1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2018 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
41 #include "observable.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
67 #include "progspace-and-thread.h"
68 #include "common/gdb_optional.h"
69 #include "arch-utils.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal
);
75 static void sig_print_header (void);
77 static int follow_fork (void);
79 static int follow_fork_inferior (int follow_child
, int detach_fork
);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info
*tp
);
85 void nullify_last_target_wait_ptid (void);
87 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
89 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
91 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
93 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
95 /* Asynchronous signal handler registered as event loop source for
96 when we have pending events ready to be passed to the core. */
97 static struct async_event_handler
*infrun_async_inferior_event_token
;
99 /* Stores whether infrun_async was previously enabled or disabled.
100 Starts off as -1, indicating "never enabled/disabled". */
101 static int infrun_is_async
= -1;
106 infrun_async (int enable
)
108 if (infrun_is_async
!= enable
)
110 infrun_is_async
= enable
;
113 fprintf_unfiltered (gdb_stdlog
,
114 "infrun: infrun_async(%d)\n",
118 mark_async_event_handler (infrun_async_inferior_event_token
);
120 clear_async_event_handler (infrun_async_inferior_event_token
);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token
);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 int step_stop_if_no_debug
= 0;
137 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
138 struct cmd_list_element
*c
, const char *value
)
140 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid
;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static int detach_fork
= 1;
156 int debug_displaced
= 0;
158 show_debug_displaced (struct ui_file
*file
, int from_tty
,
159 struct cmd_list_element
*c
, const char *value
)
161 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
164 unsigned int debug_infrun
= 0;
166 show_debug_infrun (struct ui_file
*file
, int from_tty
,
167 struct cmd_list_element
*c
, const char *value
)
169 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
173 /* Support for disabling address space randomization. */
175 int disable_randomization
= 1;
178 show_disable_randomization (struct ui_file
*file
, int from_tty
,
179 struct cmd_list_element
*c
, const char *value
)
181 if (target_supports_disable_randomization ())
182 fprintf_filtered (file
,
183 _("Disabling randomization of debuggee's "
184 "virtual address space is %s.\n"),
187 fputs_filtered (_("Disabling randomization of debuggee's "
188 "virtual address space is unsupported on\n"
189 "this platform.\n"), file
);
193 set_disable_randomization (const char *args
, int from_tty
,
194 struct cmd_list_element
*c
)
196 if (!target_supports_disable_randomization ())
197 error (_("Disabling randomization of debuggee's "
198 "virtual address space is unsupported on\n"
202 /* User interface for non-stop mode. */
205 static int non_stop_1
= 0;
208 set_non_stop (const char *args
, int from_tty
,
209 struct cmd_list_element
*c
)
211 if (target_has_execution
)
213 non_stop_1
= non_stop
;
214 error (_("Cannot change this setting while the inferior is running."));
217 non_stop
= non_stop_1
;
221 show_non_stop (struct ui_file
*file
, int from_tty
,
222 struct cmd_list_element
*c
, const char *value
)
224 fprintf_filtered (file
,
225 _("Controlling the inferior in non-stop mode is %s.\n"),
229 /* "Observer mode" is somewhat like a more extreme version of
230 non-stop, in which all GDB operations that might affect the
231 target's execution have been disabled. */
233 int observer_mode
= 0;
234 static int observer_mode_1
= 0;
237 set_observer_mode (const char *args
, int from_tty
,
238 struct cmd_list_element
*c
)
240 if (target_has_execution
)
242 observer_mode_1
= observer_mode
;
243 error (_("Cannot change this setting while the inferior is running."));
246 observer_mode
= observer_mode_1
;
248 may_write_registers
= !observer_mode
;
249 may_write_memory
= !observer_mode
;
250 may_insert_breakpoints
= !observer_mode
;
251 may_insert_tracepoints
= !observer_mode
;
252 /* We can insert fast tracepoints in or out of observer mode,
253 but enable them if we're going into this mode. */
255 may_insert_fast_tracepoints
= 1;
256 may_stop
= !observer_mode
;
257 update_target_permissions ();
259 /* Going *into* observer mode we must force non-stop, then
260 going out we leave it that way. */
263 pagination_enabled
= 0;
264 non_stop
= non_stop_1
= 1;
268 printf_filtered (_("Observer mode is now %s.\n"),
269 (observer_mode
? "on" : "off"));
273 show_observer_mode (struct ui_file
*file
, int from_tty
,
274 struct cmd_list_element
*c
, const char *value
)
276 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
279 /* This updates the value of observer mode based on changes in
280 permissions. Note that we are deliberately ignoring the values of
281 may-write-registers and may-write-memory, since the user may have
282 reason to enable these during a session, for instance to turn on a
283 debugging-related global. */
286 update_observer_mode (void)
290 newval
= (!may_insert_breakpoints
291 && !may_insert_tracepoints
292 && may_insert_fast_tracepoints
296 /* Let the user know if things change. */
297 if (newval
!= observer_mode
)
298 printf_filtered (_("Observer mode is now %s.\n"),
299 (newval
? "on" : "off"));
301 observer_mode
= observer_mode_1
= newval
;
304 /* Tables of how to react to signals; the user sets them. */
306 static unsigned char *signal_stop
;
307 static unsigned char *signal_print
;
308 static unsigned char *signal_program
;
310 /* Table of signals that are registered with "catch signal". A
311 non-zero entry indicates that the signal is caught by some "catch
312 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
314 static unsigned char *signal_catch
;
316 /* Table of signals that the target may silently handle.
317 This is automatically determined from the flags above,
318 and simply cached here. */
319 static unsigned char *signal_pass
;
321 #define SET_SIGS(nsigs,sigs,flags) \
323 int signum = (nsigs); \
324 while (signum-- > 0) \
325 if ((sigs)[signum]) \
326 (flags)[signum] = 1; \
329 #define UNSET_SIGS(nsigs,sigs,flags) \
331 int signum = (nsigs); \
332 while (signum-- > 0) \
333 if ((sigs)[signum]) \
334 (flags)[signum] = 0; \
337 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
338 this function is to avoid exporting `signal_program'. */
341 update_signals_program_target (void)
343 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
346 /* Value to pass to target_resume() to cause all threads to resume. */
348 #define RESUME_ALL minus_one_ptid
350 /* Command list pointer for the "stop" placeholder. */
352 static struct cmd_list_element
*stop_command
;
354 /* Nonzero if we want to give control to the user when we're notified
355 of shared library events by the dynamic linker. */
356 int stop_on_solib_events
;
358 /* Enable or disable optional shared library event breakpoints
359 as appropriate when the above flag is changed. */
362 set_stop_on_solib_events (const char *args
,
363 int from_tty
, struct cmd_list_element
*c
)
365 update_solib_breakpoints ();
369 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
370 struct cmd_list_element
*c
, const char *value
)
372 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
376 /* Nonzero after stop if current stack frame should be printed. */
378 static int stop_print_frame
;
380 /* This is a cached copy of the pid/waitstatus of the last event
381 returned by target_wait()/deprecated_target_wait_hook(). This
382 information is returned by get_last_target_status(). */
383 static ptid_t target_last_wait_ptid
;
384 static struct target_waitstatus target_last_waitstatus
;
386 void init_thread_stepping_state (struct thread_info
*tss
);
388 static const char follow_fork_mode_child
[] = "child";
389 static const char follow_fork_mode_parent
[] = "parent";
391 static const char *const follow_fork_mode_kind_names
[] = {
392 follow_fork_mode_child
,
393 follow_fork_mode_parent
,
397 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
399 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
400 struct cmd_list_element
*c
, const char *value
)
402 fprintf_filtered (file
,
403 _("Debugger response to a program "
404 "call of fork or vfork is \"%s\".\n"),
409 /* Handle changes to the inferior list based on the type of fork,
410 which process is being followed, and whether the other process
411 should be detached. On entry inferior_ptid must be the ptid of
412 the fork parent. At return inferior_ptid is the ptid of the
413 followed inferior. */
416 follow_fork_inferior (int follow_child
, int detach_fork
)
419 ptid_t parent_ptid
, child_ptid
;
421 has_vforked
= (inferior_thread ()->pending_follow
.kind
422 == TARGET_WAITKIND_VFORKED
);
423 parent_ptid
= inferior_ptid
;
424 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
427 && !non_stop
/* Non-stop always resumes both branches. */
428 && current_ui
->prompt_state
== PROMPT_BLOCKED
429 && !(follow_child
|| detach_fork
|| sched_multi
))
431 /* The parent stays blocked inside the vfork syscall until the
432 child execs or exits. If we don't let the child run, then
433 the parent stays blocked. If we're telling the parent to run
434 in the foreground, the user will not be able to ctrl-c to get
435 back the terminal, effectively hanging the debug session. */
436 fprintf_filtered (gdb_stderr
, _("\
437 Can not resume the parent process over vfork in the foreground while\n\
438 holding the child stopped. Try \"set detach-on-fork\" or \
439 \"set schedule-multiple\".\n"));
440 /* FIXME output string > 80 columns. */
446 /* Detach new forked process? */
449 /* Before detaching from the child, remove all breakpoints
450 from it. If we forked, then this has already been taken
451 care of by infrun.c. If we vforked however, any
452 breakpoint inserted in the parent is visible in the
453 child, even those added while stopped in a vfork
454 catchpoint. This will remove the breakpoints from the
455 parent also, but they'll be reinserted below. */
458 /* Keep breakpoints list in sync. */
459 remove_breakpoints_inf (current_inferior ());
462 if (print_inferior_events
)
464 /* Ensure that we have a process ptid. */
465 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
467 target_terminal::ours_for_output ();
468 fprintf_filtered (gdb_stdlog
,
469 _("[Detaching after %s from child %s]\n"),
470 has_vforked
? "vfork" : "fork",
471 target_pid_to_str (process_ptid
));
476 struct inferior
*parent_inf
, *child_inf
;
478 /* Add process to GDB's tables. */
479 child_inf
= add_inferior (child_ptid
.pid ());
481 parent_inf
= current_inferior ();
482 child_inf
->attach_flag
= parent_inf
->attach_flag
;
483 copy_terminal_info (child_inf
, parent_inf
);
484 child_inf
->gdbarch
= parent_inf
->gdbarch
;
485 copy_inferior_target_desc_info (child_inf
, parent_inf
);
487 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
489 inferior_ptid
= child_ptid
;
490 add_thread_silent (inferior_ptid
);
491 set_current_inferior (child_inf
);
492 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
494 /* If this is a vfork child, then the address-space is
495 shared with the parent. */
498 child_inf
->pspace
= parent_inf
->pspace
;
499 child_inf
->aspace
= parent_inf
->aspace
;
501 /* The parent will be frozen until the child is done
502 with the shared region. Keep track of the
504 child_inf
->vfork_parent
= parent_inf
;
505 child_inf
->pending_detach
= 0;
506 parent_inf
->vfork_child
= child_inf
;
507 parent_inf
->pending_detach
= 0;
511 child_inf
->aspace
= new_address_space ();
512 child_inf
->pspace
= new program_space (child_inf
->aspace
);
513 child_inf
->removable
= 1;
514 set_current_program_space (child_inf
->pspace
);
515 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
517 /* Let the shared library layer (e.g., solib-svr4) learn
518 about this new process, relocate the cloned exec, pull
519 in shared libraries, and install the solib event
520 breakpoint. If a "cloned-VM" event was propagated
521 better throughout the core, this wouldn't be
523 solib_create_inferior_hook (0);
529 struct inferior
*parent_inf
;
531 parent_inf
= current_inferior ();
533 /* If we detached from the child, then we have to be careful
534 to not insert breakpoints in the parent until the child
535 is done with the shared memory region. However, if we're
536 staying attached to the child, then we can and should
537 insert breakpoints, so that we can debug it. A
538 subsequent child exec or exit is enough to know when does
539 the child stops using the parent's address space. */
540 parent_inf
->waiting_for_vfork_done
= detach_fork
;
541 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
546 /* Follow the child. */
547 struct inferior
*parent_inf
, *child_inf
;
548 struct program_space
*parent_pspace
;
550 if (print_inferior_events
)
552 std::string parent_pid
= target_pid_to_str (parent_ptid
);
553 std::string child_pid
= target_pid_to_str (child_ptid
);
555 target_terminal::ours_for_output ();
556 fprintf_filtered (gdb_stdlog
,
557 _("[Attaching after %s %s to child %s]\n"),
559 has_vforked
? "vfork" : "fork",
563 /* Add the new inferior first, so that the target_detach below
564 doesn't unpush the target. */
566 child_inf
= add_inferior (child_ptid
.pid ());
568 parent_inf
= current_inferior ();
569 child_inf
->attach_flag
= parent_inf
->attach_flag
;
570 copy_terminal_info (child_inf
, parent_inf
);
571 child_inf
->gdbarch
= parent_inf
->gdbarch
;
572 copy_inferior_target_desc_info (child_inf
, parent_inf
);
574 parent_pspace
= parent_inf
->pspace
;
576 /* If we're vforking, we want to hold on to the parent until the
577 child exits or execs. At child exec or exit time we can
578 remove the old breakpoints from the parent and detach or
579 resume debugging it. Otherwise, detach the parent now; we'll
580 want to reuse it's program/address spaces, but we can't set
581 them to the child before removing breakpoints from the
582 parent, otherwise, the breakpoints module could decide to
583 remove breakpoints from the wrong process (since they'd be
584 assigned to the same address space). */
588 gdb_assert (child_inf
->vfork_parent
== NULL
);
589 gdb_assert (parent_inf
->vfork_child
== NULL
);
590 child_inf
->vfork_parent
= parent_inf
;
591 child_inf
->pending_detach
= 0;
592 parent_inf
->vfork_child
= child_inf
;
593 parent_inf
->pending_detach
= detach_fork
;
594 parent_inf
->waiting_for_vfork_done
= 0;
596 else if (detach_fork
)
598 if (print_inferior_events
)
600 /* Ensure that we have a process ptid. */
601 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
603 target_terminal::ours_for_output ();
604 fprintf_filtered (gdb_stdlog
,
605 _("[Detaching after fork from "
607 target_pid_to_str (process_ptid
));
610 target_detach (parent_inf
, 0);
613 /* Note that the detach above makes PARENT_INF dangling. */
615 /* Add the child thread to the appropriate lists, and switch to
616 this new thread, before cloning the program space, and
617 informing the solib layer about this new process. */
619 inferior_ptid
= child_ptid
;
620 add_thread_silent (inferior_ptid
);
621 set_current_inferior (child_inf
);
623 /* If this is a vfork child, then the address-space is shared
624 with the parent. If we detached from the parent, then we can
625 reuse the parent's program/address spaces. */
626 if (has_vforked
|| detach_fork
)
628 child_inf
->pspace
= parent_pspace
;
629 child_inf
->aspace
= child_inf
->pspace
->aspace
;
633 child_inf
->aspace
= new_address_space ();
634 child_inf
->pspace
= new program_space (child_inf
->aspace
);
635 child_inf
->removable
= 1;
636 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
637 set_current_program_space (child_inf
->pspace
);
638 clone_program_space (child_inf
->pspace
, parent_pspace
);
640 /* Let the shared library layer (e.g., solib-svr4) learn
641 about this new process, relocate the cloned exec, pull in
642 shared libraries, and install the solib event breakpoint.
643 If a "cloned-VM" event was propagated better throughout
644 the core, this wouldn't be required. */
645 solib_create_inferior_hook (0);
649 return target_follow_fork (follow_child
, detach_fork
);
652 /* Tell the target to follow the fork we're stopped at. Returns true
653 if the inferior should be resumed; false, if the target for some
654 reason decided it's best not to resume. */
659 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
660 int should_resume
= 1;
661 struct thread_info
*tp
;
663 /* Copy user stepping state to the new inferior thread. FIXME: the
664 followed fork child thread should have a copy of most of the
665 parent thread structure's run control related fields, not just these.
666 Initialized to avoid "may be used uninitialized" warnings from gcc. */
667 struct breakpoint
*step_resume_breakpoint
= NULL
;
668 struct breakpoint
*exception_resume_breakpoint
= NULL
;
669 CORE_ADDR step_range_start
= 0;
670 CORE_ADDR step_range_end
= 0;
671 struct frame_id step_frame_id
= { 0 };
672 struct thread_fsm
*thread_fsm
= NULL
;
677 struct target_waitstatus wait_status
;
679 /* Get the last target status returned by target_wait(). */
680 get_last_target_status (&wait_ptid
, &wait_status
);
682 /* If not stopped at a fork event, then there's nothing else to
684 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
685 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
688 /* Check if we switched over from WAIT_PTID, since the event was
690 if (wait_ptid
!= minus_one_ptid
691 && inferior_ptid
!= wait_ptid
)
693 /* We did. Switch back to WAIT_PTID thread, to tell the
694 target to follow it (in either direction). We'll
695 afterwards refuse to resume, and inform the user what
697 thread_info
*wait_thread
698 = find_thread_ptid (wait_ptid
);
699 switch_to_thread (wait_thread
);
704 tp
= inferior_thread ();
706 /* If there were any forks/vforks that were caught and are now to be
707 followed, then do so now. */
708 switch (tp
->pending_follow
.kind
)
710 case TARGET_WAITKIND_FORKED
:
711 case TARGET_WAITKIND_VFORKED
:
713 ptid_t parent
, child
;
715 /* If the user did a next/step, etc, over a fork call,
716 preserve the stepping state in the fork child. */
717 if (follow_child
&& should_resume
)
719 step_resume_breakpoint
= clone_momentary_breakpoint
720 (tp
->control
.step_resume_breakpoint
);
721 step_range_start
= tp
->control
.step_range_start
;
722 step_range_end
= tp
->control
.step_range_end
;
723 step_frame_id
= tp
->control
.step_frame_id
;
724 exception_resume_breakpoint
725 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
726 thread_fsm
= tp
->thread_fsm
;
728 /* For now, delete the parent's sr breakpoint, otherwise,
729 parent/child sr breakpoints are considered duplicates,
730 and the child version will not be installed. Remove
731 this when the breakpoints module becomes aware of
732 inferiors and address spaces. */
733 delete_step_resume_breakpoint (tp
);
734 tp
->control
.step_range_start
= 0;
735 tp
->control
.step_range_end
= 0;
736 tp
->control
.step_frame_id
= null_frame_id
;
737 delete_exception_resume_breakpoint (tp
);
738 tp
->thread_fsm
= NULL
;
741 parent
= inferior_ptid
;
742 child
= tp
->pending_follow
.value
.related_pid
;
744 /* Set up inferior(s) as specified by the caller, and tell the
745 target to do whatever is necessary to follow either parent
747 if (follow_fork_inferior (follow_child
, detach_fork
))
749 /* Target refused to follow, or there's some other reason
750 we shouldn't resume. */
755 /* This pending follow fork event is now handled, one way
756 or another. The previous selected thread may be gone
757 from the lists by now, but if it is still around, need
758 to clear the pending follow request. */
759 tp
= find_thread_ptid (parent
);
761 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
763 /* This makes sure we don't try to apply the "Switched
764 over from WAIT_PID" logic above. */
765 nullify_last_target_wait_ptid ();
767 /* If we followed the child, switch to it... */
770 thread_info
*child_thr
= find_thread_ptid (child
);
771 switch_to_thread (child_thr
);
773 /* ... and preserve the stepping state, in case the
774 user was stepping over the fork call. */
777 tp
= inferior_thread ();
778 tp
->control
.step_resume_breakpoint
779 = step_resume_breakpoint
;
780 tp
->control
.step_range_start
= step_range_start
;
781 tp
->control
.step_range_end
= step_range_end
;
782 tp
->control
.step_frame_id
= step_frame_id
;
783 tp
->control
.exception_resume_breakpoint
784 = exception_resume_breakpoint
;
785 tp
->thread_fsm
= thread_fsm
;
789 /* If we get here, it was because we're trying to
790 resume from a fork catchpoint, but, the user
791 has switched threads away from the thread that
792 forked. In that case, the resume command
793 issued is most likely not applicable to the
794 child, so just warn, and refuse to resume. */
795 warning (_("Not resuming: switched threads "
796 "before following fork child."));
799 /* Reset breakpoints in the child as appropriate. */
800 follow_inferior_reset_breakpoints ();
805 case TARGET_WAITKIND_SPURIOUS
:
806 /* Nothing to follow. */
809 internal_error (__FILE__
, __LINE__
,
810 "Unexpected pending_follow.kind %d\n",
811 tp
->pending_follow
.kind
);
815 return should_resume
;
819 follow_inferior_reset_breakpoints (void)
821 struct thread_info
*tp
= inferior_thread ();
823 /* Was there a step_resume breakpoint? (There was if the user
824 did a "next" at the fork() call.) If so, explicitly reset its
825 thread number. Cloned step_resume breakpoints are disabled on
826 creation, so enable it here now that it is associated with the
829 step_resumes are a form of bp that are made to be per-thread.
830 Since we created the step_resume bp when the parent process
831 was being debugged, and now are switching to the child process,
832 from the breakpoint package's viewpoint, that's a switch of
833 "threads". We must update the bp's notion of which thread
834 it is for, or it'll be ignored when it triggers. */
836 if (tp
->control
.step_resume_breakpoint
)
838 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
839 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
842 /* Treat exception_resume breakpoints like step_resume breakpoints. */
843 if (tp
->control
.exception_resume_breakpoint
)
845 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
846 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
849 /* Reinsert all breakpoints in the child. The user may have set
850 breakpoints after catching the fork, in which case those
851 were never set in the child, but only in the parent. This makes
852 sure the inserted breakpoints match the breakpoint list. */
854 breakpoint_re_set ();
855 insert_breakpoints ();
858 /* The child has exited or execed: resume threads of the parent the
859 user wanted to be executing. */
862 proceed_after_vfork_done (struct thread_info
*thread
,
865 int pid
= * (int *) arg
;
867 if (thread
->ptid
.pid () == pid
868 && thread
->state
== THREAD_RUNNING
869 && !thread
->executing
870 && !thread
->stop_requested
871 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
874 fprintf_unfiltered (gdb_stdlog
,
875 "infrun: resuming vfork parent thread %s\n",
876 target_pid_to_str (thread
->ptid
));
878 switch_to_thread (thread
);
879 clear_proceed_status (0);
880 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
886 /* Save/restore inferior_ptid, current program space and current
887 inferior. Only use this if the current context points at an exited
888 inferior (and therefore there's no current thread to save). */
889 class scoped_restore_exited_inferior
892 scoped_restore_exited_inferior ()
893 : m_saved_ptid (&inferior_ptid
)
897 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
898 scoped_restore_current_program_space m_pspace
;
899 scoped_restore_current_inferior m_inferior
;
902 /* Called whenever we notice an exec or exit event, to handle
903 detaching or resuming a vfork parent. */
906 handle_vfork_child_exec_or_exit (int exec
)
908 struct inferior
*inf
= current_inferior ();
910 if (inf
->vfork_parent
)
912 int resume_parent
= -1;
914 /* This exec or exit marks the end of the shared memory region
915 between the parent and the child. If the user wanted to
916 detach from the parent, now is the time. */
918 if (inf
->vfork_parent
->pending_detach
)
920 struct thread_info
*tp
;
921 struct program_space
*pspace
;
922 struct address_space
*aspace
;
924 /* follow-fork child, detach-on-fork on. */
926 inf
->vfork_parent
->pending_detach
= 0;
928 gdb::optional
<scoped_restore_exited_inferior
>
929 maybe_restore_inferior
;
930 gdb::optional
<scoped_restore_current_pspace_and_thread
>
931 maybe_restore_thread
;
933 /* If we're handling a child exit, then inferior_ptid points
934 at the inferior's pid, not to a thread. */
936 maybe_restore_inferior
.emplace ();
938 maybe_restore_thread
.emplace ();
940 /* We're letting loose of the parent. */
941 tp
= any_live_thread_of_inferior (inf
->vfork_parent
);
942 switch_to_thread (tp
);
944 /* We're about to detach from the parent, which implicitly
945 removes breakpoints from its address space. There's a
946 catch here: we want to reuse the spaces for the child,
947 but, parent/child are still sharing the pspace at this
948 point, although the exec in reality makes the kernel give
949 the child a fresh set of new pages. The problem here is
950 that the breakpoints module being unaware of this, would
951 likely chose the child process to write to the parent
952 address space. Swapping the child temporarily away from
953 the spaces has the desired effect. Yes, this is "sort
956 pspace
= inf
->pspace
;
957 aspace
= inf
->aspace
;
961 if (print_inferior_events
)
964 = target_pid_to_str (ptid_t (inf
->vfork_parent
->pid
));
966 target_terminal::ours_for_output ();
970 fprintf_filtered (gdb_stdlog
,
971 _("[Detaching vfork parent %s "
972 "after child exec]\n"), pidstr
);
976 fprintf_filtered (gdb_stdlog
,
977 _("[Detaching vfork parent %s "
978 "after child exit]\n"), pidstr
);
982 target_detach (inf
->vfork_parent
, 0);
985 inf
->pspace
= pspace
;
986 inf
->aspace
= aspace
;
990 /* We're staying attached to the parent, so, really give the
991 child a new address space. */
992 inf
->pspace
= new program_space (maybe_new_address_space ());
993 inf
->aspace
= inf
->pspace
->aspace
;
995 set_current_program_space (inf
->pspace
);
997 resume_parent
= inf
->vfork_parent
->pid
;
999 /* Break the bonds. */
1000 inf
->vfork_parent
->vfork_child
= NULL
;
1004 struct program_space
*pspace
;
1006 /* If this is a vfork child exiting, then the pspace and
1007 aspaces were shared with the parent. Since we're
1008 reporting the process exit, we'll be mourning all that is
1009 found in the address space, and switching to null_ptid,
1010 preparing to start a new inferior. But, since we don't
1011 want to clobber the parent's address/program spaces, we
1012 go ahead and create a new one for this exiting
1015 /* Switch to null_ptid while running clone_program_space, so
1016 that clone_program_space doesn't want to read the
1017 selected frame of a dead process. */
1018 scoped_restore restore_ptid
1019 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1021 /* This inferior is dead, so avoid giving the breakpoints
1022 module the option to write through to it (cloning a
1023 program space resets breakpoints). */
1026 pspace
= new program_space (maybe_new_address_space ());
1027 set_current_program_space (pspace
);
1029 inf
->symfile_flags
= SYMFILE_NO_READ
;
1030 clone_program_space (pspace
, inf
->vfork_parent
->pspace
);
1031 inf
->pspace
= pspace
;
1032 inf
->aspace
= pspace
->aspace
;
1034 resume_parent
= inf
->vfork_parent
->pid
;
1035 /* Break the bonds. */
1036 inf
->vfork_parent
->vfork_child
= NULL
;
1039 inf
->vfork_parent
= NULL
;
1041 gdb_assert (current_program_space
== inf
->pspace
);
1043 if (non_stop
&& resume_parent
!= -1)
1045 /* If the user wanted the parent to be running, let it go
1047 scoped_restore_current_thread restore_thread
;
1050 fprintf_unfiltered (gdb_stdlog
,
1051 "infrun: resuming vfork parent process %d\n",
1054 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1059 /* Enum strings for "set|show follow-exec-mode". */
1061 static const char follow_exec_mode_new
[] = "new";
1062 static const char follow_exec_mode_same
[] = "same";
1063 static const char *const follow_exec_mode_names
[] =
1065 follow_exec_mode_new
,
1066 follow_exec_mode_same
,
1070 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1072 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1073 struct cmd_list_element
*c
, const char *value
)
1075 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1078 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1081 follow_exec (ptid_t ptid
, char *exec_file_target
)
1083 struct thread_info
*th
, *tmp
;
1084 struct inferior
*inf
= current_inferior ();
1085 int pid
= ptid
.pid ();
1086 ptid_t process_ptid
;
1088 /* This is an exec event that we actually wish to pay attention to.
1089 Refresh our symbol table to the newly exec'd program, remove any
1090 momentary bp's, etc.
1092 If there are breakpoints, they aren't really inserted now,
1093 since the exec() transformed our inferior into a fresh set
1096 We want to preserve symbolic breakpoints on the list, since
1097 we have hopes that they can be reset after the new a.out's
1098 symbol table is read.
1100 However, any "raw" breakpoints must be removed from the list
1101 (e.g., the solib bp's), since their address is probably invalid
1104 And, we DON'T want to call delete_breakpoints() here, since
1105 that may write the bp's "shadow contents" (the instruction
1106 value that was overwritten witha TRAP instruction). Since
1107 we now have a new a.out, those shadow contents aren't valid. */
1109 mark_breakpoints_out ();
1111 /* The target reports the exec event to the main thread, even if
1112 some other thread does the exec, and even if the main thread was
1113 stopped or already gone. We may still have non-leader threads of
1114 the process on our list. E.g., on targets that don't have thread
1115 exit events (like remote); or on native Linux in non-stop mode if
1116 there were only two threads in the inferior and the non-leader
1117 one is the one that execs (and nothing forces an update of the
1118 thread list up to here). When debugging remotely, it's best to
1119 avoid extra traffic, when possible, so avoid syncing the thread
1120 list with the target, and instead go ahead and delete all threads
1121 of the process but one that reported the event. Note this must
1122 be done before calling update_breakpoints_after_exec, as
1123 otherwise clearing the threads' resources would reference stale
1124 thread breakpoints -- it may have been one of these threads that
1125 stepped across the exec. We could just clear their stepping
1126 states, but as long as we're iterating, might as well delete
1127 them. Deleting them now rather than at the next user-visible
1128 stop provides a nicer sequence of events for user and MI
1130 ALL_THREADS_SAFE (th
, tmp
)
1131 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1134 /* We also need to clear any left over stale state for the
1135 leader/event thread. E.g., if there was any step-resume
1136 breakpoint or similar, it's gone now. We cannot truly
1137 step-to-next statement through an exec(). */
1138 th
= inferior_thread ();
1139 th
->control
.step_resume_breakpoint
= NULL
;
1140 th
->control
.exception_resume_breakpoint
= NULL
;
1141 th
->control
.single_step_breakpoints
= NULL
;
1142 th
->control
.step_range_start
= 0;
1143 th
->control
.step_range_end
= 0;
1145 /* The user may have had the main thread held stopped in the
1146 previous image (e.g., schedlock on, or non-stop). Release
1148 th
->stop_requested
= 0;
1150 update_breakpoints_after_exec ();
1152 /* What is this a.out's name? */
1153 process_ptid
= ptid_t (pid
);
1154 printf_unfiltered (_("%s is executing new program: %s\n"),
1155 target_pid_to_str (process_ptid
),
1158 /* We've followed the inferior through an exec. Therefore, the
1159 inferior has essentially been killed & reborn. */
1161 gdb_flush (gdb_stdout
);
1163 breakpoint_init_inferior (inf_execd
);
1165 gdb::unique_xmalloc_ptr
<char> exec_file_host
1166 = exec_file_find (exec_file_target
, NULL
);
1168 /* If we were unable to map the executable target pathname onto a host
1169 pathname, tell the user that. Otherwise GDB's subsequent behavior
1170 is confusing. Maybe it would even be better to stop at this point
1171 so that the user can specify a file manually before continuing. */
1172 if (exec_file_host
== NULL
)
1173 warning (_("Could not load symbols for executable %s.\n"
1174 "Do you need \"set sysroot\"?"),
1177 /* Reset the shared library package. This ensures that we get a
1178 shlib event when the child reaches "_start", at which point the
1179 dld will have had a chance to initialize the child. */
1180 /* Also, loading a symbol file below may trigger symbol lookups, and
1181 we don't want those to be satisfied by the libraries of the
1182 previous incarnation of this process. */
1183 no_shared_libraries (NULL
, 0);
1185 if (follow_exec_mode_string
== follow_exec_mode_new
)
1187 /* The user wants to keep the old inferior and program spaces
1188 around. Create a new fresh one, and switch to it. */
1190 /* Do exit processing for the original inferior before adding
1191 the new inferior so we don't have two active inferiors with
1192 the same ptid, which can confuse find_inferior_ptid. */
1193 exit_inferior_silent (current_inferior ());
1195 inf
= add_inferior_with_spaces ();
1197 target_follow_exec (inf
, exec_file_target
);
1199 set_current_inferior (inf
);
1200 set_current_program_space (inf
->pspace
);
1204 /* The old description may no longer be fit for the new image.
1205 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1206 old description; we'll read a new one below. No need to do
1207 this on "follow-exec-mode new", as the old inferior stays
1208 around (its description is later cleared/refetched on
1210 target_clear_description ();
1213 gdb_assert (current_program_space
== inf
->pspace
);
1215 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1216 because the proper displacement for a PIE (Position Independent
1217 Executable) main symbol file will only be computed by
1218 solib_create_inferior_hook below. breakpoint_re_set would fail
1219 to insert the breakpoints with the zero displacement. */
1220 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1222 /* If the target can specify a description, read it. Must do this
1223 after flipping to the new executable (because the target supplied
1224 description must be compatible with the executable's
1225 architecture, and the old executable may e.g., be 32-bit, while
1226 the new one 64-bit), and before anything involving memory or
1228 target_find_description ();
1230 /* The add_thread call ends up reading registers, so do it after updating the
1231 target description. */
1232 if (follow_exec_mode_string
== follow_exec_mode_new
)
1235 solib_create_inferior_hook (0);
1237 jit_inferior_created_hook ();
1239 breakpoint_re_set ();
1241 /* Reinsert all breakpoints. (Those which were symbolic have
1242 been reset to the proper address in the new a.out, thanks
1243 to symbol_file_command...). */
1244 insert_breakpoints ();
1246 /* The next resume of this inferior should bring it to the shlib
1247 startup breakpoints. (If the user had also set bp's on
1248 "main" from the old (parent) process, then they'll auto-
1249 matically get reset there in the new process.). */
1252 /* The queue of threads that need to do a step-over operation to get
1253 past e.g., a breakpoint. What technique is used to step over the
1254 breakpoint/watchpoint does not matter -- all threads end up in the
1255 same queue, to maintain rough temporal order of execution, in order
1256 to avoid starvation, otherwise, we could e.g., find ourselves
1257 constantly stepping the same couple threads past their breakpoints
1258 over and over, if the single-step finish fast enough. */
1259 struct thread_info
*step_over_queue_head
;
1261 /* Bit flags indicating what the thread needs to step over. */
1263 enum step_over_what_flag
1265 /* Step over a breakpoint. */
1266 STEP_OVER_BREAKPOINT
= 1,
1268 /* Step past a non-continuable watchpoint, in order to let the
1269 instruction execute so we can evaluate the watchpoint
1271 STEP_OVER_WATCHPOINT
= 2
1273 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1275 /* Info about an instruction that is being stepped over. */
1277 struct step_over_info
1279 /* If we're stepping past a breakpoint, this is the address space
1280 and address of the instruction the breakpoint is set at. We'll
1281 skip inserting all breakpoints here. Valid iff ASPACE is
1283 const address_space
*aspace
;
1286 /* The instruction being stepped over triggers a nonsteppable
1287 watchpoint. If true, we'll skip inserting watchpoints. */
1288 int nonsteppable_watchpoint_p
;
1290 /* The thread's global number. */
1294 /* The step-over info of the location that is being stepped over.
1296 Note that with async/breakpoint always-inserted mode, a user might
1297 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1298 being stepped over. As setting a new breakpoint inserts all
1299 breakpoints, we need to make sure the breakpoint being stepped over
1300 isn't inserted then. We do that by only clearing the step-over
1301 info when the step-over is actually finished (or aborted).
1303 Presently GDB can only step over one breakpoint at any given time.
1304 Given threads that can't run code in the same address space as the
1305 breakpoint's can't really miss the breakpoint, GDB could be taught
1306 to step-over at most one breakpoint per address space (so this info
1307 could move to the address space object if/when GDB is extended).
1308 The set of breakpoints being stepped over will normally be much
1309 smaller than the set of all breakpoints, so a flag in the
1310 breakpoint location structure would be wasteful. A separate list
1311 also saves complexity and run-time, as otherwise we'd have to go
1312 through all breakpoint locations clearing their flag whenever we
1313 start a new sequence. Similar considerations weigh against storing
1314 this info in the thread object. Plus, not all step overs actually
1315 have breakpoint locations -- e.g., stepping past a single-step
1316 breakpoint, or stepping to complete a non-continuable
1318 static struct step_over_info step_over_info
;
1320 /* Record the address of the breakpoint/instruction we're currently
1322 N.B. We record the aspace and address now, instead of say just the thread,
1323 because when we need the info later the thread may be running. */
1326 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1327 int nonsteppable_watchpoint_p
,
1330 step_over_info
.aspace
= aspace
;
1331 step_over_info
.address
= address
;
1332 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1333 step_over_info
.thread
= thread
;
1336 /* Called when we're not longer stepping over a breakpoint / an
1337 instruction, so all breakpoints are free to be (re)inserted. */
1340 clear_step_over_info (void)
1343 fprintf_unfiltered (gdb_stdlog
,
1344 "infrun: clear_step_over_info\n");
1345 step_over_info
.aspace
= NULL
;
1346 step_over_info
.address
= 0;
1347 step_over_info
.nonsteppable_watchpoint_p
= 0;
1348 step_over_info
.thread
= -1;
1354 stepping_past_instruction_at (struct address_space
*aspace
,
1357 return (step_over_info
.aspace
!= NULL
1358 && breakpoint_address_match (aspace
, address
,
1359 step_over_info
.aspace
,
1360 step_over_info
.address
));
1366 thread_is_stepping_over_breakpoint (int thread
)
1368 return (step_over_info
.thread
!= -1
1369 && thread
== step_over_info
.thread
);
1375 stepping_past_nonsteppable_watchpoint (void)
1377 return step_over_info
.nonsteppable_watchpoint_p
;
1380 /* Returns true if step-over info is valid. */
1383 step_over_info_valid_p (void)
1385 return (step_over_info
.aspace
!= NULL
1386 || stepping_past_nonsteppable_watchpoint ());
1390 /* Displaced stepping. */
1392 /* In non-stop debugging mode, we must take special care to manage
1393 breakpoints properly; in particular, the traditional strategy for
1394 stepping a thread past a breakpoint it has hit is unsuitable.
1395 'Displaced stepping' is a tactic for stepping one thread past a
1396 breakpoint it has hit while ensuring that other threads running
1397 concurrently will hit the breakpoint as they should.
1399 The traditional way to step a thread T off a breakpoint in a
1400 multi-threaded program in all-stop mode is as follows:
1402 a0) Initially, all threads are stopped, and breakpoints are not
1404 a1) We single-step T, leaving breakpoints uninserted.
1405 a2) We insert breakpoints, and resume all threads.
1407 In non-stop debugging, however, this strategy is unsuitable: we
1408 don't want to have to stop all threads in the system in order to
1409 continue or step T past a breakpoint. Instead, we use displaced
1412 n0) Initially, T is stopped, other threads are running, and
1413 breakpoints are inserted.
1414 n1) We copy the instruction "under" the breakpoint to a separate
1415 location, outside the main code stream, making any adjustments
1416 to the instruction, register, and memory state as directed by
1418 n2) We single-step T over the instruction at its new location.
1419 n3) We adjust the resulting register and memory state as directed
1420 by T's architecture. This includes resetting T's PC to point
1421 back into the main instruction stream.
1424 This approach depends on the following gdbarch methods:
1426 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1427 indicate where to copy the instruction, and how much space must
1428 be reserved there. We use these in step n1.
1430 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1431 address, and makes any necessary adjustments to the instruction,
1432 register contents, and memory. We use this in step n1.
1434 - gdbarch_displaced_step_fixup adjusts registers and memory after
1435 we have successfuly single-stepped the instruction, to yield the
1436 same effect the instruction would have had if we had executed it
1437 at its original address. We use this in step n3.
1439 The gdbarch_displaced_step_copy_insn and
1440 gdbarch_displaced_step_fixup functions must be written so that
1441 copying an instruction with gdbarch_displaced_step_copy_insn,
1442 single-stepping across the copied instruction, and then applying
1443 gdbarch_displaced_insn_fixup should have the same effects on the
1444 thread's memory and registers as stepping the instruction in place
1445 would have. Exactly which responsibilities fall to the copy and
1446 which fall to the fixup is up to the author of those functions.
1448 See the comments in gdbarch.sh for details.
1450 Note that displaced stepping and software single-step cannot
1451 currently be used in combination, although with some care I think
1452 they could be made to. Software single-step works by placing
1453 breakpoints on all possible subsequent instructions; if the
1454 displaced instruction is a PC-relative jump, those breakpoints
1455 could fall in very strange places --- on pages that aren't
1456 executable, or at addresses that are not proper instruction
1457 boundaries. (We do generally let other threads run while we wait
1458 to hit the software single-step breakpoint, and they might
1459 encounter such a corrupted instruction.) One way to work around
1460 this would be to have gdbarch_displaced_step_copy_insn fully
1461 simulate the effect of PC-relative instructions (and return NULL)
1462 on architectures that use software single-stepping.
1464 In non-stop mode, we can have independent and simultaneous step
1465 requests, so more than one thread may need to simultaneously step
1466 over a breakpoint. The current implementation assumes there is
1467 only one scratch space per process. In this case, we have to
1468 serialize access to the scratch space. If thread A wants to step
1469 over a breakpoint, but we are currently waiting for some other
1470 thread to complete a displaced step, we leave thread A stopped and
1471 place it in the displaced_step_request_queue. Whenever a displaced
1472 step finishes, we pick the next thread in the queue and start a new
1473 displaced step operation on it. See displaced_step_prepare and
1474 displaced_step_fixup for details. */
1476 /* Default destructor for displaced_step_closure. */
1478 displaced_step_closure::~displaced_step_closure () = default;
1480 /* Per-inferior displaced stepping state. */
1481 struct displaced_step_inferior_state
1483 /* Pointer to next in linked list. */
1484 struct displaced_step_inferior_state
*next
;
1486 /* The process this displaced step state refers to. */
1489 /* True if preparing a displaced step ever failed. If so, we won't
1490 try displaced stepping for this inferior again. */
1493 /* If this is not nullptr, this is the thread carrying out a
1494 displaced single-step in process PID. This thread's state will
1495 require fixing up once it has completed its step. */
1496 thread_info
*step_thread
;
1498 /* The architecture the thread had when we stepped it. */
1499 struct gdbarch
*step_gdbarch
;
1501 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1502 for post-step cleanup. */
1503 struct displaced_step_closure
*step_closure
;
1505 /* The address of the original instruction, and the copy we
1507 CORE_ADDR step_original
, step_copy
;
1509 /* Saved contents of copy area. */
1510 gdb_byte
*step_saved_copy
;
1513 /* The list of states of processes involved in displaced stepping
1515 static struct displaced_step_inferior_state
*displaced_step_inferior_states
;
1517 /* Get the displaced stepping state of process PID. */
1519 static struct displaced_step_inferior_state
*
1520 get_displaced_stepping_state (inferior
*inf
)
1522 struct displaced_step_inferior_state
*state
;
1524 for (state
= displaced_step_inferior_states
;
1526 state
= state
->next
)
1527 if (state
->inf
== inf
)
1533 /* Returns true if any inferior has a thread doing a displaced
1537 displaced_step_in_progress_any_inferior (void)
1539 struct displaced_step_inferior_state
*state
;
1541 for (state
= displaced_step_inferior_states
;
1543 state
= state
->next
)
1544 if (state
->step_thread
!= nullptr)
1550 /* Return true if thread represented by PTID is doing a displaced
1554 displaced_step_in_progress_thread (thread_info
*thread
)
1556 struct displaced_step_inferior_state
*displaced
;
1558 gdb_assert (thread
!= NULL
);
1560 displaced
= get_displaced_stepping_state (thread
->inf
);
1562 return (displaced
!= NULL
&& displaced
->step_thread
== thread
);
1565 /* Return true if process PID has a thread doing a displaced step. */
1568 displaced_step_in_progress (inferior
*inf
)
1570 struct displaced_step_inferior_state
*displaced
;
1572 displaced
= get_displaced_stepping_state (inf
);
1573 if (displaced
!= NULL
&& displaced
->step_thread
!= nullptr)
1579 /* Add a new displaced stepping state for process PID to the displaced
1580 stepping state list, or return a pointer to an already existing
1581 entry, if it already exists. Never returns NULL. */
1583 static struct displaced_step_inferior_state
*
1584 add_displaced_stepping_state (inferior
*inf
)
1586 struct displaced_step_inferior_state
*state
;
1588 for (state
= displaced_step_inferior_states
;
1590 state
= state
->next
)
1591 if (state
->inf
== inf
)
1594 state
= XCNEW (struct displaced_step_inferior_state
);
1596 state
->next
= displaced_step_inferior_states
;
1597 displaced_step_inferior_states
= state
;
1602 /* If inferior is in displaced stepping, and ADDR equals to starting address
1603 of copy area, return corresponding displaced_step_closure. Otherwise,
1606 struct displaced_step_closure
*
1607 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1609 struct displaced_step_inferior_state
*displaced
1610 = get_displaced_stepping_state (current_inferior ());
1612 /* If checking the mode of displaced instruction in copy area. */
1613 if (displaced
!= NULL
1614 && displaced
->step_thread
!= nullptr
1615 && displaced
->step_copy
== addr
)
1616 return displaced
->step_closure
;
1621 /* Remove the displaced stepping state of process PID. */
1624 remove_displaced_stepping_state (inferior
*inf
)
1626 struct displaced_step_inferior_state
*it
, **prev_next_p
;
1628 gdb_assert (inf
!= nullptr);
1630 it
= displaced_step_inferior_states
;
1631 prev_next_p
= &displaced_step_inferior_states
;
1636 *prev_next_p
= it
->next
;
1641 prev_next_p
= &it
->next
;
1647 infrun_inferior_exit (struct inferior
*inf
)
1649 remove_displaced_stepping_state (inf
);
1652 /* If ON, and the architecture supports it, GDB will use displaced
1653 stepping to step over breakpoints. If OFF, or if the architecture
1654 doesn't support it, GDB will instead use the traditional
1655 hold-and-step approach. If AUTO (which is the default), GDB will
1656 decide which technique to use to step over breakpoints depending on
1657 which of all-stop or non-stop mode is active --- displaced stepping
1658 in non-stop mode; hold-and-step in all-stop mode. */
1660 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1663 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1664 struct cmd_list_element
*c
,
1667 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1668 fprintf_filtered (file
,
1669 _("Debugger's willingness to use displaced stepping "
1670 "to step over breakpoints is %s (currently %s).\n"),
1671 value
, target_is_non_stop_p () ? "on" : "off");
1673 fprintf_filtered (file
,
1674 _("Debugger's willingness to use displaced stepping "
1675 "to step over breakpoints is %s.\n"), value
);
1678 /* Return non-zero if displaced stepping can/should be used to step
1679 over breakpoints of thread TP. */
1682 use_displaced_stepping (struct thread_info
*tp
)
1684 struct regcache
*regcache
= get_thread_regcache (tp
);
1685 struct gdbarch
*gdbarch
= regcache
->arch ();
1686 struct displaced_step_inferior_state
*displaced_state
;
1688 displaced_state
= get_displaced_stepping_state (tp
->inf
);
1690 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1691 && target_is_non_stop_p ())
1692 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1693 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1694 && find_record_target () == NULL
1695 && (displaced_state
== NULL
1696 || !displaced_state
->failed_before
));
1699 /* Clean out any stray displaced stepping state. */
1701 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1703 /* Indicate that there is no cleanup pending. */
1704 displaced
->step_thread
= nullptr;
1706 delete displaced
->step_closure
;
1707 displaced
->step_closure
= NULL
;
1711 displaced_step_clear_cleanup (void *arg
)
1713 struct displaced_step_inferior_state
*state
1714 = (struct displaced_step_inferior_state
*) arg
;
1716 displaced_step_clear (state
);
1719 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1721 displaced_step_dump_bytes (struct ui_file
*file
,
1722 const gdb_byte
*buf
,
1727 for (i
= 0; i
< len
; i
++)
1728 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1729 fputs_unfiltered ("\n", file
);
1732 /* Prepare to single-step, using displaced stepping.
1734 Note that we cannot use displaced stepping when we have a signal to
1735 deliver. If we have a signal to deliver and an instruction to step
1736 over, then after the step, there will be no indication from the
1737 target whether the thread entered a signal handler or ignored the
1738 signal and stepped over the instruction successfully --- both cases
1739 result in a simple SIGTRAP. In the first case we mustn't do a
1740 fixup, and in the second case we must --- but we can't tell which.
1741 Comments in the code for 'random signals' in handle_inferior_event
1742 explain how we handle this case instead.
1744 Returns 1 if preparing was successful -- this thread is going to be
1745 stepped now; 0 if displaced stepping this thread got queued; or -1
1746 if this instruction can't be displaced stepped. */
1749 displaced_step_prepare_throw (thread_info
*tp
)
1751 struct cleanup
*ignore_cleanups
;
1752 regcache
*regcache
= get_thread_regcache (tp
);
1753 struct gdbarch
*gdbarch
= regcache
->arch ();
1754 const address_space
*aspace
= regcache
->aspace ();
1755 CORE_ADDR original
, copy
;
1757 struct displaced_step_closure
*closure
;
1758 struct displaced_step_inferior_state
*displaced
;
1761 /* We should never reach this function if the architecture does not
1762 support displaced stepping. */
1763 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1765 /* Nor if the thread isn't meant to step over a breakpoint. */
1766 gdb_assert (tp
->control
.trap_expected
);
1768 /* Disable range stepping while executing in the scratch pad. We
1769 want a single-step even if executing the displaced instruction in
1770 the scratch buffer lands within the stepping range (e.g., a
1772 tp
->control
.may_range_step
= 0;
1774 /* We have to displaced step one thread at a time, as we only have
1775 access to a single scratch space per inferior. */
1777 displaced
= add_displaced_stepping_state (tp
->inf
);
1779 if (displaced
->step_thread
!= nullptr)
1781 /* Already waiting for a displaced step to finish. Defer this
1782 request and place in queue. */
1784 if (debug_displaced
)
1785 fprintf_unfiltered (gdb_stdlog
,
1786 "displaced: deferring step of %s\n",
1787 target_pid_to_str (tp
->ptid
));
1789 thread_step_over_chain_enqueue (tp
);
1794 if (debug_displaced
)
1795 fprintf_unfiltered (gdb_stdlog
,
1796 "displaced: stepping %s now\n",
1797 target_pid_to_str (tp
->ptid
));
1800 displaced_step_clear (displaced
);
1802 scoped_restore_current_thread restore_thread
;
1804 switch_to_thread (tp
);
1806 original
= regcache_read_pc (regcache
);
1808 copy
= gdbarch_displaced_step_location (gdbarch
);
1809 len
= gdbarch_max_insn_length (gdbarch
);
1811 if (breakpoint_in_range_p (aspace
, copy
, len
))
1813 /* There's a breakpoint set in the scratch pad location range
1814 (which is usually around the entry point). We'd either
1815 install it before resuming, which would overwrite/corrupt the
1816 scratch pad, or if it was already inserted, this displaced
1817 step would overwrite it. The latter is OK in the sense that
1818 we already assume that no thread is going to execute the code
1819 in the scratch pad range (after initial startup) anyway, but
1820 the former is unacceptable. Simply punt and fallback to
1821 stepping over this breakpoint in-line. */
1822 if (debug_displaced
)
1824 fprintf_unfiltered (gdb_stdlog
,
1825 "displaced: breakpoint set in scratch pad. "
1826 "Stepping over breakpoint in-line instead.\n");
1832 /* Save the original contents of the copy area. */
1833 displaced
->step_saved_copy
= (gdb_byte
*) xmalloc (len
);
1834 ignore_cleanups
= make_cleanup (free_current_contents
,
1835 &displaced
->step_saved_copy
);
1836 status
= target_read_memory (copy
, displaced
->step_saved_copy
, len
);
1838 throw_error (MEMORY_ERROR
,
1839 _("Error accessing memory address %s (%s) for "
1840 "displaced-stepping scratch space."),
1841 paddress (gdbarch
, copy
), safe_strerror (status
));
1842 if (debug_displaced
)
1844 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1845 paddress (gdbarch
, copy
));
1846 displaced_step_dump_bytes (gdb_stdlog
,
1847 displaced
->step_saved_copy
,
1851 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1852 original
, copy
, regcache
);
1853 if (closure
== NULL
)
1855 /* The architecture doesn't know how or want to displaced step
1856 this instruction or instruction sequence. Fallback to
1857 stepping over the breakpoint in-line. */
1858 do_cleanups (ignore_cleanups
);
1862 /* Save the information we need to fix things up if the step
1864 displaced
->step_thread
= tp
;
1865 displaced
->step_gdbarch
= gdbarch
;
1866 displaced
->step_closure
= closure
;
1867 displaced
->step_original
= original
;
1868 displaced
->step_copy
= copy
;
1870 make_cleanup (displaced_step_clear_cleanup
, displaced
);
1872 /* Resume execution at the copy. */
1873 regcache_write_pc (regcache
, copy
);
1875 discard_cleanups (ignore_cleanups
);
1877 if (debug_displaced
)
1878 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1879 paddress (gdbarch
, copy
));
1884 /* Wrapper for displaced_step_prepare_throw that disabled further
1885 attempts at displaced stepping if we get a memory error. */
1888 displaced_step_prepare (thread_info
*thread
)
1894 prepared
= displaced_step_prepare_throw (thread
);
1896 CATCH (ex
, RETURN_MASK_ERROR
)
1898 struct displaced_step_inferior_state
*displaced_state
;
1900 if (ex
.error
!= MEMORY_ERROR
1901 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1902 throw_exception (ex
);
1906 fprintf_unfiltered (gdb_stdlog
,
1907 "infrun: disabling displaced stepping: %s\n",
1911 /* Be verbose if "set displaced-stepping" is "on", silent if
1913 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1915 warning (_("disabling displaced stepping: %s"),
1919 /* Disable further displaced stepping attempts. */
1921 = get_displaced_stepping_state (thread
->inf
);
1922 displaced_state
->failed_before
= 1;
1930 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1931 const gdb_byte
*myaddr
, int len
)
1933 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1935 inferior_ptid
= ptid
;
1936 write_memory (memaddr
, myaddr
, len
);
1939 /* Restore the contents of the copy area for thread PTID. */
1942 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1945 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1947 write_memory_ptid (ptid
, displaced
->step_copy
,
1948 displaced
->step_saved_copy
, len
);
1949 if (debug_displaced
)
1950 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1951 target_pid_to_str (ptid
),
1952 paddress (displaced
->step_gdbarch
,
1953 displaced
->step_copy
));
1956 /* If we displaced stepped an instruction successfully, adjust
1957 registers and memory to yield the same effect the instruction would
1958 have had if we had executed it at its original address, and return
1959 1. If the instruction didn't complete, relocate the PC and return
1960 -1. If the thread wasn't displaced stepping, return 0. */
1963 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1965 struct cleanup
*old_cleanups
;
1966 struct displaced_step_inferior_state
*displaced
1967 = get_displaced_stepping_state (event_thread
->inf
);
1970 /* Was any thread of this process doing a displaced step? */
1971 if (displaced
== NULL
)
1974 /* Was this event for the thread we displaced? */
1975 if (displaced
->step_thread
!= event_thread
)
1978 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, displaced
);
1980 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1982 /* Fixup may need to read memory/registers. Switch to the thread
1983 that we're fixing up. Also, target_stopped_by_watchpoint checks
1984 the current thread. */
1985 switch_to_thread (event_thread
);
1987 /* Did the instruction complete successfully? */
1988 if (signal
== GDB_SIGNAL_TRAP
1989 && !(target_stopped_by_watchpoint ()
1990 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1991 || target_have_steppable_watchpoint
)))
1993 /* Fix up the resulting state. */
1994 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1995 displaced
->step_closure
,
1996 displaced
->step_original
,
1997 displaced
->step_copy
,
1998 get_thread_regcache (displaced
->step_thread
));
2003 /* Since the instruction didn't complete, all we can do is
2005 struct regcache
*regcache
= get_thread_regcache (event_thread
);
2006 CORE_ADDR pc
= regcache_read_pc (regcache
);
2008 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
2009 regcache_write_pc (regcache
, pc
);
2013 do_cleanups (old_cleanups
);
2015 displaced
->step_thread
= nullptr;
2020 /* Data to be passed around while handling an event. This data is
2021 discarded between events. */
2022 struct execution_control_state
2025 /* The thread that got the event, if this was a thread event; NULL
2027 struct thread_info
*event_thread
;
2029 struct target_waitstatus ws
;
2030 int stop_func_filled_in
;
2031 CORE_ADDR stop_func_start
;
2032 CORE_ADDR stop_func_end
;
2033 const char *stop_func_name
;
2036 /* True if the event thread hit the single-step breakpoint of
2037 another thread. Thus the event doesn't cause a stop, the thread
2038 needs to be single-stepped past the single-step breakpoint before
2039 we can switch back to the original stepping thread. */
2040 int hit_singlestep_breakpoint
;
2043 /* Clear ECS and set it to point at TP. */
2046 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
2048 memset (ecs
, 0, sizeof (*ecs
));
2049 ecs
->event_thread
= tp
;
2050 ecs
->ptid
= tp
->ptid
;
2053 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
2054 static void prepare_to_wait (struct execution_control_state
*ecs
);
2055 static int keep_going_stepped_thread (struct thread_info
*tp
);
2056 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
2058 /* Are there any pending step-over requests? If so, run all we can
2059 now and return true. Otherwise, return false. */
2062 start_step_over (void)
2064 struct thread_info
*tp
, *next
;
2066 /* Don't start a new step-over if we already have an in-line
2067 step-over operation ongoing. */
2068 if (step_over_info_valid_p ())
2071 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
2073 struct execution_control_state ecss
;
2074 struct execution_control_state
*ecs
= &ecss
;
2075 step_over_what step_what
;
2076 int must_be_in_line
;
2078 gdb_assert (!tp
->stop_requested
);
2080 next
= thread_step_over_chain_next (tp
);
2082 /* If this inferior already has a displaced step in process,
2083 don't start a new one. */
2084 if (displaced_step_in_progress (tp
->inf
))
2087 step_what
= thread_still_needs_step_over (tp
);
2088 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
2089 || ((step_what
& STEP_OVER_BREAKPOINT
)
2090 && !use_displaced_stepping (tp
)));
2092 /* We currently stop all threads of all processes to step-over
2093 in-line. If we need to start a new in-line step-over, let
2094 any pending displaced steps finish first. */
2095 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2098 thread_step_over_chain_remove (tp
);
2100 if (step_over_queue_head
== NULL
)
2103 fprintf_unfiltered (gdb_stdlog
,
2104 "infrun: step-over queue now empty\n");
2107 if (tp
->control
.trap_expected
2111 internal_error (__FILE__
, __LINE__
,
2112 "[%s] has inconsistent state: "
2113 "trap_expected=%d, resumed=%d, executing=%d\n",
2114 target_pid_to_str (tp
->ptid
),
2115 tp
->control
.trap_expected
,
2121 fprintf_unfiltered (gdb_stdlog
,
2122 "infrun: resuming [%s] for step-over\n",
2123 target_pid_to_str (tp
->ptid
));
2125 /* keep_going_pass_signal skips the step-over if the breakpoint
2126 is no longer inserted. In all-stop, we want to keep looking
2127 for a thread that needs a step-over instead of resuming TP,
2128 because we wouldn't be able to resume anything else until the
2129 target stops again. In non-stop, the resume always resumes
2130 only TP, so it's OK to let the thread resume freely. */
2131 if (!target_is_non_stop_p () && !step_what
)
2134 switch_to_thread (tp
);
2135 reset_ecs (ecs
, tp
);
2136 keep_going_pass_signal (ecs
);
2138 if (!ecs
->wait_some_more
)
2139 error (_("Command aborted."));
2141 gdb_assert (tp
->resumed
);
2143 /* If we started a new in-line step-over, we're done. */
2144 if (step_over_info_valid_p ())
2146 gdb_assert (tp
->control
.trap_expected
);
2150 if (!target_is_non_stop_p ())
2152 /* On all-stop, shouldn't have resumed unless we needed a
2154 gdb_assert (tp
->control
.trap_expected
2155 || tp
->step_after_step_resume_breakpoint
);
2157 /* With remote targets (at least), in all-stop, we can't
2158 issue any further remote commands until the program stops
2163 /* Either the thread no longer needed a step-over, or a new
2164 displaced stepping sequence started. Even in the latter
2165 case, continue looking. Maybe we can also start another
2166 displaced step on a thread of other process. */
2172 /* Update global variables holding ptids to hold NEW_PTID if they were
2173 holding OLD_PTID. */
2175 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2177 if (inferior_ptid
== old_ptid
)
2178 inferior_ptid
= new_ptid
;
2183 static const char schedlock_off
[] = "off";
2184 static const char schedlock_on
[] = "on";
2185 static const char schedlock_step
[] = "step";
2186 static const char schedlock_replay
[] = "replay";
2187 static const char *const scheduler_enums
[] = {
2194 static const char *scheduler_mode
= schedlock_replay
;
2196 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2197 struct cmd_list_element
*c
, const char *value
)
2199 fprintf_filtered (file
,
2200 _("Mode for locking scheduler "
2201 "during execution is \"%s\".\n"),
2206 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2208 if (!target_can_lock_scheduler
)
2210 scheduler_mode
= schedlock_off
;
2211 error (_("Target '%s' cannot support this command."), target_shortname
);
2215 /* True if execution commands resume all threads of all processes by
2216 default; otherwise, resume only threads of the current inferior
2218 int sched_multi
= 0;
2220 /* Try to setup for software single stepping over the specified location.
2221 Return 1 if target_resume() should use hardware single step.
2223 GDBARCH the current gdbarch.
2224 PC the location to step over. */
2227 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2231 if (execution_direction
== EXEC_FORWARD
2232 && gdbarch_software_single_step_p (gdbarch
))
2233 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2241 user_visible_resume_ptid (int step
)
2247 /* With non-stop mode on, threads are always handled
2249 resume_ptid
= inferior_ptid
;
2251 else if ((scheduler_mode
== schedlock_on
)
2252 || (scheduler_mode
== schedlock_step
&& step
))
2254 /* User-settable 'scheduler' mode requires solo thread
2256 resume_ptid
= inferior_ptid
;
2258 else if ((scheduler_mode
== schedlock_replay
)
2259 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2261 /* User-settable 'scheduler' mode requires solo thread resume in replay
2263 resume_ptid
= inferior_ptid
;
2265 else if (!sched_multi
&& target_supports_multi_process ())
2267 /* Resume all threads of the current process (and none of other
2269 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2273 /* Resume all threads of all processes. */
2274 resume_ptid
= RESUME_ALL
;
2280 /* Return a ptid representing the set of threads that we will resume,
2281 in the perspective of the target, assuming run control handling
2282 does not require leaving some threads stopped (e.g., stepping past
2283 breakpoint). USER_STEP indicates whether we're about to start the
2284 target for a stepping command. */
2287 internal_resume_ptid (int user_step
)
2289 /* In non-stop, we always control threads individually. Note that
2290 the target may always work in non-stop mode even with "set
2291 non-stop off", in which case user_visible_resume_ptid could
2292 return a wildcard ptid. */
2293 if (target_is_non_stop_p ())
2294 return inferior_ptid
;
2296 return user_visible_resume_ptid (user_step
);
2299 /* Wrapper for target_resume, that handles infrun-specific
2303 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2305 struct thread_info
*tp
= inferior_thread ();
2307 gdb_assert (!tp
->stop_requested
);
2309 /* Install inferior's terminal modes. */
2310 target_terminal::inferior ();
2312 /* Avoid confusing the next resume, if the next stop/resume
2313 happens to apply to another thread. */
2314 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2316 /* Advise target which signals may be handled silently.
2318 If we have removed breakpoints because we are stepping over one
2319 in-line (in any thread), we need to receive all signals to avoid
2320 accidentally skipping a breakpoint during execution of a signal
2323 Likewise if we're displaced stepping, otherwise a trap for a
2324 breakpoint in a signal handler might be confused with the
2325 displaced step finishing. We don't make the displaced_step_fixup
2326 step distinguish the cases instead, because:
2328 - a backtrace while stopped in the signal handler would show the
2329 scratch pad as frame older than the signal handler, instead of
2330 the real mainline code.
2332 - when the thread is later resumed, the signal handler would
2333 return to the scratch pad area, which would no longer be
2335 if (step_over_info_valid_p ()
2336 || displaced_step_in_progress (tp
->inf
))
2337 target_pass_signals (0, NULL
);
2339 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
2341 target_resume (resume_ptid
, step
, sig
);
2343 target_commit_resume ();
2346 /* Resume the inferior. SIG is the signal to give the inferior
2347 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2348 call 'resume', which handles exceptions. */
2351 resume_1 (enum gdb_signal sig
)
2353 struct regcache
*regcache
= get_current_regcache ();
2354 struct gdbarch
*gdbarch
= regcache
->arch ();
2355 struct thread_info
*tp
= inferior_thread ();
2356 CORE_ADDR pc
= regcache_read_pc (regcache
);
2357 const address_space
*aspace
= regcache
->aspace ();
2359 /* This represents the user's step vs continue request. When
2360 deciding whether "set scheduler-locking step" applies, it's the
2361 user's intention that counts. */
2362 const int user_step
= tp
->control
.stepping_command
;
2363 /* This represents what we'll actually request the target to do.
2364 This can decay from a step to a continue, if e.g., we need to
2365 implement single-stepping with breakpoints (software
2369 gdb_assert (!tp
->stop_requested
);
2370 gdb_assert (!thread_is_in_step_over_chain (tp
));
2372 if (tp
->suspend
.waitstatus_pending_p
)
2377 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2379 fprintf_unfiltered (gdb_stdlog
,
2380 "infrun: resume: thread %s has pending wait "
2381 "status %s (currently_stepping=%d).\n",
2382 target_pid_to_str (tp
->ptid
), statstr
.c_str (),
2383 currently_stepping (tp
));
2388 /* FIXME: What should we do if we are supposed to resume this
2389 thread with a signal? Maybe we should maintain a queue of
2390 pending signals to deliver. */
2391 if (sig
!= GDB_SIGNAL_0
)
2393 warning (_("Couldn't deliver signal %s to %s."),
2394 gdb_signal_to_name (sig
), target_pid_to_str (tp
->ptid
));
2397 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2399 if (target_can_async_p ())
2402 /* Tell the event loop we have an event to process. */
2403 mark_async_event_handler (infrun_async_inferior_event_token
);
2408 tp
->stepped_breakpoint
= 0;
2410 /* Depends on stepped_breakpoint. */
2411 step
= currently_stepping (tp
);
2413 if (current_inferior ()->waiting_for_vfork_done
)
2415 /* Don't try to single-step a vfork parent that is waiting for
2416 the child to get out of the shared memory region (by exec'ing
2417 or exiting). This is particularly important on software
2418 single-step archs, as the child process would trip on the
2419 software single step breakpoint inserted for the parent
2420 process. Since the parent will not actually execute any
2421 instruction until the child is out of the shared region (such
2422 are vfork's semantics), it is safe to simply continue it.
2423 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2424 the parent, and tell it to `keep_going', which automatically
2425 re-sets it stepping. */
2427 fprintf_unfiltered (gdb_stdlog
,
2428 "infrun: resume : clear step\n");
2433 fprintf_unfiltered (gdb_stdlog
,
2434 "infrun: resume (step=%d, signal=%s), "
2435 "trap_expected=%d, current thread [%s] at %s\n",
2436 step
, gdb_signal_to_symbol_string (sig
),
2437 tp
->control
.trap_expected
,
2438 target_pid_to_str (inferior_ptid
),
2439 paddress (gdbarch
, pc
));
2441 /* Normally, by the time we reach `resume', the breakpoints are either
2442 removed or inserted, as appropriate. The exception is if we're sitting
2443 at a permanent breakpoint; we need to step over it, but permanent
2444 breakpoints can't be removed. So we have to test for it here. */
2445 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2447 if (sig
!= GDB_SIGNAL_0
)
2449 /* We have a signal to pass to the inferior. The resume
2450 may, or may not take us to the signal handler. If this
2451 is a step, we'll need to stop in the signal handler, if
2452 there's one, (if the target supports stepping into
2453 handlers), or in the next mainline instruction, if
2454 there's no handler. If this is a continue, we need to be
2455 sure to run the handler with all breakpoints inserted.
2456 In all cases, set a breakpoint at the current address
2457 (where the handler returns to), and once that breakpoint
2458 is hit, resume skipping the permanent breakpoint. If
2459 that breakpoint isn't hit, then we've stepped into the
2460 signal handler (or hit some other event). We'll delete
2461 the step-resume breakpoint then. */
2464 fprintf_unfiltered (gdb_stdlog
,
2465 "infrun: resume: skipping permanent breakpoint, "
2466 "deliver signal first\n");
2468 clear_step_over_info ();
2469 tp
->control
.trap_expected
= 0;
2471 if (tp
->control
.step_resume_breakpoint
== NULL
)
2473 /* Set a "high-priority" step-resume, as we don't want
2474 user breakpoints at PC to trigger (again) when this
2476 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2477 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2479 tp
->step_after_step_resume_breakpoint
= step
;
2482 insert_breakpoints ();
2486 /* There's no signal to pass, we can go ahead and skip the
2487 permanent breakpoint manually. */
2489 fprintf_unfiltered (gdb_stdlog
,
2490 "infrun: resume: skipping permanent breakpoint\n");
2491 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2492 /* Update pc to reflect the new address from which we will
2493 execute instructions. */
2494 pc
= regcache_read_pc (regcache
);
2498 /* We've already advanced the PC, so the stepping part
2499 is done. Now we need to arrange for a trap to be
2500 reported to handle_inferior_event. Set a breakpoint
2501 at the current PC, and run to it. Don't update
2502 prev_pc, because if we end in
2503 switch_back_to_stepped_thread, we want the "expected
2504 thread advanced also" branch to be taken. IOW, we
2505 don't want this thread to step further from PC
2507 gdb_assert (!step_over_info_valid_p ());
2508 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2509 insert_breakpoints ();
2511 resume_ptid
= internal_resume_ptid (user_step
);
2512 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2519 /* If we have a breakpoint to step over, make sure to do a single
2520 step only. Same if we have software watchpoints. */
2521 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2522 tp
->control
.may_range_step
= 0;
2524 /* If enabled, step over breakpoints by executing a copy of the
2525 instruction at a different address.
2527 We can't use displaced stepping when we have a signal to deliver;
2528 the comments for displaced_step_prepare explain why. The
2529 comments in the handle_inferior event for dealing with 'random
2530 signals' explain what we do instead.
2532 We can't use displaced stepping when we are waiting for vfork_done
2533 event, displaced stepping breaks the vfork child similarly as single
2534 step software breakpoint. */
2535 if (tp
->control
.trap_expected
2536 && use_displaced_stepping (tp
)
2537 && !step_over_info_valid_p ()
2538 && sig
== GDB_SIGNAL_0
2539 && !current_inferior ()->waiting_for_vfork_done
)
2541 int prepared
= displaced_step_prepare (tp
);
2546 fprintf_unfiltered (gdb_stdlog
,
2547 "Got placed in step-over queue\n");
2549 tp
->control
.trap_expected
= 0;
2552 else if (prepared
< 0)
2554 /* Fallback to stepping over the breakpoint in-line. */
2556 if (target_is_non_stop_p ())
2557 stop_all_threads ();
2559 set_step_over_info (regcache
->aspace (),
2560 regcache_read_pc (regcache
), 0, tp
->global_num
);
2562 step
= maybe_software_singlestep (gdbarch
, pc
);
2564 insert_breakpoints ();
2566 else if (prepared
> 0)
2568 struct displaced_step_inferior_state
*displaced
;
2570 /* Update pc to reflect the new address from which we will
2571 execute instructions due to displaced stepping. */
2572 pc
= regcache_read_pc (get_thread_regcache (tp
));
2574 displaced
= get_displaced_stepping_state (tp
->inf
);
2575 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2576 displaced
->step_closure
);
2580 /* Do we need to do it the hard way, w/temp breakpoints? */
2582 step
= maybe_software_singlestep (gdbarch
, pc
);
2584 /* Currently, our software single-step implementation leads to different
2585 results than hardware single-stepping in one situation: when stepping
2586 into delivering a signal which has an associated signal handler,
2587 hardware single-step will stop at the first instruction of the handler,
2588 while software single-step will simply skip execution of the handler.
2590 For now, this difference in behavior is accepted since there is no
2591 easy way to actually implement single-stepping into a signal handler
2592 without kernel support.
2594 However, there is one scenario where this difference leads to follow-on
2595 problems: if we're stepping off a breakpoint by removing all breakpoints
2596 and then single-stepping. In this case, the software single-step
2597 behavior means that even if there is a *breakpoint* in the signal
2598 handler, GDB still would not stop.
2600 Fortunately, we can at least fix this particular issue. We detect
2601 here the case where we are about to deliver a signal while software
2602 single-stepping with breakpoints removed. In this situation, we
2603 revert the decisions to remove all breakpoints and insert single-
2604 step breakpoints, and instead we install a step-resume breakpoint
2605 at the current address, deliver the signal without stepping, and
2606 once we arrive back at the step-resume breakpoint, actually step
2607 over the breakpoint we originally wanted to step over. */
2608 if (thread_has_single_step_breakpoints_set (tp
)
2609 && sig
!= GDB_SIGNAL_0
2610 && step_over_info_valid_p ())
2612 /* If we have nested signals or a pending signal is delivered
2613 immediately after a handler returns, might might already have
2614 a step-resume breakpoint set on the earlier handler. We cannot
2615 set another step-resume breakpoint; just continue on until the
2616 original breakpoint is hit. */
2617 if (tp
->control
.step_resume_breakpoint
== NULL
)
2619 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2620 tp
->step_after_step_resume_breakpoint
= 1;
2623 delete_single_step_breakpoints (tp
);
2625 clear_step_over_info ();
2626 tp
->control
.trap_expected
= 0;
2628 insert_breakpoints ();
2631 /* If STEP is set, it's a request to use hardware stepping
2632 facilities. But in that case, we should never
2633 use singlestep breakpoint. */
2634 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2636 /* Decide the set of threads to ask the target to resume. */
2637 if (tp
->control
.trap_expected
)
2639 /* We're allowing a thread to run past a breakpoint it has
2640 hit, either by single-stepping the thread with the breakpoint
2641 removed, or by displaced stepping, with the breakpoint inserted.
2642 In the former case, we need to single-step only this thread,
2643 and keep others stopped, as they can miss this breakpoint if
2644 allowed to run. That's not really a problem for displaced
2645 stepping, but, we still keep other threads stopped, in case
2646 another thread is also stopped for a breakpoint waiting for
2647 its turn in the displaced stepping queue. */
2648 resume_ptid
= inferior_ptid
;
2651 resume_ptid
= internal_resume_ptid (user_step
);
2653 if (execution_direction
!= EXEC_REVERSE
2654 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2656 /* There are two cases where we currently need to step a
2657 breakpoint instruction when we have a signal to deliver:
2659 - See handle_signal_stop where we handle random signals that
2660 could take out us out of the stepping range. Normally, in
2661 that case we end up continuing (instead of stepping) over the
2662 signal handler with a breakpoint at PC, but there are cases
2663 where we should _always_ single-step, even if we have a
2664 step-resume breakpoint, like when a software watchpoint is
2665 set. Assuming single-stepping and delivering a signal at the
2666 same time would takes us to the signal handler, then we could
2667 have removed the breakpoint at PC to step over it. However,
2668 some hardware step targets (like e.g., Mac OS) can't step
2669 into signal handlers, and for those, we need to leave the
2670 breakpoint at PC inserted, as otherwise if the handler
2671 recurses and executes PC again, it'll miss the breakpoint.
2672 So we leave the breakpoint inserted anyway, but we need to
2673 record that we tried to step a breakpoint instruction, so
2674 that adjust_pc_after_break doesn't end up confused.
2676 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2677 in one thread after another thread that was stepping had been
2678 momentarily paused for a step-over. When we re-resume the
2679 stepping thread, it may be resumed from that address with a
2680 breakpoint that hasn't trapped yet. Seen with
2681 gdb.threads/non-stop-fair-events.exp, on targets that don't
2682 do displaced stepping. */
2685 fprintf_unfiltered (gdb_stdlog
,
2686 "infrun: resume: [%s] stepped breakpoint\n",
2687 target_pid_to_str (tp
->ptid
));
2689 tp
->stepped_breakpoint
= 1;
2691 /* Most targets can step a breakpoint instruction, thus
2692 executing it normally. But if this one cannot, just
2693 continue and we will hit it anyway. */
2694 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2699 && tp
->control
.trap_expected
2700 && use_displaced_stepping (tp
)
2701 && !step_over_info_valid_p ())
2703 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2704 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2705 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2708 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2709 paddress (resume_gdbarch
, actual_pc
));
2710 read_memory (actual_pc
, buf
, sizeof (buf
));
2711 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2714 if (tp
->control
.may_range_step
)
2716 /* If we're resuming a thread with the PC out of the step
2717 range, then we're doing some nested/finer run control
2718 operation, like stepping the thread out of the dynamic
2719 linker or the displaced stepping scratch pad. We
2720 shouldn't have allowed a range step then. */
2721 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2724 do_target_resume (resume_ptid
, step
, sig
);
2728 /* Resume the inferior. SIG is the signal to give the inferior
2729 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2730 rolls back state on error. */
2733 resume (gdb_signal sig
)
2739 CATCH (ex
, RETURN_MASK_ALL
)
2741 /* If resuming is being aborted for any reason, delete any
2742 single-step breakpoint resume_1 may have created, to avoid
2743 confusing the following resumption, and to avoid leaving
2744 single-step breakpoints perturbing other threads, in case
2745 we're running in non-stop mode. */
2746 if (inferior_ptid
!= null_ptid
)
2747 delete_single_step_breakpoints (inferior_thread ());
2748 throw_exception (ex
);
2758 /* Counter that tracks number of user visible stops. This can be used
2759 to tell whether a command has proceeded the inferior past the
2760 current location. This allows e.g., inferior function calls in
2761 breakpoint commands to not interrupt the command list. When the
2762 call finishes successfully, the inferior is standing at the same
2763 breakpoint as if nothing happened (and so we don't call
2765 static ULONGEST current_stop_id
;
2772 return current_stop_id
;
2775 /* Called when we report a user visible stop. */
2783 /* Clear out all variables saying what to do when inferior is continued.
2784 First do this, then set the ones you want, then call `proceed'. */
2787 clear_proceed_status_thread (struct thread_info
*tp
)
2790 fprintf_unfiltered (gdb_stdlog
,
2791 "infrun: clear_proceed_status_thread (%s)\n",
2792 target_pid_to_str (tp
->ptid
));
2794 /* If we're starting a new sequence, then the previous finished
2795 single-step is no longer relevant. */
2796 if (tp
->suspend
.waitstatus_pending_p
)
2798 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2801 fprintf_unfiltered (gdb_stdlog
,
2802 "infrun: clear_proceed_status: pending "
2803 "event of %s was a finished step. "
2805 target_pid_to_str (tp
->ptid
));
2807 tp
->suspend
.waitstatus_pending_p
= 0;
2808 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2810 else if (debug_infrun
)
2813 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2815 fprintf_unfiltered (gdb_stdlog
,
2816 "infrun: clear_proceed_status_thread: thread %s "
2817 "has pending wait status %s "
2818 "(currently_stepping=%d).\n",
2819 target_pid_to_str (tp
->ptid
), statstr
.c_str (),
2820 currently_stepping (tp
));
2824 /* If this signal should not be seen by program, give it zero.
2825 Used for debugging signals. */
2826 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2827 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2829 thread_fsm_delete (tp
->thread_fsm
);
2830 tp
->thread_fsm
= NULL
;
2832 tp
->control
.trap_expected
= 0;
2833 tp
->control
.step_range_start
= 0;
2834 tp
->control
.step_range_end
= 0;
2835 tp
->control
.may_range_step
= 0;
2836 tp
->control
.step_frame_id
= null_frame_id
;
2837 tp
->control
.step_stack_frame_id
= null_frame_id
;
2838 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2839 tp
->control
.step_start_function
= NULL
;
2840 tp
->stop_requested
= 0;
2842 tp
->control
.stop_step
= 0;
2844 tp
->control
.proceed_to_finish
= 0;
2846 tp
->control
.stepping_command
= 0;
2848 /* Discard any remaining commands or status from previous stop. */
2849 bpstat_clear (&tp
->control
.stop_bpstat
);
2853 clear_proceed_status (int step
)
2855 /* With scheduler-locking replay, stop replaying other threads if we're
2856 not replaying the user-visible resume ptid.
2858 This is a convenience feature to not require the user to explicitly
2859 stop replaying the other threads. We're assuming that the user's
2860 intent is to resume tracing the recorded process. */
2861 if (!non_stop
&& scheduler_mode
== schedlock_replay
2862 && target_record_is_replaying (minus_one_ptid
)
2863 && !target_record_will_replay (user_visible_resume_ptid (step
),
2864 execution_direction
))
2865 target_record_stop_replaying ();
2869 struct thread_info
*tp
;
2872 resume_ptid
= user_visible_resume_ptid (step
);
2874 /* In all-stop mode, delete the per-thread status of all threads
2875 we're about to resume, implicitly and explicitly. */
2876 ALL_NON_EXITED_THREADS (tp
)
2878 if (!tp
->ptid
.matches (resume_ptid
))
2880 clear_proceed_status_thread (tp
);
2884 if (inferior_ptid
!= null_ptid
)
2886 struct inferior
*inferior
;
2890 /* If in non-stop mode, only delete the per-thread status of
2891 the current thread. */
2892 clear_proceed_status_thread (inferior_thread ());
2895 inferior
= current_inferior ();
2896 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2899 gdb::observers::about_to_proceed
.notify ();
2902 /* Returns true if TP is still stopped at a breakpoint that needs
2903 stepping-over in order to make progress. If the breakpoint is gone
2904 meanwhile, we can skip the whole step-over dance. */
2907 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2909 if (tp
->stepping_over_breakpoint
)
2911 struct regcache
*regcache
= get_thread_regcache (tp
);
2913 if (breakpoint_here_p (regcache
->aspace (),
2914 regcache_read_pc (regcache
))
2915 == ordinary_breakpoint_here
)
2918 tp
->stepping_over_breakpoint
= 0;
2924 /* Check whether thread TP still needs to start a step-over in order
2925 to make progress when resumed. Returns an bitwise or of enum
2926 step_over_what bits, indicating what needs to be stepped over. */
2928 static step_over_what
2929 thread_still_needs_step_over (struct thread_info
*tp
)
2931 step_over_what what
= 0;
2933 if (thread_still_needs_step_over_bp (tp
))
2934 what
|= STEP_OVER_BREAKPOINT
;
2936 if (tp
->stepping_over_watchpoint
2937 && !target_have_steppable_watchpoint
)
2938 what
|= STEP_OVER_WATCHPOINT
;
2943 /* Returns true if scheduler locking applies. STEP indicates whether
2944 we're about to do a step/next-like command to a thread. */
2947 schedlock_applies (struct thread_info
*tp
)
2949 return (scheduler_mode
== schedlock_on
2950 || (scheduler_mode
== schedlock_step
2951 && tp
->control
.stepping_command
)
2952 || (scheduler_mode
== schedlock_replay
2953 && target_record_will_replay (minus_one_ptid
,
2954 execution_direction
)));
2957 /* Basic routine for continuing the program in various fashions.
2959 ADDR is the address to resume at, or -1 for resume where stopped.
2960 SIGGNAL is the signal to give it, or 0 for none,
2961 or -1 for act according to how it stopped.
2962 STEP is nonzero if should trap after one instruction.
2963 -1 means return after that and print nothing.
2964 You should probably set various step_... variables
2965 before calling here, if you are stepping.
2967 You should call clear_proceed_status before calling proceed. */
2970 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2972 struct regcache
*regcache
;
2973 struct gdbarch
*gdbarch
;
2974 struct thread_info
*tp
;
2977 struct execution_control_state ecss
;
2978 struct execution_control_state
*ecs
= &ecss
;
2981 /* If we're stopped at a fork/vfork, follow the branch set by the
2982 "set follow-fork-mode" command; otherwise, we'll just proceed
2983 resuming the current thread. */
2984 if (!follow_fork ())
2986 /* The target for some reason decided not to resume. */
2988 if (target_can_async_p ())
2989 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2993 /* We'll update this if & when we switch to a new thread. */
2994 previous_inferior_ptid
= inferior_ptid
;
2996 regcache
= get_current_regcache ();
2997 gdbarch
= regcache
->arch ();
2998 const address_space
*aspace
= regcache
->aspace ();
3000 pc
= regcache_read_pc (regcache
);
3001 tp
= inferior_thread ();
3003 /* Fill in with reasonable starting values. */
3004 init_thread_stepping_state (tp
);
3006 gdb_assert (!thread_is_in_step_over_chain (tp
));
3008 if (addr
== (CORE_ADDR
) -1)
3010 if (pc
== tp
->suspend
.stop_pc
3011 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3012 && execution_direction
!= EXEC_REVERSE
)
3013 /* There is a breakpoint at the address we will resume at,
3014 step one instruction before inserting breakpoints so that
3015 we do not stop right away (and report a second hit at this
3018 Note, we don't do this in reverse, because we won't
3019 actually be executing the breakpoint insn anyway.
3020 We'll be (un-)executing the previous instruction. */
3021 tp
->stepping_over_breakpoint
= 1;
3022 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3023 && gdbarch_single_step_through_delay (gdbarch
,
3024 get_current_frame ()))
3025 /* We stepped onto an instruction that needs to be stepped
3026 again before re-inserting the breakpoint, do so. */
3027 tp
->stepping_over_breakpoint
= 1;
3031 regcache_write_pc (regcache
, addr
);
3034 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3035 tp
->suspend
.stop_signal
= siggnal
;
3037 resume_ptid
= user_visible_resume_ptid (tp
->control
.stepping_command
);
3039 /* If an exception is thrown from this point on, make sure to
3040 propagate GDB's knowledge of the executing state to the
3041 frontend/user running state. */
3042 scoped_finish_thread_state
finish_state (resume_ptid
);
3044 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3045 threads (e.g., we might need to set threads stepping over
3046 breakpoints first), from the user/frontend's point of view, all
3047 threads in RESUME_PTID are now running. Unless we're calling an
3048 inferior function, as in that case we pretend the inferior
3049 doesn't run at all. */
3050 if (!tp
->control
.in_infcall
)
3051 set_running (resume_ptid
, 1);
3054 fprintf_unfiltered (gdb_stdlog
,
3055 "infrun: proceed (addr=%s, signal=%s)\n",
3056 paddress (gdbarch
, addr
),
3057 gdb_signal_to_symbol_string (siggnal
));
3059 annotate_starting ();
3061 /* Make sure that output from GDB appears before output from the
3063 gdb_flush (gdb_stdout
);
3065 /* Since we've marked the inferior running, give it the terminal. A
3066 QUIT/Ctrl-C from here on is forwarded to the target (which can
3067 still detect attempts to unblock a stuck connection with repeated
3068 Ctrl-C from within target_pass_ctrlc). */
3069 target_terminal::inferior ();
3071 /* In a multi-threaded task we may select another thread and
3072 then continue or step.
3074 But if a thread that we're resuming had stopped at a breakpoint,
3075 it will immediately cause another breakpoint stop without any
3076 execution (i.e. it will report a breakpoint hit incorrectly). So
3077 we must step over it first.
3079 Look for threads other than the current (TP) that reported a
3080 breakpoint hit and haven't been resumed yet since. */
3082 /* If scheduler locking applies, we can avoid iterating over all
3084 if (!non_stop
&& !schedlock_applies (tp
))
3086 struct thread_info
*current
= tp
;
3088 ALL_NON_EXITED_THREADS (tp
)
3090 /* Ignore the current thread here. It's handled
3095 /* Ignore threads of processes we're not resuming. */
3096 if (!tp
->ptid
.matches (resume_ptid
))
3099 if (!thread_still_needs_step_over (tp
))
3102 gdb_assert (!thread_is_in_step_over_chain (tp
));
3105 fprintf_unfiltered (gdb_stdlog
,
3106 "infrun: need to step-over [%s] first\n",
3107 target_pid_to_str (tp
->ptid
));
3109 thread_step_over_chain_enqueue (tp
);
3115 /* Enqueue the current thread last, so that we move all other
3116 threads over their breakpoints first. */
3117 if (tp
->stepping_over_breakpoint
)
3118 thread_step_over_chain_enqueue (tp
);
3120 /* If the thread isn't started, we'll still need to set its prev_pc,
3121 so that switch_back_to_stepped_thread knows the thread hasn't
3122 advanced. Must do this before resuming any thread, as in
3123 all-stop/remote, once we resume we can't send any other packet
3124 until the target stops again. */
3125 tp
->prev_pc
= regcache_read_pc (regcache
);
3128 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3130 started
= start_step_over ();
3132 if (step_over_info_valid_p ())
3134 /* Either this thread started a new in-line step over, or some
3135 other thread was already doing one. In either case, don't
3136 resume anything else until the step-over is finished. */
3138 else if (started
&& !target_is_non_stop_p ())
3140 /* A new displaced stepping sequence was started. In all-stop,
3141 we can't talk to the target anymore until it next stops. */
3143 else if (!non_stop
&& target_is_non_stop_p ())
3145 /* In all-stop, but the target is always in non-stop mode.
3146 Start all other threads that are implicitly resumed too. */
3147 ALL_NON_EXITED_THREADS (tp
)
3149 /* Ignore threads of processes we're not resuming. */
3150 if (!tp
->ptid
.matches (resume_ptid
))
3156 fprintf_unfiltered (gdb_stdlog
,
3157 "infrun: proceed: [%s] resumed\n",
3158 target_pid_to_str (tp
->ptid
));
3159 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3163 if (thread_is_in_step_over_chain (tp
))
3166 fprintf_unfiltered (gdb_stdlog
,
3167 "infrun: proceed: [%s] needs step-over\n",
3168 target_pid_to_str (tp
->ptid
));
3173 fprintf_unfiltered (gdb_stdlog
,
3174 "infrun: proceed: resuming %s\n",
3175 target_pid_to_str (tp
->ptid
));
3177 reset_ecs (ecs
, tp
);
3178 switch_to_thread (tp
);
3179 keep_going_pass_signal (ecs
);
3180 if (!ecs
->wait_some_more
)
3181 error (_("Command aborted."));
3184 else if (!tp
->resumed
&& !thread_is_in_step_over_chain (tp
))
3186 /* The thread wasn't started, and isn't queued, run it now. */
3187 reset_ecs (ecs
, tp
);
3188 switch_to_thread (tp
);
3189 keep_going_pass_signal (ecs
);
3190 if (!ecs
->wait_some_more
)
3191 error (_("Command aborted."));
3195 target_commit_resume ();
3197 finish_state
.release ();
3199 /* Tell the event loop to wait for it to stop. If the target
3200 supports asynchronous execution, it'll do this from within
3202 if (!target_can_async_p ())
3203 mark_async_event_handler (infrun_async_inferior_event_token
);
3207 /* Start remote-debugging of a machine over a serial link. */
3210 start_remote (int from_tty
)
3212 struct inferior
*inferior
;
3214 inferior
= current_inferior ();
3215 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3217 /* Always go on waiting for the target, regardless of the mode. */
3218 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3219 indicate to wait_for_inferior that a target should timeout if
3220 nothing is returned (instead of just blocking). Because of this,
3221 targets expecting an immediate response need to, internally, set
3222 things up so that the target_wait() is forced to eventually
3224 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3225 differentiate to its caller what the state of the target is after
3226 the initial open has been performed. Here we're assuming that
3227 the target has stopped. It should be possible to eventually have
3228 target_open() return to the caller an indication that the target
3229 is currently running and GDB state should be set to the same as
3230 for an async run. */
3231 wait_for_inferior ();
3233 /* Now that the inferior has stopped, do any bookkeeping like
3234 loading shared libraries. We want to do this before normal_stop,
3235 so that the displayed frame is up to date. */
3236 post_create_inferior (current_top_target (), from_tty
);
3241 /* Initialize static vars when a new inferior begins. */
3244 init_wait_for_inferior (void)
3246 /* These are meaningless until the first time through wait_for_inferior. */
3248 breakpoint_init_inferior (inf_starting
);
3250 clear_proceed_status (0);
3252 target_last_wait_ptid
= minus_one_ptid
;
3254 previous_inferior_ptid
= inferior_ptid
;
3256 /* Discard any skipped inlined frames. */
3257 clear_inline_frame_state (minus_one_ptid
);
3262 static void handle_inferior_event (struct execution_control_state
*ecs
);
3264 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3265 struct execution_control_state
*ecs
);
3266 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3267 struct execution_control_state
*ecs
);
3268 static void handle_signal_stop (struct execution_control_state
*ecs
);
3269 static void check_exception_resume (struct execution_control_state
*,
3270 struct frame_info
*);
3272 static void end_stepping_range (struct execution_control_state
*ecs
);
3273 static void stop_waiting (struct execution_control_state
*ecs
);
3274 static void keep_going (struct execution_control_state
*ecs
);
3275 static void process_event_stop_test (struct execution_control_state
*ecs
);
3276 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3278 /* This function is attached as a "thread_stop_requested" observer.
3279 Cleanup local state that assumed the PTID was to be resumed, and
3280 report the stop to the frontend. */
3283 infrun_thread_stop_requested (ptid_t ptid
)
3285 struct thread_info
*tp
;
3287 /* PTID was requested to stop. If the thread was already stopped,
3288 but the user/frontend doesn't know about that yet (e.g., the
3289 thread had been temporarily paused for some step-over), set up
3290 for reporting the stop now. */
3291 ALL_NON_EXITED_THREADS (tp
)
3292 if (tp
->ptid
.matches (ptid
))
3294 if (tp
->state
!= THREAD_RUNNING
)
3299 /* Remove matching threads from the step-over queue, so
3300 start_step_over doesn't try to resume them
3302 if (thread_is_in_step_over_chain (tp
))
3303 thread_step_over_chain_remove (tp
);
3305 /* If the thread is stopped, but the user/frontend doesn't
3306 know about that yet, queue a pending event, as if the
3307 thread had just stopped now. Unless the thread already had
3309 if (!tp
->suspend
.waitstatus_pending_p
)
3311 tp
->suspend
.waitstatus_pending_p
= 1;
3312 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3313 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3316 /* Clear the inline-frame state, since we're re-processing the
3318 clear_inline_frame_state (tp
->ptid
);
3320 /* If this thread was paused because some other thread was
3321 doing an inline-step over, let that finish first. Once
3322 that happens, we'll restart all threads and consume pending
3323 stop events then. */
3324 if (step_over_info_valid_p ())
3327 /* Otherwise we can process the (new) pending event now. Set
3328 it so this pending event is considered by
3335 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3337 if (target_last_wait_ptid
== tp
->ptid
)
3338 nullify_last_target_wait_ptid ();
3341 /* Delete the step resume, single-step and longjmp/exception resume
3342 breakpoints of TP. */
3345 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3347 delete_step_resume_breakpoint (tp
);
3348 delete_exception_resume_breakpoint (tp
);
3349 delete_single_step_breakpoints (tp
);
3352 /* If the target still has execution, call FUNC for each thread that
3353 just stopped. In all-stop, that's all the non-exited threads; in
3354 non-stop, that's the current thread, only. */
3356 typedef void (*for_each_just_stopped_thread_callback_func
)
3357 (struct thread_info
*tp
);
3360 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3362 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3365 if (target_is_non_stop_p ())
3367 /* If in non-stop mode, only the current thread stopped. */
3368 func (inferior_thread ());
3372 struct thread_info
*tp
;
3374 /* In all-stop mode, all threads have stopped. */
3375 ALL_NON_EXITED_THREADS (tp
)
3382 /* Delete the step resume and longjmp/exception resume breakpoints of
3383 the threads that just stopped. */
3386 delete_just_stopped_threads_infrun_breakpoints (void)
3388 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3391 /* Delete the single-step breakpoints of the threads that just
3395 delete_just_stopped_threads_single_step_breakpoints (void)
3397 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3400 /* A cleanup wrapper. */
3403 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg
)
3405 delete_just_stopped_threads_infrun_breakpoints ();
3411 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3412 const struct target_waitstatus
*ws
)
3414 std::string status_string
= target_waitstatus_to_string (ws
);
3417 /* The text is split over several lines because it was getting too long.
3418 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3419 output as a unit; we want only one timestamp printed if debug_timestamp
3422 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3425 waiton_ptid
.tid ());
3426 if (waiton_ptid
.pid () != -1)
3427 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
));
3428 stb
.printf (", status) =\n");
3429 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3433 target_pid_to_str (result_ptid
));
3434 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3436 /* This uses %s in part to handle %'s in the text, but also to avoid
3437 a gcc error: the format attribute requires a string literal. */
3438 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3441 /* Select a thread at random, out of those which are resumed and have
3444 static struct thread_info
*
3445 random_pending_event_thread (ptid_t waiton_ptid
)
3447 struct thread_info
*event_tp
;
3449 int random_selector
;
3451 /* First see how many events we have. Count only resumed threads
3452 that have an event pending. */
3453 ALL_NON_EXITED_THREADS (event_tp
)
3454 if (event_tp
->ptid
.matches (waiton_ptid
)
3455 && event_tp
->resumed
3456 && event_tp
->suspend
.waitstatus_pending_p
)
3459 if (num_events
== 0)
3462 /* Now randomly pick a thread out of those that have had events. */
3463 random_selector
= (int)
3464 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
3466 if (debug_infrun
&& num_events
> 1)
3467 fprintf_unfiltered (gdb_stdlog
,
3468 "infrun: Found %d events, selecting #%d\n",
3469 num_events
, random_selector
);
3471 /* Select the Nth thread that has had an event. */
3472 ALL_NON_EXITED_THREADS (event_tp
)
3473 if (event_tp
->ptid
.matches (waiton_ptid
)
3474 && event_tp
->resumed
3475 && event_tp
->suspend
.waitstatus_pending_p
)
3476 if (random_selector
-- == 0)
3482 /* Wrapper for target_wait that first checks whether threads have
3483 pending statuses to report before actually asking the target for
3487 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3490 struct thread_info
*tp
;
3492 /* First check if there is a resumed thread with a wait status
3494 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3496 tp
= random_pending_event_thread (ptid
);
3501 fprintf_unfiltered (gdb_stdlog
,
3502 "infrun: Waiting for specific thread %s.\n",
3503 target_pid_to_str (ptid
));
3505 /* We have a specific thread to check. */
3506 tp
= find_thread_ptid (ptid
);
3507 gdb_assert (tp
!= NULL
);
3508 if (!tp
->suspend
.waitstatus_pending_p
)
3513 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3514 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3516 struct regcache
*regcache
= get_thread_regcache (tp
);
3517 struct gdbarch
*gdbarch
= regcache
->arch ();
3521 pc
= regcache_read_pc (regcache
);
3523 if (pc
!= tp
->suspend
.stop_pc
)
3526 fprintf_unfiltered (gdb_stdlog
,
3527 "infrun: PC of %s changed. was=%s, now=%s\n",
3528 target_pid_to_str (tp
->ptid
),
3529 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3530 paddress (gdbarch
, pc
));
3533 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3536 fprintf_unfiltered (gdb_stdlog
,
3537 "infrun: previous breakpoint of %s, at %s gone\n",
3538 target_pid_to_str (tp
->ptid
),
3539 paddress (gdbarch
, pc
));
3547 fprintf_unfiltered (gdb_stdlog
,
3548 "infrun: pending event of %s cancelled.\n",
3549 target_pid_to_str (tp
->ptid
));
3551 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3552 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3561 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3563 fprintf_unfiltered (gdb_stdlog
,
3564 "infrun: Using pending wait status %s for %s.\n",
3566 target_pid_to_str (tp
->ptid
));
3569 /* Now that we've selected our final event LWP, un-adjust its PC
3570 if it was a software breakpoint (and the target doesn't
3571 always adjust the PC itself). */
3572 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3573 && !target_supports_stopped_by_sw_breakpoint ())
3575 struct regcache
*regcache
;
3576 struct gdbarch
*gdbarch
;
3579 regcache
= get_thread_regcache (tp
);
3580 gdbarch
= regcache
->arch ();
3582 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3587 pc
= regcache_read_pc (regcache
);
3588 regcache_write_pc (regcache
, pc
+ decr_pc
);
3592 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3593 *status
= tp
->suspend
.waitstatus
;
3594 tp
->suspend
.waitstatus_pending_p
= 0;
3596 /* Wake up the event loop again, until all pending events are
3598 if (target_is_async_p ())
3599 mark_async_event_handler (infrun_async_inferior_event_token
);
3603 /* But if we don't find one, we'll have to wait. */
3605 if (deprecated_target_wait_hook
)
3606 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3608 event_ptid
= target_wait (ptid
, status
, options
);
3613 /* Prepare and stabilize the inferior for detaching it. E.g.,
3614 detaching while a thread is displaced stepping is a recipe for
3615 crashing it, as nothing would readjust the PC out of the scratch
3619 prepare_for_detach (void)
3621 struct inferior
*inf
= current_inferior ();
3622 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3624 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3626 /* Is any thread of this process displaced stepping? If not,
3627 there's nothing else to do. */
3628 if (displaced
== NULL
|| displaced
->step_thread
== nullptr)
3632 fprintf_unfiltered (gdb_stdlog
,
3633 "displaced-stepping in-process while detaching");
3635 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3637 while (displaced
->step_thread
!= nullptr)
3639 struct execution_control_state ecss
;
3640 struct execution_control_state
*ecs
;
3643 memset (ecs
, 0, sizeof (*ecs
));
3645 overlay_cache_invalid
= 1;
3646 /* Flush target cache before starting to handle each event.
3647 Target was running and cache could be stale. This is just a
3648 heuristic. Running threads may modify target memory, but we
3649 don't get any event. */
3650 target_dcache_invalidate ();
3652 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3655 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3657 /* If an error happens while handling the event, propagate GDB's
3658 knowledge of the executing state to the frontend/user running
3660 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3662 /* Now figure out what to do with the result of the result. */
3663 handle_inferior_event (ecs
);
3665 /* No error, don't finish the state yet. */
3666 finish_state
.release ();
3668 /* Breakpoints and watchpoints are not installed on the target
3669 at this point, and signals are passed directly to the
3670 inferior, so this must mean the process is gone. */
3671 if (!ecs
->wait_some_more
)
3673 restore_detaching
.release ();
3674 error (_("Program exited while detaching"));
3678 restore_detaching
.release ();
3681 /* Wait for control to return from inferior to debugger.
3683 If inferior gets a signal, we may decide to start it up again
3684 instead of returning. That is why there is a loop in this function.
3685 When this function actually returns it means the inferior
3686 should be left stopped and GDB should read more commands. */
3689 wait_for_inferior (void)
3691 struct cleanup
*old_cleanups
;
3695 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3698 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
,
3701 /* If an error happens while handling the event, propagate GDB's
3702 knowledge of the executing state to the frontend/user running
3704 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3708 struct execution_control_state ecss
;
3709 struct execution_control_state
*ecs
= &ecss
;
3710 ptid_t waiton_ptid
= minus_one_ptid
;
3712 memset (ecs
, 0, sizeof (*ecs
));
3714 overlay_cache_invalid
= 1;
3716 /* Flush target cache before starting to handle each event.
3717 Target was running and cache could be stale. This is just a
3718 heuristic. Running threads may modify target memory, but we
3719 don't get any event. */
3720 target_dcache_invalidate ();
3722 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3725 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3727 /* Now figure out what to do with the result of the result. */
3728 handle_inferior_event (ecs
);
3730 if (!ecs
->wait_some_more
)
3734 /* No error, don't finish the state yet. */
3735 finish_state
.release ();
3737 do_cleanups (old_cleanups
);
3740 /* Cleanup that reinstalls the readline callback handler, if the
3741 target is running in the background. If while handling the target
3742 event something triggered a secondary prompt, like e.g., a
3743 pagination prompt, we'll have removed the callback handler (see
3744 gdb_readline_wrapper_line). Need to do this as we go back to the
3745 event loop, ready to process further input. Note this has no
3746 effect if the handler hasn't actually been removed, because calling
3747 rl_callback_handler_install resets the line buffer, thus losing
3751 reinstall_readline_callback_handler_cleanup (void *arg
)
3753 struct ui
*ui
= current_ui
;
3757 /* We're not going back to the top level event loop yet. Don't
3758 install the readline callback, as it'd prep the terminal,
3759 readline-style (raw, noecho) (e.g., --batch). We'll install
3760 it the next time the prompt is displayed, when we're ready
3765 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3766 gdb_rl_callback_handler_reinstall ();
3769 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3770 that's just the event thread. In all-stop, that's all threads. */
3773 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3775 struct thread_info
*thr
= ecs
->event_thread
;
3777 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3778 thread_fsm_clean_up (thr
->thread_fsm
, thr
);
3782 ALL_NON_EXITED_THREADS (thr
)
3784 if (thr
->thread_fsm
== NULL
)
3786 if (thr
== ecs
->event_thread
)
3789 switch_to_thread (thr
);
3790 thread_fsm_clean_up (thr
->thread_fsm
, thr
);
3793 if (ecs
->event_thread
!= NULL
)
3794 switch_to_thread (ecs
->event_thread
);
3798 /* Helper for all_uis_check_sync_execution_done that works on the
3802 check_curr_ui_sync_execution_done (void)
3804 struct ui
*ui
= current_ui
;
3806 if (ui
->prompt_state
== PROMPT_NEEDED
3808 && !gdb_in_secondary_prompt_p (ui
))
3810 target_terminal::ours ();
3811 gdb::observers::sync_execution_done
.notify ();
3812 ui_register_input_event_handler (ui
);
3819 all_uis_check_sync_execution_done (void)
3821 SWITCH_THRU_ALL_UIS ()
3823 check_curr_ui_sync_execution_done ();
3830 all_uis_on_sync_execution_starting (void)
3832 SWITCH_THRU_ALL_UIS ()
3834 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3835 async_disable_stdin ();
3839 /* Asynchronous version of wait_for_inferior. It is called by the
3840 event loop whenever a change of state is detected on the file
3841 descriptor corresponding to the target. It can be called more than
3842 once to complete a single execution command. In such cases we need
3843 to keep the state in a global variable ECSS. If it is the last time
3844 that this function is called for a single execution command, then
3845 report to the user that the inferior has stopped, and do the
3846 necessary cleanups. */
3849 fetch_inferior_event (void *client_data
)
3851 struct execution_control_state ecss
;
3852 struct execution_control_state
*ecs
= &ecss
;
3853 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
3855 ptid_t waiton_ptid
= minus_one_ptid
;
3857 memset (ecs
, 0, sizeof (*ecs
));
3859 /* Events are always processed with the main UI as current UI. This
3860 way, warnings, debug output, etc. are always consistently sent to
3861 the main console. */
3862 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3864 /* End up with readline processing input, if necessary. */
3865 make_cleanup (reinstall_readline_callback_handler_cleanup
, NULL
);
3867 /* We're handling a live event, so make sure we're doing live
3868 debugging. If we're looking at traceframes while the target is
3869 running, we're going to need to get back to that mode after
3870 handling the event. */
3871 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3874 maybe_restore_traceframe
.emplace ();
3875 set_current_traceframe (-1);
3878 gdb::optional
<scoped_restore_current_thread
> maybe_restore_thread
;
3881 /* In non-stop mode, the user/frontend should not notice a thread
3882 switch due to internal events. Make sure we reverse to the
3883 user selected thread and frame after handling the event and
3884 running any breakpoint commands. */
3885 maybe_restore_thread
.emplace ();
3887 overlay_cache_invalid
= 1;
3888 /* Flush target cache before starting to handle each event. Target
3889 was running and cache could be stale. This is just a heuristic.
3890 Running threads may modify target memory, but we don't get any
3892 target_dcache_invalidate ();
3894 scoped_restore save_exec_dir
3895 = make_scoped_restore (&execution_direction
, target_execution_direction ());
3897 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3898 target_can_async_p () ? TARGET_WNOHANG
: 0);
3901 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3903 /* If an error happens while handling the event, propagate GDB's
3904 knowledge of the executing state to the frontend/user running
3906 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3907 scoped_finish_thread_state
finish_state (finish_ptid
);
3909 /* Get executed before make_cleanup_restore_current_thread above to apply
3910 still for the thread which has thrown the exception. */
3911 struct cleanup
*ts_old_chain
= make_bpstat_clear_actions_cleanup ();
3913 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
, NULL
);
3915 /* Now figure out what to do with the result of the result. */
3916 handle_inferior_event (ecs
);
3918 if (!ecs
->wait_some_more
)
3920 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3921 int should_stop
= 1;
3922 struct thread_info
*thr
= ecs
->event_thread
;
3924 delete_just_stopped_threads_infrun_breakpoints ();
3928 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3930 if (thread_fsm
!= NULL
)
3931 should_stop
= thread_fsm_should_stop (thread_fsm
, thr
);
3940 int should_notify_stop
= 1;
3943 clean_up_just_stopped_threads_fsms (ecs
);
3945 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3948 = thread_fsm_should_notify_stop (thr
->thread_fsm
);
3951 if (should_notify_stop
)
3953 /* We may not find an inferior if this was a process exit. */
3954 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3955 proceeded
= normal_stop ();
3960 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3966 discard_cleanups (ts_old_chain
);
3968 /* No error, don't finish the thread states yet. */
3969 finish_state
.release ();
3971 /* Revert thread and frame. */
3972 do_cleanups (old_chain
);
3974 /* If a UI was in sync execution mode, and now isn't, restore its
3975 prompt (a synchronous execution command has finished, and we're
3976 ready for input). */
3977 all_uis_check_sync_execution_done ();
3980 && exec_done_display_p
3981 && (inferior_ptid
== null_ptid
3982 || inferior_thread ()->state
!= THREAD_RUNNING
))
3983 printf_unfiltered (_("completed.\n"));
3986 /* Record the frame and location we're currently stepping through. */
3988 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3990 struct thread_info
*tp
= inferior_thread ();
3992 tp
->control
.step_frame_id
= get_frame_id (frame
);
3993 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3995 tp
->current_symtab
= sal
.symtab
;
3996 tp
->current_line
= sal
.line
;
3999 /* Clear context switchable stepping state. */
4002 init_thread_stepping_state (struct thread_info
*tss
)
4004 tss
->stepped_breakpoint
= 0;
4005 tss
->stepping_over_breakpoint
= 0;
4006 tss
->stepping_over_watchpoint
= 0;
4007 tss
->step_after_step_resume_breakpoint
= 0;
4010 /* Set the cached copy of the last ptid/waitstatus. */
4013 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
4015 target_last_wait_ptid
= ptid
;
4016 target_last_waitstatus
= status
;
4019 /* Return the cached copy of the last pid/waitstatus returned by
4020 target_wait()/deprecated_target_wait_hook(). The data is actually
4021 cached by handle_inferior_event(), which gets called immediately
4022 after target_wait()/deprecated_target_wait_hook(). */
4025 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
4027 *ptidp
= target_last_wait_ptid
;
4028 *status
= target_last_waitstatus
;
4032 nullify_last_target_wait_ptid (void)
4034 target_last_wait_ptid
= minus_one_ptid
;
4037 /* Switch thread contexts. */
4040 context_switch (execution_control_state
*ecs
)
4043 && ecs
->ptid
!= inferior_ptid
4044 && ecs
->event_thread
!= inferior_thread ())
4046 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4047 target_pid_to_str (inferior_ptid
));
4048 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4049 target_pid_to_str (ecs
->ptid
));
4052 switch_to_thread (ecs
->event_thread
);
4055 /* If the target can't tell whether we've hit breakpoints
4056 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4057 check whether that could have been caused by a breakpoint. If so,
4058 adjust the PC, per gdbarch_decr_pc_after_break. */
4061 adjust_pc_after_break (struct thread_info
*thread
,
4062 struct target_waitstatus
*ws
)
4064 struct regcache
*regcache
;
4065 struct gdbarch
*gdbarch
;
4066 CORE_ADDR breakpoint_pc
, decr_pc
;
4068 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4069 we aren't, just return.
4071 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4072 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4073 implemented by software breakpoints should be handled through the normal
4076 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4077 different signals (SIGILL or SIGEMT for instance), but it is less
4078 clear where the PC is pointing afterwards. It may not match
4079 gdbarch_decr_pc_after_break. I don't know any specific target that
4080 generates these signals at breakpoints (the code has been in GDB since at
4081 least 1992) so I can not guess how to handle them here.
4083 In earlier versions of GDB, a target with
4084 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4085 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4086 target with both of these set in GDB history, and it seems unlikely to be
4087 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4089 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4092 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4095 /* In reverse execution, when a breakpoint is hit, the instruction
4096 under it has already been de-executed. The reported PC always
4097 points at the breakpoint address, so adjusting it further would
4098 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4101 B1 0x08000000 : INSN1
4102 B2 0x08000001 : INSN2
4104 PC -> 0x08000003 : INSN4
4106 Say you're stopped at 0x08000003 as above. Reverse continuing
4107 from that point should hit B2 as below. Reading the PC when the
4108 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4109 been de-executed already.
4111 B1 0x08000000 : INSN1
4112 B2 PC -> 0x08000001 : INSN2
4116 We can't apply the same logic as for forward execution, because
4117 we would wrongly adjust the PC to 0x08000000, since there's a
4118 breakpoint at PC - 1. We'd then report a hit on B1, although
4119 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4121 if (execution_direction
== EXEC_REVERSE
)
4124 /* If the target can tell whether the thread hit a SW breakpoint,
4125 trust it. Targets that can tell also adjust the PC
4127 if (target_supports_stopped_by_sw_breakpoint ())
4130 /* Note that relying on whether a breakpoint is planted in memory to
4131 determine this can fail. E.g,. the breakpoint could have been
4132 removed since. Or the thread could have been told to step an
4133 instruction the size of a breakpoint instruction, and only
4134 _after_ was a breakpoint inserted at its address. */
4136 /* If this target does not decrement the PC after breakpoints, then
4137 we have nothing to do. */
4138 regcache
= get_thread_regcache (thread
);
4139 gdbarch
= regcache
->arch ();
4141 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4145 const address_space
*aspace
= regcache
->aspace ();
4147 /* Find the location where (if we've hit a breakpoint) the
4148 breakpoint would be. */
4149 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4151 /* If the target can't tell whether a software breakpoint triggered,
4152 fallback to figuring it out based on breakpoints we think were
4153 inserted in the target, and on whether the thread was stepped or
4156 /* Check whether there actually is a software breakpoint inserted at
4159 If in non-stop mode, a race condition is possible where we've
4160 removed a breakpoint, but stop events for that breakpoint were
4161 already queued and arrive later. To suppress those spurious
4162 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4163 and retire them after a number of stop events are reported. Note
4164 this is an heuristic and can thus get confused. The real fix is
4165 to get the "stopped by SW BP and needs adjustment" info out of
4166 the target/kernel (and thus never reach here; see above). */
4167 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4168 || (target_is_non_stop_p ()
4169 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4171 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4173 if (record_full_is_used ())
4174 restore_operation_disable
.emplace
4175 (record_full_gdb_operation_disable_set ());
4177 /* When using hardware single-step, a SIGTRAP is reported for both
4178 a completed single-step and a software breakpoint. Need to
4179 differentiate between the two, as the latter needs adjusting
4180 but the former does not.
4182 The SIGTRAP can be due to a completed hardware single-step only if
4183 - we didn't insert software single-step breakpoints
4184 - this thread is currently being stepped
4186 If any of these events did not occur, we must have stopped due
4187 to hitting a software breakpoint, and have to back up to the
4190 As a special case, we could have hardware single-stepped a
4191 software breakpoint. In this case (prev_pc == breakpoint_pc),
4192 we also need to back up to the breakpoint address. */
4194 if (thread_has_single_step_breakpoints_set (thread
)
4195 || !currently_stepping (thread
)
4196 || (thread
->stepped_breakpoint
4197 && thread
->prev_pc
== breakpoint_pc
))
4198 regcache_write_pc (regcache
, breakpoint_pc
);
4203 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4205 for (frame
= get_prev_frame (frame
);
4207 frame
= get_prev_frame (frame
))
4209 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4211 if (get_frame_type (frame
) != INLINE_FRAME
)
4218 /* If the event thread has the stop requested flag set, pretend it
4219 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4223 handle_stop_requested (struct execution_control_state
*ecs
)
4225 if (ecs
->event_thread
->stop_requested
)
4227 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4228 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4229 handle_signal_stop (ecs
);
4235 /* Auxiliary function that handles syscall entry/return events.
4236 It returns 1 if the inferior should keep going (and GDB
4237 should ignore the event), or 0 if the event deserves to be
4241 handle_syscall_event (struct execution_control_state
*ecs
)
4243 struct regcache
*regcache
;
4246 context_switch (ecs
);
4248 regcache
= get_thread_regcache (ecs
->event_thread
);
4249 syscall_number
= ecs
->ws
.value
.syscall_number
;
4250 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4252 if (catch_syscall_enabled () > 0
4253 && catching_syscall_number (syscall_number
) > 0)
4256 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4259 ecs
->event_thread
->control
.stop_bpstat
4260 = bpstat_stop_status (regcache
->aspace (),
4261 ecs
->event_thread
->suspend
.stop_pc
,
4262 ecs
->event_thread
, &ecs
->ws
);
4264 if (handle_stop_requested (ecs
))
4267 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4269 /* Catchpoint hit. */
4274 if (handle_stop_requested (ecs
))
4277 /* If no catchpoint triggered for this, then keep going. */
4282 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4285 fill_in_stop_func (struct gdbarch
*gdbarch
,
4286 struct execution_control_state
*ecs
)
4288 if (!ecs
->stop_func_filled_in
)
4290 /* Don't care about return value; stop_func_start and stop_func_name
4291 will both be 0 if it doesn't work. */
4292 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4293 &ecs
->stop_func_name
,
4294 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
4295 ecs
->stop_func_start
4296 += gdbarch_deprecated_function_start_offset (gdbarch
);
4298 if (gdbarch_skip_entrypoint_p (gdbarch
))
4299 ecs
->stop_func_start
= gdbarch_skip_entrypoint (gdbarch
,
4300 ecs
->stop_func_start
);
4302 ecs
->stop_func_filled_in
= 1;
4307 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4309 static enum stop_kind
4310 get_inferior_stop_soon (execution_control_state
*ecs
)
4312 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
4314 gdb_assert (inf
!= NULL
);
4315 return inf
->control
.stop_soon
;
4318 /* Wait for one event. Store the resulting waitstatus in WS, and
4319 return the event ptid. */
4322 wait_one (struct target_waitstatus
*ws
)
4325 ptid_t wait_ptid
= minus_one_ptid
;
4327 overlay_cache_invalid
= 1;
4329 /* Flush target cache before starting to handle each event.
4330 Target was running and cache could be stale. This is just a
4331 heuristic. Running threads may modify target memory, but we
4332 don't get any event. */
4333 target_dcache_invalidate ();
4335 if (deprecated_target_wait_hook
)
4336 event_ptid
= deprecated_target_wait_hook (wait_ptid
, ws
, 0);
4338 event_ptid
= target_wait (wait_ptid
, ws
, 0);
4341 print_target_wait_results (wait_ptid
, event_ptid
, ws
);
4346 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4347 instead of the current thread. */
4348 #define THREAD_STOPPED_BY(REASON) \
4350 thread_stopped_by_ ## REASON (ptid_t ptid) \
4352 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4353 inferior_ptid = ptid; \
4355 return target_stopped_by_ ## REASON (); \
4358 /* Generate thread_stopped_by_watchpoint. */
4359 THREAD_STOPPED_BY (watchpoint
)
4360 /* Generate thread_stopped_by_sw_breakpoint. */
4361 THREAD_STOPPED_BY (sw_breakpoint
)
4362 /* Generate thread_stopped_by_hw_breakpoint. */
4363 THREAD_STOPPED_BY (hw_breakpoint
)
4365 /* Save the thread's event and stop reason to process it later. */
4368 save_waitstatus (struct thread_info
*tp
, struct target_waitstatus
*ws
)
4372 std::string statstr
= target_waitstatus_to_string (ws
);
4374 fprintf_unfiltered (gdb_stdlog
,
4375 "infrun: saving status %s for %d.%ld.%ld\n",
4382 /* Record for later. */
4383 tp
->suspend
.waitstatus
= *ws
;
4384 tp
->suspend
.waitstatus_pending_p
= 1;
4386 struct regcache
*regcache
= get_thread_regcache (tp
);
4387 const address_space
*aspace
= regcache
->aspace ();
4389 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4390 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4392 CORE_ADDR pc
= regcache_read_pc (regcache
);
4394 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4396 if (thread_stopped_by_watchpoint (tp
->ptid
))
4398 tp
->suspend
.stop_reason
4399 = TARGET_STOPPED_BY_WATCHPOINT
;
4401 else if (target_supports_stopped_by_sw_breakpoint ()
4402 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4404 tp
->suspend
.stop_reason
4405 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4407 else if (target_supports_stopped_by_hw_breakpoint ()
4408 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4410 tp
->suspend
.stop_reason
4411 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4413 else if (!target_supports_stopped_by_hw_breakpoint ()
4414 && hardware_breakpoint_inserted_here_p (aspace
,
4417 tp
->suspend
.stop_reason
4418 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4420 else if (!target_supports_stopped_by_sw_breakpoint ()
4421 && software_breakpoint_inserted_here_p (aspace
,
4424 tp
->suspend
.stop_reason
4425 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4427 else if (!thread_has_single_step_breakpoints_set (tp
)
4428 && currently_stepping (tp
))
4430 tp
->suspend
.stop_reason
4431 = TARGET_STOPPED_BY_SINGLE_STEP
;
4436 /* A cleanup that disables thread create/exit events. */
4439 disable_thread_events (void *arg
)
4441 target_thread_events (0);
4447 stop_all_threads (void)
4449 /* We may need multiple passes to discover all threads. */
4452 struct cleanup
*old_chain
;
4454 gdb_assert (target_is_non_stop_p ());
4457 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4459 scoped_restore_current_thread restore_thread
;
4461 target_thread_events (1);
4462 old_chain
= make_cleanup (disable_thread_events
, NULL
);
4464 /* Request threads to stop, and then wait for the stops. Because
4465 threads we already know about can spawn more threads while we're
4466 trying to stop them, and we only learn about new threads when we
4467 update the thread list, do this in a loop, and keep iterating
4468 until two passes find no threads that need to be stopped. */
4469 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4472 fprintf_unfiltered (gdb_stdlog
,
4473 "infrun: stop_all_threads, pass=%d, "
4474 "iterations=%d\n", pass
, iterations
);
4478 struct target_waitstatus ws
;
4480 struct thread_info
*t
;
4482 update_thread_list ();
4484 /* Go through all threads looking for threads that we need
4485 to tell the target to stop. */
4486 ALL_NON_EXITED_THREADS (t
)
4490 /* If already stopping, don't request a stop again.
4491 We just haven't seen the notification yet. */
4492 if (!t
->stop_requested
)
4495 fprintf_unfiltered (gdb_stdlog
,
4496 "infrun: %s executing, "
4498 target_pid_to_str (t
->ptid
));
4499 target_stop (t
->ptid
);
4500 t
->stop_requested
= 1;
4505 fprintf_unfiltered (gdb_stdlog
,
4506 "infrun: %s executing, "
4507 "already stopping\n",
4508 target_pid_to_str (t
->ptid
));
4511 if (t
->stop_requested
)
4517 fprintf_unfiltered (gdb_stdlog
,
4518 "infrun: %s not executing\n",
4519 target_pid_to_str (t
->ptid
));
4521 /* The thread may be not executing, but still be
4522 resumed with a pending status to process. */
4530 /* If we find new threads on the second iteration, restart
4531 over. We want to see two iterations in a row with all
4536 event_ptid
= wait_one (&ws
);
4538 if (ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4540 /* All resumed threads exited. */
4542 else if (ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4543 || ws
.kind
== TARGET_WAITKIND_EXITED
4544 || ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4548 ptid_t ptid
= ptid_t (ws
.value
.integer
);
4550 fprintf_unfiltered (gdb_stdlog
,
4551 "infrun: %s exited while "
4552 "stopping threads\n",
4553 target_pid_to_str (ptid
));
4560 t
= find_thread_ptid (event_ptid
);
4562 t
= add_thread (event_ptid
);
4564 t
->stop_requested
= 0;
4567 t
->control
.may_range_step
= 0;
4569 /* This may be the first time we see the inferior report
4571 inf
= find_inferior_ptid (event_ptid
);
4572 if (inf
->needs_setup
)
4574 switch_to_thread_no_regs (t
);
4578 if (ws
.kind
== TARGET_WAITKIND_STOPPED
4579 && ws
.value
.sig
== GDB_SIGNAL_0
)
4581 /* We caught the event that we intended to catch, so
4582 there's no event pending. */
4583 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4584 t
->suspend
.waitstatus_pending_p
= 0;
4586 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4588 /* Add it back to the step-over queue. */
4591 fprintf_unfiltered (gdb_stdlog
,
4592 "infrun: displaced-step of %s "
4593 "canceled: adding back to the "
4594 "step-over queue\n",
4595 target_pid_to_str (t
->ptid
));
4597 t
->control
.trap_expected
= 0;
4598 thread_step_over_chain_enqueue (t
);
4603 enum gdb_signal sig
;
4604 struct regcache
*regcache
;
4608 std::string statstr
= target_waitstatus_to_string (&ws
);
4610 fprintf_unfiltered (gdb_stdlog
,
4611 "infrun: target_wait %s, saving "
4612 "status for %d.%ld.%ld\n",
4619 /* Record for later. */
4620 save_waitstatus (t
, &ws
);
4622 sig
= (ws
.kind
== TARGET_WAITKIND_STOPPED
4623 ? ws
.value
.sig
: GDB_SIGNAL_0
);
4625 if (displaced_step_fixup (t
, sig
) < 0)
4627 /* Add it back to the step-over queue. */
4628 t
->control
.trap_expected
= 0;
4629 thread_step_over_chain_enqueue (t
);
4632 regcache
= get_thread_regcache (t
);
4633 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4637 fprintf_unfiltered (gdb_stdlog
,
4638 "infrun: saved stop_pc=%s for %s "
4639 "(currently_stepping=%d)\n",
4640 paddress (target_gdbarch (),
4641 t
->suspend
.stop_pc
),
4642 target_pid_to_str (t
->ptid
),
4643 currently_stepping (t
));
4650 do_cleanups (old_chain
);
4653 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4656 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4659 handle_no_resumed (struct execution_control_state
*ecs
)
4661 struct inferior
*inf
;
4662 struct thread_info
*thread
;
4664 if (target_can_async_p ())
4671 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4679 /* There were no unwaited-for children left in the target, but,
4680 we're not synchronously waiting for events either. Just
4684 fprintf_unfiltered (gdb_stdlog
,
4685 "infrun: TARGET_WAITKIND_NO_RESUMED "
4686 "(ignoring: bg)\n");
4687 prepare_to_wait (ecs
);
4692 /* Otherwise, if we were running a synchronous execution command, we
4693 may need to cancel it and give the user back the terminal.
4695 In non-stop mode, the target can't tell whether we've already
4696 consumed previous stop events, so it can end up sending us a
4697 no-resumed event like so:
4699 #0 - thread 1 is left stopped
4701 #1 - thread 2 is resumed and hits breakpoint
4702 -> TARGET_WAITKIND_STOPPED
4704 #2 - thread 3 is resumed and exits
4705 this is the last resumed thread, so
4706 -> TARGET_WAITKIND_NO_RESUMED
4708 #3 - gdb processes stop for thread 2 and decides to re-resume
4711 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4712 thread 2 is now resumed, so the event should be ignored.
4714 IOW, if the stop for thread 2 doesn't end a foreground command,
4715 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4716 event. But it could be that the event meant that thread 2 itself
4717 (or whatever other thread was the last resumed thread) exited.
4719 To address this we refresh the thread list and check whether we
4720 have resumed threads _now_. In the example above, this removes
4721 thread 3 from the thread list. If thread 2 was re-resumed, we
4722 ignore this event. If we find no thread resumed, then we cancel
4723 the synchronous command show "no unwaited-for " to the user. */
4724 update_thread_list ();
4726 ALL_NON_EXITED_THREADS (thread
)
4728 if (thread
->executing
4729 || thread
->suspend
.waitstatus_pending_p
)
4731 /* There were no unwaited-for children left in the target at
4732 some point, but there are now. Just ignore. */
4734 fprintf_unfiltered (gdb_stdlog
,
4735 "infrun: TARGET_WAITKIND_NO_RESUMED "
4736 "(ignoring: found resumed)\n");
4737 prepare_to_wait (ecs
);
4742 /* Note however that we may find no resumed thread because the whole
4743 process exited meanwhile (thus updating the thread list results
4744 in an empty thread list). In this case we know we'll be getting
4745 a process exit event shortly. */
4751 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4755 fprintf_unfiltered (gdb_stdlog
,
4756 "infrun: TARGET_WAITKIND_NO_RESUMED "
4757 "(expect process exit)\n");
4758 prepare_to_wait (ecs
);
4763 /* Go ahead and report the event. */
4767 /* Given an execution control state that has been freshly filled in by
4768 an event from the inferior, figure out what it means and take
4771 The alternatives are:
4773 1) stop_waiting and return; to really stop and return to the
4776 2) keep_going and return; to wait for the next event (set
4777 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4781 handle_inferior_event_1 (struct execution_control_state
*ecs
)
4783 enum stop_kind stop_soon
;
4785 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4787 /* We had an event in the inferior, but we are not interested in
4788 handling it at this level. The lower layers have already
4789 done what needs to be done, if anything.
4791 One of the possible circumstances for this is when the
4792 inferior produces output for the console. The inferior has
4793 not stopped, and we are ignoring the event. Another possible
4794 circumstance is any event which the lower level knows will be
4795 reported multiple times without an intervening resume. */
4797 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
4798 prepare_to_wait (ecs
);
4802 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4805 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4806 prepare_to_wait (ecs
);
4810 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4811 && handle_no_resumed (ecs
))
4814 /* Cache the last pid/waitstatus. */
4815 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4817 /* Always clear state belonging to the previous time we stopped. */
4818 stop_stack_dummy
= STOP_NONE
;
4820 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4822 /* No unwaited-for children left. IOW, all resumed children
4825 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4827 stop_print_frame
= 0;
4832 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
4833 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
4835 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
4836 /* If it's a new thread, add it to the thread database. */
4837 if (ecs
->event_thread
== NULL
)
4838 ecs
->event_thread
= add_thread (ecs
->ptid
);
4840 /* Disable range stepping. If the next step request could use a
4841 range, this will be end up re-enabled then. */
4842 ecs
->event_thread
->control
.may_range_step
= 0;
4845 /* Dependent on valid ECS->EVENT_THREAD. */
4846 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
4848 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4849 reinit_frame_cache ();
4851 breakpoint_retire_moribund ();
4853 /* First, distinguish signals caused by the debugger from signals
4854 that have to do with the program's own actions. Note that
4855 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4856 on the operating system version. Here we detect when a SIGILL or
4857 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4858 something similar for SIGSEGV, since a SIGSEGV will be generated
4859 when we're trying to execute a breakpoint instruction on a
4860 non-executable stack. This happens for call dummy breakpoints
4861 for architectures like SPARC that place call dummies on the
4863 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
4864 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
4865 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
4866 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
4868 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4870 if (breakpoint_inserted_here_p (regcache
->aspace (),
4871 regcache_read_pc (regcache
)))
4874 fprintf_unfiltered (gdb_stdlog
,
4875 "infrun: Treating signal as SIGTRAP\n");
4876 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
4880 /* Mark the non-executing threads accordingly. In all-stop, all
4881 threads of all processes are stopped when we get any event
4882 reported. In non-stop mode, only the event thread stops. */
4886 if (!target_is_non_stop_p ())
4887 mark_ptid
= minus_one_ptid
;
4888 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
4889 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4891 /* If we're handling a process exit in non-stop mode, even
4892 though threads haven't been deleted yet, one would think
4893 that there is nothing to do, as threads of the dead process
4894 will be soon deleted, and threads of any other process were
4895 left running. However, on some targets, threads survive a
4896 process exit event. E.g., for the "checkpoint" command,
4897 when the current checkpoint/fork exits, linux-fork.c
4898 automatically switches to another fork from within
4899 target_mourn_inferior, by associating the same
4900 inferior/thread to another fork. We haven't mourned yet at
4901 this point, but we must mark any threads left in the
4902 process as not-executing so that finish_thread_state marks
4903 them stopped (in the user's perspective) if/when we present
4904 the stop to the user. */
4905 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
4908 mark_ptid
= ecs
->ptid
;
4910 set_executing (mark_ptid
, 0);
4912 /* Likewise the resumed flag. */
4913 set_resumed (mark_ptid
, 0);
4916 switch (ecs
->ws
.kind
)
4918 case TARGET_WAITKIND_LOADED
:
4920 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
4921 context_switch (ecs
);
4922 /* Ignore gracefully during startup of the inferior, as it might
4923 be the shell which has just loaded some objects, otherwise
4924 add the symbols for the newly loaded objects. Also ignore at
4925 the beginning of an attach or remote session; we will query
4926 the full list of libraries once the connection is
4929 stop_soon
= get_inferior_stop_soon (ecs
);
4930 if (stop_soon
== NO_STOP_QUIETLY
)
4932 struct regcache
*regcache
;
4934 regcache
= get_thread_regcache (ecs
->event_thread
);
4936 handle_solib_event ();
4938 ecs
->event_thread
->control
.stop_bpstat
4939 = bpstat_stop_status (regcache
->aspace (),
4940 ecs
->event_thread
->suspend
.stop_pc
,
4941 ecs
->event_thread
, &ecs
->ws
);
4943 if (handle_stop_requested (ecs
))
4946 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4948 /* A catchpoint triggered. */
4949 process_event_stop_test (ecs
);
4953 /* If requested, stop when the dynamic linker notifies
4954 gdb of events. This allows the user to get control
4955 and place breakpoints in initializer routines for
4956 dynamically loaded objects (among other things). */
4957 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4958 if (stop_on_solib_events
)
4960 /* Make sure we print "Stopped due to solib-event" in
4962 stop_print_frame
= 1;
4969 /* If we are skipping through a shell, or through shared library
4970 loading that we aren't interested in, resume the program. If
4971 we're running the program normally, also resume. */
4972 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4974 /* Loading of shared libraries might have changed breakpoint
4975 addresses. Make sure new breakpoints are inserted. */
4976 if (stop_soon
== NO_STOP_QUIETLY
)
4977 insert_breakpoints ();
4978 resume (GDB_SIGNAL_0
);
4979 prepare_to_wait (ecs
);
4983 /* But stop if we're attaching or setting up a remote
4985 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4986 || stop_soon
== STOP_QUIETLY_REMOTE
)
4989 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4994 internal_error (__FILE__
, __LINE__
,
4995 _("unhandled stop_soon: %d"), (int) stop_soon
);
4997 case TARGET_WAITKIND_SPURIOUS
:
4999 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5000 if (handle_stop_requested (ecs
))
5002 context_switch (ecs
);
5003 resume (GDB_SIGNAL_0
);
5004 prepare_to_wait (ecs
);
5007 case TARGET_WAITKIND_THREAD_CREATED
:
5009 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5010 if (handle_stop_requested (ecs
))
5012 context_switch (ecs
);
5013 if (!switch_back_to_stepped_thread (ecs
))
5017 case TARGET_WAITKIND_EXITED
:
5018 case TARGET_WAITKIND_SIGNALLED
:
5021 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5022 fprintf_unfiltered (gdb_stdlog
,
5023 "infrun: TARGET_WAITKIND_EXITED\n");
5025 fprintf_unfiltered (gdb_stdlog
,
5026 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5029 inferior_ptid
= ecs
->ptid
;
5030 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
5031 set_current_program_space (current_inferior ()->pspace
);
5032 handle_vfork_child_exec_or_exit (0);
5033 target_terminal::ours (); /* Must do this before mourn anyway. */
5035 /* Clearing any previous state of convenience variables. */
5036 clear_exit_convenience_vars ();
5038 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5040 /* Record the exit code in the convenience variable $_exitcode, so
5041 that the user can inspect this again later. */
5042 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5043 (LONGEST
) ecs
->ws
.value
.integer
);
5045 /* Also record this in the inferior itself. */
5046 current_inferior ()->has_exit_code
= 1;
5047 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5049 /* Support the --return-child-result option. */
5050 return_child_result_value
= ecs
->ws
.value
.integer
;
5052 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5056 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5058 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5060 /* Set the value of the internal variable $_exitsignal,
5061 which holds the signal uncaught by the inferior. */
5062 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5063 gdbarch_gdb_signal_to_target (gdbarch
,
5064 ecs
->ws
.value
.sig
));
5068 /* We don't have access to the target's method used for
5069 converting between signal numbers (GDB's internal
5070 representation <-> target's representation).
5071 Therefore, we cannot do a good job at displaying this
5072 information to the user. It's better to just warn
5073 her about it (if infrun debugging is enabled), and
5076 fprintf_filtered (gdb_stdlog
, _("\
5077 Cannot fill $_exitsignal with the correct signal number.\n"));
5080 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5083 gdb_flush (gdb_stdout
);
5084 target_mourn_inferior (inferior_ptid
);
5085 stop_print_frame
= 0;
5089 /* The following are the only cases in which we keep going;
5090 the above cases end in a continue or goto. */
5091 case TARGET_WAITKIND_FORKED
:
5092 case TARGET_WAITKIND_VFORKED
:
5095 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5096 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
5098 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_VFORKED\n");
5101 /* Check whether the inferior is displaced stepping. */
5103 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5104 struct gdbarch
*gdbarch
= regcache
->arch ();
5106 /* If checking displaced stepping is supported, and thread
5107 ecs->ptid is displaced stepping. */
5108 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5110 struct inferior
*parent_inf
5111 = find_inferior_ptid (ecs
->ptid
);
5112 struct regcache
*child_regcache
;
5113 CORE_ADDR parent_pc
;
5115 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5116 indicating that the displaced stepping of syscall instruction
5117 has been done. Perform cleanup for parent process here. Note
5118 that this operation also cleans up the child process for vfork,
5119 because their pages are shared. */
5120 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5121 /* Start a new step-over in another thread if there's one
5125 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5127 struct displaced_step_inferior_state
*displaced
5128 = get_displaced_stepping_state (parent_inf
);
5130 /* Restore scratch pad for child process. */
5131 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5134 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5135 the child's PC is also within the scratchpad. Set the child's PC
5136 to the parent's PC value, which has already been fixed up.
5137 FIXME: we use the parent's aspace here, although we're touching
5138 the child, because the child hasn't been added to the inferior
5139 list yet at this point. */
5142 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
5144 parent_inf
->aspace
);
5145 /* Read PC value of parent process. */
5146 parent_pc
= regcache_read_pc (regcache
);
5148 if (debug_displaced
)
5149 fprintf_unfiltered (gdb_stdlog
,
5150 "displaced: write child pc from %s to %s\n",
5152 regcache_read_pc (child_regcache
)),
5153 paddress (gdbarch
, parent_pc
));
5155 regcache_write_pc (child_regcache
, parent_pc
);
5159 context_switch (ecs
);
5161 /* Immediately detach breakpoints from the child before there's
5162 any chance of letting the user delete breakpoints from the
5163 breakpoint lists. If we don't do this early, it's easy to
5164 leave left over traps in the child, vis: "break foo; catch
5165 fork; c; <fork>; del; c; <child calls foo>". We only follow
5166 the fork on the last `continue', and by that time the
5167 breakpoint at "foo" is long gone from the breakpoint table.
5168 If we vforked, then we don't need to unpatch here, since both
5169 parent and child are sharing the same memory pages; we'll
5170 need to unpatch at follow/detach time instead to be certain
5171 that new breakpoints added between catchpoint hit time and
5172 vfork follow are detached. */
5173 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5175 /* This won't actually modify the breakpoint list, but will
5176 physically remove the breakpoints from the child. */
5177 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5180 delete_just_stopped_threads_single_step_breakpoints ();
5182 /* In case the event is caught by a catchpoint, remember that
5183 the event is to be followed at the next resume of the thread,
5184 and not immediately. */
5185 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5187 ecs
->event_thread
->suspend
.stop_pc
5188 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5190 ecs
->event_thread
->control
.stop_bpstat
5191 = bpstat_stop_status (get_current_regcache ()->aspace (),
5192 ecs
->event_thread
->suspend
.stop_pc
,
5193 ecs
->event_thread
, &ecs
->ws
);
5195 if (handle_stop_requested (ecs
))
5198 /* If no catchpoint triggered for this, then keep going. Note
5199 that we're interested in knowing the bpstat actually causes a
5200 stop, not just if it may explain the signal. Software
5201 watchpoints, for example, always appear in the bpstat. */
5202 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5206 = (follow_fork_mode_string
== follow_fork_mode_child
);
5208 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5210 should_resume
= follow_fork ();
5212 thread_info
*parent
= ecs
->event_thread
;
5213 thread_info
*child
= find_thread_ptid (ecs
->ws
.value
.related_pid
);
5215 /* At this point, the parent is marked running, and the
5216 child is marked stopped. */
5218 /* If not resuming the parent, mark it stopped. */
5219 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5220 parent
->set_running (false);
5222 /* If resuming the child, mark it running. */
5223 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5224 child
->set_running (true);
5226 /* In non-stop mode, also resume the other branch. */
5227 if (!detach_fork
&& (non_stop
5228 || (sched_multi
&& target_is_non_stop_p ())))
5231 switch_to_thread (parent
);
5233 switch_to_thread (child
);
5235 ecs
->event_thread
= inferior_thread ();
5236 ecs
->ptid
= inferior_ptid
;
5241 switch_to_thread (child
);
5243 switch_to_thread (parent
);
5245 ecs
->event_thread
= inferior_thread ();
5246 ecs
->ptid
= inferior_ptid
;
5254 process_event_stop_test (ecs
);
5257 case TARGET_WAITKIND_VFORK_DONE
:
5258 /* Done with the shared memory region. Re-insert breakpoints in
5259 the parent, and keep going. */
5262 fprintf_unfiltered (gdb_stdlog
,
5263 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5265 context_switch (ecs
);
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 switch_to_thread_no_regs (ecs
->event_thread
);
5287 /* Do whatever is necessary to the parent branch of the vfork. */
5288 handle_vfork_child_exec_or_exit (1);
5290 /* This causes the eventpoints and symbol table to be reset.
5291 Must do this now, before trying to determine whether to
5293 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5295 /* In follow_exec we may have deleted the original thread and
5296 created a new one. Make sure that the event thread is the
5297 execd thread for that case (this is a nop otherwise). */
5298 ecs
->event_thread
= inferior_thread ();
5300 ecs
->event_thread
->suspend
.stop_pc
5301 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5303 ecs
->event_thread
->control
.stop_bpstat
5304 = bpstat_stop_status (get_current_regcache ()->aspace (),
5305 ecs
->event_thread
->suspend
.stop_pc
,
5306 ecs
->event_thread
, &ecs
->ws
);
5308 /* Note that this may be referenced from inside
5309 bpstat_stop_status above, through inferior_has_execd. */
5310 xfree (ecs
->ws
.value
.execd_pathname
);
5311 ecs
->ws
.value
.execd_pathname
= NULL
;
5313 if (handle_stop_requested (ecs
))
5316 /* If no catchpoint triggered for this, then keep going. */
5317 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5319 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5323 process_event_stop_test (ecs
);
5326 /* Be careful not to try to gather much state about a thread
5327 that's in a syscall. It's frequently a losing proposition. */
5328 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5330 fprintf_unfiltered (gdb_stdlog
,
5331 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5332 /* Getting the current syscall number. */
5333 if (handle_syscall_event (ecs
) == 0)
5334 process_event_stop_test (ecs
);
5337 /* Before examining the threads further, step this thread to
5338 get it entirely out of the syscall. (We get notice of the
5339 event when the thread is just on the verge of exiting a
5340 syscall. Stepping one instruction seems to get it back
5342 case TARGET_WAITKIND_SYSCALL_RETURN
:
5344 fprintf_unfiltered (gdb_stdlog
,
5345 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5346 if (handle_syscall_event (ecs
) == 0)
5347 process_event_stop_test (ecs
);
5350 case TARGET_WAITKIND_STOPPED
:
5352 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
5353 handle_signal_stop (ecs
);
5356 case TARGET_WAITKIND_NO_HISTORY
:
5358 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5359 /* Reverse execution: target ran out of history info. */
5361 /* Switch to the stopped thread. */
5362 context_switch (ecs
);
5364 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5366 delete_just_stopped_threads_single_step_breakpoints ();
5367 ecs
->event_thread
->suspend
.stop_pc
5368 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5370 if (handle_stop_requested (ecs
))
5373 gdb::observers::no_history
.notify ();
5379 /* A wrapper around handle_inferior_event_1, which also makes sure
5380 that all temporary struct value objects that were created during
5381 the handling of the event get deleted at the end. */
5384 handle_inferior_event (struct execution_control_state
*ecs
)
5386 struct value
*mark
= value_mark ();
5388 handle_inferior_event_1 (ecs
);
5389 /* Purge all temporary values created during the event handling,
5390 as it could be a long time before we return to the command level
5391 where such values would otherwise be purged. */
5392 value_free_to_mark (mark
);
5395 /* Restart threads back to what they were trying to do back when we
5396 paused them for an in-line step-over. The EVENT_THREAD thread is
5400 restart_threads (struct thread_info
*event_thread
)
5402 struct thread_info
*tp
;
5404 /* In case the instruction just stepped spawned a new thread. */
5405 update_thread_list ();
5407 ALL_NON_EXITED_THREADS (tp
)
5409 if (tp
== event_thread
)
5412 fprintf_unfiltered (gdb_stdlog
,
5413 "infrun: restart threads: "
5414 "[%s] is event thread\n",
5415 target_pid_to_str (tp
->ptid
));
5419 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5422 fprintf_unfiltered (gdb_stdlog
,
5423 "infrun: restart threads: "
5424 "[%s] not meant to be running\n",
5425 target_pid_to_str (tp
->ptid
));
5432 fprintf_unfiltered (gdb_stdlog
,
5433 "infrun: restart threads: [%s] resumed\n",
5434 target_pid_to_str (tp
->ptid
));
5435 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5439 if (thread_is_in_step_over_chain (tp
))
5442 fprintf_unfiltered (gdb_stdlog
,
5443 "infrun: restart threads: "
5444 "[%s] needs step-over\n",
5445 target_pid_to_str (tp
->ptid
));
5446 gdb_assert (!tp
->resumed
);
5451 if (tp
->suspend
.waitstatus_pending_p
)
5454 fprintf_unfiltered (gdb_stdlog
,
5455 "infrun: restart threads: "
5456 "[%s] has pending status\n",
5457 target_pid_to_str (tp
->ptid
));
5462 gdb_assert (!tp
->stop_requested
);
5464 /* If some thread needs to start a step-over at this point, it
5465 should still be in the step-over queue, and thus skipped
5467 if (thread_still_needs_step_over (tp
))
5469 internal_error (__FILE__
, __LINE__
,
5470 "thread [%s] needs a step-over, but not in "
5471 "step-over queue\n",
5472 target_pid_to_str (tp
->ptid
));
5475 if (currently_stepping (tp
))
5478 fprintf_unfiltered (gdb_stdlog
,
5479 "infrun: restart threads: [%s] was stepping\n",
5480 target_pid_to_str (tp
->ptid
));
5481 keep_going_stepped_thread (tp
);
5485 struct execution_control_state ecss
;
5486 struct execution_control_state
*ecs
= &ecss
;
5489 fprintf_unfiltered (gdb_stdlog
,
5490 "infrun: restart threads: [%s] continuing\n",
5491 target_pid_to_str (tp
->ptid
));
5492 reset_ecs (ecs
, tp
);
5493 switch_to_thread (tp
);
5494 keep_going_pass_signal (ecs
);
5499 /* Callback for iterate_over_threads. Find a resumed thread that has
5500 a pending waitstatus. */
5503 resumed_thread_with_pending_status (struct thread_info
*tp
,
5507 && tp
->suspend
.waitstatus_pending_p
);
5510 /* Called when we get an event that may finish an in-line or
5511 out-of-line (displaced stepping) step-over started previously.
5512 Return true if the event is processed and we should go back to the
5513 event loop; false if the caller should continue processing the
5517 finish_step_over (struct execution_control_state
*ecs
)
5519 int had_step_over_info
;
5521 displaced_step_fixup (ecs
->event_thread
,
5522 ecs
->event_thread
->suspend
.stop_signal
);
5524 had_step_over_info
= step_over_info_valid_p ();
5526 if (had_step_over_info
)
5528 /* If we're stepping over a breakpoint with all threads locked,
5529 then only the thread that was stepped should be reporting
5531 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5533 clear_step_over_info ();
5536 if (!target_is_non_stop_p ())
5539 /* Start a new step-over in another thread if there's one that
5543 /* If we were stepping over a breakpoint before, and haven't started
5544 a new in-line step-over sequence, then restart all other threads
5545 (except the event thread). We can't do this in all-stop, as then
5546 e.g., we wouldn't be able to issue any other remote packet until
5547 these other threads stop. */
5548 if (had_step_over_info
&& !step_over_info_valid_p ())
5550 struct thread_info
*pending
;
5552 /* If we only have threads with pending statuses, the restart
5553 below won't restart any thread and so nothing re-inserts the
5554 breakpoint we just stepped over. But we need it inserted
5555 when we later process the pending events, otherwise if
5556 another thread has a pending event for this breakpoint too,
5557 we'd discard its event (because the breakpoint that
5558 originally caused the event was no longer inserted). */
5559 context_switch (ecs
);
5560 insert_breakpoints ();
5562 restart_threads (ecs
->event_thread
);
5564 /* If we have events pending, go through handle_inferior_event
5565 again, picking up a pending event at random. This avoids
5566 thread starvation. */
5568 /* But not if we just stepped over a watchpoint in order to let
5569 the instruction execute so we can evaluate its expression.
5570 The set of watchpoints that triggered is recorded in the
5571 breakpoint objects themselves (see bp->watchpoint_triggered).
5572 If we processed another event first, that other event could
5573 clobber this info. */
5574 if (ecs
->event_thread
->stepping_over_watchpoint
)
5577 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5579 if (pending
!= NULL
)
5581 struct thread_info
*tp
= ecs
->event_thread
;
5582 struct regcache
*regcache
;
5586 fprintf_unfiltered (gdb_stdlog
,
5587 "infrun: found resumed threads with "
5588 "pending events, saving status\n");
5591 gdb_assert (pending
!= tp
);
5593 /* Record the event thread's event for later. */
5594 save_waitstatus (tp
, &ecs
->ws
);
5595 /* This was cleared early, by handle_inferior_event. Set it
5596 so this pending event is considered by
5600 gdb_assert (!tp
->executing
);
5602 regcache
= get_thread_regcache (tp
);
5603 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5607 fprintf_unfiltered (gdb_stdlog
,
5608 "infrun: saved stop_pc=%s for %s "
5609 "(currently_stepping=%d)\n",
5610 paddress (target_gdbarch (),
5611 tp
->suspend
.stop_pc
),
5612 target_pid_to_str (tp
->ptid
),
5613 currently_stepping (tp
));
5616 /* This in-line step-over finished; clear this so we won't
5617 start a new one. This is what handle_signal_stop would
5618 do, if we returned false. */
5619 tp
->stepping_over_breakpoint
= 0;
5621 /* Wake up the event loop again. */
5622 mark_async_event_handler (infrun_async_inferior_event_token
);
5624 prepare_to_wait (ecs
);
5632 /* Come here when the program has stopped with a signal. */
5635 handle_signal_stop (struct execution_control_state
*ecs
)
5637 struct frame_info
*frame
;
5638 struct gdbarch
*gdbarch
;
5639 int stopped_by_watchpoint
;
5640 enum stop_kind stop_soon
;
5643 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5645 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5647 /* Do we need to clean up the state of a thread that has
5648 completed a displaced single-step? (Doing so usually affects
5649 the PC, so do it here, before we set stop_pc.) */
5650 if (finish_step_over (ecs
))
5653 /* If we either finished a single-step or hit a breakpoint, but
5654 the user wanted this thread to be stopped, pretend we got a
5655 SIG0 (generic unsignaled stop). */
5656 if (ecs
->event_thread
->stop_requested
5657 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5658 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5660 ecs
->event_thread
->suspend
.stop_pc
5661 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5665 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5666 struct gdbarch
*gdbarch
= regcache
->arch ();
5667 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
5669 inferior_ptid
= ecs
->ptid
;
5671 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5673 ecs
->event_thread
->suspend
.stop_pc
));
5674 if (target_stopped_by_watchpoint ())
5678 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5680 if (target_stopped_data_address (current_top_target (), &addr
))
5681 fprintf_unfiltered (gdb_stdlog
,
5682 "infrun: stopped data address = %s\n",
5683 paddress (gdbarch
, addr
));
5685 fprintf_unfiltered (gdb_stdlog
,
5686 "infrun: (no data address available)\n");
5690 /* This is originated from start_remote(), start_inferior() and
5691 shared libraries hook functions. */
5692 stop_soon
= get_inferior_stop_soon (ecs
);
5693 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5695 context_switch (ecs
);
5697 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5698 stop_print_frame
= 1;
5703 /* This originates from attach_command(). We need to overwrite
5704 the stop_signal here, because some kernels don't ignore a
5705 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5706 See more comments in inferior.h. On the other hand, if we
5707 get a non-SIGSTOP, report it to the user - assume the backend
5708 will handle the SIGSTOP if it should show up later.
5710 Also consider that the attach is complete when we see a
5711 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5712 target extended-remote report it instead of a SIGSTOP
5713 (e.g. gdbserver). We already rely on SIGTRAP being our
5714 signal, so this is no exception.
5716 Also consider that the attach is complete when we see a
5717 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5718 the target to stop all threads of the inferior, in case the
5719 low level attach operation doesn't stop them implicitly. If
5720 they weren't stopped implicitly, then the stub will report a
5721 GDB_SIGNAL_0, meaning: stopped for no particular reason
5722 other than GDB's request. */
5723 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5724 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5725 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5726 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5728 stop_print_frame
= 1;
5730 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5734 /* See if something interesting happened to the non-current thread. If
5735 so, then switch to that thread. */
5736 if (ecs
->ptid
!= inferior_ptid
)
5739 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5741 context_switch (ecs
);
5743 if (deprecated_context_hook
)
5744 deprecated_context_hook (ecs
->event_thread
->global_num
);
5747 /* At this point, get hold of the now-current thread's frame. */
5748 frame
= get_current_frame ();
5749 gdbarch
= get_frame_arch (frame
);
5751 /* Pull the single step breakpoints out of the target. */
5752 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5754 struct regcache
*regcache
;
5757 regcache
= get_thread_regcache (ecs
->event_thread
);
5758 const address_space
*aspace
= regcache
->aspace ();
5760 pc
= regcache_read_pc (regcache
);
5762 /* However, before doing so, if this single-step breakpoint was
5763 actually for another thread, set this thread up for moving
5765 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5768 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5772 fprintf_unfiltered (gdb_stdlog
,
5773 "infrun: [%s] hit another thread's "
5774 "single-step breakpoint\n",
5775 target_pid_to_str (ecs
->ptid
));
5777 ecs
->hit_singlestep_breakpoint
= 1;
5784 fprintf_unfiltered (gdb_stdlog
,
5785 "infrun: [%s] hit its "
5786 "single-step breakpoint\n",
5787 target_pid_to_str (ecs
->ptid
));
5791 delete_just_stopped_threads_single_step_breakpoints ();
5793 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5794 && ecs
->event_thread
->control
.trap_expected
5795 && ecs
->event_thread
->stepping_over_watchpoint
)
5796 stopped_by_watchpoint
= 0;
5798 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5800 /* If necessary, step over this watchpoint. We'll be back to display
5802 if (stopped_by_watchpoint
5803 && (target_have_steppable_watchpoint
5804 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5806 /* At this point, we are stopped at an instruction which has
5807 attempted to write to a piece of memory under control of
5808 a watchpoint. The instruction hasn't actually executed
5809 yet. If we were to evaluate the watchpoint expression
5810 now, we would get the old value, and therefore no change
5811 would seem to have occurred.
5813 In order to make watchpoints work `right', we really need
5814 to complete the memory write, and then evaluate the
5815 watchpoint expression. We do this by single-stepping the
5818 It may not be necessary to disable the watchpoint to step over
5819 it. For example, the PA can (with some kernel cooperation)
5820 single step over a watchpoint without disabling the watchpoint.
5822 It is far more common to need to disable a watchpoint to step
5823 the inferior over it. If we have non-steppable watchpoints,
5824 we must disable the current watchpoint; it's simplest to
5825 disable all watchpoints.
5827 Any breakpoint at PC must also be stepped over -- if there's
5828 one, it will have already triggered before the watchpoint
5829 triggered, and we either already reported it to the user, or
5830 it didn't cause a stop and we called keep_going. In either
5831 case, if there was a breakpoint at PC, we must be trying to
5833 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5838 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5839 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5840 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5841 ecs
->event_thread
->control
.stop_step
= 0;
5842 stop_print_frame
= 1;
5843 stopped_by_random_signal
= 0;
5844 bpstat stop_chain
= NULL
;
5846 /* Hide inlined functions starting here, unless we just performed stepi or
5847 nexti. After stepi and nexti, always show the innermost frame (not any
5848 inline function call sites). */
5849 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5851 const address_space
*aspace
5852 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5854 /* skip_inline_frames is expensive, so we avoid it if we can
5855 determine that the address is one where functions cannot have
5856 been inlined. This improves performance with inferiors that
5857 load a lot of shared libraries, because the solib event
5858 breakpoint is defined as the address of a function (i.e. not
5859 inline). Note that we have to check the previous PC as well
5860 as the current one to catch cases when we have just
5861 single-stepped off a breakpoint prior to reinstating it.
5862 Note that we're assuming that the code we single-step to is
5863 not inline, but that's not definitive: there's nothing
5864 preventing the event breakpoint function from containing
5865 inlined code, and the single-step ending up there. If the
5866 user had set a breakpoint on that inlined code, the missing
5867 skip_inline_frames call would break things. Fortunately
5868 that's an extremely unlikely scenario. */
5869 if (!pc_at_non_inline_function (aspace
,
5870 ecs
->event_thread
->suspend
.stop_pc
,
5872 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5873 && ecs
->event_thread
->control
.trap_expected
5874 && pc_at_non_inline_function (aspace
,
5875 ecs
->event_thread
->prev_pc
,
5878 stop_chain
= build_bpstat_chain (aspace
,
5879 ecs
->event_thread
->suspend
.stop_pc
,
5881 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5883 /* Re-fetch current thread's frame in case that invalidated
5885 frame
= get_current_frame ();
5886 gdbarch
= get_frame_arch (frame
);
5890 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5891 && ecs
->event_thread
->control
.trap_expected
5892 && gdbarch_single_step_through_delay_p (gdbarch
)
5893 && currently_stepping (ecs
->event_thread
))
5895 /* We're trying to step off a breakpoint. Turns out that we're
5896 also on an instruction that needs to be stepped multiple
5897 times before it's been fully executing. E.g., architectures
5898 with a delay slot. It needs to be stepped twice, once for
5899 the instruction and once for the delay slot. */
5900 int step_through_delay
5901 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5903 if (debug_infrun
&& step_through_delay
)
5904 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5905 if (ecs
->event_thread
->control
.step_range_end
== 0
5906 && step_through_delay
)
5908 /* The user issued a continue when stopped at a breakpoint.
5909 Set up for another trap and get out of here. */
5910 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5914 else if (step_through_delay
)
5916 /* The user issued a step when stopped at a breakpoint.
5917 Maybe we should stop, maybe we should not - the delay
5918 slot *might* correspond to a line of source. In any
5919 case, don't decide that here, just set
5920 ecs->stepping_over_breakpoint, making sure we
5921 single-step again before breakpoints are re-inserted. */
5922 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5926 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5927 handles this event. */
5928 ecs
->event_thread
->control
.stop_bpstat
5929 = bpstat_stop_status (get_current_regcache ()->aspace (),
5930 ecs
->event_thread
->suspend
.stop_pc
,
5931 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
5933 /* Following in case break condition called a
5935 stop_print_frame
= 1;
5937 /* This is where we handle "moribund" watchpoints. Unlike
5938 software breakpoints traps, hardware watchpoint traps are
5939 always distinguishable from random traps. If no high-level
5940 watchpoint is associated with the reported stop data address
5941 anymore, then the bpstat does not explain the signal ---
5942 simply make sure to ignore it if `stopped_by_watchpoint' is
5946 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5947 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5949 && stopped_by_watchpoint
)
5950 fprintf_unfiltered (gdb_stdlog
,
5951 "infrun: no user watchpoint explains "
5952 "watchpoint SIGTRAP, ignoring\n");
5954 /* NOTE: cagney/2003-03-29: These checks for a random signal
5955 at one stage in the past included checks for an inferior
5956 function call's call dummy's return breakpoint. The original
5957 comment, that went with the test, read:
5959 ``End of a stack dummy. Some systems (e.g. Sony news) give
5960 another signal besides SIGTRAP, so check here as well as
5963 If someone ever tries to get call dummys on a
5964 non-executable stack to work (where the target would stop
5965 with something like a SIGSEGV), then those tests might need
5966 to be re-instated. Given, however, that the tests were only
5967 enabled when momentary breakpoints were not being used, I
5968 suspect that it won't be the case.
5970 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5971 be necessary for call dummies on a non-executable stack on
5974 /* See if the breakpoints module can explain the signal. */
5976 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5977 ecs
->event_thread
->suspend
.stop_signal
);
5979 /* Maybe this was a trap for a software breakpoint that has since
5981 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5983 if (program_breakpoint_here_p (gdbarch
,
5984 ecs
->event_thread
->suspend
.stop_pc
))
5986 struct regcache
*regcache
;
5989 /* Re-adjust PC to what the program would see if GDB was not
5991 regcache
= get_thread_regcache (ecs
->event_thread
);
5992 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
5995 gdb::optional
<scoped_restore_tmpl
<int>>
5996 restore_operation_disable
;
5998 if (record_full_is_used ())
5999 restore_operation_disable
.emplace
6000 (record_full_gdb_operation_disable_set ());
6002 regcache_write_pc (regcache
,
6003 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6008 /* A delayed software breakpoint event. Ignore the trap. */
6010 fprintf_unfiltered (gdb_stdlog
,
6011 "infrun: delayed software breakpoint "
6012 "trap, ignoring\n");
6017 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6018 has since been removed. */
6019 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6021 /* A delayed hardware breakpoint event. Ignore the trap. */
6023 fprintf_unfiltered (gdb_stdlog
,
6024 "infrun: delayed hardware breakpoint/watchpoint "
6025 "trap, ignoring\n");
6029 /* If not, perhaps stepping/nexting can. */
6031 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6032 && currently_stepping (ecs
->event_thread
));
6034 /* Perhaps the thread hit a single-step breakpoint of _another_
6035 thread. Single-step breakpoints are transparent to the
6036 breakpoints module. */
6038 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6040 /* No? Perhaps we got a moribund watchpoint. */
6042 random_signal
= !stopped_by_watchpoint
;
6044 /* Always stop if the user explicitly requested this thread to
6046 if (ecs
->event_thread
->stop_requested
)
6050 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6053 /* For the program's own signals, act according to
6054 the signal handling tables. */
6058 /* Signal not for debugging purposes. */
6059 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
6060 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6063 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6064 gdb_signal_to_symbol_string (stop_signal
));
6066 stopped_by_random_signal
= 1;
6068 /* Always stop on signals if we're either just gaining control
6069 of the program, or the user explicitly requested this thread
6070 to remain stopped. */
6071 if (stop_soon
!= NO_STOP_QUIETLY
6072 || ecs
->event_thread
->stop_requested
6074 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6080 /* Notify observers the signal has "handle print" set. Note we
6081 returned early above if stopping; normal_stop handles the
6082 printing in that case. */
6083 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6085 /* The signal table tells us to print about this signal. */
6086 target_terminal::ours_for_output ();
6087 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6088 target_terminal::inferior ();
6091 /* Clear the signal if it should not be passed. */
6092 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6093 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6095 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6096 && ecs
->event_thread
->control
.trap_expected
6097 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6099 /* We were just starting a new sequence, attempting to
6100 single-step off of a breakpoint and expecting a SIGTRAP.
6101 Instead this signal arrives. This signal will take us out
6102 of the stepping range so GDB needs to remember to, when
6103 the signal handler returns, resume stepping off that
6105 /* To simplify things, "continue" is forced to use the same
6106 code paths as single-step - set a breakpoint at the
6107 signal return address and then, once hit, step off that
6110 fprintf_unfiltered (gdb_stdlog
,
6111 "infrun: signal arrived while stepping over "
6114 insert_hp_step_resume_breakpoint_at_frame (frame
);
6115 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6116 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6117 ecs
->event_thread
->control
.trap_expected
= 0;
6119 /* If we were nexting/stepping some other thread, switch to
6120 it, so that we don't continue it, losing control. */
6121 if (!switch_back_to_stepped_thread (ecs
))
6126 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6127 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6129 || ecs
->event_thread
->control
.step_range_end
== 1)
6130 && frame_id_eq (get_stack_frame_id (frame
),
6131 ecs
->event_thread
->control
.step_stack_frame_id
)
6132 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6134 /* The inferior is about to take a signal that will take it
6135 out of the single step range. Set a breakpoint at the
6136 current PC (which is presumably where the signal handler
6137 will eventually return) and then allow the inferior to
6140 Note that this is only needed for a signal delivered
6141 while in the single-step range. Nested signals aren't a
6142 problem as they eventually all return. */
6144 fprintf_unfiltered (gdb_stdlog
,
6145 "infrun: signal may take us out of "
6146 "single-step range\n");
6148 clear_step_over_info ();
6149 insert_hp_step_resume_breakpoint_at_frame (frame
);
6150 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6151 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6152 ecs
->event_thread
->control
.trap_expected
= 0;
6157 /* Note: step_resume_breakpoint may be non-NULL. This occures
6158 when either there's a nested signal, or when there's a
6159 pending signal enabled just as the signal handler returns
6160 (leaving the inferior at the step-resume-breakpoint without
6161 actually executing it). Either way continue until the
6162 breakpoint is really hit. */
6164 if (!switch_back_to_stepped_thread (ecs
))
6167 fprintf_unfiltered (gdb_stdlog
,
6168 "infrun: random signal, keep going\n");
6175 process_event_stop_test (ecs
);
6178 /* Come here when we've got some debug event / signal we can explain
6179 (IOW, not a random signal), and test whether it should cause a
6180 stop, or whether we should resume the inferior (transparently).
6181 E.g., could be a breakpoint whose condition evaluates false; we
6182 could be still stepping within the line; etc. */
6185 process_event_stop_test (struct execution_control_state
*ecs
)
6187 struct symtab_and_line stop_pc_sal
;
6188 struct frame_info
*frame
;
6189 struct gdbarch
*gdbarch
;
6190 CORE_ADDR jmp_buf_pc
;
6191 struct bpstat_what what
;
6193 /* Handle cases caused by hitting a breakpoint. */
6195 frame
= get_current_frame ();
6196 gdbarch
= get_frame_arch (frame
);
6198 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6200 if (what
.call_dummy
)
6202 stop_stack_dummy
= what
.call_dummy
;
6205 /* A few breakpoint types have callbacks associated (e.g.,
6206 bp_jit_event). Run them now. */
6207 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6209 /* If we hit an internal event that triggers symbol changes, the
6210 current frame will be invalidated within bpstat_what (e.g., if we
6211 hit an internal solib event). Re-fetch it. */
6212 frame
= get_current_frame ();
6213 gdbarch
= get_frame_arch (frame
);
6215 switch (what
.main_action
)
6217 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6218 /* If we hit the breakpoint at longjmp while stepping, we
6219 install a momentary breakpoint at the target of the
6223 fprintf_unfiltered (gdb_stdlog
,
6224 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6226 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6228 if (what
.is_longjmp
)
6230 struct value
*arg_value
;
6232 /* If we set the longjmp breakpoint via a SystemTap probe,
6233 then use it to extract the arguments. The destination PC
6234 is the third argument to the probe. */
6235 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6238 jmp_buf_pc
= value_as_address (arg_value
);
6239 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6241 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6242 || !gdbarch_get_longjmp_target (gdbarch
,
6243 frame
, &jmp_buf_pc
))
6246 fprintf_unfiltered (gdb_stdlog
,
6247 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6248 "(!gdbarch_get_longjmp_target)\n");
6253 /* Insert a breakpoint at resume address. */
6254 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6257 check_exception_resume (ecs
, frame
);
6261 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6263 struct frame_info
*init_frame
;
6265 /* There are several cases to consider.
6267 1. The initiating frame no longer exists. In this case we
6268 must stop, because the exception or longjmp has gone too
6271 2. The initiating frame exists, and is the same as the
6272 current frame. We stop, because the exception or longjmp
6275 3. The initiating frame exists and is different from the
6276 current frame. This means the exception or longjmp has
6277 been caught beneath the initiating frame, so keep going.
6279 4. longjmp breakpoint has been placed just to protect
6280 against stale dummy frames and user is not interested in
6281 stopping around longjmps. */
6284 fprintf_unfiltered (gdb_stdlog
,
6285 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6287 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6289 delete_exception_resume_breakpoint (ecs
->event_thread
);
6291 if (what
.is_longjmp
)
6293 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6295 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6303 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6307 struct frame_id current_id
6308 = get_frame_id (get_current_frame ());
6309 if (frame_id_eq (current_id
,
6310 ecs
->event_thread
->initiating_frame
))
6312 /* Case 2. Fall through. */
6322 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6324 delete_step_resume_breakpoint (ecs
->event_thread
);
6326 end_stepping_range (ecs
);
6330 case BPSTAT_WHAT_SINGLE
:
6332 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6333 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6334 /* Still need to check other stuff, at least the case where we
6335 are stepping and step out of the right range. */
6338 case BPSTAT_WHAT_STEP_RESUME
:
6340 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6342 delete_step_resume_breakpoint (ecs
->event_thread
);
6343 if (ecs
->event_thread
->control
.proceed_to_finish
6344 && execution_direction
== EXEC_REVERSE
)
6346 struct thread_info
*tp
= ecs
->event_thread
;
6348 /* We are finishing a function in reverse, and just hit the
6349 step-resume breakpoint at the start address of the
6350 function, and we're almost there -- just need to back up
6351 by one more single-step, which should take us back to the
6353 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6357 fill_in_stop_func (gdbarch
, ecs
);
6358 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6359 && execution_direction
== EXEC_REVERSE
)
6361 /* We are stepping over a function call in reverse, and just
6362 hit the step-resume breakpoint at the start address of
6363 the function. Go back to single-stepping, which should
6364 take us back to the function call. */
6365 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6371 case BPSTAT_WHAT_STOP_NOISY
:
6373 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6374 stop_print_frame
= 1;
6376 /* Assume the thread stopped for a breapoint. We'll still check
6377 whether a/the breakpoint is there when the thread is next
6379 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6384 case BPSTAT_WHAT_STOP_SILENT
:
6386 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6387 stop_print_frame
= 0;
6389 /* Assume the thread stopped for a breapoint. We'll still check
6390 whether a/the breakpoint is there when the thread is next
6392 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6396 case BPSTAT_WHAT_HP_STEP_RESUME
:
6398 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6400 delete_step_resume_breakpoint (ecs
->event_thread
);
6401 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6403 /* Back when the step-resume breakpoint was inserted, we
6404 were trying to single-step off a breakpoint. Go back to
6406 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6407 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6413 case BPSTAT_WHAT_KEEP_CHECKING
:
6417 /* If we stepped a permanent breakpoint and we had a high priority
6418 step-resume breakpoint for the address we stepped, but we didn't
6419 hit it, then we must have stepped into the signal handler. The
6420 step-resume was only necessary to catch the case of _not_
6421 stepping into the handler, so delete it, and fall through to
6422 checking whether the step finished. */
6423 if (ecs
->event_thread
->stepped_breakpoint
)
6425 struct breakpoint
*sr_bp
6426 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6429 && sr_bp
->loc
->permanent
6430 && sr_bp
->type
== bp_hp_step_resume
6431 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6434 fprintf_unfiltered (gdb_stdlog
,
6435 "infrun: stepped permanent breakpoint, stopped in "
6437 delete_step_resume_breakpoint (ecs
->event_thread
);
6438 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6442 /* We come here if we hit a breakpoint but should not stop for it.
6443 Possibly we also were stepping and should stop for that. So fall
6444 through and test for stepping. But, if not stepping, do not
6447 /* In all-stop mode, if we're currently stepping but have stopped in
6448 some other thread, we need to switch back to the stepped thread. */
6449 if (switch_back_to_stepped_thread (ecs
))
6452 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6455 fprintf_unfiltered (gdb_stdlog
,
6456 "infrun: step-resume breakpoint is inserted\n");
6458 /* Having a step-resume breakpoint overrides anything
6459 else having to do with stepping commands until
6460 that breakpoint is reached. */
6465 if (ecs
->event_thread
->control
.step_range_end
== 0)
6468 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6469 /* Likewise if we aren't even stepping. */
6474 /* Re-fetch current thread's frame in case the code above caused
6475 the frame cache to be re-initialized, making our FRAME variable
6476 a dangling pointer. */
6477 frame
= get_current_frame ();
6478 gdbarch
= get_frame_arch (frame
);
6479 fill_in_stop_func (gdbarch
, ecs
);
6481 /* If stepping through a line, keep going if still within it.
6483 Note that step_range_end is the address of the first instruction
6484 beyond the step range, and NOT the address of the last instruction
6487 Note also that during reverse execution, we may be stepping
6488 through a function epilogue and therefore must detect when
6489 the current-frame changes in the middle of a line. */
6491 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6493 && (execution_direction
!= EXEC_REVERSE
6494 || frame_id_eq (get_frame_id (frame
),
6495 ecs
->event_thread
->control
.step_frame_id
)))
6499 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6500 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6501 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6503 /* Tentatively re-enable range stepping; `resume' disables it if
6504 necessary (e.g., if we're stepping over a breakpoint or we
6505 have software watchpoints). */
6506 ecs
->event_thread
->control
.may_range_step
= 1;
6508 /* When stepping backward, stop at beginning of line range
6509 (unless it's the function entry point, in which case
6510 keep going back to the call point). */
6511 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6512 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6513 && stop_pc
!= ecs
->stop_func_start
6514 && execution_direction
== EXEC_REVERSE
)
6515 end_stepping_range (ecs
);
6522 /* We stepped out of the stepping range. */
6524 /* If we are stepping at the source level and entered the runtime
6525 loader dynamic symbol resolution code...
6527 EXEC_FORWARD: we keep on single stepping until we exit the run
6528 time loader code and reach the callee's address.
6530 EXEC_REVERSE: we've already executed the callee (backward), and
6531 the runtime loader code is handled just like any other
6532 undebuggable function call. Now we need only keep stepping
6533 backward through the trampoline code, and that's handled further
6534 down, so there is nothing for us to do here. */
6536 if (execution_direction
!= EXEC_REVERSE
6537 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6538 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6540 CORE_ADDR pc_after_resolver
=
6541 gdbarch_skip_solib_resolver (gdbarch
,
6542 ecs
->event_thread
->suspend
.stop_pc
);
6545 fprintf_unfiltered (gdb_stdlog
,
6546 "infrun: stepped into dynsym resolve code\n");
6548 if (pc_after_resolver
)
6550 /* Set up a step-resume breakpoint at the address
6551 indicated by SKIP_SOLIB_RESOLVER. */
6552 symtab_and_line sr_sal
;
6553 sr_sal
.pc
= pc_after_resolver
;
6554 sr_sal
.pspace
= get_frame_program_space (frame
);
6556 insert_step_resume_breakpoint_at_sal (gdbarch
,
6557 sr_sal
, null_frame_id
);
6564 /* Step through an indirect branch thunk. */
6565 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6566 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6567 ecs
->event_thread
->suspend
.stop_pc
))
6570 fprintf_unfiltered (gdb_stdlog
,
6571 "infrun: stepped into indirect branch thunk\n");
6576 if (ecs
->event_thread
->control
.step_range_end
!= 1
6577 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6578 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6579 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6582 fprintf_unfiltered (gdb_stdlog
,
6583 "infrun: stepped into signal trampoline\n");
6584 /* The inferior, while doing a "step" or "next", has ended up in
6585 a signal trampoline (either by a signal being delivered or by
6586 the signal handler returning). Just single-step until the
6587 inferior leaves the trampoline (either by calling the handler
6593 /* If we're in the return path from a shared library trampoline,
6594 we want to proceed through the trampoline when stepping. */
6595 /* macro/2012-04-25: This needs to come before the subroutine
6596 call check below as on some targets return trampolines look
6597 like subroutine calls (MIPS16 return thunks). */
6598 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6599 ecs
->event_thread
->suspend
.stop_pc
,
6600 ecs
->stop_func_name
)
6601 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6603 /* Determine where this trampoline returns. */
6604 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6605 CORE_ADDR real_stop_pc
6606 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6609 fprintf_unfiltered (gdb_stdlog
,
6610 "infrun: stepped into solib return tramp\n");
6612 /* Only proceed through if we know where it's going. */
6615 /* And put the step-breakpoint there and go until there. */
6616 symtab_and_line sr_sal
;
6617 sr_sal
.pc
= real_stop_pc
;
6618 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6619 sr_sal
.pspace
= get_frame_program_space (frame
);
6621 /* Do not specify what the fp should be when we stop since
6622 on some machines the prologue is where the new fp value
6624 insert_step_resume_breakpoint_at_sal (gdbarch
,
6625 sr_sal
, null_frame_id
);
6627 /* Restart without fiddling with the step ranges or
6634 /* Check for subroutine calls. The check for the current frame
6635 equalling the step ID is not necessary - the check of the
6636 previous frame's ID is sufficient - but it is a common case and
6637 cheaper than checking the previous frame's ID.
6639 NOTE: frame_id_eq will never report two invalid frame IDs as
6640 being equal, so to get into this block, both the current and
6641 previous frame must have valid frame IDs. */
6642 /* The outer_frame_id check is a heuristic to detect stepping
6643 through startup code. If we step over an instruction which
6644 sets the stack pointer from an invalid value to a valid value,
6645 we may detect that as a subroutine call from the mythical
6646 "outermost" function. This could be fixed by marking
6647 outermost frames as !stack_p,code_p,special_p. Then the
6648 initial outermost frame, before sp was valid, would
6649 have code_addr == &_start. See the comment in frame_id_eq
6651 if (!frame_id_eq (get_stack_frame_id (frame
),
6652 ecs
->event_thread
->control
.step_stack_frame_id
)
6653 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6654 ecs
->event_thread
->control
.step_stack_frame_id
)
6655 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6657 || (ecs
->event_thread
->control
.step_start_function
6658 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6660 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6661 CORE_ADDR real_stop_pc
;
6664 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6666 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6668 /* I presume that step_over_calls is only 0 when we're
6669 supposed to be stepping at the assembly language level
6670 ("stepi"). Just stop. */
6671 /* And this works the same backward as frontward. MVS */
6672 end_stepping_range (ecs
);
6676 /* Reverse stepping through solib trampolines. */
6678 if (execution_direction
== EXEC_REVERSE
6679 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6680 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6681 || (ecs
->stop_func_start
== 0
6682 && in_solib_dynsym_resolve_code (stop_pc
))))
6684 /* Any solib trampoline code can be handled in reverse
6685 by simply continuing to single-step. We have already
6686 executed the solib function (backwards), and a few
6687 steps will take us back through the trampoline to the
6693 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6695 /* We're doing a "next".
6697 Normal (forward) execution: set a breakpoint at the
6698 callee's return address (the address at which the caller
6701 Reverse (backward) execution. set the step-resume
6702 breakpoint at the start of the function that we just
6703 stepped into (backwards), and continue to there. When we
6704 get there, we'll need to single-step back to the caller. */
6706 if (execution_direction
== EXEC_REVERSE
)
6708 /* If we're already at the start of the function, we've either
6709 just stepped backward into a single instruction function,
6710 or stepped back out of a signal handler to the first instruction
6711 of the function. Just keep going, which will single-step back
6713 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6715 /* Normal function call return (static or dynamic). */
6716 symtab_and_line sr_sal
;
6717 sr_sal
.pc
= ecs
->stop_func_start
;
6718 sr_sal
.pspace
= get_frame_program_space (frame
);
6719 insert_step_resume_breakpoint_at_sal (gdbarch
,
6720 sr_sal
, null_frame_id
);
6724 insert_step_resume_breakpoint_at_caller (frame
);
6730 /* If we are in a function call trampoline (a stub between the
6731 calling routine and the real function), locate the real
6732 function. That's what tells us (a) whether we want to step
6733 into it at all, and (b) what prologue we want to run to the
6734 end of, if we do step into it. */
6735 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6736 if (real_stop_pc
== 0)
6737 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6738 if (real_stop_pc
!= 0)
6739 ecs
->stop_func_start
= real_stop_pc
;
6741 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6743 symtab_and_line sr_sal
;
6744 sr_sal
.pc
= ecs
->stop_func_start
;
6745 sr_sal
.pspace
= get_frame_program_space (frame
);
6747 insert_step_resume_breakpoint_at_sal (gdbarch
,
6748 sr_sal
, null_frame_id
);
6753 /* If we have line number information for the function we are
6754 thinking of stepping into and the function isn't on the skip
6757 If there are several symtabs at that PC (e.g. with include
6758 files), just want to know whether *any* of them have line
6759 numbers. find_pc_line handles this. */
6761 struct symtab_and_line tmp_sal
;
6763 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6764 if (tmp_sal
.line
!= 0
6765 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6768 if (execution_direction
== EXEC_REVERSE
)
6769 handle_step_into_function_backward (gdbarch
, ecs
);
6771 handle_step_into_function (gdbarch
, ecs
);
6776 /* If we have no line number and the step-stop-if-no-debug is
6777 set, we stop the step so that the user has a chance to switch
6778 in assembly mode. */
6779 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6780 && step_stop_if_no_debug
)
6782 end_stepping_range (ecs
);
6786 if (execution_direction
== EXEC_REVERSE
)
6788 /* If we're already at the start of the function, we've either just
6789 stepped backward into a single instruction function without line
6790 number info, or stepped back out of a signal handler to the first
6791 instruction of the function without line number info. Just keep
6792 going, which will single-step back to the caller. */
6793 if (ecs
->stop_func_start
!= stop_pc
)
6795 /* Set a breakpoint at callee's start address.
6796 From there we can step once and be back in the caller. */
6797 symtab_and_line sr_sal
;
6798 sr_sal
.pc
= ecs
->stop_func_start
;
6799 sr_sal
.pspace
= get_frame_program_space (frame
);
6800 insert_step_resume_breakpoint_at_sal (gdbarch
,
6801 sr_sal
, null_frame_id
);
6805 /* Set a breakpoint at callee's return address (the address
6806 at which the caller will resume). */
6807 insert_step_resume_breakpoint_at_caller (frame
);
6813 /* Reverse stepping through solib trampolines. */
6815 if (execution_direction
== EXEC_REVERSE
6816 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6818 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6820 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6821 || (ecs
->stop_func_start
== 0
6822 && in_solib_dynsym_resolve_code (stop_pc
)))
6824 /* Any solib trampoline code can be handled in reverse
6825 by simply continuing to single-step. We have already
6826 executed the solib function (backwards), and a few
6827 steps will take us back through the trampoline to the
6832 else if (in_solib_dynsym_resolve_code (stop_pc
))
6834 /* Stepped backward into the solib dynsym resolver.
6835 Set a breakpoint at its start and continue, then
6836 one more step will take us out. */
6837 symtab_and_line sr_sal
;
6838 sr_sal
.pc
= ecs
->stop_func_start
;
6839 sr_sal
.pspace
= get_frame_program_space (frame
);
6840 insert_step_resume_breakpoint_at_sal (gdbarch
,
6841 sr_sal
, null_frame_id
);
6847 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6849 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6850 the trampoline processing logic, however, there are some trampolines
6851 that have no names, so we should do trampoline handling first. */
6852 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6853 && ecs
->stop_func_name
== NULL
6854 && stop_pc_sal
.line
== 0)
6857 fprintf_unfiltered (gdb_stdlog
,
6858 "infrun: stepped into undebuggable function\n");
6860 /* The inferior just stepped into, or returned to, an
6861 undebuggable function (where there is no debugging information
6862 and no line number corresponding to the address where the
6863 inferior stopped). Since we want to skip this kind of code,
6864 we keep going until the inferior returns from this
6865 function - unless the user has asked us not to (via
6866 set step-mode) or we no longer know how to get back
6867 to the call site. */
6868 if (step_stop_if_no_debug
6869 || !frame_id_p (frame_unwind_caller_id (frame
)))
6871 /* If we have no line number and the step-stop-if-no-debug
6872 is set, we stop the step so that the user has a chance to
6873 switch in assembly mode. */
6874 end_stepping_range (ecs
);
6879 /* Set a breakpoint at callee's return address (the address
6880 at which the caller will resume). */
6881 insert_step_resume_breakpoint_at_caller (frame
);
6887 if (ecs
->event_thread
->control
.step_range_end
== 1)
6889 /* It is stepi or nexti. We always want to stop stepping after
6892 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6893 end_stepping_range (ecs
);
6897 if (stop_pc_sal
.line
== 0)
6899 /* We have no line number information. That means to stop
6900 stepping (does this always happen right after one instruction,
6901 when we do "s" in a function with no line numbers,
6902 or can this happen as a result of a return or longjmp?). */
6904 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6905 end_stepping_range (ecs
);
6909 /* Look for "calls" to inlined functions, part one. If the inline
6910 frame machinery detected some skipped call sites, we have entered
6911 a new inline function. */
6913 if (frame_id_eq (get_frame_id (get_current_frame ()),
6914 ecs
->event_thread
->control
.step_frame_id
)
6915 && inline_skipped_frames (ecs
->event_thread
))
6918 fprintf_unfiltered (gdb_stdlog
,
6919 "infrun: stepped into inlined function\n");
6921 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6923 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6925 /* For "step", we're going to stop. But if the call site
6926 for this inlined function is on the same source line as
6927 we were previously stepping, go down into the function
6928 first. Otherwise stop at the call site. */
6930 if (call_sal
.line
== ecs
->event_thread
->current_line
6931 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6932 step_into_inline_frame (ecs
->event_thread
);
6934 end_stepping_range (ecs
);
6939 /* For "next", we should stop at the call site if it is on a
6940 different source line. Otherwise continue through the
6941 inlined function. */
6942 if (call_sal
.line
== ecs
->event_thread
->current_line
6943 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6946 end_stepping_range (ecs
);
6951 /* Look for "calls" to inlined functions, part two. If we are still
6952 in the same real function we were stepping through, but we have
6953 to go further up to find the exact frame ID, we are stepping
6954 through a more inlined call beyond its call site. */
6956 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6957 && !frame_id_eq (get_frame_id (get_current_frame ()),
6958 ecs
->event_thread
->control
.step_frame_id
)
6959 && stepped_in_from (get_current_frame (),
6960 ecs
->event_thread
->control
.step_frame_id
))
6963 fprintf_unfiltered (gdb_stdlog
,
6964 "infrun: stepping through inlined function\n");
6966 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6969 end_stepping_range (ecs
);
6973 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
6974 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6975 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6977 /* We are at the start of a different line. So stop. Note that
6978 we don't stop if we step into the middle of a different line.
6979 That is said to make things like for (;;) statements work
6982 fprintf_unfiltered (gdb_stdlog
,
6983 "infrun: stepped to a different line\n");
6984 end_stepping_range (ecs
);
6988 /* We aren't done stepping.
6990 Optimize by setting the stepping range to the line.
6991 (We might not be in the original line, but if we entered a
6992 new line in mid-statement, we continue stepping. This makes
6993 things like for(;;) statements work better.) */
6995 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6996 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6997 ecs
->event_thread
->control
.may_range_step
= 1;
6998 set_step_info (frame
, stop_pc_sal
);
7001 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7005 /* In all-stop mode, if we're currently stepping but have stopped in
7006 some other thread, we may need to switch back to the stepped
7007 thread. Returns true we set the inferior running, false if we left
7008 it stopped (and the event needs further processing). */
7011 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7013 if (!target_is_non_stop_p ())
7015 struct thread_info
*tp
;
7016 struct thread_info
*stepping_thread
;
7018 /* If any thread is blocked on some internal breakpoint, and we
7019 simply need to step over that breakpoint to get it going
7020 again, do that first. */
7022 /* However, if we see an event for the stepping thread, then we
7023 know all other threads have been moved past their breakpoints
7024 already. Let the caller check whether the step is finished,
7025 etc., before deciding to move it past a breakpoint. */
7026 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7029 /* Check if the current thread is blocked on an incomplete
7030 step-over, interrupted by a random signal. */
7031 if (ecs
->event_thread
->control
.trap_expected
7032 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7036 fprintf_unfiltered (gdb_stdlog
,
7037 "infrun: need to finish step-over of [%s]\n",
7038 target_pid_to_str (ecs
->event_thread
->ptid
));
7044 /* Check if the current thread is blocked by a single-step
7045 breakpoint of another thread. */
7046 if (ecs
->hit_singlestep_breakpoint
)
7050 fprintf_unfiltered (gdb_stdlog
,
7051 "infrun: need to step [%s] over single-step "
7053 target_pid_to_str (ecs
->ptid
));
7059 /* If this thread needs yet another step-over (e.g., stepping
7060 through a delay slot), do it first before moving on to
7062 if (thread_still_needs_step_over (ecs
->event_thread
))
7066 fprintf_unfiltered (gdb_stdlog
,
7067 "infrun: thread [%s] still needs step-over\n",
7068 target_pid_to_str (ecs
->event_thread
->ptid
));
7074 /* If scheduler locking applies even if not stepping, there's no
7075 need to walk over threads. Above we've checked whether the
7076 current thread is stepping. If some other thread not the
7077 event thread is stepping, then it must be that scheduler
7078 locking is not in effect. */
7079 if (schedlock_applies (ecs
->event_thread
))
7082 /* Otherwise, we no longer expect a trap in the current thread.
7083 Clear the trap_expected flag before switching back -- this is
7084 what keep_going does as well, if we call it. */
7085 ecs
->event_thread
->control
.trap_expected
= 0;
7087 /* Likewise, clear the signal if it should not be passed. */
7088 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7089 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7091 /* Do all pending step-overs before actually proceeding with
7093 if (start_step_over ())
7095 prepare_to_wait (ecs
);
7099 /* Look for the stepping/nexting thread. */
7100 stepping_thread
= NULL
;
7102 ALL_NON_EXITED_THREADS (tp
)
7104 /* Ignore threads of processes the caller is not
7107 && tp
->ptid
.pid () != ecs
->ptid
.pid ())
7110 /* When stepping over a breakpoint, we lock all threads
7111 except the one that needs to move past the breakpoint.
7112 If a non-event thread has this set, the "incomplete
7113 step-over" check above should have caught it earlier. */
7114 if (tp
->control
.trap_expected
)
7116 internal_error (__FILE__
, __LINE__
,
7117 "[%s] has inconsistent state: "
7118 "trap_expected=%d\n",
7119 target_pid_to_str (tp
->ptid
),
7120 tp
->control
.trap_expected
);
7123 /* Did we find the stepping thread? */
7124 if (tp
->control
.step_range_end
)
7126 /* Yep. There should only one though. */
7127 gdb_assert (stepping_thread
== NULL
);
7129 /* The event thread is handled at the top, before we
7131 gdb_assert (tp
!= ecs
->event_thread
);
7133 /* If some thread other than the event thread is
7134 stepping, then scheduler locking can't be in effect,
7135 otherwise we wouldn't have resumed the current event
7136 thread in the first place. */
7137 gdb_assert (!schedlock_applies (tp
));
7139 stepping_thread
= tp
;
7143 if (stepping_thread
!= NULL
)
7146 fprintf_unfiltered (gdb_stdlog
,
7147 "infrun: switching back to stepped thread\n");
7149 if (keep_going_stepped_thread (stepping_thread
))
7151 prepare_to_wait (ecs
);
7160 /* Set a previously stepped thread back to stepping. Returns true on
7161 success, false if the resume is not possible (e.g., the thread
7165 keep_going_stepped_thread (struct thread_info
*tp
)
7167 struct frame_info
*frame
;
7168 struct execution_control_state ecss
;
7169 struct execution_control_state
*ecs
= &ecss
;
7171 /* If the stepping thread exited, then don't try to switch back and
7172 resume it, which could fail in several different ways depending
7173 on the target. Instead, just keep going.
7175 We can find a stepping dead thread in the thread list in two
7178 - The target supports thread exit events, and when the target
7179 tries to delete the thread from the thread list, inferior_ptid
7180 pointed at the exiting thread. In such case, calling
7181 delete_thread does not really remove the thread from the list;
7182 instead, the thread is left listed, with 'exited' state.
7184 - The target's debug interface does not support thread exit
7185 events, and so we have no idea whatsoever if the previously
7186 stepping thread is still alive. For that reason, we need to
7187 synchronously query the target now. */
7189 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7192 fprintf_unfiltered (gdb_stdlog
,
7193 "infrun: not resuming previously "
7194 "stepped thread, it has vanished\n");
7201 fprintf_unfiltered (gdb_stdlog
,
7202 "infrun: resuming previously stepped thread\n");
7204 reset_ecs (ecs
, tp
);
7205 switch_to_thread (tp
);
7207 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7208 frame
= get_current_frame ();
7210 /* If the PC of the thread we were trying to single-step has
7211 changed, then that thread has trapped or been signaled, but the
7212 event has not been reported to GDB yet. Re-poll the target
7213 looking for this particular thread's event (i.e. temporarily
7214 enable schedlock) by:
7216 - setting a break at the current PC
7217 - resuming that particular thread, only (by setting trap
7220 This prevents us continuously moving the single-step breakpoint
7221 forward, one instruction at a time, overstepping. */
7223 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7228 fprintf_unfiltered (gdb_stdlog
,
7229 "infrun: expected thread advanced also (%s -> %s)\n",
7230 paddress (target_gdbarch (), tp
->prev_pc
),
7231 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7233 /* Clear the info of the previous step-over, as it's no longer
7234 valid (if the thread was trying to step over a breakpoint, it
7235 has already succeeded). It's what keep_going would do too,
7236 if we called it. Do this before trying to insert the sss
7237 breakpoint, otherwise if we were previously trying to step
7238 over this exact address in another thread, the breakpoint is
7240 clear_step_over_info ();
7241 tp
->control
.trap_expected
= 0;
7243 insert_single_step_breakpoint (get_frame_arch (frame
),
7244 get_frame_address_space (frame
),
7245 tp
->suspend
.stop_pc
);
7248 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7249 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7254 fprintf_unfiltered (gdb_stdlog
,
7255 "infrun: expected thread still hasn't advanced\n");
7257 keep_going_pass_signal (ecs
);
7262 /* Is thread TP in the middle of (software or hardware)
7263 single-stepping? (Note the result of this function must never be
7264 passed directly as target_resume's STEP parameter.) */
7267 currently_stepping (struct thread_info
*tp
)
7269 return ((tp
->control
.step_range_end
7270 && tp
->control
.step_resume_breakpoint
== NULL
)
7271 || tp
->control
.trap_expected
7272 || tp
->stepped_breakpoint
7273 || bpstat_should_step ());
7276 /* Inferior has stepped into a subroutine call with source code that
7277 we should not step over. Do step to the first line of code in
7281 handle_step_into_function (struct gdbarch
*gdbarch
,
7282 struct execution_control_state
*ecs
)
7284 fill_in_stop_func (gdbarch
, ecs
);
7286 compunit_symtab
*cust
7287 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7288 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7289 ecs
->stop_func_start
7290 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7292 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7293 /* Use the step_resume_break to step until the end of the prologue,
7294 even if that involves jumps (as it seems to on the vax under
7296 /* If the prologue ends in the middle of a source line, continue to
7297 the end of that source line (if it is still within the function).
7298 Otherwise, just go to end of prologue. */
7299 if (stop_func_sal
.end
7300 && stop_func_sal
.pc
!= ecs
->stop_func_start
7301 && stop_func_sal
.end
< ecs
->stop_func_end
)
7302 ecs
->stop_func_start
= stop_func_sal
.end
;
7304 /* Architectures which require breakpoint adjustment might not be able
7305 to place a breakpoint at the computed address. If so, the test
7306 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7307 ecs->stop_func_start to an address at which a breakpoint may be
7308 legitimately placed.
7310 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7311 made, GDB will enter an infinite loop when stepping through
7312 optimized code consisting of VLIW instructions which contain
7313 subinstructions corresponding to different source lines. On
7314 FR-V, it's not permitted to place a breakpoint on any but the
7315 first subinstruction of a VLIW instruction. When a breakpoint is
7316 set, GDB will adjust the breakpoint address to the beginning of
7317 the VLIW instruction. Thus, we need to make the corresponding
7318 adjustment here when computing the stop address. */
7320 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7322 ecs
->stop_func_start
7323 = gdbarch_adjust_breakpoint_address (gdbarch
,
7324 ecs
->stop_func_start
);
7327 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7329 /* We are already there: stop now. */
7330 end_stepping_range (ecs
);
7335 /* Put the step-breakpoint there and go until there. */
7336 symtab_and_line sr_sal
;
7337 sr_sal
.pc
= ecs
->stop_func_start
;
7338 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7339 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7341 /* Do not specify what the fp should be when we stop since on
7342 some machines the prologue is where the new fp value is
7344 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7346 /* And make sure stepping stops right away then. */
7347 ecs
->event_thread
->control
.step_range_end
7348 = ecs
->event_thread
->control
.step_range_start
;
7353 /* Inferior has stepped backward into a subroutine call with source
7354 code that we should not step over. Do step to the beginning of the
7355 last line of code in it. */
7358 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7359 struct execution_control_state
*ecs
)
7361 struct compunit_symtab
*cust
;
7362 struct symtab_and_line stop_func_sal
;
7364 fill_in_stop_func (gdbarch
, ecs
);
7366 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7367 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7368 ecs
->stop_func_start
7369 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7371 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7373 /* OK, we're just going to keep stepping here. */
7374 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7376 /* We're there already. Just stop stepping now. */
7377 end_stepping_range (ecs
);
7381 /* Else just reset the step range and keep going.
7382 No step-resume breakpoint, they don't work for
7383 epilogues, which can have multiple entry paths. */
7384 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7385 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7391 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7392 This is used to both functions and to skip over code. */
7395 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7396 struct symtab_and_line sr_sal
,
7397 struct frame_id sr_id
,
7398 enum bptype sr_type
)
7400 /* There should never be more than one step-resume or longjmp-resume
7401 breakpoint per thread, so we should never be setting a new
7402 step_resume_breakpoint when one is already active. */
7403 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7404 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7407 fprintf_unfiltered (gdb_stdlog
,
7408 "infrun: inserting step-resume breakpoint at %s\n",
7409 paddress (gdbarch
, sr_sal
.pc
));
7411 inferior_thread ()->control
.step_resume_breakpoint
7412 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7416 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7417 struct symtab_and_line sr_sal
,
7418 struct frame_id sr_id
)
7420 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7425 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7426 This is used to skip a potential signal handler.
7428 This is called with the interrupted function's frame. The signal
7429 handler, when it returns, will resume the interrupted function at
7433 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7435 gdb_assert (return_frame
!= NULL
);
7437 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7439 symtab_and_line sr_sal
;
7440 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7441 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7442 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7444 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7445 get_stack_frame_id (return_frame
),
7449 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7450 is used to skip a function after stepping into it (for "next" or if
7451 the called function has no debugging information).
7453 The current function has almost always been reached by single
7454 stepping a call or return instruction. NEXT_FRAME belongs to the
7455 current function, and the breakpoint will be set at the caller's
7458 This is a separate function rather than reusing
7459 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7460 get_prev_frame, which may stop prematurely (see the implementation
7461 of frame_unwind_caller_id for an example). */
7464 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7466 /* We shouldn't have gotten here if we don't know where the call site
7468 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7470 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7472 symtab_and_line sr_sal
;
7473 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7474 frame_unwind_caller_pc (next_frame
));
7475 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7476 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7478 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7479 frame_unwind_caller_id (next_frame
));
7482 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7483 new breakpoint at the target of a jmp_buf. The handling of
7484 longjmp-resume uses the same mechanisms used for handling
7485 "step-resume" breakpoints. */
7488 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7490 /* There should never be more than one longjmp-resume breakpoint per
7491 thread, so we should never be setting a new
7492 longjmp_resume_breakpoint when one is already active. */
7493 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7496 fprintf_unfiltered (gdb_stdlog
,
7497 "infrun: inserting longjmp-resume breakpoint at %s\n",
7498 paddress (gdbarch
, pc
));
7500 inferior_thread ()->control
.exception_resume_breakpoint
=
7501 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7504 /* Insert an exception resume breakpoint. TP is the thread throwing
7505 the exception. The block B is the block of the unwinder debug hook
7506 function. FRAME is the frame corresponding to the call to this
7507 function. SYM is the symbol of the function argument holding the
7508 target PC of the exception. */
7511 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7512 const struct block
*b
,
7513 struct frame_info
*frame
,
7518 struct block_symbol vsym
;
7519 struct value
*value
;
7521 struct breakpoint
*bp
;
7523 vsym
= lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym
),
7525 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7526 /* If the value was optimized out, revert to the old behavior. */
7527 if (! value_optimized_out (value
))
7529 handler
= value_as_address (value
);
7532 fprintf_unfiltered (gdb_stdlog
,
7533 "infrun: exception resume at %lx\n",
7534 (unsigned long) handler
);
7536 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7538 bp_exception_resume
).release ();
7540 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7543 bp
->thread
= tp
->global_num
;
7544 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7547 CATCH (e
, RETURN_MASK_ERROR
)
7549 /* We want to ignore errors here. */
7554 /* A helper for check_exception_resume that sets an
7555 exception-breakpoint based on a SystemTap probe. */
7558 insert_exception_resume_from_probe (struct thread_info
*tp
,
7559 const struct bound_probe
*probe
,
7560 struct frame_info
*frame
)
7562 struct value
*arg_value
;
7564 struct breakpoint
*bp
;
7566 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7570 handler
= value_as_address (arg_value
);
7573 fprintf_unfiltered (gdb_stdlog
,
7574 "infrun: exception resume at %s\n",
7575 paddress (get_objfile_arch (probe
->objfile
),
7578 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7579 handler
, bp_exception_resume
).release ();
7580 bp
->thread
= tp
->global_num
;
7581 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7584 /* This is called when an exception has been intercepted. Check to
7585 see whether the exception's destination is of interest, and if so,
7586 set an exception resume breakpoint there. */
7589 check_exception_resume (struct execution_control_state
*ecs
,
7590 struct frame_info
*frame
)
7592 struct bound_probe probe
;
7593 struct symbol
*func
;
7595 /* First see if this exception unwinding breakpoint was set via a
7596 SystemTap probe point. If so, the probe has two arguments: the
7597 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7598 set a breakpoint there. */
7599 probe
= find_probe_by_pc (get_frame_pc (frame
));
7602 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7606 func
= get_frame_function (frame
);
7612 const struct block
*b
;
7613 struct block_iterator iter
;
7617 /* The exception breakpoint is a thread-specific breakpoint on
7618 the unwinder's debug hook, declared as:
7620 void _Unwind_DebugHook (void *cfa, void *handler);
7622 The CFA argument indicates the frame to which control is
7623 about to be transferred. HANDLER is the destination PC.
7625 We ignore the CFA and set a temporary breakpoint at HANDLER.
7626 This is not extremely efficient but it avoids issues in gdb
7627 with computing the DWARF CFA, and it also works even in weird
7628 cases such as throwing an exception from inside a signal
7631 b
= SYMBOL_BLOCK_VALUE (func
);
7632 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7634 if (!SYMBOL_IS_ARGUMENT (sym
))
7641 insert_exception_resume_breakpoint (ecs
->event_thread
,
7647 CATCH (e
, RETURN_MASK_ERROR
)
7654 stop_waiting (struct execution_control_state
*ecs
)
7657 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7659 /* Let callers know we don't want to wait for the inferior anymore. */
7660 ecs
->wait_some_more
= 0;
7662 /* If all-stop, but the target is always in non-stop mode, stop all
7663 threads now that we're presenting the stop to the user. */
7664 if (!non_stop
&& target_is_non_stop_p ())
7665 stop_all_threads ();
7668 /* Like keep_going, but passes the signal to the inferior, even if the
7669 signal is set to nopass. */
7672 keep_going_pass_signal (struct execution_control_state
*ecs
)
7674 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7675 gdb_assert (!ecs
->event_thread
->resumed
);
7677 /* Save the pc before execution, to compare with pc after stop. */
7678 ecs
->event_thread
->prev_pc
7679 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7681 if (ecs
->event_thread
->control
.trap_expected
)
7683 struct thread_info
*tp
= ecs
->event_thread
;
7686 fprintf_unfiltered (gdb_stdlog
,
7687 "infrun: %s has trap_expected set, "
7688 "resuming to collect trap\n",
7689 target_pid_to_str (tp
->ptid
));
7691 /* We haven't yet gotten our trap, and either: intercepted a
7692 non-signal event (e.g., a fork); or took a signal which we
7693 are supposed to pass through to the inferior. Simply
7695 resume (ecs
->event_thread
->suspend
.stop_signal
);
7697 else if (step_over_info_valid_p ())
7699 /* Another thread is stepping over a breakpoint in-line. If
7700 this thread needs a step-over too, queue the request. In
7701 either case, this resume must be deferred for later. */
7702 struct thread_info
*tp
= ecs
->event_thread
;
7704 if (ecs
->hit_singlestep_breakpoint
7705 || thread_still_needs_step_over (tp
))
7708 fprintf_unfiltered (gdb_stdlog
,
7709 "infrun: step-over already in progress: "
7710 "step-over for %s deferred\n",
7711 target_pid_to_str (tp
->ptid
));
7712 thread_step_over_chain_enqueue (tp
);
7717 fprintf_unfiltered (gdb_stdlog
,
7718 "infrun: step-over in progress: "
7719 "resume of %s deferred\n",
7720 target_pid_to_str (tp
->ptid
));
7725 struct regcache
*regcache
= get_current_regcache ();
7728 step_over_what step_what
;
7730 /* Either the trap was not expected, but we are continuing
7731 anyway (if we got a signal, the user asked it be passed to
7734 We got our expected trap, but decided we should resume from
7737 We're going to run this baby now!
7739 Note that insert_breakpoints won't try to re-insert
7740 already inserted breakpoints. Therefore, we don't
7741 care if breakpoints were already inserted, or not. */
7743 /* If we need to step over a breakpoint, and we're not using
7744 displaced stepping to do so, insert all breakpoints
7745 (watchpoints, etc.) but the one we're stepping over, step one
7746 instruction, and then re-insert the breakpoint when that step
7749 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7751 remove_bp
= (ecs
->hit_singlestep_breakpoint
7752 || (step_what
& STEP_OVER_BREAKPOINT
));
7753 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7755 /* We can't use displaced stepping if we need to step past a
7756 watchpoint. The instruction copied to the scratch pad would
7757 still trigger the watchpoint. */
7759 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7761 set_step_over_info (regcache
->aspace (),
7762 regcache_read_pc (regcache
), remove_wps
,
7763 ecs
->event_thread
->global_num
);
7765 else if (remove_wps
)
7766 set_step_over_info (NULL
, 0, remove_wps
, -1);
7768 /* If we now need to do an in-line step-over, we need to stop
7769 all other threads. Note this must be done before
7770 insert_breakpoints below, because that removes the breakpoint
7771 we're about to step over, otherwise other threads could miss
7773 if (step_over_info_valid_p () && target_is_non_stop_p ())
7774 stop_all_threads ();
7776 /* Stop stepping if inserting breakpoints fails. */
7779 insert_breakpoints ();
7781 CATCH (e
, RETURN_MASK_ERROR
)
7783 exception_print (gdb_stderr
, e
);
7785 clear_step_over_info ();
7790 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7792 resume (ecs
->event_thread
->suspend
.stop_signal
);
7795 prepare_to_wait (ecs
);
7798 /* Called when we should continue running the inferior, because the
7799 current event doesn't cause a user visible stop. This does the
7800 resuming part; waiting for the next event is done elsewhere. */
7803 keep_going (struct execution_control_state
*ecs
)
7805 if (ecs
->event_thread
->control
.trap_expected
7806 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7807 ecs
->event_thread
->control
.trap_expected
= 0;
7809 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7810 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7811 keep_going_pass_signal (ecs
);
7814 /* This function normally comes after a resume, before
7815 handle_inferior_event exits. It takes care of any last bits of
7816 housekeeping, and sets the all-important wait_some_more flag. */
7819 prepare_to_wait (struct execution_control_state
*ecs
)
7822 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7824 ecs
->wait_some_more
= 1;
7826 if (!target_is_async_p ())
7827 mark_infrun_async_event_handler ();
7830 /* We are done with the step range of a step/next/si/ni command.
7831 Called once for each n of a "step n" operation. */
7834 end_stepping_range (struct execution_control_state
*ecs
)
7836 ecs
->event_thread
->control
.stop_step
= 1;
7840 /* Several print_*_reason functions to print why the inferior has stopped.
7841 We always print something when the inferior exits, or receives a signal.
7842 The rest of the cases are dealt with later on in normal_stop and
7843 print_it_typical. Ideally there should be a call to one of these
7844 print_*_reason functions functions from handle_inferior_event each time
7845 stop_waiting is called.
7847 Note that we don't call these directly, instead we delegate that to
7848 the interpreters, through observers. Interpreters then call these
7849 with whatever uiout is right. */
7852 print_end_stepping_range_reason (struct ui_out
*uiout
)
7854 /* For CLI-like interpreters, print nothing. */
7856 if (uiout
->is_mi_like_p ())
7858 uiout
->field_string ("reason",
7859 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7864 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7866 annotate_signalled ();
7867 if (uiout
->is_mi_like_p ())
7869 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7870 uiout
->text ("\nProgram terminated with signal ");
7871 annotate_signal_name ();
7872 uiout
->field_string ("signal-name",
7873 gdb_signal_to_name (siggnal
));
7874 annotate_signal_name_end ();
7876 annotate_signal_string ();
7877 uiout
->field_string ("signal-meaning",
7878 gdb_signal_to_string (siggnal
));
7879 annotate_signal_string_end ();
7880 uiout
->text (".\n");
7881 uiout
->text ("The program no longer exists.\n");
7885 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7887 struct inferior
*inf
= current_inferior ();
7888 const char *pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7890 annotate_exited (exitstatus
);
7893 if (uiout
->is_mi_like_p ())
7894 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7895 uiout
->text ("[Inferior ");
7896 uiout
->text (plongest (inf
->num
));
7898 uiout
->text (pidstr
);
7899 uiout
->text (") exited with code ");
7900 uiout
->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus
);
7901 uiout
->text ("]\n");
7905 if (uiout
->is_mi_like_p ())
7907 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7908 uiout
->text ("[Inferior ");
7909 uiout
->text (plongest (inf
->num
));
7911 uiout
->text (pidstr
);
7912 uiout
->text (") exited normally]\n");
7916 /* Some targets/architectures can do extra processing/display of
7917 segmentation faults. E.g., Intel MPX boundary faults.
7918 Call the architecture dependent function to handle the fault. */
7921 handle_segmentation_fault (struct ui_out
*uiout
)
7923 struct regcache
*regcache
= get_current_regcache ();
7924 struct gdbarch
*gdbarch
= regcache
->arch ();
7926 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7927 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7931 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7933 struct thread_info
*thr
= inferior_thread ();
7937 if (uiout
->is_mi_like_p ())
7939 else if (show_thread_that_caused_stop ())
7943 uiout
->text ("\nThread ");
7944 uiout
->field_fmt ("thread-id", "%s", print_thread_id (thr
));
7946 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7949 uiout
->text (" \"");
7950 uiout
->field_fmt ("name", "%s", name
);
7955 uiout
->text ("\nProgram");
7957 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7958 uiout
->text (" stopped");
7961 uiout
->text (" received signal ");
7962 annotate_signal_name ();
7963 if (uiout
->is_mi_like_p ())
7965 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7966 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7967 annotate_signal_name_end ();
7969 annotate_signal_string ();
7970 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7972 if (siggnal
== GDB_SIGNAL_SEGV
)
7973 handle_segmentation_fault (uiout
);
7975 annotate_signal_string_end ();
7977 uiout
->text (".\n");
7981 print_no_history_reason (struct ui_out
*uiout
)
7983 uiout
->text ("\nNo more reverse-execution history.\n");
7986 /* Print current location without a level number, if we have changed
7987 functions or hit a breakpoint. Print source line if we have one.
7988 bpstat_print contains the logic deciding in detail what to print,
7989 based on the event(s) that just occurred. */
7992 print_stop_location (struct target_waitstatus
*ws
)
7995 enum print_what source_flag
;
7996 int do_frame_printing
= 1;
7997 struct thread_info
*tp
= inferior_thread ();
7999 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8003 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8004 should) carry around the function and does (or should) use
8005 that when doing a frame comparison. */
8006 if (tp
->control
.stop_step
8007 && frame_id_eq (tp
->control
.step_frame_id
,
8008 get_frame_id (get_current_frame ()))
8009 && (tp
->control
.step_start_function
8010 == find_pc_function (tp
->suspend
.stop_pc
)))
8012 /* Finished step, just print source line. */
8013 source_flag
= SRC_LINE
;
8017 /* Print location and source line. */
8018 source_flag
= SRC_AND_LOC
;
8021 case PRINT_SRC_AND_LOC
:
8022 /* Print location and source line. */
8023 source_flag
= SRC_AND_LOC
;
8025 case PRINT_SRC_ONLY
:
8026 source_flag
= SRC_LINE
;
8029 /* Something bogus. */
8030 source_flag
= SRC_LINE
;
8031 do_frame_printing
= 0;
8034 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8037 /* The behavior of this routine with respect to the source
8039 SRC_LINE: Print only source line
8040 LOCATION: Print only location
8041 SRC_AND_LOC: Print location and source line. */
8042 if (do_frame_printing
)
8043 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8049 print_stop_event (struct ui_out
*uiout
)
8051 struct target_waitstatus last
;
8053 struct thread_info
*tp
;
8055 get_last_target_status (&last_ptid
, &last
);
8058 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8060 print_stop_location (&last
);
8062 /* Display the auto-display expressions. */
8066 tp
= inferior_thread ();
8067 if (tp
->thread_fsm
!= NULL
8068 && thread_fsm_finished_p (tp
->thread_fsm
))
8070 struct return_value_info
*rv
;
8072 rv
= thread_fsm_return_value (tp
->thread_fsm
);
8074 print_return_value (uiout
, rv
);
8081 maybe_remove_breakpoints (void)
8083 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8085 if (remove_breakpoints ())
8087 target_terminal::ours_for_output ();
8088 printf_filtered (_("Cannot remove breakpoints because "
8089 "program is no longer writable.\nFurther "
8090 "execution is probably impossible.\n"));
8095 /* The execution context that just caused a normal stop. */
8102 /* The event PTID. */
8106 /* If stopp for a thread event, this is the thread that caused the
8108 struct thread_info
*thread
;
8110 /* The inferior that caused the stop. */
8114 /* Returns a new stop context. If stopped for a thread event, this
8115 takes a strong reference to the thread. */
8117 static struct stop_context
*
8118 save_stop_context (void)
8120 struct stop_context
*sc
= XNEW (struct stop_context
);
8122 sc
->stop_id
= get_stop_id ();
8123 sc
->ptid
= inferior_ptid
;
8124 sc
->inf_num
= current_inferior ()->num
;
8126 if (inferior_ptid
!= null_ptid
)
8128 /* Take a strong reference so that the thread can't be deleted
8130 sc
->thread
= inferior_thread ();
8131 sc
->thread
->incref ();
8139 /* Release a stop context previously created with save_stop_context.
8140 Releases the strong reference to the thread as well. */
8143 release_stop_context_cleanup (void *arg
)
8145 struct stop_context
*sc
= (struct stop_context
*) arg
;
8147 if (sc
->thread
!= NULL
)
8148 sc
->thread
->decref ();
8152 /* Return true if the current context no longer matches the saved stop
8156 stop_context_changed (struct stop_context
*prev
)
8158 if (prev
->ptid
!= inferior_ptid
)
8160 if (prev
->inf_num
!= current_inferior ()->num
)
8162 if (prev
->thread
!= NULL
&& prev
->thread
->state
!= THREAD_STOPPED
)
8164 if (get_stop_id () != prev
->stop_id
)
8174 struct target_waitstatus last
;
8177 get_last_target_status (&last_ptid
, &last
);
8181 /* If an exception is thrown from this point on, make sure to
8182 propagate GDB's knowledge of the executing state to the
8183 frontend/user running state. A QUIT is an easy exception to see
8184 here, so do this before any filtered output. */
8186 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8189 maybe_finish_thread_state
.emplace (minus_one_ptid
);
8190 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8191 || last
.kind
== TARGET_WAITKIND_EXITED
)
8193 /* On some targets, we may still have live threads in the
8194 inferior when we get a process exit event. E.g., for
8195 "checkpoint", when the current checkpoint/fork exits,
8196 linux-fork.c automatically switches to another fork from
8197 within target_mourn_inferior. */
8198 if (inferior_ptid
!= null_ptid
)
8199 maybe_finish_thread_state
.emplace (ptid_t (inferior_ptid
.pid ()));
8201 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8202 maybe_finish_thread_state
.emplace (inferior_ptid
);
8204 /* As we're presenting a stop, and potentially removing breakpoints,
8205 update the thread list so we can tell whether there are threads
8206 running on the target. With target remote, for example, we can
8207 only learn about new threads when we explicitly update the thread
8208 list. Do this before notifying the interpreters about signal
8209 stops, end of stepping ranges, etc., so that the "new thread"
8210 output is emitted before e.g., "Program received signal FOO",
8211 instead of after. */
8212 update_thread_list ();
8214 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8215 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8217 /* As with the notification of thread events, we want to delay
8218 notifying the user that we've switched thread context until
8219 the inferior actually stops.
8221 There's no point in saying anything if the inferior has exited.
8222 Note that SIGNALLED here means "exited with a signal", not
8223 "received a signal".
8225 Also skip saying anything in non-stop mode. In that mode, as we
8226 don't want GDB to switch threads behind the user's back, to avoid
8227 races where the user is typing a command to apply to thread x,
8228 but GDB switches to thread y before the user finishes entering
8229 the command, fetch_inferior_event installs a cleanup to restore
8230 the current thread back to the thread the user had selected right
8231 after this event is handled, so we're not really switching, only
8232 informing of a stop. */
8234 && previous_inferior_ptid
!= inferior_ptid
8235 && target_has_execution
8236 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8237 && last
.kind
!= TARGET_WAITKIND_EXITED
8238 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8240 SWITCH_THRU_ALL_UIS ()
8242 target_terminal::ours_for_output ();
8243 printf_filtered (_("[Switching to %s]\n"),
8244 target_pid_to_str (inferior_ptid
));
8245 annotate_thread_changed ();
8247 previous_inferior_ptid
= inferior_ptid
;
8250 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8252 SWITCH_THRU_ALL_UIS ()
8253 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8255 target_terminal::ours_for_output ();
8256 printf_filtered (_("No unwaited-for children left.\n"));
8260 /* Note: this depends on the update_thread_list call above. */
8261 maybe_remove_breakpoints ();
8263 /* If an auto-display called a function and that got a signal,
8264 delete that auto-display to avoid an infinite recursion. */
8266 if (stopped_by_random_signal
)
8267 disable_current_display ();
8269 SWITCH_THRU_ALL_UIS ()
8271 async_enable_stdin ();
8274 /* Let the user/frontend see the threads as stopped. */
8275 maybe_finish_thread_state
.reset ();
8277 /* Select innermost stack frame - i.e., current frame is frame 0,
8278 and current location is based on that. Handle the case where the
8279 dummy call is returning after being stopped. E.g. the dummy call
8280 previously hit a breakpoint. (If the dummy call returns
8281 normally, we won't reach here.) Do this before the stop hook is
8282 run, so that it doesn't get to see the temporary dummy frame,
8283 which is not where we'll present the stop. */
8284 if (has_stack_frames ())
8286 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8288 /* Pop the empty frame that contains the stack dummy. This
8289 also restores inferior state prior to the call (struct
8290 infcall_suspend_state). */
8291 struct frame_info
*frame
= get_current_frame ();
8293 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8295 /* frame_pop calls reinit_frame_cache as the last thing it
8296 does which means there's now no selected frame. */
8299 select_frame (get_current_frame ());
8301 /* Set the current source location. */
8302 set_current_sal_from_frame (get_current_frame ());
8305 /* Look up the hook_stop and run it (CLI internally handles problem
8306 of stop_command's pre-hook not existing). */
8307 if (stop_command
!= NULL
)
8309 struct stop_context
*saved_context
= save_stop_context ();
8310 struct cleanup
*old_chain
8311 = make_cleanup (release_stop_context_cleanup
, saved_context
);
8315 execute_cmd_pre_hook (stop_command
);
8317 CATCH (ex
, RETURN_MASK_ALL
)
8319 exception_fprintf (gdb_stderr
, ex
,
8320 "Error while running hook_stop:\n");
8324 /* If the stop hook resumes the target, then there's no point in
8325 trying to notify about the previous stop; its context is
8326 gone. Likewise if the command switches thread or inferior --
8327 the observers would print a stop for the wrong
8329 if (stop_context_changed (saved_context
))
8331 do_cleanups (old_chain
);
8334 do_cleanups (old_chain
);
8337 /* Notify observers about the stop. This is where the interpreters
8338 print the stop event. */
8339 if (inferior_ptid
!= null_ptid
)
8340 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8343 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8345 annotate_stopped ();
8347 if (target_has_execution
)
8349 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8350 && last
.kind
!= TARGET_WAITKIND_EXITED
)
8351 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8352 Delete any breakpoint that is to be deleted at the next stop. */
8353 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8356 /* Try to get rid of automatically added inferiors that are no
8357 longer needed. Keeping those around slows down things linearly.
8358 Note that this never removes the current inferior. */
8365 signal_stop_state (int signo
)
8367 return signal_stop
[signo
];
8371 signal_print_state (int signo
)
8373 return signal_print
[signo
];
8377 signal_pass_state (int signo
)
8379 return signal_program
[signo
];
8383 signal_cache_update (int signo
)
8387 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8388 signal_cache_update (signo
);
8393 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8394 && signal_print
[signo
] == 0
8395 && signal_program
[signo
] == 1
8396 && signal_catch
[signo
] == 0);
8400 signal_stop_update (int signo
, int state
)
8402 int ret
= signal_stop
[signo
];
8404 signal_stop
[signo
] = state
;
8405 signal_cache_update (signo
);
8410 signal_print_update (int signo
, int state
)
8412 int ret
= signal_print
[signo
];
8414 signal_print
[signo
] = state
;
8415 signal_cache_update (signo
);
8420 signal_pass_update (int signo
, int state
)
8422 int ret
= signal_program
[signo
];
8424 signal_program
[signo
] = state
;
8425 signal_cache_update (signo
);
8429 /* Update the global 'signal_catch' from INFO and notify the
8433 signal_catch_update (const unsigned int *info
)
8437 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8438 signal_catch
[i
] = info
[i
] > 0;
8439 signal_cache_update (-1);
8440 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8444 sig_print_header (void)
8446 printf_filtered (_("Signal Stop\tPrint\tPass "
8447 "to program\tDescription\n"));
8451 sig_print_info (enum gdb_signal oursig
)
8453 const char *name
= gdb_signal_to_name (oursig
);
8454 int name_padding
= 13 - strlen (name
);
8456 if (name_padding
<= 0)
8459 printf_filtered ("%s", name
);
8460 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8461 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8462 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8463 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8464 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8467 /* Specify how various signals in the inferior should be handled. */
8470 handle_command (const char *args
, int from_tty
)
8472 int digits
, wordlen
;
8473 int sigfirst
, signum
, siglast
;
8474 enum gdb_signal oursig
;
8477 unsigned char *sigs
;
8481 error_no_arg (_("signal to handle"));
8484 /* Allocate and zero an array of flags for which signals to handle. */
8486 nsigs
= (int) GDB_SIGNAL_LAST
;
8487 sigs
= (unsigned char *) alloca (nsigs
);
8488 memset (sigs
, 0, nsigs
);
8490 /* Break the command line up into args. */
8492 gdb_argv
built_argv (args
);
8494 /* Walk through the args, looking for signal oursigs, signal names, and
8495 actions. Signal numbers and signal names may be interspersed with
8496 actions, with the actions being performed for all signals cumulatively
8497 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8499 for (char *arg
: built_argv
)
8501 wordlen
= strlen (arg
);
8502 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8506 sigfirst
= siglast
= -1;
8508 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8510 /* Apply action to all signals except those used by the
8511 debugger. Silently skip those. */
8514 siglast
= nsigs
- 1;
8516 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8518 SET_SIGS (nsigs
, sigs
, signal_stop
);
8519 SET_SIGS (nsigs
, sigs
, signal_print
);
8521 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8523 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8525 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8527 SET_SIGS (nsigs
, sigs
, signal_print
);
8529 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8531 SET_SIGS (nsigs
, sigs
, signal_program
);
8533 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8535 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8537 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8539 SET_SIGS (nsigs
, sigs
, signal_program
);
8541 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8543 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8544 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8546 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8548 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8550 else if (digits
> 0)
8552 /* It is numeric. The numeric signal refers to our own
8553 internal signal numbering from target.h, not to host/target
8554 signal number. This is a feature; users really should be
8555 using symbolic names anyway, and the common ones like
8556 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8558 sigfirst
= siglast
= (int)
8559 gdb_signal_from_command (atoi (arg
));
8560 if (arg
[digits
] == '-')
8563 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8565 if (sigfirst
> siglast
)
8567 /* Bet he didn't figure we'd think of this case... */
8575 oursig
= gdb_signal_from_name (arg
);
8576 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8578 sigfirst
= siglast
= (int) oursig
;
8582 /* Not a number and not a recognized flag word => complain. */
8583 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8587 /* If any signal numbers or symbol names were found, set flags for
8588 which signals to apply actions to. */
8590 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8592 switch ((enum gdb_signal
) signum
)
8594 case GDB_SIGNAL_TRAP
:
8595 case GDB_SIGNAL_INT
:
8596 if (!allsigs
&& !sigs
[signum
])
8598 if (query (_("%s is used by the debugger.\n\
8599 Are you sure you want to change it? "),
8600 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8606 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8607 gdb_flush (gdb_stdout
);
8612 case GDB_SIGNAL_DEFAULT
:
8613 case GDB_SIGNAL_UNKNOWN
:
8614 /* Make sure that "all" doesn't print these. */
8623 for (signum
= 0; signum
< nsigs
; signum
++)
8626 signal_cache_update (-1);
8627 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8628 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
8632 /* Show the results. */
8633 sig_print_header ();
8634 for (; signum
< nsigs
; signum
++)
8636 sig_print_info ((enum gdb_signal
) signum
);
8643 /* Complete the "handle" command. */
8646 handle_completer (struct cmd_list_element
*ignore
,
8647 completion_tracker
&tracker
,
8648 const char *text
, const char *word
)
8650 static const char * const keywords
[] =
8664 signal_completer (ignore
, tracker
, text
, word
);
8665 complete_on_enum (tracker
, keywords
, word
, word
);
8669 gdb_signal_from_command (int num
)
8671 if (num
>= 1 && num
<= 15)
8672 return (enum gdb_signal
) num
;
8673 error (_("Only signals 1-15 are valid as numeric signals.\n\
8674 Use \"info signals\" for a list of symbolic signals."));
8677 /* Print current contents of the tables set by the handle command.
8678 It is possible we should just be printing signals actually used
8679 by the current target (but for things to work right when switching
8680 targets, all signals should be in the signal tables). */
8683 info_signals_command (const char *signum_exp
, int from_tty
)
8685 enum gdb_signal oursig
;
8687 sig_print_header ();
8691 /* First see if this is a symbol name. */
8692 oursig
= gdb_signal_from_name (signum_exp
);
8693 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8695 /* No, try numeric. */
8697 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8699 sig_print_info (oursig
);
8703 printf_filtered ("\n");
8704 /* These ugly casts brought to you by the native VAX compiler. */
8705 for (oursig
= GDB_SIGNAL_FIRST
;
8706 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8707 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8711 if (oursig
!= GDB_SIGNAL_UNKNOWN
8712 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8713 sig_print_info (oursig
);
8716 printf_filtered (_("\nUse the \"handle\" command "
8717 "to change these tables.\n"));
8720 /* The $_siginfo convenience variable is a bit special. We don't know
8721 for sure the type of the value until we actually have a chance to
8722 fetch the data. The type can change depending on gdbarch, so it is
8723 also dependent on which thread you have selected.
8725 1. making $_siginfo be an internalvar that creates a new value on
8728 2. making the value of $_siginfo be an lval_computed value. */
8730 /* This function implements the lval_computed support for reading a
8734 siginfo_value_read (struct value
*v
)
8736 LONGEST transferred
;
8738 /* If we can access registers, so can we access $_siginfo. Likewise
8740 validate_registers_access ();
8743 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8745 value_contents_all_raw (v
),
8747 TYPE_LENGTH (value_type (v
)));
8749 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8750 error (_("Unable to read siginfo"));
8753 /* This function implements the lval_computed support for writing a
8757 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8759 LONGEST transferred
;
8761 /* If we can access registers, so can we access $_siginfo. Likewise
8763 validate_registers_access ();
8765 transferred
= target_write (current_top_target (),
8766 TARGET_OBJECT_SIGNAL_INFO
,
8768 value_contents_all_raw (fromval
),
8770 TYPE_LENGTH (value_type (fromval
)));
8772 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8773 error (_("Unable to write siginfo"));
8776 static const struct lval_funcs siginfo_value_funcs
=
8782 /* Return a new value with the correct type for the siginfo object of
8783 the current thread using architecture GDBARCH. Return a void value
8784 if there's no object available. */
8786 static struct value
*
8787 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8790 if (target_has_stack
8791 && inferior_ptid
!= null_ptid
8792 && gdbarch_get_siginfo_type_p (gdbarch
))
8794 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8796 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8799 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8803 /* infcall_suspend_state contains state about the program itself like its
8804 registers and any signal it received when it last stopped.
8805 This state must be restored regardless of how the inferior function call
8806 ends (either successfully, or after it hits a breakpoint or signal)
8807 if the program is to properly continue where it left off. */
8809 struct infcall_suspend_state
8811 struct thread_suspend_state thread_suspend
;
8814 readonly_detached_regcache
*registers
;
8816 /* Format of SIGINFO_DATA or NULL if it is not present. */
8817 struct gdbarch
*siginfo_gdbarch
;
8819 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8820 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8821 content would be invalid. */
8822 gdb_byte
*siginfo_data
;
8825 struct infcall_suspend_state
*
8826 save_infcall_suspend_state (void)
8828 struct infcall_suspend_state
*inf_state
;
8829 struct thread_info
*tp
= inferior_thread ();
8830 struct regcache
*regcache
= get_current_regcache ();
8831 struct gdbarch
*gdbarch
= regcache
->arch ();
8832 gdb_byte
*siginfo_data
= NULL
;
8834 if (gdbarch_get_siginfo_type_p (gdbarch
))
8836 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8837 size_t len
= TYPE_LENGTH (type
);
8838 struct cleanup
*back_to
;
8840 siginfo_data
= (gdb_byte
*) xmalloc (len
);
8841 back_to
= make_cleanup (xfree
, siginfo_data
);
8843 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8844 siginfo_data
, 0, len
) == len
)
8845 discard_cleanups (back_to
);
8848 /* Errors ignored. */
8849 do_cleanups (back_to
);
8850 siginfo_data
= NULL
;
8854 inf_state
= XCNEW (struct infcall_suspend_state
);
8858 inf_state
->siginfo_gdbarch
= gdbarch
;
8859 inf_state
->siginfo_data
= siginfo_data
;
8862 inf_state
->thread_suspend
= tp
->suspend
;
8864 /* run_inferior_call will not use the signal due to its `proceed' call with
8865 GDB_SIGNAL_0 anyway. */
8866 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8868 inf_state
->registers
= new readonly_detached_regcache (*regcache
);
8873 /* Restore inferior session state to INF_STATE. */
8876 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8878 struct thread_info
*tp
= inferior_thread ();
8879 struct regcache
*regcache
= get_current_regcache ();
8880 struct gdbarch
*gdbarch
= regcache
->arch ();
8882 tp
->suspend
= inf_state
->thread_suspend
;
8884 if (inf_state
->siginfo_gdbarch
== gdbarch
)
8886 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8888 /* Errors ignored. */
8889 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8890 inf_state
->siginfo_data
, 0, TYPE_LENGTH (type
));
8893 /* The inferior can be gone if the user types "print exit(0)"
8894 (and perhaps other times). */
8895 if (target_has_execution
)
8896 /* NB: The register write goes through to the target. */
8897 regcache
->restore (inf_state
->registers
);
8899 discard_infcall_suspend_state (inf_state
);
8903 do_restore_infcall_suspend_state_cleanup (void *state
)
8905 restore_infcall_suspend_state ((struct infcall_suspend_state
*) state
);
8909 make_cleanup_restore_infcall_suspend_state
8910 (struct infcall_suspend_state
*inf_state
)
8912 return make_cleanup (do_restore_infcall_suspend_state_cleanup
, inf_state
);
8916 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8918 delete inf_state
->registers
;
8919 xfree (inf_state
->siginfo_data
);
8923 readonly_detached_regcache
*
8924 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8926 return inf_state
->registers
;
8929 /* infcall_control_state contains state regarding gdb's control of the
8930 inferior itself like stepping control. It also contains session state like
8931 the user's currently selected frame. */
8933 struct infcall_control_state
8935 struct thread_control_state thread_control
;
8936 struct inferior_control_state inferior_control
;
8939 enum stop_stack_kind stop_stack_dummy
;
8940 int stopped_by_random_signal
;
8942 /* ID if the selected frame when the inferior function call was made. */
8943 struct frame_id selected_frame_id
;
8946 /* Save all of the information associated with the inferior<==>gdb
8949 struct infcall_control_state
*
8950 save_infcall_control_state (void)
8952 struct infcall_control_state
*inf_status
=
8953 XNEW (struct infcall_control_state
);
8954 struct thread_info
*tp
= inferior_thread ();
8955 struct inferior
*inf
= current_inferior ();
8957 inf_status
->thread_control
= tp
->control
;
8958 inf_status
->inferior_control
= inf
->control
;
8960 tp
->control
.step_resume_breakpoint
= NULL
;
8961 tp
->control
.exception_resume_breakpoint
= NULL
;
8963 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8964 chain. If caller's caller is walking the chain, they'll be happier if we
8965 hand them back the original chain when restore_infcall_control_state is
8967 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8970 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8971 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8973 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
8979 restore_selected_frame (const frame_id
&fid
)
8981 frame_info
*frame
= frame_find_by_id (fid
);
8983 /* If inf_status->selected_frame_id is NULL, there was no previously
8987 warning (_("Unable to restore previously selected frame."));
8991 select_frame (frame
);
8994 /* Restore inferior session state to INF_STATUS. */
8997 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8999 struct thread_info
*tp
= inferior_thread ();
9000 struct inferior
*inf
= current_inferior ();
9002 if (tp
->control
.step_resume_breakpoint
)
9003 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9005 if (tp
->control
.exception_resume_breakpoint
)
9006 tp
->control
.exception_resume_breakpoint
->disposition
9007 = disp_del_at_next_stop
;
9009 /* Handle the bpstat_copy of the chain. */
9010 bpstat_clear (&tp
->control
.stop_bpstat
);
9012 tp
->control
= inf_status
->thread_control
;
9013 inf
->control
= inf_status
->inferior_control
;
9016 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9017 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9019 if (target_has_stack
)
9021 /* The point of the try/catch is that if the stack is clobbered,
9022 walking the stack might encounter a garbage pointer and
9023 error() trying to dereference it. */
9026 restore_selected_frame (inf_status
->selected_frame_id
);
9028 CATCH (ex
, RETURN_MASK_ERROR
)
9030 exception_fprintf (gdb_stderr
, ex
,
9031 "Unable to restore previously selected frame:\n");
9032 /* Error in restoring the selected frame. Select the
9034 select_frame (get_current_frame ());
9043 do_restore_infcall_control_state_cleanup (void *sts
)
9045 restore_infcall_control_state ((struct infcall_control_state
*) sts
);
9049 make_cleanup_restore_infcall_control_state
9050 (struct infcall_control_state
*inf_status
)
9052 return make_cleanup (do_restore_infcall_control_state_cleanup
, inf_status
);
9056 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9058 if (inf_status
->thread_control
.step_resume_breakpoint
)
9059 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9060 = disp_del_at_next_stop
;
9062 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9063 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9064 = disp_del_at_next_stop
;
9066 /* See save_infcall_control_state for info on stop_bpstat. */
9067 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9075 clear_exit_convenience_vars (void)
9077 clear_internalvar (lookup_internalvar ("_exitsignal"));
9078 clear_internalvar (lookup_internalvar ("_exitcode"));
9082 /* User interface for reverse debugging:
9083 Set exec-direction / show exec-direction commands
9084 (returns error unless target implements to_set_exec_direction method). */
9086 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9087 static const char exec_forward
[] = "forward";
9088 static const char exec_reverse
[] = "reverse";
9089 static const char *exec_direction
= exec_forward
;
9090 static const char *const exec_direction_names
[] = {
9097 set_exec_direction_func (const char *args
, int from_tty
,
9098 struct cmd_list_element
*cmd
)
9100 if (target_can_execute_reverse
)
9102 if (!strcmp (exec_direction
, exec_forward
))
9103 execution_direction
= EXEC_FORWARD
;
9104 else if (!strcmp (exec_direction
, exec_reverse
))
9105 execution_direction
= EXEC_REVERSE
;
9109 exec_direction
= exec_forward
;
9110 error (_("Target does not support this operation."));
9115 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9116 struct cmd_list_element
*cmd
, const char *value
)
9118 switch (execution_direction
) {
9120 fprintf_filtered (out
, _("Forward.\n"));
9123 fprintf_filtered (out
, _("Reverse.\n"));
9126 internal_error (__FILE__
, __LINE__
,
9127 _("bogus execution_direction value: %d"),
9128 (int) execution_direction
);
9133 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9134 struct cmd_list_element
*c
, const char *value
)
9136 fprintf_filtered (file
, _("Resuming the execution of threads "
9137 "of all processes is %s.\n"), value
);
9140 /* Implementation of `siginfo' variable. */
9142 static const struct internalvar_funcs siginfo_funcs
=
9149 /* Callback for infrun's target events source. This is marked when a
9150 thread has a pending status to process. */
9153 infrun_async_inferior_event_handler (gdb_client_data data
)
9155 inferior_event_handler (INF_REG_EVENT
, NULL
);
9159 _initialize_infrun (void)
9163 struct cmd_list_element
*c
;
9165 /* Register extra event sources in the event loop. */
9166 infrun_async_inferior_event_token
9167 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9169 add_info ("signals", info_signals_command
, _("\
9170 What debugger does when program gets various signals.\n\
9171 Specify a signal as argument to print info on that signal only."));
9172 add_info_alias ("handle", "signals", 0);
9174 c
= add_com ("handle", class_run
, handle_command
, _("\
9175 Specify how to handle signals.\n\
9176 Usage: handle SIGNAL [ACTIONS]\n\
9177 Args are signals and actions to apply to those signals.\n\
9178 If no actions are specified, the current settings for the specified signals\n\
9179 will be displayed instead.\n\
9181 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9182 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9183 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9184 The special arg \"all\" is recognized to mean all signals except those\n\
9185 used by the debugger, typically SIGTRAP and SIGINT.\n\
9187 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9188 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9189 Stop means reenter debugger if this signal happens (implies print).\n\
9190 Print means print a message if this signal happens.\n\
9191 Pass means let program see this signal; otherwise program doesn't know.\n\
9192 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9193 Pass and Stop may be combined.\n\
9195 Multiple signals may be specified. Signal numbers and signal names\n\
9196 may be interspersed with actions, with the actions being performed for\n\
9197 all signals cumulatively specified."));
9198 set_cmd_completer (c
, handle_completer
);
9201 stop_command
= add_cmd ("stop", class_obscure
,
9202 not_just_help_class_command
, _("\
9203 There is no `stop' command, but you can set a hook on `stop'.\n\
9204 This allows you to set a list of commands to be run each time execution\n\
9205 of the program stops."), &cmdlist
);
9207 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9208 Set inferior debugging."), _("\
9209 Show inferior debugging."), _("\
9210 When non-zero, inferior specific debugging is enabled."),
9213 &setdebuglist
, &showdebuglist
);
9215 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9216 &debug_displaced
, _("\
9217 Set displaced stepping debugging."), _("\
9218 Show displaced stepping debugging."), _("\
9219 When non-zero, displaced stepping specific debugging is enabled."),
9221 show_debug_displaced
,
9222 &setdebuglist
, &showdebuglist
);
9224 add_setshow_boolean_cmd ("non-stop", no_class
,
9226 Set whether gdb controls the inferior in non-stop mode."), _("\
9227 Show whether gdb controls the inferior in non-stop mode."), _("\
9228 When debugging a multi-threaded program and this setting is\n\
9229 off (the default, also called all-stop mode), when one thread stops\n\
9230 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9231 all other threads in the program while you interact with the thread of\n\
9232 interest. When you continue or step a thread, you can allow the other\n\
9233 threads to run, or have them remain stopped, but while you inspect any\n\
9234 thread's state, all threads stop.\n\
9236 In non-stop mode, when one thread stops, other threads can continue\n\
9237 to run freely. You'll be able to step each thread independently,\n\
9238 leave it stopped or free to run as needed."),
9244 numsigs
= (int) GDB_SIGNAL_LAST
;
9245 signal_stop
= XNEWVEC (unsigned char, numsigs
);
9246 signal_print
= XNEWVEC (unsigned char, numsigs
);
9247 signal_program
= XNEWVEC (unsigned char, numsigs
);
9248 signal_catch
= XNEWVEC (unsigned char, numsigs
);
9249 signal_pass
= XNEWVEC (unsigned char, numsigs
);
9250 for (i
= 0; i
< numsigs
; i
++)
9253 signal_print
[i
] = 1;
9254 signal_program
[i
] = 1;
9255 signal_catch
[i
] = 0;
9258 /* Signals caused by debugger's own actions should not be given to
9259 the program afterwards.
9261 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9262 explicitly specifies that it should be delivered to the target
9263 program. Typically, that would occur when a user is debugging a
9264 target monitor on a simulator: the target monitor sets a
9265 breakpoint; the simulator encounters this breakpoint and halts
9266 the simulation handing control to GDB; GDB, noting that the stop
9267 address doesn't map to any known breakpoint, returns control back
9268 to the simulator; the simulator then delivers the hardware
9269 equivalent of a GDB_SIGNAL_TRAP to the program being
9271 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9272 signal_program
[GDB_SIGNAL_INT
] = 0;
9274 /* Signals that are not errors should not normally enter the debugger. */
9275 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9276 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9277 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9278 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9279 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9280 signal_print
[GDB_SIGNAL_PROF
] = 0;
9281 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9282 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9283 signal_stop
[GDB_SIGNAL_IO
] = 0;
9284 signal_print
[GDB_SIGNAL_IO
] = 0;
9285 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9286 signal_print
[GDB_SIGNAL_POLL
] = 0;
9287 signal_stop
[GDB_SIGNAL_URG
] = 0;
9288 signal_print
[GDB_SIGNAL_URG
] = 0;
9289 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9290 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9291 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9292 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9294 /* These signals are used internally by user-level thread
9295 implementations. (See signal(5) on Solaris.) Like the above
9296 signals, a healthy program receives and handles them as part of
9297 its normal operation. */
9298 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9299 signal_print
[GDB_SIGNAL_LWP
] = 0;
9300 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9301 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9302 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9303 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9304 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9305 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9307 /* Update cached state. */
9308 signal_cache_update (-1);
9310 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9311 &stop_on_solib_events
, _("\
9312 Set stopping for shared library events."), _("\
9313 Show stopping for shared library events."), _("\
9314 If nonzero, gdb will give control to the user when the dynamic linker\n\
9315 notifies gdb of shared library events. The most common event of interest\n\
9316 to the user would be loading/unloading of a new library."),
9317 set_stop_on_solib_events
,
9318 show_stop_on_solib_events
,
9319 &setlist
, &showlist
);
9321 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9322 follow_fork_mode_kind_names
,
9323 &follow_fork_mode_string
, _("\
9324 Set debugger response to a program call of fork or vfork."), _("\
9325 Show debugger response to a program call of fork or vfork."), _("\
9326 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9327 parent - the original process is debugged after a fork\n\
9328 child - the new process is debugged after a fork\n\
9329 The unfollowed process will continue to run.\n\
9330 By default, the debugger will follow the parent process."),
9332 show_follow_fork_mode_string
,
9333 &setlist
, &showlist
);
9335 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9336 follow_exec_mode_names
,
9337 &follow_exec_mode_string
, _("\
9338 Set debugger response to a program call of exec."), _("\
9339 Show debugger response to a program call of exec."), _("\
9340 An exec call replaces the program image of a process.\n\
9342 follow-exec-mode can be:\n\
9344 new - the debugger creates a new inferior and rebinds the process\n\
9345 to this new inferior. The program the process was running before\n\
9346 the exec call can be restarted afterwards by restarting the original\n\
9349 same - the debugger keeps the process bound to the same inferior.\n\
9350 The new executable image replaces the previous executable loaded in\n\
9351 the inferior. Restarting the inferior after the exec call restarts\n\
9352 the executable the process was running after the exec call.\n\
9354 By default, the debugger will use the same inferior."),
9356 show_follow_exec_mode_string
,
9357 &setlist
, &showlist
);
9359 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9360 scheduler_enums
, &scheduler_mode
, _("\
9361 Set mode for locking scheduler during execution."), _("\
9362 Show mode for locking scheduler during execution."), _("\
9363 off == no locking (threads may preempt at any time)\n\
9364 on == full locking (no thread except the current thread may run)\n\
9365 This applies to both normal execution and replay mode.\n\
9366 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9367 In this mode, other threads may run during other commands.\n\
9368 This applies to both normal execution and replay mode.\n\
9369 replay == scheduler locked in replay mode and unlocked during normal execution."),
9370 set_schedlock_func
, /* traps on target vector */
9371 show_scheduler_mode
,
9372 &setlist
, &showlist
);
9374 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9375 Set mode for resuming threads of all processes."), _("\
9376 Show mode for resuming threads of all processes."), _("\
9377 When on, execution commands (such as 'continue' or 'next') resume all\n\
9378 threads of all processes. When off (which is the default), execution\n\
9379 commands only resume the threads of the current process. The set of\n\
9380 threads that are resumed is further refined by the scheduler-locking\n\
9381 mode (see help set scheduler-locking)."),
9383 show_schedule_multiple
,
9384 &setlist
, &showlist
);
9386 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9387 Set mode of the step operation."), _("\
9388 Show mode of the step operation."), _("\
9389 When set, doing a step over a function without debug line information\n\
9390 will stop at the first instruction of that function. Otherwise, the\n\
9391 function is skipped and the step command stops at a different source line."),
9393 show_step_stop_if_no_debug
,
9394 &setlist
, &showlist
);
9396 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9397 &can_use_displaced_stepping
, _("\
9398 Set debugger's willingness to use displaced stepping."), _("\
9399 Show debugger's willingness to use displaced stepping."), _("\
9400 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9401 supported by the target architecture. If off, gdb will not use displaced\n\
9402 stepping to step over breakpoints, even if such is supported by the target\n\
9403 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9404 if the target architecture supports it and non-stop mode is active, but will not\n\
9405 use it in all-stop mode (see help set non-stop)."),
9407 show_can_use_displaced_stepping
,
9408 &setlist
, &showlist
);
9410 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9411 &exec_direction
, _("Set direction of execution.\n\
9412 Options are 'forward' or 'reverse'."),
9413 _("Show direction of execution (forward/reverse)."),
9414 _("Tells gdb whether to execute forward or backward."),
9415 set_exec_direction_func
, show_exec_direction_func
,
9416 &setlist
, &showlist
);
9418 /* Set/show detach-on-fork: user-settable mode. */
9420 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9421 Set whether gdb will detach the child of a fork."), _("\
9422 Show whether gdb will detach the child of a fork."), _("\
9423 Tells gdb whether to detach the child of a fork."),
9424 NULL
, NULL
, &setlist
, &showlist
);
9426 /* Set/show disable address space randomization mode. */
9428 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9429 &disable_randomization
, _("\
9430 Set disabling of debuggee's virtual address space randomization."), _("\
9431 Show disabling of debuggee's virtual address space randomization."), _("\
9432 When this mode is on (which is the default), randomization of the virtual\n\
9433 address space is disabled. Standalone programs run with the randomization\n\
9434 enabled by default on some platforms."),
9435 &set_disable_randomization
,
9436 &show_disable_randomization
,
9437 &setlist
, &showlist
);
9439 /* ptid initializations */
9440 inferior_ptid
= null_ptid
;
9441 target_last_wait_ptid
= minus_one_ptid
;
9443 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9444 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9445 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9446 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9448 /* Explicitly create without lookup, since that tries to create a
9449 value with a void typed value, and when we get here, gdbarch
9450 isn't initialized yet. At this point, we're quite sure there
9451 isn't another convenience variable of the same name. */
9452 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9454 add_setshow_boolean_cmd ("observer", no_class
,
9455 &observer_mode_1
, _("\
9456 Set whether gdb controls the inferior in observer mode."), _("\
9457 Show whether gdb controls the inferior in observer mode."), _("\
9458 In observer mode, GDB can get data from the inferior, but not\n\
9459 affect its execution. Registers and memory may not be changed,\n\
9460 breakpoints may not be set, and the program cannot be interrupted\n\