1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2021 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"
40 #include "observable.h"
45 #include "mi/mi-common.h"
46 #include "event-top.h"
48 #include "record-full.h"
49 #include "inline-frame.h"
51 #include "tracepoint.h"
55 #include "completer.h"
56 #include "target-descriptions.h"
57 #include "target-dcache.h"
60 #include "gdbsupport/event-loop.h"
61 #include "thread-fsm.h"
62 #include "gdbsupport/enum-flags.h"
63 #include "progspace-and-thread.h"
64 #include "gdbsupport/gdb_optional.h"
65 #include "arch-utils.h"
66 #include "gdbsupport/scope-exit.h"
67 #include "gdbsupport/forward-scope-exit.h"
68 #include "gdbsupport/gdb_select.h"
69 #include <unordered_map>
70 #include "async-event.h"
71 #include "gdbsupport/selftest.h"
72 #include "scoped-mock-context.h"
73 #include "test-target.h"
74 #include "gdbsupport/common-debug.h"
76 /* Prototypes for local functions */
78 static void sig_print_info (enum gdb_signal
);
80 static void sig_print_header (void);
82 static void follow_inferior_reset_breakpoints (void);
84 static bool currently_stepping (struct thread_info
*tp
);
86 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
88 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
90 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
92 static bool maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
94 static void resume (gdb_signal sig
);
96 static void wait_for_inferior (inferior
*inf
);
98 /* Asynchronous signal handler registered as event loop source for
99 when we have pending events ready to be passed to the core. */
100 static struct async_event_handler
*infrun_async_inferior_event_token
;
102 /* Stores whether infrun_async was previously enabled or disabled.
103 Starts off as -1, indicating "never enabled/disabled". */
104 static int infrun_is_async
= -1;
109 infrun_async (int enable
)
111 if (infrun_is_async
!= enable
)
113 infrun_is_async
= enable
;
115 infrun_debug_printf ("enable=%d", enable
);
118 mark_async_event_handler (infrun_async_inferior_event_token
);
120 clear_async_event_handler (infrun_async_inferior_event_token
);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token
);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 bool step_stop_if_no_debug
= false;
137 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
138 struct cmd_list_element
*c
, const char *value
)
140 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid
;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static bool detach_fork
= true;
156 bool debug_infrun
= false;
158 show_debug_infrun (struct ui_file
*file
, int from_tty
,
159 struct cmd_list_element
*c
, const char *value
)
161 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
164 /* Support for disabling address space randomization. */
166 bool disable_randomization
= true;
169 show_disable_randomization (struct ui_file
*file
, int from_tty
,
170 struct cmd_list_element
*c
, const char *value
)
172 if (target_supports_disable_randomization ())
173 fprintf_filtered (file
,
174 _("Disabling randomization of debuggee's "
175 "virtual address space is %s.\n"),
178 fputs_filtered (_("Disabling randomization of debuggee's "
179 "virtual address space is unsupported on\n"
180 "this platform.\n"), file
);
184 set_disable_randomization (const char *args
, int from_tty
,
185 struct cmd_list_element
*c
)
187 if (!target_supports_disable_randomization ())
188 error (_("Disabling randomization of debuggee's "
189 "virtual address space is unsupported on\n"
193 /* User interface for non-stop mode. */
195 bool non_stop
= false;
196 static bool non_stop_1
= false;
199 set_non_stop (const char *args
, int from_tty
,
200 struct cmd_list_element
*c
)
202 if (target_has_execution ())
204 non_stop_1
= non_stop
;
205 error (_("Cannot change this setting while the inferior is running."));
208 non_stop
= non_stop_1
;
212 show_non_stop (struct ui_file
*file
, int from_tty
,
213 struct cmd_list_element
*c
, const char *value
)
215 fprintf_filtered (file
,
216 _("Controlling the inferior in non-stop mode is %s.\n"),
220 /* "Observer mode" is somewhat like a more extreme version of
221 non-stop, in which all GDB operations that might affect the
222 target's execution have been disabled. */
224 static bool observer_mode
= false;
225 static bool observer_mode_1
= false;
228 set_observer_mode (const char *args
, int from_tty
,
229 struct cmd_list_element
*c
)
231 if (target_has_execution ())
233 observer_mode_1
= observer_mode
;
234 error (_("Cannot change this setting while the inferior is running."));
237 observer_mode
= observer_mode_1
;
239 may_write_registers
= !observer_mode
;
240 may_write_memory
= !observer_mode
;
241 may_insert_breakpoints
= !observer_mode
;
242 may_insert_tracepoints
= !observer_mode
;
243 /* We can insert fast tracepoints in or out of observer mode,
244 but enable them if we're going into this mode. */
246 may_insert_fast_tracepoints
= true;
247 may_stop
= !observer_mode
;
248 update_target_permissions ();
250 /* Going *into* observer mode we must force non-stop, then
251 going out we leave it that way. */
254 pagination_enabled
= 0;
255 non_stop
= non_stop_1
= true;
259 printf_filtered (_("Observer mode is now %s.\n"),
260 (observer_mode
? "on" : "off"));
264 show_observer_mode (struct ui_file
*file
, int from_tty
,
265 struct cmd_list_element
*c
, const char *value
)
267 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
270 /* This updates the value of observer mode based on changes in
271 permissions. Note that we are deliberately ignoring the values of
272 may-write-registers and may-write-memory, since the user may have
273 reason to enable these during a session, for instance to turn on a
274 debugging-related global. */
277 update_observer_mode (void)
279 bool newval
= (!may_insert_breakpoints
280 && !may_insert_tracepoints
281 && may_insert_fast_tracepoints
285 /* Let the user know if things change. */
286 if (newval
!= observer_mode
)
287 printf_filtered (_("Observer mode is now %s.\n"),
288 (newval
? "on" : "off"));
290 observer_mode
= observer_mode_1
= newval
;
293 /* Tables of how to react to signals; the user sets them. */
295 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
296 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
297 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
299 /* Table of signals that are registered with "catch signal". A
300 non-zero entry indicates that the signal is caught by some "catch
302 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
304 /* Table of signals that the target may silently handle.
305 This is automatically determined from the flags above,
306 and simply cached here. */
307 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
309 #define SET_SIGS(nsigs,sigs,flags) \
311 int signum = (nsigs); \
312 while (signum-- > 0) \
313 if ((sigs)[signum]) \
314 (flags)[signum] = 1; \
317 #define UNSET_SIGS(nsigs,sigs,flags) \
319 int signum = (nsigs); \
320 while (signum-- > 0) \
321 if ((sigs)[signum]) \
322 (flags)[signum] = 0; \
325 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
326 this function is to avoid exporting `signal_program'. */
329 update_signals_program_target (void)
331 target_program_signals (signal_program
);
334 /* Value to pass to target_resume() to cause all threads to resume. */
336 #define RESUME_ALL minus_one_ptid
338 /* Command list pointer for the "stop" placeholder. */
340 static struct cmd_list_element
*stop_command
;
342 /* Nonzero if we want to give control to the user when we're notified
343 of shared library events by the dynamic linker. */
344 int stop_on_solib_events
;
346 /* Enable or disable optional shared library event breakpoints
347 as appropriate when the above flag is changed. */
350 set_stop_on_solib_events (const char *args
,
351 int from_tty
, struct cmd_list_element
*c
)
353 update_solib_breakpoints ();
357 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
358 struct cmd_list_element
*c
, const char *value
)
360 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
364 /* True after stop if current stack frame should be printed. */
366 static bool stop_print_frame
;
368 /* This is a cached copy of the target/ptid/waitstatus of the last
369 event returned by target_wait()/deprecated_target_wait_hook().
370 This information is returned by get_last_target_status(). */
371 static process_stratum_target
*target_last_proc_target
;
372 static ptid_t target_last_wait_ptid
;
373 static struct target_waitstatus target_last_waitstatus
;
375 void init_thread_stepping_state (struct thread_info
*tss
);
377 static const char follow_fork_mode_child
[] = "child";
378 static const char follow_fork_mode_parent
[] = "parent";
380 static const char *const follow_fork_mode_kind_names
[] = {
381 follow_fork_mode_child
,
382 follow_fork_mode_parent
,
386 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
388 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
389 struct cmd_list_element
*c
, const char *value
)
391 fprintf_filtered (file
,
392 _("Debugger response to a program "
393 "call of fork or vfork is \"%s\".\n"),
398 /* Handle changes to the inferior list based on the type of fork,
399 which process is being followed, and whether the other process
400 should be detached. On entry inferior_ptid must be the ptid of
401 the fork parent. At return inferior_ptid is the ptid of the
402 followed inferior. */
405 follow_fork_inferior (bool follow_child
, bool detach_fork
)
408 ptid_t parent_ptid
, child_ptid
;
410 has_vforked
= (inferior_thread ()->pending_follow
.kind
411 == TARGET_WAITKIND_VFORKED
);
412 parent_ptid
= inferior_ptid
;
413 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
416 && !non_stop
/* Non-stop always resumes both branches. */
417 && current_ui
->prompt_state
== PROMPT_BLOCKED
418 && !(follow_child
|| detach_fork
|| sched_multi
))
420 /* The parent stays blocked inside the vfork syscall until the
421 child execs or exits. If we don't let the child run, then
422 the parent stays blocked. If we're telling the parent to run
423 in the foreground, the user will not be able to ctrl-c to get
424 back the terminal, effectively hanging the debug session. */
425 fprintf_filtered (gdb_stderr
, _("\
426 Can not resume the parent process over vfork in the foreground while\n\
427 holding the child stopped. Try \"set detach-on-fork\" or \
428 \"set schedule-multiple\".\n"));
434 /* Detach new forked process? */
437 /* Before detaching from the child, remove all breakpoints
438 from it. If we forked, then this has already been taken
439 care of by infrun.c. If we vforked however, any
440 breakpoint inserted in the parent is visible in the
441 child, even those added while stopped in a vfork
442 catchpoint. This will remove the breakpoints from the
443 parent also, but they'll be reinserted below. */
446 /* Keep breakpoints list in sync. */
447 remove_breakpoints_inf (current_inferior ());
450 if (print_inferior_events
)
452 /* Ensure that we have a process ptid. */
453 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
455 target_terminal::ours_for_output ();
456 fprintf_filtered (gdb_stdlog
,
457 _("[Detaching after %s from child %s]\n"),
458 has_vforked
? "vfork" : "fork",
459 target_pid_to_str (process_ptid
).c_str ());
464 struct inferior
*parent_inf
, *child_inf
;
466 /* Add process to GDB's tables. */
467 child_inf
= add_inferior (child_ptid
.pid ());
469 parent_inf
= current_inferior ();
470 child_inf
->attach_flag
= parent_inf
->attach_flag
;
471 copy_terminal_info (child_inf
, parent_inf
);
472 child_inf
->gdbarch
= parent_inf
->gdbarch
;
473 copy_inferior_target_desc_info (child_inf
, parent_inf
);
475 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
477 set_current_inferior (child_inf
);
478 switch_to_no_thread ();
479 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
480 push_target (parent_inf
->process_target ());
481 thread_info
*child_thr
482 = add_thread_silent (child_inf
->process_target (), child_ptid
);
484 /* If this is a vfork child, then the address-space is
485 shared with the parent. */
488 child_inf
->pspace
= parent_inf
->pspace
;
489 child_inf
->aspace
= parent_inf
->aspace
;
493 /* The parent will be frozen until the child is done
494 with the shared region. Keep track of the
496 child_inf
->vfork_parent
= parent_inf
;
497 child_inf
->pending_detach
= 0;
498 parent_inf
->vfork_child
= child_inf
;
499 parent_inf
->pending_detach
= 0;
501 /* Now that the inferiors and program spaces are all
502 wired up, we can switch to the child thread (which
503 switches inferior and program space too). */
504 switch_to_thread (child_thr
);
508 child_inf
->aspace
= new_address_space ();
509 child_inf
->pspace
= new program_space (child_inf
->aspace
);
510 child_inf
->removable
= 1;
511 set_current_program_space (child_inf
->pspace
);
512 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
514 /* solib_create_inferior_hook relies on the current
516 switch_to_thread (child_thr
);
518 /* Let the shared library layer (e.g., solib-svr4) learn
519 about this new process, relocate the cloned exec, pull
520 in shared libraries, and install the solib event
521 breakpoint. If a "cloned-VM" event was propagated
522 better throughout the core, this wouldn't be
524 solib_create_inferior_hook (0);
530 struct inferior
*parent_inf
;
532 parent_inf
= current_inferior ();
534 /* If we detached from the child, then we have to be careful
535 to not insert breakpoints in the parent until the child
536 is done with the shared memory region. However, if we're
537 staying attached to the child, then we can and should
538 insert breakpoints, so that we can debug it. A
539 subsequent child exec or exit is enough to know when does
540 the child stops using the parent's address space. */
541 parent_inf
->waiting_for_vfork_done
= detach_fork
;
542 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
547 /* Follow the child. */
548 struct inferior
*parent_inf
, *child_inf
;
549 struct program_space
*parent_pspace
;
551 if (print_inferior_events
)
553 std::string parent_pid
= target_pid_to_str (parent_ptid
);
554 std::string child_pid
= target_pid_to_str (child_ptid
);
556 target_terminal::ours_for_output ();
557 fprintf_filtered (gdb_stdlog
,
558 _("[Attaching after %s %s to child %s]\n"),
560 has_vforked
? "vfork" : "fork",
564 /* Add the new inferior first, so that the target_detach below
565 doesn't unpush the target. */
567 child_inf
= add_inferior (child_ptid
.pid ());
569 parent_inf
= current_inferior ();
570 child_inf
->attach_flag
= parent_inf
->attach_flag
;
571 copy_terminal_info (child_inf
, parent_inf
);
572 child_inf
->gdbarch
= parent_inf
->gdbarch
;
573 copy_inferior_target_desc_info (child_inf
, parent_inf
);
575 parent_pspace
= parent_inf
->pspace
;
577 process_stratum_target
*target
= parent_inf
->process_target ();
580 /* Hold a strong reference to the target while (maybe)
581 detaching the parent. Otherwise detaching could close the
583 auto target_ref
= target_ops_ref::new_reference (target
);
585 /* If we're vforking, we want to hold on to the parent until
586 the child exits or execs. At child exec or exit time we
587 can remove the old breakpoints from the parent and detach
588 or resume debugging it. Otherwise, detach the parent now;
589 we'll want to reuse it's program/address spaces, but we
590 can't set them to the child before removing breakpoints
591 from the parent, otherwise, the breakpoints module could
592 decide to remove breakpoints from the wrong process (since
593 they'd be assigned to the same address space). */
597 gdb_assert (child_inf
->vfork_parent
== NULL
);
598 gdb_assert (parent_inf
->vfork_child
== NULL
);
599 child_inf
->vfork_parent
= parent_inf
;
600 child_inf
->pending_detach
= 0;
601 parent_inf
->vfork_child
= child_inf
;
602 parent_inf
->pending_detach
= detach_fork
;
603 parent_inf
->waiting_for_vfork_done
= 0;
605 else if (detach_fork
)
607 if (print_inferior_events
)
609 /* Ensure that we have a process ptid. */
610 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
612 target_terminal::ours_for_output ();
613 fprintf_filtered (gdb_stdlog
,
614 _("[Detaching after fork from "
616 target_pid_to_str (process_ptid
).c_str ());
619 target_detach (parent_inf
, 0);
623 /* Note that the detach above makes PARENT_INF dangling. */
625 /* Add the child thread to the appropriate lists, and switch
626 to this new thread, before cloning the program space, and
627 informing the solib layer about this new process. */
629 set_current_inferior (child_inf
);
630 push_target (target
);
633 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
635 /* If this is a vfork child, then the address-space is shared
636 with the parent. If we detached from the parent, then we can
637 reuse the parent's program/address spaces. */
638 if (has_vforked
|| detach_fork
)
640 child_inf
->pspace
= parent_pspace
;
641 child_inf
->aspace
= child_inf
->pspace
->aspace
;
647 child_inf
->aspace
= new_address_space ();
648 child_inf
->pspace
= new program_space (child_inf
->aspace
);
649 child_inf
->removable
= 1;
650 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
651 set_current_program_space (child_inf
->pspace
);
652 clone_program_space (child_inf
->pspace
, parent_pspace
);
654 /* Let the shared library layer (e.g., solib-svr4) learn
655 about this new process, relocate the cloned exec, pull in
656 shared libraries, and install the solib event breakpoint.
657 If a "cloned-VM" event was propagated better throughout
658 the core, this wouldn't be required. */
659 solib_create_inferior_hook (0);
662 switch_to_thread (child_thr
);
665 return target_follow_fork (follow_child
, detach_fork
);
668 /* Tell the target to follow the fork we're stopped at. Returns true
669 if the inferior should be resumed; false, if the target for some
670 reason decided it's best not to resume. */
675 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
676 bool should_resume
= true;
677 struct thread_info
*tp
;
679 /* Copy user stepping state to the new inferior thread. FIXME: the
680 followed fork child thread should have a copy of most of the
681 parent thread structure's run control related fields, not just these.
682 Initialized to avoid "may be used uninitialized" warnings from gcc. */
683 struct breakpoint
*step_resume_breakpoint
= NULL
;
684 struct breakpoint
*exception_resume_breakpoint
= NULL
;
685 CORE_ADDR step_range_start
= 0;
686 CORE_ADDR step_range_end
= 0;
687 int current_line
= 0;
688 symtab
*current_symtab
= NULL
;
689 struct frame_id step_frame_id
= { 0 };
690 struct thread_fsm
*thread_fsm
= NULL
;
694 process_stratum_target
*wait_target
;
696 struct target_waitstatus wait_status
;
698 /* Get the last target status returned by target_wait(). */
699 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
701 /* If not stopped at a fork event, then there's nothing else to
703 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
704 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
707 /* Check if we switched over from WAIT_PTID, since the event was
709 if (wait_ptid
!= minus_one_ptid
710 && (current_inferior ()->process_target () != wait_target
711 || inferior_ptid
!= wait_ptid
))
713 /* We did. Switch back to WAIT_PTID thread, to tell the
714 target to follow it (in either direction). We'll
715 afterwards refuse to resume, and inform the user what
717 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
718 switch_to_thread (wait_thread
);
719 should_resume
= false;
723 tp
= inferior_thread ();
725 /* If there were any forks/vforks that were caught and are now to be
726 followed, then do so now. */
727 switch (tp
->pending_follow
.kind
)
729 case TARGET_WAITKIND_FORKED
:
730 case TARGET_WAITKIND_VFORKED
:
732 ptid_t parent
, child
;
734 /* If the user did a next/step, etc, over a fork call,
735 preserve the stepping state in the fork child. */
736 if (follow_child
&& should_resume
)
738 step_resume_breakpoint
= clone_momentary_breakpoint
739 (tp
->control
.step_resume_breakpoint
);
740 step_range_start
= tp
->control
.step_range_start
;
741 step_range_end
= tp
->control
.step_range_end
;
742 current_line
= tp
->current_line
;
743 current_symtab
= tp
->current_symtab
;
744 step_frame_id
= tp
->control
.step_frame_id
;
745 exception_resume_breakpoint
746 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
747 thread_fsm
= tp
->thread_fsm
;
749 /* For now, delete the parent's sr breakpoint, otherwise,
750 parent/child sr breakpoints are considered duplicates,
751 and the child version will not be installed. Remove
752 this when the breakpoints module becomes aware of
753 inferiors and address spaces. */
754 delete_step_resume_breakpoint (tp
);
755 tp
->control
.step_range_start
= 0;
756 tp
->control
.step_range_end
= 0;
757 tp
->control
.step_frame_id
= null_frame_id
;
758 delete_exception_resume_breakpoint (tp
);
759 tp
->thread_fsm
= NULL
;
762 parent
= inferior_ptid
;
763 child
= tp
->pending_follow
.value
.related_pid
;
765 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
766 /* Set up inferior(s) as specified by the caller, and tell the
767 target to do whatever is necessary to follow either parent
769 if (follow_fork_inferior (follow_child
, detach_fork
))
771 /* Target refused to follow, or there's some other reason
772 we shouldn't resume. */
777 /* This pending follow fork event is now handled, one way
778 or another. The previous selected thread may be gone
779 from the lists by now, but if it is still around, need
780 to clear the pending follow request. */
781 tp
= find_thread_ptid (parent_targ
, parent
);
783 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
785 /* This makes sure we don't try to apply the "Switched
786 over from WAIT_PID" logic above. */
787 nullify_last_target_wait_ptid ();
789 /* If we followed the child, switch to it... */
792 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
793 switch_to_thread (child_thr
);
795 /* ... and preserve the stepping state, in case the
796 user was stepping over the fork call. */
799 tp
= inferior_thread ();
800 tp
->control
.step_resume_breakpoint
801 = step_resume_breakpoint
;
802 tp
->control
.step_range_start
= step_range_start
;
803 tp
->control
.step_range_end
= step_range_end
;
804 tp
->current_line
= current_line
;
805 tp
->current_symtab
= current_symtab
;
806 tp
->control
.step_frame_id
= step_frame_id
;
807 tp
->control
.exception_resume_breakpoint
808 = exception_resume_breakpoint
;
809 tp
->thread_fsm
= thread_fsm
;
813 /* If we get here, it was because we're trying to
814 resume from a fork catchpoint, but, the user
815 has switched threads away from the thread that
816 forked. In that case, the resume command
817 issued is most likely not applicable to the
818 child, so just warn, and refuse to resume. */
819 warning (_("Not resuming: switched threads "
820 "before following fork child."));
823 /* Reset breakpoints in the child as appropriate. */
824 follow_inferior_reset_breakpoints ();
829 case TARGET_WAITKIND_SPURIOUS
:
830 /* Nothing to follow. */
833 internal_error (__FILE__
, __LINE__
,
834 "Unexpected pending_follow.kind %d\n",
835 tp
->pending_follow
.kind
);
839 return should_resume
;
843 follow_inferior_reset_breakpoints (void)
845 struct thread_info
*tp
= inferior_thread ();
847 /* Was there a step_resume breakpoint? (There was if the user
848 did a "next" at the fork() call.) If so, explicitly reset its
849 thread number. Cloned step_resume breakpoints are disabled on
850 creation, so enable it here now that it is associated with the
853 step_resumes are a form of bp that are made to be per-thread.
854 Since we created the step_resume bp when the parent process
855 was being debugged, and now are switching to the child process,
856 from the breakpoint package's viewpoint, that's a switch of
857 "threads". We must update the bp's notion of which thread
858 it is for, or it'll be ignored when it triggers. */
860 if (tp
->control
.step_resume_breakpoint
)
862 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
863 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
866 /* Treat exception_resume breakpoints like step_resume breakpoints. */
867 if (tp
->control
.exception_resume_breakpoint
)
869 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
870 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
873 /* Reinsert all breakpoints in the child. The user may have set
874 breakpoints after catching the fork, in which case those
875 were never set in the child, but only in the parent. This makes
876 sure the inserted breakpoints match the breakpoint list. */
878 breakpoint_re_set ();
879 insert_breakpoints ();
882 /* The child has exited or execed: resume threads of the parent the
883 user wanted to be executing. */
886 proceed_after_vfork_done (struct thread_info
*thread
,
889 int pid
= * (int *) arg
;
891 if (thread
->ptid
.pid () == pid
892 && thread
->state
== THREAD_RUNNING
893 && !thread
->executing
894 && !thread
->stop_requested
895 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
897 infrun_debug_printf ("resuming vfork parent thread %s",
898 target_pid_to_str (thread
->ptid
).c_str ());
900 switch_to_thread (thread
);
901 clear_proceed_status (0);
902 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
908 /* Called whenever we notice an exec or exit event, to handle
909 detaching or resuming a vfork parent. */
912 handle_vfork_child_exec_or_exit (int exec
)
914 struct inferior
*inf
= current_inferior ();
916 if (inf
->vfork_parent
)
918 int resume_parent
= -1;
920 /* This exec or exit marks the end of the shared memory region
921 between the parent and the child. Break the bonds. */
922 inferior
*vfork_parent
= inf
->vfork_parent
;
923 inf
->vfork_parent
->vfork_child
= NULL
;
924 inf
->vfork_parent
= NULL
;
926 /* If the user wanted to detach from the parent, now is the
928 if (vfork_parent
->pending_detach
)
930 struct program_space
*pspace
;
931 struct address_space
*aspace
;
933 /* follow-fork child, detach-on-fork on. */
935 vfork_parent
->pending_detach
= 0;
937 scoped_restore_current_pspace_and_thread restore_thread
;
939 /* We're letting loose of the parent. */
940 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
941 switch_to_thread (tp
);
943 /* We're about to detach from the parent, which implicitly
944 removes breakpoints from its address space. There's a
945 catch here: we want to reuse the spaces for the child,
946 but, parent/child are still sharing the pspace at this
947 point, although the exec in reality makes the kernel give
948 the child a fresh set of new pages. The problem here is
949 that the breakpoints module being unaware of this, would
950 likely chose the child process to write to the parent
951 address space. Swapping the child temporarily away from
952 the spaces has the desired effect. Yes, this is "sort
955 pspace
= inf
->pspace
;
956 aspace
= inf
->aspace
;
960 if (print_inferior_events
)
963 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
965 target_terminal::ours_for_output ();
969 fprintf_filtered (gdb_stdlog
,
970 _("[Detaching vfork parent %s "
971 "after child exec]\n"), pidstr
.c_str ());
975 fprintf_filtered (gdb_stdlog
,
976 _("[Detaching vfork parent %s "
977 "after child exit]\n"), pidstr
.c_str ());
981 target_detach (vfork_parent
, 0);
984 inf
->pspace
= pspace
;
985 inf
->aspace
= aspace
;
989 /* We're staying attached to the parent, so, really give the
990 child a new address space. */
991 inf
->pspace
= new program_space (maybe_new_address_space ());
992 inf
->aspace
= inf
->pspace
->aspace
;
994 set_current_program_space (inf
->pspace
);
996 resume_parent
= vfork_parent
->pid
;
1000 /* If this is a vfork child exiting, then the pspace and
1001 aspaces were shared with the parent. Since we're
1002 reporting the process exit, we'll be mourning all that is
1003 found in the address space, and switching to null_ptid,
1004 preparing to start a new inferior. But, since we don't
1005 want to clobber the parent's address/program spaces, we
1006 go ahead and create a new one for this exiting
1009 /* Switch to no-thread while running clone_program_space, so
1010 that clone_program_space doesn't want to read the
1011 selected frame of a dead process. */
1012 scoped_restore_current_thread restore_thread
;
1013 switch_to_no_thread ();
1015 inf
->pspace
= new program_space (maybe_new_address_space ());
1016 inf
->aspace
= inf
->pspace
->aspace
;
1017 set_current_program_space (inf
->pspace
);
1019 inf
->symfile_flags
= SYMFILE_NO_READ
;
1020 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1022 resume_parent
= vfork_parent
->pid
;
1025 gdb_assert (current_program_space
== inf
->pspace
);
1027 if (non_stop
&& resume_parent
!= -1)
1029 /* If the user wanted the parent to be running, let it go
1031 scoped_restore_current_thread restore_thread
;
1033 infrun_debug_printf ("resuming vfork parent process %d",
1036 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1041 /* Enum strings for "set|show follow-exec-mode". */
1043 static const char follow_exec_mode_new
[] = "new";
1044 static const char follow_exec_mode_same
[] = "same";
1045 static const char *const follow_exec_mode_names
[] =
1047 follow_exec_mode_new
,
1048 follow_exec_mode_same
,
1052 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1054 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1055 struct cmd_list_element
*c
, const char *value
)
1057 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1060 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1063 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1065 struct inferior
*inf
= current_inferior ();
1066 int pid
= ptid
.pid ();
1067 ptid_t process_ptid
;
1069 /* Switch terminal for any messages produced e.g. by
1070 breakpoint_re_set. */
1071 target_terminal::ours_for_output ();
1073 /* This is an exec event that we actually wish to pay attention to.
1074 Refresh our symbol table to the newly exec'd program, remove any
1075 momentary bp's, etc.
1077 If there are breakpoints, they aren't really inserted now,
1078 since the exec() transformed our inferior into a fresh set
1081 We want to preserve symbolic breakpoints on the list, since
1082 we have hopes that they can be reset after the new a.out's
1083 symbol table is read.
1085 However, any "raw" breakpoints must be removed from the list
1086 (e.g., the solib bp's), since their address is probably invalid
1089 And, we DON'T want to call delete_breakpoints() here, since
1090 that may write the bp's "shadow contents" (the instruction
1091 value that was overwritten with a TRAP instruction). Since
1092 we now have a new a.out, those shadow contents aren't valid. */
1094 mark_breakpoints_out ();
1096 /* The target reports the exec event to the main thread, even if
1097 some other thread does the exec, and even if the main thread was
1098 stopped or already gone. We may still have non-leader threads of
1099 the process on our list. E.g., on targets that don't have thread
1100 exit events (like remote); or on native Linux in non-stop mode if
1101 there were only two threads in the inferior and the non-leader
1102 one is the one that execs (and nothing forces an update of the
1103 thread list up to here). When debugging remotely, it's best to
1104 avoid extra traffic, when possible, so avoid syncing the thread
1105 list with the target, and instead go ahead and delete all threads
1106 of the process but one that reported the event. Note this must
1107 be done before calling update_breakpoints_after_exec, as
1108 otherwise clearing the threads' resources would reference stale
1109 thread breakpoints -- it may have been one of these threads that
1110 stepped across the exec. We could just clear their stepping
1111 states, but as long as we're iterating, might as well delete
1112 them. Deleting them now rather than at the next user-visible
1113 stop provides a nicer sequence of events for user and MI
1115 for (thread_info
*th
: all_threads_safe ())
1116 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1119 /* We also need to clear any left over stale state for the
1120 leader/event thread. E.g., if there was any step-resume
1121 breakpoint or similar, it's gone now. We cannot truly
1122 step-to-next statement through an exec(). */
1123 thread_info
*th
= inferior_thread ();
1124 th
->control
.step_resume_breakpoint
= NULL
;
1125 th
->control
.exception_resume_breakpoint
= NULL
;
1126 th
->control
.single_step_breakpoints
= NULL
;
1127 th
->control
.step_range_start
= 0;
1128 th
->control
.step_range_end
= 0;
1130 /* The user may have had the main thread held stopped in the
1131 previous image (e.g., schedlock on, or non-stop). Release
1133 th
->stop_requested
= 0;
1135 update_breakpoints_after_exec ();
1137 /* What is this a.out's name? */
1138 process_ptid
= ptid_t (pid
);
1139 printf_unfiltered (_("%s is executing new program: %s\n"),
1140 target_pid_to_str (process_ptid
).c_str (),
1143 /* We've followed the inferior through an exec. Therefore, the
1144 inferior has essentially been killed & reborn. */
1146 breakpoint_init_inferior (inf_execd
);
1148 gdb::unique_xmalloc_ptr
<char> exec_file_host
1149 = exec_file_find (exec_file_target
, NULL
);
1151 /* If we were unable to map the executable target pathname onto a host
1152 pathname, tell the user that. Otherwise GDB's subsequent behavior
1153 is confusing. Maybe it would even be better to stop at this point
1154 so that the user can specify a file manually before continuing. */
1155 if (exec_file_host
== NULL
)
1156 warning (_("Could not load symbols for executable %s.\n"
1157 "Do you need \"set sysroot\"?"),
1160 /* Reset the shared library package. This ensures that we get a
1161 shlib event when the child reaches "_start", at which point the
1162 dld will have had a chance to initialize the child. */
1163 /* Also, loading a symbol file below may trigger symbol lookups, and
1164 we don't want those to be satisfied by the libraries of the
1165 previous incarnation of this process. */
1166 no_shared_libraries (NULL
, 0);
1168 if (follow_exec_mode_string
== follow_exec_mode_new
)
1170 /* The user wants to keep the old inferior and program spaces
1171 around. Create a new fresh one, and switch to it. */
1173 /* Do exit processing for the original inferior before setting the new
1174 inferior's pid. Having two inferiors with the same pid would confuse
1175 find_inferior_p(t)id. Transfer the terminal state and info from the
1176 old to the new inferior. */
1177 inf
= add_inferior_with_spaces ();
1178 swap_terminal_info (inf
, current_inferior ());
1179 exit_inferior_silent (current_inferior ());
1182 target_follow_exec (inf
, exec_file_target
);
1184 inferior
*org_inferior
= current_inferior ();
1185 switch_to_inferior_no_thread (inf
);
1186 push_target (org_inferior
->process_target ());
1187 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1188 switch_to_thread (thr
);
1192 /* The old description may no longer be fit for the new image.
1193 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1194 old description; we'll read a new one below. No need to do
1195 this on "follow-exec-mode new", as the old inferior stays
1196 around (its description is later cleared/refetched on
1198 target_clear_description ();
1201 gdb_assert (current_program_space
== inf
->pspace
);
1203 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1204 because the proper displacement for a PIE (Position Independent
1205 Executable) main symbol file will only be computed by
1206 solib_create_inferior_hook below. breakpoint_re_set would fail
1207 to insert the breakpoints with the zero displacement. */
1208 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1210 /* If the target can specify a description, read it. Must do this
1211 after flipping to the new executable (because the target supplied
1212 description must be compatible with the executable's
1213 architecture, and the old executable may e.g., be 32-bit, while
1214 the new one 64-bit), and before anything involving memory or
1216 target_find_description ();
1218 gdb::observers::inferior_execd
.notify (inf
);
1220 breakpoint_re_set ();
1222 /* Reinsert all breakpoints. (Those which were symbolic have
1223 been reset to the proper address in the new a.out, thanks
1224 to symbol_file_command...). */
1225 insert_breakpoints ();
1227 /* The next resume of this inferior should bring it to the shlib
1228 startup breakpoints. (If the user had also set bp's on
1229 "main" from the old (parent) process, then they'll auto-
1230 matically get reset there in the new process.). */
1233 /* The chain of threads that need to do a step-over operation to get
1234 past e.g., a breakpoint. What technique is used to step over the
1235 breakpoint/watchpoint does not matter -- all threads end up in the
1236 same queue, to maintain rough temporal order of execution, in order
1237 to avoid starvation, otherwise, we could e.g., find ourselves
1238 constantly stepping the same couple threads past their breakpoints
1239 over and over, if the single-step finish fast enough. */
1240 struct thread_info
*global_thread_step_over_chain_head
;
1242 /* Bit flags indicating what the thread needs to step over. */
1244 enum step_over_what_flag
1246 /* Step over a breakpoint. */
1247 STEP_OVER_BREAKPOINT
= 1,
1249 /* Step past a non-continuable watchpoint, in order to let the
1250 instruction execute so we can evaluate the watchpoint
1252 STEP_OVER_WATCHPOINT
= 2
1254 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1256 /* Info about an instruction that is being stepped over. */
1258 struct step_over_info
1260 /* If we're stepping past a breakpoint, this is the address space
1261 and address of the instruction the breakpoint is set at. We'll
1262 skip inserting all breakpoints here. Valid iff ASPACE is
1264 const address_space
*aspace
= nullptr;
1265 CORE_ADDR address
= 0;
1267 /* The instruction being stepped over triggers a nonsteppable
1268 watchpoint. If true, we'll skip inserting watchpoints. */
1269 int nonsteppable_watchpoint_p
= 0;
1271 /* The thread's global number. */
1275 /* The step-over info of the location that is being stepped over.
1277 Note that with async/breakpoint always-inserted mode, a user might
1278 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1279 being stepped over. As setting a new breakpoint inserts all
1280 breakpoints, we need to make sure the breakpoint being stepped over
1281 isn't inserted then. We do that by only clearing the step-over
1282 info when the step-over is actually finished (or aborted).
1284 Presently GDB can only step over one breakpoint at any given time.
1285 Given threads that can't run code in the same address space as the
1286 breakpoint's can't really miss the breakpoint, GDB could be taught
1287 to step-over at most one breakpoint per address space (so this info
1288 could move to the address space object if/when GDB is extended).
1289 The set of breakpoints being stepped over will normally be much
1290 smaller than the set of all breakpoints, so a flag in the
1291 breakpoint location structure would be wasteful. A separate list
1292 also saves complexity and run-time, as otherwise we'd have to go
1293 through all breakpoint locations clearing their flag whenever we
1294 start a new sequence. Similar considerations weigh against storing
1295 this info in the thread object. Plus, not all step overs actually
1296 have breakpoint locations -- e.g., stepping past a single-step
1297 breakpoint, or stepping to complete a non-continuable
1299 static struct step_over_info step_over_info
;
1301 /* Record the address of the breakpoint/instruction we're currently
1303 N.B. We record the aspace and address now, instead of say just the thread,
1304 because when we need the info later the thread may be running. */
1307 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1308 int nonsteppable_watchpoint_p
,
1311 step_over_info
.aspace
= aspace
;
1312 step_over_info
.address
= address
;
1313 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1314 step_over_info
.thread
= thread
;
1317 /* Called when we're not longer stepping over a breakpoint / an
1318 instruction, so all breakpoints are free to be (re)inserted. */
1321 clear_step_over_info (void)
1323 infrun_debug_printf ("clearing step over info");
1324 step_over_info
.aspace
= NULL
;
1325 step_over_info
.address
= 0;
1326 step_over_info
.nonsteppable_watchpoint_p
= 0;
1327 step_over_info
.thread
= -1;
1333 stepping_past_instruction_at (struct address_space
*aspace
,
1336 return (step_over_info
.aspace
!= NULL
1337 && breakpoint_address_match (aspace
, address
,
1338 step_over_info
.aspace
,
1339 step_over_info
.address
));
1345 thread_is_stepping_over_breakpoint (int thread
)
1347 return (step_over_info
.thread
!= -1
1348 && thread
== step_over_info
.thread
);
1354 stepping_past_nonsteppable_watchpoint (void)
1356 return step_over_info
.nonsteppable_watchpoint_p
;
1359 /* Returns true if step-over info is valid. */
1362 step_over_info_valid_p (void)
1364 return (step_over_info
.aspace
!= NULL
1365 || stepping_past_nonsteppable_watchpoint ());
1369 /* Displaced stepping. */
1371 /* In non-stop debugging mode, we must take special care to manage
1372 breakpoints properly; in particular, the traditional strategy for
1373 stepping a thread past a breakpoint it has hit is unsuitable.
1374 'Displaced stepping' is a tactic for stepping one thread past a
1375 breakpoint it has hit while ensuring that other threads running
1376 concurrently will hit the breakpoint as they should.
1378 The traditional way to step a thread T off a breakpoint in a
1379 multi-threaded program in all-stop mode is as follows:
1381 a0) Initially, all threads are stopped, and breakpoints are not
1383 a1) We single-step T, leaving breakpoints uninserted.
1384 a2) We insert breakpoints, and resume all threads.
1386 In non-stop debugging, however, this strategy is unsuitable: we
1387 don't want to have to stop all threads in the system in order to
1388 continue or step T past a breakpoint. Instead, we use displaced
1391 n0) Initially, T is stopped, other threads are running, and
1392 breakpoints are inserted.
1393 n1) We copy the instruction "under" the breakpoint to a separate
1394 location, outside the main code stream, making any adjustments
1395 to the instruction, register, and memory state as directed by
1397 n2) We single-step T over the instruction at its new location.
1398 n3) We adjust the resulting register and memory state as directed
1399 by T's architecture. This includes resetting T's PC to point
1400 back into the main instruction stream.
1403 This approach depends on the following gdbarch methods:
1405 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1406 indicate where to copy the instruction, and how much space must
1407 be reserved there. We use these in step n1.
1409 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1410 address, and makes any necessary adjustments to the instruction,
1411 register contents, and memory. We use this in step n1.
1413 - gdbarch_displaced_step_fixup adjusts registers and memory after
1414 we have successfully single-stepped the instruction, to yield the
1415 same effect the instruction would have had if we had executed it
1416 at its original address. We use this in step n3.
1418 The gdbarch_displaced_step_copy_insn and
1419 gdbarch_displaced_step_fixup functions must be written so that
1420 copying an instruction with gdbarch_displaced_step_copy_insn,
1421 single-stepping across the copied instruction, and then applying
1422 gdbarch_displaced_insn_fixup should have the same effects on the
1423 thread's memory and registers as stepping the instruction in place
1424 would have. Exactly which responsibilities fall to the copy and
1425 which fall to the fixup is up to the author of those functions.
1427 See the comments in gdbarch.sh for details.
1429 Note that displaced stepping and software single-step cannot
1430 currently be used in combination, although with some care I think
1431 they could be made to. Software single-step works by placing
1432 breakpoints on all possible subsequent instructions; if the
1433 displaced instruction is a PC-relative jump, those breakpoints
1434 could fall in very strange places --- on pages that aren't
1435 executable, or at addresses that are not proper instruction
1436 boundaries. (We do generally let other threads run while we wait
1437 to hit the software single-step breakpoint, and they might
1438 encounter such a corrupted instruction.) One way to work around
1439 this would be to have gdbarch_displaced_step_copy_insn fully
1440 simulate the effect of PC-relative instructions (and return NULL)
1441 on architectures that use software single-stepping.
1443 In non-stop mode, we can have independent and simultaneous step
1444 requests, so more than one thread may need to simultaneously step
1445 over a breakpoint. The current implementation assumes there is
1446 only one scratch space per process. In this case, we have to
1447 serialize access to the scratch space. If thread A wants to step
1448 over a breakpoint, but we are currently waiting for some other
1449 thread to complete a displaced step, we leave thread A stopped and
1450 place it in the displaced_step_request_queue. Whenever a displaced
1451 step finishes, we pick the next thread in the queue and start a new
1452 displaced step operation on it. See displaced_step_prepare and
1453 displaced_step_finish for details. */
1455 /* Return true if THREAD is doing a displaced step. */
1458 displaced_step_in_progress_thread (thread_info
*thread
)
1460 gdb_assert (thread
!= NULL
);
1462 return thread
->displaced_step_state
.in_progress ();
1465 /* Return true if INF has a thread doing a displaced step. */
1468 displaced_step_in_progress (inferior
*inf
)
1470 return inf
->displaced_step_state
.in_progress_count
> 0;
1473 /* Return true if any thread is doing a displaced step. */
1476 displaced_step_in_progress_any_thread ()
1478 for (inferior
*inf
: all_non_exited_inferiors ())
1480 if (displaced_step_in_progress (inf
))
1488 infrun_inferior_exit (struct inferior
*inf
)
1490 inf
->displaced_step_state
.reset ();
1494 infrun_inferior_execd (inferior
*inf
)
1496 /* If some threads where was doing a displaced step in this inferior at the
1497 moment of the exec, they no longer exist. Even if the exec'ing thread
1498 doing a displaced step, we don't want to to any fixup nor restore displaced
1499 stepping buffer bytes. */
1500 inf
->displaced_step_state
.reset ();
1502 for (thread_info
*thread
: inf
->threads ())
1503 thread
->displaced_step_state
.reset ();
1505 /* Since an in-line step is done with everything else stopped, if there was
1506 one in progress at the time of the exec, it must have been the exec'ing
1508 clear_step_over_info ();
1511 /* If ON, and the architecture supports it, GDB will use displaced
1512 stepping to step over breakpoints. If OFF, or if the architecture
1513 doesn't support it, GDB will instead use the traditional
1514 hold-and-step approach. If AUTO (which is the default), GDB will
1515 decide which technique to use to step over breakpoints depending on
1516 whether the target works in a non-stop way (see use_displaced_stepping). */
1518 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1521 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1522 struct cmd_list_element
*c
,
1525 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1526 fprintf_filtered (file
,
1527 _("Debugger's willingness to use displaced stepping "
1528 "to step over breakpoints is %s (currently %s).\n"),
1529 value
, target_is_non_stop_p () ? "on" : "off");
1531 fprintf_filtered (file
,
1532 _("Debugger's willingness to use displaced stepping "
1533 "to step over breakpoints is %s.\n"), value
);
1536 /* Return true if the gdbarch implements the required methods to use
1537 displaced stepping. */
1540 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1542 /* Only check for the presence of `prepare`. The gdbarch verification ensures
1543 that if `prepare` is provided, so is `finish`. */
1544 return gdbarch_displaced_step_prepare_p (arch
);
1547 /* Return non-zero if displaced stepping can/should be used to step
1548 over breakpoints of thread TP. */
1551 use_displaced_stepping (thread_info
*tp
)
1553 /* If the user disabled it explicitly, don't use displaced stepping. */
1554 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1557 /* If "auto", only use displaced stepping if the target operates in a non-stop
1559 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1560 && !target_is_non_stop_p ())
1563 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1565 /* If the architecture doesn't implement displaced stepping, don't use
1567 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1570 /* If recording, don't use displaced stepping. */
1571 if (find_record_target () != nullptr)
1574 /* If displaced stepping failed before for this inferior, don't bother trying
1576 if (tp
->inf
->displaced_step_state
.failed_before
)
1582 /* Simple function wrapper around displaced_step_thread_state::reset. */
1585 displaced_step_reset (displaced_step_thread_state
*displaced
)
1587 displaced
->reset ();
1590 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1591 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1593 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1598 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1602 for (size_t i
= 0; i
< len
; i
++)
1605 ret
+= string_printf ("%02x", buf
[i
]);
1607 ret
+= string_printf (" %02x", buf
[i
]);
1613 /* Prepare to single-step, using displaced stepping.
1615 Note that we cannot use displaced stepping when we have a signal to
1616 deliver. If we have a signal to deliver and an instruction to step
1617 over, then after the step, there will be no indication from the
1618 target whether the thread entered a signal handler or ignored the
1619 signal and stepped over the instruction successfully --- both cases
1620 result in a simple SIGTRAP. In the first case we mustn't do a
1621 fixup, and in the second case we must --- but we can't tell which.
1622 Comments in the code for 'random signals' in handle_inferior_event
1623 explain how we handle this case instead.
1625 Returns DISPLACED_STEP_PREPARE_STATUS_OK if preparing was successful -- this
1626 thread is going to be stepped now; DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
1627 if displaced stepping this thread got queued; or
1628 DISPLACED_STEP_PREPARE_STATUS_CANT if this instruction can't be displaced
1631 static displaced_step_prepare_status
1632 displaced_step_prepare_throw (thread_info
*tp
)
1634 regcache
*regcache
= get_thread_regcache (tp
);
1635 struct gdbarch
*gdbarch
= regcache
->arch ();
1636 displaced_step_thread_state
&disp_step_thread_state
1637 = tp
->displaced_step_state
;
1639 /* We should never reach this function if the architecture does not
1640 support displaced stepping. */
1641 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1643 /* Nor if the thread isn't meant to step over a breakpoint. */
1644 gdb_assert (tp
->control
.trap_expected
);
1646 /* Disable range stepping while executing in the scratch pad. We
1647 want a single-step even if executing the displaced instruction in
1648 the scratch buffer lands within the stepping range (e.g., a
1650 tp
->control
.may_range_step
= 0;
1652 /* We are about to start a displaced step for this thread. If one is already
1653 in progress, something's wrong. */
1654 gdb_assert (!disp_step_thread_state
.in_progress ());
1656 if (tp
->inf
->displaced_step_state
.unavailable
)
1658 /* The gdbarch tells us it's not worth asking to try a prepare because
1659 it is likely that it will return unavailable, so don't bother asking. */
1661 displaced_debug_printf ("deferring step of %s",
1662 target_pid_to_str (tp
->ptid
).c_str ());
1664 global_thread_step_over_chain_enqueue (tp
);
1665 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1668 displaced_debug_printf ("displaced-stepping %s now",
1669 target_pid_to_str (tp
->ptid
).c_str ());
1671 scoped_restore_current_thread restore_thread
;
1673 switch_to_thread (tp
);
1675 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1676 CORE_ADDR displaced_pc
;
1678 displaced_step_prepare_status status
1679 = gdbarch_displaced_step_prepare (gdbarch
, tp
, displaced_pc
);
1681 if (status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
1683 displaced_debug_printf ("failed to prepare (%s)",
1684 target_pid_to_str (tp
->ptid
).c_str ());
1686 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1688 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1690 /* Not enough displaced stepping resources available, defer this
1691 request by placing it the queue. */
1693 displaced_debug_printf ("not enough resources available, "
1694 "deferring step of %s",
1695 target_pid_to_str (tp
->ptid
).c_str ());
1697 global_thread_step_over_chain_enqueue (tp
);
1699 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1702 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1704 /* Save the information we need to fix things up if the step
1706 disp_step_thread_state
.set (gdbarch
);
1708 tp
->inf
->displaced_step_state
.in_progress_count
++;
1710 displaced_debug_printf ("prepared successfully thread=%s, "
1711 "original_pc=%s, displaced_pc=%s",
1712 target_pid_to_str (tp
->ptid
).c_str (),
1713 paddress (gdbarch
, original_pc
),
1714 paddress (gdbarch
, displaced_pc
));
1716 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1719 /* Wrapper for displaced_step_prepare_throw that disabled further
1720 attempts at displaced stepping if we get a memory error. */
1722 static displaced_step_prepare_status
1723 displaced_step_prepare (thread_info
*thread
)
1725 displaced_step_prepare_status status
1726 = DISPLACED_STEP_PREPARE_STATUS_CANT
;
1730 status
= displaced_step_prepare_throw (thread
);
1732 catch (const gdb_exception_error
&ex
)
1734 if (ex
.error
!= MEMORY_ERROR
1735 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1738 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1741 /* Be verbose if "set displaced-stepping" is "on", silent if
1743 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1745 warning (_("disabling displaced stepping: %s"),
1749 /* Disable further displaced stepping attempts. */
1750 thread
->inf
->displaced_step_state
.failed_before
= 1;
1756 /* If we displaced stepped an instruction successfully, adjust registers and
1757 memory to yield the same effect the instruction would have had if we had
1758 executed it at its original address, and return
1759 DISPLACED_STEP_FINISH_STATUS_OK. If the instruction didn't complete,
1760 relocate the PC and return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED.
1762 If the thread wasn't displaced stepping, return
1763 DISPLACED_STEP_FINISH_STATUS_OK as well. */
1765 static displaced_step_finish_status
1766 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1768 displaced_step_thread_state
*displaced
= &event_thread
->displaced_step_state
;
1770 /* Was this thread performing a displaced step? */
1771 if (!displaced
->in_progress ())
1772 return DISPLACED_STEP_FINISH_STATUS_OK
;
1774 gdb_assert (event_thread
->inf
->displaced_step_state
.in_progress_count
> 0);
1775 event_thread
->inf
->displaced_step_state
.in_progress_count
--;
1777 /* Fixup may need to read memory/registers. Switch to the thread
1778 that we're fixing up. Also, target_stopped_by_watchpoint checks
1779 the current thread, and displaced_step_restore performs ptid-dependent
1780 memory accesses using current_inferior() and current_top_target(). */
1781 switch_to_thread (event_thread
);
1783 displaced_step_reset_cleanup
cleanup (displaced
);
1785 /* Do the fixup, and release the resources acquired to do the displaced
1787 return gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1788 event_thread
, signal
);
1791 /* Data to be passed around while handling an event. This data is
1792 discarded between events. */
1793 struct execution_control_state
1795 process_stratum_target
*target
;
1797 /* The thread that got the event, if this was a thread event; NULL
1799 struct thread_info
*event_thread
;
1801 struct target_waitstatus ws
;
1802 int stop_func_filled_in
;
1803 CORE_ADDR stop_func_start
;
1804 CORE_ADDR stop_func_end
;
1805 const char *stop_func_name
;
1808 /* True if the event thread hit the single-step breakpoint of
1809 another thread. Thus the event doesn't cause a stop, the thread
1810 needs to be single-stepped past the single-step breakpoint before
1811 we can switch back to the original stepping thread. */
1812 int hit_singlestep_breakpoint
;
1815 /* Clear ECS and set it to point at TP. */
1818 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1820 memset (ecs
, 0, sizeof (*ecs
));
1821 ecs
->event_thread
= tp
;
1822 ecs
->ptid
= tp
->ptid
;
1825 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1826 static void prepare_to_wait (struct execution_control_state
*ecs
);
1827 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1828 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1830 /* Are there any pending step-over requests? If so, run all we can
1831 now and return true. Otherwise, return false. */
1834 start_step_over (void)
1836 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
1840 /* Don't start a new step-over if we already have an in-line
1841 step-over operation ongoing. */
1842 if (step_over_info_valid_p ())
1845 /* Steal the global thread step over chain. As we try to initiate displaced
1846 steps, threads will be enqueued in the global chain if no buffers are
1847 available. If we iterated on the global chain directly, we might iterate
1849 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1850 global_thread_step_over_chain_head
= NULL
;
1852 infrun_debug_printf ("stealing global queue of threads to step, length = %d",
1853 thread_step_over_chain_length (threads_to_step
));
1855 bool started
= false;
1857 /* On scope exit (whatever the reason, return or exception), if there are
1858 threads left in the THREADS_TO_STEP chain, put back these threads in the
1862 if (threads_to_step
== nullptr)
1863 infrun_debug_printf ("step-over queue now empty");
1866 infrun_debug_printf ("putting back %d threads to step in global queue",
1867 thread_step_over_chain_length (threads_to_step
));
1869 global_thread_step_over_chain_enqueue_chain (threads_to_step
);
1873 for (thread_info
*tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1875 struct execution_control_state ecss
;
1876 struct execution_control_state
*ecs
= &ecss
;
1877 step_over_what step_what
;
1878 int must_be_in_line
;
1880 gdb_assert (!tp
->stop_requested
);
1882 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1884 if (tp
->inf
->displaced_step_state
.unavailable
)
1886 /* The arch told us to not even try preparing another displaced step
1887 for this inferior. Just leave the thread in THREADS_TO_STEP, it
1888 will get moved to the global chain on scope exit. */
1892 /* Remove thread from the THREADS_TO_STEP chain. If anything goes wrong
1893 while we try to prepare the displaced step, we don't add it back to
1894 the global step over chain. This is to avoid a thread staying in the
1895 step over chain indefinitely if something goes wrong when resuming it
1896 If the error is intermittent and it still needs a step over, it will
1897 get enqueued again when we try to resume it normally. */
1898 thread_step_over_chain_remove (&threads_to_step
, tp
);
1900 step_what
= thread_still_needs_step_over (tp
);
1901 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1902 || ((step_what
& STEP_OVER_BREAKPOINT
)
1903 && !use_displaced_stepping (tp
)));
1905 /* We currently stop all threads of all processes to step-over
1906 in-line. If we need to start a new in-line step-over, let
1907 any pending displaced steps finish first. */
1908 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1910 global_thread_step_over_chain_enqueue (tp
);
1914 if (tp
->control
.trap_expected
1918 internal_error (__FILE__
, __LINE__
,
1919 "[%s] has inconsistent state: "
1920 "trap_expected=%d, resumed=%d, executing=%d\n",
1921 target_pid_to_str (tp
->ptid
).c_str (),
1922 tp
->control
.trap_expected
,
1927 infrun_debug_printf ("resuming [%s] for step-over",
1928 target_pid_to_str (tp
->ptid
).c_str ());
1930 /* keep_going_pass_signal skips the step-over if the breakpoint
1931 is no longer inserted. In all-stop, we want to keep looking
1932 for a thread that needs a step-over instead of resuming TP,
1933 because we wouldn't be able to resume anything else until the
1934 target stops again. In non-stop, the resume always resumes
1935 only TP, so it's OK to let the thread resume freely. */
1936 if (!target_is_non_stop_p () && !step_what
)
1939 switch_to_thread (tp
);
1940 reset_ecs (ecs
, tp
);
1941 keep_going_pass_signal (ecs
);
1943 if (!ecs
->wait_some_more
)
1944 error (_("Command aborted."));
1946 /* If the thread's step over could not be initiated because no buffers
1947 were available, it was re-added to the global step over chain. */
1950 infrun_debug_printf ("[%s] was resumed.",
1951 target_pid_to_str (tp
->ptid
).c_str ());
1952 gdb_assert (!thread_is_in_step_over_chain (tp
));
1956 infrun_debug_printf ("[%s] was NOT resumed.",
1957 target_pid_to_str (tp
->ptid
).c_str ());
1958 gdb_assert (thread_is_in_step_over_chain (tp
));
1961 /* If we started a new in-line step-over, we're done. */
1962 if (step_over_info_valid_p ())
1964 gdb_assert (tp
->control
.trap_expected
);
1969 if (!target_is_non_stop_p ())
1971 /* On all-stop, shouldn't have resumed unless we needed a
1973 gdb_assert (tp
->control
.trap_expected
1974 || tp
->step_after_step_resume_breakpoint
);
1976 /* With remote targets (at least), in all-stop, we can't
1977 issue any further remote commands until the program stops
1983 /* Either the thread no longer needed a step-over, or a new
1984 displaced stepping sequence started. Even in the latter
1985 case, continue looking. Maybe we can also start another
1986 displaced step on a thread of other process. */
1992 /* Update global variables holding ptids to hold NEW_PTID if they were
1993 holding OLD_PTID. */
1995 infrun_thread_ptid_changed (process_stratum_target
*target
,
1996 ptid_t old_ptid
, ptid_t new_ptid
)
1998 if (inferior_ptid
== old_ptid
1999 && current_inferior ()->process_target () == target
)
2000 inferior_ptid
= new_ptid
;
2005 static const char schedlock_off
[] = "off";
2006 static const char schedlock_on
[] = "on";
2007 static const char schedlock_step
[] = "step";
2008 static const char schedlock_replay
[] = "replay";
2009 static const char *const scheduler_enums
[] = {
2016 static const char *scheduler_mode
= schedlock_replay
;
2018 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2019 struct cmd_list_element
*c
, const char *value
)
2021 fprintf_filtered (file
,
2022 _("Mode for locking scheduler "
2023 "during execution is \"%s\".\n"),
2028 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2030 if (!target_can_lock_scheduler ())
2032 scheduler_mode
= schedlock_off
;
2033 error (_("Target '%s' cannot support this command."), target_shortname
);
2037 /* True if execution commands resume all threads of all processes by
2038 default; otherwise, resume only threads of the current inferior
2040 bool sched_multi
= false;
2042 /* Try to setup for software single stepping over the specified location.
2043 Return true if target_resume() should use hardware single step.
2045 GDBARCH the current gdbarch.
2046 PC the location to step over. */
2049 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2051 bool hw_step
= true;
2053 if (execution_direction
== EXEC_FORWARD
2054 && gdbarch_software_single_step_p (gdbarch
))
2055 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2063 user_visible_resume_ptid (int step
)
2069 /* With non-stop mode on, threads are always handled
2071 resume_ptid
= inferior_ptid
;
2073 else if ((scheduler_mode
== schedlock_on
)
2074 || (scheduler_mode
== schedlock_step
&& step
))
2076 /* User-settable 'scheduler' mode requires solo thread
2078 resume_ptid
= inferior_ptid
;
2080 else if ((scheduler_mode
== schedlock_replay
)
2081 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2083 /* User-settable 'scheduler' mode requires solo thread resume in replay
2085 resume_ptid
= inferior_ptid
;
2087 else if (!sched_multi
&& target_supports_multi_process ())
2089 /* Resume all threads of the current process (and none of other
2091 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2095 /* Resume all threads of all processes. */
2096 resume_ptid
= RESUME_ALL
;
2104 process_stratum_target
*
2105 user_visible_resume_target (ptid_t resume_ptid
)
2107 return (resume_ptid
== minus_one_ptid
&& sched_multi
2109 : current_inferior ()->process_target ());
2112 /* Return a ptid representing the set of threads that we will resume,
2113 in the perspective of the target, assuming run control handling
2114 does not require leaving some threads stopped (e.g., stepping past
2115 breakpoint). USER_STEP indicates whether we're about to start the
2116 target for a stepping command. */
2119 internal_resume_ptid (int user_step
)
2121 /* In non-stop, we always control threads individually. Note that
2122 the target may always work in non-stop mode even with "set
2123 non-stop off", in which case user_visible_resume_ptid could
2124 return a wildcard ptid. */
2125 if (target_is_non_stop_p ())
2126 return inferior_ptid
;
2128 return user_visible_resume_ptid (user_step
);
2131 /* Wrapper for target_resume, that handles infrun-specific
2135 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2137 struct thread_info
*tp
= inferior_thread ();
2139 gdb_assert (!tp
->stop_requested
);
2141 /* Install inferior's terminal modes. */
2142 target_terminal::inferior ();
2144 /* Avoid confusing the next resume, if the next stop/resume
2145 happens to apply to another thread. */
2146 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2148 /* Advise target which signals may be handled silently.
2150 If we have removed breakpoints because we are stepping over one
2151 in-line (in any thread), we need to receive all signals to avoid
2152 accidentally skipping a breakpoint during execution of a signal
2155 Likewise if we're displaced stepping, otherwise a trap for a
2156 breakpoint in a signal handler might be confused with the
2157 displaced step finishing. We don't make the displaced_step_finish
2158 step distinguish the cases instead, because:
2160 - a backtrace while stopped in the signal handler would show the
2161 scratch pad as frame older than the signal handler, instead of
2162 the real mainline code.
2164 - when the thread is later resumed, the signal handler would
2165 return to the scratch pad area, which would no longer be
2167 if (step_over_info_valid_p ()
2168 || displaced_step_in_progress (tp
->inf
))
2169 target_pass_signals ({});
2171 target_pass_signals (signal_pass
);
2173 target_resume (resume_ptid
, step
, sig
);
2175 target_commit_resume ();
2177 if (target_can_async_p ())
2181 /* Resume the inferior. SIG is the signal to give the inferior
2182 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2183 call 'resume', which handles exceptions. */
2186 resume_1 (enum gdb_signal sig
)
2188 struct regcache
*regcache
= get_current_regcache ();
2189 struct gdbarch
*gdbarch
= regcache
->arch ();
2190 struct thread_info
*tp
= inferior_thread ();
2191 const address_space
*aspace
= regcache
->aspace ();
2193 /* This represents the user's step vs continue request. When
2194 deciding whether "set scheduler-locking step" applies, it's the
2195 user's intention that counts. */
2196 const int user_step
= tp
->control
.stepping_command
;
2197 /* This represents what we'll actually request the target to do.
2198 This can decay from a step to a continue, if e.g., we need to
2199 implement single-stepping with breakpoints (software
2203 gdb_assert (!tp
->stop_requested
);
2204 gdb_assert (!thread_is_in_step_over_chain (tp
));
2206 if (tp
->suspend
.waitstatus_pending_p
)
2209 ("thread %s has pending wait "
2210 "status %s (currently_stepping=%d).",
2211 target_pid_to_str (tp
->ptid
).c_str (),
2212 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2213 currently_stepping (tp
));
2215 tp
->inf
->process_target ()->threads_executing
= true;
2218 /* FIXME: What should we do if we are supposed to resume this
2219 thread with a signal? Maybe we should maintain a queue of
2220 pending signals to deliver. */
2221 if (sig
!= GDB_SIGNAL_0
)
2223 warning (_("Couldn't deliver signal %s to %s."),
2224 gdb_signal_to_name (sig
),
2225 target_pid_to_str (tp
->ptid
).c_str ());
2228 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2230 if (target_can_async_p ())
2233 /* Tell the event loop we have an event to process. */
2234 mark_async_event_handler (infrun_async_inferior_event_token
);
2239 tp
->stepped_breakpoint
= 0;
2241 /* Depends on stepped_breakpoint. */
2242 step
= currently_stepping (tp
);
2244 if (current_inferior ()->waiting_for_vfork_done
)
2246 /* Don't try to single-step a vfork parent that is waiting for
2247 the child to get out of the shared memory region (by exec'ing
2248 or exiting). This is particularly important on software
2249 single-step archs, as the child process would trip on the
2250 software single step breakpoint inserted for the parent
2251 process. Since the parent will not actually execute any
2252 instruction until the child is out of the shared region (such
2253 are vfork's semantics), it is safe to simply continue it.
2254 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2255 the parent, and tell it to `keep_going', which automatically
2256 re-sets it stepping. */
2257 infrun_debug_printf ("resume : clear step");
2261 CORE_ADDR pc
= regcache_read_pc (regcache
);
2263 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2264 "current thread [%s] at %s",
2265 step
, gdb_signal_to_symbol_string (sig
),
2266 tp
->control
.trap_expected
,
2267 target_pid_to_str (inferior_ptid
).c_str (),
2268 paddress (gdbarch
, pc
));
2270 /* Normally, by the time we reach `resume', the breakpoints are either
2271 removed or inserted, as appropriate. The exception is if we're sitting
2272 at a permanent breakpoint; we need to step over it, but permanent
2273 breakpoints can't be removed. So we have to test for it here. */
2274 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2276 if (sig
!= GDB_SIGNAL_0
)
2278 /* We have a signal to pass to the inferior. The resume
2279 may, or may not take us to the signal handler. If this
2280 is a step, we'll need to stop in the signal handler, if
2281 there's one, (if the target supports stepping into
2282 handlers), or in the next mainline instruction, if
2283 there's no handler. If this is a continue, we need to be
2284 sure to run the handler with all breakpoints inserted.
2285 In all cases, set a breakpoint at the current address
2286 (where the handler returns to), and once that breakpoint
2287 is hit, resume skipping the permanent breakpoint. If
2288 that breakpoint isn't hit, then we've stepped into the
2289 signal handler (or hit some other event). We'll delete
2290 the step-resume breakpoint then. */
2292 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2293 "deliver signal first");
2295 clear_step_over_info ();
2296 tp
->control
.trap_expected
= 0;
2298 if (tp
->control
.step_resume_breakpoint
== NULL
)
2300 /* Set a "high-priority" step-resume, as we don't want
2301 user breakpoints at PC to trigger (again) when this
2303 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2304 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2306 tp
->step_after_step_resume_breakpoint
= step
;
2309 insert_breakpoints ();
2313 /* There's no signal to pass, we can go ahead and skip the
2314 permanent breakpoint manually. */
2315 infrun_debug_printf ("skipping permanent breakpoint");
2316 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2317 /* Update pc to reflect the new address from which we will
2318 execute instructions. */
2319 pc
= regcache_read_pc (regcache
);
2323 /* We've already advanced the PC, so the stepping part
2324 is done. Now we need to arrange for a trap to be
2325 reported to handle_inferior_event. Set a breakpoint
2326 at the current PC, and run to it. Don't update
2327 prev_pc, because if we end in
2328 switch_back_to_stepped_thread, we want the "expected
2329 thread advanced also" branch to be taken. IOW, we
2330 don't want this thread to step further from PC
2332 gdb_assert (!step_over_info_valid_p ());
2333 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2334 insert_breakpoints ();
2336 resume_ptid
= internal_resume_ptid (user_step
);
2337 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2344 /* If we have a breakpoint to step over, make sure to do a single
2345 step only. Same if we have software watchpoints. */
2346 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2347 tp
->control
.may_range_step
= 0;
2349 /* If displaced stepping is enabled, step over breakpoints by executing a
2350 copy of the instruction at a different address.
2352 We can't use displaced stepping when we have a signal to deliver;
2353 the comments for displaced_step_prepare explain why. The
2354 comments in the handle_inferior event for dealing with 'random
2355 signals' explain what we do instead.
2357 We can't use displaced stepping when we are waiting for vfork_done
2358 event, displaced stepping breaks the vfork child similarly as single
2359 step software breakpoint. */
2360 if (tp
->control
.trap_expected
2361 && use_displaced_stepping (tp
)
2362 && !step_over_info_valid_p ()
2363 && sig
== GDB_SIGNAL_0
2364 && !current_inferior ()->waiting_for_vfork_done
)
2366 displaced_step_prepare_status prepare_status
2367 = displaced_step_prepare (tp
);
2369 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2371 infrun_debug_printf ("Got placed in step-over queue");
2373 tp
->control
.trap_expected
= 0;
2376 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
2378 /* Fallback to stepping over the breakpoint in-line. */
2380 if (target_is_non_stop_p ())
2381 stop_all_threads ();
2383 set_step_over_info (regcache
->aspace (),
2384 regcache_read_pc (regcache
), 0, tp
->global_num
);
2386 step
= maybe_software_singlestep (gdbarch
, pc
);
2388 insert_breakpoints ();
2390 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2392 /* Update pc to reflect the new address from which we will
2393 execute instructions due to displaced stepping. */
2394 pc
= regcache_read_pc (get_thread_regcache (tp
));
2396 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2399 gdb_assert_not_reached (_("Invalid displaced_step_prepare_status "
2403 /* Do we need to do it the hard way, w/temp breakpoints? */
2405 step
= maybe_software_singlestep (gdbarch
, pc
);
2407 /* Currently, our software single-step implementation leads to different
2408 results than hardware single-stepping in one situation: when stepping
2409 into delivering a signal which has an associated signal handler,
2410 hardware single-step will stop at the first instruction of the handler,
2411 while software single-step will simply skip execution of the handler.
2413 For now, this difference in behavior is accepted since there is no
2414 easy way to actually implement single-stepping into a signal handler
2415 without kernel support.
2417 However, there is one scenario where this difference leads to follow-on
2418 problems: if we're stepping off a breakpoint by removing all breakpoints
2419 and then single-stepping. In this case, the software single-step
2420 behavior means that even if there is a *breakpoint* in the signal
2421 handler, GDB still would not stop.
2423 Fortunately, we can at least fix this particular issue. We detect
2424 here the case where we are about to deliver a signal while software
2425 single-stepping with breakpoints removed. In this situation, we
2426 revert the decisions to remove all breakpoints and insert single-
2427 step breakpoints, and instead we install a step-resume breakpoint
2428 at the current address, deliver the signal without stepping, and
2429 once we arrive back at the step-resume breakpoint, actually step
2430 over the breakpoint we originally wanted to step over. */
2431 if (thread_has_single_step_breakpoints_set (tp
)
2432 && sig
!= GDB_SIGNAL_0
2433 && step_over_info_valid_p ())
2435 /* If we have nested signals or a pending signal is delivered
2436 immediately after a handler returns, might already have
2437 a step-resume breakpoint set on the earlier handler. We cannot
2438 set another step-resume breakpoint; just continue on until the
2439 original breakpoint is hit. */
2440 if (tp
->control
.step_resume_breakpoint
== NULL
)
2442 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2443 tp
->step_after_step_resume_breakpoint
= 1;
2446 delete_single_step_breakpoints (tp
);
2448 clear_step_over_info ();
2449 tp
->control
.trap_expected
= 0;
2451 insert_breakpoints ();
2454 /* If STEP is set, it's a request to use hardware stepping
2455 facilities. But in that case, we should never
2456 use singlestep breakpoint. */
2457 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2459 /* Decide the set of threads to ask the target to resume. */
2460 if (tp
->control
.trap_expected
)
2462 /* We're allowing a thread to run past a breakpoint it has
2463 hit, either by single-stepping the thread with the breakpoint
2464 removed, or by displaced stepping, with the breakpoint inserted.
2465 In the former case, we need to single-step only this thread,
2466 and keep others stopped, as they can miss this breakpoint if
2467 allowed to run. That's not really a problem for displaced
2468 stepping, but, we still keep other threads stopped, in case
2469 another thread is also stopped for a breakpoint waiting for
2470 its turn in the displaced stepping queue. */
2471 resume_ptid
= inferior_ptid
;
2474 resume_ptid
= internal_resume_ptid (user_step
);
2476 if (execution_direction
!= EXEC_REVERSE
2477 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2479 /* There are two cases where we currently need to step a
2480 breakpoint instruction when we have a signal to deliver:
2482 - See handle_signal_stop where we handle random signals that
2483 could take out us out of the stepping range. Normally, in
2484 that case we end up continuing (instead of stepping) over the
2485 signal handler with a breakpoint at PC, but there are cases
2486 where we should _always_ single-step, even if we have a
2487 step-resume breakpoint, like when a software watchpoint is
2488 set. Assuming single-stepping and delivering a signal at the
2489 same time would takes us to the signal handler, then we could
2490 have removed the breakpoint at PC to step over it. However,
2491 some hardware step targets (like e.g., Mac OS) can't step
2492 into signal handlers, and for those, we need to leave the
2493 breakpoint at PC inserted, as otherwise if the handler
2494 recurses and executes PC again, it'll miss the breakpoint.
2495 So we leave the breakpoint inserted anyway, but we need to
2496 record that we tried to step a breakpoint instruction, so
2497 that adjust_pc_after_break doesn't end up confused.
2499 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2500 in one thread after another thread that was stepping had been
2501 momentarily paused for a step-over. When we re-resume the
2502 stepping thread, it may be resumed from that address with a
2503 breakpoint that hasn't trapped yet. Seen with
2504 gdb.threads/non-stop-fair-events.exp, on targets that don't
2505 do displaced stepping. */
2507 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2508 target_pid_to_str (tp
->ptid
).c_str ());
2510 tp
->stepped_breakpoint
= 1;
2512 /* Most targets can step a breakpoint instruction, thus
2513 executing it normally. But if this one cannot, just
2514 continue and we will hit it anyway. */
2515 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2520 && tp
->control
.trap_expected
2521 && use_displaced_stepping (tp
)
2522 && !step_over_info_valid_p ())
2524 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2525 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2526 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2529 read_memory (actual_pc
, buf
, sizeof (buf
));
2530 displaced_debug_printf ("run %s: %s",
2531 paddress (resume_gdbarch
, actual_pc
),
2532 displaced_step_dump_bytes
2533 (buf
, sizeof (buf
)).c_str ());
2536 if (tp
->control
.may_range_step
)
2538 /* If we're resuming a thread with the PC out of the step
2539 range, then we're doing some nested/finer run control
2540 operation, like stepping the thread out of the dynamic
2541 linker or the displaced stepping scratch pad. We
2542 shouldn't have allowed a range step then. */
2543 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2546 do_target_resume (resume_ptid
, step
, sig
);
2550 /* Resume the inferior. SIG is the signal to give the inferior
2551 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2552 rolls back state on error. */
2555 resume (gdb_signal sig
)
2561 catch (const gdb_exception
&ex
)
2563 /* If resuming is being aborted for any reason, delete any
2564 single-step breakpoint resume_1 may have created, to avoid
2565 confusing the following resumption, and to avoid leaving
2566 single-step breakpoints perturbing other threads, in case
2567 we're running in non-stop mode. */
2568 if (inferior_ptid
!= null_ptid
)
2569 delete_single_step_breakpoints (inferior_thread ());
2579 /* Counter that tracks number of user visible stops. This can be used
2580 to tell whether a command has proceeded the inferior past the
2581 current location. This allows e.g., inferior function calls in
2582 breakpoint commands to not interrupt the command list. When the
2583 call finishes successfully, the inferior is standing at the same
2584 breakpoint as if nothing happened (and so we don't call
2586 static ULONGEST current_stop_id
;
2593 return current_stop_id
;
2596 /* Called when we report a user visible stop. */
2604 /* Clear out all variables saying what to do when inferior is continued.
2605 First do this, then set the ones you want, then call `proceed'. */
2608 clear_proceed_status_thread (struct thread_info
*tp
)
2610 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2612 /* If we're starting a new sequence, then the previous finished
2613 single-step is no longer relevant. */
2614 if (tp
->suspend
.waitstatus_pending_p
)
2616 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2618 infrun_debug_printf ("pending event of %s was a finished step. "
2620 target_pid_to_str (tp
->ptid
).c_str ());
2622 tp
->suspend
.waitstatus_pending_p
= 0;
2623 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2628 ("thread %s has pending wait status %s (currently_stepping=%d).",
2629 target_pid_to_str (tp
->ptid
).c_str (),
2630 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2631 currently_stepping (tp
));
2635 /* If this signal should not be seen by program, give it zero.
2636 Used for debugging signals. */
2637 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2638 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2640 delete tp
->thread_fsm
;
2641 tp
->thread_fsm
= NULL
;
2643 tp
->control
.trap_expected
= 0;
2644 tp
->control
.step_range_start
= 0;
2645 tp
->control
.step_range_end
= 0;
2646 tp
->control
.may_range_step
= 0;
2647 tp
->control
.step_frame_id
= null_frame_id
;
2648 tp
->control
.step_stack_frame_id
= null_frame_id
;
2649 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2650 tp
->control
.step_start_function
= NULL
;
2651 tp
->stop_requested
= 0;
2653 tp
->control
.stop_step
= 0;
2655 tp
->control
.proceed_to_finish
= 0;
2657 tp
->control
.stepping_command
= 0;
2659 /* Discard any remaining commands or status from previous stop. */
2660 bpstat_clear (&tp
->control
.stop_bpstat
);
2664 clear_proceed_status (int step
)
2666 /* With scheduler-locking replay, stop replaying other threads if we're
2667 not replaying the user-visible resume ptid.
2669 This is a convenience feature to not require the user to explicitly
2670 stop replaying the other threads. We're assuming that the user's
2671 intent is to resume tracing the recorded process. */
2672 if (!non_stop
&& scheduler_mode
== schedlock_replay
2673 && target_record_is_replaying (minus_one_ptid
)
2674 && !target_record_will_replay (user_visible_resume_ptid (step
),
2675 execution_direction
))
2676 target_record_stop_replaying ();
2678 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2680 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2681 process_stratum_target
*resume_target
2682 = user_visible_resume_target (resume_ptid
);
2684 /* In all-stop mode, delete the per-thread status of all threads
2685 we're about to resume, implicitly and explicitly. */
2686 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2687 clear_proceed_status_thread (tp
);
2690 if (inferior_ptid
!= null_ptid
)
2692 struct inferior
*inferior
;
2696 /* If in non-stop mode, only delete the per-thread status of
2697 the current thread. */
2698 clear_proceed_status_thread (inferior_thread ());
2701 inferior
= current_inferior ();
2702 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2705 gdb::observers::about_to_proceed
.notify ();
2708 /* Returns true if TP is still stopped at a breakpoint that needs
2709 stepping-over in order to make progress. If the breakpoint is gone
2710 meanwhile, we can skip the whole step-over dance. */
2713 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2715 if (tp
->stepping_over_breakpoint
)
2717 struct regcache
*regcache
= get_thread_regcache (tp
);
2719 if (breakpoint_here_p (regcache
->aspace (),
2720 regcache_read_pc (regcache
))
2721 == ordinary_breakpoint_here
)
2724 tp
->stepping_over_breakpoint
= 0;
2730 /* Check whether thread TP still needs to start a step-over in order
2731 to make progress when resumed. Returns an bitwise or of enum
2732 step_over_what bits, indicating what needs to be stepped over. */
2734 static step_over_what
2735 thread_still_needs_step_over (struct thread_info
*tp
)
2737 step_over_what what
= 0;
2739 if (thread_still_needs_step_over_bp (tp
))
2740 what
|= STEP_OVER_BREAKPOINT
;
2742 if (tp
->stepping_over_watchpoint
2743 && !target_have_steppable_watchpoint ())
2744 what
|= STEP_OVER_WATCHPOINT
;
2749 /* Returns true if scheduler locking applies. STEP indicates whether
2750 we're about to do a step/next-like command to a thread. */
2753 schedlock_applies (struct thread_info
*tp
)
2755 return (scheduler_mode
== schedlock_on
2756 || (scheduler_mode
== schedlock_step
2757 && tp
->control
.stepping_command
)
2758 || (scheduler_mode
== schedlock_replay
2759 && target_record_will_replay (minus_one_ptid
,
2760 execution_direction
)));
2763 /* Calls target_commit_resume on all targets. */
2766 commit_resume_all_targets ()
2768 scoped_restore_current_thread restore_thread
;
2770 /* Map between process_target and a representative inferior. This
2771 is to avoid committing a resume in the same target more than
2772 once. Resumptions must be idempotent, so this is an
2774 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2776 for (inferior
*inf
: all_non_exited_inferiors ())
2777 if (inf
->has_execution ())
2778 conn_inf
[inf
->process_target ()] = inf
;
2780 for (const auto &ci
: conn_inf
)
2782 inferior
*inf
= ci
.second
;
2783 switch_to_inferior_no_thread (inf
);
2784 target_commit_resume ();
2788 /* Check that all the targets we're about to resume are in non-stop
2789 mode. Ideally, we'd only care whether all targets support
2790 target-async, but we're not there yet. E.g., stop_all_threads
2791 doesn't know how to handle all-stop targets. Also, the remote
2792 protocol in all-stop mode is synchronous, irrespective of
2793 target-async, which means that things like a breakpoint re-set
2794 triggered by one target would try to read memory from all targets
2798 check_multi_target_resumption (process_stratum_target
*resume_target
)
2800 if (!non_stop
&& resume_target
== nullptr)
2802 scoped_restore_current_thread restore_thread
;
2804 /* This is used to track whether we're resuming more than one
2806 process_stratum_target
*first_connection
= nullptr;
2808 /* The first inferior we see with a target that does not work in
2809 always-non-stop mode. */
2810 inferior
*first_not_non_stop
= nullptr;
2812 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2814 switch_to_inferior_no_thread (inf
);
2816 if (!target_has_execution ())
2819 process_stratum_target
*proc_target
2820 = current_inferior ()->process_target();
2822 if (!target_is_non_stop_p ())
2823 first_not_non_stop
= inf
;
2825 if (first_connection
== nullptr)
2826 first_connection
= proc_target
;
2827 else if (first_connection
!= proc_target
2828 && first_not_non_stop
!= nullptr)
2830 switch_to_inferior_no_thread (first_not_non_stop
);
2832 proc_target
= current_inferior ()->process_target();
2834 error (_("Connection %d (%s) does not support "
2835 "multi-target resumption."),
2836 proc_target
->connection_number
,
2837 make_target_connection_string (proc_target
).c_str ());
2843 /* Basic routine for continuing the program in various fashions.
2845 ADDR is the address to resume at, or -1 for resume where stopped.
2846 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2847 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2849 You should call clear_proceed_status before calling proceed. */
2852 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2854 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
2856 struct regcache
*regcache
;
2857 struct gdbarch
*gdbarch
;
2859 struct execution_control_state ecss
;
2860 struct execution_control_state
*ecs
= &ecss
;
2863 /* If we're stopped at a fork/vfork, follow the branch set by the
2864 "set follow-fork-mode" command; otherwise, we'll just proceed
2865 resuming the current thread. */
2866 if (!follow_fork ())
2868 /* The target for some reason decided not to resume. */
2870 if (target_can_async_p ())
2871 inferior_event_handler (INF_EXEC_COMPLETE
);
2875 /* We'll update this if & when we switch to a new thread. */
2876 previous_inferior_ptid
= inferior_ptid
;
2878 regcache
= get_current_regcache ();
2879 gdbarch
= regcache
->arch ();
2880 const address_space
*aspace
= regcache
->aspace ();
2882 pc
= regcache_read_pc_protected (regcache
);
2884 thread_info
*cur_thr
= inferior_thread ();
2886 /* Fill in with reasonable starting values. */
2887 init_thread_stepping_state (cur_thr
);
2889 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2892 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2893 process_stratum_target
*resume_target
2894 = user_visible_resume_target (resume_ptid
);
2896 check_multi_target_resumption (resume_target
);
2898 if (addr
== (CORE_ADDR
) -1)
2900 if (pc
== cur_thr
->suspend
.stop_pc
2901 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2902 && execution_direction
!= EXEC_REVERSE
)
2903 /* There is a breakpoint at the address we will resume at,
2904 step one instruction before inserting breakpoints so that
2905 we do not stop right away (and report a second hit at this
2908 Note, we don't do this in reverse, because we won't
2909 actually be executing the breakpoint insn anyway.
2910 We'll be (un-)executing the previous instruction. */
2911 cur_thr
->stepping_over_breakpoint
= 1;
2912 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2913 && gdbarch_single_step_through_delay (gdbarch
,
2914 get_current_frame ()))
2915 /* We stepped onto an instruction that needs to be stepped
2916 again before re-inserting the breakpoint, do so. */
2917 cur_thr
->stepping_over_breakpoint
= 1;
2921 regcache_write_pc (regcache
, addr
);
2924 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2925 cur_thr
->suspend
.stop_signal
= siggnal
;
2927 /* If an exception is thrown from this point on, make sure to
2928 propagate GDB's knowledge of the executing state to the
2929 frontend/user running state. */
2930 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2932 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2933 threads (e.g., we might need to set threads stepping over
2934 breakpoints first), from the user/frontend's point of view, all
2935 threads in RESUME_PTID are now running. Unless we're calling an
2936 inferior function, as in that case we pretend the inferior
2937 doesn't run at all. */
2938 if (!cur_thr
->control
.in_infcall
)
2939 set_running (resume_target
, resume_ptid
, true);
2941 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2942 gdb_signal_to_symbol_string (siggnal
));
2944 annotate_starting ();
2946 /* Make sure that output from GDB appears before output from the
2948 gdb_flush (gdb_stdout
);
2950 /* Since we've marked the inferior running, give it the terminal. A
2951 QUIT/Ctrl-C from here on is forwarded to the target (which can
2952 still detect attempts to unblock a stuck connection with repeated
2953 Ctrl-C from within target_pass_ctrlc). */
2954 target_terminal::inferior ();
2956 /* In a multi-threaded task we may select another thread and
2957 then continue or step.
2959 But if a thread that we're resuming had stopped at a breakpoint,
2960 it will immediately cause another breakpoint stop without any
2961 execution (i.e. it will report a breakpoint hit incorrectly). So
2962 we must step over it first.
2964 Look for threads other than the current (TP) that reported a
2965 breakpoint hit and haven't been resumed yet since. */
2967 /* If scheduler locking applies, we can avoid iterating over all
2969 if (!non_stop
&& !schedlock_applies (cur_thr
))
2971 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
2974 switch_to_thread_no_regs (tp
);
2976 /* Ignore the current thread here. It's handled
2981 if (!thread_still_needs_step_over (tp
))
2984 gdb_assert (!thread_is_in_step_over_chain (tp
));
2986 infrun_debug_printf ("need to step-over [%s] first",
2987 target_pid_to_str (tp
->ptid
).c_str ());
2989 global_thread_step_over_chain_enqueue (tp
);
2992 switch_to_thread (cur_thr
);
2995 /* Enqueue the current thread last, so that we move all other
2996 threads over their breakpoints first. */
2997 if (cur_thr
->stepping_over_breakpoint
)
2998 global_thread_step_over_chain_enqueue (cur_thr
);
3000 /* If the thread isn't started, we'll still need to set its prev_pc,
3001 so that switch_back_to_stepped_thread knows the thread hasn't
3002 advanced. Must do this before resuming any thread, as in
3003 all-stop/remote, once we resume we can't send any other packet
3004 until the target stops again. */
3005 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3008 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3010 started
= start_step_over ();
3012 if (step_over_info_valid_p ())
3014 /* Either this thread started a new in-line step over, or some
3015 other thread was already doing one. In either case, don't
3016 resume anything else until the step-over is finished. */
3018 else if (started
&& !target_is_non_stop_p ())
3020 /* A new displaced stepping sequence was started. In all-stop,
3021 we can't talk to the target anymore until it next stops. */
3023 else if (!non_stop
&& target_is_non_stop_p ())
3025 INFRUN_SCOPED_DEBUG_START_END
3026 ("resuming threads, all-stop-on-top-of-non-stop");
3028 /* In all-stop, but the target is always in non-stop mode.
3029 Start all other threads that are implicitly resumed too. */
3030 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3033 switch_to_thread_no_regs (tp
);
3035 if (!tp
->inf
->has_execution ())
3037 infrun_debug_printf ("[%s] target has no execution",
3038 target_pid_to_str (tp
->ptid
).c_str ());
3044 infrun_debug_printf ("[%s] resumed",
3045 target_pid_to_str (tp
->ptid
).c_str ());
3046 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3050 if (thread_is_in_step_over_chain (tp
))
3052 infrun_debug_printf ("[%s] needs step-over",
3053 target_pid_to_str (tp
->ptid
).c_str ());
3057 infrun_debug_printf ("resuming %s",
3058 target_pid_to_str (tp
->ptid
).c_str ());
3060 reset_ecs (ecs
, tp
);
3061 switch_to_thread (tp
);
3062 keep_going_pass_signal (ecs
);
3063 if (!ecs
->wait_some_more
)
3064 error (_("Command aborted."));
3067 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3069 /* The thread wasn't started, and isn't queued, run it now. */
3070 reset_ecs (ecs
, cur_thr
);
3071 switch_to_thread (cur_thr
);
3072 keep_going_pass_signal (ecs
);
3073 if (!ecs
->wait_some_more
)
3074 error (_("Command aborted."));
3078 commit_resume_all_targets ();
3080 finish_state
.release ();
3082 /* If we've switched threads above, switch back to the previously
3083 current thread. We don't want the user to see a different
3085 switch_to_thread (cur_thr
);
3087 /* Tell the event loop to wait for it to stop. If the target
3088 supports asynchronous execution, it'll do this from within
3090 if (!target_can_async_p ())
3091 mark_async_event_handler (infrun_async_inferior_event_token
);
3095 /* Start remote-debugging of a machine over a serial link. */
3098 start_remote (int from_tty
)
3100 inferior
*inf
= current_inferior ();
3101 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3103 /* Always go on waiting for the target, regardless of the mode. */
3104 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3105 indicate to wait_for_inferior that a target should timeout if
3106 nothing is returned (instead of just blocking). Because of this,
3107 targets expecting an immediate response need to, internally, set
3108 things up so that the target_wait() is forced to eventually
3110 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3111 differentiate to its caller what the state of the target is after
3112 the initial open has been performed. Here we're assuming that
3113 the target has stopped. It should be possible to eventually have
3114 target_open() return to the caller an indication that the target
3115 is currently running and GDB state should be set to the same as
3116 for an async run. */
3117 wait_for_inferior (inf
);
3119 /* Now that the inferior has stopped, do any bookkeeping like
3120 loading shared libraries. We want to do this before normal_stop,
3121 so that the displayed frame is up to date. */
3122 post_create_inferior (from_tty
);
3127 /* Initialize static vars when a new inferior begins. */
3130 init_wait_for_inferior (void)
3132 /* These are meaningless until the first time through wait_for_inferior. */
3134 breakpoint_init_inferior (inf_starting
);
3136 clear_proceed_status (0);
3138 nullify_last_target_wait_ptid ();
3140 previous_inferior_ptid
= inferior_ptid
;
3145 static void handle_inferior_event (struct execution_control_state
*ecs
);
3147 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3148 struct execution_control_state
*ecs
);
3149 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3150 struct execution_control_state
*ecs
);
3151 static void handle_signal_stop (struct execution_control_state
*ecs
);
3152 static void check_exception_resume (struct execution_control_state
*,
3153 struct frame_info
*);
3155 static void end_stepping_range (struct execution_control_state
*ecs
);
3156 static void stop_waiting (struct execution_control_state
*ecs
);
3157 static void keep_going (struct execution_control_state
*ecs
);
3158 static void process_event_stop_test (struct execution_control_state
*ecs
);
3159 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3161 /* This function is attached as a "thread_stop_requested" observer.
3162 Cleanup local state that assumed the PTID was to be resumed, and
3163 report the stop to the frontend. */
3166 infrun_thread_stop_requested (ptid_t ptid
)
3168 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3170 /* PTID was requested to stop. If the thread was already stopped,
3171 but the user/frontend doesn't know about that yet (e.g., the
3172 thread had been temporarily paused for some step-over), set up
3173 for reporting the stop now. */
3174 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3176 if (tp
->state
!= THREAD_RUNNING
)
3181 /* Remove matching threads from the step-over queue, so
3182 start_step_over doesn't try to resume them
3184 if (thread_is_in_step_over_chain (tp
))
3185 global_thread_step_over_chain_remove (tp
);
3187 /* If the thread is stopped, but the user/frontend doesn't
3188 know about that yet, queue a pending event, as if the
3189 thread had just stopped now. Unless the thread already had
3191 if (!tp
->suspend
.waitstatus_pending_p
)
3193 tp
->suspend
.waitstatus_pending_p
= 1;
3194 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3195 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3198 /* Clear the inline-frame state, since we're re-processing the
3200 clear_inline_frame_state (tp
);
3202 /* If this thread was paused because some other thread was
3203 doing an inline-step over, let that finish first. Once
3204 that happens, we'll restart all threads and consume pending
3205 stop events then. */
3206 if (step_over_info_valid_p ())
3209 /* Otherwise we can process the (new) pending event now. Set
3210 it so this pending event is considered by
3217 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3219 if (target_last_proc_target
== tp
->inf
->process_target ()
3220 && target_last_wait_ptid
== tp
->ptid
)
3221 nullify_last_target_wait_ptid ();
3224 /* Delete the step resume, single-step and longjmp/exception resume
3225 breakpoints of TP. */
3228 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3230 delete_step_resume_breakpoint (tp
);
3231 delete_exception_resume_breakpoint (tp
);
3232 delete_single_step_breakpoints (tp
);
3235 /* If the target still has execution, call FUNC for each thread that
3236 just stopped. In all-stop, that's all the non-exited threads; in
3237 non-stop, that's the current thread, only. */
3239 typedef void (*for_each_just_stopped_thread_callback_func
)
3240 (struct thread_info
*tp
);
3243 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3245 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3248 if (target_is_non_stop_p ())
3250 /* If in non-stop mode, only the current thread stopped. */
3251 func (inferior_thread ());
3255 /* In all-stop mode, all threads have stopped. */
3256 for (thread_info
*tp
: all_non_exited_threads ())
3261 /* Delete the step resume and longjmp/exception resume breakpoints of
3262 the threads that just stopped. */
3265 delete_just_stopped_threads_infrun_breakpoints (void)
3267 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3270 /* Delete the single-step breakpoints of the threads that just
3274 delete_just_stopped_threads_single_step_breakpoints (void)
3276 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3282 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3283 const struct target_waitstatus
*ws
)
3285 infrun_debug_printf ("target_wait (%d.%ld.%ld [%s], status) =",
3289 target_pid_to_str (waiton_ptid
).c_str ());
3290 infrun_debug_printf (" %d.%ld.%ld [%s],",
3294 target_pid_to_str (result_ptid
).c_str ());
3295 infrun_debug_printf (" %s", target_waitstatus_to_string (ws
).c_str ());
3298 /* Select a thread at random, out of those which are resumed and have
3301 static struct thread_info
*
3302 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3306 auto has_event
= [&] (thread_info
*tp
)
3308 return (tp
->ptid
.matches (waiton_ptid
)
3310 && tp
->suspend
.waitstatus_pending_p
);
3313 /* First see how many events we have. Count only resumed threads
3314 that have an event pending. */
3315 for (thread_info
*tp
: inf
->non_exited_threads ())
3319 if (num_events
== 0)
3322 /* Now randomly pick a thread out of those that have had events. */
3323 int random_selector
= (int) ((num_events
* (double) rand ())
3324 / (RAND_MAX
+ 1.0));
3327 infrun_debug_printf ("Found %d events, selecting #%d",
3328 num_events
, random_selector
);
3330 /* Select the Nth thread that has had an event. */
3331 for (thread_info
*tp
: inf
->non_exited_threads ())
3333 if (random_selector
-- == 0)
3336 gdb_assert_not_reached ("event thread not found");
3339 /* Wrapper for target_wait that first checks whether threads have
3340 pending statuses to report before actually asking the target for
3341 more events. INF is the inferior we're using to call target_wait
3345 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3346 target_waitstatus
*status
, target_wait_flags options
)
3349 struct thread_info
*tp
;
3351 /* We know that we are looking for an event in the target of inferior
3352 INF, but we don't know which thread the event might come from. As
3353 such we want to make sure that INFERIOR_PTID is reset so that none of
3354 the wait code relies on it - doing so is always a mistake. */
3355 switch_to_inferior_no_thread (inf
);
3357 /* First check if there is a resumed thread with a wait status
3359 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3361 tp
= random_pending_event_thread (inf
, ptid
);
3365 infrun_debug_printf ("Waiting for specific thread %s.",
3366 target_pid_to_str (ptid
).c_str ());
3368 /* We have a specific thread to check. */
3369 tp
= find_thread_ptid (inf
, ptid
);
3370 gdb_assert (tp
!= NULL
);
3371 if (!tp
->suspend
.waitstatus_pending_p
)
3376 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3377 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3379 struct regcache
*regcache
= get_thread_regcache (tp
);
3380 struct gdbarch
*gdbarch
= regcache
->arch ();
3384 pc
= regcache_read_pc (regcache
);
3386 if (pc
!= tp
->suspend
.stop_pc
)
3388 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3389 target_pid_to_str (tp
->ptid
).c_str (),
3390 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3391 paddress (gdbarch
, pc
));
3394 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3396 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3397 target_pid_to_str (tp
->ptid
).c_str (),
3398 paddress (gdbarch
, pc
));
3405 infrun_debug_printf ("pending event of %s cancelled.",
3406 target_pid_to_str (tp
->ptid
).c_str ());
3408 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3409 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3415 infrun_debug_printf ("Using pending wait status %s for %s.",
3416 target_waitstatus_to_string
3417 (&tp
->suspend
.waitstatus
).c_str (),
3418 target_pid_to_str (tp
->ptid
).c_str ());
3420 /* Now that we've selected our final event LWP, un-adjust its PC
3421 if it was a software breakpoint (and the target doesn't
3422 always adjust the PC itself). */
3423 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3424 && !target_supports_stopped_by_sw_breakpoint ())
3426 struct regcache
*regcache
;
3427 struct gdbarch
*gdbarch
;
3430 regcache
= get_thread_regcache (tp
);
3431 gdbarch
= regcache
->arch ();
3433 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3438 pc
= regcache_read_pc (regcache
);
3439 regcache_write_pc (regcache
, pc
+ decr_pc
);
3443 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3444 *status
= tp
->suspend
.waitstatus
;
3445 tp
->suspend
.waitstatus_pending_p
= 0;
3447 /* Wake up the event loop again, until all pending events are
3449 if (target_is_async_p ())
3450 mark_async_event_handler (infrun_async_inferior_event_token
);
3454 /* But if we don't find one, we'll have to wait. */
3456 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3458 if (!target_can_async_p ())
3459 options
&= ~TARGET_WNOHANG
;
3461 if (deprecated_target_wait_hook
)
3462 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3464 event_ptid
= target_wait (ptid
, status
, options
);
3469 /* Wrapper for target_wait that first checks whether threads have
3470 pending statuses to report before actually asking the target for
3471 more events. Polls for events from all inferiors/targets. */
3474 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3475 target_wait_flags options
)
3477 int num_inferiors
= 0;
3478 int random_selector
;
3480 /* For fairness, we pick the first inferior/target to poll at random
3481 out of all inferiors that may report events, and then continue
3482 polling the rest of the inferior list starting from that one in a
3483 circular fashion until the whole list is polled once. */
3485 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3487 return (inf
->process_target () != NULL
3488 && ptid_t (inf
->pid
).matches (wait_ptid
));
3491 /* First see how many matching inferiors we have. */
3492 for (inferior
*inf
: all_inferiors ())
3493 if (inferior_matches (inf
))
3496 if (num_inferiors
== 0)
3498 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3502 /* Now randomly pick an inferior out of those that matched. */
3503 random_selector
= (int)
3504 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3506 if (num_inferiors
> 1)
3507 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3508 num_inferiors
, random_selector
);
3510 /* Select the Nth inferior that matched. */
3512 inferior
*selected
= nullptr;
3514 for (inferior
*inf
: all_inferiors ())
3515 if (inferior_matches (inf
))
3516 if (random_selector
-- == 0)
3522 /* Now poll for events out of each of the matching inferior's
3523 targets, starting from the selected one. */
3525 auto do_wait
= [&] (inferior
*inf
)
3527 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3528 ecs
->target
= inf
->process_target ();
3529 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3532 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3533 here spuriously after the target is all stopped and we've already
3534 reported the stop to the user, polling for events. */
3535 scoped_restore_current_thread restore_thread
;
3537 int inf_num
= selected
->num
;
3538 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3539 if (inferior_matches (inf
))
3543 for (inferior
*inf
= inferior_list
;
3544 inf
!= NULL
&& inf
->num
< inf_num
;
3546 if (inferior_matches (inf
))
3550 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3554 /* An event reported by wait_one. */
3556 struct wait_one_event
3558 /* The target the event came out of. */
3559 process_stratum_target
*target
;
3561 /* The PTID the event was for. */
3564 /* The waitstatus. */
3565 target_waitstatus ws
;
3568 static bool handle_one (const wait_one_event
&event
);
3569 static void restart_threads (struct thread_info
*event_thread
);
3571 /* Prepare and stabilize the inferior for detaching it. E.g.,
3572 detaching while a thread is displaced stepping is a recipe for
3573 crashing it, as nothing would readjust the PC out of the scratch
3577 prepare_for_detach (void)
3579 struct inferior
*inf
= current_inferior ();
3580 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3581 scoped_restore_current_thread restore_thread
;
3583 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3585 /* Remove all threads of INF from the global step-over chain. We
3586 want to stop any ongoing step-over, not start any new one. */
3588 for (thread_info
*tp
= global_thread_step_over_chain_head
;
3592 next
= global_thread_step_over_chain_next (tp
);
3594 global_thread_step_over_chain_remove (tp
);
3597 /* If we were already in the middle of an inline step-over, and the
3598 thread stepping belongs to the inferior we're detaching, we need
3599 to restart the threads of other inferiors. */
3600 if (step_over_info
.thread
!= -1)
3602 infrun_debug_printf ("inline step-over in-process while detaching");
3604 thread_info
*thr
= find_thread_global_id (step_over_info
.thread
);
3605 if (thr
->inf
== inf
)
3607 /* Since we removed threads of INF from the step-over chain,
3608 we know this won't start a step-over for INF. */
3609 clear_step_over_info ();
3611 if (target_is_non_stop_p ())
3613 /* Start a new step-over in another thread if there's
3614 one that needs it. */
3617 /* Restart all other threads (except the
3618 previously-stepping thread, since that one is still
3620 if (!step_over_info_valid_p ())
3621 restart_threads (thr
);
3626 if (displaced_step_in_progress (inf
))
3628 infrun_debug_printf ("displaced-stepping in-process while detaching");
3630 /* Stop threads currently displaced stepping, aborting it. */
3632 for (thread_info
*thr
: inf
->non_exited_threads ())
3634 if (thr
->displaced_step_state
.in_progress ())
3638 if (!thr
->stop_requested
)
3640 target_stop (thr
->ptid
);
3641 thr
->stop_requested
= true;
3645 thr
->resumed
= false;
3649 while (displaced_step_in_progress (inf
))
3651 wait_one_event event
;
3653 event
.target
= inf
->process_target ();
3654 event
.ptid
= do_target_wait_1 (inf
, pid_ptid
, &event
.ws
, 0);
3657 print_target_wait_results (pid_ptid
, event
.ptid
, &event
.ws
);
3662 /* It's OK to leave some of the threads of INF stopped, since
3663 they'll be detached shortly. */
3667 /* Wait for control to return from inferior to debugger.
3669 If inferior gets a signal, we may decide to start it up again
3670 instead of returning. That is why there is a loop in this function.
3671 When this function actually returns it means the inferior
3672 should be left stopped and GDB should read more commands. */
3675 wait_for_inferior (inferior
*inf
)
3677 infrun_debug_printf ("wait_for_inferior ()");
3679 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3681 /* If an error happens while handling the event, propagate GDB's
3682 knowledge of the executing state to the frontend/user running
3684 scoped_finish_thread_state finish_state
3685 (inf
->process_target (), minus_one_ptid
);
3689 struct execution_control_state ecss
;
3690 struct execution_control_state
*ecs
= &ecss
;
3692 memset (ecs
, 0, sizeof (*ecs
));
3694 overlay_cache_invalid
= 1;
3696 /* Flush target cache before starting to handle each event.
3697 Target was running and cache could be stale. This is just a
3698 heuristic. Running threads may modify target memory, but we
3699 don't get any event. */
3700 target_dcache_invalidate ();
3702 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3703 ecs
->target
= inf
->process_target ();
3706 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3708 /* Now figure out what to do with the result of the result. */
3709 handle_inferior_event (ecs
);
3711 if (!ecs
->wait_some_more
)
3715 /* No error, don't finish the state yet. */
3716 finish_state
.release ();
3719 /* Cleanup that reinstalls the readline callback handler, if the
3720 target is running in the background. If while handling the target
3721 event something triggered a secondary prompt, like e.g., a
3722 pagination prompt, we'll have removed the callback handler (see
3723 gdb_readline_wrapper_line). Need to do this as we go back to the
3724 event loop, ready to process further input. Note this has no
3725 effect if the handler hasn't actually been removed, because calling
3726 rl_callback_handler_install resets the line buffer, thus losing
3730 reinstall_readline_callback_handler_cleanup ()
3732 struct ui
*ui
= current_ui
;
3736 /* We're not going back to the top level event loop yet. Don't
3737 install the readline callback, as it'd prep the terminal,
3738 readline-style (raw, noecho) (e.g., --batch). We'll install
3739 it the next time the prompt is displayed, when we're ready
3744 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3745 gdb_rl_callback_handler_reinstall ();
3748 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3749 that's just the event thread. In all-stop, that's all threads. */
3752 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3754 if (ecs
->event_thread
!= NULL
3755 && ecs
->event_thread
->thread_fsm
!= NULL
)
3756 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3760 for (thread_info
*thr
: all_non_exited_threads ())
3762 if (thr
->thread_fsm
== NULL
)
3764 if (thr
== ecs
->event_thread
)
3767 switch_to_thread (thr
);
3768 thr
->thread_fsm
->clean_up (thr
);
3771 if (ecs
->event_thread
!= NULL
)
3772 switch_to_thread (ecs
->event_thread
);
3776 /* Helper for all_uis_check_sync_execution_done that works on the
3780 check_curr_ui_sync_execution_done (void)
3782 struct ui
*ui
= current_ui
;
3784 if (ui
->prompt_state
== PROMPT_NEEDED
3786 && !gdb_in_secondary_prompt_p (ui
))
3788 target_terminal::ours ();
3789 gdb::observers::sync_execution_done
.notify ();
3790 ui_register_input_event_handler (ui
);
3797 all_uis_check_sync_execution_done (void)
3799 SWITCH_THRU_ALL_UIS ()
3801 check_curr_ui_sync_execution_done ();
3808 all_uis_on_sync_execution_starting (void)
3810 SWITCH_THRU_ALL_UIS ()
3812 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3813 async_disable_stdin ();
3817 /* Asynchronous version of wait_for_inferior. It is called by the
3818 event loop whenever a change of state is detected on the file
3819 descriptor corresponding to the target. It can be called more than
3820 once to complete a single execution command. In such cases we need
3821 to keep the state in a global variable ECSS. If it is the last time
3822 that this function is called for a single execution command, then
3823 report to the user that the inferior has stopped, and do the
3824 necessary cleanups. */
3827 fetch_inferior_event ()
3829 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
3831 struct execution_control_state ecss
;
3832 struct execution_control_state
*ecs
= &ecss
;
3835 memset (ecs
, 0, sizeof (*ecs
));
3837 /* Events are always processed with the main UI as current UI. This
3838 way, warnings, debug output, etc. are always consistently sent to
3839 the main console. */
3840 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3842 /* Temporarily disable pagination. Otherwise, the user would be
3843 given an option to press 'q' to quit, which would cause an early
3844 exit and could leave GDB in a half-baked state. */
3845 scoped_restore save_pagination
3846 = make_scoped_restore (&pagination_enabled
, false);
3848 /* End up with readline processing input, if necessary. */
3850 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3852 /* We're handling a live event, so make sure we're doing live
3853 debugging. If we're looking at traceframes while the target is
3854 running, we're going to need to get back to that mode after
3855 handling the event. */
3856 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3859 maybe_restore_traceframe
.emplace ();
3860 set_current_traceframe (-1);
3863 /* The user/frontend should not notice a thread switch due to
3864 internal events. Make sure we revert to the user selected
3865 thread and frame after handling the event and running any
3866 breakpoint commands. */
3867 scoped_restore_current_thread restore_thread
;
3869 overlay_cache_invalid
= 1;
3870 /* Flush target cache before starting to handle each event. Target
3871 was running and cache could be stale. This is just a heuristic.
3872 Running threads may modify target memory, but we don't get any
3874 target_dcache_invalidate ();
3876 scoped_restore save_exec_dir
3877 = make_scoped_restore (&execution_direction
,
3878 target_execution_direction ());
3880 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3883 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3885 /* Switch to the target that generated the event, so we can do
3887 switch_to_target_no_thread (ecs
->target
);
3890 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3892 /* If an error happens while handling the event, propagate GDB's
3893 knowledge of the executing state to the frontend/user running
3895 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3896 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3898 /* Get executed before scoped_restore_current_thread above to apply
3899 still for the thread which has thrown the exception. */
3900 auto defer_bpstat_clear
3901 = make_scope_exit (bpstat_clear_actions
);
3902 auto defer_delete_threads
3903 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3905 /* Now figure out what to do with the result of the result. */
3906 handle_inferior_event (ecs
);
3908 if (!ecs
->wait_some_more
)
3910 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3911 bool should_stop
= true;
3912 struct thread_info
*thr
= ecs
->event_thread
;
3914 delete_just_stopped_threads_infrun_breakpoints ();
3918 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3920 if (thread_fsm
!= NULL
)
3921 should_stop
= thread_fsm
->should_stop (thr
);
3930 bool should_notify_stop
= true;
3933 clean_up_just_stopped_threads_fsms (ecs
);
3935 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3936 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3938 if (should_notify_stop
)
3940 /* We may not find an inferior if this was a process exit. */
3941 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3942 proceeded
= normal_stop ();
3947 inferior_event_handler (INF_EXEC_COMPLETE
);
3951 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3952 previously selected thread is gone. We have two
3953 choices - switch to no thread selected, or restore the
3954 previously selected thread (now exited). We chose the
3955 later, just because that's what GDB used to do. After
3956 this, "info threads" says "The current thread <Thread
3957 ID 2> has terminated." instead of "No thread
3961 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3962 restore_thread
.dont_restore ();
3966 defer_delete_threads
.release ();
3967 defer_bpstat_clear
.release ();
3969 /* No error, don't finish the thread states yet. */
3970 finish_state
.release ();
3972 /* This scope is used to ensure that readline callbacks are
3973 reinstalled here. */
3976 /* If a UI was in sync execution mode, and now isn't, restore its
3977 prompt (a synchronous execution command has finished, and we're
3978 ready for input). */
3979 all_uis_check_sync_execution_done ();
3982 && exec_done_display_p
3983 && (inferior_ptid
== null_ptid
3984 || inferior_thread ()->state
!= THREAD_RUNNING
))
3985 printf_unfiltered (_("completed.\n"));
3991 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
3992 struct symtab_and_line sal
)
3994 /* This can be removed once this function no longer implicitly relies on the
3995 inferior_ptid value. */
3996 gdb_assert (inferior_ptid
== tp
->ptid
);
3998 tp
->control
.step_frame_id
= get_frame_id (frame
);
3999 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4001 tp
->current_symtab
= sal
.symtab
;
4002 tp
->current_line
= sal
.line
;
4005 /* Clear context switchable stepping state. */
4008 init_thread_stepping_state (struct thread_info
*tss
)
4010 tss
->stepped_breakpoint
= 0;
4011 tss
->stepping_over_breakpoint
= 0;
4012 tss
->stepping_over_watchpoint
= 0;
4013 tss
->step_after_step_resume_breakpoint
= 0;
4019 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4020 target_waitstatus status
)
4022 target_last_proc_target
= target
;
4023 target_last_wait_ptid
= ptid
;
4024 target_last_waitstatus
= status
;
4030 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4031 target_waitstatus
*status
)
4033 if (target
!= nullptr)
4034 *target
= target_last_proc_target
;
4035 if (ptid
!= nullptr)
4036 *ptid
= target_last_wait_ptid
;
4037 if (status
!= nullptr)
4038 *status
= target_last_waitstatus
;
4044 nullify_last_target_wait_ptid (void)
4046 target_last_proc_target
= nullptr;
4047 target_last_wait_ptid
= minus_one_ptid
;
4048 target_last_waitstatus
= {};
4051 /* Switch thread contexts. */
4054 context_switch (execution_control_state
*ecs
)
4056 if (ecs
->ptid
!= inferior_ptid
4057 && (inferior_ptid
== null_ptid
4058 || ecs
->event_thread
!= inferior_thread ()))
4060 infrun_debug_printf ("Switching context from %s to %s",
4061 target_pid_to_str (inferior_ptid
).c_str (),
4062 target_pid_to_str (ecs
->ptid
).c_str ());
4065 switch_to_thread (ecs
->event_thread
);
4068 /* If the target can't tell whether we've hit breakpoints
4069 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4070 check whether that could have been caused by a breakpoint. If so,
4071 adjust the PC, per gdbarch_decr_pc_after_break. */
4074 adjust_pc_after_break (struct thread_info
*thread
,
4075 struct target_waitstatus
*ws
)
4077 struct regcache
*regcache
;
4078 struct gdbarch
*gdbarch
;
4079 CORE_ADDR breakpoint_pc
, decr_pc
;
4081 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4082 we aren't, just return.
4084 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4085 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4086 implemented by software breakpoints should be handled through the normal
4089 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4090 different signals (SIGILL or SIGEMT for instance), but it is less
4091 clear where the PC is pointing afterwards. It may not match
4092 gdbarch_decr_pc_after_break. I don't know any specific target that
4093 generates these signals at breakpoints (the code has been in GDB since at
4094 least 1992) so I can not guess how to handle them here.
4096 In earlier versions of GDB, a target with
4097 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4098 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4099 target with both of these set in GDB history, and it seems unlikely to be
4100 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4102 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4105 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4108 /* In reverse execution, when a breakpoint is hit, the instruction
4109 under it has already been de-executed. The reported PC always
4110 points at the breakpoint address, so adjusting it further would
4111 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4114 B1 0x08000000 : INSN1
4115 B2 0x08000001 : INSN2
4117 PC -> 0x08000003 : INSN4
4119 Say you're stopped at 0x08000003 as above. Reverse continuing
4120 from that point should hit B2 as below. Reading the PC when the
4121 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4122 been de-executed already.
4124 B1 0x08000000 : INSN1
4125 B2 PC -> 0x08000001 : INSN2
4129 We can't apply the same logic as for forward execution, because
4130 we would wrongly adjust the PC to 0x08000000, since there's a
4131 breakpoint at PC - 1. We'd then report a hit on B1, although
4132 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4134 if (execution_direction
== EXEC_REVERSE
)
4137 /* If the target can tell whether the thread hit a SW breakpoint,
4138 trust it. Targets that can tell also adjust the PC
4140 if (target_supports_stopped_by_sw_breakpoint ())
4143 /* Note that relying on whether a breakpoint is planted in memory to
4144 determine this can fail. E.g,. the breakpoint could have been
4145 removed since. Or the thread could have been told to step an
4146 instruction the size of a breakpoint instruction, and only
4147 _after_ was a breakpoint inserted at its address. */
4149 /* If this target does not decrement the PC after breakpoints, then
4150 we have nothing to do. */
4151 regcache
= get_thread_regcache (thread
);
4152 gdbarch
= regcache
->arch ();
4154 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4158 const address_space
*aspace
= regcache
->aspace ();
4160 /* Find the location where (if we've hit a breakpoint) the
4161 breakpoint would be. */
4162 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4164 /* If the target can't tell whether a software breakpoint triggered,
4165 fallback to figuring it out based on breakpoints we think were
4166 inserted in the target, and on whether the thread was stepped or
4169 /* Check whether there actually is a software breakpoint inserted at
4172 If in non-stop mode, a race condition is possible where we've
4173 removed a breakpoint, but stop events for that breakpoint were
4174 already queued and arrive later. To suppress those spurious
4175 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4176 and retire them after a number of stop events are reported. Note
4177 this is an heuristic and can thus get confused. The real fix is
4178 to get the "stopped by SW BP and needs adjustment" info out of
4179 the target/kernel (and thus never reach here; see above). */
4180 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4181 || (target_is_non_stop_p ()
4182 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4184 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4186 if (record_full_is_used ())
4187 restore_operation_disable
.emplace
4188 (record_full_gdb_operation_disable_set ());
4190 /* When using hardware single-step, a SIGTRAP is reported for both
4191 a completed single-step and a software breakpoint. Need to
4192 differentiate between the two, as the latter needs adjusting
4193 but the former does not.
4195 The SIGTRAP can be due to a completed hardware single-step only if
4196 - we didn't insert software single-step breakpoints
4197 - this thread is currently being stepped
4199 If any of these events did not occur, we must have stopped due
4200 to hitting a software breakpoint, and have to back up to the
4203 As a special case, we could have hardware single-stepped a
4204 software breakpoint. In this case (prev_pc == breakpoint_pc),
4205 we also need to back up to the breakpoint address. */
4207 if (thread_has_single_step_breakpoints_set (thread
)
4208 || !currently_stepping (thread
)
4209 || (thread
->stepped_breakpoint
4210 && thread
->prev_pc
== breakpoint_pc
))
4211 regcache_write_pc (regcache
, breakpoint_pc
);
4216 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4218 for (frame
= get_prev_frame (frame
);
4220 frame
= get_prev_frame (frame
))
4222 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4225 if (get_frame_type (frame
) != INLINE_FRAME
)
4232 /* Look for an inline frame that is marked for skip.
4233 If PREV_FRAME is TRUE start at the previous frame,
4234 otherwise start at the current frame. Stop at the
4235 first non-inline frame, or at the frame where the
4239 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4241 struct frame_info
*frame
= get_current_frame ();
4244 frame
= get_prev_frame (frame
);
4246 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4248 const char *fn
= NULL
;
4249 symtab_and_line sal
;
4252 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4254 if (get_frame_type (frame
) != INLINE_FRAME
)
4257 sal
= find_frame_sal (frame
);
4258 sym
= get_frame_function (frame
);
4261 fn
= sym
->print_name ();
4264 && function_name_is_marked_for_skip (fn
, sal
))
4271 /* If the event thread has the stop requested flag set, pretend it
4272 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4276 handle_stop_requested (struct execution_control_state
*ecs
)
4278 if (ecs
->event_thread
->stop_requested
)
4280 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4281 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4282 handle_signal_stop (ecs
);
4288 /* Auxiliary function that handles syscall entry/return events.
4289 It returns true if the inferior should keep going (and GDB
4290 should ignore the event), or false if the event deserves to be
4294 handle_syscall_event (struct execution_control_state
*ecs
)
4296 struct regcache
*regcache
;
4299 context_switch (ecs
);
4301 regcache
= get_thread_regcache (ecs
->event_thread
);
4302 syscall_number
= ecs
->ws
.value
.syscall_number
;
4303 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4305 if (catch_syscall_enabled () > 0
4306 && catching_syscall_number (syscall_number
) > 0)
4308 infrun_debug_printf ("syscall number=%d", syscall_number
);
4310 ecs
->event_thread
->control
.stop_bpstat
4311 = bpstat_stop_status (regcache
->aspace (),
4312 ecs
->event_thread
->suspend
.stop_pc
,
4313 ecs
->event_thread
, &ecs
->ws
);
4315 if (handle_stop_requested (ecs
))
4318 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4320 /* Catchpoint hit. */
4325 if (handle_stop_requested (ecs
))
4328 /* If no catchpoint triggered for this, then keep going. */
4334 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4337 fill_in_stop_func (struct gdbarch
*gdbarch
,
4338 struct execution_control_state
*ecs
)
4340 if (!ecs
->stop_func_filled_in
)
4343 const general_symbol_info
*gsi
;
4345 /* Don't care about return value; stop_func_start and stop_func_name
4346 will both be 0 if it doesn't work. */
4347 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4349 &ecs
->stop_func_start
,
4350 &ecs
->stop_func_end
,
4352 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4354 /* The call to find_pc_partial_function, above, will set
4355 stop_func_start and stop_func_end to the start and end
4356 of the range containing the stop pc. If this range
4357 contains the entry pc for the block (which is always the
4358 case for contiguous blocks), advance stop_func_start past
4359 the function's start offset and entrypoint. Note that
4360 stop_func_start is NOT advanced when in a range of a
4361 non-contiguous block that does not contain the entry pc. */
4362 if (block
!= nullptr
4363 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4364 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4366 ecs
->stop_func_start
4367 += gdbarch_deprecated_function_start_offset (gdbarch
);
4369 if (gdbarch_skip_entrypoint_p (gdbarch
))
4370 ecs
->stop_func_start
4371 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4374 ecs
->stop_func_filled_in
= 1;
4379 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4381 static enum stop_kind
4382 get_inferior_stop_soon (execution_control_state
*ecs
)
4384 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4386 gdb_assert (inf
!= NULL
);
4387 return inf
->control
.stop_soon
;
4390 /* Poll for one event out of the current target. Store the resulting
4391 waitstatus in WS, and return the event ptid. Does not block. */
4394 poll_one_curr_target (struct target_waitstatus
*ws
)
4398 overlay_cache_invalid
= 1;
4400 /* Flush target cache before starting to handle each event.
4401 Target was running and cache could be stale. This is just a
4402 heuristic. Running threads may modify target memory, but we
4403 don't get any event. */
4404 target_dcache_invalidate ();
4406 if (deprecated_target_wait_hook
)
4407 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4409 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4412 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4417 /* Wait for one event out of any target. */
4419 static wait_one_event
4424 for (inferior
*inf
: all_inferiors ())
4426 process_stratum_target
*target
= inf
->process_target ();
4428 || !target
->is_async_p ()
4429 || !target
->threads_executing
)
4432 switch_to_inferior_no_thread (inf
);
4434 wait_one_event event
;
4435 event
.target
= target
;
4436 event
.ptid
= poll_one_curr_target (&event
.ws
);
4438 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4440 /* If nothing is resumed, remove the target from the
4444 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4448 /* Block waiting for some event. */
4455 for (inferior
*inf
: all_inferiors ())
4457 process_stratum_target
*target
= inf
->process_target ();
4459 || !target
->is_async_p ()
4460 || !target
->threads_executing
)
4463 int fd
= target
->async_wait_fd ();
4464 FD_SET (fd
, &readfds
);
4471 /* No waitable targets left. All must be stopped. */
4472 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4477 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4483 perror_with_name ("interruptible_select");
4488 /* Save the thread's event and stop reason to process it later. */
4491 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4493 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4494 target_waitstatus_to_string (ws
).c_str (),
4499 /* Record for later. */
4500 tp
->suspend
.waitstatus
= *ws
;
4501 tp
->suspend
.waitstatus_pending_p
= 1;
4503 struct regcache
*regcache
= get_thread_regcache (tp
);
4504 const address_space
*aspace
= regcache
->aspace ();
4506 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4507 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4509 CORE_ADDR pc
= regcache_read_pc (regcache
);
4511 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4513 scoped_restore_current_thread restore_thread
;
4514 switch_to_thread (tp
);
4516 if (target_stopped_by_watchpoint ())
4518 tp
->suspend
.stop_reason
4519 = TARGET_STOPPED_BY_WATCHPOINT
;
4521 else if (target_supports_stopped_by_sw_breakpoint ()
4522 && target_stopped_by_sw_breakpoint ())
4524 tp
->suspend
.stop_reason
4525 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4527 else if (target_supports_stopped_by_hw_breakpoint ()
4528 && target_stopped_by_hw_breakpoint ())
4530 tp
->suspend
.stop_reason
4531 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4533 else if (!target_supports_stopped_by_hw_breakpoint ()
4534 && hardware_breakpoint_inserted_here_p (aspace
,
4537 tp
->suspend
.stop_reason
4538 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4540 else if (!target_supports_stopped_by_sw_breakpoint ()
4541 && software_breakpoint_inserted_here_p (aspace
,
4544 tp
->suspend
.stop_reason
4545 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4547 else if (!thread_has_single_step_breakpoints_set (tp
)
4548 && currently_stepping (tp
))
4550 tp
->suspend
.stop_reason
4551 = TARGET_STOPPED_BY_SINGLE_STEP
;
4556 /* Mark the non-executing threads accordingly. In all-stop, all
4557 threads of all processes are stopped when we get any event
4558 reported. In non-stop mode, only the event thread stops. */
4561 mark_non_executing_threads (process_stratum_target
*target
,
4563 struct target_waitstatus ws
)
4567 if (!target_is_non_stop_p ())
4568 mark_ptid
= minus_one_ptid
;
4569 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4570 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4572 /* If we're handling a process exit in non-stop mode, even
4573 though threads haven't been deleted yet, one would think
4574 that there is nothing to do, as threads of the dead process
4575 will be soon deleted, and threads of any other process were
4576 left running. However, on some targets, threads survive a
4577 process exit event. E.g., for the "checkpoint" command,
4578 when the current checkpoint/fork exits, linux-fork.c
4579 automatically switches to another fork from within
4580 target_mourn_inferior, by associating the same
4581 inferior/thread to another fork. We haven't mourned yet at
4582 this point, but we must mark any threads left in the
4583 process as not-executing so that finish_thread_state marks
4584 them stopped (in the user's perspective) if/when we present
4585 the stop to the user. */
4586 mark_ptid
= ptid_t (event_ptid
.pid ());
4589 mark_ptid
= event_ptid
;
4591 set_executing (target
, mark_ptid
, false);
4593 /* Likewise the resumed flag. */
4594 set_resumed (target
, mark_ptid
, false);
4597 /* Handle one event after stopping threads. If the eventing thread
4598 reports back any interesting event, we leave it pending. If the
4599 eventing thread was in the middle of a displaced step, we
4600 cancel/finish it, and unless the thread's inferior is being
4601 detached, put the thread back in the step-over chain. Returns true
4602 if there are no resumed threads left in the target (thus there's no
4603 point in waiting further), false otherwise. */
4606 handle_one (const wait_one_event
&event
)
4609 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4610 target_pid_to_str (event
.ptid
).c_str ());
4612 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4614 /* All resumed threads exited. */
4617 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4618 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4619 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4621 /* One thread/process exited/signalled. */
4623 thread_info
*t
= nullptr;
4625 /* The target may have reported just a pid. If so, try
4626 the first non-exited thread. */
4627 if (event
.ptid
.is_pid ())
4629 int pid
= event
.ptid
.pid ();
4630 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4631 for (thread_info
*tp
: inf
->non_exited_threads ())
4637 /* If there is no available thread, the event would
4638 have to be appended to a per-inferior event list,
4639 which does not exist (and if it did, we'd have
4640 to adjust run control command to be able to
4641 resume such an inferior). We assert here instead
4642 of going into an infinite loop. */
4643 gdb_assert (t
!= nullptr);
4646 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4650 t
= find_thread_ptid (event
.target
, event
.ptid
);
4651 /* Check if this is the first time we see this thread.
4652 Don't bother adding if it individually exited. */
4654 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4655 t
= add_thread (event
.target
, event
.ptid
);
4660 /* Set the threads as non-executing to avoid
4661 another stop attempt on them. */
4662 switch_to_thread_no_regs (t
);
4663 mark_non_executing_threads (event
.target
, event
.ptid
,
4665 save_waitstatus (t
, &event
.ws
);
4666 t
->stop_requested
= false;
4671 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4673 t
= add_thread (event
.target
, event
.ptid
);
4675 t
->stop_requested
= 0;
4678 t
->control
.may_range_step
= 0;
4680 /* This may be the first time we see the inferior report
4682 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4683 if (inf
->needs_setup
)
4685 switch_to_thread_no_regs (t
);
4689 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4690 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4692 /* We caught the event that we intended to catch, so
4693 there's no event pending. */
4694 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4695 t
->suspend
.waitstatus_pending_p
= 0;
4697 if (displaced_step_finish (t
, GDB_SIGNAL_0
)
4698 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4700 /* Add it back to the step-over queue. */
4702 ("displaced-step of %s canceled",
4703 target_pid_to_str (t
->ptid
).c_str ());
4705 t
->control
.trap_expected
= 0;
4706 if (!t
->inf
->detaching
)
4707 global_thread_step_over_chain_enqueue (t
);
4712 enum gdb_signal sig
;
4713 struct regcache
*regcache
;
4716 ("target_wait %s, saving status for %d.%ld.%ld",
4717 target_waitstatus_to_string (&event
.ws
).c_str (),
4718 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4720 /* Record for later. */
4721 save_waitstatus (t
, &event
.ws
);
4723 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4724 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4726 if (displaced_step_finish (t
, sig
)
4727 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4729 /* Add it back to the step-over queue. */
4730 t
->control
.trap_expected
= 0;
4731 if (!t
->inf
->detaching
)
4732 global_thread_step_over_chain_enqueue (t
);
4735 regcache
= get_thread_regcache (t
);
4736 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4738 infrun_debug_printf ("saved stop_pc=%s for %s "
4739 "(currently_stepping=%d)",
4740 paddress (target_gdbarch (),
4741 t
->suspend
.stop_pc
),
4742 target_pid_to_str (t
->ptid
).c_str (),
4743 currently_stepping (t
));
4753 stop_all_threads (void)
4755 /* We may need multiple passes to discover all threads. */
4759 gdb_assert (exists_non_stop_target ());
4761 infrun_debug_printf ("starting");
4763 scoped_restore_current_thread restore_thread
;
4765 /* Enable thread events of all targets. */
4766 for (auto *target
: all_non_exited_process_targets ())
4768 switch_to_target_no_thread (target
);
4769 target_thread_events (true);
4774 /* Disable thread events of all targets. */
4775 for (auto *target
: all_non_exited_process_targets ())
4777 switch_to_target_no_thread (target
);
4778 target_thread_events (false);
4781 /* Use debug_prefixed_printf directly to get a meaningful function
4784 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4787 /* Request threads to stop, and then wait for the stops. Because
4788 threads we already know about can spawn more threads while we're
4789 trying to stop them, and we only learn about new threads when we
4790 update the thread list, do this in a loop, and keep iterating
4791 until two passes find no threads that need to be stopped. */
4792 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4794 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4797 int waits_needed
= 0;
4799 for (auto *target
: all_non_exited_process_targets ())
4801 switch_to_target_no_thread (target
);
4802 update_thread_list ();
4805 /* Go through all threads looking for threads that we need
4806 to tell the target to stop. */
4807 for (thread_info
*t
: all_non_exited_threads ())
4809 /* For a single-target setting with an all-stop target,
4810 we would not even arrive here. For a multi-target
4811 setting, until GDB is able to handle a mixture of
4812 all-stop and non-stop targets, simply skip all-stop
4813 targets' threads. This should be fine due to the
4814 protection of 'check_multi_target_resumption'. */
4816 switch_to_thread_no_regs (t
);
4817 if (!target_is_non_stop_p ())
4822 /* If already stopping, don't request a stop again.
4823 We just haven't seen the notification yet. */
4824 if (!t
->stop_requested
)
4826 infrun_debug_printf (" %s executing, need stop",
4827 target_pid_to_str (t
->ptid
).c_str ());
4828 target_stop (t
->ptid
);
4829 t
->stop_requested
= 1;
4833 infrun_debug_printf (" %s executing, already stopping",
4834 target_pid_to_str (t
->ptid
).c_str ());
4837 if (t
->stop_requested
)
4842 infrun_debug_printf (" %s not executing",
4843 target_pid_to_str (t
->ptid
).c_str ());
4845 /* The thread may be not executing, but still be
4846 resumed with a pending status to process. */
4851 if (waits_needed
== 0)
4854 /* If we find new threads on the second iteration, restart
4855 over. We want to see two iterations in a row with all
4860 for (int i
= 0; i
< waits_needed
; i
++)
4862 wait_one_event event
= wait_one ();
4863 if (handle_one (event
))
4870 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4873 handle_no_resumed (struct execution_control_state
*ecs
)
4875 if (target_can_async_p ())
4877 bool any_sync
= false;
4879 for (ui
*ui
: all_uis ())
4881 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4889 /* There were no unwaited-for children left in the target, but,
4890 we're not synchronously waiting for events either. Just
4893 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4894 prepare_to_wait (ecs
);
4899 /* Otherwise, if we were running a synchronous execution command, we
4900 may need to cancel it and give the user back the terminal.
4902 In non-stop mode, the target can't tell whether we've already
4903 consumed previous stop events, so it can end up sending us a
4904 no-resumed event like so:
4906 #0 - thread 1 is left stopped
4908 #1 - thread 2 is resumed and hits breakpoint
4909 -> TARGET_WAITKIND_STOPPED
4911 #2 - thread 3 is resumed and exits
4912 this is the last resumed thread, so
4913 -> TARGET_WAITKIND_NO_RESUMED
4915 #3 - gdb processes stop for thread 2 and decides to re-resume
4918 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4919 thread 2 is now resumed, so the event should be ignored.
4921 IOW, if the stop for thread 2 doesn't end a foreground command,
4922 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4923 event. But it could be that the event meant that thread 2 itself
4924 (or whatever other thread was the last resumed thread) exited.
4926 To address this we refresh the thread list and check whether we
4927 have resumed threads _now_. In the example above, this removes
4928 thread 3 from the thread list. If thread 2 was re-resumed, we
4929 ignore this event. If we find no thread resumed, then we cancel
4930 the synchronous command and show "no unwaited-for " to the
4933 inferior
*curr_inf
= current_inferior ();
4935 scoped_restore_current_thread restore_thread
;
4937 for (auto *target
: all_non_exited_process_targets ())
4939 switch_to_target_no_thread (target
);
4940 update_thread_list ();
4945 - the current target has no thread executing, and
4946 - the current inferior is native, and
4947 - the current inferior is the one which has the terminal, and
4950 then a Ctrl-C from this point on would remain stuck in the
4951 kernel, until a thread resumes and dequeues it. That would
4952 result in the GDB CLI not reacting to Ctrl-C, not able to
4953 interrupt the program. To address this, if the current inferior
4954 no longer has any thread executing, we give the terminal to some
4955 other inferior that has at least one thread executing. */
4956 bool swap_terminal
= true;
4958 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4959 whether to report it to the user. */
4960 bool ignore_event
= false;
4962 for (thread_info
*thread
: all_non_exited_threads ())
4964 if (swap_terminal
&& thread
->executing
)
4966 if (thread
->inf
!= curr_inf
)
4968 target_terminal::ours ();
4970 switch_to_thread (thread
);
4971 target_terminal::inferior ();
4973 swap_terminal
= false;
4977 && (thread
->executing
4978 || thread
->suspend
.waitstatus_pending_p
))
4980 /* Either there were no unwaited-for children left in the
4981 target at some point, but there are now, or some target
4982 other than the eventing one has unwaited-for children
4983 left. Just ignore. */
4984 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4985 "(ignoring: found resumed)");
4987 ignore_event
= true;
4990 if (ignore_event
&& !swap_terminal
)
4996 switch_to_inferior_no_thread (curr_inf
);
4997 prepare_to_wait (ecs
);
5001 /* Go ahead and report the event. */
5005 /* Given an execution control state that has been freshly filled in by
5006 an event from the inferior, figure out what it means and take
5009 The alternatives are:
5011 1) stop_waiting and return; to really stop and return to the
5014 2) keep_going and return; to wait for the next event (set
5015 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5019 handle_inferior_event (struct execution_control_state
*ecs
)
5021 /* Make sure that all temporary struct value objects that were
5022 created during the handling of the event get deleted at the
5024 scoped_value_mark free_values
;
5026 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5028 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5030 /* We had an event in the inferior, but we are not interested in
5031 handling it at this level. The lower layers have already
5032 done what needs to be done, if anything.
5034 One of the possible circumstances for this is when the
5035 inferior produces output for the console. The inferior has
5036 not stopped, and we are ignoring the event. Another possible
5037 circumstance is any event which the lower level knows will be
5038 reported multiple times without an intervening resume. */
5039 prepare_to_wait (ecs
);
5043 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5045 prepare_to_wait (ecs
);
5049 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5050 && handle_no_resumed (ecs
))
5053 /* Cache the last target/ptid/waitstatus. */
5054 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5056 /* Always clear state belonging to the previous time we stopped. */
5057 stop_stack_dummy
= STOP_NONE
;
5059 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5061 /* No unwaited-for children left. IOW, all resumed children
5063 stop_print_frame
= false;
5068 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5069 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5071 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5072 /* If it's a new thread, add it to the thread database. */
5073 if (ecs
->event_thread
== NULL
)
5074 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5076 /* Disable range stepping. If the next step request could use a
5077 range, this will be end up re-enabled then. */
5078 ecs
->event_thread
->control
.may_range_step
= 0;
5081 /* Dependent on valid ECS->EVENT_THREAD. */
5082 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5084 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5085 reinit_frame_cache ();
5087 breakpoint_retire_moribund ();
5089 /* First, distinguish signals caused by the debugger from signals
5090 that have to do with the program's own actions. Note that
5091 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5092 on the operating system version. Here we detect when a SIGILL or
5093 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5094 something similar for SIGSEGV, since a SIGSEGV will be generated
5095 when we're trying to execute a breakpoint instruction on a
5096 non-executable stack. This happens for call dummy breakpoints
5097 for architectures like SPARC that place call dummies on the
5099 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5100 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5101 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5102 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5104 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5106 if (breakpoint_inserted_here_p (regcache
->aspace (),
5107 regcache_read_pc (regcache
)))
5109 infrun_debug_printf ("Treating signal as SIGTRAP");
5110 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5114 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5116 switch (ecs
->ws
.kind
)
5118 case TARGET_WAITKIND_LOADED
:
5120 context_switch (ecs
);
5121 /* Ignore gracefully during startup of the inferior, as it might
5122 be the shell which has just loaded some objects, otherwise
5123 add the symbols for the newly loaded objects. Also ignore at
5124 the beginning of an attach or remote session; we will query
5125 the full list of libraries once the connection is
5128 stop_kind stop_soon
= get_inferior_stop_soon (ecs
);
5129 if (stop_soon
== NO_STOP_QUIETLY
)
5131 struct regcache
*regcache
;
5133 regcache
= get_thread_regcache (ecs
->event_thread
);
5135 handle_solib_event ();
5137 ecs
->event_thread
->control
.stop_bpstat
5138 = bpstat_stop_status (regcache
->aspace (),
5139 ecs
->event_thread
->suspend
.stop_pc
,
5140 ecs
->event_thread
, &ecs
->ws
);
5142 if (handle_stop_requested (ecs
))
5145 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5147 /* A catchpoint triggered. */
5148 process_event_stop_test (ecs
);
5152 /* If requested, stop when the dynamic linker notifies
5153 gdb of events. This allows the user to get control
5154 and place breakpoints in initializer routines for
5155 dynamically loaded objects (among other things). */
5156 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5157 if (stop_on_solib_events
)
5159 /* Make sure we print "Stopped due to solib-event" in
5161 stop_print_frame
= true;
5168 /* If we are skipping through a shell, or through shared library
5169 loading that we aren't interested in, resume the program. If
5170 we're running the program normally, also resume. */
5171 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5173 /* Loading of shared libraries might have changed breakpoint
5174 addresses. Make sure new breakpoints are inserted. */
5175 if (stop_soon
== NO_STOP_QUIETLY
)
5176 insert_breakpoints ();
5177 resume (GDB_SIGNAL_0
);
5178 prepare_to_wait (ecs
);
5182 /* But stop if we're attaching or setting up a remote
5184 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5185 || stop_soon
== STOP_QUIETLY_REMOTE
)
5187 infrun_debug_printf ("quietly stopped");
5192 internal_error (__FILE__
, __LINE__
,
5193 _("unhandled stop_soon: %d"), (int) stop_soon
);
5196 case TARGET_WAITKIND_SPURIOUS
:
5197 if (handle_stop_requested (ecs
))
5199 context_switch (ecs
);
5200 resume (GDB_SIGNAL_0
);
5201 prepare_to_wait (ecs
);
5204 case TARGET_WAITKIND_THREAD_CREATED
:
5205 if (handle_stop_requested (ecs
))
5207 context_switch (ecs
);
5208 if (!switch_back_to_stepped_thread (ecs
))
5212 case TARGET_WAITKIND_EXITED
:
5213 case TARGET_WAITKIND_SIGNALLED
:
5215 /* Depending on the system, ecs->ptid may point to a thread or
5216 to a process. On some targets, target_mourn_inferior may
5217 need to have access to the just-exited thread. That is the
5218 case of GNU/Linux's "checkpoint" support, for example.
5219 Call the switch_to_xxx routine as appropriate. */
5220 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5222 switch_to_thread (thr
);
5225 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5226 switch_to_inferior_no_thread (inf
);
5229 handle_vfork_child_exec_or_exit (0);
5230 target_terminal::ours (); /* Must do this before mourn anyway. */
5232 /* Clearing any previous state of convenience variables. */
5233 clear_exit_convenience_vars ();
5235 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5237 /* Record the exit code in the convenience variable $_exitcode, so
5238 that the user can inspect this again later. */
5239 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5240 (LONGEST
) ecs
->ws
.value
.integer
);
5242 /* Also record this in the inferior itself. */
5243 current_inferior ()->has_exit_code
= 1;
5244 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5246 /* Support the --return-child-result option. */
5247 return_child_result_value
= ecs
->ws
.value
.integer
;
5249 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5253 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5255 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5257 /* Set the value of the internal variable $_exitsignal,
5258 which holds the signal uncaught by the inferior. */
5259 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5260 gdbarch_gdb_signal_to_target (gdbarch
,
5261 ecs
->ws
.value
.sig
));
5265 /* We don't have access to the target's method used for
5266 converting between signal numbers (GDB's internal
5267 representation <-> target's representation).
5268 Therefore, we cannot do a good job at displaying this
5269 information to the user. It's better to just warn
5270 her about it (if infrun debugging is enabled), and
5272 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5276 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5279 gdb_flush (gdb_stdout
);
5280 target_mourn_inferior (inferior_ptid
);
5281 stop_print_frame
= false;
5285 case TARGET_WAITKIND_FORKED
:
5286 case TARGET_WAITKIND_VFORKED
:
5287 /* Check whether the inferior is displaced stepping. */
5289 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5290 struct gdbarch
*gdbarch
= regcache
->arch ();
5291 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5293 /* If this is a fork (child gets its own address space copy) and some
5294 displaced step buffers were in use at the time of the fork, restore
5295 the displaced step buffer bytes in the child process. */
5296 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5297 gdbarch_displaced_step_restore_all_in_ptid
5298 (gdbarch
, parent_inf
, ecs
->ws
.value
.related_pid
);
5300 /* If displaced stepping is supported, and thread ecs->ptid is
5301 displaced stepping. */
5302 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5304 struct regcache
*child_regcache
;
5305 CORE_ADDR parent_pc
;
5307 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5308 indicating that the displaced stepping of syscall instruction
5309 has been done. Perform cleanup for parent process here. Note
5310 that this operation also cleans up the child process for vfork,
5311 because their pages are shared. */
5312 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5313 /* Start a new step-over in another thread if there's one
5317 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5318 the child's PC is also within the scratchpad. Set the child's PC
5319 to the parent's PC value, which has already been fixed up.
5320 FIXME: we use the parent's aspace here, although we're touching
5321 the child, because the child hasn't been added to the inferior
5322 list yet at this point. */
5325 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5326 ecs
->ws
.value
.related_pid
,
5328 parent_inf
->aspace
);
5329 /* Read PC value of parent process. */
5330 parent_pc
= regcache_read_pc (regcache
);
5332 displaced_debug_printf ("write child pc from %s to %s",
5334 regcache_read_pc (child_regcache
)),
5335 paddress (gdbarch
, parent_pc
));
5337 regcache_write_pc (child_regcache
, parent_pc
);
5341 context_switch (ecs
);
5343 /* Immediately detach breakpoints from the child before there's
5344 any chance of letting the user delete breakpoints from the
5345 breakpoint lists. If we don't do this early, it's easy to
5346 leave left over traps in the child, vis: "break foo; catch
5347 fork; c; <fork>; del; c; <child calls foo>". We only follow
5348 the fork on the last `continue', and by that time the
5349 breakpoint at "foo" is long gone from the breakpoint table.
5350 If we vforked, then we don't need to unpatch here, since both
5351 parent and child are sharing the same memory pages; we'll
5352 need to unpatch at follow/detach time instead to be certain
5353 that new breakpoints added between catchpoint hit time and
5354 vfork follow are detached. */
5355 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5357 /* This won't actually modify the breakpoint list, but will
5358 physically remove the breakpoints from the child. */
5359 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5362 delete_just_stopped_threads_single_step_breakpoints ();
5364 /* In case the event is caught by a catchpoint, remember that
5365 the event is to be followed at the next resume of the thread,
5366 and not immediately. */
5367 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5369 ecs
->event_thread
->suspend
.stop_pc
5370 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5372 ecs
->event_thread
->control
.stop_bpstat
5373 = bpstat_stop_status (get_current_regcache ()->aspace (),
5374 ecs
->event_thread
->suspend
.stop_pc
,
5375 ecs
->event_thread
, &ecs
->ws
);
5377 if (handle_stop_requested (ecs
))
5380 /* If no catchpoint triggered for this, then keep going. Note
5381 that we're interested in knowing the bpstat actually causes a
5382 stop, not just if it may explain the signal. Software
5383 watchpoints, for example, always appear in the bpstat. */
5384 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5387 = (follow_fork_mode_string
== follow_fork_mode_child
);
5389 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5391 process_stratum_target
*targ
5392 = ecs
->event_thread
->inf
->process_target ();
5394 bool should_resume
= follow_fork ();
5396 /* Note that one of these may be an invalid pointer,
5397 depending on detach_fork. */
5398 thread_info
*parent
= ecs
->event_thread
;
5400 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5402 /* At this point, the parent is marked running, and the
5403 child is marked stopped. */
5405 /* If not resuming the parent, mark it stopped. */
5406 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5407 parent
->set_running (false);
5409 /* If resuming the child, mark it running. */
5410 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5411 child
->set_running (true);
5413 /* In non-stop mode, also resume the other branch. */
5414 if (!detach_fork
&& (non_stop
5415 || (sched_multi
&& target_is_non_stop_p ())))
5418 switch_to_thread (parent
);
5420 switch_to_thread (child
);
5422 ecs
->event_thread
= inferior_thread ();
5423 ecs
->ptid
= inferior_ptid
;
5428 switch_to_thread (child
);
5430 switch_to_thread (parent
);
5432 ecs
->event_thread
= inferior_thread ();
5433 ecs
->ptid
= inferior_ptid
;
5441 process_event_stop_test (ecs
);
5444 case TARGET_WAITKIND_VFORK_DONE
:
5445 /* Done with the shared memory region. Re-insert breakpoints in
5446 the parent, and keep going. */
5448 context_switch (ecs
);
5450 current_inferior ()->waiting_for_vfork_done
= 0;
5451 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5453 if (handle_stop_requested (ecs
))
5456 /* This also takes care of reinserting breakpoints in the
5457 previously locked inferior. */
5461 case TARGET_WAITKIND_EXECD
:
5463 /* Note we can't read registers yet (the stop_pc), because we
5464 don't yet know the inferior's post-exec architecture.
5465 'stop_pc' is explicitly read below instead. */
5466 switch_to_thread_no_regs (ecs
->event_thread
);
5468 /* Do whatever is necessary to the parent branch of the vfork. */
5469 handle_vfork_child_exec_or_exit (1);
5471 /* This causes the eventpoints and symbol table to be reset.
5472 Must do this now, before trying to determine whether to
5474 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5476 /* In follow_exec we may have deleted the original thread and
5477 created a new one. Make sure that the event thread is the
5478 execd thread for that case (this is a nop otherwise). */
5479 ecs
->event_thread
= inferior_thread ();
5481 ecs
->event_thread
->suspend
.stop_pc
5482 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5484 ecs
->event_thread
->control
.stop_bpstat
5485 = bpstat_stop_status (get_current_regcache ()->aspace (),
5486 ecs
->event_thread
->suspend
.stop_pc
,
5487 ecs
->event_thread
, &ecs
->ws
);
5489 /* Note that this may be referenced from inside
5490 bpstat_stop_status above, through inferior_has_execd. */
5491 xfree (ecs
->ws
.value
.execd_pathname
);
5492 ecs
->ws
.value
.execd_pathname
= NULL
;
5494 if (handle_stop_requested (ecs
))
5497 /* If no catchpoint triggered for this, then keep going. */
5498 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5500 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5504 process_event_stop_test (ecs
);
5507 /* Be careful not to try to gather much state about a thread
5508 that's in a syscall. It's frequently a losing proposition. */
5509 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5510 /* Getting the current syscall number. */
5511 if (handle_syscall_event (ecs
) == 0)
5512 process_event_stop_test (ecs
);
5515 /* Before examining the threads further, step this thread to
5516 get it entirely out of the syscall. (We get notice of the
5517 event when the thread is just on the verge of exiting a
5518 syscall. Stepping one instruction seems to get it back
5520 case TARGET_WAITKIND_SYSCALL_RETURN
:
5521 if (handle_syscall_event (ecs
) == 0)
5522 process_event_stop_test (ecs
);
5525 case TARGET_WAITKIND_STOPPED
:
5526 handle_signal_stop (ecs
);
5529 case TARGET_WAITKIND_NO_HISTORY
:
5530 /* Reverse execution: target ran out of history info. */
5532 /* Switch to the stopped thread. */
5533 context_switch (ecs
);
5534 infrun_debug_printf ("stopped");
5536 delete_just_stopped_threads_single_step_breakpoints ();
5537 ecs
->event_thread
->suspend
.stop_pc
5538 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5540 if (handle_stop_requested (ecs
))
5543 gdb::observers::no_history
.notify ();
5549 /* Restart threads back to what they were trying to do back when we
5550 paused them for an in-line step-over. The EVENT_THREAD thread is
5554 restart_threads (struct thread_info
*event_thread
)
5556 /* In case the instruction just stepped spawned a new thread. */
5557 update_thread_list ();
5559 for (thread_info
*tp
: all_non_exited_threads ())
5561 if (tp
->inf
->detaching
)
5563 infrun_debug_printf ("restart threads: [%s] inferior detaching",
5564 target_pid_to_str (tp
->ptid
).c_str ());
5568 switch_to_thread_no_regs (tp
);
5570 if (tp
== event_thread
)
5572 infrun_debug_printf ("restart threads: [%s] is event thread",
5573 target_pid_to_str (tp
->ptid
).c_str ());
5577 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5579 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5580 target_pid_to_str (tp
->ptid
).c_str ());
5586 infrun_debug_printf ("restart threads: [%s] resumed",
5587 target_pid_to_str (tp
->ptid
).c_str ());
5588 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5592 if (thread_is_in_step_over_chain (tp
))
5594 infrun_debug_printf ("restart threads: [%s] needs step-over",
5595 target_pid_to_str (tp
->ptid
).c_str ());
5596 gdb_assert (!tp
->resumed
);
5601 if (tp
->suspend
.waitstatus_pending_p
)
5603 infrun_debug_printf ("restart threads: [%s] has pending status",
5604 target_pid_to_str (tp
->ptid
).c_str ());
5609 gdb_assert (!tp
->stop_requested
);
5611 /* If some thread needs to start a step-over at this point, it
5612 should still be in the step-over queue, and thus skipped
5614 if (thread_still_needs_step_over (tp
))
5616 internal_error (__FILE__
, __LINE__
,
5617 "thread [%s] needs a step-over, but not in "
5618 "step-over queue\n",
5619 target_pid_to_str (tp
->ptid
).c_str ());
5622 if (currently_stepping (tp
))
5624 infrun_debug_printf ("restart threads: [%s] was stepping",
5625 target_pid_to_str (tp
->ptid
).c_str ());
5626 keep_going_stepped_thread (tp
);
5630 struct execution_control_state ecss
;
5631 struct execution_control_state
*ecs
= &ecss
;
5633 infrun_debug_printf ("restart threads: [%s] continuing",
5634 target_pid_to_str (tp
->ptid
).c_str ());
5635 reset_ecs (ecs
, tp
);
5636 switch_to_thread (tp
);
5637 keep_going_pass_signal (ecs
);
5642 /* Callback for iterate_over_threads. Find a resumed thread that has
5643 a pending waitstatus. */
5646 resumed_thread_with_pending_status (struct thread_info
*tp
,
5650 && tp
->suspend
.waitstatus_pending_p
);
5653 /* Called when we get an event that may finish an in-line or
5654 out-of-line (displaced stepping) step-over started previously.
5655 Return true if the event is processed and we should go back to the
5656 event loop; false if the caller should continue processing the
5660 finish_step_over (struct execution_control_state
*ecs
)
5662 displaced_step_finish (ecs
->event_thread
,
5663 ecs
->event_thread
->suspend
.stop_signal
);
5665 bool had_step_over_info
= step_over_info_valid_p ();
5667 if (had_step_over_info
)
5669 /* If we're stepping over a breakpoint with all threads locked,
5670 then only the thread that was stepped should be reporting
5672 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5674 clear_step_over_info ();
5677 if (!target_is_non_stop_p ())
5680 /* Start a new step-over in another thread if there's one that
5684 /* If we were stepping over a breakpoint before, and haven't started
5685 a new in-line step-over sequence, then restart all other threads
5686 (except the event thread). We can't do this in all-stop, as then
5687 e.g., we wouldn't be able to issue any other remote packet until
5688 these other threads stop. */
5689 if (had_step_over_info
&& !step_over_info_valid_p ())
5691 struct thread_info
*pending
;
5693 /* If we only have threads with pending statuses, the restart
5694 below won't restart any thread and so nothing re-inserts the
5695 breakpoint we just stepped over. But we need it inserted
5696 when we later process the pending events, otherwise if
5697 another thread has a pending event for this breakpoint too,
5698 we'd discard its event (because the breakpoint that
5699 originally caused the event was no longer inserted). */
5700 context_switch (ecs
);
5701 insert_breakpoints ();
5703 restart_threads (ecs
->event_thread
);
5705 /* If we have events pending, go through handle_inferior_event
5706 again, picking up a pending event at random. This avoids
5707 thread starvation. */
5709 /* But not if we just stepped over a watchpoint in order to let
5710 the instruction execute so we can evaluate its expression.
5711 The set of watchpoints that triggered is recorded in the
5712 breakpoint objects themselves (see bp->watchpoint_triggered).
5713 If we processed another event first, that other event could
5714 clobber this info. */
5715 if (ecs
->event_thread
->stepping_over_watchpoint
)
5718 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5720 if (pending
!= NULL
)
5722 struct thread_info
*tp
= ecs
->event_thread
;
5723 struct regcache
*regcache
;
5725 infrun_debug_printf ("found resumed threads with "
5726 "pending events, saving status");
5728 gdb_assert (pending
!= tp
);
5730 /* Record the event thread's event for later. */
5731 save_waitstatus (tp
, &ecs
->ws
);
5732 /* This was cleared early, by handle_inferior_event. Set it
5733 so this pending event is considered by
5737 gdb_assert (!tp
->executing
);
5739 regcache
= get_thread_regcache (tp
);
5740 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5742 infrun_debug_printf ("saved stop_pc=%s for %s "
5743 "(currently_stepping=%d)",
5744 paddress (target_gdbarch (),
5745 tp
->suspend
.stop_pc
),
5746 target_pid_to_str (tp
->ptid
).c_str (),
5747 currently_stepping (tp
));
5749 /* This in-line step-over finished; clear this so we won't
5750 start a new one. This is what handle_signal_stop would
5751 do, if we returned false. */
5752 tp
->stepping_over_breakpoint
= 0;
5754 /* Wake up the event loop again. */
5755 mark_async_event_handler (infrun_async_inferior_event_token
);
5757 prepare_to_wait (ecs
);
5765 /* Come here when the program has stopped with a signal. */
5768 handle_signal_stop (struct execution_control_state
*ecs
)
5770 struct frame_info
*frame
;
5771 struct gdbarch
*gdbarch
;
5772 int stopped_by_watchpoint
;
5773 enum stop_kind stop_soon
;
5776 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5778 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5780 /* Do we need to clean up the state of a thread that has
5781 completed a displaced single-step? (Doing so usually affects
5782 the PC, so do it here, before we set stop_pc.) */
5783 if (finish_step_over (ecs
))
5786 /* If we either finished a single-step or hit a breakpoint, but
5787 the user wanted this thread to be stopped, pretend we got a
5788 SIG0 (generic unsignaled stop). */
5789 if (ecs
->event_thread
->stop_requested
5790 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5791 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5793 ecs
->event_thread
->suspend
.stop_pc
5794 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5796 context_switch (ecs
);
5798 if (deprecated_context_hook
)
5799 deprecated_context_hook (ecs
->event_thread
->global_num
);
5803 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5804 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5806 infrun_debug_printf ("stop_pc=%s",
5807 paddress (reg_gdbarch
,
5808 ecs
->event_thread
->suspend
.stop_pc
));
5809 if (target_stopped_by_watchpoint ())
5813 infrun_debug_printf ("stopped by watchpoint");
5815 if (target_stopped_data_address (current_top_target (), &addr
))
5816 infrun_debug_printf ("stopped data address=%s",
5817 paddress (reg_gdbarch
, addr
));
5819 infrun_debug_printf ("(no data address available)");
5823 /* This is originated from start_remote(), start_inferior() and
5824 shared libraries hook functions. */
5825 stop_soon
= get_inferior_stop_soon (ecs
);
5826 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5828 infrun_debug_printf ("quietly stopped");
5829 stop_print_frame
= true;
5834 /* This originates from attach_command(). We need to overwrite
5835 the stop_signal here, because some kernels don't ignore a
5836 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5837 See more comments in inferior.h. On the other hand, if we
5838 get a non-SIGSTOP, report it to the user - assume the backend
5839 will handle the SIGSTOP if it should show up later.
5841 Also consider that the attach is complete when we see a
5842 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5843 target extended-remote report it instead of a SIGSTOP
5844 (e.g. gdbserver). We already rely on SIGTRAP being our
5845 signal, so this is no exception.
5847 Also consider that the attach is complete when we see a
5848 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5849 the target to stop all threads of the inferior, in case the
5850 low level attach operation doesn't stop them implicitly. If
5851 they weren't stopped implicitly, then the stub will report a
5852 GDB_SIGNAL_0, meaning: stopped for no particular reason
5853 other than GDB's request. */
5854 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5855 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5856 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5857 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5859 stop_print_frame
= true;
5861 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5865 /* At this point, get hold of the now-current thread's frame. */
5866 frame
= get_current_frame ();
5867 gdbarch
= get_frame_arch (frame
);
5869 /* Pull the single step breakpoints out of the target. */
5870 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5872 struct regcache
*regcache
;
5875 regcache
= get_thread_regcache (ecs
->event_thread
);
5876 const address_space
*aspace
= regcache
->aspace ();
5878 pc
= regcache_read_pc (regcache
);
5880 /* However, before doing so, if this single-step breakpoint was
5881 actually for another thread, set this thread up for moving
5883 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5886 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5888 infrun_debug_printf ("[%s] hit another thread's single-step "
5890 target_pid_to_str (ecs
->ptid
).c_str ());
5891 ecs
->hit_singlestep_breakpoint
= 1;
5896 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5897 target_pid_to_str (ecs
->ptid
).c_str ());
5900 delete_just_stopped_threads_single_step_breakpoints ();
5902 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5903 && ecs
->event_thread
->control
.trap_expected
5904 && ecs
->event_thread
->stepping_over_watchpoint
)
5905 stopped_by_watchpoint
= 0;
5907 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5909 /* If necessary, step over this watchpoint. We'll be back to display
5911 if (stopped_by_watchpoint
5912 && (target_have_steppable_watchpoint ()
5913 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5915 /* At this point, we are stopped at an instruction which has
5916 attempted to write to a piece of memory under control of
5917 a watchpoint. The instruction hasn't actually executed
5918 yet. If we were to evaluate the watchpoint expression
5919 now, we would get the old value, and therefore no change
5920 would seem to have occurred.
5922 In order to make watchpoints work `right', we really need
5923 to complete the memory write, and then evaluate the
5924 watchpoint expression. We do this by single-stepping the
5927 It may not be necessary to disable the watchpoint to step over
5928 it. For example, the PA can (with some kernel cooperation)
5929 single step over a watchpoint without disabling the watchpoint.
5931 It is far more common to need to disable a watchpoint to step
5932 the inferior over it. If we have non-steppable watchpoints,
5933 we must disable the current watchpoint; it's simplest to
5934 disable all watchpoints.
5936 Any breakpoint at PC must also be stepped over -- if there's
5937 one, it will have already triggered before the watchpoint
5938 triggered, and we either already reported it to the user, or
5939 it didn't cause a stop and we called keep_going. In either
5940 case, if there was a breakpoint at PC, we must be trying to
5942 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5947 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5948 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5949 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5950 ecs
->event_thread
->control
.stop_step
= 0;
5951 stop_print_frame
= true;
5952 stopped_by_random_signal
= 0;
5953 bpstat stop_chain
= NULL
;
5955 /* Hide inlined functions starting here, unless we just performed stepi or
5956 nexti. After stepi and nexti, always show the innermost frame (not any
5957 inline function call sites). */
5958 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5960 const address_space
*aspace
5961 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5963 /* skip_inline_frames is expensive, so we avoid it if we can
5964 determine that the address is one where functions cannot have
5965 been inlined. This improves performance with inferiors that
5966 load a lot of shared libraries, because the solib event
5967 breakpoint is defined as the address of a function (i.e. not
5968 inline). Note that we have to check the previous PC as well
5969 as the current one to catch cases when we have just
5970 single-stepped off a breakpoint prior to reinstating it.
5971 Note that we're assuming that the code we single-step to is
5972 not inline, but that's not definitive: there's nothing
5973 preventing the event breakpoint function from containing
5974 inlined code, and the single-step ending up there. If the
5975 user had set a breakpoint on that inlined code, the missing
5976 skip_inline_frames call would break things. Fortunately
5977 that's an extremely unlikely scenario. */
5978 if (!pc_at_non_inline_function (aspace
,
5979 ecs
->event_thread
->suspend
.stop_pc
,
5981 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5982 && ecs
->event_thread
->control
.trap_expected
5983 && pc_at_non_inline_function (aspace
,
5984 ecs
->event_thread
->prev_pc
,
5987 stop_chain
= build_bpstat_chain (aspace
,
5988 ecs
->event_thread
->suspend
.stop_pc
,
5990 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5992 /* Re-fetch current thread's frame in case that invalidated
5994 frame
= get_current_frame ();
5995 gdbarch
= get_frame_arch (frame
);
5999 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6000 && ecs
->event_thread
->control
.trap_expected
6001 && gdbarch_single_step_through_delay_p (gdbarch
)
6002 && currently_stepping (ecs
->event_thread
))
6004 /* We're trying to step off a breakpoint. Turns out that we're
6005 also on an instruction that needs to be stepped multiple
6006 times before it's been fully executing. E.g., architectures
6007 with a delay slot. It needs to be stepped twice, once for
6008 the instruction and once for the delay slot. */
6009 int step_through_delay
6010 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6012 if (step_through_delay
)
6013 infrun_debug_printf ("step through delay");
6015 if (ecs
->event_thread
->control
.step_range_end
== 0
6016 && step_through_delay
)
6018 /* The user issued a continue when stopped at a breakpoint.
6019 Set up for another trap and get out of here. */
6020 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6024 else if (step_through_delay
)
6026 /* The user issued a step when stopped at a breakpoint.
6027 Maybe we should stop, maybe we should not - the delay
6028 slot *might* correspond to a line of source. In any
6029 case, don't decide that here, just set
6030 ecs->stepping_over_breakpoint, making sure we
6031 single-step again before breakpoints are re-inserted. */
6032 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6036 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6037 handles this event. */
6038 ecs
->event_thread
->control
.stop_bpstat
6039 = bpstat_stop_status (get_current_regcache ()->aspace (),
6040 ecs
->event_thread
->suspend
.stop_pc
,
6041 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6043 /* Following in case break condition called a
6045 stop_print_frame
= true;
6047 /* This is where we handle "moribund" watchpoints. Unlike
6048 software breakpoints traps, hardware watchpoint traps are
6049 always distinguishable from random traps. If no high-level
6050 watchpoint is associated with the reported stop data address
6051 anymore, then the bpstat does not explain the signal ---
6052 simply make sure to ignore it if `stopped_by_watchpoint' is
6055 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6056 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6058 && stopped_by_watchpoint
)
6060 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6064 /* NOTE: cagney/2003-03-29: These checks for a random signal
6065 at one stage in the past included checks for an inferior
6066 function call's call dummy's return breakpoint. The original
6067 comment, that went with the test, read:
6069 ``End of a stack dummy. Some systems (e.g. Sony news) give
6070 another signal besides SIGTRAP, so check here as well as
6073 If someone ever tries to get call dummys on a
6074 non-executable stack to work (where the target would stop
6075 with something like a SIGSEGV), then those tests might need
6076 to be re-instated. Given, however, that the tests were only
6077 enabled when momentary breakpoints were not being used, I
6078 suspect that it won't be the case.
6080 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6081 be necessary for call dummies on a non-executable stack on
6084 /* See if the breakpoints module can explain the signal. */
6086 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6087 ecs
->event_thread
->suspend
.stop_signal
);
6089 /* Maybe this was a trap for a software breakpoint that has since
6091 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6093 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6094 ecs
->event_thread
->suspend
.stop_pc
))
6096 struct regcache
*regcache
;
6099 /* Re-adjust PC to what the program would see if GDB was not
6101 regcache
= get_thread_regcache (ecs
->event_thread
);
6102 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6105 gdb::optional
<scoped_restore_tmpl
<int>>
6106 restore_operation_disable
;
6108 if (record_full_is_used ())
6109 restore_operation_disable
.emplace
6110 (record_full_gdb_operation_disable_set ());
6112 regcache_write_pc (regcache
,
6113 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6118 /* A delayed software breakpoint event. Ignore the trap. */
6119 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6124 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6125 has since been removed. */
6126 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6128 /* A delayed hardware breakpoint event. Ignore the trap. */
6129 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6134 /* If not, perhaps stepping/nexting can. */
6136 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6137 && currently_stepping (ecs
->event_thread
));
6139 /* Perhaps the thread hit a single-step breakpoint of _another_
6140 thread. Single-step breakpoints are transparent to the
6141 breakpoints module. */
6143 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6145 /* No? Perhaps we got a moribund watchpoint. */
6147 random_signal
= !stopped_by_watchpoint
;
6149 /* Always stop if the user explicitly requested this thread to
6151 if (ecs
->event_thread
->stop_requested
)
6154 infrun_debug_printf ("user-requested stop");
6157 /* For the program's own signals, act according to
6158 the signal handling tables. */
6162 /* Signal not for debugging purposes. */
6163 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6165 infrun_debug_printf ("random signal (%s)",
6166 gdb_signal_to_symbol_string (stop_signal
));
6168 stopped_by_random_signal
= 1;
6170 /* Always stop on signals if we're either just gaining control
6171 of the program, or the user explicitly requested this thread
6172 to remain stopped. */
6173 if (stop_soon
!= NO_STOP_QUIETLY
6174 || ecs
->event_thread
->stop_requested
6175 || signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
))
6181 /* Notify observers the signal has "handle print" set. Note we
6182 returned early above if stopping; normal_stop handles the
6183 printing in that case. */
6184 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6186 /* The signal table tells us to print about this signal. */
6187 target_terminal::ours_for_output ();
6188 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6189 target_terminal::inferior ();
6192 /* Clear the signal if it should not be passed. */
6193 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6194 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6196 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6197 && ecs
->event_thread
->control
.trap_expected
6198 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6200 /* We were just starting a new sequence, attempting to
6201 single-step off of a breakpoint and expecting a SIGTRAP.
6202 Instead this signal arrives. This signal will take us out
6203 of the stepping range so GDB needs to remember to, when
6204 the signal handler returns, resume stepping off that
6206 /* To simplify things, "continue" is forced to use the same
6207 code paths as single-step - set a breakpoint at the
6208 signal return address and then, once hit, step off that
6210 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6212 insert_hp_step_resume_breakpoint_at_frame (frame
);
6213 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6214 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6215 ecs
->event_thread
->control
.trap_expected
= 0;
6217 /* If we were nexting/stepping some other thread, switch to
6218 it, so that we don't continue it, losing control. */
6219 if (!switch_back_to_stepped_thread (ecs
))
6224 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6225 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6227 || ecs
->event_thread
->control
.step_range_end
== 1)
6228 && frame_id_eq (get_stack_frame_id (frame
),
6229 ecs
->event_thread
->control
.step_stack_frame_id
)
6230 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6232 /* The inferior is about to take a signal that will take it
6233 out of the single step range. Set a breakpoint at the
6234 current PC (which is presumably where the signal handler
6235 will eventually return) and then allow the inferior to
6238 Note that this is only needed for a signal delivered
6239 while in the single-step range. Nested signals aren't a
6240 problem as they eventually all return. */
6241 infrun_debug_printf ("signal may take us out of single-step range");
6243 clear_step_over_info ();
6244 insert_hp_step_resume_breakpoint_at_frame (frame
);
6245 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6246 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6247 ecs
->event_thread
->control
.trap_expected
= 0;
6252 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6253 when either there's a nested signal, or when there's a
6254 pending signal enabled just as the signal handler returns
6255 (leaving the inferior at the step-resume-breakpoint without
6256 actually executing it). Either way continue until the
6257 breakpoint is really hit. */
6259 if (!switch_back_to_stepped_thread (ecs
))
6261 infrun_debug_printf ("random signal, keep going");
6268 process_event_stop_test (ecs
);
6271 /* Come here when we've got some debug event / signal we can explain
6272 (IOW, not a random signal), and test whether it should cause a
6273 stop, or whether we should resume the inferior (transparently).
6274 E.g., could be a breakpoint whose condition evaluates false; we
6275 could be still stepping within the line; etc. */
6278 process_event_stop_test (struct execution_control_state
*ecs
)
6280 struct symtab_and_line stop_pc_sal
;
6281 struct frame_info
*frame
;
6282 struct gdbarch
*gdbarch
;
6283 CORE_ADDR jmp_buf_pc
;
6284 struct bpstat_what what
;
6286 /* Handle cases caused by hitting a breakpoint. */
6288 frame
= get_current_frame ();
6289 gdbarch
= get_frame_arch (frame
);
6291 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6293 if (what
.call_dummy
)
6295 stop_stack_dummy
= what
.call_dummy
;
6298 /* A few breakpoint types have callbacks associated (e.g.,
6299 bp_jit_event). Run them now. */
6300 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6302 /* If we hit an internal event that triggers symbol changes, the
6303 current frame will be invalidated within bpstat_what (e.g., if we
6304 hit an internal solib event). Re-fetch it. */
6305 frame
= get_current_frame ();
6306 gdbarch
= get_frame_arch (frame
);
6308 switch (what
.main_action
)
6310 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6311 /* If we hit the breakpoint at longjmp while stepping, we
6312 install a momentary breakpoint at the target of the
6315 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6317 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6319 if (what
.is_longjmp
)
6321 struct value
*arg_value
;
6323 /* If we set the longjmp breakpoint via a SystemTap probe,
6324 then use it to extract the arguments. The destination PC
6325 is the third argument to the probe. */
6326 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6329 jmp_buf_pc
= value_as_address (arg_value
);
6330 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6332 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6333 || !gdbarch_get_longjmp_target (gdbarch
,
6334 frame
, &jmp_buf_pc
))
6336 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6337 "(!gdbarch_get_longjmp_target)");
6342 /* Insert a breakpoint at resume address. */
6343 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6346 check_exception_resume (ecs
, frame
);
6350 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6352 struct frame_info
*init_frame
;
6354 /* There are several cases to consider.
6356 1. The initiating frame no longer exists. In this case we
6357 must stop, because the exception or longjmp has gone too
6360 2. The initiating frame exists, and is the same as the
6361 current frame. We stop, because the exception or longjmp
6364 3. The initiating frame exists and is different from the
6365 current frame. This means the exception or longjmp has
6366 been caught beneath the initiating frame, so keep going.
6368 4. longjmp breakpoint has been placed just to protect
6369 against stale dummy frames and user is not interested in
6370 stopping around longjmps. */
6372 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6374 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6376 delete_exception_resume_breakpoint (ecs
->event_thread
);
6378 if (what
.is_longjmp
)
6380 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6382 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6390 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6394 struct frame_id current_id
6395 = get_frame_id (get_current_frame ());
6396 if (frame_id_eq (current_id
,
6397 ecs
->event_thread
->initiating_frame
))
6399 /* Case 2. Fall through. */
6409 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6411 delete_step_resume_breakpoint (ecs
->event_thread
);
6413 end_stepping_range (ecs
);
6417 case BPSTAT_WHAT_SINGLE
:
6418 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6419 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6420 /* Still need to check other stuff, at least the case where we
6421 are stepping and step out of the right range. */
6424 case BPSTAT_WHAT_STEP_RESUME
:
6425 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6427 delete_step_resume_breakpoint (ecs
->event_thread
);
6428 if (ecs
->event_thread
->control
.proceed_to_finish
6429 && execution_direction
== EXEC_REVERSE
)
6431 struct thread_info
*tp
= ecs
->event_thread
;
6433 /* We are finishing a function in reverse, and just hit the
6434 step-resume breakpoint at the start address of the
6435 function, and we're almost there -- just need to back up
6436 by one more single-step, which should take us back to the
6438 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6442 fill_in_stop_func (gdbarch
, ecs
);
6443 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6444 && execution_direction
== EXEC_REVERSE
)
6446 /* We are stepping over a function call in reverse, and just
6447 hit the step-resume breakpoint at the start address of
6448 the function. Go back to single-stepping, which should
6449 take us back to the function call. */
6450 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6456 case BPSTAT_WHAT_STOP_NOISY
:
6457 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6458 stop_print_frame
= true;
6460 /* Assume the thread stopped for a breakpoint. We'll still check
6461 whether a/the breakpoint is there when the thread is next
6463 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6468 case BPSTAT_WHAT_STOP_SILENT
:
6469 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6470 stop_print_frame
= false;
6472 /* Assume the thread stopped for a breakpoint. We'll still check
6473 whether a/the breakpoint is there when the thread is next
6475 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6479 case BPSTAT_WHAT_HP_STEP_RESUME
:
6480 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6482 delete_step_resume_breakpoint (ecs
->event_thread
);
6483 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6485 /* Back when the step-resume breakpoint was inserted, we
6486 were trying to single-step off a breakpoint. Go back to
6488 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6489 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6495 case BPSTAT_WHAT_KEEP_CHECKING
:
6499 /* If we stepped a permanent breakpoint and we had a high priority
6500 step-resume breakpoint for the address we stepped, but we didn't
6501 hit it, then we must have stepped into the signal handler. The
6502 step-resume was only necessary to catch the case of _not_
6503 stepping into the handler, so delete it, and fall through to
6504 checking whether the step finished. */
6505 if (ecs
->event_thread
->stepped_breakpoint
)
6507 struct breakpoint
*sr_bp
6508 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6511 && sr_bp
->loc
->permanent
6512 && sr_bp
->type
== bp_hp_step_resume
6513 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6515 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6516 delete_step_resume_breakpoint (ecs
->event_thread
);
6517 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6521 /* We come here if we hit a breakpoint but should not stop for it.
6522 Possibly we also were stepping and should stop for that. So fall
6523 through and test for stepping. But, if not stepping, do not
6526 /* In all-stop mode, if we're currently stepping but have stopped in
6527 some other thread, we need to switch back to the stepped thread. */
6528 if (switch_back_to_stepped_thread (ecs
))
6531 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6533 infrun_debug_printf ("step-resume breakpoint is inserted");
6535 /* Having a step-resume breakpoint overrides anything
6536 else having to do with stepping commands until
6537 that breakpoint is reached. */
6542 if (ecs
->event_thread
->control
.step_range_end
== 0)
6544 infrun_debug_printf ("no stepping, continue");
6545 /* Likewise if we aren't even stepping. */
6550 /* Re-fetch current thread's frame in case the code above caused
6551 the frame cache to be re-initialized, making our FRAME variable
6552 a dangling pointer. */
6553 frame
= get_current_frame ();
6554 gdbarch
= get_frame_arch (frame
);
6555 fill_in_stop_func (gdbarch
, ecs
);
6557 /* If stepping through a line, keep going if still within it.
6559 Note that step_range_end is the address of the first instruction
6560 beyond the step range, and NOT the address of the last instruction
6563 Note also that during reverse execution, we may be stepping
6564 through a function epilogue and therefore must detect when
6565 the current-frame changes in the middle of a line. */
6567 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6569 && (execution_direction
!= EXEC_REVERSE
6570 || frame_id_eq (get_frame_id (frame
),
6571 ecs
->event_thread
->control
.step_frame_id
)))
6574 ("stepping inside range [%s-%s]",
6575 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6576 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6578 /* Tentatively re-enable range stepping; `resume' disables it if
6579 necessary (e.g., if we're stepping over a breakpoint or we
6580 have software watchpoints). */
6581 ecs
->event_thread
->control
.may_range_step
= 1;
6583 /* When stepping backward, stop at beginning of line range
6584 (unless it's the function entry point, in which case
6585 keep going back to the call point). */
6586 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6587 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6588 && stop_pc
!= ecs
->stop_func_start
6589 && execution_direction
== EXEC_REVERSE
)
6590 end_stepping_range (ecs
);
6597 /* We stepped out of the stepping range. */
6599 /* If we are stepping at the source level and entered the runtime
6600 loader dynamic symbol resolution code...
6602 EXEC_FORWARD: we keep on single stepping until we exit the run
6603 time loader code and reach the callee's address.
6605 EXEC_REVERSE: we've already executed the callee (backward), and
6606 the runtime loader code is handled just like any other
6607 undebuggable function call. Now we need only keep stepping
6608 backward through the trampoline code, and that's handled further
6609 down, so there is nothing for us to do here. */
6611 if (execution_direction
!= EXEC_REVERSE
6612 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6613 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6615 CORE_ADDR pc_after_resolver
=
6616 gdbarch_skip_solib_resolver (gdbarch
,
6617 ecs
->event_thread
->suspend
.stop_pc
);
6619 infrun_debug_printf ("stepped into dynsym resolve code");
6621 if (pc_after_resolver
)
6623 /* Set up a step-resume breakpoint at the address
6624 indicated by SKIP_SOLIB_RESOLVER. */
6625 symtab_and_line sr_sal
;
6626 sr_sal
.pc
= pc_after_resolver
;
6627 sr_sal
.pspace
= get_frame_program_space (frame
);
6629 insert_step_resume_breakpoint_at_sal (gdbarch
,
6630 sr_sal
, null_frame_id
);
6637 /* Step through an indirect branch thunk. */
6638 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6639 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6640 ecs
->event_thread
->suspend
.stop_pc
))
6642 infrun_debug_printf ("stepped into indirect branch thunk");
6647 if (ecs
->event_thread
->control
.step_range_end
!= 1
6648 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6649 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6650 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6652 infrun_debug_printf ("stepped into signal trampoline");
6653 /* The inferior, while doing a "step" or "next", has ended up in
6654 a signal trampoline (either by a signal being delivered or by
6655 the signal handler returning). Just single-step until the
6656 inferior leaves the trampoline (either by calling the handler
6662 /* If we're in the return path from a shared library trampoline,
6663 we want to proceed through the trampoline when stepping. */
6664 /* macro/2012-04-25: This needs to come before the subroutine
6665 call check below as on some targets return trampolines look
6666 like subroutine calls (MIPS16 return thunks). */
6667 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6668 ecs
->event_thread
->suspend
.stop_pc
,
6669 ecs
->stop_func_name
)
6670 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6672 /* Determine where this trampoline returns. */
6673 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6674 CORE_ADDR real_stop_pc
6675 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6677 infrun_debug_printf ("stepped into solib return tramp");
6679 /* Only proceed through if we know where it's going. */
6682 /* And put the step-breakpoint there and go until there. */
6683 symtab_and_line sr_sal
;
6684 sr_sal
.pc
= real_stop_pc
;
6685 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6686 sr_sal
.pspace
= get_frame_program_space (frame
);
6688 /* Do not specify what the fp should be when we stop since
6689 on some machines the prologue is where the new fp value
6691 insert_step_resume_breakpoint_at_sal (gdbarch
,
6692 sr_sal
, null_frame_id
);
6694 /* Restart without fiddling with the step ranges or
6701 /* Check for subroutine calls. The check for the current frame
6702 equalling the step ID is not necessary - the check of the
6703 previous frame's ID is sufficient - but it is a common case and
6704 cheaper than checking the previous frame's ID.
6706 NOTE: frame_id_eq will never report two invalid frame IDs as
6707 being equal, so to get into this block, both the current and
6708 previous frame must have valid frame IDs. */
6709 /* The outer_frame_id check is a heuristic to detect stepping
6710 through startup code. If we step over an instruction which
6711 sets the stack pointer from an invalid value to a valid value,
6712 we may detect that as a subroutine call from the mythical
6713 "outermost" function. This could be fixed by marking
6714 outermost frames as !stack_p,code_p,special_p. Then the
6715 initial outermost frame, before sp was valid, would
6716 have code_addr == &_start. See the comment in frame_id_eq
6718 if (!frame_id_eq (get_stack_frame_id (frame
),
6719 ecs
->event_thread
->control
.step_stack_frame_id
)
6720 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6721 ecs
->event_thread
->control
.step_stack_frame_id
)
6722 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6724 || (ecs
->event_thread
->control
.step_start_function
6725 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6727 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6728 CORE_ADDR real_stop_pc
;
6730 infrun_debug_printf ("stepped into subroutine");
6732 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6734 /* I presume that step_over_calls is only 0 when we're
6735 supposed to be stepping at the assembly language level
6736 ("stepi"). Just stop. */
6737 /* And this works the same backward as frontward. MVS */
6738 end_stepping_range (ecs
);
6742 /* Reverse stepping through solib trampolines. */
6744 if (execution_direction
== EXEC_REVERSE
6745 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6746 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6747 || (ecs
->stop_func_start
== 0
6748 && in_solib_dynsym_resolve_code (stop_pc
))))
6750 /* Any solib trampoline code can be handled in reverse
6751 by simply continuing to single-step. We have already
6752 executed the solib function (backwards), and a few
6753 steps will take us back through the trampoline to the
6759 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6761 /* We're doing a "next".
6763 Normal (forward) execution: set a breakpoint at the
6764 callee's return address (the address at which the caller
6767 Reverse (backward) execution. set the step-resume
6768 breakpoint at the start of the function that we just
6769 stepped into (backwards), and continue to there. When we
6770 get there, we'll need to single-step back to the caller. */
6772 if (execution_direction
== EXEC_REVERSE
)
6774 /* If we're already at the start of the function, we've either
6775 just stepped backward into a single instruction function,
6776 or stepped back out of a signal handler to the first instruction
6777 of the function. Just keep going, which will single-step back
6779 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6781 /* Normal function call return (static or dynamic). */
6782 symtab_and_line sr_sal
;
6783 sr_sal
.pc
= ecs
->stop_func_start
;
6784 sr_sal
.pspace
= get_frame_program_space (frame
);
6785 insert_step_resume_breakpoint_at_sal (gdbarch
,
6786 sr_sal
, null_frame_id
);
6790 insert_step_resume_breakpoint_at_caller (frame
);
6796 /* If we are in a function call trampoline (a stub between the
6797 calling routine and the real function), locate the real
6798 function. That's what tells us (a) whether we want to step
6799 into it at all, and (b) what prologue we want to run to the
6800 end of, if we do step into it. */
6801 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6802 if (real_stop_pc
== 0)
6803 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6804 if (real_stop_pc
!= 0)
6805 ecs
->stop_func_start
= real_stop_pc
;
6807 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6809 symtab_and_line sr_sal
;
6810 sr_sal
.pc
= ecs
->stop_func_start
;
6811 sr_sal
.pspace
= get_frame_program_space (frame
);
6813 insert_step_resume_breakpoint_at_sal (gdbarch
,
6814 sr_sal
, null_frame_id
);
6819 /* If we have line number information for the function we are
6820 thinking of stepping into and the function isn't on the skip
6823 If there are several symtabs at that PC (e.g. with include
6824 files), just want to know whether *any* of them have line
6825 numbers. find_pc_line handles this. */
6827 struct symtab_and_line tmp_sal
;
6829 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6830 if (tmp_sal
.line
!= 0
6831 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6833 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6835 if (execution_direction
== EXEC_REVERSE
)
6836 handle_step_into_function_backward (gdbarch
, ecs
);
6838 handle_step_into_function (gdbarch
, ecs
);
6843 /* If we have no line number and the step-stop-if-no-debug is
6844 set, we stop the step so that the user has a chance to switch
6845 in assembly mode. */
6846 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6847 && step_stop_if_no_debug
)
6849 end_stepping_range (ecs
);
6853 if (execution_direction
== EXEC_REVERSE
)
6855 /* If we're already at the start of the function, we've either just
6856 stepped backward into a single instruction function without line
6857 number info, or stepped back out of a signal handler to the first
6858 instruction of the function without line number info. Just keep
6859 going, which will single-step back to the caller. */
6860 if (ecs
->stop_func_start
!= stop_pc
)
6862 /* Set a breakpoint at callee's start address.
6863 From there we can step once and be back in the caller. */
6864 symtab_and_line sr_sal
;
6865 sr_sal
.pc
= ecs
->stop_func_start
;
6866 sr_sal
.pspace
= get_frame_program_space (frame
);
6867 insert_step_resume_breakpoint_at_sal (gdbarch
,
6868 sr_sal
, null_frame_id
);
6872 /* Set a breakpoint at callee's return address (the address
6873 at which the caller will resume). */
6874 insert_step_resume_breakpoint_at_caller (frame
);
6880 /* Reverse stepping through solib trampolines. */
6882 if (execution_direction
== EXEC_REVERSE
6883 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6885 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6887 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6888 || (ecs
->stop_func_start
== 0
6889 && in_solib_dynsym_resolve_code (stop_pc
)))
6891 /* Any solib trampoline code can be handled in reverse
6892 by simply continuing to single-step. We have already
6893 executed the solib function (backwards), and a few
6894 steps will take us back through the trampoline to the
6899 else if (in_solib_dynsym_resolve_code (stop_pc
))
6901 /* Stepped backward into the solib dynsym resolver.
6902 Set a breakpoint at its start and continue, then
6903 one more step will take us out. */
6904 symtab_and_line sr_sal
;
6905 sr_sal
.pc
= ecs
->stop_func_start
;
6906 sr_sal
.pspace
= get_frame_program_space (frame
);
6907 insert_step_resume_breakpoint_at_sal (gdbarch
,
6908 sr_sal
, null_frame_id
);
6914 /* This always returns the sal for the inner-most frame when we are in a
6915 stack of inlined frames, even if GDB actually believes that it is in a
6916 more outer frame. This is checked for below by calls to
6917 inline_skipped_frames. */
6918 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6920 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6921 the trampoline processing logic, however, there are some trampolines
6922 that have no names, so we should do trampoline handling first. */
6923 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6924 && ecs
->stop_func_name
== NULL
6925 && stop_pc_sal
.line
== 0)
6927 infrun_debug_printf ("stepped into undebuggable function");
6929 /* The inferior just stepped into, or returned to, an
6930 undebuggable function (where there is no debugging information
6931 and no line number corresponding to the address where the
6932 inferior stopped). Since we want to skip this kind of code,
6933 we keep going until the inferior returns from this
6934 function - unless the user has asked us not to (via
6935 set step-mode) or we no longer know how to get back
6936 to the call site. */
6937 if (step_stop_if_no_debug
6938 || !frame_id_p (frame_unwind_caller_id (frame
)))
6940 /* If we have no line number and the step-stop-if-no-debug
6941 is set, we stop the step so that the user has a chance to
6942 switch in assembly mode. */
6943 end_stepping_range (ecs
);
6948 /* Set a breakpoint at callee's return address (the address
6949 at which the caller will resume). */
6950 insert_step_resume_breakpoint_at_caller (frame
);
6956 if (ecs
->event_thread
->control
.step_range_end
== 1)
6958 /* It is stepi or nexti. We always want to stop stepping after
6960 infrun_debug_printf ("stepi/nexti");
6961 end_stepping_range (ecs
);
6965 if (stop_pc_sal
.line
== 0)
6967 /* We have no line number information. That means to stop
6968 stepping (does this always happen right after one instruction,
6969 when we do "s" in a function with no line numbers,
6970 or can this happen as a result of a return or longjmp?). */
6971 infrun_debug_printf ("line number info");
6972 end_stepping_range (ecs
);
6976 /* Look for "calls" to inlined functions, part one. If the inline
6977 frame machinery detected some skipped call sites, we have entered
6978 a new inline function. */
6980 if (frame_id_eq (get_frame_id (get_current_frame ()),
6981 ecs
->event_thread
->control
.step_frame_id
)
6982 && inline_skipped_frames (ecs
->event_thread
))
6984 infrun_debug_printf ("stepped into inlined function");
6986 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6988 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6990 /* For "step", we're going to stop. But if the call site
6991 for this inlined function is on the same source line as
6992 we were previously stepping, go down into the function
6993 first. Otherwise stop at the call site. */
6995 if (call_sal
.line
== ecs
->event_thread
->current_line
6996 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6998 step_into_inline_frame (ecs
->event_thread
);
6999 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7006 end_stepping_range (ecs
);
7011 /* For "next", we should stop at the call site if it is on a
7012 different source line. Otherwise continue through the
7013 inlined function. */
7014 if (call_sal
.line
== ecs
->event_thread
->current_line
7015 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7018 end_stepping_range (ecs
);
7023 /* Look for "calls" to inlined functions, part two. If we are still
7024 in the same real function we were stepping through, but we have
7025 to go further up to find the exact frame ID, we are stepping
7026 through a more inlined call beyond its call site. */
7028 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7029 && !frame_id_eq (get_frame_id (get_current_frame ()),
7030 ecs
->event_thread
->control
.step_frame_id
)
7031 && stepped_in_from (get_current_frame (),
7032 ecs
->event_thread
->control
.step_frame_id
))
7034 infrun_debug_printf ("stepping through inlined function");
7036 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7037 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7040 end_stepping_range (ecs
);
7044 bool refresh_step_info
= true;
7045 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7046 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7047 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7049 /* We are at a different line. */
7051 if (stop_pc_sal
.is_stmt
)
7053 /* We are at the start of a statement.
7055 So stop. Note that we don't stop if we step into the middle of a
7056 statement. That is said to make things like for (;;) statements
7058 infrun_debug_printf ("stepped to a different line");
7059 end_stepping_range (ecs
);
7062 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7063 ecs
->event_thread
->control
.step_frame_id
))
7065 /* We are not at the start of a statement, and we have not changed
7068 We ignore this line table entry, and continue stepping forward,
7069 looking for a better place to stop. */
7070 refresh_step_info
= false;
7071 infrun_debug_printf ("stepped to a different line, but "
7072 "it's not the start of a statement");
7076 /* We are not the start of a statement, and we have changed frame.
7078 We ignore this line table entry, and continue stepping forward,
7079 looking for a better place to stop. Keep refresh_step_info at
7080 true to note that the frame has changed, but ignore the line
7081 number to make sure we don't ignore a subsequent entry with the
7082 same line number. */
7083 stop_pc_sal
.line
= 0;
7084 infrun_debug_printf ("stepped to a different frame, but "
7085 "it's not the start of a statement");
7089 /* We aren't done stepping.
7091 Optimize by setting the stepping range to the line.
7092 (We might not be in the original line, but if we entered a
7093 new line in mid-statement, we continue stepping. This makes
7094 things like for(;;) statements work better.)
7096 If we entered a SAL that indicates a non-statement line table entry,
7097 then we update the stepping range, but we don't update the step info,
7098 which includes things like the line number we are stepping away from.
7099 This means we will stop when we find a line table entry that is marked
7100 as is-statement, even if it matches the non-statement one we just
7103 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7104 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7105 ecs
->event_thread
->control
.may_range_step
= 1;
7106 if (refresh_step_info
)
7107 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7109 infrun_debug_printf ("keep going");
7113 static bool restart_stepped_thread (process_stratum_target
*resume_target
,
7114 ptid_t resume_ptid
);
7116 /* In all-stop mode, if we're currently stepping but have stopped in
7117 some other thread, we may need to switch back to the stepped
7118 thread. Returns true we set the inferior running, false if we left
7119 it stopped (and the event needs further processing). */
7122 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7124 if (!target_is_non_stop_p ())
7126 /* If any thread is blocked on some internal breakpoint, and we
7127 simply need to step over that breakpoint to get it going
7128 again, do that first. */
7130 /* However, if we see an event for the stepping thread, then we
7131 know all other threads have been moved past their breakpoints
7132 already. Let the caller check whether the step is finished,
7133 etc., before deciding to move it past a breakpoint. */
7134 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7137 /* Check if the current thread is blocked on an incomplete
7138 step-over, interrupted by a random signal. */
7139 if (ecs
->event_thread
->control
.trap_expected
7140 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7143 ("need to finish step-over of [%s]",
7144 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7149 /* Check if the current thread is blocked by a single-step
7150 breakpoint of another thread. */
7151 if (ecs
->hit_singlestep_breakpoint
)
7153 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7154 target_pid_to_str (ecs
->ptid
).c_str ());
7159 /* If this thread needs yet another step-over (e.g., stepping
7160 through a delay slot), do it first before moving on to
7162 if (thread_still_needs_step_over (ecs
->event_thread
))
7165 ("thread [%s] still needs step-over",
7166 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7171 /* If scheduler locking applies even if not stepping, there's no
7172 need to walk over threads. Above we've checked whether the
7173 current thread is stepping. If some other thread not the
7174 event thread is stepping, then it must be that scheduler
7175 locking is not in effect. */
7176 if (schedlock_applies (ecs
->event_thread
))
7179 /* Otherwise, we no longer expect a trap in the current thread.
7180 Clear the trap_expected flag before switching back -- this is
7181 what keep_going does as well, if we call it. */
7182 ecs
->event_thread
->control
.trap_expected
= 0;
7184 /* Likewise, clear the signal if it should not be passed. */
7185 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7186 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7188 if (restart_stepped_thread (ecs
->target
, ecs
->ptid
))
7190 prepare_to_wait (ecs
);
7194 switch_to_thread (ecs
->event_thread
);
7200 /* Look for the thread that was stepping, and resume it.
7201 RESUME_TARGET / RESUME_PTID indicate the set of threads the caller
7202 is resuming. Return true if a thread was started, false
7206 restart_stepped_thread (process_stratum_target
*resume_target
,
7209 /* Do all pending step-overs before actually proceeding with
7211 if (start_step_over ())
7214 for (thread_info
*tp
: all_threads_safe ())
7216 if (tp
->state
== THREAD_EXITED
)
7219 if (tp
->suspend
.waitstatus_pending_p
)
7222 /* Ignore threads of processes the caller is not
7225 && (tp
->inf
->process_target () != resume_target
7226 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7229 if (tp
->control
.trap_expected
)
7231 infrun_debug_printf ("switching back to stepped thread (step-over)");
7233 if (keep_going_stepped_thread (tp
))
7238 for (thread_info
*tp
: all_threads_safe ())
7240 if (tp
->state
== THREAD_EXITED
)
7243 if (tp
->suspend
.waitstatus_pending_p
)
7246 /* Ignore threads of processes the caller is not
7249 && (tp
->inf
->process_target () != resume_target
7250 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7253 /* Did we find the stepping thread? */
7254 if (tp
->control
.step_range_end
)
7256 infrun_debug_printf ("switching back to stepped thread (stepping)");
7258 if (keep_going_stepped_thread (tp
))
7269 restart_after_all_stop_detach (process_stratum_target
*proc_target
)
7271 /* Note we don't check target_is_non_stop_p() here, because the
7272 current inferior may no longer have a process_stratum target
7273 pushed, as we just detached. */
7275 /* See if we have a THREAD_RUNNING thread that need to be
7276 re-resumed. If we have any thread that is already executing,
7277 then we don't need to resume the target -- it is already been
7278 resumed. With the remote target (in all-stop), it's even
7279 impossible to issue another resumption if the target is already
7280 resumed, until the target reports a stop. */
7281 for (thread_info
*thr
: all_threads (proc_target
))
7283 if (thr
->state
!= THREAD_RUNNING
)
7286 /* If we have any thread that is already executing, then we
7287 don't need to resume the target -- it is already been
7292 /* If we have a pending event to process, skip resuming the
7293 target and go straight to processing it. */
7294 if (thr
->resumed
&& thr
->suspend
.waitstatus_pending_p
)
7298 /* Alright, we need to re-resume the target. If a thread was
7299 stepping, we need to restart it stepping. */
7300 if (restart_stepped_thread (proc_target
, minus_one_ptid
))
7303 /* Otherwise, find the first THREAD_RUNNING thread and resume
7305 for (thread_info
*thr
: all_threads (proc_target
))
7307 if (thr
->state
!= THREAD_RUNNING
)
7310 execution_control_state ecs
;
7311 reset_ecs (&ecs
, thr
);
7312 switch_to_thread (thr
);
7318 /* Set a previously stepped thread back to stepping. Returns true on
7319 success, false if the resume is not possible (e.g., the thread
7323 keep_going_stepped_thread (struct thread_info
*tp
)
7325 struct frame_info
*frame
;
7326 struct execution_control_state ecss
;
7327 struct execution_control_state
*ecs
= &ecss
;
7329 /* If the stepping thread exited, then don't try to switch back and
7330 resume it, which could fail in several different ways depending
7331 on the target. Instead, just keep going.
7333 We can find a stepping dead thread in the thread list in two
7336 - The target supports thread exit events, and when the target
7337 tries to delete the thread from the thread list, inferior_ptid
7338 pointed at the exiting thread. In such case, calling
7339 delete_thread does not really remove the thread from the list;
7340 instead, the thread is left listed, with 'exited' state.
7342 - The target's debug interface does not support thread exit
7343 events, and so we have no idea whatsoever if the previously
7344 stepping thread is still alive. For that reason, we need to
7345 synchronously query the target now. */
7347 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7349 infrun_debug_printf ("not resuming previously stepped thread, it has "
7356 infrun_debug_printf ("resuming previously stepped thread");
7358 reset_ecs (ecs
, tp
);
7359 switch_to_thread (tp
);
7361 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7362 frame
= get_current_frame ();
7364 /* If the PC of the thread we were trying to single-step has
7365 changed, then that thread has trapped or been signaled, but the
7366 event has not been reported to GDB yet. Re-poll the target
7367 looking for this particular thread's event (i.e. temporarily
7368 enable schedlock) by:
7370 - setting a break at the current PC
7371 - resuming that particular thread, only (by setting trap
7374 This prevents us continuously moving the single-step breakpoint
7375 forward, one instruction at a time, overstepping. */
7377 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7381 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7382 paddress (target_gdbarch (), tp
->prev_pc
),
7383 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7385 /* Clear the info of the previous step-over, as it's no longer
7386 valid (if the thread was trying to step over a breakpoint, it
7387 has already succeeded). It's what keep_going would do too,
7388 if we called it. Do this before trying to insert the sss
7389 breakpoint, otherwise if we were previously trying to step
7390 over this exact address in another thread, the breakpoint is
7392 clear_step_over_info ();
7393 tp
->control
.trap_expected
= 0;
7395 insert_single_step_breakpoint (get_frame_arch (frame
),
7396 get_frame_address_space (frame
),
7397 tp
->suspend
.stop_pc
);
7400 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7401 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7405 infrun_debug_printf ("expected thread still hasn't advanced");
7407 keep_going_pass_signal (ecs
);
7413 /* Is thread TP in the middle of (software or hardware)
7414 single-stepping? (Note the result of this function must never be
7415 passed directly as target_resume's STEP parameter.) */
7418 currently_stepping (struct thread_info
*tp
)
7420 return ((tp
->control
.step_range_end
7421 && tp
->control
.step_resume_breakpoint
== NULL
)
7422 || tp
->control
.trap_expected
7423 || tp
->stepped_breakpoint
7424 || bpstat_should_step ());
7427 /* Inferior has stepped into a subroutine call with source code that
7428 we should not step over. Do step to the first line of code in
7432 handle_step_into_function (struct gdbarch
*gdbarch
,
7433 struct execution_control_state
*ecs
)
7435 fill_in_stop_func (gdbarch
, ecs
);
7437 compunit_symtab
*cust
7438 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7439 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7440 ecs
->stop_func_start
7441 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7443 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7444 /* Use the step_resume_break to step until the end of the prologue,
7445 even if that involves jumps (as it seems to on the vax under
7447 /* If the prologue ends in the middle of a source line, continue to
7448 the end of that source line (if it is still within the function).
7449 Otherwise, just go to end of prologue. */
7450 if (stop_func_sal
.end
7451 && stop_func_sal
.pc
!= ecs
->stop_func_start
7452 && stop_func_sal
.end
< ecs
->stop_func_end
)
7453 ecs
->stop_func_start
= stop_func_sal
.end
;
7455 /* Architectures which require breakpoint adjustment might not be able
7456 to place a breakpoint at the computed address. If so, the test
7457 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7458 ecs->stop_func_start to an address at which a breakpoint may be
7459 legitimately placed.
7461 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7462 made, GDB will enter an infinite loop when stepping through
7463 optimized code consisting of VLIW instructions which contain
7464 subinstructions corresponding to different source lines. On
7465 FR-V, it's not permitted to place a breakpoint on any but the
7466 first subinstruction of a VLIW instruction. When a breakpoint is
7467 set, GDB will adjust the breakpoint address to the beginning of
7468 the VLIW instruction. Thus, we need to make the corresponding
7469 adjustment here when computing the stop address. */
7471 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7473 ecs
->stop_func_start
7474 = gdbarch_adjust_breakpoint_address (gdbarch
,
7475 ecs
->stop_func_start
);
7478 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7480 /* We are already there: stop now. */
7481 end_stepping_range (ecs
);
7486 /* Put the step-breakpoint there and go until there. */
7487 symtab_and_line sr_sal
;
7488 sr_sal
.pc
= ecs
->stop_func_start
;
7489 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7490 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7492 /* Do not specify what the fp should be when we stop since on
7493 some machines the prologue is where the new fp value is
7495 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7497 /* And make sure stepping stops right away then. */
7498 ecs
->event_thread
->control
.step_range_end
7499 = ecs
->event_thread
->control
.step_range_start
;
7504 /* Inferior has stepped backward into a subroutine call with source
7505 code that we should not step over. Do step to the beginning of the
7506 last line of code in it. */
7509 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7510 struct execution_control_state
*ecs
)
7512 struct compunit_symtab
*cust
;
7513 struct symtab_and_line stop_func_sal
;
7515 fill_in_stop_func (gdbarch
, ecs
);
7517 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7518 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7519 ecs
->stop_func_start
7520 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7522 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7524 /* OK, we're just going to keep stepping here. */
7525 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7527 /* We're there already. Just stop stepping now. */
7528 end_stepping_range (ecs
);
7532 /* Else just reset the step range and keep going.
7533 No step-resume breakpoint, they don't work for
7534 epilogues, which can have multiple entry paths. */
7535 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7536 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7542 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7543 This is used to both functions and to skip over code. */
7546 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7547 struct symtab_and_line sr_sal
,
7548 struct frame_id sr_id
,
7549 enum bptype sr_type
)
7551 /* There should never be more than one step-resume or longjmp-resume
7552 breakpoint per thread, so we should never be setting a new
7553 step_resume_breakpoint when one is already active. */
7554 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7555 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7557 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7558 paddress (gdbarch
, sr_sal
.pc
));
7560 inferior_thread ()->control
.step_resume_breakpoint
7561 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7565 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7566 struct symtab_and_line sr_sal
,
7567 struct frame_id sr_id
)
7569 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7574 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7575 This is used to skip a potential signal handler.
7577 This is called with the interrupted function's frame. The signal
7578 handler, when it returns, will resume the interrupted function at
7582 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7584 gdb_assert (return_frame
!= NULL
);
7586 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7588 symtab_and_line sr_sal
;
7589 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7590 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7591 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7593 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7594 get_stack_frame_id (return_frame
),
7598 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7599 is used to skip a function after stepping into it (for "next" or if
7600 the called function has no debugging information).
7602 The current function has almost always been reached by single
7603 stepping a call or return instruction. NEXT_FRAME belongs to the
7604 current function, and the breakpoint will be set at the caller's
7607 This is a separate function rather than reusing
7608 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7609 get_prev_frame, which may stop prematurely (see the implementation
7610 of frame_unwind_caller_id for an example). */
7613 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7615 /* We shouldn't have gotten here if we don't know where the call site
7617 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7619 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7621 symtab_and_line sr_sal
;
7622 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7623 frame_unwind_caller_pc (next_frame
));
7624 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7625 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7627 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7628 frame_unwind_caller_id (next_frame
));
7631 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7632 new breakpoint at the target of a jmp_buf. The handling of
7633 longjmp-resume uses the same mechanisms used for handling
7634 "step-resume" breakpoints. */
7637 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7639 /* There should never be more than one longjmp-resume breakpoint per
7640 thread, so we should never be setting a new
7641 longjmp_resume_breakpoint when one is already active. */
7642 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7644 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7645 paddress (gdbarch
, pc
));
7647 inferior_thread ()->control
.exception_resume_breakpoint
=
7648 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7651 /* Insert an exception resume breakpoint. TP is the thread throwing
7652 the exception. The block B is the block of the unwinder debug hook
7653 function. FRAME is the frame corresponding to the call to this
7654 function. SYM is the symbol of the function argument holding the
7655 target PC of the exception. */
7658 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7659 const struct block
*b
,
7660 struct frame_info
*frame
,
7665 struct block_symbol vsym
;
7666 struct value
*value
;
7668 struct breakpoint
*bp
;
7670 vsym
= lookup_symbol_search_name (sym
->search_name (),
7672 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7673 /* If the value was optimized out, revert to the old behavior. */
7674 if (! value_optimized_out (value
))
7676 handler
= value_as_address (value
);
7678 infrun_debug_printf ("exception resume at %lx",
7679 (unsigned long) handler
);
7681 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7683 bp_exception_resume
).release ();
7685 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7688 bp
->thread
= tp
->global_num
;
7689 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7692 catch (const gdb_exception_error
&e
)
7694 /* We want to ignore errors here. */
7698 /* A helper for check_exception_resume that sets an
7699 exception-breakpoint based on a SystemTap probe. */
7702 insert_exception_resume_from_probe (struct thread_info
*tp
,
7703 const struct bound_probe
*probe
,
7704 struct frame_info
*frame
)
7706 struct value
*arg_value
;
7708 struct breakpoint
*bp
;
7710 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7714 handler
= value_as_address (arg_value
);
7716 infrun_debug_printf ("exception resume at %s",
7717 paddress (probe
->objfile
->arch (), handler
));
7719 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7720 handler
, bp_exception_resume
).release ();
7721 bp
->thread
= tp
->global_num
;
7722 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7725 /* This is called when an exception has been intercepted. Check to
7726 see whether the exception's destination is of interest, and if so,
7727 set an exception resume breakpoint there. */
7730 check_exception_resume (struct execution_control_state
*ecs
,
7731 struct frame_info
*frame
)
7733 struct bound_probe probe
;
7734 struct symbol
*func
;
7736 /* First see if this exception unwinding breakpoint was set via a
7737 SystemTap probe point. If so, the probe has two arguments: the
7738 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7739 set a breakpoint there. */
7740 probe
= find_probe_by_pc (get_frame_pc (frame
));
7743 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7747 func
= get_frame_function (frame
);
7753 const struct block
*b
;
7754 struct block_iterator iter
;
7758 /* The exception breakpoint is a thread-specific breakpoint on
7759 the unwinder's debug hook, declared as:
7761 void _Unwind_DebugHook (void *cfa, void *handler);
7763 The CFA argument indicates the frame to which control is
7764 about to be transferred. HANDLER is the destination PC.
7766 We ignore the CFA and set a temporary breakpoint at HANDLER.
7767 This is not extremely efficient but it avoids issues in gdb
7768 with computing the DWARF CFA, and it also works even in weird
7769 cases such as throwing an exception from inside a signal
7772 b
= SYMBOL_BLOCK_VALUE (func
);
7773 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7775 if (!SYMBOL_IS_ARGUMENT (sym
))
7782 insert_exception_resume_breakpoint (ecs
->event_thread
,
7788 catch (const gdb_exception_error
&e
)
7794 stop_waiting (struct execution_control_state
*ecs
)
7796 infrun_debug_printf ("stop_waiting");
7798 /* Let callers know we don't want to wait for the inferior anymore. */
7799 ecs
->wait_some_more
= 0;
7801 /* If all-stop, but there exists a non-stop target, stop all
7802 threads now that we're presenting the stop to the user. */
7803 if (!non_stop
&& exists_non_stop_target ())
7804 stop_all_threads ();
7807 /* Like keep_going, but passes the signal to the inferior, even if the
7808 signal is set to nopass. */
7811 keep_going_pass_signal (struct execution_control_state
*ecs
)
7813 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7814 gdb_assert (!ecs
->event_thread
->resumed
);
7816 /* Save the pc before execution, to compare with pc after stop. */
7817 ecs
->event_thread
->prev_pc
7818 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7820 if (ecs
->event_thread
->control
.trap_expected
)
7822 struct thread_info
*tp
= ecs
->event_thread
;
7824 infrun_debug_printf ("%s has trap_expected set, "
7825 "resuming to collect trap",
7826 target_pid_to_str (tp
->ptid
).c_str ());
7828 /* We haven't yet gotten our trap, and either: intercepted a
7829 non-signal event (e.g., a fork); or took a signal which we
7830 are supposed to pass through to the inferior. Simply
7832 resume (ecs
->event_thread
->suspend
.stop_signal
);
7834 else if (step_over_info_valid_p ())
7836 /* Another thread is stepping over a breakpoint in-line. If
7837 this thread needs a step-over too, queue the request. In
7838 either case, this resume must be deferred for later. */
7839 struct thread_info
*tp
= ecs
->event_thread
;
7841 if (ecs
->hit_singlestep_breakpoint
7842 || thread_still_needs_step_over (tp
))
7844 infrun_debug_printf ("step-over already in progress: "
7845 "step-over for %s deferred",
7846 target_pid_to_str (tp
->ptid
).c_str ());
7847 global_thread_step_over_chain_enqueue (tp
);
7851 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7852 target_pid_to_str (tp
->ptid
).c_str ());
7857 struct regcache
*regcache
= get_current_regcache ();
7860 step_over_what step_what
;
7862 /* Either the trap was not expected, but we are continuing
7863 anyway (if we got a signal, the user asked it be passed to
7866 We got our expected trap, but decided we should resume from
7869 We're going to run this baby now!
7871 Note that insert_breakpoints won't try to re-insert
7872 already inserted breakpoints. Therefore, we don't
7873 care if breakpoints were already inserted, or not. */
7875 /* If we need to step over a breakpoint, and we're not using
7876 displaced stepping to do so, insert all breakpoints
7877 (watchpoints, etc.) but the one we're stepping over, step one
7878 instruction, and then re-insert the breakpoint when that step
7881 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7883 remove_bp
= (ecs
->hit_singlestep_breakpoint
7884 || (step_what
& STEP_OVER_BREAKPOINT
));
7885 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7887 /* We can't use displaced stepping if we need to step past a
7888 watchpoint. The instruction copied to the scratch pad would
7889 still trigger the watchpoint. */
7891 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7893 set_step_over_info (regcache
->aspace (),
7894 regcache_read_pc (regcache
), remove_wps
,
7895 ecs
->event_thread
->global_num
);
7897 else if (remove_wps
)
7898 set_step_over_info (NULL
, 0, remove_wps
, -1);
7900 /* If we now need to do an in-line step-over, we need to stop
7901 all other threads. Note this must be done before
7902 insert_breakpoints below, because that removes the breakpoint
7903 we're about to step over, otherwise other threads could miss
7905 if (step_over_info_valid_p () && target_is_non_stop_p ())
7906 stop_all_threads ();
7908 /* Stop stepping if inserting breakpoints fails. */
7911 insert_breakpoints ();
7913 catch (const gdb_exception_error
&e
)
7915 exception_print (gdb_stderr
, e
);
7917 clear_step_over_info ();
7921 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7923 resume (ecs
->event_thread
->suspend
.stop_signal
);
7926 prepare_to_wait (ecs
);
7929 /* Called when we should continue running the inferior, because the
7930 current event doesn't cause a user visible stop. This does the
7931 resuming part; waiting for the next event is done elsewhere. */
7934 keep_going (struct execution_control_state
*ecs
)
7936 if (ecs
->event_thread
->control
.trap_expected
7937 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7938 ecs
->event_thread
->control
.trap_expected
= 0;
7940 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7941 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7942 keep_going_pass_signal (ecs
);
7945 /* This function normally comes after a resume, before
7946 handle_inferior_event exits. It takes care of any last bits of
7947 housekeeping, and sets the all-important wait_some_more flag. */
7950 prepare_to_wait (struct execution_control_state
*ecs
)
7952 infrun_debug_printf ("prepare_to_wait");
7954 ecs
->wait_some_more
= 1;
7956 /* If the target can't async, emulate it by marking the infrun event
7957 handler such that as soon as we get back to the event-loop, we
7958 immediately end up in fetch_inferior_event again calling
7960 if (!target_can_async_p ())
7961 mark_infrun_async_event_handler ();
7964 /* We are done with the step range of a step/next/si/ni command.
7965 Called once for each n of a "step n" operation. */
7968 end_stepping_range (struct execution_control_state
*ecs
)
7970 ecs
->event_thread
->control
.stop_step
= 1;
7974 /* Several print_*_reason functions to print why the inferior has stopped.
7975 We always print something when the inferior exits, or receives a signal.
7976 The rest of the cases are dealt with later on in normal_stop and
7977 print_it_typical. Ideally there should be a call to one of these
7978 print_*_reason functions functions from handle_inferior_event each time
7979 stop_waiting is called.
7981 Note that we don't call these directly, instead we delegate that to
7982 the interpreters, through observers. Interpreters then call these
7983 with whatever uiout is right. */
7986 print_end_stepping_range_reason (struct ui_out
*uiout
)
7988 /* For CLI-like interpreters, print nothing. */
7990 if (uiout
->is_mi_like_p ())
7992 uiout
->field_string ("reason",
7993 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7998 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8000 annotate_signalled ();
8001 if (uiout
->is_mi_like_p ())
8003 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8004 uiout
->text ("\nProgram terminated with signal ");
8005 annotate_signal_name ();
8006 uiout
->field_string ("signal-name",
8007 gdb_signal_to_name (siggnal
));
8008 annotate_signal_name_end ();
8010 annotate_signal_string ();
8011 uiout
->field_string ("signal-meaning",
8012 gdb_signal_to_string (siggnal
));
8013 annotate_signal_string_end ();
8014 uiout
->text (".\n");
8015 uiout
->text ("The program no longer exists.\n");
8019 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8021 struct inferior
*inf
= current_inferior ();
8022 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8024 annotate_exited (exitstatus
);
8027 if (uiout
->is_mi_like_p ())
8028 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8029 std::string exit_code_str
8030 = string_printf ("0%o", (unsigned int) exitstatus
);
8031 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8032 plongest (inf
->num
), pidstr
.c_str (),
8033 string_field ("exit-code", exit_code_str
.c_str ()));
8037 if (uiout
->is_mi_like_p ())
8039 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8040 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8041 plongest (inf
->num
), pidstr
.c_str ());
8046 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8048 struct thread_info
*thr
= inferior_thread ();
8052 if (uiout
->is_mi_like_p ())
8054 else if (show_thread_that_caused_stop ())
8058 uiout
->text ("\nThread ");
8059 uiout
->field_string ("thread-id", print_thread_id (thr
));
8061 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8064 uiout
->text (" \"");
8065 uiout
->field_string ("name", name
);
8070 uiout
->text ("\nProgram");
8072 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8073 uiout
->text (" stopped");
8076 uiout
->text (" received signal ");
8077 annotate_signal_name ();
8078 if (uiout
->is_mi_like_p ())
8080 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8081 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8082 annotate_signal_name_end ();
8084 annotate_signal_string ();
8085 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8087 struct regcache
*regcache
= get_current_regcache ();
8088 struct gdbarch
*gdbarch
= regcache
->arch ();
8089 if (gdbarch_report_signal_info_p (gdbarch
))
8090 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8092 annotate_signal_string_end ();
8094 uiout
->text (".\n");
8098 print_no_history_reason (struct ui_out
*uiout
)
8100 uiout
->text ("\nNo more reverse-execution history.\n");
8103 /* Print current location without a level number, if we have changed
8104 functions or hit a breakpoint. Print source line if we have one.
8105 bpstat_print contains the logic deciding in detail what to print,
8106 based on the event(s) that just occurred. */
8109 print_stop_location (struct target_waitstatus
*ws
)
8112 enum print_what source_flag
;
8113 int do_frame_printing
= 1;
8114 struct thread_info
*tp
= inferior_thread ();
8116 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8120 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8121 should) carry around the function and does (or should) use
8122 that when doing a frame comparison. */
8123 if (tp
->control
.stop_step
8124 && frame_id_eq (tp
->control
.step_frame_id
,
8125 get_frame_id (get_current_frame ()))
8126 && (tp
->control
.step_start_function
8127 == find_pc_function (tp
->suspend
.stop_pc
)))
8129 /* Finished step, just print source line. */
8130 source_flag
= SRC_LINE
;
8134 /* Print location and source line. */
8135 source_flag
= SRC_AND_LOC
;
8138 case PRINT_SRC_AND_LOC
:
8139 /* Print location and source line. */
8140 source_flag
= SRC_AND_LOC
;
8142 case PRINT_SRC_ONLY
:
8143 source_flag
= SRC_LINE
;
8146 /* Something bogus. */
8147 source_flag
= SRC_LINE
;
8148 do_frame_printing
= 0;
8151 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8154 /* The behavior of this routine with respect to the source
8156 SRC_LINE: Print only source line
8157 LOCATION: Print only location
8158 SRC_AND_LOC: Print location and source line. */
8159 if (do_frame_printing
)
8160 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8166 print_stop_event (struct ui_out
*uiout
, bool displays
)
8168 struct target_waitstatus last
;
8169 struct thread_info
*tp
;
8171 get_last_target_status (nullptr, nullptr, &last
);
8174 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8176 print_stop_location (&last
);
8178 /* Display the auto-display expressions. */
8183 tp
= inferior_thread ();
8184 if (tp
->thread_fsm
!= NULL
8185 && tp
->thread_fsm
->finished_p ())
8187 struct return_value_info
*rv
;
8189 rv
= tp
->thread_fsm
->return_value ();
8191 print_return_value (uiout
, rv
);
8198 maybe_remove_breakpoints (void)
8200 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8202 if (remove_breakpoints ())
8204 target_terminal::ours_for_output ();
8205 printf_filtered (_("Cannot remove breakpoints because "
8206 "program is no longer writable.\nFurther "
8207 "execution is probably impossible.\n"));
8212 /* The execution context that just caused a normal stop. */
8218 DISABLE_COPY_AND_ASSIGN (stop_context
);
8220 bool changed () const;
8225 /* The event PTID. */
8229 /* If stopp for a thread event, this is the thread that caused the
8231 thread_info_ref thread
;
8233 /* The inferior that caused the stop. */
8237 /* Initializes a new stop context. If stopped for a thread event, this
8238 takes a strong reference to the thread. */
8240 stop_context::stop_context ()
8242 stop_id
= get_stop_id ();
8243 ptid
= inferior_ptid
;
8244 inf_num
= current_inferior ()->num
;
8246 if (inferior_ptid
!= null_ptid
)
8248 /* Take a strong reference so that the thread can't be deleted
8250 thread
= thread_info_ref::new_reference (inferior_thread ());
8254 /* Return true if the current context no longer matches the saved stop
8258 stop_context::changed () const
8260 if (ptid
!= inferior_ptid
)
8262 if (inf_num
!= current_inferior ()->num
)
8264 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8266 if (get_stop_id () != stop_id
)
8276 struct target_waitstatus last
;
8278 get_last_target_status (nullptr, nullptr, &last
);
8282 /* If an exception is thrown from this point on, make sure to
8283 propagate GDB's knowledge of the executing state to the
8284 frontend/user running state. A QUIT is an easy exception to see
8285 here, so do this before any filtered output. */
8287 ptid_t finish_ptid
= null_ptid
;
8290 finish_ptid
= minus_one_ptid
;
8291 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8292 || last
.kind
== TARGET_WAITKIND_EXITED
)
8294 /* On some targets, we may still have live threads in the
8295 inferior when we get a process exit event. E.g., for
8296 "checkpoint", when the current checkpoint/fork exits,
8297 linux-fork.c automatically switches to another fork from
8298 within target_mourn_inferior. */
8299 if (inferior_ptid
!= null_ptid
)
8300 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8302 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8303 finish_ptid
= inferior_ptid
;
8305 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8306 if (finish_ptid
!= null_ptid
)
8308 maybe_finish_thread_state
.emplace
8309 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8312 /* As we're presenting a stop, and potentially removing breakpoints,
8313 update the thread list so we can tell whether there are threads
8314 running on the target. With target remote, for example, we can
8315 only learn about new threads when we explicitly update the thread
8316 list. Do this before notifying the interpreters about signal
8317 stops, end of stepping ranges, etc., so that the "new thread"
8318 output is emitted before e.g., "Program received signal FOO",
8319 instead of after. */
8320 update_thread_list ();
8322 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8323 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8325 /* As with the notification of thread events, we want to delay
8326 notifying the user that we've switched thread context until
8327 the inferior actually stops.
8329 There's no point in saying anything if the inferior has exited.
8330 Note that SIGNALLED here means "exited with a signal", not
8331 "received a signal".
8333 Also skip saying anything in non-stop mode. In that mode, as we
8334 don't want GDB to switch threads behind the user's back, to avoid
8335 races where the user is typing a command to apply to thread x,
8336 but GDB switches to thread y before the user finishes entering
8337 the command, fetch_inferior_event installs a cleanup to restore
8338 the current thread back to the thread the user had selected right
8339 after this event is handled, so we're not really switching, only
8340 informing of a stop. */
8342 && previous_inferior_ptid
!= inferior_ptid
8343 && target_has_execution ()
8344 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8345 && last
.kind
!= TARGET_WAITKIND_EXITED
8346 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8348 SWITCH_THRU_ALL_UIS ()
8350 target_terminal::ours_for_output ();
8351 printf_filtered (_("[Switching to %s]\n"),
8352 target_pid_to_str (inferior_ptid
).c_str ());
8353 annotate_thread_changed ();
8355 previous_inferior_ptid
= inferior_ptid
;
8358 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8360 SWITCH_THRU_ALL_UIS ()
8361 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8363 target_terminal::ours_for_output ();
8364 printf_filtered (_("No unwaited-for children left.\n"));
8368 /* Note: this depends on the update_thread_list call above. */
8369 maybe_remove_breakpoints ();
8371 /* If an auto-display called a function and that got a signal,
8372 delete that auto-display to avoid an infinite recursion. */
8374 if (stopped_by_random_signal
)
8375 disable_current_display ();
8377 SWITCH_THRU_ALL_UIS ()
8379 async_enable_stdin ();
8382 /* Let the user/frontend see the threads as stopped. */
8383 maybe_finish_thread_state
.reset ();
8385 /* Select innermost stack frame - i.e., current frame is frame 0,
8386 and current location is based on that. Handle the case where the
8387 dummy call is returning after being stopped. E.g. the dummy call
8388 previously hit a breakpoint. (If the dummy call returns
8389 normally, we won't reach here.) Do this before the stop hook is
8390 run, so that it doesn't get to see the temporary dummy frame,
8391 which is not where we'll present the stop. */
8392 if (has_stack_frames ())
8394 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8396 /* Pop the empty frame that contains the stack dummy. This
8397 also restores inferior state prior to the call (struct
8398 infcall_suspend_state). */
8399 struct frame_info
*frame
= get_current_frame ();
8401 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8403 /* frame_pop calls reinit_frame_cache as the last thing it
8404 does which means there's now no selected frame. */
8407 select_frame (get_current_frame ());
8409 /* Set the current source location. */
8410 set_current_sal_from_frame (get_current_frame ());
8413 /* Look up the hook_stop and run it (CLI internally handles problem
8414 of stop_command's pre-hook not existing). */
8415 if (stop_command
!= NULL
)
8417 stop_context saved_context
;
8421 execute_cmd_pre_hook (stop_command
);
8423 catch (const gdb_exception
&ex
)
8425 exception_fprintf (gdb_stderr
, ex
,
8426 "Error while running hook_stop:\n");
8429 /* If the stop hook resumes the target, then there's no point in
8430 trying to notify about the previous stop; its context is
8431 gone. Likewise if the command switches thread or inferior --
8432 the observers would print a stop for the wrong
8434 if (saved_context
.changed ())
8438 /* Notify observers about the stop. This is where the interpreters
8439 print the stop event. */
8440 if (inferior_ptid
!= null_ptid
)
8441 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8444 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8446 annotate_stopped ();
8448 if (target_has_execution ())
8450 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8451 && last
.kind
!= TARGET_WAITKIND_EXITED
8452 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8453 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8454 Delete any breakpoint that is to be deleted at the next stop. */
8455 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8458 /* Try to get rid of automatically added inferiors that are no
8459 longer needed. Keeping those around slows down things linearly.
8460 Note that this never removes the current inferior. */
8467 signal_stop_state (int signo
)
8469 return signal_stop
[signo
];
8473 signal_print_state (int signo
)
8475 return signal_print
[signo
];
8479 signal_pass_state (int signo
)
8481 return signal_program
[signo
];
8485 signal_cache_update (int signo
)
8489 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8490 signal_cache_update (signo
);
8495 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8496 && signal_print
[signo
] == 0
8497 && signal_program
[signo
] == 1
8498 && signal_catch
[signo
] == 0);
8502 signal_stop_update (int signo
, int state
)
8504 int ret
= signal_stop
[signo
];
8506 signal_stop
[signo
] = state
;
8507 signal_cache_update (signo
);
8512 signal_print_update (int signo
, int state
)
8514 int ret
= signal_print
[signo
];
8516 signal_print
[signo
] = state
;
8517 signal_cache_update (signo
);
8522 signal_pass_update (int signo
, int state
)
8524 int ret
= signal_program
[signo
];
8526 signal_program
[signo
] = state
;
8527 signal_cache_update (signo
);
8531 /* Update the global 'signal_catch' from INFO and notify the
8535 signal_catch_update (const unsigned int *info
)
8539 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8540 signal_catch
[i
] = info
[i
] > 0;
8541 signal_cache_update (-1);
8542 target_pass_signals (signal_pass
);
8546 sig_print_header (void)
8548 printf_filtered (_("Signal Stop\tPrint\tPass "
8549 "to program\tDescription\n"));
8553 sig_print_info (enum gdb_signal oursig
)
8555 const char *name
= gdb_signal_to_name (oursig
);
8556 int name_padding
= 13 - strlen (name
);
8558 if (name_padding
<= 0)
8561 printf_filtered ("%s", name
);
8562 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8563 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8564 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8565 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8566 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8569 /* Specify how various signals in the inferior should be handled. */
8572 handle_command (const char *args
, int from_tty
)
8574 int digits
, wordlen
;
8575 int sigfirst
, siglast
;
8576 enum gdb_signal oursig
;
8581 error_no_arg (_("signal to handle"));
8584 /* Allocate and zero an array of flags for which signals to handle. */
8586 const size_t nsigs
= GDB_SIGNAL_LAST
;
8587 unsigned char sigs
[nsigs
] {};
8589 /* Break the command line up into args. */
8591 gdb_argv
built_argv (args
);
8593 /* Walk through the args, looking for signal oursigs, signal names, and
8594 actions. Signal numbers and signal names may be interspersed with
8595 actions, with the actions being performed for all signals cumulatively
8596 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8598 for (char *arg
: built_argv
)
8600 wordlen
= strlen (arg
);
8601 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8605 sigfirst
= siglast
= -1;
8607 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8609 /* Apply action to all signals except those used by the
8610 debugger. Silently skip those. */
8613 siglast
= nsigs
- 1;
8615 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8617 SET_SIGS (nsigs
, sigs
, signal_stop
);
8618 SET_SIGS (nsigs
, sigs
, signal_print
);
8620 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8622 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8624 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8626 SET_SIGS (nsigs
, sigs
, signal_print
);
8628 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8630 SET_SIGS (nsigs
, sigs
, signal_program
);
8632 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8634 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8636 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8638 SET_SIGS (nsigs
, sigs
, signal_program
);
8640 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8642 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8643 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8645 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8647 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8649 else if (digits
> 0)
8651 /* It is numeric. The numeric signal refers to our own
8652 internal signal numbering from target.h, not to host/target
8653 signal number. This is a feature; users really should be
8654 using symbolic names anyway, and the common ones like
8655 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8657 sigfirst
= siglast
= (int)
8658 gdb_signal_from_command (atoi (arg
));
8659 if (arg
[digits
] == '-')
8662 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8664 if (sigfirst
> siglast
)
8666 /* Bet he didn't figure we'd think of this case... */
8667 std::swap (sigfirst
, siglast
);
8672 oursig
= gdb_signal_from_name (arg
);
8673 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8675 sigfirst
= siglast
= (int) oursig
;
8679 /* Not a number and not a recognized flag word => complain. */
8680 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8684 /* If any signal numbers or symbol names were found, set flags for
8685 which signals to apply actions to. */
8687 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8689 switch ((enum gdb_signal
) signum
)
8691 case GDB_SIGNAL_TRAP
:
8692 case GDB_SIGNAL_INT
:
8693 if (!allsigs
&& !sigs
[signum
])
8695 if (query (_("%s is used by the debugger.\n\
8696 Are you sure you want to change it? "),
8697 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8702 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8706 case GDB_SIGNAL_DEFAULT
:
8707 case GDB_SIGNAL_UNKNOWN
:
8708 /* Make sure that "all" doesn't print these. */
8717 for (int signum
= 0; signum
< nsigs
; signum
++)
8720 signal_cache_update (-1);
8721 target_pass_signals (signal_pass
);
8722 target_program_signals (signal_program
);
8726 /* Show the results. */
8727 sig_print_header ();
8728 for (; signum
< nsigs
; signum
++)
8730 sig_print_info ((enum gdb_signal
) signum
);
8737 /* Complete the "handle" command. */
8740 handle_completer (struct cmd_list_element
*ignore
,
8741 completion_tracker
&tracker
,
8742 const char *text
, const char *word
)
8744 static const char * const keywords
[] =
8758 signal_completer (ignore
, tracker
, text
, word
);
8759 complete_on_enum (tracker
, keywords
, word
, word
);
8763 gdb_signal_from_command (int num
)
8765 if (num
>= 1 && num
<= 15)
8766 return (enum gdb_signal
) num
;
8767 error (_("Only signals 1-15 are valid as numeric signals.\n\
8768 Use \"info signals\" for a list of symbolic signals."));
8771 /* Print current contents of the tables set by the handle command.
8772 It is possible we should just be printing signals actually used
8773 by the current target (but for things to work right when switching
8774 targets, all signals should be in the signal tables). */
8777 info_signals_command (const char *signum_exp
, int from_tty
)
8779 enum gdb_signal oursig
;
8781 sig_print_header ();
8785 /* First see if this is a symbol name. */
8786 oursig
= gdb_signal_from_name (signum_exp
);
8787 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8789 /* No, try numeric. */
8791 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8793 sig_print_info (oursig
);
8797 printf_filtered ("\n");
8798 /* These ugly casts brought to you by the native VAX compiler. */
8799 for (oursig
= GDB_SIGNAL_FIRST
;
8800 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8801 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8805 if (oursig
!= GDB_SIGNAL_UNKNOWN
8806 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8807 sig_print_info (oursig
);
8810 printf_filtered (_("\nUse the \"handle\" command "
8811 "to change these tables.\n"));
8814 /* The $_siginfo convenience variable is a bit special. We don't know
8815 for sure the type of the value until we actually have a chance to
8816 fetch the data. The type can change depending on gdbarch, so it is
8817 also dependent on which thread you have selected.
8819 1. making $_siginfo be an internalvar that creates a new value on
8822 2. making the value of $_siginfo be an lval_computed value. */
8824 /* This function implements the lval_computed support for reading a
8828 siginfo_value_read (struct value
*v
)
8830 LONGEST transferred
;
8832 /* If we can access registers, so can we access $_siginfo. Likewise
8834 validate_registers_access ();
8837 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8839 value_contents_all_raw (v
),
8841 TYPE_LENGTH (value_type (v
)));
8843 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8844 error (_("Unable to read siginfo"));
8847 /* This function implements the lval_computed support for writing a
8851 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8853 LONGEST transferred
;
8855 /* If we can access registers, so can we access $_siginfo. Likewise
8857 validate_registers_access ();
8859 transferred
= target_write (current_top_target (),
8860 TARGET_OBJECT_SIGNAL_INFO
,
8862 value_contents_all_raw (fromval
),
8864 TYPE_LENGTH (value_type (fromval
)));
8866 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8867 error (_("Unable to write siginfo"));
8870 static const struct lval_funcs siginfo_value_funcs
=
8876 /* Return a new value with the correct type for the siginfo object of
8877 the current thread using architecture GDBARCH. Return a void value
8878 if there's no object available. */
8880 static struct value
*
8881 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8884 if (target_has_stack ()
8885 && inferior_ptid
!= null_ptid
8886 && gdbarch_get_siginfo_type_p (gdbarch
))
8888 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8890 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8893 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8897 /* infcall_suspend_state contains state about the program itself like its
8898 registers and any signal it received when it last stopped.
8899 This state must be restored regardless of how the inferior function call
8900 ends (either successfully, or after it hits a breakpoint or signal)
8901 if the program is to properly continue where it left off. */
8903 class infcall_suspend_state
8906 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8907 once the inferior function call has finished. */
8908 infcall_suspend_state (struct gdbarch
*gdbarch
,
8909 const struct thread_info
*tp
,
8910 struct regcache
*regcache
)
8911 : m_thread_suspend (tp
->suspend
),
8912 m_registers (new readonly_detached_regcache (*regcache
))
8914 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8916 if (gdbarch_get_siginfo_type_p (gdbarch
))
8918 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8919 size_t len
= TYPE_LENGTH (type
);
8921 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8923 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8924 siginfo_data
.get (), 0, len
) != len
)
8926 /* Errors ignored. */
8927 siginfo_data
.reset (nullptr);
8933 m_siginfo_gdbarch
= gdbarch
;
8934 m_siginfo_data
= std::move (siginfo_data
);
8938 /* Return a pointer to the stored register state. */
8940 readonly_detached_regcache
*registers () const
8942 return m_registers
.get ();
8945 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8947 void restore (struct gdbarch
*gdbarch
,
8948 struct thread_info
*tp
,
8949 struct regcache
*regcache
) const
8951 tp
->suspend
= m_thread_suspend
;
8953 if (m_siginfo_gdbarch
== gdbarch
)
8955 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8957 /* Errors ignored. */
8958 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8959 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8962 /* The inferior can be gone if the user types "print exit(0)"
8963 (and perhaps other times). */
8964 if (target_has_execution ())
8965 /* NB: The register write goes through to the target. */
8966 regcache
->restore (registers ());
8970 /* How the current thread stopped before the inferior function call was
8972 struct thread_suspend_state m_thread_suspend
;
8974 /* The registers before the inferior function call was executed. */
8975 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8977 /* Format of SIGINFO_DATA or NULL if it is not present. */
8978 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8980 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8981 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8982 content would be invalid. */
8983 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8986 infcall_suspend_state_up
8987 save_infcall_suspend_state ()
8989 struct thread_info
*tp
= inferior_thread ();
8990 struct regcache
*regcache
= get_current_regcache ();
8991 struct gdbarch
*gdbarch
= regcache
->arch ();
8993 infcall_suspend_state_up inf_state
8994 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8996 /* Having saved the current state, adjust the thread state, discarding
8997 any stop signal information. The stop signal is not useful when
8998 starting an inferior function call, and run_inferior_call will not use
8999 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9000 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9005 /* Restore inferior session state to INF_STATE. */
9008 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9010 struct thread_info
*tp
= inferior_thread ();
9011 struct regcache
*regcache
= get_current_regcache ();
9012 struct gdbarch
*gdbarch
= regcache
->arch ();
9014 inf_state
->restore (gdbarch
, tp
, regcache
);
9015 discard_infcall_suspend_state (inf_state
);
9019 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9024 readonly_detached_regcache
*
9025 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9027 return inf_state
->registers ();
9030 /* infcall_control_state contains state regarding gdb's control of the
9031 inferior itself like stepping control. It also contains session state like
9032 the user's currently selected frame. */
9034 struct infcall_control_state
9036 struct thread_control_state thread_control
;
9037 struct inferior_control_state inferior_control
;
9040 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9041 int stopped_by_random_signal
= 0;
9043 /* ID and level of the selected frame when the inferior function
9045 struct frame_id selected_frame_id
{};
9046 int selected_frame_level
= -1;
9049 /* Save all of the information associated with the inferior<==>gdb
9052 infcall_control_state_up
9053 save_infcall_control_state ()
9055 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9056 struct thread_info
*tp
= inferior_thread ();
9057 struct inferior
*inf
= current_inferior ();
9059 inf_status
->thread_control
= tp
->control
;
9060 inf_status
->inferior_control
= inf
->control
;
9062 tp
->control
.step_resume_breakpoint
= NULL
;
9063 tp
->control
.exception_resume_breakpoint
= NULL
;
9065 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9066 chain. If caller's caller is walking the chain, they'll be happier if we
9067 hand them back the original chain when restore_infcall_control_state is
9069 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9072 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9073 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9075 save_selected_frame (&inf_status
->selected_frame_id
,
9076 &inf_status
->selected_frame_level
);
9081 /* Restore inferior session state to INF_STATUS. */
9084 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9086 struct thread_info
*tp
= inferior_thread ();
9087 struct inferior
*inf
= current_inferior ();
9089 if (tp
->control
.step_resume_breakpoint
)
9090 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9092 if (tp
->control
.exception_resume_breakpoint
)
9093 tp
->control
.exception_resume_breakpoint
->disposition
9094 = disp_del_at_next_stop
;
9096 /* Handle the bpstat_copy of the chain. */
9097 bpstat_clear (&tp
->control
.stop_bpstat
);
9099 tp
->control
= inf_status
->thread_control
;
9100 inf
->control
= inf_status
->inferior_control
;
9103 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9104 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9106 if (target_has_stack ())
9108 restore_selected_frame (inf_status
->selected_frame_id
,
9109 inf_status
->selected_frame_level
);
9116 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9118 if (inf_status
->thread_control
.step_resume_breakpoint
)
9119 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9120 = disp_del_at_next_stop
;
9122 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9123 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9124 = disp_del_at_next_stop
;
9126 /* See save_infcall_control_state for info on stop_bpstat. */
9127 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9135 clear_exit_convenience_vars (void)
9137 clear_internalvar (lookup_internalvar ("_exitsignal"));
9138 clear_internalvar (lookup_internalvar ("_exitcode"));
9142 /* User interface for reverse debugging:
9143 Set exec-direction / show exec-direction commands
9144 (returns error unless target implements to_set_exec_direction method). */
9146 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9147 static const char exec_forward
[] = "forward";
9148 static const char exec_reverse
[] = "reverse";
9149 static const char *exec_direction
= exec_forward
;
9150 static const char *const exec_direction_names
[] = {
9157 set_exec_direction_func (const char *args
, int from_tty
,
9158 struct cmd_list_element
*cmd
)
9160 if (target_can_execute_reverse ())
9162 if (!strcmp (exec_direction
, exec_forward
))
9163 execution_direction
= EXEC_FORWARD
;
9164 else if (!strcmp (exec_direction
, exec_reverse
))
9165 execution_direction
= EXEC_REVERSE
;
9169 exec_direction
= exec_forward
;
9170 error (_("Target does not support this operation."));
9175 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9176 struct cmd_list_element
*cmd
, const char *value
)
9178 switch (execution_direction
) {
9180 fprintf_filtered (out
, _("Forward.\n"));
9183 fprintf_filtered (out
, _("Reverse.\n"));
9186 internal_error (__FILE__
, __LINE__
,
9187 _("bogus execution_direction value: %d"),
9188 (int) execution_direction
);
9193 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9194 struct cmd_list_element
*c
, const char *value
)
9196 fprintf_filtered (file
, _("Resuming the execution of threads "
9197 "of all processes is %s.\n"), value
);
9200 /* Implementation of `siginfo' variable. */
9202 static const struct internalvar_funcs siginfo_funcs
=
9209 /* Callback for infrun's target events source. This is marked when a
9210 thread has a pending status to process. */
9213 infrun_async_inferior_event_handler (gdb_client_data data
)
9215 clear_async_event_handler (infrun_async_inferior_event_token
);
9216 inferior_event_handler (INF_REG_EVENT
);
9223 /* Verify that when two threads with the same ptid exist (from two different
9224 targets) and one of them changes ptid, we only update inferior_ptid if
9225 it is appropriate. */
9228 infrun_thread_ptid_changed ()
9230 gdbarch
*arch
= current_inferior ()->gdbarch
;
9232 /* The thread which inferior_ptid represents changes ptid. */
9234 scoped_restore_current_pspace_and_thread restore
;
9236 scoped_mock_context
<test_target_ops
> target1 (arch
);
9237 scoped_mock_context
<test_target_ops
> target2 (arch
);
9238 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9240 ptid_t
old_ptid (111, 222);
9241 ptid_t
new_ptid (111, 333);
9243 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9244 target1
.mock_thread
.ptid
= old_ptid
;
9245 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9246 target2
.mock_thread
.ptid
= old_ptid
;
9248 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9249 set_current_inferior (&target1
.mock_inferior
);
9251 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9253 gdb_assert (inferior_ptid
== new_ptid
);
9256 /* A thread with the same ptid as inferior_ptid, but from another target,
9259 scoped_restore_current_pspace_and_thread restore
;
9261 scoped_mock_context
<test_target_ops
> target1 (arch
);
9262 scoped_mock_context
<test_target_ops
> target2 (arch
);
9263 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9265 ptid_t
old_ptid (111, 222);
9266 ptid_t
new_ptid (111, 333);
9268 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9269 target1
.mock_thread
.ptid
= old_ptid
;
9270 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9271 target2
.mock_thread
.ptid
= old_ptid
;
9273 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9274 set_current_inferior (&target2
.mock_inferior
);
9276 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9278 gdb_assert (inferior_ptid
== old_ptid
);
9282 } /* namespace selftests */
9284 #endif /* GDB_SELF_TEST */
9286 void _initialize_infrun ();
9288 _initialize_infrun ()
9290 struct cmd_list_element
*c
;
9292 /* Register extra event sources in the event loop. */
9293 infrun_async_inferior_event_token
9294 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9297 add_info ("signals", info_signals_command
, _("\
9298 What debugger does when program gets various signals.\n\
9299 Specify a signal as argument to print info on that signal only."));
9300 add_info_alias ("handle", "signals", 0);
9302 c
= add_com ("handle", class_run
, handle_command
, _("\
9303 Specify how to handle signals.\n\
9304 Usage: handle SIGNAL [ACTIONS]\n\
9305 Args are signals and actions to apply to those signals.\n\
9306 If no actions are specified, the current settings for the specified signals\n\
9307 will be displayed instead.\n\
9309 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9310 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9311 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9312 The special arg \"all\" is recognized to mean all signals except those\n\
9313 used by the debugger, typically SIGTRAP and SIGINT.\n\
9315 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9316 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9317 Stop means reenter debugger if this signal happens (implies print).\n\
9318 Print means print a message if this signal happens.\n\
9319 Pass means let program see this signal; otherwise program doesn't know.\n\
9320 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9321 Pass and Stop may be combined.\n\
9323 Multiple signals may be specified. Signal numbers and signal names\n\
9324 may be interspersed with actions, with the actions being performed for\n\
9325 all signals cumulatively specified."));
9326 set_cmd_completer (c
, handle_completer
);
9329 stop_command
= add_cmd ("stop", class_obscure
,
9330 not_just_help_class_command
, _("\
9331 There is no `stop' command, but you can set a hook on `stop'.\n\
9332 This allows you to set a list of commands to be run each time execution\n\
9333 of the program stops."), &cmdlist
);
9335 add_setshow_boolean_cmd
9336 ("infrun", class_maintenance
, &debug_infrun
,
9337 _("Set inferior debugging."),
9338 _("Show inferior debugging."),
9339 _("When non-zero, inferior specific debugging is enabled."),
9340 NULL
, show_debug_infrun
, &setdebuglist
, &showdebuglist
);
9342 add_setshow_boolean_cmd ("non-stop", no_class
,
9344 Set whether gdb controls the inferior in non-stop mode."), _("\
9345 Show whether gdb controls the inferior in non-stop mode."), _("\
9346 When debugging a multi-threaded program and this setting is\n\
9347 off (the default, also called all-stop mode), when one thread stops\n\
9348 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9349 all other threads in the program while you interact with the thread of\n\
9350 interest. When you continue or step a thread, you can allow the other\n\
9351 threads to run, or have them remain stopped, but while you inspect any\n\
9352 thread's state, all threads stop.\n\
9354 In non-stop mode, when one thread stops, other threads can continue\n\
9355 to run freely. You'll be able to step each thread independently,\n\
9356 leave it stopped or free to run as needed."),
9362 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9365 signal_print
[i
] = 1;
9366 signal_program
[i
] = 1;
9367 signal_catch
[i
] = 0;
9370 /* Signals caused by debugger's own actions should not be given to
9371 the program afterwards.
9373 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9374 explicitly specifies that it should be delivered to the target
9375 program. Typically, that would occur when a user is debugging a
9376 target monitor on a simulator: the target monitor sets a
9377 breakpoint; the simulator encounters this breakpoint and halts
9378 the simulation handing control to GDB; GDB, noting that the stop
9379 address doesn't map to any known breakpoint, returns control back
9380 to the simulator; the simulator then delivers the hardware
9381 equivalent of a GDB_SIGNAL_TRAP to the program being
9383 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9384 signal_program
[GDB_SIGNAL_INT
] = 0;
9386 /* Signals that are not errors should not normally enter the debugger. */
9387 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9388 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9389 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9390 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9391 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9392 signal_print
[GDB_SIGNAL_PROF
] = 0;
9393 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9394 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9395 signal_stop
[GDB_SIGNAL_IO
] = 0;
9396 signal_print
[GDB_SIGNAL_IO
] = 0;
9397 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9398 signal_print
[GDB_SIGNAL_POLL
] = 0;
9399 signal_stop
[GDB_SIGNAL_URG
] = 0;
9400 signal_print
[GDB_SIGNAL_URG
] = 0;
9401 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9402 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9403 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9404 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9406 /* These signals are used internally by user-level thread
9407 implementations. (See signal(5) on Solaris.) Like the above
9408 signals, a healthy program receives and handles them as part of
9409 its normal operation. */
9410 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9411 signal_print
[GDB_SIGNAL_LWP
] = 0;
9412 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9413 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9414 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9415 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9416 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9417 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9419 /* Update cached state. */
9420 signal_cache_update (-1);
9422 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9423 &stop_on_solib_events
, _("\
9424 Set stopping for shared library events."), _("\
9425 Show stopping for shared library events."), _("\
9426 If nonzero, gdb will give control to the user when the dynamic linker\n\
9427 notifies gdb of shared library events. The most common event of interest\n\
9428 to the user would be loading/unloading of a new library."),
9429 set_stop_on_solib_events
,
9430 show_stop_on_solib_events
,
9431 &setlist
, &showlist
);
9433 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9434 follow_fork_mode_kind_names
,
9435 &follow_fork_mode_string
, _("\
9436 Set debugger response to a program call of fork or vfork."), _("\
9437 Show debugger response to a program call of fork or vfork."), _("\
9438 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9439 parent - the original process is debugged after a fork\n\
9440 child - the new process is debugged after a fork\n\
9441 The unfollowed process will continue to run.\n\
9442 By default, the debugger will follow the parent process."),
9444 show_follow_fork_mode_string
,
9445 &setlist
, &showlist
);
9447 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9448 follow_exec_mode_names
,
9449 &follow_exec_mode_string
, _("\
9450 Set debugger response to a program call of exec."), _("\
9451 Show debugger response to a program call of exec."), _("\
9452 An exec call replaces the program image of a process.\n\
9454 follow-exec-mode can be:\n\
9456 new - the debugger creates a new inferior and rebinds the process\n\
9457 to this new inferior. The program the process was running before\n\
9458 the exec call can be restarted afterwards by restarting the original\n\
9461 same - the debugger keeps the process bound to the same inferior.\n\
9462 The new executable image replaces the previous executable loaded in\n\
9463 the inferior. Restarting the inferior after the exec call restarts\n\
9464 the executable the process was running after the exec call.\n\
9466 By default, the debugger will use the same inferior."),
9468 show_follow_exec_mode_string
,
9469 &setlist
, &showlist
);
9471 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9472 scheduler_enums
, &scheduler_mode
, _("\
9473 Set mode for locking scheduler during execution."), _("\
9474 Show mode for locking scheduler during execution."), _("\
9475 off == no locking (threads may preempt at any time)\n\
9476 on == full locking (no thread except the current thread may run)\n\
9477 This applies to both normal execution and replay mode.\n\
9478 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9479 In this mode, other threads may run during other commands.\n\
9480 This applies to both normal execution and replay mode.\n\
9481 replay == scheduler locked in replay mode and unlocked during normal execution."),
9482 set_schedlock_func
, /* traps on target vector */
9483 show_scheduler_mode
,
9484 &setlist
, &showlist
);
9486 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9487 Set mode for resuming threads of all processes."), _("\
9488 Show mode for resuming threads of all processes."), _("\
9489 When on, execution commands (such as 'continue' or 'next') resume all\n\
9490 threads of all processes. When off (which is the default), execution\n\
9491 commands only resume the threads of the current process. The set of\n\
9492 threads that are resumed is further refined by the scheduler-locking\n\
9493 mode (see help set scheduler-locking)."),
9495 show_schedule_multiple
,
9496 &setlist
, &showlist
);
9498 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9499 Set mode of the step operation."), _("\
9500 Show mode of the step operation."), _("\
9501 When set, doing a step over a function without debug line information\n\
9502 will stop at the first instruction of that function. Otherwise, the\n\
9503 function is skipped and the step command stops at a different source line."),
9505 show_step_stop_if_no_debug
,
9506 &setlist
, &showlist
);
9508 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9509 &can_use_displaced_stepping
, _("\
9510 Set debugger's willingness to use displaced stepping."), _("\
9511 Show debugger's willingness to use displaced stepping."), _("\
9512 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9513 supported by the target architecture. If off, gdb will not use displaced\n\
9514 stepping to step over breakpoints, even if such is supported by the target\n\
9515 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9516 if the target architecture supports it and non-stop mode is active, but will not\n\
9517 use it in all-stop mode (see help set non-stop)."),
9519 show_can_use_displaced_stepping
,
9520 &setlist
, &showlist
);
9522 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9523 &exec_direction
, _("Set direction of execution.\n\
9524 Options are 'forward' or 'reverse'."),
9525 _("Show direction of execution (forward/reverse)."),
9526 _("Tells gdb whether to execute forward or backward."),
9527 set_exec_direction_func
, show_exec_direction_func
,
9528 &setlist
, &showlist
);
9530 /* Set/show detach-on-fork: user-settable mode. */
9532 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9533 Set whether gdb will detach the child of a fork."), _("\
9534 Show whether gdb will detach the child of a fork."), _("\
9535 Tells gdb whether to detach the child of a fork."),
9536 NULL
, NULL
, &setlist
, &showlist
);
9538 /* Set/show disable address space randomization mode. */
9540 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9541 &disable_randomization
, _("\
9542 Set disabling of debuggee's virtual address space randomization."), _("\
9543 Show disabling of debuggee's virtual address space randomization."), _("\
9544 When this mode is on (which is the default), randomization of the virtual\n\
9545 address space is disabled. Standalone programs run with the randomization\n\
9546 enabled by default on some platforms."),
9547 &set_disable_randomization
,
9548 &show_disable_randomization
,
9549 &setlist
, &showlist
);
9551 /* ptid initializations */
9552 inferior_ptid
= null_ptid
;
9553 target_last_wait_ptid
= minus_one_ptid
;
9555 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9556 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9557 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9558 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9559 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
);
9561 /* Explicitly create without lookup, since that tries to create a
9562 value with a void typed value, and when we get here, gdbarch
9563 isn't initialized yet. At this point, we're quite sure there
9564 isn't another convenience variable of the same name. */
9565 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9567 add_setshow_boolean_cmd ("observer", no_class
,
9568 &observer_mode_1
, _("\
9569 Set whether gdb controls the inferior in observer mode."), _("\
9570 Show whether gdb controls the inferior in observer mode."), _("\
9571 In observer mode, GDB can get data from the inferior, but not\n\
9572 affect its execution. Registers and memory may not be changed,\n\
9573 breakpoints may not be set, and the program cannot be interrupted\n\
9581 selftests::register_test ("infrun_thread_ptid_changed",
9582 selftests::infrun_thread_ptid_changed
);