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 child_inf
->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 child_inf
->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 target_follow_fork (follow_child
, detach_fork
);
670 /* Tell the target to follow the fork we're stopped at. Returns true
671 if the inferior should be resumed; false, if the target for some
672 reason decided it's best not to resume. */
677 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
678 bool should_resume
= true;
679 struct thread_info
*tp
;
681 /* Copy user stepping state to the new inferior thread. FIXME: the
682 followed fork child thread should have a copy of most of the
683 parent thread structure's run control related fields, not just these.
684 Initialized to avoid "may be used uninitialized" warnings from gcc. */
685 struct breakpoint
*step_resume_breakpoint
= NULL
;
686 struct breakpoint
*exception_resume_breakpoint
= NULL
;
687 CORE_ADDR step_range_start
= 0;
688 CORE_ADDR step_range_end
= 0;
689 int current_line
= 0;
690 symtab
*current_symtab
= NULL
;
691 struct frame_id step_frame_id
= { 0 };
692 struct thread_fsm
*thread_fsm
= NULL
;
696 process_stratum_target
*wait_target
;
698 struct target_waitstatus wait_status
;
700 /* Get the last target status returned by target_wait(). */
701 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
703 /* If not stopped at a fork event, then there's nothing else to
705 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
706 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
709 /* Check if we switched over from WAIT_PTID, since the event was
711 if (wait_ptid
!= minus_one_ptid
712 && (current_inferior ()->process_target () != wait_target
713 || inferior_ptid
!= wait_ptid
))
715 /* We did. Switch back to WAIT_PTID thread, to tell the
716 target to follow it (in either direction). We'll
717 afterwards refuse to resume, and inform the user what
719 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
720 switch_to_thread (wait_thread
);
721 should_resume
= false;
725 tp
= inferior_thread ();
727 /* If there were any forks/vforks that were caught and are now to be
728 followed, then do so now. */
729 switch (tp
->pending_follow
.kind
)
731 case TARGET_WAITKIND_FORKED
:
732 case TARGET_WAITKIND_VFORKED
:
734 ptid_t parent
, child
;
736 /* If the user did a next/step, etc, over a fork call,
737 preserve the stepping state in the fork child. */
738 if (follow_child
&& should_resume
)
740 step_resume_breakpoint
= clone_momentary_breakpoint
741 (tp
->control
.step_resume_breakpoint
);
742 step_range_start
= tp
->control
.step_range_start
;
743 step_range_end
= tp
->control
.step_range_end
;
744 current_line
= tp
->current_line
;
745 current_symtab
= tp
->current_symtab
;
746 step_frame_id
= tp
->control
.step_frame_id
;
747 exception_resume_breakpoint
748 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
749 thread_fsm
= tp
->thread_fsm
;
751 /* For now, delete the parent's sr breakpoint, otherwise,
752 parent/child sr breakpoints are considered duplicates,
753 and the child version will not be installed. Remove
754 this when the breakpoints module becomes aware of
755 inferiors and address spaces. */
756 delete_step_resume_breakpoint (tp
);
757 tp
->control
.step_range_start
= 0;
758 tp
->control
.step_range_end
= 0;
759 tp
->control
.step_frame_id
= null_frame_id
;
760 delete_exception_resume_breakpoint (tp
);
761 tp
->thread_fsm
= NULL
;
764 parent
= inferior_ptid
;
765 child
= tp
->pending_follow
.value
.related_pid
;
767 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
768 /* Set up inferior(s) as specified by the caller, and tell the
769 target to do whatever is necessary to follow either parent
771 if (follow_fork_inferior (follow_child
, detach_fork
))
773 /* Target refused to follow, or there's some other reason
774 we shouldn't resume. */
779 /* This pending follow fork event is now handled, one way
780 or another. The previous selected thread may be gone
781 from the lists by now, but if it is still around, need
782 to clear the pending follow request. */
783 tp
= find_thread_ptid (parent_targ
, parent
);
785 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
787 /* This makes sure we don't try to apply the "Switched
788 over from WAIT_PID" logic above. */
789 nullify_last_target_wait_ptid ();
791 /* If we followed the child, switch to it... */
794 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
795 switch_to_thread (child_thr
);
797 /* ... and preserve the stepping state, in case the
798 user was stepping over the fork call. */
801 tp
= inferior_thread ();
802 tp
->control
.step_resume_breakpoint
803 = step_resume_breakpoint
;
804 tp
->control
.step_range_start
= step_range_start
;
805 tp
->control
.step_range_end
= step_range_end
;
806 tp
->current_line
= current_line
;
807 tp
->current_symtab
= current_symtab
;
808 tp
->control
.step_frame_id
= step_frame_id
;
809 tp
->control
.exception_resume_breakpoint
810 = exception_resume_breakpoint
;
811 tp
->thread_fsm
= thread_fsm
;
815 /* If we get here, it was because we're trying to
816 resume from a fork catchpoint, but, the user
817 has switched threads away from the thread that
818 forked. In that case, the resume command
819 issued is most likely not applicable to the
820 child, so just warn, and refuse to resume. */
821 warning (_("Not resuming: switched threads "
822 "before following fork child."));
825 /* Reset breakpoints in the child as appropriate. */
826 follow_inferior_reset_breakpoints ();
831 case TARGET_WAITKIND_SPURIOUS
:
832 /* Nothing to follow. */
835 internal_error (__FILE__
, __LINE__
,
836 "Unexpected pending_follow.kind %d\n",
837 tp
->pending_follow
.kind
);
841 return should_resume
;
845 follow_inferior_reset_breakpoints (void)
847 struct thread_info
*tp
= inferior_thread ();
849 /* Was there a step_resume breakpoint? (There was if the user
850 did a "next" at the fork() call.) If so, explicitly reset its
851 thread number. Cloned step_resume breakpoints are disabled on
852 creation, so enable it here now that it is associated with the
855 step_resumes are a form of bp that are made to be per-thread.
856 Since we created the step_resume bp when the parent process
857 was being debugged, and now are switching to the child process,
858 from the breakpoint package's viewpoint, that's a switch of
859 "threads". We must update the bp's notion of which thread
860 it is for, or it'll be ignored when it triggers. */
862 if (tp
->control
.step_resume_breakpoint
)
864 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
865 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
868 /* Treat exception_resume breakpoints like step_resume breakpoints. */
869 if (tp
->control
.exception_resume_breakpoint
)
871 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
872 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
875 /* Reinsert all breakpoints in the child. The user may have set
876 breakpoints after catching the fork, in which case those
877 were never set in the child, but only in the parent. This makes
878 sure the inserted breakpoints match the breakpoint list. */
880 breakpoint_re_set ();
881 insert_breakpoints ();
884 /* The child has exited or execed: resume threads of the parent the
885 user wanted to be executing. */
888 proceed_after_vfork_done (struct thread_info
*thread
,
891 int pid
= * (int *) arg
;
893 if (thread
->ptid
.pid () == pid
894 && thread
->state
== THREAD_RUNNING
895 && !thread
->executing
896 && !thread
->stop_requested
897 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
899 infrun_debug_printf ("resuming vfork parent thread %s",
900 target_pid_to_str (thread
->ptid
).c_str ());
902 switch_to_thread (thread
);
903 clear_proceed_status (0);
904 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
910 /* Called whenever we notice an exec or exit event, to handle
911 detaching or resuming a vfork parent. */
914 handle_vfork_child_exec_or_exit (int exec
)
916 struct inferior
*inf
= current_inferior ();
918 if (inf
->vfork_parent
)
920 int resume_parent
= -1;
922 /* This exec or exit marks the end of the shared memory region
923 between the parent and the child. Break the bonds. */
924 inferior
*vfork_parent
= inf
->vfork_parent
;
925 inf
->vfork_parent
->vfork_child
= NULL
;
926 inf
->vfork_parent
= NULL
;
928 /* If the user wanted to detach from the parent, now is the
930 if (vfork_parent
->pending_detach
)
932 struct program_space
*pspace
;
933 struct address_space
*aspace
;
935 /* follow-fork child, detach-on-fork on. */
937 vfork_parent
->pending_detach
= 0;
939 scoped_restore_current_pspace_and_thread restore_thread
;
941 /* We're letting loose of the parent. */
942 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
943 switch_to_thread (tp
);
945 /* We're about to detach from the parent, which implicitly
946 removes breakpoints from its address space. There's a
947 catch here: we want to reuse the spaces for the child,
948 but, parent/child are still sharing the pspace at this
949 point, although the exec in reality makes the kernel give
950 the child a fresh set of new pages. The problem here is
951 that the breakpoints module being unaware of this, would
952 likely chose the child process to write to the parent
953 address space. Swapping the child temporarily away from
954 the spaces has the desired effect. Yes, this is "sort
957 pspace
= inf
->pspace
;
958 aspace
= inf
->aspace
;
962 if (print_inferior_events
)
965 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
967 target_terminal::ours_for_output ();
971 fprintf_filtered (gdb_stdlog
,
972 _("[Detaching vfork parent %s "
973 "after child exec]\n"), pidstr
.c_str ());
977 fprintf_filtered (gdb_stdlog
,
978 _("[Detaching vfork parent %s "
979 "after child exit]\n"), pidstr
.c_str ());
983 target_detach (vfork_parent
, 0);
986 inf
->pspace
= pspace
;
987 inf
->aspace
= aspace
;
991 /* We're staying attached to the parent, so, really give the
992 child a new address space. */
993 inf
->pspace
= new program_space (maybe_new_address_space ());
994 inf
->aspace
= inf
->pspace
->aspace
;
996 set_current_program_space (inf
->pspace
);
998 resume_parent
= vfork_parent
->pid
;
1002 /* If this is a vfork child exiting, then the pspace and
1003 aspaces were shared with the parent. Since we're
1004 reporting the process exit, we'll be mourning all that is
1005 found in the address space, and switching to null_ptid,
1006 preparing to start a new inferior. But, since we don't
1007 want to clobber the parent's address/program spaces, we
1008 go ahead and create a new one for this exiting
1011 /* Switch to no-thread while running clone_program_space, so
1012 that clone_program_space doesn't want to read the
1013 selected frame of a dead process. */
1014 scoped_restore_current_thread restore_thread
;
1015 switch_to_no_thread ();
1017 inf
->pspace
= new program_space (maybe_new_address_space ());
1018 inf
->aspace
= inf
->pspace
->aspace
;
1019 set_current_program_space (inf
->pspace
);
1021 inf
->symfile_flags
= SYMFILE_NO_READ
;
1022 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1024 resume_parent
= vfork_parent
->pid
;
1027 gdb_assert (current_program_space
== inf
->pspace
);
1029 if (non_stop
&& resume_parent
!= -1)
1031 /* If the user wanted the parent to be running, let it go
1033 scoped_restore_current_thread restore_thread
;
1035 infrun_debug_printf ("resuming vfork parent process %d",
1038 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1043 /* Enum strings for "set|show follow-exec-mode". */
1045 static const char follow_exec_mode_new
[] = "new";
1046 static const char follow_exec_mode_same
[] = "same";
1047 static const char *const follow_exec_mode_names
[] =
1049 follow_exec_mode_new
,
1050 follow_exec_mode_same
,
1054 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1056 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1057 struct cmd_list_element
*c
, const char *value
)
1059 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1062 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1065 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1067 struct inferior
*inf
= current_inferior ();
1068 int pid
= ptid
.pid ();
1069 ptid_t process_ptid
;
1071 /* Switch terminal for any messages produced e.g. by
1072 breakpoint_re_set. */
1073 target_terminal::ours_for_output ();
1075 /* This is an exec event that we actually wish to pay attention to.
1076 Refresh our symbol table to the newly exec'd program, remove any
1077 momentary bp's, etc.
1079 If there are breakpoints, they aren't really inserted now,
1080 since the exec() transformed our inferior into a fresh set
1083 We want to preserve symbolic breakpoints on the list, since
1084 we have hopes that they can be reset after the new a.out's
1085 symbol table is read.
1087 However, any "raw" breakpoints must be removed from the list
1088 (e.g., the solib bp's), since their address is probably invalid
1091 And, we DON'T want to call delete_breakpoints() here, since
1092 that may write the bp's "shadow contents" (the instruction
1093 value that was overwritten with a TRAP instruction). Since
1094 we now have a new a.out, those shadow contents aren't valid. */
1096 mark_breakpoints_out ();
1098 /* The target reports the exec event to the main thread, even if
1099 some other thread does the exec, and even if the main thread was
1100 stopped or already gone. We may still have non-leader threads of
1101 the process on our list. E.g., on targets that don't have thread
1102 exit events (like remote); or on native Linux in non-stop mode if
1103 there were only two threads in the inferior and the non-leader
1104 one is the one that execs (and nothing forces an update of the
1105 thread list up to here). When debugging remotely, it's best to
1106 avoid extra traffic, when possible, so avoid syncing the thread
1107 list with the target, and instead go ahead and delete all threads
1108 of the process but one that reported the event. Note this must
1109 be done before calling update_breakpoints_after_exec, as
1110 otherwise clearing the threads' resources would reference stale
1111 thread breakpoints -- it may have been one of these threads that
1112 stepped across the exec. We could just clear their stepping
1113 states, but as long as we're iterating, might as well delete
1114 them. Deleting them now rather than at the next user-visible
1115 stop provides a nicer sequence of events for user and MI
1117 for (thread_info
*th
: all_threads_safe ())
1118 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1121 /* We also need to clear any left over stale state for the
1122 leader/event thread. E.g., if there was any step-resume
1123 breakpoint or similar, it's gone now. We cannot truly
1124 step-to-next statement through an exec(). */
1125 thread_info
*th
= inferior_thread ();
1126 th
->control
.step_resume_breakpoint
= NULL
;
1127 th
->control
.exception_resume_breakpoint
= NULL
;
1128 th
->control
.single_step_breakpoints
= NULL
;
1129 th
->control
.step_range_start
= 0;
1130 th
->control
.step_range_end
= 0;
1132 /* The user may have had the main thread held stopped in the
1133 previous image (e.g., schedlock on, or non-stop). Release
1135 th
->stop_requested
= 0;
1137 update_breakpoints_after_exec ();
1139 /* What is this a.out's name? */
1140 process_ptid
= ptid_t (pid
);
1141 printf_unfiltered (_("%s is executing new program: %s\n"),
1142 target_pid_to_str (process_ptid
).c_str (),
1145 /* We've followed the inferior through an exec. Therefore, the
1146 inferior has essentially been killed & reborn. */
1148 breakpoint_init_inferior (inf_execd
);
1150 gdb::unique_xmalloc_ptr
<char> exec_file_host
1151 = exec_file_find (exec_file_target
, NULL
);
1153 /* If we were unable to map the executable target pathname onto a host
1154 pathname, tell the user that. Otherwise GDB's subsequent behavior
1155 is confusing. Maybe it would even be better to stop at this point
1156 so that the user can specify a file manually before continuing. */
1157 if (exec_file_host
== NULL
)
1158 warning (_("Could not load symbols for executable %s.\n"
1159 "Do you need \"set sysroot\"?"),
1162 /* Reset the shared library package. This ensures that we get a
1163 shlib event when the child reaches "_start", at which point the
1164 dld will have had a chance to initialize the child. */
1165 /* Also, loading a symbol file below may trigger symbol lookups, and
1166 we don't want those to be satisfied by the libraries of the
1167 previous incarnation of this process. */
1168 no_shared_libraries (NULL
, 0);
1170 if (follow_exec_mode_string
== follow_exec_mode_new
)
1172 /* The user wants to keep the old inferior and program spaces
1173 around. Create a new fresh one, and switch to it. */
1175 /* Do exit processing for the original inferior before setting the new
1176 inferior's pid. Having two inferiors with the same pid would confuse
1177 find_inferior_p(t)id. Transfer the terminal state and info from the
1178 old to the new inferior. */
1179 inf
= add_inferior_with_spaces ();
1180 swap_terminal_info (inf
, current_inferior ());
1181 exit_inferior_silent (current_inferior ());
1184 target_follow_exec (inf
, exec_file_target
);
1186 inferior
*org_inferior
= current_inferior ();
1187 switch_to_inferior_no_thread (inf
);
1188 inf
->push_target (org_inferior
->process_target ());
1189 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1190 switch_to_thread (thr
);
1194 /* The old description may no longer be fit for the new image.
1195 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1196 old description; we'll read a new one below. No need to do
1197 this on "follow-exec-mode new", as the old inferior stays
1198 around (its description is later cleared/refetched on
1200 target_clear_description ();
1203 gdb_assert (current_program_space
== inf
->pspace
);
1205 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1206 because the proper displacement for a PIE (Position Independent
1207 Executable) main symbol file will only be computed by
1208 solib_create_inferior_hook below. breakpoint_re_set would fail
1209 to insert the breakpoints with the zero displacement. */
1210 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1212 /* If the target can specify a description, read it. Must do this
1213 after flipping to the new executable (because the target supplied
1214 description must be compatible with the executable's
1215 architecture, and the old executable may e.g., be 32-bit, while
1216 the new one 64-bit), and before anything involving memory or
1218 target_find_description ();
1220 gdb::observers::inferior_execd
.notify (inf
);
1222 breakpoint_re_set ();
1224 /* Reinsert all breakpoints. (Those which were symbolic have
1225 been reset to the proper address in the new a.out, thanks
1226 to symbol_file_command...). */
1227 insert_breakpoints ();
1229 /* The next resume of this inferior should bring it to the shlib
1230 startup breakpoints. (If the user had also set bp's on
1231 "main" from the old (parent) process, then they'll auto-
1232 matically get reset there in the new process.). */
1235 /* The chain of threads that need to do a step-over operation to get
1236 past e.g., a breakpoint. What technique is used to step over the
1237 breakpoint/watchpoint does not matter -- all threads end up in the
1238 same queue, to maintain rough temporal order of execution, in order
1239 to avoid starvation, otherwise, we could e.g., find ourselves
1240 constantly stepping the same couple threads past their breakpoints
1241 over and over, if the single-step finish fast enough. */
1242 struct thread_info
*global_thread_step_over_chain_head
;
1244 /* Bit flags indicating what the thread needs to step over. */
1246 enum step_over_what_flag
1248 /* Step over a breakpoint. */
1249 STEP_OVER_BREAKPOINT
= 1,
1251 /* Step past a non-continuable watchpoint, in order to let the
1252 instruction execute so we can evaluate the watchpoint
1254 STEP_OVER_WATCHPOINT
= 2
1256 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1258 /* Info about an instruction that is being stepped over. */
1260 struct step_over_info
1262 /* If we're stepping past a breakpoint, this is the address space
1263 and address of the instruction the breakpoint is set at. We'll
1264 skip inserting all breakpoints here. Valid iff ASPACE is
1266 const address_space
*aspace
= nullptr;
1267 CORE_ADDR address
= 0;
1269 /* The instruction being stepped over triggers a nonsteppable
1270 watchpoint. If true, we'll skip inserting watchpoints. */
1271 int nonsteppable_watchpoint_p
= 0;
1273 /* The thread's global number. */
1277 /* The step-over info of the location that is being stepped over.
1279 Note that with async/breakpoint always-inserted mode, a user might
1280 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1281 being stepped over. As setting a new breakpoint inserts all
1282 breakpoints, we need to make sure the breakpoint being stepped over
1283 isn't inserted then. We do that by only clearing the step-over
1284 info when the step-over is actually finished (or aborted).
1286 Presently GDB can only step over one breakpoint at any given time.
1287 Given threads that can't run code in the same address space as the
1288 breakpoint's can't really miss the breakpoint, GDB could be taught
1289 to step-over at most one breakpoint per address space (so this info
1290 could move to the address space object if/when GDB is extended).
1291 The set of breakpoints being stepped over will normally be much
1292 smaller than the set of all breakpoints, so a flag in the
1293 breakpoint location structure would be wasteful. A separate list
1294 also saves complexity and run-time, as otherwise we'd have to go
1295 through all breakpoint locations clearing their flag whenever we
1296 start a new sequence. Similar considerations weigh against storing
1297 this info in the thread object. Plus, not all step overs actually
1298 have breakpoint locations -- e.g., stepping past a single-step
1299 breakpoint, or stepping to complete a non-continuable
1301 static struct step_over_info step_over_info
;
1303 /* Record the address of the breakpoint/instruction we're currently
1305 N.B. We record the aspace and address now, instead of say just the thread,
1306 because when we need the info later the thread may be running. */
1309 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1310 int nonsteppable_watchpoint_p
,
1313 step_over_info
.aspace
= aspace
;
1314 step_over_info
.address
= address
;
1315 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1316 step_over_info
.thread
= thread
;
1319 /* Called when we're not longer stepping over a breakpoint / an
1320 instruction, so all breakpoints are free to be (re)inserted. */
1323 clear_step_over_info (void)
1325 infrun_debug_printf ("clearing step over info");
1326 step_over_info
.aspace
= NULL
;
1327 step_over_info
.address
= 0;
1328 step_over_info
.nonsteppable_watchpoint_p
= 0;
1329 step_over_info
.thread
= -1;
1335 stepping_past_instruction_at (struct address_space
*aspace
,
1338 return (step_over_info
.aspace
!= NULL
1339 && breakpoint_address_match (aspace
, address
,
1340 step_over_info
.aspace
,
1341 step_over_info
.address
));
1347 thread_is_stepping_over_breakpoint (int thread
)
1349 return (step_over_info
.thread
!= -1
1350 && thread
== step_over_info
.thread
);
1356 stepping_past_nonsteppable_watchpoint (void)
1358 return step_over_info
.nonsteppable_watchpoint_p
;
1361 /* Returns true if step-over info is valid. */
1364 step_over_info_valid_p (void)
1366 return (step_over_info
.aspace
!= NULL
1367 || stepping_past_nonsteppable_watchpoint ());
1371 /* Displaced stepping. */
1373 /* In non-stop debugging mode, we must take special care to manage
1374 breakpoints properly; in particular, the traditional strategy for
1375 stepping a thread past a breakpoint it has hit is unsuitable.
1376 'Displaced stepping' is a tactic for stepping one thread past a
1377 breakpoint it has hit while ensuring that other threads running
1378 concurrently will hit the breakpoint as they should.
1380 The traditional way to step a thread T off a breakpoint in a
1381 multi-threaded program in all-stop mode is as follows:
1383 a0) Initially, all threads are stopped, and breakpoints are not
1385 a1) We single-step T, leaving breakpoints uninserted.
1386 a2) We insert breakpoints, and resume all threads.
1388 In non-stop debugging, however, this strategy is unsuitable: we
1389 don't want to have to stop all threads in the system in order to
1390 continue or step T past a breakpoint. Instead, we use displaced
1393 n0) Initially, T is stopped, other threads are running, and
1394 breakpoints are inserted.
1395 n1) We copy the instruction "under" the breakpoint to a separate
1396 location, outside the main code stream, making any adjustments
1397 to the instruction, register, and memory state as directed by
1399 n2) We single-step T over the instruction at its new location.
1400 n3) We adjust the resulting register and memory state as directed
1401 by T's architecture. This includes resetting T's PC to point
1402 back into the main instruction stream.
1405 This approach depends on the following gdbarch methods:
1407 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1408 indicate where to copy the instruction, and how much space must
1409 be reserved there. We use these in step n1.
1411 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1412 address, and makes any necessary adjustments to the instruction,
1413 register contents, and memory. We use this in step n1.
1415 - gdbarch_displaced_step_fixup adjusts registers and memory after
1416 we have successfully single-stepped the instruction, to yield the
1417 same effect the instruction would have had if we had executed it
1418 at its original address. We use this in step n3.
1420 The gdbarch_displaced_step_copy_insn and
1421 gdbarch_displaced_step_fixup functions must be written so that
1422 copying an instruction with gdbarch_displaced_step_copy_insn,
1423 single-stepping across the copied instruction, and then applying
1424 gdbarch_displaced_insn_fixup should have the same effects on the
1425 thread's memory and registers as stepping the instruction in place
1426 would have. Exactly which responsibilities fall to the copy and
1427 which fall to the fixup is up to the author of those functions.
1429 See the comments in gdbarch.sh for details.
1431 Note that displaced stepping and software single-step cannot
1432 currently be used in combination, although with some care I think
1433 they could be made to. Software single-step works by placing
1434 breakpoints on all possible subsequent instructions; if the
1435 displaced instruction is a PC-relative jump, those breakpoints
1436 could fall in very strange places --- on pages that aren't
1437 executable, or at addresses that are not proper instruction
1438 boundaries. (We do generally let other threads run while we wait
1439 to hit the software single-step breakpoint, and they might
1440 encounter such a corrupted instruction.) One way to work around
1441 this would be to have gdbarch_displaced_step_copy_insn fully
1442 simulate the effect of PC-relative instructions (and return NULL)
1443 on architectures that use software single-stepping.
1445 In non-stop mode, we can have independent and simultaneous step
1446 requests, so more than one thread may need to simultaneously step
1447 over a breakpoint. The current implementation assumes there is
1448 only one scratch space per process. In this case, we have to
1449 serialize access to the scratch space. If thread A wants to step
1450 over a breakpoint, but we are currently waiting for some other
1451 thread to complete a displaced step, we leave thread A stopped and
1452 place it in the displaced_step_request_queue. Whenever a displaced
1453 step finishes, we pick the next thread in the queue and start a new
1454 displaced step operation on it. See displaced_step_prepare and
1455 displaced_step_finish for details. */
1457 /* Return true if THREAD is doing a displaced step. */
1460 displaced_step_in_progress_thread (thread_info
*thread
)
1462 gdb_assert (thread
!= NULL
);
1464 return thread
->displaced_step_state
.in_progress ();
1467 /* Return true if INF has a thread doing a displaced step. */
1470 displaced_step_in_progress (inferior
*inf
)
1472 return inf
->displaced_step_state
.in_progress_count
> 0;
1475 /* Return true if any thread is doing a displaced step. */
1478 displaced_step_in_progress_any_thread ()
1480 for (inferior
*inf
: all_non_exited_inferiors ())
1482 if (displaced_step_in_progress (inf
))
1490 infrun_inferior_exit (struct inferior
*inf
)
1492 inf
->displaced_step_state
.reset ();
1496 infrun_inferior_execd (inferior
*inf
)
1498 /* If some threads where was doing a displaced step in this inferior at the
1499 moment of the exec, they no longer exist. Even if the exec'ing thread
1500 doing a displaced step, we don't want to to any fixup nor restore displaced
1501 stepping buffer bytes. */
1502 inf
->displaced_step_state
.reset ();
1504 for (thread_info
*thread
: inf
->threads ())
1505 thread
->displaced_step_state
.reset ();
1507 /* Since an in-line step is done with everything else stopped, if there was
1508 one in progress at the time of the exec, it must have been the exec'ing
1510 clear_step_over_info ();
1513 /* If ON, and the architecture supports it, GDB will use displaced
1514 stepping to step over breakpoints. If OFF, or if the architecture
1515 doesn't support it, GDB will instead use the traditional
1516 hold-and-step approach. If AUTO (which is the default), GDB will
1517 decide which technique to use to step over breakpoints depending on
1518 whether the target works in a non-stop way (see use_displaced_stepping). */
1520 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1523 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1524 struct cmd_list_element
*c
,
1527 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1528 fprintf_filtered (file
,
1529 _("Debugger's willingness to use displaced stepping "
1530 "to step over breakpoints is %s (currently %s).\n"),
1531 value
, target_is_non_stop_p () ? "on" : "off");
1533 fprintf_filtered (file
,
1534 _("Debugger's willingness to use displaced stepping "
1535 "to step over breakpoints is %s.\n"), value
);
1538 /* Return true if the gdbarch implements the required methods to use
1539 displaced stepping. */
1542 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1544 /* Only check for the presence of `prepare`. The gdbarch verification ensures
1545 that if `prepare` is provided, so is `finish`. */
1546 return gdbarch_displaced_step_prepare_p (arch
);
1549 /* Return non-zero if displaced stepping can/should be used to step
1550 over breakpoints of thread TP. */
1553 use_displaced_stepping (thread_info
*tp
)
1555 /* If the user disabled it explicitly, don't use displaced stepping. */
1556 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1559 /* If "auto", only use displaced stepping if the target operates in a non-stop
1561 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1562 && !target_is_non_stop_p ())
1565 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1567 /* If the architecture doesn't implement displaced stepping, don't use
1569 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1572 /* If recording, don't use displaced stepping. */
1573 if (find_record_target () != nullptr)
1576 /* If displaced stepping failed before for this inferior, don't bother trying
1578 if (tp
->inf
->displaced_step_state
.failed_before
)
1584 /* Simple function wrapper around displaced_step_thread_state::reset. */
1587 displaced_step_reset (displaced_step_thread_state
*displaced
)
1589 displaced
->reset ();
1592 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1593 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1595 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1600 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1604 for (size_t i
= 0; i
< len
; i
++)
1607 ret
+= string_printf ("%02x", buf
[i
]);
1609 ret
+= string_printf (" %02x", buf
[i
]);
1615 /* Prepare to single-step, using displaced stepping.
1617 Note that we cannot use displaced stepping when we have a signal to
1618 deliver. If we have a signal to deliver and an instruction to step
1619 over, then after the step, there will be no indication from the
1620 target whether the thread entered a signal handler or ignored the
1621 signal and stepped over the instruction successfully --- both cases
1622 result in a simple SIGTRAP. In the first case we mustn't do a
1623 fixup, and in the second case we must --- but we can't tell which.
1624 Comments in the code for 'random signals' in handle_inferior_event
1625 explain how we handle this case instead.
1627 Returns DISPLACED_STEP_PREPARE_STATUS_OK if preparing was successful -- this
1628 thread is going to be stepped now; DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
1629 if displaced stepping this thread got queued; or
1630 DISPLACED_STEP_PREPARE_STATUS_CANT if this instruction can't be displaced
1633 static displaced_step_prepare_status
1634 displaced_step_prepare_throw (thread_info
*tp
)
1636 regcache
*regcache
= get_thread_regcache (tp
);
1637 struct gdbarch
*gdbarch
= regcache
->arch ();
1638 displaced_step_thread_state
&disp_step_thread_state
1639 = tp
->displaced_step_state
;
1641 /* We should never reach this function if the architecture does not
1642 support displaced stepping. */
1643 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1645 /* Nor if the thread isn't meant to step over a breakpoint. */
1646 gdb_assert (tp
->control
.trap_expected
);
1648 /* Disable range stepping while executing in the scratch pad. We
1649 want a single-step even if executing the displaced instruction in
1650 the scratch buffer lands within the stepping range (e.g., a
1652 tp
->control
.may_range_step
= 0;
1654 /* We are about to start a displaced step for this thread. If one is already
1655 in progress, something's wrong. */
1656 gdb_assert (!disp_step_thread_state
.in_progress ());
1658 if (tp
->inf
->displaced_step_state
.unavailable
)
1660 /* The gdbarch tells us it's not worth asking to try a prepare because
1661 it is likely that it will return unavailable, so don't bother asking. */
1663 displaced_debug_printf ("deferring step of %s",
1664 target_pid_to_str (tp
->ptid
).c_str ());
1666 global_thread_step_over_chain_enqueue (tp
);
1667 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1670 displaced_debug_printf ("displaced-stepping %s now",
1671 target_pid_to_str (tp
->ptid
).c_str ());
1673 scoped_restore_current_thread restore_thread
;
1675 switch_to_thread (tp
);
1677 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1678 CORE_ADDR displaced_pc
;
1680 displaced_step_prepare_status status
1681 = gdbarch_displaced_step_prepare (gdbarch
, tp
, displaced_pc
);
1683 if (status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
1685 displaced_debug_printf ("failed to prepare (%s)",
1686 target_pid_to_str (tp
->ptid
).c_str ());
1688 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1690 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1692 /* Not enough displaced stepping resources available, defer this
1693 request by placing it the queue. */
1695 displaced_debug_printf ("not enough resources available, "
1696 "deferring step of %s",
1697 target_pid_to_str (tp
->ptid
).c_str ());
1699 global_thread_step_over_chain_enqueue (tp
);
1701 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1704 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1706 /* Save the information we need to fix things up if the step
1708 disp_step_thread_state
.set (gdbarch
);
1710 tp
->inf
->displaced_step_state
.in_progress_count
++;
1712 displaced_debug_printf ("prepared successfully thread=%s, "
1713 "original_pc=%s, displaced_pc=%s",
1714 target_pid_to_str (tp
->ptid
).c_str (),
1715 paddress (gdbarch
, original_pc
),
1716 paddress (gdbarch
, displaced_pc
));
1718 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1721 /* Wrapper for displaced_step_prepare_throw that disabled further
1722 attempts at displaced stepping if we get a memory error. */
1724 static displaced_step_prepare_status
1725 displaced_step_prepare (thread_info
*thread
)
1727 displaced_step_prepare_status status
1728 = DISPLACED_STEP_PREPARE_STATUS_CANT
;
1732 status
= displaced_step_prepare_throw (thread
);
1734 catch (const gdb_exception_error
&ex
)
1736 if (ex
.error
!= MEMORY_ERROR
1737 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1740 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1743 /* Be verbose if "set displaced-stepping" is "on", silent if
1745 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1747 warning (_("disabling displaced stepping: %s"),
1751 /* Disable further displaced stepping attempts. */
1752 thread
->inf
->displaced_step_state
.failed_before
= 1;
1758 /* If we displaced stepped an instruction successfully, adjust registers and
1759 memory to yield the same effect the instruction would have had if we had
1760 executed it at its original address, and return
1761 DISPLACED_STEP_FINISH_STATUS_OK. If the instruction didn't complete,
1762 relocate the PC and return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED.
1764 If the thread wasn't displaced stepping, return
1765 DISPLACED_STEP_FINISH_STATUS_OK as well. */
1767 static displaced_step_finish_status
1768 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1770 displaced_step_thread_state
*displaced
= &event_thread
->displaced_step_state
;
1772 /* Was this thread performing a displaced step? */
1773 if (!displaced
->in_progress ())
1774 return DISPLACED_STEP_FINISH_STATUS_OK
;
1776 gdb_assert (event_thread
->inf
->displaced_step_state
.in_progress_count
> 0);
1777 event_thread
->inf
->displaced_step_state
.in_progress_count
--;
1779 /* Fixup may need to read memory/registers. Switch to the thread
1780 that we're fixing up. Also, target_stopped_by_watchpoint checks
1781 the current thread, and displaced_step_restore performs ptid-dependent
1782 memory accesses using current_inferior(). */
1783 switch_to_thread (event_thread
);
1785 displaced_step_reset_cleanup
cleanup (displaced
);
1787 /* Do the fixup, and release the resources acquired to do the displaced
1789 return gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1790 event_thread
, signal
);
1793 /* Data to be passed around while handling an event. This data is
1794 discarded between events. */
1795 struct execution_control_state
1797 process_stratum_target
*target
;
1799 /* The thread that got the event, if this was a thread event; NULL
1801 struct thread_info
*event_thread
;
1803 struct target_waitstatus ws
;
1804 int stop_func_filled_in
;
1805 CORE_ADDR stop_func_start
;
1806 CORE_ADDR stop_func_end
;
1807 const char *stop_func_name
;
1810 /* True if the event thread hit the single-step breakpoint of
1811 another thread. Thus the event doesn't cause a stop, the thread
1812 needs to be single-stepped past the single-step breakpoint before
1813 we can switch back to the original stepping thread. */
1814 int hit_singlestep_breakpoint
;
1817 /* Clear ECS and set it to point at TP. */
1820 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1822 memset (ecs
, 0, sizeof (*ecs
));
1823 ecs
->event_thread
= tp
;
1824 ecs
->ptid
= tp
->ptid
;
1827 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1828 static void prepare_to_wait (struct execution_control_state
*ecs
);
1829 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1830 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1832 /* Are there any pending step-over requests? If so, run all we can
1833 now and return true. Otherwise, return false. */
1836 start_step_over (void)
1838 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
1842 /* Don't start a new step-over if we already have an in-line
1843 step-over operation ongoing. */
1844 if (step_over_info_valid_p ())
1847 /* Steal the global thread step over chain. As we try to initiate displaced
1848 steps, threads will be enqueued in the global chain if no buffers are
1849 available. If we iterated on the global chain directly, we might iterate
1851 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1852 global_thread_step_over_chain_head
= NULL
;
1854 infrun_debug_printf ("stealing global queue of threads to step, length = %d",
1855 thread_step_over_chain_length (threads_to_step
));
1857 bool started
= false;
1859 /* On scope exit (whatever the reason, return or exception), if there are
1860 threads left in the THREADS_TO_STEP chain, put back these threads in the
1864 if (threads_to_step
== nullptr)
1865 infrun_debug_printf ("step-over queue now empty");
1868 infrun_debug_printf ("putting back %d threads to step in global queue",
1869 thread_step_over_chain_length (threads_to_step
));
1871 global_thread_step_over_chain_enqueue_chain (threads_to_step
);
1875 for (thread_info
*tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1877 struct execution_control_state ecss
;
1878 struct execution_control_state
*ecs
= &ecss
;
1879 step_over_what step_what
;
1880 int must_be_in_line
;
1882 gdb_assert (!tp
->stop_requested
);
1884 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1886 if (tp
->inf
->displaced_step_state
.unavailable
)
1888 /* The arch told us to not even try preparing another displaced step
1889 for this inferior. Just leave the thread in THREADS_TO_STEP, it
1890 will get moved to the global chain on scope exit. */
1894 /* Remove thread from the THREADS_TO_STEP chain. If anything goes wrong
1895 while we try to prepare the displaced step, we don't add it back to
1896 the global step over chain. This is to avoid a thread staying in the
1897 step over chain indefinitely if something goes wrong when resuming it
1898 If the error is intermittent and it still needs a step over, it will
1899 get enqueued again when we try to resume it normally. */
1900 thread_step_over_chain_remove (&threads_to_step
, tp
);
1902 step_what
= thread_still_needs_step_over (tp
);
1903 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1904 || ((step_what
& STEP_OVER_BREAKPOINT
)
1905 && !use_displaced_stepping (tp
)));
1907 /* We currently stop all threads of all processes to step-over
1908 in-line. If we need to start a new in-line step-over, let
1909 any pending displaced steps finish first. */
1910 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1912 global_thread_step_over_chain_enqueue (tp
);
1916 if (tp
->control
.trap_expected
1920 internal_error (__FILE__
, __LINE__
,
1921 "[%s] has inconsistent state: "
1922 "trap_expected=%d, resumed=%d, executing=%d\n",
1923 target_pid_to_str (tp
->ptid
).c_str (),
1924 tp
->control
.trap_expected
,
1929 infrun_debug_printf ("resuming [%s] for step-over",
1930 target_pid_to_str (tp
->ptid
).c_str ());
1932 /* keep_going_pass_signal skips the step-over if the breakpoint
1933 is no longer inserted. In all-stop, we want to keep looking
1934 for a thread that needs a step-over instead of resuming TP,
1935 because we wouldn't be able to resume anything else until the
1936 target stops again. In non-stop, the resume always resumes
1937 only TP, so it's OK to let the thread resume freely. */
1938 if (!target_is_non_stop_p () && !step_what
)
1941 switch_to_thread (tp
);
1942 reset_ecs (ecs
, tp
);
1943 keep_going_pass_signal (ecs
);
1945 if (!ecs
->wait_some_more
)
1946 error (_("Command aborted."));
1948 /* If the thread's step over could not be initiated because no buffers
1949 were available, it was re-added to the global step over chain. */
1952 infrun_debug_printf ("[%s] was resumed.",
1953 target_pid_to_str (tp
->ptid
).c_str ());
1954 gdb_assert (!thread_is_in_step_over_chain (tp
));
1958 infrun_debug_printf ("[%s] was NOT resumed.",
1959 target_pid_to_str (tp
->ptid
).c_str ());
1960 gdb_assert (thread_is_in_step_over_chain (tp
));
1963 /* If we started a new in-line step-over, we're done. */
1964 if (step_over_info_valid_p ())
1966 gdb_assert (tp
->control
.trap_expected
);
1971 if (!target_is_non_stop_p ())
1973 /* On all-stop, shouldn't have resumed unless we needed a
1975 gdb_assert (tp
->control
.trap_expected
1976 || tp
->step_after_step_resume_breakpoint
);
1978 /* With remote targets (at least), in all-stop, we can't
1979 issue any further remote commands until the program stops
1985 /* Either the thread no longer needed a step-over, or a new
1986 displaced stepping sequence started. Even in the latter
1987 case, continue looking. Maybe we can also start another
1988 displaced step on a thread of other process. */
1994 /* Update global variables holding ptids to hold NEW_PTID if they were
1995 holding OLD_PTID. */
1997 infrun_thread_ptid_changed (process_stratum_target
*target
,
1998 ptid_t old_ptid
, ptid_t new_ptid
)
2000 if (inferior_ptid
== old_ptid
2001 && current_inferior ()->process_target () == target
)
2002 inferior_ptid
= new_ptid
;
2007 static const char schedlock_off
[] = "off";
2008 static const char schedlock_on
[] = "on";
2009 static const char schedlock_step
[] = "step";
2010 static const char schedlock_replay
[] = "replay";
2011 static const char *const scheduler_enums
[] = {
2018 static const char *scheduler_mode
= schedlock_replay
;
2020 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2021 struct cmd_list_element
*c
, const char *value
)
2023 fprintf_filtered (file
,
2024 _("Mode for locking scheduler "
2025 "during execution is \"%s\".\n"),
2030 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2032 if (!target_can_lock_scheduler ())
2034 scheduler_mode
= schedlock_off
;
2035 error (_("Target '%s' cannot support this command."),
2036 target_shortname ());
2040 /* True if execution commands resume all threads of all processes by
2041 default; otherwise, resume only threads of the current inferior
2043 bool sched_multi
= false;
2045 /* Try to setup for software single stepping over the specified location.
2046 Return true if target_resume() should use hardware single step.
2048 GDBARCH the current gdbarch.
2049 PC the location to step over. */
2052 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2054 bool hw_step
= true;
2056 if (execution_direction
== EXEC_FORWARD
2057 && gdbarch_software_single_step_p (gdbarch
))
2058 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2066 user_visible_resume_ptid (int step
)
2072 /* With non-stop mode on, threads are always handled
2074 resume_ptid
= inferior_ptid
;
2076 else if ((scheduler_mode
== schedlock_on
)
2077 || (scheduler_mode
== schedlock_step
&& step
))
2079 /* User-settable 'scheduler' mode requires solo thread
2081 resume_ptid
= inferior_ptid
;
2083 else if ((scheduler_mode
== schedlock_replay
)
2084 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2086 /* User-settable 'scheduler' mode requires solo thread resume in replay
2088 resume_ptid
= inferior_ptid
;
2090 else if (!sched_multi
&& target_supports_multi_process ())
2092 /* Resume all threads of the current process (and none of other
2094 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2098 /* Resume all threads of all processes. */
2099 resume_ptid
= RESUME_ALL
;
2107 process_stratum_target
*
2108 user_visible_resume_target (ptid_t resume_ptid
)
2110 return (resume_ptid
== minus_one_ptid
&& sched_multi
2112 : current_inferior ()->process_target ());
2115 /* Return a ptid representing the set of threads that we will resume,
2116 in the perspective of the target, assuming run control handling
2117 does not require leaving some threads stopped (e.g., stepping past
2118 breakpoint). USER_STEP indicates whether we're about to start the
2119 target for a stepping command. */
2122 internal_resume_ptid (int user_step
)
2124 /* In non-stop, we always control threads individually. Note that
2125 the target may always work in non-stop mode even with "set
2126 non-stop off", in which case user_visible_resume_ptid could
2127 return a wildcard ptid. */
2128 if (target_is_non_stop_p ())
2129 return inferior_ptid
;
2131 return user_visible_resume_ptid (user_step
);
2134 /* Wrapper for target_resume, that handles infrun-specific
2138 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2140 struct thread_info
*tp
= inferior_thread ();
2142 gdb_assert (!tp
->stop_requested
);
2144 /* Install inferior's terminal modes. */
2145 target_terminal::inferior ();
2147 /* Avoid confusing the next resume, if the next stop/resume
2148 happens to apply to another thread. */
2149 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2151 /* Advise target which signals may be handled silently.
2153 If we have removed breakpoints because we are stepping over one
2154 in-line (in any thread), we need to receive all signals to avoid
2155 accidentally skipping a breakpoint during execution of a signal
2158 Likewise if we're displaced stepping, otherwise a trap for a
2159 breakpoint in a signal handler might be confused with the
2160 displaced step finishing. We don't make the displaced_step_finish
2161 step distinguish the cases instead, because:
2163 - a backtrace while stopped in the signal handler would show the
2164 scratch pad as frame older than the signal handler, instead of
2165 the real mainline code.
2167 - when the thread is later resumed, the signal handler would
2168 return to the scratch pad area, which would no longer be
2170 if (step_over_info_valid_p ()
2171 || displaced_step_in_progress (tp
->inf
))
2172 target_pass_signals ({});
2174 target_pass_signals (signal_pass
);
2176 target_resume (resume_ptid
, step
, sig
);
2178 if (target_can_async_p ())
2182 /* Resume the inferior. SIG is the signal to give the inferior
2183 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2184 call 'resume', which handles exceptions. */
2187 resume_1 (enum gdb_signal sig
)
2189 struct regcache
*regcache
= get_current_regcache ();
2190 struct gdbarch
*gdbarch
= regcache
->arch ();
2191 struct thread_info
*tp
= inferior_thread ();
2192 const address_space
*aspace
= regcache
->aspace ();
2194 /* This represents the user's step vs continue request. When
2195 deciding whether "set scheduler-locking step" applies, it's the
2196 user's intention that counts. */
2197 const int user_step
= tp
->control
.stepping_command
;
2198 /* This represents what we'll actually request the target to do.
2199 This can decay from a step to a continue, if e.g., we need to
2200 implement single-stepping with breakpoints (software
2204 gdb_assert (!tp
->stop_requested
);
2205 gdb_assert (!thread_is_in_step_over_chain (tp
));
2207 if (tp
->suspend
.waitstatus_pending_p
)
2210 ("thread %s has pending wait "
2211 "status %s (currently_stepping=%d).",
2212 target_pid_to_str (tp
->ptid
).c_str (),
2213 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2214 currently_stepping (tp
));
2216 tp
->inf
->process_target ()->threads_executing
= true;
2219 /* FIXME: What should we do if we are supposed to resume this
2220 thread with a signal? Maybe we should maintain a queue of
2221 pending signals to deliver. */
2222 if (sig
!= GDB_SIGNAL_0
)
2224 warning (_("Couldn't deliver signal %s to %s."),
2225 gdb_signal_to_name (sig
),
2226 target_pid_to_str (tp
->ptid
).c_str ());
2229 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2231 if (target_can_async_p ())
2234 /* Tell the event loop we have an event to process. */
2235 mark_async_event_handler (infrun_async_inferior_event_token
);
2240 tp
->stepped_breakpoint
= 0;
2242 /* Depends on stepped_breakpoint. */
2243 step
= currently_stepping (tp
);
2245 if (current_inferior ()->waiting_for_vfork_done
)
2247 /* Don't try to single-step a vfork parent that is waiting for
2248 the child to get out of the shared memory region (by exec'ing
2249 or exiting). This is particularly important on software
2250 single-step archs, as the child process would trip on the
2251 software single step breakpoint inserted for the parent
2252 process. Since the parent will not actually execute any
2253 instruction until the child is out of the shared region (such
2254 are vfork's semantics), it is safe to simply continue it.
2255 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2256 the parent, and tell it to `keep_going', which automatically
2257 re-sets it stepping. */
2258 infrun_debug_printf ("resume : clear step");
2262 CORE_ADDR pc
= regcache_read_pc (regcache
);
2264 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2265 "current thread [%s] at %s",
2266 step
, gdb_signal_to_symbol_string (sig
),
2267 tp
->control
.trap_expected
,
2268 target_pid_to_str (inferior_ptid
).c_str (),
2269 paddress (gdbarch
, pc
));
2271 /* Normally, by the time we reach `resume', the breakpoints are either
2272 removed or inserted, as appropriate. The exception is if we're sitting
2273 at a permanent breakpoint; we need to step over it, but permanent
2274 breakpoints can't be removed. So we have to test for it here. */
2275 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2277 if (sig
!= GDB_SIGNAL_0
)
2279 /* We have a signal to pass to the inferior. The resume
2280 may, or may not take us to the signal handler. If this
2281 is a step, we'll need to stop in the signal handler, if
2282 there's one, (if the target supports stepping into
2283 handlers), or in the next mainline instruction, if
2284 there's no handler. If this is a continue, we need to be
2285 sure to run the handler with all breakpoints inserted.
2286 In all cases, set a breakpoint at the current address
2287 (where the handler returns to), and once that breakpoint
2288 is hit, resume skipping the permanent breakpoint. If
2289 that breakpoint isn't hit, then we've stepped into the
2290 signal handler (or hit some other event). We'll delete
2291 the step-resume breakpoint then. */
2293 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2294 "deliver signal first");
2296 clear_step_over_info ();
2297 tp
->control
.trap_expected
= 0;
2299 if (tp
->control
.step_resume_breakpoint
== NULL
)
2301 /* Set a "high-priority" step-resume, as we don't want
2302 user breakpoints at PC to trigger (again) when this
2304 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2305 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2307 tp
->step_after_step_resume_breakpoint
= step
;
2310 insert_breakpoints ();
2314 /* There's no signal to pass, we can go ahead and skip the
2315 permanent breakpoint manually. */
2316 infrun_debug_printf ("skipping permanent breakpoint");
2317 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2318 /* Update pc to reflect the new address from which we will
2319 execute instructions. */
2320 pc
= regcache_read_pc (regcache
);
2324 /* We've already advanced the PC, so the stepping part
2325 is done. Now we need to arrange for a trap to be
2326 reported to handle_inferior_event. Set a breakpoint
2327 at the current PC, and run to it. Don't update
2328 prev_pc, because if we end in
2329 switch_back_to_stepped_thread, we want the "expected
2330 thread advanced also" branch to be taken. IOW, we
2331 don't want this thread to step further from PC
2333 gdb_assert (!step_over_info_valid_p ());
2334 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2335 insert_breakpoints ();
2337 resume_ptid
= internal_resume_ptid (user_step
);
2338 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2345 /* If we have a breakpoint to step over, make sure to do a single
2346 step only. Same if we have software watchpoints. */
2347 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2348 tp
->control
.may_range_step
= 0;
2350 /* If displaced stepping is enabled, step over breakpoints by executing a
2351 copy of the instruction at a different address.
2353 We can't use displaced stepping when we have a signal to deliver;
2354 the comments for displaced_step_prepare explain why. The
2355 comments in the handle_inferior event for dealing with 'random
2356 signals' explain what we do instead.
2358 We can't use displaced stepping when we are waiting for vfork_done
2359 event, displaced stepping breaks the vfork child similarly as single
2360 step software breakpoint. */
2361 if (tp
->control
.trap_expected
2362 && use_displaced_stepping (tp
)
2363 && !step_over_info_valid_p ()
2364 && sig
== GDB_SIGNAL_0
2365 && !current_inferior ()->waiting_for_vfork_done
)
2367 displaced_step_prepare_status prepare_status
2368 = displaced_step_prepare (tp
);
2370 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2372 infrun_debug_printf ("Got placed in step-over queue");
2374 tp
->control
.trap_expected
= 0;
2377 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
2379 /* Fallback to stepping over the breakpoint in-line. */
2381 if (target_is_non_stop_p ())
2382 stop_all_threads ();
2384 set_step_over_info (regcache
->aspace (),
2385 regcache_read_pc (regcache
), 0, tp
->global_num
);
2387 step
= maybe_software_singlestep (gdbarch
, pc
);
2389 insert_breakpoints ();
2391 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2393 /* Update pc to reflect the new address from which we will
2394 execute instructions due to displaced stepping. */
2395 pc
= regcache_read_pc (get_thread_regcache (tp
));
2397 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2400 gdb_assert_not_reached (_("Invalid displaced_step_prepare_status "
2404 /* Do we need to do it the hard way, w/temp breakpoints? */
2406 step
= maybe_software_singlestep (gdbarch
, pc
);
2408 /* Currently, our software single-step implementation leads to different
2409 results than hardware single-stepping in one situation: when stepping
2410 into delivering a signal which has an associated signal handler,
2411 hardware single-step will stop at the first instruction of the handler,
2412 while software single-step will simply skip execution of the handler.
2414 For now, this difference in behavior is accepted since there is no
2415 easy way to actually implement single-stepping into a signal handler
2416 without kernel support.
2418 However, there is one scenario where this difference leads to follow-on
2419 problems: if we're stepping off a breakpoint by removing all breakpoints
2420 and then single-stepping. In this case, the software single-step
2421 behavior means that even if there is a *breakpoint* in the signal
2422 handler, GDB still would not stop.
2424 Fortunately, we can at least fix this particular issue. We detect
2425 here the case where we are about to deliver a signal while software
2426 single-stepping with breakpoints removed. In this situation, we
2427 revert the decisions to remove all breakpoints and insert single-
2428 step breakpoints, and instead we install a step-resume breakpoint
2429 at the current address, deliver the signal without stepping, and
2430 once we arrive back at the step-resume breakpoint, actually step
2431 over the breakpoint we originally wanted to step over. */
2432 if (thread_has_single_step_breakpoints_set (tp
)
2433 && sig
!= GDB_SIGNAL_0
2434 && step_over_info_valid_p ())
2436 /* If we have nested signals or a pending signal is delivered
2437 immediately after a handler returns, might already have
2438 a step-resume breakpoint set on the earlier handler. We cannot
2439 set another step-resume breakpoint; just continue on until the
2440 original breakpoint is hit. */
2441 if (tp
->control
.step_resume_breakpoint
== NULL
)
2443 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2444 tp
->step_after_step_resume_breakpoint
= 1;
2447 delete_single_step_breakpoints (tp
);
2449 clear_step_over_info ();
2450 tp
->control
.trap_expected
= 0;
2452 insert_breakpoints ();
2455 /* If STEP is set, it's a request to use hardware stepping
2456 facilities. But in that case, we should never
2457 use singlestep breakpoint. */
2458 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2460 /* Decide the set of threads to ask the target to resume. */
2461 if (tp
->control
.trap_expected
)
2463 /* We're allowing a thread to run past a breakpoint it has
2464 hit, either by single-stepping the thread with the breakpoint
2465 removed, or by displaced stepping, with the breakpoint inserted.
2466 In the former case, we need to single-step only this thread,
2467 and keep others stopped, as they can miss this breakpoint if
2468 allowed to run. That's not really a problem for displaced
2469 stepping, but, we still keep other threads stopped, in case
2470 another thread is also stopped for a breakpoint waiting for
2471 its turn in the displaced stepping queue. */
2472 resume_ptid
= inferior_ptid
;
2475 resume_ptid
= internal_resume_ptid (user_step
);
2477 if (execution_direction
!= EXEC_REVERSE
2478 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2480 /* There are two cases where we currently need to step a
2481 breakpoint instruction when we have a signal to deliver:
2483 - See handle_signal_stop where we handle random signals that
2484 could take out us out of the stepping range. Normally, in
2485 that case we end up continuing (instead of stepping) over the
2486 signal handler with a breakpoint at PC, but there are cases
2487 where we should _always_ single-step, even if we have a
2488 step-resume breakpoint, like when a software watchpoint is
2489 set. Assuming single-stepping and delivering a signal at the
2490 same time would takes us to the signal handler, then we could
2491 have removed the breakpoint at PC to step over it. However,
2492 some hardware step targets (like e.g., Mac OS) can't step
2493 into signal handlers, and for those, we need to leave the
2494 breakpoint at PC inserted, as otherwise if the handler
2495 recurses and executes PC again, it'll miss the breakpoint.
2496 So we leave the breakpoint inserted anyway, but we need to
2497 record that we tried to step a breakpoint instruction, so
2498 that adjust_pc_after_break doesn't end up confused.
2500 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2501 in one thread after another thread that was stepping had been
2502 momentarily paused for a step-over. When we re-resume the
2503 stepping thread, it may be resumed from that address with a
2504 breakpoint that hasn't trapped yet. Seen with
2505 gdb.threads/non-stop-fair-events.exp, on targets that don't
2506 do displaced stepping. */
2508 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2509 target_pid_to_str (tp
->ptid
).c_str ());
2511 tp
->stepped_breakpoint
= 1;
2513 /* Most targets can step a breakpoint instruction, thus
2514 executing it normally. But if this one cannot, just
2515 continue and we will hit it anyway. */
2516 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2521 && tp
->control
.trap_expected
2522 && use_displaced_stepping (tp
)
2523 && !step_over_info_valid_p ())
2525 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2526 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2527 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2530 read_memory (actual_pc
, buf
, sizeof (buf
));
2531 displaced_debug_printf ("run %s: %s",
2532 paddress (resume_gdbarch
, actual_pc
),
2533 displaced_step_dump_bytes
2534 (buf
, sizeof (buf
)).c_str ());
2537 if (tp
->control
.may_range_step
)
2539 /* If we're resuming a thread with the PC out of the step
2540 range, then we're doing some nested/finer run control
2541 operation, like stepping the thread out of the dynamic
2542 linker or the displaced stepping scratch pad. We
2543 shouldn't have allowed a range step then. */
2544 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2547 do_target_resume (resume_ptid
, step
, sig
);
2551 /* Resume the inferior. SIG is the signal to give the inferior
2552 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2553 rolls back state on error. */
2556 resume (gdb_signal sig
)
2562 catch (const gdb_exception
&ex
)
2564 /* If resuming is being aborted for any reason, delete any
2565 single-step breakpoint resume_1 may have created, to avoid
2566 confusing the following resumption, and to avoid leaving
2567 single-step breakpoints perturbing other threads, in case
2568 we're running in non-stop mode. */
2569 if (inferior_ptid
!= null_ptid
)
2570 delete_single_step_breakpoints (inferior_thread ());
2580 /* Counter that tracks number of user visible stops. This can be used
2581 to tell whether a command has proceeded the inferior past the
2582 current location. This allows e.g., inferior function calls in
2583 breakpoint commands to not interrupt the command list. When the
2584 call finishes successfully, the inferior is standing at the same
2585 breakpoint as if nothing happened (and so we don't call
2587 static ULONGEST current_stop_id
;
2594 return current_stop_id
;
2597 /* Called when we report a user visible stop. */
2605 /* Clear out all variables saying what to do when inferior is continued.
2606 First do this, then set the ones you want, then call `proceed'. */
2609 clear_proceed_status_thread (struct thread_info
*tp
)
2611 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2613 /* If we're starting a new sequence, then the previous finished
2614 single-step is no longer relevant. */
2615 if (tp
->suspend
.waitstatus_pending_p
)
2617 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2619 infrun_debug_printf ("pending event of %s was a finished step. "
2621 target_pid_to_str (tp
->ptid
).c_str ());
2623 tp
->suspend
.waitstatus_pending_p
= 0;
2624 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2629 ("thread %s has pending wait status %s (currently_stepping=%d).",
2630 target_pid_to_str (tp
->ptid
).c_str (),
2631 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2632 currently_stepping (tp
));
2636 /* If this signal should not be seen by program, give it zero.
2637 Used for debugging signals. */
2638 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2639 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2641 delete tp
->thread_fsm
;
2642 tp
->thread_fsm
= NULL
;
2644 tp
->control
.trap_expected
= 0;
2645 tp
->control
.step_range_start
= 0;
2646 tp
->control
.step_range_end
= 0;
2647 tp
->control
.may_range_step
= 0;
2648 tp
->control
.step_frame_id
= null_frame_id
;
2649 tp
->control
.step_stack_frame_id
= null_frame_id
;
2650 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2651 tp
->control
.step_start_function
= NULL
;
2652 tp
->stop_requested
= 0;
2654 tp
->control
.stop_step
= 0;
2656 tp
->control
.proceed_to_finish
= 0;
2658 tp
->control
.stepping_command
= 0;
2660 /* Discard any remaining commands or status from previous stop. */
2661 bpstat_clear (&tp
->control
.stop_bpstat
);
2665 clear_proceed_status (int step
)
2667 /* With scheduler-locking replay, stop replaying other threads if we're
2668 not replaying the user-visible resume ptid.
2670 This is a convenience feature to not require the user to explicitly
2671 stop replaying the other threads. We're assuming that the user's
2672 intent is to resume tracing the recorded process. */
2673 if (!non_stop
&& scheduler_mode
== schedlock_replay
2674 && target_record_is_replaying (minus_one_ptid
)
2675 && !target_record_will_replay (user_visible_resume_ptid (step
),
2676 execution_direction
))
2677 target_record_stop_replaying ();
2679 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2681 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2682 process_stratum_target
*resume_target
2683 = user_visible_resume_target (resume_ptid
);
2685 /* In all-stop mode, delete the per-thread status of all threads
2686 we're about to resume, implicitly and explicitly. */
2687 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2688 clear_proceed_status_thread (tp
);
2691 if (inferior_ptid
!= null_ptid
)
2693 struct inferior
*inferior
;
2697 /* If in non-stop mode, only delete the per-thread status of
2698 the current thread. */
2699 clear_proceed_status_thread (inferior_thread ());
2702 inferior
= current_inferior ();
2703 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2706 gdb::observers::about_to_proceed
.notify ();
2709 /* Returns true if TP is still stopped at a breakpoint that needs
2710 stepping-over in order to make progress. If the breakpoint is gone
2711 meanwhile, we can skip the whole step-over dance. */
2714 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2716 if (tp
->stepping_over_breakpoint
)
2718 struct regcache
*regcache
= get_thread_regcache (tp
);
2720 if (breakpoint_here_p (regcache
->aspace (),
2721 regcache_read_pc (regcache
))
2722 == ordinary_breakpoint_here
)
2725 tp
->stepping_over_breakpoint
= 0;
2731 /* Check whether thread TP still needs to start a step-over in order
2732 to make progress when resumed. Returns an bitwise or of enum
2733 step_over_what bits, indicating what needs to be stepped over. */
2735 static step_over_what
2736 thread_still_needs_step_over (struct thread_info
*tp
)
2738 step_over_what what
= 0;
2740 if (thread_still_needs_step_over_bp (tp
))
2741 what
|= STEP_OVER_BREAKPOINT
;
2743 if (tp
->stepping_over_watchpoint
2744 && !target_have_steppable_watchpoint ())
2745 what
|= STEP_OVER_WATCHPOINT
;
2750 /* Returns true if scheduler locking applies. STEP indicates whether
2751 we're about to do a step/next-like command to a thread. */
2754 schedlock_applies (struct thread_info
*tp
)
2756 return (scheduler_mode
== schedlock_on
2757 || (scheduler_mode
== schedlock_step
2758 && tp
->control
.stepping_command
)
2759 || (scheduler_mode
== schedlock_replay
2760 && target_record_will_replay (minus_one_ptid
,
2761 execution_direction
)));
2764 /* Set process_stratum_target::COMMIT_RESUMED_STATE in all target
2765 stacks that have threads executing and don't have threads with
2769 maybe_set_commit_resumed_all_targets ()
2771 scoped_restore_current_thread restore_thread
;
2773 for (inferior
*inf
: all_non_exited_inferiors ())
2775 process_stratum_target
*proc_target
= inf
->process_target ();
2777 if (proc_target
->commit_resumed_state
)
2779 /* We already set this in a previous iteration, via another
2780 inferior sharing the process_stratum target. */
2784 /* If the target has no resumed threads, it would be useless to
2785 ask it to commit the resumed threads. */
2786 if (!proc_target
->threads_executing
)
2788 infrun_debug_printf ("not requesting commit-resumed for target "
2789 "%s, no resumed threads",
2790 proc_target
->shortname ());
2794 /* As an optimization, if a thread from this target has some
2795 status to report, handle it before requiring the target to
2796 commit its resumed threads: handling the status might lead to
2797 resuming more threads. */
2798 bool has_thread_with_pending_status
= false;
2799 for (thread_info
*thread
: all_non_exited_threads (proc_target
))
2800 if (thread
->resumed
&& thread
->suspend
.waitstatus_pending_p
)
2802 has_thread_with_pending_status
= true;
2806 if (has_thread_with_pending_status
)
2808 infrun_debug_printf ("not requesting commit-resumed for target %s, a"
2809 " thread has a pending waitstatus",
2810 proc_target
->shortname ());
2814 switch_to_inferior_no_thread (inf
);
2816 if (target_has_pending_events ())
2818 infrun_debug_printf ("not requesting commit-resumed for target %s, "
2819 "target has pending events",
2820 proc_target
->shortname ());
2824 infrun_debug_printf ("enabling commit-resumed for target %s",
2825 proc_target
->shortname ());
2827 proc_target
->commit_resumed_state
= true;
2834 maybe_call_commit_resumed_all_targets ()
2836 scoped_restore_current_thread restore_thread
;
2838 for (inferior
*inf
: all_non_exited_inferiors ())
2840 process_stratum_target
*proc_target
= inf
->process_target ();
2842 if (!proc_target
->commit_resumed_state
)
2845 switch_to_inferior_no_thread (inf
);
2847 infrun_debug_printf ("calling commit_resumed for target %s",
2848 proc_target
->shortname());
2850 target_commit_resumed ();
2854 /* To track nesting of scoped_disable_commit_resumed objects, ensuring
2855 that only the outermost one attempts to re-enable
2857 static bool enable_commit_resumed
= true;
2861 scoped_disable_commit_resumed::scoped_disable_commit_resumed
2862 (const char *reason
)
2863 : m_reason (reason
),
2864 m_prev_enable_commit_resumed (enable_commit_resumed
)
2866 infrun_debug_printf ("reason=%s", m_reason
);
2868 enable_commit_resumed
= false;
2870 for (inferior
*inf
: all_non_exited_inferiors ())
2872 process_stratum_target
*proc_target
= inf
->process_target ();
2874 if (m_prev_enable_commit_resumed
)
2876 /* This is the outermost instance: force all
2877 COMMIT_RESUMED_STATE to false. */
2878 proc_target
->commit_resumed_state
= false;
2882 /* This is not the outermost instance, we expect
2883 COMMIT_RESUMED_STATE to have been cleared by the
2884 outermost instance. */
2885 gdb_assert (!proc_target
->commit_resumed_state
);
2893 scoped_disable_commit_resumed::reset ()
2899 infrun_debug_printf ("reason=%s", m_reason
);
2901 gdb_assert (!enable_commit_resumed
);
2903 enable_commit_resumed
= m_prev_enable_commit_resumed
;
2905 if (m_prev_enable_commit_resumed
)
2907 /* This is the outermost instance, re-enable
2908 COMMIT_RESUMED_STATE on the targets where it's possible. */
2909 maybe_set_commit_resumed_all_targets ();
2913 /* This is not the outermost instance, we expect
2914 COMMIT_RESUMED_STATE to still be false. */
2915 for (inferior
*inf
: all_non_exited_inferiors ())
2917 process_stratum_target
*proc_target
= inf
->process_target ();
2918 gdb_assert (!proc_target
->commit_resumed_state
);
2925 scoped_disable_commit_resumed::~scoped_disable_commit_resumed ()
2933 scoped_disable_commit_resumed::reset_and_commit ()
2936 maybe_call_commit_resumed_all_targets ();
2941 scoped_enable_commit_resumed::scoped_enable_commit_resumed
2942 (const char *reason
)
2943 : m_reason (reason
),
2944 m_prev_enable_commit_resumed (enable_commit_resumed
)
2946 infrun_debug_printf ("reason=%s", m_reason
);
2948 if (!enable_commit_resumed
)
2950 enable_commit_resumed
= true;
2952 /* Re-enable COMMIT_RESUMED_STATE on the targets where it's
2954 maybe_set_commit_resumed_all_targets ();
2956 maybe_call_commit_resumed_all_targets ();
2962 scoped_enable_commit_resumed::~scoped_enable_commit_resumed ()
2964 infrun_debug_printf ("reason=%s", m_reason
);
2966 gdb_assert (enable_commit_resumed
);
2968 enable_commit_resumed
= m_prev_enable_commit_resumed
;
2970 if (!enable_commit_resumed
)
2972 /* Force all COMMIT_RESUMED_STATE back to false. */
2973 for (inferior
*inf
: all_non_exited_inferiors ())
2975 process_stratum_target
*proc_target
= inf
->process_target ();
2976 proc_target
->commit_resumed_state
= false;
2981 /* Check that all the targets we're about to resume are in non-stop
2982 mode. Ideally, we'd only care whether all targets support
2983 target-async, but we're not there yet. E.g., stop_all_threads
2984 doesn't know how to handle all-stop targets. Also, the remote
2985 protocol in all-stop mode is synchronous, irrespective of
2986 target-async, which means that things like a breakpoint re-set
2987 triggered by one target would try to read memory from all targets
2991 check_multi_target_resumption (process_stratum_target
*resume_target
)
2993 if (!non_stop
&& resume_target
== nullptr)
2995 scoped_restore_current_thread restore_thread
;
2997 /* This is used to track whether we're resuming more than one
2999 process_stratum_target
*first_connection
= nullptr;
3001 /* The first inferior we see with a target that does not work in
3002 always-non-stop mode. */
3003 inferior
*first_not_non_stop
= nullptr;
3005 for (inferior
*inf
: all_non_exited_inferiors ())
3007 switch_to_inferior_no_thread (inf
);
3009 if (!target_has_execution ())
3012 process_stratum_target
*proc_target
3013 = current_inferior ()->process_target();
3015 if (!target_is_non_stop_p ())
3016 first_not_non_stop
= inf
;
3018 if (first_connection
== nullptr)
3019 first_connection
= proc_target
;
3020 else if (first_connection
!= proc_target
3021 && first_not_non_stop
!= nullptr)
3023 switch_to_inferior_no_thread (first_not_non_stop
);
3025 proc_target
= current_inferior ()->process_target();
3027 error (_("Connection %d (%s) does not support "
3028 "multi-target resumption."),
3029 proc_target
->connection_number
,
3030 make_target_connection_string (proc_target
).c_str ());
3036 /* Basic routine for continuing the program in various fashions.
3038 ADDR is the address to resume at, or -1 for resume where stopped.
3039 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
3040 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
3042 You should call clear_proceed_status before calling proceed. */
3045 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
3047 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
3049 struct regcache
*regcache
;
3050 struct gdbarch
*gdbarch
;
3052 struct execution_control_state ecss
;
3053 struct execution_control_state
*ecs
= &ecss
;
3056 /* If we're stopped at a fork/vfork, follow the branch set by the
3057 "set follow-fork-mode" command; otherwise, we'll just proceed
3058 resuming the current thread. */
3059 if (!follow_fork ())
3061 /* The target for some reason decided not to resume. */
3063 if (target_can_async_p ())
3064 inferior_event_handler (INF_EXEC_COMPLETE
);
3068 /* We'll update this if & when we switch to a new thread. */
3069 previous_inferior_ptid
= inferior_ptid
;
3071 regcache
= get_current_regcache ();
3072 gdbarch
= regcache
->arch ();
3073 const address_space
*aspace
= regcache
->aspace ();
3075 pc
= regcache_read_pc_protected (regcache
);
3077 thread_info
*cur_thr
= inferior_thread ();
3079 /* Fill in with reasonable starting values. */
3080 init_thread_stepping_state (cur_thr
);
3082 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
3085 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
3086 process_stratum_target
*resume_target
3087 = user_visible_resume_target (resume_ptid
);
3089 check_multi_target_resumption (resume_target
);
3091 if (addr
== (CORE_ADDR
) -1)
3093 if (pc
== cur_thr
->suspend
.stop_pc
3094 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3095 && execution_direction
!= EXEC_REVERSE
)
3096 /* There is a breakpoint at the address we will resume at,
3097 step one instruction before inserting breakpoints so that
3098 we do not stop right away (and report a second hit at this
3101 Note, we don't do this in reverse, because we won't
3102 actually be executing the breakpoint insn anyway.
3103 We'll be (un-)executing the previous instruction. */
3104 cur_thr
->stepping_over_breakpoint
= 1;
3105 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3106 && gdbarch_single_step_through_delay (gdbarch
,
3107 get_current_frame ()))
3108 /* We stepped onto an instruction that needs to be stepped
3109 again before re-inserting the breakpoint, do so. */
3110 cur_thr
->stepping_over_breakpoint
= 1;
3114 regcache_write_pc (regcache
, addr
);
3117 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3118 cur_thr
->suspend
.stop_signal
= siggnal
;
3120 /* If an exception is thrown from this point on, make sure to
3121 propagate GDB's knowledge of the executing state to the
3122 frontend/user running state. */
3123 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3125 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3126 threads (e.g., we might need to set threads stepping over
3127 breakpoints first), from the user/frontend's point of view, all
3128 threads in RESUME_PTID are now running. Unless we're calling an
3129 inferior function, as in that case we pretend the inferior
3130 doesn't run at all. */
3131 if (!cur_thr
->control
.in_infcall
)
3132 set_running (resume_target
, resume_ptid
, true);
3134 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3135 gdb_signal_to_symbol_string (siggnal
));
3137 annotate_starting ();
3139 /* Make sure that output from GDB appears before output from the
3141 gdb_flush (gdb_stdout
);
3143 /* Since we've marked the inferior running, give it the terminal. A
3144 QUIT/Ctrl-C from here on is forwarded to the target (which can
3145 still detect attempts to unblock a stuck connection with repeated
3146 Ctrl-C from within target_pass_ctrlc). */
3147 target_terminal::inferior ();
3149 /* In a multi-threaded task we may select another thread and
3150 then continue or step.
3152 But if a thread that we're resuming had stopped at a breakpoint,
3153 it will immediately cause another breakpoint stop without any
3154 execution (i.e. it will report a breakpoint hit incorrectly). So
3155 we must step over it first.
3157 Look for threads other than the current (TP) that reported a
3158 breakpoint hit and haven't been resumed yet since. */
3160 /* If scheduler locking applies, we can avoid iterating over all
3162 if (!non_stop
&& !schedlock_applies (cur_thr
))
3164 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3167 switch_to_thread_no_regs (tp
);
3169 /* Ignore the current thread here. It's handled
3174 if (!thread_still_needs_step_over (tp
))
3177 gdb_assert (!thread_is_in_step_over_chain (tp
));
3179 infrun_debug_printf ("need to step-over [%s] first",
3180 target_pid_to_str (tp
->ptid
).c_str ());
3182 global_thread_step_over_chain_enqueue (tp
);
3185 switch_to_thread (cur_thr
);
3188 /* Enqueue the current thread last, so that we move all other
3189 threads over their breakpoints first. */
3190 if (cur_thr
->stepping_over_breakpoint
)
3191 global_thread_step_over_chain_enqueue (cur_thr
);
3193 /* If the thread isn't started, we'll still need to set its prev_pc,
3194 so that switch_back_to_stepped_thread knows the thread hasn't
3195 advanced. Must do this before resuming any thread, as in
3196 all-stop/remote, once we resume we can't send any other packet
3197 until the target stops again. */
3198 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3201 scoped_disable_commit_resumed
disable_commit_resumed ("proceeding");
3203 started
= start_step_over ();
3205 if (step_over_info_valid_p ())
3207 /* Either this thread started a new in-line step over, or some
3208 other thread was already doing one. In either case, don't
3209 resume anything else until the step-over is finished. */
3211 else if (started
&& !target_is_non_stop_p ())
3213 /* A new displaced stepping sequence was started. In all-stop,
3214 we can't talk to the target anymore until it next stops. */
3216 else if (!non_stop
&& target_is_non_stop_p ())
3218 INFRUN_SCOPED_DEBUG_START_END
3219 ("resuming threads, all-stop-on-top-of-non-stop");
3221 /* In all-stop, but the target is always in non-stop mode.
3222 Start all other threads that are implicitly resumed too. */
3223 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3226 switch_to_thread_no_regs (tp
);
3228 if (!tp
->inf
->has_execution ())
3230 infrun_debug_printf ("[%s] target has no execution",
3231 target_pid_to_str (tp
->ptid
).c_str ());
3237 infrun_debug_printf ("[%s] resumed",
3238 target_pid_to_str (tp
->ptid
).c_str ());
3239 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3243 if (thread_is_in_step_over_chain (tp
))
3245 infrun_debug_printf ("[%s] needs step-over",
3246 target_pid_to_str (tp
->ptid
).c_str ());
3250 infrun_debug_printf ("resuming %s",
3251 target_pid_to_str (tp
->ptid
).c_str ());
3253 reset_ecs (ecs
, tp
);
3254 switch_to_thread (tp
);
3255 keep_going_pass_signal (ecs
);
3256 if (!ecs
->wait_some_more
)
3257 error (_("Command aborted."));
3260 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3262 /* The thread wasn't started, and isn't queued, run it now. */
3263 reset_ecs (ecs
, cur_thr
);
3264 switch_to_thread (cur_thr
);
3265 keep_going_pass_signal (ecs
);
3266 if (!ecs
->wait_some_more
)
3267 error (_("Command aborted."));
3270 disable_commit_resumed
.reset_and_commit ();
3273 finish_state
.release ();
3275 /* If we've switched threads above, switch back to the previously
3276 current thread. We don't want the user to see a different
3278 switch_to_thread (cur_thr
);
3280 /* Tell the event loop to wait for it to stop. If the target
3281 supports asynchronous execution, it'll do this from within
3283 if (!target_can_async_p ())
3284 mark_async_event_handler (infrun_async_inferior_event_token
);
3288 /* Start remote-debugging of a machine over a serial link. */
3291 start_remote (int from_tty
)
3293 inferior
*inf
= current_inferior ();
3294 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3296 /* Always go on waiting for the target, regardless of the mode. */
3297 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3298 indicate to wait_for_inferior that a target should timeout if
3299 nothing is returned (instead of just blocking). Because of this,
3300 targets expecting an immediate response need to, internally, set
3301 things up so that the target_wait() is forced to eventually
3303 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3304 differentiate to its caller what the state of the target is after
3305 the initial open has been performed. Here we're assuming that
3306 the target has stopped. It should be possible to eventually have
3307 target_open() return to the caller an indication that the target
3308 is currently running and GDB state should be set to the same as
3309 for an async run. */
3310 wait_for_inferior (inf
);
3312 /* Now that the inferior has stopped, do any bookkeeping like
3313 loading shared libraries. We want to do this before normal_stop,
3314 so that the displayed frame is up to date. */
3315 post_create_inferior (from_tty
);
3320 /* Initialize static vars when a new inferior begins. */
3323 init_wait_for_inferior (void)
3325 /* These are meaningless until the first time through wait_for_inferior. */
3327 breakpoint_init_inferior (inf_starting
);
3329 clear_proceed_status (0);
3331 nullify_last_target_wait_ptid ();
3333 previous_inferior_ptid
= inferior_ptid
;
3338 static void handle_inferior_event (struct execution_control_state
*ecs
);
3340 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3341 struct execution_control_state
*ecs
);
3342 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3343 struct execution_control_state
*ecs
);
3344 static void handle_signal_stop (struct execution_control_state
*ecs
);
3345 static void check_exception_resume (struct execution_control_state
*,
3346 struct frame_info
*);
3348 static void end_stepping_range (struct execution_control_state
*ecs
);
3349 static void stop_waiting (struct execution_control_state
*ecs
);
3350 static void keep_going (struct execution_control_state
*ecs
);
3351 static void process_event_stop_test (struct execution_control_state
*ecs
);
3352 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3354 /* This function is attached as a "thread_stop_requested" observer.
3355 Cleanup local state that assumed the PTID was to be resumed, and
3356 report the stop to the frontend. */
3359 infrun_thread_stop_requested (ptid_t ptid
)
3361 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3363 /* PTID was requested to stop. If the thread was already stopped,
3364 but the user/frontend doesn't know about that yet (e.g., the
3365 thread had been temporarily paused for some step-over), set up
3366 for reporting the stop now. */
3367 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3369 if (tp
->state
!= THREAD_RUNNING
)
3374 /* Remove matching threads from the step-over queue, so
3375 start_step_over doesn't try to resume them
3377 if (thread_is_in_step_over_chain (tp
))
3378 global_thread_step_over_chain_remove (tp
);
3380 /* If the thread is stopped, but the user/frontend doesn't
3381 know about that yet, queue a pending event, as if the
3382 thread had just stopped now. Unless the thread already had
3384 if (!tp
->suspend
.waitstatus_pending_p
)
3386 tp
->suspend
.waitstatus_pending_p
= 1;
3387 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3388 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3391 /* Clear the inline-frame state, since we're re-processing the
3393 clear_inline_frame_state (tp
);
3395 /* If this thread was paused because some other thread was
3396 doing an inline-step over, let that finish first. Once
3397 that happens, we'll restart all threads and consume pending
3398 stop events then. */
3399 if (step_over_info_valid_p ())
3402 /* Otherwise we can process the (new) pending event now. Set
3403 it so this pending event is considered by
3410 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3412 if (target_last_proc_target
== tp
->inf
->process_target ()
3413 && target_last_wait_ptid
== tp
->ptid
)
3414 nullify_last_target_wait_ptid ();
3417 /* Delete the step resume, single-step and longjmp/exception resume
3418 breakpoints of TP. */
3421 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3423 delete_step_resume_breakpoint (tp
);
3424 delete_exception_resume_breakpoint (tp
);
3425 delete_single_step_breakpoints (tp
);
3428 /* If the target still has execution, call FUNC for each thread that
3429 just stopped. In all-stop, that's all the non-exited threads; in
3430 non-stop, that's the current thread, only. */
3432 typedef void (*for_each_just_stopped_thread_callback_func
)
3433 (struct thread_info
*tp
);
3436 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3438 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3441 if (target_is_non_stop_p ())
3443 /* If in non-stop mode, only the current thread stopped. */
3444 func (inferior_thread ());
3448 /* In all-stop mode, all threads have stopped. */
3449 for (thread_info
*tp
: all_non_exited_threads ())
3454 /* Delete the step resume and longjmp/exception resume breakpoints of
3455 the threads that just stopped. */
3458 delete_just_stopped_threads_infrun_breakpoints (void)
3460 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3463 /* Delete the single-step breakpoints of the threads that just
3467 delete_just_stopped_threads_single_step_breakpoints (void)
3469 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3475 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3476 const struct target_waitstatus
*ws
)
3478 infrun_debug_printf ("target_wait (%d.%ld.%ld [%s], status) =",
3482 target_pid_to_str (waiton_ptid
).c_str ());
3483 infrun_debug_printf (" %d.%ld.%ld [%s],",
3487 target_pid_to_str (result_ptid
).c_str ());
3488 infrun_debug_printf (" %s", target_waitstatus_to_string (ws
).c_str ());
3491 /* Select a thread at random, out of those which are resumed and have
3494 static struct thread_info
*
3495 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3499 auto has_event
= [&] (thread_info
*tp
)
3501 return (tp
->ptid
.matches (waiton_ptid
)
3503 && tp
->suspend
.waitstatus_pending_p
);
3506 /* First see how many events we have. Count only resumed threads
3507 that have an event pending. */
3508 for (thread_info
*tp
: inf
->non_exited_threads ())
3512 if (num_events
== 0)
3515 /* Now randomly pick a thread out of those that have had events. */
3516 int random_selector
= (int) ((num_events
* (double) rand ())
3517 / (RAND_MAX
+ 1.0));
3520 infrun_debug_printf ("Found %d events, selecting #%d",
3521 num_events
, random_selector
);
3523 /* Select the Nth thread that has had an event. */
3524 for (thread_info
*tp
: inf
->non_exited_threads ())
3526 if (random_selector
-- == 0)
3529 gdb_assert_not_reached ("event thread not found");
3532 /* Wrapper for target_wait that first checks whether threads have
3533 pending statuses to report before actually asking the target for
3534 more events. INF is the inferior we're using to call target_wait
3538 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3539 target_waitstatus
*status
, target_wait_flags options
)
3542 struct thread_info
*tp
;
3544 /* We know that we are looking for an event in the target of inferior
3545 INF, but we don't know which thread the event might come from. As
3546 such we want to make sure that INFERIOR_PTID is reset so that none of
3547 the wait code relies on it - doing so is always a mistake. */
3548 switch_to_inferior_no_thread (inf
);
3550 /* First check if there is a resumed thread with a wait status
3552 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3554 tp
= random_pending_event_thread (inf
, ptid
);
3558 infrun_debug_printf ("Waiting for specific thread %s.",
3559 target_pid_to_str (ptid
).c_str ());
3561 /* We have a specific thread to check. */
3562 tp
= find_thread_ptid (inf
, ptid
);
3563 gdb_assert (tp
!= NULL
);
3564 if (!tp
->suspend
.waitstatus_pending_p
)
3569 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3570 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3572 struct regcache
*regcache
= get_thread_regcache (tp
);
3573 struct gdbarch
*gdbarch
= regcache
->arch ();
3577 pc
= regcache_read_pc (regcache
);
3579 if (pc
!= tp
->suspend
.stop_pc
)
3581 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3582 target_pid_to_str (tp
->ptid
).c_str (),
3583 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3584 paddress (gdbarch
, pc
));
3587 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3589 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3590 target_pid_to_str (tp
->ptid
).c_str (),
3591 paddress (gdbarch
, pc
));
3598 infrun_debug_printf ("pending event of %s cancelled.",
3599 target_pid_to_str (tp
->ptid
).c_str ());
3601 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3602 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3608 infrun_debug_printf ("Using pending wait status %s for %s.",
3609 target_waitstatus_to_string
3610 (&tp
->suspend
.waitstatus
).c_str (),
3611 target_pid_to_str (tp
->ptid
).c_str ());
3613 /* Now that we've selected our final event LWP, un-adjust its PC
3614 if it was a software breakpoint (and the target doesn't
3615 always adjust the PC itself). */
3616 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3617 && !target_supports_stopped_by_sw_breakpoint ())
3619 struct regcache
*regcache
;
3620 struct gdbarch
*gdbarch
;
3623 regcache
= get_thread_regcache (tp
);
3624 gdbarch
= regcache
->arch ();
3626 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3631 pc
= regcache_read_pc (regcache
);
3632 regcache_write_pc (regcache
, pc
+ decr_pc
);
3636 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3637 *status
= tp
->suspend
.waitstatus
;
3638 tp
->suspend
.waitstatus_pending_p
= 0;
3640 /* Wake up the event loop again, until all pending events are
3642 if (target_is_async_p ())
3643 mark_async_event_handler (infrun_async_inferior_event_token
);
3647 /* But if we don't find one, we'll have to wait. */
3649 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3651 if (!target_can_async_p ())
3652 options
&= ~TARGET_WNOHANG
;
3654 if (deprecated_target_wait_hook
)
3655 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3657 event_ptid
= target_wait (ptid
, status
, options
);
3662 /* Wrapper for target_wait that first checks whether threads have
3663 pending statuses to report before actually asking the target for
3664 more events. Polls for events from all inferiors/targets. */
3667 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3668 target_wait_flags options
)
3670 int num_inferiors
= 0;
3671 int random_selector
;
3673 /* For fairness, we pick the first inferior/target to poll at random
3674 out of all inferiors that may report events, and then continue
3675 polling the rest of the inferior list starting from that one in a
3676 circular fashion until the whole list is polled once. */
3678 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3680 return (inf
->process_target () != NULL
3681 && ptid_t (inf
->pid
).matches (wait_ptid
));
3684 /* First see how many matching inferiors we have. */
3685 for (inferior
*inf
: all_inferiors ())
3686 if (inferior_matches (inf
))
3689 if (num_inferiors
== 0)
3691 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3695 /* Now randomly pick an inferior out of those that matched. */
3696 random_selector
= (int)
3697 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3699 if (num_inferiors
> 1)
3700 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3701 num_inferiors
, random_selector
);
3703 /* Select the Nth inferior that matched. */
3705 inferior
*selected
= nullptr;
3707 for (inferior
*inf
: all_inferiors ())
3708 if (inferior_matches (inf
))
3709 if (random_selector
-- == 0)
3715 /* Now poll for events out of each of the matching inferior's
3716 targets, starting from the selected one. */
3718 auto do_wait
= [&] (inferior
*inf
)
3720 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3721 ecs
->target
= inf
->process_target ();
3722 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3725 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3726 here spuriously after the target is all stopped and we've already
3727 reported the stop to the user, polling for events. */
3728 scoped_restore_current_thread restore_thread
;
3730 int inf_num
= selected
->num
;
3731 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3732 if (inferior_matches (inf
))
3736 for (inferior
*inf
= inferior_list
;
3737 inf
!= NULL
&& inf
->num
< inf_num
;
3739 if (inferior_matches (inf
))
3743 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3747 /* An event reported by wait_one. */
3749 struct wait_one_event
3751 /* The target the event came out of. */
3752 process_stratum_target
*target
;
3754 /* The PTID the event was for. */
3757 /* The waitstatus. */
3758 target_waitstatus ws
;
3761 static bool handle_one (const wait_one_event
&event
);
3762 static void restart_threads (struct thread_info
*event_thread
);
3764 /* Prepare and stabilize the inferior for detaching it. E.g.,
3765 detaching while a thread is displaced stepping is a recipe for
3766 crashing it, as nothing would readjust the PC out of the scratch
3770 prepare_for_detach (void)
3772 struct inferior
*inf
= current_inferior ();
3773 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3774 scoped_restore_current_thread restore_thread
;
3776 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3778 /* Remove all threads of INF from the global step-over chain. We
3779 want to stop any ongoing step-over, not start any new one. */
3781 for (thread_info
*tp
= global_thread_step_over_chain_head
;
3785 next
= global_thread_step_over_chain_next (tp
);
3787 global_thread_step_over_chain_remove (tp
);
3790 /* If we were already in the middle of an inline step-over, and the
3791 thread stepping belongs to the inferior we're detaching, we need
3792 to restart the threads of other inferiors. */
3793 if (step_over_info
.thread
!= -1)
3795 infrun_debug_printf ("inline step-over in-process while detaching");
3797 thread_info
*thr
= find_thread_global_id (step_over_info
.thread
);
3798 if (thr
->inf
== inf
)
3800 /* Since we removed threads of INF from the step-over chain,
3801 we know this won't start a step-over for INF. */
3802 clear_step_over_info ();
3804 if (target_is_non_stop_p ())
3806 /* Start a new step-over in another thread if there's
3807 one that needs it. */
3810 /* Restart all other threads (except the
3811 previously-stepping thread, since that one is still
3813 if (!step_over_info_valid_p ())
3814 restart_threads (thr
);
3819 if (displaced_step_in_progress (inf
))
3821 infrun_debug_printf ("displaced-stepping in-process while detaching");
3823 /* Stop threads currently displaced stepping, aborting it. */
3825 for (thread_info
*thr
: inf
->non_exited_threads ())
3827 if (thr
->displaced_step_state
.in_progress ())
3831 if (!thr
->stop_requested
)
3833 target_stop (thr
->ptid
);
3834 thr
->stop_requested
= true;
3838 thr
->resumed
= false;
3842 while (displaced_step_in_progress (inf
))
3844 wait_one_event event
;
3846 event
.target
= inf
->process_target ();
3847 event
.ptid
= do_target_wait_1 (inf
, pid_ptid
, &event
.ws
, 0);
3850 print_target_wait_results (pid_ptid
, event
.ptid
, &event
.ws
);
3855 /* It's OK to leave some of the threads of INF stopped, since
3856 they'll be detached shortly. */
3860 /* Wait for control to return from inferior to debugger.
3862 If inferior gets a signal, we may decide to start it up again
3863 instead of returning. That is why there is a loop in this function.
3864 When this function actually returns it means the inferior
3865 should be left stopped and GDB should read more commands. */
3868 wait_for_inferior (inferior
*inf
)
3870 infrun_debug_printf ("wait_for_inferior ()");
3872 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3874 /* If an error happens while handling the event, propagate GDB's
3875 knowledge of the executing state to the frontend/user running
3877 scoped_finish_thread_state finish_state
3878 (inf
->process_target (), minus_one_ptid
);
3882 struct execution_control_state ecss
;
3883 struct execution_control_state
*ecs
= &ecss
;
3885 memset (ecs
, 0, sizeof (*ecs
));
3887 overlay_cache_invalid
= 1;
3889 /* Flush target cache before starting to handle each event.
3890 Target was running and cache could be stale. This is just a
3891 heuristic. Running threads may modify target memory, but we
3892 don't get any event. */
3893 target_dcache_invalidate ();
3895 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3896 ecs
->target
= inf
->process_target ();
3899 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3901 /* Now figure out what to do with the result of the result. */
3902 handle_inferior_event (ecs
);
3904 if (!ecs
->wait_some_more
)
3908 /* No error, don't finish the state yet. */
3909 finish_state
.release ();
3912 /* Cleanup that reinstalls the readline callback handler, if the
3913 target is running in the background. If while handling the target
3914 event something triggered a secondary prompt, like e.g., a
3915 pagination prompt, we'll have removed the callback handler (see
3916 gdb_readline_wrapper_line). Need to do this as we go back to the
3917 event loop, ready to process further input. Note this has no
3918 effect if the handler hasn't actually been removed, because calling
3919 rl_callback_handler_install resets the line buffer, thus losing
3923 reinstall_readline_callback_handler_cleanup ()
3925 struct ui
*ui
= current_ui
;
3929 /* We're not going back to the top level event loop yet. Don't
3930 install the readline callback, as it'd prep the terminal,
3931 readline-style (raw, noecho) (e.g., --batch). We'll install
3932 it the next time the prompt is displayed, when we're ready
3937 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3938 gdb_rl_callback_handler_reinstall ();
3941 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3942 that's just the event thread. In all-stop, that's all threads. */
3945 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3947 if (ecs
->event_thread
!= NULL
3948 && ecs
->event_thread
->thread_fsm
!= NULL
)
3949 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3953 for (thread_info
*thr
: all_non_exited_threads ())
3955 if (thr
->thread_fsm
== NULL
)
3957 if (thr
== ecs
->event_thread
)
3960 switch_to_thread (thr
);
3961 thr
->thread_fsm
->clean_up (thr
);
3964 if (ecs
->event_thread
!= NULL
)
3965 switch_to_thread (ecs
->event_thread
);
3969 /* Helper for all_uis_check_sync_execution_done that works on the
3973 check_curr_ui_sync_execution_done (void)
3975 struct ui
*ui
= current_ui
;
3977 if (ui
->prompt_state
== PROMPT_NEEDED
3979 && !gdb_in_secondary_prompt_p (ui
))
3981 target_terminal::ours ();
3982 gdb::observers::sync_execution_done
.notify ();
3983 ui_register_input_event_handler (ui
);
3990 all_uis_check_sync_execution_done (void)
3992 SWITCH_THRU_ALL_UIS ()
3994 check_curr_ui_sync_execution_done ();
4001 all_uis_on_sync_execution_starting (void)
4003 SWITCH_THRU_ALL_UIS ()
4005 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
4006 async_disable_stdin ();
4010 /* Asynchronous version of wait_for_inferior. It is called by the
4011 event loop whenever a change of state is detected on the file
4012 descriptor corresponding to the target. It can be called more than
4013 once to complete a single execution command. In such cases we need
4014 to keep the state in a global variable ECSS. If it is the last time
4015 that this function is called for a single execution command, then
4016 report to the user that the inferior has stopped, and do the
4017 necessary cleanups. */
4020 fetch_inferior_event ()
4022 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
4024 struct execution_control_state ecss
;
4025 struct execution_control_state
*ecs
= &ecss
;
4028 memset (ecs
, 0, sizeof (*ecs
));
4030 /* Events are always processed with the main UI as current UI. This
4031 way, warnings, debug output, etc. are always consistently sent to
4032 the main console. */
4033 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
4035 /* Temporarily disable pagination. Otherwise, the user would be
4036 given an option to press 'q' to quit, which would cause an early
4037 exit and could leave GDB in a half-baked state. */
4038 scoped_restore save_pagination
4039 = make_scoped_restore (&pagination_enabled
, false);
4041 /* End up with readline processing input, if necessary. */
4043 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
4045 /* We're handling a live event, so make sure we're doing live
4046 debugging. If we're looking at traceframes while the target is
4047 running, we're going to need to get back to that mode after
4048 handling the event. */
4049 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
4052 maybe_restore_traceframe
.emplace ();
4053 set_current_traceframe (-1);
4056 /* The user/frontend should not notice a thread switch due to
4057 internal events. Make sure we revert to the user selected
4058 thread and frame after handling the event and running any
4059 breakpoint commands. */
4060 scoped_restore_current_thread restore_thread
;
4062 overlay_cache_invalid
= 1;
4063 /* Flush target cache before starting to handle each event. Target
4064 was running and cache could be stale. This is just a heuristic.
4065 Running threads may modify target memory, but we don't get any
4067 target_dcache_invalidate ();
4069 scoped_restore save_exec_dir
4070 = make_scoped_restore (&execution_direction
,
4071 target_execution_direction ());
4073 /* Allow targets to pause their resumed threads while we handle
4075 scoped_disable_commit_resumed
disable_commit_resumed ("handling event");
4077 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
4079 infrun_debug_printf ("do_target_wait returned no event");
4080 disable_commit_resumed
.reset_and_commit ();
4084 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
4086 /* Switch to the target that generated the event, so we can do
4088 switch_to_target_no_thread (ecs
->target
);
4091 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
4093 /* If an error happens while handling the event, propagate GDB's
4094 knowledge of the executing state to the frontend/user running
4096 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
4097 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
4099 /* Get executed before scoped_restore_current_thread above to apply
4100 still for the thread which has thrown the exception. */
4101 auto defer_bpstat_clear
4102 = make_scope_exit (bpstat_clear_actions
);
4103 auto defer_delete_threads
4104 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4106 /* Now figure out what to do with the result of the result. */
4107 handle_inferior_event (ecs
);
4109 if (!ecs
->wait_some_more
)
4111 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4112 bool should_stop
= true;
4113 struct thread_info
*thr
= ecs
->event_thread
;
4115 delete_just_stopped_threads_infrun_breakpoints ();
4119 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4121 if (thread_fsm
!= NULL
)
4122 should_stop
= thread_fsm
->should_stop (thr
);
4131 bool should_notify_stop
= true;
4134 clean_up_just_stopped_threads_fsms (ecs
);
4136 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4137 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4139 if (should_notify_stop
)
4141 /* We may not find an inferior if this was a process exit. */
4142 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4143 proceeded
= normal_stop ();
4148 inferior_event_handler (INF_EXEC_COMPLETE
);
4152 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4153 previously selected thread is gone. We have two
4154 choices - switch to no thread selected, or restore the
4155 previously selected thread (now exited). We chose the
4156 later, just because that's what GDB used to do. After
4157 this, "info threads" says "The current thread <Thread
4158 ID 2> has terminated." instead of "No thread
4162 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4163 restore_thread
.dont_restore ();
4167 defer_delete_threads
.release ();
4168 defer_bpstat_clear
.release ();
4170 /* No error, don't finish the thread states yet. */
4171 finish_state
.release ();
4173 disable_commit_resumed
.reset_and_commit ();
4175 /* This scope is used to ensure that readline callbacks are
4176 reinstalled here. */
4179 /* If a UI was in sync execution mode, and now isn't, restore its
4180 prompt (a synchronous execution command has finished, and we're
4181 ready for input). */
4182 all_uis_check_sync_execution_done ();
4185 && exec_done_display_p
4186 && (inferior_ptid
== null_ptid
4187 || inferior_thread ()->state
!= THREAD_RUNNING
))
4188 printf_unfiltered (_("completed.\n"));
4194 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4195 struct symtab_and_line sal
)
4197 /* This can be removed once this function no longer implicitly relies on the
4198 inferior_ptid value. */
4199 gdb_assert (inferior_ptid
== tp
->ptid
);
4201 tp
->control
.step_frame_id
= get_frame_id (frame
);
4202 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4204 tp
->current_symtab
= sal
.symtab
;
4205 tp
->current_line
= sal
.line
;
4208 /* Clear context switchable stepping state. */
4211 init_thread_stepping_state (struct thread_info
*tss
)
4213 tss
->stepped_breakpoint
= 0;
4214 tss
->stepping_over_breakpoint
= 0;
4215 tss
->stepping_over_watchpoint
= 0;
4216 tss
->step_after_step_resume_breakpoint
= 0;
4222 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4223 target_waitstatus status
)
4225 target_last_proc_target
= target
;
4226 target_last_wait_ptid
= ptid
;
4227 target_last_waitstatus
= status
;
4233 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4234 target_waitstatus
*status
)
4236 if (target
!= nullptr)
4237 *target
= target_last_proc_target
;
4238 if (ptid
!= nullptr)
4239 *ptid
= target_last_wait_ptid
;
4240 if (status
!= nullptr)
4241 *status
= target_last_waitstatus
;
4247 nullify_last_target_wait_ptid (void)
4249 target_last_proc_target
= nullptr;
4250 target_last_wait_ptid
= minus_one_ptid
;
4251 target_last_waitstatus
= {};
4254 /* Switch thread contexts. */
4257 context_switch (execution_control_state
*ecs
)
4259 if (ecs
->ptid
!= inferior_ptid
4260 && (inferior_ptid
== null_ptid
4261 || ecs
->event_thread
!= inferior_thread ()))
4263 infrun_debug_printf ("Switching context from %s to %s",
4264 target_pid_to_str (inferior_ptid
).c_str (),
4265 target_pid_to_str (ecs
->ptid
).c_str ());
4268 switch_to_thread (ecs
->event_thread
);
4271 /* If the target can't tell whether we've hit breakpoints
4272 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4273 check whether that could have been caused by a breakpoint. If so,
4274 adjust the PC, per gdbarch_decr_pc_after_break. */
4277 adjust_pc_after_break (struct thread_info
*thread
,
4278 struct target_waitstatus
*ws
)
4280 struct regcache
*regcache
;
4281 struct gdbarch
*gdbarch
;
4282 CORE_ADDR breakpoint_pc
, decr_pc
;
4284 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4285 we aren't, just return.
4287 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4288 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4289 implemented by software breakpoints should be handled through the normal
4292 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4293 different signals (SIGILL or SIGEMT for instance), but it is less
4294 clear where the PC is pointing afterwards. It may not match
4295 gdbarch_decr_pc_after_break. I don't know any specific target that
4296 generates these signals at breakpoints (the code has been in GDB since at
4297 least 1992) so I can not guess how to handle them here.
4299 In earlier versions of GDB, a target with
4300 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4301 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4302 target with both of these set in GDB history, and it seems unlikely to be
4303 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4305 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4308 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4311 /* In reverse execution, when a breakpoint is hit, the instruction
4312 under it has already been de-executed. The reported PC always
4313 points at the breakpoint address, so adjusting it further would
4314 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4317 B1 0x08000000 : INSN1
4318 B2 0x08000001 : INSN2
4320 PC -> 0x08000003 : INSN4
4322 Say you're stopped at 0x08000003 as above. Reverse continuing
4323 from that point should hit B2 as below. Reading the PC when the
4324 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4325 been de-executed already.
4327 B1 0x08000000 : INSN1
4328 B2 PC -> 0x08000001 : INSN2
4332 We can't apply the same logic as for forward execution, because
4333 we would wrongly adjust the PC to 0x08000000, since there's a
4334 breakpoint at PC - 1. We'd then report a hit on B1, although
4335 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4337 if (execution_direction
== EXEC_REVERSE
)
4340 /* If the target can tell whether the thread hit a SW breakpoint,
4341 trust it. Targets that can tell also adjust the PC
4343 if (target_supports_stopped_by_sw_breakpoint ())
4346 /* Note that relying on whether a breakpoint is planted in memory to
4347 determine this can fail. E.g,. the breakpoint could have been
4348 removed since. Or the thread could have been told to step an
4349 instruction the size of a breakpoint instruction, and only
4350 _after_ was a breakpoint inserted at its address. */
4352 /* If this target does not decrement the PC after breakpoints, then
4353 we have nothing to do. */
4354 regcache
= get_thread_regcache (thread
);
4355 gdbarch
= regcache
->arch ();
4357 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4361 const address_space
*aspace
= regcache
->aspace ();
4363 /* Find the location where (if we've hit a breakpoint) the
4364 breakpoint would be. */
4365 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4367 /* If the target can't tell whether a software breakpoint triggered,
4368 fallback to figuring it out based on breakpoints we think were
4369 inserted in the target, and on whether the thread was stepped or
4372 /* Check whether there actually is a software breakpoint inserted at
4375 If in non-stop mode, a race condition is possible where we've
4376 removed a breakpoint, but stop events for that breakpoint were
4377 already queued and arrive later. To suppress those spurious
4378 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4379 and retire them after a number of stop events are reported. Note
4380 this is an heuristic and can thus get confused. The real fix is
4381 to get the "stopped by SW BP and needs adjustment" info out of
4382 the target/kernel (and thus never reach here; see above). */
4383 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4384 || (target_is_non_stop_p ()
4385 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4387 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4389 if (record_full_is_used ())
4390 restore_operation_disable
.emplace
4391 (record_full_gdb_operation_disable_set ());
4393 /* When using hardware single-step, a SIGTRAP is reported for both
4394 a completed single-step and a software breakpoint. Need to
4395 differentiate between the two, as the latter needs adjusting
4396 but the former does not.
4398 The SIGTRAP can be due to a completed hardware single-step only if
4399 - we didn't insert software single-step breakpoints
4400 - this thread is currently being stepped
4402 If any of these events did not occur, we must have stopped due
4403 to hitting a software breakpoint, and have to back up to the
4406 As a special case, we could have hardware single-stepped a
4407 software breakpoint. In this case (prev_pc == breakpoint_pc),
4408 we also need to back up to the breakpoint address. */
4410 if (thread_has_single_step_breakpoints_set (thread
)
4411 || !currently_stepping (thread
)
4412 || (thread
->stepped_breakpoint
4413 && thread
->prev_pc
== breakpoint_pc
))
4414 regcache_write_pc (regcache
, breakpoint_pc
);
4419 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4421 for (frame
= get_prev_frame (frame
);
4423 frame
= get_prev_frame (frame
))
4425 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4428 if (get_frame_type (frame
) != INLINE_FRAME
)
4435 /* Look for an inline frame that is marked for skip.
4436 If PREV_FRAME is TRUE start at the previous frame,
4437 otherwise start at the current frame. Stop at the
4438 first non-inline frame, or at the frame where the
4442 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4444 struct frame_info
*frame
= get_current_frame ();
4447 frame
= get_prev_frame (frame
);
4449 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4451 const char *fn
= NULL
;
4452 symtab_and_line sal
;
4455 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4457 if (get_frame_type (frame
) != INLINE_FRAME
)
4460 sal
= find_frame_sal (frame
);
4461 sym
= get_frame_function (frame
);
4464 fn
= sym
->print_name ();
4467 && function_name_is_marked_for_skip (fn
, sal
))
4474 /* If the event thread has the stop requested flag set, pretend it
4475 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4479 handle_stop_requested (struct execution_control_state
*ecs
)
4481 if (ecs
->event_thread
->stop_requested
)
4483 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4484 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4485 handle_signal_stop (ecs
);
4491 /* Auxiliary function that handles syscall entry/return events.
4492 It returns true if the inferior should keep going (and GDB
4493 should ignore the event), or false if the event deserves to be
4497 handle_syscall_event (struct execution_control_state
*ecs
)
4499 struct regcache
*regcache
;
4502 context_switch (ecs
);
4504 regcache
= get_thread_regcache (ecs
->event_thread
);
4505 syscall_number
= ecs
->ws
.value
.syscall_number
;
4506 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4508 if (catch_syscall_enabled () > 0
4509 && catching_syscall_number (syscall_number
) > 0)
4511 infrun_debug_printf ("syscall number=%d", syscall_number
);
4513 ecs
->event_thread
->control
.stop_bpstat
4514 = bpstat_stop_status (regcache
->aspace (),
4515 ecs
->event_thread
->suspend
.stop_pc
,
4516 ecs
->event_thread
, &ecs
->ws
);
4518 if (handle_stop_requested (ecs
))
4521 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4523 /* Catchpoint hit. */
4528 if (handle_stop_requested (ecs
))
4531 /* If no catchpoint triggered for this, then keep going. */
4537 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4540 fill_in_stop_func (struct gdbarch
*gdbarch
,
4541 struct execution_control_state
*ecs
)
4543 if (!ecs
->stop_func_filled_in
)
4546 const general_symbol_info
*gsi
;
4548 /* Don't care about return value; stop_func_start and stop_func_name
4549 will both be 0 if it doesn't work. */
4550 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4552 &ecs
->stop_func_start
,
4553 &ecs
->stop_func_end
,
4555 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4557 /* The call to find_pc_partial_function, above, will set
4558 stop_func_start and stop_func_end to the start and end
4559 of the range containing the stop pc. If this range
4560 contains the entry pc for the block (which is always the
4561 case for contiguous blocks), advance stop_func_start past
4562 the function's start offset and entrypoint. Note that
4563 stop_func_start is NOT advanced when in a range of a
4564 non-contiguous block that does not contain the entry pc. */
4565 if (block
!= nullptr
4566 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4567 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4569 ecs
->stop_func_start
4570 += gdbarch_deprecated_function_start_offset (gdbarch
);
4572 if (gdbarch_skip_entrypoint_p (gdbarch
))
4573 ecs
->stop_func_start
4574 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4577 ecs
->stop_func_filled_in
= 1;
4582 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4584 static enum stop_kind
4585 get_inferior_stop_soon (execution_control_state
*ecs
)
4587 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4589 gdb_assert (inf
!= NULL
);
4590 return inf
->control
.stop_soon
;
4593 /* Poll for one event out of the current target. Store the resulting
4594 waitstatus in WS, and return the event ptid. Does not block. */
4597 poll_one_curr_target (struct target_waitstatus
*ws
)
4601 overlay_cache_invalid
= 1;
4603 /* Flush target cache before starting to handle each event.
4604 Target was running and cache could be stale. This is just a
4605 heuristic. Running threads may modify target memory, but we
4606 don't get any event. */
4607 target_dcache_invalidate ();
4609 if (deprecated_target_wait_hook
)
4610 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4612 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4615 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4620 /* Wait for one event out of any target. */
4622 static wait_one_event
4627 for (inferior
*inf
: all_inferiors ())
4629 process_stratum_target
*target
= inf
->process_target ();
4631 || !target
->is_async_p ()
4632 || !target
->threads_executing
)
4635 switch_to_inferior_no_thread (inf
);
4637 wait_one_event event
;
4638 event
.target
= target
;
4639 event
.ptid
= poll_one_curr_target (&event
.ws
);
4641 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4643 /* If nothing is resumed, remove the target from the
4647 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4651 /* Block waiting for some event. */
4658 for (inferior
*inf
: all_inferiors ())
4660 process_stratum_target
*target
= inf
->process_target ();
4662 || !target
->is_async_p ()
4663 || !target
->threads_executing
)
4666 int fd
= target
->async_wait_fd ();
4667 FD_SET (fd
, &readfds
);
4674 /* No waitable targets left. All must be stopped. */
4675 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4680 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4686 perror_with_name ("interruptible_select");
4691 /* Save the thread's event and stop reason to process it later. */
4694 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4696 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4697 target_waitstatus_to_string (ws
).c_str (),
4702 /* Record for later. */
4703 tp
->suspend
.waitstatus
= *ws
;
4704 tp
->suspend
.waitstatus_pending_p
= 1;
4706 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4707 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4709 struct regcache
*regcache
= get_thread_regcache (tp
);
4710 const address_space
*aspace
= regcache
->aspace ();
4711 CORE_ADDR pc
= regcache_read_pc (regcache
);
4713 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4715 scoped_restore_current_thread restore_thread
;
4716 switch_to_thread (tp
);
4718 if (target_stopped_by_watchpoint ())
4720 tp
->suspend
.stop_reason
4721 = TARGET_STOPPED_BY_WATCHPOINT
;
4723 else if (target_supports_stopped_by_sw_breakpoint ()
4724 && target_stopped_by_sw_breakpoint ())
4726 tp
->suspend
.stop_reason
4727 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4729 else if (target_supports_stopped_by_hw_breakpoint ()
4730 && target_stopped_by_hw_breakpoint ())
4732 tp
->suspend
.stop_reason
4733 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4735 else if (!target_supports_stopped_by_hw_breakpoint ()
4736 && hardware_breakpoint_inserted_here_p (aspace
,
4739 tp
->suspend
.stop_reason
4740 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4742 else if (!target_supports_stopped_by_sw_breakpoint ()
4743 && software_breakpoint_inserted_here_p (aspace
,
4746 tp
->suspend
.stop_reason
4747 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4749 else if (!thread_has_single_step_breakpoints_set (tp
)
4750 && currently_stepping (tp
))
4752 tp
->suspend
.stop_reason
4753 = TARGET_STOPPED_BY_SINGLE_STEP
;
4758 /* Mark the non-executing threads accordingly. In all-stop, all
4759 threads of all processes are stopped when we get any event
4760 reported. In non-stop mode, only the event thread stops. */
4763 mark_non_executing_threads (process_stratum_target
*target
,
4765 struct target_waitstatus ws
)
4769 if (!target_is_non_stop_p ())
4770 mark_ptid
= minus_one_ptid
;
4771 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4772 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4774 /* If we're handling a process exit in non-stop mode, even
4775 though threads haven't been deleted yet, one would think
4776 that there is nothing to do, as threads of the dead process
4777 will be soon deleted, and threads of any other process were
4778 left running. However, on some targets, threads survive a
4779 process exit event. E.g., for the "checkpoint" command,
4780 when the current checkpoint/fork exits, linux-fork.c
4781 automatically switches to another fork from within
4782 target_mourn_inferior, by associating the same
4783 inferior/thread to another fork. We haven't mourned yet at
4784 this point, but we must mark any threads left in the
4785 process as not-executing so that finish_thread_state marks
4786 them stopped (in the user's perspective) if/when we present
4787 the stop to the user. */
4788 mark_ptid
= ptid_t (event_ptid
.pid ());
4791 mark_ptid
= event_ptid
;
4793 set_executing (target
, mark_ptid
, false);
4795 /* Likewise the resumed flag. */
4796 set_resumed (target
, mark_ptid
, false);
4799 /* Handle one event after stopping threads. If the eventing thread
4800 reports back any interesting event, we leave it pending. If the
4801 eventing thread was in the middle of a displaced step, we
4802 cancel/finish it, and unless the thread's inferior is being
4803 detached, put the thread back in the step-over chain. Returns true
4804 if there are no resumed threads left in the target (thus there's no
4805 point in waiting further), false otherwise. */
4808 handle_one (const wait_one_event
&event
)
4811 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4812 target_pid_to_str (event
.ptid
).c_str ());
4814 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4816 /* All resumed threads exited. */
4819 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4820 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4821 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4823 /* One thread/process exited/signalled. */
4825 thread_info
*t
= nullptr;
4827 /* The target may have reported just a pid. If so, try
4828 the first non-exited thread. */
4829 if (event
.ptid
.is_pid ())
4831 int pid
= event
.ptid
.pid ();
4832 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4833 for (thread_info
*tp
: inf
->non_exited_threads ())
4839 /* If there is no available thread, the event would
4840 have to be appended to a per-inferior event list,
4841 which does not exist (and if it did, we'd have
4842 to adjust run control command to be able to
4843 resume such an inferior). We assert here instead
4844 of going into an infinite loop. */
4845 gdb_assert (t
!= nullptr);
4848 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4852 t
= find_thread_ptid (event
.target
, event
.ptid
);
4853 /* Check if this is the first time we see this thread.
4854 Don't bother adding if it individually exited. */
4856 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4857 t
= add_thread (event
.target
, event
.ptid
);
4862 /* Set the threads as non-executing to avoid
4863 another stop attempt on them. */
4864 switch_to_thread_no_regs (t
);
4865 mark_non_executing_threads (event
.target
, event
.ptid
,
4867 save_waitstatus (t
, &event
.ws
);
4868 t
->stop_requested
= false;
4873 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4875 t
= add_thread (event
.target
, event
.ptid
);
4877 t
->stop_requested
= 0;
4880 t
->control
.may_range_step
= 0;
4882 /* This may be the first time we see the inferior report
4884 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4885 if (inf
->needs_setup
)
4887 switch_to_thread_no_regs (t
);
4891 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4892 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4894 /* We caught the event that we intended to catch, so
4895 there's no event pending. */
4896 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4897 t
->suspend
.waitstatus_pending_p
= 0;
4899 if (displaced_step_finish (t
, GDB_SIGNAL_0
)
4900 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4902 /* Add it back to the step-over queue. */
4904 ("displaced-step of %s canceled",
4905 target_pid_to_str (t
->ptid
).c_str ());
4907 t
->control
.trap_expected
= 0;
4908 if (!t
->inf
->detaching
)
4909 global_thread_step_over_chain_enqueue (t
);
4914 enum gdb_signal sig
;
4915 struct regcache
*regcache
;
4918 ("target_wait %s, saving status for %d.%ld.%ld",
4919 target_waitstatus_to_string (&event
.ws
).c_str (),
4920 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4922 /* Record for later. */
4923 save_waitstatus (t
, &event
.ws
);
4925 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4926 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4928 if (displaced_step_finish (t
, sig
)
4929 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4931 /* Add it back to the step-over queue. */
4932 t
->control
.trap_expected
= 0;
4933 if (!t
->inf
->detaching
)
4934 global_thread_step_over_chain_enqueue (t
);
4937 regcache
= get_thread_regcache (t
);
4938 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4940 infrun_debug_printf ("saved stop_pc=%s for %s "
4941 "(currently_stepping=%d)",
4942 paddress (target_gdbarch (),
4943 t
->suspend
.stop_pc
),
4944 target_pid_to_str (t
->ptid
).c_str (),
4945 currently_stepping (t
));
4955 stop_all_threads (void)
4957 /* We may need multiple passes to discover all threads. */
4961 gdb_assert (exists_non_stop_target ());
4963 infrun_debug_printf ("starting");
4965 scoped_restore_current_thread restore_thread
;
4967 /* Enable thread events of all targets. */
4968 for (auto *target
: all_non_exited_process_targets ())
4970 switch_to_target_no_thread (target
);
4971 target_thread_events (true);
4976 /* Disable thread events of all targets. */
4977 for (auto *target
: all_non_exited_process_targets ())
4979 switch_to_target_no_thread (target
);
4980 target_thread_events (false);
4983 /* Use debug_prefixed_printf directly to get a meaningful function
4986 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4989 /* Request threads to stop, and then wait for the stops. Because
4990 threads we already know about can spawn more threads while we're
4991 trying to stop them, and we only learn about new threads when we
4992 update the thread list, do this in a loop, and keep iterating
4993 until two passes find no threads that need to be stopped. */
4994 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4996 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4999 int waits_needed
= 0;
5001 for (auto *target
: all_non_exited_process_targets ())
5003 switch_to_target_no_thread (target
);
5004 update_thread_list ();
5007 /* Go through all threads looking for threads that we need
5008 to tell the target to stop. */
5009 for (thread_info
*t
: all_non_exited_threads ())
5011 /* For a single-target setting with an all-stop target,
5012 we would not even arrive here. For a multi-target
5013 setting, until GDB is able to handle a mixture of
5014 all-stop and non-stop targets, simply skip all-stop
5015 targets' threads. This should be fine due to the
5016 protection of 'check_multi_target_resumption'. */
5018 switch_to_thread_no_regs (t
);
5019 if (!target_is_non_stop_p ())
5024 /* If already stopping, don't request a stop again.
5025 We just haven't seen the notification yet. */
5026 if (!t
->stop_requested
)
5028 infrun_debug_printf (" %s executing, need stop",
5029 target_pid_to_str (t
->ptid
).c_str ());
5030 target_stop (t
->ptid
);
5031 t
->stop_requested
= 1;
5035 infrun_debug_printf (" %s executing, already stopping",
5036 target_pid_to_str (t
->ptid
).c_str ());
5039 if (t
->stop_requested
)
5044 infrun_debug_printf (" %s not executing",
5045 target_pid_to_str (t
->ptid
).c_str ());
5047 /* The thread may be not executing, but still be
5048 resumed with a pending status to process. */
5053 if (waits_needed
== 0)
5056 /* If we find new threads on the second iteration, restart
5057 over. We want to see two iterations in a row with all
5062 for (int i
= 0; i
< waits_needed
; i
++)
5064 wait_one_event event
= wait_one ();
5065 if (handle_one (event
))
5072 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
5075 handle_no_resumed (struct execution_control_state
*ecs
)
5077 if (target_can_async_p ())
5079 bool any_sync
= false;
5081 for (ui
*ui
: all_uis ())
5083 if (ui
->prompt_state
== PROMPT_BLOCKED
)
5091 /* There were no unwaited-for children left in the target, but,
5092 we're not synchronously waiting for events either. Just
5095 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
5096 prepare_to_wait (ecs
);
5101 /* Otherwise, if we were running a synchronous execution command, we
5102 may need to cancel it and give the user back the terminal.
5104 In non-stop mode, the target can't tell whether we've already
5105 consumed previous stop events, so it can end up sending us a
5106 no-resumed event like so:
5108 #0 - thread 1 is left stopped
5110 #1 - thread 2 is resumed and hits breakpoint
5111 -> TARGET_WAITKIND_STOPPED
5113 #2 - thread 3 is resumed and exits
5114 this is the last resumed thread, so
5115 -> TARGET_WAITKIND_NO_RESUMED
5117 #3 - gdb processes stop for thread 2 and decides to re-resume
5120 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
5121 thread 2 is now resumed, so the event should be ignored.
5123 IOW, if the stop for thread 2 doesn't end a foreground command,
5124 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
5125 event. But it could be that the event meant that thread 2 itself
5126 (or whatever other thread was the last resumed thread) exited.
5128 To address this we refresh the thread list and check whether we
5129 have resumed threads _now_. In the example above, this removes
5130 thread 3 from the thread list. If thread 2 was re-resumed, we
5131 ignore this event. If we find no thread resumed, then we cancel
5132 the synchronous command and show "no unwaited-for " to the
5135 inferior
*curr_inf
= current_inferior ();
5137 scoped_restore_current_thread restore_thread
;
5139 for (auto *target
: all_non_exited_process_targets ())
5141 switch_to_target_no_thread (target
);
5142 update_thread_list ();
5147 - the current target has no thread executing, and
5148 - the current inferior is native, and
5149 - the current inferior is the one which has the terminal, and
5152 then a Ctrl-C from this point on would remain stuck in the
5153 kernel, until a thread resumes and dequeues it. That would
5154 result in the GDB CLI not reacting to Ctrl-C, not able to
5155 interrupt the program. To address this, if the current inferior
5156 no longer has any thread executing, we give the terminal to some
5157 other inferior that has at least one thread executing. */
5158 bool swap_terminal
= true;
5160 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
5161 whether to report it to the user. */
5162 bool ignore_event
= false;
5164 for (thread_info
*thread
: all_non_exited_threads ())
5166 if (swap_terminal
&& thread
->executing
)
5168 if (thread
->inf
!= curr_inf
)
5170 target_terminal::ours ();
5172 switch_to_thread (thread
);
5173 target_terminal::inferior ();
5175 swap_terminal
= false;
5179 && (thread
->executing
5180 || thread
->suspend
.waitstatus_pending_p
))
5182 /* Either there were no unwaited-for children left in the
5183 target at some point, but there are now, or some target
5184 other than the eventing one has unwaited-for children
5185 left. Just ignore. */
5186 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5187 "(ignoring: found resumed)");
5189 ignore_event
= true;
5192 if (ignore_event
&& !swap_terminal
)
5198 switch_to_inferior_no_thread (curr_inf
);
5199 prepare_to_wait (ecs
);
5203 /* Go ahead and report the event. */
5207 /* Given an execution control state that has been freshly filled in by
5208 an event from the inferior, figure out what it means and take
5211 The alternatives are:
5213 1) stop_waiting and return; to really stop and return to the
5216 2) keep_going and return; to wait for the next event (set
5217 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5221 handle_inferior_event (struct execution_control_state
*ecs
)
5223 /* Make sure that all temporary struct value objects that were
5224 created during the handling of the event get deleted at the
5226 scoped_value_mark free_values
;
5228 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5230 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5232 /* We had an event in the inferior, but we are not interested in
5233 handling it at this level. The lower layers have already
5234 done what needs to be done, if anything.
5236 One of the possible circumstances for this is when the
5237 inferior produces output for the console. The inferior has
5238 not stopped, and we are ignoring the event. Another possible
5239 circumstance is any event which the lower level knows will be
5240 reported multiple times without an intervening resume. */
5241 prepare_to_wait (ecs
);
5245 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5247 prepare_to_wait (ecs
);
5251 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5252 && handle_no_resumed (ecs
))
5255 /* Cache the last target/ptid/waitstatus. */
5256 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5258 /* Always clear state belonging to the previous time we stopped. */
5259 stop_stack_dummy
= STOP_NONE
;
5261 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5263 /* No unwaited-for children left. IOW, all resumed children
5265 stop_print_frame
= false;
5270 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5271 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5273 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5274 /* If it's a new thread, add it to the thread database. */
5275 if (ecs
->event_thread
== NULL
)
5276 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5278 /* Disable range stepping. If the next step request could use a
5279 range, this will be end up re-enabled then. */
5280 ecs
->event_thread
->control
.may_range_step
= 0;
5283 /* Dependent on valid ECS->EVENT_THREAD. */
5284 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5286 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5287 reinit_frame_cache ();
5289 breakpoint_retire_moribund ();
5291 /* First, distinguish signals caused by the debugger from signals
5292 that have to do with the program's own actions. Note that
5293 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5294 on the operating system version. Here we detect when a SIGILL or
5295 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5296 something similar for SIGSEGV, since a SIGSEGV will be generated
5297 when we're trying to execute a breakpoint instruction on a
5298 non-executable stack. This happens for call dummy breakpoints
5299 for architectures like SPARC that place call dummies on the
5301 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5302 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5303 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5304 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5306 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5308 if (breakpoint_inserted_here_p (regcache
->aspace (),
5309 regcache_read_pc (regcache
)))
5311 infrun_debug_printf ("Treating signal as SIGTRAP");
5312 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5316 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5318 switch (ecs
->ws
.kind
)
5320 case TARGET_WAITKIND_LOADED
:
5322 context_switch (ecs
);
5323 /* Ignore gracefully during startup of the inferior, as it might
5324 be the shell which has just loaded some objects, otherwise
5325 add the symbols for the newly loaded objects. Also ignore at
5326 the beginning of an attach or remote session; we will query
5327 the full list of libraries once the connection is
5330 stop_kind stop_soon
= get_inferior_stop_soon (ecs
);
5331 if (stop_soon
== NO_STOP_QUIETLY
)
5333 struct regcache
*regcache
;
5335 regcache
= get_thread_regcache (ecs
->event_thread
);
5337 handle_solib_event ();
5339 ecs
->event_thread
->control
.stop_bpstat
5340 = bpstat_stop_status (regcache
->aspace (),
5341 ecs
->event_thread
->suspend
.stop_pc
,
5342 ecs
->event_thread
, &ecs
->ws
);
5344 if (handle_stop_requested (ecs
))
5347 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5349 /* A catchpoint triggered. */
5350 process_event_stop_test (ecs
);
5354 /* If requested, stop when the dynamic linker notifies
5355 gdb of events. This allows the user to get control
5356 and place breakpoints in initializer routines for
5357 dynamically loaded objects (among other things). */
5358 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5359 if (stop_on_solib_events
)
5361 /* Make sure we print "Stopped due to solib-event" in
5363 stop_print_frame
= true;
5370 /* If we are skipping through a shell, or through shared library
5371 loading that we aren't interested in, resume the program. If
5372 we're running the program normally, also resume. */
5373 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5375 /* Loading of shared libraries might have changed breakpoint
5376 addresses. Make sure new breakpoints are inserted. */
5377 if (stop_soon
== NO_STOP_QUIETLY
)
5378 insert_breakpoints ();
5379 resume (GDB_SIGNAL_0
);
5380 prepare_to_wait (ecs
);
5384 /* But stop if we're attaching or setting up a remote
5386 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5387 || stop_soon
== STOP_QUIETLY_REMOTE
)
5389 infrun_debug_printf ("quietly stopped");
5394 internal_error (__FILE__
, __LINE__
,
5395 _("unhandled stop_soon: %d"), (int) stop_soon
);
5398 case TARGET_WAITKIND_SPURIOUS
:
5399 if (handle_stop_requested (ecs
))
5401 context_switch (ecs
);
5402 resume (GDB_SIGNAL_0
);
5403 prepare_to_wait (ecs
);
5406 case TARGET_WAITKIND_THREAD_CREATED
:
5407 if (handle_stop_requested (ecs
))
5409 context_switch (ecs
);
5410 if (!switch_back_to_stepped_thread (ecs
))
5414 case TARGET_WAITKIND_EXITED
:
5415 case TARGET_WAITKIND_SIGNALLED
:
5417 /* Depending on the system, ecs->ptid may point to a thread or
5418 to a process. On some targets, target_mourn_inferior may
5419 need to have access to the just-exited thread. That is the
5420 case of GNU/Linux's "checkpoint" support, for example.
5421 Call the switch_to_xxx routine as appropriate. */
5422 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5424 switch_to_thread (thr
);
5427 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5428 switch_to_inferior_no_thread (inf
);
5431 handle_vfork_child_exec_or_exit (0);
5432 target_terminal::ours (); /* Must do this before mourn anyway. */
5434 /* Clearing any previous state of convenience variables. */
5435 clear_exit_convenience_vars ();
5437 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5439 /* Record the exit code in the convenience variable $_exitcode, so
5440 that the user can inspect this again later. */
5441 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5442 (LONGEST
) ecs
->ws
.value
.integer
);
5444 /* Also record this in the inferior itself. */
5445 current_inferior ()->has_exit_code
= 1;
5446 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5448 /* Support the --return-child-result option. */
5449 return_child_result_value
= ecs
->ws
.value
.integer
;
5451 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5455 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5457 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5459 /* Set the value of the internal variable $_exitsignal,
5460 which holds the signal uncaught by the inferior. */
5461 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5462 gdbarch_gdb_signal_to_target (gdbarch
,
5463 ecs
->ws
.value
.sig
));
5467 /* We don't have access to the target's method used for
5468 converting between signal numbers (GDB's internal
5469 representation <-> target's representation).
5470 Therefore, we cannot do a good job at displaying this
5471 information to the user. It's better to just warn
5472 her about it (if infrun debugging is enabled), and
5474 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5478 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5481 gdb_flush (gdb_stdout
);
5482 target_mourn_inferior (inferior_ptid
);
5483 stop_print_frame
= false;
5487 case TARGET_WAITKIND_FORKED
:
5488 case TARGET_WAITKIND_VFORKED
:
5489 /* Check whether the inferior is displaced stepping. */
5491 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5492 struct gdbarch
*gdbarch
= regcache
->arch ();
5493 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5495 /* If this is a fork (child gets its own address space copy) and some
5496 displaced step buffers were in use at the time of the fork, restore
5497 the displaced step buffer bytes in the child process. */
5498 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5499 gdbarch_displaced_step_restore_all_in_ptid
5500 (gdbarch
, parent_inf
, ecs
->ws
.value
.related_pid
);
5502 /* If displaced stepping is supported, and thread ecs->ptid is
5503 displaced stepping. */
5504 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5506 struct regcache
*child_regcache
;
5507 CORE_ADDR parent_pc
;
5509 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5510 indicating that the displaced stepping of syscall instruction
5511 has been done. Perform cleanup for parent process here. Note
5512 that this operation also cleans up the child process for vfork,
5513 because their pages are shared. */
5514 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5515 /* Start a new step-over in another thread if there's one
5519 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5520 the child's PC is also within the scratchpad. Set the child's PC
5521 to the parent's PC value, which has already been fixed up.
5522 FIXME: we use the parent's aspace here, although we're touching
5523 the child, because the child hasn't been added to the inferior
5524 list yet at this point. */
5527 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5528 ecs
->ws
.value
.related_pid
,
5530 parent_inf
->aspace
);
5531 /* Read PC value of parent process. */
5532 parent_pc
= regcache_read_pc (regcache
);
5534 displaced_debug_printf ("write child pc from %s to %s",
5536 regcache_read_pc (child_regcache
)),
5537 paddress (gdbarch
, parent_pc
));
5539 regcache_write_pc (child_regcache
, parent_pc
);
5543 context_switch (ecs
);
5545 /* Immediately detach breakpoints from the child before there's
5546 any chance of letting the user delete breakpoints from the
5547 breakpoint lists. If we don't do this early, it's easy to
5548 leave left over traps in the child, vis: "break foo; catch
5549 fork; c; <fork>; del; c; <child calls foo>". We only follow
5550 the fork on the last `continue', and by that time the
5551 breakpoint at "foo" is long gone from the breakpoint table.
5552 If we vforked, then we don't need to unpatch here, since both
5553 parent and child are sharing the same memory pages; we'll
5554 need to unpatch at follow/detach time instead to be certain
5555 that new breakpoints added between catchpoint hit time and
5556 vfork follow are detached. */
5557 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5559 /* This won't actually modify the breakpoint list, but will
5560 physically remove the breakpoints from the child. */
5561 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5564 delete_just_stopped_threads_single_step_breakpoints ();
5566 /* In case the event is caught by a catchpoint, remember that
5567 the event is to be followed at the next resume of the thread,
5568 and not immediately. */
5569 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5571 ecs
->event_thread
->suspend
.stop_pc
5572 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5574 ecs
->event_thread
->control
.stop_bpstat
5575 = bpstat_stop_status (get_current_regcache ()->aspace (),
5576 ecs
->event_thread
->suspend
.stop_pc
,
5577 ecs
->event_thread
, &ecs
->ws
);
5579 if (handle_stop_requested (ecs
))
5582 /* If no catchpoint triggered for this, then keep going. Note
5583 that we're interested in knowing the bpstat actually causes a
5584 stop, not just if it may explain the signal. Software
5585 watchpoints, for example, always appear in the bpstat. */
5586 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5589 = (follow_fork_mode_string
== follow_fork_mode_child
);
5591 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5593 process_stratum_target
*targ
5594 = ecs
->event_thread
->inf
->process_target ();
5596 bool should_resume
= follow_fork ();
5598 /* Note that one of these may be an invalid pointer,
5599 depending on detach_fork. */
5600 thread_info
*parent
= ecs
->event_thread
;
5602 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5604 /* At this point, the parent is marked running, and the
5605 child is marked stopped. */
5607 /* If not resuming the parent, mark it stopped. */
5608 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5609 parent
->set_running (false);
5611 /* If resuming the child, mark it running. */
5612 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5613 child
->set_running (true);
5615 /* In non-stop mode, also resume the other branch. */
5616 if (!detach_fork
&& (non_stop
5617 || (sched_multi
&& target_is_non_stop_p ())))
5620 switch_to_thread (parent
);
5622 switch_to_thread (child
);
5624 ecs
->event_thread
= inferior_thread ();
5625 ecs
->ptid
= inferior_ptid
;
5630 switch_to_thread (child
);
5632 switch_to_thread (parent
);
5634 ecs
->event_thread
= inferior_thread ();
5635 ecs
->ptid
= inferior_ptid
;
5643 process_event_stop_test (ecs
);
5646 case TARGET_WAITKIND_VFORK_DONE
:
5647 /* Done with the shared memory region. Re-insert breakpoints in
5648 the parent, and keep going. */
5650 context_switch (ecs
);
5652 current_inferior ()->waiting_for_vfork_done
= 0;
5653 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5655 if (handle_stop_requested (ecs
))
5658 /* This also takes care of reinserting breakpoints in the
5659 previously locked inferior. */
5663 case TARGET_WAITKIND_EXECD
:
5665 /* Note we can't read registers yet (the stop_pc), because we
5666 don't yet know the inferior's post-exec architecture.
5667 'stop_pc' is explicitly read below instead. */
5668 switch_to_thread_no_regs (ecs
->event_thread
);
5670 /* Do whatever is necessary to the parent branch of the vfork. */
5671 handle_vfork_child_exec_or_exit (1);
5673 /* This causes the eventpoints and symbol table to be reset.
5674 Must do this now, before trying to determine whether to
5676 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5678 /* In follow_exec we may have deleted the original thread and
5679 created a new one. Make sure that the event thread is the
5680 execd thread for that case (this is a nop otherwise). */
5681 ecs
->event_thread
= inferior_thread ();
5683 ecs
->event_thread
->suspend
.stop_pc
5684 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5686 ecs
->event_thread
->control
.stop_bpstat
5687 = bpstat_stop_status (get_current_regcache ()->aspace (),
5688 ecs
->event_thread
->suspend
.stop_pc
,
5689 ecs
->event_thread
, &ecs
->ws
);
5691 /* Note that this may be referenced from inside
5692 bpstat_stop_status above, through inferior_has_execd. */
5693 xfree (ecs
->ws
.value
.execd_pathname
);
5694 ecs
->ws
.value
.execd_pathname
= NULL
;
5696 if (handle_stop_requested (ecs
))
5699 /* If no catchpoint triggered for this, then keep going. */
5700 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5702 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5706 process_event_stop_test (ecs
);
5709 /* Be careful not to try to gather much state about a thread
5710 that's in a syscall. It's frequently a losing proposition. */
5711 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5712 /* Getting the current syscall number. */
5713 if (handle_syscall_event (ecs
) == 0)
5714 process_event_stop_test (ecs
);
5717 /* Before examining the threads further, step this thread to
5718 get it entirely out of the syscall. (We get notice of the
5719 event when the thread is just on the verge of exiting a
5720 syscall. Stepping one instruction seems to get it back
5722 case TARGET_WAITKIND_SYSCALL_RETURN
:
5723 if (handle_syscall_event (ecs
) == 0)
5724 process_event_stop_test (ecs
);
5727 case TARGET_WAITKIND_STOPPED
:
5728 handle_signal_stop (ecs
);
5731 case TARGET_WAITKIND_NO_HISTORY
:
5732 /* Reverse execution: target ran out of history info. */
5734 /* Switch to the stopped thread. */
5735 context_switch (ecs
);
5736 infrun_debug_printf ("stopped");
5738 delete_just_stopped_threads_single_step_breakpoints ();
5739 ecs
->event_thread
->suspend
.stop_pc
5740 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5742 if (handle_stop_requested (ecs
))
5745 gdb::observers::no_history
.notify ();
5751 /* Restart threads back to what they were trying to do back when we
5752 paused them for an in-line step-over. The EVENT_THREAD thread is
5756 restart_threads (struct thread_info
*event_thread
)
5758 /* In case the instruction just stepped spawned a new thread. */
5759 update_thread_list ();
5761 for (thread_info
*tp
: all_non_exited_threads ())
5763 if (tp
->inf
->detaching
)
5765 infrun_debug_printf ("restart threads: [%s] inferior detaching",
5766 target_pid_to_str (tp
->ptid
).c_str ());
5770 switch_to_thread_no_regs (tp
);
5772 if (tp
== event_thread
)
5774 infrun_debug_printf ("restart threads: [%s] is event thread",
5775 target_pid_to_str (tp
->ptid
).c_str ());
5779 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5781 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5782 target_pid_to_str (tp
->ptid
).c_str ());
5788 infrun_debug_printf ("restart threads: [%s] resumed",
5789 target_pid_to_str (tp
->ptid
).c_str ());
5790 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5794 if (thread_is_in_step_over_chain (tp
))
5796 infrun_debug_printf ("restart threads: [%s] needs step-over",
5797 target_pid_to_str (tp
->ptid
).c_str ());
5798 gdb_assert (!tp
->resumed
);
5803 if (tp
->suspend
.waitstatus_pending_p
)
5805 infrun_debug_printf ("restart threads: [%s] has pending status",
5806 target_pid_to_str (tp
->ptid
).c_str ());
5811 gdb_assert (!tp
->stop_requested
);
5813 /* If some thread needs to start a step-over at this point, it
5814 should still be in the step-over queue, and thus skipped
5816 if (thread_still_needs_step_over (tp
))
5818 internal_error (__FILE__
, __LINE__
,
5819 "thread [%s] needs a step-over, but not in "
5820 "step-over queue\n",
5821 target_pid_to_str (tp
->ptid
).c_str ());
5824 if (currently_stepping (tp
))
5826 infrun_debug_printf ("restart threads: [%s] was stepping",
5827 target_pid_to_str (tp
->ptid
).c_str ());
5828 keep_going_stepped_thread (tp
);
5832 struct execution_control_state ecss
;
5833 struct execution_control_state
*ecs
= &ecss
;
5835 infrun_debug_printf ("restart threads: [%s] continuing",
5836 target_pid_to_str (tp
->ptid
).c_str ());
5837 reset_ecs (ecs
, tp
);
5838 switch_to_thread (tp
);
5839 keep_going_pass_signal (ecs
);
5844 /* Callback for iterate_over_threads. Find a resumed thread that has
5845 a pending waitstatus. */
5848 resumed_thread_with_pending_status (struct thread_info
*tp
,
5852 && tp
->suspend
.waitstatus_pending_p
);
5855 /* Called when we get an event that may finish an in-line or
5856 out-of-line (displaced stepping) step-over started previously.
5857 Return true if the event is processed and we should go back to the
5858 event loop; false if the caller should continue processing the
5862 finish_step_over (struct execution_control_state
*ecs
)
5864 displaced_step_finish (ecs
->event_thread
,
5865 ecs
->event_thread
->suspend
.stop_signal
);
5867 bool had_step_over_info
= step_over_info_valid_p ();
5869 if (had_step_over_info
)
5871 /* If we're stepping over a breakpoint with all threads locked,
5872 then only the thread that was stepped should be reporting
5874 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5876 clear_step_over_info ();
5879 if (!target_is_non_stop_p ())
5882 /* Start a new step-over in another thread if there's one that
5886 /* If we were stepping over a breakpoint before, and haven't started
5887 a new in-line step-over sequence, then restart all other threads
5888 (except the event thread). We can't do this in all-stop, as then
5889 e.g., we wouldn't be able to issue any other remote packet until
5890 these other threads stop. */
5891 if (had_step_over_info
&& !step_over_info_valid_p ())
5893 struct thread_info
*pending
;
5895 /* If we only have threads with pending statuses, the restart
5896 below won't restart any thread and so nothing re-inserts the
5897 breakpoint we just stepped over. But we need it inserted
5898 when we later process the pending events, otherwise if
5899 another thread has a pending event for this breakpoint too,
5900 we'd discard its event (because the breakpoint that
5901 originally caused the event was no longer inserted). */
5902 context_switch (ecs
);
5903 insert_breakpoints ();
5905 restart_threads (ecs
->event_thread
);
5907 /* If we have events pending, go through handle_inferior_event
5908 again, picking up a pending event at random. This avoids
5909 thread starvation. */
5911 /* But not if we just stepped over a watchpoint in order to let
5912 the instruction execute so we can evaluate its expression.
5913 The set of watchpoints that triggered is recorded in the
5914 breakpoint objects themselves (see bp->watchpoint_triggered).
5915 If we processed another event first, that other event could
5916 clobber this info. */
5917 if (ecs
->event_thread
->stepping_over_watchpoint
)
5920 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5922 if (pending
!= NULL
)
5924 struct thread_info
*tp
= ecs
->event_thread
;
5925 struct regcache
*regcache
;
5927 infrun_debug_printf ("found resumed threads with "
5928 "pending events, saving status");
5930 gdb_assert (pending
!= tp
);
5932 /* Record the event thread's event for later. */
5933 save_waitstatus (tp
, &ecs
->ws
);
5934 /* This was cleared early, by handle_inferior_event. Set it
5935 so this pending event is considered by
5939 gdb_assert (!tp
->executing
);
5941 regcache
= get_thread_regcache (tp
);
5942 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5944 infrun_debug_printf ("saved stop_pc=%s for %s "
5945 "(currently_stepping=%d)",
5946 paddress (target_gdbarch (),
5947 tp
->suspend
.stop_pc
),
5948 target_pid_to_str (tp
->ptid
).c_str (),
5949 currently_stepping (tp
));
5951 /* This in-line step-over finished; clear this so we won't
5952 start a new one. This is what handle_signal_stop would
5953 do, if we returned false. */
5954 tp
->stepping_over_breakpoint
= 0;
5956 /* Wake up the event loop again. */
5957 mark_async_event_handler (infrun_async_inferior_event_token
);
5959 prepare_to_wait (ecs
);
5967 /* Come here when the program has stopped with a signal. */
5970 handle_signal_stop (struct execution_control_state
*ecs
)
5972 struct frame_info
*frame
;
5973 struct gdbarch
*gdbarch
;
5974 int stopped_by_watchpoint
;
5975 enum stop_kind stop_soon
;
5978 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5980 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5982 /* Do we need to clean up the state of a thread that has
5983 completed a displaced single-step? (Doing so usually affects
5984 the PC, so do it here, before we set stop_pc.) */
5985 if (finish_step_over (ecs
))
5988 /* If we either finished a single-step or hit a breakpoint, but
5989 the user wanted this thread to be stopped, pretend we got a
5990 SIG0 (generic unsignaled stop). */
5991 if (ecs
->event_thread
->stop_requested
5992 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5993 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5995 ecs
->event_thread
->suspend
.stop_pc
5996 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5998 context_switch (ecs
);
6000 if (deprecated_context_hook
)
6001 deprecated_context_hook (ecs
->event_thread
->global_num
);
6005 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
6006 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
6008 infrun_debug_printf ("stop_pc=%s",
6009 paddress (reg_gdbarch
,
6010 ecs
->event_thread
->suspend
.stop_pc
));
6011 if (target_stopped_by_watchpoint ())
6015 infrun_debug_printf ("stopped by watchpoint");
6017 if (target_stopped_data_address (current_inferior ()->top_target (),
6019 infrun_debug_printf ("stopped data address=%s",
6020 paddress (reg_gdbarch
, addr
));
6022 infrun_debug_printf ("(no data address available)");
6026 /* This is originated from start_remote(), start_inferior() and
6027 shared libraries hook functions. */
6028 stop_soon
= get_inferior_stop_soon (ecs
);
6029 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
6031 infrun_debug_printf ("quietly stopped");
6032 stop_print_frame
= true;
6037 /* This originates from attach_command(). We need to overwrite
6038 the stop_signal here, because some kernels don't ignore a
6039 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
6040 See more comments in inferior.h. On the other hand, if we
6041 get a non-SIGSTOP, report it to the user - assume the backend
6042 will handle the SIGSTOP if it should show up later.
6044 Also consider that the attach is complete when we see a
6045 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
6046 target extended-remote report it instead of a SIGSTOP
6047 (e.g. gdbserver). We already rely on SIGTRAP being our
6048 signal, so this is no exception.
6050 Also consider that the attach is complete when we see a
6051 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
6052 the target to stop all threads of the inferior, in case the
6053 low level attach operation doesn't stop them implicitly. If
6054 they weren't stopped implicitly, then the stub will report a
6055 GDB_SIGNAL_0, meaning: stopped for no particular reason
6056 other than GDB's request. */
6057 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
6058 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
6059 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6060 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
6062 stop_print_frame
= true;
6064 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6068 /* At this point, get hold of the now-current thread's frame. */
6069 frame
= get_current_frame ();
6070 gdbarch
= get_frame_arch (frame
);
6072 /* Pull the single step breakpoints out of the target. */
6073 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
6075 struct regcache
*regcache
;
6078 regcache
= get_thread_regcache (ecs
->event_thread
);
6079 const address_space
*aspace
= regcache
->aspace ();
6081 pc
= regcache_read_pc (regcache
);
6083 /* However, before doing so, if this single-step breakpoint was
6084 actually for another thread, set this thread up for moving
6086 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
6089 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
6091 infrun_debug_printf ("[%s] hit another thread's single-step "
6093 target_pid_to_str (ecs
->ptid
).c_str ());
6094 ecs
->hit_singlestep_breakpoint
= 1;
6099 infrun_debug_printf ("[%s] hit its single-step breakpoint",
6100 target_pid_to_str (ecs
->ptid
).c_str ());
6103 delete_just_stopped_threads_single_step_breakpoints ();
6105 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6106 && ecs
->event_thread
->control
.trap_expected
6107 && ecs
->event_thread
->stepping_over_watchpoint
)
6108 stopped_by_watchpoint
= 0;
6110 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6112 /* If necessary, step over this watchpoint. We'll be back to display
6114 if (stopped_by_watchpoint
6115 && (target_have_steppable_watchpoint ()
6116 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6118 /* At this point, we are stopped at an instruction which has
6119 attempted to write to a piece of memory under control of
6120 a watchpoint. The instruction hasn't actually executed
6121 yet. If we were to evaluate the watchpoint expression
6122 now, we would get the old value, and therefore no change
6123 would seem to have occurred.
6125 In order to make watchpoints work `right', we really need
6126 to complete the memory write, and then evaluate the
6127 watchpoint expression. We do this by single-stepping the
6130 It may not be necessary to disable the watchpoint to step over
6131 it. For example, the PA can (with some kernel cooperation)
6132 single step over a watchpoint without disabling the watchpoint.
6134 It is far more common to need to disable a watchpoint to step
6135 the inferior over it. If we have non-steppable watchpoints,
6136 we must disable the current watchpoint; it's simplest to
6137 disable all watchpoints.
6139 Any breakpoint at PC must also be stepped over -- if there's
6140 one, it will have already triggered before the watchpoint
6141 triggered, and we either already reported it to the user, or
6142 it didn't cause a stop and we called keep_going. In either
6143 case, if there was a breakpoint at PC, we must be trying to
6145 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6150 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6151 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6152 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6153 ecs
->event_thread
->control
.stop_step
= 0;
6154 stop_print_frame
= true;
6155 stopped_by_random_signal
= 0;
6156 bpstat stop_chain
= NULL
;
6158 /* Hide inlined functions starting here, unless we just performed stepi or
6159 nexti. After stepi and nexti, always show the innermost frame (not any
6160 inline function call sites). */
6161 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6163 const address_space
*aspace
6164 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6166 /* skip_inline_frames is expensive, so we avoid it if we can
6167 determine that the address is one where functions cannot have
6168 been inlined. This improves performance with inferiors that
6169 load a lot of shared libraries, because the solib event
6170 breakpoint is defined as the address of a function (i.e. not
6171 inline). Note that we have to check the previous PC as well
6172 as the current one to catch cases when we have just
6173 single-stepped off a breakpoint prior to reinstating it.
6174 Note that we're assuming that the code we single-step to is
6175 not inline, but that's not definitive: there's nothing
6176 preventing the event breakpoint function from containing
6177 inlined code, and the single-step ending up there. If the
6178 user had set a breakpoint on that inlined code, the missing
6179 skip_inline_frames call would break things. Fortunately
6180 that's an extremely unlikely scenario. */
6181 if (!pc_at_non_inline_function (aspace
,
6182 ecs
->event_thread
->suspend
.stop_pc
,
6184 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6185 && ecs
->event_thread
->control
.trap_expected
6186 && pc_at_non_inline_function (aspace
,
6187 ecs
->event_thread
->prev_pc
,
6190 stop_chain
= build_bpstat_chain (aspace
,
6191 ecs
->event_thread
->suspend
.stop_pc
,
6193 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6195 /* Re-fetch current thread's frame in case that invalidated
6197 frame
= get_current_frame ();
6198 gdbarch
= get_frame_arch (frame
);
6202 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6203 && ecs
->event_thread
->control
.trap_expected
6204 && gdbarch_single_step_through_delay_p (gdbarch
)
6205 && currently_stepping (ecs
->event_thread
))
6207 /* We're trying to step off a breakpoint. Turns out that we're
6208 also on an instruction that needs to be stepped multiple
6209 times before it's been fully executing. E.g., architectures
6210 with a delay slot. It needs to be stepped twice, once for
6211 the instruction and once for the delay slot. */
6212 int step_through_delay
6213 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6215 if (step_through_delay
)
6216 infrun_debug_printf ("step through delay");
6218 if (ecs
->event_thread
->control
.step_range_end
== 0
6219 && step_through_delay
)
6221 /* The user issued a continue when stopped at a breakpoint.
6222 Set up for another trap and get out of here. */
6223 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6227 else if (step_through_delay
)
6229 /* The user issued a step when stopped at a breakpoint.
6230 Maybe we should stop, maybe we should not - the delay
6231 slot *might* correspond to a line of source. In any
6232 case, don't decide that here, just set
6233 ecs->stepping_over_breakpoint, making sure we
6234 single-step again before breakpoints are re-inserted. */
6235 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6239 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6240 handles this event. */
6241 ecs
->event_thread
->control
.stop_bpstat
6242 = bpstat_stop_status (get_current_regcache ()->aspace (),
6243 ecs
->event_thread
->suspend
.stop_pc
,
6244 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6246 /* Following in case break condition called a
6248 stop_print_frame
= true;
6250 /* This is where we handle "moribund" watchpoints. Unlike
6251 software breakpoints traps, hardware watchpoint traps are
6252 always distinguishable from random traps. If no high-level
6253 watchpoint is associated with the reported stop data address
6254 anymore, then the bpstat does not explain the signal ---
6255 simply make sure to ignore it if `stopped_by_watchpoint' is
6258 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6259 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6261 && stopped_by_watchpoint
)
6263 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6267 /* NOTE: cagney/2003-03-29: These checks for a random signal
6268 at one stage in the past included checks for an inferior
6269 function call's call dummy's return breakpoint. The original
6270 comment, that went with the test, read:
6272 ``End of a stack dummy. Some systems (e.g. Sony news) give
6273 another signal besides SIGTRAP, so check here as well as
6276 If someone ever tries to get call dummys on a
6277 non-executable stack to work (where the target would stop
6278 with something like a SIGSEGV), then those tests might need
6279 to be re-instated. Given, however, that the tests were only
6280 enabled when momentary breakpoints were not being used, I
6281 suspect that it won't be the case.
6283 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6284 be necessary for call dummies on a non-executable stack on
6287 /* See if the breakpoints module can explain the signal. */
6289 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6290 ecs
->event_thread
->suspend
.stop_signal
);
6292 /* Maybe this was a trap for a software breakpoint that has since
6294 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6296 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6297 ecs
->event_thread
->suspend
.stop_pc
))
6299 struct regcache
*regcache
;
6302 /* Re-adjust PC to what the program would see if GDB was not
6304 regcache
= get_thread_regcache (ecs
->event_thread
);
6305 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6308 gdb::optional
<scoped_restore_tmpl
<int>>
6309 restore_operation_disable
;
6311 if (record_full_is_used ())
6312 restore_operation_disable
.emplace
6313 (record_full_gdb_operation_disable_set ());
6315 regcache_write_pc (regcache
,
6316 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6321 /* A delayed software breakpoint event. Ignore the trap. */
6322 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6327 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6328 has since been removed. */
6329 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6331 /* A delayed hardware breakpoint event. Ignore the trap. */
6332 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6337 /* If not, perhaps stepping/nexting can. */
6339 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6340 && currently_stepping (ecs
->event_thread
));
6342 /* Perhaps the thread hit a single-step breakpoint of _another_
6343 thread. Single-step breakpoints are transparent to the
6344 breakpoints module. */
6346 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6348 /* No? Perhaps we got a moribund watchpoint. */
6350 random_signal
= !stopped_by_watchpoint
;
6352 /* Always stop if the user explicitly requested this thread to
6354 if (ecs
->event_thread
->stop_requested
)
6357 infrun_debug_printf ("user-requested stop");
6360 /* For the program's own signals, act according to
6361 the signal handling tables. */
6365 /* Signal not for debugging purposes. */
6366 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6368 infrun_debug_printf ("random signal (%s)",
6369 gdb_signal_to_symbol_string (stop_signal
));
6371 stopped_by_random_signal
= 1;
6373 /* Always stop on signals if we're either just gaining control
6374 of the program, or the user explicitly requested this thread
6375 to remain stopped. */
6376 if (stop_soon
!= NO_STOP_QUIETLY
6377 || ecs
->event_thread
->stop_requested
6378 || signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
))
6384 /* Notify observers the signal has "handle print" set. Note we
6385 returned early above if stopping; normal_stop handles the
6386 printing in that case. */
6387 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6389 /* The signal table tells us to print about this signal. */
6390 target_terminal::ours_for_output ();
6391 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6392 target_terminal::inferior ();
6395 /* Clear the signal if it should not be passed. */
6396 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6397 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6399 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6400 && ecs
->event_thread
->control
.trap_expected
6401 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6403 /* We were just starting a new sequence, attempting to
6404 single-step off of a breakpoint and expecting a SIGTRAP.
6405 Instead this signal arrives. This signal will take us out
6406 of the stepping range so GDB needs to remember to, when
6407 the signal handler returns, resume stepping off that
6409 /* To simplify things, "continue" is forced to use the same
6410 code paths as single-step - set a breakpoint at the
6411 signal return address and then, once hit, step off that
6413 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6415 insert_hp_step_resume_breakpoint_at_frame (frame
);
6416 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6417 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6418 ecs
->event_thread
->control
.trap_expected
= 0;
6420 /* If we were nexting/stepping some other thread, switch to
6421 it, so that we don't continue it, losing control. */
6422 if (!switch_back_to_stepped_thread (ecs
))
6427 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6428 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6430 || ecs
->event_thread
->control
.step_range_end
== 1)
6431 && frame_id_eq (get_stack_frame_id (frame
),
6432 ecs
->event_thread
->control
.step_stack_frame_id
)
6433 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6435 /* The inferior is about to take a signal that will take it
6436 out of the single step range. Set a breakpoint at the
6437 current PC (which is presumably where the signal handler
6438 will eventually return) and then allow the inferior to
6441 Note that this is only needed for a signal delivered
6442 while in the single-step range. Nested signals aren't a
6443 problem as they eventually all return. */
6444 infrun_debug_printf ("signal may take us out of single-step range");
6446 clear_step_over_info ();
6447 insert_hp_step_resume_breakpoint_at_frame (frame
);
6448 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6449 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6450 ecs
->event_thread
->control
.trap_expected
= 0;
6455 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6456 when either there's a nested signal, or when there's a
6457 pending signal enabled just as the signal handler returns
6458 (leaving the inferior at the step-resume-breakpoint without
6459 actually executing it). Either way continue until the
6460 breakpoint is really hit. */
6462 if (!switch_back_to_stepped_thread (ecs
))
6464 infrun_debug_printf ("random signal, keep going");
6471 process_event_stop_test (ecs
);
6474 /* Come here when we've got some debug event / signal we can explain
6475 (IOW, not a random signal), and test whether it should cause a
6476 stop, or whether we should resume the inferior (transparently).
6477 E.g., could be a breakpoint whose condition evaluates false; we
6478 could be still stepping within the line; etc. */
6481 process_event_stop_test (struct execution_control_state
*ecs
)
6483 struct symtab_and_line stop_pc_sal
;
6484 struct frame_info
*frame
;
6485 struct gdbarch
*gdbarch
;
6486 CORE_ADDR jmp_buf_pc
;
6487 struct bpstat_what what
;
6489 /* Handle cases caused by hitting a breakpoint. */
6491 frame
= get_current_frame ();
6492 gdbarch
= get_frame_arch (frame
);
6494 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6496 if (what
.call_dummy
)
6498 stop_stack_dummy
= what
.call_dummy
;
6501 /* A few breakpoint types have callbacks associated (e.g.,
6502 bp_jit_event). Run them now. */
6503 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6505 /* If we hit an internal event that triggers symbol changes, the
6506 current frame will be invalidated within bpstat_what (e.g., if we
6507 hit an internal solib event). Re-fetch it. */
6508 frame
= get_current_frame ();
6509 gdbarch
= get_frame_arch (frame
);
6511 switch (what
.main_action
)
6513 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6514 /* If we hit the breakpoint at longjmp while stepping, we
6515 install a momentary breakpoint at the target of the
6518 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6520 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6522 if (what
.is_longjmp
)
6524 struct value
*arg_value
;
6526 /* If we set the longjmp breakpoint via a SystemTap probe,
6527 then use it to extract the arguments. The destination PC
6528 is the third argument to the probe. */
6529 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6532 jmp_buf_pc
= value_as_address (arg_value
);
6533 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6535 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6536 || !gdbarch_get_longjmp_target (gdbarch
,
6537 frame
, &jmp_buf_pc
))
6539 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6540 "(!gdbarch_get_longjmp_target)");
6545 /* Insert a breakpoint at resume address. */
6546 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6549 check_exception_resume (ecs
, frame
);
6553 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6555 struct frame_info
*init_frame
;
6557 /* There are several cases to consider.
6559 1. The initiating frame no longer exists. In this case we
6560 must stop, because the exception or longjmp has gone too
6563 2. The initiating frame exists, and is the same as the
6564 current frame. We stop, because the exception or longjmp
6567 3. The initiating frame exists and is different from the
6568 current frame. This means the exception or longjmp has
6569 been caught beneath the initiating frame, so keep going.
6571 4. longjmp breakpoint has been placed just to protect
6572 against stale dummy frames and user is not interested in
6573 stopping around longjmps. */
6575 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6577 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6579 delete_exception_resume_breakpoint (ecs
->event_thread
);
6581 if (what
.is_longjmp
)
6583 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6585 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6593 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6597 struct frame_id current_id
6598 = get_frame_id (get_current_frame ());
6599 if (frame_id_eq (current_id
,
6600 ecs
->event_thread
->initiating_frame
))
6602 /* Case 2. Fall through. */
6612 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6614 delete_step_resume_breakpoint (ecs
->event_thread
);
6616 end_stepping_range (ecs
);
6620 case BPSTAT_WHAT_SINGLE
:
6621 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6622 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6623 /* Still need to check other stuff, at least the case where we
6624 are stepping and step out of the right range. */
6627 case BPSTAT_WHAT_STEP_RESUME
:
6628 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6630 delete_step_resume_breakpoint (ecs
->event_thread
);
6631 if (ecs
->event_thread
->control
.proceed_to_finish
6632 && execution_direction
== EXEC_REVERSE
)
6634 struct thread_info
*tp
= ecs
->event_thread
;
6636 /* We are finishing a function in reverse, and just hit the
6637 step-resume breakpoint at the start address of the
6638 function, and we're almost there -- just need to back up
6639 by one more single-step, which should take us back to the
6641 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6645 fill_in_stop_func (gdbarch
, ecs
);
6646 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6647 && execution_direction
== EXEC_REVERSE
)
6649 /* We are stepping over a function call in reverse, and just
6650 hit the step-resume breakpoint at the start address of
6651 the function. Go back to single-stepping, which should
6652 take us back to the function call. */
6653 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6659 case BPSTAT_WHAT_STOP_NOISY
:
6660 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6661 stop_print_frame
= true;
6663 /* Assume the thread stopped for a breakpoint. We'll still check
6664 whether a/the breakpoint is there when the thread is next
6666 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6671 case BPSTAT_WHAT_STOP_SILENT
:
6672 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6673 stop_print_frame
= false;
6675 /* Assume the thread stopped for a breakpoint. We'll still check
6676 whether a/the breakpoint is there when the thread is next
6678 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6682 case BPSTAT_WHAT_HP_STEP_RESUME
:
6683 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6685 delete_step_resume_breakpoint (ecs
->event_thread
);
6686 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6688 /* Back when the step-resume breakpoint was inserted, we
6689 were trying to single-step off a breakpoint. Go back to
6691 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6692 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6698 case BPSTAT_WHAT_KEEP_CHECKING
:
6702 /* If we stepped a permanent breakpoint and we had a high priority
6703 step-resume breakpoint for the address we stepped, but we didn't
6704 hit it, then we must have stepped into the signal handler. The
6705 step-resume was only necessary to catch the case of _not_
6706 stepping into the handler, so delete it, and fall through to
6707 checking whether the step finished. */
6708 if (ecs
->event_thread
->stepped_breakpoint
)
6710 struct breakpoint
*sr_bp
6711 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6714 && sr_bp
->loc
->permanent
6715 && sr_bp
->type
== bp_hp_step_resume
6716 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6718 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6719 delete_step_resume_breakpoint (ecs
->event_thread
);
6720 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6724 /* We come here if we hit a breakpoint but should not stop for it.
6725 Possibly we also were stepping and should stop for that. So fall
6726 through and test for stepping. But, if not stepping, do not
6729 /* In all-stop mode, if we're currently stepping but have stopped in
6730 some other thread, we need to switch back to the stepped thread. */
6731 if (switch_back_to_stepped_thread (ecs
))
6734 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6736 infrun_debug_printf ("step-resume breakpoint is inserted");
6738 /* Having a step-resume breakpoint overrides anything
6739 else having to do with stepping commands until
6740 that breakpoint is reached. */
6745 if (ecs
->event_thread
->control
.step_range_end
== 0)
6747 infrun_debug_printf ("no stepping, continue");
6748 /* Likewise if we aren't even stepping. */
6753 /* Re-fetch current thread's frame in case the code above caused
6754 the frame cache to be re-initialized, making our FRAME variable
6755 a dangling pointer. */
6756 frame
= get_current_frame ();
6757 gdbarch
= get_frame_arch (frame
);
6758 fill_in_stop_func (gdbarch
, ecs
);
6760 /* If stepping through a line, keep going if still within it.
6762 Note that step_range_end is the address of the first instruction
6763 beyond the step range, and NOT the address of the last instruction
6766 Note also that during reverse execution, we may be stepping
6767 through a function epilogue and therefore must detect when
6768 the current-frame changes in the middle of a line. */
6770 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6772 && (execution_direction
!= EXEC_REVERSE
6773 || frame_id_eq (get_frame_id (frame
),
6774 ecs
->event_thread
->control
.step_frame_id
)))
6777 ("stepping inside range [%s-%s]",
6778 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6779 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6781 /* Tentatively re-enable range stepping; `resume' disables it if
6782 necessary (e.g., if we're stepping over a breakpoint or we
6783 have software watchpoints). */
6784 ecs
->event_thread
->control
.may_range_step
= 1;
6786 /* When stepping backward, stop at beginning of line range
6787 (unless it's the function entry point, in which case
6788 keep going back to the call point). */
6789 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6790 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6791 && stop_pc
!= ecs
->stop_func_start
6792 && execution_direction
== EXEC_REVERSE
)
6793 end_stepping_range (ecs
);
6800 /* We stepped out of the stepping range. */
6802 /* If we are stepping at the source level and entered the runtime
6803 loader dynamic symbol resolution code...
6805 EXEC_FORWARD: we keep on single stepping until we exit the run
6806 time loader code and reach the callee's address.
6808 EXEC_REVERSE: we've already executed the callee (backward), and
6809 the runtime loader code is handled just like any other
6810 undebuggable function call. Now we need only keep stepping
6811 backward through the trampoline code, and that's handled further
6812 down, so there is nothing for us to do here. */
6814 if (execution_direction
!= EXEC_REVERSE
6815 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6816 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6818 CORE_ADDR pc_after_resolver
=
6819 gdbarch_skip_solib_resolver (gdbarch
,
6820 ecs
->event_thread
->suspend
.stop_pc
);
6822 infrun_debug_printf ("stepped into dynsym resolve code");
6824 if (pc_after_resolver
)
6826 /* Set up a step-resume breakpoint at the address
6827 indicated by SKIP_SOLIB_RESOLVER. */
6828 symtab_and_line sr_sal
;
6829 sr_sal
.pc
= pc_after_resolver
;
6830 sr_sal
.pspace
= get_frame_program_space (frame
);
6832 insert_step_resume_breakpoint_at_sal (gdbarch
,
6833 sr_sal
, null_frame_id
);
6840 /* Step through an indirect branch thunk. */
6841 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6842 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6843 ecs
->event_thread
->suspend
.stop_pc
))
6845 infrun_debug_printf ("stepped into indirect branch thunk");
6850 if (ecs
->event_thread
->control
.step_range_end
!= 1
6851 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6852 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6853 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6855 infrun_debug_printf ("stepped into signal trampoline");
6856 /* The inferior, while doing a "step" or "next", has ended up in
6857 a signal trampoline (either by a signal being delivered or by
6858 the signal handler returning). Just single-step until the
6859 inferior leaves the trampoline (either by calling the handler
6865 /* If we're in the return path from a shared library trampoline,
6866 we want to proceed through the trampoline when stepping. */
6867 /* macro/2012-04-25: This needs to come before the subroutine
6868 call check below as on some targets return trampolines look
6869 like subroutine calls (MIPS16 return thunks). */
6870 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6871 ecs
->event_thread
->suspend
.stop_pc
,
6872 ecs
->stop_func_name
)
6873 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6875 /* Determine where this trampoline returns. */
6876 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6877 CORE_ADDR real_stop_pc
6878 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6880 infrun_debug_printf ("stepped into solib return tramp");
6882 /* Only proceed through if we know where it's going. */
6885 /* And put the step-breakpoint there and go until there. */
6886 symtab_and_line sr_sal
;
6887 sr_sal
.pc
= real_stop_pc
;
6888 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6889 sr_sal
.pspace
= get_frame_program_space (frame
);
6891 /* Do not specify what the fp should be when we stop since
6892 on some machines the prologue is where the new fp value
6894 insert_step_resume_breakpoint_at_sal (gdbarch
,
6895 sr_sal
, null_frame_id
);
6897 /* Restart without fiddling with the step ranges or
6904 /* Check for subroutine calls. The check for the current frame
6905 equalling the step ID is not necessary - the check of the
6906 previous frame's ID is sufficient - but it is a common case and
6907 cheaper than checking the previous frame's ID.
6909 NOTE: frame_id_eq will never report two invalid frame IDs as
6910 being equal, so to get into this block, both the current and
6911 previous frame must have valid frame IDs. */
6912 /* The outer_frame_id check is a heuristic to detect stepping
6913 through startup code. If we step over an instruction which
6914 sets the stack pointer from an invalid value to a valid value,
6915 we may detect that as a subroutine call from the mythical
6916 "outermost" function. This could be fixed by marking
6917 outermost frames as !stack_p,code_p,special_p. Then the
6918 initial outermost frame, before sp was valid, would
6919 have code_addr == &_start. See the comment in frame_id_eq
6921 if (!frame_id_eq (get_stack_frame_id (frame
),
6922 ecs
->event_thread
->control
.step_stack_frame_id
)
6923 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6924 ecs
->event_thread
->control
.step_stack_frame_id
)
6925 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6927 || (ecs
->event_thread
->control
.step_start_function
6928 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6930 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6931 CORE_ADDR real_stop_pc
;
6933 infrun_debug_printf ("stepped into subroutine");
6935 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6937 /* I presume that step_over_calls is only 0 when we're
6938 supposed to be stepping at the assembly language level
6939 ("stepi"). Just stop. */
6940 /* And this works the same backward as frontward. MVS */
6941 end_stepping_range (ecs
);
6945 /* Reverse stepping through solib trampolines. */
6947 if (execution_direction
== EXEC_REVERSE
6948 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6949 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6950 || (ecs
->stop_func_start
== 0
6951 && in_solib_dynsym_resolve_code (stop_pc
))))
6953 /* Any solib trampoline code can be handled in reverse
6954 by simply continuing to single-step. We have already
6955 executed the solib function (backwards), and a few
6956 steps will take us back through the trampoline to the
6962 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6964 /* We're doing a "next".
6966 Normal (forward) execution: set a breakpoint at the
6967 callee's return address (the address at which the caller
6970 Reverse (backward) execution. set the step-resume
6971 breakpoint at the start of the function that we just
6972 stepped into (backwards), and continue to there. When we
6973 get there, we'll need to single-step back to the caller. */
6975 if (execution_direction
== EXEC_REVERSE
)
6977 /* If we're already at the start of the function, we've either
6978 just stepped backward into a single instruction function,
6979 or stepped back out of a signal handler to the first instruction
6980 of the function. Just keep going, which will single-step back
6982 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6984 /* Normal function call return (static or dynamic). */
6985 symtab_and_line sr_sal
;
6986 sr_sal
.pc
= ecs
->stop_func_start
;
6987 sr_sal
.pspace
= get_frame_program_space (frame
);
6988 insert_step_resume_breakpoint_at_sal (gdbarch
,
6989 sr_sal
, null_frame_id
);
6993 insert_step_resume_breakpoint_at_caller (frame
);
6999 /* If we are in a function call trampoline (a stub between the
7000 calling routine and the real function), locate the real
7001 function. That's what tells us (a) whether we want to step
7002 into it at all, and (b) what prologue we want to run to the
7003 end of, if we do step into it. */
7004 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
7005 if (real_stop_pc
== 0)
7006 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
7007 if (real_stop_pc
!= 0)
7008 ecs
->stop_func_start
= real_stop_pc
;
7010 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
7012 symtab_and_line sr_sal
;
7013 sr_sal
.pc
= ecs
->stop_func_start
;
7014 sr_sal
.pspace
= get_frame_program_space (frame
);
7016 insert_step_resume_breakpoint_at_sal (gdbarch
,
7017 sr_sal
, null_frame_id
);
7022 /* If we have line number information for the function we are
7023 thinking of stepping into and the function isn't on the skip
7026 If there are several symtabs at that PC (e.g. with include
7027 files), just want to know whether *any* of them have line
7028 numbers. find_pc_line handles this. */
7030 struct symtab_and_line tmp_sal
;
7032 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7033 if (tmp_sal
.line
!= 0
7034 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
7036 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
7038 if (execution_direction
== EXEC_REVERSE
)
7039 handle_step_into_function_backward (gdbarch
, ecs
);
7041 handle_step_into_function (gdbarch
, ecs
);
7046 /* If we have no line number and the step-stop-if-no-debug is
7047 set, we stop the step so that the user has a chance to switch
7048 in assembly mode. */
7049 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7050 && step_stop_if_no_debug
)
7052 end_stepping_range (ecs
);
7056 if (execution_direction
== EXEC_REVERSE
)
7058 /* If we're already at the start of the function, we've either just
7059 stepped backward into a single instruction function without line
7060 number info, or stepped back out of a signal handler to the first
7061 instruction of the function without line number info. Just keep
7062 going, which will single-step back to the caller. */
7063 if (ecs
->stop_func_start
!= stop_pc
)
7065 /* Set a breakpoint at callee's start address.
7066 From there we can step once and be back in the caller. */
7067 symtab_and_line sr_sal
;
7068 sr_sal
.pc
= ecs
->stop_func_start
;
7069 sr_sal
.pspace
= get_frame_program_space (frame
);
7070 insert_step_resume_breakpoint_at_sal (gdbarch
,
7071 sr_sal
, null_frame_id
);
7075 /* Set a breakpoint at callee's return address (the address
7076 at which the caller will resume). */
7077 insert_step_resume_breakpoint_at_caller (frame
);
7083 /* Reverse stepping through solib trampolines. */
7085 if (execution_direction
== EXEC_REVERSE
7086 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7088 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7090 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7091 || (ecs
->stop_func_start
== 0
7092 && in_solib_dynsym_resolve_code (stop_pc
)))
7094 /* Any solib trampoline code can be handled in reverse
7095 by simply continuing to single-step. We have already
7096 executed the solib function (backwards), and a few
7097 steps will take us back through the trampoline to the
7102 else if (in_solib_dynsym_resolve_code (stop_pc
))
7104 /* Stepped backward into the solib dynsym resolver.
7105 Set a breakpoint at its start and continue, then
7106 one more step will take us out. */
7107 symtab_and_line sr_sal
;
7108 sr_sal
.pc
= ecs
->stop_func_start
;
7109 sr_sal
.pspace
= get_frame_program_space (frame
);
7110 insert_step_resume_breakpoint_at_sal (gdbarch
,
7111 sr_sal
, null_frame_id
);
7117 /* This always returns the sal for the inner-most frame when we are in a
7118 stack of inlined frames, even if GDB actually believes that it is in a
7119 more outer frame. This is checked for below by calls to
7120 inline_skipped_frames. */
7121 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7123 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7124 the trampoline processing logic, however, there are some trampolines
7125 that have no names, so we should do trampoline handling first. */
7126 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7127 && ecs
->stop_func_name
== NULL
7128 && stop_pc_sal
.line
== 0)
7130 infrun_debug_printf ("stepped into undebuggable function");
7132 /* The inferior just stepped into, or returned to, an
7133 undebuggable function (where there is no debugging information
7134 and no line number corresponding to the address where the
7135 inferior stopped). Since we want to skip this kind of code,
7136 we keep going until the inferior returns from this
7137 function - unless the user has asked us not to (via
7138 set step-mode) or we no longer know how to get back
7139 to the call site. */
7140 if (step_stop_if_no_debug
7141 || !frame_id_p (frame_unwind_caller_id (frame
)))
7143 /* If we have no line number and the step-stop-if-no-debug
7144 is set, we stop the step so that the user has a chance to
7145 switch in assembly mode. */
7146 end_stepping_range (ecs
);
7151 /* Set a breakpoint at callee's return address (the address
7152 at which the caller will resume). */
7153 insert_step_resume_breakpoint_at_caller (frame
);
7159 if (ecs
->event_thread
->control
.step_range_end
== 1)
7161 /* It is stepi or nexti. We always want to stop stepping after
7163 infrun_debug_printf ("stepi/nexti");
7164 end_stepping_range (ecs
);
7168 if (stop_pc_sal
.line
== 0)
7170 /* We have no line number information. That means to stop
7171 stepping (does this always happen right after one instruction,
7172 when we do "s" in a function with no line numbers,
7173 or can this happen as a result of a return or longjmp?). */
7174 infrun_debug_printf ("line number info");
7175 end_stepping_range (ecs
);
7179 /* Look for "calls" to inlined functions, part one. If the inline
7180 frame machinery detected some skipped call sites, we have entered
7181 a new inline function. */
7183 if (frame_id_eq (get_frame_id (get_current_frame ()),
7184 ecs
->event_thread
->control
.step_frame_id
)
7185 && inline_skipped_frames (ecs
->event_thread
))
7187 infrun_debug_printf ("stepped into inlined function");
7189 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7191 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7193 /* For "step", we're going to stop. But if the call site
7194 for this inlined function is on the same source line as
7195 we were previously stepping, go down into the function
7196 first. Otherwise stop at the call site. */
7198 if (call_sal
.line
== ecs
->event_thread
->current_line
7199 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7201 step_into_inline_frame (ecs
->event_thread
);
7202 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7209 end_stepping_range (ecs
);
7214 /* For "next", we should stop at the call site if it is on a
7215 different source line. Otherwise continue through the
7216 inlined function. */
7217 if (call_sal
.line
== ecs
->event_thread
->current_line
7218 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7221 end_stepping_range (ecs
);
7226 /* Look for "calls" to inlined functions, part two. If we are still
7227 in the same real function we were stepping through, but we have
7228 to go further up to find the exact frame ID, we are stepping
7229 through a more inlined call beyond its call site. */
7231 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7232 && !frame_id_eq (get_frame_id (get_current_frame ()),
7233 ecs
->event_thread
->control
.step_frame_id
)
7234 && stepped_in_from (get_current_frame (),
7235 ecs
->event_thread
->control
.step_frame_id
))
7237 infrun_debug_printf ("stepping through inlined function");
7239 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7240 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7243 end_stepping_range (ecs
);
7247 bool refresh_step_info
= true;
7248 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7249 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7250 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7252 /* We are at a different line. */
7254 if (stop_pc_sal
.is_stmt
)
7256 /* We are at the start of a statement.
7258 So stop. Note that we don't stop if we step into the middle of a
7259 statement. That is said to make things like for (;;) statements
7261 infrun_debug_printf ("stepped to a different line");
7262 end_stepping_range (ecs
);
7265 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7266 ecs
->event_thread
->control
.step_frame_id
))
7268 /* We are not at the start of a statement, and we have not changed
7271 We ignore this line table entry, and continue stepping forward,
7272 looking for a better place to stop. */
7273 refresh_step_info
= false;
7274 infrun_debug_printf ("stepped to a different line, but "
7275 "it's not the start of a statement");
7279 /* We are not the start of a statement, and we have changed frame.
7281 We ignore this line table entry, and continue stepping forward,
7282 looking for a better place to stop. Keep refresh_step_info at
7283 true to note that the frame has changed, but ignore the line
7284 number to make sure we don't ignore a subsequent entry with the
7285 same line number. */
7286 stop_pc_sal
.line
= 0;
7287 infrun_debug_printf ("stepped to a different frame, but "
7288 "it's not the start of a statement");
7292 /* We aren't done stepping.
7294 Optimize by setting the stepping range to the line.
7295 (We might not be in the original line, but if we entered a
7296 new line in mid-statement, we continue stepping. This makes
7297 things like for(;;) statements work better.)
7299 If we entered a SAL that indicates a non-statement line table entry,
7300 then we update the stepping range, but we don't update the step info,
7301 which includes things like the line number we are stepping away from.
7302 This means we will stop when we find a line table entry that is marked
7303 as is-statement, even if it matches the non-statement one we just
7306 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7307 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7308 ecs
->event_thread
->control
.may_range_step
= 1;
7309 if (refresh_step_info
)
7310 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7312 infrun_debug_printf ("keep going");
7316 static bool restart_stepped_thread (process_stratum_target
*resume_target
,
7317 ptid_t resume_ptid
);
7319 /* In all-stop mode, if we're currently stepping but have stopped in
7320 some other thread, we may need to switch back to the stepped
7321 thread. Returns true we set the inferior running, false if we left
7322 it stopped (and the event needs further processing). */
7325 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7327 if (!target_is_non_stop_p ())
7329 /* If any thread is blocked on some internal breakpoint, and we
7330 simply need to step over that breakpoint to get it going
7331 again, do that first. */
7333 /* However, if we see an event for the stepping thread, then we
7334 know all other threads have been moved past their breakpoints
7335 already. Let the caller check whether the step is finished,
7336 etc., before deciding to move it past a breakpoint. */
7337 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7340 /* Check if the current thread is blocked on an incomplete
7341 step-over, interrupted by a random signal. */
7342 if (ecs
->event_thread
->control
.trap_expected
7343 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7346 ("need to finish step-over of [%s]",
7347 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7352 /* Check if the current thread is blocked by a single-step
7353 breakpoint of another thread. */
7354 if (ecs
->hit_singlestep_breakpoint
)
7356 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7357 target_pid_to_str (ecs
->ptid
).c_str ());
7362 /* If this thread needs yet another step-over (e.g., stepping
7363 through a delay slot), do it first before moving on to
7365 if (thread_still_needs_step_over (ecs
->event_thread
))
7368 ("thread [%s] still needs step-over",
7369 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7374 /* If scheduler locking applies even if not stepping, there's no
7375 need to walk over threads. Above we've checked whether the
7376 current thread is stepping. If some other thread not the
7377 event thread is stepping, then it must be that scheduler
7378 locking is not in effect. */
7379 if (schedlock_applies (ecs
->event_thread
))
7382 /* Otherwise, we no longer expect a trap in the current thread.
7383 Clear the trap_expected flag before switching back -- this is
7384 what keep_going does as well, if we call it. */
7385 ecs
->event_thread
->control
.trap_expected
= 0;
7387 /* Likewise, clear the signal if it should not be passed. */
7388 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7389 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7391 if (restart_stepped_thread (ecs
->target
, ecs
->ptid
))
7393 prepare_to_wait (ecs
);
7397 switch_to_thread (ecs
->event_thread
);
7403 /* Look for the thread that was stepping, and resume it.
7404 RESUME_TARGET / RESUME_PTID indicate the set of threads the caller
7405 is resuming. Return true if a thread was started, false
7409 restart_stepped_thread (process_stratum_target
*resume_target
,
7412 /* Do all pending step-overs before actually proceeding with
7414 if (start_step_over ())
7417 for (thread_info
*tp
: all_threads_safe ())
7419 if (tp
->state
== THREAD_EXITED
)
7422 if (tp
->suspend
.waitstatus_pending_p
)
7425 /* Ignore threads of processes the caller is not
7428 && (tp
->inf
->process_target () != resume_target
7429 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7432 if (tp
->control
.trap_expected
)
7434 infrun_debug_printf ("switching back to stepped thread (step-over)");
7436 if (keep_going_stepped_thread (tp
))
7441 for (thread_info
*tp
: all_threads_safe ())
7443 if (tp
->state
== THREAD_EXITED
)
7446 if (tp
->suspend
.waitstatus_pending_p
)
7449 /* Ignore threads of processes the caller is not
7452 && (tp
->inf
->process_target () != resume_target
7453 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7456 /* Did we find the stepping thread? */
7457 if (tp
->control
.step_range_end
)
7459 infrun_debug_printf ("switching back to stepped thread (stepping)");
7461 if (keep_going_stepped_thread (tp
))
7472 restart_after_all_stop_detach (process_stratum_target
*proc_target
)
7474 /* Note we don't check target_is_non_stop_p() here, because the
7475 current inferior may no longer have a process_stratum target
7476 pushed, as we just detached. */
7478 /* See if we have a THREAD_RUNNING thread that need to be
7479 re-resumed. If we have any thread that is already executing,
7480 then we don't need to resume the target -- it is already been
7481 resumed. With the remote target (in all-stop), it's even
7482 impossible to issue another resumption if the target is already
7483 resumed, until the target reports a stop. */
7484 for (thread_info
*thr
: all_threads (proc_target
))
7486 if (thr
->state
!= THREAD_RUNNING
)
7489 /* If we have any thread that is already executing, then we
7490 don't need to resume the target -- it is already been
7495 /* If we have a pending event to process, skip resuming the
7496 target and go straight to processing it. */
7497 if (thr
->resumed
&& thr
->suspend
.waitstatus_pending_p
)
7501 /* Alright, we need to re-resume the target. If a thread was
7502 stepping, we need to restart it stepping. */
7503 if (restart_stepped_thread (proc_target
, minus_one_ptid
))
7506 /* Otherwise, find the first THREAD_RUNNING thread and resume
7508 for (thread_info
*thr
: all_threads (proc_target
))
7510 if (thr
->state
!= THREAD_RUNNING
)
7513 execution_control_state ecs
;
7514 reset_ecs (&ecs
, thr
);
7515 switch_to_thread (thr
);
7521 /* Set a previously stepped thread back to stepping. Returns true on
7522 success, false if the resume is not possible (e.g., the thread
7526 keep_going_stepped_thread (struct thread_info
*tp
)
7528 struct frame_info
*frame
;
7529 struct execution_control_state ecss
;
7530 struct execution_control_state
*ecs
= &ecss
;
7532 /* If the stepping thread exited, then don't try to switch back and
7533 resume it, which could fail in several different ways depending
7534 on the target. Instead, just keep going.
7536 We can find a stepping dead thread in the thread list in two
7539 - The target supports thread exit events, and when the target
7540 tries to delete the thread from the thread list, inferior_ptid
7541 pointed at the exiting thread. In such case, calling
7542 delete_thread does not really remove the thread from the list;
7543 instead, the thread is left listed, with 'exited' state.
7545 - The target's debug interface does not support thread exit
7546 events, and so we have no idea whatsoever if the previously
7547 stepping thread is still alive. For that reason, we need to
7548 synchronously query the target now. */
7550 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7552 infrun_debug_printf ("not resuming previously stepped thread, it has "
7559 infrun_debug_printf ("resuming previously stepped thread");
7561 reset_ecs (ecs
, tp
);
7562 switch_to_thread (tp
);
7564 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7565 frame
= get_current_frame ();
7567 /* If the PC of the thread we were trying to single-step has
7568 changed, then that thread has trapped or been signaled, but the
7569 event has not been reported to GDB yet. Re-poll the target
7570 looking for this particular thread's event (i.e. temporarily
7571 enable schedlock) by:
7573 - setting a break at the current PC
7574 - resuming that particular thread, only (by setting trap
7577 This prevents us continuously moving the single-step breakpoint
7578 forward, one instruction at a time, overstepping. */
7580 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7584 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7585 paddress (target_gdbarch (), tp
->prev_pc
),
7586 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7588 /* Clear the info of the previous step-over, as it's no longer
7589 valid (if the thread was trying to step over a breakpoint, it
7590 has already succeeded). It's what keep_going would do too,
7591 if we called it. Do this before trying to insert the sss
7592 breakpoint, otherwise if we were previously trying to step
7593 over this exact address in another thread, the breakpoint is
7595 clear_step_over_info ();
7596 tp
->control
.trap_expected
= 0;
7598 insert_single_step_breakpoint (get_frame_arch (frame
),
7599 get_frame_address_space (frame
),
7600 tp
->suspend
.stop_pc
);
7603 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7604 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7608 infrun_debug_printf ("expected thread still hasn't advanced");
7610 keep_going_pass_signal (ecs
);
7616 /* Is thread TP in the middle of (software or hardware)
7617 single-stepping? (Note the result of this function must never be
7618 passed directly as target_resume's STEP parameter.) */
7621 currently_stepping (struct thread_info
*tp
)
7623 return ((tp
->control
.step_range_end
7624 && tp
->control
.step_resume_breakpoint
== NULL
)
7625 || tp
->control
.trap_expected
7626 || tp
->stepped_breakpoint
7627 || bpstat_should_step ());
7630 /* Inferior has stepped into a subroutine call with source code that
7631 we should not step over. Do step to the first line of code in
7635 handle_step_into_function (struct gdbarch
*gdbarch
,
7636 struct execution_control_state
*ecs
)
7638 fill_in_stop_func (gdbarch
, ecs
);
7640 compunit_symtab
*cust
7641 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7642 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7643 ecs
->stop_func_start
7644 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7646 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7647 /* Use the step_resume_break to step until the end of the prologue,
7648 even if that involves jumps (as it seems to on the vax under
7650 /* If the prologue ends in the middle of a source line, continue to
7651 the end of that source line (if it is still within the function).
7652 Otherwise, just go to end of prologue. */
7653 if (stop_func_sal
.end
7654 && stop_func_sal
.pc
!= ecs
->stop_func_start
7655 && stop_func_sal
.end
< ecs
->stop_func_end
)
7656 ecs
->stop_func_start
= stop_func_sal
.end
;
7658 /* Architectures which require breakpoint adjustment might not be able
7659 to place a breakpoint at the computed address. If so, the test
7660 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7661 ecs->stop_func_start to an address at which a breakpoint may be
7662 legitimately placed.
7664 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7665 made, GDB will enter an infinite loop when stepping through
7666 optimized code consisting of VLIW instructions which contain
7667 subinstructions corresponding to different source lines. On
7668 FR-V, it's not permitted to place a breakpoint on any but the
7669 first subinstruction of a VLIW instruction. When a breakpoint is
7670 set, GDB will adjust the breakpoint address to the beginning of
7671 the VLIW instruction. Thus, we need to make the corresponding
7672 adjustment here when computing the stop address. */
7674 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7676 ecs
->stop_func_start
7677 = gdbarch_adjust_breakpoint_address (gdbarch
,
7678 ecs
->stop_func_start
);
7681 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7683 /* We are already there: stop now. */
7684 end_stepping_range (ecs
);
7689 /* Put the step-breakpoint there and go until there. */
7690 symtab_and_line sr_sal
;
7691 sr_sal
.pc
= ecs
->stop_func_start
;
7692 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7693 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7695 /* Do not specify what the fp should be when we stop since on
7696 some machines the prologue is where the new fp value is
7698 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7700 /* And make sure stepping stops right away then. */
7701 ecs
->event_thread
->control
.step_range_end
7702 = ecs
->event_thread
->control
.step_range_start
;
7707 /* Inferior has stepped backward into a subroutine call with source
7708 code that we should not step over. Do step to the beginning of the
7709 last line of code in it. */
7712 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7713 struct execution_control_state
*ecs
)
7715 struct compunit_symtab
*cust
;
7716 struct symtab_and_line stop_func_sal
;
7718 fill_in_stop_func (gdbarch
, ecs
);
7720 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7721 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7722 ecs
->stop_func_start
7723 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7725 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7727 /* OK, we're just going to keep stepping here. */
7728 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7730 /* We're there already. Just stop stepping now. */
7731 end_stepping_range (ecs
);
7735 /* Else just reset the step range and keep going.
7736 No step-resume breakpoint, they don't work for
7737 epilogues, which can have multiple entry paths. */
7738 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7739 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7745 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7746 This is used to both functions and to skip over code. */
7749 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7750 struct symtab_and_line sr_sal
,
7751 struct frame_id sr_id
,
7752 enum bptype sr_type
)
7754 /* There should never be more than one step-resume or longjmp-resume
7755 breakpoint per thread, so we should never be setting a new
7756 step_resume_breakpoint when one is already active. */
7757 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7758 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7760 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7761 paddress (gdbarch
, sr_sal
.pc
));
7763 inferior_thread ()->control
.step_resume_breakpoint
7764 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7768 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7769 struct symtab_and_line sr_sal
,
7770 struct frame_id sr_id
)
7772 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7777 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7778 This is used to skip a potential signal handler.
7780 This is called with the interrupted function's frame. The signal
7781 handler, when it returns, will resume the interrupted function at
7785 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7787 gdb_assert (return_frame
!= NULL
);
7789 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7791 symtab_and_line sr_sal
;
7792 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7793 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7794 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7796 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7797 get_stack_frame_id (return_frame
),
7801 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7802 is used to skip a function after stepping into it (for "next" or if
7803 the called function has no debugging information).
7805 The current function has almost always been reached by single
7806 stepping a call or return instruction. NEXT_FRAME belongs to the
7807 current function, and the breakpoint will be set at the caller's
7810 This is a separate function rather than reusing
7811 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7812 get_prev_frame, which may stop prematurely (see the implementation
7813 of frame_unwind_caller_id for an example). */
7816 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7818 /* We shouldn't have gotten here if we don't know where the call site
7820 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7822 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7824 symtab_and_line sr_sal
;
7825 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7826 frame_unwind_caller_pc (next_frame
));
7827 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7828 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7830 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7831 frame_unwind_caller_id (next_frame
));
7834 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7835 new breakpoint at the target of a jmp_buf. The handling of
7836 longjmp-resume uses the same mechanisms used for handling
7837 "step-resume" breakpoints. */
7840 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7842 /* There should never be more than one longjmp-resume breakpoint per
7843 thread, so we should never be setting a new
7844 longjmp_resume_breakpoint when one is already active. */
7845 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7847 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7848 paddress (gdbarch
, pc
));
7850 inferior_thread ()->control
.exception_resume_breakpoint
=
7851 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7854 /* Insert an exception resume breakpoint. TP is the thread throwing
7855 the exception. The block B is the block of the unwinder debug hook
7856 function. FRAME is the frame corresponding to the call to this
7857 function. SYM is the symbol of the function argument holding the
7858 target PC of the exception. */
7861 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7862 const struct block
*b
,
7863 struct frame_info
*frame
,
7868 struct block_symbol vsym
;
7869 struct value
*value
;
7871 struct breakpoint
*bp
;
7873 vsym
= lookup_symbol_search_name (sym
->search_name (),
7875 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7876 /* If the value was optimized out, revert to the old behavior. */
7877 if (! value_optimized_out (value
))
7879 handler
= value_as_address (value
);
7881 infrun_debug_printf ("exception resume at %lx",
7882 (unsigned long) handler
);
7884 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7886 bp_exception_resume
).release ();
7888 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7891 bp
->thread
= tp
->global_num
;
7892 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7895 catch (const gdb_exception_error
&e
)
7897 /* We want to ignore errors here. */
7901 /* A helper for check_exception_resume that sets an
7902 exception-breakpoint based on a SystemTap probe. */
7905 insert_exception_resume_from_probe (struct thread_info
*tp
,
7906 const struct bound_probe
*probe
,
7907 struct frame_info
*frame
)
7909 struct value
*arg_value
;
7911 struct breakpoint
*bp
;
7913 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7917 handler
= value_as_address (arg_value
);
7919 infrun_debug_printf ("exception resume at %s",
7920 paddress (probe
->objfile
->arch (), handler
));
7922 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7923 handler
, bp_exception_resume
).release ();
7924 bp
->thread
= tp
->global_num
;
7925 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7928 /* This is called when an exception has been intercepted. Check to
7929 see whether the exception's destination is of interest, and if so,
7930 set an exception resume breakpoint there. */
7933 check_exception_resume (struct execution_control_state
*ecs
,
7934 struct frame_info
*frame
)
7936 struct bound_probe probe
;
7937 struct symbol
*func
;
7939 /* First see if this exception unwinding breakpoint was set via a
7940 SystemTap probe point. If so, the probe has two arguments: the
7941 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7942 set a breakpoint there. */
7943 probe
= find_probe_by_pc (get_frame_pc (frame
));
7946 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7950 func
= get_frame_function (frame
);
7956 const struct block
*b
;
7957 struct block_iterator iter
;
7961 /* The exception breakpoint is a thread-specific breakpoint on
7962 the unwinder's debug hook, declared as:
7964 void _Unwind_DebugHook (void *cfa, void *handler);
7966 The CFA argument indicates the frame to which control is
7967 about to be transferred. HANDLER is the destination PC.
7969 We ignore the CFA and set a temporary breakpoint at HANDLER.
7970 This is not extremely efficient but it avoids issues in gdb
7971 with computing the DWARF CFA, and it also works even in weird
7972 cases such as throwing an exception from inside a signal
7975 b
= SYMBOL_BLOCK_VALUE (func
);
7976 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7978 if (!SYMBOL_IS_ARGUMENT (sym
))
7985 insert_exception_resume_breakpoint (ecs
->event_thread
,
7991 catch (const gdb_exception_error
&e
)
7997 stop_waiting (struct execution_control_state
*ecs
)
7999 infrun_debug_printf ("stop_waiting");
8001 /* Let callers know we don't want to wait for the inferior anymore. */
8002 ecs
->wait_some_more
= 0;
8004 /* If all-stop, but there exists a non-stop target, stop all
8005 threads now that we're presenting the stop to the user. */
8006 if (!non_stop
&& exists_non_stop_target ())
8007 stop_all_threads ();
8010 /* Like keep_going, but passes the signal to the inferior, even if the
8011 signal is set to nopass. */
8014 keep_going_pass_signal (struct execution_control_state
*ecs
)
8016 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
8017 gdb_assert (!ecs
->event_thread
->resumed
);
8019 /* Save the pc before execution, to compare with pc after stop. */
8020 ecs
->event_thread
->prev_pc
8021 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
8023 if (ecs
->event_thread
->control
.trap_expected
)
8025 struct thread_info
*tp
= ecs
->event_thread
;
8027 infrun_debug_printf ("%s has trap_expected set, "
8028 "resuming to collect trap",
8029 target_pid_to_str (tp
->ptid
).c_str ());
8031 /* We haven't yet gotten our trap, and either: intercepted a
8032 non-signal event (e.g., a fork); or took a signal which we
8033 are supposed to pass through to the inferior. Simply
8035 resume (ecs
->event_thread
->suspend
.stop_signal
);
8037 else if (step_over_info_valid_p ())
8039 /* Another thread is stepping over a breakpoint in-line. If
8040 this thread needs a step-over too, queue the request. In
8041 either case, this resume must be deferred for later. */
8042 struct thread_info
*tp
= ecs
->event_thread
;
8044 if (ecs
->hit_singlestep_breakpoint
8045 || thread_still_needs_step_over (tp
))
8047 infrun_debug_printf ("step-over already in progress: "
8048 "step-over for %s deferred",
8049 target_pid_to_str (tp
->ptid
).c_str ());
8050 global_thread_step_over_chain_enqueue (tp
);
8054 infrun_debug_printf ("step-over in progress: resume of %s deferred",
8055 target_pid_to_str (tp
->ptid
).c_str ());
8060 struct regcache
*regcache
= get_current_regcache ();
8063 step_over_what step_what
;
8065 /* Either the trap was not expected, but we are continuing
8066 anyway (if we got a signal, the user asked it be passed to
8069 We got our expected trap, but decided we should resume from
8072 We're going to run this baby now!
8074 Note that insert_breakpoints won't try to re-insert
8075 already inserted breakpoints. Therefore, we don't
8076 care if breakpoints were already inserted, or not. */
8078 /* If we need to step over a breakpoint, and we're not using
8079 displaced stepping to do so, insert all breakpoints
8080 (watchpoints, etc.) but the one we're stepping over, step one
8081 instruction, and then re-insert the breakpoint when that step
8084 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
8086 remove_bp
= (ecs
->hit_singlestep_breakpoint
8087 || (step_what
& STEP_OVER_BREAKPOINT
));
8088 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8090 /* We can't use displaced stepping if we need to step past a
8091 watchpoint. The instruction copied to the scratch pad would
8092 still trigger the watchpoint. */
8094 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8096 set_step_over_info (regcache
->aspace (),
8097 regcache_read_pc (regcache
), remove_wps
,
8098 ecs
->event_thread
->global_num
);
8100 else if (remove_wps
)
8101 set_step_over_info (NULL
, 0, remove_wps
, -1);
8103 /* If we now need to do an in-line step-over, we need to stop
8104 all other threads. Note this must be done before
8105 insert_breakpoints below, because that removes the breakpoint
8106 we're about to step over, otherwise other threads could miss
8108 if (step_over_info_valid_p () && target_is_non_stop_p ())
8109 stop_all_threads ();
8111 /* Stop stepping if inserting breakpoints fails. */
8114 insert_breakpoints ();
8116 catch (const gdb_exception_error
&e
)
8118 exception_print (gdb_stderr
, e
);
8120 clear_step_over_info ();
8124 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8126 resume (ecs
->event_thread
->suspend
.stop_signal
);
8129 prepare_to_wait (ecs
);
8132 /* Called when we should continue running the inferior, because the
8133 current event doesn't cause a user visible stop. This does the
8134 resuming part; waiting for the next event is done elsewhere. */
8137 keep_going (struct execution_control_state
*ecs
)
8139 if (ecs
->event_thread
->control
.trap_expected
8140 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8141 ecs
->event_thread
->control
.trap_expected
= 0;
8143 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8144 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8145 keep_going_pass_signal (ecs
);
8148 /* This function normally comes after a resume, before
8149 handle_inferior_event exits. It takes care of any last bits of
8150 housekeeping, and sets the all-important wait_some_more flag. */
8153 prepare_to_wait (struct execution_control_state
*ecs
)
8155 infrun_debug_printf ("prepare_to_wait");
8157 ecs
->wait_some_more
= 1;
8159 /* If the target can't async, emulate it by marking the infrun event
8160 handler such that as soon as we get back to the event-loop, we
8161 immediately end up in fetch_inferior_event again calling
8163 if (!target_can_async_p ())
8164 mark_infrun_async_event_handler ();
8167 /* We are done with the step range of a step/next/si/ni command.
8168 Called once for each n of a "step n" operation. */
8171 end_stepping_range (struct execution_control_state
*ecs
)
8173 ecs
->event_thread
->control
.stop_step
= 1;
8177 /* Several print_*_reason functions to print why the inferior has stopped.
8178 We always print something when the inferior exits, or receives a signal.
8179 The rest of the cases are dealt with later on in normal_stop and
8180 print_it_typical. Ideally there should be a call to one of these
8181 print_*_reason functions functions from handle_inferior_event each time
8182 stop_waiting is called.
8184 Note that we don't call these directly, instead we delegate that to
8185 the interpreters, through observers. Interpreters then call these
8186 with whatever uiout is right. */
8189 print_end_stepping_range_reason (struct ui_out
*uiout
)
8191 /* For CLI-like interpreters, print nothing. */
8193 if (uiout
->is_mi_like_p ())
8195 uiout
->field_string ("reason",
8196 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8201 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8203 annotate_signalled ();
8204 if (uiout
->is_mi_like_p ())
8206 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8207 uiout
->text ("\nProgram terminated with signal ");
8208 annotate_signal_name ();
8209 uiout
->field_string ("signal-name",
8210 gdb_signal_to_name (siggnal
));
8211 annotate_signal_name_end ();
8213 annotate_signal_string ();
8214 uiout
->field_string ("signal-meaning",
8215 gdb_signal_to_string (siggnal
));
8216 annotate_signal_string_end ();
8217 uiout
->text (".\n");
8218 uiout
->text ("The program no longer exists.\n");
8222 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8224 struct inferior
*inf
= current_inferior ();
8225 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8227 annotate_exited (exitstatus
);
8230 if (uiout
->is_mi_like_p ())
8231 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8232 std::string exit_code_str
8233 = string_printf ("0%o", (unsigned int) exitstatus
);
8234 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8235 plongest (inf
->num
), pidstr
.c_str (),
8236 string_field ("exit-code", exit_code_str
.c_str ()));
8240 if (uiout
->is_mi_like_p ())
8242 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8243 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8244 plongest (inf
->num
), pidstr
.c_str ());
8249 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8251 struct thread_info
*thr
= inferior_thread ();
8255 if (uiout
->is_mi_like_p ())
8257 else if (show_thread_that_caused_stop ())
8261 uiout
->text ("\nThread ");
8262 uiout
->field_string ("thread-id", print_thread_id (thr
));
8264 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8267 uiout
->text (" \"");
8268 uiout
->field_string ("name", name
);
8273 uiout
->text ("\nProgram");
8275 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8276 uiout
->text (" stopped");
8279 uiout
->text (" received signal ");
8280 annotate_signal_name ();
8281 if (uiout
->is_mi_like_p ())
8283 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8284 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8285 annotate_signal_name_end ();
8287 annotate_signal_string ();
8288 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8290 struct regcache
*regcache
= get_current_regcache ();
8291 struct gdbarch
*gdbarch
= regcache
->arch ();
8292 if (gdbarch_report_signal_info_p (gdbarch
))
8293 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8295 annotate_signal_string_end ();
8297 uiout
->text (".\n");
8301 print_no_history_reason (struct ui_out
*uiout
)
8303 uiout
->text ("\nNo more reverse-execution history.\n");
8306 /* Print current location without a level number, if we have changed
8307 functions or hit a breakpoint. Print source line if we have one.
8308 bpstat_print contains the logic deciding in detail what to print,
8309 based on the event(s) that just occurred. */
8312 print_stop_location (struct target_waitstatus
*ws
)
8315 enum print_what source_flag
;
8316 int do_frame_printing
= 1;
8317 struct thread_info
*tp
= inferior_thread ();
8319 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8323 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8324 should) carry around the function and does (or should) use
8325 that when doing a frame comparison. */
8326 if (tp
->control
.stop_step
8327 && frame_id_eq (tp
->control
.step_frame_id
,
8328 get_frame_id (get_current_frame ()))
8329 && (tp
->control
.step_start_function
8330 == find_pc_function (tp
->suspend
.stop_pc
)))
8332 /* Finished step, just print source line. */
8333 source_flag
= SRC_LINE
;
8337 /* Print location and source line. */
8338 source_flag
= SRC_AND_LOC
;
8341 case PRINT_SRC_AND_LOC
:
8342 /* Print location and source line. */
8343 source_flag
= SRC_AND_LOC
;
8345 case PRINT_SRC_ONLY
:
8346 source_flag
= SRC_LINE
;
8349 /* Something bogus. */
8350 source_flag
= SRC_LINE
;
8351 do_frame_printing
= 0;
8354 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8357 /* The behavior of this routine with respect to the source
8359 SRC_LINE: Print only source line
8360 LOCATION: Print only location
8361 SRC_AND_LOC: Print location and source line. */
8362 if (do_frame_printing
)
8363 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8369 print_stop_event (struct ui_out
*uiout
, bool displays
)
8371 struct target_waitstatus last
;
8372 struct thread_info
*tp
;
8374 get_last_target_status (nullptr, nullptr, &last
);
8377 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8379 print_stop_location (&last
);
8381 /* Display the auto-display expressions. */
8386 tp
= inferior_thread ();
8387 if (tp
->thread_fsm
!= NULL
8388 && tp
->thread_fsm
->finished_p ())
8390 struct return_value_info
*rv
;
8392 rv
= tp
->thread_fsm
->return_value ();
8394 print_return_value (uiout
, rv
);
8401 maybe_remove_breakpoints (void)
8403 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8405 if (remove_breakpoints ())
8407 target_terminal::ours_for_output ();
8408 printf_filtered (_("Cannot remove breakpoints because "
8409 "program is no longer writable.\nFurther "
8410 "execution is probably impossible.\n"));
8415 /* The execution context that just caused a normal stop. */
8421 DISABLE_COPY_AND_ASSIGN (stop_context
);
8423 bool changed () const;
8428 /* The event PTID. */
8432 /* If stopp for a thread event, this is the thread that caused the
8434 thread_info_ref thread
;
8436 /* The inferior that caused the stop. */
8440 /* Initializes a new stop context. If stopped for a thread event, this
8441 takes a strong reference to the thread. */
8443 stop_context::stop_context ()
8445 stop_id
= get_stop_id ();
8446 ptid
= inferior_ptid
;
8447 inf_num
= current_inferior ()->num
;
8449 if (inferior_ptid
!= null_ptid
)
8451 /* Take a strong reference so that the thread can't be deleted
8453 thread
= thread_info_ref::new_reference (inferior_thread ());
8457 /* Return true if the current context no longer matches the saved stop
8461 stop_context::changed () const
8463 if (ptid
!= inferior_ptid
)
8465 if (inf_num
!= current_inferior ()->num
)
8467 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8469 if (get_stop_id () != stop_id
)
8479 struct target_waitstatus last
;
8481 get_last_target_status (nullptr, nullptr, &last
);
8485 /* If an exception is thrown from this point on, make sure to
8486 propagate GDB's knowledge of the executing state to the
8487 frontend/user running state. A QUIT is an easy exception to see
8488 here, so do this before any filtered output. */
8490 ptid_t finish_ptid
= null_ptid
;
8493 finish_ptid
= minus_one_ptid
;
8494 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8495 || last
.kind
== TARGET_WAITKIND_EXITED
)
8497 /* On some targets, we may still have live threads in the
8498 inferior when we get a process exit event. E.g., for
8499 "checkpoint", when the current checkpoint/fork exits,
8500 linux-fork.c automatically switches to another fork from
8501 within target_mourn_inferior. */
8502 if (inferior_ptid
!= null_ptid
)
8503 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8505 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8506 finish_ptid
= inferior_ptid
;
8508 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8509 if (finish_ptid
!= null_ptid
)
8511 maybe_finish_thread_state
.emplace
8512 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8515 /* As we're presenting a stop, and potentially removing breakpoints,
8516 update the thread list so we can tell whether there are threads
8517 running on the target. With target remote, for example, we can
8518 only learn about new threads when we explicitly update the thread
8519 list. Do this before notifying the interpreters about signal
8520 stops, end of stepping ranges, etc., so that the "new thread"
8521 output is emitted before e.g., "Program received signal FOO",
8522 instead of after. */
8523 update_thread_list ();
8525 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8526 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8528 /* As with the notification of thread events, we want to delay
8529 notifying the user that we've switched thread context until
8530 the inferior actually stops.
8532 There's no point in saying anything if the inferior has exited.
8533 Note that SIGNALLED here means "exited with a signal", not
8534 "received a signal".
8536 Also skip saying anything in non-stop mode. In that mode, as we
8537 don't want GDB to switch threads behind the user's back, to avoid
8538 races where the user is typing a command to apply to thread x,
8539 but GDB switches to thread y before the user finishes entering
8540 the command, fetch_inferior_event installs a cleanup to restore
8541 the current thread back to the thread the user had selected right
8542 after this event is handled, so we're not really switching, only
8543 informing of a stop. */
8545 && previous_inferior_ptid
!= inferior_ptid
8546 && target_has_execution ()
8547 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8548 && last
.kind
!= TARGET_WAITKIND_EXITED
8549 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8551 SWITCH_THRU_ALL_UIS ()
8553 target_terminal::ours_for_output ();
8554 printf_filtered (_("[Switching to %s]\n"),
8555 target_pid_to_str (inferior_ptid
).c_str ());
8556 annotate_thread_changed ();
8558 previous_inferior_ptid
= inferior_ptid
;
8561 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8563 SWITCH_THRU_ALL_UIS ()
8564 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8566 target_terminal::ours_for_output ();
8567 printf_filtered (_("No unwaited-for children left.\n"));
8571 /* Note: this depends on the update_thread_list call above. */
8572 maybe_remove_breakpoints ();
8574 /* If an auto-display called a function and that got a signal,
8575 delete that auto-display to avoid an infinite recursion. */
8577 if (stopped_by_random_signal
)
8578 disable_current_display ();
8580 SWITCH_THRU_ALL_UIS ()
8582 async_enable_stdin ();
8585 /* Let the user/frontend see the threads as stopped. */
8586 maybe_finish_thread_state
.reset ();
8588 /* Select innermost stack frame - i.e., current frame is frame 0,
8589 and current location is based on that. Handle the case where the
8590 dummy call is returning after being stopped. E.g. the dummy call
8591 previously hit a breakpoint. (If the dummy call returns
8592 normally, we won't reach here.) Do this before the stop hook is
8593 run, so that it doesn't get to see the temporary dummy frame,
8594 which is not where we'll present the stop. */
8595 if (has_stack_frames ())
8597 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8599 /* Pop the empty frame that contains the stack dummy. This
8600 also restores inferior state prior to the call (struct
8601 infcall_suspend_state). */
8602 struct frame_info
*frame
= get_current_frame ();
8604 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8606 /* frame_pop calls reinit_frame_cache as the last thing it
8607 does which means there's now no selected frame. */
8610 select_frame (get_current_frame ());
8612 /* Set the current source location. */
8613 set_current_sal_from_frame (get_current_frame ());
8616 /* Look up the hook_stop and run it (CLI internally handles problem
8617 of stop_command's pre-hook not existing). */
8618 if (stop_command
!= NULL
)
8620 stop_context saved_context
;
8624 execute_cmd_pre_hook (stop_command
);
8626 catch (const gdb_exception
&ex
)
8628 exception_fprintf (gdb_stderr
, ex
,
8629 "Error while running hook_stop:\n");
8632 /* If the stop hook resumes the target, then there's no point in
8633 trying to notify about the previous stop; its context is
8634 gone. Likewise if the command switches thread or inferior --
8635 the observers would print a stop for the wrong
8637 if (saved_context
.changed ())
8641 /* Notify observers about the stop. This is where the interpreters
8642 print the stop event. */
8643 if (inferior_ptid
!= null_ptid
)
8644 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8647 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8649 annotate_stopped ();
8651 if (target_has_execution ())
8653 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8654 && last
.kind
!= TARGET_WAITKIND_EXITED
8655 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8656 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8657 Delete any breakpoint that is to be deleted at the next stop. */
8658 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8661 /* Try to get rid of automatically added inferiors that are no
8662 longer needed. Keeping those around slows down things linearly.
8663 Note that this never removes the current inferior. */
8670 signal_stop_state (int signo
)
8672 return signal_stop
[signo
];
8676 signal_print_state (int signo
)
8678 return signal_print
[signo
];
8682 signal_pass_state (int signo
)
8684 return signal_program
[signo
];
8688 signal_cache_update (int signo
)
8692 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8693 signal_cache_update (signo
);
8698 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8699 && signal_print
[signo
] == 0
8700 && signal_program
[signo
] == 1
8701 && signal_catch
[signo
] == 0);
8705 signal_stop_update (int signo
, int state
)
8707 int ret
= signal_stop
[signo
];
8709 signal_stop
[signo
] = state
;
8710 signal_cache_update (signo
);
8715 signal_print_update (int signo
, int state
)
8717 int ret
= signal_print
[signo
];
8719 signal_print
[signo
] = state
;
8720 signal_cache_update (signo
);
8725 signal_pass_update (int signo
, int state
)
8727 int ret
= signal_program
[signo
];
8729 signal_program
[signo
] = state
;
8730 signal_cache_update (signo
);
8734 /* Update the global 'signal_catch' from INFO and notify the
8738 signal_catch_update (const unsigned int *info
)
8742 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8743 signal_catch
[i
] = info
[i
] > 0;
8744 signal_cache_update (-1);
8745 target_pass_signals (signal_pass
);
8749 sig_print_header (void)
8751 printf_filtered (_("Signal Stop\tPrint\tPass "
8752 "to program\tDescription\n"));
8756 sig_print_info (enum gdb_signal oursig
)
8758 const char *name
= gdb_signal_to_name (oursig
);
8759 int name_padding
= 13 - strlen (name
);
8761 if (name_padding
<= 0)
8764 printf_filtered ("%s", name
);
8765 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8766 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8767 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8768 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8769 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8772 /* Specify how various signals in the inferior should be handled. */
8775 handle_command (const char *args
, int from_tty
)
8777 int digits
, wordlen
;
8778 int sigfirst
, siglast
;
8779 enum gdb_signal oursig
;
8784 error_no_arg (_("signal to handle"));
8787 /* Allocate and zero an array of flags for which signals to handle. */
8789 const size_t nsigs
= GDB_SIGNAL_LAST
;
8790 unsigned char sigs
[nsigs
] {};
8792 /* Break the command line up into args. */
8794 gdb_argv
built_argv (args
);
8796 /* Walk through the args, looking for signal oursigs, signal names, and
8797 actions. Signal numbers and signal names may be interspersed with
8798 actions, with the actions being performed for all signals cumulatively
8799 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8801 for (char *arg
: built_argv
)
8803 wordlen
= strlen (arg
);
8804 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8808 sigfirst
= siglast
= -1;
8810 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8812 /* Apply action to all signals except those used by the
8813 debugger. Silently skip those. */
8816 siglast
= nsigs
- 1;
8818 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8820 SET_SIGS (nsigs
, sigs
, signal_stop
);
8821 SET_SIGS (nsigs
, sigs
, signal_print
);
8823 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8825 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8827 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8829 SET_SIGS (nsigs
, sigs
, signal_print
);
8831 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8833 SET_SIGS (nsigs
, sigs
, signal_program
);
8835 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8837 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8839 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8841 SET_SIGS (nsigs
, sigs
, signal_program
);
8843 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8845 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8846 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8848 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8850 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8852 else if (digits
> 0)
8854 /* It is numeric. The numeric signal refers to our own
8855 internal signal numbering from target.h, not to host/target
8856 signal number. This is a feature; users really should be
8857 using symbolic names anyway, and the common ones like
8858 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8860 sigfirst
= siglast
= (int)
8861 gdb_signal_from_command (atoi (arg
));
8862 if (arg
[digits
] == '-')
8865 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8867 if (sigfirst
> siglast
)
8869 /* Bet he didn't figure we'd think of this case... */
8870 std::swap (sigfirst
, siglast
);
8875 oursig
= gdb_signal_from_name (arg
);
8876 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8878 sigfirst
= siglast
= (int) oursig
;
8882 /* Not a number and not a recognized flag word => complain. */
8883 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8887 /* If any signal numbers or symbol names were found, set flags for
8888 which signals to apply actions to. */
8890 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8892 switch ((enum gdb_signal
) signum
)
8894 case GDB_SIGNAL_TRAP
:
8895 case GDB_SIGNAL_INT
:
8896 if (!allsigs
&& !sigs
[signum
])
8898 if (query (_("%s is used by the debugger.\n\
8899 Are you sure you want to change it? "),
8900 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8905 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8909 case GDB_SIGNAL_DEFAULT
:
8910 case GDB_SIGNAL_UNKNOWN
:
8911 /* Make sure that "all" doesn't print these. */
8920 for (int signum
= 0; signum
< nsigs
; signum
++)
8923 signal_cache_update (-1);
8924 target_pass_signals (signal_pass
);
8925 target_program_signals (signal_program
);
8929 /* Show the results. */
8930 sig_print_header ();
8931 for (; signum
< nsigs
; signum
++)
8933 sig_print_info ((enum gdb_signal
) signum
);
8940 /* Complete the "handle" command. */
8943 handle_completer (struct cmd_list_element
*ignore
,
8944 completion_tracker
&tracker
,
8945 const char *text
, const char *word
)
8947 static const char * const keywords
[] =
8961 signal_completer (ignore
, tracker
, text
, word
);
8962 complete_on_enum (tracker
, keywords
, word
, word
);
8966 gdb_signal_from_command (int num
)
8968 if (num
>= 1 && num
<= 15)
8969 return (enum gdb_signal
) num
;
8970 error (_("Only signals 1-15 are valid as numeric signals.\n\
8971 Use \"info signals\" for a list of symbolic signals."));
8974 /* Print current contents of the tables set by the handle command.
8975 It is possible we should just be printing signals actually used
8976 by the current target (but for things to work right when switching
8977 targets, all signals should be in the signal tables). */
8980 info_signals_command (const char *signum_exp
, int from_tty
)
8982 enum gdb_signal oursig
;
8984 sig_print_header ();
8988 /* First see if this is a symbol name. */
8989 oursig
= gdb_signal_from_name (signum_exp
);
8990 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8992 /* No, try numeric. */
8994 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8996 sig_print_info (oursig
);
9000 printf_filtered ("\n");
9001 /* These ugly casts brought to you by the native VAX compiler. */
9002 for (oursig
= GDB_SIGNAL_FIRST
;
9003 (int) oursig
< (int) GDB_SIGNAL_LAST
;
9004 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
9008 if (oursig
!= GDB_SIGNAL_UNKNOWN
9009 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
9010 sig_print_info (oursig
);
9013 printf_filtered (_("\nUse the \"handle\" command "
9014 "to change these tables.\n"));
9017 /* The $_siginfo convenience variable is a bit special. We don't know
9018 for sure the type of the value until we actually have a chance to
9019 fetch the data. The type can change depending on gdbarch, so it is
9020 also dependent on which thread you have selected.
9022 1. making $_siginfo be an internalvar that creates a new value on
9025 2. making the value of $_siginfo be an lval_computed value. */
9027 /* This function implements the lval_computed support for reading a
9031 siginfo_value_read (struct value
*v
)
9033 LONGEST transferred
;
9035 /* If we can access registers, so can we access $_siginfo. Likewise
9037 validate_registers_access ();
9040 target_read (current_inferior ()->top_target (),
9041 TARGET_OBJECT_SIGNAL_INFO
,
9043 value_contents_all_raw (v
),
9045 TYPE_LENGTH (value_type (v
)));
9047 if (transferred
!= TYPE_LENGTH (value_type (v
)))
9048 error (_("Unable to read siginfo"));
9051 /* This function implements the lval_computed support for writing a
9055 siginfo_value_write (struct value
*v
, struct value
*fromval
)
9057 LONGEST transferred
;
9059 /* If we can access registers, so can we access $_siginfo. Likewise
9061 validate_registers_access ();
9063 transferred
= target_write (current_inferior ()->top_target (),
9064 TARGET_OBJECT_SIGNAL_INFO
,
9066 value_contents_all_raw (fromval
),
9068 TYPE_LENGTH (value_type (fromval
)));
9070 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
9071 error (_("Unable to write siginfo"));
9074 static const struct lval_funcs siginfo_value_funcs
=
9080 /* Return a new value with the correct type for the siginfo object of
9081 the current thread using architecture GDBARCH. Return a void value
9082 if there's no object available. */
9084 static struct value
*
9085 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9088 if (target_has_stack ()
9089 && inferior_ptid
!= null_ptid
9090 && gdbarch_get_siginfo_type_p (gdbarch
))
9092 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9094 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9097 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9101 /* infcall_suspend_state contains state about the program itself like its
9102 registers and any signal it received when it last stopped.
9103 This state must be restored regardless of how the inferior function call
9104 ends (either successfully, or after it hits a breakpoint or signal)
9105 if the program is to properly continue where it left off. */
9107 class infcall_suspend_state
9110 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9111 once the inferior function call has finished. */
9112 infcall_suspend_state (struct gdbarch
*gdbarch
,
9113 const struct thread_info
*tp
,
9114 struct regcache
*regcache
)
9115 : m_thread_suspend (tp
->suspend
),
9116 m_registers (new readonly_detached_regcache (*regcache
))
9118 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9120 if (gdbarch_get_siginfo_type_p (gdbarch
))
9122 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9123 size_t len
= TYPE_LENGTH (type
);
9125 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9127 if (target_read (current_inferior ()->top_target (),
9128 TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9129 siginfo_data
.get (), 0, len
) != len
)
9131 /* Errors ignored. */
9132 siginfo_data
.reset (nullptr);
9138 m_siginfo_gdbarch
= gdbarch
;
9139 m_siginfo_data
= std::move (siginfo_data
);
9143 /* Return a pointer to the stored register state. */
9145 readonly_detached_regcache
*registers () const
9147 return m_registers
.get ();
9150 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9152 void restore (struct gdbarch
*gdbarch
,
9153 struct thread_info
*tp
,
9154 struct regcache
*regcache
) const
9156 tp
->suspend
= m_thread_suspend
;
9158 if (m_siginfo_gdbarch
== gdbarch
)
9160 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9162 /* Errors ignored. */
9163 target_write (current_inferior ()->top_target (),
9164 TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9165 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9168 /* The inferior can be gone if the user types "print exit(0)"
9169 (and perhaps other times). */
9170 if (target_has_execution ())
9171 /* NB: The register write goes through to the target. */
9172 regcache
->restore (registers ());
9176 /* How the current thread stopped before the inferior function call was
9178 struct thread_suspend_state m_thread_suspend
;
9180 /* The registers before the inferior function call was executed. */
9181 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9183 /* Format of SIGINFO_DATA or NULL if it is not present. */
9184 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9186 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9187 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9188 content would be invalid. */
9189 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9192 infcall_suspend_state_up
9193 save_infcall_suspend_state ()
9195 struct thread_info
*tp
= inferior_thread ();
9196 struct regcache
*regcache
= get_current_regcache ();
9197 struct gdbarch
*gdbarch
= regcache
->arch ();
9199 infcall_suspend_state_up inf_state
9200 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9202 /* Having saved the current state, adjust the thread state, discarding
9203 any stop signal information. The stop signal is not useful when
9204 starting an inferior function call, and run_inferior_call will not use
9205 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9206 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9211 /* Restore inferior session state to INF_STATE. */
9214 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9216 struct thread_info
*tp
= inferior_thread ();
9217 struct regcache
*regcache
= get_current_regcache ();
9218 struct gdbarch
*gdbarch
= regcache
->arch ();
9220 inf_state
->restore (gdbarch
, tp
, regcache
);
9221 discard_infcall_suspend_state (inf_state
);
9225 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9230 readonly_detached_regcache
*
9231 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9233 return inf_state
->registers ();
9236 /* infcall_control_state contains state regarding gdb's control of the
9237 inferior itself like stepping control. It also contains session state like
9238 the user's currently selected frame. */
9240 struct infcall_control_state
9242 struct thread_control_state thread_control
;
9243 struct inferior_control_state inferior_control
;
9246 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9247 int stopped_by_random_signal
= 0;
9249 /* ID and level of the selected frame when the inferior function
9251 struct frame_id selected_frame_id
{};
9252 int selected_frame_level
= -1;
9255 /* Save all of the information associated with the inferior<==>gdb
9258 infcall_control_state_up
9259 save_infcall_control_state ()
9261 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9262 struct thread_info
*tp
= inferior_thread ();
9263 struct inferior
*inf
= current_inferior ();
9265 inf_status
->thread_control
= tp
->control
;
9266 inf_status
->inferior_control
= inf
->control
;
9268 tp
->control
.step_resume_breakpoint
= NULL
;
9269 tp
->control
.exception_resume_breakpoint
= NULL
;
9271 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9272 chain. If caller's caller is walking the chain, they'll be happier if we
9273 hand them back the original chain when restore_infcall_control_state is
9275 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9278 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9279 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9281 save_selected_frame (&inf_status
->selected_frame_id
,
9282 &inf_status
->selected_frame_level
);
9287 /* Restore inferior session state to INF_STATUS. */
9290 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9292 struct thread_info
*tp
= inferior_thread ();
9293 struct inferior
*inf
= current_inferior ();
9295 if (tp
->control
.step_resume_breakpoint
)
9296 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9298 if (tp
->control
.exception_resume_breakpoint
)
9299 tp
->control
.exception_resume_breakpoint
->disposition
9300 = disp_del_at_next_stop
;
9302 /* Handle the bpstat_copy of the chain. */
9303 bpstat_clear (&tp
->control
.stop_bpstat
);
9305 tp
->control
= inf_status
->thread_control
;
9306 inf
->control
= inf_status
->inferior_control
;
9309 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9310 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9312 if (target_has_stack ())
9314 restore_selected_frame (inf_status
->selected_frame_id
,
9315 inf_status
->selected_frame_level
);
9322 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9324 if (inf_status
->thread_control
.step_resume_breakpoint
)
9325 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9326 = disp_del_at_next_stop
;
9328 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9329 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9330 = disp_del_at_next_stop
;
9332 /* See save_infcall_control_state for info on stop_bpstat. */
9333 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9341 clear_exit_convenience_vars (void)
9343 clear_internalvar (lookup_internalvar ("_exitsignal"));
9344 clear_internalvar (lookup_internalvar ("_exitcode"));
9348 /* User interface for reverse debugging:
9349 Set exec-direction / show exec-direction commands
9350 (returns error unless target implements to_set_exec_direction method). */
9352 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9353 static const char exec_forward
[] = "forward";
9354 static const char exec_reverse
[] = "reverse";
9355 static const char *exec_direction
= exec_forward
;
9356 static const char *const exec_direction_names
[] = {
9363 set_exec_direction_func (const char *args
, int from_tty
,
9364 struct cmd_list_element
*cmd
)
9366 if (target_can_execute_reverse ())
9368 if (!strcmp (exec_direction
, exec_forward
))
9369 execution_direction
= EXEC_FORWARD
;
9370 else if (!strcmp (exec_direction
, exec_reverse
))
9371 execution_direction
= EXEC_REVERSE
;
9375 exec_direction
= exec_forward
;
9376 error (_("Target does not support this operation."));
9381 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9382 struct cmd_list_element
*cmd
, const char *value
)
9384 switch (execution_direction
) {
9386 fprintf_filtered (out
, _("Forward.\n"));
9389 fprintf_filtered (out
, _("Reverse.\n"));
9392 internal_error (__FILE__
, __LINE__
,
9393 _("bogus execution_direction value: %d"),
9394 (int) execution_direction
);
9399 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9400 struct cmd_list_element
*c
, const char *value
)
9402 fprintf_filtered (file
, _("Resuming the execution of threads "
9403 "of all processes is %s.\n"), value
);
9406 /* Implementation of `siginfo' variable. */
9408 static const struct internalvar_funcs siginfo_funcs
=
9415 /* Callback for infrun's target events source. This is marked when a
9416 thread has a pending status to process. */
9419 infrun_async_inferior_event_handler (gdb_client_data data
)
9421 clear_async_event_handler (infrun_async_inferior_event_token
);
9422 inferior_event_handler (INF_REG_EVENT
);
9429 /* Verify that when two threads with the same ptid exist (from two different
9430 targets) and one of them changes ptid, we only update inferior_ptid if
9431 it is appropriate. */
9434 infrun_thread_ptid_changed ()
9436 gdbarch
*arch
= current_inferior ()->gdbarch
;
9438 /* The thread which inferior_ptid represents changes ptid. */
9440 scoped_restore_current_pspace_and_thread restore
;
9442 scoped_mock_context
<test_target_ops
> target1 (arch
);
9443 scoped_mock_context
<test_target_ops
> target2 (arch
);
9444 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9446 ptid_t
old_ptid (111, 222);
9447 ptid_t
new_ptid (111, 333);
9449 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9450 target1
.mock_thread
.ptid
= old_ptid
;
9451 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9452 target2
.mock_thread
.ptid
= old_ptid
;
9454 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9455 set_current_inferior (&target1
.mock_inferior
);
9457 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9459 gdb_assert (inferior_ptid
== new_ptid
);
9462 /* A thread with the same ptid as inferior_ptid, but from another target,
9465 scoped_restore_current_pspace_and_thread restore
;
9467 scoped_mock_context
<test_target_ops
> target1 (arch
);
9468 scoped_mock_context
<test_target_ops
> target2 (arch
);
9469 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9471 ptid_t
old_ptid (111, 222);
9472 ptid_t
new_ptid (111, 333);
9474 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9475 target1
.mock_thread
.ptid
= old_ptid
;
9476 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9477 target2
.mock_thread
.ptid
= old_ptid
;
9479 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9480 set_current_inferior (&target2
.mock_inferior
);
9482 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9484 gdb_assert (inferior_ptid
== old_ptid
);
9488 } /* namespace selftests */
9490 #endif /* GDB_SELF_TEST */
9492 void _initialize_infrun ();
9494 _initialize_infrun ()
9496 struct cmd_list_element
*c
;
9498 /* Register extra event sources in the event loop. */
9499 infrun_async_inferior_event_token
9500 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9503 add_info ("signals", info_signals_command
, _("\
9504 What debugger does when program gets various signals.\n\
9505 Specify a signal as argument to print info on that signal only."));
9506 add_info_alias ("handle", "signals", 0);
9508 c
= add_com ("handle", class_run
, handle_command
, _("\
9509 Specify how to handle signals.\n\
9510 Usage: handle SIGNAL [ACTIONS]\n\
9511 Args are signals and actions to apply to those signals.\n\
9512 If no actions are specified, the current settings for the specified signals\n\
9513 will be displayed instead.\n\
9515 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9516 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9517 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9518 The special arg \"all\" is recognized to mean all signals except those\n\
9519 used by the debugger, typically SIGTRAP and SIGINT.\n\
9521 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9522 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9523 Stop means reenter debugger if this signal happens (implies print).\n\
9524 Print means print a message if this signal happens.\n\
9525 Pass means let program see this signal; otherwise program doesn't know.\n\
9526 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9527 Pass and Stop may be combined.\n\
9529 Multiple signals may be specified. Signal numbers and signal names\n\
9530 may be interspersed with actions, with the actions being performed for\n\
9531 all signals cumulatively specified."));
9532 set_cmd_completer (c
, handle_completer
);
9535 stop_command
= add_cmd ("stop", class_obscure
,
9536 not_just_help_class_command
, _("\
9537 There is no `stop' command, but you can set a hook on `stop'.\n\
9538 This allows you to set a list of commands to be run each time execution\n\
9539 of the program stops."), &cmdlist
);
9541 add_setshow_boolean_cmd
9542 ("infrun", class_maintenance
, &debug_infrun
,
9543 _("Set inferior debugging."),
9544 _("Show inferior debugging."),
9545 _("When non-zero, inferior specific debugging is enabled."),
9546 NULL
, show_debug_infrun
, &setdebuglist
, &showdebuglist
);
9548 add_setshow_boolean_cmd ("non-stop", no_class
,
9550 Set whether gdb controls the inferior in non-stop mode."), _("\
9551 Show whether gdb controls the inferior in non-stop mode."), _("\
9552 When debugging a multi-threaded program and this setting is\n\
9553 off (the default, also called all-stop mode), when one thread stops\n\
9554 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9555 all other threads in the program while you interact with the thread of\n\
9556 interest. When you continue or step a thread, you can allow the other\n\
9557 threads to run, or have them remain stopped, but while you inspect any\n\
9558 thread's state, all threads stop.\n\
9560 In non-stop mode, when one thread stops, other threads can continue\n\
9561 to run freely. You'll be able to step each thread independently,\n\
9562 leave it stopped or free to run as needed."),
9568 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9571 signal_print
[i
] = 1;
9572 signal_program
[i
] = 1;
9573 signal_catch
[i
] = 0;
9576 /* Signals caused by debugger's own actions should not be given to
9577 the program afterwards.
9579 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9580 explicitly specifies that it should be delivered to the target
9581 program. Typically, that would occur when a user is debugging a
9582 target monitor on a simulator: the target monitor sets a
9583 breakpoint; the simulator encounters this breakpoint and halts
9584 the simulation handing control to GDB; GDB, noting that the stop
9585 address doesn't map to any known breakpoint, returns control back
9586 to the simulator; the simulator then delivers the hardware
9587 equivalent of a GDB_SIGNAL_TRAP to the program being
9589 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9590 signal_program
[GDB_SIGNAL_INT
] = 0;
9592 /* Signals that are not errors should not normally enter the debugger. */
9593 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9594 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9595 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9596 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9597 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9598 signal_print
[GDB_SIGNAL_PROF
] = 0;
9599 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9600 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9601 signal_stop
[GDB_SIGNAL_IO
] = 0;
9602 signal_print
[GDB_SIGNAL_IO
] = 0;
9603 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9604 signal_print
[GDB_SIGNAL_POLL
] = 0;
9605 signal_stop
[GDB_SIGNAL_URG
] = 0;
9606 signal_print
[GDB_SIGNAL_URG
] = 0;
9607 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9608 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9609 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9610 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9612 /* These signals are used internally by user-level thread
9613 implementations. (See signal(5) on Solaris.) Like the above
9614 signals, a healthy program receives and handles them as part of
9615 its normal operation. */
9616 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9617 signal_print
[GDB_SIGNAL_LWP
] = 0;
9618 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9619 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9620 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9621 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9622 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9623 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9625 /* Update cached state. */
9626 signal_cache_update (-1);
9628 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9629 &stop_on_solib_events
, _("\
9630 Set stopping for shared library events."), _("\
9631 Show stopping for shared library events."), _("\
9632 If nonzero, gdb will give control to the user when the dynamic linker\n\
9633 notifies gdb of shared library events. The most common event of interest\n\
9634 to the user would be loading/unloading of a new library."),
9635 set_stop_on_solib_events
,
9636 show_stop_on_solib_events
,
9637 &setlist
, &showlist
);
9639 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9640 follow_fork_mode_kind_names
,
9641 &follow_fork_mode_string
, _("\
9642 Set debugger response to a program call of fork or vfork."), _("\
9643 Show debugger response to a program call of fork or vfork."), _("\
9644 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9645 parent - the original process is debugged after a fork\n\
9646 child - the new process is debugged after a fork\n\
9647 The unfollowed process will continue to run.\n\
9648 By default, the debugger will follow the parent process."),
9650 show_follow_fork_mode_string
,
9651 &setlist
, &showlist
);
9653 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9654 follow_exec_mode_names
,
9655 &follow_exec_mode_string
, _("\
9656 Set debugger response to a program call of exec."), _("\
9657 Show debugger response to a program call of exec."), _("\
9658 An exec call replaces the program image of a process.\n\
9660 follow-exec-mode can be:\n\
9662 new - the debugger creates a new inferior and rebinds the process\n\
9663 to this new inferior. The program the process was running before\n\
9664 the exec call can be restarted afterwards by restarting the original\n\
9667 same - the debugger keeps the process bound to the same inferior.\n\
9668 The new executable image replaces the previous executable loaded in\n\
9669 the inferior. Restarting the inferior after the exec call restarts\n\
9670 the executable the process was running after the exec call.\n\
9672 By default, the debugger will use the same inferior."),
9674 show_follow_exec_mode_string
,
9675 &setlist
, &showlist
);
9677 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9678 scheduler_enums
, &scheduler_mode
, _("\
9679 Set mode for locking scheduler during execution."), _("\
9680 Show mode for locking scheduler during execution."), _("\
9681 off == no locking (threads may preempt at any time)\n\
9682 on == full locking (no thread except the current thread may run)\n\
9683 This applies to both normal execution and replay mode.\n\
9684 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9685 In this mode, other threads may run during other commands.\n\
9686 This applies to both normal execution and replay mode.\n\
9687 replay == scheduler locked in replay mode and unlocked during normal execution."),
9688 set_schedlock_func
, /* traps on target vector */
9689 show_scheduler_mode
,
9690 &setlist
, &showlist
);
9692 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9693 Set mode for resuming threads of all processes."), _("\
9694 Show mode for resuming threads of all processes."), _("\
9695 When on, execution commands (such as 'continue' or 'next') resume all\n\
9696 threads of all processes. When off (which is the default), execution\n\
9697 commands only resume the threads of the current process. The set of\n\
9698 threads that are resumed is further refined by the scheduler-locking\n\
9699 mode (see help set scheduler-locking)."),
9701 show_schedule_multiple
,
9702 &setlist
, &showlist
);
9704 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9705 Set mode of the step operation."), _("\
9706 Show mode of the step operation."), _("\
9707 When set, doing a step over a function without debug line information\n\
9708 will stop at the first instruction of that function. Otherwise, the\n\
9709 function is skipped and the step command stops at a different source line."),
9711 show_step_stop_if_no_debug
,
9712 &setlist
, &showlist
);
9714 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9715 &can_use_displaced_stepping
, _("\
9716 Set debugger's willingness to use displaced stepping."), _("\
9717 Show debugger's willingness to use displaced stepping."), _("\
9718 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9719 supported by the target architecture. If off, gdb will not use displaced\n\
9720 stepping to step over breakpoints, even if such is supported by the target\n\
9721 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9722 if the target architecture supports it and non-stop mode is active, but will not\n\
9723 use it in all-stop mode (see help set non-stop)."),
9725 show_can_use_displaced_stepping
,
9726 &setlist
, &showlist
);
9728 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9729 &exec_direction
, _("Set direction of execution.\n\
9730 Options are 'forward' or 'reverse'."),
9731 _("Show direction of execution (forward/reverse)."),
9732 _("Tells gdb whether to execute forward or backward."),
9733 set_exec_direction_func
, show_exec_direction_func
,
9734 &setlist
, &showlist
);
9736 /* Set/show detach-on-fork: user-settable mode. */
9738 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9739 Set whether gdb will detach the child of a fork."), _("\
9740 Show whether gdb will detach the child of a fork."), _("\
9741 Tells gdb whether to detach the child of a fork."),
9742 NULL
, NULL
, &setlist
, &showlist
);
9744 /* Set/show disable address space randomization mode. */
9746 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9747 &disable_randomization
, _("\
9748 Set disabling of debuggee's virtual address space randomization."), _("\
9749 Show disabling of debuggee's virtual address space randomization."), _("\
9750 When this mode is on (which is the default), randomization of the virtual\n\
9751 address space is disabled. Standalone programs run with the randomization\n\
9752 enabled by default on some platforms."),
9753 &set_disable_randomization
,
9754 &show_disable_randomization
,
9755 &setlist
, &showlist
);
9757 /* ptid initializations */
9758 inferior_ptid
= null_ptid
;
9759 target_last_wait_ptid
= minus_one_ptid
;
9761 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
,
9763 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
,
9765 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
, "infrun");
9766 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
, "infrun");
9767 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
, "infrun");
9769 /* Explicitly create without lookup, since that tries to create a
9770 value with a void typed value, and when we get here, gdbarch
9771 isn't initialized yet. At this point, we're quite sure there
9772 isn't another convenience variable of the same name. */
9773 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9775 add_setshow_boolean_cmd ("observer", no_class
,
9776 &observer_mode_1
, _("\
9777 Set whether gdb controls the inferior in observer mode."), _("\
9778 Show whether gdb controls the inferior in observer mode."), _("\
9779 In observer mode, GDB can get data from the inferior, but not\n\
9780 affect its execution. Registers and memory may not be changed,\n\
9781 breakpoints may not be set, and the program cannot be interrupted\n\
9789 selftests::register_test ("infrun_thread_ptid_changed",
9790 selftests::infrun_thread_ptid_changed
);