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 return target_follow_fork (follow_child
, detach_fork
);
668 /* Tell the target to follow the fork we're stopped at. Returns true
669 if the inferior should be resumed; false, if the target for some
670 reason decided it's best not to resume. */
675 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
676 bool should_resume
= true;
677 struct thread_info
*tp
;
679 /* Copy user stepping state to the new inferior thread. FIXME: the
680 followed fork child thread should have a copy of most of the
681 parent thread structure's run control related fields, not just these.
682 Initialized to avoid "may be used uninitialized" warnings from gcc. */
683 struct breakpoint
*step_resume_breakpoint
= NULL
;
684 struct breakpoint
*exception_resume_breakpoint
= NULL
;
685 CORE_ADDR step_range_start
= 0;
686 CORE_ADDR step_range_end
= 0;
687 int current_line
= 0;
688 symtab
*current_symtab
= NULL
;
689 struct frame_id step_frame_id
= { 0 };
690 struct thread_fsm
*thread_fsm
= NULL
;
694 process_stratum_target
*wait_target
;
696 struct target_waitstatus wait_status
;
698 /* Get the last target status returned by target_wait(). */
699 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
701 /* If not stopped at a fork event, then there's nothing else to
703 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
704 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
707 /* Check if we switched over from WAIT_PTID, since the event was
709 if (wait_ptid
!= minus_one_ptid
710 && (current_inferior ()->process_target () != wait_target
711 || inferior_ptid
!= wait_ptid
))
713 /* We did. Switch back to WAIT_PTID thread, to tell the
714 target to follow it (in either direction). We'll
715 afterwards refuse to resume, and inform the user what
717 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
718 switch_to_thread (wait_thread
);
719 should_resume
= false;
723 tp
= inferior_thread ();
725 /* If there were any forks/vforks that were caught and are now to be
726 followed, then do so now. */
727 switch (tp
->pending_follow
.kind
)
729 case TARGET_WAITKIND_FORKED
:
730 case TARGET_WAITKIND_VFORKED
:
732 ptid_t parent
, child
;
734 /* If the user did a next/step, etc, over a fork call,
735 preserve the stepping state in the fork child. */
736 if (follow_child
&& should_resume
)
738 step_resume_breakpoint
= clone_momentary_breakpoint
739 (tp
->control
.step_resume_breakpoint
);
740 step_range_start
= tp
->control
.step_range_start
;
741 step_range_end
= tp
->control
.step_range_end
;
742 current_line
= tp
->current_line
;
743 current_symtab
= tp
->current_symtab
;
744 step_frame_id
= tp
->control
.step_frame_id
;
745 exception_resume_breakpoint
746 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
747 thread_fsm
= tp
->thread_fsm
;
749 /* For now, delete the parent's sr breakpoint, otherwise,
750 parent/child sr breakpoints are considered duplicates,
751 and the child version will not be installed. Remove
752 this when the breakpoints module becomes aware of
753 inferiors and address spaces. */
754 delete_step_resume_breakpoint (tp
);
755 tp
->control
.step_range_start
= 0;
756 tp
->control
.step_range_end
= 0;
757 tp
->control
.step_frame_id
= null_frame_id
;
758 delete_exception_resume_breakpoint (tp
);
759 tp
->thread_fsm
= NULL
;
762 parent
= inferior_ptid
;
763 child
= tp
->pending_follow
.value
.related_pid
;
765 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
766 /* Set up inferior(s) as specified by the caller, and tell the
767 target to do whatever is necessary to follow either parent
769 if (follow_fork_inferior (follow_child
, detach_fork
))
771 /* Target refused to follow, or there's some other reason
772 we shouldn't resume. */
777 /* This pending follow fork event is now handled, one way
778 or another. The previous selected thread may be gone
779 from the lists by now, but if it is still around, need
780 to clear the pending follow request. */
781 tp
= find_thread_ptid (parent_targ
, parent
);
783 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
785 /* This makes sure we don't try to apply the "Switched
786 over from WAIT_PID" logic above. */
787 nullify_last_target_wait_ptid ();
789 /* If we followed the child, switch to it... */
792 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
793 switch_to_thread (child_thr
);
795 /* ... and preserve the stepping state, in case the
796 user was stepping over the fork call. */
799 tp
= inferior_thread ();
800 tp
->control
.step_resume_breakpoint
801 = step_resume_breakpoint
;
802 tp
->control
.step_range_start
= step_range_start
;
803 tp
->control
.step_range_end
= step_range_end
;
804 tp
->current_line
= current_line
;
805 tp
->current_symtab
= current_symtab
;
806 tp
->control
.step_frame_id
= step_frame_id
;
807 tp
->control
.exception_resume_breakpoint
808 = exception_resume_breakpoint
;
809 tp
->thread_fsm
= thread_fsm
;
813 /* If we get here, it was because we're trying to
814 resume from a fork catchpoint, but, the user
815 has switched threads away from the thread that
816 forked. In that case, the resume command
817 issued is most likely not applicable to the
818 child, so just warn, and refuse to resume. */
819 warning (_("Not resuming: switched threads "
820 "before following fork child."));
823 /* Reset breakpoints in the child as appropriate. */
824 follow_inferior_reset_breakpoints ();
829 case TARGET_WAITKIND_SPURIOUS
:
830 /* Nothing to follow. */
833 internal_error (__FILE__
, __LINE__
,
834 "Unexpected pending_follow.kind %d\n",
835 tp
->pending_follow
.kind
);
839 return should_resume
;
843 follow_inferior_reset_breakpoints (void)
845 struct thread_info
*tp
= inferior_thread ();
847 /* Was there a step_resume breakpoint? (There was if the user
848 did a "next" at the fork() call.) If so, explicitly reset its
849 thread number. Cloned step_resume breakpoints are disabled on
850 creation, so enable it here now that it is associated with the
853 step_resumes are a form of bp that are made to be per-thread.
854 Since we created the step_resume bp when the parent process
855 was being debugged, and now are switching to the child process,
856 from the breakpoint package's viewpoint, that's a switch of
857 "threads". We must update the bp's notion of which thread
858 it is for, or it'll be ignored when it triggers. */
860 if (tp
->control
.step_resume_breakpoint
)
862 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
863 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
866 /* Treat exception_resume breakpoints like step_resume breakpoints. */
867 if (tp
->control
.exception_resume_breakpoint
)
869 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
870 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
873 /* Reinsert all breakpoints in the child. The user may have set
874 breakpoints after catching the fork, in which case those
875 were never set in the child, but only in the parent. This makes
876 sure the inserted breakpoints match the breakpoint list. */
878 breakpoint_re_set ();
879 insert_breakpoints ();
882 /* The child has exited or execed: resume threads of the parent the
883 user wanted to be executing. */
886 proceed_after_vfork_done (struct thread_info
*thread
,
889 int pid
= * (int *) arg
;
891 if (thread
->ptid
.pid () == pid
892 && thread
->state
== THREAD_RUNNING
893 && !thread
->executing
894 && !thread
->stop_requested
895 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
897 infrun_debug_printf ("resuming vfork parent thread %s",
898 target_pid_to_str (thread
->ptid
).c_str ());
900 switch_to_thread (thread
);
901 clear_proceed_status (0);
902 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
908 /* Called whenever we notice an exec or exit event, to handle
909 detaching or resuming a vfork parent. */
912 handle_vfork_child_exec_or_exit (int exec
)
914 struct inferior
*inf
= current_inferior ();
916 if (inf
->vfork_parent
)
918 int resume_parent
= -1;
920 /* This exec or exit marks the end of the shared memory region
921 between the parent and the child. Break the bonds. */
922 inferior
*vfork_parent
= inf
->vfork_parent
;
923 inf
->vfork_parent
->vfork_child
= NULL
;
924 inf
->vfork_parent
= NULL
;
926 /* If the user wanted to detach from the parent, now is the
928 if (vfork_parent
->pending_detach
)
930 struct program_space
*pspace
;
931 struct address_space
*aspace
;
933 /* follow-fork child, detach-on-fork on. */
935 vfork_parent
->pending_detach
= 0;
937 scoped_restore_current_pspace_and_thread restore_thread
;
939 /* We're letting loose of the parent. */
940 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
941 switch_to_thread (tp
);
943 /* We're about to detach from the parent, which implicitly
944 removes breakpoints from its address space. There's a
945 catch here: we want to reuse the spaces for the child,
946 but, parent/child are still sharing the pspace at this
947 point, although the exec in reality makes the kernel give
948 the child a fresh set of new pages. The problem here is
949 that the breakpoints module being unaware of this, would
950 likely chose the child process to write to the parent
951 address space. Swapping the child temporarily away from
952 the spaces has the desired effect. Yes, this is "sort
955 pspace
= inf
->pspace
;
956 aspace
= inf
->aspace
;
960 if (print_inferior_events
)
963 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
965 target_terminal::ours_for_output ();
969 fprintf_filtered (gdb_stdlog
,
970 _("[Detaching vfork parent %s "
971 "after child exec]\n"), pidstr
.c_str ());
975 fprintf_filtered (gdb_stdlog
,
976 _("[Detaching vfork parent %s "
977 "after child exit]\n"), pidstr
.c_str ());
981 target_detach (vfork_parent
, 0);
984 inf
->pspace
= pspace
;
985 inf
->aspace
= aspace
;
989 /* We're staying attached to the parent, so, really give the
990 child a new address space. */
991 inf
->pspace
= new program_space (maybe_new_address_space ());
992 inf
->aspace
= inf
->pspace
->aspace
;
994 set_current_program_space (inf
->pspace
);
996 resume_parent
= vfork_parent
->pid
;
1000 /* If this is a vfork child exiting, then the pspace and
1001 aspaces were shared with the parent. Since we're
1002 reporting the process exit, we'll be mourning all that is
1003 found in the address space, and switching to null_ptid,
1004 preparing to start a new inferior. But, since we don't
1005 want to clobber the parent's address/program spaces, we
1006 go ahead and create a new one for this exiting
1009 /* Switch to no-thread while running clone_program_space, so
1010 that clone_program_space doesn't want to read the
1011 selected frame of a dead process. */
1012 scoped_restore_current_thread restore_thread
;
1013 switch_to_no_thread ();
1015 inf
->pspace
= new program_space (maybe_new_address_space ());
1016 inf
->aspace
= inf
->pspace
->aspace
;
1017 set_current_program_space (inf
->pspace
);
1019 inf
->symfile_flags
= SYMFILE_NO_READ
;
1020 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1022 resume_parent
= vfork_parent
->pid
;
1025 gdb_assert (current_program_space
== inf
->pspace
);
1027 if (non_stop
&& resume_parent
!= -1)
1029 /* If the user wanted the parent to be running, let it go
1031 scoped_restore_current_thread restore_thread
;
1033 infrun_debug_printf ("resuming vfork parent process %d",
1036 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1041 /* Enum strings for "set|show follow-exec-mode". */
1043 static const char follow_exec_mode_new
[] = "new";
1044 static const char follow_exec_mode_same
[] = "same";
1045 static const char *const follow_exec_mode_names
[] =
1047 follow_exec_mode_new
,
1048 follow_exec_mode_same
,
1052 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1054 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1055 struct cmd_list_element
*c
, const char *value
)
1057 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1060 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1063 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1065 struct inferior
*inf
= current_inferior ();
1066 int pid
= ptid
.pid ();
1067 ptid_t process_ptid
;
1069 /* Switch terminal for any messages produced e.g. by
1070 breakpoint_re_set. */
1071 target_terminal::ours_for_output ();
1073 /* This is an exec event that we actually wish to pay attention to.
1074 Refresh our symbol table to the newly exec'd program, remove any
1075 momentary bp's, etc.
1077 If there are breakpoints, they aren't really inserted now,
1078 since the exec() transformed our inferior into a fresh set
1081 We want to preserve symbolic breakpoints on the list, since
1082 we have hopes that they can be reset after the new a.out's
1083 symbol table is read.
1085 However, any "raw" breakpoints must be removed from the list
1086 (e.g., the solib bp's), since their address is probably invalid
1089 And, we DON'T want to call delete_breakpoints() here, since
1090 that may write the bp's "shadow contents" (the instruction
1091 value that was overwritten with a TRAP instruction). Since
1092 we now have a new a.out, those shadow contents aren't valid. */
1094 mark_breakpoints_out ();
1096 /* The target reports the exec event to the main thread, even if
1097 some other thread does the exec, and even if the main thread was
1098 stopped or already gone. We may still have non-leader threads of
1099 the process on our list. E.g., on targets that don't have thread
1100 exit events (like remote); or on native Linux in non-stop mode if
1101 there were only two threads in the inferior and the non-leader
1102 one is the one that execs (and nothing forces an update of the
1103 thread list up to here). When debugging remotely, it's best to
1104 avoid extra traffic, when possible, so avoid syncing the thread
1105 list with the target, and instead go ahead and delete all threads
1106 of the process but one that reported the event. Note this must
1107 be done before calling update_breakpoints_after_exec, as
1108 otherwise clearing the threads' resources would reference stale
1109 thread breakpoints -- it may have been one of these threads that
1110 stepped across the exec. We could just clear their stepping
1111 states, but as long as we're iterating, might as well delete
1112 them. Deleting them now rather than at the next user-visible
1113 stop provides a nicer sequence of events for user and MI
1115 for (thread_info
*th
: all_threads_safe ())
1116 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1119 /* We also need to clear any left over stale state for the
1120 leader/event thread. E.g., if there was any step-resume
1121 breakpoint or similar, it's gone now. We cannot truly
1122 step-to-next statement through an exec(). */
1123 thread_info
*th
= inferior_thread ();
1124 th
->control
.step_resume_breakpoint
= NULL
;
1125 th
->control
.exception_resume_breakpoint
= NULL
;
1126 th
->control
.single_step_breakpoints
= NULL
;
1127 th
->control
.step_range_start
= 0;
1128 th
->control
.step_range_end
= 0;
1130 /* The user may have had the main thread held stopped in the
1131 previous image (e.g., schedlock on, or non-stop). Release
1133 th
->stop_requested
= 0;
1135 update_breakpoints_after_exec ();
1137 /* What is this a.out's name? */
1138 process_ptid
= ptid_t (pid
);
1139 printf_unfiltered (_("%s is executing new program: %s\n"),
1140 target_pid_to_str (process_ptid
).c_str (),
1143 /* We've followed the inferior through an exec. Therefore, the
1144 inferior has essentially been killed & reborn. */
1146 breakpoint_init_inferior (inf_execd
);
1148 gdb::unique_xmalloc_ptr
<char> exec_file_host
1149 = exec_file_find (exec_file_target
, NULL
);
1151 /* If we were unable to map the executable target pathname onto a host
1152 pathname, tell the user that. Otherwise GDB's subsequent behavior
1153 is confusing. Maybe it would even be better to stop at this point
1154 so that the user can specify a file manually before continuing. */
1155 if (exec_file_host
== NULL
)
1156 warning (_("Could not load symbols for executable %s.\n"
1157 "Do you need \"set sysroot\"?"),
1160 /* Reset the shared library package. This ensures that we get a
1161 shlib event when the child reaches "_start", at which point the
1162 dld will have had a chance to initialize the child. */
1163 /* Also, loading a symbol file below may trigger symbol lookups, and
1164 we don't want those to be satisfied by the libraries of the
1165 previous incarnation of this process. */
1166 no_shared_libraries (NULL
, 0);
1168 if (follow_exec_mode_string
== follow_exec_mode_new
)
1170 /* The user wants to keep the old inferior and program spaces
1171 around. Create a new fresh one, and switch to it. */
1173 /* Do exit processing for the original inferior before setting the new
1174 inferior's pid. Having two inferiors with the same pid would confuse
1175 find_inferior_p(t)id. Transfer the terminal state and info from the
1176 old to the new inferior. */
1177 inf
= add_inferior_with_spaces ();
1178 swap_terminal_info (inf
, current_inferior ());
1179 exit_inferior_silent (current_inferior ());
1182 target_follow_exec (inf
, exec_file_target
);
1184 inferior
*org_inferior
= current_inferior ();
1185 switch_to_inferior_no_thread (inf
);
1186 inf
->push_target (org_inferior
->process_target ());
1187 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1188 switch_to_thread (thr
);
1192 /* The old description may no longer be fit for the new image.
1193 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1194 old description; we'll read a new one below. No need to do
1195 this on "follow-exec-mode new", as the old inferior stays
1196 around (its description is later cleared/refetched on
1198 target_clear_description ();
1201 gdb_assert (current_program_space
== inf
->pspace
);
1203 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1204 because the proper displacement for a PIE (Position Independent
1205 Executable) main symbol file will only be computed by
1206 solib_create_inferior_hook below. breakpoint_re_set would fail
1207 to insert the breakpoints with the zero displacement. */
1208 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1210 /* If the target can specify a description, read it. Must do this
1211 after flipping to the new executable (because the target supplied
1212 description must be compatible with the executable's
1213 architecture, and the old executable may e.g., be 32-bit, while
1214 the new one 64-bit), and before anything involving memory or
1216 target_find_description ();
1218 gdb::observers::inferior_execd
.notify (inf
);
1220 breakpoint_re_set ();
1222 /* Reinsert all breakpoints. (Those which were symbolic have
1223 been reset to the proper address in the new a.out, thanks
1224 to symbol_file_command...). */
1225 insert_breakpoints ();
1227 /* The next resume of this inferior should bring it to the shlib
1228 startup breakpoints. (If the user had also set bp's on
1229 "main" from the old (parent) process, then they'll auto-
1230 matically get reset there in the new process.). */
1233 /* The chain of threads that need to do a step-over operation to get
1234 past e.g., a breakpoint. What technique is used to step over the
1235 breakpoint/watchpoint does not matter -- all threads end up in the
1236 same queue, to maintain rough temporal order of execution, in order
1237 to avoid starvation, otherwise, we could e.g., find ourselves
1238 constantly stepping the same couple threads past their breakpoints
1239 over and over, if the single-step finish fast enough. */
1240 struct thread_info
*global_thread_step_over_chain_head
;
1242 /* Bit flags indicating what the thread needs to step over. */
1244 enum step_over_what_flag
1246 /* Step over a breakpoint. */
1247 STEP_OVER_BREAKPOINT
= 1,
1249 /* Step past a non-continuable watchpoint, in order to let the
1250 instruction execute so we can evaluate the watchpoint
1252 STEP_OVER_WATCHPOINT
= 2
1254 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1256 /* Info about an instruction that is being stepped over. */
1258 struct step_over_info
1260 /* If we're stepping past a breakpoint, this is the address space
1261 and address of the instruction the breakpoint is set at. We'll
1262 skip inserting all breakpoints here. Valid iff ASPACE is
1264 const address_space
*aspace
= nullptr;
1265 CORE_ADDR address
= 0;
1267 /* The instruction being stepped over triggers a nonsteppable
1268 watchpoint. If true, we'll skip inserting watchpoints. */
1269 int nonsteppable_watchpoint_p
= 0;
1271 /* The thread's global number. */
1275 /* The step-over info of the location that is being stepped over.
1277 Note that with async/breakpoint always-inserted mode, a user might
1278 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1279 being stepped over. As setting a new breakpoint inserts all
1280 breakpoints, we need to make sure the breakpoint being stepped over
1281 isn't inserted then. We do that by only clearing the step-over
1282 info when the step-over is actually finished (or aborted).
1284 Presently GDB can only step over one breakpoint at any given time.
1285 Given threads that can't run code in the same address space as the
1286 breakpoint's can't really miss the breakpoint, GDB could be taught
1287 to step-over at most one breakpoint per address space (so this info
1288 could move to the address space object if/when GDB is extended).
1289 The set of breakpoints being stepped over will normally be much
1290 smaller than the set of all breakpoints, so a flag in the
1291 breakpoint location structure would be wasteful. A separate list
1292 also saves complexity and run-time, as otherwise we'd have to go
1293 through all breakpoint locations clearing their flag whenever we
1294 start a new sequence. Similar considerations weigh against storing
1295 this info in the thread object. Plus, not all step overs actually
1296 have breakpoint locations -- e.g., stepping past a single-step
1297 breakpoint, or stepping to complete a non-continuable
1299 static struct step_over_info step_over_info
;
1301 /* Record the address of the breakpoint/instruction we're currently
1303 N.B. We record the aspace and address now, instead of say just the thread,
1304 because when we need the info later the thread may be running. */
1307 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1308 int nonsteppable_watchpoint_p
,
1311 step_over_info
.aspace
= aspace
;
1312 step_over_info
.address
= address
;
1313 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1314 step_over_info
.thread
= thread
;
1317 /* Called when we're not longer stepping over a breakpoint / an
1318 instruction, so all breakpoints are free to be (re)inserted. */
1321 clear_step_over_info (void)
1323 infrun_debug_printf ("clearing step over info");
1324 step_over_info
.aspace
= NULL
;
1325 step_over_info
.address
= 0;
1326 step_over_info
.nonsteppable_watchpoint_p
= 0;
1327 step_over_info
.thread
= -1;
1333 stepping_past_instruction_at (struct address_space
*aspace
,
1336 return (step_over_info
.aspace
!= NULL
1337 && breakpoint_address_match (aspace
, address
,
1338 step_over_info
.aspace
,
1339 step_over_info
.address
));
1345 thread_is_stepping_over_breakpoint (int thread
)
1347 return (step_over_info
.thread
!= -1
1348 && thread
== step_over_info
.thread
);
1354 stepping_past_nonsteppable_watchpoint (void)
1356 return step_over_info
.nonsteppable_watchpoint_p
;
1359 /* Returns true if step-over info is valid. */
1362 step_over_info_valid_p (void)
1364 return (step_over_info
.aspace
!= NULL
1365 || stepping_past_nonsteppable_watchpoint ());
1369 /* Displaced stepping. */
1371 /* In non-stop debugging mode, we must take special care to manage
1372 breakpoints properly; in particular, the traditional strategy for
1373 stepping a thread past a breakpoint it has hit is unsuitable.
1374 'Displaced stepping' is a tactic for stepping one thread past a
1375 breakpoint it has hit while ensuring that other threads running
1376 concurrently will hit the breakpoint as they should.
1378 The traditional way to step a thread T off a breakpoint in a
1379 multi-threaded program in all-stop mode is as follows:
1381 a0) Initially, all threads are stopped, and breakpoints are not
1383 a1) We single-step T, leaving breakpoints uninserted.
1384 a2) We insert breakpoints, and resume all threads.
1386 In non-stop debugging, however, this strategy is unsuitable: we
1387 don't want to have to stop all threads in the system in order to
1388 continue or step T past a breakpoint. Instead, we use displaced
1391 n0) Initially, T is stopped, other threads are running, and
1392 breakpoints are inserted.
1393 n1) We copy the instruction "under" the breakpoint to a separate
1394 location, outside the main code stream, making any adjustments
1395 to the instruction, register, and memory state as directed by
1397 n2) We single-step T over the instruction at its new location.
1398 n3) We adjust the resulting register and memory state as directed
1399 by T's architecture. This includes resetting T's PC to point
1400 back into the main instruction stream.
1403 This approach depends on the following gdbarch methods:
1405 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1406 indicate where to copy the instruction, and how much space must
1407 be reserved there. We use these in step n1.
1409 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1410 address, and makes any necessary adjustments to the instruction,
1411 register contents, and memory. We use this in step n1.
1413 - gdbarch_displaced_step_fixup adjusts registers and memory after
1414 we have successfully single-stepped the instruction, to yield the
1415 same effect the instruction would have had if we had executed it
1416 at its original address. We use this in step n3.
1418 The gdbarch_displaced_step_copy_insn and
1419 gdbarch_displaced_step_fixup functions must be written so that
1420 copying an instruction with gdbarch_displaced_step_copy_insn,
1421 single-stepping across the copied instruction, and then applying
1422 gdbarch_displaced_insn_fixup should have the same effects on the
1423 thread's memory and registers as stepping the instruction in place
1424 would have. Exactly which responsibilities fall to the copy and
1425 which fall to the fixup is up to the author of those functions.
1427 See the comments in gdbarch.sh for details.
1429 Note that displaced stepping and software single-step cannot
1430 currently be used in combination, although with some care I think
1431 they could be made to. Software single-step works by placing
1432 breakpoints on all possible subsequent instructions; if the
1433 displaced instruction is a PC-relative jump, those breakpoints
1434 could fall in very strange places --- on pages that aren't
1435 executable, or at addresses that are not proper instruction
1436 boundaries. (We do generally let other threads run while we wait
1437 to hit the software single-step breakpoint, and they might
1438 encounter such a corrupted instruction.) One way to work around
1439 this would be to have gdbarch_displaced_step_copy_insn fully
1440 simulate the effect of PC-relative instructions (and return NULL)
1441 on architectures that use software single-stepping.
1443 In non-stop mode, we can have independent and simultaneous step
1444 requests, so more than one thread may need to simultaneously step
1445 over a breakpoint. The current implementation assumes there is
1446 only one scratch space per process. In this case, we have to
1447 serialize access to the scratch space. If thread A wants to step
1448 over a breakpoint, but we are currently waiting for some other
1449 thread to complete a displaced step, we leave thread A stopped and
1450 place it in the displaced_step_request_queue. Whenever a displaced
1451 step finishes, we pick the next thread in the queue and start a new
1452 displaced step operation on it. See displaced_step_prepare and
1453 displaced_step_finish for details. */
1455 /* Return true if THREAD is doing a displaced step. */
1458 displaced_step_in_progress_thread (thread_info
*thread
)
1460 gdb_assert (thread
!= NULL
);
1462 return thread
->displaced_step_state
.in_progress ();
1465 /* Return true if INF has a thread doing a displaced step. */
1468 displaced_step_in_progress (inferior
*inf
)
1470 return inf
->displaced_step_state
.in_progress_count
> 0;
1473 /* Return true if any thread is doing a displaced step. */
1476 displaced_step_in_progress_any_thread ()
1478 for (inferior
*inf
: all_non_exited_inferiors ())
1480 if (displaced_step_in_progress (inf
))
1488 infrun_inferior_exit (struct inferior
*inf
)
1490 inf
->displaced_step_state
.reset ();
1494 infrun_inferior_execd (inferior
*inf
)
1496 /* If some threads where was doing a displaced step in this inferior at the
1497 moment of the exec, they no longer exist. Even if the exec'ing thread
1498 doing a displaced step, we don't want to to any fixup nor restore displaced
1499 stepping buffer bytes. */
1500 inf
->displaced_step_state
.reset ();
1502 for (thread_info
*thread
: inf
->threads ())
1503 thread
->displaced_step_state
.reset ();
1505 /* Since an in-line step is done with everything else stopped, if there was
1506 one in progress at the time of the exec, it must have been the exec'ing
1508 clear_step_over_info ();
1511 /* If ON, and the architecture supports it, GDB will use displaced
1512 stepping to step over breakpoints. If OFF, or if the architecture
1513 doesn't support it, GDB will instead use the traditional
1514 hold-and-step approach. If AUTO (which is the default), GDB will
1515 decide which technique to use to step over breakpoints depending on
1516 whether the target works in a non-stop way (see use_displaced_stepping). */
1518 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1521 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1522 struct cmd_list_element
*c
,
1525 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1526 fprintf_filtered (file
,
1527 _("Debugger's willingness to use displaced stepping "
1528 "to step over breakpoints is %s (currently %s).\n"),
1529 value
, target_is_non_stop_p () ? "on" : "off");
1531 fprintf_filtered (file
,
1532 _("Debugger's willingness to use displaced stepping "
1533 "to step over breakpoints is %s.\n"), value
);
1536 /* Return true if the gdbarch implements the required methods to use
1537 displaced stepping. */
1540 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1542 /* Only check for the presence of `prepare`. The gdbarch verification ensures
1543 that if `prepare` is provided, so is `finish`. */
1544 return gdbarch_displaced_step_prepare_p (arch
);
1547 /* Return non-zero if displaced stepping can/should be used to step
1548 over breakpoints of thread TP. */
1551 use_displaced_stepping (thread_info
*tp
)
1553 /* If the user disabled it explicitly, don't use displaced stepping. */
1554 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1557 /* If "auto", only use displaced stepping if the target operates in a non-stop
1559 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1560 && !target_is_non_stop_p ())
1563 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1565 /* If the architecture doesn't implement displaced stepping, don't use
1567 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1570 /* If recording, don't use displaced stepping. */
1571 if (find_record_target () != nullptr)
1574 /* If displaced stepping failed before for this inferior, don't bother trying
1576 if (tp
->inf
->displaced_step_state
.failed_before
)
1582 /* Simple function wrapper around displaced_step_thread_state::reset. */
1585 displaced_step_reset (displaced_step_thread_state
*displaced
)
1587 displaced
->reset ();
1590 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1591 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1593 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1598 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1602 for (size_t i
= 0; i
< len
; i
++)
1605 ret
+= string_printf ("%02x", buf
[i
]);
1607 ret
+= string_printf (" %02x", buf
[i
]);
1613 /* Prepare to single-step, using displaced stepping.
1615 Note that we cannot use displaced stepping when we have a signal to
1616 deliver. If we have a signal to deliver and an instruction to step
1617 over, then after the step, there will be no indication from the
1618 target whether the thread entered a signal handler or ignored the
1619 signal and stepped over the instruction successfully --- both cases
1620 result in a simple SIGTRAP. In the first case we mustn't do a
1621 fixup, and in the second case we must --- but we can't tell which.
1622 Comments in the code for 'random signals' in handle_inferior_event
1623 explain how we handle this case instead.
1625 Returns DISPLACED_STEP_PREPARE_STATUS_OK if preparing was successful -- this
1626 thread is going to be stepped now; DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
1627 if displaced stepping this thread got queued; or
1628 DISPLACED_STEP_PREPARE_STATUS_CANT if this instruction can't be displaced
1631 static displaced_step_prepare_status
1632 displaced_step_prepare_throw (thread_info
*tp
)
1634 regcache
*regcache
= get_thread_regcache (tp
);
1635 struct gdbarch
*gdbarch
= regcache
->arch ();
1636 displaced_step_thread_state
&disp_step_thread_state
1637 = tp
->displaced_step_state
;
1639 /* We should never reach this function if the architecture does not
1640 support displaced stepping. */
1641 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1643 /* Nor if the thread isn't meant to step over a breakpoint. */
1644 gdb_assert (tp
->control
.trap_expected
);
1646 /* Disable range stepping while executing in the scratch pad. We
1647 want a single-step even if executing the displaced instruction in
1648 the scratch buffer lands within the stepping range (e.g., a
1650 tp
->control
.may_range_step
= 0;
1652 /* We are about to start a displaced step for this thread. If one is already
1653 in progress, something's wrong. */
1654 gdb_assert (!disp_step_thread_state
.in_progress ());
1656 if (tp
->inf
->displaced_step_state
.unavailable
)
1658 /* The gdbarch tells us it's not worth asking to try a prepare because
1659 it is likely that it will return unavailable, so don't bother asking. */
1661 displaced_debug_printf ("deferring step of %s",
1662 target_pid_to_str (tp
->ptid
).c_str ());
1664 global_thread_step_over_chain_enqueue (tp
);
1665 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1668 displaced_debug_printf ("displaced-stepping %s now",
1669 target_pid_to_str (tp
->ptid
).c_str ());
1671 scoped_restore_current_thread restore_thread
;
1673 switch_to_thread (tp
);
1675 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1676 CORE_ADDR displaced_pc
;
1678 displaced_step_prepare_status status
1679 = gdbarch_displaced_step_prepare (gdbarch
, tp
, displaced_pc
);
1681 if (status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
1683 displaced_debug_printf ("failed to prepare (%s)",
1684 target_pid_to_str (tp
->ptid
).c_str ());
1686 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1688 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1690 /* Not enough displaced stepping resources available, defer this
1691 request by placing it the queue. */
1693 displaced_debug_printf ("not enough resources available, "
1694 "deferring step of %s",
1695 target_pid_to_str (tp
->ptid
).c_str ());
1697 global_thread_step_over_chain_enqueue (tp
);
1699 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1702 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1704 /* Save the information we need to fix things up if the step
1706 disp_step_thread_state
.set (gdbarch
);
1708 tp
->inf
->displaced_step_state
.in_progress_count
++;
1710 displaced_debug_printf ("prepared successfully thread=%s, "
1711 "original_pc=%s, displaced_pc=%s",
1712 target_pid_to_str (tp
->ptid
).c_str (),
1713 paddress (gdbarch
, original_pc
),
1714 paddress (gdbarch
, displaced_pc
));
1716 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1719 /* Wrapper for displaced_step_prepare_throw that disabled further
1720 attempts at displaced stepping if we get a memory error. */
1722 static displaced_step_prepare_status
1723 displaced_step_prepare (thread_info
*thread
)
1725 displaced_step_prepare_status status
1726 = DISPLACED_STEP_PREPARE_STATUS_CANT
;
1730 status
= displaced_step_prepare_throw (thread
);
1732 catch (const gdb_exception_error
&ex
)
1734 if (ex
.error
!= MEMORY_ERROR
1735 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1738 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1741 /* Be verbose if "set displaced-stepping" is "on", silent if
1743 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1745 warning (_("disabling displaced stepping: %s"),
1749 /* Disable further displaced stepping attempts. */
1750 thread
->inf
->displaced_step_state
.failed_before
= 1;
1756 /* If we displaced stepped an instruction successfully, adjust registers and
1757 memory to yield the same effect the instruction would have had if we had
1758 executed it at its original address, and return
1759 DISPLACED_STEP_FINISH_STATUS_OK. If the instruction didn't complete,
1760 relocate the PC and return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED.
1762 If the thread wasn't displaced stepping, return
1763 DISPLACED_STEP_FINISH_STATUS_OK as well. */
1765 static displaced_step_finish_status
1766 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1768 displaced_step_thread_state
*displaced
= &event_thread
->displaced_step_state
;
1770 /* Was this thread performing a displaced step? */
1771 if (!displaced
->in_progress ())
1772 return DISPLACED_STEP_FINISH_STATUS_OK
;
1774 gdb_assert (event_thread
->inf
->displaced_step_state
.in_progress_count
> 0);
1775 event_thread
->inf
->displaced_step_state
.in_progress_count
--;
1777 /* Fixup may need to read memory/registers. Switch to the thread
1778 that we're fixing up. Also, target_stopped_by_watchpoint checks
1779 the current thread, and displaced_step_restore performs ptid-dependent
1780 memory accesses using current_inferior(). */
1781 switch_to_thread (event_thread
);
1783 displaced_step_reset_cleanup
cleanup (displaced
);
1785 /* Do the fixup, and release the resources acquired to do the displaced
1787 return gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1788 event_thread
, signal
);
1791 /* Data to be passed around while handling an event. This data is
1792 discarded between events. */
1793 struct execution_control_state
1795 process_stratum_target
*target
;
1797 /* The thread that got the event, if this was a thread event; NULL
1799 struct thread_info
*event_thread
;
1801 struct target_waitstatus ws
;
1802 int stop_func_filled_in
;
1803 CORE_ADDR stop_func_start
;
1804 CORE_ADDR stop_func_end
;
1805 const char *stop_func_name
;
1808 /* True if the event thread hit the single-step breakpoint of
1809 another thread. Thus the event doesn't cause a stop, the thread
1810 needs to be single-stepped past the single-step breakpoint before
1811 we can switch back to the original stepping thread. */
1812 int hit_singlestep_breakpoint
;
1815 /* Clear ECS and set it to point at TP. */
1818 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1820 memset (ecs
, 0, sizeof (*ecs
));
1821 ecs
->event_thread
= tp
;
1822 ecs
->ptid
= tp
->ptid
;
1825 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1826 static void prepare_to_wait (struct execution_control_state
*ecs
);
1827 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1828 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1830 /* Are there any pending step-over requests? If so, run all we can
1831 now and return true. Otherwise, return false. */
1834 start_step_over (void)
1836 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
1840 /* Don't start a new step-over if we already have an in-line
1841 step-over operation ongoing. */
1842 if (step_over_info_valid_p ())
1845 /* Steal the global thread step over chain. As we try to initiate displaced
1846 steps, threads will be enqueued in the global chain if no buffers are
1847 available. If we iterated on the global chain directly, we might iterate
1849 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1850 global_thread_step_over_chain_head
= NULL
;
1852 infrun_debug_printf ("stealing global queue of threads to step, length = %d",
1853 thread_step_over_chain_length (threads_to_step
));
1855 bool started
= false;
1857 /* On scope exit (whatever the reason, return or exception), if there are
1858 threads left in the THREADS_TO_STEP chain, put back these threads in the
1862 if (threads_to_step
== nullptr)
1863 infrun_debug_printf ("step-over queue now empty");
1866 infrun_debug_printf ("putting back %d threads to step in global queue",
1867 thread_step_over_chain_length (threads_to_step
));
1869 global_thread_step_over_chain_enqueue_chain (threads_to_step
);
1873 for (thread_info
*tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1875 struct execution_control_state ecss
;
1876 struct execution_control_state
*ecs
= &ecss
;
1877 step_over_what step_what
;
1878 int must_be_in_line
;
1880 gdb_assert (!tp
->stop_requested
);
1882 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1884 if (tp
->inf
->displaced_step_state
.unavailable
)
1886 /* The arch told us to not even try preparing another displaced step
1887 for this inferior. Just leave the thread in THREADS_TO_STEP, it
1888 will get moved to the global chain on scope exit. */
1892 /* Remove thread from the THREADS_TO_STEP chain. If anything goes wrong
1893 while we try to prepare the displaced step, we don't add it back to
1894 the global step over chain. This is to avoid a thread staying in the
1895 step over chain indefinitely if something goes wrong when resuming it
1896 If the error is intermittent and it still needs a step over, it will
1897 get enqueued again when we try to resume it normally. */
1898 thread_step_over_chain_remove (&threads_to_step
, tp
);
1900 step_what
= thread_still_needs_step_over (tp
);
1901 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1902 || ((step_what
& STEP_OVER_BREAKPOINT
)
1903 && !use_displaced_stepping (tp
)));
1905 /* We currently stop all threads of all processes to step-over
1906 in-line. If we need to start a new in-line step-over, let
1907 any pending displaced steps finish first. */
1908 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1910 global_thread_step_over_chain_enqueue (tp
);
1914 if (tp
->control
.trap_expected
1918 internal_error (__FILE__
, __LINE__
,
1919 "[%s] has inconsistent state: "
1920 "trap_expected=%d, resumed=%d, executing=%d\n",
1921 target_pid_to_str (tp
->ptid
).c_str (),
1922 tp
->control
.trap_expected
,
1927 infrun_debug_printf ("resuming [%s] for step-over",
1928 target_pid_to_str (tp
->ptid
).c_str ());
1930 /* keep_going_pass_signal skips the step-over if the breakpoint
1931 is no longer inserted. In all-stop, we want to keep looking
1932 for a thread that needs a step-over instead of resuming TP,
1933 because we wouldn't be able to resume anything else until the
1934 target stops again. In non-stop, the resume always resumes
1935 only TP, so it's OK to let the thread resume freely. */
1936 if (!target_is_non_stop_p () && !step_what
)
1939 switch_to_thread (tp
);
1940 reset_ecs (ecs
, tp
);
1941 keep_going_pass_signal (ecs
);
1943 if (!ecs
->wait_some_more
)
1944 error (_("Command aborted."));
1946 /* If the thread's step over could not be initiated because no buffers
1947 were available, it was re-added to the global step over chain. */
1950 infrun_debug_printf ("[%s] was resumed.",
1951 target_pid_to_str (tp
->ptid
).c_str ());
1952 gdb_assert (!thread_is_in_step_over_chain (tp
));
1956 infrun_debug_printf ("[%s] was NOT resumed.",
1957 target_pid_to_str (tp
->ptid
).c_str ());
1958 gdb_assert (thread_is_in_step_over_chain (tp
));
1961 /* If we started a new in-line step-over, we're done. */
1962 if (step_over_info_valid_p ())
1964 gdb_assert (tp
->control
.trap_expected
);
1969 if (!target_is_non_stop_p ())
1971 /* On all-stop, shouldn't have resumed unless we needed a
1973 gdb_assert (tp
->control
.trap_expected
1974 || tp
->step_after_step_resume_breakpoint
);
1976 /* With remote targets (at least), in all-stop, we can't
1977 issue any further remote commands until the program stops
1983 /* Either the thread no longer needed a step-over, or a new
1984 displaced stepping sequence started. Even in the latter
1985 case, continue looking. Maybe we can also start another
1986 displaced step on a thread of other process. */
1992 /* Update global variables holding ptids to hold NEW_PTID if they were
1993 holding OLD_PTID. */
1995 infrun_thread_ptid_changed (process_stratum_target
*target
,
1996 ptid_t old_ptid
, ptid_t new_ptid
)
1998 if (inferior_ptid
== old_ptid
1999 && current_inferior ()->process_target () == target
)
2000 inferior_ptid
= new_ptid
;
2005 static const char schedlock_off
[] = "off";
2006 static const char schedlock_on
[] = "on";
2007 static const char schedlock_step
[] = "step";
2008 static const char schedlock_replay
[] = "replay";
2009 static const char *const scheduler_enums
[] = {
2016 static const char *scheduler_mode
= schedlock_replay
;
2018 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2019 struct cmd_list_element
*c
, const char *value
)
2021 fprintf_filtered (file
,
2022 _("Mode for locking scheduler "
2023 "during execution is \"%s\".\n"),
2028 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2030 if (!target_can_lock_scheduler ())
2032 scheduler_mode
= schedlock_off
;
2033 error (_("Target '%s' cannot support this command."),
2034 target_shortname ());
2038 /* True if execution commands resume all threads of all processes by
2039 default; otherwise, resume only threads of the current inferior
2041 bool sched_multi
= false;
2043 /* Try to setup for software single stepping over the specified location.
2044 Return true if target_resume() should use hardware single step.
2046 GDBARCH the current gdbarch.
2047 PC the location to step over. */
2050 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2052 bool hw_step
= true;
2054 if (execution_direction
== EXEC_FORWARD
2055 && gdbarch_software_single_step_p (gdbarch
))
2056 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2064 user_visible_resume_ptid (int step
)
2070 /* With non-stop mode on, threads are always handled
2072 resume_ptid
= inferior_ptid
;
2074 else if ((scheduler_mode
== schedlock_on
)
2075 || (scheduler_mode
== schedlock_step
&& step
))
2077 /* User-settable 'scheduler' mode requires solo thread
2079 resume_ptid
= inferior_ptid
;
2081 else if ((scheduler_mode
== schedlock_replay
)
2082 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2084 /* User-settable 'scheduler' mode requires solo thread resume in replay
2086 resume_ptid
= inferior_ptid
;
2088 else if (!sched_multi
&& target_supports_multi_process ())
2090 /* Resume all threads of the current process (and none of other
2092 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2096 /* Resume all threads of all processes. */
2097 resume_ptid
= RESUME_ALL
;
2105 process_stratum_target
*
2106 user_visible_resume_target (ptid_t resume_ptid
)
2108 return (resume_ptid
== minus_one_ptid
&& sched_multi
2110 : current_inferior ()->process_target ());
2113 /* Return a ptid representing the set of threads that we will resume,
2114 in the perspective of the target, assuming run control handling
2115 does not require leaving some threads stopped (e.g., stepping past
2116 breakpoint). USER_STEP indicates whether we're about to start the
2117 target for a stepping command. */
2120 internal_resume_ptid (int user_step
)
2122 /* In non-stop, we always control threads individually. Note that
2123 the target may always work in non-stop mode even with "set
2124 non-stop off", in which case user_visible_resume_ptid could
2125 return a wildcard ptid. */
2126 if (target_is_non_stop_p ())
2127 return inferior_ptid
;
2129 return user_visible_resume_ptid (user_step
);
2132 /* Wrapper for target_resume, that handles infrun-specific
2136 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2138 struct thread_info
*tp
= inferior_thread ();
2140 gdb_assert (!tp
->stop_requested
);
2142 /* Install inferior's terminal modes. */
2143 target_terminal::inferior ();
2145 /* Avoid confusing the next resume, if the next stop/resume
2146 happens to apply to another thread. */
2147 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2149 /* Advise target which signals may be handled silently.
2151 If we have removed breakpoints because we are stepping over one
2152 in-line (in any thread), we need to receive all signals to avoid
2153 accidentally skipping a breakpoint during execution of a signal
2156 Likewise if we're displaced stepping, otherwise a trap for a
2157 breakpoint in a signal handler might be confused with the
2158 displaced step finishing. We don't make the displaced_step_finish
2159 step distinguish the cases instead, because:
2161 - a backtrace while stopped in the signal handler would show the
2162 scratch pad as frame older than the signal handler, instead of
2163 the real mainline code.
2165 - when the thread is later resumed, the signal handler would
2166 return to the scratch pad area, which would no longer be
2168 if (step_over_info_valid_p ()
2169 || displaced_step_in_progress (tp
->inf
))
2170 target_pass_signals ({});
2172 target_pass_signals (signal_pass
);
2174 target_resume (resume_ptid
, step
, sig
);
2176 target_commit_resume ();
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 /* Calls target_commit_resume on all targets. */
2767 commit_resume_all_targets ()
2769 scoped_restore_current_thread restore_thread
;
2771 /* Map between process_target and a representative inferior. This
2772 is to avoid committing a resume in the same target more than
2773 once. Resumptions must be idempotent, so this is an
2775 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2777 for (inferior
*inf
: all_non_exited_inferiors ())
2778 if (inf
->has_execution ())
2779 conn_inf
[inf
->process_target ()] = inf
;
2781 for (const auto &ci
: conn_inf
)
2783 inferior
*inf
= ci
.second
;
2784 switch_to_inferior_no_thread (inf
);
2785 target_commit_resume ();
2789 /* Check that all the targets we're about to resume are in non-stop
2790 mode. Ideally, we'd only care whether all targets support
2791 target-async, but we're not there yet. E.g., stop_all_threads
2792 doesn't know how to handle all-stop targets. Also, the remote
2793 protocol in all-stop mode is synchronous, irrespective of
2794 target-async, which means that things like a breakpoint re-set
2795 triggered by one target would try to read memory from all targets
2799 check_multi_target_resumption (process_stratum_target
*resume_target
)
2801 if (!non_stop
&& resume_target
== nullptr)
2803 scoped_restore_current_thread restore_thread
;
2805 /* This is used to track whether we're resuming more than one
2807 process_stratum_target
*first_connection
= nullptr;
2809 /* The first inferior we see with a target that does not work in
2810 always-non-stop mode. */
2811 inferior
*first_not_non_stop
= nullptr;
2813 for (inferior
*inf
: all_non_exited_inferiors ())
2815 switch_to_inferior_no_thread (inf
);
2817 if (!target_has_execution ())
2820 process_stratum_target
*proc_target
2821 = current_inferior ()->process_target();
2823 if (!target_is_non_stop_p ())
2824 first_not_non_stop
= inf
;
2826 if (first_connection
== nullptr)
2827 first_connection
= proc_target
;
2828 else if (first_connection
!= proc_target
2829 && first_not_non_stop
!= nullptr)
2831 switch_to_inferior_no_thread (first_not_non_stop
);
2833 proc_target
= current_inferior ()->process_target();
2835 error (_("Connection %d (%s) does not support "
2836 "multi-target resumption."),
2837 proc_target
->connection_number
,
2838 make_target_connection_string (proc_target
).c_str ());
2844 /* Basic routine for continuing the program in various fashions.
2846 ADDR is the address to resume at, or -1 for resume where stopped.
2847 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2848 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2850 You should call clear_proceed_status before calling proceed. */
2853 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2855 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
2857 struct regcache
*regcache
;
2858 struct gdbarch
*gdbarch
;
2860 struct execution_control_state ecss
;
2861 struct execution_control_state
*ecs
= &ecss
;
2864 /* If we're stopped at a fork/vfork, follow the branch set by the
2865 "set follow-fork-mode" command; otherwise, we'll just proceed
2866 resuming the current thread. */
2867 if (!follow_fork ())
2869 /* The target for some reason decided not to resume. */
2871 if (target_can_async_p ())
2872 inferior_event_handler (INF_EXEC_COMPLETE
);
2876 /* We'll update this if & when we switch to a new thread. */
2877 previous_inferior_ptid
= inferior_ptid
;
2879 regcache
= get_current_regcache ();
2880 gdbarch
= regcache
->arch ();
2881 const address_space
*aspace
= regcache
->aspace ();
2883 pc
= regcache_read_pc_protected (regcache
);
2885 thread_info
*cur_thr
= inferior_thread ();
2887 /* Fill in with reasonable starting values. */
2888 init_thread_stepping_state (cur_thr
);
2890 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2893 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2894 process_stratum_target
*resume_target
2895 = user_visible_resume_target (resume_ptid
);
2897 check_multi_target_resumption (resume_target
);
2899 if (addr
== (CORE_ADDR
) -1)
2901 if (pc
== cur_thr
->suspend
.stop_pc
2902 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2903 && execution_direction
!= EXEC_REVERSE
)
2904 /* There is a breakpoint at the address we will resume at,
2905 step one instruction before inserting breakpoints so that
2906 we do not stop right away (and report a second hit at this
2909 Note, we don't do this in reverse, because we won't
2910 actually be executing the breakpoint insn anyway.
2911 We'll be (un-)executing the previous instruction. */
2912 cur_thr
->stepping_over_breakpoint
= 1;
2913 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2914 && gdbarch_single_step_through_delay (gdbarch
,
2915 get_current_frame ()))
2916 /* We stepped onto an instruction that needs to be stepped
2917 again before re-inserting the breakpoint, do so. */
2918 cur_thr
->stepping_over_breakpoint
= 1;
2922 regcache_write_pc (regcache
, addr
);
2925 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2926 cur_thr
->suspend
.stop_signal
= siggnal
;
2928 /* If an exception is thrown from this point on, make sure to
2929 propagate GDB's knowledge of the executing state to the
2930 frontend/user running state. */
2931 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2933 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2934 threads (e.g., we might need to set threads stepping over
2935 breakpoints first), from the user/frontend's point of view, all
2936 threads in RESUME_PTID are now running. Unless we're calling an
2937 inferior function, as in that case we pretend the inferior
2938 doesn't run at all. */
2939 if (!cur_thr
->control
.in_infcall
)
2940 set_running (resume_target
, resume_ptid
, true);
2942 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2943 gdb_signal_to_symbol_string (siggnal
));
2945 annotate_starting ();
2947 /* Make sure that output from GDB appears before output from the
2949 gdb_flush (gdb_stdout
);
2951 /* Since we've marked the inferior running, give it the terminal. A
2952 QUIT/Ctrl-C from here on is forwarded to the target (which can
2953 still detect attempts to unblock a stuck connection with repeated
2954 Ctrl-C from within target_pass_ctrlc). */
2955 target_terminal::inferior ();
2957 /* In a multi-threaded task we may select another thread and
2958 then continue or step.
2960 But if a thread that we're resuming had stopped at a breakpoint,
2961 it will immediately cause another breakpoint stop without any
2962 execution (i.e. it will report a breakpoint hit incorrectly). So
2963 we must step over it first.
2965 Look for threads other than the current (TP) that reported a
2966 breakpoint hit and haven't been resumed yet since. */
2968 /* If scheduler locking applies, we can avoid iterating over all
2970 if (!non_stop
&& !schedlock_applies (cur_thr
))
2972 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
2975 switch_to_thread_no_regs (tp
);
2977 /* Ignore the current thread here. It's handled
2982 if (!thread_still_needs_step_over (tp
))
2985 gdb_assert (!thread_is_in_step_over_chain (tp
));
2987 infrun_debug_printf ("need to step-over [%s] first",
2988 target_pid_to_str (tp
->ptid
).c_str ());
2990 global_thread_step_over_chain_enqueue (tp
);
2993 switch_to_thread (cur_thr
);
2996 /* Enqueue the current thread last, so that we move all other
2997 threads over their breakpoints first. */
2998 if (cur_thr
->stepping_over_breakpoint
)
2999 global_thread_step_over_chain_enqueue (cur_thr
);
3001 /* If the thread isn't started, we'll still need to set its prev_pc,
3002 so that switch_back_to_stepped_thread knows the thread hasn't
3003 advanced. Must do this before resuming any thread, as in
3004 all-stop/remote, once we resume we can't send any other packet
3005 until the target stops again. */
3006 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3009 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3011 started
= start_step_over ();
3013 if (step_over_info_valid_p ())
3015 /* Either this thread started a new in-line step over, or some
3016 other thread was already doing one. In either case, don't
3017 resume anything else until the step-over is finished. */
3019 else if (started
&& !target_is_non_stop_p ())
3021 /* A new displaced stepping sequence was started. In all-stop,
3022 we can't talk to the target anymore until it next stops. */
3024 else if (!non_stop
&& target_is_non_stop_p ())
3026 INFRUN_SCOPED_DEBUG_START_END
3027 ("resuming threads, all-stop-on-top-of-non-stop");
3029 /* In all-stop, but the target is always in non-stop mode.
3030 Start all other threads that are implicitly resumed too. */
3031 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3034 switch_to_thread_no_regs (tp
);
3036 if (!tp
->inf
->has_execution ())
3038 infrun_debug_printf ("[%s] target has no execution",
3039 target_pid_to_str (tp
->ptid
).c_str ());
3045 infrun_debug_printf ("[%s] resumed",
3046 target_pid_to_str (tp
->ptid
).c_str ());
3047 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3051 if (thread_is_in_step_over_chain (tp
))
3053 infrun_debug_printf ("[%s] needs step-over",
3054 target_pid_to_str (tp
->ptid
).c_str ());
3058 infrun_debug_printf ("resuming %s",
3059 target_pid_to_str (tp
->ptid
).c_str ());
3061 reset_ecs (ecs
, tp
);
3062 switch_to_thread (tp
);
3063 keep_going_pass_signal (ecs
);
3064 if (!ecs
->wait_some_more
)
3065 error (_("Command aborted."));
3068 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3070 /* The thread wasn't started, and isn't queued, run it now. */
3071 reset_ecs (ecs
, cur_thr
);
3072 switch_to_thread (cur_thr
);
3073 keep_going_pass_signal (ecs
);
3074 if (!ecs
->wait_some_more
)
3075 error (_("Command aborted."));
3079 commit_resume_all_targets ();
3081 finish_state
.release ();
3083 /* If we've switched threads above, switch back to the previously
3084 current thread. We don't want the user to see a different
3086 switch_to_thread (cur_thr
);
3088 /* Tell the event loop to wait for it to stop. If the target
3089 supports asynchronous execution, it'll do this from within
3091 if (!target_can_async_p ())
3092 mark_async_event_handler (infrun_async_inferior_event_token
);
3096 /* Start remote-debugging of a machine over a serial link. */
3099 start_remote (int from_tty
)
3101 inferior
*inf
= current_inferior ();
3102 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3104 /* Always go on waiting for the target, regardless of the mode. */
3105 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3106 indicate to wait_for_inferior that a target should timeout if
3107 nothing is returned (instead of just blocking). Because of this,
3108 targets expecting an immediate response need to, internally, set
3109 things up so that the target_wait() is forced to eventually
3111 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3112 differentiate to its caller what the state of the target is after
3113 the initial open has been performed. Here we're assuming that
3114 the target has stopped. It should be possible to eventually have
3115 target_open() return to the caller an indication that the target
3116 is currently running and GDB state should be set to the same as
3117 for an async run. */
3118 wait_for_inferior (inf
);
3120 /* Now that the inferior has stopped, do any bookkeeping like
3121 loading shared libraries. We want to do this before normal_stop,
3122 so that the displayed frame is up to date. */
3123 post_create_inferior (from_tty
);
3128 /* Initialize static vars when a new inferior begins. */
3131 init_wait_for_inferior (void)
3133 /* These are meaningless until the first time through wait_for_inferior. */
3135 breakpoint_init_inferior (inf_starting
);
3137 clear_proceed_status (0);
3139 nullify_last_target_wait_ptid ();
3141 previous_inferior_ptid
= inferior_ptid
;
3146 static void handle_inferior_event (struct execution_control_state
*ecs
);
3148 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3149 struct execution_control_state
*ecs
);
3150 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3151 struct execution_control_state
*ecs
);
3152 static void handle_signal_stop (struct execution_control_state
*ecs
);
3153 static void check_exception_resume (struct execution_control_state
*,
3154 struct frame_info
*);
3156 static void end_stepping_range (struct execution_control_state
*ecs
);
3157 static void stop_waiting (struct execution_control_state
*ecs
);
3158 static void keep_going (struct execution_control_state
*ecs
);
3159 static void process_event_stop_test (struct execution_control_state
*ecs
);
3160 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3162 /* This function is attached as a "thread_stop_requested" observer.
3163 Cleanup local state that assumed the PTID was to be resumed, and
3164 report the stop to the frontend. */
3167 infrun_thread_stop_requested (ptid_t ptid
)
3169 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3171 /* PTID was requested to stop. If the thread was already stopped,
3172 but the user/frontend doesn't know about that yet (e.g., the
3173 thread had been temporarily paused for some step-over), set up
3174 for reporting the stop now. */
3175 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3177 if (tp
->state
!= THREAD_RUNNING
)
3182 /* Remove matching threads from the step-over queue, so
3183 start_step_over doesn't try to resume them
3185 if (thread_is_in_step_over_chain (tp
))
3186 global_thread_step_over_chain_remove (tp
);
3188 /* If the thread is stopped, but the user/frontend doesn't
3189 know about that yet, queue a pending event, as if the
3190 thread had just stopped now. Unless the thread already had
3192 if (!tp
->suspend
.waitstatus_pending_p
)
3194 tp
->suspend
.waitstatus_pending_p
= 1;
3195 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3196 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3199 /* Clear the inline-frame state, since we're re-processing the
3201 clear_inline_frame_state (tp
);
3203 /* If this thread was paused because some other thread was
3204 doing an inline-step over, let that finish first. Once
3205 that happens, we'll restart all threads and consume pending
3206 stop events then. */
3207 if (step_over_info_valid_p ())
3210 /* Otherwise we can process the (new) pending event now. Set
3211 it so this pending event is considered by
3218 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3220 if (target_last_proc_target
== tp
->inf
->process_target ()
3221 && target_last_wait_ptid
== tp
->ptid
)
3222 nullify_last_target_wait_ptid ();
3225 /* Delete the step resume, single-step and longjmp/exception resume
3226 breakpoints of TP. */
3229 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3231 delete_step_resume_breakpoint (tp
);
3232 delete_exception_resume_breakpoint (tp
);
3233 delete_single_step_breakpoints (tp
);
3236 /* If the target still has execution, call FUNC for each thread that
3237 just stopped. In all-stop, that's all the non-exited threads; in
3238 non-stop, that's the current thread, only. */
3240 typedef void (*for_each_just_stopped_thread_callback_func
)
3241 (struct thread_info
*tp
);
3244 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3246 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3249 if (target_is_non_stop_p ())
3251 /* If in non-stop mode, only the current thread stopped. */
3252 func (inferior_thread ());
3256 /* In all-stop mode, all threads have stopped. */
3257 for (thread_info
*tp
: all_non_exited_threads ())
3262 /* Delete the step resume and longjmp/exception resume breakpoints of
3263 the threads that just stopped. */
3266 delete_just_stopped_threads_infrun_breakpoints (void)
3268 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3271 /* Delete the single-step breakpoints of the threads that just
3275 delete_just_stopped_threads_single_step_breakpoints (void)
3277 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3283 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3284 const struct target_waitstatus
*ws
)
3286 infrun_debug_printf ("target_wait (%d.%ld.%ld [%s], status) =",
3290 target_pid_to_str (waiton_ptid
).c_str ());
3291 infrun_debug_printf (" %d.%ld.%ld [%s],",
3295 target_pid_to_str (result_ptid
).c_str ());
3296 infrun_debug_printf (" %s", target_waitstatus_to_string (ws
).c_str ());
3299 /* Select a thread at random, out of those which are resumed and have
3302 static struct thread_info
*
3303 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3307 auto has_event
= [&] (thread_info
*tp
)
3309 return (tp
->ptid
.matches (waiton_ptid
)
3311 && tp
->suspend
.waitstatus_pending_p
);
3314 /* First see how many events we have. Count only resumed threads
3315 that have an event pending. */
3316 for (thread_info
*tp
: inf
->non_exited_threads ())
3320 if (num_events
== 0)
3323 /* Now randomly pick a thread out of those that have had events. */
3324 int random_selector
= (int) ((num_events
* (double) rand ())
3325 / (RAND_MAX
+ 1.0));
3328 infrun_debug_printf ("Found %d events, selecting #%d",
3329 num_events
, random_selector
);
3331 /* Select the Nth thread that has had an event. */
3332 for (thread_info
*tp
: inf
->non_exited_threads ())
3334 if (random_selector
-- == 0)
3337 gdb_assert_not_reached ("event thread not found");
3340 /* Wrapper for target_wait that first checks whether threads have
3341 pending statuses to report before actually asking the target for
3342 more events. INF is the inferior we're using to call target_wait
3346 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3347 target_waitstatus
*status
, target_wait_flags options
)
3350 struct thread_info
*tp
;
3352 /* We know that we are looking for an event in the target of inferior
3353 INF, but we don't know which thread the event might come from. As
3354 such we want to make sure that INFERIOR_PTID is reset so that none of
3355 the wait code relies on it - doing so is always a mistake. */
3356 switch_to_inferior_no_thread (inf
);
3358 /* First check if there is a resumed thread with a wait status
3360 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3362 tp
= random_pending_event_thread (inf
, ptid
);
3366 infrun_debug_printf ("Waiting for specific thread %s.",
3367 target_pid_to_str (ptid
).c_str ());
3369 /* We have a specific thread to check. */
3370 tp
= find_thread_ptid (inf
, ptid
);
3371 gdb_assert (tp
!= NULL
);
3372 if (!tp
->suspend
.waitstatus_pending_p
)
3377 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3378 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3380 struct regcache
*regcache
= get_thread_regcache (tp
);
3381 struct gdbarch
*gdbarch
= regcache
->arch ();
3385 pc
= regcache_read_pc (regcache
);
3387 if (pc
!= tp
->suspend
.stop_pc
)
3389 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3390 target_pid_to_str (tp
->ptid
).c_str (),
3391 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3392 paddress (gdbarch
, pc
));
3395 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3397 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3398 target_pid_to_str (tp
->ptid
).c_str (),
3399 paddress (gdbarch
, pc
));
3406 infrun_debug_printf ("pending event of %s cancelled.",
3407 target_pid_to_str (tp
->ptid
).c_str ());
3409 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3410 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3416 infrun_debug_printf ("Using pending wait status %s for %s.",
3417 target_waitstatus_to_string
3418 (&tp
->suspend
.waitstatus
).c_str (),
3419 target_pid_to_str (tp
->ptid
).c_str ());
3421 /* Now that we've selected our final event LWP, un-adjust its PC
3422 if it was a software breakpoint (and the target doesn't
3423 always adjust the PC itself). */
3424 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3425 && !target_supports_stopped_by_sw_breakpoint ())
3427 struct regcache
*regcache
;
3428 struct gdbarch
*gdbarch
;
3431 regcache
= get_thread_regcache (tp
);
3432 gdbarch
= regcache
->arch ();
3434 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3439 pc
= regcache_read_pc (regcache
);
3440 regcache_write_pc (regcache
, pc
+ decr_pc
);
3444 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3445 *status
= tp
->suspend
.waitstatus
;
3446 tp
->suspend
.waitstatus_pending_p
= 0;
3448 /* Wake up the event loop again, until all pending events are
3450 if (target_is_async_p ())
3451 mark_async_event_handler (infrun_async_inferior_event_token
);
3455 /* But if we don't find one, we'll have to wait. */
3457 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3459 if (!target_can_async_p ())
3460 options
&= ~TARGET_WNOHANG
;
3462 if (deprecated_target_wait_hook
)
3463 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3465 event_ptid
= target_wait (ptid
, status
, options
);
3470 /* Wrapper for target_wait that first checks whether threads have
3471 pending statuses to report before actually asking the target for
3472 more events. Polls for events from all inferiors/targets. */
3475 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3476 target_wait_flags options
)
3478 int num_inferiors
= 0;
3479 int random_selector
;
3481 /* For fairness, we pick the first inferior/target to poll at random
3482 out of all inferiors that may report events, and then continue
3483 polling the rest of the inferior list starting from that one in a
3484 circular fashion until the whole list is polled once. */
3486 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3488 return (inf
->process_target () != NULL
3489 && ptid_t (inf
->pid
).matches (wait_ptid
));
3492 /* First see how many matching inferiors we have. */
3493 for (inferior
*inf
: all_inferiors ())
3494 if (inferior_matches (inf
))
3497 if (num_inferiors
== 0)
3499 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3503 /* Now randomly pick an inferior out of those that matched. */
3504 random_selector
= (int)
3505 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3507 if (num_inferiors
> 1)
3508 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3509 num_inferiors
, random_selector
);
3511 /* Select the Nth inferior that matched. */
3513 inferior
*selected
= nullptr;
3515 for (inferior
*inf
: all_inferiors ())
3516 if (inferior_matches (inf
))
3517 if (random_selector
-- == 0)
3523 /* Now poll for events out of each of the matching inferior's
3524 targets, starting from the selected one. */
3526 auto do_wait
= [&] (inferior
*inf
)
3528 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3529 ecs
->target
= inf
->process_target ();
3530 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3533 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3534 here spuriously after the target is all stopped and we've already
3535 reported the stop to the user, polling for events. */
3536 scoped_restore_current_thread restore_thread
;
3538 int inf_num
= selected
->num
;
3539 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3540 if (inferior_matches (inf
))
3544 for (inferior
*inf
= inferior_list
;
3545 inf
!= NULL
&& inf
->num
< inf_num
;
3547 if (inferior_matches (inf
))
3551 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3555 /* An event reported by wait_one. */
3557 struct wait_one_event
3559 /* The target the event came out of. */
3560 process_stratum_target
*target
;
3562 /* The PTID the event was for. */
3565 /* The waitstatus. */
3566 target_waitstatus ws
;
3569 static bool handle_one (const wait_one_event
&event
);
3570 static void restart_threads (struct thread_info
*event_thread
);
3572 /* Prepare and stabilize the inferior for detaching it. E.g.,
3573 detaching while a thread is displaced stepping is a recipe for
3574 crashing it, as nothing would readjust the PC out of the scratch
3578 prepare_for_detach (void)
3580 struct inferior
*inf
= current_inferior ();
3581 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3582 scoped_restore_current_thread restore_thread
;
3584 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3586 /* Remove all threads of INF from the global step-over chain. We
3587 want to stop any ongoing step-over, not start any new one. */
3589 for (thread_info
*tp
= global_thread_step_over_chain_head
;
3593 next
= global_thread_step_over_chain_next (tp
);
3595 global_thread_step_over_chain_remove (tp
);
3598 /* If we were already in the middle of an inline step-over, and the
3599 thread stepping belongs to the inferior we're detaching, we need
3600 to restart the threads of other inferiors. */
3601 if (step_over_info
.thread
!= -1)
3603 infrun_debug_printf ("inline step-over in-process while detaching");
3605 thread_info
*thr
= find_thread_global_id (step_over_info
.thread
);
3606 if (thr
->inf
== inf
)
3608 /* Since we removed threads of INF from the step-over chain,
3609 we know this won't start a step-over for INF. */
3610 clear_step_over_info ();
3612 if (target_is_non_stop_p ())
3614 /* Start a new step-over in another thread if there's
3615 one that needs it. */
3618 /* Restart all other threads (except the
3619 previously-stepping thread, since that one is still
3621 if (!step_over_info_valid_p ())
3622 restart_threads (thr
);
3627 if (displaced_step_in_progress (inf
))
3629 infrun_debug_printf ("displaced-stepping in-process while detaching");
3631 /* Stop threads currently displaced stepping, aborting it. */
3633 for (thread_info
*thr
: inf
->non_exited_threads ())
3635 if (thr
->displaced_step_state
.in_progress ())
3639 if (!thr
->stop_requested
)
3641 target_stop (thr
->ptid
);
3642 thr
->stop_requested
= true;
3646 thr
->resumed
= false;
3650 while (displaced_step_in_progress (inf
))
3652 wait_one_event event
;
3654 event
.target
= inf
->process_target ();
3655 event
.ptid
= do_target_wait_1 (inf
, pid_ptid
, &event
.ws
, 0);
3658 print_target_wait_results (pid_ptid
, event
.ptid
, &event
.ws
);
3663 /* It's OK to leave some of the threads of INF stopped, since
3664 they'll be detached shortly. */
3668 /* Wait for control to return from inferior to debugger.
3670 If inferior gets a signal, we may decide to start it up again
3671 instead of returning. That is why there is a loop in this function.
3672 When this function actually returns it means the inferior
3673 should be left stopped and GDB should read more commands. */
3676 wait_for_inferior (inferior
*inf
)
3678 infrun_debug_printf ("wait_for_inferior ()");
3680 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3682 /* If an error happens while handling the event, propagate GDB's
3683 knowledge of the executing state to the frontend/user running
3685 scoped_finish_thread_state finish_state
3686 (inf
->process_target (), minus_one_ptid
);
3690 struct execution_control_state ecss
;
3691 struct execution_control_state
*ecs
= &ecss
;
3693 memset (ecs
, 0, sizeof (*ecs
));
3695 overlay_cache_invalid
= 1;
3697 /* Flush target cache before starting to handle each event.
3698 Target was running and cache could be stale. This is just a
3699 heuristic. Running threads may modify target memory, but we
3700 don't get any event. */
3701 target_dcache_invalidate ();
3703 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3704 ecs
->target
= inf
->process_target ();
3707 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3709 /* Now figure out what to do with the result of the result. */
3710 handle_inferior_event (ecs
);
3712 if (!ecs
->wait_some_more
)
3716 /* No error, don't finish the state yet. */
3717 finish_state
.release ();
3720 /* Cleanup that reinstalls the readline callback handler, if the
3721 target is running in the background. If while handling the target
3722 event something triggered a secondary prompt, like e.g., a
3723 pagination prompt, we'll have removed the callback handler (see
3724 gdb_readline_wrapper_line). Need to do this as we go back to the
3725 event loop, ready to process further input. Note this has no
3726 effect if the handler hasn't actually been removed, because calling
3727 rl_callback_handler_install resets the line buffer, thus losing
3731 reinstall_readline_callback_handler_cleanup ()
3733 struct ui
*ui
= current_ui
;
3737 /* We're not going back to the top level event loop yet. Don't
3738 install the readline callback, as it'd prep the terminal,
3739 readline-style (raw, noecho) (e.g., --batch). We'll install
3740 it the next time the prompt is displayed, when we're ready
3745 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3746 gdb_rl_callback_handler_reinstall ();
3749 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3750 that's just the event thread. In all-stop, that's all threads. */
3753 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3755 if (ecs
->event_thread
!= NULL
3756 && ecs
->event_thread
->thread_fsm
!= NULL
)
3757 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3761 for (thread_info
*thr
: all_non_exited_threads ())
3763 if (thr
->thread_fsm
== NULL
)
3765 if (thr
== ecs
->event_thread
)
3768 switch_to_thread (thr
);
3769 thr
->thread_fsm
->clean_up (thr
);
3772 if (ecs
->event_thread
!= NULL
)
3773 switch_to_thread (ecs
->event_thread
);
3777 /* Helper for all_uis_check_sync_execution_done that works on the
3781 check_curr_ui_sync_execution_done (void)
3783 struct ui
*ui
= current_ui
;
3785 if (ui
->prompt_state
== PROMPT_NEEDED
3787 && !gdb_in_secondary_prompt_p (ui
))
3789 target_terminal::ours ();
3790 gdb::observers::sync_execution_done
.notify ();
3791 ui_register_input_event_handler (ui
);
3798 all_uis_check_sync_execution_done (void)
3800 SWITCH_THRU_ALL_UIS ()
3802 check_curr_ui_sync_execution_done ();
3809 all_uis_on_sync_execution_starting (void)
3811 SWITCH_THRU_ALL_UIS ()
3813 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3814 async_disable_stdin ();
3818 /* Asynchronous version of wait_for_inferior. It is called by the
3819 event loop whenever a change of state is detected on the file
3820 descriptor corresponding to the target. It can be called more than
3821 once to complete a single execution command. In such cases we need
3822 to keep the state in a global variable ECSS. If it is the last time
3823 that this function is called for a single execution command, then
3824 report to the user that the inferior has stopped, and do the
3825 necessary cleanups. */
3828 fetch_inferior_event ()
3830 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
3832 struct execution_control_state ecss
;
3833 struct execution_control_state
*ecs
= &ecss
;
3836 memset (ecs
, 0, sizeof (*ecs
));
3838 /* Events are always processed with the main UI as current UI. This
3839 way, warnings, debug output, etc. are always consistently sent to
3840 the main console. */
3841 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3843 /* Temporarily disable pagination. Otherwise, the user would be
3844 given an option to press 'q' to quit, which would cause an early
3845 exit and could leave GDB in a half-baked state. */
3846 scoped_restore save_pagination
3847 = make_scoped_restore (&pagination_enabled
, false);
3849 /* End up with readline processing input, if necessary. */
3851 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3853 /* We're handling a live event, so make sure we're doing live
3854 debugging. If we're looking at traceframes while the target is
3855 running, we're going to need to get back to that mode after
3856 handling the event. */
3857 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3860 maybe_restore_traceframe
.emplace ();
3861 set_current_traceframe (-1);
3864 /* The user/frontend should not notice a thread switch due to
3865 internal events. Make sure we revert to the user selected
3866 thread and frame after handling the event and running any
3867 breakpoint commands. */
3868 scoped_restore_current_thread restore_thread
;
3870 overlay_cache_invalid
= 1;
3871 /* Flush target cache before starting to handle each event. Target
3872 was running and cache could be stale. This is just a heuristic.
3873 Running threads may modify target memory, but we don't get any
3875 target_dcache_invalidate ();
3877 scoped_restore save_exec_dir
3878 = make_scoped_restore (&execution_direction
,
3879 target_execution_direction ());
3881 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3884 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3886 /* Switch to the target that generated the event, so we can do
3888 switch_to_target_no_thread (ecs
->target
);
3891 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3893 /* If an error happens while handling the event, propagate GDB's
3894 knowledge of the executing state to the frontend/user running
3896 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3897 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3899 /* Get executed before scoped_restore_current_thread above to apply
3900 still for the thread which has thrown the exception. */
3901 auto defer_bpstat_clear
3902 = make_scope_exit (bpstat_clear_actions
);
3903 auto defer_delete_threads
3904 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3906 /* Now figure out what to do with the result of the result. */
3907 handle_inferior_event (ecs
);
3909 if (!ecs
->wait_some_more
)
3911 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3912 bool should_stop
= true;
3913 struct thread_info
*thr
= ecs
->event_thread
;
3915 delete_just_stopped_threads_infrun_breakpoints ();
3919 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3921 if (thread_fsm
!= NULL
)
3922 should_stop
= thread_fsm
->should_stop (thr
);
3931 bool should_notify_stop
= true;
3934 clean_up_just_stopped_threads_fsms (ecs
);
3936 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3937 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3939 if (should_notify_stop
)
3941 /* We may not find an inferior if this was a process exit. */
3942 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3943 proceeded
= normal_stop ();
3948 inferior_event_handler (INF_EXEC_COMPLETE
);
3952 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3953 previously selected thread is gone. We have two
3954 choices - switch to no thread selected, or restore the
3955 previously selected thread (now exited). We chose the
3956 later, just because that's what GDB used to do. After
3957 this, "info threads" says "The current thread <Thread
3958 ID 2> has terminated." instead of "No thread
3962 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3963 restore_thread
.dont_restore ();
3967 defer_delete_threads
.release ();
3968 defer_bpstat_clear
.release ();
3970 /* No error, don't finish the thread states yet. */
3971 finish_state
.release ();
3973 /* This scope is used to ensure that readline callbacks are
3974 reinstalled here. */
3977 /* If a UI was in sync execution mode, and now isn't, restore its
3978 prompt (a synchronous execution command has finished, and we're
3979 ready for input). */
3980 all_uis_check_sync_execution_done ();
3983 && exec_done_display_p
3984 && (inferior_ptid
== null_ptid
3985 || inferior_thread ()->state
!= THREAD_RUNNING
))
3986 printf_unfiltered (_("completed.\n"));
3992 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
3993 struct symtab_and_line sal
)
3995 /* This can be removed once this function no longer implicitly relies on the
3996 inferior_ptid value. */
3997 gdb_assert (inferior_ptid
== tp
->ptid
);
3999 tp
->control
.step_frame_id
= get_frame_id (frame
);
4000 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4002 tp
->current_symtab
= sal
.symtab
;
4003 tp
->current_line
= sal
.line
;
4006 /* Clear context switchable stepping state. */
4009 init_thread_stepping_state (struct thread_info
*tss
)
4011 tss
->stepped_breakpoint
= 0;
4012 tss
->stepping_over_breakpoint
= 0;
4013 tss
->stepping_over_watchpoint
= 0;
4014 tss
->step_after_step_resume_breakpoint
= 0;
4020 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4021 target_waitstatus status
)
4023 target_last_proc_target
= target
;
4024 target_last_wait_ptid
= ptid
;
4025 target_last_waitstatus
= status
;
4031 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4032 target_waitstatus
*status
)
4034 if (target
!= nullptr)
4035 *target
= target_last_proc_target
;
4036 if (ptid
!= nullptr)
4037 *ptid
= target_last_wait_ptid
;
4038 if (status
!= nullptr)
4039 *status
= target_last_waitstatus
;
4045 nullify_last_target_wait_ptid (void)
4047 target_last_proc_target
= nullptr;
4048 target_last_wait_ptid
= minus_one_ptid
;
4049 target_last_waitstatus
= {};
4052 /* Switch thread contexts. */
4055 context_switch (execution_control_state
*ecs
)
4057 if (ecs
->ptid
!= inferior_ptid
4058 && (inferior_ptid
== null_ptid
4059 || ecs
->event_thread
!= inferior_thread ()))
4061 infrun_debug_printf ("Switching context from %s to %s",
4062 target_pid_to_str (inferior_ptid
).c_str (),
4063 target_pid_to_str (ecs
->ptid
).c_str ());
4066 switch_to_thread (ecs
->event_thread
);
4069 /* If the target can't tell whether we've hit breakpoints
4070 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4071 check whether that could have been caused by a breakpoint. If so,
4072 adjust the PC, per gdbarch_decr_pc_after_break. */
4075 adjust_pc_after_break (struct thread_info
*thread
,
4076 struct target_waitstatus
*ws
)
4078 struct regcache
*regcache
;
4079 struct gdbarch
*gdbarch
;
4080 CORE_ADDR breakpoint_pc
, decr_pc
;
4082 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4083 we aren't, just return.
4085 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4086 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4087 implemented by software breakpoints should be handled through the normal
4090 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4091 different signals (SIGILL or SIGEMT for instance), but it is less
4092 clear where the PC is pointing afterwards. It may not match
4093 gdbarch_decr_pc_after_break. I don't know any specific target that
4094 generates these signals at breakpoints (the code has been in GDB since at
4095 least 1992) so I can not guess how to handle them here.
4097 In earlier versions of GDB, a target with
4098 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4099 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4100 target with both of these set in GDB history, and it seems unlikely to be
4101 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4103 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4106 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4109 /* In reverse execution, when a breakpoint is hit, the instruction
4110 under it has already been de-executed. The reported PC always
4111 points at the breakpoint address, so adjusting it further would
4112 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4115 B1 0x08000000 : INSN1
4116 B2 0x08000001 : INSN2
4118 PC -> 0x08000003 : INSN4
4120 Say you're stopped at 0x08000003 as above. Reverse continuing
4121 from that point should hit B2 as below. Reading the PC when the
4122 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4123 been de-executed already.
4125 B1 0x08000000 : INSN1
4126 B2 PC -> 0x08000001 : INSN2
4130 We can't apply the same logic as for forward execution, because
4131 we would wrongly adjust the PC to 0x08000000, since there's a
4132 breakpoint at PC - 1. We'd then report a hit on B1, although
4133 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4135 if (execution_direction
== EXEC_REVERSE
)
4138 /* If the target can tell whether the thread hit a SW breakpoint,
4139 trust it. Targets that can tell also adjust the PC
4141 if (target_supports_stopped_by_sw_breakpoint ())
4144 /* Note that relying on whether a breakpoint is planted in memory to
4145 determine this can fail. E.g,. the breakpoint could have been
4146 removed since. Or the thread could have been told to step an
4147 instruction the size of a breakpoint instruction, and only
4148 _after_ was a breakpoint inserted at its address. */
4150 /* If this target does not decrement the PC after breakpoints, then
4151 we have nothing to do. */
4152 regcache
= get_thread_regcache (thread
);
4153 gdbarch
= regcache
->arch ();
4155 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4159 const address_space
*aspace
= regcache
->aspace ();
4161 /* Find the location where (if we've hit a breakpoint) the
4162 breakpoint would be. */
4163 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4165 /* If the target can't tell whether a software breakpoint triggered,
4166 fallback to figuring it out based on breakpoints we think were
4167 inserted in the target, and on whether the thread was stepped or
4170 /* Check whether there actually is a software breakpoint inserted at
4173 If in non-stop mode, a race condition is possible where we've
4174 removed a breakpoint, but stop events for that breakpoint were
4175 already queued and arrive later. To suppress those spurious
4176 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4177 and retire them after a number of stop events are reported. Note
4178 this is an heuristic and can thus get confused. The real fix is
4179 to get the "stopped by SW BP and needs adjustment" info out of
4180 the target/kernel (and thus never reach here; see above). */
4181 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4182 || (target_is_non_stop_p ()
4183 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4185 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4187 if (record_full_is_used ())
4188 restore_operation_disable
.emplace
4189 (record_full_gdb_operation_disable_set ());
4191 /* When using hardware single-step, a SIGTRAP is reported for both
4192 a completed single-step and a software breakpoint. Need to
4193 differentiate between the two, as the latter needs adjusting
4194 but the former does not.
4196 The SIGTRAP can be due to a completed hardware single-step only if
4197 - we didn't insert software single-step breakpoints
4198 - this thread is currently being stepped
4200 If any of these events did not occur, we must have stopped due
4201 to hitting a software breakpoint, and have to back up to the
4204 As a special case, we could have hardware single-stepped a
4205 software breakpoint. In this case (prev_pc == breakpoint_pc),
4206 we also need to back up to the breakpoint address. */
4208 if (thread_has_single_step_breakpoints_set (thread
)
4209 || !currently_stepping (thread
)
4210 || (thread
->stepped_breakpoint
4211 && thread
->prev_pc
== breakpoint_pc
))
4212 regcache_write_pc (regcache
, breakpoint_pc
);
4217 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4219 for (frame
= get_prev_frame (frame
);
4221 frame
= get_prev_frame (frame
))
4223 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4226 if (get_frame_type (frame
) != INLINE_FRAME
)
4233 /* Look for an inline frame that is marked for skip.
4234 If PREV_FRAME is TRUE start at the previous frame,
4235 otherwise start at the current frame. Stop at the
4236 first non-inline frame, or at the frame where the
4240 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4242 struct frame_info
*frame
= get_current_frame ();
4245 frame
= get_prev_frame (frame
);
4247 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4249 const char *fn
= NULL
;
4250 symtab_and_line sal
;
4253 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4255 if (get_frame_type (frame
) != INLINE_FRAME
)
4258 sal
= find_frame_sal (frame
);
4259 sym
= get_frame_function (frame
);
4262 fn
= sym
->print_name ();
4265 && function_name_is_marked_for_skip (fn
, sal
))
4272 /* If the event thread has the stop requested flag set, pretend it
4273 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4277 handle_stop_requested (struct execution_control_state
*ecs
)
4279 if (ecs
->event_thread
->stop_requested
)
4281 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4282 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4283 handle_signal_stop (ecs
);
4289 /* Auxiliary function that handles syscall entry/return events.
4290 It returns true if the inferior should keep going (and GDB
4291 should ignore the event), or false if the event deserves to be
4295 handle_syscall_event (struct execution_control_state
*ecs
)
4297 struct regcache
*regcache
;
4300 context_switch (ecs
);
4302 regcache
= get_thread_regcache (ecs
->event_thread
);
4303 syscall_number
= ecs
->ws
.value
.syscall_number
;
4304 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4306 if (catch_syscall_enabled () > 0
4307 && catching_syscall_number (syscall_number
) > 0)
4309 infrun_debug_printf ("syscall number=%d", syscall_number
);
4311 ecs
->event_thread
->control
.stop_bpstat
4312 = bpstat_stop_status (regcache
->aspace (),
4313 ecs
->event_thread
->suspend
.stop_pc
,
4314 ecs
->event_thread
, &ecs
->ws
);
4316 if (handle_stop_requested (ecs
))
4319 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4321 /* Catchpoint hit. */
4326 if (handle_stop_requested (ecs
))
4329 /* If no catchpoint triggered for this, then keep going. */
4335 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4338 fill_in_stop_func (struct gdbarch
*gdbarch
,
4339 struct execution_control_state
*ecs
)
4341 if (!ecs
->stop_func_filled_in
)
4344 const general_symbol_info
*gsi
;
4346 /* Don't care about return value; stop_func_start and stop_func_name
4347 will both be 0 if it doesn't work. */
4348 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4350 &ecs
->stop_func_start
,
4351 &ecs
->stop_func_end
,
4353 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4355 /* The call to find_pc_partial_function, above, will set
4356 stop_func_start and stop_func_end to the start and end
4357 of the range containing the stop pc. If this range
4358 contains the entry pc for the block (which is always the
4359 case for contiguous blocks), advance stop_func_start past
4360 the function's start offset and entrypoint. Note that
4361 stop_func_start is NOT advanced when in a range of a
4362 non-contiguous block that does not contain the entry pc. */
4363 if (block
!= nullptr
4364 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4365 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4367 ecs
->stop_func_start
4368 += gdbarch_deprecated_function_start_offset (gdbarch
);
4370 if (gdbarch_skip_entrypoint_p (gdbarch
))
4371 ecs
->stop_func_start
4372 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4375 ecs
->stop_func_filled_in
= 1;
4380 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4382 static enum stop_kind
4383 get_inferior_stop_soon (execution_control_state
*ecs
)
4385 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4387 gdb_assert (inf
!= NULL
);
4388 return inf
->control
.stop_soon
;
4391 /* Poll for one event out of the current target. Store the resulting
4392 waitstatus in WS, and return the event ptid. Does not block. */
4395 poll_one_curr_target (struct target_waitstatus
*ws
)
4399 overlay_cache_invalid
= 1;
4401 /* Flush target cache before starting to handle each event.
4402 Target was running and cache could be stale. This is just a
4403 heuristic. Running threads may modify target memory, but we
4404 don't get any event. */
4405 target_dcache_invalidate ();
4407 if (deprecated_target_wait_hook
)
4408 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4410 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4413 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4418 /* Wait for one event out of any target. */
4420 static wait_one_event
4425 for (inferior
*inf
: all_inferiors ())
4427 process_stratum_target
*target
= inf
->process_target ();
4429 || !target
->is_async_p ()
4430 || !target
->threads_executing
)
4433 switch_to_inferior_no_thread (inf
);
4435 wait_one_event event
;
4436 event
.target
= target
;
4437 event
.ptid
= poll_one_curr_target (&event
.ws
);
4439 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4441 /* If nothing is resumed, remove the target from the
4445 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4449 /* Block waiting for some event. */
4456 for (inferior
*inf
: all_inferiors ())
4458 process_stratum_target
*target
= inf
->process_target ();
4460 || !target
->is_async_p ()
4461 || !target
->threads_executing
)
4464 int fd
= target
->async_wait_fd ();
4465 FD_SET (fd
, &readfds
);
4472 /* No waitable targets left. All must be stopped. */
4473 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4478 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4484 perror_with_name ("interruptible_select");
4489 /* Save the thread's event and stop reason to process it later. */
4492 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4494 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4495 target_waitstatus_to_string (ws
).c_str (),
4500 /* Record for later. */
4501 tp
->suspend
.waitstatus
= *ws
;
4502 tp
->suspend
.waitstatus_pending_p
= 1;
4504 struct regcache
*regcache
= get_thread_regcache (tp
);
4505 const address_space
*aspace
= regcache
->aspace ();
4507 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4508 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4510 CORE_ADDR pc
= regcache_read_pc (regcache
);
4512 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4514 scoped_restore_current_thread restore_thread
;
4515 switch_to_thread (tp
);
4517 if (target_stopped_by_watchpoint ())
4519 tp
->suspend
.stop_reason
4520 = TARGET_STOPPED_BY_WATCHPOINT
;
4522 else if (target_supports_stopped_by_sw_breakpoint ()
4523 && target_stopped_by_sw_breakpoint ())
4525 tp
->suspend
.stop_reason
4526 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4528 else if (target_supports_stopped_by_hw_breakpoint ()
4529 && target_stopped_by_hw_breakpoint ())
4531 tp
->suspend
.stop_reason
4532 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4534 else if (!target_supports_stopped_by_hw_breakpoint ()
4535 && hardware_breakpoint_inserted_here_p (aspace
,
4538 tp
->suspend
.stop_reason
4539 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4541 else if (!target_supports_stopped_by_sw_breakpoint ()
4542 && software_breakpoint_inserted_here_p (aspace
,
4545 tp
->suspend
.stop_reason
4546 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4548 else if (!thread_has_single_step_breakpoints_set (tp
)
4549 && currently_stepping (tp
))
4551 tp
->suspend
.stop_reason
4552 = TARGET_STOPPED_BY_SINGLE_STEP
;
4557 /* Mark the non-executing threads accordingly. In all-stop, all
4558 threads of all processes are stopped when we get any event
4559 reported. In non-stop mode, only the event thread stops. */
4562 mark_non_executing_threads (process_stratum_target
*target
,
4564 struct target_waitstatus ws
)
4568 if (!target_is_non_stop_p ())
4569 mark_ptid
= minus_one_ptid
;
4570 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4571 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4573 /* If we're handling a process exit in non-stop mode, even
4574 though threads haven't been deleted yet, one would think
4575 that there is nothing to do, as threads of the dead process
4576 will be soon deleted, and threads of any other process were
4577 left running. However, on some targets, threads survive a
4578 process exit event. E.g., for the "checkpoint" command,
4579 when the current checkpoint/fork exits, linux-fork.c
4580 automatically switches to another fork from within
4581 target_mourn_inferior, by associating the same
4582 inferior/thread to another fork. We haven't mourned yet at
4583 this point, but we must mark any threads left in the
4584 process as not-executing so that finish_thread_state marks
4585 them stopped (in the user's perspective) if/when we present
4586 the stop to the user. */
4587 mark_ptid
= ptid_t (event_ptid
.pid ());
4590 mark_ptid
= event_ptid
;
4592 set_executing (target
, mark_ptid
, false);
4594 /* Likewise the resumed flag. */
4595 set_resumed (target
, mark_ptid
, false);
4598 /* Handle one event after stopping threads. If the eventing thread
4599 reports back any interesting event, we leave it pending. If the
4600 eventing thread was in the middle of a displaced step, we
4601 cancel/finish it, and unless the thread's inferior is being
4602 detached, put the thread back in the step-over chain. Returns true
4603 if there are no resumed threads left in the target (thus there's no
4604 point in waiting further), false otherwise. */
4607 handle_one (const wait_one_event
&event
)
4610 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4611 target_pid_to_str (event
.ptid
).c_str ());
4613 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4615 /* All resumed threads exited. */
4618 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4619 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4620 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4622 /* One thread/process exited/signalled. */
4624 thread_info
*t
= nullptr;
4626 /* The target may have reported just a pid. If so, try
4627 the first non-exited thread. */
4628 if (event
.ptid
.is_pid ())
4630 int pid
= event
.ptid
.pid ();
4631 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4632 for (thread_info
*tp
: inf
->non_exited_threads ())
4638 /* If there is no available thread, the event would
4639 have to be appended to a per-inferior event list,
4640 which does not exist (and if it did, we'd have
4641 to adjust run control command to be able to
4642 resume such an inferior). We assert here instead
4643 of going into an infinite loop. */
4644 gdb_assert (t
!= nullptr);
4647 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4651 t
= find_thread_ptid (event
.target
, event
.ptid
);
4652 /* Check if this is the first time we see this thread.
4653 Don't bother adding if it individually exited. */
4655 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4656 t
= add_thread (event
.target
, event
.ptid
);
4661 /* Set the threads as non-executing to avoid
4662 another stop attempt on them. */
4663 switch_to_thread_no_regs (t
);
4664 mark_non_executing_threads (event
.target
, event
.ptid
,
4666 save_waitstatus (t
, &event
.ws
);
4667 t
->stop_requested
= false;
4672 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4674 t
= add_thread (event
.target
, event
.ptid
);
4676 t
->stop_requested
= 0;
4679 t
->control
.may_range_step
= 0;
4681 /* This may be the first time we see the inferior report
4683 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4684 if (inf
->needs_setup
)
4686 switch_to_thread_no_regs (t
);
4690 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4691 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4693 /* We caught the event that we intended to catch, so
4694 there's no event pending. */
4695 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4696 t
->suspend
.waitstatus_pending_p
= 0;
4698 if (displaced_step_finish (t
, GDB_SIGNAL_0
)
4699 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4701 /* Add it back to the step-over queue. */
4703 ("displaced-step of %s canceled",
4704 target_pid_to_str (t
->ptid
).c_str ());
4706 t
->control
.trap_expected
= 0;
4707 if (!t
->inf
->detaching
)
4708 global_thread_step_over_chain_enqueue (t
);
4713 enum gdb_signal sig
;
4714 struct regcache
*regcache
;
4717 ("target_wait %s, saving status for %d.%ld.%ld",
4718 target_waitstatus_to_string (&event
.ws
).c_str (),
4719 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4721 /* Record for later. */
4722 save_waitstatus (t
, &event
.ws
);
4724 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4725 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4727 if (displaced_step_finish (t
, sig
)
4728 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4730 /* Add it back to the step-over queue. */
4731 t
->control
.trap_expected
= 0;
4732 if (!t
->inf
->detaching
)
4733 global_thread_step_over_chain_enqueue (t
);
4736 regcache
= get_thread_regcache (t
);
4737 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4739 infrun_debug_printf ("saved stop_pc=%s for %s "
4740 "(currently_stepping=%d)",
4741 paddress (target_gdbarch (),
4742 t
->suspend
.stop_pc
),
4743 target_pid_to_str (t
->ptid
).c_str (),
4744 currently_stepping (t
));
4754 stop_all_threads (void)
4756 /* We may need multiple passes to discover all threads. */
4760 gdb_assert (exists_non_stop_target ());
4762 infrun_debug_printf ("starting");
4764 scoped_restore_current_thread restore_thread
;
4766 /* Enable thread events of all targets. */
4767 for (auto *target
: all_non_exited_process_targets ())
4769 switch_to_target_no_thread (target
);
4770 target_thread_events (true);
4775 /* Disable thread events of all targets. */
4776 for (auto *target
: all_non_exited_process_targets ())
4778 switch_to_target_no_thread (target
);
4779 target_thread_events (false);
4782 /* Use debug_prefixed_printf directly to get a meaningful function
4785 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4788 /* Request threads to stop, and then wait for the stops. Because
4789 threads we already know about can spawn more threads while we're
4790 trying to stop them, and we only learn about new threads when we
4791 update the thread list, do this in a loop, and keep iterating
4792 until two passes find no threads that need to be stopped. */
4793 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4795 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4798 int waits_needed
= 0;
4800 for (auto *target
: all_non_exited_process_targets ())
4802 switch_to_target_no_thread (target
);
4803 update_thread_list ();
4806 /* Go through all threads looking for threads that we need
4807 to tell the target to stop. */
4808 for (thread_info
*t
: all_non_exited_threads ())
4810 /* For a single-target setting with an all-stop target,
4811 we would not even arrive here. For a multi-target
4812 setting, until GDB is able to handle a mixture of
4813 all-stop and non-stop targets, simply skip all-stop
4814 targets' threads. This should be fine due to the
4815 protection of 'check_multi_target_resumption'. */
4817 switch_to_thread_no_regs (t
);
4818 if (!target_is_non_stop_p ())
4823 /* If already stopping, don't request a stop again.
4824 We just haven't seen the notification yet. */
4825 if (!t
->stop_requested
)
4827 infrun_debug_printf (" %s executing, need stop",
4828 target_pid_to_str (t
->ptid
).c_str ());
4829 target_stop (t
->ptid
);
4830 t
->stop_requested
= 1;
4834 infrun_debug_printf (" %s executing, already stopping",
4835 target_pid_to_str (t
->ptid
).c_str ());
4838 if (t
->stop_requested
)
4843 infrun_debug_printf (" %s not executing",
4844 target_pid_to_str (t
->ptid
).c_str ());
4846 /* The thread may be not executing, but still be
4847 resumed with a pending status to process. */
4852 if (waits_needed
== 0)
4855 /* If we find new threads on the second iteration, restart
4856 over. We want to see two iterations in a row with all
4861 for (int i
= 0; i
< waits_needed
; i
++)
4863 wait_one_event event
= wait_one ();
4864 if (handle_one (event
))
4871 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4874 handle_no_resumed (struct execution_control_state
*ecs
)
4876 if (target_can_async_p ())
4878 bool any_sync
= false;
4880 for (ui
*ui
: all_uis ())
4882 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4890 /* There were no unwaited-for children left in the target, but,
4891 we're not synchronously waiting for events either. Just
4894 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4895 prepare_to_wait (ecs
);
4900 /* Otherwise, if we were running a synchronous execution command, we
4901 may need to cancel it and give the user back the terminal.
4903 In non-stop mode, the target can't tell whether we've already
4904 consumed previous stop events, so it can end up sending us a
4905 no-resumed event like so:
4907 #0 - thread 1 is left stopped
4909 #1 - thread 2 is resumed and hits breakpoint
4910 -> TARGET_WAITKIND_STOPPED
4912 #2 - thread 3 is resumed and exits
4913 this is the last resumed thread, so
4914 -> TARGET_WAITKIND_NO_RESUMED
4916 #3 - gdb processes stop for thread 2 and decides to re-resume
4919 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4920 thread 2 is now resumed, so the event should be ignored.
4922 IOW, if the stop for thread 2 doesn't end a foreground command,
4923 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4924 event. But it could be that the event meant that thread 2 itself
4925 (or whatever other thread was the last resumed thread) exited.
4927 To address this we refresh the thread list and check whether we
4928 have resumed threads _now_. In the example above, this removes
4929 thread 3 from the thread list. If thread 2 was re-resumed, we
4930 ignore this event. If we find no thread resumed, then we cancel
4931 the synchronous command and show "no unwaited-for " to the
4934 inferior
*curr_inf
= current_inferior ();
4936 scoped_restore_current_thread restore_thread
;
4938 for (auto *target
: all_non_exited_process_targets ())
4940 switch_to_target_no_thread (target
);
4941 update_thread_list ();
4946 - the current target has no thread executing, and
4947 - the current inferior is native, and
4948 - the current inferior is the one which has the terminal, and
4951 then a Ctrl-C from this point on would remain stuck in the
4952 kernel, until a thread resumes and dequeues it. That would
4953 result in the GDB CLI not reacting to Ctrl-C, not able to
4954 interrupt the program. To address this, if the current inferior
4955 no longer has any thread executing, we give the terminal to some
4956 other inferior that has at least one thread executing. */
4957 bool swap_terminal
= true;
4959 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4960 whether to report it to the user. */
4961 bool ignore_event
= false;
4963 for (thread_info
*thread
: all_non_exited_threads ())
4965 if (swap_terminal
&& thread
->executing
)
4967 if (thread
->inf
!= curr_inf
)
4969 target_terminal::ours ();
4971 switch_to_thread (thread
);
4972 target_terminal::inferior ();
4974 swap_terminal
= false;
4978 && (thread
->executing
4979 || thread
->suspend
.waitstatus_pending_p
))
4981 /* Either there were no unwaited-for children left in the
4982 target at some point, but there are now, or some target
4983 other than the eventing one has unwaited-for children
4984 left. Just ignore. */
4985 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4986 "(ignoring: found resumed)");
4988 ignore_event
= true;
4991 if (ignore_event
&& !swap_terminal
)
4997 switch_to_inferior_no_thread (curr_inf
);
4998 prepare_to_wait (ecs
);
5002 /* Go ahead and report the event. */
5006 /* Given an execution control state that has been freshly filled in by
5007 an event from the inferior, figure out what it means and take
5010 The alternatives are:
5012 1) stop_waiting and return; to really stop and return to the
5015 2) keep_going and return; to wait for the next event (set
5016 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5020 handle_inferior_event (struct execution_control_state
*ecs
)
5022 /* Make sure that all temporary struct value objects that were
5023 created during the handling of the event get deleted at the
5025 scoped_value_mark free_values
;
5027 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5029 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5031 /* We had an event in the inferior, but we are not interested in
5032 handling it at this level. The lower layers have already
5033 done what needs to be done, if anything.
5035 One of the possible circumstances for this is when the
5036 inferior produces output for the console. The inferior has
5037 not stopped, and we are ignoring the event. Another possible
5038 circumstance is any event which the lower level knows will be
5039 reported multiple times without an intervening resume. */
5040 prepare_to_wait (ecs
);
5044 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5046 prepare_to_wait (ecs
);
5050 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5051 && handle_no_resumed (ecs
))
5054 /* Cache the last target/ptid/waitstatus. */
5055 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5057 /* Always clear state belonging to the previous time we stopped. */
5058 stop_stack_dummy
= STOP_NONE
;
5060 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5062 /* No unwaited-for children left. IOW, all resumed children
5064 stop_print_frame
= false;
5069 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5070 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5072 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5073 /* If it's a new thread, add it to the thread database. */
5074 if (ecs
->event_thread
== NULL
)
5075 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5077 /* Disable range stepping. If the next step request could use a
5078 range, this will be end up re-enabled then. */
5079 ecs
->event_thread
->control
.may_range_step
= 0;
5082 /* Dependent on valid ECS->EVENT_THREAD. */
5083 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5085 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5086 reinit_frame_cache ();
5088 breakpoint_retire_moribund ();
5090 /* First, distinguish signals caused by the debugger from signals
5091 that have to do with the program's own actions. Note that
5092 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5093 on the operating system version. Here we detect when a SIGILL or
5094 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5095 something similar for SIGSEGV, since a SIGSEGV will be generated
5096 when we're trying to execute a breakpoint instruction on a
5097 non-executable stack. This happens for call dummy breakpoints
5098 for architectures like SPARC that place call dummies on the
5100 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5101 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5102 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5103 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5105 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5107 if (breakpoint_inserted_here_p (regcache
->aspace (),
5108 regcache_read_pc (regcache
)))
5110 infrun_debug_printf ("Treating signal as SIGTRAP");
5111 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5115 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5117 switch (ecs
->ws
.kind
)
5119 case TARGET_WAITKIND_LOADED
:
5121 context_switch (ecs
);
5122 /* Ignore gracefully during startup of the inferior, as it might
5123 be the shell which has just loaded some objects, otherwise
5124 add the symbols for the newly loaded objects. Also ignore at
5125 the beginning of an attach or remote session; we will query
5126 the full list of libraries once the connection is
5129 stop_kind stop_soon
= get_inferior_stop_soon (ecs
);
5130 if (stop_soon
== NO_STOP_QUIETLY
)
5132 struct regcache
*regcache
;
5134 regcache
= get_thread_regcache (ecs
->event_thread
);
5136 handle_solib_event ();
5138 ecs
->event_thread
->control
.stop_bpstat
5139 = bpstat_stop_status (regcache
->aspace (),
5140 ecs
->event_thread
->suspend
.stop_pc
,
5141 ecs
->event_thread
, &ecs
->ws
);
5143 if (handle_stop_requested (ecs
))
5146 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5148 /* A catchpoint triggered. */
5149 process_event_stop_test (ecs
);
5153 /* If requested, stop when the dynamic linker notifies
5154 gdb of events. This allows the user to get control
5155 and place breakpoints in initializer routines for
5156 dynamically loaded objects (among other things). */
5157 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5158 if (stop_on_solib_events
)
5160 /* Make sure we print "Stopped due to solib-event" in
5162 stop_print_frame
= true;
5169 /* If we are skipping through a shell, or through shared library
5170 loading that we aren't interested in, resume the program. If
5171 we're running the program normally, also resume. */
5172 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5174 /* Loading of shared libraries might have changed breakpoint
5175 addresses. Make sure new breakpoints are inserted. */
5176 if (stop_soon
== NO_STOP_QUIETLY
)
5177 insert_breakpoints ();
5178 resume (GDB_SIGNAL_0
);
5179 prepare_to_wait (ecs
);
5183 /* But stop if we're attaching or setting up a remote
5185 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5186 || stop_soon
== STOP_QUIETLY_REMOTE
)
5188 infrun_debug_printf ("quietly stopped");
5193 internal_error (__FILE__
, __LINE__
,
5194 _("unhandled stop_soon: %d"), (int) stop_soon
);
5197 case TARGET_WAITKIND_SPURIOUS
:
5198 if (handle_stop_requested (ecs
))
5200 context_switch (ecs
);
5201 resume (GDB_SIGNAL_0
);
5202 prepare_to_wait (ecs
);
5205 case TARGET_WAITKIND_THREAD_CREATED
:
5206 if (handle_stop_requested (ecs
))
5208 context_switch (ecs
);
5209 if (!switch_back_to_stepped_thread (ecs
))
5213 case TARGET_WAITKIND_EXITED
:
5214 case TARGET_WAITKIND_SIGNALLED
:
5216 /* Depending on the system, ecs->ptid may point to a thread or
5217 to a process. On some targets, target_mourn_inferior may
5218 need to have access to the just-exited thread. That is the
5219 case of GNU/Linux's "checkpoint" support, for example.
5220 Call the switch_to_xxx routine as appropriate. */
5221 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5223 switch_to_thread (thr
);
5226 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5227 switch_to_inferior_no_thread (inf
);
5230 handle_vfork_child_exec_or_exit (0);
5231 target_terminal::ours (); /* Must do this before mourn anyway. */
5233 /* Clearing any previous state of convenience variables. */
5234 clear_exit_convenience_vars ();
5236 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5238 /* Record the exit code in the convenience variable $_exitcode, so
5239 that the user can inspect this again later. */
5240 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5241 (LONGEST
) ecs
->ws
.value
.integer
);
5243 /* Also record this in the inferior itself. */
5244 current_inferior ()->has_exit_code
= 1;
5245 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5247 /* Support the --return-child-result option. */
5248 return_child_result_value
= ecs
->ws
.value
.integer
;
5250 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5254 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5256 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5258 /* Set the value of the internal variable $_exitsignal,
5259 which holds the signal uncaught by the inferior. */
5260 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5261 gdbarch_gdb_signal_to_target (gdbarch
,
5262 ecs
->ws
.value
.sig
));
5266 /* We don't have access to the target's method used for
5267 converting between signal numbers (GDB's internal
5268 representation <-> target's representation).
5269 Therefore, we cannot do a good job at displaying this
5270 information to the user. It's better to just warn
5271 her about it (if infrun debugging is enabled), and
5273 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5277 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5280 gdb_flush (gdb_stdout
);
5281 target_mourn_inferior (inferior_ptid
);
5282 stop_print_frame
= false;
5286 case TARGET_WAITKIND_FORKED
:
5287 case TARGET_WAITKIND_VFORKED
:
5288 /* Check whether the inferior is displaced stepping. */
5290 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5291 struct gdbarch
*gdbarch
= regcache
->arch ();
5292 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5294 /* If this is a fork (child gets its own address space copy) and some
5295 displaced step buffers were in use at the time of the fork, restore
5296 the displaced step buffer bytes in the child process. */
5297 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5298 gdbarch_displaced_step_restore_all_in_ptid
5299 (gdbarch
, parent_inf
, ecs
->ws
.value
.related_pid
);
5301 /* If displaced stepping is supported, and thread ecs->ptid is
5302 displaced stepping. */
5303 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5305 struct regcache
*child_regcache
;
5306 CORE_ADDR parent_pc
;
5308 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5309 indicating that the displaced stepping of syscall instruction
5310 has been done. Perform cleanup for parent process here. Note
5311 that this operation also cleans up the child process for vfork,
5312 because their pages are shared. */
5313 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5314 /* Start a new step-over in another thread if there's one
5318 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5319 the child's PC is also within the scratchpad. Set the child's PC
5320 to the parent's PC value, which has already been fixed up.
5321 FIXME: we use the parent's aspace here, although we're touching
5322 the child, because the child hasn't been added to the inferior
5323 list yet at this point. */
5326 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5327 ecs
->ws
.value
.related_pid
,
5329 parent_inf
->aspace
);
5330 /* Read PC value of parent process. */
5331 parent_pc
= regcache_read_pc (regcache
);
5333 displaced_debug_printf ("write child pc from %s to %s",
5335 regcache_read_pc (child_regcache
)),
5336 paddress (gdbarch
, parent_pc
));
5338 regcache_write_pc (child_regcache
, parent_pc
);
5342 context_switch (ecs
);
5344 /* Immediately detach breakpoints from the child before there's
5345 any chance of letting the user delete breakpoints from the
5346 breakpoint lists. If we don't do this early, it's easy to
5347 leave left over traps in the child, vis: "break foo; catch
5348 fork; c; <fork>; del; c; <child calls foo>". We only follow
5349 the fork on the last `continue', and by that time the
5350 breakpoint at "foo" is long gone from the breakpoint table.
5351 If we vforked, then we don't need to unpatch here, since both
5352 parent and child are sharing the same memory pages; we'll
5353 need to unpatch at follow/detach time instead to be certain
5354 that new breakpoints added between catchpoint hit time and
5355 vfork follow are detached. */
5356 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5358 /* This won't actually modify the breakpoint list, but will
5359 physically remove the breakpoints from the child. */
5360 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5363 delete_just_stopped_threads_single_step_breakpoints ();
5365 /* In case the event is caught by a catchpoint, remember that
5366 the event is to be followed at the next resume of the thread,
5367 and not immediately. */
5368 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5370 ecs
->event_thread
->suspend
.stop_pc
5371 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5373 ecs
->event_thread
->control
.stop_bpstat
5374 = bpstat_stop_status (get_current_regcache ()->aspace (),
5375 ecs
->event_thread
->suspend
.stop_pc
,
5376 ecs
->event_thread
, &ecs
->ws
);
5378 if (handle_stop_requested (ecs
))
5381 /* If no catchpoint triggered for this, then keep going. Note
5382 that we're interested in knowing the bpstat actually causes a
5383 stop, not just if it may explain the signal. Software
5384 watchpoints, for example, always appear in the bpstat. */
5385 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5388 = (follow_fork_mode_string
== follow_fork_mode_child
);
5390 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5392 process_stratum_target
*targ
5393 = ecs
->event_thread
->inf
->process_target ();
5395 bool should_resume
= follow_fork ();
5397 /* Note that one of these may be an invalid pointer,
5398 depending on detach_fork. */
5399 thread_info
*parent
= ecs
->event_thread
;
5401 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5403 /* At this point, the parent is marked running, and the
5404 child is marked stopped. */
5406 /* If not resuming the parent, mark it stopped. */
5407 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5408 parent
->set_running (false);
5410 /* If resuming the child, mark it running. */
5411 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5412 child
->set_running (true);
5414 /* In non-stop mode, also resume the other branch. */
5415 if (!detach_fork
&& (non_stop
5416 || (sched_multi
&& target_is_non_stop_p ())))
5419 switch_to_thread (parent
);
5421 switch_to_thread (child
);
5423 ecs
->event_thread
= inferior_thread ();
5424 ecs
->ptid
= inferior_ptid
;
5429 switch_to_thread (child
);
5431 switch_to_thread (parent
);
5433 ecs
->event_thread
= inferior_thread ();
5434 ecs
->ptid
= inferior_ptid
;
5442 process_event_stop_test (ecs
);
5445 case TARGET_WAITKIND_VFORK_DONE
:
5446 /* Done with the shared memory region. Re-insert breakpoints in
5447 the parent, and keep going. */
5449 context_switch (ecs
);
5451 current_inferior ()->waiting_for_vfork_done
= 0;
5452 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5454 if (handle_stop_requested (ecs
))
5457 /* This also takes care of reinserting breakpoints in the
5458 previously locked inferior. */
5462 case TARGET_WAITKIND_EXECD
:
5464 /* Note we can't read registers yet (the stop_pc), because we
5465 don't yet know the inferior's post-exec architecture.
5466 'stop_pc' is explicitly read below instead. */
5467 switch_to_thread_no_regs (ecs
->event_thread
);
5469 /* Do whatever is necessary to the parent branch of the vfork. */
5470 handle_vfork_child_exec_or_exit (1);
5472 /* This causes the eventpoints and symbol table to be reset.
5473 Must do this now, before trying to determine whether to
5475 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5477 /* In follow_exec we may have deleted the original thread and
5478 created a new one. Make sure that the event thread is the
5479 execd thread for that case (this is a nop otherwise). */
5480 ecs
->event_thread
= inferior_thread ();
5482 ecs
->event_thread
->suspend
.stop_pc
5483 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5485 ecs
->event_thread
->control
.stop_bpstat
5486 = bpstat_stop_status (get_current_regcache ()->aspace (),
5487 ecs
->event_thread
->suspend
.stop_pc
,
5488 ecs
->event_thread
, &ecs
->ws
);
5490 /* Note that this may be referenced from inside
5491 bpstat_stop_status above, through inferior_has_execd. */
5492 xfree (ecs
->ws
.value
.execd_pathname
);
5493 ecs
->ws
.value
.execd_pathname
= NULL
;
5495 if (handle_stop_requested (ecs
))
5498 /* If no catchpoint triggered for this, then keep going. */
5499 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5501 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5505 process_event_stop_test (ecs
);
5508 /* Be careful not to try to gather much state about a thread
5509 that's in a syscall. It's frequently a losing proposition. */
5510 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5511 /* Getting the current syscall number. */
5512 if (handle_syscall_event (ecs
) == 0)
5513 process_event_stop_test (ecs
);
5516 /* Before examining the threads further, step this thread to
5517 get it entirely out of the syscall. (We get notice of the
5518 event when the thread is just on the verge of exiting a
5519 syscall. Stepping one instruction seems to get it back
5521 case TARGET_WAITKIND_SYSCALL_RETURN
:
5522 if (handle_syscall_event (ecs
) == 0)
5523 process_event_stop_test (ecs
);
5526 case TARGET_WAITKIND_STOPPED
:
5527 handle_signal_stop (ecs
);
5530 case TARGET_WAITKIND_NO_HISTORY
:
5531 /* Reverse execution: target ran out of history info. */
5533 /* Switch to the stopped thread. */
5534 context_switch (ecs
);
5535 infrun_debug_printf ("stopped");
5537 delete_just_stopped_threads_single_step_breakpoints ();
5538 ecs
->event_thread
->suspend
.stop_pc
5539 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5541 if (handle_stop_requested (ecs
))
5544 gdb::observers::no_history
.notify ();
5550 /* Restart threads back to what they were trying to do back when we
5551 paused them for an in-line step-over. The EVENT_THREAD thread is
5555 restart_threads (struct thread_info
*event_thread
)
5557 /* In case the instruction just stepped spawned a new thread. */
5558 update_thread_list ();
5560 for (thread_info
*tp
: all_non_exited_threads ())
5562 if (tp
->inf
->detaching
)
5564 infrun_debug_printf ("restart threads: [%s] inferior detaching",
5565 target_pid_to_str (tp
->ptid
).c_str ());
5569 switch_to_thread_no_regs (tp
);
5571 if (tp
== event_thread
)
5573 infrun_debug_printf ("restart threads: [%s] is event thread",
5574 target_pid_to_str (tp
->ptid
).c_str ());
5578 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5580 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5581 target_pid_to_str (tp
->ptid
).c_str ());
5587 infrun_debug_printf ("restart threads: [%s] resumed",
5588 target_pid_to_str (tp
->ptid
).c_str ());
5589 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5593 if (thread_is_in_step_over_chain (tp
))
5595 infrun_debug_printf ("restart threads: [%s] needs step-over",
5596 target_pid_to_str (tp
->ptid
).c_str ());
5597 gdb_assert (!tp
->resumed
);
5602 if (tp
->suspend
.waitstatus_pending_p
)
5604 infrun_debug_printf ("restart threads: [%s] has pending status",
5605 target_pid_to_str (tp
->ptid
).c_str ());
5610 gdb_assert (!tp
->stop_requested
);
5612 /* If some thread needs to start a step-over at this point, it
5613 should still be in the step-over queue, and thus skipped
5615 if (thread_still_needs_step_over (tp
))
5617 internal_error (__FILE__
, __LINE__
,
5618 "thread [%s] needs a step-over, but not in "
5619 "step-over queue\n",
5620 target_pid_to_str (tp
->ptid
).c_str ());
5623 if (currently_stepping (tp
))
5625 infrun_debug_printf ("restart threads: [%s] was stepping",
5626 target_pid_to_str (tp
->ptid
).c_str ());
5627 keep_going_stepped_thread (tp
);
5631 struct execution_control_state ecss
;
5632 struct execution_control_state
*ecs
= &ecss
;
5634 infrun_debug_printf ("restart threads: [%s] continuing",
5635 target_pid_to_str (tp
->ptid
).c_str ());
5636 reset_ecs (ecs
, tp
);
5637 switch_to_thread (tp
);
5638 keep_going_pass_signal (ecs
);
5643 /* Callback for iterate_over_threads. Find a resumed thread that has
5644 a pending waitstatus. */
5647 resumed_thread_with_pending_status (struct thread_info
*tp
,
5651 && tp
->suspend
.waitstatus_pending_p
);
5654 /* Called when we get an event that may finish an in-line or
5655 out-of-line (displaced stepping) step-over started previously.
5656 Return true if the event is processed and we should go back to the
5657 event loop; false if the caller should continue processing the
5661 finish_step_over (struct execution_control_state
*ecs
)
5663 displaced_step_finish (ecs
->event_thread
,
5664 ecs
->event_thread
->suspend
.stop_signal
);
5666 bool had_step_over_info
= step_over_info_valid_p ();
5668 if (had_step_over_info
)
5670 /* If we're stepping over a breakpoint with all threads locked,
5671 then only the thread that was stepped should be reporting
5673 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5675 clear_step_over_info ();
5678 if (!target_is_non_stop_p ())
5681 /* Start a new step-over in another thread if there's one that
5685 /* If we were stepping over a breakpoint before, and haven't started
5686 a new in-line step-over sequence, then restart all other threads
5687 (except the event thread). We can't do this in all-stop, as then
5688 e.g., we wouldn't be able to issue any other remote packet until
5689 these other threads stop. */
5690 if (had_step_over_info
&& !step_over_info_valid_p ())
5692 struct thread_info
*pending
;
5694 /* If we only have threads with pending statuses, the restart
5695 below won't restart any thread and so nothing re-inserts the
5696 breakpoint we just stepped over. But we need it inserted
5697 when we later process the pending events, otherwise if
5698 another thread has a pending event for this breakpoint too,
5699 we'd discard its event (because the breakpoint that
5700 originally caused the event was no longer inserted). */
5701 context_switch (ecs
);
5702 insert_breakpoints ();
5704 restart_threads (ecs
->event_thread
);
5706 /* If we have events pending, go through handle_inferior_event
5707 again, picking up a pending event at random. This avoids
5708 thread starvation. */
5710 /* But not if we just stepped over a watchpoint in order to let
5711 the instruction execute so we can evaluate its expression.
5712 The set of watchpoints that triggered is recorded in the
5713 breakpoint objects themselves (see bp->watchpoint_triggered).
5714 If we processed another event first, that other event could
5715 clobber this info. */
5716 if (ecs
->event_thread
->stepping_over_watchpoint
)
5719 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5721 if (pending
!= NULL
)
5723 struct thread_info
*tp
= ecs
->event_thread
;
5724 struct regcache
*regcache
;
5726 infrun_debug_printf ("found resumed threads with "
5727 "pending events, saving status");
5729 gdb_assert (pending
!= tp
);
5731 /* Record the event thread's event for later. */
5732 save_waitstatus (tp
, &ecs
->ws
);
5733 /* This was cleared early, by handle_inferior_event. Set it
5734 so this pending event is considered by
5738 gdb_assert (!tp
->executing
);
5740 regcache
= get_thread_regcache (tp
);
5741 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5743 infrun_debug_printf ("saved stop_pc=%s for %s "
5744 "(currently_stepping=%d)",
5745 paddress (target_gdbarch (),
5746 tp
->suspend
.stop_pc
),
5747 target_pid_to_str (tp
->ptid
).c_str (),
5748 currently_stepping (tp
));
5750 /* This in-line step-over finished; clear this so we won't
5751 start a new one. This is what handle_signal_stop would
5752 do, if we returned false. */
5753 tp
->stepping_over_breakpoint
= 0;
5755 /* Wake up the event loop again. */
5756 mark_async_event_handler (infrun_async_inferior_event_token
);
5758 prepare_to_wait (ecs
);
5766 /* Come here when the program has stopped with a signal. */
5769 handle_signal_stop (struct execution_control_state
*ecs
)
5771 struct frame_info
*frame
;
5772 struct gdbarch
*gdbarch
;
5773 int stopped_by_watchpoint
;
5774 enum stop_kind stop_soon
;
5777 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5779 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5781 /* Do we need to clean up the state of a thread that has
5782 completed a displaced single-step? (Doing so usually affects
5783 the PC, so do it here, before we set stop_pc.) */
5784 if (finish_step_over (ecs
))
5787 /* If we either finished a single-step or hit a breakpoint, but
5788 the user wanted this thread to be stopped, pretend we got a
5789 SIG0 (generic unsignaled stop). */
5790 if (ecs
->event_thread
->stop_requested
5791 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5792 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5794 ecs
->event_thread
->suspend
.stop_pc
5795 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5797 context_switch (ecs
);
5799 if (deprecated_context_hook
)
5800 deprecated_context_hook (ecs
->event_thread
->global_num
);
5804 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5805 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5807 infrun_debug_printf ("stop_pc=%s",
5808 paddress (reg_gdbarch
,
5809 ecs
->event_thread
->suspend
.stop_pc
));
5810 if (target_stopped_by_watchpoint ())
5814 infrun_debug_printf ("stopped by watchpoint");
5816 if (target_stopped_data_address (current_inferior ()->top_target (),
5818 infrun_debug_printf ("stopped data address=%s",
5819 paddress (reg_gdbarch
, addr
));
5821 infrun_debug_printf ("(no data address available)");
5825 /* This is originated from start_remote(), start_inferior() and
5826 shared libraries hook functions. */
5827 stop_soon
= get_inferior_stop_soon (ecs
);
5828 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5830 infrun_debug_printf ("quietly stopped");
5831 stop_print_frame
= true;
5836 /* This originates from attach_command(). We need to overwrite
5837 the stop_signal here, because some kernels don't ignore a
5838 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5839 See more comments in inferior.h. On the other hand, if we
5840 get a non-SIGSTOP, report it to the user - assume the backend
5841 will handle the SIGSTOP if it should show up later.
5843 Also consider that the attach is complete when we see a
5844 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5845 target extended-remote report it instead of a SIGSTOP
5846 (e.g. gdbserver). We already rely on SIGTRAP being our
5847 signal, so this is no exception.
5849 Also consider that the attach is complete when we see a
5850 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5851 the target to stop all threads of the inferior, in case the
5852 low level attach operation doesn't stop them implicitly. If
5853 they weren't stopped implicitly, then the stub will report a
5854 GDB_SIGNAL_0, meaning: stopped for no particular reason
5855 other than GDB's request. */
5856 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5857 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5858 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5859 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5861 stop_print_frame
= true;
5863 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5867 /* At this point, get hold of the now-current thread's frame. */
5868 frame
= get_current_frame ();
5869 gdbarch
= get_frame_arch (frame
);
5871 /* Pull the single step breakpoints out of the target. */
5872 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5874 struct regcache
*regcache
;
5877 regcache
= get_thread_regcache (ecs
->event_thread
);
5878 const address_space
*aspace
= regcache
->aspace ();
5880 pc
= regcache_read_pc (regcache
);
5882 /* However, before doing so, if this single-step breakpoint was
5883 actually for another thread, set this thread up for moving
5885 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5888 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5890 infrun_debug_printf ("[%s] hit another thread's single-step "
5892 target_pid_to_str (ecs
->ptid
).c_str ());
5893 ecs
->hit_singlestep_breakpoint
= 1;
5898 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5899 target_pid_to_str (ecs
->ptid
).c_str ());
5902 delete_just_stopped_threads_single_step_breakpoints ();
5904 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5905 && ecs
->event_thread
->control
.trap_expected
5906 && ecs
->event_thread
->stepping_over_watchpoint
)
5907 stopped_by_watchpoint
= 0;
5909 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5911 /* If necessary, step over this watchpoint. We'll be back to display
5913 if (stopped_by_watchpoint
5914 && (target_have_steppable_watchpoint ()
5915 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5917 /* At this point, we are stopped at an instruction which has
5918 attempted to write to a piece of memory under control of
5919 a watchpoint. The instruction hasn't actually executed
5920 yet. If we were to evaluate the watchpoint expression
5921 now, we would get the old value, and therefore no change
5922 would seem to have occurred.
5924 In order to make watchpoints work `right', we really need
5925 to complete the memory write, and then evaluate the
5926 watchpoint expression. We do this by single-stepping the
5929 It may not be necessary to disable the watchpoint to step over
5930 it. For example, the PA can (with some kernel cooperation)
5931 single step over a watchpoint without disabling the watchpoint.
5933 It is far more common to need to disable a watchpoint to step
5934 the inferior over it. If we have non-steppable watchpoints,
5935 we must disable the current watchpoint; it's simplest to
5936 disable all watchpoints.
5938 Any breakpoint at PC must also be stepped over -- if there's
5939 one, it will have already triggered before the watchpoint
5940 triggered, and we either already reported it to the user, or
5941 it didn't cause a stop and we called keep_going. In either
5942 case, if there was a breakpoint at PC, we must be trying to
5944 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5949 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5950 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5951 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5952 ecs
->event_thread
->control
.stop_step
= 0;
5953 stop_print_frame
= true;
5954 stopped_by_random_signal
= 0;
5955 bpstat stop_chain
= NULL
;
5957 /* Hide inlined functions starting here, unless we just performed stepi or
5958 nexti. After stepi and nexti, always show the innermost frame (not any
5959 inline function call sites). */
5960 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5962 const address_space
*aspace
5963 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5965 /* skip_inline_frames is expensive, so we avoid it if we can
5966 determine that the address is one where functions cannot have
5967 been inlined. This improves performance with inferiors that
5968 load a lot of shared libraries, because the solib event
5969 breakpoint is defined as the address of a function (i.e. not
5970 inline). Note that we have to check the previous PC as well
5971 as the current one to catch cases when we have just
5972 single-stepped off a breakpoint prior to reinstating it.
5973 Note that we're assuming that the code we single-step to is
5974 not inline, but that's not definitive: there's nothing
5975 preventing the event breakpoint function from containing
5976 inlined code, and the single-step ending up there. If the
5977 user had set a breakpoint on that inlined code, the missing
5978 skip_inline_frames call would break things. Fortunately
5979 that's an extremely unlikely scenario. */
5980 if (!pc_at_non_inline_function (aspace
,
5981 ecs
->event_thread
->suspend
.stop_pc
,
5983 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5984 && ecs
->event_thread
->control
.trap_expected
5985 && pc_at_non_inline_function (aspace
,
5986 ecs
->event_thread
->prev_pc
,
5989 stop_chain
= build_bpstat_chain (aspace
,
5990 ecs
->event_thread
->suspend
.stop_pc
,
5992 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5994 /* Re-fetch current thread's frame in case that invalidated
5996 frame
= get_current_frame ();
5997 gdbarch
= get_frame_arch (frame
);
6001 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6002 && ecs
->event_thread
->control
.trap_expected
6003 && gdbarch_single_step_through_delay_p (gdbarch
)
6004 && currently_stepping (ecs
->event_thread
))
6006 /* We're trying to step off a breakpoint. Turns out that we're
6007 also on an instruction that needs to be stepped multiple
6008 times before it's been fully executing. E.g., architectures
6009 with a delay slot. It needs to be stepped twice, once for
6010 the instruction and once for the delay slot. */
6011 int step_through_delay
6012 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6014 if (step_through_delay
)
6015 infrun_debug_printf ("step through delay");
6017 if (ecs
->event_thread
->control
.step_range_end
== 0
6018 && step_through_delay
)
6020 /* The user issued a continue when stopped at a breakpoint.
6021 Set up for another trap and get out of here. */
6022 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6026 else if (step_through_delay
)
6028 /* The user issued a step when stopped at a breakpoint.
6029 Maybe we should stop, maybe we should not - the delay
6030 slot *might* correspond to a line of source. In any
6031 case, don't decide that here, just set
6032 ecs->stepping_over_breakpoint, making sure we
6033 single-step again before breakpoints are re-inserted. */
6034 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6038 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6039 handles this event. */
6040 ecs
->event_thread
->control
.stop_bpstat
6041 = bpstat_stop_status (get_current_regcache ()->aspace (),
6042 ecs
->event_thread
->suspend
.stop_pc
,
6043 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6045 /* Following in case break condition called a
6047 stop_print_frame
= true;
6049 /* This is where we handle "moribund" watchpoints. Unlike
6050 software breakpoints traps, hardware watchpoint traps are
6051 always distinguishable from random traps. If no high-level
6052 watchpoint is associated with the reported stop data address
6053 anymore, then the bpstat does not explain the signal ---
6054 simply make sure to ignore it if `stopped_by_watchpoint' is
6057 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6058 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6060 && stopped_by_watchpoint
)
6062 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6066 /* NOTE: cagney/2003-03-29: These checks for a random signal
6067 at one stage in the past included checks for an inferior
6068 function call's call dummy's return breakpoint. The original
6069 comment, that went with the test, read:
6071 ``End of a stack dummy. Some systems (e.g. Sony news) give
6072 another signal besides SIGTRAP, so check here as well as
6075 If someone ever tries to get call dummys on a
6076 non-executable stack to work (where the target would stop
6077 with something like a SIGSEGV), then those tests might need
6078 to be re-instated. Given, however, that the tests were only
6079 enabled when momentary breakpoints were not being used, I
6080 suspect that it won't be the case.
6082 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6083 be necessary for call dummies on a non-executable stack on
6086 /* See if the breakpoints module can explain the signal. */
6088 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6089 ecs
->event_thread
->suspend
.stop_signal
);
6091 /* Maybe this was a trap for a software breakpoint that has since
6093 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6095 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6096 ecs
->event_thread
->suspend
.stop_pc
))
6098 struct regcache
*regcache
;
6101 /* Re-adjust PC to what the program would see if GDB was not
6103 regcache
= get_thread_regcache (ecs
->event_thread
);
6104 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6107 gdb::optional
<scoped_restore_tmpl
<int>>
6108 restore_operation_disable
;
6110 if (record_full_is_used ())
6111 restore_operation_disable
.emplace
6112 (record_full_gdb_operation_disable_set ());
6114 regcache_write_pc (regcache
,
6115 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6120 /* A delayed software breakpoint event. Ignore the trap. */
6121 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6126 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6127 has since been removed. */
6128 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6130 /* A delayed hardware breakpoint event. Ignore the trap. */
6131 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6136 /* If not, perhaps stepping/nexting can. */
6138 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6139 && currently_stepping (ecs
->event_thread
));
6141 /* Perhaps the thread hit a single-step breakpoint of _another_
6142 thread. Single-step breakpoints are transparent to the
6143 breakpoints module. */
6145 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6147 /* No? Perhaps we got a moribund watchpoint. */
6149 random_signal
= !stopped_by_watchpoint
;
6151 /* Always stop if the user explicitly requested this thread to
6153 if (ecs
->event_thread
->stop_requested
)
6156 infrun_debug_printf ("user-requested stop");
6159 /* For the program's own signals, act according to
6160 the signal handling tables. */
6164 /* Signal not for debugging purposes. */
6165 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6167 infrun_debug_printf ("random signal (%s)",
6168 gdb_signal_to_symbol_string (stop_signal
));
6170 stopped_by_random_signal
= 1;
6172 /* Always stop on signals if we're either just gaining control
6173 of the program, or the user explicitly requested this thread
6174 to remain stopped. */
6175 if (stop_soon
!= NO_STOP_QUIETLY
6176 || ecs
->event_thread
->stop_requested
6177 || signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
))
6183 /* Notify observers the signal has "handle print" set. Note we
6184 returned early above if stopping; normal_stop handles the
6185 printing in that case. */
6186 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6188 /* The signal table tells us to print about this signal. */
6189 target_terminal::ours_for_output ();
6190 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6191 target_terminal::inferior ();
6194 /* Clear the signal if it should not be passed. */
6195 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6196 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6198 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6199 && ecs
->event_thread
->control
.trap_expected
6200 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6202 /* We were just starting a new sequence, attempting to
6203 single-step off of a breakpoint and expecting a SIGTRAP.
6204 Instead this signal arrives. This signal will take us out
6205 of the stepping range so GDB needs to remember to, when
6206 the signal handler returns, resume stepping off that
6208 /* To simplify things, "continue" is forced to use the same
6209 code paths as single-step - set a breakpoint at the
6210 signal return address and then, once hit, step off that
6212 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6214 insert_hp_step_resume_breakpoint_at_frame (frame
);
6215 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6216 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6217 ecs
->event_thread
->control
.trap_expected
= 0;
6219 /* If we were nexting/stepping some other thread, switch to
6220 it, so that we don't continue it, losing control. */
6221 if (!switch_back_to_stepped_thread (ecs
))
6226 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6227 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6229 || ecs
->event_thread
->control
.step_range_end
== 1)
6230 && frame_id_eq (get_stack_frame_id (frame
),
6231 ecs
->event_thread
->control
.step_stack_frame_id
)
6232 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6234 /* The inferior is about to take a signal that will take it
6235 out of the single step range. Set a breakpoint at the
6236 current PC (which is presumably where the signal handler
6237 will eventually return) and then allow the inferior to
6240 Note that this is only needed for a signal delivered
6241 while in the single-step range. Nested signals aren't a
6242 problem as they eventually all return. */
6243 infrun_debug_printf ("signal may take us out of single-step range");
6245 clear_step_over_info ();
6246 insert_hp_step_resume_breakpoint_at_frame (frame
);
6247 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6248 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6249 ecs
->event_thread
->control
.trap_expected
= 0;
6254 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6255 when either there's a nested signal, or when there's a
6256 pending signal enabled just as the signal handler returns
6257 (leaving the inferior at the step-resume-breakpoint without
6258 actually executing it). Either way continue until the
6259 breakpoint is really hit. */
6261 if (!switch_back_to_stepped_thread (ecs
))
6263 infrun_debug_printf ("random signal, keep going");
6270 process_event_stop_test (ecs
);
6273 /* Come here when we've got some debug event / signal we can explain
6274 (IOW, not a random signal), and test whether it should cause a
6275 stop, or whether we should resume the inferior (transparently).
6276 E.g., could be a breakpoint whose condition evaluates false; we
6277 could be still stepping within the line; etc. */
6280 process_event_stop_test (struct execution_control_state
*ecs
)
6282 struct symtab_and_line stop_pc_sal
;
6283 struct frame_info
*frame
;
6284 struct gdbarch
*gdbarch
;
6285 CORE_ADDR jmp_buf_pc
;
6286 struct bpstat_what what
;
6288 /* Handle cases caused by hitting a breakpoint. */
6290 frame
= get_current_frame ();
6291 gdbarch
= get_frame_arch (frame
);
6293 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6295 if (what
.call_dummy
)
6297 stop_stack_dummy
= what
.call_dummy
;
6300 /* A few breakpoint types have callbacks associated (e.g.,
6301 bp_jit_event). Run them now. */
6302 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6304 /* If we hit an internal event that triggers symbol changes, the
6305 current frame will be invalidated within bpstat_what (e.g., if we
6306 hit an internal solib event). Re-fetch it. */
6307 frame
= get_current_frame ();
6308 gdbarch
= get_frame_arch (frame
);
6310 switch (what
.main_action
)
6312 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6313 /* If we hit the breakpoint at longjmp while stepping, we
6314 install a momentary breakpoint at the target of the
6317 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6319 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6321 if (what
.is_longjmp
)
6323 struct value
*arg_value
;
6325 /* If we set the longjmp breakpoint via a SystemTap probe,
6326 then use it to extract the arguments. The destination PC
6327 is the third argument to the probe. */
6328 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6331 jmp_buf_pc
= value_as_address (arg_value
);
6332 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6334 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6335 || !gdbarch_get_longjmp_target (gdbarch
,
6336 frame
, &jmp_buf_pc
))
6338 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6339 "(!gdbarch_get_longjmp_target)");
6344 /* Insert a breakpoint at resume address. */
6345 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6348 check_exception_resume (ecs
, frame
);
6352 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6354 struct frame_info
*init_frame
;
6356 /* There are several cases to consider.
6358 1. The initiating frame no longer exists. In this case we
6359 must stop, because the exception or longjmp has gone too
6362 2. The initiating frame exists, and is the same as the
6363 current frame. We stop, because the exception or longjmp
6366 3. The initiating frame exists and is different from the
6367 current frame. This means the exception or longjmp has
6368 been caught beneath the initiating frame, so keep going.
6370 4. longjmp breakpoint has been placed just to protect
6371 against stale dummy frames and user is not interested in
6372 stopping around longjmps. */
6374 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6376 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6378 delete_exception_resume_breakpoint (ecs
->event_thread
);
6380 if (what
.is_longjmp
)
6382 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6384 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6392 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6396 struct frame_id current_id
6397 = get_frame_id (get_current_frame ());
6398 if (frame_id_eq (current_id
,
6399 ecs
->event_thread
->initiating_frame
))
6401 /* Case 2. Fall through. */
6411 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6413 delete_step_resume_breakpoint (ecs
->event_thread
);
6415 end_stepping_range (ecs
);
6419 case BPSTAT_WHAT_SINGLE
:
6420 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6421 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6422 /* Still need to check other stuff, at least the case where we
6423 are stepping and step out of the right range. */
6426 case BPSTAT_WHAT_STEP_RESUME
:
6427 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6429 delete_step_resume_breakpoint (ecs
->event_thread
);
6430 if (ecs
->event_thread
->control
.proceed_to_finish
6431 && execution_direction
== EXEC_REVERSE
)
6433 struct thread_info
*tp
= ecs
->event_thread
;
6435 /* We are finishing a function in reverse, and just hit the
6436 step-resume breakpoint at the start address of the
6437 function, and we're almost there -- just need to back up
6438 by one more single-step, which should take us back to the
6440 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6444 fill_in_stop_func (gdbarch
, ecs
);
6445 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6446 && execution_direction
== EXEC_REVERSE
)
6448 /* We are stepping over a function call in reverse, and just
6449 hit the step-resume breakpoint at the start address of
6450 the function. Go back to single-stepping, which should
6451 take us back to the function call. */
6452 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6458 case BPSTAT_WHAT_STOP_NOISY
:
6459 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6460 stop_print_frame
= true;
6462 /* Assume the thread stopped for a breakpoint. We'll still check
6463 whether a/the breakpoint is there when the thread is next
6465 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6470 case BPSTAT_WHAT_STOP_SILENT
:
6471 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6472 stop_print_frame
= false;
6474 /* Assume the thread stopped for a breakpoint. We'll still check
6475 whether a/the breakpoint is there when the thread is next
6477 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6481 case BPSTAT_WHAT_HP_STEP_RESUME
:
6482 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6484 delete_step_resume_breakpoint (ecs
->event_thread
);
6485 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6487 /* Back when the step-resume breakpoint was inserted, we
6488 were trying to single-step off a breakpoint. Go back to
6490 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6491 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6497 case BPSTAT_WHAT_KEEP_CHECKING
:
6501 /* If we stepped a permanent breakpoint and we had a high priority
6502 step-resume breakpoint for the address we stepped, but we didn't
6503 hit it, then we must have stepped into the signal handler. The
6504 step-resume was only necessary to catch the case of _not_
6505 stepping into the handler, so delete it, and fall through to
6506 checking whether the step finished. */
6507 if (ecs
->event_thread
->stepped_breakpoint
)
6509 struct breakpoint
*sr_bp
6510 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6513 && sr_bp
->loc
->permanent
6514 && sr_bp
->type
== bp_hp_step_resume
6515 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6517 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6518 delete_step_resume_breakpoint (ecs
->event_thread
);
6519 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6523 /* We come here if we hit a breakpoint but should not stop for it.
6524 Possibly we also were stepping and should stop for that. So fall
6525 through and test for stepping. But, if not stepping, do not
6528 /* In all-stop mode, if we're currently stepping but have stopped in
6529 some other thread, we need to switch back to the stepped thread. */
6530 if (switch_back_to_stepped_thread (ecs
))
6533 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6535 infrun_debug_printf ("step-resume breakpoint is inserted");
6537 /* Having a step-resume breakpoint overrides anything
6538 else having to do with stepping commands until
6539 that breakpoint is reached. */
6544 if (ecs
->event_thread
->control
.step_range_end
== 0)
6546 infrun_debug_printf ("no stepping, continue");
6547 /* Likewise if we aren't even stepping. */
6552 /* Re-fetch current thread's frame in case the code above caused
6553 the frame cache to be re-initialized, making our FRAME variable
6554 a dangling pointer. */
6555 frame
= get_current_frame ();
6556 gdbarch
= get_frame_arch (frame
);
6557 fill_in_stop_func (gdbarch
, ecs
);
6559 /* If stepping through a line, keep going if still within it.
6561 Note that step_range_end is the address of the first instruction
6562 beyond the step range, and NOT the address of the last instruction
6565 Note also that during reverse execution, we may be stepping
6566 through a function epilogue and therefore must detect when
6567 the current-frame changes in the middle of a line. */
6569 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6571 && (execution_direction
!= EXEC_REVERSE
6572 || frame_id_eq (get_frame_id (frame
),
6573 ecs
->event_thread
->control
.step_frame_id
)))
6576 ("stepping inside range [%s-%s]",
6577 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6578 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6580 /* Tentatively re-enable range stepping; `resume' disables it if
6581 necessary (e.g., if we're stepping over a breakpoint or we
6582 have software watchpoints). */
6583 ecs
->event_thread
->control
.may_range_step
= 1;
6585 /* When stepping backward, stop at beginning of line range
6586 (unless it's the function entry point, in which case
6587 keep going back to the call point). */
6588 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6589 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6590 && stop_pc
!= ecs
->stop_func_start
6591 && execution_direction
== EXEC_REVERSE
)
6592 end_stepping_range (ecs
);
6599 /* We stepped out of the stepping range. */
6601 /* If we are stepping at the source level and entered the runtime
6602 loader dynamic symbol resolution code...
6604 EXEC_FORWARD: we keep on single stepping until we exit the run
6605 time loader code and reach the callee's address.
6607 EXEC_REVERSE: we've already executed the callee (backward), and
6608 the runtime loader code is handled just like any other
6609 undebuggable function call. Now we need only keep stepping
6610 backward through the trampoline code, and that's handled further
6611 down, so there is nothing for us to do here. */
6613 if (execution_direction
!= EXEC_REVERSE
6614 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6615 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6617 CORE_ADDR pc_after_resolver
=
6618 gdbarch_skip_solib_resolver (gdbarch
,
6619 ecs
->event_thread
->suspend
.stop_pc
);
6621 infrun_debug_printf ("stepped into dynsym resolve code");
6623 if (pc_after_resolver
)
6625 /* Set up a step-resume breakpoint at the address
6626 indicated by SKIP_SOLIB_RESOLVER. */
6627 symtab_and_line sr_sal
;
6628 sr_sal
.pc
= pc_after_resolver
;
6629 sr_sal
.pspace
= get_frame_program_space (frame
);
6631 insert_step_resume_breakpoint_at_sal (gdbarch
,
6632 sr_sal
, null_frame_id
);
6639 /* Step through an indirect branch thunk. */
6640 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6641 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6642 ecs
->event_thread
->suspend
.stop_pc
))
6644 infrun_debug_printf ("stepped into indirect branch thunk");
6649 if (ecs
->event_thread
->control
.step_range_end
!= 1
6650 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6651 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6652 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6654 infrun_debug_printf ("stepped into signal trampoline");
6655 /* The inferior, while doing a "step" or "next", has ended up in
6656 a signal trampoline (either by a signal being delivered or by
6657 the signal handler returning). Just single-step until the
6658 inferior leaves the trampoline (either by calling the handler
6664 /* If we're in the return path from a shared library trampoline,
6665 we want to proceed through the trampoline when stepping. */
6666 /* macro/2012-04-25: This needs to come before the subroutine
6667 call check below as on some targets return trampolines look
6668 like subroutine calls (MIPS16 return thunks). */
6669 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6670 ecs
->event_thread
->suspend
.stop_pc
,
6671 ecs
->stop_func_name
)
6672 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6674 /* Determine where this trampoline returns. */
6675 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6676 CORE_ADDR real_stop_pc
6677 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6679 infrun_debug_printf ("stepped into solib return tramp");
6681 /* Only proceed through if we know where it's going. */
6684 /* And put the step-breakpoint there and go until there. */
6685 symtab_and_line sr_sal
;
6686 sr_sal
.pc
= real_stop_pc
;
6687 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6688 sr_sal
.pspace
= get_frame_program_space (frame
);
6690 /* Do not specify what the fp should be when we stop since
6691 on some machines the prologue is where the new fp value
6693 insert_step_resume_breakpoint_at_sal (gdbarch
,
6694 sr_sal
, null_frame_id
);
6696 /* Restart without fiddling with the step ranges or
6703 /* Check for subroutine calls. The check for the current frame
6704 equalling the step ID is not necessary - the check of the
6705 previous frame's ID is sufficient - but it is a common case and
6706 cheaper than checking the previous frame's ID.
6708 NOTE: frame_id_eq will never report two invalid frame IDs as
6709 being equal, so to get into this block, both the current and
6710 previous frame must have valid frame IDs. */
6711 /* The outer_frame_id check is a heuristic to detect stepping
6712 through startup code. If we step over an instruction which
6713 sets the stack pointer from an invalid value to a valid value,
6714 we may detect that as a subroutine call from the mythical
6715 "outermost" function. This could be fixed by marking
6716 outermost frames as !stack_p,code_p,special_p. Then the
6717 initial outermost frame, before sp was valid, would
6718 have code_addr == &_start. See the comment in frame_id_eq
6720 if (!frame_id_eq (get_stack_frame_id (frame
),
6721 ecs
->event_thread
->control
.step_stack_frame_id
)
6722 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6723 ecs
->event_thread
->control
.step_stack_frame_id
)
6724 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6726 || (ecs
->event_thread
->control
.step_start_function
6727 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6729 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6730 CORE_ADDR real_stop_pc
;
6732 infrun_debug_printf ("stepped into subroutine");
6734 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6736 /* I presume that step_over_calls is only 0 when we're
6737 supposed to be stepping at the assembly language level
6738 ("stepi"). Just stop. */
6739 /* And this works the same backward as frontward. MVS */
6740 end_stepping_range (ecs
);
6744 /* Reverse stepping through solib trampolines. */
6746 if (execution_direction
== EXEC_REVERSE
6747 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6748 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6749 || (ecs
->stop_func_start
== 0
6750 && in_solib_dynsym_resolve_code (stop_pc
))))
6752 /* Any solib trampoline code can be handled in reverse
6753 by simply continuing to single-step. We have already
6754 executed the solib function (backwards), and a few
6755 steps will take us back through the trampoline to the
6761 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6763 /* We're doing a "next".
6765 Normal (forward) execution: set a breakpoint at the
6766 callee's return address (the address at which the caller
6769 Reverse (backward) execution. set the step-resume
6770 breakpoint at the start of the function that we just
6771 stepped into (backwards), and continue to there. When we
6772 get there, we'll need to single-step back to the caller. */
6774 if (execution_direction
== EXEC_REVERSE
)
6776 /* If we're already at the start of the function, we've either
6777 just stepped backward into a single instruction function,
6778 or stepped back out of a signal handler to the first instruction
6779 of the function. Just keep going, which will single-step back
6781 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6783 /* Normal function call return (static or dynamic). */
6784 symtab_and_line sr_sal
;
6785 sr_sal
.pc
= ecs
->stop_func_start
;
6786 sr_sal
.pspace
= get_frame_program_space (frame
);
6787 insert_step_resume_breakpoint_at_sal (gdbarch
,
6788 sr_sal
, null_frame_id
);
6792 insert_step_resume_breakpoint_at_caller (frame
);
6798 /* If we are in a function call trampoline (a stub between the
6799 calling routine and the real function), locate the real
6800 function. That's what tells us (a) whether we want to step
6801 into it at all, and (b) what prologue we want to run to the
6802 end of, if we do step into it. */
6803 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6804 if (real_stop_pc
== 0)
6805 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6806 if (real_stop_pc
!= 0)
6807 ecs
->stop_func_start
= real_stop_pc
;
6809 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6811 symtab_and_line sr_sal
;
6812 sr_sal
.pc
= ecs
->stop_func_start
;
6813 sr_sal
.pspace
= get_frame_program_space (frame
);
6815 insert_step_resume_breakpoint_at_sal (gdbarch
,
6816 sr_sal
, null_frame_id
);
6821 /* If we have line number information for the function we are
6822 thinking of stepping into and the function isn't on the skip
6825 If there are several symtabs at that PC (e.g. with include
6826 files), just want to know whether *any* of them have line
6827 numbers. find_pc_line handles this. */
6829 struct symtab_and_line tmp_sal
;
6831 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6832 if (tmp_sal
.line
!= 0
6833 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6835 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6837 if (execution_direction
== EXEC_REVERSE
)
6838 handle_step_into_function_backward (gdbarch
, ecs
);
6840 handle_step_into_function (gdbarch
, ecs
);
6845 /* If we have no line number and the step-stop-if-no-debug is
6846 set, we stop the step so that the user has a chance to switch
6847 in assembly mode. */
6848 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6849 && step_stop_if_no_debug
)
6851 end_stepping_range (ecs
);
6855 if (execution_direction
== EXEC_REVERSE
)
6857 /* If we're already at the start of the function, we've either just
6858 stepped backward into a single instruction function without line
6859 number info, or stepped back out of a signal handler to the first
6860 instruction of the function without line number info. Just keep
6861 going, which will single-step back to the caller. */
6862 if (ecs
->stop_func_start
!= stop_pc
)
6864 /* Set a breakpoint at callee's start address.
6865 From there we can step once and be back in the caller. */
6866 symtab_and_line sr_sal
;
6867 sr_sal
.pc
= ecs
->stop_func_start
;
6868 sr_sal
.pspace
= get_frame_program_space (frame
);
6869 insert_step_resume_breakpoint_at_sal (gdbarch
,
6870 sr_sal
, null_frame_id
);
6874 /* Set a breakpoint at callee's return address (the address
6875 at which the caller will resume). */
6876 insert_step_resume_breakpoint_at_caller (frame
);
6882 /* Reverse stepping through solib trampolines. */
6884 if (execution_direction
== EXEC_REVERSE
6885 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6887 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6889 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6890 || (ecs
->stop_func_start
== 0
6891 && in_solib_dynsym_resolve_code (stop_pc
)))
6893 /* Any solib trampoline code can be handled in reverse
6894 by simply continuing to single-step. We have already
6895 executed the solib function (backwards), and a few
6896 steps will take us back through the trampoline to the
6901 else if (in_solib_dynsym_resolve_code (stop_pc
))
6903 /* Stepped backward into the solib dynsym resolver.
6904 Set a breakpoint at its start and continue, then
6905 one more step will take us out. */
6906 symtab_and_line sr_sal
;
6907 sr_sal
.pc
= ecs
->stop_func_start
;
6908 sr_sal
.pspace
= get_frame_program_space (frame
);
6909 insert_step_resume_breakpoint_at_sal (gdbarch
,
6910 sr_sal
, null_frame_id
);
6916 /* This always returns the sal for the inner-most frame when we are in a
6917 stack of inlined frames, even if GDB actually believes that it is in a
6918 more outer frame. This is checked for below by calls to
6919 inline_skipped_frames. */
6920 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6922 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6923 the trampoline processing logic, however, there are some trampolines
6924 that have no names, so we should do trampoline handling first. */
6925 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6926 && ecs
->stop_func_name
== NULL
6927 && stop_pc_sal
.line
== 0)
6929 infrun_debug_printf ("stepped into undebuggable function");
6931 /* The inferior just stepped into, or returned to, an
6932 undebuggable function (where there is no debugging information
6933 and no line number corresponding to the address where the
6934 inferior stopped). Since we want to skip this kind of code,
6935 we keep going until the inferior returns from this
6936 function - unless the user has asked us not to (via
6937 set step-mode) or we no longer know how to get back
6938 to the call site. */
6939 if (step_stop_if_no_debug
6940 || !frame_id_p (frame_unwind_caller_id (frame
)))
6942 /* If we have no line number and the step-stop-if-no-debug
6943 is set, we stop the step so that the user has a chance to
6944 switch in assembly mode. */
6945 end_stepping_range (ecs
);
6950 /* Set a breakpoint at callee's return address (the address
6951 at which the caller will resume). */
6952 insert_step_resume_breakpoint_at_caller (frame
);
6958 if (ecs
->event_thread
->control
.step_range_end
== 1)
6960 /* It is stepi or nexti. We always want to stop stepping after
6962 infrun_debug_printf ("stepi/nexti");
6963 end_stepping_range (ecs
);
6967 if (stop_pc_sal
.line
== 0)
6969 /* We have no line number information. That means to stop
6970 stepping (does this always happen right after one instruction,
6971 when we do "s" in a function with no line numbers,
6972 or can this happen as a result of a return or longjmp?). */
6973 infrun_debug_printf ("line number info");
6974 end_stepping_range (ecs
);
6978 /* Look for "calls" to inlined functions, part one. If the inline
6979 frame machinery detected some skipped call sites, we have entered
6980 a new inline function. */
6982 if (frame_id_eq (get_frame_id (get_current_frame ()),
6983 ecs
->event_thread
->control
.step_frame_id
)
6984 && inline_skipped_frames (ecs
->event_thread
))
6986 infrun_debug_printf ("stepped into inlined function");
6988 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6990 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6992 /* For "step", we're going to stop. But if the call site
6993 for this inlined function is on the same source line as
6994 we were previously stepping, go down into the function
6995 first. Otherwise stop at the call site. */
6997 if (call_sal
.line
== ecs
->event_thread
->current_line
6998 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7000 step_into_inline_frame (ecs
->event_thread
);
7001 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7008 end_stepping_range (ecs
);
7013 /* For "next", we should stop at the call site if it is on a
7014 different source line. Otherwise continue through the
7015 inlined function. */
7016 if (call_sal
.line
== ecs
->event_thread
->current_line
7017 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7020 end_stepping_range (ecs
);
7025 /* Look for "calls" to inlined functions, part two. If we are still
7026 in the same real function we were stepping through, but we have
7027 to go further up to find the exact frame ID, we are stepping
7028 through a more inlined call beyond its call site. */
7030 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7031 && !frame_id_eq (get_frame_id (get_current_frame ()),
7032 ecs
->event_thread
->control
.step_frame_id
)
7033 && stepped_in_from (get_current_frame (),
7034 ecs
->event_thread
->control
.step_frame_id
))
7036 infrun_debug_printf ("stepping through inlined function");
7038 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7039 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7042 end_stepping_range (ecs
);
7046 bool refresh_step_info
= true;
7047 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7048 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7049 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7051 /* We are at a different line. */
7053 if (stop_pc_sal
.is_stmt
)
7055 /* We are at the start of a statement.
7057 So stop. Note that we don't stop if we step into the middle of a
7058 statement. That is said to make things like for (;;) statements
7060 infrun_debug_printf ("stepped to a different line");
7061 end_stepping_range (ecs
);
7064 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7065 ecs
->event_thread
->control
.step_frame_id
))
7067 /* We are not at the start of a statement, and we have not changed
7070 We ignore this line table entry, and continue stepping forward,
7071 looking for a better place to stop. */
7072 refresh_step_info
= false;
7073 infrun_debug_printf ("stepped to a different line, but "
7074 "it's not the start of a statement");
7078 /* We are not the start of a statement, and we have changed frame.
7080 We ignore this line table entry, and continue stepping forward,
7081 looking for a better place to stop. Keep refresh_step_info at
7082 true to note that the frame has changed, but ignore the line
7083 number to make sure we don't ignore a subsequent entry with the
7084 same line number. */
7085 stop_pc_sal
.line
= 0;
7086 infrun_debug_printf ("stepped to a different frame, but "
7087 "it's not the start of a statement");
7091 /* We aren't done stepping.
7093 Optimize by setting the stepping range to the line.
7094 (We might not be in the original line, but if we entered a
7095 new line in mid-statement, we continue stepping. This makes
7096 things like for(;;) statements work better.)
7098 If we entered a SAL that indicates a non-statement line table entry,
7099 then we update the stepping range, but we don't update the step info,
7100 which includes things like the line number we are stepping away from.
7101 This means we will stop when we find a line table entry that is marked
7102 as is-statement, even if it matches the non-statement one we just
7105 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7106 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7107 ecs
->event_thread
->control
.may_range_step
= 1;
7108 if (refresh_step_info
)
7109 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7111 infrun_debug_printf ("keep going");
7115 static bool restart_stepped_thread (process_stratum_target
*resume_target
,
7116 ptid_t resume_ptid
);
7118 /* In all-stop mode, if we're currently stepping but have stopped in
7119 some other thread, we may need to switch back to the stepped
7120 thread. Returns true we set the inferior running, false if we left
7121 it stopped (and the event needs further processing). */
7124 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7126 if (!target_is_non_stop_p ())
7128 /* If any thread is blocked on some internal breakpoint, and we
7129 simply need to step over that breakpoint to get it going
7130 again, do that first. */
7132 /* However, if we see an event for the stepping thread, then we
7133 know all other threads have been moved past their breakpoints
7134 already. Let the caller check whether the step is finished,
7135 etc., before deciding to move it past a breakpoint. */
7136 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7139 /* Check if the current thread is blocked on an incomplete
7140 step-over, interrupted by a random signal. */
7141 if (ecs
->event_thread
->control
.trap_expected
7142 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7145 ("need to finish step-over of [%s]",
7146 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7151 /* Check if the current thread is blocked by a single-step
7152 breakpoint of another thread. */
7153 if (ecs
->hit_singlestep_breakpoint
)
7155 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7156 target_pid_to_str (ecs
->ptid
).c_str ());
7161 /* If this thread needs yet another step-over (e.g., stepping
7162 through a delay slot), do it first before moving on to
7164 if (thread_still_needs_step_over (ecs
->event_thread
))
7167 ("thread [%s] still needs step-over",
7168 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7173 /* If scheduler locking applies even if not stepping, there's no
7174 need to walk over threads. Above we've checked whether the
7175 current thread is stepping. If some other thread not the
7176 event thread is stepping, then it must be that scheduler
7177 locking is not in effect. */
7178 if (schedlock_applies (ecs
->event_thread
))
7181 /* Otherwise, we no longer expect a trap in the current thread.
7182 Clear the trap_expected flag before switching back -- this is
7183 what keep_going does as well, if we call it. */
7184 ecs
->event_thread
->control
.trap_expected
= 0;
7186 /* Likewise, clear the signal if it should not be passed. */
7187 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7188 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7190 if (restart_stepped_thread (ecs
->target
, ecs
->ptid
))
7192 prepare_to_wait (ecs
);
7196 switch_to_thread (ecs
->event_thread
);
7202 /* Look for the thread that was stepping, and resume it.
7203 RESUME_TARGET / RESUME_PTID indicate the set of threads the caller
7204 is resuming. Return true if a thread was started, false
7208 restart_stepped_thread (process_stratum_target
*resume_target
,
7211 /* Do all pending step-overs before actually proceeding with
7213 if (start_step_over ())
7216 for (thread_info
*tp
: all_threads_safe ())
7218 if (tp
->state
== THREAD_EXITED
)
7221 if (tp
->suspend
.waitstatus_pending_p
)
7224 /* Ignore threads of processes the caller is not
7227 && (tp
->inf
->process_target () != resume_target
7228 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7231 if (tp
->control
.trap_expected
)
7233 infrun_debug_printf ("switching back to stepped thread (step-over)");
7235 if (keep_going_stepped_thread (tp
))
7240 for (thread_info
*tp
: all_threads_safe ())
7242 if (tp
->state
== THREAD_EXITED
)
7245 if (tp
->suspend
.waitstatus_pending_p
)
7248 /* Ignore threads of processes the caller is not
7251 && (tp
->inf
->process_target () != resume_target
7252 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7255 /* Did we find the stepping thread? */
7256 if (tp
->control
.step_range_end
)
7258 infrun_debug_printf ("switching back to stepped thread (stepping)");
7260 if (keep_going_stepped_thread (tp
))
7271 restart_after_all_stop_detach (process_stratum_target
*proc_target
)
7273 /* Note we don't check target_is_non_stop_p() here, because the
7274 current inferior may no longer have a process_stratum target
7275 pushed, as we just detached. */
7277 /* See if we have a THREAD_RUNNING thread that need to be
7278 re-resumed. If we have any thread that is already executing,
7279 then we don't need to resume the target -- it is already been
7280 resumed. With the remote target (in all-stop), it's even
7281 impossible to issue another resumption if the target is already
7282 resumed, until the target reports a stop. */
7283 for (thread_info
*thr
: all_threads (proc_target
))
7285 if (thr
->state
!= THREAD_RUNNING
)
7288 /* If we have any thread that is already executing, then we
7289 don't need to resume the target -- it is already been
7294 /* If we have a pending event to process, skip resuming the
7295 target and go straight to processing it. */
7296 if (thr
->resumed
&& thr
->suspend
.waitstatus_pending_p
)
7300 /* Alright, we need to re-resume the target. If a thread was
7301 stepping, we need to restart it stepping. */
7302 if (restart_stepped_thread (proc_target
, minus_one_ptid
))
7305 /* Otherwise, find the first THREAD_RUNNING thread and resume
7307 for (thread_info
*thr
: all_threads (proc_target
))
7309 if (thr
->state
!= THREAD_RUNNING
)
7312 execution_control_state ecs
;
7313 reset_ecs (&ecs
, thr
);
7314 switch_to_thread (thr
);
7320 /* Set a previously stepped thread back to stepping. Returns true on
7321 success, false if the resume is not possible (e.g., the thread
7325 keep_going_stepped_thread (struct thread_info
*tp
)
7327 struct frame_info
*frame
;
7328 struct execution_control_state ecss
;
7329 struct execution_control_state
*ecs
= &ecss
;
7331 /* If the stepping thread exited, then don't try to switch back and
7332 resume it, which could fail in several different ways depending
7333 on the target. Instead, just keep going.
7335 We can find a stepping dead thread in the thread list in two
7338 - The target supports thread exit events, and when the target
7339 tries to delete the thread from the thread list, inferior_ptid
7340 pointed at the exiting thread. In such case, calling
7341 delete_thread does not really remove the thread from the list;
7342 instead, the thread is left listed, with 'exited' state.
7344 - The target's debug interface does not support thread exit
7345 events, and so we have no idea whatsoever if the previously
7346 stepping thread is still alive. For that reason, we need to
7347 synchronously query the target now. */
7349 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7351 infrun_debug_printf ("not resuming previously stepped thread, it has "
7358 infrun_debug_printf ("resuming previously stepped thread");
7360 reset_ecs (ecs
, tp
);
7361 switch_to_thread (tp
);
7363 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7364 frame
= get_current_frame ();
7366 /* If the PC of the thread we were trying to single-step has
7367 changed, then that thread has trapped or been signaled, but the
7368 event has not been reported to GDB yet. Re-poll the target
7369 looking for this particular thread's event (i.e. temporarily
7370 enable schedlock) by:
7372 - setting a break at the current PC
7373 - resuming that particular thread, only (by setting trap
7376 This prevents us continuously moving the single-step breakpoint
7377 forward, one instruction at a time, overstepping. */
7379 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7383 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7384 paddress (target_gdbarch (), tp
->prev_pc
),
7385 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7387 /* Clear the info of the previous step-over, as it's no longer
7388 valid (if the thread was trying to step over a breakpoint, it
7389 has already succeeded). It's what keep_going would do too,
7390 if we called it. Do this before trying to insert the sss
7391 breakpoint, otherwise if we were previously trying to step
7392 over this exact address in another thread, the breakpoint is
7394 clear_step_over_info ();
7395 tp
->control
.trap_expected
= 0;
7397 insert_single_step_breakpoint (get_frame_arch (frame
),
7398 get_frame_address_space (frame
),
7399 tp
->suspend
.stop_pc
);
7402 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7403 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7407 infrun_debug_printf ("expected thread still hasn't advanced");
7409 keep_going_pass_signal (ecs
);
7415 /* Is thread TP in the middle of (software or hardware)
7416 single-stepping? (Note the result of this function must never be
7417 passed directly as target_resume's STEP parameter.) */
7420 currently_stepping (struct thread_info
*tp
)
7422 return ((tp
->control
.step_range_end
7423 && tp
->control
.step_resume_breakpoint
== NULL
)
7424 || tp
->control
.trap_expected
7425 || tp
->stepped_breakpoint
7426 || bpstat_should_step ());
7429 /* Inferior has stepped into a subroutine call with source code that
7430 we should not step over. Do step to the first line of code in
7434 handle_step_into_function (struct gdbarch
*gdbarch
,
7435 struct execution_control_state
*ecs
)
7437 fill_in_stop_func (gdbarch
, ecs
);
7439 compunit_symtab
*cust
7440 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7441 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7442 ecs
->stop_func_start
7443 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7445 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7446 /* Use the step_resume_break to step until the end of the prologue,
7447 even if that involves jumps (as it seems to on the vax under
7449 /* If the prologue ends in the middle of a source line, continue to
7450 the end of that source line (if it is still within the function).
7451 Otherwise, just go to end of prologue. */
7452 if (stop_func_sal
.end
7453 && stop_func_sal
.pc
!= ecs
->stop_func_start
7454 && stop_func_sal
.end
< ecs
->stop_func_end
)
7455 ecs
->stop_func_start
= stop_func_sal
.end
;
7457 /* Architectures which require breakpoint adjustment might not be able
7458 to place a breakpoint at the computed address. If so, the test
7459 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7460 ecs->stop_func_start to an address at which a breakpoint may be
7461 legitimately placed.
7463 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7464 made, GDB will enter an infinite loop when stepping through
7465 optimized code consisting of VLIW instructions which contain
7466 subinstructions corresponding to different source lines. On
7467 FR-V, it's not permitted to place a breakpoint on any but the
7468 first subinstruction of a VLIW instruction. When a breakpoint is
7469 set, GDB will adjust the breakpoint address to the beginning of
7470 the VLIW instruction. Thus, we need to make the corresponding
7471 adjustment here when computing the stop address. */
7473 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7475 ecs
->stop_func_start
7476 = gdbarch_adjust_breakpoint_address (gdbarch
,
7477 ecs
->stop_func_start
);
7480 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7482 /* We are already there: stop now. */
7483 end_stepping_range (ecs
);
7488 /* Put the step-breakpoint there and go until there. */
7489 symtab_and_line sr_sal
;
7490 sr_sal
.pc
= ecs
->stop_func_start
;
7491 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7492 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7494 /* Do not specify what the fp should be when we stop since on
7495 some machines the prologue is where the new fp value is
7497 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7499 /* And make sure stepping stops right away then. */
7500 ecs
->event_thread
->control
.step_range_end
7501 = ecs
->event_thread
->control
.step_range_start
;
7506 /* Inferior has stepped backward into a subroutine call with source
7507 code that we should not step over. Do step to the beginning of the
7508 last line of code in it. */
7511 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7512 struct execution_control_state
*ecs
)
7514 struct compunit_symtab
*cust
;
7515 struct symtab_and_line stop_func_sal
;
7517 fill_in_stop_func (gdbarch
, ecs
);
7519 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7520 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7521 ecs
->stop_func_start
7522 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7524 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7526 /* OK, we're just going to keep stepping here. */
7527 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7529 /* We're there already. Just stop stepping now. */
7530 end_stepping_range (ecs
);
7534 /* Else just reset the step range and keep going.
7535 No step-resume breakpoint, they don't work for
7536 epilogues, which can have multiple entry paths. */
7537 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7538 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7544 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7545 This is used to both functions and to skip over code. */
7548 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7549 struct symtab_and_line sr_sal
,
7550 struct frame_id sr_id
,
7551 enum bptype sr_type
)
7553 /* There should never be more than one step-resume or longjmp-resume
7554 breakpoint per thread, so we should never be setting a new
7555 step_resume_breakpoint when one is already active. */
7556 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7557 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7559 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7560 paddress (gdbarch
, sr_sal
.pc
));
7562 inferior_thread ()->control
.step_resume_breakpoint
7563 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7567 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7568 struct symtab_and_line sr_sal
,
7569 struct frame_id sr_id
)
7571 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7576 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7577 This is used to skip a potential signal handler.
7579 This is called with the interrupted function's frame. The signal
7580 handler, when it returns, will resume the interrupted function at
7584 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7586 gdb_assert (return_frame
!= NULL
);
7588 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7590 symtab_and_line sr_sal
;
7591 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7592 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7593 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7595 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7596 get_stack_frame_id (return_frame
),
7600 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7601 is used to skip a function after stepping into it (for "next" or if
7602 the called function has no debugging information).
7604 The current function has almost always been reached by single
7605 stepping a call or return instruction. NEXT_FRAME belongs to the
7606 current function, and the breakpoint will be set at the caller's
7609 This is a separate function rather than reusing
7610 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7611 get_prev_frame, which may stop prematurely (see the implementation
7612 of frame_unwind_caller_id for an example). */
7615 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7617 /* We shouldn't have gotten here if we don't know where the call site
7619 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7621 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7623 symtab_and_line sr_sal
;
7624 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7625 frame_unwind_caller_pc (next_frame
));
7626 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7627 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7629 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7630 frame_unwind_caller_id (next_frame
));
7633 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7634 new breakpoint at the target of a jmp_buf. The handling of
7635 longjmp-resume uses the same mechanisms used for handling
7636 "step-resume" breakpoints. */
7639 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7641 /* There should never be more than one longjmp-resume breakpoint per
7642 thread, so we should never be setting a new
7643 longjmp_resume_breakpoint when one is already active. */
7644 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7646 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7647 paddress (gdbarch
, pc
));
7649 inferior_thread ()->control
.exception_resume_breakpoint
=
7650 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7653 /* Insert an exception resume breakpoint. TP is the thread throwing
7654 the exception. The block B is the block of the unwinder debug hook
7655 function. FRAME is the frame corresponding to the call to this
7656 function. SYM is the symbol of the function argument holding the
7657 target PC of the exception. */
7660 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7661 const struct block
*b
,
7662 struct frame_info
*frame
,
7667 struct block_symbol vsym
;
7668 struct value
*value
;
7670 struct breakpoint
*bp
;
7672 vsym
= lookup_symbol_search_name (sym
->search_name (),
7674 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7675 /* If the value was optimized out, revert to the old behavior. */
7676 if (! value_optimized_out (value
))
7678 handler
= value_as_address (value
);
7680 infrun_debug_printf ("exception resume at %lx",
7681 (unsigned long) handler
);
7683 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7685 bp_exception_resume
).release ();
7687 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7690 bp
->thread
= tp
->global_num
;
7691 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7694 catch (const gdb_exception_error
&e
)
7696 /* We want to ignore errors here. */
7700 /* A helper for check_exception_resume that sets an
7701 exception-breakpoint based on a SystemTap probe. */
7704 insert_exception_resume_from_probe (struct thread_info
*tp
,
7705 const struct bound_probe
*probe
,
7706 struct frame_info
*frame
)
7708 struct value
*arg_value
;
7710 struct breakpoint
*bp
;
7712 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7716 handler
= value_as_address (arg_value
);
7718 infrun_debug_printf ("exception resume at %s",
7719 paddress (probe
->objfile
->arch (), handler
));
7721 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7722 handler
, bp_exception_resume
).release ();
7723 bp
->thread
= tp
->global_num
;
7724 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7727 /* This is called when an exception has been intercepted. Check to
7728 see whether the exception's destination is of interest, and if so,
7729 set an exception resume breakpoint there. */
7732 check_exception_resume (struct execution_control_state
*ecs
,
7733 struct frame_info
*frame
)
7735 struct bound_probe probe
;
7736 struct symbol
*func
;
7738 /* First see if this exception unwinding breakpoint was set via a
7739 SystemTap probe point. If so, the probe has two arguments: the
7740 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7741 set a breakpoint there. */
7742 probe
= find_probe_by_pc (get_frame_pc (frame
));
7745 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7749 func
= get_frame_function (frame
);
7755 const struct block
*b
;
7756 struct block_iterator iter
;
7760 /* The exception breakpoint is a thread-specific breakpoint on
7761 the unwinder's debug hook, declared as:
7763 void _Unwind_DebugHook (void *cfa, void *handler);
7765 The CFA argument indicates the frame to which control is
7766 about to be transferred. HANDLER is the destination PC.
7768 We ignore the CFA and set a temporary breakpoint at HANDLER.
7769 This is not extremely efficient but it avoids issues in gdb
7770 with computing the DWARF CFA, and it also works even in weird
7771 cases such as throwing an exception from inside a signal
7774 b
= SYMBOL_BLOCK_VALUE (func
);
7775 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7777 if (!SYMBOL_IS_ARGUMENT (sym
))
7784 insert_exception_resume_breakpoint (ecs
->event_thread
,
7790 catch (const gdb_exception_error
&e
)
7796 stop_waiting (struct execution_control_state
*ecs
)
7798 infrun_debug_printf ("stop_waiting");
7800 /* Let callers know we don't want to wait for the inferior anymore. */
7801 ecs
->wait_some_more
= 0;
7803 /* If all-stop, but there exists a non-stop target, stop all
7804 threads now that we're presenting the stop to the user. */
7805 if (!non_stop
&& exists_non_stop_target ())
7806 stop_all_threads ();
7809 /* Like keep_going, but passes the signal to the inferior, even if the
7810 signal is set to nopass. */
7813 keep_going_pass_signal (struct execution_control_state
*ecs
)
7815 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7816 gdb_assert (!ecs
->event_thread
->resumed
);
7818 /* Save the pc before execution, to compare with pc after stop. */
7819 ecs
->event_thread
->prev_pc
7820 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7822 if (ecs
->event_thread
->control
.trap_expected
)
7824 struct thread_info
*tp
= ecs
->event_thread
;
7826 infrun_debug_printf ("%s has trap_expected set, "
7827 "resuming to collect trap",
7828 target_pid_to_str (tp
->ptid
).c_str ());
7830 /* We haven't yet gotten our trap, and either: intercepted a
7831 non-signal event (e.g., a fork); or took a signal which we
7832 are supposed to pass through to the inferior. Simply
7834 resume (ecs
->event_thread
->suspend
.stop_signal
);
7836 else if (step_over_info_valid_p ())
7838 /* Another thread is stepping over a breakpoint in-line. If
7839 this thread needs a step-over too, queue the request. In
7840 either case, this resume must be deferred for later. */
7841 struct thread_info
*tp
= ecs
->event_thread
;
7843 if (ecs
->hit_singlestep_breakpoint
7844 || thread_still_needs_step_over (tp
))
7846 infrun_debug_printf ("step-over already in progress: "
7847 "step-over for %s deferred",
7848 target_pid_to_str (tp
->ptid
).c_str ());
7849 global_thread_step_over_chain_enqueue (tp
);
7853 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7854 target_pid_to_str (tp
->ptid
).c_str ());
7859 struct regcache
*regcache
= get_current_regcache ();
7862 step_over_what step_what
;
7864 /* Either the trap was not expected, but we are continuing
7865 anyway (if we got a signal, the user asked it be passed to
7868 We got our expected trap, but decided we should resume from
7871 We're going to run this baby now!
7873 Note that insert_breakpoints won't try to re-insert
7874 already inserted breakpoints. Therefore, we don't
7875 care if breakpoints were already inserted, or not. */
7877 /* If we need to step over a breakpoint, and we're not using
7878 displaced stepping to do so, insert all breakpoints
7879 (watchpoints, etc.) but the one we're stepping over, step one
7880 instruction, and then re-insert the breakpoint when that step
7883 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7885 remove_bp
= (ecs
->hit_singlestep_breakpoint
7886 || (step_what
& STEP_OVER_BREAKPOINT
));
7887 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7889 /* We can't use displaced stepping if we need to step past a
7890 watchpoint. The instruction copied to the scratch pad would
7891 still trigger the watchpoint. */
7893 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7895 set_step_over_info (regcache
->aspace (),
7896 regcache_read_pc (regcache
), remove_wps
,
7897 ecs
->event_thread
->global_num
);
7899 else if (remove_wps
)
7900 set_step_over_info (NULL
, 0, remove_wps
, -1);
7902 /* If we now need to do an in-line step-over, we need to stop
7903 all other threads. Note this must be done before
7904 insert_breakpoints below, because that removes the breakpoint
7905 we're about to step over, otherwise other threads could miss
7907 if (step_over_info_valid_p () && target_is_non_stop_p ())
7908 stop_all_threads ();
7910 /* Stop stepping if inserting breakpoints fails. */
7913 insert_breakpoints ();
7915 catch (const gdb_exception_error
&e
)
7917 exception_print (gdb_stderr
, e
);
7919 clear_step_over_info ();
7923 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7925 resume (ecs
->event_thread
->suspend
.stop_signal
);
7928 prepare_to_wait (ecs
);
7931 /* Called when we should continue running the inferior, because the
7932 current event doesn't cause a user visible stop. This does the
7933 resuming part; waiting for the next event is done elsewhere. */
7936 keep_going (struct execution_control_state
*ecs
)
7938 if (ecs
->event_thread
->control
.trap_expected
7939 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7940 ecs
->event_thread
->control
.trap_expected
= 0;
7942 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7943 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7944 keep_going_pass_signal (ecs
);
7947 /* This function normally comes after a resume, before
7948 handle_inferior_event exits. It takes care of any last bits of
7949 housekeeping, and sets the all-important wait_some_more flag. */
7952 prepare_to_wait (struct execution_control_state
*ecs
)
7954 infrun_debug_printf ("prepare_to_wait");
7956 ecs
->wait_some_more
= 1;
7958 /* If the target can't async, emulate it by marking the infrun event
7959 handler such that as soon as we get back to the event-loop, we
7960 immediately end up in fetch_inferior_event again calling
7962 if (!target_can_async_p ())
7963 mark_infrun_async_event_handler ();
7966 /* We are done with the step range of a step/next/si/ni command.
7967 Called once for each n of a "step n" operation. */
7970 end_stepping_range (struct execution_control_state
*ecs
)
7972 ecs
->event_thread
->control
.stop_step
= 1;
7976 /* Several print_*_reason functions to print why the inferior has stopped.
7977 We always print something when the inferior exits, or receives a signal.
7978 The rest of the cases are dealt with later on in normal_stop and
7979 print_it_typical. Ideally there should be a call to one of these
7980 print_*_reason functions functions from handle_inferior_event each time
7981 stop_waiting is called.
7983 Note that we don't call these directly, instead we delegate that to
7984 the interpreters, through observers. Interpreters then call these
7985 with whatever uiout is right. */
7988 print_end_stepping_range_reason (struct ui_out
*uiout
)
7990 /* For CLI-like interpreters, print nothing. */
7992 if (uiout
->is_mi_like_p ())
7994 uiout
->field_string ("reason",
7995 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8000 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8002 annotate_signalled ();
8003 if (uiout
->is_mi_like_p ())
8005 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8006 uiout
->text ("\nProgram terminated with signal ");
8007 annotate_signal_name ();
8008 uiout
->field_string ("signal-name",
8009 gdb_signal_to_name (siggnal
));
8010 annotate_signal_name_end ();
8012 annotate_signal_string ();
8013 uiout
->field_string ("signal-meaning",
8014 gdb_signal_to_string (siggnal
));
8015 annotate_signal_string_end ();
8016 uiout
->text (".\n");
8017 uiout
->text ("The program no longer exists.\n");
8021 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8023 struct inferior
*inf
= current_inferior ();
8024 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8026 annotate_exited (exitstatus
);
8029 if (uiout
->is_mi_like_p ())
8030 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8031 std::string exit_code_str
8032 = string_printf ("0%o", (unsigned int) exitstatus
);
8033 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8034 plongest (inf
->num
), pidstr
.c_str (),
8035 string_field ("exit-code", exit_code_str
.c_str ()));
8039 if (uiout
->is_mi_like_p ())
8041 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8042 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8043 plongest (inf
->num
), pidstr
.c_str ());
8048 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8050 struct thread_info
*thr
= inferior_thread ();
8054 if (uiout
->is_mi_like_p ())
8056 else if (show_thread_that_caused_stop ())
8060 uiout
->text ("\nThread ");
8061 uiout
->field_string ("thread-id", print_thread_id (thr
));
8063 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8066 uiout
->text (" \"");
8067 uiout
->field_string ("name", name
);
8072 uiout
->text ("\nProgram");
8074 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8075 uiout
->text (" stopped");
8078 uiout
->text (" received signal ");
8079 annotate_signal_name ();
8080 if (uiout
->is_mi_like_p ())
8082 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8083 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8084 annotate_signal_name_end ();
8086 annotate_signal_string ();
8087 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8089 struct regcache
*regcache
= get_current_regcache ();
8090 struct gdbarch
*gdbarch
= regcache
->arch ();
8091 if (gdbarch_report_signal_info_p (gdbarch
))
8092 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8094 annotate_signal_string_end ();
8096 uiout
->text (".\n");
8100 print_no_history_reason (struct ui_out
*uiout
)
8102 uiout
->text ("\nNo more reverse-execution history.\n");
8105 /* Print current location without a level number, if we have changed
8106 functions or hit a breakpoint. Print source line if we have one.
8107 bpstat_print contains the logic deciding in detail what to print,
8108 based on the event(s) that just occurred. */
8111 print_stop_location (struct target_waitstatus
*ws
)
8114 enum print_what source_flag
;
8115 int do_frame_printing
= 1;
8116 struct thread_info
*tp
= inferior_thread ();
8118 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8122 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8123 should) carry around the function and does (or should) use
8124 that when doing a frame comparison. */
8125 if (tp
->control
.stop_step
8126 && frame_id_eq (tp
->control
.step_frame_id
,
8127 get_frame_id (get_current_frame ()))
8128 && (tp
->control
.step_start_function
8129 == find_pc_function (tp
->suspend
.stop_pc
)))
8131 /* Finished step, just print source line. */
8132 source_flag
= SRC_LINE
;
8136 /* Print location and source line. */
8137 source_flag
= SRC_AND_LOC
;
8140 case PRINT_SRC_AND_LOC
:
8141 /* Print location and source line. */
8142 source_flag
= SRC_AND_LOC
;
8144 case PRINT_SRC_ONLY
:
8145 source_flag
= SRC_LINE
;
8148 /* Something bogus. */
8149 source_flag
= SRC_LINE
;
8150 do_frame_printing
= 0;
8153 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8156 /* The behavior of this routine with respect to the source
8158 SRC_LINE: Print only source line
8159 LOCATION: Print only location
8160 SRC_AND_LOC: Print location and source line. */
8161 if (do_frame_printing
)
8162 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8168 print_stop_event (struct ui_out
*uiout
, bool displays
)
8170 struct target_waitstatus last
;
8171 struct thread_info
*tp
;
8173 get_last_target_status (nullptr, nullptr, &last
);
8176 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8178 print_stop_location (&last
);
8180 /* Display the auto-display expressions. */
8185 tp
= inferior_thread ();
8186 if (tp
->thread_fsm
!= NULL
8187 && tp
->thread_fsm
->finished_p ())
8189 struct return_value_info
*rv
;
8191 rv
= tp
->thread_fsm
->return_value ();
8193 print_return_value (uiout
, rv
);
8200 maybe_remove_breakpoints (void)
8202 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8204 if (remove_breakpoints ())
8206 target_terminal::ours_for_output ();
8207 printf_filtered (_("Cannot remove breakpoints because "
8208 "program is no longer writable.\nFurther "
8209 "execution is probably impossible.\n"));
8214 /* The execution context that just caused a normal stop. */
8220 DISABLE_COPY_AND_ASSIGN (stop_context
);
8222 bool changed () const;
8227 /* The event PTID. */
8231 /* If stopp for a thread event, this is the thread that caused the
8233 thread_info_ref thread
;
8235 /* The inferior that caused the stop. */
8239 /* Initializes a new stop context. If stopped for a thread event, this
8240 takes a strong reference to the thread. */
8242 stop_context::stop_context ()
8244 stop_id
= get_stop_id ();
8245 ptid
= inferior_ptid
;
8246 inf_num
= current_inferior ()->num
;
8248 if (inferior_ptid
!= null_ptid
)
8250 /* Take a strong reference so that the thread can't be deleted
8252 thread
= thread_info_ref::new_reference (inferior_thread ());
8256 /* Return true if the current context no longer matches the saved stop
8260 stop_context::changed () const
8262 if (ptid
!= inferior_ptid
)
8264 if (inf_num
!= current_inferior ()->num
)
8266 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8268 if (get_stop_id () != stop_id
)
8278 struct target_waitstatus last
;
8280 get_last_target_status (nullptr, nullptr, &last
);
8284 /* If an exception is thrown from this point on, make sure to
8285 propagate GDB's knowledge of the executing state to the
8286 frontend/user running state. A QUIT is an easy exception to see
8287 here, so do this before any filtered output. */
8289 ptid_t finish_ptid
= null_ptid
;
8292 finish_ptid
= minus_one_ptid
;
8293 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8294 || last
.kind
== TARGET_WAITKIND_EXITED
)
8296 /* On some targets, we may still have live threads in the
8297 inferior when we get a process exit event. E.g., for
8298 "checkpoint", when the current checkpoint/fork exits,
8299 linux-fork.c automatically switches to another fork from
8300 within target_mourn_inferior. */
8301 if (inferior_ptid
!= null_ptid
)
8302 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8304 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8305 finish_ptid
= inferior_ptid
;
8307 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8308 if (finish_ptid
!= null_ptid
)
8310 maybe_finish_thread_state
.emplace
8311 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8314 /* As we're presenting a stop, and potentially removing breakpoints,
8315 update the thread list so we can tell whether there are threads
8316 running on the target. With target remote, for example, we can
8317 only learn about new threads when we explicitly update the thread
8318 list. Do this before notifying the interpreters about signal
8319 stops, end of stepping ranges, etc., so that the "new thread"
8320 output is emitted before e.g., "Program received signal FOO",
8321 instead of after. */
8322 update_thread_list ();
8324 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8325 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8327 /* As with the notification of thread events, we want to delay
8328 notifying the user that we've switched thread context until
8329 the inferior actually stops.
8331 There's no point in saying anything if the inferior has exited.
8332 Note that SIGNALLED here means "exited with a signal", not
8333 "received a signal".
8335 Also skip saying anything in non-stop mode. In that mode, as we
8336 don't want GDB to switch threads behind the user's back, to avoid
8337 races where the user is typing a command to apply to thread x,
8338 but GDB switches to thread y before the user finishes entering
8339 the command, fetch_inferior_event installs a cleanup to restore
8340 the current thread back to the thread the user had selected right
8341 after this event is handled, so we're not really switching, only
8342 informing of a stop. */
8344 && previous_inferior_ptid
!= inferior_ptid
8345 && target_has_execution ()
8346 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8347 && last
.kind
!= TARGET_WAITKIND_EXITED
8348 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8350 SWITCH_THRU_ALL_UIS ()
8352 target_terminal::ours_for_output ();
8353 printf_filtered (_("[Switching to %s]\n"),
8354 target_pid_to_str (inferior_ptid
).c_str ());
8355 annotate_thread_changed ();
8357 previous_inferior_ptid
= inferior_ptid
;
8360 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8362 SWITCH_THRU_ALL_UIS ()
8363 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8365 target_terminal::ours_for_output ();
8366 printf_filtered (_("No unwaited-for children left.\n"));
8370 /* Note: this depends on the update_thread_list call above. */
8371 maybe_remove_breakpoints ();
8373 /* If an auto-display called a function and that got a signal,
8374 delete that auto-display to avoid an infinite recursion. */
8376 if (stopped_by_random_signal
)
8377 disable_current_display ();
8379 SWITCH_THRU_ALL_UIS ()
8381 async_enable_stdin ();
8384 /* Let the user/frontend see the threads as stopped. */
8385 maybe_finish_thread_state
.reset ();
8387 /* Select innermost stack frame - i.e., current frame is frame 0,
8388 and current location is based on that. Handle the case where the
8389 dummy call is returning after being stopped. E.g. the dummy call
8390 previously hit a breakpoint. (If the dummy call returns
8391 normally, we won't reach here.) Do this before the stop hook is
8392 run, so that it doesn't get to see the temporary dummy frame,
8393 which is not where we'll present the stop. */
8394 if (has_stack_frames ())
8396 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8398 /* Pop the empty frame that contains the stack dummy. This
8399 also restores inferior state prior to the call (struct
8400 infcall_suspend_state). */
8401 struct frame_info
*frame
= get_current_frame ();
8403 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8405 /* frame_pop calls reinit_frame_cache as the last thing it
8406 does which means there's now no selected frame. */
8409 select_frame (get_current_frame ());
8411 /* Set the current source location. */
8412 set_current_sal_from_frame (get_current_frame ());
8415 /* Look up the hook_stop and run it (CLI internally handles problem
8416 of stop_command's pre-hook not existing). */
8417 if (stop_command
!= NULL
)
8419 stop_context saved_context
;
8423 execute_cmd_pre_hook (stop_command
);
8425 catch (const gdb_exception
&ex
)
8427 exception_fprintf (gdb_stderr
, ex
,
8428 "Error while running hook_stop:\n");
8431 /* If the stop hook resumes the target, then there's no point in
8432 trying to notify about the previous stop; its context is
8433 gone. Likewise if the command switches thread or inferior --
8434 the observers would print a stop for the wrong
8436 if (saved_context
.changed ())
8440 /* Notify observers about the stop. This is where the interpreters
8441 print the stop event. */
8442 if (inferior_ptid
!= null_ptid
)
8443 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8446 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8448 annotate_stopped ();
8450 if (target_has_execution ())
8452 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8453 && last
.kind
!= TARGET_WAITKIND_EXITED
8454 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8455 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8456 Delete any breakpoint that is to be deleted at the next stop. */
8457 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8460 /* Try to get rid of automatically added inferiors that are no
8461 longer needed. Keeping those around slows down things linearly.
8462 Note that this never removes the current inferior. */
8469 signal_stop_state (int signo
)
8471 return signal_stop
[signo
];
8475 signal_print_state (int signo
)
8477 return signal_print
[signo
];
8481 signal_pass_state (int signo
)
8483 return signal_program
[signo
];
8487 signal_cache_update (int signo
)
8491 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8492 signal_cache_update (signo
);
8497 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8498 && signal_print
[signo
] == 0
8499 && signal_program
[signo
] == 1
8500 && signal_catch
[signo
] == 0);
8504 signal_stop_update (int signo
, int state
)
8506 int ret
= signal_stop
[signo
];
8508 signal_stop
[signo
] = state
;
8509 signal_cache_update (signo
);
8514 signal_print_update (int signo
, int state
)
8516 int ret
= signal_print
[signo
];
8518 signal_print
[signo
] = state
;
8519 signal_cache_update (signo
);
8524 signal_pass_update (int signo
, int state
)
8526 int ret
= signal_program
[signo
];
8528 signal_program
[signo
] = state
;
8529 signal_cache_update (signo
);
8533 /* Update the global 'signal_catch' from INFO and notify the
8537 signal_catch_update (const unsigned int *info
)
8541 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8542 signal_catch
[i
] = info
[i
] > 0;
8543 signal_cache_update (-1);
8544 target_pass_signals (signal_pass
);
8548 sig_print_header (void)
8550 printf_filtered (_("Signal Stop\tPrint\tPass "
8551 "to program\tDescription\n"));
8555 sig_print_info (enum gdb_signal oursig
)
8557 const char *name
= gdb_signal_to_name (oursig
);
8558 int name_padding
= 13 - strlen (name
);
8560 if (name_padding
<= 0)
8563 printf_filtered ("%s", name
);
8564 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8565 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8566 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8567 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8568 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8571 /* Specify how various signals in the inferior should be handled. */
8574 handle_command (const char *args
, int from_tty
)
8576 int digits
, wordlen
;
8577 int sigfirst
, siglast
;
8578 enum gdb_signal oursig
;
8583 error_no_arg (_("signal to handle"));
8586 /* Allocate and zero an array of flags for which signals to handle. */
8588 const size_t nsigs
= GDB_SIGNAL_LAST
;
8589 unsigned char sigs
[nsigs
] {};
8591 /* Break the command line up into args. */
8593 gdb_argv
built_argv (args
);
8595 /* Walk through the args, looking for signal oursigs, signal names, and
8596 actions. Signal numbers and signal names may be interspersed with
8597 actions, with the actions being performed for all signals cumulatively
8598 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8600 for (char *arg
: built_argv
)
8602 wordlen
= strlen (arg
);
8603 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8607 sigfirst
= siglast
= -1;
8609 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8611 /* Apply action to all signals except those used by the
8612 debugger. Silently skip those. */
8615 siglast
= nsigs
- 1;
8617 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8619 SET_SIGS (nsigs
, sigs
, signal_stop
);
8620 SET_SIGS (nsigs
, sigs
, signal_print
);
8622 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8624 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8626 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8628 SET_SIGS (nsigs
, sigs
, signal_print
);
8630 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8632 SET_SIGS (nsigs
, sigs
, signal_program
);
8634 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8636 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8638 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8640 SET_SIGS (nsigs
, sigs
, signal_program
);
8642 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8644 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8645 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8647 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8649 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8651 else if (digits
> 0)
8653 /* It is numeric. The numeric signal refers to our own
8654 internal signal numbering from target.h, not to host/target
8655 signal number. This is a feature; users really should be
8656 using symbolic names anyway, and the common ones like
8657 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8659 sigfirst
= siglast
= (int)
8660 gdb_signal_from_command (atoi (arg
));
8661 if (arg
[digits
] == '-')
8664 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8666 if (sigfirst
> siglast
)
8668 /* Bet he didn't figure we'd think of this case... */
8669 std::swap (sigfirst
, siglast
);
8674 oursig
= gdb_signal_from_name (arg
);
8675 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8677 sigfirst
= siglast
= (int) oursig
;
8681 /* Not a number and not a recognized flag word => complain. */
8682 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8686 /* If any signal numbers or symbol names were found, set flags for
8687 which signals to apply actions to. */
8689 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8691 switch ((enum gdb_signal
) signum
)
8693 case GDB_SIGNAL_TRAP
:
8694 case GDB_SIGNAL_INT
:
8695 if (!allsigs
&& !sigs
[signum
])
8697 if (query (_("%s is used by the debugger.\n\
8698 Are you sure you want to change it? "),
8699 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8704 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8708 case GDB_SIGNAL_DEFAULT
:
8709 case GDB_SIGNAL_UNKNOWN
:
8710 /* Make sure that "all" doesn't print these. */
8719 for (int signum
= 0; signum
< nsigs
; signum
++)
8722 signal_cache_update (-1);
8723 target_pass_signals (signal_pass
);
8724 target_program_signals (signal_program
);
8728 /* Show the results. */
8729 sig_print_header ();
8730 for (; signum
< nsigs
; signum
++)
8732 sig_print_info ((enum gdb_signal
) signum
);
8739 /* Complete the "handle" command. */
8742 handle_completer (struct cmd_list_element
*ignore
,
8743 completion_tracker
&tracker
,
8744 const char *text
, const char *word
)
8746 static const char * const keywords
[] =
8760 signal_completer (ignore
, tracker
, text
, word
);
8761 complete_on_enum (tracker
, keywords
, word
, word
);
8765 gdb_signal_from_command (int num
)
8767 if (num
>= 1 && num
<= 15)
8768 return (enum gdb_signal
) num
;
8769 error (_("Only signals 1-15 are valid as numeric signals.\n\
8770 Use \"info signals\" for a list of symbolic signals."));
8773 /* Print current contents of the tables set by the handle command.
8774 It is possible we should just be printing signals actually used
8775 by the current target (but for things to work right when switching
8776 targets, all signals should be in the signal tables). */
8779 info_signals_command (const char *signum_exp
, int from_tty
)
8781 enum gdb_signal oursig
;
8783 sig_print_header ();
8787 /* First see if this is a symbol name. */
8788 oursig
= gdb_signal_from_name (signum_exp
);
8789 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8791 /* No, try numeric. */
8793 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8795 sig_print_info (oursig
);
8799 printf_filtered ("\n");
8800 /* These ugly casts brought to you by the native VAX compiler. */
8801 for (oursig
= GDB_SIGNAL_FIRST
;
8802 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8803 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8807 if (oursig
!= GDB_SIGNAL_UNKNOWN
8808 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8809 sig_print_info (oursig
);
8812 printf_filtered (_("\nUse the \"handle\" command "
8813 "to change these tables.\n"));
8816 /* The $_siginfo convenience variable is a bit special. We don't know
8817 for sure the type of the value until we actually have a chance to
8818 fetch the data. The type can change depending on gdbarch, so it is
8819 also dependent on which thread you have selected.
8821 1. making $_siginfo be an internalvar that creates a new value on
8824 2. making the value of $_siginfo be an lval_computed value. */
8826 /* This function implements the lval_computed support for reading a
8830 siginfo_value_read (struct value
*v
)
8832 LONGEST transferred
;
8834 /* If we can access registers, so can we access $_siginfo. Likewise
8836 validate_registers_access ();
8839 target_read (current_inferior ()->top_target (),
8840 TARGET_OBJECT_SIGNAL_INFO
,
8842 value_contents_all_raw (v
),
8844 TYPE_LENGTH (value_type (v
)));
8846 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8847 error (_("Unable to read siginfo"));
8850 /* This function implements the lval_computed support for writing a
8854 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8856 LONGEST transferred
;
8858 /* If we can access registers, so can we access $_siginfo. Likewise
8860 validate_registers_access ();
8862 transferred
= target_write (current_inferior ()->top_target (),
8863 TARGET_OBJECT_SIGNAL_INFO
,
8865 value_contents_all_raw (fromval
),
8867 TYPE_LENGTH (value_type (fromval
)));
8869 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8870 error (_("Unable to write siginfo"));
8873 static const struct lval_funcs siginfo_value_funcs
=
8879 /* Return a new value with the correct type for the siginfo object of
8880 the current thread using architecture GDBARCH. Return a void value
8881 if there's no object available. */
8883 static struct value
*
8884 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8887 if (target_has_stack ()
8888 && inferior_ptid
!= null_ptid
8889 && gdbarch_get_siginfo_type_p (gdbarch
))
8891 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8893 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8896 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8900 /* infcall_suspend_state contains state about the program itself like its
8901 registers and any signal it received when it last stopped.
8902 This state must be restored regardless of how the inferior function call
8903 ends (either successfully, or after it hits a breakpoint or signal)
8904 if the program is to properly continue where it left off. */
8906 class infcall_suspend_state
8909 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8910 once the inferior function call has finished. */
8911 infcall_suspend_state (struct gdbarch
*gdbarch
,
8912 const struct thread_info
*tp
,
8913 struct regcache
*regcache
)
8914 : m_thread_suspend (tp
->suspend
),
8915 m_registers (new readonly_detached_regcache (*regcache
))
8917 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8919 if (gdbarch_get_siginfo_type_p (gdbarch
))
8921 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8922 size_t len
= TYPE_LENGTH (type
);
8924 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8926 if (target_read (current_inferior ()->top_target (),
8927 TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8928 siginfo_data
.get (), 0, len
) != len
)
8930 /* Errors ignored. */
8931 siginfo_data
.reset (nullptr);
8937 m_siginfo_gdbarch
= gdbarch
;
8938 m_siginfo_data
= std::move (siginfo_data
);
8942 /* Return a pointer to the stored register state. */
8944 readonly_detached_regcache
*registers () const
8946 return m_registers
.get ();
8949 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8951 void restore (struct gdbarch
*gdbarch
,
8952 struct thread_info
*tp
,
8953 struct regcache
*regcache
) const
8955 tp
->suspend
= m_thread_suspend
;
8957 if (m_siginfo_gdbarch
== gdbarch
)
8959 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8961 /* Errors ignored. */
8962 target_write (current_inferior ()->top_target (),
8963 TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8964 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8967 /* The inferior can be gone if the user types "print exit(0)"
8968 (and perhaps other times). */
8969 if (target_has_execution ())
8970 /* NB: The register write goes through to the target. */
8971 regcache
->restore (registers ());
8975 /* How the current thread stopped before the inferior function call was
8977 struct thread_suspend_state m_thread_suspend
;
8979 /* The registers before the inferior function call was executed. */
8980 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8982 /* Format of SIGINFO_DATA or NULL if it is not present. */
8983 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8985 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8986 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8987 content would be invalid. */
8988 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8991 infcall_suspend_state_up
8992 save_infcall_suspend_state ()
8994 struct thread_info
*tp
= inferior_thread ();
8995 struct regcache
*regcache
= get_current_regcache ();
8996 struct gdbarch
*gdbarch
= regcache
->arch ();
8998 infcall_suspend_state_up inf_state
8999 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9001 /* Having saved the current state, adjust the thread state, discarding
9002 any stop signal information. The stop signal is not useful when
9003 starting an inferior function call, and run_inferior_call will not use
9004 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9005 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9010 /* Restore inferior session state to INF_STATE. */
9013 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9015 struct thread_info
*tp
= inferior_thread ();
9016 struct regcache
*regcache
= get_current_regcache ();
9017 struct gdbarch
*gdbarch
= regcache
->arch ();
9019 inf_state
->restore (gdbarch
, tp
, regcache
);
9020 discard_infcall_suspend_state (inf_state
);
9024 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9029 readonly_detached_regcache
*
9030 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9032 return inf_state
->registers ();
9035 /* infcall_control_state contains state regarding gdb's control of the
9036 inferior itself like stepping control. It also contains session state like
9037 the user's currently selected frame. */
9039 struct infcall_control_state
9041 struct thread_control_state thread_control
;
9042 struct inferior_control_state inferior_control
;
9045 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9046 int stopped_by_random_signal
= 0;
9048 /* ID and level of the selected frame when the inferior function
9050 struct frame_id selected_frame_id
{};
9051 int selected_frame_level
= -1;
9054 /* Save all of the information associated with the inferior<==>gdb
9057 infcall_control_state_up
9058 save_infcall_control_state ()
9060 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9061 struct thread_info
*tp
= inferior_thread ();
9062 struct inferior
*inf
= current_inferior ();
9064 inf_status
->thread_control
= tp
->control
;
9065 inf_status
->inferior_control
= inf
->control
;
9067 tp
->control
.step_resume_breakpoint
= NULL
;
9068 tp
->control
.exception_resume_breakpoint
= NULL
;
9070 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9071 chain. If caller's caller is walking the chain, they'll be happier if we
9072 hand them back the original chain when restore_infcall_control_state is
9074 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9077 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9078 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9080 save_selected_frame (&inf_status
->selected_frame_id
,
9081 &inf_status
->selected_frame_level
);
9086 /* Restore inferior session state to INF_STATUS. */
9089 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9091 struct thread_info
*tp
= inferior_thread ();
9092 struct inferior
*inf
= current_inferior ();
9094 if (tp
->control
.step_resume_breakpoint
)
9095 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9097 if (tp
->control
.exception_resume_breakpoint
)
9098 tp
->control
.exception_resume_breakpoint
->disposition
9099 = disp_del_at_next_stop
;
9101 /* Handle the bpstat_copy of the chain. */
9102 bpstat_clear (&tp
->control
.stop_bpstat
);
9104 tp
->control
= inf_status
->thread_control
;
9105 inf
->control
= inf_status
->inferior_control
;
9108 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9109 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9111 if (target_has_stack ())
9113 restore_selected_frame (inf_status
->selected_frame_id
,
9114 inf_status
->selected_frame_level
);
9121 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9123 if (inf_status
->thread_control
.step_resume_breakpoint
)
9124 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9125 = disp_del_at_next_stop
;
9127 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9128 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9129 = disp_del_at_next_stop
;
9131 /* See save_infcall_control_state for info on stop_bpstat. */
9132 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9140 clear_exit_convenience_vars (void)
9142 clear_internalvar (lookup_internalvar ("_exitsignal"));
9143 clear_internalvar (lookup_internalvar ("_exitcode"));
9147 /* User interface for reverse debugging:
9148 Set exec-direction / show exec-direction commands
9149 (returns error unless target implements to_set_exec_direction method). */
9151 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9152 static const char exec_forward
[] = "forward";
9153 static const char exec_reverse
[] = "reverse";
9154 static const char *exec_direction
= exec_forward
;
9155 static const char *const exec_direction_names
[] = {
9162 set_exec_direction_func (const char *args
, int from_tty
,
9163 struct cmd_list_element
*cmd
)
9165 if (target_can_execute_reverse ())
9167 if (!strcmp (exec_direction
, exec_forward
))
9168 execution_direction
= EXEC_FORWARD
;
9169 else if (!strcmp (exec_direction
, exec_reverse
))
9170 execution_direction
= EXEC_REVERSE
;
9174 exec_direction
= exec_forward
;
9175 error (_("Target does not support this operation."));
9180 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9181 struct cmd_list_element
*cmd
, const char *value
)
9183 switch (execution_direction
) {
9185 fprintf_filtered (out
, _("Forward.\n"));
9188 fprintf_filtered (out
, _("Reverse.\n"));
9191 internal_error (__FILE__
, __LINE__
,
9192 _("bogus execution_direction value: %d"),
9193 (int) execution_direction
);
9198 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9199 struct cmd_list_element
*c
, const char *value
)
9201 fprintf_filtered (file
, _("Resuming the execution of threads "
9202 "of all processes is %s.\n"), value
);
9205 /* Implementation of `siginfo' variable. */
9207 static const struct internalvar_funcs siginfo_funcs
=
9214 /* Callback for infrun's target events source. This is marked when a
9215 thread has a pending status to process. */
9218 infrun_async_inferior_event_handler (gdb_client_data data
)
9220 clear_async_event_handler (infrun_async_inferior_event_token
);
9221 inferior_event_handler (INF_REG_EVENT
);
9228 /* Verify that when two threads with the same ptid exist (from two different
9229 targets) and one of them changes ptid, we only update inferior_ptid if
9230 it is appropriate. */
9233 infrun_thread_ptid_changed ()
9235 gdbarch
*arch
= current_inferior ()->gdbarch
;
9237 /* The thread which inferior_ptid represents changes ptid. */
9239 scoped_restore_current_pspace_and_thread restore
;
9241 scoped_mock_context
<test_target_ops
> target1 (arch
);
9242 scoped_mock_context
<test_target_ops
> target2 (arch
);
9243 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9245 ptid_t
old_ptid (111, 222);
9246 ptid_t
new_ptid (111, 333);
9248 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9249 target1
.mock_thread
.ptid
= old_ptid
;
9250 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9251 target2
.mock_thread
.ptid
= old_ptid
;
9253 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9254 set_current_inferior (&target1
.mock_inferior
);
9256 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9258 gdb_assert (inferior_ptid
== new_ptid
);
9261 /* A thread with the same ptid as inferior_ptid, but from another target,
9264 scoped_restore_current_pspace_and_thread restore
;
9266 scoped_mock_context
<test_target_ops
> target1 (arch
);
9267 scoped_mock_context
<test_target_ops
> target2 (arch
);
9268 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9270 ptid_t
old_ptid (111, 222);
9271 ptid_t
new_ptid (111, 333);
9273 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9274 target1
.mock_thread
.ptid
= old_ptid
;
9275 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9276 target2
.mock_thread
.ptid
= old_ptid
;
9278 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9279 set_current_inferior (&target2
.mock_inferior
);
9281 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9283 gdb_assert (inferior_ptid
== old_ptid
);
9287 } /* namespace selftests */
9289 #endif /* GDB_SELF_TEST */
9291 void _initialize_infrun ();
9293 _initialize_infrun ()
9295 struct cmd_list_element
*c
;
9297 /* Register extra event sources in the event loop. */
9298 infrun_async_inferior_event_token
9299 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9302 add_info ("signals", info_signals_command
, _("\
9303 What debugger does when program gets various signals.\n\
9304 Specify a signal as argument to print info on that signal only."));
9305 add_info_alias ("handle", "signals", 0);
9307 c
= add_com ("handle", class_run
, handle_command
, _("\
9308 Specify how to handle signals.\n\
9309 Usage: handle SIGNAL [ACTIONS]\n\
9310 Args are signals and actions to apply to those signals.\n\
9311 If no actions are specified, the current settings for the specified signals\n\
9312 will be displayed instead.\n\
9314 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9315 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9316 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9317 The special arg \"all\" is recognized to mean all signals except those\n\
9318 used by the debugger, typically SIGTRAP and SIGINT.\n\
9320 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9321 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9322 Stop means reenter debugger if this signal happens (implies print).\n\
9323 Print means print a message if this signal happens.\n\
9324 Pass means let program see this signal; otherwise program doesn't know.\n\
9325 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9326 Pass and Stop may be combined.\n\
9328 Multiple signals may be specified. Signal numbers and signal names\n\
9329 may be interspersed with actions, with the actions being performed for\n\
9330 all signals cumulatively specified."));
9331 set_cmd_completer (c
, handle_completer
);
9334 stop_command
= add_cmd ("stop", class_obscure
,
9335 not_just_help_class_command
, _("\
9336 There is no `stop' command, but you can set a hook on `stop'.\n\
9337 This allows you to set a list of commands to be run each time execution\n\
9338 of the program stops."), &cmdlist
);
9340 add_setshow_boolean_cmd
9341 ("infrun", class_maintenance
, &debug_infrun
,
9342 _("Set inferior debugging."),
9343 _("Show inferior debugging."),
9344 _("When non-zero, inferior specific debugging is enabled."),
9345 NULL
, show_debug_infrun
, &setdebuglist
, &showdebuglist
);
9347 add_setshow_boolean_cmd ("non-stop", no_class
,
9349 Set whether gdb controls the inferior in non-stop mode."), _("\
9350 Show whether gdb controls the inferior in non-stop mode."), _("\
9351 When debugging a multi-threaded program and this setting is\n\
9352 off (the default, also called all-stop mode), when one thread stops\n\
9353 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9354 all other threads in the program while you interact with the thread of\n\
9355 interest. When you continue or step a thread, you can allow the other\n\
9356 threads to run, or have them remain stopped, but while you inspect any\n\
9357 thread's state, all threads stop.\n\
9359 In non-stop mode, when one thread stops, other threads can continue\n\
9360 to run freely. You'll be able to step each thread independently,\n\
9361 leave it stopped or free to run as needed."),
9367 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9370 signal_print
[i
] = 1;
9371 signal_program
[i
] = 1;
9372 signal_catch
[i
] = 0;
9375 /* Signals caused by debugger's own actions should not be given to
9376 the program afterwards.
9378 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9379 explicitly specifies that it should be delivered to the target
9380 program. Typically, that would occur when a user is debugging a
9381 target monitor on a simulator: the target monitor sets a
9382 breakpoint; the simulator encounters this breakpoint and halts
9383 the simulation handing control to GDB; GDB, noting that the stop
9384 address doesn't map to any known breakpoint, returns control back
9385 to the simulator; the simulator then delivers the hardware
9386 equivalent of a GDB_SIGNAL_TRAP to the program being
9388 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9389 signal_program
[GDB_SIGNAL_INT
] = 0;
9391 /* Signals that are not errors should not normally enter the debugger. */
9392 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9393 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9394 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9395 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9396 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9397 signal_print
[GDB_SIGNAL_PROF
] = 0;
9398 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9399 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9400 signal_stop
[GDB_SIGNAL_IO
] = 0;
9401 signal_print
[GDB_SIGNAL_IO
] = 0;
9402 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9403 signal_print
[GDB_SIGNAL_POLL
] = 0;
9404 signal_stop
[GDB_SIGNAL_URG
] = 0;
9405 signal_print
[GDB_SIGNAL_URG
] = 0;
9406 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9407 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9408 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9409 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9411 /* These signals are used internally by user-level thread
9412 implementations. (See signal(5) on Solaris.) Like the above
9413 signals, a healthy program receives and handles them as part of
9414 its normal operation. */
9415 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9416 signal_print
[GDB_SIGNAL_LWP
] = 0;
9417 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9418 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9419 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9420 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9421 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9422 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9424 /* Update cached state. */
9425 signal_cache_update (-1);
9427 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9428 &stop_on_solib_events
, _("\
9429 Set stopping for shared library events."), _("\
9430 Show stopping for shared library events."), _("\
9431 If nonzero, gdb will give control to the user when the dynamic linker\n\
9432 notifies gdb of shared library events. The most common event of interest\n\
9433 to the user would be loading/unloading of a new library."),
9434 set_stop_on_solib_events
,
9435 show_stop_on_solib_events
,
9436 &setlist
, &showlist
);
9438 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9439 follow_fork_mode_kind_names
,
9440 &follow_fork_mode_string
, _("\
9441 Set debugger response to a program call of fork or vfork."), _("\
9442 Show debugger response to a program call of fork or vfork."), _("\
9443 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9444 parent - the original process is debugged after a fork\n\
9445 child - the new process is debugged after a fork\n\
9446 The unfollowed process will continue to run.\n\
9447 By default, the debugger will follow the parent process."),
9449 show_follow_fork_mode_string
,
9450 &setlist
, &showlist
);
9452 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9453 follow_exec_mode_names
,
9454 &follow_exec_mode_string
, _("\
9455 Set debugger response to a program call of exec."), _("\
9456 Show debugger response to a program call of exec."), _("\
9457 An exec call replaces the program image of a process.\n\
9459 follow-exec-mode can be:\n\
9461 new - the debugger creates a new inferior and rebinds the process\n\
9462 to this new inferior. The program the process was running before\n\
9463 the exec call can be restarted afterwards by restarting the original\n\
9466 same - the debugger keeps the process bound to the same inferior.\n\
9467 The new executable image replaces the previous executable loaded in\n\
9468 the inferior. Restarting the inferior after the exec call restarts\n\
9469 the executable the process was running after the exec call.\n\
9471 By default, the debugger will use the same inferior."),
9473 show_follow_exec_mode_string
,
9474 &setlist
, &showlist
);
9476 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9477 scheduler_enums
, &scheduler_mode
, _("\
9478 Set mode for locking scheduler during execution."), _("\
9479 Show mode for locking scheduler during execution."), _("\
9480 off == no locking (threads may preempt at any time)\n\
9481 on == full locking (no thread except the current thread may run)\n\
9482 This applies to both normal execution and replay mode.\n\
9483 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9484 In this mode, other threads may run during other commands.\n\
9485 This applies to both normal execution and replay mode.\n\
9486 replay == scheduler locked in replay mode and unlocked during normal execution."),
9487 set_schedlock_func
, /* traps on target vector */
9488 show_scheduler_mode
,
9489 &setlist
, &showlist
);
9491 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9492 Set mode for resuming threads of all processes."), _("\
9493 Show mode for resuming threads of all processes."), _("\
9494 When on, execution commands (such as 'continue' or 'next') resume all\n\
9495 threads of all processes. When off (which is the default), execution\n\
9496 commands only resume the threads of the current process. The set of\n\
9497 threads that are resumed is further refined by the scheduler-locking\n\
9498 mode (see help set scheduler-locking)."),
9500 show_schedule_multiple
,
9501 &setlist
, &showlist
);
9503 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9504 Set mode of the step operation."), _("\
9505 Show mode of the step operation."), _("\
9506 When set, doing a step over a function without debug line information\n\
9507 will stop at the first instruction of that function. Otherwise, the\n\
9508 function is skipped and the step command stops at a different source line."),
9510 show_step_stop_if_no_debug
,
9511 &setlist
, &showlist
);
9513 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9514 &can_use_displaced_stepping
, _("\
9515 Set debugger's willingness to use displaced stepping."), _("\
9516 Show debugger's willingness to use displaced stepping."), _("\
9517 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9518 supported by the target architecture. If off, gdb will not use displaced\n\
9519 stepping to step over breakpoints, even if such is supported by the target\n\
9520 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9521 if the target architecture supports it and non-stop mode is active, but will not\n\
9522 use it in all-stop mode (see help set non-stop)."),
9524 show_can_use_displaced_stepping
,
9525 &setlist
, &showlist
);
9527 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9528 &exec_direction
, _("Set direction of execution.\n\
9529 Options are 'forward' or 'reverse'."),
9530 _("Show direction of execution (forward/reverse)."),
9531 _("Tells gdb whether to execute forward or backward."),
9532 set_exec_direction_func
, show_exec_direction_func
,
9533 &setlist
, &showlist
);
9535 /* Set/show detach-on-fork: user-settable mode. */
9537 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9538 Set whether gdb will detach the child of a fork."), _("\
9539 Show whether gdb will detach the child of a fork."), _("\
9540 Tells gdb whether to detach the child of a fork."),
9541 NULL
, NULL
, &setlist
, &showlist
);
9543 /* Set/show disable address space randomization mode. */
9545 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9546 &disable_randomization
, _("\
9547 Set disabling of debuggee's virtual address space randomization."), _("\
9548 Show disabling of debuggee's virtual address space randomization."), _("\
9549 When this mode is on (which is the default), randomization of the virtual\n\
9550 address space is disabled. Standalone programs run with the randomization\n\
9551 enabled by default on some platforms."),
9552 &set_disable_randomization
,
9553 &show_disable_randomization
,
9554 &setlist
, &showlist
);
9556 /* ptid initializations */
9557 inferior_ptid
= null_ptid
;
9558 target_last_wait_ptid
= minus_one_ptid
;
9560 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9561 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9562 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9563 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9564 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
);
9566 /* Explicitly create without lookup, since that tries to create a
9567 value with a void typed value, and when we get here, gdbarch
9568 isn't initialized yet. At this point, we're quite sure there
9569 isn't another convenience variable of the same name. */
9570 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9572 add_setshow_boolean_cmd ("observer", no_class
,
9573 &observer_mode_1
, _("\
9574 Set whether gdb controls the inferior in observer mode."), _("\
9575 Show whether gdb controls the inferior in observer mode."), _("\
9576 In observer mode, GDB can get data from the inferior, but not\n\
9577 affect its execution. Registers and memory may not be changed,\n\
9578 breakpoints may not be set, and the program cannot be interrupted\n\
9586 selftests::register_test ("infrun_thread_ptid_changed",
9587 selftests::infrun_thread_ptid_changed
);