1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2023 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/>. */
22 #include "displaced-stepping.h"
28 #include "breakpoint.h"
32 #include "target-connection.h"
33 #include "gdbthread.h"
41 #include "observable.h"
46 #include "mi/mi-common.h"
47 #include "event-top.h"
49 #include "record-full.h"
50 #include "inline-frame.h"
52 #include "tracepoint.h"
56 #include "completer.h"
57 #include "target-descriptions.h"
58 #include "target-dcache.h"
61 #include "gdbsupport/event-loop.h"
62 #include "thread-fsm.h"
63 #include "gdbsupport/enum-flags.h"
64 #include "progspace-and-thread.h"
65 #include "gdbsupport/gdb_optional.h"
66 #include "arch-utils.h"
67 #include "gdbsupport/scope-exit.h"
68 #include "gdbsupport/forward-scope-exit.h"
69 #include "gdbsupport/gdb_select.h"
70 #include <unordered_map>
71 #include "async-event.h"
72 #include "gdbsupport/selftest.h"
73 #include "scoped-mock-context.h"
74 #include "test-target.h"
75 #include "gdbsupport/common-debug.h"
76 #include "gdbsupport/buildargv.h"
77 #include "extension.h"
81 /* Prototypes for local functions */
83 static void sig_print_info (enum gdb_signal
);
85 static void sig_print_header (void);
87 static void follow_inferior_reset_breakpoints (void);
89 static bool currently_stepping (struct thread_info
*tp
);
91 static void insert_hp_step_resume_breakpoint_at_frame (frame_info_ptr
);
93 static void insert_step_resume_breakpoint_at_caller (frame_info_ptr
);
95 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
97 static bool maybe_software_singlestep (struct gdbarch
*gdbarch
);
99 static void resume (gdb_signal sig
);
101 static void wait_for_inferior (inferior
*inf
);
103 static void restart_threads (struct thread_info
*event_thread
,
104 inferior
*inf
= nullptr);
106 static bool start_step_over (void);
108 static bool step_over_info_valid_p (void);
110 /* Asynchronous signal handler registered as event loop source for
111 when we have pending events ready to be passed to the core. */
112 static struct async_event_handler
*infrun_async_inferior_event_token
;
114 /* Stores whether infrun_async was previously enabled or disabled.
115 Starts off as -1, indicating "never enabled/disabled". */
116 static int infrun_is_async
= -1;
121 infrun_async (int enable
)
123 if (infrun_is_async
!= enable
)
125 infrun_is_async
= enable
;
127 infrun_debug_printf ("enable=%d", enable
);
130 mark_async_event_handler (infrun_async_inferior_event_token
);
132 clear_async_event_handler (infrun_async_inferior_event_token
);
139 mark_infrun_async_event_handler (void)
141 mark_async_event_handler (infrun_async_inferior_event_token
);
144 /* When set, stop the 'step' command if we enter a function which has
145 no line number information. The normal behavior is that we step
146 over such function. */
147 bool step_stop_if_no_debug
= false;
149 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
150 struct cmd_list_element
*c
, const char *value
)
152 gdb_printf (file
, _("Mode of the step operation is %s.\n"), value
);
155 /* proceed and normal_stop use this to notify the user when the
156 inferior stopped in a different thread than it had been running in.
157 It can also be used to find for which thread normal_stop last
159 static thread_info_ref previous_thread
;
164 update_previous_thread ()
166 if (inferior_ptid
== null_ptid
)
167 previous_thread
= nullptr;
169 previous_thread
= thread_info_ref::new_reference (inferior_thread ());
175 get_previous_thread ()
177 return previous_thread
.get ();
180 /* If set (default for legacy reasons), when following a fork, GDB
181 will detach from one of the fork branches, child or parent.
182 Exactly which branch is detached depends on 'set follow-fork-mode'
185 static bool detach_fork
= true;
187 bool debug_infrun
= false;
189 show_debug_infrun (struct ui_file
*file
, int from_tty
,
190 struct cmd_list_element
*c
, const char *value
)
192 gdb_printf (file
, _("Inferior debugging is %s.\n"), value
);
195 /* Support for disabling address space randomization. */
197 bool disable_randomization
= true;
200 show_disable_randomization (struct ui_file
*file
, int from_tty
,
201 struct cmd_list_element
*c
, const char *value
)
203 if (target_supports_disable_randomization ())
205 _("Disabling randomization of debuggee's "
206 "virtual address space is %s.\n"),
209 gdb_puts (_("Disabling randomization of debuggee's "
210 "virtual address space is unsupported on\n"
211 "this platform.\n"), file
);
215 set_disable_randomization (const char *args
, int from_tty
,
216 struct cmd_list_element
*c
)
218 if (!target_supports_disable_randomization ())
219 error (_("Disabling randomization of debuggee's "
220 "virtual address space is unsupported on\n"
224 /* User interface for non-stop mode. */
226 bool non_stop
= false;
227 static bool non_stop_1
= false;
230 set_non_stop (const char *args
, int from_tty
,
231 struct cmd_list_element
*c
)
233 if (target_has_execution ())
235 non_stop_1
= non_stop
;
236 error (_("Cannot change this setting while the inferior is running."));
239 non_stop
= non_stop_1
;
243 show_non_stop (struct ui_file
*file
, int from_tty
,
244 struct cmd_list_element
*c
, const char *value
)
247 _("Controlling the inferior in non-stop mode is %s.\n"),
251 /* "Observer mode" is somewhat like a more extreme version of
252 non-stop, in which all GDB operations that might affect the
253 target's execution have been disabled. */
255 static bool observer_mode
= false;
256 static bool observer_mode_1
= false;
259 set_observer_mode (const char *args
, int from_tty
,
260 struct cmd_list_element
*c
)
262 if (target_has_execution ())
264 observer_mode_1
= observer_mode
;
265 error (_("Cannot change this setting while the inferior is running."));
268 observer_mode
= observer_mode_1
;
270 may_write_registers
= !observer_mode
;
271 may_write_memory
= !observer_mode
;
272 may_insert_breakpoints
= !observer_mode
;
273 may_insert_tracepoints
= !observer_mode
;
274 /* We can insert fast tracepoints in or out of observer mode,
275 but enable them if we're going into this mode. */
277 may_insert_fast_tracepoints
= true;
278 may_stop
= !observer_mode
;
279 update_target_permissions ();
281 /* Going *into* observer mode we must force non-stop, then
282 going out we leave it that way. */
285 pagination_enabled
= false;
286 non_stop
= non_stop_1
= true;
290 gdb_printf (_("Observer mode is now %s.\n"),
291 (observer_mode
? "on" : "off"));
295 show_observer_mode (struct ui_file
*file
, int from_tty
,
296 struct cmd_list_element
*c
, const char *value
)
298 gdb_printf (file
, _("Observer mode is %s.\n"), value
);
301 /* This updates the value of observer mode based on changes in
302 permissions. Note that we are deliberately ignoring the values of
303 may-write-registers and may-write-memory, since the user may have
304 reason to enable these during a session, for instance to turn on a
305 debugging-related global. */
308 update_observer_mode (void)
310 bool newval
= (!may_insert_breakpoints
311 && !may_insert_tracepoints
312 && may_insert_fast_tracepoints
316 /* Let the user know if things change. */
317 if (newval
!= observer_mode
)
318 gdb_printf (_("Observer mode is now %s.\n"),
319 (newval
? "on" : "off"));
321 observer_mode
= observer_mode_1
= newval
;
324 /* Tables of how to react to signals; the user sets them. */
326 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
327 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
328 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
330 /* Table of signals that are registered with "catch signal". A
331 non-zero entry indicates that the signal is caught by some "catch
333 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
335 /* Table of signals that the target may silently handle.
336 This is automatically determined from the flags above,
337 and simply cached here. */
338 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
340 #define SET_SIGS(nsigs,sigs,flags) \
342 int signum = (nsigs); \
343 while (signum-- > 0) \
344 if ((sigs)[signum]) \
345 (flags)[signum] = 1; \
348 #define UNSET_SIGS(nsigs,sigs,flags) \
350 int signum = (nsigs); \
351 while (signum-- > 0) \
352 if ((sigs)[signum]) \
353 (flags)[signum] = 0; \
356 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
357 this function is to avoid exporting `signal_program'. */
360 update_signals_program_target (void)
362 target_program_signals (signal_program
);
365 /* Value to pass to target_resume() to cause all threads to resume. */
367 #define RESUME_ALL minus_one_ptid
369 /* Command list pointer for the "stop" placeholder. */
371 static struct cmd_list_element
*stop_command
;
373 /* Nonzero if we want to give control to the user when we're notified
374 of shared library events by the dynamic linker. */
375 int stop_on_solib_events
;
377 /* Enable or disable optional shared library event breakpoints
378 as appropriate when the above flag is changed. */
381 set_stop_on_solib_events (const char *args
,
382 int from_tty
, struct cmd_list_element
*c
)
384 update_solib_breakpoints ();
388 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
389 struct cmd_list_element
*c
, const char *value
)
391 gdb_printf (file
, _("Stopping for shared library events is %s.\n"),
395 /* True after stop if current stack frame should be printed. */
397 static bool stop_print_frame
;
399 /* This is a cached copy of the target/ptid/waitstatus of the last
400 event returned by target_wait().
401 This information is returned by get_last_target_status(). */
402 static process_stratum_target
*target_last_proc_target
;
403 static ptid_t target_last_wait_ptid
;
404 static struct target_waitstatus target_last_waitstatus
;
406 void init_thread_stepping_state (struct thread_info
*tss
);
408 static const char follow_fork_mode_child
[] = "child";
409 static const char follow_fork_mode_parent
[] = "parent";
411 static const char *const follow_fork_mode_kind_names
[] = {
412 follow_fork_mode_child
,
413 follow_fork_mode_parent
,
417 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
419 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
420 struct cmd_list_element
*c
, const char *value
)
423 _("Debugger response to a program "
424 "call of fork or vfork is \"%s\".\n"),
429 /* Handle changes to the inferior list based on the type of fork,
430 which process is being followed, and whether the other process
431 should be detached. On entry inferior_ptid must be the ptid of
432 the fork parent. At return inferior_ptid is the ptid of the
433 followed inferior. */
436 follow_fork_inferior (bool follow_child
, bool detach_fork
)
438 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
440 infrun_debug_printf ("follow_child = %d, detach_fork = %d",
441 follow_child
, detach_fork
);
443 target_waitkind fork_kind
= inferior_thread ()->pending_follow
.kind ();
444 gdb_assert (fork_kind
== TARGET_WAITKIND_FORKED
445 || fork_kind
== TARGET_WAITKIND_VFORKED
);
446 bool has_vforked
= fork_kind
== TARGET_WAITKIND_VFORKED
;
447 ptid_t parent_ptid
= inferior_ptid
;
448 ptid_t child_ptid
= inferior_thread ()->pending_follow
.child_ptid ();
451 && !non_stop
/* Non-stop always resumes both branches. */
452 && current_ui
->prompt_state
== PROMPT_BLOCKED
453 && !(follow_child
|| detach_fork
|| sched_multi
))
455 /* The parent stays blocked inside the vfork syscall until the
456 child execs or exits. If we don't let the child run, then
457 the parent stays blocked. If we're telling the parent to run
458 in the foreground, the user will not be able to ctrl-c to get
459 back the terminal, effectively hanging the debug session. */
460 gdb_printf (gdb_stderr
, _("\
461 Can not resume the parent process over vfork in the foreground while\n\
462 holding the child stopped. Try \"set detach-on-fork\" or \
463 \"set schedule-multiple\".\n"));
467 inferior
*parent_inf
= current_inferior ();
468 inferior
*child_inf
= nullptr;
470 gdb_assert (parent_inf
->thread_waiting_for_vfork_done
== nullptr);
474 /* Detach new forked process? */
477 /* Before detaching from the child, remove all breakpoints
478 from it. If we forked, then this has already been taken
479 care of by infrun.c. If we vforked however, any
480 breakpoint inserted in the parent is visible in the
481 child, even those added while stopped in a vfork
482 catchpoint. This will remove the breakpoints from the
483 parent also, but they'll be reinserted below. */
486 /* Keep breakpoints list in sync. */
487 remove_breakpoints_inf (current_inferior ());
490 if (print_inferior_events
)
492 /* Ensure that we have a process ptid. */
493 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
495 target_terminal::ours_for_output ();
496 gdb_printf (_("[Detaching after %s from child %s]\n"),
497 has_vforked
? "vfork" : "fork",
498 target_pid_to_str (process_ptid
).c_str ());
503 /* Add process to GDB's tables. */
504 child_inf
= add_inferior (child_ptid
.pid ());
506 child_inf
->attach_flag
= parent_inf
->attach_flag
;
507 copy_terminal_info (child_inf
, parent_inf
);
508 child_inf
->set_arch (parent_inf
->arch ());
509 child_inf
->tdesc_info
= parent_inf
->tdesc_info
;
511 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
513 /* If this is a vfork child, then the address-space is
514 shared with the parent. */
517 child_inf
->pspace
= parent_inf
->pspace
;
518 child_inf
->aspace
= parent_inf
->aspace
;
520 exec_on_vfork (child_inf
);
522 /* The parent will be frozen until the child is done
523 with the shared region. Keep track of the
525 child_inf
->vfork_parent
= parent_inf
;
526 child_inf
->pending_detach
= false;
527 parent_inf
->vfork_child
= child_inf
;
528 parent_inf
->pending_detach
= false;
532 child_inf
->aspace
= new address_space ();
533 child_inf
->pspace
= new program_space (child_inf
->aspace
);
534 child_inf
->removable
= true;
535 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
541 /* If we detached from the child, then we have to be careful
542 to not insert breakpoints in the parent until the child
543 is done with the shared memory region. However, if we're
544 staying attached to the child, then we can and should
545 insert breakpoints, so that we can debug it. A
546 subsequent child exec or exit is enough to know when does
547 the child stops using the parent's address space. */
548 parent_inf
->thread_waiting_for_vfork_done
549 = detach_fork
? inferior_thread () : nullptr;
550 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
553 ("parent_inf->thread_waiting_for_vfork_done == %s",
554 (parent_inf
->thread_waiting_for_vfork_done
== nullptr
556 : (parent_inf
->thread_waiting_for_vfork_done
557 ->ptid
.to_string ().c_str ())));
562 /* Follow the child. */
564 if (print_inferior_events
)
566 std::string parent_pid
= target_pid_to_str (parent_ptid
);
567 std::string child_pid
= target_pid_to_str (child_ptid
);
569 target_terminal::ours_for_output ();
570 gdb_printf (_("[Attaching after %s %s to child %s]\n"),
572 has_vforked
? "vfork" : "fork",
576 /* Add the new inferior first, so that the target_detach below
577 doesn't unpush the target. */
579 child_inf
= add_inferior (child_ptid
.pid ());
581 child_inf
->attach_flag
= parent_inf
->attach_flag
;
582 copy_terminal_info (child_inf
, parent_inf
);
583 child_inf
->set_arch (parent_inf
->arch ());
584 child_inf
->tdesc_info
= parent_inf
->tdesc_info
;
588 /* If this is a vfork child, then the address-space is shared
590 child_inf
->aspace
= parent_inf
->aspace
;
591 child_inf
->pspace
= parent_inf
->pspace
;
593 exec_on_vfork (child_inf
);
595 else if (detach_fork
)
597 /* We follow the child and detach from the parent: move the parent's
598 program space to the child. This simplifies some things, like
599 doing "next" over fork() and landing on the expected line in the
600 child (note, that is broken with "set detach-on-fork off").
602 Before assigning brand new spaces for the parent, remove
603 breakpoints from it: because the new pspace won't match
604 currently inserted locations, the normal detach procedure
605 wouldn't remove them, and we would leave them inserted when
607 remove_breakpoints_inf (parent_inf
);
609 child_inf
->aspace
= parent_inf
->aspace
;
610 child_inf
->pspace
= parent_inf
->pspace
;
611 parent_inf
->aspace
= new address_space ();
612 parent_inf
->pspace
= new program_space (parent_inf
->aspace
);
613 clone_program_space (parent_inf
->pspace
, child_inf
->pspace
);
615 /* The parent inferior is still the current one, so keep things
617 set_current_program_space (parent_inf
->pspace
);
621 child_inf
->aspace
= new address_space ();
622 child_inf
->pspace
= new program_space (child_inf
->aspace
);
623 child_inf
->removable
= true;
624 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
625 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
629 gdb_assert (current_inferior () == parent_inf
);
631 /* If we are setting up an inferior for the child, target_follow_fork is
632 responsible for pushing the appropriate targets on the new inferior's
633 target stack and adding the initial thread (with ptid CHILD_PTID).
635 If we are not setting up an inferior for the child (because following
636 the parent and detach_fork is true), it is responsible for detaching
638 target_follow_fork (child_inf
, child_ptid
, fork_kind
, follow_child
,
641 gdb::observers::inferior_forked
.notify (parent_inf
, child_inf
, fork_kind
);
643 /* target_follow_fork must leave the parent as the current inferior. If we
644 want to follow the child, we make it the current one below. */
645 gdb_assert (current_inferior () == parent_inf
);
647 /* If there is a child inferior, target_follow_fork must have created a thread
649 if (child_inf
!= nullptr)
650 gdb_assert (!child_inf
->thread_list
.empty ());
652 /* Clear the parent thread's pending follow field. Do this before calling
653 target_detach, so that the target can differentiate the two following
656 - We continue past a fork with "follow-fork-mode == child" &&
657 "detach-on-fork on", and therefore detach the parent. In that
658 case the target should not detach the fork child.
659 - We run to a fork catchpoint and the user types "detach". In that
660 case, the target should detach the fork child in addition to the
663 The former case will have pending_follow cleared, the later will have
664 pending_follow set. */
665 thread_info
*parent_thread
= parent_inf
->find_thread (parent_ptid
);
666 gdb_assert (parent_thread
!= nullptr);
667 parent_thread
->pending_follow
.set_spurious ();
669 /* Detach the parent if needed. */
672 /* If we're vforking, we want to hold on to the parent until
673 the child exits or execs. At child exec or exit time we
674 can remove the old breakpoints from the parent and detach
675 or resume debugging it. Otherwise, detach the parent now;
676 we'll want to reuse it's program/address spaces, but we
677 can't set them to the child before removing breakpoints
678 from the parent, otherwise, the breakpoints module could
679 decide to remove breakpoints from the wrong process (since
680 they'd be assigned to the same address space). */
684 gdb_assert (child_inf
->vfork_parent
== nullptr);
685 gdb_assert (parent_inf
->vfork_child
== nullptr);
686 child_inf
->vfork_parent
= parent_inf
;
687 child_inf
->pending_detach
= false;
688 parent_inf
->vfork_child
= child_inf
;
689 parent_inf
->pending_detach
= detach_fork
;
691 else if (detach_fork
)
693 if (print_inferior_events
)
695 /* Ensure that we have a process ptid. */
696 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
698 target_terminal::ours_for_output ();
699 gdb_printf (_("[Detaching after fork from "
701 target_pid_to_str (process_ptid
).c_str ());
704 target_detach (parent_inf
, 0);
708 /* If we ended up creating a new inferior, call post_create_inferior to inform
709 the various subcomponents. */
710 if (child_inf
!= nullptr)
712 /* If FOLLOW_CHILD, we leave CHILD_INF as the current inferior
713 (do not restore the parent as the current inferior). */
714 gdb::optional
<scoped_restore_current_thread
> maybe_restore
;
716 if (!follow_child
&& !sched_multi
)
717 maybe_restore
.emplace ();
719 switch_to_thread (*child_inf
->threads ().begin ());
720 post_create_inferior (0);
726 /* Set the last target status as TP having stopped. */
729 set_last_target_status_stopped (thread_info
*tp
)
731 set_last_target_status (tp
->inf
->process_target (), tp
->ptid
,
732 target_waitstatus
{}.set_stopped (GDB_SIGNAL_0
));
735 /* Tell the target to follow the fork we're stopped at. Returns true
736 if the inferior should be resumed; false, if the target for some
737 reason decided it's best not to resume. */
742 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
744 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
745 bool should_resume
= true;
747 /* Copy user stepping state to the new inferior thread. FIXME: the
748 followed fork child thread should have a copy of most of the
749 parent thread structure's run control related fields, not just these.
750 Initialized to avoid "may be used uninitialized" warnings from gcc. */
751 struct breakpoint
*step_resume_breakpoint
= nullptr;
752 struct breakpoint
*exception_resume_breakpoint
= nullptr;
753 CORE_ADDR step_range_start
= 0;
754 CORE_ADDR step_range_end
= 0;
755 int current_line
= 0;
756 symtab
*current_symtab
= nullptr;
757 struct frame_id step_frame_id
= { 0 };
761 thread_info
*cur_thr
= inferior_thread ();
764 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
765 process_stratum_target
*resume_target
766 = user_visible_resume_target (resume_ptid
);
768 /* Check if there's a thread that we're about to resume, other
769 than the current, with an unfollowed fork/vfork. If so,
770 switch back to it, to tell the target to follow it (in either
771 direction). We'll afterwards refuse to resume, and inform
772 the user what happened. */
773 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
779 /* follow_fork_inferior clears tp->pending_follow, and below
780 we'll need the value after the follow_fork_inferior
782 target_waitkind kind
= tp
->pending_follow
.kind ();
784 if (kind
!= TARGET_WAITKIND_SPURIOUS
)
786 infrun_debug_printf ("need to follow-fork [%s] first",
787 tp
->ptid
.to_string ().c_str ());
789 switch_to_thread (tp
);
791 /* Set up inferior(s) as specified by the caller, and
792 tell the target to do whatever is necessary to follow
793 either parent or child. */
796 /* The thread that started the execution command
797 won't exist in the child. Abort the command and
798 immediately stop in this thread, in the child,
800 should_resume
= false;
804 /* Following the parent, so let the thread fork its
805 child freely, it won't influence the current
806 execution command. */
807 if (follow_fork_inferior (follow_child
, detach_fork
))
809 /* Target refused to follow, or there's some
810 other reason we shouldn't resume. */
811 switch_to_thread (cur_thr
);
812 set_last_target_status_stopped (cur_thr
);
816 /* If we're following a vfork, when we need to leave
817 the just-forked thread as selected, as we need to
818 solo-resume it to collect the VFORK_DONE event.
819 If we're following a fork, however, switch back
820 to the original thread that we continue stepping
822 if (kind
!= TARGET_WAITKIND_VFORKED
)
824 gdb_assert (kind
== TARGET_WAITKIND_FORKED
);
825 switch_to_thread (cur_thr
);
834 thread_info
*tp
= inferior_thread ();
836 /* If there were any forks/vforks that were caught and are now to be
837 followed, then do so now. */
838 switch (tp
->pending_follow
.kind ())
840 case TARGET_WAITKIND_FORKED
:
841 case TARGET_WAITKIND_VFORKED
:
843 ptid_t parent
, child
;
844 std::unique_ptr
<struct thread_fsm
> thread_fsm
;
846 /* If the user did a next/step, etc, over a fork call,
847 preserve the stepping state in the fork child. */
848 if (follow_child
&& should_resume
)
850 step_resume_breakpoint
= clone_momentary_breakpoint
851 (tp
->control
.step_resume_breakpoint
);
852 step_range_start
= tp
->control
.step_range_start
;
853 step_range_end
= tp
->control
.step_range_end
;
854 current_line
= tp
->current_line
;
855 current_symtab
= tp
->current_symtab
;
856 step_frame_id
= tp
->control
.step_frame_id
;
857 exception_resume_breakpoint
858 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
859 thread_fsm
= tp
->release_thread_fsm ();
861 /* For now, delete the parent's sr breakpoint, otherwise,
862 parent/child sr breakpoints are considered duplicates,
863 and the child version will not be installed. Remove
864 this when the breakpoints module becomes aware of
865 inferiors and address spaces. */
866 delete_step_resume_breakpoint (tp
);
867 tp
->control
.step_range_start
= 0;
868 tp
->control
.step_range_end
= 0;
869 tp
->control
.step_frame_id
= null_frame_id
;
870 delete_exception_resume_breakpoint (tp
);
873 parent
= inferior_ptid
;
874 child
= tp
->pending_follow
.child_ptid ();
876 /* If handling a vfork, stop all the inferior's threads, they will be
877 restarted when the vfork shared region is complete. */
878 if (tp
->pending_follow
.kind () == TARGET_WAITKIND_VFORKED
879 && target_is_non_stop_p ())
880 stop_all_threads ("handling vfork", tp
->inf
);
882 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
883 /* Set up inferior(s) as specified by the caller, and tell the
884 target to do whatever is necessary to follow either parent
886 if (follow_fork_inferior (follow_child
, detach_fork
))
888 /* Target refused to follow, or there's some other reason
889 we shouldn't resume. */
894 /* If we followed the child, switch to it... */
897 tp
= parent_targ
->find_thread (child
);
898 switch_to_thread (tp
);
900 /* ... and preserve the stepping state, in case the
901 user was stepping over the fork call. */
904 tp
->control
.step_resume_breakpoint
905 = step_resume_breakpoint
;
906 tp
->control
.step_range_start
= step_range_start
;
907 tp
->control
.step_range_end
= step_range_end
;
908 tp
->current_line
= current_line
;
909 tp
->current_symtab
= current_symtab
;
910 tp
->control
.step_frame_id
= step_frame_id
;
911 tp
->control
.exception_resume_breakpoint
912 = exception_resume_breakpoint
;
913 tp
->set_thread_fsm (std::move (thread_fsm
));
917 /* If we get here, it was because we're trying to
918 resume from a fork catchpoint, but, the user
919 has switched threads away from the thread that
920 forked. In that case, the resume command
921 issued is most likely not applicable to the
922 child, so just warn, and refuse to resume. */
923 warning (_("Not resuming: switched threads "
924 "before following fork child."));
927 /* Reset breakpoints in the child as appropriate. */
928 follow_inferior_reset_breakpoints ();
933 case TARGET_WAITKIND_SPURIOUS
:
934 /* Nothing to follow. */
937 internal_error ("Unexpected pending_follow.kind %d\n",
938 tp
->pending_follow
.kind ());
943 set_last_target_status_stopped (tp
);
944 return should_resume
;
948 follow_inferior_reset_breakpoints (void)
950 struct thread_info
*tp
= inferior_thread ();
952 /* Was there a step_resume breakpoint? (There was if the user
953 did a "next" at the fork() call.) If so, explicitly reset its
954 thread number. Cloned step_resume breakpoints are disabled on
955 creation, so enable it here now that it is associated with the
958 step_resumes are a form of bp that are made to be per-thread.
959 Since we created the step_resume bp when the parent process
960 was being debugged, and now are switching to the child process,
961 from the breakpoint package's viewpoint, that's a switch of
962 "threads". We must update the bp's notion of which thread
963 it is for, or it'll be ignored when it triggers. */
965 if (tp
->control
.step_resume_breakpoint
)
967 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
968 tp
->control
.step_resume_breakpoint
->first_loc ().enabled
= 1;
971 /* Treat exception_resume breakpoints like step_resume breakpoints. */
972 if (tp
->control
.exception_resume_breakpoint
)
974 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
975 tp
->control
.exception_resume_breakpoint
->first_loc ().enabled
= 1;
978 /* Reinsert all breakpoints in the child. The user may have set
979 breakpoints after catching the fork, in which case those
980 were never set in the child, but only in the parent. This makes
981 sure the inserted breakpoints match the breakpoint list. */
983 breakpoint_re_set ();
984 insert_breakpoints ();
987 /* The child has exited or execed: resume THREAD, a thread of the parent,
988 if it was meant to be executing. */
991 proceed_after_vfork_done (thread_info
*thread
)
993 if (thread
->state
== THREAD_RUNNING
994 && !thread
->executing ()
995 && !thread
->stop_requested
996 && thread
->stop_signal () == GDB_SIGNAL_0
)
998 infrun_debug_printf ("resuming vfork parent thread %s",
999 thread
->ptid
.to_string ().c_str ());
1001 switch_to_thread (thread
);
1002 clear_proceed_status (0);
1003 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
1007 /* Called whenever we notice an exec or exit event, to handle
1008 detaching or resuming a vfork parent. */
1011 handle_vfork_child_exec_or_exit (int exec
)
1013 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
1015 struct inferior
*inf
= current_inferior ();
1017 if (inf
->vfork_parent
)
1019 inferior
*resume_parent
= nullptr;
1021 /* This exec or exit marks the end of the shared memory region
1022 between the parent and the child. Break the bonds. */
1023 inferior
*vfork_parent
= inf
->vfork_parent
;
1024 inf
->vfork_parent
->vfork_child
= nullptr;
1025 inf
->vfork_parent
= nullptr;
1027 /* If the user wanted to detach from the parent, now is the
1029 if (vfork_parent
->pending_detach
)
1031 struct program_space
*pspace
;
1032 struct address_space
*aspace
;
1034 /* follow-fork child, detach-on-fork on. */
1036 vfork_parent
->pending_detach
= false;
1038 scoped_restore_current_pspace_and_thread restore_thread
;
1040 /* We're letting loose of the parent. */
1041 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
1042 switch_to_thread (tp
);
1044 /* We're about to detach from the parent, which implicitly
1045 removes breakpoints from its address space. There's a
1046 catch here: we want to reuse the spaces for the child,
1047 but, parent/child are still sharing the pspace at this
1048 point, although the exec in reality makes the kernel give
1049 the child a fresh set of new pages. The problem here is
1050 that the breakpoints module being unaware of this, would
1051 likely chose the child process to write to the parent
1052 address space. Swapping the child temporarily away from
1053 the spaces has the desired effect. Yes, this is "sort
1056 pspace
= inf
->pspace
;
1057 aspace
= inf
->aspace
;
1058 inf
->aspace
= nullptr;
1059 inf
->pspace
= nullptr;
1061 if (print_inferior_events
)
1064 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
1066 target_terminal::ours_for_output ();
1070 gdb_printf (_("[Detaching vfork parent %s "
1071 "after child exec]\n"), pidstr
.c_str ());
1075 gdb_printf (_("[Detaching vfork parent %s "
1076 "after child exit]\n"), pidstr
.c_str ());
1080 target_detach (vfork_parent
, 0);
1083 inf
->pspace
= pspace
;
1084 inf
->aspace
= aspace
;
1088 /* We're staying attached to the parent, so, really give the
1089 child a new address space. */
1090 inf
->pspace
= new program_space (maybe_new_address_space ());
1091 inf
->aspace
= inf
->pspace
->aspace
;
1092 inf
->removable
= true;
1093 set_current_program_space (inf
->pspace
);
1095 resume_parent
= vfork_parent
;
1099 /* If this is a vfork child exiting, then the pspace and
1100 aspaces were shared with the parent. Since we're
1101 reporting the process exit, we'll be mourning all that is
1102 found in the address space, and switching to null_ptid,
1103 preparing to start a new inferior. But, since we don't
1104 want to clobber the parent's address/program spaces, we
1105 go ahead and create a new one for this exiting
1108 /* Switch to no-thread while running clone_program_space, so
1109 that clone_program_space doesn't want to read the
1110 selected frame of a dead process. */
1111 scoped_restore_current_thread restore_thread
;
1112 switch_to_no_thread ();
1114 inf
->pspace
= new program_space (maybe_new_address_space ());
1115 inf
->aspace
= inf
->pspace
->aspace
;
1116 set_current_program_space (inf
->pspace
);
1117 inf
->removable
= true;
1118 inf
->symfile_flags
= SYMFILE_NO_READ
;
1119 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1121 resume_parent
= vfork_parent
;
1124 gdb_assert (current_program_space
== inf
->pspace
);
1126 if (non_stop
&& resume_parent
!= nullptr)
1128 /* If the user wanted the parent to be running, let it go
1130 scoped_restore_current_thread restore_thread
;
1132 infrun_debug_printf ("resuming vfork parent process %d",
1133 resume_parent
->pid
);
1135 for (thread_info
*thread
: resume_parent
->threads ())
1136 proceed_after_vfork_done (thread
);
1141 /* Handle TARGET_WAITKIND_VFORK_DONE. */
1144 handle_vfork_done (thread_info
*event_thread
)
1146 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
1148 /* We only care about this event if inferior::thread_waiting_for_vfork_done is
1149 set, that is if we are waiting for a vfork child not under our control
1150 (because we detached it) to exec or exit.
1152 If an inferior has vforked and we are debugging the child, we don't use
1153 the vfork-done event to get notified about the end of the shared address
1154 space window. We rely instead on the child's exec or exit event, and the
1155 inferior::vfork_{parent,child} fields are used instead. See
1156 handle_vfork_child_exec_or_exit for that. */
1157 if (event_thread
->inf
->thread_waiting_for_vfork_done
== nullptr)
1159 infrun_debug_printf ("not waiting for a vfork-done event");
1163 /* We stopped all threads (other than the vforking thread) of the inferior in
1164 follow_fork and kept them stopped until now. It should therefore not be
1165 possible for another thread to have reported a vfork during that window.
1166 If THREAD_WAITING_FOR_VFORK_DONE is set, it has to be the same thread whose
1167 vfork-done we are handling right now. */
1168 gdb_assert (event_thread
->inf
->thread_waiting_for_vfork_done
== event_thread
);
1170 event_thread
->inf
->thread_waiting_for_vfork_done
= nullptr;
1171 event_thread
->inf
->pspace
->breakpoints_not_allowed
= 0;
1173 /* On non-stop targets, we stopped all the inferior's threads in follow_fork,
1174 resume them now. On all-stop targets, everything that needs to be resumed
1175 will be when we resume the event thread. */
1176 if (target_is_non_stop_p ())
1178 /* restart_threads and start_step_over may change the current thread, make
1179 sure we leave the event thread as the current thread. */
1180 scoped_restore_current_thread restore_thread
;
1182 insert_breakpoints ();
1185 if (!step_over_info_valid_p ())
1186 restart_threads (event_thread
, event_thread
->inf
);
1190 /* Enum strings for "set|show follow-exec-mode". */
1192 static const char follow_exec_mode_new
[] = "new";
1193 static const char follow_exec_mode_same
[] = "same";
1194 static const char *const follow_exec_mode_names
[] =
1196 follow_exec_mode_new
,
1197 follow_exec_mode_same
,
1201 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1203 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1204 struct cmd_list_element
*c
, const char *value
)
1206 gdb_printf (file
, _("Follow exec mode is \"%s\".\n"), value
);
1209 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1212 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1214 int pid
= ptid
.pid ();
1215 ptid_t process_ptid
;
1217 /* Switch terminal for any messages produced e.g. by
1218 breakpoint_re_set. */
1219 target_terminal::ours_for_output ();
1221 /* This is an exec event that we actually wish to pay attention to.
1222 Refresh our symbol table to the newly exec'd program, remove any
1223 momentary bp's, etc.
1225 If there are breakpoints, they aren't really inserted now,
1226 since the exec() transformed our inferior into a fresh set
1229 We want to preserve symbolic breakpoints on the list, since
1230 we have hopes that they can be reset after the new a.out's
1231 symbol table is read.
1233 However, any "raw" breakpoints must be removed from the list
1234 (e.g., the solib bp's), since their address is probably invalid
1237 And, we DON'T want to call delete_breakpoints() here, since
1238 that may write the bp's "shadow contents" (the instruction
1239 value that was overwritten with a TRAP instruction). Since
1240 we now have a new a.out, those shadow contents aren't valid. */
1242 mark_breakpoints_out ();
1244 /* The target reports the exec event to the main thread, even if
1245 some other thread does the exec, and even if the main thread was
1246 stopped or already gone. We may still have non-leader threads of
1247 the process on our list. E.g., on targets that don't have thread
1248 exit events (like remote); or on native Linux in non-stop mode if
1249 there were only two threads in the inferior and the non-leader
1250 one is the one that execs (and nothing forces an update of the
1251 thread list up to here). When debugging remotely, it's best to
1252 avoid extra traffic, when possible, so avoid syncing the thread
1253 list with the target, and instead go ahead and delete all threads
1254 of the process but one that reported the event. Note this must
1255 be done before calling update_breakpoints_after_exec, as
1256 otherwise clearing the threads' resources would reference stale
1257 thread breakpoints -- it may have been one of these threads that
1258 stepped across the exec. We could just clear their stepping
1259 states, but as long as we're iterating, might as well delete
1260 them. Deleting them now rather than at the next user-visible
1261 stop provides a nicer sequence of events for user and MI
1263 for (thread_info
*th
: all_threads_safe ())
1264 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1267 /* We also need to clear any left over stale state for the
1268 leader/event thread. E.g., if there was any step-resume
1269 breakpoint or similar, it's gone now. We cannot truly
1270 step-to-next statement through an exec(). */
1271 thread_info
*th
= inferior_thread ();
1272 th
->control
.step_resume_breakpoint
= nullptr;
1273 th
->control
.exception_resume_breakpoint
= nullptr;
1274 th
->control
.single_step_breakpoints
= nullptr;
1275 th
->control
.step_range_start
= 0;
1276 th
->control
.step_range_end
= 0;
1278 /* The user may have had the main thread held stopped in the
1279 previous image (e.g., schedlock on, or non-stop). Release
1281 th
->stop_requested
= 0;
1283 update_breakpoints_after_exec ();
1285 /* What is this a.out's name? */
1286 process_ptid
= ptid_t (pid
);
1287 gdb_printf (_("%s is executing new program: %s\n"),
1288 target_pid_to_str (process_ptid
).c_str (),
1291 /* We've followed the inferior through an exec. Therefore, the
1292 inferior has essentially been killed & reborn. */
1294 breakpoint_init_inferior (inf_execd
);
1296 gdb::unique_xmalloc_ptr
<char> exec_file_host
1297 = exec_file_find (exec_file_target
, nullptr);
1299 /* If we were unable to map the executable target pathname onto a host
1300 pathname, tell the user that. Otherwise GDB's subsequent behavior
1301 is confusing. Maybe it would even be better to stop at this point
1302 so that the user can specify a file manually before continuing. */
1303 if (exec_file_host
== nullptr)
1304 warning (_("Could not load symbols for executable %s.\n"
1305 "Do you need \"set sysroot\"?"),
1308 /* Reset the shared library package. This ensures that we get a
1309 shlib event when the child reaches "_start", at which point the
1310 dld will have had a chance to initialize the child. */
1311 /* Also, loading a symbol file below may trigger symbol lookups, and
1312 we don't want those to be satisfied by the libraries of the
1313 previous incarnation of this process. */
1314 no_shared_libraries (nullptr, 0);
1316 inferior
*execing_inferior
= current_inferior ();
1317 inferior
*following_inferior
;
1319 if (follow_exec_mode_string
== follow_exec_mode_new
)
1321 /* The user wants to keep the old inferior and program spaces
1322 around. Create a new fresh one, and switch to it. */
1324 /* Do exit processing for the original inferior before setting the new
1325 inferior's pid. Having two inferiors with the same pid would confuse
1326 find_inferior_p(t)id. Transfer the terminal state and info from the
1327 old to the new inferior. */
1328 following_inferior
= add_inferior_with_spaces ();
1330 swap_terminal_info (following_inferior
, execing_inferior
);
1331 exit_inferior (execing_inferior
);
1333 following_inferior
->pid
= pid
;
1337 /* follow-exec-mode is "same", we continue execution in the execing
1339 following_inferior
= execing_inferior
;
1341 /* The old description may no longer be fit for the new image.
1342 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1343 old description; we'll read a new one below. No need to do
1344 this on "follow-exec-mode new", as the old inferior stays
1345 around (its description is later cleared/refetched on
1347 target_clear_description ();
1350 target_follow_exec (following_inferior
, ptid
, exec_file_target
);
1352 gdb_assert (current_inferior () == following_inferior
);
1353 gdb_assert (current_program_space
== following_inferior
->pspace
);
1355 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1356 because the proper displacement for a PIE (Position Independent
1357 Executable) main symbol file will only be computed by
1358 solib_create_inferior_hook below. breakpoint_re_set would fail
1359 to insert the breakpoints with the zero displacement. */
1360 try_open_exec_file (exec_file_host
.get (), following_inferior
,
1361 SYMFILE_DEFER_BP_RESET
);
1363 /* If the target can specify a description, read it. Must do this
1364 after flipping to the new executable (because the target supplied
1365 description must be compatible with the executable's
1366 architecture, and the old executable may e.g., be 32-bit, while
1367 the new one 64-bit), and before anything involving memory or
1369 target_find_description ();
1371 gdb::observers::inferior_execd
.notify (execing_inferior
, following_inferior
);
1373 breakpoint_re_set ();
1375 /* Reinsert all breakpoints. (Those which were symbolic have
1376 been reset to the proper address in the new a.out, thanks
1377 to symbol_file_command...). */
1378 insert_breakpoints ();
1380 /* The next resume of this inferior should bring it to the shlib
1381 startup breakpoints. (If the user had also set bp's on
1382 "main" from the old (parent) process, then they'll auto-
1383 matically get reset there in the new process.). */
1386 /* The chain of threads that need to do a step-over operation to get
1387 past e.g., a breakpoint. What technique is used to step over the
1388 breakpoint/watchpoint does not matter -- all threads end up in the
1389 same queue, to maintain rough temporal order of execution, in order
1390 to avoid starvation, otherwise, we could e.g., find ourselves
1391 constantly stepping the same couple threads past their breakpoints
1392 over and over, if the single-step finish fast enough. */
1393 thread_step_over_list global_thread_step_over_list
;
1395 /* Bit flags indicating what the thread needs to step over. */
1397 enum step_over_what_flag
1399 /* Step over a breakpoint. */
1400 STEP_OVER_BREAKPOINT
= 1,
1402 /* Step past a non-continuable watchpoint, in order to let the
1403 instruction execute so we can evaluate the watchpoint
1405 STEP_OVER_WATCHPOINT
= 2
1407 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1409 /* Info about an instruction that is being stepped over. */
1411 struct step_over_info
1413 /* If we're stepping past a breakpoint, this is the address space
1414 and address of the instruction the breakpoint is set at. We'll
1415 skip inserting all breakpoints here. Valid iff ASPACE is
1417 const address_space
*aspace
= nullptr;
1418 CORE_ADDR address
= 0;
1420 /* The instruction being stepped over triggers a nonsteppable
1421 watchpoint. If true, we'll skip inserting watchpoints. */
1422 int nonsteppable_watchpoint_p
= 0;
1424 /* The thread's global number. */
1428 /* The step-over info of the location that is being stepped over.
1430 Note that with async/breakpoint always-inserted mode, a user might
1431 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1432 being stepped over. As setting a new breakpoint inserts all
1433 breakpoints, we need to make sure the breakpoint being stepped over
1434 isn't inserted then. We do that by only clearing the step-over
1435 info when the step-over is actually finished (or aborted).
1437 Presently GDB can only step over one breakpoint at any given time.
1438 Given threads that can't run code in the same address space as the
1439 breakpoint's can't really miss the breakpoint, GDB could be taught
1440 to step-over at most one breakpoint per address space (so this info
1441 could move to the address space object if/when GDB is extended).
1442 The set of breakpoints being stepped over will normally be much
1443 smaller than the set of all breakpoints, so a flag in the
1444 breakpoint location structure would be wasteful. A separate list
1445 also saves complexity and run-time, as otherwise we'd have to go
1446 through all breakpoint locations clearing their flag whenever we
1447 start a new sequence. Similar considerations weigh against storing
1448 this info in the thread object. Plus, not all step overs actually
1449 have breakpoint locations -- e.g., stepping past a single-step
1450 breakpoint, or stepping to complete a non-continuable
1452 static struct step_over_info step_over_info
;
1454 /* Record the address of the breakpoint/instruction we're currently
1456 N.B. We record the aspace and address now, instead of say just the thread,
1457 because when we need the info later the thread may be running. */
1460 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1461 int nonsteppable_watchpoint_p
,
1464 step_over_info
.aspace
= aspace
;
1465 step_over_info
.address
= address
;
1466 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1467 step_over_info
.thread
= thread
;
1470 /* Called when we're not longer stepping over a breakpoint / an
1471 instruction, so all breakpoints are free to be (re)inserted. */
1474 clear_step_over_info (void)
1476 infrun_debug_printf ("clearing step over info");
1477 step_over_info
.aspace
= nullptr;
1478 step_over_info
.address
= 0;
1479 step_over_info
.nonsteppable_watchpoint_p
= 0;
1480 step_over_info
.thread
= -1;
1486 stepping_past_instruction_at (struct address_space
*aspace
,
1489 return (step_over_info
.aspace
!= nullptr
1490 && breakpoint_address_match (aspace
, address
,
1491 step_over_info
.aspace
,
1492 step_over_info
.address
));
1498 thread_is_stepping_over_breakpoint (int thread
)
1500 return (step_over_info
.thread
!= -1
1501 && thread
== step_over_info
.thread
);
1507 stepping_past_nonsteppable_watchpoint (void)
1509 return step_over_info
.nonsteppable_watchpoint_p
;
1512 /* Returns true if step-over info is valid. */
1515 step_over_info_valid_p (void)
1517 return (step_over_info
.aspace
!= nullptr
1518 || stepping_past_nonsteppable_watchpoint ());
1522 /* Displaced stepping. */
1524 /* In non-stop debugging mode, we must take special care to manage
1525 breakpoints properly; in particular, the traditional strategy for
1526 stepping a thread past a breakpoint it has hit is unsuitable.
1527 'Displaced stepping' is a tactic for stepping one thread past a
1528 breakpoint it has hit while ensuring that other threads running
1529 concurrently will hit the breakpoint as they should.
1531 The traditional way to step a thread T off a breakpoint in a
1532 multi-threaded program in all-stop mode is as follows:
1534 a0) Initially, all threads are stopped, and breakpoints are not
1536 a1) We single-step T, leaving breakpoints uninserted.
1537 a2) We insert breakpoints, and resume all threads.
1539 In non-stop debugging, however, this strategy is unsuitable: we
1540 don't want to have to stop all threads in the system in order to
1541 continue or step T past a breakpoint. Instead, we use displaced
1544 n0) Initially, T is stopped, other threads are running, and
1545 breakpoints are inserted.
1546 n1) We copy the instruction "under" the breakpoint to a separate
1547 location, outside the main code stream, making any adjustments
1548 to the instruction, register, and memory state as directed by
1550 n2) We single-step T over the instruction at its new location.
1551 n3) We adjust the resulting register and memory state as directed
1552 by T's architecture. This includes resetting T's PC to point
1553 back into the main instruction stream.
1556 This approach depends on the following gdbarch methods:
1558 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1559 indicate where to copy the instruction, and how much space must
1560 be reserved there. We use these in step n1.
1562 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1563 address, and makes any necessary adjustments to the instruction,
1564 register contents, and memory. We use this in step n1.
1566 - gdbarch_displaced_step_fixup adjusts registers and memory after
1567 we have successfully single-stepped the instruction, to yield the
1568 same effect the instruction would have had if we had executed it
1569 at its original address. We use this in step n3.
1571 The gdbarch_displaced_step_copy_insn and
1572 gdbarch_displaced_step_fixup functions must be written so that
1573 copying an instruction with gdbarch_displaced_step_copy_insn,
1574 single-stepping across the copied instruction, and then applying
1575 gdbarch_displaced_insn_fixup should have the same effects on the
1576 thread's memory and registers as stepping the instruction in place
1577 would have. Exactly which responsibilities fall to the copy and
1578 which fall to the fixup is up to the author of those functions.
1580 See the comments in gdbarch.sh for details.
1582 Note that displaced stepping and software single-step cannot
1583 currently be used in combination, although with some care I think
1584 they could be made to. Software single-step works by placing
1585 breakpoints on all possible subsequent instructions; if the
1586 displaced instruction is a PC-relative jump, those breakpoints
1587 could fall in very strange places --- on pages that aren't
1588 executable, or at addresses that are not proper instruction
1589 boundaries. (We do generally let other threads run while we wait
1590 to hit the software single-step breakpoint, and they might
1591 encounter such a corrupted instruction.) One way to work around
1592 this would be to have gdbarch_displaced_step_copy_insn fully
1593 simulate the effect of PC-relative instructions (and return NULL)
1594 on architectures that use software single-stepping.
1596 In non-stop mode, we can have independent and simultaneous step
1597 requests, so more than one thread may need to simultaneously step
1598 over a breakpoint. The current implementation assumes there is
1599 only one scratch space per process. In this case, we have to
1600 serialize access to the scratch space. If thread A wants to step
1601 over a breakpoint, but we are currently waiting for some other
1602 thread to complete a displaced step, we leave thread A stopped and
1603 place it in the displaced_step_request_queue. Whenever a displaced
1604 step finishes, we pick the next thread in the queue and start a new
1605 displaced step operation on it. See displaced_step_prepare and
1606 displaced_step_finish for details. */
1608 /* Return true if THREAD is doing a displaced step. */
1611 displaced_step_in_progress_thread (thread_info
*thread
)
1613 gdb_assert (thread
!= nullptr);
1615 return thread
->displaced_step_state
.in_progress ();
1618 /* Return true if INF has a thread doing a displaced step. */
1621 displaced_step_in_progress (inferior
*inf
)
1623 return inf
->displaced_step_state
.in_progress_count
> 0;
1626 /* Return true if any thread is doing a displaced step. */
1629 displaced_step_in_progress_any_thread ()
1631 for (inferior
*inf
: all_non_exited_inferiors ())
1633 if (displaced_step_in_progress (inf
))
1641 infrun_inferior_exit (struct inferior
*inf
)
1643 inf
->displaced_step_state
.reset ();
1644 inf
->thread_waiting_for_vfork_done
= nullptr;
1648 infrun_inferior_execd (inferior
*exec_inf
, inferior
*follow_inf
)
1650 /* If some threads where was doing a displaced step in this inferior at the
1651 moment of the exec, they no longer exist. Even if the exec'ing thread
1652 doing a displaced step, we don't want to to any fixup nor restore displaced
1653 stepping buffer bytes. */
1654 follow_inf
->displaced_step_state
.reset ();
1656 for (thread_info
*thread
: follow_inf
->threads ())
1657 thread
->displaced_step_state
.reset ();
1659 /* Since an in-line step is done with everything else stopped, if there was
1660 one in progress at the time of the exec, it must have been the exec'ing
1662 clear_step_over_info ();
1664 follow_inf
->thread_waiting_for_vfork_done
= nullptr;
1667 /* If ON, and the architecture supports it, GDB will use displaced
1668 stepping to step over breakpoints. If OFF, or if the architecture
1669 doesn't support it, GDB will instead use the traditional
1670 hold-and-step approach. If AUTO (which is the default), GDB will
1671 decide which technique to use to step over breakpoints depending on
1672 whether the target works in a non-stop way (see use_displaced_stepping). */
1674 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1677 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1678 struct cmd_list_element
*c
,
1681 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1683 _("Debugger's willingness to use displaced stepping "
1684 "to step over breakpoints is %s (currently %s).\n"),
1685 value
, target_is_non_stop_p () ? "on" : "off");
1688 _("Debugger's willingness to use displaced stepping "
1689 "to step over breakpoints is %s.\n"), value
);
1692 /* Return true if the gdbarch implements the required methods to use
1693 displaced stepping. */
1696 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1698 /* Only check for the presence of `prepare`. The gdbarch verification ensures
1699 that if `prepare` is provided, so is `finish`. */
1700 return gdbarch_displaced_step_prepare_p (arch
);
1703 /* Return non-zero if displaced stepping can/should be used to step
1704 over breakpoints of thread TP. */
1707 use_displaced_stepping (thread_info
*tp
)
1709 /* If the user disabled it explicitly, don't use displaced stepping. */
1710 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1713 /* If "auto", only use displaced stepping if the target operates in a non-stop
1715 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1716 && !target_is_non_stop_p ())
1719 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1721 /* If the architecture doesn't implement displaced stepping, don't use
1723 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1726 /* If recording, don't use displaced stepping. */
1727 if (find_record_target () != nullptr)
1730 /* If displaced stepping failed before for this inferior, don't bother trying
1732 if (tp
->inf
->displaced_step_state
.failed_before
)
1738 /* Simple function wrapper around displaced_step_thread_state::reset. */
1741 displaced_step_reset (displaced_step_thread_state
*displaced
)
1743 displaced
->reset ();
1746 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1747 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1749 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1751 /* Prepare to single-step, using displaced stepping.
1753 Note that we cannot use displaced stepping when we have a signal to
1754 deliver. If we have a signal to deliver and an instruction to step
1755 over, then after the step, there will be no indication from the
1756 target whether the thread entered a signal handler or ignored the
1757 signal and stepped over the instruction successfully --- both cases
1758 result in a simple SIGTRAP. In the first case we mustn't do a
1759 fixup, and in the second case we must --- but we can't tell which.
1760 Comments in the code for 'random signals' in handle_inferior_event
1761 explain how we handle this case instead.
1763 Returns DISPLACED_STEP_PREPARE_STATUS_OK if preparing was successful -- this
1764 thread is going to be stepped now; DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
1765 if displaced stepping this thread got queued; or
1766 DISPLACED_STEP_PREPARE_STATUS_CANT if this instruction can't be displaced
1769 static displaced_step_prepare_status
1770 displaced_step_prepare_throw (thread_info
*tp
)
1772 regcache
*regcache
= get_thread_regcache (tp
);
1773 struct gdbarch
*gdbarch
= regcache
->arch ();
1774 displaced_step_thread_state
&disp_step_thread_state
1775 = tp
->displaced_step_state
;
1777 /* We should never reach this function if the architecture does not
1778 support displaced stepping. */
1779 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1781 /* Nor if the thread isn't meant to step over a breakpoint. */
1782 gdb_assert (tp
->control
.trap_expected
);
1784 /* Disable range stepping while executing in the scratch pad. We
1785 want a single-step even if executing the displaced instruction in
1786 the scratch buffer lands within the stepping range (e.g., a
1788 tp
->control
.may_range_step
= 0;
1790 /* We are about to start a displaced step for this thread. If one is already
1791 in progress, something's wrong. */
1792 gdb_assert (!disp_step_thread_state
.in_progress ());
1794 if (tp
->inf
->displaced_step_state
.unavailable
)
1796 /* The gdbarch tells us it's not worth asking to try a prepare because
1797 it is likely that it will return unavailable, so don't bother asking. */
1799 displaced_debug_printf ("deferring step of %s",
1800 tp
->ptid
.to_string ().c_str ());
1802 global_thread_step_over_chain_enqueue (tp
);
1803 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1806 displaced_debug_printf ("displaced-stepping %s now",
1807 tp
->ptid
.to_string ().c_str ());
1809 scoped_restore_current_thread restore_thread
;
1811 switch_to_thread (tp
);
1813 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1814 CORE_ADDR displaced_pc
;
1816 /* Display the instruction we are going to displaced step. */
1817 if (debug_displaced
)
1819 string_file tmp_stream
;
1820 int dislen
= gdb_print_insn (gdbarch
, original_pc
, &tmp_stream
,
1825 gdb::byte_vector
insn_buf (dislen
);
1826 read_memory (original_pc
, insn_buf
.data (), insn_buf
.size ());
1828 std::string insn_bytes
= bytes_to_string (insn_buf
);
1830 displaced_debug_printf ("original insn %s: %s \t %s",
1831 paddress (gdbarch
, original_pc
),
1832 insn_bytes
.c_str (),
1833 tmp_stream
.string ().c_str ());
1836 displaced_debug_printf ("original insn %s: invalid length: %d",
1837 paddress (gdbarch
, original_pc
), dislen
);
1840 displaced_step_prepare_status status
1841 = gdbarch_displaced_step_prepare (gdbarch
, tp
, displaced_pc
);
1843 if (status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
1845 displaced_debug_printf ("failed to prepare (%s)",
1846 tp
->ptid
.to_string ().c_str ());
1848 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1850 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1852 /* Not enough displaced stepping resources available, defer this
1853 request by placing it the queue. */
1855 displaced_debug_printf ("not enough resources available, "
1856 "deferring step of %s",
1857 tp
->ptid
.to_string ().c_str ());
1859 global_thread_step_over_chain_enqueue (tp
);
1861 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1864 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1866 /* Save the information we need to fix things up if the step
1868 disp_step_thread_state
.set (gdbarch
);
1870 tp
->inf
->displaced_step_state
.in_progress_count
++;
1872 displaced_debug_printf ("prepared successfully thread=%s, "
1873 "original_pc=%s, displaced_pc=%s",
1874 tp
->ptid
.to_string ().c_str (),
1875 paddress (gdbarch
, original_pc
),
1876 paddress (gdbarch
, displaced_pc
));
1878 /* Display the new displaced instruction(s). */
1879 if (debug_displaced
)
1881 string_file tmp_stream
;
1882 CORE_ADDR addr
= displaced_pc
;
1884 /* If displaced stepping is going to use h/w single step then we know
1885 that the replacement instruction can only be a single instruction,
1886 in that case set the end address at the next byte.
1888 Otherwise the displaced stepping copy instruction routine could
1889 have generated multiple instructions, and all we know is that they
1890 must fit within the LEN bytes of the buffer. */
1892 = addr
+ (gdbarch_displaced_step_hw_singlestep (gdbarch
)
1893 ? 1 : gdbarch_displaced_step_buffer_length (gdbarch
));
1897 int dislen
= gdb_print_insn (gdbarch
, addr
, &tmp_stream
, nullptr);
1900 displaced_debug_printf
1901 ("replacement insn %s: invalid length: %d",
1902 paddress (gdbarch
, addr
), dislen
);
1906 gdb::byte_vector
insn_buf (dislen
);
1907 read_memory (addr
, insn_buf
.data (), insn_buf
.size ());
1909 std::string insn_bytes
= bytes_to_string (insn_buf
);
1910 std::string insn_str
= tmp_stream
.release ();
1911 displaced_debug_printf ("replacement insn %s: %s \t %s",
1912 paddress (gdbarch
, addr
),
1913 insn_bytes
.c_str (),
1919 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1922 /* Wrapper for displaced_step_prepare_throw that disabled further
1923 attempts at displaced stepping if we get a memory error. */
1925 static displaced_step_prepare_status
1926 displaced_step_prepare (thread_info
*thread
)
1928 displaced_step_prepare_status status
1929 = DISPLACED_STEP_PREPARE_STATUS_CANT
;
1933 status
= displaced_step_prepare_throw (thread
);
1935 catch (const gdb_exception_error
&ex
)
1937 if (ex
.error
!= MEMORY_ERROR
1938 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1941 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1944 /* Be verbose if "set displaced-stepping" is "on", silent if
1946 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1948 warning (_("disabling displaced stepping: %s"),
1952 /* Disable further displaced stepping attempts. */
1953 thread
->inf
->displaced_step_state
.failed_before
= 1;
1959 /* If we displaced stepped an instruction successfully, adjust registers and
1960 memory to yield the same effect the instruction would have had if we had
1961 executed it at its original address, and return
1962 DISPLACED_STEP_FINISH_STATUS_OK. If the instruction didn't complete,
1963 relocate the PC and return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED.
1965 If the thread wasn't displaced stepping, return
1966 DISPLACED_STEP_FINISH_STATUS_OK as well. */
1968 static displaced_step_finish_status
1969 displaced_step_finish (thread_info
*event_thread
,
1970 const target_waitstatus
&event_status
)
1972 displaced_step_thread_state
*displaced
= &event_thread
->displaced_step_state
;
1974 /* Was this thread performing a displaced step? */
1975 if (!displaced
->in_progress ())
1976 return DISPLACED_STEP_FINISH_STATUS_OK
;
1978 gdb_assert (event_thread
->inf
->displaced_step_state
.in_progress_count
> 0);
1979 event_thread
->inf
->displaced_step_state
.in_progress_count
--;
1981 /* Fixup may need to read memory/registers. Switch to the thread
1982 that we're fixing up. Also, target_stopped_by_watchpoint checks
1983 the current thread, and displaced_step_restore performs ptid-dependent
1984 memory accesses using current_inferior(). */
1985 switch_to_thread (event_thread
);
1987 displaced_step_reset_cleanup
cleanup (displaced
);
1989 /* Do the fixup, and release the resources acquired to do the displaced
1991 return gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1992 event_thread
, event_status
);
1995 /* Data to be passed around while handling an event. This data is
1996 discarded between events. */
1997 struct execution_control_state
1999 explicit execution_control_state (thread_info
*thr
= nullptr)
2000 : ptid (thr
== nullptr ? null_ptid
: thr
->ptid
),
2005 process_stratum_target
*target
= nullptr;
2007 /* The thread that got the event, if this was a thread event; NULL
2009 struct thread_info
*event_thread
;
2011 struct target_waitstatus ws
;
2012 int stop_func_filled_in
= 0;
2013 CORE_ADDR stop_func_alt_start
= 0;
2014 CORE_ADDR stop_func_start
= 0;
2015 CORE_ADDR stop_func_end
= 0;
2016 const char *stop_func_name
= nullptr;
2017 int wait_some_more
= 0;
2019 /* True if the event thread hit the single-step breakpoint of
2020 another thread. Thus the event doesn't cause a stop, the thread
2021 needs to be single-stepped past the single-step breakpoint before
2022 we can switch back to the original stepping thread. */
2023 int hit_singlestep_breakpoint
= 0;
2026 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
2027 static void prepare_to_wait (struct execution_control_state
*ecs
);
2028 static bool keep_going_stepped_thread (struct thread_info
*tp
);
2029 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
2031 /* Are there any pending step-over requests? If so, run all we can
2032 now and return true. Otherwise, return false. */
2035 start_step_over (void)
2037 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
2039 /* Don't start a new step-over if we already have an in-line
2040 step-over operation ongoing. */
2041 if (step_over_info_valid_p ())
2044 /* Steal the global thread step over chain. As we try to initiate displaced
2045 steps, threads will be enqueued in the global chain if no buffers are
2046 available. If we iterated on the global chain directly, we might iterate
2048 thread_step_over_list threads_to_step
2049 = std::move (global_thread_step_over_list
);
2051 infrun_debug_printf ("stealing global queue of threads to step, length = %d",
2052 thread_step_over_chain_length (threads_to_step
));
2054 bool started
= false;
2056 /* On scope exit (whatever the reason, return or exception), if there are
2057 threads left in the THREADS_TO_STEP chain, put back these threads in the
2061 if (threads_to_step
.empty ())
2062 infrun_debug_printf ("step-over queue now empty");
2065 infrun_debug_printf ("putting back %d threads to step in global queue",
2066 thread_step_over_chain_length (threads_to_step
));
2068 global_thread_step_over_chain_enqueue_chain
2069 (std::move (threads_to_step
));
2073 thread_step_over_list_safe_range range
2074 = make_thread_step_over_list_safe_range (threads_to_step
);
2076 for (thread_info
*tp
: range
)
2078 step_over_what step_what
;
2079 int must_be_in_line
;
2081 gdb_assert (!tp
->stop_requested
);
2083 if (tp
->inf
->displaced_step_state
.unavailable
)
2085 /* The arch told us to not even try preparing another displaced step
2086 for this inferior. Just leave the thread in THREADS_TO_STEP, it
2087 will get moved to the global chain on scope exit. */
2091 if (tp
->inf
->thread_waiting_for_vfork_done
!= nullptr)
2093 /* When we stop all threads, handling a vfork, any thread in the step
2094 over chain remains there. A user could also try to continue a
2095 thread stopped at a breakpoint while another thread is waiting for
2096 a vfork-done event. In any case, we don't want to start a step
2101 /* Remove thread from the THREADS_TO_STEP chain. If anything goes wrong
2102 while we try to prepare the displaced step, we don't add it back to
2103 the global step over chain. This is to avoid a thread staying in the
2104 step over chain indefinitely if something goes wrong when resuming it
2105 If the error is intermittent and it still needs a step over, it will
2106 get enqueued again when we try to resume it normally. */
2107 threads_to_step
.erase (threads_to_step
.iterator_to (*tp
));
2109 step_what
= thread_still_needs_step_over (tp
);
2110 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
2111 || ((step_what
& STEP_OVER_BREAKPOINT
)
2112 && !use_displaced_stepping (tp
)));
2114 /* We currently stop all threads of all processes to step-over
2115 in-line. If we need to start a new in-line step-over, let
2116 any pending displaced steps finish first. */
2117 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
2119 global_thread_step_over_chain_enqueue (tp
);
2123 if (tp
->control
.trap_expected
2125 || tp
->executing ())
2127 internal_error ("[%s] has inconsistent state: "
2128 "trap_expected=%d, resumed=%d, executing=%d\n",
2129 tp
->ptid
.to_string ().c_str (),
2130 tp
->control
.trap_expected
,
2135 infrun_debug_printf ("resuming [%s] for step-over",
2136 tp
->ptid
.to_string ().c_str ());
2138 /* keep_going_pass_signal skips the step-over if the breakpoint
2139 is no longer inserted. In all-stop, we want to keep looking
2140 for a thread that needs a step-over instead of resuming TP,
2141 because we wouldn't be able to resume anything else until the
2142 target stops again. In non-stop, the resume always resumes
2143 only TP, so it's OK to let the thread resume freely. */
2144 if (!target_is_non_stop_p () && !step_what
)
2147 switch_to_thread (tp
);
2148 execution_control_state
ecs (tp
);
2149 keep_going_pass_signal (&ecs
);
2151 if (!ecs
.wait_some_more
)
2152 error (_("Command aborted."));
2154 /* If the thread's step over could not be initiated because no buffers
2155 were available, it was re-added to the global step over chain. */
2158 infrun_debug_printf ("[%s] was resumed.",
2159 tp
->ptid
.to_string ().c_str ());
2160 gdb_assert (!thread_is_in_step_over_chain (tp
));
2164 infrun_debug_printf ("[%s] was NOT resumed.",
2165 tp
->ptid
.to_string ().c_str ());
2166 gdb_assert (thread_is_in_step_over_chain (tp
));
2169 /* If we started a new in-line step-over, we're done. */
2170 if (step_over_info_valid_p ())
2172 gdb_assert (tp
->control
.trap_expected
);
2177 if (!target_is_non_stop_p ())
2179 /* On all-stop, shouldn't have resumed unless we needed a
2181 gdb_assert (tp
->control
.trap_expected
2182 || tp
->step_after_step_resume_breakpoint
);
2184 /* With remote targets (at least), in all-stop, we can't
2185 issue any further remote commands until the program stops
2191 /* Either the thread no longer needed a step-over, or a new
2192 displaced stepping sequence started. Even in the latter
2193 case, continue looking. Maybe we can also start another
2194 displaced step on a thread of other process. */
2200 /* Update global variables holding ptids to hold NEW_PTID if they were
2201 holding OLD_PTID. */
2203 infrun_thread_ptid_changed (process_stratum_target
*target
,
2204 ptid_t old_ptid
, ptid_t new_ptid
)
2206 if (inferior_ptid
== old_ptid
2207 && current_inferior ()->process_target () == target
)
2208 inferior_ptid
= new_ptid
;
2213 static const char schedlock_off
[] = "off";
2214 static const char schedlock_on
[] = "on";
2215 static const char schedlock_step
[] = "step";
2216 static const char schedlock_replay
[] = "replay";
2217 static const char *const scheduler_enums
[] = {
2224 static const char *scheduler_mode
= schedlock_replay
;
2226 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2227 struct cmd_list_element
*c
, const char *value
)
2230 _("Mode for locking scheduler "
2231 "during execution is \"%s\".\n"),
2236 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2238 if (!target_can_lock_scheduler ())
2240 scheduler_mode
= schedlock_off
;
2241 error (_("Target '%s' cannot support this command."),
2242 target_shortname ());
2246 /* True if execution commands resume all threads of all processes by
2247 default; otherwise, resume only threads of the current inferior
2249 bool sched_multi
= false;
2251 /* Try to setup for software single stepping. Return true if target_resume()
2252 should use hardware single step.
2254 GDBARCH the current gdbarch. */
2257 maybe_software_singlestep (struct gdbarch
*gdbarch
)
2259 bool hw_step
= true;
2261 if (execution_direction
== EXEC_FORWARD
2262 && gdbarch_software_single_step_p (gdbarch
))
2263 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2271 user_visible_resume_ptid (int step
)
2277 /* With non-stop mode on, threads are always handled
2279 resume_ptid
= inferior_ptid
;
2281 else if ((scheduler_mode
== schedlock_on
)
2282 || (scheduler_mode
== schedlock_step
&& step
))
2284 /* User-settable 'scheduler' mode requires solo thread
2286 resume_ptid
= inferior_ptid
;
2288 else if ((scheduler_mode
== schedlock_replay
)
2289 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2291 /* User-settable 'scheduler' mode requires solo thread resume in replay
2293 resume_ptid
= inferior_ptid
;
2295 else if (!sched_multi
&& target_supports_multi_process ())
2297 /* Resume all threads of the current process (and none of other
2299 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2303 /* Resume all threads of all processes. */
2304 resume_ptid
= RESUME_ALL
;
2312 process_stratum_target
*
2313 user_visible_resume_target (ptid_t resume_ptid
)
2315 return (resume_ptid
== minus_one_ptid
&& sched_multi
2317 : current_inferior ()->process_target ());
2320 /* Find a thread from the inferiors that we'll resume that is waiting
2321 for a vfork-done event. */
2323 static thread_info
*
2324 find_thread_waiting_for_vfork_done ()
2326 gdb_assert (!target_is_non_stop_p ());
2330 for (inferior
*inf
: all_non_exited_inferiors ())
2331 if (inf
->thread_waiting_for_vfork_done
!= nullptr)
2332 return inf
->thread_waiting_for_vfork_done
;
2336 inferior
*cur_inf
= current_inferior ();
2337 if (cur_inf
->thread_waiting_for_vfork_done
!= nullptr)
2338 return cur_inf
->thread_waiting_for_vfork_done
;
2343 /* Return a ptid representing the set of threads that we will resume,
2344 in the perspective of the target, assuming run control handling
2345 does not require leaving some threads stopped (e.g., stepping past
2346 breakpoint). USER_STEP indicates whether we're about to start the
2347 target for a stepping command. */
2350 internal_resume_ptid (int user_step
)
2352 /* In non-stop, we always control threads individually. Note that
2353 the target may always work in non-stop mode even with "set
2354 non-stop off", in which case user_visible_resume_ptid could
2355 return a wildcard ptid. */
2356 if (target_is_non_stop_p ())
2357 return inferior_ptid
;
2359 /* The rest of the function assumes non-stop==off and
2360 target-non-stop==off.
2362 If a thread is waiting for a vfork-done event, it means breakpoints are out
2363 for this inferior (well, program space in fact). We don't want to resume
2364 any thread other than the one waiting for vfork done, otherwise these other
2365 threads could miss breakpoints. So if a thread in the resumption set is
2366 waiting for a vfork-done event, resume only that thread.
2368 The resumption set width depends on whether schedule-multiple is on or off.
2370 Note that if the target_resume interface was more flexible, we could be
2371 smarter here when schedule-multiple is on. For example, imagine 3
2372 inferiors with 2 threads each (1.1, 1.2, 2.1, 2.2, 3.1 and 3.2). Threads
2373 2.1 and 3.2 are both waiting for a vfork-done event. Then we could ask the
2374 target(s) to resume:
2376 - All threads of inferior 1
2380 Since we don't have that flexibility (we can only pass one ptid), just
2381 resume the first thread waiting for a vfork-done event we find (e.g. thread
2383 thread_info
*thr
= find_thread_waiting_for_vfork_done ();
2386 /* If we have a thread that is waiting for a vfork-done event,
2387 then we should have switched to it earlier. Calling
2388 target_resume with thread scope is only possible when the
2389 current thread matches the thread scope. */
2390 gdb_assert (thr
->ptid
== inferior_ptid
);
2391 gdb_assert (thr
->inf
->process_target ()
2392 == inferior_thread ()->inf
->process_target ());
2396 return user_visible_resume_ptid (user_step
);
2399 /* Wrapper for target_resume, that handles infrun-specific
2403 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2405 struct thread_info
*tp
= inferior_thread ();
2407 gdb_assert (!tp
->stop_requested
);
2409 /* Install inferior's terminal modes. */
2410 target_terminal::inferior ();
2412 /* Avoid confusing the next resume, if the next stop/resume
2413 happens to apply to another thread. */
2414 tp
->set_stop_signal (GDB_SIGNAL_0
);
2416 /* Advise target which signals may be handled silently.
2418 If we have removed breakpoints because we are stepping over one
2419 in-line (in any thread), we need to receive all signals to avoid
2420 accidentally skipping a breakpoint during execution of a signal
2423 Likewise if we're displaced stepping, otherwise a trap for a
2424 breakpoint in a signal handler might be confused with the
2425 displaced step finishing. We don't make the displaced_step_finish
2426 step distinguish the cases instead, because:
2428 - a backtrace while stopped in the signal handler would show the
2429 scratch pad as frame older than the signal handler, instead of
2430 the real mainline code.
2432 - when the thread is later resumed, the signal handler would
2433 return to the scratch pad area, which would no longer be
2435 if (step_over_info_valid_p ()
2436 || displaced_step_in_progress (tp
->inf
))
2437 target_pass_signals ({});
2439 target_pass_signals (signal_pass
);
2441 infrun_debug_printf ("resume_ptid=%s, step=%d, sig=%s",
2442 resume_ptid
.to_string ().c_str (),
2443 step
, gdb_signal_to_symbol_string (sig
));
2445 target_resume (resume_ptid
, step
, sig
);
2448 /* Resume the inferior. SIG is the signal to give the inferior
2449 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2450 call 'resume', which handles exceptions. */
2453 resume_1 (enum gdb_signal sig
)
2455 struct regcache
*regcache
= get_current_regcache ();
2456 struct gdbarch
*gdbarch
= regcache
->arch ();
2457 struct thread_info
*tp
= inferior_thread ();
2458 const address_space
*aspace
= regcache
->aspace ();
2460 /* This represents the user's step vs continue request. When
2461 deciding whether "set scheduler-locking step" applies, it's the
2462 user's intention that counts. */
2463 const int user_step
= tp
->control
.stepping_command
;
2464 /* This represents what we'll actually request the target to do.
2465 This can decay from a step to a continue, if e.g., we need to
2466 implement single-stepping with breakpoints (software
2470 gdb_assert (!tp
->stop_requested
);
2471 gdb_assert (!thread_is_in_step_over_chain (tp
));
2473 if (tp
->has_pending_waitstatus ())
2476 ("thread %s has pending wait "
2477 "status %s (currently_stepping=%d).",
2478 tp
->ptid
.to_string ().c_str (),
2479 tp
->pending_waitstatus ().to_string ().c_str (),
2480 currently_stepping (tp
));
2482 tp
->inf
->process_target ()->threads_executing
= true;
2483 tp
->set_resumed (true);
2485 /* FIXME: What should we do if we are supposed to resume this
2486 thread with a signal? Maybe we should maintain a queue of
2487 pending signals to deliver. */
2488 if (sig
!= GDB_SIGNAL_0
)
2490 warning (_("Couldn't deliver signal %s to %s."),
2491 gdb_signal_to_name (sig
),
2492 tp
->ptid
.to_string ().c_str ());
2495 tp
->set_stop_signal (GDB_SIGNAL_0
);
2497 if (target_can_async_p ())
2499 target_async (true);
2500 /* Tell the event loop we have an event to process. */
2501 mark_async_event_handler (infrun_async_inferior_event_token
);
2506 tp
->stepped_breakpoint
= 0;
2508 /* Depends on stepped_breakpoint. */
2509 step
= currently_stepping (tp
);
2511 if (current_inferior ()->thread_waiting_for_vfork_done
!= nullptr)
2513 /* Don't try to single-step a vfork parent that is waiting for
2514 the child to get out of the shared memory region (by exec'ing
2515 or exiting). This is particularly important on software
2516 single-step archs, as the child process would trip on the
2517 software single step breakpoint inserted for the parent
2518 process. Since the parent will not actually execute any
2519 instruction until the child is out of the shared region (such
2520 are vfork's semantics), it is safe to simply continue it.
2521 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2522 the parent, and tell it to `keep_going', which automatically
2523 re-sets it stepping. */
2524 infrun_debug_printf ("resume : clear step");
2528 CORE_ADDR pc
= regcache_read_pc (regcache
);
2530 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2531 "current thread [%s] at %s",
2532 step
, gdb_signal_to_symbol_string (sig
),
2533 tp
->control
.trap_expected
,
2534 inferior_ptid
.to_string ().c_str (),
2535 paddress (gdbarch
, pc
));
2537 /* Normally, by the time we reach `resume', the breakpoints are either
2538 removed or inserted, as appropriate. The exception is if we're sitting
2539 at a permanent breakpoint; we need to step over it, but permanent
2540 breakpoints can't be removed. So we have to test for it here. */
2541 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2543 if (sig
!= GDB_SIGNAL_0
)
2545 /* We have a signal to pass to the inferior. The resume
2546 may, or may not take us to the signal handler. If this
2547 is a step, we'll need to stop in the signal handler, if
2548 there's one, (if the target supports stepping into
2549 handlers), or in the next mainline instruction, if
2550 there's no handler. If this is a continue, we need to be
2551 sure to run the handler with all breakpoints inserted.
2552 In all cases, set a breakpoint at the current address
2553 (where the handler returns to), and once that breakpoint
2554 is hit, resume skipping the permanent breakpoint. If
2555 that breakpoint isn't hit, then we've stepped into the
2556 signal handler (or hit some other event). We'll delete
2557 the step-resume breakpoint then. */
2559 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2560 "deliver signal first");
2562 clear_step_over_info ();
2563 tp
->control
.trap_expected
= 0;
2565 if (tp
->control
.step_resume_breakpoint
== nullptr)
2567 /* Set a "high-priority" step-resume, as we don't want
2568 user breakpoints at PC to trigger (again) when this
2570 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2571 gdb_assert (tp
->control
.step_resume_breakpoint
->first_loc ()
2574 tp
->step_after_step_resume_breakpoint
= step
;
2577 insert_breakpoints ();
2581 /* There's no signal to pass, we can go ahead and skip the
2582 permanent breakpoint manually. */
2583 infrun_debug_printf ("skipping permanent breakpoint");
2584 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2585 /* Update pc to reflect the new address from which we will
2586 execute instructions. */
2587 pc
= regcache_read_pc (regcache
);
2591 /* We've already advanced the PC, so the stepping part
2592 is done. Now we need to arrange for a trap to be
2593 reported to handle_inferior_event. Set a breakpoint
2594 at the current PC, and run to it. Don't update
2595 prev_pc, because if we end in
2596 switch_back_to_stepped_thread, we want the "expected
2597 thread advanced also" branch to be taken. IOW, we
2598 don't want this thread to step further from PC
2600 gdb_assert (!step_over_info_valid_p ());
2601 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2602 insert_breakpoints ();
2604 resume_ptid
= internal_resume_ptid (user_step
);
2605 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2606 tp
->set_resumed (true);
2612 /* If we have a breakpoint to step over, make sure to do a single
2613 step only. Same if we have software watchpoints. */
2614 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2615 tp
->control
.may_range_step
= 0;
2617 /* If displaced stepping is enabled, step over breakpoints by executing a
2618 copy of the instruction at a different address.
2620 We can't use displaced stepping when we have a signal to deliver;
2621 the comments for displaced_step_prepare explain why. The
2622 comments in the handle_inferior event for dealing with 'random
2623 signals' explain what we do instead.
2625 We can't use displaced stepping when we are waiting for vfork_done
2626 event, displaced stepping breaks the vfork child similarly as single
2627 step software breakpoint. */
2628 if (tp
->control
.trap_expected
2629 && use_displaced_stepping (tp
)
2630 && !step_over_info_valid_p ()
2631 && sig
== GDB_SIGNAL_0
2632 && current_inferior ()->thread_waiting_for_vfork_done
== nullptr)
2634 displaced_step_prepare_status prepare_status
2635 = displaced_step_prepare (tp
);
2637 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2639 infrun_debug_printf ("Got placed in step-over queue");
2641 tp
->control
.trap_expected
= 0;
2644 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
2646 /* Fallback to stepping over the breakpoint in-line. */
2648 if (target_is_non_stop_p ())
2649 stop_all_threads ("displaced stepping falling back on inline stepping");
2651 set_step_over_info (regcache
->aspace (),
2652 regcache_read_pc (regcache
), 0, tp
->global_num
);
2654 step
= maybe_software_singlestep (gdbarch
);
2656 insert_breakpoints ();
2658 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2660 /* Update pc to reflect the new address from which we will
2661 execute instructions due to displaced stepping. */
2662 pc
= regcache_read_pc (get_thread_regcache (tp
));
2664 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2667 gdb_assert_not_reached ("Invalid displaced_step_prepare_status "
2671 /* Do we need to do it the hard way, w/temp breakpoints? */
2673 step
= maybe_software_singlestep (gdbarch
);
2675 /* Currently, our software single-step implementation leads to different
2676 results than hardware single-stepping in one situation: when stepping
2677 into delivering a signal which has an associated signal handler,
2678 hardware single-step will stop at the first instruction of the handler,
2679 while software single-step will simply skip execution of the handler.
2681 For now, this difference in behavior is accepted since there is no
2682 easy way to actually implement single-stepping into a signal handler
2683 without kernel support.
2685 However, there is one scenario where this difference leads to follow-on
2686 problems: if we're stepping off a breakpoint by removing all breakpoints
2687 and then single-stepping. In this case, the software single-step
2688 behavior means that even if there is a *breakpoint* in the signal
2689 handler, GDB still would not stop.
2691 Fortunately, we can at least fix this particular issue. We detect
2692 here the case where we are about to deliver a signal while software
2693 single-stepping with breakpoints removed. In this situation, we
2694 revert the decisions to remove all breakpoints and insert single-
2695 step breakpoints, and instead we install a step-resume breakpoint
2696 at the current address, deliver the signal without stepping, and
2697 once we arrive back at the step-resume breakpoint, actually step
2698 over the breakpoint we originally wanted to step over. */
2699 if (thread_has_single_step_breakpoints_set (tp
)
2700 && sig
!= GDB_SIGNAL_0
2701 && step_over_info_valid_p ())
2703 /* If we have nested signals or a pending signal is delivered
2704 immediately after a handler returns, might already have
2705 a step-resume breakpoint set on the earlier handler. We cannot
2706 set another step-resume breakpoint; just continue on until the
2707 original breakpoint is hit. */
2708 if (tp
->control
.step_resume_breakpoint
== nullptr)
2710 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2711 tp
->step_after_step_resume_breakpoint
= 1;
2714 delete_single_step_breakpoints (tp
);
2716 clear_step_over_info ();
2717 tp
->control
.trap_expected
= 0;
2719 insert_breakpoints ();
2722 /* If STEP is set, it's a request to use hardware stepping
2723 facilities. But in that case, we should never
2724 use singlestep breakpoint. */
2725 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2727 /* Decide the set of threads to ask the target to resume. */
2728 if (tp
->control
.trap_expected
)
2730 /* We're allowing a thread to run past a breakpoint it has
2731 hit, either by single-stepping the thread with the breakpoint
2732 removed, or by displaced stepping, with the breakpoint inserted.
2733 In the former case, we need to single-step only this thread,
2734 and keep others stopped, as they can miss this breakpoint if
2735 allowed to run. That's not really a problem for displaced
2736 stepping, but, we still keep other threads stopped, in case
2737 another thread is also stopped for a breakpoint waiting for
2738 its turn in the displaced stepping queue. */
2739 resume_ptid
= inferior_ptid
;
2742 resume_ptid
= internal_resume_ptid (user_step
);
2744 if (execution_direction
!= EXEC_REVERSE
2745 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2747 /* There are two cases where we currently need to step a
2748 breakpoint instruction when we have a signal to deliver:
2750 - See handle_signal_stop where we handle random signals that
2751 could take out us out of the stepping range. Normally, in
2752 that case we end up continuing (instead of stepping) over the
2753 signal handler with a breakpoint at PC, but there are cases
2754 where we should _always_ single-step, even if we have a
2755 step-resume breakpoint, like when a software watchpoint is
2756 set. Assuming single-stepping and delivering a signal at the
2757 same time would takes us to the signal handler, then we could
2758 have removed the breakpoint at PC to step over it. However,
2759 some hardware step targets (like e.g., Mac OS) can't step
2760 into signal handlers, and for those, we need to leave the
2761 breakpoint at PC inserted, as otherwise if the handler
2762 recurses and executes PC again, it'll miss the breakpoint.
2763 So we leave the breakpoint inserted anyway, but we need to
2764 record that we tried to step a breakpoint instruction, so
2765 that adjust_pc_after_break doesn't end up confused.
2767 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2768 in one thread after another thread that was stepping had been
2769 momentarily paused for a step-over. When we re-resume the
2770 stepping thread, it may be resumed from that address with a
2771 breakpoint that hasn't trapped yet. Seen with
2772 gdb.threads/non-stop-fair-events.exp, on targets that don't
2773 do displaced stepping. */
2775 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2776 tp
->ptid
.to_string ().c_str ());
2778 tp
->stepped_breakpoint
= 1;
2780 /* Most targets can step a breakpoint instruction, thus
2781 executing it normally. But if this one cannot, just
2782 continue and we will hit it anyway. */
2783 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2787 if (tp
->control
.may_range_step
)
2789 /* If we're resuming a thread with the PC out of the step
2790 range, then we're doing some nested/finer run control
2791 operation, like stepping the thread out of the dynamic
2792 linker or the displaced stepping scratch pad. We
2793 shouldn't have allowed a range step then. */
2794 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2797 do_target_resume (resume_ptid
, step
, sig
);
2798 tp
->set_resumed (true);
2801 /* Resume the inferior. SIG is the signal to give the inferior
2802 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2803 rolls back state on error. */
2806 resume (gdb_signal sig
)
2812 catch (const gdb_exception
&ex
)
2814 /* If resuming is being aborted for any reason, delete any
2815 single-step breakpoint resume_1 may have created, to avoid
2816 confusing the following resumption, and to avoid leaving
2817 single-step breakpoints perturbing other threads, in case
2818 we're running in non-stop mode. */
2819 if (inferior_ptid
!= null_ptid
)
2820 delete_single_step_breakpoints (inferior_thread ());
2830 /* Counter that tracks number of user visible stops. This can be used
2831 to tell whether a command has proceeded the inferior past the
2832 current location. This allows e.g., inferior function calls in
2833 breakpoint commands to not interrupt the command list. When the
2834 call finishes successfully, the inferior is standing at the same
2835 breakpoint as if nothing happened (and so we don't call
2837 static ULONGEST current_stop_id
;
2844 return current_stop_id
;
2847 /* Called when we report a user visible stop. */
2855 /* Clear out all variables saying what to do when inferior is continued.
2856 First do this, then set the ones you want, then call `proceed'. */
2859 clear_proceed_status_thread (struct thread_info
*tp
)
2861 infrun_debug_printf ("%s", tp
->ptid
.to_string ().c_str ());
2863 /* If we're starting a new sequence, then the previous finished
2864 single-step is no longer relevant. */
2865 if (tp
->has_pending_waitstatus ())
2867 if (tp
->stop_reason () == TARGET_STOPPED_BY_SINGLE_STEP
)
2869 infrun_debug_printf ("pending event of %s was a finished step. "
2871 tp
->ptid
.to_string ().c_str ());
2873 tp
->clear_pending_waitstatus ();
2874 tp
->set_stop_reason (TARGET_STOPPED_BY_NO_REASON
);
2879 ("thread %s has pending wait status %s (currently_stepping=%d).",
2880 tp
->ptid
.to_string ().c_str (),
2881 tp
->pending_waitstatus ().to_string ().c_str (),
2882 currently_stepping (tp
));
2886 /* If this signal should not be seen by program, give it zero.
2887 Used for debugging signals. */
2888 if (!signal_pass_state (tp
->stop_signal ()))
2889 tp
->set_stop_signal (GDB_SIGNAL_0
);
2891 tp
->release_thread_fsm ();
2893 tp
->control
.trap_expected
= 0;
2894 tp
->control
.step_range_start
= 0;
2895 tp
->control
.step_range_end
= 0;
2896 tp
->control
.may_range_step
= 0;
2897 tp
->control
.step_frame_id
= null_frame_id
;
2898 tp
->control
.step_stack_frame_id
= null_frame_id
;
2899 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2900 tp
->control
.step_start_function
= nullptr;
2901 tp
->stop_requested
= 0;
2903 tp
->control
.stop_step
= 0;
2905 tp
->control
.proceed_to_finish
= 0;
2907 tp
->control
.stepping_command
= 0;
2909 /* Discard any remaining commands or status from previous stop. */
2910 bpstat_clear (&tp
->control
.stop_bpstat
);
2913 /* Notify the current interpreter and observers that the target is about to
2917 notify_about_to_proceed ()
2919 top_level_interpreter ()->on_about_to_proceed ();
2920 gdb::observers::about_to_proceed
.notify ();
2924 clear_proceed_status (int step
)
2926 /* With scheduler-locking replay, stop replaying other threads if we're
2927 not replaying the user-visible resume ptid.
2929 This is a convenience feature to not require the user to explicitly
2930 stop replaying the other threads. We're assuming that the user's
2931 intent is to resume tracing the recorded process. */
2932 if (!non_stop
&& scheduler_mode
== schedlock_replay
2933 && target_record_is_replaying (minus_one_ptid
)
2934 && !target_record_will_replay (user_visible_resume_ptid (step
),
2935 execution_direction
))
2936 target_record_stop_replaying ();
2938 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2940 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2941 process_stratum_target
*resume_target
2942 = user_visible_resume_target (resume_ptid
);
2944 /* In all-stop mode, delete the per-thread status of all threads
2945 we're about to resume, implicitly and explicitly. */
2946 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2947 clear_proceed_status_thread (tp
);
2950 if (inferior_ptid
!= null_ptid
)
2952 struct inferior
*inferior
;
2956 /* If in non-stop mode, only delete the per-thread status of
2957 the current thread. */
2958 clear_proceed_status_thread (inferior_thread ());
2961 inferior
= current_inferior ();
2962 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2965 notify_about_to_proceed ();
2968 /* Returns true if TP is still stopped at a breakpoint that needs
2969 stepping-over in order to make progress. If the breakpoint is gone
2970 meanwhile, we can skip the whole step-over dance. */
2973 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2975 if (tp
->stepping_over_breakpoint
)
2977 struct regcache
*regcache
= get_thread_regcache (tp
);
2979 if (breakpoint_here_p (regcache
->aspace (),
2980 regcache_read_pc (regcache
))
2981 == ordinary_breakpoint_here
)
2984 tp
->stepping_over_breakpoint
= 0;
2990 /* Check whether thread TP still needs to start a step-over in order
2991 to make progress when resumed. Returns an bitwise or of enum
2992 step_over_what bits, indicating what needs to be stepped over. */
2994 static step_over_what
2995 thread_still_needs_step_over (struct thread_info
*tp
)
2997 step_over_what what
= 0;
2999 if (thread_still_needs_step_over_bp (tp
))
3000 what
|= STEP_OVER_BREAKPOINT
;
3002 if (tp
->stepping_over_watchpoint
3003 && !target_have_steppable_watchpoint ())
3004 what
|= STEP_OVER_WATCHPOINT
;
3009 /* Returns true if scheduler locking applies. STEP indicates whether
3010 we're about to do a step/next-like command to a thread. */
3013 schedlock_applies (struct thread_info
*tp
)
3015 return (scheduler_mode
== schedlock_on
3016 || (scheduler_mode
== schedlock_step
3017 && tp
->control
.stepping_command
)
3018 || (scheduler_mode
== schedlock_replay
3019 && target_record_will_replay (minus_one_ptid
,
3020 execution_direction
)));
3023 /* Set process_stratum_target::COMMIT_RESUMED_STATE in all target
3024 stacks that have threads executing and don't have threads with
3028 maybe_set_commit_resumed_all_targets ()
3030 scoped_restore_current_thread restore_thread
;
3032 for (inferior
*inf
: all_non_exited_inferiors ())
3034 process_stratum_target
*proc_target
= inf
->process_target ();
3036 if (proc_target
->commit_resumed_state
)
3038 /* We already set this in a previous iteration, via another
3039 inferior sharing the process_stratum target. */
3043 /* If the target has no resumed threads, it would be useless to
3044 ask it to commit the resumed threads. */
3045 if (!proc_target
->threads_executing
)
3047 infrun_debug_printf ("not requesting commit-resumed for target "
3048 "%s, no resumed threads",
3049 proc_target
->shortname ());
3053 /* As an optimization, if a thread from this target has some
3054 status to report, handle it before requiring the target to
3055 commit its resumed threads: handling the status might lead to
3056 resuming more threads. */
3057 if (proc_target
->has_resumed_with_pending_wait_status ())
3059 infrun_debug_printf ("not requesting commit-resumed for target %s, a"
3060 " thread has a pending waitstatus",
3061 proc_target
->shortname ());
3065 switch_to_inferior_no_thread (inf
);
3067 if (target_has_pending_events ())
3069 infrun_debug_printf ("not requesting commit-resumed for target %s, "
3070 "target has pending events",
3071 proc_target
->shortname ());
3075 infrun_debug_printf ("enabling commit-resumed for target %s",
3076 proc_target
->shortname ());
3078 proc_target
->commit_resumed_state
= true;
3085 maybe_call_commit_resumed_all_targets ()
3087 scoped_restore_current_thread restore_thread
;
3089 for (inferior
*inf
: all_non_exited_inferiors ())
3091 process_stratum_target
*proc_target
= inf
->process_target ();
3093 if (!proc_target
->commit_resumed_state
)
3096 switch_to_inferior_no_thread (inf
);
3098 infrun_debug_printf ("calling commit_resumed for target %s",
3099 proc_target
->shortname());
3101 target_commit_resumed ();
3105 /* To track nesting of scoped_disable_commit_resumed objects, ensuring
3106 that only the outermost one attempts to re-enable
3108 static bool enable_commit_resumed
= true;
3112 scoped_disable_commit_resumed::scoped_disable_commit_resumed
3113 (const char *reason
)
3114 : m_reason (reason
),
3115 m_prev_enable_commit_resumed (enable_commit_resumed
)
3117 infrun_debug_printf ("reason=%s", m_reason
);
3119 enable_commit_resumed
= false;
3121 for (inferior
*inf
: all_non_exited_inferiors ())
3123 process_stratum_target
*proc_target
= inf
->process_target ();
3125 if (m_prev_enable_commit_resumed
)
3127 /* This is the outermost instance: force all
3128 COMMIT_RESUMED_STATE to false. */
3129 proc_target
->commit_resumed_state
= false;
3133 /* This is not the outermost instance, we expect
3134 COMMIT_RESUMED_STATE to have been cleared by the
3135 outermost instance. */
3136 gdb_assert (!proc_target
->commit_resumed_state
);
3144 scoped_disable_commit_resumed::reset ()
3150 infrun_debug_printf ("reason=%s", m_reason
);
3152 gdb_assert (!enable_commit_resumed
);
3154 enable_commit_resumed
= m_prev_enable_commit_resumed
;
3156 if (m_prev_enable_commit_resumed
)
3158 /* This is the outermost instance, re-enable
3159 COMMIT_RESUMED_STATE on the targets where it's possible. */
3160 maybe_set_commit_resumed_all_targets ();
3164 /* This is not the outermost instance, we expect
3165 COMMIT_RESUMED_STATE to still be false. */
3166 for (inferior
*inf
: all_non_exited_inferiors ())
3168 process_stratum_target
*proc_target
= inf
->process_target ();
3169 gdb_assert (!proc_target
->commit_resumed_state
);
3176 scoped_disable_commit_resumed::~scoped_disable_commit_resumed ()
3184 scoped_disable_commit_resumed::reset_and_commit ()
3187 maybe_call_commit_resumed_all_targets ();
3192 scoped_enable_commit_resumed::scoped_enable_commit_resumed
3193 (const char *reason
)
3194 : m_reason (reason
),
3195 m_prev_enable_commit_resumed (enable_commit_resumed
)
3197 infrun_debug_printf ("reason=%s", m_reason
);
3199 if (!enable_commit_resumed
)
3201 enable_commit_resumed
= true;
3203 /* Re-enable COMMIT_RESUMED_STATE on the targets where it's
3205 maybe_set_commit_resumed_all_targets ();
3207 maybe_call_commit_resumed_all_targets ();
3213 scoped_enable_commit_resumed::~scoped_enable_commit_resumed ()
3215 infrun_debug_printf ("reason=%s", m_reason
);
3217 gdb_assert (enable_commit_resumed
);
3219 enable_commit_resumed
= m_prev_enable_commit_resumed
;
3221 if (!enable_commit_resumed
)
3223 /* Force all COMMIT_RESUMED_STATE back to false. */
3224 for (inferior
*inf
: all_non_exited_inferiors ())
3226 process_stratum_target
*proc_target
= inf
->process_target ();
3227 proc_target
->commit_resumed_state
= false;
3232 /* Check that all the targets we're about to resume are in non-stop
3233 mode. Ideally, we'd only care whether all targets support
3234 target-async, but we're not there yet. E.g., stop_all_threads
3235 doesn't know how to handle all-stop targets. Also, the remote
3236 protocol in all-stop mode is synchronous, irrespective of
3237 target-async, which means that things like a breakpoint re-set
3238 triggered by one target would try to read memory from all targets
3242 check_multi_target_resumption (process_stratum_target
*resume_target
)
3244 if (!non_stop
&& resume_target
== nullptr)
3246 scoped_restore_current_thread restore_thread
;
3248 /* This is used to track whether we're resuming more than one
3250 process_stratum_target
*first_connection
= nullptr;
3252 /* The first inferior we see with a target that does not work in
3253 always-non-stop mode. */
3254 inferior
*first_not_non_stop
= nullptr;
3256 for (inferior
*inf
: all_non_exited_inferiors ())
3258 switch_to_inferior_no_thread (inf
);
3260 if (!target_has_execution ())
3263 process_stratum_target
*proc_target
3264 = current_inferior ()->process_target();
3266 if (!target_is_non_stop_p ())
3267 first_not_non_stop
= inf
;
3269 if (first_connection
== nullptr)
3270 first_connection
= proc_target
;
3271 else if (first_connection
!= proc_target
3272 && first_not_non_stop
!= nullptr)
3274 switch_to_inferior_no_thread (first_not_non_stop
);
3276 proc_target
= current_inferior ()->process_target();
3278 error (_("Connection %d (%s) does not support "
3279 "multi-target resumption."),
3280 proc_target
->connection_number
,
3281 make_target_connection_string (proc_target
).c_str ());
3287 /* Helper function for `proceed`. Check if thread TP is suitable for
3288 resuming, and, if it is, switch to the thread and call
3289 `keep_going_pass_signal`. If TP is not suitable for resuming then this
3290 function will just return without switching threads. */
3293 proceed_resume_thread_checked (thread_info
*tp
)
3295 if (!tp
->inf
->has_execution ())
3297 infrun_debug_printf ("[%s] target has no execution",
3298 tp
->ptid
.to_string ().c_str ());
3304 infrun_debug_printf ("[%s] resumed",
3305 tp
->ptid
.to_string ().c_str ());
3306 gdb_assert (tp
->executing () || tp
->has_pending_waitstatus ());
3310 if (thread_is_in_step_over_chain (tp
))
3312 infrun_debug_printf ("[%s] needs step-over",
3313 tp
->ptid
.to_string ().c_str ());
3317 /* When handling a vfork GDB removes all breakpoints from the program
3318 space in which the vfork is being handled. If we are following the
3319 parent then GDB will set the thread_waiting_for_vfork_done member of
3320 the parent inferior. In this case we should take care to only resume
3321 the vfork parent thread, the kernel will hold this thread suspended
3322 until the vfork child has exited or execd, at which point the parent
3323 will be resumed and a VFORK_DONE event sent to GDB. */
3324 if (tp
->inf
->thread_waiting_for_vfork_done
!= nullptr)
3326 if (target_is_non_stop_p ())
3328 /* For non-stop targets, regardless of whether GDB is using
3329 all-stop or non-stop mode, threads are controlled
3332 When a thread is handling a vfork, breakpoints are removed
3333 from the inferior (well, program space in fact), so it is
3334 critical that we don't try to resume any thread other than the
3336 if (tp
!= tp
->inf
->thread_waiting_for_vfork_done
)
3338 infrun_debug_printf ("[%s] thread %s of this inferior is "
3339 "waiting for vfork-done",
3340 tp
->ptid
.to_string ().c_str (),
3341 tp
->inf
->thread_waiting_for_vfork_done
3342 ->ptid
.to_string ().c_str ());
3348 /* For all-stop targets, when we attempt to resume the inferior,
3349 we will only resume the vfork parent thread, this is handled
3350 in internal_resume_ptid.
3352 Additionally, we will always be called with the vfork parent
3353 thread as the current thread (TP) thanks to follow_fork, as
3354 such the following assertion should hold.
3356 Beyond this there is nothing more that needs to be done
3358 gdb_assert (tp
== tp
->inf
->thread_waiting_for_vfork_done
);
3362 /* When handling a vfork GDB removes all breakpoints from the program
3363 space in which the vfork is being handled. If we are following the
3364 child then GDB will set vfork_child member of the vfork parent
3365 inferior. Once the child has either exited or execd then GDB will
3366 detach from the parent process. Until that point GDB should not
3367 resume any thread in the parent process. */
3368 if (tp
->inf
->vfork_child
!= nullptr)
3370 infrun_debug_printf ("[%s] thread is part of a vfork parent, child is %d",
3371 tp
->ptid
.to_string ().c_str (),
3372 tp
->inf
->vfork_child
->pid
);
3376 infrun_debug_printf ("resuming %s",
3377 tp
->ptid
.to_string ().c_str ());
3379 execution_control_state
ecs (tp
);
3380 switch_to_thread (tp
);
3381 keep_going_pass_signal (&ecs
);
3382 if (!ecs
.wait_some_more
)
3383 error (_("Command aborted."));
3386 /* Basic routine for continuing the program in various fashions.
3388 ADDR is the address to resume at, or -1 for resume where stopped.
3389 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
3390 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
3392 You should call clear_proceed_status before calling proceed. */
3395 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
3397 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
3399 struct regcache
*regcache
;
3400 struct gdbarch
*gdbarch
;
3403 /* If we're stopped at a fork/vfork, switch to either the parent or child
3404 thread as defined by the "set follow-fork-mode" command, or, if both
3405 the parent and child are controlled by GDB, and schedule-multiple is
3406 on, follow the child. If none of the above apply then we just proceed
3407 resuming the current thread. */
3408 if (!follow_fork ())
3410 /* The target for some reason decided not to resume. */
3412 if (target_can_async_p ())
3413 inferior_event_handler (INF_EXEC_COMPLETE
);
3417 /* We'll update this if & when we switch to a new thread. */
3418 update_previous_thread ();
3420 regcache
= get_current_regcache ();
3421 gdbarch
= regcache
->arch ();
3422 const address_space
*aspace
= regcache
->aspace ();
3424 pc
= regcache_read_pc_protected (regcache
);
3426 thread_info
*cur_thr
= inferior_thread ();
3428 infrun_debug_printf ("cur_thr = %s", cur_thr
->ptid
.to_string ().c_str ());
3430 /* Fill in with reasonable starting values. */
3431 init_thread_stepping_state (cur_thr
);
3433 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
3436 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
3437 process_stratum_target
*resume_target
3438 = user_visible_resume_target (resume_ptid
);
3440 check_multi_target_resumption (resume_target
);
3442 if (addr
== (CORE_ADDR
) -1)
3444 if (cur_thr
->stop_pc_p ()
3445 && pc
== cur_thr
->stop_pc ()
3446 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3447 && execution_direction
!= EXEC_REVERSE
)
3448 /* There is a breakpoint at the address we will resume at,
3449 step one instruction before inserting breakpoints so that
3450 we do not stop right away (and report a second hit at this
3453 Note, we don't do this in reverse, because we won't
3454 actually be executing the breakpoint insn anyway.
3455 We'll be (un-)executing the previous instruction. */
3456 cur_thr
->stepping_over_breakpoint
= 1;
3457 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3458 && gdbarch_single_step_through_delay (gdbarch
,
3459 get_current_frame ()))
3460 /* We stepped onto an instruction that needs to be stepped
3461 again before re-inserting the breakpoint, do so. */
3462 cur_thr
->stepping_over_breakpoint
= 1;
3466 regcache_write_pc (regcache
, addr
);
3469 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3470 cur_thr
->set_stop_signal (siggnal
);
3472 /* If an exception is thrown from this point on, make sure to
3473 propagate GDB's knowledge of the executing state to the
3474 frontend/user running state. */
3475 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3477 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3478 threads (e.g., we might need to set threads stepping over
3479 breakpoints first), from the user/frontend's point of view, all
3480 threads in RESUME_PTID are now running. Unless we're calling an
3481 inferior function, as in that case we pretend the inferior
3482 doesn't run at all. */
3483 if (!cur_thr
->control
.in_infcall
)
3484 set_running (resume_target
, resume_ptid
, true);
3486 infrun_debug_printf ("addr=%s, signal=%s, resume_ptid=%s",
3487 paddress (gdbarch
, addr
),
3488 gdb_signal_to_symbol_string (siggnal
),
3489 resume_ptid
.to_string ().c_str ());
3491 annotate_starting ();
3493 /* Make sure that output from GDB appears before output from the
3495 gdb_flush (gdb_stdout
);
3497 /* Since we've marked the inferior running, give it the terminal. A
3498 QUIT/Ctrl-C from here on is forwarded to the target (which can
3499 still detect attempts to unblock a stuck connection with repeated
3500 Ctrl-C from within target_pass_ctrlc). */
3501 target_terminal::inferior ();
3503 /* In a multi-threaded task we may select another thread and
3504 then continue or step.
3506 But if a thread that we're resuming had stopped at a breakpoint,
3507 it will immediately cause another breakpoint stop without any
3508 execution (i.e. it will report a breakpoint hit incorrectly). So
3509 we must step over it first.
3511 Look for threads other than the current (TP) that reported a
3512 breakpoint hit and haven't been resumed yet since. */
3514 /* If scheduler locking applies, we can avoid iterating over all
3516 if (!non_stop
&& !schedlock_applies (cur_thr
))
3518 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3521 switch_to_thread_no_regs (tp
);
3523 /* Ignore the current thread here. It's handled
3528 if (!thread_still_needs_step_over (tp
))
3531 gdb_assert (!thread_is_in_step_over_chain (tp
));
3533 infrun_debug_printf ("need to step-over [%s] first",
3534 tp
->ptid
.to_string ().c_str ());
3536 global_thread_step_over_chain_enqueue (tp
);
3539 switch_to_thread (cur_thr
);
3542 /* Enqueue the current thread last, so that we move all other
3543 threads over their breakpoints first. */
3544 if (cur_thr
->stepping_over_breakpoint
)
3545 global_thread_step_over_chain_enqueue (cur_thr
);
3547 /* If the thread isn't started, we'll still need to set its prev_pc,
3548 so that switch_back_to_stepped_thread knows the thread hasn't
3549 advanced. Must do this before resuming any thread, as in
3550 all-stop/remote, once we resume we can't send any other packet
3551 until the target stops again. */
3552 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3555 scoped_disable_commit_resumed
disable_commit_resumed ("proceeding");
3556 bool step_over_started
= start_step_over ();
3558 if (step_over_info_valid_p ())
3560 /* Either this thread started a new in-line step over, or some
3561 other thread was already doing one. In either case, don't
3562 resume anything else until the step-over is finished. */
3564 else if (step_over_started
&& !target_is_non_stop_p ())
3566 /* A new displaced stepping sequence was started. In all-stop,
3567 we can't talk to the target anymore until it next stops. */
3569 else if (!non_stop
&& target_is_non_stop_p ())
3571 INFRUN_SCOPED_DEBUG_START_END
3572 ("resuming threads, all-stop-on-top-of-non-stop");
3574 /* In all-stop, but the target is always in non-stop mode.
3575 Start all other threads that are implicitly resumed too. */
3576 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3579 switch_to_thread_no_regs (tp
);
3580 proceed_resume_thread_checked (tp
);
3584 proceed_resume_thread_checked (cur_thr
);
3586 disable_commit_resumed
.reset_and_commit ();
3589 finish_state
.release ();
3591 /* If we've switched threads above, switch back to the previously
3592 current thread. We don't want the user to see a different
3594 switch_to_thread (cur_thr
);
3596 /* Tell the event loop to wait for it to stop. If the target
3597 supports asynchronous execution, it'll do this from within
3599 if (!target_can_async_p ())
3600 mark_async_event_handler (infrun_async_inferior_event_token
);
3604 /* Start remote-debugging of a machine over a serial link. */
3607 start_remote (int from_tty
)
3609 inferior
*inf
= current_inferior ();
3610 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3612 /* Always go on waiting for the target, regardless of the mode. */
3613 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3614 indicate to wait_for_inferior that a target should timeout if
3615 nothing is returned (instead of just blocking). Because of this,
3616 targets expecting an immediate response need to, internally, set
3617 things up so that the target_wait() is forced to eventually
3619 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3620 differentiate to its caller what the state of the target is after
3621 the initial open has been performed. Here we're assuming that
3622 the target has stopped. It should be possible to eventually have
3623 target_open() return to the caller an indication that the target
3624 is currently running and GDB state should be set to the same as
3625 for an async run. */
3626 wait_for_inferior (inf
);
3628 /* Now that the inferior has stopped, do any bookkeeping like
3629 loading shared libraries. We want to do this before normal_stop,
3630 so that the displayed frame is up to date. */
3631 post_create_inferior (from_tty
);
3636 /* Initialize static vars when a new inferior begins. */
3639 init_wait_for_inferior (void)
3641 /* These are meaningless until the first time through wait_for_inferior. */
3643 breakpoint_init_inferior (inf_starting
);
3645 clear_proceed_status (0);
3647 nullify_last_target_wait_ptid ();
3649 update_previous_thread ();
3654 static void handle_inferior_event (struct execution_control_state
*ecs
);
3656 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3657 struct execution_control_state
*ecs
);
3658 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3659 struct execution_control_state
*ecs
);
3660 static void handle_signal_stop (struct execution_control_state
*ecs
);
3661 static void check_exception_resume (struct execution_control_state
*,
3664 static void end_stepping_range (struct execution_control_state
*ecs
);
3665 static void stop_waiting (struct execution_control_state
*ecs
);
3666 static void keep_going (struct execution_control_state
*ecs
);
3667 static void process_event_stop_test (struct execution_control_state
*ecs
);
3668 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3670 /* This function is attached as a "thread_stop_requested" observer.
3671 Cleanup local state that assumed the PTID was to be resumed, and
3672 report the stop to the frontend. */
3675 infrun_thread_stop_requested (ptid_t ptid
)
3677 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3679 /* PTID was requested to stop. If the thread was already stopped,
3680 but the user/frontend doesn't know about that yet (e.g., the
3681 thread had been temporarily paused for some step-over), set up
3682 for reporting the stop now. */
3683 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3685 if (tp
->state
!= THREAD_RUNNING
)
3687 if (tp
->executing ())
3690 /* Remove matching threads from the step-over queue, so
3691 start_step_over doesn't try to resume them
3693 if (thread_is_in_step_over_chain (tp
))
3694 global_thread_step_over_chain_remove (tp
);
3696 /* If the thread is stopped, but the user/frontend doesn't
3697 know about that yet, queue a pending event, as if the
3698 thread had just stopped now. Unless the thread already had
3700 if (!tp
->has_pending_waitstatus ())
3702 target_waitstatus ws
;
3703 ws
.set_stopped (GDB_SIGNAL_0
);
3704 tp
->set_pending_waitstatus (ws
);
3707 /* Clear the inline-frame state, since we're re-processing the
3709 clear_inline_frame_state (tp
);
3711 /* If this thread was paused because some other thread was
3712 doing an inline-step over, let that finish first. Once
3713 that happens, we'll restart all threads and consume pending
3714 stop events then. */
3715 if (step_over_info_valid_p ())
3718 /* Otherwise we can process the (new) pending event now. Set
3719 it so this pending event is considered by
3721 tp
->set_resumed (true);
3725 /* Delete the step resume, single-step and longjmp/exception resume
3726 breakpoints of TP. */
3729 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3731 delete_step_resume_breakpoint (tp
);
3732 delete_exception_resume_breakpoint (tp
);
3733 delete_single_step_breakpoints (tp
);
3736 /* If the target still has execution, call FUNC for each thread that
3737 just stopped. In all-stop, that's all the non-exited threads; in
3738 non-stop, that's the current thread, only. */
3740 typedef void (*for_each_just_stopped_thread_callback_func
)
3741 (struct thread_info
*tp
);
3744 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3746 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3749 if (target_is_non_stop_p ())
3751 /* If in non-stop mode, only the current thread stopped. */
3752 func (inferior_thread ());
3756 /* In all-stop mode, all threads have stopped. */
3757 for (thread_info
*tp
: all_non_exited_threads ())
3762 /* Delete the step resume and longjmp/exception resume breakpoints of
3763 the threads that just stopped. */
3766 delete_just_stopped_threads_infrun_breakpoints (void)
3768 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3771 /* Delete the single-step breakpoints of the threads that just
3775 delete_just_stopped_threads_single_step_breakpoints (void)
3777 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3783 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3784 const struct target_waitstatus
&ws
)
3786 infrun_debug_printf ("target_wait (%s [%s], status) =",
3787 waiton_ptid
.to_string ().c_str (),
3788 target_pid_to_str (waiton_ptid
).c_str ());
3789 infrun_debug_printf (" %s [%s],",
3790 result_ptid
.to_string ().c_str (),
3791 target_pid_to_str (result_ptid
).c_str ());
3792 infrun_debug_printf (" %s", ws
.to_string ().c_str ());
3795 /* Select a thread at random, out of those which are resumed and have
3798 static struct thread_info
*
3799 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3801 process_stratum_target
*proc_target
= inf
->process_target ();
3803 = proc_target
->random_resumed_with_pending_wait_status (inf
, waiton_ptid
);
3805 if (thread
== nullptr)
3807 infrun_debug_printf ("None found.");
3811 infrun_debug_printf ("Found %s.", thread
->ptid
.to_string ().c_str ());
3812 gdb_assert (thread
->resumed ());
3813 gdb_assert (thread
->has_pending_waitstatus ());
3818 /* Wrapper for target_wait that first checks whether threads have
3819 pending statuses to report before actually asking the target for
3820 more events. INF is the inferior we're using to call target_wait
3824 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3825 target_waitstatus
*status
, target_wait_flags options
)
3827 struct thread_info
*tp
;
3829 /* We know that we are looking for an event in the target of inferior
3830 INF, but we don't know which thread the event might come from. As
3831 such we want to make sure that INFERIOR_PTID is reset so that none of
3832 the wait code relies on it - doing so is always a mistake. */
3833 switch_to_inferior_no_thread (inf
);
3835 /* First check if there is a resumed thread with a wait status
3837 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3839 tp
= random_pending_event_thread (inf
, ptid
);
3843 infrun_debug_printf ("Waiting for specific thread %s.",
3844 ptid
.to_string ().c_str ());
3846 /* We have a specific thread to check. */
3847 tp
= inf
->find_thread (ptid
);
3848 gdb_assert (tp
!= nullptr);
3849 if (!tp
->has_pending_waitstatus ())
3854 && (tp
->stop_reason () == TARGET_STOPPED_BY_SW_BREAKPOINT
3855 || tp
->stop_reason () == TARGET_STOPPED_BY_HW_BREAKPOINT
))
3857 struct regcache
*regcache
= get_thread_regcache (tp
);
3858 struct gdbarch
*gdbarch
= regcache
->arch ();
3862 pc
= regcache_read_pc (regcache
);
3864 if (pc
!= tp
->stop_pc ())
3866 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3867 tp
->ptid
.to_string ().c_str (),
3868 paddress (gdbarch
, tp
->stop_pc ()),
3869 paddress (gdbarch
, pc
));
3872 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3874 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3875 tp
->ptid
.to_string ().c_str (),
3876 paddress (gdbarch
, pc
));
3883 infrun_debug_printf ("pending event of %s cancelled.",
3884 tp
->ptid
.to_string ().c_str ());
3886 tp
->clear_pending_waitstatus ();
3887 target_waitstatus ws
;
3889 tp
->set_pending_waitstatus (ws
);
3890 tp
->set_stop_reason (TARGET_STOPPED_BY_NO_REASON
);
3896 infrun_debug_printf ("Using pending wait status %s for %s.",
3897 tp
->pending_waitstatus ().to_string ().c_str (),
3898 tp
->ptid
.to_string ().c_str ());
3900 /* Now that we've selected our final event LWP, un-adjust its PC
3901 if it was a software breakpoint (and the target doesn't
3902 always adjust the PC itself). */
3903 if (tp
->stop_reason () == TARGET_STOPPED_BY_SW_BREAKPOINT
3904 && !target_supports_stopped_by_sw_breakpoint ())
3906 struct regcache
*regcache
;
3907 struct gdbarch
*gdbarch
;
3910 regcache
= get_thread_regcache (tp
);
3911 gdbarch
= regcache
->arch ();
3913 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3918 pc
= regcache_read_pc (regcache
);
3919 regcache_write_pc (regcache
, pc
+ decr_pc
);
3923 tp
->set_stop_reason (TARGET_STOPPED_BY_NO_REASON
);
3924 *status
= tp
->pending_waitstatus ();
3925 tp
->clear_pending_waitstatus ();
3927 /* Wake up the event loop again, until all pending events are
3929 if (target_is_async_p ())
3930 mark_async_event_handler (infrun_async_inferior_event_token
);
3934 /* But if we don't find one, we'll have to wait. */
3936 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3938 if (!target_can_async_p ())
3939 options
&= ~TARGET_WNOHANG
;
3941 return target_wait (ptid
, status
, options
);
3944 /* Wrapper for target_wait that first checks whether threads have
3945 pending statuses to report before actually asking the target for
3946 more events. Polls for events from all inferiors/targets. */
3949 do_target_wait (execution_control_state
*ecs
, target_wait_flags options
)
3951 int num_inferiors
= 0;
3952 int random_selector
;
3954 /* For fairness, we pick the first inferior/target to poll at random
3955 out of all inferiors that may report events, and then continue
3956 polling the rest of the inferior list starting from that one in a
3957 circular fashion until the whole list is polled once. */
3959 auto inferior_matches
= [] (inferior
*inf
)
3961 return inf
->process_target () != nullptr;
3964 /* First see how many matching inferiors we have. */
3965 for (inferior
*inf
: all_inferiors ())
3966 if (inferior_matches (inf
))
3969 if (num_inferiors
== 0)
3971 ecs
->ws
.set_ignore ();
3975 /* Now randomly pick an inferior out of those that matched. */
3976 random_selector
= (int)
3977 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3979 if (num_inferiors
> 1)
3980 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3981 num_inferiors
, random_selector
);
3983 /* Select the Nth inferior that matched. */
3985 inferior
*selected
= nullptr;
3987 for (inferior
*inf
: all_inferiors ())
3988 if (inferior_matches (inf
))
3989 if (random_selector
-- == 0)
3995 /* Now poll for events out of each of the matching inferior's
3996 targets, starting from the selected one. */
3998 auto do_wait
= [&] (inferior
*inf
)
4000 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, options
);
4001 ecs
->target
= inf
->process_target ();
4002 return (ecs
->ws
.kind () != TARGET_WAITKIND_IGNORE
);
4005 /* Needed in 'all-stop + target-non-stop' mode, because we end up
4006 here spuriously after the target is all stopped and we've already
4007 reported the stop to the user, polling for events. */
4008 scoped_restore_current_thread restore_thread
;
4010 intrusive_list_iterator
<inferior
> start
4011 = inferior_list
.iterator_to (*selected
);
4013 for (intrusive_list_iterator
<inferior
> it
= start
;
4014 it
!= inferior_list
.end ();
4017 inferior
*inf
= &*it
;
4019 if (inferior_matches (inf
) && do_wait (inf
))
4023 for (intrusive_list_iterator
<inferior
> it
= inferior_list
.begin ();
4027 inferior
*inf
= &*it
;
4029 if (inferior_matches (inf
) && do_wait (inf
))
4033 ecs
->ws
.set_ignore ();
4037 /* An event reported by wait_one. */
4039 struct wait_one_event
4041 /* The target the event came out of. */
4042 process_stratum_target
*target
;
4044 /* The PTID the event was for. */
4047 /* The waitstatus. */
4048 target_waitstatus ws
;
4051 static bool handle_one (const wait_one_event
&event
);
4053 /* Prepare and stabilize the inferior for detaching it. E.g.,
4054 detaching while a thread is displaced stepping is a recipe for
4055 crashing it, as nothing would readjust the PC out of the scratch
4059 prepare_for_detach (void)
4061 struct inferior
*inf
= current_inferior ();
4062 ptid_t pid_ptid
= ptid_t (inf
->pid
);
4063 scoped_restore_current_thread restore_thread
;
4065 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
4067 /* Remove all threads of INF from the global step-over chain. We
4068 want to stop any ongoing step-over, not start any new one. */
4069 thread_step_over_list_safe_range range
4070 = make_thread_step_over_list_safe_range (global_thread_step_over_list
);
4072 for (thread_info
*tp
: range
)
4075 infrun_debug_printf ("removing thread %s from global step over chain",
4076 tp
->ptid
.to_string ().c_str ());
4077 global_thread_step_over_chain_remove (tp
);
4080 /* If we were already in the middle of an inline step-over, and the
4081 thread stepping belongs to the inferior we're detaching, we need
4082 to restart the threads of other inferiors. */
4083 if (step_over_info
.thread
!= -1)
4085 infrun_debug_printf ("inline step-over in-process while detaching");
4087 thread_info
*thr
= find_thread_global_id (step_over_info
.thread
);
4088 if (thr
->inf
== inf
)
4090 /* Since we removed threads of INF from the step-over chain,
4091 we know this won't start a step-over for INF. */
4092 clear_step_over_info ();
4094 if (target_is_non_stop_p ())
4096 /* Start a new step-over in another thread if there's
4097 one that needs it. */
4100 /* Restart all other threads (except the
4101 previously-stepping thread, since that one is still
4103 if (!step_over_info_valid_p ())
4104 restart_threads (thr
);
4109 if (displaced_step_in_progress (inf
))
4111 infrun_debug_printf ("displaced-stepping in-process while detaching");
4113 /* Stop threads currently displaced stepping, aborting it. */
4115 for (thread_info
*thr
: inf
->non_exited_threads ())
4117 if (thr
->displaced_step_state
.in_progress ())
4119 if (thr
->executing ())
4121 if (!thr
->stop_requested
)
4123 target_stop (thr
->ptid
);
4124 thr
->stop_requested
= true;
4128 thr
->set_resumed (false);
4132 while (displaced_step_in_progress (inf
))
4134 wait_one_event event
;
4136 event
.target
= inf
->process_target ();
4137 event
.ptid
= do_target_wait_1 (inf
, pid_ptid
, &event
.ws
, 0);
4140 print_target_wait_results (pid_ptid
, event
.ptid
, event
.ws
);
4145 /* It's OK to leave some of the threads of INF stopped, since
4146 they'll be detached shortly. */
4150 /* If all-stop, but there exists a non-stop target, stop all threads
4151 now that we're presenting the stop to the user. */
4154 stop_all_threads_if_all_stop_mode ()
4156 if (!non_stop
&& exists_non_stop_target ())
4157 stop_all_threads ("presenting stop to user in all-stop");
4160 /* Wait for control to return from inferior to debugger.
4162 If inferior gets a signal, we may decide to start it up again
4163 instead of returning. That is why there is a loop in this function.
4164 When this function actually returns it means the inferior
4165 should be left stopped and GDB should read more commands. */
4168 wait_for_inferior (inferior
*inf
)
4170 infrun_debug_printf ("wait_for_inferior ()");
4172 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
4174 /* If an error happens while handling the event, propagate GDB's
4175 knowledge of the executing state to the frontend/user running
4177 scoped_finish_thread_state finish_state
4178 (inf
->process_target (), minus_one_ptid
);
4182 execution_control_state ecs
;
4184 overlay_cache_invalid
= 1;
4186 /* Flush target cache before starting to handle each event.
4187 Target was running and cache could be stale. This is just a
4188 heuristic. Running threads may modify target memory, but we
4189 don't get any event. */
4190 target_dcache_invalidate ();
4192 ecs
.ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
.ws
, 0);
4193 ecs
.target
= inf
->process_target ();
4196 print_target_wait_results (minus_one_ptid
, ecs
.ptid
, ecs
.ws
);
4198 /* Now figure out what to do with the result of the result. */
4199 handle_inferior_event (&ecs
);
4201 if (!ecs
.wait_some_more
)
4205 stop_all_threads_if_all_stop_mode ();
4207 /* No error, don't finish the state yet. */
4208 finish_state
.release ();
4211 /* Cleanup that reinstalls the readline callback handler, if the
4212 target is running in the background. If while handling the target
4213 event something triggered a secondary prompt, like e.g., a
4214 pagination prompt, we'll have removed the callback handler (see
4215 gdb_readline_wrapper_line). Need to do this as we go back to the
4216 event loop, ready to process further input. Note this has no
4217 effect if the handler hasn't actually been removed, because calling
4218 rl_callback_handler_install resets the line buffer, thus losing
4222 reinstall_readline_callback_handler_cleanup ()
4224 struct ui
*ui
= current_ui
;
4228 /* We're not going back to the top level event loop yet. Don't
4229 install the readline callback, as it'd prep the terminal,
4230 readline-style (raw, noecho) (e.g., --batch). We'll install
4231 it the next time the prompt is displayed, when we're ready
4236 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
4237 gdb_rl_callback_handler_reinstall ();
4240 /* Clean up the FSMs of threads that are now stopped. In non-stop,
4241 that's just the event thread. In all-stop, that's all threads. */
4244 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
4246 /* The first clean_up call below assumes the event thread is the current
4248 if (ecs
->event_thread
!= nullptr)
4249 gdb_assert (ecs
->event_thread
== inferior_thread ());
4251 if (ecs
->event_thread
!= nullptr
4252 && ecs
->event_thread
->thread_fsm () != nullptr)
4253 ecs
->event_thread
->thread_fsm ()->clean_up (ecs
->event_thread
);
4257 scoped_restore_current_thread restore_thread
;
4259 for (thread_info
*thr
: all_non_exited_threads ())
4261 if (thr
->thread_fsm () == nullptr)
4263 if (thr
== ecs
->event_thread
)
4266 switch_to_thread (thr
);
4267 thr
->thread_fsm ()->clean_up (thr
);
4272 /* Helper for all_uis_check_sync_execution_done that works on the
4276 check_curr_ui_sync_execution_done (void)
4278 struct ui
*ui
= current_ui
;
4280 if (ui
->prompt_state
== PROMPT_NEEDED
4282 && !gdb_in_secondary_prompt_p (ui
))
4284 target_terminal::ours ();
4285 top_level_interpreter ()->on_sync_execution_done ();
4286 ui
->register_file_handler ();
4293 all_uis_check_sync_execution_done (void)
4295 SWITCH_THRU_ALL_UIS ()
4297 check_curr_ui_sync_execution_done ();
4304 all_uis_on_sync_execution_starting (void)
4306 SWITCH_THRU_ALL_UIS ()
4308 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
4309 async_disable_stdin ();
4313 /* A quit_handler callback installed while we're handling inferior
4317 infrun_quit_handler ()
4319 if (target_terminal::is_ours ())
4323 default_quit_handler would throw a quit in this case, but if
4324 we're handling an event while we have the terminal, it means
4325 the target is running a background execution command, and
4326 thus when users press Ctrl-C, they're wanting to interrupt
4327 whatever command they were executing in the command line.
4331 (gdb) foo bar whatever<ctrl-c>
4333 That Ctrl-C should clear the input line, not interrupt event
4334 handling if it happens that the user types Ctrl-C at just the
4337 It's as-if background event handling was handled by a
4338 separate background thread.
4340 To be clear, the Ctrl-C is not lost -- it will be processed
4341 by the next QUIT call once we're out of fetch_inferior_event
4346 if (check_quit_flag ())
4347 target_pass_ctrlc ();
4351 /* Asynchronous version of wait_for_inferior. It is called by the
4352 event loop whenever a change of state is detected on the file
4353 descriptor corresponding to the target. It can be called more than
4354 once to complete a single execution command. In such cases we need
4355 to keep the state in a global variable ECSS. If it is the last time
4356 that this function is called for a single execution command, then
4357 report to the user that the inferior has stopped, and do the
4358 necessary cleanups. */
4361 fetch_inferior_event ()
4363 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
4365 execution_control_state ecs
;
4368 /* Events are always processed with the main UI as current UI. This
4369 way, warnings, debug output, etc. are always consistently sent to
4370 the main console. */
4371 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
4373 /* Temporarily disable pagination. Otherwise, the user would be
4374 given an option to press 'q' to quit, which would cause an early
4375 exit and could leave GDB in a half-baked state. */
4376 scoped_restore save_pagination
4377 = make_scoped_restore (&pagination_enabled
, false);
4379 /* Install a quit handler that does nothing if we have the terminal
4380 (meaning the target is running a background execution command),
4381 so that Ctrl-C never interrupts GDB before the event is fully
4383 scoped_restore restore_quit_handler
4384 = make_scoped_restore (&quit_handler
, infrun_quit_handler
);
4386 /* Make sure a SIGINT does not interrupt an extension language while
4387 we're handling an event. That could interrupt a Python unwinder
4388 or a Python observer or some such. A Ctrl-C should either be
4389 forwarded to the inferior if the inferior has the terminal, or,
4390 if GDB has the terminal, should interrupt the command the user is
4391 typing in the CLI. */
4392 scoped_disable_cooperative_sigint_handling restore_coop_sigint
;
4394 /* End up with readline processing input, if necessary. */
4396 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
4398 /* We're handling a live event, so make sure we're doing live
4399 debugging. If we're looking at traceframes while the target is
4400 running, we're going to need to get back to that mode after
4401 handling the event. */
4402 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
4405 maybe_restore_traceframe
.emplace ();
4406 set_current_traceframe (-1);
4409 /* The user/frontend should not notice a thread switch due to
4410 internal events. Make sure we revert to the user selected
4411 thread and frame after handling the event and running any
4412 breakpoint commands. */
4413 scoped_restore_current_thread restore_thread
;
4415 overlay_cache_invalid
= 1;
4416 /* Flush target cache before starting to handle each event. Target
4417 was running and cache could be stale. This is just a heuristic.
4418 Running threads may modify target memory, but we don't get any
4420 target_dcache_invalidate ();
4422 scoped_restore save_exec_dir
4423 = make_scoped_restore (&execution_direction
,
4424 target_execution_direction ());
4426 /* Allow targets to pause their resumed threads while we handle
4428 scoped_disable_commit_resumed
disable_commit_resumed ("handling event");
4430 if (!do_target_wait (&ecs
, TARGET_WNOHANG
))
4432 infrun_debug_printf ("do_target_wait returned no event");
4433 disable_commit_resumed
.reset_and_commit ();
4437 gdb_assert (ecs
.ws
.kind () != TARGET_WAITKIND_IGNORE
);
4439 /* Switch to the inferior that generated the event, so we can do
4440 target calls. If the event was not associated to a ptid, */
4441 if (ecs
.ptid
!= null_ptid
4442 && ecs
.ptid
!= minus_one_ptid
)
4443 switch_to_inferior_no_thread (find_inferior_ptid (ecs
.target
, ecs
.ptid
));
4445 switch_to_target_no_thread (ecs
.target
);
4448 print_target_wait_results (minus_one_ptid
, ecs
.ptid
, ecs
.ws
);
4450 /* If an error happens while handling the event, propagate GDB's
4451 knowledge of the executing state to the frontend/user running
4453 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
.ptid
;
4454 scoped_finish_thread_state
finish_state (ecs
.target
, finish_ptid
);
4456 /* Get executed before scoped_restore_current_thread above to apply
4457 still for the thread which has thrown the exception. */
4458 auto defer_bpstat_clear
4459 = make_scope_exit (bpstat_clear_actions
);
4460 auto defer_delete_threads
4461 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4463 int stop_id
= get_stop_id ();
4465 /* Now figure out what to do with the result of the result. */
4466 handle_inferior_event (&ecs
);
4468 if (!ecs
.wait_some_more
)
4470 struct inferior
*inf
= find_inferior_ptid (ecs
.target
, ecs
.ptid
);
4471 bool should_stop
= true;
4472 struct thread_info
*thr
= ecs
.event_thread
;
4474 delete_just_stopped_threads_infrun_breakpoints ();
4476 if (thr
!= nullptr && thr
->thread_fsm () != nullptr)
4477 should_stop
= thr
->thread_fsm ()->should_stop (thr
);
4485 bool should_notify_stop
= true;
4486 bool proceeded
= false;
4488 stop_all_threads_if_all_stop_mode ();
4490 clean_up_just_stopped_threads_fsms (&ecs
);
4492 if (stop_id
!= get_stop_id ())
4494 /* If the stop-id has changed then a stop has already been
4495 presented to the user in handle_inferior_event, this is
4496 likely a failed inferior call. As the stop has already
4497 been announced then we should not notify again.
4499 Also, if the prompt state is not PROMPT_NEEDED then GDB
4500 will not be ready for user input after this function. */
4501 should_notify_stop
= false;
4502 gdb_assert (current_ui
->prompt_state
== PROMPT_NEEDED
);
4504 else if (thr
!= nullptr && thr
->thread_fsm () != nullptr)
4506 = thr
->thread_fsm ()->should_notify_stop ();
4508 if (should_notify_stop
)
4510 /* We may not find an inferior if this was a process exit. */
4511 if (inf
== nullptr || inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4512 proceeded
= normal_stop ();
4517 inferior_event_handler (INF_EXEC_COMPLETE
);
4521 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4522 previously selected thread is gone. We have two
4523 choices - switch to no thread selected, or restore the
4524 previously selected thread (now exited). We chose the
4525 later, just because that's what GDB used to do. After
4526 this, "info threads" says "The current thread <Thread
4527 ID 2> has terminated." instead of "No thread
4531 && ecs
.ws
.kind () != TARGET_WAITKIND_NO_RESUMED
)
4532 restore_thread
.dont_restore ();
4536 defer_delete_threads
.release ();
4537 defer_bpstat_clear
.release ();
4539 /* No error, don't finish the thread states yet. */
4540 finish_state
.release ();
4542 disable_commit_resumed
.reset_and_commit ();
4544 /* This scope is used to ensure that readline callbacks are
4545 reinstalled here. */
4548 /* Handling this event might have caused some inferiors to become prunable.
4549 For example, the exit of an inferior that was automatically added. Try
4550 to get rid of them. Keeping those around slows down things linearly.
4552 Note that this never removes the current inferior. Therefore, call this
4553 after RESTORE_THREAD went out of scope, in case the event inferior (which was
4554 temporarily made the current inferior) is meant to be deleted.
4556 Call this before all_uis_check_sync_execution_done, so that notifications about
4557 removed inferiors appear before the prompt. */
4560 /* If a UI was in sync execution mode, and now isn't, restore its
4561 prompt (a synchronous execution command has finished, and we're
4562 ready for input). */
4563 all_uis_check_sync_execution_done ();
4566 && exec_done_display_p
4567 && (inferior_ptid
== null_ptid
4568 || inferior_thread ()->state
!= THREAD_RUNNING
))
4569 gdb_printf (_("completed.\n"));
4575 set_step_info (thread_info
*tp
, frame_info_ptr frame
,
4576 struct symtab_and_line sal
)
4578 /* This can be removed once this function no longer implicitly relies on the
4579 inferior_ptid value. */
4580 gdb_assert (inferior_ptid
== tp
->ptid
);
4582 tp
->control
.step_frame_id
= get_frame_id (frame
);
4583 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4585 tp
->current_symtab
= sal
.symtab
;
4586 tp
->current_line
= sal
.line
;
4589 ("symtab = %s, line = %d, step_frame_id = %s, step_stack_frame_id = %s",
4590 tp
->current_symtab
!= nullptr ? tp
->current_symtab
->filename
: "<null>",
4592 tp
->control
.step_frame_id
.to_string ().c_str (),
4593 tp
->control
.step_stack_frame_id
.to_string ().c_str ());
4596 /* Clear context switchable stepping state. */
4599 init_thread_stepping_state (struct thread_info
*tss
)
4601 tss
->stepped_breakpoint
= 0;
4602 tss
->stepping_over_breakpoint
= 0;
4603 tss
->stepping_over_watchpoint
= 0;
4604 tss
->step_after_step_resume_breakpoint
= 0;
4610 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4611 const target_waitstatus
&status
)
4613 target_last_proc_target
= target
;
4614 target_last_wait_ptid
= ptid
;
4615 target_last_waitstatus
= status
;
4621 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4622 target_waitstatus
*status
)
4624 if (target
!= nullptr)
4625 *target
= target_last_proc_target
;
4626 if (ptid
!= nullptr)
4627 *ptid
= target_last_wait_ptid
;
4628 if (status
!= nullptr)
4629 *status
= target_last_waitstatus
;
4635 nullify_last_target_wait_ptid (void)
4637 target_last_proc_target
= nullptr;
4638 target_last_wait_ptid
= minus_one_ptid
;
4639 target_last_waitstatus
= {};
4642 /* Switch thread contexts. */
4645 context_switch (execution_control_state
*ecs
)
4647 if (ecs
->ptid
!= inferior_ptid
4648 && (inferior_ptid
== null_ptid
4649 || ecs
->event_thread
!= inferior_thread ()))
4651 infrun_debug_printf ("Switching context from %s to %s",
4652 inferior_ptid
.to_string ().c_str (),
4653 ecs
->ptid
.to_string ().c_str ());
4656 switch_to_thread (ecs
->event_thread
);
4659 /* If the target can't tell whether we've hit breakpoints
4660 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4661 check whether that could have been caused by a breakpoint. If so,
4662 adjust the PC, per gdbarch_decr_pc_after_break. */
4665 adjust_pc_after_break (struct thread_info
*thread
,
4666 const target_waitstatus
&ws
)
4668 struct regcache
*regcache
;
4669 struct gdbarch
*gdbarch
;
4670 CORE_ADDR breakpoint_pc
, decr_pc
;
4672 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4673 we aren't, just return.
4675 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4676 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4677 implemented by software breakpoints should be handled through the normal
4680 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4681 different signals (SIGILL or SIGEMT for instance), but it is less
4682 clear where the PC is pointing afterwards. It may not match
4683 gdbarch_decr_pc_after_break. I don't know any specific target that
4684 generates these signals at breakpoints (the code has been in GDB since at
4685 least 1992) so I can not guess how to handle them here.
4687 In earlier versions of GDB, a target with
4688 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4689 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4690 target with both of these set in GDB history, and it seems unlikely to be
4691 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4693 if (ws
.kind () != TARGET_WAITKIND_STOPPED
)
4696 if (ws
.sig () != GDB_SIGNAL_TRAP
)
4699 /* In reverse execution, when a breakpoint is hit, the instruction
4700 under it has already been de-executed. The reported PC always
4701 points at the breakpoint address, so adjusting it further would
4702 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4705 B1 0x08000000 : INSN1
4706 B2 0x08000001 : INSN2
4708 PC -> 0x08000003 : INSN4
4710 Say you're stopped at 0x08000003 as above. Reverse continuing
4711 from that point should hit B2 as below. Reading the PC when the
4712 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4713 been de-executed already.
4715 B1 0x08000000 : INSN1
4716 B2 PC -> 0x08000001 : INSN2
4720 We can't apply the same logic as for forward execution, because
4721 we would wrongly adjust the PC to 0x08000000, since there's a
4722 breakpoint at PC - 1. We'd then report a hit on B1, although
4723 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4725 if (execution_direction
== EXEC_REVERSE
)
4728 /* If the target can tell whether the thread hit a SW breakpoint,
4729 trust it. Targets that can tell also adjust the PC
4731 if (target_supports_stopped_by_sw_breakpoint ())
4734 /* Note that relying on whether a breakpoint is planted in memory to
4735 determine this can fail. E.g,. the breakpoint could have been
4736 removed since. Or the thread could have been told to step an
4737 instruction the size of a breakpoint instruction, and only
4738 _after_ was a breakpoint inserted at its address. */
4740 /* If this target does not decrement the PC after breakpoints, then
4741 we have nothing to do. */
4742 regcache
= get_thread_regcache (thread
);
4743 gdbarch
= regcache
->arch ();
4745 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4749 const address_space
*aspace
= regcache
->aspace ();
4751 /* Find the location where (if we've hit a breakpoint) the
4752 breakpoint would be. */
4753 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4755 /* If the target can't tell whether a software breakpoint triggered,
4756 fallback to figuring it out based on breakpoints we think were
4757 inserted in the target, and on whether the thread was stepped or
4760 /* Check whether there actually is a software breakpoint inserted at
4763 If in non-stop mode, a race condition is possible where we've
4764 removed a breakpoint, but stop events for that breakpoint were
4765 already queued and arrive later. To suppress those spurious
4766 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4767 and retire them after a number of stop events are reported. Note
4768 this is an heuristic and can thus get confused. The real fix is
4769 to get the "stopped by SW BP and needs adjustment" info out of
4770 the target/kernel (and thus never reach here; see above). */
4771 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4772 || (target_is_non_stop_p ()
4773 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4775 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4777 if (record_full_is_used ())
4778 restore_operation_disable
.emplace
4779 (record_full_gdb_operation_disable_set ());
4781 /* When using hardware single-step, a SIGTRAP is reported for both
4782 a completed single-step and a software breakpoint. Need to
4783 differentiate between the two, as the latter needs adjusting
4784 but the former does not.
4786 The SIGTRAP can be due to a completed hardware single-step only if
4787 - we didn't insert software single-step breakpoints
4788 - this thread is currently being stepped
4790 If any of these events did not occur, we must have stopped due
4791 to hitting a software breakpoint, and have to back up to the
4794 As a special case, we could have hardware single-stepped a
4795 software breakpoint. In this case (prev_pc == breakpoint_pc),
4796 we also need to back up to the breakpoint address. */
4798 if (thread_has_single_step_breakpoints_set (thread
)
4799 || !currently_stepping (thread
)
4800 || (thread
->stepped_breakpoint
4801 && thread
->prev_pc
== breakpoint_pc
))
4802 regcache_write_pc (regcache
, breakpoint_pc
);
4807 stepped_in_from (frame_info_ptr frame
, struct frame_id step_frame_id
)
4809 for (frame
= get_prev_frame (frame
);
4811 frame
= get_prev_frame (frame
))
4813 if (get_frame_id (frame
) == step_frame_id
)
4816 if (get_frame_type (frame
) != INLINE_FRAME
)
4823 /* Look for an inline frame that is marked for skip.
4824 If PREV_FRAME is TRUE start at the previous frame,
4825 otherwise start at the current frame. Stop at the
4826 first non-inline frame, or at the frame where the
4830 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4832 frame_info_ptr frame
= get_current_frame ();
4835 frame
= get_prev_frame (frame
);
4837 for (; frame
!= nullptr; frame
= get_prev_frame (frame
))
4839 const char *fn
= nullptr;
4840 symtab_and_line sal
;
4843 if (get_frame_id (frame
) == tp
->control
.step_frame_id
)
4845 if (get_frame_type (frame
) != INLINE_FRAME
)
4848 sal
= find_frame_sal (frame
);
4849 sym
= get_frame_function (frame
);
4852 fn
= sym
->print_name ();
4855 && function_name_is_marked_for_skip (fn
, sal
))
4862 /* If the event thread has the stop requested flag set, pretend it
4863 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4867 handle_stop_requested (struct execution_control_state
*ecs
)
4869 if (ecs
->event_thread
->stop_requested
)
4871 ecs
->ws
.set_stopped (GDB_SIGNAL_0
);
4872 handle_signal_stop (ecs
);
4878 /* Auxiliary function that handles syscall entry/return events.
4879 It returns true if the inferior should keep going (and GDB
4880 should ignore the event), or false if the event deserves to be
4884 handle_syscall_event (struct execution_control_state
*ecs
)
4886 struct regcache
*regcache
;
4889 context_switch (ecs
);
4891 regcache
= get_thread_regcache (ecs
->event_thread
);
4892 syscall_number
= ecs
->ws
.syscall_number ();
4893 ecs
->event_thread
->set_stop_pc (regcache_read_pc (regcache
));
4895 if (catch_syscall_enabled () > 0
4896 && catching_syscall_number (syscall_number
))
4898 infrun_debug_printf ("syscall number=%d", syscall_number
);
4900 ecs
->event_thread
->control
.stop_bpstat
4901 = bpstat_stop_status_nowatch (regcache
->aspace (),
4902 ecs
->event_thread
->stop_pc (),
4903 ecs
->event_thread
, ecs
->ws
);
4905 if (handle_stop_requested (ecs
))
4908 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4910 /* Catchpoint hit. */
4915 if (handle_stop_requested (ecs
))
4918 /* If no catchpoint triggered for this, then keep going. */
4924 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4927 fill_in_stop_func (struct gdbarch
*gdbarch
,
4928 struct execution_control_state
*ecs
)
4930 if (!ecs
->stop_func_filled_in
)
4933 const general_symbol_info
*gsi
;
4935 /* Don't care about return value; stop_func_start and stop_func_name
4936 will both be 0 if it doesn't work. */
4937 find_pc_partial_function_sym (ecs
->event_thread
->stop_pc (),
4939 &ecs
->stop_func_start
,
4940 &ecs
->stop_func_end
,
4942 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4944 /* The call to find_pc_partial_function, above, will set
4945 stop_func_start and stop_func_end to the start and end
4946 of the range containing the stop pc. If this range
4947 contains the entry pc for the block (which is always the
4948 case for contiguous blocks), advance stop_func_start past
4949 the function's start offset and entrypoint. Note that
4950 stop_func_start is NOT advanced when in a range of a
4951 non-contiguous block that does not contain the entry pc. */
4952 if (block
!= nullptr
4953 && ecs
->stop_func_start
<= block
->entry_pc ()
4954 && block
->entry_pc () < ecs
->stop_func_end
)
4956 ecs
->stop_func_start
4957 += gdbarch_deprecated_function_start_offset (gdbarch
);
4959 /* PowerPC functions have a Local Entry Point (LEP) and a Global
4960 Entry Point (GEP). There is only one Entry Point (GEP = LEP) for
4961 other architectures. */
4962 ecs
->stop_func_alt_start
= ecs
->stop_func_start
;
4964 if (gdbarch_skip_entrypoint_p (gdbarch
))
4965 ecs
->stop_func_start
4966 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4969 ecs
->stop_func_filled_in
= 1;
4974 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4976 static enum stop_kind
4977 get_inferior_stop_soon (execution_control_state
*ecs
)
4979 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4981 gdb_assert (inf
!= nullptr);
4982 return inf
->control
.stop_soon
;
4985 /* Poll for one event out of the current target. Store the resulting
4986 waitstatus in WS, and return the event ptid. Does not block. */
4989 poll_one_curr_target (struct target_waitstatus
*ws
)
4993 overlay_cache_invalid
= 1;
4995 /* Flush target cache before starting to handle each event.
4996 Target was running and cache could be stale. This is just a
4997 heuristic. Running threads may modify target memory, but we
4998 don't get any event. */
4999 target_dcache_invalidate ();
5001 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
5004 print_target_wait_results (minus_one_ptid
, event_ptid
, *ws
);
5009 /* Wait for one event out of any target. */
5011 static wait_one_event
5016 for (inferior
*inf
: all_inferiors ())
5018 process_stratum_target
*target
= inf
->process_target ();
5019 if (target
== nullptr
5020 || !target
->is_async_p ()
5021 || !target
->threads_executing
)
5024 switch_to_inferior_no_thread (inf
);
5026 wait_one_event event
;
5027 event
.target
= target
;
5028 event
.ptid
= poll_one_curr_target (&event
.ws
);
5030 if (event
.ws
.kind () == TARGET_WAITKIND_NO_RESUMED
)
5032 /* If nothing is resumed, remove the target from the
5034 target_async (false);
5036 else if (event
.ws
.kind () != TARGET_WAITKIND_IGNORE
)
5040 /* Block waiting for some event. */
5047 for (inferior
*inf
: all_inferiors ())
5049 process_stratum_target
*target
= inf
->process_target ();
5050 if (target
== nullptr
5051 || !target
->is_async_p ()
5052 || !target
->threads_executing
)
5055 int fd
= target
->async_wait_fd ();
5056 FD_SET (fd
, &readfds
);
5063 /* No waitable targets left. All must be stopped. */
5064 target_waitstatus ws
;
5065 ws
.set_no_resumed ();
5066 return {nullptr, minus_one_ptid
, std::move (ws
)};
5071 int numfds
= interruptible_select (nfds
, &readfds
, 0, nullptr, 0);
5077 perror_with_name ("interruptible_select");
5082 /* Save the thread's event and stop reason to process it later. */
5085 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
&ws
)
5087 infrun_debug_printf ("saving status %s for %s",
5088 ws
.to_string ().c_str (),
5089 tp
->ptid
.to_string ().c_str ());
5091 /* Record for later. */
5092 tp
->set_pending_waitstatus (ws
);
5094 if (ws
.kind () == TARGET_WAITKIND_STOPPED
5095 && ws
.sig () == GDB_SIGNAL_TRAP
)
5097 struct regcache
*regcache
= get_thread_regcache (tp
);
5098 const address_space
*aspace
= regcache
->aspace ();
5099 CORE_ADDR pc
= regcache_read_pc (regcache
);
5101 adjust_pc_after_break (tp
, tp
->pending_waitstatus ());
5103 scoped_restore_current_thread restore_thread
;
5104 switch_to_thread (tp
);
5106 if (target_stopped_by_watchpoint ())
5107 tp
->set_stop_reason (TARGET_STOPPED_BY_WATCHPOINT
);
5108 else if (target_supports_stopped_by_sw_breakpoint ()
5109 && target_stopped_by_sw_breakpoint ())
5110 tp
->set_stop_reason (TARGET_STOPPED_BY_SW_BREAKPOINT
);
5111 else if (target_supports_stopped_by_hw_breakpoint ()
5112 && target_stopped_by_hw_breakpoint ())
5113 tp
->set_stop_reason (TARGET_STOPPED_BY_HW_BREAKPOINT
);
5114 else if (!target_supports_stopped_by_hw_breakpoint ()
5115 && hardware_breakpoint_inserted_here_p (aspace
, pc
))
5116 tp
->set_stop_reason (TARGET_STOPPED_BY_HW_BREAKPOINT
);
5117 else if (!target_supports_stopped_by_sw_breakpoint ()
5118 && software_breakpoint_inserted_here_p (aspace
, pc
))
5119 tp
->set_stop_reason (TARGET_STOPPED_BY_SW_BREAKPOINT
);
5120 else if (!thread_has_single_step_breakpoints_set (tp
)
5121 && currently_stepping (tp
))
5122 tp
->set_stop_reason (TARGET_STOPPED_BY_SINGLE_STEP
);
5126 /* Mark the non-executing threads accordingly. In all-stop, all
5127 threads of all processes are stopped when we get any event
5128 reported. In non-stop mode, only the event thread stops. */
5131 mark_non_executing_threads (process_stratum_target
*target
,
5133 const target_waitstatus
&ws
)
5137 if (!target_is_non_stop_p ())
5138 mark_ptid
= minus_one_ptid
;
5139 else if (ws
.kind () == TARGET_WAITKIND_SIGNALLED
5140 || ws
.kind () == TARGET_WAITKIND_EXITED
)
5142 /* If we're handling a process exit in non-stop mode, even
5143 though threads haven't been deleted yet, one would think
5144 that there is nothing to do, as threads of the dead process
5145 will be soon deleted, and threads of any other process were
5146 left running. However, on some targets, threads survive a
5147 process exit event. E.g., for the "checkpoint" command,
5148 when the current checkpoint/fork exits, linux-fork.c
5149 automatically switches to another fork from within
5150 target_mourn_inferior, by associating the same
5151 inferior/thread to another fork. We haven't mourned yet at
5152 this point, but we must mark any threads left in the
5153 process as not-executing so that finish_thread_state marks
5154 them stopped (in the user's perspective) if/when we present
5155 the stop to the user. */
5156 mark_ptid
= ptid_t (event_ptid
.pid ());
5159 mark_ptid
= event_ptid
;
5161 set_executing (target
, mark_ptid
, false);
5163 /* Likewise the resumed flag. */
5164 set_resumed (target
, mark_ptid
, false);
5167 /* Handle one event after stopping threads. If the eventing thread
5168 reports back any interesting event, we leave it pending. If the
5169 eventing thread was in the middle of a displaced step, we
5170 cancel/finish it, and unless the thread's inferior is being
5171 detached, put the thread back in the step-over chain. Returns true
5172 if there are no resumed threads left in the target (thus there's no
5173 point in waiting further), false otherwise. */
5176 handle_one (const wait_one_event
&event
)
5179 ("%s %s", event
.ws
.to_string ().c_str (),
5180 event
.ptid
.to_string ().c_str ());
5182 if (event
.ws
.kind () == TARGET_WAITKIND_NO_RESUMED
)
5184 /* All resumed threads exited. */
5187 else if (event
.ws
.kind () == TARGET_WAITKIND_THREAD_EXITED
5188 || event
.ws
.kind () == TARGET_WAITKIND_EXITED
5189 || event
.ws
.kind () == TARGET_WAITKIND_SIGNALLED
)
5191 /* One thread/process exited/signalled. */
5193 thread_info
*t
= nullptr;
5195 /* The target may have reported just a pid. If so, try
5196 the first non-exited thread. */
5197 if (event
.ptid
.is_pid ())
5199 int pid
= event
.ptid
.pid ();
5200 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
5201 for (thread_info
*tp
: inf
->non_exited_threads ())
5207 /* If there is no available thread, the event would
5208 have to be appended to a per-inferior event list,
5209 which does not exist (and if it did, we'd have
5210 to adjust run control command to be able to
5211 resume such an inferior). We assert here instead
5212 of going into an infinite loop. */
5213 gdb_assert (t
!= nullptr);
5216 ("using %s", t
->ptid
.to_string ().c_str ());
5220 t
= event
.target
->find_thread (event
.ptid
);
5221 /* Check if this is the first time we see this thread.
5222 Don't bother adding if it individually exited. */
5224 && event
.ws
.kind () != TARGET_WAITKIND_THREAD_EXITED
)
5225 t
= add_thread (event
.target
, event
.ptid
);
5230 /* Set the threads as non-executing to avoid
5231 another stop attempt on them. */
5232 switch_to_thread_no_regs (t
);
5233 mark_non_executing_threads (event
.target
, event
.ptid
,
5235 save_waitstatus (t
, event
.ws
);
5236 t
->stop_requested
= false;
5241 thread_info
*t
= event
.target
->find_thread (event
.ptid
);
5243 t
= add_thread (event
.target
, event
.ptid
);
5245 t
->stop_requested
= 0;
5246 t
->set_executing (false);
5247 t
->set_resumed (false);
5248 t
->control
.may_range_step
= 0;
5250 /* This may be the first time we see the inferior report
5252 if (t
->inf
->needs_setup
)
5254 switch_to_thread_no_regs (t
);
5258 if (event
.ws
.kind () == TARGET_WAITKIND_STOPPED
5259 && event
.ws
.sig () == GDB_SIGNAL_0
)
5261 /* We caught the event that we intended to catch, so
5262 there's no event to save as pending. */
5264 if (displaced_step_finish (t
, event
.ws
)
5265 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
5267 /* Add it back to the step-over queue. */
5269 ("displaced-step of %s canceled",
5270 t
->ptid
.to_string ().c_str ());
5272 t
->control
.trap_expected
= 0;
5273 if (!t
->inf
->detaching
)
5274 global_thread_step_over_chain_enqueue (t
);
5279 struct regcache
*regcache
;
5282 ("target_wait %s, saving status for %s",
5283 event
.ws
.to_string ().c_str (),
5284 t
->ptid
.to_string ().c_str ());
5286 /* Record for later. */
5287 save_waitstatus (t
, event
.ws
);
5289 if (displaced_step_finish (t
, event
.ws
)
5290 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
5292 /* Add it back to the step-over queue. */
5293 t
->control
.trap_expected
= 0;
5294 if (!t
->inf
->detaching
)
5295 global_thread_step_over_chain_enqueue (t
);
5298 regcache
= get_thread_regcache (t
);
5299 t
->set_stop_pc (regcache_read_pc (regcache
));
5301 infrun_debug_printf ("saved stop_pc=%s for %s "
5302 "(currently_stepping=%d)",
5303 paddress (current_inferior ()->arch (),
5305 t
->ptid
.to_string ().c_str (),
5306 currently_stepping (t
));
5316 stop_all_threads (const char *reason
, inferior
*inf
)
5318 /* We may need multiple passes to discover all threads. */
5322 gdb_assert (exists_non_stop_target ());
5324 INFRUN_SCOPED_DEBUG_START_END ("reason=%s, inf=%d", reason
,
5325 inf
!= nullptr ? inf
->num
: -1);
5327 infrun_debug_show_threads ("non-exited threads",
5328 all_non_exited_threads ());
5330 scoped_restore_current_thread restore_thread
;
5332 /* Enable thread events on relevant targets. */
5333 for (auto *target
: all_non_exited_process_targets ())
5335 if (inf
!= nullptr && inf
->process_target () != target
)
5338 switch_to_target_no_thread (target
);
5339 target_thread_events (true);
5344 /* Disable thread events on relevant targets. */
5345 for (auto *target
: all_non_exited_process_targets ())
5347 if (inf
!= nullptr && inf
->process_target () != target
)
5350 switch_to_target_no_thread (target
);
5351 target_thread_events (false);
5354 /* Use debug_prefixed_printf directly to get a meaningful function
5357 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
5360 /* Request threads to stop, and then wait for the stops. Because
5361 threads we already know about can spawn more threads while we're
5362 trying to stop them, and we only learn about new threads when we
5363 update the thread list, do this in a loop, and keep iterating
5364 until two passes find no threads that need to be stopped. */
5365 for (pass
= 0; pass
< 2; pass
++, iterations
++)
5367 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
5370 int waits_needed
= 0;
5372 for (auto *target
: all_non_exited_process_targets ())
5374 if (inf
!= nullptr && inf
->process_target () != target
)
5377 switch_to_target_no_thread (target
);
5378 update_thread_list ();
5381 /* Go through all threads looking for threads that we need
5382 to tell the target to stop. */
5383 for (thread_info
*t
: all_non_exited_threads ())
5385 if (inf
!= nullptr && t
->inf
!= inf
)
5388 /* For a single-target setting with an all-stop target,
5389 we would not even arrive here. For a multi-target
5390 setting, until GDB is able to handle a mixture of
5391 all-stop and non-stop targets, simply skip all-stop
5392 targets' threads. This should be fine due to the
5393 protection of 'check_multi_target_resumption'. */
5395 switch_to_thread_no_regs (t
);
5396 if (!target_is_non_stop_p ())
5399 if (t
->executing ())
5401 /* If already stopping, don't request a stop again.
5402 We just haven't seen the notification yet. */
5403 if (!t
->stop_requested
)
5405 infrun_debug_printf (" %s executing, need stop",
5406 t
->ptid
.to_string ().c_str ());
5407 target_stop (t
->ptid
);
5408 t
->stop_requested
= 1;
5412 infrun_debug_printf (" %s executing, already stopping",
5413 t
->ptid
.to_string ().c_str ());
5416 if (t
->stop_requested
)
5421 infrun_debug_printf (" %s not executing",
5422 t
->ptid
.to_string ().c_str ());
5424 /* The thread may be not executing, but still be
5425 resumed with a pending status to process. */
5426 t
->set_resumed (false);
5430 if (waits_needed
== 0)
5433 /* If we find new threads on the second iteration, restart
5434 over. We want to see two iterations in a row with all
5439 for (int i
= 0; i
< waits_needed
; i
++)
5441 wait_one_event event
= wait_one ();
5442 if (handle_one (event
))
5449 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
5452 handle_no_resumed (struct execution_control_state
*ecs
)
5454 if (target_can_async_p ())
5456 bool any_sync
= false;
5458 for (ui
*ui
: all_uis ())
5460 if (ui
->prompt_state
== PROMPT_BLOCKED
)
5468 /* There were no unwaited-for children left in the target, but,
5469 we're not synchronously waiting for events either. Just
5472 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
5473 prepare_to_wait (ecs
);
5478 /* Otherwise, if we were running a synchronous execution command, we
5479 may need to cancel it and give the user back the terminal.
5481 In non-stop mode, the target can't tell whether we've already
5482 consumed previous stop events, so it can end up sending us a
5483 no-resumed event like so:
5485 #0 - thread 1 is left stopped
5487 #1 - thread 2 is resumed and hits breakpoint
5488 -> TARGET_WAITKIND_STOPPED
5490 #2 - thread 3 is resumed and exits
5491 this is the last resumed thread, so
5492 -> TARGET_WAITKIND_NO_RESUMED
5494 #3 - gdb processes stop for thread 2 and decides to re-resume
5497 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
5498 thread 2 is now resumed, so the event should be ignored.
5500 IOW, if the stop for thread 2 doesn't end a foreground command,
5501 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
5502 event. But it could be that the event meant that thread 2 itself
5503 (or whatever other thread was the last resumed thread) exited.
5505 To address this we refresh the thread list and check whether we
5506 have resumed threads _now_. In the example above, this removes
5507 thread 3 from the thread list. If thread 2 was re-resumed, we
5508 ignore this event. If we find no thread resumed, then we cancel
5509 the synchronous command and show "no unwaited-for " to the
5512 inferior
*curr_inf
= current_inferior ();
5514 scoped_restore_current_thread restore_thread
;
5515 update_thread_list ();
5519 - the current target has no thread executing, and
5520 - the current inferior is native, and
5521 - the current inferior is the one which has the terminal, and
5524 then a Ctrl-C from this point on would remain stuck in the
5525 kernel, until a thread resumes and dequeues it. That would
5526 result in the GDB CLI not reacting to Ctrl-C, not able to
5527 interrupt the program. To address this, if the current inferior
5528 no longer has any thread executing, we give the terminal to some
5529 other inferior that has at least one thread executing. */
5530 bool swap_terminal
= true;
5532 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
5533 whether to report it to the user. */
5534 bool ignore_event
= false;
5536 for (thread_info
*thread
: all_non_exited_threads ())
5538 if (swap_terminal
&& thread
->executing ())
5540 if (thread
->inf
!= curr_inf
)
5542 target_terminal::ours ();
5544 switch_to_thread (thread
);
5545 target_terminal::inferior ();
5547 swap_terminal
= false;
5550 if (!ignore_event
&& thread
->resumed ())
5552 /* Either there were no unwaited-for children left in the
5553 target at some point, but there are now, or some target
5554 other than the eventing one has unwaited-for children
5555 left. Just ignore. */
5556 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5557 "(ignoring: found resumed)");
5559 ignore_event
= true;
5562 if (ignore_event
&& !swap_terminal
)
5568 switch_to_inferior_no_thread (curr_inf
);
5569 prepare_to_wait (ecs
);
5573 /* Go ahead and report the event. */
5577 /* Given an execution control state that has been freshly filled in by
5578 an event from the inferior, figure out what it means and take
5581 The alternatives are:
5583 1) stop_waiting and return; to really stop and return to the
5586 2) keep_going and return; to wait for the next event (set
5587 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5591 handle_inferior_event (struct execution_control_state
*ecs
)
5593 /* Make sure that all temporary struct value objects that were
5594 created during the handling of the event get deleted at the
5596 scoped_value_mark free_values
;
5598 infrun_debug_printf ("%s", ecs
->ws
.to_string ().c_str ());
5600 if (ecs
->ws
.kind () == TARGET_WAITKIND_IGNORE
)
5602 /* We had an event in the inferior, but we are not interested in
5603 handling it at this level. The lower layers have already
5604 done what needs to be done, if anything.
5606 One of the possible circumstances for this is when the
5607 inferior produces output for the console. The inferior has
5608 not stopped, and we are ignoring the event. Another possible
5609 circumstance is any event which the lower level knows will be
5610 reported multiple times without an intervening resume. */
5611 prepare_to_wait (ecs
);
5615 if (ecs
->ws
.kind () == TARGET_WAITKIND_THREAD_EXITED
)
5617 prepare_to_wait (ecs
);
5621 if (ecs
->ws
.kind () == TARGET_WAITKIND_NO_RESUMED
5622 && handle_no_resumed (ecs
))
5625 /* Cache the last target/ptid/waitstatus. */
5626 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5628 /* Always clear state belonging to the previous time we stopped. */
5629 stop_stack_dummy
= STOP_NONE
;
5631 if (ecs
->ws
.kind () == TARGET_WAITKIND_NO_RESUMED
)
5633 /* No unwaited-for children left. IOW, all resumed children
5635 stop_print_frame
= false;
5640 if (ecs
->ws
.kind () != TARGET_WAITKIND_EXITED
5641 && ecs
->ws
.kind () != TARGET_WAITKIND_SIGNALLED
)
5643 ecs
->event_thread
= ecs
->target
->find_thread (ecs
->ptid
);
5644 /* If it's a new thread, add it to the thread database. */
5645 if (ecs
->event_thread
== nullptr)
5646 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5648 /* Disable range stepping. If the next step request could use a
5649 range, this will be end up re-enabled then. */
5650 ecs
->event_thread
->control
.may_range_step
= 0;
5653 /* Dependent on valid ECS->EVENT_THREAD. */
5654 adjust_pc_after_break (ecs
->event_thread
, ecs
->ws
);
5656 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5657 reinit_frame_cache ();
5659 breakpoint_retire_moribund ();
5661 /* First, distinguish signals caused by the debugger from signals
5662 that have to do with the program's own actions. Note that
5663 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5664 on the operating system version. Here we detect when a SIGILL or
5665 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5666 something similar for SIGSEGV, since a SIGSEGV will be generated
5667 when we're trying to execute a breakpoint instruction on a
5668 non-executable stack. This happens for call dummy breakpoints
5669 for architectures like SPARC that place call dummies on the
5671 if (ecs
->ws
.kind () == TARGET_WAITKIND_STOPPED
5672 && (ecs
->ws
.sig () == GDB_SIGNAL_ILL
5673 || ecs
->ws
.sig () == GDB_SIGNAL_SEGV
5674 || ecs
->ws
.sig () == GDB_SIGNAL_EMT
))
5676 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5678 if (breakpoint_inserted_here_p (regcache
->aspace (),
5679 regcache_read_pc (regcache
)))
5681 infrun_debug_printf ("Treating signal as SIGTRAP");
5682 ecs
->ws
.set_stopped (GDB_SIGNAL_TRAP
);
5686 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5688 switch (ecs
->ws
.kind ())
5690 case TARGET_WAITKIND_LOADED
:
5692 context_switch (ecs
);
5693 /* Ignore gracefully during startup of the inferior, as it might
5694 be the shell which has just loaded some objects, otherwise
5695 add the symbols for the newly loaded objects. Also ignore at
5696 the beginning of an attach or remote session; we will query
5697 the full list of libraries once the connection is
5700 stop_kind stop_soon
= get_inferior_stop_soon (ecs
);
5701 if (stop_soon
== NO_STOP_QUIETLY
)
5703 struct regcache
*regcache
;
5705 regcache
= get_thread_regcache (ecs
->event_thread
);
5707 handle_solib_event ();
5709 ecs
->event_thread
->set_stop_pc (regcache_read_pc (regcache
));
5710 ecs
->event_thread
->control
.stop_bpstat
5711 = bpstat_stop_status_nowatch (regcache
->aspace (),
5712 ecs
->event_thread
->stop_pc (),
5713 ecs
->event_thread
, ecs
->ws
);
5715 if (handle_stop_requested (ecs
))
5718 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5720 /* A catchpoint triggered. */
5721 process_event_stop_test (ecs
);
5725 /* If requested, stop when the dynamic linker notifies
5726 gdb of events. This allows the user to get control
5727 and place breakpoints in initializer routines for
5728 dynamically loaded objects (among other things). */
5729 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
5730 if (stop_on_solib_events
)
5732 /* Make sure we print "Stopped due to solib-event" in
5734 stop_print_frame
= true;
5741 /* If we are skipping through a shell, or through shared library
5742 loading that we aren't interested in, resume the program. If
5743 we're running the program normally, also resume. */
5744 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5746 /* Loading of shared libraries might have changed breakpoint
5747 addresses. Make sure new breakpoints are inserted. */
5748 if (stop_soon
== NO_STOP_QUIETLY
)
5749 insert_breakpoints ();
5750 resume (GDB_SIGNAL_0
);
5751 prepare_to_wait (ecs
);
5755 /* But stop if we're attaching or setting up a remote
5757 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5758 || stop_soon
== STOP_QUIETLY_REMOTE
)
5760 infrun_debug_printf ("quietly stopped");
5765 internal_error (_("unhandled stop_soon: %d"), (int) stop_soon
);
5768 case TARGET_WAITKIND_SPURIOUS
:
5769 if (handle_stop_requested (ecs
))
5771 context_switch (ecs
);
5772 resume (GDB_SIGNAL_0
);
5773 prepare_to_wait (ecs
);
5776 case TARGET_WAITKIND_THREAD_CREATED
:
5777 if (handle_stop_requested (ecs
))
5779 context_switch (ecs
);
5780 if (!switch_back_to_stepped_thread (ecs
))
5784 case TARGET_WAITKIND_EXITED
:
5785 case TARGET_WAITKIND_SIGNALLED
:
5787 /* Depending on the system, ecs->ptid may point to a thread or
5788 to a process. On some targets, target_mourn_inferior may
5789 need to have access to the just-exited thread. That is the
5790 case of GNU/Linux's "checkpoint" support, for example.
5791 Call the switch_to_xxx routine as appropriate. */
5792 thread_info
*thr
= ecs
->target
->find_thread (ecs
->ptid
);
5794 switch_to_thread (thr
);
5797 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5798 switch_to_inferior_no_thread (inf
);
5801 handle_vfork_child_exec_or_exit (0);
5802 target_terminal::ours (); /* Must do this before mourn anyway. */
5804 /* Clearing any previous state of convenience variables. */
5805 clear_exit_convenience_vars ();
5807 if (ecs
->ws
.kind () == TARGET_WAITKIND_EXITED
)
5809 /* Record the exit code in the convenience variable $_exitcode, so
5810 that the user can inspect this again later. */
5811 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5812 (LONGEST
) ecs
->ws
.exit_status ());
5814 /* Also record this in the inferior itself. */
5815 current_inferior ()->has_exit_code
= true;
5816 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.exit_status ();
5818 /* Support the --return-child-result option. */
5819 return_child_result_value
= ecs
->ws
.exit_status ();
5821 interps_notify_exited (ecs
->ws
.exit_status ());
5825 struct gdbarch
*gdbarch
= current_inferior ()->arch ();
5827 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5829 /* Set the value of the internal variable $_exitsignal,
5830 which holds the signal uncaught by the inferior. */
5831 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5832 gdbarch_gdb_signal_to_target (gdbarch
,
5837 /* We don't have access to the target's method used for
5838 converting between signal numbers (GDB's internal
5839 representation <-> target's representation).
5840 Therefore, we cannot do a good job at displaying this
5841 information to the user. It's better to just warn
5842 her about it (if infrun debugging is enabled), and
5844 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5848 interps_notify_signal_exited (ecs
->ws
.sig ());
5851 gdb_flush (gdb_stdout
);
5852 target_mourn_inferior (inferior_ptid
);
5853 stop_print_frame
= false;
5857 case TARGET_WAITKIND_FORKED
:
5858 case TARGET_WAITKIND_VFORKED
:
5859 /* Check whether the inferior is displaced stepping. */
5861 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5862 struct gdbarch
*gdbarch
= regcache
->arch ();
5863 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5865 /* If this is a fork (child gets its own address space copy)
5866 and some displaced step buffers were in use at the time of
5867 the fork, restore the displaced step buffer bytes in the
5870 Architectures which support displaced stepping and fork
5871 events must supply an implementation of
5872 gdbarch_displaced_step_restore_all_in_ptid. This is not
5873 enforced during gdbarch validation to support architectures
5874 which support displaced stepping but not forks. */
5875 if (ecs
->ws
.kind () == TARGET_WAITKIND_FORKED
5876 && gdbarch_supports_displaced_stepping (gdbarch
))
5877 gdbarch_displaced_step_restore_all_in_ptid
5878 (gdbarch
, parent_inf
, ecs
->ws
.child_ptid ());
5880 /* If displaced stepping is supported, and thread ecs->ptid is
5881 displaced stepping. */
5882 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5884 struct regcache
*child_regcache
;
5885 CORE_ADDR parent_pc
;
5887 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5888 indicating that the displaced stepping of syscall instruction
5889 has been done. Perform cleanup for parent process here. Note
5890 that this operation also cleans up the child process for vfork,
5891 because their pages are shared. */
5892 displaced_step_finish (ecs
->event_thread
, ecs
->ws
);
5893 /* Start a new step-over in another thread if there's one
5897 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5898 the child's PC is also within the scratchpad. Set the child's PC
5899 to the parent's PC value, which has already been fixed up.
5900 FIXME: we use the parent's aspace here, although we're touching
5901 the child, because the child hasn't been added to the inferior
5902 list yet at this point. */
5905 = get_thread_arch_aspace_regcache (parent_inf
,
5906 ecs
->ws
.child_ptid (),
5908 parent_inf
->aspace
);
5909 /* Read PC value of parent process. */
5910 parent_pc
= regcache_read_pc (regcache
);
5912 displaced_debug_printf ("write child pc from %s to %s",
5914 regcache_read_pc (child_regcache
)),
5915 paddress (gdbarch
, parent_pc
));
5917 regcache_write_pc (child_regcache
, parent_pc
);
5921 context_switch (ecs
);
5923 /* Immediately detach breakpoints from the child before there's
5924 any chance of letting the user delete breakpoints from the
5925 breakpoint lists. If we don't do this early, it's easy to
5926 leave left over traps in the child, vis: "break foo; catch
5927 fork; c; <fork>; del; c; <child calls foo>". We only follow
5928 the fork on the last `continue', and by that time the
5929 breakpoint at "foo" is long gone from the breakpoint table.
5930 If we vforked, then we don't need to unpatch here, since both
5931 parent and child are sharing the same memory pages; we'll
5932 need to unpatch at follow/detach time instead to be certain
5933 that new breakpoints added between catchpoint hit time and
5934 vfork follow are detached. */
5935 if (ecs
->ws
.kind () != TARGET_WAITKIND_VFORKED
)
5937 /* This won't actually modify the breakpoint list, but will
5938 physically remove the breakpoints from the child. */
5939 detach_breakpoints (ecs
->ws
.child_ptid ());
5942 delete_just_stopped_threads_single_step_breakpoints ();
5944 /* In case the event is caught by a catchpoint, remember that
5945 the event is to be followed at the next resume of the thread,
5946 and not immediately. */
5947 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5949 ecs
->event_thread
->set_stop_pc
5950 (regcache_read_pc (get_thread_regcache (ecs
->event_thread
)));
5952 ecs
->event_thread
->control
.stop_bpstat
5953 = bpstat_stop_status_nowatch (get_current_regcache ()->aspace (),
5954 ecs
->event_thread
->stop_pc (),
5955 ecs
->event_thread
, ecs
->ws
);
5957 if (handle_stop_requested (ecs
))
5960 /* If no catchpoint triggered for this, then keep going. Note
5961 that we're interested in knowing the bpstat actually causes a
5962 stop, not just if it may explain the signal. Software
5963 watchpoints, for example, always appear in the bpstat. */
5964 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5967 = (follow_fork_mode_string
== follow_fork_mode_child
);
5969 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
5971 process_stratum_target
*targ
5972 = ecs
->event_thread
->inf
->process_target ();
5974 bool should_resume
= follow_fork ();
5976 /* Note that one of these may be an invalid pointer,
5977 depending on detach_fork. */
5978 thread_info
*parent
= ecs
->event_thread
;
5979 thread_info
*child
= targ
->find_thread (ecs
->ws
.child_ptid ());
5981 /* At this point, the parent is marked running, and the
5982 child is marked stopped. */
5984 /* If not resuming the parent, mark it stopped. */
5985 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5986 parent
->set_running (false);
5988 /* If resuming the child, mark it running. */
5989 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5990 child
->set_running (true);
5992 /* In non-stop mode, also resume the other branch. */
5993 if (!detach_fork
&& (non_stop
5994 || (sched_multi
&& target_is_non_stop_p ())))
5997 switch_to_thread (parent
);
5999 switch_to_thread (child
);
6001 ecs
->event_thread
= inferior_thread ();
6002 ecs
->ptid
= inferior_ptid
;
6007 switch_to_thread (child
);
6009 switch_to_thread (parent
);
6011 ecs
->event_thread
= inferior_thread ();
6012 ecs
->ptid
= inferior_ptid
;
6016 /* Never call switch_back_to_stepped_thread if we are waiting for
6017 vfork-done (waiting for an external vfork child to exec or
6018 exit). We will resume only the vforking thread for the purpose
6019 of collecting the vfork-done event, and we will restart any
6020 step once the critical shared address space window is done. */
6023 && parent
->inf
->thread_waiting_for_vfork_done
!= nullptr)
6024 || !switch_back_to_stepped_thread (ecs
))
6031 process_event_stop_test (ecs
);
6034 case TARGET_WAITKIND_VFORK_DONE
:
6035 /* Done with the shared memory region. Re-insert breakpoints in
6036 the parent, and keep going. */
6038 context_switch (ecs
);
6040 handle_vfork_done (ecs
->event_thread
);
6041 gdb_assert (inferior_thread () == ecs
->event_thread
);
6043 if (handle_stop_requested (ecs
))
6046 if (!switch_back_to_stepped_thread (ecs
))
6048 gdb_assert (inferior_thread () == ecs
->event_thread
);
6049 /* This also takes care of reinserting breakpoints in the
6050 previously locked inferior. */
6055 case TARGET_WAITKIND_EXECD
:
6057 /* Note we can't read registers yet (the stop_pc), because we
6058 don't yet know the inferior's post-exec architecture.
6059 'stop_pc' is explicitly read below instead. */
6060 switch_to_thread_no_regs (ecs
->event_thread
);
6062 /* Do whatever is necessary to the parent branch of the vfork. */
6063 handle_vfork_child_exec_or_exit (1);
6065 /* This causes the eventpoints and symbol table to be reset.
6066 Must do this now, before trying to determine whether to
6068 follow_exec (inferior_ptid
, ecs
->ws
.execd_pathname ());
6070 /* In follow_exec we may have deleted the original thread and
6071 created a new one. Make sure that the event thread is the
6072 execd thread for that case (this is a nop otherwise). */
6073 ecs
->event_thread
= inferior_thread ();
6075 ecs
->event_thread
->set_stop_pc
6076 (regcache_read_pc (get_thread_regcache (ecs
->event_thread
)));
6078 ecs
->event_thread
->control
.stop_bpstat
6079 = bpstat_stop_status_nowatch (get_current_regcache ()->aspace (),
6080 ecs
->event_thread
->stop_pc (),
6081 ecs
->event_thread
, ecs
->ws
);
6083 if (handle_stop_requested (ecs
))
6086 /* If no catchpoint triggered for this, then keep going. */
6087 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
6089 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
6093 process_event_stop_test (ecs
);
6096 /* Be careful not to try to gather much state about a thread
6097 that's in a syscall. It's frequently a losing proposition. */
6098 case TARGET_WAITKIND_SYSCALL_ENTRY
:
6099 /* Getting the current syscall number. */
6100 if (handle_syscall_event (ecs
) == 0)
6101 process_event_stop_test (ecs
);
6104 /* Before examining the threads further, step this thread to
6105 get it entirely out of the syscall. (We get notice of the
6106 event when the thread is just on the verge of exiting a
6107 syscall. Stepping one instruction seems to get it back
6109 case TARGET_WAITKIND_SYSCALL_RETURN
:
6110 if (handle_syscall_event (ecs
) == 0)
6111 process_event_stop_test (ecs
);
6114 case TARGET_WAITKIND_STOPPED
:
6115 handle_signal_stop (ecs
);
6118 case TARGET_WAITKIND_NO_HISTORY
:
6119 /* Reverse execution: target ran out of history info. */
6121 /* Switch to the stopped thread. */
6122 context_switch (ecs
);
6123 infrun_debug_printf ("stopped");
6125 delete_just_stopped_threads_single_step_breakpoints ();
6126 ecs
->event_thread
->set_stop_pc
6127 (regcache_read_pc (get_thread_regcache (inferior_thread ())));
6129 if (handle_stop_requested (ecs
))
6132 interps_notify_no_history ();
6138 /* Restart threads back to what they were trying to do back when we
6139 paused them (because of an in-line step-over or vfork, for example).
6140 The EVENT_THREAD thread is ignored (not restarted).
6142 If INF is non-nullptr, only resume threads from INF. */
6145 restart_threads (struct thread_info
*event_thread
, inferior
*inf
)
6147 INFRUN_SCOPED_DEBUG_START_END ("event_thread=%s, inf=%d",
6148 event_thread
->ptid
.to_string ().c_str (),
6149 inf
!= nullptr ? inf
->num
: -1);
6151 gdb_assert (!step_over_info_valid_p ());
6153 /* In case the instruction just stepped spawned a new thread. */
6154 update_thread_list ();
6156 for (thread_info
*tp
: all_non_exited_threads ())
6158 if (inf
!= nullptr && tp
->inf
!= inf
)
6161 if (tp
->inf
->detaching
)
6163 infrun_debug_printf ("restart threads: [%s] inferior detaching",
6164 tp
->ptid
.to_string ().c_str ());
6168 switch_to_thread_no_regs (tp
);
6170 if (tp
== event_thread
)
6172 infrun_debug_printf ("restart threads: [%s] is event thread",
6173 tp
->ptid
.to_string ().c_str ());
6177 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
6179 infrun_debug_printf ("restart threads: [%s] not meant to be running",
6180 tp
->ptid
.to_string ().c_str ());
6186 infrun_debug_printf ("restart threads: [%s] resumed",
6187 tp
->ptid
.to_string ().c_str ());
6188 gdb_assert (tp
->executing () || tp
->has_pending_waitstatus ());
6192 if (thread_is_in_step_over_chain (tp
))
6194 infrun_debug_printf ("restart threads: [%s] needs step-over",
6195 tp
->ptid
.to_string ().c_str ());
6196 gdb_assert (!tp
->resumed ());
6201 if (tp
->has_pending_waitstatus ())
6203 infrun_debug_printf ("restart threads: [%s] has pending status",
6204 tp
->ptid
.to_string ().c_str ());
6205 tp
->set_resumed (true);
6209 gdb_assert (!tp
->stop_requested
);
6211 /* If some thread needs to start a step-over at this point, it
6212 should still be in the step-over queue, and thus skipped
6214 if (thread_still_needs_step_over (tp
))
6216 internal_error ("thread [%s] needs a step-over, but not in "
6217 "step-over queue\n",
6218 tp
->ptid
.to_string ().c_str ());
6221 if (currently_stepping (tp
))
6223 infrun_debug_printf ("restart threads: [%s] was stepping",
6224 tp
->ptid
.to_string ().c_str ());
6225 keep_going_stepped_thread (tp
);
6229 infrun_debug_printf ("restart threads: [%s] continuing",
6230 tp
->ptid
.to_string ().c_str ());
6231 execution_control_state
ecs (tp
);
6232 switch_to_thread (tp
);
6233 keep_going_pass_signal (&ecs
);
6238 /* Callback for iterate_over_threads. Find a resumed thread that has
6239 a pending waitstatus. */
6242 resumed_thread_with_pending_status (struct thread_info
*tp
,
6245 return tp
->resumed () && tp
->has_pending_waitstatus ();
6248 /* Called when we get an event that may finish an in-line or
6249 out-of-line (displaced stepping) step-over started previously.
6250 Return true if the event is processed and we should go back to the
6251 event loop; false if the caller should continue processing the
6255 finish_step_over (struct execution_control_state
*ecs
)
6257 displaced_step_finish (ecs
->event_thread
, ecs
->ws
);
6259 bool had_step_over_info
= step_over_info_valid_p ();
6261 if (had_step_over_info
)
6263 /* If we're stepping over a breakpoint with all threads locked,
6264 then only the thread that was stepped should be reporting
6266 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
6268 clear_step_over_info ();
6271 if (!target_is_non_stop_p ())
6274 /* Start a new step-over in another thread if there's one that
6278 /* If we were stepping over a breakpoint before, and haven't started
6279 a new in-line step-over sequence, then restart all other threads
6280 (except the event thread). We can't do this in all-stop, as then
6281 e.g., we wouldn't be able to issue any other remote packet until
6282 these other threads stop. */
6283 if (had_step_over_info
&& !step_over_info_valid_p ())
6285 struct thread_info
*pending
;
6287 /* If we only have threads with pending statuses, the restart
6288 below won't restart any thread and so nothing re-inserts the
6289 breakpoint we just stepped over. But we need it inserted
6290 when we later process the pending events, otherwise if
6291 another thread has a pending event for this breakpoint too,
6292 we'd discard its event (because the breakpoint that
6293 originally caused the event was no longer inserted). */
6294 context_switch (ecs
);
6295 insert_breakpoints ();
6297 restart_threads (ecs
->event_thread
);
6299 /* If we have events pending, go through handle_inferior_event
6300 again, picking up a pending event at random. This avoids
6301 thread starvation. */
6303 /* But not if we just stepped over a watchpoint in order to let
6304 the instruction execute so we can evaluate its expression.
6305 The set of watchpoints that triggered is recorded in the
6306 breakpoint objects themselves (see bp->watchpoint_triggered).
6307 If we processed another event first, that other event could
6308 clobber this info. */
6309 if (ecs
->event_thread
->stepping_over_watchpoint
)
6312 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
6314 if (pending
!= nullptr)
6316 struct thread_info
*tp
= ecs
->event_thread
;
6317 struct regcache
*regcache
;
6319 infrun_debug_printf ("found resumed threads with "
6320 "pending events, saving status");
6322 gdb_assert (pending
!= tp
);
6324 /* Record the event thread's event for later. */
6325 save_waitstatus (tp
, ecs
->ws
);
6326 /* This was cleared early, by handle_inferior_event. Set it
6327 so this pending event is considered by
6329 tp
->set_resumed (true);
6331 gdb_assert (!tp
->executing ());
6333 regcache
= get_thread_regcache (tp
);
6334 tp
->set_stop_pc (regcache_read_pc (regcache
));
6336 infrun_debug_printf ("saved stop_pc=%s for %s "
6337 "(currently_stepping=%d)",
6338 paddress (current_inferior ()->arch (),
6340 tp
->ptid
.to_string ().c_str (),
6341 currently_stepping (tp
));
6343 /* This in-line step-over finished; clear this so we won't
6344 start a new one. This is what handle_signal_stop would
6345 do, if we returned false. */
6346 tp
->stepping_over_breakpoint
= 0;
6348 /* Wake up the event loop again. */
6349 mark_async_event_handler (infrun_async_inferior_event_token
);
6351 prepare_to_wait (ecs
);
6362 notify_signal_received (gdb_signal sig
)
6364 interps_notify_signal_received (sig
);
6365 gdb::observers::signal_received
.notify (sig
);
6371 notify_normal_stop (bpstat
*bs
, int print_frame
)
6373 interps_notify_normal_stop (bs
, print_frame
);
6374 gdb::observers::normal_stop
.notify (bs
, print_frame
);
6379 void notify_user_selected_context_changed (user_selected_what selection
)
6381 interps_notify_user_selected_context_changed (selection
);
6382 gdb::observers::user_selected_context_changed
.notify (selection
);
6385 /* Come here when the program has stopped with a signal. */
6388 handle_signal_stop (struct execution_control_state
*ecs
)
6390 frame_info_ptr frame
;
6391 struct gdbarch
*gdbarch
;
6392 int stopped_by_watchpoint
;
6393 enum stop_kind stop_soon
;
6396 gdb_assert (ecs
->ws
.kind () == TARGET_WAITKIND_STOPPED
);
6398 ecs
->event_thread
->set_stop_signal (ecs
->ws
.sig ());
6400 /* Do we need to clean up the state of a thread that has
6401 completed a displaced single-step? (Doing so usually affects
6402 the PC, so do it here, before we set stop_pc.) */
6403 if (finish_step_over (ecs
))
6406 /* If we either finished a single-step or hit a breakpoint, but
6407 the user wanted this thread to be stopped, pretend we got a
6408 SIG0 (generic unsignaled stop). */
6409 if (ecs
->event_thread
->stop_requested
6410 && ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
)
6411 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
6413 ecs
->event_thread
->set_stop_pc
6414 (regcache_read_pc (get_thread_regcache (ecs
->event_thread
)));
6416 context_switch (ecs
);
6418 if (deprecated_context_hook
)
6419 deprecated_context_hook (ecs
->event_thread
->global_num
);
6423 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
6424 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
6427 ("stop_pc=%s", paddress (reg_gdbarch
, ecs
->event_thread
->stop_pc ()));
6428 if (target_stopped_by_watchpoint ())
6432 infrun_debug_printf ("stopped by watchpoint");
6434 if (target_stopped_data_address (current_inferior ()->top_target (),
6436 infrun_debug_printf ("stopped data address=%s",
6437 paddress (reg_gdbarch
, addr
));
6439 infrun_debug_printf ("(no data address available)");
6443 /* This is originated from start_remote(), start_inferior() and
6444 shared libraries hook functions. */
6445 stop_soon
= get_inferior_stop_soon (ecs
);
6446 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
6448 infrun_debug_printf ("quietly stopped");
6449 stop_print_frame
= true;
6454 /* This originates from attach_command(). We need to overwrite
6455 the stop_signal here, because some kernels don't ignore a
6456 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
6457 See more comments in inferior.h. On the other hand, if we
6458 get a non-SIGSTOP, report it to the user - assume the backend
6459 will handle the SIGSTOP if it should show up later.
6461 Also consider that the attach is complete when we see a
6462 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
6463 target extended-remote report it instead of a SIGSTOP
6464 (e.g. gdbserver). We already rely on SIGTRAP being our
6465 signal, so this is no exception.
6467 Also consider that the attach is complete when we see a
6468 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
6469 the target to stop all threads of the inferior, in case the
6470 low level attach operation doesn't stop them implicitly. If
6471 they weren't stopped implicitly, then the stub will report a
6472 GDB_SIGNAL_0, meaning: stopped for no particular reason
6473 other than GDB's request. */
6474 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
6475 && (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_STOP
6476 || ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6477 || ecs
->event_thread
->stop_signal () == GDB_SIGNAL_0
))
6479 stop_print_frame
= true;
6481 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
6485 /* At this point, get hold of the now-current thread's frame. */
6486 frame
= get_current_frame ();
6487 gdbarch
= get_frame_arch (frame
);
6489 /* Pull the single step breakpoints out of the target. */
6490 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
)
6492 struct regcache
*regcache
;
6495 regcache
= get_thread_regcache (ecs
->event_thread
);
6496 const address_space
*aspace
= regcache
->aspace ();
6498 pc
= regcache_read_pc (regcache
);
6500 /* However, before doing so, if this single-step breakpoint was
6501 actually for another thread, set this thread up for moving
6503 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
6506 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
6508 infrun_debug_printf ("[%s] hit another thread's single-step "
6510 ecs
->ptid
.to_string ().c_str ());
6511 ecs
->hit_singlestep_breakpoint
= 1;
6516 infrun_debug_printf ("[%s] hit its single-step breakpoint",
6517 ecs
->ptid
.to_string ().c_str ());
6520 delete_just_stopped_threads_single_step_breakpoints ();
6522 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6523 && ecs
->event_thread
->control
.trap_expected
6524 && ecs
->event_thread
->stepping_over_watchpoint
)
6525 stopped_by_watchpoint
= 0;
6527 stopped_by_watchpoint
= watchpoints_triggered (ecs
->ws
);
6529 /* If necessary, step over this watchpoint. We'll be back to display
6531 if (stopped_by_watchpoint
6532 && (target_have_steppable_watchpoint ()
6533 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6535 /* At this point, we are stopped at an instruction which has
6536 attempted to write to a piece of memory under control of
6537 a watchpoint. The instruction hasn't actually executed
6538 yet. If we were to evaluate the watchpoint expression
6539 now, we would get the old value, and therefore no change
6540 would seem to have occurred.
6542 In order to make watchpoints work `right', we really need
6543 to complete the memory write, and then evaluate the
6544 watchpoint expression. We do this by single-stepping the
6547 It may not be necessary to disable the watchpoint to step over
6548 it. For example, the PA can (with some kernel cooperation)
6549 single step over a watchpoint without disabling the watchpoint.
6551 It is far more common to need to disable a watchpoint to step
6552 the inferior over it. If we have non-steppable watchpoints,
6553 we must disable the current watchpoint; it's simplest to
6554 disable all watchpoints.
6556 Any breakpoint at PC must also be stepped over -- if there's
6557 one, it will have already triggered before the watchpoint
6558 triggered, and we either already reported it to the user, or
6559 it didn't cause a stop and we called keep_going. In either
6560 case, if there was a breakpoint at PC, we must be trying to
6562 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6567 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6568 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6569 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6570 ecs
->event_thread
->control
.stop_step
= 0;
6571 stop_print_frame
= true;
6572 stopped_by_random_signal
= 0;
6573 bpstat
*stop_chain
= nullptr;
6575 /* Hide inlined functions starting here, unless we just performed stepi or
6576 nexti. After stepi and nexti, always show the innermost frame (not any
6577 inline function call sites). */
6578 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6580 const address_space
*aspace
6581 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6583 /* skip_inline_frames is expensive, so we avoid it if we can
6584 determine that the address is one where functions cannot have
6585 been inlined. This improves performance with inferiors that
6586 load a lot of shared libraries, because the solib event
6587 breakpoint is defined as the address of a function (i.e. not
6588 inline). Note that we have to check the previous PC as well
6589 as the current one to catch cases when we have just
6590 single-stepped off a breakpoint prior to reinstating it.
6591 Note that we're assuming that the code we single-step to is
6592 not inline, but that's not definitive: there's nothing
6593 preventing the event breakpoint function from containing
6594 inlined code, and the single-step ending up there. If the
6595 user had set a breakpoint on that inlined code, the missing
6596 skip_inline_frames call would break things. Fortunately
6597 that's an extremely unlikely scenario. */
6598 if (!pc_at_non_inline_function (aspace
,
6599 ecs
->event_thread
->stop_pc (),
6601 && !(ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6602 && ecs
->event_thread
->control
.trap_expected
6603 && pc_at_non_inline_function (aspace
,
6604 ecs
->event_thread
->prev_pc
,
6607 stop_chain
= build_bpstat_chain (aspace
,
6608 ecs
->event_thread
->stop_pc (),
6610 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6612 /* Re-fetch current thread's frame in case that invalidated
6614 frame
= get_current_frame ();
6615 gdbarch
= get_frame_arch (frame
);
6619 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6620 && ecs
->event_thread
->control
.trap_expected
6621 && gdbarch_single_step_through_delay_p (gdbarch
)
6622 && currently_stepping (ecs
->event_thread
))
6624 /* We're trying to step off a breakpoint. Turns out that we're
6625 also on an instruction that needs to be stepped multiple
6626 times before it's been fully executing. E.g., architectures
6627 with a delay slot. It needs to be stepped twice, once for
6628 the instruction and once for the delay slot. */
6629 int step_through_delay
6630 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6632 if (step_through_delay
)
6633 infrun_debug_printf ("step through delay");
6635 if (ecs
->event_thread
->control
.step_range_end
== 0
6636 && step_through_delay
)
6638 /* The user issued a continue when stopped at a breakpoint.
6639 Set up for another trap and get out of here. */
6640 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6644 else if (step_through_delay
)
6646 /* The user issued a step when stopped at a breakpoint.
6647 Maybe we should stop, maybe we should not - the delay
6648 slot *might* correspond to a line of source. In any
6649 case, don't decide that here, just set
6650 ecs->stepping_over_breakpoint, making sure we
6651 single-step again before breakpoints are re-inserted. */
6652 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6656 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6657 handles this event. */
6658 ecs
->event_thread
->control
.stop_bpstat
6659 = bpstat_stop_status (get_current_regcache ()->aspace (),
6660 ecs
->event_thread
->stop_pc (),
6661 ecs
->event_thread
, ecs
->ws
, stop_chain
);
6663 /* Following in case break condition called a
6665 stop_print_frame
= true;
6667 /* This is where we handle "moribund" watchpoints. Unlike
6668 software breakpoints traps, hardware watchpoint traps are
6669 always distinguishable from random traps. If no high-level
6670 watchpoint is associated with the reported stop data address
6671 anymore, then the bpstat does not explain the signal ---
6672 simply make sure to ignore it if `stopped_by_watchpoint' is
6675 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6676 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6678 && stopped_by_watchpoint
)
6680 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6684 /* NOTE: cagney/2003-03-29: These checks for a random signal
6685 at one stage in the past included checks for an inferior
6686 function call's call dummy's return breakpoint. The original
6687 comment, that went with the test, read:
6689 ``End of a stack dummy. Some systems (e.g. Sony news) give
6690 another signal besides SIGTRAP, so check here as well as
6693 If someone ever tries to get call dummys on a
6694 non-executable stack to work (where the target would stop
6695 with something like a SIGSEGV), then those tests might need
6696 to be re-instated. Given, however, that the tests were only
6697 enabled when momentary breakpoints were not being used, I
6698 suspect that it won't be the case.
6700 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6701 be necessary for call dummies on a non-executable stack on
6704 /* See if the breakpoints module can explain the signal. */
6706 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6707 ecs
->event_thread
->stop_signal ());
6709 /* Maybe this was a trap for a software breakpoint that has since
6711 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6713 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6714 ecs
->event_thread
->stop_pc ()))
6716 struct regcache
*regcache
;
6719 /* Re-adjust PC to what the program would see if GDB was not
6721 regcache
= get_thread_regcache (ecs
->event_thread
);
6722 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6725 gdb::optional
<scoped_restore_tmpl
<int>>
6726 restore_operation_disable
;
6728 if (record_full_is_used ())
6729 restore_operation_disable
.emplace
6730 (record_full_gdb_operation_disable_set ());
6732 regcache_write_pc (regcache
,
6733 ecs
->event_thread
->stop_pc () + decr_pc
);
6738 /* A delayed software breakpoint event. Ignore the trap. */
6739 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6744 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6745 has since been removed. */
6746 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6748 /* A delayed hardware breakpoint event. Ignore the trap. */
6749 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6754 /* If not, perhaps stepping/nexting can. */
6756 random_signal
= !(ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6757 && currently_stepping (ecs
->event_thread
));
6759 /* Perhaps the thread hit a single-step breakpoint of _another_
6760 thread. Single-step breakpoints are transparent to the
6761 breakpoints module. */
6763 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6765 /* No? Perhaps we got a moribund watchpoint. */
6767 random_signal
= !stopped_by_watchpoint
;
6769 /* Always stop if the user explicitly requested this thread to
6771 if (ecs
->event_thread
->stop_requested
)
6774 infrun_debug_printf ("user-requested stop");
6777 /* For the program's own signals, act according to
6778 the signal handling tables. */
6782 /* Signal not for debugging purposes. */
6783 enum gdb_signal stop_signal
= ecs
->event_thread
->stop_signal ();
6785 infrun_debug_printf ("random signal (%s)",
6786 gdb_signal_to_symbol_string (stop_signal
));
6788 stopped_by_random_signal
= 1;
6790 /* Always stop on signals if we're either just gaining control
6791 of the program, or the user explicitly requested this thread
6792 to remain stopped. */
6793 if (stop_soon
!= NO_STOP_QUIETLY
6794 || ecs
->event_thread
->stop_requested
6795 || signal_stop_state (ecs
->event_thread
->stop_signal ()))
6801 /* Notify observers the signal has "handle print" set. Note we
6802 returned early above if stopping; normal_stop handles the
6803 printing in that case. */
6804 if (signal_print
[ecs
->event_thread
->stop_signal ()])
6806 /* The signal table tells us to print about this signal. */
6807 target_terminal::ours_for_output ();
6808 notify_signal_received (ecs
->event_thread
->stop_signal ());
6809 target_terminal::inferior ();
6812 /* Clear the signal if it should not be passed. */
6813 if (signal_program
[ecs
->event_thread
->stop_signal ()] == 0)
6814 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
6816 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->stop_pc ()
6817 && ecs
->event_thread
->control
.trap_expected
6818 && ecs
->event_thread
->control
.step_resume_breakpoint
== nullptr)
6820 /* We were just starting a new sequence, attempting to
6821 single-step off of a breakpoint and expecting a SIGTRAP.
6822 Instead this signal arrives. This signal will take us out
6823 of the stepping range so GDB needs to remember to, when
6824 the signal handler returns, resume stepping off that
6826 /* To simplify things, "continue" is forced to use the same
6827 code paths as single-step - set a breakpoint at the
6828 signal return address and then, once hit, step off that
6830 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6832 insert_hp_step_resume_breakpoint_at_frame (frame
);
6833 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6834 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6835 ecs
->event_thread
->control
.trap_expected
= 0;
6837 /* If we were nexting/stepping some other thread, switch to
6838 it, so that we don't continue it, losing control. */
6839 if (!switch_back_to_stepped_thread (ecs
))
6844 if (ecs
->event_thread
->stop_signal () != GDB_SIGNAL_0
6845 && (pc_in_thread_step_range (ecs
->event_thread
->stop_pc (),
6847 || ecs
->event_thread
->control
.step_range_end
== 1)
6848 && (get_stack_frame_id (frame
)
6849 == ecs
->event_thread
->control
.step_stack_frame_id
)
6850 && ecs
->event_thread
->control
.step_resume_breakpoint
== nullptr)
6852 /* The inferior is about to take a signal that will take it
6853 out of the single step range. Set a breakpoint at the
6854 current PC (which is presumably where the signal handler
6855 will eventually return) and then allow the inferior to
6858 Note that this is only needed for a signal delivered
6859 while in the single-step range. Nested signals aren't a
6860 problem as they eventually all return. */
6861 infrun_debug_printf ("signal may take us out of single-step range");
6863 clear_step_over_info ();
6864 insert_hp_step_resume_breakpoint_at_frame (frame
);
6865 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6866 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6867 ecs
->event_thread
->control
.trap_expected
= 0;
6872 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6873 when either there's a nested signal, or when there's a
6874 pending signal enabled just as the signal handler returns
6875 (leaving the inferior at the step-resume-breakpoint without
6876 actually executing it). Either way continue until the
6877 breakpoint is really hit. */
6879 if (!switch_back_to_stepped_thread (ecs
))
6881 infrun_debug_printf ("random signal, keep going");
6888 process_event_stop_test (ecs
);
6891 /* Come here when we've got some debug event / signal we can explain
6892 (IOW, not a random signal), and test whether it should cause a
6893 stop, or whether we should resume the inferior (transparently).
6894 E.g., could be a breakpoint whose condition evaluates false; we
6895 could be still stepping within the line; etc. */
6898 process_event_stop_test (struct execution_control_state
*ecs
)
6900 struct symtab_and_line stop_pc_sal
;
6901 frame_info_ptr frame
;
6902 struct gdbarch
*gdbarch
;
6903 CORE_ADDR jmp_buf_pc
;
6904 struct bpstat_what what
;
6906 /* Handle cases caused by hitting a breakpoint. */
6908 frame
= get_current_frame ();
6909 gdbarch
= get_frame_arch (frame
);
6911 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6913 if (what
.call_dummy
)
6915 stop_stack_dummy
= what
.call_dummy
;
6918 /* A few breakpoint types have callbacks associated (e.g.,
6919 bp_jit_event). Run them now. */
6920 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6922 /* If we hit an internal event that triggers symbol changes, the
6923 current frame will be invalidated within bpstat_what (e.g., if we
6924 hit an internal solib event). Re-fetch it. */
6925 frame
= get_current_frame ();
6926 gdbarch
= get_frame_arch (frame
);
6928 switch (what
.main_action
)
6930 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6931 /* If we hit the breakpoint at longjmp while stepping, we
6932 install a momentary breakpoint at the target of the
6935 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6937 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6939 if (what
.is_longjmp
)
6941 struct value
*arg_value
;
6943 /* If we set the longjmp breakpoint via a SystemTap probe,
6944 then use it to extract the arguments. The destination PC
6945 is the third argument to the probe. */
6946 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6949 jmp_buf_pc
= value_as_address (arg_value
);
6950 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6952 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6953 || !gdbarch_get_longjmp_target (gdbarch
,
6954 frame
, &jmp_buf_pc
))
6956 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6957 "(!gdbarch_get_longjmp_target)");
6962 /* Insert a breakpoint at resume address. */
6963 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6966 check_exception_resume (ecs
, frame
);
6970 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6972 frame_info_ptr init_frame
;
6974 /* There are several cases to consider.
6976 1. The initiating frame no longer exists. In this case we
6977 must stop, because the exception or longjmp has gone too
6980 2. The initiating frame exists, and is the same as the
6981 current frame. We stop, because the exception or longjmp
6984 3. The initiating frame exists and is different from the
6985 current frame. This means the exception or longjmp has
6986 been caught beneath the initiating frame, so keep going.
6988 4. longjmp breakpoint has been placed just to protect
6989 against stale dummy frames and user is not interested in
6990 stopping around longjmps. */
6992 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6994 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6996 delete_exception_resume_breakpoint (ecs
->event_thread
);
6998 if (what
.is_longjmp
)
7000 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
7002 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
7010 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
7014 struct frame_id current_id
7015 = get_frame_id (get_current_frame ());
7016 if (current_id
== ecs
->event_thread
->initiating_frame
)
7018 /* Case 2. Fall through. */
7028 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
7030 delete_step_resume_breakpoint (ecs
->event_thread
);
7032 end_stepping_range (ecs
);
7036 case BPSTAT_WHAT_SINGLE
:
7037 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
7038 ecs
->event_thread
->stepping_over_breakpoint
= 1;
7039 /* Still need to check other stuff, at least the case where we
7040 are stepping and step out of the right range. */
7043 case BPSTAT_WHAT_STEP_RESUME
:
7044 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
7046 delete_step_resume_breakpoint (ecs
->event_thread
);
7047 if (ecs
->event_thread
->control
.proceed_to_finish
7048 && execution_direction
== EXEC_REVERSE
)
7050 struct thread_info
*tp
= ecs
->event_thread
;
7052 /* We are finishing a function in reverse, and just hit the
7053 step-resume breakpoint at the start address of the
7054 function, and we're almost there -- just need to back up
7055 by one more single-step, which should take us back to the
7057 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
7061 fill_in_stop_func (gdbarch
, ecs
);
7062 if (ecs
->event_thread
->stop_pc () == ecs
->stop_func_start
7063 && execution_direction
== EXEC_REVERSE
)
7065 /* We are stepping over a function call in reverse, and just
7066 hit the step-resume breakpoint at the start address of
7067 the function. Go back to single-stepping, which should
7068 take us back to the function call. */
7069 ecs
->event_thread
->stepping_over_breakpoint
= 1;
7075 case BPSTAT_WHAT_STOP_NOISY
:
7076 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
7077 stop_print_frame
= true;
7079 /* Assume the thread stopped for a breakpoint. We'll still check
7080 whether a/the breakpoint is there when the thread is next
7082 ecs
->event_thread
->stepping_over_breakpoint
= 1;
7087 case BPSTAT_WHAT_STOP_SILENT
:
7088 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
7089 stop_print_frame
= false;
7091 /* Assume the thread stopped for a breakpoint. We'll still check
7092 whether a/the breakpoint is there when the thread is next
7094 ecs
->event_thread
->stepping_over_breakpoint
= 1;
7098 case BPSTAT_WHAT_HP_STEP_RESUME
:
7099 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
7101 delete_step_resume_breakpoint (ecs
->event_thread
);
7102 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
7104 /* Back when the step-resume breakpoint was inserted, we
7105 were trying to single-step off a breakpoint. Go back to
7107 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
7108 ecs
->event_thread
->stepping_over_breakpoint
= 1;
7114 case BPSTAT_WHAT_KEEP_CHECKING
:
7118 /* If we stepped a permanent breakpoint and we had a high priority
7119 step-resume breakpoint for the address we stepped, but we didn't
7120 hit it, then we must have stepped into the signal handler. The
7121 step-resume was only necessary to catch the case of _not_
7122 stepping into the handler, so delete it, and fall through to
7123 checking whether the step finished. */
7124 if (ecs
->event_thread
->stepped_breakpoint
)
7126 struct breakpoint
*sr_bp
7127 = ecs
->event_thread
->control
.step_resume_breakpoint
;
7129 if (sr_bp
!= nullptr
7130 && sr_bp
->first_loc ().permanent
7131 && sr_bp
->type
== bp_hp_step_resume
7132 && sr_bp
->first_loc ().address
== ecs
->event_thread
->prev_pc
)
7134 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
7135 delete_step_resume_breakpoint (ecs
->event_thread
);
7136 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
7140 /* We come here if we hit a breakpoint but should not stop for it.
7141 Possibly we also were stepping and should stop for that. So fall
7142 through and test for stepping. But, if not stepping, do not
7145 /* In all-stop mode, if we're currently stepping but have stopped in
7146 some other thread, we need to switch back to the stepped thread. */
7147 if (switch_back_to_stepped_thread (ecs
))
7150 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
7152 infrun_debug_printf ("step-resume breakpoint is inserted");
7154 /* Having a step-resume breakpoint overrides anything
7155 else having to do with stepping commands until
7156 that breakpoint is reached. */
7161 if (ecs
->event_thread
->control
.step_range_end
== 0)
7163 infrun_debug_printf ("no stepping, continue");
7164 /* Likewise if we aren't even stepping. */
7169 /* Re-fetch current thread's frame in case the code above caused
7170 the frame cache to be re-initialized, making our FRAME variable
7171 a dangling pointer. */
7172 frame
= get_current_frame ();
7173 gdbarch
= get_frame_arch (frame
);
7174 fill_in_stop_func (gdbarch
, ecs
);
7176 /* If stepping through a line, keep going if still within it.
7178 Note that step_range_end is the address of the first instruction
7179 beyond the step range, and NOT the address of the last instruction
7182 Note also that during reverse execution, we may be stepping
7183 through a function epilogue and therefore must detect when
7184 the current-frame changes in the middle of a line. */
7186 if (pc_in_thread_step_range (ecs
->event_thread
->stop_pc (),
7188 && (execution_direction
!= EXEC_REVERSE
7189 || get_frame_id (frame
) == ecs
->event_thread
->control
.step_frame_id
))
7192 ("stepping inside range [%s-%s]",
7193 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
7194 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
7196 /* Tentatively re-enable range stepping; `resume' disables it if
7197 necessary (e.g., if we're stepping over a breakpoint or we
7198 have software watchpoints). */
7199 ecs
->event_thread
->control
.may_range_step
= 1;
7201 /* When stepping backward, stop at beginning of line range
7202 (unless it's the function entry point, in which case
7203 keep going back to the call point). */
7204 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
7205 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
7206 && stop_pc
!= ecs
->stop_func_start
7207 && execution_direction
== EXEC_REVERSE
)
7208 end_stepping_range (ecs
);
7215 /* We stepped out of the stepping range. */
7217 /* If we are stepping at the source level and entered the runtime
7218 loader dynamic symbol resolution code...
7220 EXEC_FORWARD: we keep on single stepping until we exit the run
7221 time loader code and reach the callee's address.
7223 EXEC_REVERSE: we've already executed the callee (backward), and
7224 the runtime loader code is handled just like any other
7225 undebuggable function call. Now we need only keep stepping
7226 backward through the trampoline code, and that's handled further
7227 down, so there is nothing for us to do here. */
7229 if (execution_direction
!= EXEC_REVERSE
7230 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7231 && in_solib_dynsym_resolve_code (ecs
->event_thread
->stop_pc ())
7232 && (ecs
->event_thread
->control
.step_start_function
== nullptr
7233 || !in_solib_dynsym_resolve_code (
7234 ecs
->event_thread
->control
.step_start_function
->value_block ()
7237 CORE_ADDR pc_after_resolver
=
7238 gdbarch_skip_solib_resolver (gdbarch
, ecs
->event_thread
->stop_pc ());
7240 infrun_debug_printf ("stepped into dynsym resolve code");
7242 if (pc_after_resolver
)
7244 /* Set up a step-resume breakpoint at the address
7245 indicated by SKIP_SOLIB_RESOLVER. */
7246 symtab_and_line sr_sal
;
7247 sr_sal
.pc
= pc_after_resolver
;
7248 sr_sal
.pspace
= get_frame_program_space (frame
);
7250 insert_step_resume_breakpoint_at_sal (gdbarch
,
7251 sr_sal
, null_frame_id
);
7258 /* Step through an indirect branch thunk. */
7259 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
7260 && gdbarch_in_indirect_branch_thunk (gdbarch
,
7261 ecs
->event_thread
->stop_pc ()))
7263 infrun_debug_printf ("stepped into indirect branch thunk");
7268 if (ecs
->event_thread
->control
.step_range_end
!= 1
7269 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7270 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
7271 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
7273 infrun_debug_printf ("stepped into signal trampoline");
7274 /* The inferior, while doing a "step" or "next", has ended up in
7275 a signal trampoline (either by a signal being delivered or by
7276 the signal handler returning). Just single-step until the
7277 inferior leaves the trampoline (either by calling the handler
7283 /* If we're in the return path from a shared library trampoline,
7284 we want to proceed through the trampoline when stepping. */
7285 /* macro/2012-04-25: This needs to come before the subroutine
7286 call check below as on some targets return trampolines look
7287 like subroutine calls (MIPS16 return thunks). */
7288 if (gdbarch_in_solib_return_trampoline (gdbarch
,
7289 ecs
->event_thread
->stop_pc (),
7290 ecs
->stop_func_name
)
7291 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7293 /* Determine where this trampoline returns. */
7294 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
7295 CORE_ADDR real_stop_pc
7296 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
7298 infrun_debug_printf ("stepped into solib return tramp");
7300 /* Only proceed through if we know where it's going. */
7303 /* And put the step-breakpoint there and go until there. */
7304 symtab_and_line sr_sal
;
7305 sr_sal
.pc
= real_stop_pc
;
7306 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7307 sr_sal
.pspace
= get_frame_program_space (frame
);
7309 /* Do not specify what the fp should be when we stop since
7310 on some machines the prologue is where the new fp value
7312 insert_step_resume_breakpoint_at_sal (gdbarch
,
7313 sr_sal
, null_frame_id
);
7315 /* Restart without fiddling with the step ranges or
7322 /* Check for subroutine calls. The check for the current frame
7323 equalling the step ID is not necessary - the check of the
7324 previous frame's ID is sufficient - but it is a common case and
7325 cheaper than checking the previous frame's ID.
7327 NOTE: frame_id::operator== will never report two invalid frame IDs as
7328 being equal, so to get into this block, both the current and
7329 previous frame must have valid frame IDs. */
7330 /* The outer_frame_id check is a heuristic to detect stepping
7331 through startup code. If we step over an instruction which
7332 sets the stack pointer from an invalid value to a valid value,
7333 we may detect that as a subroutine call from the mythical
7334 "outermost" function. This could be fixed by marking
7335 outermost frames as !stack_p,code_p,special_p. Then the
7336 initial outermost frame, before sp was valid, would
7337 have code_addr == &_start. See the comment in frame_id::operator==
7340 /* We want "nexti" to step into, not over, signal handlers invoked
7341 by the kernel, therefore this subroutine check should not trigger
7342 for a signal handler invocation. On most platforms, this is already
7343 not the case, as the kernel puts a signal trampoline frame onto the
7344 stack to handle proper return after the handler, and therefore at this
7345 point, the current frame is a grandchild of the step frame, not a
7346 child. However, on some platforms, the kernel actually uses a
7347 trampoline to handle *invocation* of the handler. In that case,
7348 when executing the first instruction of the trampoline, this check
7349 would erroneously detect the trampoline invocation as a subroutine
7350 call. Fix this by checking for SIGTRAMP_FRAME. */
7351 if ((get_stack_frame_id (frame
)
7352 != ecs
->event_thread
->control
.step_stack_frame_id
)
7353 && get_frame_type (frame
) != SIGTRAMP_FRAME
7354 && ((frame_unwind_caller_id (get_current_frame ())
7355 == ecs
->event_thread
->control
.step_stack_frame_id
)
7356 && ((ecs
->event_thread
->control
.step_stack_frame_id
7358 || (ecs
->event_thread
->control
.step_start_function
7359 != find_pc_function (ecs
->event_thread
->stop_pc ())))))
7361 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
7362 CORE_ADDR real_stop_pc
;
7364 infrun_debug_printf ("stepped into subroutine");
7366 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
7368 /* I presume that step_over_calls is only 0 when we're
7369 supposed to be stepping at the assembly language level
7370 ("stepi"). Just stop. */
7371 /* And this works the same backward as frontward. MVS */
7372 end_stepping_range (ecs
);
7376 /* Reverse stepping through solib trampolines. */
7378 if (execution_direction
== EXEC_REVERSE
7379 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
7380 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7381 || (ecs
->stop_func_start
== 0
7382 && in_solib_dynsym_resolve_code (stop_pc
))))
7384 /* Any solib trampoline code can be handled in reverse
7385 by simply continuing to single-step. We have already
7386 executed the solib function (backwards), and a few
7387 steps will take us back through the trampoline to the
7393 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
7395 /* We're doing a "next".
7397 Normal (forward) execution: set a breakpoint at the
7398 callee's return address (the address at which the caller
7401 Reverse (backward) execution. set the step-resume
7402 breakpoint at the start of the function that we just
7403 stepped into (backwards), and continue to there. When we
7404 get there, we'll need to single-step back to the caller. */
7406 if (execution_direction
== EXEC_REVERSE
)
7408 /* If we're already at the start of the function, we've either
7409 just stepped backward into a single instruction function,
7410 or stepped back out of a signal handler to the first instruction
7411 of the function. Just keep going, which will single-step back
7413 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
7415 /* Normal function call return (static or dynamic). */
7416 symtab_and_line sr_sal
;
7417 sr_sal
.pc
= ecs
->stop_func_start
;
7418 sr_sal
.pspace
= get_frame_program_space (frame
);
7419 insert_step_resume_breakpoint_at_sal (gdbarch
,
7420 sr_sal
, get_stack_frame_id (frame
));
7424 insert_step_resume_breakpoint_at_caller (frame
);
7430 /* If we are in a function call trampoline (a stub between the
7431 calling routine and the real function), locate the real
7432 function. That's what tells us (a) whether we want to step
7433 into it at all, and (b) what prologue we want to run to the
7434 end of, if we do step into it. */
7435 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
7436 if (real_stop_pc
== 0)
7437 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
7438 if (real_stop_pc
!= 0)
7439 ecs
->stop_func_start
= real_stop_pc
;
7441 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
7443 symtab_and_line sr_sal
;
7444 sr_sal
.pc
= ecs
->stop_func_start
;
7445 sr_sal
.pspace
= get_frame_program_space (frame
);
7447 insert_step_resume_breakpoint_at_sal (gdbarch
,
7448 sr_sal
, null_frame_id
);
7453 /* If we have line number information for the function we are
7454 thinking of stepping into and the function isn't on the skip
7457 If there are several symtabs at that PC (e.g. with include
7458 files), just want to know whether *any* of them have line
7459 numbers. find_pc_line handles this. */
7461 struct symtab_and_line tmp_sal
;
7463 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7464 if (tmp_sal
.line
!= 0
7465 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
7467 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
7469 if (execution_direction
== EXEC_REVERSE
)
7470 handle_step_into_function_backward (gdbarch
, ecs
);
7472 handle_step_into_function (gdbarch
, ecs
);
7477 /* If we have no line number and the step-stop-if-no-debug is
7478 set, we stop the step so that the user has a chance to switch
7479 in assembly mode. */
7480 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7481 && step_stop_if_no_debug
)
7483 end_stepping_range (ecs
);
7487 if (execution_direction
== EXEC_REVERSE
)
7489 /* If we're already at the start of the function, we've either just
7490 stepped backward into a single instruction function without line
7491 number info, or stepped back out of a signal handler to the first
7492 instruction of the function without line number info. Just keep
7493 going, which will single-step back to the caller. */
7494 if (ecs
->stop_func_start
!= stop_pc
)
7496 /* Set a breakpoint at callee's start address.
7497 From there we can step once and be back in the caller. */
7498 symtab_and_line sr_sal
;
7499 sr_sal
.pc
= ecs
->stop_func_start
;
7500 sr_sal
.pspace
= get_frame_program_space (frame
);
7501 insert_step_resume_breakpoint_at_sal (gdbarch
,
7502 sr_sal
, null_frame_id
);
7506 /* Set a breakpoint at callee's return address (the address
7507 at which the caller will resume). */
7508 insert_step_resume_breakpoint_at_caller (frame
);
7514 /* Reverse stepping through solib trampolines. */
7516 if (execution_direction
== EXEC_REVERSE
7517 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7519 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
7521 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7522 || (ecs
->stop_func_start
== 0
7523 && in_solib_dynsym_resolve_code (stop_pc
)))
7525 /* Any solib trampoline code can be handled in reverse
7526 by simply continuing to single-step. We have already
7527 executed the solib function (backwards), and a few
7528 steps will take us back through the trampoline to the
7533 else if (in_solib_dynsym_resolve_code (stop_pc
))
7535 /* Stepped backward into the solib dynsym resolver.
7536 Set a breakpoint at its start and continue, then
7537 one more step will take us out. */
7538 symtab_and_line sr_sal
;
7539 sr_sal
.pc
= ecs
->stop_func_start
;
7540 sr_sal
.pspace
= get_frame_program_space (frame
);
7541 insert_step_resume_breakpoint_at_sal (gdbarch
,
7542 sr_sal
, null_frame_id
);
7548 /* This always returns the sal for the inner-most frame when we are in a
7549 stack of inlined frames, even if GDB actually believes that it is in a
7550 more outer frame. This is checked for below by calls to
7551 inline_skipped_frames. */
7552 stop_pc_sal
= find_pc_line (ecs
->event_thread
->stop_pc (), 0);
7554 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7555 the trampoline processing logic, however, there are some trampolines
7556 that have no names, so we should do trampoline handling first. */
7557 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7558 && ecs
->stop_func_name
== nullptr
7559 && stop_pc_sal
.line
== 0)
7561 infrun_debug_printf ("stepped into undebuggable function");
7563 /* The inferior just stepped into, or returned to, an
7564 undebuggable function (where there is no debugging information
7565 and no line number corresponding to the address where the
7566 inferior stopped). Since we want to skip this kind of code,
7567 we keep going until the inferior returns from this
7568 function - unless the user has asked us not to (via
7569 set step-mode) or we no longer know how to get back
7570 to the call site. */
7571 if (step_stop_if_no_debug
7572 || !frame_id_p (frame_unwind_caller_id (frame
)))
7574 /* If we have no line number and the step-stop-if-no-debug
7575 is set, we stop the step so that the user has a chance to
7576 switch in assembly mode. */
7577 end_stepping_range (ecs
);
7582 /* Set a breakpoint at callee's return address (the address
7583 at which the caller will resume). */
7584 insert_step_resume_breakpoint_at_caller (frame
);
7590 if (execution_direction
== EXEC_REVERSE
7591 && ecs
->event_thread
->control
.proceed_to_finish
7592 && ecs
->event_thread
->stop_pc () >= ecs
->stop_func_alt_start
7593 && ecs
->event_thread
->stop_pc () < ecs
->stop_func_start
)
7595 /* We are executing the reverse-finish command.
7596 If the system supports multiple entry points and we are finishing a
7597 function in reverse. If we are between the entry points single-step
7598 back to the alternate entry point. If we are at the alternate entry
7599 point -- just need to back up by one more single-step, which
7600 should take us back to the function call. */
7601 ecs
->event_thread
->control
.step_range_start
7602 = ecs
->event_thread
->control
.step_range_end
= 1;
7608 if (ecs
->event_thread
->control
.step_range_end
== 1)
7610 /* It is stepi or nexti. We always want to stop stepping after
7612 infrun_debug_printf ("stepi/nexti");
7613 end_stepping_range (ecs
);
7617 if (stop_pc_sal
.line
== 0)
7619 /* We have no line number information. That means to stop
7620 stepping (does this always happen right after one instruction,
7621 when we do "s" in a function with no line numbers,
7622 or can this happen as a result of a return or longjmp?). */
7623 infrun_debug_printf ("line number info");
7624 end_stepping_range (ecs
);
7628 /* Look for "calls" to inlined functions, part one. If the inline
7629 frame machinery detected some skipped call sites, we have entered
7630 a new inline function. */
7632 if ((get_frame_id (get_current_frame ())
7633 == ecs
->event_thread
->control
.step_frame_id
)
7634 && inline_skipped_frames (ecs
->event_thread
))
7636 infrun_debug_printf ("stepped into inlined function");
7638 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7640 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7642 /* For "step", we're going to stop. But if the call site
7643 for this inlined function is on the same source line as
7644 we were previously stepping, go down into the function
7645 first. Otherwise stop at the call site. */
7647 if (call_sal
.line
== ecs
->event_thread
->current_line
7648 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7650 step_into_inline_frame (ecs
->event_thread
);
7651 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7658 end_stepping_range (ecs
);
7663 /* For "next", we should stop at the call site if it is on a
7664 different source line. Otherwise continue through the
7665 inlined function. */
7666 if (call_sal
.line
== ecs
->event_thread
->current_line
7667 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7670 end_stepping_range (ecs
);
7675 /* Look for "calls" to inlined functions, part two. If we are still
7676 in the same real function we were stepping through, but we have
7677 to go further up to find the exact frame ID, we are stepping
7678 through a more inlined call beyond its call site. */
7680 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7681 && (get_frame_id (get_current_frame ())
7682 != ecs
->event_thread
->control
.step_frame_id
)
7683 && stepped_in_from (get_current_frame (),
7684 ecs
->event_thread
->control
.step_frame_id
))
7686 infrun_debug_printf ("stepping through inlined function");
7688 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7689 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7692 end_stepping_range (ecs
);
7696 bool refresh_step_info
= true;
7697 if ((ecs
->event_thread
->stop_pc () == stop_pc_sal
.pc
)
7698 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7699 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7701 /* We are at a different line. */
7703 if (stop_pc_sal
.is_stmt
)
7705 /* We are at the start of a statement.
7707 So stop. Note that we don't stop if we step into the middle of a
7708 statement. That is said to make things like for (;;) statements
7710 infrun_debug_printf ("stepped to a different line");
7711 end_stepping_range (ecs
);
7714 else if (get_frame_id (get_current_frame ())
7715 == ecs
->event_thread
->control
.step_frame_id
)
7717 /* We are not at the start of a statement, and we have not changed
7720 We ignore this line table entry, and continue stepping forward,
7721 looking for a better place to stop. */
7722 refresh_step_info
= false;
7723 infrun_debug_printf ("stepped to a different line, but "
7724 "it's not the start of a statement");
7728 /* We are not the start of a statement, and we have changed frame.
7730 We ignore this line table entry, and continue stepping forward,
7731 looking for a better place to stop. Keep refresh_step_info at
7732 true to note that the frame has changed, but ignore the line
7733 number to make sure we don't ignore a subsequent entry with the
7734 same line number. */
7735 stop_pc_sal
.line
= 0;
7736 infrun_debug_printf ("stepped to a different frame, but "
7737 "it's not the start of a statement");
7741 /* We aren't done stepping.
7743 Optimize by setting the stepping range to the line.
7744 (We might not be in the original line, but if we entered a
7745 new line in mid-statement, we continue stepping. This makes
7746 things like for(;;) statements work better.)
7748 If we entered a SAL that indicates a non-statement line table entry,
7749 then we update the stepping range, but we don't update the step info,
7750 which includes things like the line number we are stepping away from.
7751 This means we will stop when we find a line table entry that is marked
7752 as is-statement, even if it matches the non-statement one we just
7755 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7756 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7757 ecs
->event_thread
->control
.may_range_step
= 1;
7759 ("updated step range, start = %s, end = %s, may_range_step = %d",
7760 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
7761 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
),
7762 ecs
->event_thread
->control
.may_range_step
);
7763 if (refresh_step_info
)
7764 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7766 infrun_debug_printf ("keep going");
7770 static bool restart_stepped_thread (process_stratum_target
*resume_target
,
7771 ptid_t resume_ptid
);
7773 /* In all-stop mode, if we're currently stepping but have stopped in
7774 some other thread, we may need to switch back to the stepped
7775 thread. Returns true we set the inferior running, false if we left
7776 it stopped (and the event needs further processing). */
7779 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7781 if (!target_is_non_stop_p ())
7783 /* If any thread is blocked on some internal breakpoint, and we
7784 simply need to step over that breakpoint to get it going
7785 again, do that first. */
7787 /* However, if we see an event for the stepping thread, then we
7788 know all other threads have been moved past their breakpoints
7789 already. Let the caller check whether the step is finished,
7790 etc., before deciding to move it past a breakpoint. */
7791 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7794 /* Check if the current thread is blocked on an incomplete
7795 step-over, interrupted by a random signal. */
7796 if (ecs
->event_thread
->control
.trap_expected
7797 && ecs
->event_thread
->stop_signal () != GDB_SIGNAL_TRAP
)
7800 ("need to finish step-over of [%s]",
7801 ecs
->event_thread
->ptid
.to_string ().c_str ());
7806 /* Check if the current thread is blocked by a single-step
7807 breakpoint of another thread. */
7808 if (ecs
->hit_singlestep_breakpoint
)
7810 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7811 ecs
->ptid
.to_string ().c_str ());
7816 /* If this thread needs yet another step-over (e.g., stepping
7817 through a delay slot), do it first before moving on to
7819 if (thread_still_needs_step_over (ecs
->event_thread
))
7822 ("thread [%s] still needs step-over",
7823 ecs
->event_thread
->ptid
.to_string ().c_str ());
7828 /* If scheduler locking applies even if not stepping, there's no
7829 need to walk over threads. Above we've checked whether the
7830 current thread is stepping. If some other thread not the
7831 event thread is stepping, then it must be that scheduler
7832 locking is not in effect. */
7833 if (schedlock_applies (ecs
->event_thread
))
7836 /* Otherwise, we no longer expect a trap in the current thread.
7837 Clear the trap_expected flag before switching back -- this is
7838 what keep_going does as well, if we call it. */
7839 ecs
->event_thread
->control
.trap_expected
= 0;
7841 /* Likewise, clear the signal if it should not be passed. */
7842 if (!signal_program
[ecs
->event_thread
->stop_signal ()])
7843 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
7845 if (restart_stepped_thread (ecs
->target
, ecs
->ptid
))
7847 prepare_to_wait (ecs
);
7851 switch_to_thread (ecs
->event_thread
);
7857 /* Look for the thread that was stepping, and resume it.
7858 RESUME_TARGET / RESUME_PTID indicate the set of threads the caller
7859 is resuming. Return true if a thread was started, false
7863 restart_stepped_thread (process_stratum_target
*resume_target
,
7866 /* Do all pending step-overs before actually proceeding with
7868 if (start_step_over ())
7871 for (thread_info
*tp
: all_threads_safe ())
7873 if (tp
->state
== THREAD_EXITED
)
7876 if (tp
->has_pending_waitstatus ())
7879 /* Ignore threads of processes the caller is not
7882 && (tp
->inf
->process_target () != resume_target
7883 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7886 if (tp
->control
.trap_expected
)
7888 infrun_debug_printf ("switching back to stepped thread (step-over)");
7890 if (keep_going_stepped_thread (tp
))
7895 for (thread_info
*tp
: all_threads_safe ())
7897 if (tp
->state
== THREAD_EXITED
)
7900 if (tp
->has_pending_waitstatus ())
7903 /* Ignore threads of processes the caller is not
7906 && (tp
->inf
->process_target () != resume_target
7907 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7910 /* Did we find the stepping thread? */
7911 if (tp
->control
.step_range_end
)
7913 infrun_debug_printf ("switching back to stepped thread (stepping)");
7915 if (keep_going_stepped_thread (tp
))
7926 restart_after_all_stop_detach (process_stratum_target
*proc_target
)
7928 /* Note we don't check target_is_non_stop_p() here, because the
7929 current inferior may no longer have a process_stratum target
7930 pushed, as we just detached. */
7932 /* See if we have a THREAD_RUNNING thread that need to be
7933 re-resumed. If we have any thread that is already executing,
7934 then we don't need to resume the target -- it is already been
7935 resumed. With the remote target (in all-stop), it's even
7936 impossible to issue another resumption if the target is already
7937 resumed, until the target reports a stop. */
7938 for (thread_info
*thr
: all_threads (proc_target
))
7940 if (thr
->state
!= THREAD_RUNNING
)
7943 /* If we have any thread that is already executing, then we
7944 don't need to resume the target -- it is already been
7946 if (thr
->executing ())
7949 /* If we have a pending event to process, skip resuming the
7950 target and go straight to processing it. */
7951 if (thr
->resumed () && thr
->has_pending_waitstatus ())
7955 /* Alright, we need to re-resume the target. If a thread was
7956 stepping, we need to restart it stepping. */
7957 if (restart_stepped_thread (proc_target
, minus_one_ptid
))
7960 /* Otherwise, find the first THREAD_RUNNING thread and resume
7962 for (thread_info
*thr
: all_threads (proc_target
))
7964 if (thr
->state
!= THREAD_RUNNING
)
7967 execution_control_state
ecs (thr
);
7968 switch_to_thread (thr
);
7974 /* Set a previously stepped thread back to stepping. Returns true on
7975 success, false if the resume is not possible (e.g., the thread
7979 keep_going_stepped_thread (struct thread_info
*tp
)
7981 frame_info_ptr frame
;
7983 /* If the stepping thread exited, then don't try to switch back and
7984 resume it, which could fail in several different ways depending
7985 on the target. Instead, just keep going.
7987 We can find a stepping dead thread in the thread list in two
7990 - The target supports thread exit events, and when the target
7991 tries to delete the thread from the thread list, inferior_ptid
7992 pointed at the exiting thread. In such case, calling
7993 delete_thread does not really remove the thread from the list;
7994 instead, the thread is left listed, with 'exited' state.
7996 - The target's debug interface does not support thread exit
7997 events, and so we have no idea whatsoever if the previously
7998 stepping thread is still alive. For that reason, we need to
7999 synchronously query the target now. */
8001 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
8003 infrun_debug_printf ("not resuming previously stepped thread, it has "
8010 infrun_debug_printf ("resuming previously stepped thread");
8012 execution_control_state
ecs (tp
);
8013 switch_to_thread (tp
);
8015 tp
->set_stop_pc (regcache_read_pc (get_thread_regcache (tp
)));
8016 frame
= get_current_frame ();
8018 /* If the PC of the thread we were trying to single-step has
8019 changed, then that thread has trapped or been signaled, but the
8020 event has not been reported to GDB yet. Re-poll the target
8021 looking for this particular thread's event (i.e. temporarily
8022 enable schedlock) by:
8024 - setting a break at the current PC
8025 - resuming that particular thread, only (by setting trap
8028 This prevents us continuously moving the single-step breakpoint
8029 forward, one instruction at a time, overstepping. */
8031 if (tp
->stop_pc () != tp
->prev_pc
)
8035 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
8036 paddress (current_inferior ()->arch (), tp
->prev_pc
),
8037 paddress (current_inferior ()->arch (),
8040 /* Clear the info of the previous step-over, as it's no longer
8041 valid (if the thread was trying to step over a breakpoint, it
8042 has already succeeded). It's what keep_going would do too,
8043 if we called it. Do this before trying to insert the sss
8044 breakpoint, otherwise if we were previously trying to step
8045 over this exact address in another thread, the breakpoint is
8047 clear_step_over_info ();
8048 tp
->control
.trap_expected
= 0;
8050 insert_single_step_breakpoint (get_frame_arch (frame
),
8051 get_frame_address_space (frame
),
8054 tp
->set_resumed (true);
8055 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
8056 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
8060 infrun_debug_printf ("expected thread still hasn't advanced");
8062 keep_going_pass_signal (&ecs
);
8068 /* Is thread TP in the middle of (software or hardware)
8069 single-stepping? (Note the result of this function must never be
8070 passed directly as target_resume's STEP parameter.) */
8073 currently_stepping (struct thread_info
*tp
)
8075 return ((tp
->control
.step_range_end
8076 && tp
->control
.step_resume_breakpoint
== nullptr)
8077 || tp
->control
.trap_expected
8078 || tp
->stepped_breakpoint
8079 || bpstat_should_step ());
8082 /* Inferior has stepped into a subroutine call with source code that
8083 we should not step over. Do step to the first line of code in
8087 handle_step_into_function (struct gdbarch
*gdbarch
,
8088 struct execution_control_state
*ecs
)
8090 fill_in_stop_func (gdbarch
, ecs
);
8092 compunit_symtab
*cust
8093 = find_pc_compunit_symtab (ecs
->event_thread
->stop_pc ());
8094 if (cust
!= nullptr && cust
->language () != language_asm
)
8095 ecs
->stop_func_start
8096 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
8098 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
8099 /* Use the step_resume_break to step until the end of the prologue,
8100 even if that involves jumps (as it seems to on the vax under
8102 /* If the prologue ends in the middle of a source line, continue to
8103 the end of that source line (if it is still within the function).
8104 Otherwise, just go to end of prologue. */
8105 if (stop_func_sal
.end
8106 && stop_func_sal
.pc
!= ecs
->stop_func_start
8107 && stop_func_sal
.end
< ecs
->stop_func_end
)
8108 ecs
->stop_func_start
= stop_func_sal
.end
;
8110 /* Architectures which require breakpoint adjustment might not be able
8111 to place a breakpoint at the computed address. If so, the test
8112 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
8113 ecs->stop_func_start to an address at which a breakpoint may be
8114 legitimately placed.
8116 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
8117 made, GDB will enter an infinite loop when stepping through
8118 optimized code consisting of VLIW instructions which contain
8119 subinstructions corresponding to different source lines. On
8120 FR-V, it's not permitted to place a breakpoint on any but the
8121 first subinstruction of a VLIW instruction. When a breakpoint is
8122 set, GDB will adjust the breakpoint address to the beginning of
8123 the VLIW instruction. Thus, we need to make the corresponding
8124 adjustment here when computing the stop address. */
8126 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
8128 ecs
->stop_func_start
8129 = gdbarch_adjust_breakpoint_address (gdbarch
,
8130 ecs
->stop_func_start
);
8133 if (ecs
->stop_func_start
== ecs
->event_thread
->stop_pc ())
8135 /* We are already there: stop now. */
8136 end_stepping_range (ecs
);
8141 /* Put the step-breakpoint there and go until there. */
8142 symtab_and_line sr_sal
;
8143 sr_sal
.pc
= ecs
->stop_func_start
;
8144 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
8145 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
8147 /* Do not specify what the fp should be when we stop since on
8148 some machines the prologue is where the new fp value is
8150 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
8152 /* And make sure stepping stops right away then. */
8153 ecs
->event_thread
->control
.step_range_end
8154 = ecs
->event_thread
->control
.step_range_start
;
8159 /* Inferior has stepped backward into a subroutine call with source
8160 code that we should not step over. Do step to the beginning of the
8161 last line of code in it. */
8164 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
8165 struct execution_control_state
*ecs
)
8167 struct compunit_symtab
*cust
;
8168 struct symtab_and_line stop_func_sal
;
8170 fill_in_stop_func (gdbarch
, ecs
);
8172 cust
= find_pc_compunit_symtab (ecs
->event_thread
->stop_pc ());
8173 if (cust
!= nullptr && cust
->language () != language_asm
)
8174 ecs
->stop_func_start
8175 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
8177 stop_func_sal
= find_pc_line (ecs
->event_thread
->stop_pc (), 0);
8179 /* OK, we're just going to keep stepping here. */
8180 if (stop_func_sal
.pc
== ecs
->event_thread
->stop_pc ())
8182 /* We're there already. Just stop stepping now. */
8183 end_stepping_range (ecs
);
8187 /* Else just reset the step range and keep going.
8188 No step-resume breakpoint, they don't work for
8189 epilogues, which can have multiple entry paths. */
8190 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
8191 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
8197 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
8198 This is used to both functions and to skip over code. */
8201 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
8202 struct symtab_and_line sr_sal
,
8203 struct frame_id sr_id
,
8204 enum bptype sr_type
)
8206 /* There should never be more than one step-resume or longjmp-resume
8207 breakpoint per thread, so we should never be setting a new
8208 step_resume_breakpoint when one is already active. */
8209 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== nullptr);
8210 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
8212 infrun_debug_printf ("inserting step-resume breakpoint at %s",
8213 paddress (gdbarch
, sr_sal
.pc
));
8215 inferior_thread ()->control
.step_resume_breakpoint
8216 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
8220 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
8221 struct symtab_and_line sr_sal
,
8222 struct frame_id sr_id
)
8224 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
8229 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
8230 This is used to skip a potential signal handler.
8232 This is called with the interrupted function's frame. The signal
8233 handler, when it returns, will resume the interrupted function at
8237 insert_hp_step_resume_breakpoint_at_frame (frame_info_ptr return_frame
)
8239 gdb_assert (return_frame
!= nullptr);
8241 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
8243 symtab_and_line sr_sal
;
8244 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
8245 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
8246 sr_sal
.pspace
= get_frame_program_space (return_frame
);
8248 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
8249 get_stack_frame_id (return_frame
),
8253 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
8254 is used to skip a function after stepping into it (for "next" or if
8255 the called function has no debugging information).
8257 The current function has almost always been reached by single
8258 stepping a call or return instruction. NEXT_FRAME belongs to the
8259 current function, and the breakpoint will be set at the caller's
8262 This is a separate function rather than reusing
8263 insert_hp_step_resume_breakpoint_at_frame in order to avoid
8264 get_prev_frame, which may stop prematurely (see the implementation
8265 of frame_unwind_caller_id for an example). */
8268 insert_step_resume_breakpoint_at_caller (frame_info_ptr next_frame
)
8270 /* We shouldn't have gotten here if we don't know where the call site
8272 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
8274 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
8276 symtab_and_line sr_sal
;
8277 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
8278 frame_unwind_caller_pc (next_frame
));
8279 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
8280 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
8282 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
8283 frame_unwind_caller_id (next_frame
));
8286 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
8287 new breakpoint at the target of a jmp_buf. The handling of
8288 longjmp-resume uses the same mechanisms used for handling
8289 "step-resume" breakpoints. */
8292 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
8294 /* There should never be more than one longjmp-resume breakpoint per
8295 thread, so we should never be setting a new
8296 longjmp_resume_breakpoint when one is already active. */
8297 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== nullptr);
8299 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
8300 paddress (gdbarch
, pc
));
8302 inferior_thread ()->control
.exception_resume_breakpoint
=
8303 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
8306 /* Insert an exception resume breakpoint. TP is the thread throwing
8307 the exception. The block B is the block of the unwinder debug hook
8308 function. FRAME is the frame corresponding to the call to this
8309 function. SYM is the symbol of the function argument holding the
8310 target PC of the exception. */
8313 insert_exception_resume_breakpoint (struct thread_info
*tp
,
8314 const struct block
*b
,
8315 frame_info_ptr frame
,
8320 struct block_symbol vsym
;
8321 struct value
*value
;
8323 struct breakpoint
*bp
;
8325 vsym
= lookup_symbol_search_name (sym
->search_name (),
8327 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
8328 /* If the value was optimized out, revert to the old behavior. */
8329 if (! value
->optimized_out ())
8331 handler
= value_as_address (value
);
8333 infrun_debug_printf ("exception resume at %lx",
8334 (unsigned long) handler
);
8336 /* set_momentary_breakpoint_at_pc creates a thread-specific
8337 breakpoint for the current inferior thread. */
8338 gdb_assert (tp
== inferior_thread ());
8339 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
8341 bp_exception_resume
).release ();
8343 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
8346 tp
->control
.exception_resume_breakpoint
= bp
;
8349 catch (const gdb_exception_error
&e
)
8351 /* We want to ignore errors here. */
8355 /* A helper for check_exception_resume that sets an
8356 exception-breakpoint based on a SystemTap probe. */
8359 insert_exception_resume_from_probe (struct thread_info
*tp
,
8360 const struct bound_probe
*probe
,
8361 frame_info_ptr frame
)
8363 struct value
*arg_value
;
8365 struct breakpoint
*bp
;
8367 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
8371 handler
= value_as_address (arg_value
);
8373 infrun_debug_printf ("exception resume at %s",
8374 paddress (probe
->objfile
->arch (), handler
));
8376 /* set_momentary_breakpoint_at_pc creates a thread-specific breakpoint
8377 for the current inferior thread. */
8378 gdb_assert (tp
== inferior_thread ());
8379 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
8380 handler
, bp_exception_resume
).release ();
8381 tp
->control
.exception_resume_breakpoint
= bp
;
8384 /* This is called when an exception has been intercepted. Check to
8385 see whether the exception's destination is of interest, and if so,
8386 set an exception resume breakpoint there. */
8389 check_exception_resume (struct execution_control_state
*ecs
,
8390 frame_info_ptr frame
)
8392 struct bound_probe probe
;
8393 struct symbol
*func
;
8395 /* First see if this exception unwinding breakpoint was set via a
8396 SystemTap probe point. If so, the probe has two arguments: the
8397 CFA and the HANDLER. We ignore the CFA, extract the handler, and
8398 set a breakpoint there. */
8399 probe
= find_probe_by_pc (get_frame_pc (frame
));
8402 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
8406 func
= get_frame_function (frame
);
8412 const struct block
*b
;
8415 /* The exception breakpoint is a thread-specific breakpoint on
8416 the unwinder's debug hook, declared as:
8418 void _Unwind_DebugHook (void *cfa, void *handler);
8420 The CFA argument indicates the frame to which control is
8421 about to be transferred. HANDLER is the destination PC.
8423 We ignore the CFA and set a temporary breakpoint at HANDLER.
8424 This is not extremely efficient but it avoids issues in gdb
8425 with computing the DWARF CFA, and it also works even in weird
8426 cases such as throwing an exception from inside a signal
8429 b
= func
->value_block ();
8430 for (struct symbol
*sym
: block_iterator_range (b
))
8432 if (!sym
->is_argument ())
8439 insert_exception_resume_breakpoint (ecs
->event_thread
,
8445 catch (const gdb_exception_error
&e
)
8451 stop_waiting (struct execution_control_state
*ecs
)
8453 infrun_debug_printf ("stop_waiting");
8455 /* Let callers know we don't want to wait for the inferior anymore. */
8456 ecs
->wait_some_more
= 0;
8459 /* Like keep_going, but passes the signal to the inferior, even if the
8460 signal is set to nopass. */
8463 keep_going_pass_signal (struct execution_control_state
*ecs
)
8465 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
8466 gdb_assert (!ecs
->event_thread
->resumed ());
8468 /* Save the pc before execution, to compare with pc after stop. */
8469 ecs
->event_thread
->prev_pc
8470 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
8472 if (ecs
->event_thread
->control
.trap_expected
)
8474 struct thread_info
*tp
= ecs
->event_thread
;
8476 infrun_debug_printf ("%s has trap_expected set, "
8477 "resuming to collect trap",
8478 tp
->ptid
.to_string ().c_str ());
8480 /* We haven't yet gotten our trap, and either: intercepted a
8481 non-signal event (e.g., a fork); or took a signal which we
8482 are supposed to pass through to the inferior. Simply
8484 resume (ecs
->event_thread
->stop_signal ());
8486 else if (step_over_info_valid_p ())
8488 /* Another thread is stepping over a breakpoint in-line. If
8489 this thread needs a step-over too, queue the request. In
8490 either case, this resume must be deferred for later. */
8491 struct thread_info
*tp
= ecs
->event_thread
;
8493 if (ecs
->hit_singlestep_breakpoint
8494 || thread_still_needs_step_over (tp
))
8496 infrun_debug_printf ("step-over already in progress: "
8497 "step-over for %s deferred",
8498 tp
->ptid
.to_string ().c_str ());
8499 global_thread_step_over_chain_enqueue (tp
);
8502 infrun_debug_printf ("step-over in progress: resume of %s deferred",
8503 tp
->ptid
.to_string ().c_str ());
8507 struct regcache
*regcache
= get_current_regcache ();
8510 step_over_what step_what
;
8512 /* Either the trap was not expected, but we are continuing
8513 anyway (if we got a signal, the user asked it be passed to
8516 We got our expected trap, but decided we should resume from
8519 We're going to run this baby now!
8521 Note that insert_breakpoints won't try to re-insert
8522 already inserted breakpoints. Therefore, we don't
8523 care if breakpoints were already inserted, or not. */
8525 /* If we need to step over a breakpoint, and we're not using
8526 displaced stepping to do so, insert all breakpoints
8527 (watchpoints, etc.) but the one we're stepping over, step one
8528 instruction, and then re-insert the breakpoint when that step
8531 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
8533 remove_bp
= (ecs
->hit_singlestep_breakpoint
8534 || (step_what
& STEP_OVER_BREAKPOINT
));
8535 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8537 /* We can't use displaced stepping if we need to step past a
8538 watchpoint. The instruction copied to the scratch pad would
8539 still trigger the watchpoint. */
8541 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8543 set_step_over_info (regcache
->aspace (),
8544 regcache_read_pc (regcache
), remove_wps
,
8545 ecs
->event_thread
->global_num
);
8547 else if (remove_wps
)
8548 set_step_over_info (nullptr, 0, remove_wps
, -1);
8550 /* If we now need to do an in-line step-over, we need to stop
8551 all other threads. Note this must be done before
8552 insert_breakpoints below, because that removes the breakpoint
8553 we're about to step over, otherwise other threads could miss
8555 if (step_over_info_valid_p () && target_is_non_stop_p ())
8556 stop_all_threads ("starting in-line step-over");
8558 /* Stop stepping if inserting breakpoints fails. */
8561 insert_breakpoints ();
8563 catch (const gdb_exception_error
&e
)
8565 exception_print (gdb_stderr
, e
);
8567 clear_step_over_info ();
8571 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8573 resume (ecs
->event_thread
->stop_signal ());
8576 prepare_to_wait (ecs
);
8579 /* Called when we should continue running the inferior, because the
8580 current event doesn't cause a user visible stop. This does the
8581 resuming part; waiting for the next event is done elsewhere. */
8584 keep_going (struct execution_control_state
*ecs
)
8586 if (ecs
->event_thread
->control
.trap_expected
8587 && ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
)
8588 ecs
->event_thread
->control
.trap_expected
= 0;
8590 if (!signal_program
[ecs
->event_thread
->stop_signal ()])
8591 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
8592 keep_going_pass_signal (ecs
);
8595 /* This function normally comes after a resume, before
8596 handle_inferior_event exits. It takes care of any last bits of
8597 housekeeping, and sets the all-important wait_some_more flag. */
8600 prepare_to_wait (struct execution_control_state
*ecs
)
8602 infrun_debug_printf ("prepare_to_wait");
8604 ecs
->wait_some_more
= 1;
8606 /* If the target can't async, emulate it by marking the infrun event
8607 handler such that as soon as we get back to the event-loop, we
8608 immediately end up in fetch_inferior_event again calling
8610 if (!target_can_async_p ())
8611 mark_infrun_async_event_handler ();
8614 /* We are done with the step range of a step/next/si/ni command.
8615 Called once for each n of a "step n" operation. */
8618 end_stepping_range (struct execution_control_state
*ecs
)
8620 ecs
->event_thread
->control
.stop_step
= 1;
8624 /* Several print_*_reason functions to print why the inferior has stopped.
8625 We always print something when the inferior exits, or receives a signal.
8626 The rest of the cases are dealt with later on in normal_stop and
8627 print_it_typical. Ideally there should be a call to one of these
8628 print_*_reason functions functions from handle_inferior_event each time
8629 stop_waiting is called.
8631 Note that we don't call these directly, instead we delegate that to
8632 the interpreters, through observers. Interpreters then call these
8633 with whatever uiout is right. */
8636 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8638 annotate_signalled ();
8639 if (uiout
->is_mi_like_p ())
8641 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8642 uiout
->text ("\nProgram terminated with signal ");
8643 annotate_signal_name ();
8644 uiout
->field_string ("signal-name",
8645 gdb_signal_to_name (siggnal
));
8646 annotate_signal_name_end ();
8648 annotate_signal_string ();
8649 uiout
->field_string ("signal-meaning",
8650 gdb_signal_to_string (siggnal
));
8651 annotate_signal_string_end ();
8652 uiout
->text (".\n");
8653 uiout
->text ("The program no longer exists.\n");
8657 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8659 struct inferior
*inf
= current_inferior ();
8660 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8662 annotate_exited (exitstatus
);
8665 if (uiout
->is_mi_like_p ())
8666 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8667 std::string exit_code_str
8668 = string_printf ("0%o", (unsigned int) exitstatus
);
8669 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8670 plongest (inf
->num
), pidstr
.c_str (),
8671 string_field ("exit-code", exit_code_str
.c_str ()));
8675 if (uiout
->is_mi_like_p ())
8677 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8678 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8679 plongest (inf
->num
), pidstr
.c_str ());
8684 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8686 struct thread_info
*thr
= inferior_thread ();
8688 infrun_debug_printf ("signal = %s", gdb_signal_to_string (siggnal
));
8692 if (uiout
->is_mi_like_p ())
8694 else if (show_thread_that_caused_stop ())
8696 uiout
->text ("\nThread ");
8697 uiout
->field_string ("thread-id", print_thread_id (thr
));
8699 const char *name
= thread_name (thr
);
8700 if (name
!= nullptr)
8702 uiout
->text (" \"");
8703 uiout
->field_string ("name", name
);
8708 uiout
->text ("\nProgram");
8710 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8711 uiout
->text (" stopped");
8714 uiout
->text (" received signal ");
8715 annotate_signal_name ();
8716 if (uiout
->is_mi_like_p ())
8718 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8719 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8720 annotate_signal_name_end ();
8722 annotate_signal_string ();
8723 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8725 struct regcache
*regcache
= get_current_regcache ();
8726 struct gdbarch
*gdbarch
= regcache
->arch ();
8727 if (gdbarch_report_signal_info_p (gdbarch
))
8728 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8730 annotate_signal_string_end ();
8732 uiout
->text (".\n");
8736 print_no_history_reason (struct ui_out
*uiout
)
8738 if (uiout
->is_mi_like_p ())
8739 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_NO_HISTORY
));
8741 uiout
->text ("\nNo more reverse-execution history.\n");
8744 /* Print current location without a level number, if we have changed
8745 functions or hit a breakpoint. Print source line if we have one.
8746 bpstat_print contains the logic deciding in detail what to print,
8747 based on the event(s) that just occurred. */
8750 print_stop_location (const target_waitstatus
&ws
)
8753 enum print_what source_flag
;
8754 int do_frame_printing
= 1;
8755 struct thread_info
*tp
= inferior_thread ();
8757 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
.kind ());
8761 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8762 should) carry around the function and does (or should) use
8763 that when doing a frame comparison. */
8764 if (tp
->control
.stop_step
8765 && (tp
->control
.step_frame_id
8766 == get_frame_id (get_current_frame ()))
8767 && (tp
->control
.step_start_function
8768 == find_pc_function (tp
->stop_pc ())))
8770 /* Finished step, just print source line. */
8771 source_flag
= SRC_LINE
;
8775 /* Print location and source line. */
8776 source_flag
= SRC_AND_LOC
;
8779 case PRINT_SRC_AND_LOC
:
8780 /* Print location and source line. */
8781 source_flag
= SRC_AND_LOC
;
8783 case PRINT_SRC_ONLY
:
8784 source_flag
= SRC_LINE
;
8787 /* Something bogus. */
8788 source_flag
= SRC_LINE
;
8789 do_frame_printing
= 0;
8792 internal_error (_("Unknown value."));
8795 /* The behavior of this routine with respect to the source
8797 SRC_LINE: Print only source line
8798 LOCATION: Print only location
8799 SRC_AND_LOC: Print location and source line. */
8800 if (do_frame_printing
)
8801 print_stack_frame (get_selected_frame (nullptr), 0, source_flag
, 1);
8807 print_stop_event (struct ui_out
*uiout
, bool displays
)
8809 struct target_waitstatus last
;
8810 struct thread_info
*tp
;
8812 get_last_target_status (nullptr, nullptr, &last
);
8815 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8817 print_stop_location (last
);
8819 /* Display the auto-display expressions. */
8824 tp
= inferior_thread ();
8825 if (tp
->thread_fsm () != nullptr
8826 && tp
->thread_fsm ()->finished_p ())
8828 struct return_value_info
*rv
;
8830 rv
= tp
->thread_fsm ()->return_value ();
8832 print_return_value (uiout
, rv
);
8839 maybe_remove_breakpoints (void)
8841 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8843 if (remove_breakpoints ())
8845 target_terminal::ours_for_output ();
8846 gdb_printf (_("Cannot remove breakpoints because "
8847 "program is no longer writable.\nFurther "
8848 "execution is probably impossible.\n"));
8853 /* The execution context that just caused a normal stop. */
8859 DISABLE_COPY_AND_ASSIGN (stop_context
);
8861 bool changed () const;
8866 /* The event PTID. */
8870 /* If stopp for a thread event, this is the thread that caused the
8872 thread_info_ref thread
;
8874 /* The inferior that caused the stop. */
8878 /* Initializes a new stop context. If stopped for a thread event, this
8879 takes a strong reference to the thread. */
8881 stop_context::stop_context ()
8883 stop_id
= get_stop_id ();
8884 ptid
= inferior_ptid
;
8885 inf_num
= current_inferior ()->num
;
8887 if (inferior_ptid
!= null_ptid
)
8889 /* Take a strong reference so that the thread can't be deleted
8891 thread
= thread_info_ref::new_reference (inferior_thread ());
8895 /* Return true if the current context no longer matches the saved stop
8899 stop_context::changed () const
8901 if (ptid
!= inferior_ptid
)
8903 if (inf_num
!= current_inferior ()->num
)
8905 if (thread
!= nullptr && thread
->state
!= THREAD_STOPPED
)
8907 if (get_stop_id () != stop_id
)
8917 struct target_waitstatus last
;
8919 get_last_target_status (nullptr, nullptr, &last
);
8923 /* If an exception is thrown from this point on, make sure to
8924 propagate GDB's knowledge of the executing state to the
8925 frontend/user running state. A QUIT is an easy exception to see
8926 here, so do this before any filtered output. */
8928 ptid_t finish_ptid
= null_ptid
;
8931 finish_ptid
= minus_one_ptid
;
8932 else if (last
.kind () == TARGET_WAITKIND_SIGNALLED
8933 || last
.kind () == TARGET_WAITKIND_EXITED
)
8935 /* On some targets, we may still have live threads in the
8936 inferior when we get a process exit event. E.g., for
8937 "checkpoint", when the current checkpoint/fork exits,
8938 linux-fork.c automatically switches to another fork from
8939 within target_mourn_inferior. */
8940 if (inferior_ptid
!= null_ptid
)
8941 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8943 else if (last
.kind () != TARGET_WAITKIND_NO_RESUMED
)
8944 finish_ptid
= inferior_ptid
;
8946 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8947 if (finish_ptid
!= null_ptid
)
8949 maybe_finish_thread_state
.emplace
8950 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8953 /* As we're presenting a stop, and potentially removing breakpoints,
8954 update the thread list so we can tell whether there are threads
8955 running on the target. With target remote, for example, we can
8956 only learn about new threads when we explicitly update the thread
8957 list. Do this before notifying the interpreters about signal
8958 stops, end of stepping ranges, etc., so that the "new thread"
8959 output is emitted before e.g., "Program received signal FOO",
8960 instead of after. */
8961 update_thread_list ();
8963 if (last
.kind () == TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8964 notify_signal_received (inferior_thread ()->stop_signal ());
8966 /* As with the notification of thread events, we want to delay
8967 notifying the user that we've switched thread context until
8968 the inferior actually stops.
8970 There's no point in saying anything if the inferior has exited.
8971 Note that SIGNALLED here means "exited with a signal", not
8972 "received a signal".
8974 Also skip saying anything in non-stop mode. In that mode, as we
8975 don't want GDB to switch threads behind the user's back, to avoid
8976 races where the user is typing a command to apply to thread x,
8977 but GDB switches to thread y before the user finishes entering
8978 the command, fetch_inferior_event installs a cleanup to restore
8979 the current thread back to the thread the user had selected right
8980 after this event is handled, so we're not really switching, only
8981 informing of a stop. */
8984 if ((last
.kind () != TARGET_WAITKIND_SIGNALLED
8985 && last
.kind () != TARGET_WAITKIND_EXITED
8986 && last
.kind () != TARGET_WAITKIND_NO_RESUMED
)
8987 && target_has_execution ()
8988 && previous_thread
!= inferior_thread ())
8990 SWITCH_THRU_ALL_UIS ()
8992 target_terminal::ours_for_output ();
8993 gdb_printf (_("[Switching to %s]\n"),
8994 target_pid_to_str (inferior_ptid
).c_str ());
8995 annotate_thread_changed ();
8999 update_previous_thread ();
9002 if (last
.kind () == TARGET_WAITKIND_NO_RESUMED
)
9004 SWITCH_THRU_ALL_UIS ()
9005 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
9007 target_terminal::ours_for_output ();
9008 gdb_printf (_("No unwaited-for children left.\n"));
9012 /* Note: this depends on the update_thread_list call above. */
9013 maybe_remove_breakpoints ();
9015 /* If an auto-display called a function and that got a signal,
9016 delete that auto-display to avoid an infinite recursion. */
9018 if (stopped_by_random_signal
)
9019 disable_current_display ();
9021 SWITCH_THRU_ALL_UIS ()
9023 async_enable_stdin ();
9026 /* Let the user/frontend see the threads as stopped. */
9027 maybe_finish_thread_state
.reset ();
9029 /* Select innermost stack frame - i.e., current frame is frame 0,
9030 and current location is based on that. Handle the case where the
9031 dummy call is returning after being stopped. E.g. the dummy call
9032 previously hit a breakpoint. (If the dummy call returns
9033 normally, we won't reach here.) Do this before the stop hook is
9034 run, so that it doesn't get to see the temporary dummy frame,
9035 which is not where we'll present the stop. */
9036 if (has_stack_frames ())
9038 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
9040 /* Pop the empty frame that contains the stack dummy. This
9041 also restores inferior state prior to the call (struct
9042 infcall_suspend_state). */
9043 frame_info_ptr frame
= get_current_frame ();
9045 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
9047 /* frame_pop calls reinit_frame_cache as the last thing it
9048 does which means there's now no selected frame. */
9051 select_frame (get_current_frame ());
9053 /* Set the current source location. */
9054 set_current_sal_from_frame (get_current_frame ());
9057 /* Look up the hook_stop and run it (CLI internally handles problem
9058 of stop_command's pre-hook not existing). */
9059 stop_context saved_context
;
9063 execute_cmd_pre_hook (stop_command
);
9065 catch (const gdb_exception_error
&ex
)
9067 exception_fprintf (gdb_stderr
, ex
,
9068 "Error while running hook_stop:\n");
9071 /* If the stop hook resumes the target, then there's no point in
9072 trying to notify about the previous stop; its context is
9073 gone. Likewise if the command switches thread or inferior --
9074 the observers would print a stop for the wrong
9076 if (saved_context
.changed ())
9079 /* Notify observers about the stop. This is where the interpreters
9080 print the stop event. */
9081 notify_normal_stop ((inferior_ptid
!= null_ptid
9082 ? inferior_thread ()->control
.stop_bpstat
9085 annotate_stopped ();
9087 if (target_has_execution ())
9089 if (last
.kind () != TARGET_WAITKIND_SIGNALLED
9090 && last
.kind () != TARGET_WAITKIND_EXITED
9091 && last
.kind () != TARGET_WAITKIND_NO_RESUMED
)
9092 /* Delete the breakpoint we stopped at, if it wants to be deleted.
9093 Delete any breakpoint that is to be deleted at the next stop. */
9094 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
9101 signal_stop_state (int signo
)
9103 return signal_stop
[signo
];
9107 signal_print_state (int signo
)
9109 return signal_print
[signo
];
9113 signal_pass_state (int signo
)
9115 return signal_program
[signo
];
9119 signal_cache_update (int signo
)
9123 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
9124 signal_cache_update (signo
);
9129 signal_pass
[signo
] = (signal_stop
[signo
] == 0
9130 && signal_print
[signo
] == 0
9131 && signal_program
[signo
] == 1
9132 && signal_catch
[signo
] == 0);
9136 signal_stop_update (int signo
, int state
)
9138 int ret
= signal_stop
[signo
];
9140 signal_stop
[signo
] = state
;
9141 signal_cache_update (signo
);
9146 signal_print_update (int signo
, int state
)
9148 int ret
= signal_print
[signo
];
9150 signal_print
[signo
] = state
;
9151 signal_cache_update (signo
);
9156 signal_pass_update (int signo
, int state
)
9158 int ret
= signal_program
[signo
];
9160 signal_program
[signo
] = state
;
9161 signal_cache_update (signo
);
9165 /* Update the global 'signal_catch' from INFO and notify the
9169 signal_catch_update (const unsigned int *info
)
9173 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
9174 signal_catch
[i
] = info
[i
] > 0;
9175 signal_cache_update (-1);
9176 target_pass_signals (signal_pass
);
9180 sig_print_header (void)
9182 gdb_printf (_("Signal Stop\tPrint\tPass "
9183 "to program\tDescription\n"));
9187 sig_print_info (enum gdb_signal oursig
)
9189 const char *name
= gdb_signal_to_name (oursig
);
9190 int name_padding
= 13 - strlen (name
);
9192 if (name_padding
<= 0)
9195 gdb_printf ("%s", name
);
9196 gdb_printf ("%*.*s ", name_padding
, name_padding
, " ");
9197 gdb_printf ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
9198 gdb_printf ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
9199 gdb_printf ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
9200 gdb_printf ("%s\n", gdb_signal_to_string (oursig
));
9203 /* Specify how various signals in the inferior should be handled. */
9206 handle_command (const char *args
, int from_tty
)
9208 int digits
, wordlen
;
9209 int sigfirst
, siglast
;
9210 enum gdb_signal oursig
;
9213 if (args
== nullptr)
9215 error_no_arg (_("signal to handle"));
9218 /* Allocate and zero an array of flags for which signals to handle. */
9220 const size_t nsigs
= GDB_SIGNAL_LAST
;
9221 unsigned char sigs
[nsigs
] {};
9223 /* Break the command line up into args. */
9225 gdb_argv
built_argv (args
);
9227 /* Walk through the args, looking for signal oursigs, signal names, and
9228 actions. Signal numbers and signal names may be interspersed with
9229 actions, with the actions being performed for all signals cumulatively
9230 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
9232 for (char *arg
: built_argv
)
9234 wordlen
= strlen (arg
);
9235 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
9239 sigfirst
= siglast
= -1;
9241 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
9243 /* Apply action to all signals except those used by the
9244 debugger. Silently skip those. */
9247 siglast
= nsigs
- 1;
9249 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
9251 SET_SIGS (nsigs
, sigs
, signal_stop
);
9252 SET_SIGS (nsigs
, sigs
, signal_print
);
9254 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
9256 UNSET_SIGS (nsigs
, sigs
, signal_program
);
9258 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
9260 SET_SIGS (nsigs
, sigs
, signal_print
);
9262 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
9264 SET_SIGS (nsigs
, sigs
, signal_program
);
9266 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
9268 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
9270 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
9272 SET_SIGS (nsigs
, sigs
, signal_program
);
9274 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
9276 UNSET_SIGS (nsigs
, sigs
, signal_print
);
9277 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
9279 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
9281 UNSET_SIGS (nsigs
, sigs
, signal_program
);
9283 else if (digits
> 0)
9285 /* It is numeric. The numeric signal refers to our own
9286 internal signal numbering from target.h, not to host/target
9287 signal number. This is a feature; users really should be
9288 using symbolic names anyway, and the common ones like
9289 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
9291 sigfirst
= siglast
= (int)
9292 gdb_signal_from_command (atoi (arg
));
9293 if (arg
[digits
] == '-')
9296 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
9298 if (sigfirst
> siglast
)
9300 /* Bet he didn't figure we'd think of this case... */
9301 std::swap (sigfirst
, siglast
);
9306 oursig
= gdb_signal_from_name (arg
);
9307 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
9309 sigfirst
= siglast
= (int) oursig
;
9313 /* Not a number and not a recognized flag word => complain. */
9314 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
9318 /* If any signal numbers or symbol names were found, set flags for
9319 which signals to apply actions to. */
9321 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
9323 switch ((enum gdb_signal
) signum
)
9325 case GDB_SIGNAL_TRAP
:
9326 case GDB_SIGNAL_INT
:
9327 if (!allsigs
&& !sigs
[signum
])
9329 if (query (_("%s is used by the debugger.\n\
9330 Are you sure you want to change it? "),
9331 gdb_signal_to_name ((enum gdb_signal
) signum
)))
9336 gdb_printf (_("Not confirmed, unchanged.\n"));
9340 case GDB_SIGNAL_DEFAULT
:
9341 case GDB_SIGNAL_UNKNOWN
:
9342 /* Make sure that "all" doesn't print these. */
9351 for (int signum
= 0; signum
< nsigs
; signum
++)
9354 signal_cache_update (-1);
9355 target_pass_signals (signal_pass
);
9356 target_program_signals (signal_program
);
9360 /* Show the results. */
9361 sig_print_header ();
9362 for (; signum
< nsigs
; signum
++)
9364 sig_print_info ((enum gdb_signal
) signum
);
9371 /* Complete the "handle" command. */
9374 handle_completer (struct cmd_list_element
*ignore
,
9375 completion_tracker
&tracker
,
9376 const char *text
, const char *word
)
9378 static const char * const keywords
[] =
9392 signal_completer (ignore
, tracker
, text
, word
);
9393 complete_on_enum (tracker
, keywords
, word
, word
);
9397 gdb_signal_from_command (int num
)
9399 if (num
>= 1 && num
<= 15)
9400 return (enum gdb_signal
) num
;
9401 error (_("Only signals 1-15 are valid as numeric signals.\n\
9402 Use \"info signals\" for a list of symbolic signals."));
9405 /* Print current contents of the tables set by the handle command.
9406 It is possible we should just be printing signals actually used
9407 by the current target (but for things to work right when switching
9408 targets, all signals should be in the signal tables). */
9411 info_signals_command (const char *signum_exp
, int from_tty
)
9413 enum gdb_signal oursig
;
9415 sig_print_header ();
9419 /* First see if this is a symbol name. */
9420 oursig
= gdb_signal_from_name (signum_exp
);
9421 if (oursig
== GDB_SIGNAL_UNKNOWN
)
9423 /* No, try numeric. */
9425 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
9427 sig_print_info (oursig
);
9432 /* These ugly casts brought to you by the native VAX compiler. */
9433 for (oursig
= GDB_SIGNAL_FIRST
;
9434 (int) oursig
< (int) GDB_SIGNAL_LAST
;
9435 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
9439 if (oursig
!= GDB_SIGNAL_UNKNOWN
9440 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
9441 sig_print_info (oursig
);
9444 gdb_printf (_("\nUse the \"handle\" command "
9445 "to change these tables.\n"));
9448 /* The $_siginfo convenience variable is a bit special. We don't know
9449 for sure the type of the value until we actually have a chance to
9450 fetch the data. The type can change depending on gdbarch, so it is
9451 also dependent on which thread you have selected.
9453 1. making $_siginfo be an internalvar that creates a new value on
9456 2. making the value of $_siginfo be an lval_computed value. */
9458 /* This function implements the lval_computed support for reading a
9462 siginfo_value_read (struct value
*v
)
9464 LONGEST transferred
;
9466 /* If we can access registers, so can we access $_siginfo. Likewise
9468 validate_registers_access ();
9471 target_read (current_inferior ()->top_target (),
9472 TARGET_OBJECT_SIGNAL_INFO
,
9474 v
->contents_all_raw ().data (),
9476 v
->type ()->length ());
9478 if (transferred
!= v
->type ()->length ())
9479 error (_("Unable to read siginfo"));
9482 /* This function implements the lval_computed support for writing a
9486 siginfo_value_write (struct value
*v
, struct value
*fromval
)
9488 LONGEST transferred
;
9490 /* If we can access registers, so can we access $_siginfo. Likewise
9492 validate_registers_access ();
9494 transferred
= target_write (current_inferior ()->top_target (),
9495 TARGET_OBJECT_SIGNAL_INFO
,
9497 fromval
->contents_all_raw ().data (),
9499 fromval
->type ()->length ());
9501 if (transferred
!= fromval
->type ()->length ())
9502 error (_("Unable to write siginfo"));
9505 static const struct lval_funcs siginfo_value_funcs
=
9511 /* Return a new value with the correct type for the siginfo object of
9512 the current thread using architecture GDBARCH. Return a void value
9513 if there's no object available. */
9515 static struct value
*
9516 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9519 if (target_has_stack ()
9520 && inferior_ptid
!= null_ptid
9521 && gdbarch_get_siginfo_type_p (gdbarch
))
9523 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9525 return value::allocate_computed (type
, &siginfo_value_funcs
, nullptr);
9528 return value::allocate (builtin_type (gdbarch
)->builtin_void
);
9532 /* infcall_suspend_state contains state about the program itself like its
9533 registers and any signal it received when it last stopped.
9534 This state must be restored regardless of how the inferior function call
9535 ends (either successfully, or after it hits a breakpoint or signal)
9536 if the program is to properly continue where it left off. */
9538 class infcall_suspend_state
9541 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9542 once the inferior function call has finished. */
9543 infcall_suspend_state (struct gdbarch
*gdbarch
,
9544 const struct thread_info
*tp
,
9545 struct regcache
*regcache
)
9546 : m_registers (new readonly_detached_regcache (*regcache
))
9548 tp
->save_suspend_to (m_thread_suspend
);
9550 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9552 if (gdbarch_get_siginfo_type_p (gdbarch
))
9554 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9555 size_t len
= type
->length ();
9557 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9559 if (target_read (current_inferior ()->top_target (),
9560 TARGET_OBJECT_SIGNAL_INFO
, nullptr,
9561 siginfo_data
.get (), 0, len
) != len
)
9563 /* Errors ignored. */
9564 siginfo_data
.reset (nullptr);
9570 m_siginfo_gdbarch
= gdbarch
;
9571 m_siginfo_data
= std::move (siginfo_data
);
9575 /* Return a pointer to the stored register state. */
9577 readonly_detached_regcache
*registers () const
9579 return m_registers
.get ();
9582 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9584 void restore (struct gdbarch
*gdbarch
,
9585 struct thread_info
*tp
,
9586 struct regcache
*regcache
) const
9588 tp
->restore_suspend_from (m_thread_suspend
);
9590 if (m_siginfo_gdbarch
== gdbarch
)
9592 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9594 /* Errors ignored. */
9595 target_write (current_inferior ()->top_target (),
9596 TARGET_OBJECT_SIGNAL_INFO
, nullptr,
9597 m_siginfo_data
.get (), 0, type
->length ());
9600 /* The inferior can be gone if the user types "print exit(0)"
9601 (and perhaps other times). */
9602 if (target_has_execution ())
9603 /* NB: The register write goes through to the target. */
9604 regcache
->restore (registers ());
9608 /* How the current thread stopped before the inferior function call was
9610 struct thread_suspend_state m_thread_suspend
;
9612 /* The registers before the inferior function call was executed. */
9613 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9615 /* Format of SIGINFO_DATA or NULL if it is not present. */
9616 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9618 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9619 gdbarch_get_siginfo_type ()->length (). For different gdbarch the
9620 content would be invalid. */
9621 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9624 infcall_suspend_state_up
9625 save_infcall_suspend_state ()
9627 struct thread_info
*tp
= inferior_thread ();
9628 struct regcache
*regcache
= get_current_regcache ();
9629 struct gdbarch
*gdbarch
= regcache
->arch ();
9631 infcall_suspend_state_up inf_state
9632 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9634 /* Having saved the current state, adjust the thread state, discarding
9635 any stop signal information. The stop signal is not useful when
9636 starting an inferior function call, and run_inferior_call will not use
9637 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9638 tp
->set_stop_signal (GDB_SIGNAL_0
);
9643 /* Restore inferior session state to INF_STATE. */
9646 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9648 struct thread_info
*tp
= inferior_thread ();
9649 struct regcache
*regcache
= get_current_regcache ();
9650 struct gdbarch
*gdbarch
= regcache
->arch ();
9652 inf_state
->restore (gdbarch
, tp
, regcache
);
9653 discard_infcall_suspend_state (inf_state
);
9657 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9662 readonly_detached_regcache
*
9663 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9665 return inf_state
->registers ();
9668 /* infcall_control_state contains state regarding gdb's control of the
9669 inferior itself like stepping control. It also contains session state like
9670 the user's currently selected frame. */
9672 struct infcall_control_state
9674 struct thread_control_state thread_control
;
9675 struct inferior_control_state inferior_control
;
9678 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9679 int stopped_by_random_signal
= 0;
9681 /* ID and level of the selected frame when the inferior function
9683 struct frame_id selected_frame_id
{};
9684 int selected_frame_level
= -1;
9687 /* Save all of the information associated with the inferior<==>gdb
9690 infcall_control_state_up
9691 save_infcall_control_state ()
9693 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9694 struct thread_info
*tp
= inferior_thread ();
9695 struct inferior
*inf
= current_inferior ();
9697 inf_status
->thread_control
= tp
->control
;
9698 inf_status
->inferior_control
= inf
->control
;
9700 tp
->control
.step_resume_breakpoint
= nullptr;
9701 tp
->control
.exception_resume_breakpoint
= nullptr;
9703 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9704 chain. If caller's caller is walking the chain, they'll be happier if we
9705 hand them back the original chain when restore_infcall_control_state is
9707 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9710 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9711 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9713 save_selected_frame (&inf_status
->selected_frame_id
,
9714 &inf_status
->selected_frame_level
);
9719 /* Restore inferior session state to INF_STATUS. */
9722 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9724 struct thread_info
*tp
= inferior_thread ();
9725 struct inferior
*inf
= current_inferior ();
9727 if (tp
->control
.step_resume_breakpoint
)
9728 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9730 if (tp
->control
.exception_resume_breakpoint
)
9731 tp
->control
.exception_resume_breakpoint
->disposition
9732 = disp_del_at_next_stop
;
9734 /* Handle the bpstat_copy of the chain. */
9735 bpstat_clear (&tp
->control
.stop_bpstat
);
9737 tp
->control
= inf_status
->thread_control
;
9738 inf
->control
= inf_status
->inferior_control
;
9741 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9742 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9744 if (target_has_stack ())
9746 restore_selected_frame (inf_status
->selected_frame_id
,
9747 inf_status
->selected_frame_level
);
9754 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9756 if (inf_status
->thread_control
.step_resume_breakpoint
)
9757 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9758 = disp_del_at_next_stop
;
9760 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9761 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9762 = disp_del_at_next_stop
;
9764 /* See save_infcall_control_state for info on stop_bpstat. */
9765 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9773 clear_exit_convenience_vars (void)
9775 clear_internalvar (lookup_internalvar ("_exitsignal"));
9776 clear_internalvar (lookup_internalvar ("_exitcode"));
9780 /* User interface for reverse debugging:
9781 Set exec-direction / show exec-direction commands
9782 (returns error unless target implements to_set_exec_direction method). */
9784 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9785 static const char exec_forward
[] = "forward";
9786 static const char exec_reverse
[] = "reverse";
9787 static const char *exec_direction
= exec_forward
;
9788 static const char *const exec_direction_names
[] = {
9795 set_exec_direction_func (const char *args
, int from_tty
,
9796 struct cmd_list_element
*cmd
)
9798 if (target_can_execute_reverse ())
9800 if (!strcmp (exec_direction
, exec_forward
))
9801 execution_direction
= EXEC_FORWARD
;
9802 else if (!strcmp (exec_direction
, exec_reverse
))
9803 execution_direction
= EXEC_REVERSE
;
9807 exec_direction
= exec_forward
;
9808 error (_("Target does not support this operation."));
9813 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9814 struct cmd_list_element
*cmd
, const char *value
)
9816 switch (execution_direction
) {
9818 gdb_printf (out
, _("Forward.\n"));
9821 gdb_printf (out
, _("Reverse.\n"));
9824 internal_error (_("bogus execution_direction value: %d"),
9825 (int) execution_direction
);
9830 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9831 struct cmd_list_element
*c
, const char *value
)
9833 gdb_printf (file
, _("Resuming the execution of threads "
9834 "of all processes is %s.\n"), value
);
9837 /* Implementation of `siginfo' variable. */
9839 static const struct internalvar_funcs siginfo_funcs
=
9845 /* Callback for infrun's target events source. This is marked when a
9846 thread has a pending status to process. */
9849 infrun_async_inferior_event_handler (gdb_client_data data
)
9851 clear_async_event_handler (infrun_async_inferior_event_token
);
9852 inferior_event_handler (INF_REG_EVENT
);
9859 /* Verify that when two threads with the same ptid exist (from two different
9860 targets) and one of them changes ptid, we only update inferior_ptid if
9861 it is appropriate. */
9864 infrun_thread_ptid_changed ()
9866 gdbarch
*arch
= current_inferior ()->arch ();
9868 /* The thread which inferior_ptid represents changes ptid. */
9870 scoped_restore_current_pspace_and_thread restore
;
9872 scoped_mock_context
<test_target_ops
> target1 (arch
);
9873 scoped_mock_context
<test_target_ops
> target2 (arch
);
9875 ptid_t
old_ptid (111, 222);
9876 ptid_t
new_ptid (111, 333);
9878 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9879 target1
.mock_thread
.ptid
= old_ptid
;
9880 target1
.mock_inferior
.ptid_thread_map
.clear ();
9881 target1
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target1
.mock_thread
;
9883 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9884 target2
.mock_thread
.ptid
= old_ptid
;
9885 target2
.mock_inferior
.ptid_thread_map
.clear ();
9886 target2
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target2
.mock_thread
;
9888 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9889 set_current_inferior (&target1
.mock_inferior
);
9891 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9893 gdb_assert (inferior_ptid
== new_ptid
);
9896 /* A thread with the same ptid as inferior_ptid, but from another target,
9899 scoped_restore_current_pspace_and_thread restore
;
9901 scoped_mock_context
<test_target_ops
> target1 (arch
);
9902 scoped_mock_context
<test_target_ops
> target2 (arch
);
9904 ptid_t
old_ptid (111, 222);
9905 ptid_t
new_ptid (111, 333);
9907 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9908 target1
.mock_thread
.ptid
= old_ptid
;
9909 target1
.mock_inferior
.ptid_thread_map
.clear ();
9910 target1
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target1
.mock_thread
;
9912 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9913 target2
.mock_thread
.ptid
= old_ptid
;
9914 target2
.mock_inferior
.ptid_thread_map
.clear ();
9915 target2
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target2
.mock_thread
;
9917 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9918 set_current_inferior (&target2
.mock_inferior
);
9920 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9922 gdb_assert (inferior_ptid
== old_ptid
);
9926 } /* namespace selftests */
9928 #endif /* GDB_SELF_TEST */
9930 void _initialize_infrun ();
9932 _initialize_infrun ()
9934 struct cmd_list_element
*c
;
9936 /* Register extra event sources in the event loop. */
9937 infrun_async_inferior_event_token
9938 = create_async_event_handler (infrun_async_inferior_event_handler
, nullptr,
9941 cmd_list_element
*info_signals_cmd
9942 = add_info ("signals", info_signals_command
, _("\
9943 What debugger does when program gets various signals.\n\
9944 Specify a signal as argument to print info on that signal only."));
9945 add_info_alias ("handle", info_signals_cmd
, 0);
9947 c
= add_com ("handle", class_run
, handle_command
, _("\
9948 Specify how to handle signals.\n\
9949 Usage: handle SIGNAL [ACTIONS]\n\
9950 Args are signals and actions to apply to those signals.\n\
9951 If no actions are specified, the current settings for the specified signals\n\
9952 will be displayed instead.\n\
9954 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9955 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9956 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9957 The special arg \"all\" is recognized to mean all signals except those\n\
9958 used by the debugger, typically SIGTRAP and SIGINT.\n\
9960 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9961 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9962 Stop means reenter debugger if this signal happens (implies print).\n\
9963 Print means print a message if this signal happens.\n\
9964 Pass means let program see this signal; otherwise program doesn't know.\n\
9965 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9966 Pass and Stop may be combined.\n\
9968 Multiple signals may be specified. Signal numbers and signal names\n\
9969 may be interspersed with actions, with the actions being performed for\n\
9970 all signals cumulatively specified."));
9971 set_cmd_completer (c
, handle_completer
);
9973 stop_command
= add_cmd ("stop", class_obscure
,
9974 not_just_help_class_command
, _("\
9975 There is no `stop' command, but you can set a hook on `stop'.\n\
9976 This allows you to set a list of commands to be run each time execution\n\
9977 of the program stops."), &cmdlist
);
9979 add_setshow_boolean_cmd
9980 ("infrun", class_maintenance
, &debug_infrun
,
9981 _("Set inferior debugging."),
9982 _("Show inferior debugging."),
9983 _("When non-zero, inferior specific debugging is enabled."),
9984 nullptr, show_debug_infrun
, &setdebuglist
, &showdebuglist
);
9986 add_setshow_boolean_cmd ("non-stop", no_class
,
9988 Set whether gdb controls the inferior in non-stop mode."), _("\
9989 Show whether gdb controls the inferior in non-stop mode."), _("\
9990 When debugging a multi-threaded program and this setting is\n\
9991 off (the default, also called all-stop mode), when one thread stops\n\
9992 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9993 all other threads in the program while you interact with the thread of\n\
9994 interest. When you continue or step a thread, you can allow the other\n\
9995 threads to run, or have them remain stopped, but while you inspect any\n\
9996 thread's state, all threads stop.\n\
9998 In non-stop mode, when one thread stops, other threads can continue\n\
9999 to run freely. You'll be able to step each thread independently,\n\
10000 leave it stopped or free to run as needed."),
10006 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
10008 signal_stop
[i
] = 1;
10009 signal_print
[i
] = 1;
10010 signal_program
[i
] = 1;
10011 signal_catch
[i
] = 0;
10014 /* Signals caused by debugger's own actions should not be given to
10015 the program afterwards.
10017 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
10018 explicitly specifies that it should be delivered to the target
10019 program. Typically, that would occur when a user is debugging a
10020 target monitor on a simulator: the target monitor sets a
10021 breakpoint; the simulator encounters this breakpoint and halts
10022 the simulation handing control to GDB; GDB, noting that the stop
10023 address doesn't map to any known breakpoint, returns control back
10024 to the simulator; the simulator then delivers the hardware
10025 equivalent of a GDB_SIGNAL_TRAP to the program being
10027 signal_program
[GDB_SIGNAL_TRAP
] = 0;
10028 signal_program
[GDB_SIGNAL_INT
] = 0;
10030 /* Signals that are not errors should not normally enter the debugger. */
10031 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
10032 signal_print
[GDB_SIGNAL_ALRM
] = 0;
10033 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
10034 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
10035 signal_stop
[GDB_SIGNAL_PROF
] = 0;
10036 signal_print
[GDB_SIGNAL_PROF
] = 0;
10037 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
10038 signal_print
[GDB_SIGNAL_CHLD
] = 0;
10039 signal_stop
[GDB_SIGNAL_IO
] = 0;
10040 signal_print
[GDB_SIGNAL_IO
] = 0;
10041 signal_stop
[GDB_SIGNAL_POLL
] = 0;
10042 signal_print
[GDB_SIGNAL_POLL
] = 0;
10043 signal_stop
[GDB_SIGNAL_URG
] = 0;
10044 signal_print
[GDB_SIGNAL_URG
] = 0;
10045 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
10046 signal_print
[GDB_SIGNAL_WINCH
] = 0;
10047 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
10048 signal_print
[GDB_SIGNAL_PRIO
] = 0;
10050 /* These signals are used internally by user-level thread
10051 implementations. (See signal(5) on Solaris.) Like the above
10052 signals, a healthy program receives and handles them as part of
10053 its normal operation. */
10054 signal_stop
[GDB_SIGNAL_LWP
] = 0;
10055 signal_print
[GDB_SIGNAL_LWP
] = 0;
10056 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
10057 signal_print
[GDB_SIGNAL_WAITING
] = 0;
10058 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
10059 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
10060 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
10061 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
10063 /* Update cached state. */
10064 signal_cache_update (-1);
10066 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
10067 &stop_on_solib_events
, _("\
10068 Set stopping for shared library events."), _("\
10069 Show stopping for shared library events."), _("\
10070 If nonzero, gdb will give control to the user when the dynamic linker\n\
10071 notifies gdb of shared library events. The most common event of interest\n\
10072 to the user would be loading/unloading of a new library."),
10073 set_stop_on_solib_events
,
10074 show_stop_on_solib_events
,
10075 &setlist
, &showlist
);
10077 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
10078 follow_fork_mode_kind_names
,
10079 &follow_fork_mode_string
, _("\
10080 Set debugger response to a program call of fork or vfork."), _("\
10081 Show debugger response to a program call of fork or vfork."), _("\
10082 A fork or vfork creates a new process. follow-fork-mode can be:\n\
10083 parent - the original process is debugged after a fork\n\
10084 child - the new process is debugged after a fork\n\
10085 The unfollowed process will continue to run.\n\
10086 By default, the debugger will follow the parent process."),
10088 show_follow_fork_mode_string
,
10089 &setlist
, &showlist
);
10091 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
10092 follow_exec_mode_names
,
10093 &follow_exec_mode_string
, _("\
10094 Set debugger response to a program call of exec."), _("\
10095 Show debugger response to a program call of exec."), _("\
10096 An exec call replaces the program image of a process.\n\
10098 follow-exec-mode can be:\n\
10100 new - the debugger creates a new inferior and rebinds the process\n\
10101 to this new inferior. The program the process was running before\n\
10102 the exec call can be restarted afterwards by restarting the original\n\
10105 same - the debugger keeps the process bound to the same inferior.\n\
10106 The new executable image replaces the previous executable loaded in\n\
10107 the inferior. Restarting the inferior after the exec call restarts\n\
10108 the executable the process was running after the exec call.\n\
10110 By default, the debugger will use the same inferior."),
10112 show_follow_exec_mode_string
,
10113 &setlist
, &showlist
);
10115 add_setshow_enum_cmd ("scheduler-locking", class_run
,
10116 scheduler_enums
, &scheduler_mode
, _("\
10117 Set mode for locking scheduler during execution."), _("\
10118 Show mode for locking scheduler during execution."), _("\
10119 off == no locking (threads may preempt at any time)\n\
10120 on == full locking (no thread except the current thread may run)\n\
10121 This applies to both normal execution and replay mode.\n\
10122 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
10123 In this mode, other threads may run during other commands.\n\
10124 This applies to both normal execution and replay mode.\n\
10125 replay == scheduler locked in replay mode and unlocked during normal execution."),
10126 set_schedlock_func
, /* traps on target vector */
10127 show_scheduler_mode
,
10128 &setlist
, &showlist
);
10130 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
10131 Set mode for resuming threads of all processes."), _("\
10132 Show mode for resuming threads of all processes."), _("\
10133 When on, execution commands (such as 'continue' or 'next') resume all\n\
10134 threads of all processes. When off (which is the default), execution\n\
10135 commands only resume the threads of the current process. The set of\n\
10136 threads that are resumed is further refined by the scheduler-locking\n\
10137 mode (see help set scheduler-locking)."),
10139 show_schedule_multiple
,
10140 &setlist
, &showlist
);
10142 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
10143 Set mode of the step operation."), _("\
10144 Show mode of the step operation."), _("\
10145 When set, doing a step over a function without debug line information\n\
10146 will stop at the first instruction of that function. Otherwise, the\n\
10147 function is skipped and the step command stops at a different source line."),
10149 show_step_stop_if_no_debug
,
10150 &setlist
, &showlist
);
10152 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
10153 &can_use_displaced_stepping
, _("\
10154 Set debugger's willingness to use displaced stepping."), _("\
10155 Show debugger's willingness to use displaced stepping."), _("\
10156 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
10157 supported by the target architecture. If off, gdb will not use displaced\n\
10158 stepping to step over breakpoints, even if such is supported by the target\n\
10159 architecture. If auto (which is the default), gdb will use displaced stepping\n\
10160 if the target architecture supports it and non-stop mode is active, but will not\n\
10161 use it in all-stop mode (see help set non-stop)."),
10163 show_can_use_displaced_stepping
,
10164 &setlist
, &showlist
);
10166 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
10167 &exec_direction
, _("Set direction of execution.\n\
10168 Options are 'forward' or 'reverse'."),
10169 _("Show direction of execution (forward/reverse)."),
10170 _("Tells gdb whether to execute forward or backward."),
10171 set_exec_direction_func
, show_exec_direction_func
,
10172 &setlist
, &showlist
);
10174 /* Set/show detach-on-fork: user-settable mode. */
10176 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
10177 Set whether gdb will detach the child of a fork."), _("\
10178 Show whether gdb will detach the child of a fork."), _("\
10179 Tells gdb whether to detach the child of a fork."),
10180 nullptr, nullptr, &setlist
, &showlist
);
10182 /* Set/show disable address space randomization mode. */
10184 add_setshow_boolean_cmd ("disable-randomization", class_support
,
10185 &disable_randomization
, _("\
10186 Set disabling of debuggee's virtual address space randomization."), _("\
10187 Show disabling of debuggee's virtual address space randomization."), _("\
10188 When this mode is on (which is the default), randomization of the virtual\n\
10189 address space is disabled. Standalone programs run with the randomization\n\
10190 enabled by default on some platforms."),
10191 &set_disable_randomization
,
10192 &show_disable_randomization
,
10193 &setlist
, &showlist
);
10195 /* ptid initializations */
10196 inferior_ptid
= null_ptid
;
10197 target_last_wait_ptid
= minus_one_ptid
;
10199 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
,
10201 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
,
10203 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
, "infrun");
10204 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
, "infrun");
10206 /* Explicitly create without lookup, since that tries to create a
10207 value with a void typed value, and when we get here, gdbarch
10208 isn't initialized yet. At this point, we're quite sure there
10209 isn't another convenience variable of the same name. */
10210 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, nullptr);
10212 add_setshow_boolean_cmd ("observer", no_class
,
10213 &observer_mode_1
, _("\
10214 Set whether gdb controls the inferior in observer mode."), _("\
10215 Show whether gdb controls the inferior in observer mode."), _("\
10216 In observer mode, GDB can get data from the inferior, but not\n\
10217 affect its execution. Registers and memory may not be changed,\n\
10218 breakpoints may not be set, and the program cannot be interrupted\n\
10221 show_observer_mode
,
10226 selftests::register_test ("infrun_thread_ptid_changed",
10227 selftests::infrun_thread_ptid_changed
);