if (breakpoint_here_p (regcache->aspace (),
2894 regcache_read_pc (regcache))
2895 == ordinary_breakpoint_here)
2898 tp->stepping_over_breakpoint = 0;
2904 /* Check whether thread TP still needs to start a step-over in order
2905 to make progress when resumed. Returns an bitwise or of enum
2906 step_over_what bits, indicating what needs to be stepped over. */
2908 static step_over_what
2909 thread_still_needs_step_over (struct thread_info *tp)
2911 step_over_what what = 0;
2913 if (thread_still_needs_step_over_bp (tp))
2914 what |= STEP_OVER_BREAKPOINT;
2916 if (tp->stepping_over_watchpoint
2917 && !target_have_steppable_watchpoint)
2918 what |= STEP_OVER_WATCHPOINT;
2923 /* Returns true if scheduler locking applies. STEP indicates whether
2924 we're about to do a step/next-like command to a thread. */
2927 schedlock_applies (struct thread_info *tp)
2929 return (scheduler_mode == schedlock_on
2930 || (scheduler_mode == schedlock_step
2931 && tp->control.stepping_command)
2932 || (scheduler_mode == schedlock_replay
2933 && target_record_will_replay (minus_one_ptid,
2934 execution_direction)));
2937 /* Basic routine for continuing the program in various fashions.
2939 ADDR is the address to resume at, or -1 for resume where stopped.
2940 SIGGNAL is the signal to give it, or 0 for none,
2941 or -1 for act according to how it stopped.
2942 STEP is nonzero if should trap after one instruction.
2943 -1 means return after that and print nothing.
2944 You should probably set various step_... variables
2945 before calling here, if you are stepping.
2947 You should call clear_proceed_status before calling proceed. */
2950 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2952 struct regcache *regcache;
2953 struct gdbarch *gdbarch;
2954 struct thread_info *tp;
2957 struct execution_control_state ecss;
2958 struct execution_control_state *ecs = &ecss;
2959 struct cleanup *old_chain;
2962 /* If we're stopped at a fork/vfork, follow the branch set by the
2963 "set follow-fork-mode" command; otherwise, we'll just proceed
2964 resuming the current thread. */
2965 if (!follow_fork ())
2967 /* The target for some reason decided not to resume. */
2969 if (target_can_async_p ())
2970 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2974 /* We'll update this if & when we switch to a new thread. */
2975 previous_inferior_ptid = inferior_ptid;
2977 regcache = get_current_regcache ();
2978 gdbarch = regcache->arch ();
2979 const address_space *aspace = regcache->aspace ();
2981 pc = regcache_read_pc (regcache);
2982 tp = inferior_thread ();
2984 /* Fill in with reasonable starting values. */
2985 init_thread_stepping_state (tp);
2987 gdb_assert (!thread_is_in_step_over_chain (tp));
2989 if (addr == (CORE_ADDR) -1)
2992 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2993 && execution_direction != EXEC_REVERSE)
2994 /* There is a breakpoint at the address we will resume at,
2995 step one instruction before inserting breakpoints so that
2996 we do not stop right away (and report a second hit at this
2999 Note, we don't do this in reverse, because we won't
3000 actually be executing the breakpoint insn anyway.
3001 We'll be (un-)executing the previous instruction. */
3002 tp->stepping_over_breakpoint = 1;
3003 else if (gdbarch_single_step_through_delay_p (gdbarch)
3004 && gdbarch_single_step_through_delay (gdbarch,
3005 get_current_frame ()))
3006 /* We stepped onto an instruction that needs to be stepped
3007 again before re-inserting the breakpoint, do so. */
3008 tp->stepping_over_breakpoint = 1;
3012 regcache_write_pc (regcache, addr);
3015 if (siggnal != GDB_SIGNAL_DEFAULT)
3016 tp->suspend.stop_signal = siggnal;
3018 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3020 /* If an exception is thrown from this point on, make sure to
3021 propagate GDB's knowledge of the executing state to the
3022 frontend/user running state. */
3023 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3025 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3026 threads (e.g., we might need to set threads stepping over
3027 breakpoints first), from the user/frontend's point of view, all
3028 threads in RESUME_PTID are now running. Unless we're calling an
3029 inferior function, as in that case we pretend the inferior
3030 doesn't run at all. */
3031 if (!tp->control.in_infcall)
3032 set_running (resume_ptid, 1);
3035 fprintf_unfiltered (gdb_stdlog,
3036 "infrun: proceed (addr=%s, signal=%s)\n",
3037 paddress (gdbarch, addr),
3038 gdb_signal_to_symbol_string (siggnal));
3040 annotate_starting ();
3042 /* Make sure that output from GDB appears before output from the
3044 gdb_flush (gdb_stdout);
3046 /* Since we've marked the inferior running, give it the terminal. A
3047 QUIT/Ctrl-C from here on is forwarded to the target (which can
3048 still detect attempts to unblock a stuck connection with repeated
3049 Ctrl-C from within target_pass_ctrlc). */
3050 target_terminal::inferior ();
3052 /* In a multi-threaded task we may select another thread and
3053 then continue or step.
3055 But if a thread that we're resuming had stopped at a breakpoint,
3056 it will immediately cause another breakpoint stop without any
3057 execution (i.e. it will report a breakpoint hit incorrectly). So
3058 we must step over it first.
3060 Look for threads other than the current (TP) that reported a
3061 breakpoint hit and haven't been resumed yet since. */
3063 /* If scheduler locking applies, we can avoid iterating over all
3065 if (!non_stop && !schedlock_applies (tp))
3067 struct thread_info *current = tp;
3069 ALL_NON_EXITED_THREADS (tp)
3071 /* Ignore the current thread here. It's handled
3076 /* Ignore threads of processes we're not resuming. */
3077 if (!ptid_match (tp->ptid, resume_ptid))
3080 if (!thread_still_needs_step_over (tp))
3083 gdb_assert (!thread_is_in_step_over_chain (tp));
3086 fprintf_unfiltered (gdb_stdlog,
3087 "infrun: need to step-over [%s] first\n",
3088 target_pid_to_str (tp->ptid));
3090 thread_step_over_chain_enqueue (tp);
3096 /* Enqueue the current thread last, so that we move all other
3097 threads over their breakpoints first. */
3098 if (tp->stepping_over_breakpoint)
3099 thread_step_over_chain_enqueue (tp);
3101 /* If the thread isn't started, we'll still need to set its prev_pc,
3102 so that switch_back_to_stepped_thread knows the thread hasn't
3103 advanced. Must do this before resuming any thread, as in
3104 all-stop/remote, once we resume we can't send any other packet
3105 until the target stops again. */
3106 tp->prev_pc = regcache_read_pc (regcache);
3109 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3111 started = start_step_over ();
3113 if (step_over_info_valid_p ())
3115 /* Either this thread started a new in-line step over, or some
3116 other thread was already doing one. In either case, don't
3117 resume anything else until the step-over is finished. */
3119 else if (started && !target_is_non_stop_p ())
3121 /* A new displaced stepping sequence was started. In all-stop,
3122 we can't talk to the target anymore until it next stops. */
3124 else if (!non_stop && target_is_non_stop_p ())
3126 /* In all-stop, but the target is always in non-stop mode.
3127 Start all other threads that are implicitly resumed too. */
3128 ALL_NON_EXITED_THREADS (tp)
3130 /* Ignore threads of processes we're not resuming. */
3131 if (!ptid_match (tp->ptid, resume_ptid))
3137 fprintf_unfiltered (gdb_stdlog,
3138 "infrun: proceed: [%s] resumed\n",
3139 target_pid_to_str (tp->ptid));
3140 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3144 if (thread_is_in_step_over_chain (tp))
3147 fprintf_unfiltered (gdb_stdlog,
3148 "infrun: proceed: [%s] needs step-over\n",
3149 target_pid_to_str (tp->ptid));
3154 fprintf_unfiltered (gdb_stdlog,
3155 "infrun: proceed: resuming %s\n",
3156 target_pid_to_str (tp->ptid));
3158 reset_ecs (ecs, tp);
3159 switch_to_thread (tp->ptid);
3160 keep_going_pass_signal (ecs);
3161 if (!ecs->wait_some_more)
3162 error (_("Command aborted."));
3165 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3167 /* The thread wasn't started, and isn't queued, run it now. */
3168 reset_ecs (ecs, tp);
3169 switch_to_thread (tp->ptid);
3170 keep_going_pass_signal (ecs);
3171 if (!ecs->wait_some_more)
3172 error (_("Command aborted."));
3176 target_commit_resume ();
3178 discard_cleanups (old_chain);
3180 /* Tell the event loop to wait for it to stop. If the target
3181 supports asynchronous execution, it'll do this from within
3183 if (!target_can_async_p ())
3184 mark_async_event_handler (infrun_async_inferior_event_token);
3188 /* Start remote-debugging of a machine over a serial link. */
3191 start_remote (int from_tty)
3193 struct inferior *inferior;
3195 inferior = current_inferior ();
3196 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3198 /* Always go on waiting for the target, regardless of the mode. */
3199 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3200 indicate to wait_for_inferior that a target should timeout if
3201 nothing is returned (instead of just blocking). Because of this,
3202 targets expecting an immediate response need to, internally, set
3203 things up so that the target_wait() is forced to eventually
3205 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3206 differentiate to its caller what the state of the target is after
3207 the initial open has been performed. Here we're assuming that
3208 the target has stopped. It should be possible to eventually have
3209 target_open() return to the caller an indication that the target
3210 is currently running and GDB state should be set to the same as
3211 for an async run. */
3212 wait_for_inferior ();
3214 /* Now that the inferior has stopped, do any bookkeeping like
3215 loading shared libraries. We want to do this before normal_stop,
3216 so that the displayed frame is up to date. */
3217 post_create_inferior (¤t_target, from_tty);
3222 /* Initialize static vars when a new inferior begins. */
3225 init_wait_for_inferior (void)
3227 /* These are meaningless until the first time through wait_for_inferior. */
3229 breakpoint_init_inferior (inf_starting);
3231 clear_proceed_status (0);
3233 target_last_wait_ptid = minus_one_ptid;
3235 previous_inferior_ptid = inferior_ptid;
3237 /* Discard any skipped inlined frames. */
3238 clear_inline_frame_state (minus_one_ptid);
3243 static void handle_inferior_event (struct execution_control_state *ecs);
3245 static void handle_step_into_function (struct gdbarch *gdbarch,
3246 struct execution_control_state *ecs);
3247 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3248 struct execution_control_state *ecs);
3249 static void handle_signal_stop (struct execution_control_state *ecs);
3250 static void check_exception_resume (struct execution_control_state *,
3251 struct frame_info *);
3253 static void end_stepping_range (struct execution_control_state *ecs);
3254 static void stop_waiting (struct execution_control_state *ecs);
3255 static void keep_going (struct execution_control_state *ecs);
3256 static void process_event_stop_test (struct execution_control_state *ecs);
3257 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3259 /* This function is attached as a "thread_stop_requested" observer.
3260 Cleanup local state that assumed the PTID was to be resumed, and
3261 report the stop to the frontend. */
3264 infrun_thread_stop_requested (ptid_t ptid)
3266 struct thread_info *tp;
3268 /* PTID was requested to stop. If the thread was already stopped,
3269 but the user/frontend doesn't know about that yet (e.g., the
3270 thread had been temporarily paused for some step-over), set up
3271 for reporting the stop now. */
3272 ALL_NON_EXITED_THREADS (tp)
3273 if (ptid_match (tp->ptid, ptid))
3275 if (tp->state != THREAD_RUNNING)
3280 /* Remove matching threads from the step-over queue, so
3281 start_step_over doesn't try to resume them
3283 if (thread_is_in_step_over_chain (tp))
3284 thread_step_over_chain_remove (tp);
3286 /* If the thread is stopped, but the user/frontend doesn't
3287 know about that yet, queue a pending event, as if the
3288 thread had just stopped now. Unless the thread already had
3290 if (!tp->suspend.waitstatus_pending_p)
3292 tp->suspend.waitstatus_pending_p = 1;
3293 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3294 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3297 /* Clear the inline-frame state, since we're re-processing the
3299 clear_inline_frame_state (tp->ptid);
3301 /* If this thread was paused because some other thread was
3302 doing an inline-step over, let that finish first. Once
3303 that happens, we'll restart all threads and consume pending
3304 stop events then. */
3305 if (step_over_info_valid_p ())
3308 /* Otherwise we can process the (new) pending event now. Set
3309 it so this pending event is considered by
3316 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3318 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3319 nullify_last_target_wait_ptid ();
3322 /* Delete the step resume, single-step and longjmp/exception resume
3323 breakpoints of TP. */
3326 delete_thread_infrun_breakpoints (struct thread_info *tp)
3328 delete_step_resume_breakpoint (tp);
3329 delete_exception_resume_breakpoint (tp);
3330 delete_single_step_breakpoints (tp);
3333 /* If the target still has execution, call FUNC for each thread that
3334 just stopped. In all-stop, that's all the non-exited threads; in
3335 non-stop, that's the current thread, only. */
3337 typedef void (*for_each_just_stopped_thread_callback_func)
3338 (struct thread_info *tp);
3341 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3343 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3346 if (target_is_non_stop_p ())
3348 /* If in non-stop mode, only the current thread stopped. */
3349 func (inferior_thread ());
3353 struct thread_info *tp;
3355 /* In all-stop mode, all threads have stopped. */
3356 ALL_NON_EXITED_THREADS (tp)
3363 /* Delete the step resume and longjmp/exception resume breakpoints of
3364 the threads that just stopped. */
3367 delete_just_stopped_threads_infrun_breakpoints (void)
3369 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3372 /* Delete the single-step breakpoints of the threads that just
3376 delete_just_stopped_threads_single_step_breakpoints (void)
3378 for_each_just_stopped_thread (delete_single_step_breakpoints);
3381 /* A cleanup wrapper. */
3384 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3386 delete_just_stopped_threads_infrun_breakpoints ();
3392 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3393 const struct target_waitstatus *ws)
3395 std::string status_string = target_waitstatus_to_string (ws);
3398 /* The text is split over several lines because it was getting too long.
3399 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3400 output as a unit; we want only one timestamp printed if debug_timestamp
3403 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3404 ptid_get_pid (waiton_ptid),
3405 ptid_get_lwp (waiton_ptid),
3406 ptid_get_tid (waiton_ptid));
3407 if (ptid_get_pid (waiton_ptid) != -1)
3408 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3409 stb.printf (", status) =\n");
3410 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3411 ptid_get_pid (result_ptid),
3412 ptid_get_lwp (result_ptid),
3413 ptid_get_tid (result_ptid),
3414 target_pid_to_str (result_ptid));
3415 stb.printf ("infrun: %s\n", status_string.c_str ());
3417 /* This uses %s in part to handle %'s in the text, but also to avoid
3418 a gcc error: the format attribute requires a string literal. */
3419 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3422 /* Select a thread at random, out of those which are resumed and have
3425 static struct thread_info *
3426 random_pending_event_thread (ptid_t waiton_ptid)
3428 struct thread_info *event_tp;
3430 int random_selector;
3432 /* First see how many events we have. Count only resumed threads
3433 that have an event pending. */
3434 ALL_NON_EXITED_THREADS (event_tp)
3435 if (ptid_match (event_tp->ptid, waiton_ptid)
3436 && event_tp->resumed
3437 && event_tp->suspend.waitstatus_pending_p)
3440 if (num_events == 0)
3443 /* Now randomly pick a thread out of those that have had events. */
3444 random_selector = (int)
3445 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3447 if (debug_infrun && num_events > 1)
3448 fprintf_unfiltered (gdb_stdlog,
3449 "infrun: Found %d events, selecting #%d\n",
3450 num_events, random_selector);
3452 /* Select the Nth thread that has had an event. */
3453 ALL_NON_EXITED_THREADS (event_tp)
3454 if (ptid_match (event_tp->ptid, waiton_ptid)
3455 && event_tp->resumed
3456 && event_tp->suspend.waitstatus_pending_p)
3457 if (random_selector-- == 0)
3463 /* Wrapper for target_wait that first checks whether threads have
3464 pending statuses to report before actually asking the target for
3468 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3471 struct thread_info *tp;
3473 /* First check if there is a resumed thread with a wait status
3475 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3477 tp = random_pending_event_thread (ptid);
3482 fprintf_unfiltered (gdb_stdlog,
3483 "infrun: Waiting for specific thread %s.\n",
3484 target_pid_to_str (ptid));
3486 /* We have a specific thread to check. */
3487 tp = find_thread_ptid (ptid);
3488 gdb_assert (tp != NULL);
3489 if (!tp->suspend.waitstatus_pending_p)
3494 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3495 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3497 struct regcache *regcache = get_thread_regcache (tp->ptid);
3498 struct gdbarch *gdbarch = regcache->arch ();
3502 pc = regcache_read_pc (regcache);
3504 if (pc != tp->suspend.stop_pc)
3507 fprintf_unfiltered (gdb_stdlog,
3508 "infrun: PC of %s changed. was=%s, now=%s\n",
3509 target_pid_to_str (tp->ptid),
3510 paddress (gdbarch, tp->prev_pc),
3511 paddress (gdbarch, pc));
3514 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3517 fprintf_unfiltered (gdb_stdlog,
3518 "infrun: previous breakpoint of %s, at %s gone\n",
3519 target_pid_to_str (tp->ptid),
3520 paddress (gdbarch, pc));
3528 fprintf_unfiltered (gdb_stdlog,
3529 "infrun: pending event of %s cancelled.\n",
3530 target_pid_to_str (tp->ptid));
3532 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3533 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3542 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3544 fprintf_unfiltered (gdb_stdlog,
3545 "infrun: Using pending wait status %s for %s.\n",
3547 target_pid_to_str (tp->ptid));
3550 /* Now that we've selected our final event LWP, un-adjust its PC
3551 if it was a software breakpoint (and the target doesn't
3552 always adjust the PC itself). */
3553 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3554 && !target_supports_stopped_by_sw_breakpoint ())
3556 struct regcache *regcache;
3557 struct gdbarch *gdbarch;
3560 regcache = get_thread_regcache (tp->ptid);
3561 gdbarch = regcache->arch ();
3563 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3568 pc = regcache_read_pc (regcache);
3569 regcache_write_pc (regcache, pc + decr_pc);
3573 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3574 *status = tp->suspend.waitstatus;
3575 tp->suspend.waitstatus_pending_p = 0;
3577 /* Wake up the event loop again, until all pending events are
3579 if (target_is_async_p ())
3580 mark_async_event_handler (infrun_async_inferior_event_token);
3584 /* But if we don't find one, we'll have to wait. */
3586 if (deprecated_target_wait_hook)
3587 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3589 event_ptid = target_wait (ptid, status, options);
3594 /* Prepare and stabilize the inferior for detaching it. E.g.,
3595 detaching while a thread is displaced stepping is a recipe for
3596 crashing it, as nothing would readjust the PC out of the scratch
3600 prepare_for_detach (void)
3602 struct inferior *inf = current_inferior ();
3603 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3604 struct displaced_step_inferior_state *displaced;
3606 displaced = get_displaced_stepping_state (inf->pid);
3608 /* Is any thread of this process displaced stepping? If not,
3609 there's nothing else to do. */
3610 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3614 fprintf_unfiltered (gdb_stdlog,
3615 "displaced-stepping in-process while detaching");
3617 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3619 while (!ptid_equal (displaced->step_ptid, null_ptid))
3621 struct cleanup *old_chain_2;
3622 struct execution_control_state ecss;
3623 struct execution_control_state *ecs;
3626 memset (ecs, 0, sizeof (*ecs));
3628 overlay_cache_invalid = 1;
3629 /* Flush target cache before starting to handle each event.
3630 Target was running and cache could be stale. This is just a
3631 heuristic. Running threads may modify target memory, but we
3632 don't get any event. */
3633 target_dcache_invalidate ();
3635 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3638 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3640 /* If an error happens while handling the event, propagate GDB's
3641 knowledge of the executing state to the frontend/user running
3643 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3646 /* Now figure out what to do with the result of the result. */
3647 handle_inferior_event (ecs);
3649 /* No error, don't finish the state yet. */
3650 discard_cleanups (old_chain_2);
3652 /* Breakpoints and watchpoints are not installed on the target
3653 at this point, and signals are passed directly to the
3654 inferior, so this must mean the process is gone. */
3655 if (!ecs->wait_some_more)
3657 restore_detaching.release ();
3658 error (_("Program exited while detaching"));
3662 restore_detaching.release ();
3665 /* Wait for control to return from inferior to debugger.
3667 If inferior gets a signal, we may decide to start it up again
3668 instead of returning. That is why there is a loop in this function.
3669 When this function actually returns it means the inferior
3670 should be left stopped and GDB should read more commands. */
3673 wait_for_inferior (void)
3675 struct cleanup *old_cleanups;
3676 struct cleanup *thread_state_chain;
3680 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3683 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3686 /* If an error happens while handling the event, propagate GDB's
3687 knowledge of the executing state to the frontend/user running
3689 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3693 struct execution_control_state ecss;
3694 struct execution_control_state *ecs = &ecss;
3695 ptid_t waiton_ptid = minus_one_ptid;
3697 memset (ecs, 0, sizeof (*ecs));
3699 overlay_cache_invalid = 1;
3701 /* Flush target cache before starting to handle each event.
3702 Target was running and cache could be stale. This is just a
3703 heuristic. Running threads may modify target memory, but we
3704 don't get any event. */
3705 target_dcache_invalidate ();
3707 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3710 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3712 /* Now figure out what to do with the result of the result. */
3713 handle_inferior_event (ecs);
3715 if (!ecs->wait_some_more)
3719 /* No error, don't finish the state yet. */
3720 discard_cleanups (thread_state_chain);
3722 do_cleanups (old_cleanups);
3725 /* Cleanup that reinstalls the readline callback handler, if the
3726 target is running in the background. If while handling the target
3727 event something triggered a secondary prompt, like e.g., a
3728 pagination prompt, we'll have removed the callback handler (see
3729 gdb_readline_wrapper_line). Need to do this as we go back to the
3730 event loop, ready to process further input. Note this has no
3731 effect if the handler hasn't actually been removed, because calling
3732 rl_callback_handler_install resets the line buffer, thus losing
3736 reinstall_readline_callback_handler_cleanup (void *arg)
3738 struct ui *ui = current_ui;
3742 /* We're not going back to the top level event loop yet. Don't
3743 install the readline callback, as it'd prep the terminal,
3744 readline-style (raw, noecho) (e.g., --batch). We'll install
3745 it the next time the prompt is displayed, when we're ready
3750 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3751 gdb_rl_callback_handler_reinstall ();
3754 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3755 that's just the event thread. In all-stop, that's all threads. */
3758 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3760 struct thread_info *thr = ecs->event_thread;
3762 if (thr != NULL && thr->thread_fsm != NULL)
3763 thread_fsm_clean_up (thr->thread_fsm, thr);
3767 ALL_NON_EXITED_THREADS (thr)
3769 if (thr->thread_fsm == NULL)
3771 if (thr == ecs->event_thread)
3774 switch_to_thread (thr->ptid);
3775 thread_fsm_clean_up (thr->thread_fsm, thr);
3778 if (ecs->event_thread != NULL)
3779 switch_to_thread (ecs->event_thread->ptid);
3783 /* Helper for all_uis_check_sync_execution_done that works on the
3787 check_curr_ui_sync_execution_done (void)
3789 struct ui *ui = current_ui;
3791 if (ui->prompt_state == PROMPT_NEEDED
3793 && !gdb_in_secondary_prompt_p (ui))
3795 target_terminal::ours ();
3796 observer_notify_sync_execution_done ();
3797 ui_register_input_event_handler (ui);
3804 all_uis_check_sync_execution_done (void)
3806 SWITCH_THRU_ALL_UIS ()
3808 check_curr_ui_sync_execution_done ();
3815 all_uis_on_sync_execution_starting (void)
3817 SWITCH_THRU_ALL_UIS ()
3819 if (current_ui->prompt_state == PROMPT_NEEDED)
3820 async_disable_stdin ();
3824 /* Asynchronous version of wait_for_inferior. It is called by the
3825 event loop whenever a change of state is detected on the file
3826 descriptor corresponding to the target. It can be called more than
3827 once to complete a single execution command. In such cases we need
3828 to keep the state in a global variable ECSS. If it is the last time
3829 that this function is called for a single execution command, then
3830 report to the user that the inferior has stopped, and do the
3831 necessary cleanups. */
3834 fetch_inferior_event (void *client_data)
3836 struct execution_control_state ecss;
3837 struct execution_control_state *ecs = &ecss;
3838 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3839 struct cleanup *ts_old_chain;
3841 ptid_t waiton_ptid = minus_one_ptid;
3843 memset (ecs, 0, sizeof (*ecs));
3845 /* Events are always processed with the main UI as current UI. This
3846 way, warnings, debug output, etc. are always consistently sent to
3847 the main console. */
3848 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3850 /* End up with readline processing input, if necessary. */
3851 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3853 /* We're handling a live event, so make sure we're doing live
3854 debugging. If we're looking at traceframes while the target is
3855 running, we're going to need to get back to that mode after
3856 handling the event. */
3859 make_cleanup_restore_current_traceframe ();
3860 set_current_traceframe (-1);
3863 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3866 /* In non-stop mode, the user/frontend should not notice a thread
3867 switch due to internal events. Make sure we reverse to the
3868 user selected thread and frame after handling the event and
3869 running any breakpoint commands. */
3870 maybe_restore_thread.emplace ();
3872 overlay_cache_invalid = 1;
3873 /* Flush target cache before starting to handle each event. Target
3874 was running and cache could be stale. This is just a heuristic.
3875 Running threads may modify target memory, but we don't get any
3877 target_dcache_invalidate ();
3879 scoped_restore save_exec_dir
3880 = make_scoped_restore (&execution_direction, target_execution_direction ());
3882 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3883 target_can_async_p () ? TARGET_WNOHANG : 0);
3886 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3888 /* If an error happens while handling the event, propagate GDB's
3889 knowledge of the executing state to the frontend/user running
3891 if (!target_is_non_stop_p ())
3892 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3894 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3896 /* Get executed before make_cleanup_restore_current_thread above to apply
3897 still for the thread which has thrown the exception. */
3898 make_bpstat_clear_actions_cleanup ();
3900 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3902 /* Now figure out what to do with the result of the result. */
3903 handle_inferior_event (ecs);
3905 if (!ecs->wait_some_more)
3907 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3908 int should_stop = 1;
3909 struct thread_info *thr = ecs->event_thread;
3910 int should_notify_stop = 1;
3912 delete_just_stopped_threads_infrun_breakpoints ();
3916 struct thread_fsm *thread_fsm = thr->thread_fsm;
3918 if (thread_fsm != NULL)
3919 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3928 clean_up_just_stopped_threads_fsms (ecs);
3930 if (thr != NULL && thr->thread_fsm != NULL)
3933 = thread_fsm_should_notify_stop (thr->thread_fsm);
3936 if (should_notify_stop)
3940 /* We may not find an inferior if this was a process exit. */
3941 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3942 proceeded = normal_stop ();
3946 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3953 /* No error, don't finish the thread states yet. */
3954 discard_cleanups (ts_old_chain);
3956 /* Revert thread and frame. */
3957 do_cleanups (old_chain);
3959 /* If a UI was in sync execution mode, and now isn't, restore its
3960 prompt (a synchronous execution command has finished, and we're
3961 ready for input). */
3962 all_uis_check_sync_execution_done ();
3965 && exec_done_display_p
3966 && (ptid_equal (inferior_ptid, null_ptid)
3967 || !is_running (inferior_ptid)))
3968 printf_unfiltered (_("completed.\n"));
3971 /* Record the frame and location we're currently stepping through. */
3973 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3975 struct thread_info *tp = inferior_thread ();
3977 tp->control.step_frame_id = get_frame_id (frame);
3978 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3980 tp->current_symtab = sal.symtab;
3981 tp->current_line = sal.line;
3984 /* Clear context switchable stepping state. */
3987 init_thread_stepping_state (struct thread_info *tss)
3989 tss->stepped_breakpoint = 0;
3990 tss->stepping_over_breakpoint = 0;
3991 tss->stepping_over_watchpoint = 0;
3992 tss->step_after_step_resume_breakpoint = 0;
3995 /* Set the cached copy of the last ptid/waitstatus. */
3998 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4000 target_last_wait_ptid = ptid;
4001 target_last_waitstatus = status;
4004 /* Return the cached copy of the last pid/waitstatus returned by
4005 target_wait()/deprecated_target_wait_hook(). The data is actually
4006 cached by handle_inferior_event(), which gets called immediately
4007 after target_wait()/deprecated_target_wait_hook(). */
4010 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4012 *ptidp = target_last_wait_ptid;
4013 *status = target_last_waitstatus;
4017 nullify_last_target_wait_ptid (void)
4019 target_last_wait_ptid = minus_one_ptid;
4022 /* Switch thread contexts. */
4025 context_switch (ptid_t ptid)
4027 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4029 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4030 target_pid_to_str (inferior_ptid));
4031 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4032 target_pid_to_str (ptid));
4035 switch_to_thread (ptid);
4038 /* If the target can't tell whether we've hit breakpoints
4039 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4040 check whether that could have been caused by a breakpoint. If so,
4041 adjust the PC, per gdbarch_decr_pc_after_break. */
4044 adjust_pc_after_break (struct thread_info *thread,
4045 struct target_waitstatus *ws)
4047 struct regcache *regcache;
4048 struct gdbarch *gdbarch;
4049 CORE_ADDR breakpoint_pc, decr_pc;
4051 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4052 we aren't, just return.
4054 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4055 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4056 implemented by software breakpoints should be handled through the normal
4059 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4060 different signals (SIGILL or SIGEMT for instance), but it is less
4061 clear where the PC is pointing afterwards. It may not match
4062 gdbarch_decr_pc_after_break. I don't know any specific target that
4063 generates these signals at breakpoints (the code has been in GDB since at
4064 least 1992) so I can not guess how to handle them here.
4066 In earlier versions of GDB, a target with
4067 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4068 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4069 target with both of these set in GDB history, and it seems unlikely to be
4070 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4072 if (ws->kind != TARGET_WAITKIND_STOPPED)
4075 if (ws->value.sig != GDB_SIGNAL_TRAP)
4078 /* In reverse execution, when a breakpoint is hit, the instruction
4079 under it has already been de-executed. The reported PC always
4080 points at the breakpoint address, so adjusting it further would
4081 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4084 B1 0x08000000 : INSN1
4085 B2 0x08000001 : INSN2
4087 PC -> 0x08000003 : INSN4
4089 Say you're stopped at 0x08000003 as above. Reverse continuing
4090 from that point should hit B2 as below. Reading the PC when the
4091 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4092 been de-executed already.
4094 B1 0x08000000 : INSN1
4095 B2 PC -> 0x08000001 : INSN2
4099 We can't apply the same logic as for forward execution, because
4100 we would wrongly adjust the PC to 0x08000000, since there's a
4101 breakpoint at PC - 1. We'd then report a hit on B1, although
4102 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4104 if (execution_direction == EXEC_REVERSE)
4107 /* If the target can tell whether the thread hit a SW breakpoint,
4108 trust it. Targets that can tell also adjust the PC
4110 if (target_supports_stopped_by_sw_breakpoint ())
4113 /* Note that relying on whether a breakpoint is planted in memory to
4114 determine this can fail. E.g,. the breakpoint could have been
4115 removed since. Or the thread could have been told to step an
4116 instruction the size of a breakpoint instruction, and only
4117 _after_ was a breakpoint inserted at its address. */
4119 /* If this target does not decrement the PC after breakpoints, then
4120 we have nothing to do. */
4121 regcache = get_thread_regcache (thread->ptid);
4122 gdbarch = regcache->arch ();
4124 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4128 const address_space *aspace = regcache->aspace ();
4130 /* Find the location where (if we've hit a breakpoint) the
4131 breakpoint would be. */
4132 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4134 /* If the target can't tell whether a software breakpoint triggered,
4135 fallback to figuring it out based on breakpoints we think were
4136 inserted in the target, and on whether the thread was stepped or
4139 /* Check whether there actually is a software breakpoint inserted at
4142 If in non-stop mode, a race condition is possible where we've
4143 removed a breakpoint, but stop events for that breakpoint were
4144 already queued and arrive later. To suppress those spurious
4145 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4146 and retire them after a number of stop events are reported. Note
4147 this is an heuristic and can thus get confused. The real fix is
4148 to get the "stopped by SW BP and needs adjustment" info out of
4149 the target/kernel (and thus never reach here; see above). */
4150 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4151 || (target_is_non_stop_p ()
4152 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4154 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4156 if (record_full_is_used ())
4157 restore_operation_disable.emplace
4158 (record_full_gdb_operation_disable_set ());
4160 /* When using hardware single-step, a SIGTRAP is reported for both
4161 a completed single-step and a software breakpoint. Need to
4162 differentiate between the two, as the latter needs adjusting
4163 but the former does not.
4165 The SIGTRAP can be due to a completed hardware single-step only if
4166 - we didn't insert software single-step breakpoints
4167 - this thread is currently being stepped
4169 If any of these events did not occur, we must have stopped due
4170 to hitting a software breakpoint, and have to back up to the
4173 As a special case, we could have hardware single-stepped a
4174 software breakpoint. In this case (prev_pc == breakpoint_pc),
4175 we also need to back up to the breakpoint address. */
4177 if (thread_has_single_step_breakpoints_set (thread)
4178 || !currently_stepping (thread)
4179 || (thread->stepped_breakpoint
4180 && thread->prev_pc == breakpoint_pc))
4181 regcache_write_pc (regcache, breakpoint_pc);
4186 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4188 for (frame = get_prev_frame (frame);
4190 frame = get_prev_frame (frame))
4192 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4194 if (get_frame_type (frame) != INLINE_FRAME)
4201 /* If the event thread has the stop requested flag set, pretend it
4202 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4206 handle_stop_requested (struct execution_control_state *ecs)
4208 if (ecs->event_thread->stop_requested)
4210 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4211 ecs->ws.value.sig = GDB_SIGNAL_0;
4212 handle_signal_stop (ecs);
4218 /* Auxiliary function that handles syscall entry/return events.
4219 It returns 1 if the inferior should keep going (and GDB
4220 should ignore the event), or 0 if the event deserves to be
4224 handle_syscall_event (struct execution_control_state *ecs)
4226 struct regcache *regcache;
4229 if (!ptid_equal (ecs->ptid, inferior_ptid))
4230 context_switch (ecs->ptid);
4232 regcache = get_thread_regcache (ecs->ptid);
4233 syscall_number = ecs->ws.value.syscall_number;
4234 stop_pc = regcache_read_pc (regcache);
4236 if (catch_syscall_enabled () > 0
4237 && catching_syscall_number (syscall_number) > 0)
4240 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4243 ecs->event_thread->control.stop_bpstat
4244 = bpstat_stop_status (regcache->aspace (),
4245 stop_pc, ecs->ptid, &ecs->ws);
4247 if (handle_stop_requested (ecs))
4250 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4252 /* Catchpoint hit. */
4257 if (handle_stop_requested (ecs))
4260 /* If no catchpoint triggered for this, then keep going. */
4265 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4268 fill_in_stop_func (struct gdbarch *gdbarch,
4269 struct execution_control_state *ecs)
4271 if (!ecs->stop_func_filled_in)
4273 /* Don't care about return value; stop_func_start and stop_func_name
4274 will both be 0 if it doesn't work. */
4275 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4276 &ecs->stop_func_start, &ecs->stop_func_end);
4277 ecs->stop_func_start
4278 += gdbarch_deprecated_function_start_offset (gdbarch);
4280 if (gdbarch_skip_entrypoint_p (gdbarch))
4281 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4282 ecs->stop_func_start);
4284 ecs->stop_func_filled_in = 1;
4289 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4291 static enum stop_kind
4292 get_inferior_stop_soon (ptid_t ptid)
4294 struct inferior *inf = find_inferior_ptid (ptid);
4296 gdb_assert (inf != NULL);
4297 return inf->control.stop_soon;
4300 /* Wait for one event. Store the resulting waitstatus in WS, and
4301 return the event ptid. */
4304 wait_one (struct target_waitstatus *ws)
4307 ptid_t wait_ptid = minus_one_ptid;
4309 overlay_cache_invalid = 1;
4311 /* Flush target cache before starting to handle each event.
4312 Target was running and cache could be stale. This is just a
4313 heuristic. Running threads may modify target memory, but we
4314 don't get any event. */
4315 target_dcache_invalidate ();
4317 if (deprecated_target_wait_hook)
4318 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4320 event_ptid = target_wait (wait_ptid, ws, 0);
4323 print_target_wait_results (wait_ptid, event_ptid, ws);
4328 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4329 instead of the current thread. */
4330 #define THREAD_STOPPED_BY(REASON) \
4332 thread_stopped_by_ ## REASON (ptid_t ptid) \
4334 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4335 inferior_ptid = ptid; \
4337 return target_stopped_by_ ## REASON (); \
4340 /* Generate thread_stopped_by_watchpoint. */
4341 THREAD_STOPPED_BY (watchpoint)
4342 /* Generate thread_stopped_by_sw_breakpoint. */
4343 THREAD_STOPPED_BY (sw_breakpoint)
4344 /* Generate thread_stopped_by_hw_breakpoint. */
4345 THREAD_STOPPED_BY (hw_breakpoint)
4347 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4350 switch_to_thread_cleanup (void *ptid_p)
4352 ptid_t ptid = *(ptid_t *) ptid_p;
4354 switch_to_thread (ptid);
4357 /* Save the thread's event and stop reason to process it later. */
4360 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4362 struct regcache *regcache;
4366 std::string statstr = target_waitstatus_to_string (ws);
4368 fprintf_unfiltered (gdb_stdlog,
4369 "infrun: saving status %s for %d.%ld.%ld\n",
4371 ptid_get_pid (tp->ptid),
4372 ptid_get_lwp (tp->ptid),
4373 ptid_get_tid (tp->ptid));
4376 /* Record for later. */
4377 tp->suspend.waitstatus = *ws;
4378 tp->suspend.waitstatus_pending_p = 1;
4380 regcache = get_thread_regcache (tp->ptid);
4381 const address_space *aspace = regcache->aspace ();
4383 if (ws->kind == TARGET_WAITKIND_STOPPED
4384 && ws->value.sig == GDB_SIGNAL_TRAP)
4386 CORE_ADDR pc = regcache_read_pc (regcache);
4388 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4390 if (thread_stopped_by_watchpoint (tp->ptid))
4392 tp->suspend.stop_reason
4393 = TARGET_STOPPED_BY_WATCHPOINT;
4395 else if (target_supports_stopped_by_sw_breakpoint ()
4396 && thread_stopped_by_sw_breakpoint (tp->ptid))
4398 tp->suspend.stop_reason
4399 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4401 else if (target_supports_stopped_by_hw_breakpoint ()
4402 && thread_stopped_by_hw_breakpoint (tp->ptid))
4404 tp->suspend.stop_reason
4405 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4407 else if (!target_supports_stopped_by_hw_breakpoint ()
4408 && hardware_breakpoint_inserted_here_p (aspace,
4411 tp->suspend.stop_reason
4412 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4414 else if (!target_supports_stopped_by_sw_breakpoint ()
4415 && software_breakpoint_inserted_here_p (aspace,
4418 tp->suspend.stop_reason
4419 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4421 else if (!thread_has_single_step_breakpoints_set (tp)
4422 && currently_stepping (tp))
4424 tp->suspend.stop_reason
4425 = TARGET_STOPPED_BY_SINGLE_STEP;
4430 /* A cleanup that disables thread create/exit events. */
4433 disable_thread_events (void *arg)
4435 target_thread_events (0);
4441 stop_all_threads (void)
4443 /* We may need multiple passes to discover all threads. */
4447 struct cleanup *old_chain;
4449 gdb_assert (target_is_non_stop_p ());
4452 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4454 entry_ptid = inferior_ptid;
4455 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4457 target_thread_events (1);
4458 make_cleanup (disable_thread_events, NULL);
4460 /* Request threads to stop, and then wait for the stops. Because
4461 threads we already know about can spawn more threads while we're
4462 trying to stop them, and we only learn about new threads when we
4463 update the thread list, do this in a loop, and keep iterating
4464 until two passes find no threads that need to be stopped. */
4465 for (pass = 0; pass < 2; pass++, iterations++)
4468 fprintf_unfiltered (gdb_stdlog,
4469 "infrun: stop_all_threads, pass=%d, "
4470 "iterations=%d\n", pass, iterations);
4474 struct target_waitstatus ws;
4476 struct thread_info *t;
4478 update_thread_list ();
4480 /* Go through all threads looking for threads that we need
4481 to tell the target to stop. */
4482 ALL_NON_EXITED_THREADS (t)
4486 /* If already stopping, don't request a stop again.
4487 We just haven't seen the notification yet. */
4488 if (!t->stop_requested)
4491 fprintf_unfiltered (gdb_stdlog,
4492 "infrun: %s executing, "
4494 target_pid_to_str (t->ptid));
4495 target_stop (t->ptid);
4496 t->stop_requested = 1;
4501 fprintf_unfiltered (gdb_stdlog,
4502 "infrun: %s executing, "
4503 "already stopping\n",
4504 target_pid_to_str (t->ptid));
4507 if (t->stop_requested)
4513 fprintf_unfiltered (gdb_stdlog,
4514 "infrun: %s not executing\n",
4515 target_pid_to_str (t->ptid));
4517 /* The thread may be not executing, but still be
4518 resumed with a pending status to process. */
4526 /* If we find new threads on the second iteration, restart
4527 over. We want to see two iterations in a row with all
4532 event_ptid = wait_one (&ws);
4533 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4535 /* All resumed threads exited. */
4537 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4538 || ws.kind == TARGET_WAITKIND_EXITED
4539 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4543 ptid_t ptid = pid_to_ptid (ws.value.integer);
4545 fprintf_unfiltered (gdb_stdlog,
4546 "infrun: %s exited while "
4547 "stopping threads\n",
4548 target_pid_to_str (ptid));
4553 struct inferior *inf;
4555 t = find_thread_ptid (event_ptid);
4557 t = add_thread (event_ptid);
4559 t->stop_requested = 0;
4562 t->control.may_range_step = 0;
4564 /* This may be the first time we see the inferior report
4566 inf = find_inferior_ptid (event_ptid);
4567 if (inf->needs_setup)
4569 switch_to_thread_no_regs (t);
4573 if (ws.kind == TARGET_WAITKIND_STOPPED
4574 && ws.value.sig == GDB_SIGNAL_0)
4576 /* We caught the event that we intended to catch, so
4577 there's no event pending. */
4578 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4579 t->suspend.waitstatus_pending_p = 0;
4581 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4583 /* Add it back to the step-over queue. */
4586 fprintf_unfiltered (gdb_stdlog,
4587 "infrun: displaced-step of %s "
4588 "canceled: adding back to the "
4589 "step-over queue\n",
4590 target_pid_to_str (t->ptid));
4592 t->control.trap_expected = 0;
4593 thread_step_over_chain_enqueue (t);
4598 enum gdb_signal sig;
4599 struct regcache *regcache;
4603 std::string statstr = target_waitstatus_to_string (&ws);
4605 fprintf_unfiltered (gdb_stdlog,
4606 "infrun: target_wait %s, saving "
4607 "status for %d.%ld.%ld\n",
4609 ptid_get_pid (t->ptid),
4610 ptid_get_lwp (t->ptid),
4611 ptid_get_tid (t->ptid));
4614 /* Record for later. */
4615 save_waitstatus (t, &ws);
4617 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4618 ? ws.value.sig : GDB_SIGNAL_0);
4620 if (displaced_step_fixup (t->ptid, sig) < 0)
4622 /* Add it back to the step-over queue. */
4623 t->control.trap_expected = 0;
4624 thread_step_over_chain_enqueue (t);
4627 regcache = get_thread_regcache (t->ptid);
4628 t->suspend.stop_pc = regcache_read_pc (regcache);
4632 fprintf_unfiltered (gdb_stdlog,
4633 "infrun: saved stop_pc=%s for %s "
4634 "(currently_stepping=%d)\n",
4635 paddress (target_gdbarch (),
4636 t->suspend.stop_pc),
4637 target_pid_to_str (t->ptid),
4638 currently_stepping (t));
4645 do_cleanups (old_chain);
4648 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4651 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4654 handle_no_resumed (struct execution_control_state *ecs)
4656 struct inferior *inf;
4657 struct thread_info *thread;
4659 if (target_can_async_p ())
4666 if (ui->prompt_state == PROMPT_BLOCKED)
4674 /* There were no unwaited-for children left in the target, but,
4675 we're not synchronously waiting for events either. Just
4679 fprintf_unfiltered (gdb_stdlog,
4680 "infrun: TARGET_WAITKIND_NO_RESUMED "
4681 "(ignoring: bg)\n");
4682 prepare_to_wait (ecs);
4687 /* Otherwise, if we were running a synchronous execution command, we
4688 may need to cancel it and give the user back the terminal.
4690 In non-stop mode, the target can't tell whether we've already
4691 consumed previous stop events, so it can end up sending us a
4692 no-resumed event like so:
4694 #0 - thread 1 is left stopped
4696 #1 - thread 2 is resumed and hits breakpoint
4697 -> TARGET_WAITKIND_STOPPED
4699 #2 - thread 3 is resumed and exits
4700 this is the last resumed thread, so
4701 -> TARGET_WAITKIND_NO_RESUMED
4703 #3 - gdb processes stop for thread 2 and decides to re-resume
4706 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4707 thread 2 is now resumed, so the event should be ignored.
4709 IOW, if the stop for thread 2 doesn't end a foreground command,
4710 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4711 event. But it could be that the event meant that thread 2 itself
4712 (or whatever other thread was the last resumed thread) exited.
4714 To address this we refresh the thread list and check whether we
4715 have resumed threads _now_. In the example above, this removes
4716 thread 3 from the thread list. If thread 2 was re-resumed, we
4717 ignore this event. If we find no thread resumed, then we cancel
4718 the synchronous command show "no unwaited-for " to the user. */
4719 update_thread_list ();
4721 ALL_NON_EXITED_THREADS (thread)
4723 if (thread->executing
4724 || thread->suspend.waitstatus_pending_p)
4726 /* There were no unwaited-for children left in the target at
4727 some point, but there are now. Just ignore. */
4729 fprintf_unfiltered (gdb_stdlog,
4730 "infrun: TARGET_WAITKIND_NO_RESUMED "
4731 "(ignoring: found resumed)\n");
4732 prepare_to_wait (ecs);
4737 /* Note however that we may find no resumed thread because the whole
4738 process exited meanwhile (thus updating the thread list results
4739 in an empty thread list). In this case we know we'll be getting
4740 a process exit event shortly. */
4746 thread = any_live_thread_of_process (inf->pid);
4750 fprintf_unfiltered (gdb_stdlog,
4751 "infrun: TARGET_WAITKIND_NO_RESUMED "
4752 "(expect process exit)\n");
4753 prepare_to_wait (ecs);
4758 /* Go ahead and report the event. */
4762 /* Given an execution control state that has been freshly filled in by
4763 an event from the inferior, figure out what it means and take
4766 The alternatives are:
4768 1) stop_waiting and return; to really stop and return to the
4771 2) keep_going and return; to wait for the next event (set
4772 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4776 handle_inferior_event_1 (struct execution_control_state *ecs)
4778 enum stop_kind stop_soon;
4780 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4782 /* We had an event in the inferior, but we are not interested in
4783 handling it at this level. The lower layers have already
4784 done what needs to be done, if anything.
4786 One of the possible circumstances for this is when the
4787 inferior produces output for the console. The inferior has
4788 not stopped, and we are ignoring the event. Another possible
4789 circumstance is any event which the lower level knows will be
4790 reported multiple times without an intervening resume. */
4792 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4793 prepare_to_wait (ecs);
4797 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4800 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4801 prepare_to_wait (ecs);
4805 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4806 && handle_no_resumed (ecs))
4809 /* Cache the last pid/waitstatus. */
4810 set_last_target_status (ecs->ptid, ecs->ws);
4812 /* Always clear state belonging to the previous time we stopped. */
4813 stop_stack_dummy = STOP_NONE;
4815 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4817 /* No unwaited-for children left. IOW, all resumed children
4820 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4822 stop_print_frame = 0;
4827 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4828 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4830 ecs->event_thread = find_thread_ptid (ecs->ptid);
4831 /* If it's a new thread, add it to the thread database. */
4832 if (ecs->event_thread == NULL)
4833 ecs->event_thread = add_thread (ecs->ptid);
4835 /* Disable range stepping. If the next step request could use a
4836 range, this will be end up re-enabled then. */
4837 ecs->event_thread->control.may_range_step = 0;
4840 /* Dependent on valid ECS->EVENT_THREAD. */
4841 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4843 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4844 reinit_frame_cache ();
4846 breakpoint_retire_moribund ();
4848 /* First, distinguish signals caused by the debugger from signals
4849 that have to do with the program's own actions. Note that
4850 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4851 on the operating system version. Here we detect when a SIGILL or
4852 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4853 something similar for SIGSEGV, since a SIGSEGV will be generated
4854 when we're trying to execute a breakpoint instruction on a
4855 non-executable stack. This happens for call dummy breakpoints
4856 for architectures like SPARC that place call dummies on the
4858 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4859 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4860 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4861 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4863 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4865 if (breakpoint_inserted_here_p (regcache->aspace (),
4866 regcache_read_pc (regcache)))
4869 fprintf_unfiltered (gdb_stdlog,
4870 "infrun: Treating signal as SIGTRAP\n");
4871 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4875 /* Mark the non-executing threads accordingly. In all-stop, all
4876 threads of all processes are stopped when we get any event
4877 reported. In non-stop mode, only the event thread stops. */
4881 if (!target_is_non_stop_p ())
4882 mark_ptid = minus_one_ptid;
4883 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4884 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4886 /* If we're handling a process exit in non-stop mode, even
4887 though threads haven't been deleted yet, one would think
4888 that there is nothing to do, as threads of the dead process
4889 will be soon deleted, and threads of any other process were
4890 left running. However, on some targets, threads survive a
4891 process exit event. E.g., for the "checkpoint" command,
4892 when the current checkpoint/fork exits, linux-fork.c
4893 automatically switches to another fork from within
4894 target_mourn_inferior, by associating the same
4895 inferior/thread to another fork. We haven't mourned yet at
4896 this point, but we must mark any threads left in the
4897 process as not-executing so that finish_thread_state marks
4898 them stopped (in the user's perspective) if/when we present
4899 the stop to the user. */
4900 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4903 mark_ptid = ecs->ptid;
4905 set_executing (mark_ptid, 0);
4907 /* Likewise the resumed flag. */
4908 set_resumed (mark_ptid, 0);
4911 switch (ecs->ws.kind)
4913 case TARGET_WAITKIND_LOADED:
4915 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4916 if (!ptid_equal (ecs->ptid, inferior_ptid))
4917 context_switch (ecs->ptid);
4918 /* Ignore gracefully during startup of the inferior, as it might
4919 be the shell which has just loaded some objects, otherwise
4920 add the symbols for the newly loaded objects. Also ignore at
4921 the beginning of an attach or remote session; we will query
4922 the full list of libraries once the connection is
4925 stop_soon = get_inferior_stop_soon (ecs->ptid);
4926 if (stop_soon == NO_STOP_QUIETLY)
4928 struct regcache *regcache;
4930 regcache = get_thread_regcache (ecs->ptid);
4932 handle_solib_event ();
4934 ecs->event_thread->control.stop_bpstat
4935 = bpstat_stop_status (regcache->aspace (),
4936 stop_pc, ecs->ptid, &ecs->ws);
4938 if (handle_stop_requested (ecs))
4941 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4943 /* A catchpoint triggered. */
4944 process_event_stop_test (ecs);
4948 /* If requested, stop when the dynamic linker notifies
4949 gdb of events. This allows the user to get control
4950 and place breakpoints in initializer routines for
4951 dynamically loaded objects (among other things). */
4952 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4953 if (stop_on_solib_events)
4955 /* Make sure we print "Stopped due to solib-event" in
4957 stop_print_frame = 1;
4964 /* If we are skipping through a shell, or through shared library
4965 loading that we aren't interested in, resume the program. If
4966 we're running the program normally, also resume. */
4967 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4969 /* Loading of shared libraries might have changed breakpoint
4970 addresses. Make sure new breakpoints are inserted. */
4971 if (stop_soon == NO_STOP_QUIETLY)
4972 insert_breakpoints ();
4973 resume (GDB_SIGNAL_0);
4974 prepare_to_wait (ecs);
4978 /* But stop if we're attaching or setting up a remote
4980 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4981 || stop_soon == STOP_QUIETLY_REMOTE)
4984 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4989 internal_error (__FILE__, __LINE__,
4990 _("unhandled stop_soon: %d"), (int) stop_soon);
4992 case TARGET_WAITKIND_SPURIOUS:
4994 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4995 if (handle_stop_requested (ecs))
4997 if (!ptid_equal (ecs->ptid, inferior_ptid))
4998 context_switch (ecs->ptid);
4999 resume (GDB_SIGNAL_0);
5000 prepare_to_wait (ecs);
5003 case TARGET_WAITKIND_THREAD_CREATED:
5005 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5006 if (handle_stop_requested (ecs))
5008 if (!ptid_equal (ecs->ptid, inferior_ptid))
5009 context_switch (ecs->ptid);
5010 if (!switch_back_to_stepped_thread (ecs))
5014 case TARGET_WAITKIND_EXITED:
5015 case TARGET_WAITKIND_SIGNALLED:
5018 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5019 fprintf_unfiltered (gdb_stdlog,
5020 "infrun: TARGET_WAITKIND_EXITED\n");
5022 fprintf_unfiltered (gdb_stdlog,
5023 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5026 inferior_ptid = ecs->ptid;
5027 set_current_inferior (find_inferior_ptid (ecs->ptid));
5028 set_current_program_space (current_inferior ()->pspace);
5029 handle_vfork_child_exec_or_exit (0);
5030 target_terminal::ours (); /* Must do this before mourn anyway. */
5032 /* Clearing any previous state of convenience variables. */
5033 clear_exit_convenience_vars ();
5035 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5037 /* Record the exit code in the convenience variable $_exitcode, so
5038 that the user can inspect this again later. */
5039 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5040 (LONGEST) ecs->ws.value.integer);
5042 /* Also record this in the inferior itself. */
5043 current_inferior ()->has_exit_code = 1;
5044 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5046 /* Support the --return-child-result option. */
5047 return_child_result_value = ecs->ws.value.integer;
5049 observer_notify_exited (ecs->ws.value.integer);
5053 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5054 struct gdbarch *gdbarch = regcache->arch ();
5056 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5058 /* Set the value of the internal variable $_exitsignal,
5059 which holds the signal uncaught by the inferior. */
5060 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5061 gdbarch_gdb_signal_to_target (gdbarch,
5062 ecs->ws.value.sig));
5066 /* We don't have access to the target's method used for
5067 converting between signal numbers (GDB's internal
5068 representation <-> target's representation).
5069 Therefore, we cannot do a good job at displaying this
5070 information to the user. It's better to just warn
5071 her about it (if infrun debugging is enabled), and
5074 fprintf_filtered (gdb_stdlog, _("\
5075 Cannot fill $_exitsignal with the correct signal number.\n"));
5078 observer_notify_signal_exited (ecs->ws.value.sig);
5081 gdb_flush (gdb_stdout);
5082 target_mourn_inferior (inferior_ptid);
5083 stop_print_frame = 0;
5087 /* The following are the only cases in which we keep going;
5088 the above cases end in a continue or goto. */
5089 case TARGET_WAITKIND_FORKED:
5090 case TARGET_WAITKIND_VFORKED:
5093 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5094 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5096 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5099 /* Check whether the inferior is displaced stepping. */
5101 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5102 struct gdbarch *gdbarch = regcache->arch ();
5104 /* If checking displaced stepping is supported, and thread
5105 ecs->ptid is displaced stepping. */
5106 if (displaced_step_in_progress_thread (ecs->ptid))
5108 struct inferior *parent_inf
5109 = find_inferior_ptid (ecs->ptid);
5110 struct regcache *child_regcache;
5111 CORE_ADDR parent_pc;
5113 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5114 indicating that the displaced stepping of syscall instruction
5115 has been done. Perform cleanup for parent process here. Note
5116 that this operation also cleans up the child process for vfork,
5117 because their pages are shared. */
5118 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
5119 /* Start a new step-over in another thread if there's one
5123 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5125 struct displaced_step_inferior_state *displaced
5126 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
5128 /* Restore scratch pad for child process. */
5129 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5132 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5133 the child's PC is also within the scratchpad. Set the child's PC
5134 to the parent's PC value, which has already been fixed up.
5135 FIXME: we use the parent's aspace here, although we're touching
5136 the child, because the child hasn't been added to the inferior
5137 list yet at this point. */
5140 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5142 parent_inf->aspace);
5143 /* Read PC value of parent process. */
5144 parent_pc = regcache_read_pc (regcache);
5146 if (debug_displaced)
5147 fprintf_unfiltered (gdb_stdlog,
5148 "displaced: write child pc from %s to %s\n",
5150 regcache_read_pc (child_regcache)),
5151 paddress (gdbarch, parent_pc));
5153 regcache_write_pc (child_regcache, parent_pc);
5157 if (!ptid_equal (ecs->ptid, inferior_ptid))
5158 context_switch (ecs->ptid);
5160 /* Immediately detach breakpoints from the child before there's
5161 any chance of letting the user delete breakpoints from the
5162 breakpoint lists. If we don't do this early, it's easy to
5163 leave left over traps in the child, vis: "break foo; catch
5164 fork; c; <fork>; del; c; <child calls foo>". We only follow
5165 the fork on the last `continue', and by that time the
5166 breakpoint at "foo" is long gone from the breakpoint table.
5167 If we vforked, then we don't need to unpatch here, since both
5168 parent and child are sharing the same memory pages; we'll
5169 need to unpatch at follow/detach time instead to be certain
5170 that new breakpoints added between catchpoint hit time and
5171 vfork follow are detached. */
5172 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5174 /* This won't actually modify the breakpoint list, but will
5175 physically remove the breakpoints from the child. */
5176 detach_breakpoints (ecs->ws.value.related_pid);
5179 delete_just_stopped_threads_single_step_breakpoints ();
5181 /* In case the event is caught by a catchpoint, remember that
5182 the event is to be followed at the next resume of the thread,
5183 and not immediately. */
5184 ecs->event_thread->pending_follow = ecs->ws;
5186 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5188 ecs->event_thread->control.stop_bpstat
5189 = bpstat_stop_status (get_current_regcache ()->aspace (),
5190 stop_pc, ecs->ptid, &ecs->ws);
5192 if (handle_stop_requested (ecs))
5195 /* If no catchpoint triggered for this, then keep going. Note
5196 that we're interested in knowing the bpstat actually causes a
5197 stop, not just if it may explain the signal. Software
5198 watchpoints, for example, always appear in the bpstat. */
5199 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5205 = (follow_fork_mode_string == follow_fork_mode_child);
5207 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5209 should_resume = follow_fork ();
5212 child = ecs->ws.value.related_pid;
5214 /* At this point, the parent is marked running, and the
5215 child is marked stopped. */
5217 /* If not resuming the parent, mark it stopped. */
5218 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5219 set_running (parent, 0);
5221 /* If resuming the child, mark it running. */
5222 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5223 set_running (child, 1);
5225 /* In non-stop mode, also resume the other branch. */
5226 if (!detach_fork && (non_stop
5227 || (sched_multi && target_is_non_stop_p ())))
5230 switch_to_thread (parent);
5232 switch_to_thread (child);
5234 ecs->event_thread = inferior_thread ();
5235 ecs->ptid = inferior_ptid;
5240 switch_to_thread (child);
5242 switch_to_thread (parent);
5244 ecs->event_thread = inferior_thread ();
5245 ecs->ptid = inferior_ptid;
5253 process_event_stop_test (ecs);
5256 case TARGET_WAITKIND_VFORK_DONE:
5257 /* Done with the shared memory region. Re-insert breakpoints in
5258 the parent, and keep going. */
5261 fprintf_unfiltered (gdb_stdlog,
5262 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5264 if (!ptid_equal (ecs->ptid, inferior_ptid))
5265 context_switch (ecs->ptid);
5267 current_inferior ()->waiting_for_vfork_done = 0;
5268 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5270 if (handle_stop_requested (ecs))
5273 /* This also takes care of reinserting breakpoints in the
5274 previously locked inferior. */
5278 case TARGET_WAITKIND_EXECD:
5280 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5282 /* Note we can't read registers yet (the stop_pc), because we
5283 don't yet know the inferior's post-exec architecture.
5284 'stop_pc' is explicitly read below instead. */
5285 if (!ptid_equal (ecs->ptid, inferior_ptid))
5286 switch_to_thread_no_regs (ecs->event_thread);
5288 /* Do whatever is necessary to the parent branch of the vfork. */
5289 handle_vfork_child_exec_or_exit (1);
5291 /* This causes the eventpoints and symbol table to be reset.
5292 Must do this now, before trying to determine whether to
5294 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5296 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5298 /* In follow_exec we may have deleted the original thread and
5299 created a new one. Make sure that the event thread is the
5300 execd thread for that case (this is a nop otherwise). */
5301 ecs->event_thread = inferior_thread ();
5303 ecs->event_thread->control.stop_bpstat
5304 = bpstat_stop_status (get_current_regcache ()->aspace (),
5305 stop_pc, ecs->ptid, &ecs->ws);
5307 /* Note that this may be referenced from inside
5308 bpstat_stop_status above, through inferior_has_execd. */
5309 xfree (ecs->ws.value.execd_pathname);
5310 ecs->ws.value.execd_pathname = NULL;
5312 if (handle_stop_requested (ecs))
5315 /* If no catchpoint triggered for this, then keep going. */
5316 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5318 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5322 process_event_stop_test (ecs);
5325 /* Be careful not to try to gather much state about a thread
5326 that's in a syscall. It's frequently a losing proposition. */
5327 case TARGET_WAITKIND_SYSCALL_ENTRY:
5329 fprintf_unfiltered (gdb_stdlog,
5330 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5331 /* Getting the current syscall number. */
5332 if (handle_syscall_event (ecs) == 0)
5333 process_event_stop_test (ecs);
5336 /* Before examining the threads further, step this thread to
5337 get it entirely out of the syscall. (We get notice of the
5338 event when the thread is just on the verge of exiting a
5339 syscall. Stepping one instruction seems to get it back
5341 case TARGET_WAITKIND_SYSCALL_RETURN:
5343 fprintf_unfiltered (gdb_stdlog,
5344 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5345 if (handle_syscall_event (ecs) == 0)
5346 process_event_stop_test (ecs);
5349 case TARGET_WAITKIND_STOPPED:
5351 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5352 handle_signal_stop (ecs);
5355 case TARGET_WAITKIND_NO_HISTORY:
5357 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5358 /* Reverse execution: target ran out of history info. */
5360 /* Switch to the stopped thread. */
5361 if (!ptid_equal (ecs->ptid, inferior_ptid))
5362 context_switch (ecs->ptid);
5364 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5366 delete_just_stopped_threads_single_step_breakpoints ();
5367 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5369 if (handle_stop_requested (ecs))
5372 observer_notify_no_history ();
5378 /* A wrapper around handle_inferior_event_1, which also makes sure
5379 that all temporary struct value objects that were created during
5380 the handling of the event get deleted at the end. */
5383 handle_inferior_event (struct execution_control_state *ecs)
5385 struct value *mark = value_mark ();
5387 handle_inferior_event_1 (ecs);
5388 /* Purge all temporary values created during the event handling,
5389 as it could be a long time before we return to the command level
5390 where such values would otherwise be purged. */
5391 value_free_to_mark (mark);
5394 /* Restart threads back to what they were trying to do back when we
5395 paused them for an in-line step-over. The EVENT_THREAD thread is
5399 restart_threads (struct thread_info *event_thread)
5401 struct thread_info *tp;
5403 /* In case the instruction just stepped spawned a new thread. */
5404 update_thread_list ();
5406 ALL_NON_EXITED_THREADS (tp)
5408 if (tp == event_thread)
5411 fprintf_unfiltered (gdb_stdlog,
5412 "infrun: restart threads: "
5413 "[%s] is event thread\n",
5414 target_pid_to_str (tp->ptid));
5418 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5421 fprintf_unfiltered (gdb_stdlog,
5422 "infrun: restart threads: "
5423 "[%s] not meant to be running\n",
5424 target_pid_to_str (tp->ptid));
5431 fprintf_unfiltered (gdb_stdlog,
5432 "infrun: restart threads: [%s] resumed\n",
5433 target_pid_to_str (tp->ptid));
5434 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5438 if (thread_is_in_step_over_chain (tp))
5441 fprintf_unfiltered (gdb_stdlog,
5442 "infrun: restart threads: "
5443 "[%s] needs step-over\n",
5444 target_pid_to_str (tp->ptid));
5445 gdb_assert (!tp->resumed);
5450 if (tp->suspend.waitstatus_pending_p)
5453 fprintf_unfiltered (gdb_stdlog,
5454 "infrun: restart threads: "
5455 "[%s] has pending status\n",
5456 target_pid_to_str (tp->ptid));
5461 gdb_assert (!tp->stop_requested);
5463 /* If some thread needs to start a step-over at this point, it
5464 should still be in the step-over queue, and thus skipped
5466 if (thread_still_needs_step_over (tp))
5468 internal_error (__FILE__, __LINE__,
5469 "thread [%s] needs a step-over, but not in "
5470 "step-over queue\n",
5471 target_pid_to_str (tp->ptid));
5474 if (currently_stepping (tp))
5477 fprintf_unfiltered (gdb_stdlog,
5478 "infrun: restart threads: [%s] was stepping\n",
5479 target_pid_to_str (tp->ptid));
5480 keep_going_stepped_thread (tp);
5484 struct execution_control_state ecss;
5485 struct execution_control_state *ecs = &ecss;
5488 fprintf_unfiltered (gdb_stdlog,
5489 "infrun: restart threads: [%s] continuing\n",
5490 target_pid_to_str (tp->ptid));
5491 reset_ecs (ecs, tp);
5492 switch_to_thread (tp->ptid);
5493 keep_going_pass_signal (ecs);
5498 /* Callback for iterate_over_threads. Find a resumed thread that has
5499 a pending waitstatus. */
5502 resumed_thread_with_pending_status (struct thread_info *tp,
5506 && tp->suspend.waitstatus_pending_p);
5509 /* Called when we get an event that may finish an in-line or
5510 out-of-line (displaced stepping) step-over started previously.
5511 Return true if the event is processed and we should go back to the
5512 event loop; false if the caller should continue processing the
5516 finish_step_over (struct execution_control_state *ecs)
5518 int had_step_over_info;
5520 displaced_step_fixup (ecs->ptid,
5521 ecs->event_thread->suspend.stop_signal);
5523 had_step_over_info = step_over_info_valid_p ();
5525 if (had_step_over_info)
5527 /* If we're stepping over a breakpoint with all threads locked,
5528 then only the thread that was stepped should be reporting
5530 gdb_assert (ecs->event_thread->control.trap_expected);
5532 clear_step_over_info ();
5535 if (!target_is_non_stop_p ())
5538 /* Start a new step-over in another thread if there's one that
5542 /* If we were stepping over a breakpoint before, and haven't started
5543 a new in-line step-over sequence, then restart all other threads
5544 (except the event thread). We can't do this in all-stop, as then
5545 e.g., we wouldn't be able to issue any other remote packet until
5546 these other threads stop. */
5547 if (had_step_over_info && !step_over_info_valid_p ())
5549 struct thread_info *pending;
5551 /* If we only have threads with pending statuses, the restart
5552 below won't restart any thread and so nothing re-inserts the
5553 breakpoint we just stepped over. But we need it inserted
5554 when we later process the pending events, otherwise if
5555 another thread has a pending event for this breakpoint too,
5556 we'd discard its event (because the breakpoint that
5557 originally caused the event was no longer inserted). */
5558 context_switch (ecs->ptid);
5559 insert_breakpoints ();
5561 restart_threads (ecs->event_thread);
5563 /* If we have events pending, go through handle_inferior_event
5564 again, picking up a pending event at random. This avoids
5565 thread starvation. */
5567 /* But not if we just stepped over a watchpoint in order to let
5568 the instruction execute so we can evaluate its expression.
5569 The set of watchpoints that triggered is recorded in the
5570 breakpoint objects themselves (see bp->watchpoint_triggered).
5571 If we processed another event first, that other event could
5572 clobber this info. */
5573 if (ecs->event_thread->stepping_over_watchpoint)
5576 pending = iterate_over_threads (resumed_thread_with_pending_status,
5578 if (pending != NULL)
5580 struct thread_info *tp = ecs->event_thread;
5581 struct regcache *regcache;
5585 fprintf_unfiltered (gdb_stdlog,
5586 "infrun: found resumed threads with "
5587 "pending events, saving status\n");
5590 gdb_assert (pending != tp);
5592 /* Record the event thread's event for later. */
5593 save_waitstatus (tp, &ecs->ws);
5594 /* This was cleared early, by handle_inferior_event. Set it
5595 so this pending event is considered by
5599 gdb_assert (!tp->executing);
5601 regcache = get_thread_regcache (tp->ptid);
5602 tp->suspend.stop_pc = regcache_read_pc (regcache);
5606 fprintf_unfiltered (gdb_stdlog,
5607 "infrun: saved stop_pc=%s for %s "
5608 "(currently_stepping=%d)\n",
5609 paddress (target_gdbarch (),
5610 tp->suspend.stop_pc),
5611 target_pid_to_str (tp->ptid),
5612 currently_stepping (tp));
5615 /* This in-line step-over finished; clear this so we won't
5616 start a new one. This is what handle_signal_stop would
5617 do, if we returned false. */
5618 tp->stepping_over_breakpoint = 0;
5620 /* Wake up the event loop again. */
5621 mark_async_event_handler (infrun_async_inferior_event_token);
5623 prepare_to_wait (ecs);
5631 /* Come here when the program has stopped with a signal. */
5634 handle_signal_stop (struct execution_control_state *ecs)
5636 struct frame_info *frame;
5637 struct gdbarch *gdbarch;
5638 int stopped_by_watchpoint;
5639 enum stop_kind stop_soon;
5642 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5644 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5646 /* Do we need to clean up the state of a thread that has
5647 completed a displaced single-step? (Doing so usually affects
5648 the PC, so do it here, before we set stop_pc.) */
5649 if (finish_step_over (ecs))
5652 /* If we either finished a single-step or hit a breakpoint, but
5653 the user wanted this thread to be stopped, pretend we got a
5654 SIG0 (generic unsignaled stop). */
5655 if (ecs->event_thread->stop_requested
5656 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5657 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5659 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5663 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5664 struct gdbarch *gdbarch = regcache->arch ();
5665 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5667 inferior_ptid = ecs->ptid;
5669 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5670 paddress (gdbarch, stop_pc));
5671 if (target_stopped_by_watchpoint ())
5675 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5677 if (target_stopped_data_address (¤t_target, &addr))
5678 fprintf_unfiltered (gdb_stdlog,
5679 "infrun: stopped data address = %s\n",
5680 paddress (gdbarch, addr));
5682 fprintf_unfiltered (gdb_stdlog,
5683 "infrun: (no data address available)\n");
5687 /* This is originated from start_remote(), start_inferior() and
5688 shared libraries hook functions. */
5689 stop_soon = get_inferior_stop_soon (ecs->ptid);
5690 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5692 if (!ptid_equal (ecs->ptid, inferior_ptid))
5693 context_switch (ecs->ptid);
5695 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5696 stop_print_frame = 1;
5701 /* This originates from attach_command(). We need to overwrite
5702 the stop_signal here, because some kernels don't ignore a
5703 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5704 See more comments in inferior.h. On the other hand, if we
5705 get a non-SIGSTOP, report it to the user - assume the backend
5706 will handle the SIGSTOP if it should show up later.
5708 Also consider that the attach is complete when we see a
5709 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5710 target extended-remote report it instead of a SIGSTOP
5711 (e.g. gdbserver). We already rely on SIGTRAP being our
5712 signal, so this is no exception.
5714 Also consider that the attach is complete when we see a
5715 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5716 the target to stop all threads of the inferior, in case the
5717 low level attach operation doesn't stop them implicitly. If
5718 they weren't stopped implicitly, then the stub will report a
5719 GDB_SIGNAL_0, meaning: stopped for no particular reason
5720 other than GDB's request. */
5721 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5722 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5723 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5724 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5726 stop_print_frame = 1;
5728 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5732 /* See if something interesting happened to the non-current thread. If
5733 so, then switch to that thread. */
5734 if (!ptid_equal (ecs->ptid, inferior_ptid))
5737 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5739 context_switch (ecs->ptid);
5741 if (deprecated_context_hook)
5742 deprecated_context_hook (ptid_to_global_thread_id (ecs->ptid));
5745 /* At this point, get hold of the now-current thread's frame. */
5746 frame = get_current_frame ();
5747 gdbarch = get_frame_arch (frame);
5749 /* Pull the single step breakpoints out of the target. */
5750 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5752 struct regcache *regcache;
5755 regcache = get_thread_regcache (ecs->ptid);
5756 const address_space *aspace = regcache->aspace ();
5758 pc = regcache_read_pc (regcache);
5760 /* However, before doing so, if this single-step breakpoint was
5761 actually for another thread, set this thread up for moving
5763 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5766 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5770 fprintf_unfiltered (gdb_stdlog,
5771 "infrun: [%s] hit another thread's "
5772 "single-step breakpoint\n",
5773 target_pid_to_str (ecs->ptid));
5775 ecs->hit_singlestep_breakpoint = 1;
5782 fprintf_unfiltered (gdb_stdlog,
5783 "infrun: [%s] hit its "
5784 "single-step breakpoint\n",
5785 target_pid_to_str (ecs->ptid));
5789 delete_just_stopped_threads_single_step_breakpoints ();
5791 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5792 && ecs->event_thread->control.trap_expected
5793 && ecs->event_thread->stepping_over_watchpoint)
5794 stopped_by_watchpoint = 0;
5796 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5798 /* If necessary, step over this watchpoint. We'll be back to display
5800 if (stopped_by_watchpoint
5801 && (target_have_steppable_watchpoint
5802 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5804 /* At this point, we are stopped at an instruction which has
5805 attempted to write to a piece of memory under control of
5806 a watchpoint. The instruction hasn't actually executed
5807 yet. If we were to evaluate the watchpoint expression
5808 now, we would get the old value, and therefore no change
5809 would seem to have occurred.
5811 In order to make watchpoints work `right', we really need
5812 to complete the memory write, and then evaluate the
5813 watchpoint expression. We do this by single-stepping the
5816 It may not be necessary to disable the watchpoint to step over
5817 it. For example, the PA can (with some kernel cooperation)
5818 single step over a watchpoint without disabling the watchpoint.
5820 It is far more common to need to disable a watchpoint to step
5821 the inferior over it. If we have non-steppable watchpoints,
5822 we must disable the current watchpoint; it's simplest to
5823 disable all watchpoints.
5825 Any breakpoint at PC must also be stepped over -- if there's
5826 one, it will have already triggered before the watchpoint
5827 triggered, and we either already reported it to the user, or
5828 it didn't cause a stop and we called keep_going. In either
5829 case, if there was a breakpoint at PC, we must be trying to
5831 ecs->event_thread->stepping_over_watchpoint = 1;
5836 ecs->event_thread->stepping_over_breakpoint = 0;
5837 ecs->event_thread->stepping_over_watchpoint = 0;
5838 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5839 ecs->event_thread->control.stop_step = 0;
5840 stop_print_frame = 1;
5841 stopped_by_random_signal = 0;
5843 /* Hide inlined functions starting here, unless we just performed stepi or
5844 nexti. After stepi and nexti, always show the innermost frame (not any
5845 inline function call sites). */
5846 if (ecs->event_thread->control.step_range_end != 1)
5848 const address_space *aspace =
5849 get_thread_regcache (ecs->ptid)->aspace ();
5851 /* skip_inline_frames is expensive, so we avoid it if we can
5852 determine that the address is one where functions cannot have
5853 been inlined. This improves performance with inferiors that
5854 load a lot of shared libraries, because the solib event
5855 breakpoint is defined as the address of a function (i.e. not
5856 inline). Note that we have to check the previous PC as well
5857 as the current one to catch cases when we have just
5858 single-stepped off a breakpoint prior to reinstating it.
5859 Note that we're assuming that the code we single-step to is
5860 not inline, but that's not definitive: there's nothing
5861 preventing the event breakpoint function from containing
5862 inlined code, and the single-step ending up there. If the
5863 user had set a breakpoint on that inlined code, the missing
5864 skip_inline_frames call would break things. Fortunately
5865 that's an extremely unlikely scenario. */
5866 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5867 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5868 && ecs->event_thread->control.trap_expected
5869 && pc_at_non_inline_function (aspace,
5870 ecs->event_thread->prev_pc,
5873 skip_inline_frames (ecs->ptid);
5875 /* Re-fetch current thread's frame in case that invalidated
5877 frame = get_current_frame ();
5878 gdbarch = get_frame_arch (frame);
5882 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5883 && ecs->event_thread->control.trap_expected
5884 && gdbarch_single_step_through_delay_p (gdbarch)
5885 && currently_stepping (ecs->event_thread))
5887 /* We're trying to step off a breakpoint. Turns out that we're
5888 also on an instruction that needs to be stepped multiple
5889 times before it's been fully executing. E.g., architectures
5890 with a delay slot. It needs to be stepped twice, once for
5891 the instruction and once for the delay slot. */
5892 int step_through_delay
5893 = gdbarch_single_step_through_delay (gdbarch, frame);
5895 if (debug_infrun && step_through_delay)
5896 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5897 if (ecs->event_thread->control.step_range_end == 0
5898 && step_through_delay)
5900 /* The user issued a continue when stopped at a breakpoint.
5901 Set up for another trap and get out of here. */
5902 ecs->event_thread->stepping_over_breakpoint = 1;
5906 else if (step_through_delay)
5908 /* The user issued a step when stopped at a breakpoint.
5909 Maybe we should stop, maybe we should not - the delay
5910 slot *might* correspond to a line of source. In any
5911 case, don't decide that here, just set
5912 ecs->stepping_over_breakpoint, making sure we
5913 single-step again before breakpoints are re-inserted. */
5914 ecs->event_thread->stepping_over_breakpoint = 1;
5918 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5919 handles this event. */
5920 ecs->event_thread->control.stop_bpstat
5921 = bpstat_stop_status (get_current_regcache ()->aspace (),
5922 stop_pc, ecs->ptid, &ecs->ws);
5924 /* Following in case break condition called a
5926 stop_print_frame = 1;
5928 /* This is where we handle "moribund" watchpoints. Unlike
5929 software breakpoints traps, hardware watchpoint traps are
5930 always distinguishable from random traps. If no high-level
5931 watchpoint is associated with the reported stop data address
5932 anymore, then the bpstat does not explain the signal ---
5933 simply make sure to ignore it if `stopped_by_watchpoint' is
5937 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5938 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5940 && stopped_by_watchpoint)
5941 fprintf_unfiltered (gdb_stdlog,
5942 "infrun: no user watchpoint explains "
5943 "watchpoint SIGTRAP, ignoring\n");
5945 /* NOTE: cagney/2003-03-29: These checks for a random signal
5946 at one stage in the past included checks for an inferior
5947 function call's call dummy's return breakpoint. The original
5948 comment, that went with the test, read:
5950 ``End of a stack dummy. Some systems (e.g. Sony news) give
5951 another signal besides SIGTRAP, so check here as well as
5954 If someone ever tries to get call dummys on a
5955 non-executable stack to work (where the target would stop
5956 with something like a SIGSEGV), then those tests might need
5957 to be re-instated. Given, however, that the tests were only
5958 enabled when momentary breakpoints were not being used, I
5959 suspect that it won't be the case.
5961 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5962 be necessary for call dummies on a non-executable stack on
5965 /* See if the breakpoints module can explain the signal. */
5967 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5968 ecs->event_thread->suspend.stop_signal);
5970 /* Maybe this was a trap for a software breakpoint that has since
5972 if (random_signal && target_stopped_by_sw_breakpoint ())
5974 if (program_breakpoint_here_p (gdbarch, stop_pc))
5976 struct regcache *regcache;
5979 /* Re-adjust PC to what the program would see if GDB was not
5981 regcache = get_thread_regcache (ecs->event_thread->ptid);
5982 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5985 gdb::optional<scoped_restore_tmpl<int>>
5986 restore_operation_disable;
5988 if (record_full_is_used ())
5989 restore_operation_disable.emplace
5990 (record_full_gdb_operation_disable_set ());
5992 regcache_write_pc (regcache, stop_pc + decr_pc);
5997 /* A delayed software breakpoint event. Ignore the trap. */
5999 fprintf_unfiltered (gdb_stdlog,
6000 "infrun: delayed software breakpoint "
6001 "trap, ignoring\n");
6006 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6007 has since been removed. */
6008 if (random_signal && target_stopped_by_hw_breakpoint ())
6010 /* A delayed hardware breakpoint event. Ignore the trap. */
6012 fprintf_unfiltered (gdb_stdlog,
6013 "infrun: delayed hardware breakpoint/watchpoint "
6014 "trap, ignoring\n");
6018 /* If not, perhaps stepping/nexting can. */
6020 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6021 && currently_stepping (ecs->event_thread));
6023 /* Perhaps the thread hit a single-step breakpoint of _another_
6024 thread. Single-step breakpoints are transparent to the
6025 breakpoints module. */
6027 random_signal = !ecs->hit_singlestep_breakpoint;
6029 /* No? Perhaps we got a moribund watchpoint. */
6031 random_signal = !stopped_by_watchpoint;
6033 /* Always stop if the user explicitly requested this thread to
6035 if (ecs->event_thread->stop_requested)
6039 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6042 /* For the program's own signals, act according to
6043 the signal handling tables. */
6047 /* Signal not for debugging purposes. */
6048 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6049 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6052 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6053 gdb_signal_to_symbol_string (stop_signal));
6055 stopped_by_random_signal = 1;
6057 /* Always stop on signals if we're either just gaining control
6058 of the program, or the user explicitly requested this thread
6059 to remain stopped. */
6060 if (stop_soon != NO_STOP_QUIETLY
6061 || ecs->event_thread->stop_requested
6063 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6069 /* Notify observers the signal has "handle print" set. Note we
6070 returned early above if stopping; normal_stop handles the
6071 printing in that case. */
6072 if (signal_print[ecs->event_thread->suspend.stop_signal])
6074 /* The signal table tells us to print about this signal. */
6075 target_terminal::ours_for_output ();
6076 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
6077 target_terminal::inferior ();
6080 /* Clear the signal if it should not be passed. */
6081 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6082 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6084 if (ecs->event_thread->prev_pc == stop_pc
6085 && ecs->event_thread->control.trap_expected
6086 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6088 /* We were just starting a new sequence, attempting to
6089 single-step off of a breakpoint and expecting a SIGTRAP.
6090 Instead this signal arrives. This signal will take us out
6091 of the stepping range so GDB needs to remember to, when
6092 the signal handler returns, resume stepping off that
6094 /* To simplify things, "continue" is forced to use the same
6095 code paths as single-step - set a breakpoint at the
6096 signal return address and then, once hit, step off that
6099 fprintf_unfiltered (gdb_stdlog,
6100 "infrun: signal arrived while stepping over "
6103 insert_hp_step_resume_breakpoint_at_frame (frame);
6104 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6105 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6106 ecs->event_thread->control.trap_expected = 0;
6108 /* If we were nexting/stepping some other thread, switch to
6109 it, so that we don't continue it, losing control. */
6110 if (!switch_back_to_stepped_thread (ecs))
6115 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6116 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6117 || ecs->event_thread->control.step_range_end == 1)
6118 && frame_id_eq (get_stack_frame_id (frame),
6119 ecs->event_thread->control.step_stack_frame_id)
6120 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6122 /* The inferior is about to take a signal that will take it
6123 out of the single step range. Set a breakpoint at the
6124 current PC (which is presumably where the signal handler
6125 will eventually return) and then allow the inferior to
6128 Note that this is only needed for a signal delivered
6129 while in the single-step range. Nested signals aren't a
6130 problem as they eventually all return. */
6132 fprintf_unfiltered (gdb_stdlog,
6133 "infrun: signal may take us out of "
6134 "single-step range\n");
6136 clear_step_over_info ();
6137 insert_hp_step_resume_breakpoint_at_frame (frame);
6138 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6139 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6140 ecs->event_thread->control.trap_expected = 0;
6145 /* Note: step_resume_breakpoint may be non-NULL. This occures
6146 when either there's a nested signal, or when there's a
6147 pending signal enabled just as the signal handler returns
6148 (leaving the inferior at the step-resume-breakpoint without
6149 actually executing it). Either way continue until the
6150 breakpoint is really hit. */
6152 if (!switch_back_to_stepped_thread (ecs))
6155 fprintf_unfiltered (gdb_stdlog,
6156 "infrun: random signal, keep going\n");
6163 process_event_stop_test (ecs);
6166 /* Come here when we've got some debug event / signal we can explain
6167 (IOW, not a random signal), and test whether it should cause a
6168 stop, or whether we should resume the inferior (transparently).
6169 E.g., could be a breakpoint whose condition evaluates false; we
6170 could be still stepping within the line; etc. */
6173 process_event_stop_test (struct execution_control_state *ecs)
6175 struct symtab_and_line stop_pc_sal;
6176 struct frame_info *frame;
6177 struct gdbarch *gdbarch;
6178 CORE_ADDR jmp_buf_pc;
6179 struct bpstat_what what;
6181 /* Handle cases caused by hitting a breakpoint. */
6183 frame = get_current_frame ();
6184 gdbarch = get_frame_arch (frame);
6186 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6188 if (what.call_dummy)
6190 stop_stack_dummy = what.call_dummy;
6193 /* A few breakpoint types have callbacks associated (e.g.,
6194 bp_jit_event). Run them now. */
6195 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6197 /* If we hit an internal event that triggers symbol changes, the
6198 current frame will be invalidated within bpstat_what (e.g., if we
6199 hit an internal solib event). Re-fetch it. */
6200 frame = get_current_frame ();
6201 gdbarch = get_frame_arch (frame);
6203 switch (what.main_action)
6205 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6206 /* If we hit the breakpoint at longjmp while stepping, we
6207 install a momentary breakpoint at the target of the
6211 fprintf_unfiltered (gdb_stdlog,
6212 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6214 ecs->event_thread->stepping_over_breakpoint = 1;
6216 if (what.is_longjmp)
6218 struct value *arg_value;
6220 /* If we set the longjmp breakpoint via a SystemTap probe,
6221 then use it to extract the arguments. The destination PC
6222 is the third argument to the probe. */
6223 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6226 jmp_buf_pc = value_as_address (arg_value);
6227 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6229 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6230 || !gdbarch_get_longjmp_target (gdbarch,
6231 frame, &jmp_buf_pc))
6234 fprintf_unfiltered (gdb_stdlog,
6235 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6236 "(!gdbarch_get_longjmp_target)\n");
6241 /* Insert a breakpoint at resume address. */
6242 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6245 check_exception_resume (ecs, frame);
6249 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6251 struct frame_info *init_frame;
6253 /* There are several cases to consider.
6255 1. The initiating frame no longer exists. In this case we
6256 must stop, because the exception or longjmp has gone too
6259 2. The initiating frame exists, and is the same as the
6260 current frame. We stop, because the exception or longjmp
6263 3. The initiating frame exists and is different from the
6264 current frame. This means the exception or longjmp has
6265 been caught beneath the initiating frame, so keep going.
6267 4. longjmp breakpoint has been placed just to protect
6268 against stale dummy frames and user is not interested in
6269 stopping around longjmps. */
6272 fprintf_unfiltered (gdb_stdlog,
6273 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6275 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6277 delete_exception_resume_breakpoint (ecs->event_thread);
6279 if (what.is_longjmp)
6281 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6283 if (!frame_id_p (ecs->event_thread->initiating_frame))
6291 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6295 struct frame_id current_id
6296 = get_frame_id (get_current_frame ());
6297 if (frame_id_eq (current_id,
6298 ecs->event_thread->initiating_frame))
6300 /* Case 2. Fall through. */
6310 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6312 delete_step_resume_breakpoint (ecs->event_thread);
6314 end_stepping_range (ecs);
6318 case BPSTAT_WHAT_SINGLE:
6320 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6321 ecs->event_thread->stepping_over_breakpoint = 1;
6322 /* Still need to check other stuff, at least the case where we
6323 are stepping and step out of the right range. */
6326 case BPSTAT_WHAT_STEP_RESUME:
6328 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6330 delete_step_resume_breakpoint (ecs->event_thread);
6331 if (ecs->event_thread->control.proceed_to_finish
6332 && execution_direction == EXEC_REVERSE)
6334 struct thread_info *tp = ecs->event_thread;
6336 /* We are finishing a function in reverse, and just hit the
6337 step-resume breakpoint at the start address of the
6338 function, and we're almost there -- just need to back up
6339 by one more single-step, which should take us back to the
6341 tp->control.step_range_start = tp->control.step_range_end = 1;
6345 fill_in_stop_func (gdbarch, ecs);
6346 if (stop_pc == ecs->stop_func_start
6347 && execution_direction == EXEC_REVERSE)
6349 /* We are stepping over a function call in reverse, and just
6350 hit the step-resume breakpoint at the start address of
6351 the function. Go back to single-stepping, which should
6352 take us back to the function call. */
6353 ecs->event_thread->stepping_over_breakpoint = 1;
6359 case BPSTAT_WHAT_STOP_NOISY:
6361 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6362 stop_print_frame = 1;
6364 /* Assume the thread stopped for a breapoint. We'll still check
6365 whether a/the breakpoint is there when the thread is next
6367 ecs->event_thread->stepping_over_breakpoint = 1;
6372 case BPSTAT_WHAT_STOP_SILENT:
6374 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6375 stop_print_frame = 0;
6377 /* Assume the thread stopped for a breapoint. We'll still check
6378 whether a/the breakpoint is there when the thread is next
6380 ecs->event_thread->stepping_over_breakpoint = 1;
6384 case BPSTAT_WHAT_HP_STEP_RESUME:
6386 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6388 delete_step_resume_breakpoint (ecs->event_thread);
6389 if (ecs->event_thread->step_after_step_resume_breakpoint)
6391 /* Back when the step-resume breakpoint was inserted, we
6392 were trying to single-step off a breakpoint. Go back to
6394 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6395 ecs->event_thread->stepping_over_breakpoint = 1;
6401 case BPSTAT_WHAT_KEEP_CHECKING:
6405 /* If we stepped a permanent breakpoint and we had a high priority
6406 step-resume breakpoint for the address we stepped, but we didn't
6407 hit it, then we must have stepped into the signal handler. The
6408 step-resume was only necessary to catch the case of _not_
6409 stepping into the handler, so delete it, and fall through to
6410 checking whether the step finished. */
6411 if (ecs->event_thread->stepped_breakpoint)
6413 struct breakpoint *sr_bp
6414 = ecs->event_thread->control.step_resume_breakpoint;
6417 && sr_bp->loc->permanent
6418 && sr_bp->type == bp_hp_step_resume
6419 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6422 fprintf_unfiltered (gdb_stdlog,
6423 "infrun: stepped permanent breakpoint, stopped in "
6425 delete_step_resume_breakpoint (ecs->event_thread);
6426 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6430 /* We come here if we hit a breakpoint but should not stop for it.
6431 Possibly we also were stepping and should stop for that. So fall
6432 through and test for stepping. But, if not stepping, do not
6435 /* In all-stop mode, if we're currently stepping but have stopped in
6436 some other thread, we need to switch back to the stepped thread. */
6437 if (switch_back_to_stepped_thread (ecs))
6440 if (ecs->event_thread->control.step_resume_breakpoint)
6443 fprintf_unfiltered (gdb_stdlog,
6444 "infrun: step-resume breakpoint is inserted\n");
6446 /* Having a step-resume breakpoint overrides anything
6447 else having to do with stepping commands until
6448 that breakpoint is reached. */
6453 if (ecs->event_thread->control.step_range_end == 0)
6456 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6457 /* Likewise if we aren't even stepping. */
6462 /* Re-fetch current thread's frame in case the code above caused
6463 the frame cache to be re-initialized, making our FRAME variable
6464 a dangling pointer. */
6465 frame = get_current_frame ();
6466 gdbarch = get_frame_arch (frame);
6467 fill_in_stop_func (gdbarch, ecs);
6469 /* If stepping through a line, keep going if still within it.
6471 Note that step_range_end is the address of the first instruction
6472 beyond the step range, and NOT the address of the last instruction
6475 Note also that during reverse execution, we may be stepping
6476 through a function epilogue and therefore must detect when
6477 the current-frame changes in the middle of a line. */
6479 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6480 && (execution_direction != EXEC_REVERSE
6481 || frame_id_eq (get_frame_id (frame),
6482 ecs->event_thread->control.step_frame_id)))
6486 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6487 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6488 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6490 /* Tentatively re-enable range stepping; `resume' disables it if
6491 necessary (e.g., if we're stepping over a breakpoint or we
6492 have software watchpoints). */
6493 ecs->event_thread->control.may_range_step = 1;
6495 /* When stepping backward, stop at beginning of line range
6496 (unless it's the function entry point, in which case
6497 keep going back to the call point). */
6498 if (stop_pc == ecs->event_thread->control.step_range_start
6499 && stop_pc != ecs->stop_func_start
6500 && execution_direction == EXEC_REVERSE)
6501 end_stepping_range (ecs);
6508 /* We stepped out of the stepping range. */
6510 /* If we are stepping at the source level and entered the runtime
6511 loader dynamic symbol resolution code...
6513 EXEC_FORWARD: we keep on single stepping until we exit the run
6514 time loader code and reach the callee's address.
6516 EXEC_REVERSE: we've already executed the callee (backward), and
6517 the runtime loader code is handled just like any other
6518 undebuggable function call. Now we need only keep stepping
6519 backward through the trampoline code, and that's handled further
6520 down, so there is nothing for us to do here. */
6522 if (execution_direction != EXEC_REVERSE
6523 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6524 && in_solib_dynsym_resolve_code (stop_pc))
6526 CORE_ADDR pc_after_resolver =
6527 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6530 fprintf_unfiltered (gdb_stdlog,
6531 "infrun: stepped into dynsym resolve code\n");
6533 if (pc_after_resolver)
6535 /* Set up a step-resume breakpoint at the address
6536 indicated by SKIP_SOLIB_RESOLVER. */
6537 symtab_and_line sr_sal;
6538 sr_sal.pc = pc_after_resolver;
6539 sr_sal.pspace = get_frame_program_space (frame);
6541 insert_step_resume_breakpoint_at_sal (gdbarch,
6542 sr_sal, null_frame_id);
6549 if (ecs->event_thread->control.step_range_end != 1
6550 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6551 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6552 && get_frame_type (frame) == SIGTRAMP_FRAME)
6555 fprintf_unfiltered (gdb_stdlog,
6556 "infrun: stepped into signal trampoline\n");
6557 /* The inferior, while doing a "step" or "next", has ended up in
6558 a signal trampoline (either by a signal being delivered or by
6559 the signal handler returning). Just single-step until the
6560 inferior leaves the trampoline (either by calling the handler
6566 /* If we're in the return path from a shared library trampoline,
6567 we want to proceed through the trampoline when stepping. */
6568 /* macro/2012-04-25: This needs to come before the subroutine
6569 call check below as on some targets return trampolines look
6570 like subroutine calls (MIPS16 return thunks). */
6571 if (gdbarch_in_solib_return_trampoline (gdbarch,
6572 stop_pc, ecs->stop_func_name)
6573 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6575 /* Determine where this trampoline returns. */
6576 CORE_ADDR real_stop_pc;
6578 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6581 fprintf_unfiltered (gdb_stdlog,
6582 "infrun: stepped into solib return tramp\n");
6584 /* Only proceed through if we know where it's going. */
6587 /* And put the step-breakpoint there and go until there. */
6588 symtab_and_line sr_sal;
6589 sr_sal.pc = real_stop_pc;
6590 sr_sal.section = find_pc_overlay (sr_sal.pc);
6591 sr_sal.pspace = get_frame_program_space (frame);
6593 /* Do not specify what the fp should be when we stop since
6594 on some machines the prologue is where the new fp value
6596 insert_step_resume_breakpoint_at_sal (gdbarch,
6597 sr_sal, null_frame_id);
6599 /* Restart without fiddling with the step ranges or
6606 /* Check for subroutine calls. The check for the current frame
6607 equalling the step ID is not necessary - the check of the
6608 previous frame's ID is sufficient - but it is a common case and
6609 cheaper than checking the previous frame's ID.
6611 NOTE: frame_id_eq will never report two invalid frame IDs as
6612 being equal, so to get into this block, both the current and
6613 previous frame must have valid frame IDs. */
6614 /* The outer_frame_id check is a heuristic to detect stepping
6615 through startup code. If we step over an instruction which
6616 sets the stack pointer from an invalid value to a valid value,
6617 we may detect that as a subroutine call from the mythical
6618 "outermost" function. This could be fixed by marking
6619 outermost frames as !stack_p,code_p,special_p. Then the
6620 initial outermost frame, before sp was valid, would
6621 have code_addr == &_start. See the comment in frame_id_eq
6623 if (!frame_id_eq (get_stack_frame_id (frame),
6624 ecs->event_thread->control.step_stack_frame_id)
6625 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6626 ecs->event_thread->control.step_stack_frame_id)
6627 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6629 || (ecs->event_thread->control.step_start_function
6630 != find_pc_function (stop_pc)))))
6632 CORE_ADDR real_stop_pc;
6635 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6637 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6639 /* I presume that step_over_calls is only 0 when we're
6640 supposed to be stepping at the assembly language level
6641 ("stepi"). Just stop. */
6642 /* And this works the same backward as frontward. MVS */
6643 end_stepping_range (ecs);
6647 /* Reverse stepping through solib trampolines. */
6649 if (execution_direction == EXEC_REVERSE
6650 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6651 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6652 || (ecs->stop_func_start == 0
6653 && in_solib_dynsym_resolve_code (stop_pc))))
6655 /* Any solib trampoline code can be handled in reverse
6656 by simply continuing to single-step. We have already
6657 executed the solib function (backwards), and a few
6658 steps will take us back through the trampoline to the
6664 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6666 /* We're doing a "next".
6668 Normal (forward) execution: set a breakpoint at the
6669 callee's return address (the address at which the caller
6672 Reverse (backward) execution. set the step-resume
6673 breakpoint at the start of the function that we just
6674 stepped into (backwards), and continue to there. When we
6675 get there, we'll need to single-step back to the caller. */
6677 if (execution_direction == EXEC_REVERSE)
6679 /* If we're already at the start of the function, we've either
6680 just stepped backward into a single instruction function,
6681 or stepped back out of a signal handler to the first instruction
6682 of the function. Just keep going, which will single-step back
6684 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6686 /* Normal function call return (static or dynamic). */
6687 symtab_and_line sr_sal;
6688 sr_sal.pc = ecs->stop_func_start;
6689 sr_sal.pspace = get_frame_program_space (frame);
6690 insert_step_resume_breakpoint_at_sal (gdbarch,
6691 sr_sal, null_frame_id);
6695 insert_step_resume_breakpoint_at_caller (frame);
6701 /* If we are in a function call trampoline (a stub between the
6702 calling routine and the real function), locate the real
6703 function. That's what tells us (a) whether we want to step
6704 into it at all, and (b) what prologue we want to run to the
6705 end of, if we do step into it. */
6706 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6707 if (real_stop_pc == 0)
6708 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6709 if (real_stop_pc != 0)
6710 ecs->stop_func_start = real_stop_pc;
6712 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6714 symtab_and_line sr_sal;
6715 sr_sal.pc = ecs->stop_func_start;
6716 sr_sal.pspace = get_frame_program_space (frame);
6718 insert_step_resume_breakpoint_at_sal (gdbarch,
6719 sr_sal, null_frame_id);
6724 /* If we have line number information for the function we are
6725 thinking of stepping into and the function isn't on the skip
6728 If there are several symtabs at that PC (e.g. with include
6729 files), just want to know whether *any* of them have line
6730 numbers. find_pc_line handles this. */
6732 struct symtab_and_line tmp_sal;
6734 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6735 if (tmp_sal.line != 0
6736 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6739 if (execution_direction == EXEC_REVERSE)
6740 handle_step_into_function_backward (gdbarch, ecs);
6742 handle_step_into_function (gdbarch, ecs);
6747 /* If we have no line number and the step-stop-if-no-debug is
6748 set, we stop the step so that the user has a chance to switch
6749 in assembly mode. */
6750 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6751 && step_stop_if_no_debug)
6753 end_stepping_range (ecs);
6757 if (execution_direction == EXEC_REVERSE)
6759 /* If we're already at the start of the function, we've either just
6760 stepped backward into a single instruction function without line
6761 number info, or stepped back out of a signal handler to the first
6762 instruction of the function without line number info. Just keep
6763 going, which will single-step back to the caller. */
6764 if (ecs->stop_func_start != stop_pc)
6766 /* Set a breakpoint at callee's start address.
6767 From there we can step once and be back in the caller. */
6768 symtab_and_line sr_sal;
6769 sr_sal.pc = ecs->stop_func_start;
6770 sr_sal.pspace = get_frame_program_space (frame);
6771 insert_step_resume_breakpoint_at_sal (gdbarch,
6772 sr_sal, null_frame_id);
6776 /* Set a breakpoint at callee's return address (the address
6777 at which the caller will resume). */
6778 insert_step_resume_breakpoint_at_caller (frame);
6784 /* Reverse stepping through solib trampolines. */
6786 if (execution_direction == EXEC_REVERSE
6787 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6789 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6790 || (ecs->stop_func_start == 0
6791 && in_solib_dynsym_resolve_code (stop_pc)))
6793 /* Any solib trampoline code can be handled in reverse
6794 by simply continuing to single-step. We have already
6795 executed the solib function (backwards), and a few
6796 steps will take us back through the trampoline to the
6801 else if (in_solib_dynsym_resolve_code (stop_pc))
6803 /* Stepped backward into the solib dynsym resolver.
6804 Set a breakpoint at its start and continue, then
6805 one more step will take us out. */
6806 symtab_and_line sr_sal;
6807 sr_sal.pc = ecs->stop_func_start;
6808 sr_sal.pspace = get_frame_program_space (frame);
6809 insert_step_resume_breakpoint_at_sal (gdbarch,
6810 sr_sal, null_frame_id);
6816 stop_pc_sal = find_pc_line (stop_pc, 0);
6818 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6819 the trampoline processing logic, however, there are some trampolines
6820 that have no names, so we should do trampoline handling first. */
6821 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6822 && ecs->stop_func_name == NULL
6823 && stop_pc_sal.line == 0)
6826 fprintf_unfiltered (gdb_stdlog,
6827 "infrun: stepped into undebuggable function\n");
6829 /* The inferior just stepped into, or returned to, an
6830 undebuggable function (where there is no debugging information
6831 and no line number corresponding to the address where the
6832 inferior stopped). Since we want to skip this kind of code,
6833 we keep going until the inferior returns from this
6834 function - unless the user has asked us not to (via
6835 set step-mode) or we no longer know how to get back
6836 to the call site. */
6837 if (step_stop_if_no_debug
6838 || !frame_id_p (frame_unwind_caller_id (frame)))
6840 /* If we have no line number and the step-stop-if-no-debug
6841 is set, we stop the step so that the user has a chance to
6842 switch in assembly mode. */
6843 end_stepping_range (ecs);
6848 /* Set a breakpoint at callee's return address (the address
6849 at which the caller will resume). */
6850 insert_step_resume_breakpoint_at_caller (frame);
6856 if (ecs->event_thread->control.step_range_end == 1)
6858 /* It is stepi or nexti. We always want to stop stepping after
6861 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6862 end_stepping_range (ecs);
6866 if (stop_pc_sal.line == 0)
6868 /* We have no line number information. That means to stop
6869 stepping (does this always happen right after one instruction,
6870 when we do "s" in a function with no line numbers,
6871 or can this happen as a result of a return or longjmp?). */
6873 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6874 end_stepping_range (ecs);
6878 /* Look for "calls" to inlined functions, part one. If the inline
6879 frame machinery detected some skipped call sites, we have entered
6880 a new inline function. */
6882 if (frame_id_eq (get_frame_id (get_current_frame ()),
6883 ecs->event_thread->control.step_frame_id)
6884 && inline_skipped_frames (ecs->ptid))
6887 fprintf_unfiltered (gdb_stdlog,
6888 "infrun: stepped into inlined function\n");
6890 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6892 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6894 /* For "step", we're going to stop. But if the call site
6895 for this inlined function is on the same source line as
6896 we were previously stepping, go down into the function
6897 first. Otherwise stop at the call site. */
6899 if (call_sal.line == ecs->event_thread->current_line
6900 && call_sal.symtab == ecs->event_thread->current_symtab)
6901 step_into_inline_frame (ecs->ptid);
6903 end_stepping_range (ecs);
6908 /* For "next", we should stop at the call site if it is on a
6909 different source line. Otherwise continue through the
6910 inlined function. */
6911 if (call_sal.line == ecs->event_thread->current_line
6912 && call_sal.symtab == ecs->event_thread->current_symtab)
6915 end_stepping_range (ecs);
6920 /* Look for "calls" to inlined functions, part two. If we are still
6921 in the same real function we were stepping through, but we have
6922 to go further up to find the exact frame ID, we are stepping
6923 through a more inlined call beyond its call site. */
6925 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6926 && !frame_id_eq (get_frame_id (get_current_frame ()),
6927 ecs->event_thread->control.step_frame_id)
6928 && stepped_in_from (get_current_frame (),
6929 ecs->event_thread->control.step_frame_id))
6932 fprintf_unfiltered (gdb_stdlog,
6933 "infrun: stepping through inlined function\n");
6935 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6938 end_stepping_range (ecs);
6942 if ((stop_pc == stop_pc_sal.pc)
6943 && (ecs->event_thread->current_line != stop_pc_sal.line
6944 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6946 /* We are at the start of a different line. So stop. Note that
6947 we don't stop if we step into the middle of a different line.
6948 That is said to make things like for (;;) statements work
6951 fprintf_unfiltered (gdb_stdlog,
6952 "infrun: stepped to a different line\n");
6953 end_stepping_range (ecs);
6957 /* We aren't done stepping.
6959 Optimize by setting the stepping range to the line.
6960 (We might not be in the original line, but if we entered a
6961 new line in mid-statement, we continue stepping. This makes
6962 things like for(;;) statements work better.) */
6964 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6965 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6966 ecs->event_thread->control.may_range_step = 1;
6967 set_step_info (frame, stop_pc_sal);
6970 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6974 /* In all-stop mode, if we're currently stepping but have stopped in
6975 some other thread, we may need to switch back to the stepped
6976 thread. Returns true we set the inferior running, false if we left
6977 it stopped (and the event needs further processing). */
6980 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6982 if (!target_is_non_stop_p ())
6984 struct thread_info *tp;
6985 struct thread_info *stepping_thread;
6987 /* If any thread is blocked on some internal breakpoint, and we
6988 simply need to step over that breakpoint to get it going
6989 again, do that first. */
6991 /* However, if we see an event for the stepping thread, then we
6992 know all other threads have been moved past their breakpoints
6993 already. Let the caller check whether the step is finished,
6994 etc., before deciding to move it past a breakpoint. */
6995 if (ecs->event_thread->control.step_range_end != 0)
6998 /* Check if the current thread is blocked on an incomplete
6999 step-over, interrupted by a random signal. */
7000 if (ecs->event_thread->control.trap_expected
7001 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7005 fprintf_unfiltered (gdb_stdlog,
7006 "infrun: need to finish step-over of [%s]\n",
7007 target_pid_to_str (ecs->event_thread->ptid));
7013 /* Check if the current thread is blocked by a single-step
7014 breakpoint of another thread. */
7015 if (ecs->hit_singlestep_breakpoint)
7019 fprintf_unfiltered (gdb_stdlog,
7020 "infrun: need to step [%s] over single-step "
7022 target_pid_to_str (ecs->ptid));
7028 /* If this thread needs yet another step-over (e.g., stepping
7029 through a delay slot), do it first before moving on to
7031 if (thread_still_needs_step_over (ecs->event_thread))
7035 fprintf_unfiltered (gdb_stdlog,
7036 "infrun: thread [%s] still needs step-over\n",
7037 target_pid_to_str (ecs->event_thread->ptid));
7043 /* If scheduler locking applies even if not stepping, there's no
7044 need to walk over threads. Above we've checked whether the
7045 current thread is stepping. If some other thread not the
7046 event thread is stepping, then it must be that scheduler
7047 locking is not in effect. */
7048 if (schedlock_applies (ecs->event_thread))
7051 /* Otherwise, we no longer expect a trap in the current thread.
7052 Clear the trap_expected flag before switching back -- this is
7053 what keep_going does as well, if we call it. */
7054 ecs->event_thread->control.trap_expected = 0;
7056 /* Likewise, clear the signal if it should not be passed. */
7057 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7058 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7060 /* Do all pending step-overs before actually proceeding with
7062 if (start_step_over ())
7064 prepare_to_wait (ecs);
7068 /* Look for the stepping/nexting thread. */
7069 stepping_thread = NULL;
7071 ALL_NON_EXITED_THREADS (tp)
7073 /* Ignore threads of processes the caller is not
7076 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7079 /* When stepping over a breakpoint, we lock all threads
7080 except the one that needs to move past the breakpoint.
7081 If a non-event thread has this set, the "incomplete
7082 step-over" check above should have caught it earlier. */
7083 if (tp->control.trap_expected)
7085 internal_error (__FILE__, __LINE__,
7086 "[%s] has inconsistent state: "
7087 "trap_expected=%d\n",
7088 target_pid_to_str (tp->ptid),
7089 tp->control.trap_expected);
7092 /* Did we find the stepping thread? */
7093 if (tp->control.step_range_end)
7095 /* Yep. There should only one though. */
7096 gdb_assert (stepping_thread == NULL);
7098 /* The event thread is handled at the top, before we
7100 gdb_assert (tp != ecs->event_thread);
7102 /* If some thread other than the event thread is
7103 stepping, then scheduler locking can't be in effect,
7104 otherwise we wouldn't have resumed the current event
7105 thread in the first place. */
7106 gdb_assert (!schedlock_applies (tp));
7108 stepping_thread = tp;
7112 if (stepping_thread != NULL)
7115 fprintf_unfiltered (gdb_stdlog,
7116 "infrun: switching back to stepped thread\n");
7118 if (keep_going_stepped_thread (stepping_thread))
7120 prepare_to_wait (ecs);
7129 /* Set a previously stepped thread back to stepping. Returns true on
7130 success, false if the resume is not possible (e.g., the thread
7134 keep_going_stepped_thread (struct thread_info *tp)
7136 struct frame_info *frame;
7137 struct execution_control_state ecss;
7138 struct execution_control_state *ecs = &ecss;
7140 /* If the stepping thread exited, then don't try to switch back and
7141 resume it, which could fail in several different ways depending
7142 on the target. Instead, just keep going.
7144 We can find a stepping dead thread in the thread list in two
7147 - The target supports thread exit events, and when the target
7148 tries to delete the thread from the thread list, inferior_ptid
7149 pointed at the exiting thread. In such case, calling
7150 delete_thread does not really remove the thread from the list;
7151 instead, the thread is left listed, with 'exited' state.
7153 - The target's debug interface does not support thread exit
7154 events, and so we have no idea whatsoever if the previously
7155 stepping thread is still alive. For that reason, we need to
7156 synchronously query the target now. */
7158 if (is_exited (tp->ptid)
7159 || !target_thread_alive (tp->ptid))
7162 fprintf_unfiltered (gdb_stdlog,
7163 "infrun: not resuming previously "
7164 "stepped thread, it has vanished\n");
7166 delete_thread (tp->ptid);
7171 fprintf_unfiltered (gdb_stdlog,
7172 "infrun: resuming previously stepped thread\n");
7174 reset_ecs (ecs, tp);
7175 switch_to_thread (tp->ptid);
7177 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7178 frame = get_current_frame ();
7180 /* If the PC of the thread we were trying to single-step has
7181 changed, then that thread has trapped or been signaled, but the
7182 event has not been reported to GDB yet. Re-poll the target
7183 looking for this particular thread's event (i.e. temporarily
7184 enable schedlock) by:
7186 - setting a break at the current PC
7187 - resuming that particular thread, only (by setting trap
7190 This prevents us continuously moving the single-step breakpoint
7191 forward, one instruction at a time, overstepping. */
7193 if (stop_pc != tp->prev_pc)
7198 fprintf_unfiltered (gdb_stdlog,
7199 "infrun: expected thread advanced also (%s -> %s)\n",
7200 paddress (target_gdbarch (), tp->prev_pc),
7201 paddress (target_gdbarch (), stop_pc));
7203 /* Clear the info of the previous step-over, as it's no longer
7204 valid (if the thread was trying to step over a breakpoint, it
7205 has already succeeded). It's what keep_going would do too,
7206 if we called it. Do this before trying to insert the sss
7207 breakpoint, otherwise if we were previously trying to step
7208 over this exact address in another thread, the breakpoint is
7210 clear_step_over_info ();
7211 tp->control.trap_expected = 0;
7213 insert_single_step_breakpoint (get_frame_arch (frame),
7214 get_frame_address_space (frame),
7218 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7219 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7224 fprintf_unfiltered (gdb_stdlog,
7225 "infrun: expected thread still hasn't advanced\n");
7227 keep_going_pass_signal (ecs);
7232 /* Is thread TP in the middle of (software or hardware)
7233 single-stepping? (Note the result of this function must never be
7234 passed directly as target_resume's STEP parameter.) */
7237 currently_stepping (struct thread_info *tp)
7239 return ((tp->control.step_range_end
7240 && tp->control.step_resume_breakpoint == NULL)
7241 || tp->control.trap_expected
7242 || tp->stepped_breakpoint
7243 || bpstat_should_step ());
7246 /* Inferior has stepped into a subroutine call with source code that
7247 we should not step over. Do step to the first line of code in
7251 handle_step_into_function (struct gdbarch *gdbarch,
7252 struct execution_control_state *ecs)
7254 fill_in_stop_func (gdbarch, ecs);
7256 compunit_symtab *cust = find_pc_compunit_symtab (stop_pc);
7257 if (cust != NULL && compunit_language (cust) != language_asm)
7258 ecs->stop_func_start
7259 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7261 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7262 /* Use the step_resume_break to step until the end of the prologue,
7263 even if that involves jumps (as it seems to on the vax under
7265 /* If the prologue ends in the middle of a source line, continue to
7266 the end of that source line (if it is still within the function).
7267 Otherwise, just go to end of prologue. */
7268 if (stop_func_sal.end
7269 && stop_func_sal.pc != ecs->stop_func_start
7270 && stop_func_sal.end < ecs->stop_func_end)
7271 ecs->stop_func_start = stop_func_sal.end;
7273 /* Architectures which require breakpoint adjustment might not be able
7274 to place a breakpoint at the computed address. If so, the test
7275 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7276 ecs->stop_func_start to an address at which a breakpoint may be
7277 legitimately placed.
7279 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7280 made, GDB will enter an infinite loop when stepping through
7281 optimized code consisting of VLIW instructions which contain
7282 subinstructions corresponding to different source lines. On
7283 FR-V, it's not permitted to place a breakpoint on any but the
7284 first subinstruction of a VLIW instruction. When a breakpoint is
7285 set, GDB will adjust the breakpoint address to the beginning of
7286 the VLIW instruction. Thus, we need to make the corresponding
7287 adjustment here when computing the stop address. */
7289 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7291 ecs->stop_func_start
7292 = gdbarch_adjust_breakpoint_address (gdbarch,
7293 ecs->stop_func_start);
7296 if (ecs->stop_func_start == stop_pc)
7298 /* We are already there: stop now. */
7299 end_stepping_range (ecs);
7304 /* Put the step-breakpoint there and go until there. */
7305 symtab_and_line sr_sal;
7306 sr_sal.pc = ecs->stop_func_start;
7307 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7308 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7310 /* Do not specify what the fp should be when we stop since on
7311 some machines the prologue is where the new fp value is
7313 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7315 /* And make sure stepping stops right away then. */
7316 ecs->event_thread->control.step_range_end
7317 = ecs->event_thread->control.step_range_start;
7322 /* Inferior has stepped backward into a subroutine call with source
7323 code that we should not step over. Do step to the beginning of the
7324 last line of code in it. */
7327 handle_step_into_function_backward (struct gdbarch *gdbarch,
7328 struct execution_control_state *ecs)
7330 struct compunit_symtab *cust;
7331 struct symtab_and_line stop_func_sal;
7333 fill_in_stop_func (gdbarch, ecs);
7335 cust = find_pc_compunit_symtab (stop_pc);
7336 if (cust != NULL && compunit_language (cust) != language_asm)
7337 ecs->stop_func_start
7338 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7340 stop_func_sal = find_pc_line (stop_pc, 0);
7342 /* OK, we're just going to keep stepping here. */
7343 if (stop_func_sal.pc == stop_pc)
7345 /* We're there already. Just stop stepping now. */
7346 end_stepping_range (ecs);
7350 /* Else just reset the step range and keep going.
7351 No step-resume breakpoint, they don't work for
7352 epilogues, which can have multiple entry paths. */
7353 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7354 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7360 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7361 This is used to both functions and to skip over code. */
7364 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7365 struct symtab_and_line sr_sal,
7366 struct frame_id sr_id,
7367 enum bptype sr_type)
7369 /* There should never be more than one step-resume or longjmp-resume
7370 breakpoint per thread, so we should never be setting a new
7371 step_resume_breakpoint when one is already active. */
7372 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7373 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7376 fprintf_unfiltered (gdb_stdlog,
7377 "infrun: inserting step-resume breakpoint at %s\n",
7378 paddress (gdbarch, sr_sal.pc));
7380 inferior_thread ()->control.step_resume_breakpoint
7381 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7385 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7386 struct symtab_and_line sr_sal,
7387 struct frame_id sr_id)
7389 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7394 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7395 This is used to skip a potential signal handler.
7397 This is called with the interrupted function's frame. The signal
7398 handler, when it returns, will resume the interrupted function at
7402 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7404 gdb_assert (return_frame != NULL);
7406 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7408 symtab_and_line sr_sal;
7409 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7410 sr_sal.section = find_pc_overlay (sr_sal.pc);
7411 sr_sal.pspace = get_frame_program_space (return_frame);
7413 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7414 get_stack_frame_id (return_frame),
7418 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7419 is used to skip a function after stepping into it (for "next" or if
7420 the called function has no debugging information).
7422 The current function has almost always been reached by single
7423 stepping a call or return instruction. NEXT_FRAME belongs to the
7424 current function, and the breakpoint will be set at the caller's
7427 This is a separate function rather than reusing
7428 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7429 get_prev_frame, which may stop prematurely (see the implementation
7430 of frame_unwind_caller_id for an example). */
7433 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7435 /* We shouldn't have gotten here if we don't know where the call site
7437 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7439 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7441 symtab_and_line sr_sal;
7442 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7443 frame_unwind_caller_pc (next_frame));
7444 sr_sal.section = find_pc_overlay (sr_sal.pc);
7445 sr_sal.pspace = frame_unwind_program_space (next_frame);
7447 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7448 frame_unwind_caller_id (next_frame));
7451 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7452 new breakpoint at the target of a jmp_buf. The handling of
7453 longjmp-resume uses the same mechanisms used for handling
7454 "step-resume" breakpoints. */
7457 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7459 /* There should never be more than one longjmp-resume breakpoint per
7460 thread, so we should never be setting a new
7461 longjmp_resume_breakpoint when one is already active. */
7462 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7465 fprintf_unfiltered (gdb_stdlog,
7466 "infrun: inserting longjmp-resume breakpoint at %s\n",
7467 paddress (gdbarch, pc));
7469 inferior_thread ()->control.exception_resume_breakpoint =
7470 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7473 /* Insert an exception resume breakpoint. TP is the thread throwing
7474 the exception. The block B is the block of the unwinder debug hook
7475 function. FRAME is the frame corresponding to the call to this
7476 function. SYM is the symbol of the function argument holding the
7477 target PC of the exception. */
7480 insert_exception_resume_breakpoint (struct thread_info *tp,
7481 const struct block *b,
7482 struct frame_info *frame,
7487 struct block_symbol vsym;
7488 struct value *value;
7490 struct breakpoint *bp;
7492 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7494 value = read_var_value (vsym.symbol, vsym.block, frame);
7495 /* If the value was optimized out, revert to the old behavior. */
7496 if (! value_optimized_out (value))
7498 handler = value_as_address (value);
7501 fprintf_unfiltered (gdb_stdlog,
7502 "infrun: exception resume at %lx\n",
7503 (unsigned long) handler);
7505 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7507 bp_exception_resume).release ();
7509 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7512 bp->thread = tp->global_num;
7513 inferior_thread ()->control.exception_resume_breakpoint = bp;
7516 CATCH (e, RETURN_MASK_ERROR)
7518 /* We want to ignore errors here. */
7523 /* A helper for check_exception_resume that sets an
7524 exception-breakpoint based on a SystemTap probe. */
7527 insert_exception_resume_from_probe (struct thread_info *tp,
7528 const struct bound_probe *probe,
7529 struct frame_info *frame)
7531 struct value *arg_value;
7533 struct breakpoint *bp;
7535 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7539 handler = value_as_address (arg_value);
7542 fprintf_unfiltered (gdb_stdlog,
7543 "infrun: exception resume at %s\n",
7544 paddress (get_objfile_arch (probe->objfile),
7547 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7548 handler, bp_exception_resume).release ();
7549 bp->thread = tp->global_num;
7550 inferior_thread ()->control.exception_resume_breakpoint = bp;
7553 /* This is called when an exception has been intercepted. Check to
7554 see whether the exception's destination is of interest, and if so,
7555 set an exception resume breakpoint there. */
7558 check_exception_resume (struct execution_control_state *ecs,
7559 struct frame_info *frame)
7561 struct bound_probe probe;
7562 struct symbol *func;
7564 /* First see if this exception unwinding breakpoint was set via a
7565 SystemTap probe point. If so, the probe has two arguments: the
7566 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7567 set a breakpoint there. */
7568 probe = find_probe_by_pc (get_frame_pc (frame));
7571 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7575 func = get_frame_function (frame);
7581 const struct block *b;
7582 struct block_iterator iter;
7586 /* The exception breakpoint is a thread-specific breakpoint on
7587 the unwinder's debug hook, declared as:
7589 void _Unwind_DebugHook (void *cfa, void *handler);
7591 The CFA argument indicates the frame to which control is
7592 about to be transferred. HANDLER is the destination PC.
7594 We ignore the CFA and set a temporary breakpoint at HANDLER.
7595 This is not extremely efficient but it avoids issues in gdb
7596 with computing the DWARF CFA, and it also works even in weird
7597 cases such as throwing an exception from inside a signal
7600 b = SYMBOL_BLOCK_VALUE (func);
7601 ALL_BLOCK_SYMBOLS (b, iter, sym)
7603 if (!SYMBOL_IS_ARGUMENT (sym))
7610 insert_exception_resume_breakpoint (ecs->event_thread,
7616 CATCH (e, RETURN_MASK_ERROR)
7623 stop_waiting (struct execution_control_state *ecs)
7626 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7628 /* Let callers know we don't want to wait for the inferior anymore. */
7629 ecs->wait_some_more = 0;
7631 /* If all-stop, but the target is always in non-stop mode, stop all
7632 threads now that we're presenting the stop to the user. */
7633 if (!non_stop && target_is_non_stop_p ())
7634 stop_all_threads ();
7637 /* Like keep_going, but passes the signal to the inferior, even if the
7638 signal is set to nopass. */
7641 keep_going_pass_signal (struct execution_control_state *ecs)
7643 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7644 gdb_assert (!ecs->event_thread->resumed);
7646 /* Save the pc before execution, to compare with pc after stop. */
7647 ecs->event_thread->prev_pc
7648 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7650 if (ecs->event_thread->control.trap_expected)
7652 struct thread_info *tp = ecs->event_thread;
7655 fprintf_unfiltered (gdb_stdlog,
7656 "infrun: %s has trap_expected set, "
7657 "resuming to collect trap\n",
7658 target_pid_to_str (tp->ptid));
7660 /* We haven't yet gotten our trap, and either: intercepted a
7661 non-signal event (e.g., a fork); or took a signal which we
7662 are supposed to pass through to the inferior. Simply
7664 resume (ecs->event_thread->suspend.stop_signal);
7666 else if (step_over_info_valid_p ())
7668 /* Another thread is stepping over a breakpoint in-line. If
7669 this thread needs a step-over too, queue the request. In
7670 either case, this resume must be deferred for later. */
7671 struct thread_info *tp = ecs->event_thread;
7673 if (ecs->hit_singlestep_breakpoint
7674 || thread_still_needs_step_over (tp))
7677 fprintf_unfiltered (gdb_stdlog,
7678 "infrun: step-over already in progress: "
7679 "step-over for %s deferred\n",
7680 target_pid_to_str (tp->ptid));
7681 thread_step_over_chain_enqueue (tp);
7686 fprintf_unfiltered (gdb_stdlog,
7687 "infrun: step-over in progress: "
7688 "resume of %s deferred\n",
7689 target_pid_to_str (tp->ptid));
7694 struct regcache *regcache = get_current_regcache ();
7697 step_over_what step_what;
7699 /* Either the trap was not expected, but we are continuing
7700 anyway (if we got a signal, the user asked it be passed to
7703 We got our expected trap, but decided we should resume from
7706 We're going to run this baby now!
7708 Note that insert_breakpoints won't try to re-insert
7709 already inserted breakpoints. Therefore, we don't
7710 care if breakpoints were already inserted, or not. */
7712 /* If we need to step over a breakpoint, and we're not using
7713 displaced stepping to do so, insert all breakpoints
7714 (watchpoints, etc.) but the one we're stepping over, step one
7715 instruction, and then re-insert the breakpoint when that step
7718 step_what = thread_still_needs_step_over (ecs->event_thread);
7720 remove_bp = (ecs->hit_singlestep_breakpoint
7721 || (step_what & STEP_OVER_BREAKPOINT));
7722 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7724 /* We can't use displaced stepping if we need to step past a
7725 watchpoint. The instruction copied to the scratch pad would
7726 still trigger the watchpoint. */
7728 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7730 set_step_over_info (regcache->aspace (),
7731 regcache_read_pc (regcache), remove_wps,
7732 ecs->event_thread->global_num);
7734 else if (remove_wps)
7735 set_step_over_info (NULL, 0, remove_wps, -1);
7737 /* If we now need to do an in-line step-over, we need to stop
7738 all other threads. Note this must be done before
7739 insert_breakpoints below, because that removes the breakpoint
7740 we're about to step over, otherwise other threads could miss
7742 if (step_over_info_valid_p () && target_is_non_stop_p ())
7743 stop_all_threads ();
7745 /* Stop stepping if inserting breakpoints fails. */
7748 insert_breakpoints ();
7750 CATCH (e, RETURN_MASK_ERROR)
7752 exception_print (gdb_stderr, e);
7758 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7760 resume (ecs->event_thread->suspend.stop_signal);
7763 prepare_to_wait (ecs);
7766 /* Called when we should continue running the inferior, because the
7767 current event doesn't cause a user visible stop. This does the
7768 resuming part; waiting for the next event is done elsewhere. */
7771 keep_going (struct execution_control_state *ecs)
7773 if (ecs->event_thread->control.trap_expected
7774 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7775 ecs->event_thread->control.trap_expected = 0;
7777 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7778 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7779 keep_going_pass_signal (ecs);
7782 /* This function normally comes after a resume, before
7783 handle_inferior_event exits. It takes care of any last bits of
7784 housekeeping, and sets the all-important wait_some_more flag. */
7787 prepare_to_wait (struct execution_control_state *ecs)
7790 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7792 ecs->wait_some_more = 1;
7794 if (!target_is_async_p ())
7795 mark_infrun_async_event_handler ();
7798 /* We are done with the step range of a step/next/si/ni command.
7799 Called once for each n of a "step n" operation. */
7802 end_stepping_range (struct execution_control_state *ecs)
7804 ecs->event_thread->control.stop_step = 1;
7808 /* Several print_*_reason functions to print why the inferior has stopped.
7809 We always print something when the inferior exits, or receives a signal.
7810 The rest of the cases are dealt with later on in normal_stop and
7811 print_it_typical. Ideally there should be a call to one of these
7812 print_*_reason functions functions from handle_inferior_event each time
7813 stop_waiting is called.
7815 Note that we don't call these directly, instead we delegate that to
7816 the interpreters, through observers. Interpreters then call these
7817 with whatever uiout is right. */
7820 print_end_stepping_range_reason (struct ui_out *uiout)
7822 /* For CLI-like interpreters, print nothing. */
7824 if (uiout->is_mi_like_p ())
7826 uiout->field_string ("reason",
7827 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7832 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7834 annotate_signalled ();
7835 if (uiout->is_mi_like_p ())
7837 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7838 uiout->text ("\nProgram terminated with signal ");
7839 annotate_signal_name ();
7840 uiout->field_string ("signal-name",
7841 gdb_signal_to_name (siggnal));
7842 annotate_signal_name_end ();
7844 annotate_signal_string ();
7845 uiout->field_string ("signal-meaning",
7846 gdb_signal_to_string (siggnal));
7847 annotate_signal_string_end ();
7848 uiout->text (".\n");
7849 uiout->text ("The program no longer exists.\n");
7853 print_exited_reason (struct ui_out *uiout, int exitstatus)
7855 struct inferior *inf = current_inferior ();
7856 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7858 annotate_exited (exitstatus);
7861 if (uiout->is_mi_like_p ())
7862 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7863 uiout->text ("[Inferior ");
7864 uiout->text (plongest (inf->num));
7866 uiout->text (pidstr);
7867 uiout->text (") exited with code ");
7868 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7869 uiout->text ("]\n");
7873 if (uiout->is_mi_like_p ())
7875 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7876 uiout->text ("[Inferior ");
7877 uiout->text (plongest (inf->num));
7879 uiout->text (pidstr);
7880 uiout->text (") exited normally]\n");
7884 /* Some targets/architectures can do extra processing/display of
7885 segmentation faults. E.g., Intel MPX boundary faults.
7886 Call the architecture dependent function to handle the fault. */
7889 handle_segmentation_fault (struct ui_out *uiout)
7891 struct regcache *regcache = get_current_regcache ();
7892 struct gdbarch *gdbarch = regcache->arch ();
7894 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7895 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7899 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7901 struct thread_info *thr = inferior_thread ();
7905 if (uiout->is_mi_like_p ())
7907 else if (show_thread_that_caused_stop ())
7911 uiout->text ("\nThread ");
7912 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7914 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7917 uiout->text (" \"");
7918 uiout->field_fmt ("name", "%s", name);
7923 uiout->text ("\nProgram");
7925 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7926 uiout->text (" stopped");
7929 uiout->text (" received signal ");
7930 annotate_signal_name ();
7931 if (uiout->is_mi_like_p ())
7933 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7934 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7935 annotate_signal_name_end ();
7937 annotate_signal_string ();
7938 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7940 if (siggnal == GDB_SIGNAL_SEGV)
7941 handle_segmentation_fault (uiout);
7943 annotate_signal_string_end ();
7945 uiout->text (".\n");
7949 print_no_history_reason (struct ui_out *uiout)
7951 uiout->text ("\nNo more reverse-execution history.\n");
7954 /* Print current location without a level number, if we have changed
7955 functions or hit a breakpoint. Print source line if we have one.
7956 bpstat_print contains the logic deciding in detail what to print,
7957 based on the event(s) that just occurred. */
7960 print_stop_location (struct target_waitstatus *ws)
7963 enum print_what source_flag;
7964 int do_frame_printing = 1;
7965 struct thread_info *tp = inferior_thread ();
7967 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7971 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7972 should) carry around the function and does (or should) use
7973 that when doing a frame comparison. */
7974 if (tp->control.stop_step
7975 && frame_id_eq (tp->control.step_frame_id,
7976 get_frame_id (get_current_frame ()))
7977 && tp->control.step_start_function == find_pc_function (stop_pc))
7979 /* Finished step, just print source line. */
7980 source_flag = SRC_LINE;
7984 /* Print location and source line. */
7985 source_flag = SRC_AND_LOC;
7988 case PRINT_SRC_AND_LOC:
7989 /* Print location and source line. */
7990 source_flag = SRC_AND_LOC;
7992 case PRINT_SRC_ONLY:
7993 source_flag = SRC_LINE;
7996 /* Something bogus. */
7997 source_flag = SRC_LINE;
7998 do_frame_printing = 0;
8001 internal_error (__FILE__, __LINE__, _("Unknown value."));
8004 /* The behavior of this routine with respect to the source
8006 SRC_LINE: Print only source line
8007 LOCATION: Print only location
8008 SRC_AND_LOC: Print location and source line. */
8009 if (do_frame_printing)
8010 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8016 print_stop_event (struct ui_out *uiout)
8018 struct target_waitstatus last;
8020 struct thread_info *tp;
8022 get_last_target_status (&last_ptid, &last);
8025 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8027 print_stop_location (&last);
8029 /* Display the auto-display expressions. */
8033 tp = inferior_thread ();
8034 if (tp->thread_fsm != NULL
8035 && thread_fsm_finished_p (tp->thread_fsm))
8037 struct return_value_info *rv;
8039 rv = thread_fsm_return_value (tp->thread_fsm);
8041 print_return_value (uiout, rv);
8048 maybe_remove_breakpoints (void)
8050 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8052 if (remove_breakpoints ())
8054 target_terminal::ours_for_output ();
8055 printf_filtered (_("Cannot remove breakpoints because "
8056 "program is no longer writable.\nFurther "
8057 "execution is probably impossible.\n"));
8062 /* The execution context that just caused a normal stop. */
8069 /* The event PTID. */
8073 /* If stopp for a thread event, this is the thread that caused the
8075 struct thread_info *thread;
8077 /* The inferior that caused the stop. */
8081 /* Returns a new stop context. If stopped for a thread event, this
8082 takes a strong reference to the thread. */
8084 static struct stop_context *
8085 save_stop_context (void)
8087 struct stop_context *sc = XNEW (struct stop_context);
8089 sc->stop_id = get_stop_id ();
8090 sc->ptid = inferior_ptid;
8091 sc->inf_num = current_inferior ()->num;
8093 if (!ptid_equal (inferior_ptid, null_ptid))
8095 /* Take a strong reference so that the thread can't be deleted
8097 sc->thread = inferior_thread ();
8098 sc->thread->incref ();
8106 /* Release a stop context previously created with save_stop_context.
8107 Releases the strong reference to the thread as well. */
8110 release_stop_context_cleanup (void *arg)
8112 struct stop_context *sc = (struct stop_context *) arg;
8114 if (sc->thread != NULL)
8115 sc->thread->decref ();
8119 /* Return true if the current context no longer matches the saved stop
8123 stop_context_changed (struct stop_context *prev)
8125 if (!ptid_equal (prev->ptid, inferior_ptid))
8127 if (prev->inf_num != current_inferior ()->num)
8129 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8131 if (get_stop_id () != prev->stop_id)
8141 struct target_waitstatus last;
8143 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
8146 get_last_target_status (&last_ptid, &last);
8150 /* If an exception is thrown from this point on, make sure to
8151 propagate GDB's knowledge of the executing state to the
8152 frontend/user running state. A QUIT is an easy exception to see
8153 here, so do this before any filtered output. */
8155 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
8156 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8157 || last.kind == TARGET_WAITKIND_EXITED)
8159 /* On some targets, we may still have live threads in the
8160 inferior when we get a process exit event. E.g., for
8161 "checkpoint", when the current checkpoint/fork exits,
8162 linux-fork.c automatically switches to another fork from
8163 within target_mourn_inferior. */
8164 if (!ptid_equal (inferior_ptid, null_ptid))
8166 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
8167 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8170 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8171 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8173 /* As we're presenting a stop, and potentially removing breakpoints,
8174 update the thread list so we can tell whether there are threads
8175 running on the target. With target remote, for example, we can
8176 only learn about new threads when we explicitly update the thread
8177 list. Do this before notifying the interpreters about signal
8178 stops, end of stepping ranges, etc., so that the "new thread"
8179 output is emitted before e.g., "Program received signal FOO",
8180 instead of after. */
8181 update_thread_list ();
8183 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8184 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8186 /* As with the notification of thread events, we want to delay
8187 notifying the user that we've switched thread context until
8188 the inferior actually stops.
8190 There's no point in saying anything if the inferior has exited.
8191 Note that SIGNALLED here means "exited with a signal", not
8192 "received a signal".
8194 Also skip saying anything in non-stop mode. In that mode, as we
8195 don't want GDB to switch threads behind the user's back, to avoid
8196 races where the user is typing a command to apply to thread x,
8197 but GDB switches to thread y before the user finishes entering
8198 the command, fetch_inferior_event installs a cleanup to restore
8199 the current thread back to the thread the user had selected right
8200 after this event is handled, so we're not really switching, only
8201 informing of a stop. */
8203 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8204 && target_has_execution
8205 && last.kind != TARGET_WAITKIND_SIGNALLED
8206 && last.kind != TARGET_WAITKIND_EXITED
8207 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8209 SWITCH_THRU_ALL_UIS ()
8211 target_terminal::ours_for_output ();
8212 printf_filtered (_("[Switching to %s]\n"),
8213 target_pid_to_str (inferior_ptid));
8214 annotate_thread_changed ();
8216 previous_inferior_ptid = inferior_ptid;
8219 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8221 SWITCH_THRU_ALL_UIS ()
8222 if (current_ui->prompt_state == PROMPT_BLOCKED)
8224 target_terminal::ours_for_output ();
8225 printf_filtered (_("No unwaited-for children left.\n"));
8229 /* Note: this depends on the update_thread_list call above. */
8230 maybe_remove_breakpoints ();
8232 /* If an auto-display called a function and that got a signal,
8233 delete that auto-display to avoid an infinite recursion. */
8235 if (stopped_by_random_signal)
8236 disable_current_display ();
8238 SWITCH_THRU_ALL_UIS ()
8240 async_enable_stdin ();
8243 /* Let the user/frontend see the threads as stopped. */
8244 do_cleanups (old_chain);
8246 /* Select innermost stack frame - i.e., current frame is frame 0,
8247 and current location is based on that. Handle the case where the
8248 dummy call is returning after being stopped. E.g. the dummy call
8249 previously hit a breakpoint. (If the dummy call returns
8250 normally, we won't reach here.) Do this before the stop hook is
8251 run, so that it doesn't get to see the temporary dummy frame,
8252 which is not where we'll present the stop. */
8253 if (has_stack_frames ())
8255 if (stop_stack_dummy == STOP_STACK_DUMMY)
8257 /* Pop the empty frame that contains the stack dummy. This
8258 also restores inferior state prior to the call (struct
8259 infcall_suspend_state). */
8260 struct frame_info *frame = get_current_frame ();
8262 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8264 /* frame_pop calls reinit_frame_cache as the last thing it
8265 does which means there's now no selected frame. */
8268 select_frame (get_current_frame ());
8270 /* Set the current source location. */
8271 set_current_sal_from_frame (get_current_frame ());
8274 /* Look up the hook_stop and run it (CLI internally handles problem
8275 of stop_command's pre-hook not existing). */
8276 if (stop_command != NULL)
8278 struct stop_context *saved_context = save_stop_context ();
8279 struct cleanup *old_chain
8280 = make_cleanup (release_stop_context_cleanup, saved_context);
8284 execute_cmd_pre_hook (stop_command);
8286 CATCH (ex, RETURN_MASK_ALL)
8288 exception_fprintf (gdb_stderr, ex,
8289 "Error while running hook_stop:\n");
8293 /* If the stop hook resumes the target, then there's no point in
8294 trying to notify about the previous stop; its context is
8295 gone. Likewise if the command switches thread or inferior --
8296 the observers would print a stop for the wrong
8298 if (stop_context_changed (saved_context))
8300 do_cleanups (old_chain);
8303 do_cleanups (old_chain);
8306 /* Notify observers about the stop. This is where the interpreters
8307 print the stop event. */
8308 if (!ptid_equal (inferior_ptid, null_ptid))
8309 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8312 observer_notify_normal_stop (NULL, stop_print_frame);
8314 annotate_stopped ();
8316 if (target_has_execution)
8318 if (last.kind != TARGET_WAITKIND_SIGNALLED
8319 && last.kind != TARGET_WAITKIND_EXITED)
8320 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8321 Delete any breakpoint that is to be deleted at the next stop. */
8322 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8325 /* Try to get rid of automatically added inferiors that are no
8326 longer needed. Keeping those around slows down things linearly.
8327 Note that this never removes the current inferior. */
8334 signal_stop_state (int signo)
8336 return signal_stop[signo];
8340 signal_print_state (int signo)
8342 return signal_print[signo];
8346 signal_pass_state (int signo)
8348 return signal_program[signo];
8352 signal_cache_update (int signo)
8356 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8357 signal_cache_update (signo);
8362 signal_pass[signo] = (signal_stop[signo] == 0
8363 && signal_print[signo] == 0
8364 && signal_program[signo] == 1
8365 && signal_catch[signo] == 0);
8369 signal_stop_update (int signo, int state)
8371 int ret = signal_stop[signo];
8373 signal_stop[signo] = state;
8374 signal_cache_update (signo);
8379 signal_print_update (int signo, int state)
8381 int ret = signal_print[signo];
8383 signal_print[signo] = state;
8384 signal_cache_update (signo);
8389 signal_pass_update (int signo, int state)
8391 int ret = signal_program[signo];
8393 signal_program[signo] = state;
8394 signal_cache_update (signo);
8398 /* Update the global 'signal_catch' from INFO and notify the
8402 signal_catch_update (const unsigned int *info)
8406 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8407 signal_catch[i] = info[i] > 0;
8408 signal_cache_update (-1);
8409 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8413 sig_print_header (void)
8415 printf_filtered (_("Signal Stop\tPrint\tPass "
8416 "to program\tDescription\n"));
8420 sig_print_info (enum gdb_signal oursig)
8422 const char *name = gdb_signal_to_name (oursig);
8423 int name_padding = 13 - strlen (name);
8425 if (name_padding <= 0)
8428 printf_filtered ("%s", name);
8429 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8430 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8431 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8432 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8433 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8436 /* Specify how various signals in the inferior should be handled. */
8439 handle_command (const char *args, int from_tty)
8441 int digits, wordlen;
8442 int sigfirst, signum, siglast;
8443 enum gdb_signal oursig;
8446 unsigned char *sigs;
8450 error_no_arg (_("signal to handle"));
8453 /* Allocate and zero an array of flags for which signals to handle. */
8455 nsigs = (int) GDB_SIGNAL_LAST;
8456 sigs = (unsigned char *) alloca (nsigs);
8457 memset (sigs, 0, nsigs);
8459 /* Break the command line up into args. */
8461 gdb_argv built_argv (args);
8463 /* Walk through the args, looking for signal oursigs, signal names, and
8464 actions. Signal numbers and signal names may be interspersed with
8465 actions, with the actions being performed for all signals cumulatively
8466 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8468 for (char *arg : built_argv)
8470 wordlen = strlen (arg);
8471 for (digits = 0; isdigit (arg[digits]); digits++)
8475 sigfirst = siglast = -1;
8477 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8479 /* Apply action to all signals except those used by the
8480 debugger. Silently skip those. */
8483 siglast = nsigs - 1;
8485 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8487 SET_SIGS (nsigs, sigs, signal_stop);
8488 SET_SIGS (nsigs, sigs, signal_print);
8490 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8492 UNSET_SIGS (nsigs, sigs, signal_program);
8494 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8496 SET_SIGS (nsigs, sigs, signal_print);
8498 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8500 SET_SIGS (nsigs, sigs, signal_program);
8502 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8504 UNSET_SIGS (nsigs, sigs, signal_stop);
8506 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8508 SET_SIGS (nsigs, sigs, signal_program);
8510 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8512 UNSET_SIGS (nsigs, sigs, signal_print);
8513 UNSET_SIGS (nsigs, sigs, signal_stop);
8515 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8517 UNSET_SIGS (nsigs, sigs, signal_program);
8519 else if (digits > 0)
8521 /* It is numeric. The numeric signal refers to our own
8522 internal signal numbering from target.h, not to host/target
8523 signal number. This is a feature; users really should be
8524 using symbolic names anyway, and the common ones like
8525 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8527 sigfirst = siglast = (int)
8528 gdb_signal_from_command (atoi (arg));
8529 if (arg[digits] == '-')
8532 gdb_signal_from_command (atoi (arg + digits + 1));
8534 if (sigfirst > siglast)
8536 /* Bet he didn't figure we'd think of this case... */
8544 oursig = gdb_signal_from_name (arg);
8545 if (oursig != GDB_SIGNAL_UNKNOWN)
8547 sigfirst = siglast = (int) oursig;
8551 /* Not a number and not a recognized flag word => complain. */
8552 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8556 /* If any signal numbers or symbol names were found, set flags for
8557 which signals to apply actions to. */
8559 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8561 switch ((enum gdb_signal) signum)
8563 case GDB_SIGNAL_TRAP:
8564 case GDB_SIGNAL_INT:
8565 if (!allsigs && !sigs[signum])
8567 if (query (_("%s is used by the debugger.\n\
8568 Are you sure you want to change it? "),
8569 gdb_signal_to_name ((enum gdb_signal) signum)))
8575 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8576 gdb_flush (gdb_stdout);
8581 case GDB_SIGNAL_DEFAULT:
8582 case GDB_SIGNAL_UNKNOWN:
8583 /* Make sure that "all" doesn't print these. */
8592 for (signum = 0; signum < nsigs; signum++)
8595 signal_cache_update (-1);
8596 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8597 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8601 /* Show the results. */
8602 sig_print_header ();
8603 for (; signum < nsigs; signum++)
8605 sig_print_info ((enum gdb_signal) signum);
8612 /* Complete the "handle" command. */
8615 handle_completer (struct cmd_list_element *ignore,
8616 completion_tracker &tracker,
8617 const char *text, const char *word)
8619 static const char * const keywords[] =
8633 signal_completer (ignore, tracker, text, word);
8634 complete_on_enum (tracker, keywords, word, word);
8638 gdb_signal_from_command (int num)
8640 if (num >= 1 && num <= 15)
8641 return (enum gdb_signal) num;
8642 error (_("Only signals 1-15 are valid as numeric signals.\n\
8643 Use \"info signals\" for a list of symbolic signals."));
8646 /* Print current contents of the tables set by the handle command.
8647 It is possible we should just be printing signals actually used
8648 by the current target (but for things to work right when switching
8649 targets, all signals should be in the signal tables). */
8652 info_signals_command (const char *signum_exp, int from_tty)
8654 enum gdb_signal oursig;
8656 sig_print_header ();
8660 /* First see if this is a symbol name. */
8661 oursig = gdb_signal_from_name (signum_exp);
8662 if (oursig == GDB_SIGNAL_UNKNOWN)
8664 /* No, try numeric. */
8666 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8668 sig_print_info (oursig);
8672 printf_filtered ("\n");
8673 /* These ugly casts brought to you by the native VAX compiler. */
8674 for (oursig = GDB_SIGNAL_FIRST;
8675 (int) oursig < (int) GDB_SIGNAL_LAST;
8676 oursig = (enum gdb_signal) ((int) oursig + 1))
8680 if (oursig != GDB_SIGNAL_UNKNOWN
8681 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8682 sig_print_info (oursig);
8685 printf_filtered (_("\nUse the \"handle\" command "
8686 "to change these tables.\n"));
8689 /* The $_siginfo convenience variable is a bit special. We don't know
8690 for sure the type of the value until we actually have a chance to
8691 fetch the data. The type can change depending on gdbarch, so it is
8692 also dependent on which thread you have selected.
8694 1. making $_siginfo be an internalvar that creates a new value on
8697 2. making the value of $_siginfo be an lval_computed value. */
8699 /* This function implements the lval_computed support for reading a
8703 siginfo_value_read (struct value *v)
8705 LONGEST transferred;
8707 /* If we can access registers, so can we access $_siginfo. Likewise
8709 validate_registers_access ();
8712 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8714 value_contents_all_raw (v),
8716 TYPE_LENGTH (value_type (v)));
8718 if (transferred != TYPE_LENGTH (value_type (v)))
8719 error (_("Unable to read siginfo"));
8722 /* This function implements the lval_computed support for writing a
8726 siginfo_value_write (struct value *v, struct value *fromval)
8728 LONGEST transferred;
8730 /* If we can access registers, so can we access $_siginfo. Likewise
8732 validate_registers_access ();
8734 transferred = target_write (¤t_target,
8735 TARGET_OBJECT_SIGNAL_INFO,
8737 value_contents_all_raw (fromval),
8739 TYPE_LENGTH (value_type (fromval)));
8741 if (transferred != TYPE_LENGTH (value_type (fromval)))
8742 error (_("Unable to write siginfo"));
8745 static const struct lval_funcs siginfo_value_funcs =
8751 /* Return a new value with the correct type for the siginfo object of
8752 the current thread using architecture GDBARCH. Return a void value
8753 if there's no object available. */
8755 static struct value *
8756 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8759 if (target_has_stack
8760 && !ptid_equal (inferior_ptid, null_ptid)
8761 && gdbarch_get_siginfo_type_p (gdbarch))
8763 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8765 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8768 return allocate_value (builtin_type (gdbarch)->builtin_void);
8772 /* infcall_suspend_state contains state about the program itself like its
8773 registers and any signal it received when it last stopped.
8774 This state must be restored regardless of how the inferior function call
8775 ends (either successfully, or after it hits a breakpoint or signal)
8776 if the program is to properly continue where it left off. */
8778 struct infcall_suspend_state
8780 struct thread_suspend_state thread_suspend;
8784 struct regcache *registers;
8786 /* Format of SIGINFO_DATA or NULL if it is not present. */
8787 struct gdbarch *siginfo_gdbarch;
8789 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8790 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8791 content would be invalid. */
8792 gdb_byte *siginfo_data;
8795 struct infcall_suspend_state *
8796 save_infcall_suspend_state (void)
8798 struct infcall_suspend_state *inf_state;
8799 struct thread_info *tp = inferior_thread ();
8800 struct regcache *regcache = get_current_regcache ();
8801 struct gdbarch *gdbarch = regcache->arch ();
8802 gdb_byte *siginfo_data = NULL;
8804 if (gdbarch_get_siginfo_type_p (gdbarch))
8806 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8807 size_t len = TYPE_LENGTH (type);
8808 struct cleanup *back_to;
8810 siginfo_data = (gdb_byte *) xmalloc (len);
8811 back_to = make_cleanup (xfree, siginfo_data);
8813 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8814 siginfo_data, 0, len) == len)
8815 discard_cleanups (back_to);
8818 /* Errors ignored. */
8819 do_cleanups (back_to);
8820 siginfo_data = NULL;
8824 inf_state = XCNEW (struct infcall_suspend_state);
8828 inf_state->siginfo_gdbarch = gdbarch;
8829 inf_state->siginfo_data = siginfo_data;
8832 inf_state->thread_suspend = tp->suspend;
8834 /* run_inferior_call will not use the signal due to its `proceed' call with
8835 GDB_SIGNAL_0 anyway. */
8836 tp->suspend.stop_signal = GDB_SIGNAL_0;
8838 inf_state->stop_pc = stop_pc;
8840 inf_state->registers = regcache_dup (regcache);
8845 /* Restore inferior session state to INF_STATE. */
8848 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8850 struct thread_info *tp = inferior_thread ();
8851 struct regcache *regcache = get_current_regcache ();
8852 struct gdbarch *gdbarch = regcache->arch ();
8854 tp->suspend = inf_state->thread_suspend;
8856 stop_pc = inf_state->stop_pc;
8858 if (inf_state->siginfo_gdbarch == gdbarch)
8860 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8862 /* Errors ignored. */
8863 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8864 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8867 /* The inferior can be gone if the user types "print exit(0)"
8868 (and perhaps other times). */
8869 if (target_has_execution)
8870 /* NB: The register write goes through to the target. */
8871 regcache_cpy (regcache, inf_state->registers);
8873 discard_infcall_suspend_state (inf_state);
8877 do_restore_infcall_suspend_state_cleanup (void *state)
8879 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8883 make_cleanup_restore_infcall_suspend_state
8884 (struct infcall_suspend_state *inf_state)
8886 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8890 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8892 delete inf_state->registers;
8893 xfree (inf_state->siginfo_data);
8898 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8900 return inf_state->registers;
8903 /* infcall_control_state contains state regarding gdb's control of the
8904 inferior itself like stepping control. It also contains session state like
8905 the user's currently selected frame. */
8907 struct infcall_control_state
8909 struct thread_control_state thread_control;
8910 struct inferior_control_state inferior_control;
8913 enum stop_stack_kind stop_stack_dummy;
8914 int stopped_by_random_signal;
8916 /* ID if the selected frame when the inferior function call was made. */
8917 struct frame_id selected_frame_id;
8920 /* Save all of the information associated with the inferior<==>gdb
8923 struct infcall_control_state *
8924 save_infcall_control_state (void)
8926 struct infcall_control_state *inf_status =
8927 XNEW (struct infcall_control_state);
8928 struct thread_info *tp = inferior_thread ();
8929 struct inferior *inf = current_inferior ();
8931 inf_status->thread_control = tp->control;
8932 inf_status->inferior_control = inf->control;
8934 tp->control.step_resume_breakpoint = NULL;
8935 tp->control.exception_resume_breakpoint = NULL;
8937 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8938 chain. If caller's caller is walking the chain, they'll be happier if we
8939 hand them back the original chain when restore_infcall_control_state is
8941 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8944 inf_status->stop_stack_dummy = stop_stack_dummy;
8945 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8947 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8953 restore_selected_frame (const frame_id &fid)
8955 frame_info *frame = frame_find_by_id (fid);
8957 /* If inf_status->selected_frame_id is NULL, there was no previously
8961 warning (_("Unable to restore previously selected frame."));
8965 select_frame (frame);
8968 /* Restore inferior session state to INF_STATUS. */
8971 restore_infcall_control_state (struct infcall_control_state *inf_status)
8973 struct thread_info *tp = inferior_thread ();
8974 struct inferior *inf = current_inferior ();
8976 if (tp->control.step_resume_breakpoint)
8977 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8979 if (tp->control.exception_resume_breakpoint)
8980 tp->control.exception_resume_breakpoint->disposition
8981 = disp_del_at_next_stop;
8983 /* Handle the bpstat_copy of the chain. */
8984 bpstat_clear (&tp->control.stop_bpstat);
8986 tp->control = inf_status->thread_control;
8987 inf->control = inf_status->inferior_control;
8990 stop_stack_dummy = inf_status->stop_stack_dummy;
8991 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8993 if (target_has_stack)
8995 /* The point of the try/catch is that if the stack is clobbered,
8996 walking the stack might encounter a garbage pointer and
8997 error() trying to dereference it. */
9000 restore_selected_frame (inf_status->selected_frame_id);
9002 CATCH (ex, RETURN_MASK_ERROR)
9004 exception_fprintf (gdb_stderr, ex,
9005 "Unable to restore previously selected frame:\n");
9006 /* Error in restoring the selected frame. Select the
9008 select_frame (get_current_frame ());
9017 do_restore_infcall_control_state_cleanup (void *sts)
9019 restore_infcall_control_state ((struct infcall_control_state *) sts);
9023 make_cleanup_restore_infcall_control_state
9024 (struct infcall_control_state *inf_status)
9026 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9030 discard_infcall_control_state (struct infcall_control_state *inf_status)
9032 if (inf_status->thread_control.step_resume_breakpoint)
9033 inf_status->thread_control.step_resume_breakpoint->disposition
9034 = disp_del_at_next_stop;
9036 if (inf_status->thread_control.exception_resume_breakpoint)
9037 inf_status->thread_control.exception_resume_breakpoint->disposition
9038 = disp_del_at_next_stop;
9040 /* See save_infcall_control_state for info on stop_bpstat. */
9041 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9049 clear_exit_convenience_vars (void)
9051 clear_internalvar (lookup_internalvar ("_exitsignal"));
9052 clear_internalvar (lookup_internalvar ("_exitcode"));
9056 /* User interface for reverse debugging:
9057 Set exec-direction / show exec-direction commands
9058 (returns error unless target implements to_set_exec_direction method). */
9060 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9061 static const char exec_forward[] = "forward";
9062 static const char exec_reverse[] = "reverse";
9063 static const char *exec_direction = exec_forward;
9064 static const char *const exec_direction_names[] = {
9071 set_exec_direction_func (const char *args, int from_tty,
9072 struct cmd_list_element *cmd)
9074 if (target_can_execute_reverse)
9076 if (!strcmp (exec_direction, exec_forward))
9077 execution_direction = EXEC_FORWARD;
9078 else if (!strcmp (exec_direction, exec_reverse))
9079 execution_direction = EXEC_REVERSE;
9083 exec_direction = exec_forward;
9084 error (_("Target does not support this operation."));
9089 show_exec_direction_func (struct ui_file *out, int from_tty,
9090 struct cmd_list_element *cmd, const char *value)
9092 switch (execution_direction) {
9094 fprintf_filtered (out, _("Forward.\n"));
9097 fprintf_filtered (out, _("Reverse.\n"));
9100 internal_error (__FILE__, __LINE__,
9101 _("bogus execution_direction value: %d"),
9102 (int) execution_direction);
9107 show_schedule_multiple (struct ui_file *file, int from_tty,
9108 struct cmd_list_element *c, const char *value)
9110 fprintf_filtered (file, _("Resuming the execution of threads "
9111 "of all processes is %s.\n"), value);
9114 /* Implementation of `siginfo' variable. */
9116 static const struct internalvar_funcs siginfo_funcs =
9123 /* Callback for infrun's target events source. This is marked when a
9124 thread has a pending status to process. */
9127 infrun_async_inferior_event_handler (gdb_client_data data)
9129 inferior_event_handler (INF_REG_EVENT, NULL);
9133 _initialize_infrun (void)
9137 struct cmd_list_element *c;
9139 /* Register extra event sources in the event loop. */
9140 infrun_async_inferior_event_token
9141 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9143 add_info ("signals", info_signals_command, _("\
9144 What debugger does when program gets various signals.\n\
9145 Specify a signal as argument to print info on that signal only."));
9146 add_info_alias ("handle", "signals", 0);
9148 c = add_com ("handle", class_run, handle_command, _("\
9149 Specify how to handle signals.\n\
9150 Usage: handle SIGNAL [ACTIONS]\n\
9151 Args are signals and actions to apply to those signals.\n\
9152 If no actions are specified, the current settings for the specified signals\n\
9153 will be displayed instead.\n\
9155 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9156 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9157 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9158 The special arg \"all\" is recognized to mean all signals except those\n\
9159 used by the debugger, typically SIGTRAP and SIGINT.\n\
9161 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9162 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9163 Stop means reenter debugger if this signal happens (implies print).\n\
9164 Print means print a message if this signal happens.\n\
9165 Pass means let program see this signal; otherwise program doesn't know.\n\
9166 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9167 Pass and Stop may be combined.\n\
9169 Multiple signals may be specified. Signal numbers and signal names\n\
9170 may be interspersed with actions, with the actions being performed for\n\
9171 all signals cumulatively specified."));
9172 set_cmd_completer (c, handle_completer);
9175 stop_command = add_cmd ("stop", class_obscure,
9176 not_just_help_class_command, _("\
9177 There is no `stop' command, but you can set a hook on `stop'.\n\
9178 This allows you to set a list of commands to be run each time execution\n\
9179 of the program stops."), &cmdlist);
9181 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9182 Set inferior debugging."), _("\
9183 Show inferior debugging."), _("\
9184 When non-zero, inferior specific debugging is enabled."),
9187 &setdebuglist, &showdebuglist);
9189 add_setshow_boolean_cmd ("displaced", class_maintenance,
9190 &debug_displaced, _("\
9191 Set displaced stepping debugging."), _("\
9192 Show displaced stepping debugging."), _("\
9193 When non-zero, displaced stepping specific debugging is enabled."),
9195 show_debug_displaced,
9196 &setdebuglist, &showdebuglist);
9198 add_setshow_boolean_cmd ("non-stop", no_class,
9200 Set whether gdb controls the inferior in non-stop mode."), _("\
9201 Show whether gdb controls the inferior in non-stop mode."), _("\
9202 When debugging a multi-threaded program and this setting is\n\
9203 off (the default, also called all-stop mode), when one thread stops\n\
9204 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9205 all other threads in the program while you interact with the thread of\n\
9206 interest. When you continue or step a thread, you can allow the other\n\
9207 threads to run, or have them remain stopped, but while you inspect any\n\
9208 thread's state, all threads stop.\n\
9210 In non-stop mode, when one thread stops, other threads can continue\n\
9211 to run freely. You'll be able to step each thread independently,\n\
9212 leave it stopped or free to run as needed."),
9218 numsigs = (int) GDB_SIGNAL_LAST;
9219 signal_stop = XNEWVEC (unsigned char, numsigs);
9220 signal_print = XNEWVEC (unsigned char, numsigs);
9221 signal_program = XNEWVEC (unsigned char, numsigs);
9222 signal_catch = XNEWVEC (unsigned char, numsigs);
9223 signal_pass = XNEWVEC (unsigned char, numsigs);
9224 for (i = 0; i < numsigs; i++)
9227 signal_print[i] = 1;
9228 signal_program[i] = 1;
9229 signal_catch[i] = 0;
9232 /* Signals caused by debugger's own actions should not be given to
9233 the program afterwards.
9235 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9236 explicitly specifies that it should be delivered to the target
9237 program. Typically, that would occur when a user is debugging a
9238 target monitor on a simulator: the target monitor sets a
9239 breakpoint; the simulator encounters this breakpoint and halts
9240 the simulation handing control to GDB; GDB, noting that the stop
9241 address doesn't map to any known breakpoint, returns control back
9242 to the simulator; the simulator then delivers the hardware
9243 equivalent of a GDB_SIGNAL_TRAP to the program being
9245 signal_program[GDB_SIGNAL_TRAP] = 0;
9246 signal_program[GDB_SIGNAL_INT] = 0;
9248 /* Signals that are not errors should not normally enter the debugger. */
9249 signal_stop[GDB_SIGNAL_ALRM] = 0;
9250 signal_print[GDB_SIGNAL_ALRM] = 0;
9251 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9252 signal_print[GDB_SIGNAL_VTALRM] = 0;
9253 signal_stop[GDB_SIGNAL_PROF] = 0;
9254 signal_print[GDB_SIGNAL_PROF] = 0;
9255 signal_stop[GDB_SIGNAL_CHLD] = 0;
9256 signal_print[GDB_SIGNAL_CHLD] = 0;
9257 signal_stop[GDB_SIGNAL_IO] = 0;
9258 signal_print[GDB_SIGNAL_IO] = 0;
9259 signal_stop[GDB_SIGNAL_POLL] = 0;
9260 signal_print[GDB_SIGNAL_POLL] = 0;
9261 signal_stop[GDB_SIGNAL_URG] = 0;
9262 signal_print[GDB_SIGNAL_URG] = 0;
9263 signal_stop[GDB_SIGNAL_WINCH] = 0;
9264 signal_print[GDB_SIGNAL_WINCH] = 0;
9265 signal_stop[GDB_SIGNAL_PRIO] = 0;
9266 signal_print[GDB_SIGNAL_PRIO] = 0;
9268 /* These signals are used internally by user-level thread
9269 implementations. (See signal(5) on Solaris.) Like the above
9270 signals, a healthy program receives and handles them as part of
9271 its normal operation. */
9272 signal_stop[GDB_SIGNAL_LWP] = 0;
9273 signal_print[GDB_SIGNAL_LWP] = 0;
9274 signal_stop[GDB_SIGNAL_WAITING] = 0;
9275 signal_print[GDB_SIGNAL_WAITING] = 0;
9276 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9277 signal_print[GDB_SIGNAL_CANCEL] = 0;
9278 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9279 signal_print[GDB_SIGNAL_LIBRT] = 0;
9281 /* Update cached state. */
9282 signal_cache_update (-1);
9284 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9285 &stop_on_solib_events, _("\
9286 Set stopping for shared library events."), _("\
9287 Show stopping for shared library events."), _("\
9288 If nonzero, gdb will give control to the user when the dynamic linker\n\
9289 notifies gdb of shared library events. The most common event of interest\n\
9290 to the user would be loading/unloading of a new library."),
9291 set_stop_on_solib_events,
9292 show_stop_on_solib_events,
9293 &setlist, &showlist);
9295 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9296 follow_fork_mode_kind_names,
9297 &follow_fork_mode_string, _("\
9298 Set debugger response to a program call of fork or vfork."), _("\
9299 Show debugger response to a program call of fork or vfork."), _("\
9300 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9301 parent - the original process is debugged after a fork\n\
9302 child - the new process is debugged after a fork\n\
9303 The unfollowed process will continue to run.\n\
9304 By default, the debugger will follow the parent process."),
9306 show_follow_fork_mode_string,
9307 &setlist, &showlist);
9309 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9310 follow_exec_mode_names,
9311 &follow_exec_mode_string, _("\
9312 Set debugger response to a program call of exec."), _("\
9313 Show debugger response to a program call of exec."), _("\
9314 An exec call replaces the program image of a process.\n\
9316 follow-exec-mode can be:\n\
9318 new - the debugger creates a new inferior and rebinds the process\n\
9319 to this new inferior. The program the process was running before\n\
9320 the exec call can be restarted afterwards by restarting the original\n\
9323 same - the debugger keeps the process bound to the same inferior.\n\
9324 The new executable image replaces the previous executable loaded in\n\
9325 the inferior. Restarting the inferior after the exec call restarts\n\
9326 the executable the process was running after the exec call.\n\
9328 By default, the debugger will use the same inferior."),
9330 show_follow_exec_mode_string,
9331 &setlist, &showlist);
9333 add_setshow_enum_cmd ("scheduler-locking", class_run,
9334 scheduler_enums, &scheduler_mode, _("\
9335 Set mode for locking scheduler during execution."), _("\
9336 Show mode for locking scheduler during execution."), _("\
9337 off == no locking (threads may preempt at any time)\n\
9338 on == full locking (no thread except the current thread may run)\n\
9339 This applies to both normal execution and replay mode.\n\
9340 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9341 In this mode, other threads may run during other commands.\n\
9342 This applies to both normal execution and replay mode.\n\
9343 replay == scheduler locked in replay mode and unlocked during normal execution."),
9344 set_schedlock_func, /* traps on target vector */
9345 show_scheduler_mode,
9346 &setlist, &showlist);
9348 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9349 Set mode for resuming threads of all processes."), _("\
9350 Show mode for resuming threads of all processes."), _("\
9351 When on, execution commands (such as 'continue' or 'next') resume all\n\
9352 threads of all processes. When off (which is the default), execution\n\
9353 commands only resume the threads of the current process. The set of\n\
9354 threads that are resumed is further refined by the scheduler-locking\n\
9355 mode (see help set scheduler-locking)."),
9357 show_schedule_multiple,
9358 &setlist, &showlist);
9360 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9361 Set mode of the step operation."), _("\
9362 Show mode of the step operation."), _("\
9363 When set, doing a step over a function without debug line information\n\
9364 will stop at the first instruction of that function. Otherwise, the\n\
9365 function is skipped and the step command stops at a different source line."),
9367 show_step_stop_if_no_debug,
9368 &setlist, &showlist);
9370 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9371 &can_use_displaced_stepping, _("\
9372 Set debugger's willingness to use displaced stepping."), _("\
9373 Show debugger's willingness to use displaced stepping."), _("\
9374 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9375 supported by the target architecture. If off, gdb will not use displaced\n\
9376 stepping to step over breakpoints, even if such is supported by the target\n\
9377 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9378 if the target architecture supports it and non-stop mode is active, but will not\n\
9379 use it in all-stop mode (see help set non-stop)."),
9381 show_can_use_displaced_stepping,
9382 &setlist, &showlist);
9384 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9385 &exec_direction, _("Set direction of execution.\n\
9386 Options are 'forward' or 'reverse'."),
9387 _("Show direction of execution (forward/reverse)."),
9388 _("Tells gdb whether to execute forward or backward."),
9389 set_exec_direction_func, show_exec_direction_func,
9390 &setlist, &showlist);
9392 /* Set/show detach-on-fork: user-settable mode. */
9394 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9395 Set whether gdb will detach the child of a fork."), _("\
9396 Show whether gdb will detach the child of a fork."), _("\
9397 Tells gdb whether to detach the child of a fork."),
9398 NULL, NULL, &setlist, &showlist);
9400 /* Set/show disable address space randomization mode. */
9402 add_setshow_boolean_cmd ("disable-randomization", class_support,
9403 &disable_randomization, _("\
9404 Set disabling of debuggee's virtual address space randomization."), _("\
9405 Show disabling of debuggee's virtual address space randomization."), _("\
9406 When this mode is on (which is the default), randomization of the virtual\n\
9407 address space is disabled. Standalone programs run with the randomization\n\
9408 enabled by default on some platforms."),
9409 &set_disable_randomization,
9410 &show_disable_randomization,
9411 &setlist, &showlist);
9413 /* ptid initializations */
9414 inferior_ptid = null_ptid;
9415 target_last_wait_ptid = minus_one_ptid;
9417 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9418 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9419 observer_attach_thread_exit (infrun_thread_thread_exit);
9420 observer_attach_inferior_exit (infrun_inferior_exit);
9422 /* Explicitly create without lookup, since that tries to create a
9423 value with a void typed value, and when we get here, gdbarch
9424 isn't initialized yet. At this point, we're quite sure there
9425 isn't another convenience variable of the same name. */
9426 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9428 add_setshow_boolean_cmd ("observer", no_class,
9429 &observer_mode_1, _("\
9430 Set whether gdb controls the inferior in observer mode."), _("\
9431 Show whether gdb controls the inferior in observer mode."), _("\
9432 In observer mode, GDB can get data from the inferior, but not\n\
9433 affect its execution. Registers and memory may not be changed,\n\
9434 breakpoints may not be set, and the program cannot be interrupted\n\