1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2021 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "displaced-stepping.h"
28 #include "breakpoint.h"
32 #include "target-connection.h"
33 #include "gdbthread.h"
40 #include "observable.h"
45 #include "mi/mi-common.h"
46 #include "event-top.h"
48 #include "record-full.h"
49 #include "inline-frame.h"
51 #include "tracepoint.h"
55 #include "completer.h"
56 #include "target-descriptions.h"
57 #include "target-dcache.h"
60 #include "gdbsupport/event-loop.h"
61 #include "thread-fsm.h"
62 #include "gdbsupport/enum-flags.h"
63 #include "progspace-and-thread.h"
64 #include "gdbsupport/gdb_optional.h"
65 #include "arch-utils.h"
66 #include "gdbsupport/scope-exit.h"
67 #include "gdbsupport/forward-scope-exit.h"
68 #include "gdbsupport/gdb_select.h"
69 #include <unordered_map>
70 #include "async-event.h"
71 #include "gdbsupport/selftest.h"
72 #include "scoped-mock-context.h"
73 #include "test-target.h"
74 #include "gdbsupport/common-debug.h"
76 /* Prototypes for local functions */
78 static void sig_print_info (enum gdb_signal
);
80 static void sig_print_header (void);
82 static void follow_inferior_reset_breakpoints (void);
84 static bool currently_stepping (struct thread_info
*tp
);
86 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
88 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
90 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
92 static bool maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
94 static void resume (gdb_signal sig
);
96 static void wait_for_inferior (inferior
*inf
);
98 /* Asynchronous signal handler registered as event loop source for
99 when we have pending events ready to be passed to the core. */
100 static struct async_event_handler
*infrun_async_inferior_event_token
;
102 /* Stores whether infrun_async was previously enabled or disabled.
103 Starts off as -1, indicating "never enabled/disabled". */
104 static int infrun_is_async
= -1;
109 infrun_async (int enable
)
111 if (infrun_is_async
!= enable
)
113 infrun_is_async
= enable
;
115 infrun_debug_printf ("enable=%d", enable
);
118 mark_async_event_handler (infrun_async_inferior_event_token
);
120 clear_async_event_handler (infrun_async_inferior_event_token
);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token
);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 bool step_stop_if_no_debug
= false;
137 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
138 struct cmd_list_element
*c
, const char *value
)
140 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid
;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static bool detach_fork
= true;
156 bool debug_infrun
= false;
158 show_debug_infrun (struct ui_file
*file
, int from_tty
,
159 struct cmd_list_element
*c
, const char *value
)
161 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
164 /* Support for disabling address space randomization. */
166 bool disable_randomization
= true;
169 show_disable_randomization (struct ui_file
*file
, int from_tty
,
170 struct cmd_list_element
*c
, const char *value
)
172 if (target_supports_disable_randomization ())
173 fprintf_filtered (file
,
174 _("Disabling randomization of debuggee's "
175 "virtual address space is %s.\n"),
178 fputs_filtered (_("Disabling randomization of debuggee's "
179 "virtual address space is unsupported on\n"
180 "this platform.\n"), file
);
184 set_disable_randomization (const char *args
, int from_tty
,
185 struct cmd_list_element
*c
)
187 if (!target_supports_disable_randomization ())
188 error (_("Disabling randomization of debuggee's "
189 "virtual address space is unsupported on\n"
193 /* User interface for non-stop mode. */
195 bool non_stop
= false;
196 static bool non_stop_1
= false;
199 set_non_stop (const char *args
, int from_tty
,
200 struct cmd_list_element
*c
)
202 if (target_has_execution ())
204 non_stop_1
= non_stop
;
205 error (_("Cannot change this setting while the inferior is running."));
208 non_stop
= non_stop_1
;
212 show_non_stop (struct ui_file
*file
, int from_tty
,
213 struct cmd_list_element
*c
, const char *value
)
215 fprintf_filtered (file
,
216 _("Controlling the inferior in non-stop mode is %s.\n"),
220 /* "Observer mode" is somewhat like a more extreme version of
221 non-stop, in which all GDB operations that might affect the
222 target's execution have been disabled. */
224 static bool observer_mode
= false;
225 static bool observer_mode_1
= false;
228 set_observer_mode (const char *args
, int from_tty
,
229 struct cmd_list_element
*c
)
231 if (target_has_execution ())
233 observer_mode_1
= observer_mode
;
234 error (_("Cannot change this setting while the inferior is running."));
237 observer_mode
= observer_mode_1
;
239 may_write_registers
= !observer_mode
;
240 may_write_memory
= !observer_mode
;
241 may_insert_breakpoints
= !observer_mode
;
242 may_insert_tracepoints
= !observer_mode
;
243 /* We can insert fast tracepoints in or out of observer mode,
244 but enable them if we're going into this mode. */
246 may_insert_fast_tracepoints
= true;
247 may_stop
= !observer_mode
;
248 update_target_permissions ();
250 /* Going *into* observer mode we must force non-stop, then
251 going out we leave it that way. */
254 pagination_enabled
= 0;
255 non_stop
= non_stop_1
= true;
259 printf_filtered (_("Observer mode is now %s.\n"),
260 (observer_mode
? "on" : "off"));
264 show_observer_mode (struct ui_file
*file
, int from_tty
,
265 struct cmd_list_element
*c
, const char *value
)
267 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
270 /* This updates the value of observer mode based on changes in
271 permissions. Note that we are deliberately ignoring the values of
272 may-write-registers and may-write-memory, since the user may have
273 reason to enable these during a session, for instance to turn on a
274 debugging-related global. */
277 update_observer_mode (void)
279 bool newval
= (!may_insert_breakpoints
280 && !may_insert_tracepoints
281 && may_insert_fast_tracepoints
285 /* Let the user know if things change. */
286 if (newval
!= observer_mode
)
287 printf_filtered (_("Observer mode is now %s.\n"),
288 (newval
? "on" : "off"));
290 observer_mode
= observer_mode_1
= newval
;
293 /* Tables of how to react to signals; the user sets them. */
295 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
296 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
297 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
299 /* Table of signals that are registered with "catch signal". A
300 non-zero entry indicates that the signal is caught by some "catch
302 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
304 /* Table of signals that the target may silently handle.
305 This is automatically determined from the flags above,
306 and simply cached here. */
307 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
309 #define SET_SIGS(nsigs,sigs,flags) \
311 int signum = (nsigs); \
312 while (signum-- > 0) \
313 if ((sigs)[signum]) \
314 (flags)[signum] = 1; \
317 #define UNSET_SIGS(nsigs,sigs,flags) \
319 int signum = (nsigs); \
320 while (signum-- > 0) \
321 if ((sigs)[signum]) \
322 (flags)[signum] = 0; \
325 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
326 this function is to avoid exporting `signal_program'. */
329 update_signals_program_target (void)
331 target_program_signals (signal_program
);
334 /* Value to pass to target_resume() to cause all threads to resume. */
336 #define RESUME_ALL minus_one_ptid
338 /* Command list pointer for the "stop" placeholder. */
340 static struct cmd_list_element
*stop_command
;
342 /* Nonzero if we want to give control to the user when we're notified
343 of shared library events by the dynamic linker. */
344 int stop_on_solib_events
;
346 /* Enable or disable optional shared library event breakpoints
347 as appropriate when the above flag is changed. */
350 set_stop_on_solib_events (const char *args
,
351 int from_tty
, struct cmd_list_element
*c
)
353 update_solib_breakpoints ();
357 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
358 struct cmd_list_element
*c
, const char *value
)
360 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
364 /* True after stop if current stack frame should be printed. */
366 static bool stop_print_frame
;
368 /* This is a cached copy of the target/ptid/waitstatus of the last
369 event returned by target_wait()/deprecated_target_wait_hook().
370 This information is returned by get_last_target_status(). */
371 static process_stratum_target
*target_last_proc_target
;
372 static ptid_t target_last_wait_ptid
;
373 static struct target_waitstatus target_last_waitstatus
;
375 void init_thread_stepping_state (struct thread_info
*tss
);
377 static const char follow_fork_mode_child
[] = "child";
378 static const char follow_fork_mode_parent
[] = "parent";
380 static const char *const follow_fork_mode_kind_names
[] = {
381 follow_fork_mode_child
,
382 follow_fork_mode_parent
,
386 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
388 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
389 struct cmd_list_element
*c
, const char *value
)
391 fprintf_filtered (file
,
392 _("Debugger response to a program "
393 "call of fork or vfork is \"%s\".\n"),
398 /* Handle changes to the inferior list based on the type of fork,
399 which process is being followed, and whether the other process
400 should be detached. On entry inferior_ptid must be the ptid of
401 the fork parent. At return inferior_ptid is the ptid of the
402 followed inferior. */
405 follow_fork_inferior (bool follow_child
, bool detach_fork
)
408 ptid_t parent_ptid
, child_ptid
;
410 has_vforked
= (inferior_thread ()->pending_follow
.kind
411 == TARGET_WAITKIND_VFORKED
);
412 parent_ptid
= inferior_ptid
;
413 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
416 && !non_stop
/* Non-stop always resumes both branches. */
417 && current_ui
->prompt_state
== PROMPT_BLOCKED
418 && !(follow_child
|| detach_fork
|| sched_multi
))
420 /* The parent stays blocked inside the vfork syscall until the
421 child execs or exits. If we don't let the child run, then
422 the parent stays blocked. If we're telling the parent to run
423 in the foreground, the user will not be able to ctrl-c to get
424 back the terminal, effectively hanging the debug session. */
425 fprintf_filtered (gdb_stderr
, _("\
426 Can not resume the parent process over vfork in the foreground while\n\
427 holding the child stopped. Try \"set detach-on-fork\" or \
428 \"set schedule-multiple\".\n"));
434 /* Detach new forked process? */
437 /* Before detaching from the child, remove all breakpoints
438 from it. If we forked, then this has already been taken
439 care of by infrun.c. If we vforked however, any
440 breakpoint inserted in the parent is visible in the
441 child, even those added while stopped in a vfork
442 catchpoint. This will remove the breakpoints from the
443 parent also, but they'll be reinserted below. */
446 /* Keep breakpoints list in sync. */
447 remove_breakpoints_inf (current_inferior ());
450 if (print_inferior_events
)
452 /* Ensure that we have a process ptid. */
453 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
455 target_terminal::ours_for_output ();
456 fprintf_filtered (gdb_stdlog
,
457 _("[Detaching after %s from child %s]\n"),
458 has_vforked
? "vfork" : "fork",
459 target_pid_to_str (process_ptid
).c_str ());
464 struct inferior
*parent_inf
, *child_inf
;
466 /* Add process to GDB's tables. */
467 child_inf
= add_inferior (child_ptid
.pid ());
469 parent_inf
= current_inferior ();
470 child_inf
->attach_flag
= parent_inf
->attach_flag
;
471 copy_terminal_info (child_inf
, parent_inf
);
472 child_inf
->gdbarch
= parent_inf
->gdbarch
;
473 copy_inferior_target_desc_info (child_inf
, parent_inf
);
475 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
477 set_current_inferior (child_inf
);
478 switch_to_no_thread ();
479 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
480 push_target (parent_inf
->process_target ());
481 thread_info
*child_thr
482 = add_thread_silent (child_inf
->process_target (), child_ptid
);
484 /* If this is a vfork child, then the address-space is
485 shared with the parent. */
488 child_inf
->pspace
= parent_inf
->pspace
;
489 child_inf
->aspace
= parent_inf
->aspace
;
493 /* The parent will be frozen until the child is done
494 with the shared region. Keep track of the
496 child_inf
->vfork_parent
= parent_inf
;
497 child_inf
->pending_detach
= 0;
498 parent_inf
->vfork_child
= child_inf
;
499 parent_inf
->pending_detach
= 0;
501 /* Now that the inferiors and program spaces are all
502 wired up, we can switch to the child thread (which
503 switches inferior and program space too). */
504 switch_to_thread (child_thr
);
508 child_inf
->aspace
= new_address_space ();
509 child_inf
->pspace
= new program_space (child_inf
->aspace
);
510 child_inf
->removable
= 1;
511 set_current_program_space (child_inf
->pspace
);
512 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
514 /* solib_create_inferior_hook relies on the current
516 switch_to_thread (child_thr
);
518 /* Let the shared library layer (e.g., solib-svr4) learn
519 about this new process, relocate the cloned exec, pull
520 in shared libraries, and install the solib event
521 breakpoint. If a "cloned-VM" event was propagated
522 better throughout the core, this wouldn't be
524 solib_create_inferior_hook (0);
530 struct inferior
*parent_inf
;
532 parent_inf
= current_inferior ();
534 /* If we detached from the child, then we have to be careful
535 to not insert breakpoints in the parent until the child
536 is done with the shared memory region. However, if we're
537 staying attached to the child, then we can and should
538 insert breakpoints, so that we can debug it. A
539 subsequent child exec or exit is enough to know when does
540 the child stops using the parent's address space. */
541 parent_inf
->waiting_for_vfork_done
= detach_fork
;
542 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
547 /* Follow the child. */
548 struct inferior
*parent_inf
, *child_inf
;
549 struct program_space
*parent_pspace
;
551 if (print_inferior_events
)
553 std::string parent_pid
= target_pid_to_str (parent_ptid
);
554 std::string child_pid
= target_pid_to_str (child_ptid
);
556 target_terminal::ours_for_output ();
557 fprintf_filtered (gdb_stdlog
,
558 _("[Attaching after %s %s to child %s]\n"),
560 has_vforked
? "vfork" : "fork",
564 /* Add the new inferior first, so that the target_detach below
565 doesn't unpush the target. */
567 child_inf
= add_inferior (child_ptid
.pid ());
569 parent_inf
= current_inferior ();
570 child_inf
->attach_flag
= parent_inf
->attach_flag
;
571 copy_terminal_info (child_inf
, parent_inf
);
572 child_inf
->gdbarch
= parent_inf
->gdbarch
;
573 copy_inferior_target_desc_info (child_inf
, parent_inf
);
575 parent_pspace
= parent_inf
->pspace
;
577 process_stratum_target
*target
= parent_inf
->process_target ();
580 /* Hold a strong reference to the target while (maybe)
581 detaching the parent. Otherwise detaching could close the
583 auto target_ref
= target_ops_ref::new_reference (target
);
585 /* If we're vforking, we want to hold on to the parent until
586 the child exits or execs. At child exec or exit time we
587 can remove the old breakpoints from the parent and detach
588 or resume debugging it. Otherwise, detach the parent now;
589 we'll want to reuse it's program/address spaces, but we
590 can't set them to the child before removing breakpoints
591 from the parent, otherwise, the breakpoints module could
592 decide to remove breakpoints from the wrong process (since
593 they'd be assigned to the same address space). */
597 gdb_assert (child_inf
->vfork_parent
== NULL
);
598 gdb_assert (parent_inf
->vfork_child
== NULL
);
599 child_inf
->vfork_parent
= parent_inf
;
600 child_inf
->pending_detach
= 0;
601 parent_inf
->vfork_child
= child_inf
;
602 parent_inf
->pending_detach
= detach_fork
;
603 parent_inf
->waiting_for_vfork_done
= 0;
605 else if (detach_fork
)
607 if (print_inferior_events
)
609 /* Ensure that we have a process ptid. */
610 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
612 target_terminal::ours_for_output ();
613 fprintf_filtered (gdb_stdlog
,
614 _("[Detaching after fork from "
616 target_pid_to_str (process_ptid
).c_str ());
619 target_detach (parent_inf
, 0);
623 /* Note that the detach above makes PARENT_INF dangling. */
625 /* Add the child thread to the appropriate lists, and switch
626 to this new thread, before cloning the program space, and
627 informing the solib layer about this new process. */
629 set_current_inferior (child_inf
);
630 push_target (target
);
633 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
635 /* If this is a vfork child, then the address-space is shared
636 with the parent. If we detached from the parent, then we can
637 reuse the parent's program/address spaces. */
638 if (has_vforked
|| detach_fork
)
640 child_inf
->pspace
= parent_pspace
;
641 child_inf
->aspace
= child_inf
->pspace
->aspace
;
647 child_inf
->aspace
= new_address_space ();
648 child_inf
->pspace
= new program_space (child_inf
->aspace
);
649 child_inf
->removable
= 1;
650 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
651 set_current_program_space (child_inf
->pspace
);
652 clone_program_space (child_inf
->pspace
, parent_pspace
);
654 /* Let the shared library layer (e.g., solib-svr4) learn
655 about this new process, relocate the cloned exec, pull in
656 shared libraries, and install the solib event breakpoint.
657 If a "cloned-VM" event was propagated better throughout
658 the core, this wouldn't be required. */
659 solib_create_inferior_hook (0);
662 switch_to_thread (child_thr
);
665 return target_follow_fork (follow_child
, detach_fork
);
668 /* Tell the target to follow the fork we're stopped at. Returns true
669 if the inferior should be resumed; false, if the target for some
670 reason decided it's best not to resume. */
675 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
676 bool should_resume
= true;
677 struct thread_info
*tp
;
679 /* Copy user stepping state to the new inferior thread. FIXME: the
680 followed fork child thread should have a copy of most of the
681 parent thread structure's run control related fields, not just these.
682 Initialized to avoid "may be used uninitialized" warnings from gcc. */
683 struct breakpoint
*step_resume_breakpoint
= NULL
;
684 struct breakpoint
*exception_resume_breakpoint
= NULL
;
685 CORE_ADDR step_range_start
= 0;
686 CORE_ADDR step_range_end
= 0;
687 int current_line
= 0;
688 symtab
*current_symtab
= NULL
;
689 struct frame_id step_frame_id
= { 0 };
690 struct thread_fsm
*thread_fsm
= NULL
;
694 process_stratum_target
*wait_target
;
696 struct target_waitstatus wait_status
;
698 /* Get the last target status returned by target_wait(). */
699 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
701 /* If not stopped at a fork event, then there's nothing else to
703 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
704 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
707 /* Check if we switched over from WAIT_PTID, since the event was
709 if (wait_ptid
!= minus_one_ptid
710 && (current_inferior ()->process_target () != wait_target
711 || inferior_ptid
!= wait_ptid
))
713 /* We did. Switch back to WAIT_PTID thread, to tell the
714 target to follow it (in either direction). We'll
715 afterwards refuse to resume, and inform the user what
717 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
718 switch_to_thread (wait_thread
);
719 should_resume
= false;
723 tp
= inferior_thread ();
725 /* If there were any forks/vforks that were caught and are now to be
726 followed, then do so now. */
727 switch (tp
->pending_follow
.kind
)
729 case TARGET_WAITKIND_FORKED
:
730 case TARGET_WAITKIND_VFORKED
:
732 ptid_t parent
, child
;
734 /* If the user did a next/step, etc, over a fork call,
735 preserve the stepping state in the fork child. */
736 if (follow_child
&& should_resume
)
738 step_resume_breakpoint
= clone_momentary_breakpoint
739 (tp
->control
.step_resume_breakpoint
);
740 step_range_start
= tp
->control
.step_range_start
;
741 step_range_end
= tp
->control
.step_range_end
;
742 current_line
= tp
->current_line
;
743 current_symtab
= tp
->current_symtab
;
744 step_frame_id
= tp
->control
.step_frame_id
;
745 exception_resume_breakpoint
746 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
747 thread_fsm
= tp
->thread_fsm
;
749 /* For now, delete the parent's sr breakpoint, otherwise,
750 parent/child sr breakpoints are considered duplicates,
751 and the child version will not be installed. Remove
752 this when the breakpoints module becomes aware of
753 inferiors and address spaces. */
754 delete_step_resume_breakpoint (tp
);
755 tp
->control
.step_range_start
= 0;
756 tp
->control
.step_range_end
= 0;
757 tp
->control
.step_frame_id
= null_frame_id
;
758 delete_exception_resume_breakpoint (tp
);
759 tp
->thread_fsm
= NULL
;
762 parent
= inferior_ptid
;
763 child
= tp
->pending_follow
.value
.related_pid
;
765 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
766 /* Set up inferior(s) as specified by the caller, and tell the
767 target to do whatever is necessary to follow either parent
769 if (follow_fork_inferior (follow_child
, detach_fork
))
771 /* Target refused to follow, or there's some other reason
772 we shouldn't resume. */
777 /* This pending follow fork event is now handled, one way
778 or another. The previous selected thread may be gone
779 from the lists by now, but if it is still around, need
780 to clear the pending follow request. */
781 tp
= find_thread_ptid (parent_targ
, parent
);
783 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
785 /* This makes sure we don't try to apply the "Switched
786 over from WAIT_PID" logic above. */
787 nullify_last_target_wait_ptid ();
789 /* If we followed the child, switch to it... */
792 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
793 switch_to_thread (child_thr
);
795 /* ... and preserve the stepping state, in case the
796 user was stepping over the fork call. */
799 tp
= inferior_thread ();
800 tp
->control
.step_resume_breakpoint
801 = step_resume_breakpoint
;
802 tp
->control
.step_range_start
= step_range_start
;
803 tp
->control
.step_range_end
= step_range_end
;
804 tp
->current_line
= current_line
;
805 tp
->current_symtab
= current_symtab
;
806 tp
->control
.step_frame_id
= step_frame_id
;
807 tp
->control
.exception_resume_breakpoint
808 = exception_resume_breakpoint
;
809 tp
->thread_fsm
= thread_fsm
;
813 /* If we get here, it was because we're trying to
814 resume from a fork catchpoint, but, the user
815 has switched threads away from the thread that
816 forked. In that case, the resume command
817 issued is most likely not applicable to the
818 child, so just warn, and refuse to resume. */
819 warning (_("Not resuming: switched threads "
820 "before following fork child."));
823 /* Reset breakpoints in the child as appropriate. */
824 follow_inferior_reset_breakpoints ();
829 case TARGET_WAITKIND_SPURIOUS
:
830 /* Nothing to follow. */
833 internal_error (__FILE__
, __LINE__
,
834 "Unexpected pending_follow.kind %d\n",
835 tp
->pending_follow
.kind
);
839 return should_resume
;
843 follow_inferior_reset_breakpoints (void)
845 struct thread_info
*tp
= inferior_thread ();
847 /* Was there a step_resume breakpoint? (There was if the user
848 did a "next" at the fork() call.) If so, explicitly reset its
849 thread number. Cloned step_resume breakpoints are disabled on
850 creation, so enable it here now that it is associated with the
853 step_resumes are a form of bp that are made to be per-thread.
854 Since we created the step_resume bp when the parent process
855 was being debugged, and now are switching to the child process,
856 from the breakpoint package's viewpoint, that's a switch of
857 "threads". We must update the bp's notion of which thread
858 it is for, or it'll be ignored when it triggers. */
860 if (tp
->control
.step_resume_breakpoint
)
862 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
863 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
866 /* Treat exception_resume breakpoints like step_resume breakpoints. */
867 if (tp
->control
.exception_resume_breakpoint
)
869 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
870 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
873 /* Reinsert all breakpoints in the child. The user may have set
874 breakpoints after catching the fork, in which case those
875 were never set in the child, but only in the parent. This makes
876 sure the inserted breakpoints match the breakpoint list. */
878 breakpoint_re_set ();
879 insert_breakpoints ();
882 /* The child has exited or execed: resume threads of the parent the
883 user wanted to be executing. */
886 proceed_after_vfork_done (struct thread_info
*thread
,
889 int pid
= * (int *) arg
;
891 if (thread
->ptid
.pid () == pid
892 && thread
->state
== THREAD_RUNNING
893 && !thread
->executing
894 && !thread
->stop_requested
895 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
897 infrun_debug_printf ("resuming vfork parent thread %s",
898 target_pid_to_str (thread
->ptid
).c_str ());
900 switch_to_thread (thread
);
901 clear_proceed_status (0);
902 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
908 /* Called whenever we notice an exec or exit event, to handle
909 detaching or resuming a vfork parent. */
912 handle_vfork_child_exec_or_exit (int exec
)
914 struct inferior
*inf
= current_inferior ();
916 if (inf
->vfork_parent
)
918 int resume_parent
= -1;
920 /* This exec or exit marks the end of the shared memory region
921 between the parent and the child. Break the bonds. */
922 inferior
*vfork_parent
= inf
->vfork_parent
;
923 inf
->vfork_parent
->vfork_child
= NULL
;
924 inf
->vfork_parent
= NULL
;
926 /* If the user wanted to detach from the parent, now is the
928 if (vfork_parent
->pending_detach
)
930 struct program_space
*pspace
;
931 struct address_space
*aspace
;
933 /* follow-fork child, detach-on-fork on. */
935 vfork_parent
->pending_detach
= 0;
937 scoped_restore_current_pspace_and_thread restore_thread
;
939 /* We're letting loose of the parent. */
940 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
941 switch_to_thread (tp
);
943 /* We're about to detach from the parent, which implicitly
944 removes breakpoints from its address space. There's a
945 catch here: we want to reuse the spaces for the child,
946 but, parent/child are still sharing the pspace at this
947 point, although the exec in reality makes the kernel give
948 the child a fresh set of new pages. The problem here is
949 that the breakpoints module being unaware of this, would
950 likely chose the child process to write to the parent
951 address space. Swapping the child temporarily away from
952 the spaces has the desired effect. Yes, this is "sort
955 pspace
= inf
->pspace
;
956 aspace
= inf
->aspace
;
960 if (print_inferior_events
)
963 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
965 target_terminal::ours_for_output ();
969 fprintf_filtered (gdb_stdlog
,
970 _("[Detaching vfork parent %s "
971 "after child exec]\n"), pidstr
.c_str ());
975 fprintf_filtered (gdb_stdlog
,
976 _("[Detaching vfork parent %s "
977 "after child exit]\n"), pidstr
.c_str ());
981 target_detach (vfork_parent
, 0);
984 inf
->pspace
= pspace
;
985 inf
->aspace
= aspace
;
989 /* We're staying attached to the parent, so, really give the
990 child a new address space. */
991 inf
->pspace
= new program_space (maybe_new_address_space ());
992 inf
->aspace
= inf
->pspace
->aspace
;
994 set_current_program_space (inf
->pspace
);
996 resume_parent
= vfork_parent
->pid
;
1000 /* If this is a vfork child exiting, then the pspace and
1001 aspaces were shared with the parent. Since we're
1002 reporting the process exit, we'll be mourning all that is
1003 found in the address space, and switching to null_ptid,
1004 preparing to start a new inferior. But, since we don't
1005 want to clobber the parent's address/program spaces, we
1006 go ahead and create a new one for this exiting
1009 /* Switch to no-thread while running clone_program_space, so
1010 that clone_program_space doesn't want to read the
1011 selected frame of a dead process. */
1012 scoped_restore_current_thread restore_thread
;
1013 switch_to_no_thread ();
1015 inf
->pspace
= new program_space (maybe_new_address_space ());
1016 inf
->aspace
= inf
->pspace
->aspace
;
1017 set_current_program_space (inf
->pspace
);
1019 inf
->symfile_flags
= SYMFILE_NO_READ
;
1020 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1022 resume_parent
= vfork_parent
->pid
;
1025 gdb_assert (current_program_space
== inf
->pspace
);
1027 if (non_stop
&& resume_parent
!= -1)
1029 /* If the user wanted the parent to be running, let it go
1031 scoped_restore_current_thread restore_thread
;
1033 infrun_debug_printf ("resuming vfork parent process %d",
1036 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1041 /* Enum strings for "set|show follow-exec-mode". */
1043 static const char follow_exec_mode_new
[] = "new";
1044 static const char follow_exec_mode_same
[] = "same";
1045 static const char *const follow_exec_mode_names
[] =
1047 follow_exec_mode_new
,
1048 follow_exec_mode_same
,
1052 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1054 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1055 struct cmd_list_element
*c
, const char *value
)
1057 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1060 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1063 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1065 struct inferior
*inf
= current_inferior ();
1066 int pid
= ptid
.pid ();
1067 ptid_t process_ptid
;
1069 /* Switch terminal for any messages produced e.g. by
1070 breakpoint_re_set. */
1071 target_terminal::ours_for_output ();
1073 /* This is an exec event that we actually wish to pay attention to.
1074 Refresh our symbol table to the newly exec'd program, remove any
1075 momentary bp's, etc.
1077 If there are breakpoints, they aren't really inserted now,
1078 since the exec() transformed our inferior into a fresh set
1081 We want to preserve symbolic breakpoints on the list, since
1082 we have hopes that they can be reset after the new a.out's
1083 symbol table is read.
1085 However, any "raw" breakpoints must be removed from the list
1086 (e.g., the solib bp's), since their address is probably invalid
1089 And, we DON'T want to call delete_breakpoints() here, since
1090 that may write the bp's "shadow contents" (the instruction
1091 value that was overwritten with a TRAP instruction). Since
1092 we now have a new a.out, those shadow contents aren't valid. */
1094 mark_breakpoints_out ();
1096 /* The target reports the exec event to the main thread, even if
1097 some other thread does the exec, and even if the main thread was
1098 stopped or already gone. We may still have non-leader threads of
1099 the process on our list. E.g., on targets that don't have thread
1100 exit events (like remote); or on native Linux in non-stop mode if
1101 there were only two threads in the inferior and the non-leader
1102 one is the one that execs (and nothing forces an update of the
1103 thread list up to here). When debugging remotely, it's best to
1104 avoid extra traffic, when possible, so avoid syncing the thread
1105 list with the target, and instead go ahead and delete all threads
1106 of the process but one that reported the event. Note this must
1107 be done before calling update_breakpoints_after_exec, as
1108 otherwise clearing the threads' resources would reference stale
1109 thread breakpoints -- it may have been one of these threads that
1110 stepped across the exec. We could just clear their stepping
1111 states, but as long as we're iterating, might as well delete
1112 them. Deleting them now rather than at the next user-visible
1113 stop provides a nicer sequence of events for user and MI
1115 for (thread_info
*th
: all_threads_safe ())
1116 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1119 /* We also need to clear any left over stale state for the
1120 leader/event thread. E.g., if there was any step-resume
1121 breakpoint or similar, it's gone now. We cannot truly
1122 step-to-next statement through an exec(). */
1123 thread_info
*th
= inferior_thread ();
1124 th
->control
.step_resume_breakpoint
= NULL
;
1125 th
->control
.exception_resume_breakpoint
= NULL
;
1126 th
->control
.single_step_breakpoints
= NULL
;
1127 th
->control
.step_range_start
= 0;
1128 th
->control
.step_range_end
= 0;
1130 /* The user may have had the main thread held stopped in the
1131 previous image (e.g., schedlock on, or non-stop). Release
1133 th
->stop_requested
= 0;
1135 update_breakpoints_after_exec ();
1137 /* What is this a.out's name? */
1138 process_ptid
= ptid_t (pid
);
1139 printf_unfiltered (_("%s is executing new program: %s\n"),
1140 target_pid_to_str (process_ptid
).c_str (),
1143 /* We've followed the inferior through an exec. Therefore, the
1144 inferior has essentially been killed & reborn. */
1146 breakpoint_init_inferior (inf_execd
);
1148 gdb::unique_xmalloc_ptr
<char> exec_file_host
1149 = exec_file_find (exec_file_target
, NULL
);
1151 /* If we were unable to map the executable target pathname onto a host
1152 pathname, tell the user that. Otherwise GDB's subsequent behavior
1153 is confusing. Maybe it would even be better to stop at this point
1154 so that the user can specify a file manually before continuing. */
1155 if (exec_file_host
== NULL
)
1156 warning (_("Could not load symbols for executable %s.\n"
1157 "Do you need \"set sysroot\"?"),
1160 /* Reset the shared library package. This ensures that we get a
1161 shlib event when the child reaches "_start", at which point the
1162 dld will have had a chance to initialize the child. */
1163 /* Also, loading a symbol file below may trigger symbol lookups, and
1164 we don't want those to be satisfied by the libraries of the
1165 previous incarnation of this process. */
1166 no_shared_libraries (NULL
, 0);
1168 if (follow_exec_mode_string
== follow_exec_mode_new
)
1170 /* The user wants to keep the old inferior and program spaces
1171 around. Create a new fresh one, and switch to it. */
1173 /* Do exit processing for the original inferior before setting the new
1174 inferior's pid. Having two inferiors with the same pid would confuse
1175 find_inferior_p(t)id. Transfer the terminal state and info from the
1176 old to the new inferior. */
1177 inf
= add_inferior_with_spaces ();
1178 swap_terminal_info (inf
, current_inferior ());
1179 exit_inferior_silent (current_inferior ());
1182 target_follow_exec (inf
, exec_file_target
);
1184 inferior
*org_inferior
= current_inferior ();
1185 switch_to_inferior_no_thread (inf
);
1186 push_target (org_inferior
->process_target ());
1187 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1188 switch_to_thread (thr
);
1192 /* The old description may no longer be fit for the new image.
1193 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1194 old description; we'll read a new one below. No need to do
1195 this on "follow-exec-mode new", as the old inferior stays
1196 around (its description is later cleared/refetched on
1198 target_clear_description ();
1201 gdb_assert (current_program_space
== inf
->pspace
);
1203 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1204 because the proper displacement for a PIE (Position Independent
1205 Executable) main symbol file will only be computed by
1206 solib_create_inferior_hook below. breakpoint_re_set would fail
1207 to insert the breakpoints with the zero displacement. */
1208 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1210 /* If the target can specify a description, read it. Must do this
1211 after flipping to the new executable (because the target supplied
1212 description must be compatible with the executable's
1213 architecture, and the old executable may e.g., be 32-bit, while
1214 the new one 64-bit), and before anything involving memory or
1216 target_find_description ();
1218 gdb::observers::inferior_execd
.notify (inf
);
1220 breakpoint_re_set ();
1222 /* Reinsert all breakpoints. (Those which were symbolic have
1223 been reset to the proper address in the new a.out, thanks
1224 to symbol_file_command...). */
1225 insert_breakpoints ();
1227 /* The next resume of this inferior should bring it to the shlib
1228 startup breakpoints. (If the user had also set bp's on
1229 "main" from the old (parent) process, then they'll auto-
1230 matically get reset there in the new process.). */
1233 /* The chain of threads that need to do a step-over operation to get
1234 past e.g., a breakpoint. What technique is used to step over the
1235 breakpoint/watchpoint does not matter -- all threads end up in the
1236 same queue, to maintain rough temporal order of execution, in order
1237 to avoid starvation, otherwise, we could e.g., find ourselves
1238 constantly stepping the same couple threads past their breakpoints
1239 over and over, if the single-step finish fast enough. */
1240 struct thread_info
*global_thread_step_over_chain_head
;
1242 /* Bit flags indicating what the thread needs to step over. */
1244 enum step_over_what_flag
1246 /* Step over a breakpoint. */
1247 STEP_OVER_BREAKPOINT
= 1,
1249 /* Step past a non-continuable watchpoint, in order to let the
1250 instruction execute so we can evaluate the watchpoint
1252 STEP_OVER_WATCHPOINT
= 2
1254 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1256 /* Info about an instruction that is being stepped over. */
1258 struct step_over_info
1260 /* If we're stepping past a breakpoint, this is the address space
1261 and address of the instruction the breakpoint is set at. We'll
1262 skip inserting all breakpoints here. Valid iff ASPACE is
1264 const address_space
*aspace
;
1267 /* The instruction being stepped over triggers a nonsteppable
1268 watchpoint. If true, we'll skip inserting watchpoints. */
1269 int nonsteppable_watchpoint_p
;
1271 /* The thread's global number. */
1275 /* The step-over info of the location that is being stepped over.
1277 Note that with async/breakpoint always-inserted mode, a user might
1278 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1279 being stepped over. As setting a new breakpoint inserts all
1280 breakpoints, we need to make sure the breakpoint being stepped over
1281 isn't inserted then. We do that by only clearing the step-over
1282 info when the step-over is actually finished (or aborted).
1284 Presently GDB can only step over one breakpoint at any given time.
1285 Given threads that can't run code in the same address space as the
1286 breakpoint's can't really miss the breakpoint, GDB could be taught
1287 to step-over at most one breakpoint per address space (so this info
1288 could move to the address space object if/when GDB is extended).
1289 The set of breakpoints being stepped over will normally be much
1290 smaller than the set of all breakpoints, so a flag in the
1291 breakpoint location structure would be wasteful. A separate list
1292 also saves complexity and run-time, as otherwise we'd have to go
1293 through all breakpoint locations clearing their flag whenever we
1294 start a new sequence. Similar considerations weigh against storing
1295 this info in the thread object. Plus, not all step overs actually
1296 have breakpoint locations -- e.g., stepping past a single-step
1297 breakpoint, or stepping to complete a non-continuable
1299 static struct step_over_info step_over_info
;
1301 /* Record the address of the breakpoint/instruction we're currently
1303 N.B. We record the aspace and address now, instead of say just the thread,
1304 because when we need the info later the thread may be running. */
1307 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1308 int nonsteppable_watchpoint_p
,
1311 step_over_info
.aspace
= aspace
;
1312 step_over_info
.address
= address
;
1313 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1314 step_over_info
.thread
= thread
;
1317 /* Called when we're not longer stepping over a breakpoint / an
1318 instruction, so all breakpoints are free to be (re)inserted. */
1321 clear_step_over_info (void)
1323 infrun_debug_printf ("clearing step over info");
1324 step_over_info
.aspace
= NULL
;
1325 step_over_info
.address
= 0;
1326 step_over_info
.nonsteppable_watchpoint_p
= 0;
1327 step_over_info
.thread
= -1;
1333 stepping_past_instruction_at (struct address_space
*aspace
,
1336 return (step_over_info
.aspace
!= NULL
1337 && breakpoint_address_match (aspace
, address
,
1338 step_over_info
.aspace
,
1339 step_over_info
.address
));
1345 thread_is_stepping_over_breakpoint (int thread
)
1347 return (step_over_info
.thread
!= -1
1348 && thread
== step_over_info
.thread
);
1354 stepping_past_nonsteppable_watchpoint (void)
1356 return step_over_info
.nonsteppable_watchpoint_p
;
1359 /* Returns true if step-over info is valid. */
1362 step_over_info_valid_p (void)
1364 return (step_over_info
.aspace
!= NULL
1365 || stepping_past_nonsteppable_watchpoint ());
1369 /* Displaced stepping. */
1371 /* In non-stop debugging mode, we must take special care to manage
1372 breakpoints properly; in particular, the traditional strategy for
1373 stepping a thread past a breakpoint it has hit is unsuitable.
1374 'Displaced stepping' is a tactic for stepping one thread past a
1375 breakpoint it has hit while ensuring that other threads running
1376 concurrently will hit the breakpoint as they should.
1378 The traditional way to step a thread T off a breakpoint in a
1379 multi-threaded program in all-stop mode is as follows:
1381 a0) Initially, all threads are stopped, and breakpoints are not
1383 a1) We single-step T, leaving breakpoints uninserted.
1384 a2) We insert breakpoints, and resume all threads.
1386 In non-stop debugging, however, this strategy is unsuitable: we
1387 don't want to have to stop all threads in the system in order to
1388 continue or step T past a breakpoint. Instead, we use displaced
1391 n0) Initially, T is stopped, other threads are running, and
1392 breakpoints are inserted.
1393 n1) We copy the instruction "under" the breakpoint to a separate
1394 location, outside the main code stream, making any adjustments
1395 to the instruction, register, and memory state as directed by
1397 n2) We single-step T over the instruction at its new location.
1398 n3) We adjust the resulting register and memory state as directed
1399 by T's architecture. This includes resetting T's PC to point
1400 back into the main instruction stream.
1403 This approach depends on the following gdbarch methods:
1405 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1406 indicate where to copy the instruction, and how much space must
1407 be reserved there. We use these in step n1.
1409 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1410 address, and makes any necessary adjustments to the instruction,
1411 register contents, and memory. We use this in step n1.
1413 - gdbarch_displaced_step_fixup adjusts registers and memory after
1414 we have successfully single-stepped the instruction, to yield the
1415 same effect the instruction would have had if we had executed it
1416 at its original address. We use this in step n3.
1418 The gdbarch_displaced_step_copy_insn and
1419 gdbarch_displaced_step_fixup functions must be written so that
1420 copying an instruction with gdbarch_displaced_step_copy_insn,
1421 single-stepping across the copied instruction, and then applying
1422 gdbarch_displaced_insn_fixup should have the same effects on the
1423 thread's memory and registers as stepping the instruction in place
1424 would have. Exactly which responsibilities fall to the copy and
1425 which fall to the fixup is up to the author of those functions.
1427 See the comments in gdbarch.sh for details.
1429 Note that displaced stepping and software single-step cannot
1430 currently be used in combination, although with some care I think
1431 they could be made to. Software single-step works by placing
1432 breakpoints on all possible subsequent instructions; if the
1433 displaced instruction is a PC-relative jump, those breakpoints
1434 could fall in very strange places --- on pages that aren't
1435 executable, or at addresses that are not proper instruction
1436 boundaries. (We do generally let other threads run while we wait
1437 to hit the software single-step breakpoint, and they might
1438 encounter such a corrupted instruction.) One way to work around
1439 this would be to have gdbarch_displaced_step_copy_insn fully
1440 simulate the effect of PC-relative instructions (and return NULL)
1441 on architectures that use software single-stepping.
1443 In non-stop mode, we can have independent and simultaneous step
1444 requests, so more than one thread may need to simultaneously step
1445 over a breakpoint. The current implementation assumes there is
1446 only one scratch space per process. In this case, we have to
1447 serialize access to the scratch space. If thread A wants to step
1448 over a breakpoint, but we are currently waiting for some other
1449 thread to complete a displaced step, we leave thread A stopped and
1450 place it in the displaced_step_request_queue. Whenever a displaced
1451 step finishes, we pick the next thread in the queue and start a new
1452 displaced step operation on it. See displaced_step_prepare and
1453 displaced_step_finish for details. */
1455 /* Return true if THREAD is doing a displaced step. */
1458 displaced_step_in_progress_thread (thread_info
*thread
)
1460 gdb_assert (thread
!= NULL
);
1462 return thread
->displaced_step_state
.in_progress ();
1465 /* Return true if INF has a thread doing a displaced step. */
1468 displaced_step_in_progress (inferior
*inf
)
1470 return inf
->displaced_step_state
.in_progress_count
> 0;
1473 /* Return true if any thread is doing a displaced step. */
1476 displaced_step_in_progress_any_thread ()
1478 for (inferior
*inf
: all_non_exited_inferiors ())
1480 if (displaced_step_in_progress (inf
))
1488 infrun_inferior_exit (struct inferior
*inf
)
1490 inf
->displaced_step_state
.reset ();
1494 infrun_inferior_execd (inferior
*inf
)
1496 /* If some threads where was doing a displaced step in this inferior at the
1497 moment of the exec, they no longer exist. Even if the exec'ing thread
1498 doing a displaced step, we don't want to to any fixup nor restore displaced
1499 stepping buffer bytes. */
1500 inf
->displaced_step_state
.reset ();
1502 for (thread_info
*thread
: inf
->threads ())
1503 thread
->displaced_step_state
.reset ();
1505 /* Since an in-line step is done with everything else stopped, if there was
1506 one in progress at the time of the exec, it must have been the exec'ing
1508 clear_step_over_info ();
1511 /* If ON, and the architecture supports it, GDB will use displaced
1512 stepping to step over breakpoints. If OFF, or if the architecture
1513 doesn't support it, GDB will instead use the traditional
1514 hold-and-step approach. If AUTO (which is the default), GDB will
1515 decide which technique to use to step over breakpoints depending on
1516 whether the target works in a non-stop way (see use_displaced_stepping). */
1518 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1521 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1522 struct cmd_list_element
*c
,
1525 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1526 fprintf_filtered (file
,
1527 _("Debugger's willingness to use displaced stepping "
1528 "to step over breakpoints is %s (currently %s).\n"),
1529 value
, target_is_non_stop_p () ? "on" : "off");
1531 fprintf_filtered (file
,
1532 _("Debugger's willingness to use displaced stepping "
1533 "to step over breakpoints is %s.\n"), value
);
1536 /* Return true if the gdbarch implements the required methods to use
1537 displaced stepping. */
1540 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1542 /* Only check for the presence of `prepare`. The gdbarch verification ensures
1543 that if `prepare` is provided, so is `finish`. */
1544 return gdbarch_displaced_step_prepare_p (arch
);
1547 /* Return non-zero if displaced stepping can/should be used to step
1548 over breakpoints of thread TP. */
1551 use_displaced_stepping (thread_info
*tp
)
1553 /* If the user disabled it explicitly, don't use displaced stepping. */
1554 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1557 /* If "auto", only use displaced stepping if the target operates in a non-stop
1559 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1560 && !target_is_non_stop_p ())
1563 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1565 /* If the architecture doesn't implement displaced stepping, don't use
1567 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1570 /* If recording, don't use displaced stepping. */
1571 if (find_record_target () != nullptr)
1574 /* If displaced stepping failed before for this inferior, don't bother trying
1576 if (tp
->inf
->displaced_step_state
.failed_before
)
1582 /* Simple function wrapper around displaced_step_thread_state::reset. */
1585 displaced_step_reset (displaced_step_thread_state
*displaced
)
1587 displaced
->reset ();
1590 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1591 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1593 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1598 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1602 for (size_t i
= 0; i
< len
; i
++)
1605 ret
+= string_printf ("%02x", buf
[i
]);
1607 ret
+= string_printf (" %02x", buf
[i
]);
1613 /* Prepare to single-step, using displaced stepping.
1615 Note that we cannot use displaced stepping when we have a signal to
1616 deliver. If we have a signal to deliver and an instruction to step
1617 over, then after the step, there will be no indication from the
1618 target whether the thread entered a signal handler or ignored the
1619 signal and stepped over the instruction successfully --- both cases
1620 result in a simple SIGTRAP. In the first case we mustn't do a
1621 fixup, and in the second case we must --- but we can't tell which.
1622 Comments in the code for 'random signals' in handle_inferior_event
1623 explain how we handle this case instead.
1625 Returns DISPLACED_STEP_PREPARE_STATUS_OK if preparing was successful -- this
1626 thread is going to be stepped now; DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
1627 if displaced stepping this thread got queued; or
1628 DISPLACED_STEP_PREPARE_STATUS_CANT if this instruction can't be displaced
1631 static displaced_step_prepare_status
1632 displaced_step_prepare_throw (thread_info
*tp
)
1634 regcache
*regcache
= get_thread_regcache (tp
);
1635 struct gdbarch
*gdbarch
= regcache
->arch ();
1636 displaced_step_thread_state
&disp_step_thread_state
1637 = tp
->displaced_step_state
;
1639 /* We should never reach this function if the architecture does not
1640 support displaced stepping. */
1641 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1643 /* Nor if the thread isn't meant to step over a breakpoint. */
1644 gdb_assert (tp
->control
.trap_expected
);
1646 /* Disable range stepping while executing in the scratch pad. We
1647 want a single-step even if executing the displaced instruction in
1648 the scratch buffer lands within the stepping range (e.g., a
1650 tp
->control
.may_range_step
= 0;
1652 /* We are about to start a displaced step for this thread. If one is already
1653 in progress, something's wrong. */
1654 gdb_assert (!disp_step_thread_state
.in_progress ());
1656 if (tp
->inf
->displaced_step_state
.unavailable
)
1658 /* The gdbarch tells us it's not worth asking to try a prepare because
1659 it is likely that it will return unavailable, so don't bother asking. */
1661 displaced_debug_printf ("deferring step of %s",
1662 target_pid_to_str (tp
->ptid
).c_str ());
1664 global_thread_step_over_chain_enqueue (tp
);
1665 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1668 displaced_debug_printf ("displaced-stepping %s now",
1669 target_pid_to_str (tp
->ptid
).c_str ());
1671 scoped_restore_current_thread restore_thread
;
1673 switch_to_thread (tp
);
1675 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1676 CORE_ADDR displaced_pc
;
1678 displaced_step_prepare_status status
1679 = gdbarch_displaced_step_prepare (gdbarch
, tp
, displaced_pc
);
1681 if (status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
1683 displaced_debug_printf ("failed to prepare (%s)",
1684 target_pid_to_str (tp
->ptid
).c_str ());
1686 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1688 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1690 /* Not enough displaced stepping resources available, defer this
1691 request by placing it the queue. */
1693 displaced_debug_printf ("not enough resources available, "
1694 "deferring step of %s",
1695 target_pid_to_str (tp
->ptid
).c_str ());
1697 global_thread_step_over_chain_enqueue (tp
);
1699 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1702 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1704 /* Save the information we need to fix things up if the step
1706 disp_step_thread_state
.set (gdbarch
);
1708 tp
->inf
->displaced_step_state
.in_progress_count
++;
1710 displaced_debug_printf ("prepared successfully thread=%s, "
1711 "original_pc=%s, displaced_pc=%s",
1712 target_pid_to_str (tp
->ptid
).c_str (),
1713 paddress (gdbarch
, original_pc
),
1714 paddress (gdbarch
, displaced_pc
));
1716 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1719 /* Wrapper for displaced_step_prepare_throw that disabled further
1720 attempts at displaced stepping if we get a memory error. */
1722 static displaced_step_prepare_status
1723 displaced_step_prepare (thread_info
*thread
)
1725 displaced_step_prepare_status status
1726 = DISPLACED_STEP_PREPARE_STATUS_CANT
;
1730 status
= displaced_step_prepare_throw (thread
);
1732 catch (const gdb_exception_error
&ex
)
1734 if (ex
.error
!= MEMORY_ERROR
1735 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1738 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1741 /* Be verbose if "set displaced-stepping" is "on", silent if
1743 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1745 warning (_("disabling displaced stepping: %s"),
1749 /* Disable further displaced stepping attempts. */
1750 thread
->inf
->displaced_step_state
.failed_before
= 1;
1756 /* If we displaced stepped an instruction successfully, adjust registers and
1757 memory to yield the same effect the instruction would have had if we had
1758 executed it at its original address, and return
1759 DISPLACED_STEP_FINISH_STATUS_OK. If the instruction didn't complete,
1760 relocate the PC and return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED.
1762 If the thread wasn't displaced stepping, return
1763 DISPLACED_STEP_FINISH_STATUS_OK as well. */
1765 static displaced_step_finish_status
1766 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1768 displaced_step_thread_state
*displaced
= &event_thread
->displaced_step_state
;
1770 /* Was this thread performing a displaced step? */
1771 if (!displaced
->in_progress ())
1772 return DISPLACED_STEP_FINISH_STATUS_OK
;
1774 gdb_assert (event_thread
->inf
->displaced_step_state
.in_progress_count
> 0);
1775 event_thread
->inf
->displaced_step_state
.in_progress_count
--;
1777 /* Fixup may need to read memory/registers. Switch to the thread
1778 that we're fixing up. Also, target_stopped_by_watchpoint checks
1779 the current thread, and displaced_step_restore performs ptid-dependent
1780 memory accesses using current_inferior() and current_top_target(). */
1781 switch_to_thread (event_thread
);
1783 displaced_step_reset_cleanup
cleanup (displaced
);
1785 /* Do the fixup, and release the resources acquired to do the displaced
1787 return gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1788 event_thread
, signal
);
1791 /* Data to be passed around while handling an event. This data is
1792 discarded between events. */
1793 struct execution_control_state
1795 process_stratum_target
*target
;
1797 /* The thread that got the event, if this was a thread event; NULL
1799 struct thread_info
*event_thread
;
1801 struct target_waitstatus ws
;
1802 int stop_func_filled_in
;
1803 CORE_ADDR stop_func_start
;
1804 CORE_ADDR stop_func_end
;
1805 const char *stop_func_name
;
1808 /* True if the event thread hit the single-step breakpoint of
1809 another thread. Thus the event doesn't cause a stop, the thread
1810 needs to be single-stepped past the single-step breakpoint before
1811 we can switch back to the original stepping thread. */
1812 int hit_singlestep_breakpoint
;
1815 /* Clear ECS and set it to point at TP. */
1818 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1820 memset (ecs
, 0, sizeof (*ecs
));
1821 ecs
->event_thread
= tp
;
1822 ecs
->ptid
= tp
->ptid
;
1825 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1826 static void prepare_to_wait (struct execution_control_state
*ecs
);
1827 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1828 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1830 /* Are there any pending step-over requests? If so, run all we can
1831 now and return true. Otherwise, return false. */
1834 start_step_over (void)
1836 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
1840 /* Don't start a new step-over if we already have an in-line
1841 step-over operation ongoing. */
1842 if (step_over_info_valid_p ())
1845 /* Steal the global thread step over chain. As we try to initiate displaced
1846 steps, threads will be enqueued in the global chain if no buffers are
1847 available. If we iterated on the global chain directly, we might iterate
1849 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1850 global_thread_step_over_chain_head
= NULL
;
1852 infrun_debug_printf ("stealing global queue of threads to step, length = %d",
1853 thread_step_over_chain_length (threads_to_step
));
1855 bool started
= false;
1857 /* On scope exit (whatever the reason, return or exception), if there are
1858 threads left in the THREADS_TO_STEP chain, put back these threads in the
1862 if (threads_to_step
== nullptr)
1863 infrun_debug_printf ("step-over queue now empty");
1866 infrun_debug_printf ("putting back %d threads to step in global queue",
1867 thread_step_over_chain_length (threads_to_step
));
1869 global_thread_step_over_chain_enqueue_chain (threads_to_step
);
1873 for (thread_info
*tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1875 struct execution_control_state ecss
;
1876 struct execution_control_state
*ecs
= &ecss
;
1877 step_over_what step_what
;
1878 int must_be_in_line
;
1880 gdb_assert (!tp
->stop_requested
);
1882 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1884 if (tp
->inf
->displaced_step_state
.unavailable
)
1886 /* The arch told us to not even try preparing another displaced step
1887 for this inferior. Just leave the thread in THREADS_TO_STEP, it
1888 will get moved to the global chain on scope exit. */
1892 /* Remove thread from the THREADS_TO_STEP chain. If anything goes wrong
1893 while we try to prepare the displaced step, we don't add it back to
1894 the global step over chain. This is to avoid a thread staying in the
1895 step over chain indefinitely if something goes wrong when resuming it
1896 If the error is intermittent and it still needs a step over, it will
1897 get enqueued again when we try to resume it normally. */
1898 thread_step_over_chain_remove (&threads_to_step
, tp
);
1900 step_what
= thread_still_needs_step_over (tp
);
1901 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1902 || ((step_what
& STEP_OVER_BREAKPOINT
)
1903 && !use_displaced_stepping (tp
)));
1905 /* We currently stop all threads of all processes to step-over
1906 in-line. If we need to start a new in-line step-over, let
1907 any pending displaced steps finish first. */
1908 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1910 global_thread_step_over_chain_enqueue (tp
);
1914 if (tp
->control
.trap_expected
1918 internal_error (__FILE__
, __LINE__
,
1919 "[%s] has inconsistent state: "
1920 "trap_expected=%d, resumed=%d, executing=%d\n",
1921 target_pid_to_str (tp
->ptid
).c_str (),
1922 tp
->control
.trap_expected
,
1927 infrun_debug_printf ("resuming [%s] for step-over",
1928 target_pid_to_str (tp
->ptid
).c_str ());
1930 /* keep_going_pass_signal skips the step-over if the breakpoint
1931 is no longer inserted. In all-stop, we want to keep looking
1932 for a thread that needs a step-over instead of resuming TP,
1933 because we wouldn't be able to resume anything else until the
1934 target stops again. In non-stop, the resume always resumes
1935 only TP, so it's OK to let the thread resume freely. */
1936 if (!target_is_non_stop_p () && !step_what
)
1939 switch_to_thread (tp
);
1940 reset_ecs (ecs
, tp
);
1941 keep_going_pass_signal (ecs
);
1943 if (!ecs
->wait_some_more
)
1944 error (_("Command aborted."));
1946 /* If the thread's step over could not be initiated because no buffers
1947 were available, it was re-added to the global step over chain. */
1950 infrun_debug_printf ("[%s] was resumed.",
1951 target_pid_to_str (tp
->ptid
).c_str ());
1952 gdb_assert (!thread_is_in_step_over_chain (tp
));
1956 infrun_debug_printf ("[%s] was NOT resumed.",
1957 target_pid_to_str (tp
->ptid
).c_str ());
1958 gdb_assert (thread_is_in_step_over_chain (tp
));
1961 /* If we started a new in-line step-over, we're done. */
1962 if (step_over_info_valid_p ())
1964 gdb_assert (tp
->control
.trap_expected
);
1969 if (!target_is_non_stop_p ())
1971 /* On all-stop, shouldn't have resumed unless we needed a
1973 gdb_assert (tp
->control
.trap_expected
1974 || tp
->step_after_step_resume_breakpoint
);
1976 /* With remote targets (at least), in all-stop, we can't
1977 issue any further remote commands until the program stops
1983 /* Either the thread no longer needed a step-over, or a new
1984 displaced stepping sequence started. Even in the latter
1985 case, continue looking. Maybe we can also start another
1986 displaced step on a thread of other process. */
1992 /* Update global variables holding ptids to hold NEW_PTID if they were
1993 holding OLD_PTID. */
1995 infrun_thread_ptid_changed (process_stratum_target
*target
,
1996 ptid_t old_ptid
, ptid_t new_ptid
)
1998 if (inferior_ptid
== old_ptid
1999 && current_inferior ()->process_target () == target
)
2000 inferior_ptid
= new_ptid
;
2005 static const char schedlock_off
[] = "off";
2006 static const char schedlock_on
[] = "on";
2007 static const char schedlock_step
[] = "step";
2008 static const char schedlock_replay
[] = "replay";
2009 static const char *const scheduler_enums
[] = {
2016 static const char *scheduler_mode
= schedlock_replay
;
2018 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2019 struct cmd_list_element
*c
, const char *value
)
2021 fprintf_filtered (file
,
2022 _("Mode for locking scheduler "
2023 "during execution is \"%s\".\n"),
2028 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2030 if (!target_can_lock_scheduler ())
2032 scheduler_mode
= schedlock_off
;
2033 error (_("Target '%s' cannot support this command."), target_shortname
);
2037 /* True if execution commands resume all threads of all processes by
2038 default; otherwise, resume only threads of the current inferior
2040 bool sched_multi
= false;
2042 /* Try to setup for software single stepping over the specified location.
2043 Return true if target_resume() should use hardware single step.
2045 GDBARCH the current gdbarch.
2046 PC the location to step over. */
2049 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2051 bool hw_step
= true;
2053 if (execution_direction
== EXEC_FORWARD
2054 && gdbarch_software_single_step_p (gdbarch
))
2055 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2063 user_visible_resume_ptid (int step
)
2069 /* With non-stop mode on, threads are always handled
2071 resume_ptid
= inferior_ptid
;
2073 else if ((scheduler_mode
== schedlock_on
)
2074 || (scheduler_mode
== schedlock_step
&& step
))
2076 /* User-settable 'scheduler' mode requires solo thread
2078 resume_ptid
= inferior_ptid
;
2080 else if ((scheduler_mode
== schedlock_replay
)
2081 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2083 /* User-settable 'scheduler' mode requires solo thread resume in replay
2085 resume_ptid
= inferior_ptid
;
2087 else if (!sched_multi
&& target_supports_multi_process ())
2089 /* Resume all threads of the current process (and none of other
2091 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2095 /* Resume all threads of all processes. */
2096 resume_ptid
= RESUME_ALL
;
2104 process_stratum_target
*
2105 user_visible_resume_target (ptid_t resume_ptid
)
2107 return (resume_ptid
== minus_one_ptid
&& sched_multi
2109 : current_inferior ()->process_target ());
2112 /* Return a ptid representing the set of threads that we will resume,
2113 in the perspective of the target, assuming run control handling
2114 does not require leaving some threads stopped (e.g., stepping past
2115 breakpoint). USER_STEP indicates whether we're about to start the
2116 target for a stepping command. */
2119 internal_resume_ptid (int user_step
)
2121 /* In non-stop, we always control threads individually. Note that
2122 the target may always work in non-stop mode even with "set
2123 non-stop off", in which case user_visible_resume_ptid could
2124 return a wildcard ptid. */
2125 if (target_is_non_stop_p ())
2126 return inferior_ptid
;
2128 return user_visible_resume_ptid (user_step
);
2131 /* Wrapper for target_resume, that handles infrun-specific
2135 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2137 struct thread_info
*tp
= inferior_thread ();
2139 gdb_assert (!tp
->stop_requested
);
2141 /* Install inferior's terminal modes. */
2142 target_terminal::inferior ();
2144 /* Avoid confusing the next resume, if the next stop/resume
2145 happens to apply to another thread. */
2146 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2148 /* Advise target which signals may be handled silently.
2150 If we have removed breakpoints because we are stepping over one
2151 in-line (in any thread), we need to receive all signals to avoid
2152 accidentally skipping a breakpoint during execution of a signal
2155 Likewise if we're displaced stepping, otherwise a trap for a
2156 breakpoint in a signal handler might be confused with the
2157 displaced step finishing. We don't make the displaced_step_finish
2158 step distinguish the cases instead, because:
2160 - a backtrace while stopped in the signal handler would show the
2161 scratch pad as frame older than the signal handler, instead of
2162 the real mainline code.
2164 - when the thread is later resumed, the signal handler would
2165 return to the scratch pad area, which would no longer be
2167 if (step_over_info_valid_p ()
2168 || displaced_step_in_progress (tp
->inf
))
2169 target_pass_signals ({});
2171 target_pass_signals (signal_pass
);
2173 target_resume (resume_ptid
, step
, sig
);
2175 target_commit_resume ();
2177 if (target_can_async_p ())
2181 /* Resume the inferior. SIG is the signal to give the inferior
2182 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2183 call 'resume', which handles exceptions. */
2186 resume_1 (enum gdb_signal sig
)
2188 struct regcache
*regcache
= get_current_regcache ();
2189 struct gdbarch
*gdbarch
= regcache
->arch ();
2190 struct thread_info
*tp
= inferior_thread ();
2191 const address_space
*aspace
= regcache
->aspace ();
2193 /* This represents the user's step vs continue request. When
2194 deciding whether "set scheduler-locking step" applies, it's the
2195 user's intention that counts. */
2196 const int user_step
= tp
->control
.stepping_command
;
2197 /* This represents what we'll actually request the target to do.
2198 This can decay from a step to a continue, if e.g., we need to
2199 implement single-stepping with breakpoints (software
2203 gdb_assert (!tp
->stop_requested
);
2204 gdb_assert (!thread_is_in_step_over_chain (tp
));
2206 if (tp
->suspend
.waitstatus_pending_p
)
2209 ("thread %s has pending wait "
2210 "status %s (currently_stepping=%d).",
2211 target_pid_to_str (tp
->ptid
).c_str (),
2212 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2213 currently_stepping (tp
));
2215 tp
->inf
->process_target ()->threads_executing
= true;
2218 /* FIXME: What should we do if we are supposed to resume this
2219 thread with a signal? Maybe we should maintain a queue of
2220 pending signals to deliver. */
2221 if (sig
!= GDB_SIGNAL_0
)
2223 warning (_("Couldn't deliver signal %s to %s."),
2224 gdb_signal_to_name (sig
),
2225 target_pid_to_str (tp
->ptid
).c_str ());
2228 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2230 if (target_can_async_p ())
2233 /* Tell the event loop we have an event to process. */
2234 mark_async_event_handler (infrun_async_inferior_event_token
);
2239 tp
->stepped_breakpoint
= 0;
2241 /* Depends on stepped_breakpoint. */
2242 step
= currently_stepping (tp
);
2244 if (current_inferior ()->waiting_for_vfork_done
)
2246 /* Don't try to single-step a vfork parent that is waiting for
2247 the child to get out of the shared memory region (by exec'ing
2248 or exiting). This is particularly important on software
2249 single-step archs, as the child process would trip on the
2250 software single step breakpoint inserted for the parent
2251 process. Since the parent will not actually execute any
2252 instruction until the child is out of the shared region (such
2253 are vfork's semantics), it is safe to simply continue it.
2254 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2255 the parent, and tell it to `keep_going', which automatically
2256 re-sets it stepping. */
2257 infrun_debug_printf ("resume : clear step");
2261 CORE_ADDR pc
= regcache_read_pc (regcache
);
2263 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2264 "current thread [%s] at %s",
2265 step
, gdb_signal_to_symbol_string (sig
),
2266 tp
->control
.trap_expected
,
2267 target_pid_to_str (inferior_ptid
).c_str (),
2268 paddress (gdbarch
, pc
));
2270 /* Normally, by the time we reach `resume', the breakpoints are either
2271 removed or inserted, as appropriate. The exception is if we're sitting
2272 at a permanent breakpoint; we need to step over it, but permanent
2273 breakpoints can't be removed. So we have to test for it here. */
2274 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2276 if (sig
!= GDB_SIGNAL_0
)
2278 /* We have a signal to pass to the inferior. The resume
2279 may, or may not take us to the signal handler. If this
2280 is a step, we'll need to stop in the signal handler, if
2281 there's one, (if the target supports stepping into
2282 handlers), or in the next mainline instruction, if
2283 there's no handler. If this is a continue, we need to be
2284 sure to run the handler with all breakpoints inserted.
2285 In all cases, set a breakpoint at the current address
2286 (where the handler returns to), and once that breakpoint
2287 is hit, resume skipping the permanent breakpoint. If
2288 that breakpoint isn't hit, then we've stepped into the
2289 signal handler (or hit some other event). We'll delete
2290 the step-resume breakpoint then. */
2292 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2293 "deliver signal first");
2295 clear_step_over_info ();
2296 tp
->control
.trap_expected
= 0;
2298 if (tp
->control
.step_resume_breakpoint
== NULL
)
2300 /* Set a "high-priority" step-resume, as we don't want
2301 user breakpoints at PC to trigger (again) when this
2303 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2304 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2306 tp
->step_after_step_resume_breakpoint
= step
;
2309 insert_breakpoints ();
2313 /* There's no signal to pass, we can go ahead and skip the
2314 permanent breakpoint manually. */
2315 infrun_debug_printf ("skipping permanent breakpoint");
2316 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2317 /* Update pc to reflect the new address from which we will
2318 execute instructions. */
2319 pc
= regcache_read_pc (regcache
);
2323 /* We've already advanced the PC, so the stepping part
2324 is done. Now we need to arrange for a trap to be
2325 reported to handle_inferior_event. Set a breakpoint
2326 at the current PC, and run to it. Don't update
2327 prev_pc, because if we end in
2328 switch_back_to_stepped_thread, we want the "expected
2329 thread advanced also" branch to be taken. IOW, we
2330 don't want this thread to step further from PC
2332 gdb_assert (!step_over_info_valid_p ());
2333 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2334 insert_breakpoints ();
2336 resume_ptid
= internal_resume_ptid (user_step
);
2337 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2344 /* If we have a breakpoint to step over, make sure to do a single
2345 step only. Same if we have software watchpoints. */
2346 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2347 tp
->control
.may_range_step
= 0;
2349 /* If displaced stepping is enabled, step over breakpoints by executing a
2350 copy of the instruction at a different address.
2352 We can't use displaced stepping when we have a signal to deliver;
2353 the comments for displaced_step_prepare explain why. The
2354 comments in the handle_inferior event for dealing with 'random
2355 signals' explain what we do instead.
2357 We can't use displaced stepping when we are waiting for vfork_done
2358 event, displaced stepping breaks the vfork child similarly as single
2359 step software breakpoint. */
2360 if (tp
->control
.trap_expected
2361 && use_displaced_stepping (tp
)
2362 && !step_over_info_valid_p ()
2363 && sig
== GDB_SIGNAL_0
2364 && !current_inferior ()->waiting_for_vfork_done
)
2366 displaced_step_prepare_status prepare_status
2367 = displaced_step_prepare (tp
);
2369 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2371 infrun_debug_printf ("Got placed in step-over queue");
2373 tp
->control
.trap_expected
= 0;
2376 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
2378 /* Fallback to stepping over the breakpoint in-line. */
2380 if (target_is_non_stop_p ())
2381 stop_all_threads ();
2383 set_step_over_info (regcache
->aspace (),
2384 regcache_read_pc (regcache
), 0, tp
->global_num
);
2386 step
= maybe_software_singlestep (gdbarch
, pc
);
2388 insert_breakpoints ();
2390 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2392 /* Update pc to reflect the new address from which we will
2393 execute instructions due to displaced stepping. */
2394 pc
= regcache_read_pc (get_thread_regcache (tp
));
2396 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2399 gdb_assert_not_reached (_("Invalid displaced_step_prepare_status "
2403 /* Do we need to do it the hard way, w/temp breakpoints? */
2405 step
= maybe_software_singlestep (gdbarch
, pc
);
2407 /* Currently, our software single-step implementation leads to different
2408 results than hardware single-stepping in one situation: when stepping
2409 into delivering a signal which has an associated signal handler,
2410 hardware single-step will stop at the first instruction of the handler,
2411 while software single-step will simply skip execution of the handler.
2413 For now, this difference in behavior is accepted since there is no
2414 easy way to actually implement single-stepping into a signal handler
2415 without kernel support.
2417 However, there is one scenario where this difference leads to follow-on
2418 problems: if we're stepping off a breakpoint by removing all breakpoints
2419 and then single-stepping. In this case, the software single-step
2420 behavior means that even if there is a *breakpoint* in the signal
2421 handler, GDB still would not stop.
2423 Fortunately, we can at least fix this particular issue. We detect
2424 here the case where we are about to deliver a signal while software
2425 single-stepping with breakpoints removed. In this situation, we
2426 revert the decisions to remove all breakpoints and insert single-
2427 step breakpoints, and instead we install a step-resume breakpoint
2428 at the current address, deliver the signal without stepping, and
2429 once we arrive back at the step-resume breakpoint, actually step
2430 over the breakpoint we originally wanted to step over. */
2431 if (thread_has_single_step_breakpoints_set (tp
)
2432 && sig
!= GDB_SIGNAL_0
2433 && step_over_info_valid_p ())
2435 /* If we have nested signals or a pending signal is delivered
2436 immediately after a handler returns, might already have
2437 a step-resume breakpoint set on the earlier handler. We cannot
2438 set another step-resume breakpoint; just continue on until the
2439 original breakpoint is hit. */
2440 if (tp
->control
.step_resume_breakpoint
== NULL
)
2442 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2443 tp
->step_after_step_resume_breakpoint
= 1;
2446 delete_single_step_breakpoints (tp
);
2448 clear_step_over_info ();
2449 tp
->control
.trap_expected
= 0;
2451 insert_breakpoints ();
2454 /* If STEP is set, it's a request to use hardware stepping
2455 facilities. But in that case, we should never
2456 use singlestep breakpoint. */
2457 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2459 /* Decide the set of threads to ask the target to resume. */
2460 if (tp
->control
.trap_expected
)
2462 /* We're allowing a thread to run past a breakpoint it has
2463 hit, either by single-stepping the thread with the breakpoint
2464 removed, or by displaced stepping, with the breakpoint inserted.
2465 In the former case, we need to single-step only this thread,
2466 and keep others stopped, as they can miss this breakpoint if
2467 allowed to run. That's not really a problem for displaced
2468 stepping, but, we still keep other threads stopped, in case
2469 another thread is also stopped for a breakpoint waiting for
2470 its turn in the displaced stepping queue. */
2471 resume_ptid
= inferior_ptid
;
2474 resume_ptid
= internal_resume_ptid (user_step
);
2476 if (execution_direction
!= EXEC_REVERSE
2477 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2479 /* There are two cases where we currently need to step a
2480 breakpoint instruction when we have a signal to deliver:
2482 - See handle_signal_stop where we handle random signals that
2483 could take out us out of the stepping range. Normally, in
2484 that case we end up continuing (instead of stepping) over the
2485 signal handler with a breakpoint at PC, but there are cases
2486 where we should _always_ single-step, even if we have a
2487 step-resume breakpoint, like when a software watchpoint is
2488 set. Assuming single-stepping and delivering a signal at the
2489 same time would takes us to the signal handler, then we could
2490 have removed the breakpoint at PC to step over it. However,
2491 some hardware step targets (like e.g., Mac OS) can't step
2492 into signal handlers, and for those, we need to leave the
2493 breakpoint at PC inserted, as otherwise if the handler
2494 recurses and executes PC again, it'll miss the breakpoint.
2495 So we leave the breakpoint inserted anyway, but we need to
2496 record that we tried to step a breakpoint instruction, so
2497 that adjust_pc_after_break doesn't end up confused.
2499 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2500 in one thread after another thread that was stepping had been
2501 momentarily paused for a step-over. When we re-resume the
2502 stepping thread, it may be resumed from that address with a
2503 breakpoint that hasn't trapped yet. Seen with
2504 gdb.threads/non-stop-fair-events.exp, on targets that don't
2505 do displaced stepping. */
2507 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2508 target_pid_to_str (tp
->ptid
).c_str ());
2510 tp
->stepped_breakpoint
= 1;
2512 /* Most targets can step a breakpoint instruction, thus
2513 executing it normally. But if this one cannot, just
2514 continue and we will hit it anyway. */
2515 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2520 && tp
->control
.trap_expected
2521 && use_displaced_stepping (tp
)
2522 && !step_over_info_valid_p ())
2524 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2525 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2526 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2529 read_memory (actual_pc
, buf
, sizeof (buf
));
2530 displaced_debug_printf ("run %s: %s",
2531 paddress (resume_gdbarch
, actual_pc
),
2532 displaced_step_dump_bytes
2533 (buf
, sizeof (buf
)).c_str ());
2536 if (tp
->control
.may_range_step
)
2538 /* If we're resuming a thread with the PC out of the step
2539 range, then we're doing some nested/finer run control
2540 operation, like stepping the thread out of the dynamic
2541 linker or the displaced stepping scratch pad. We
2542 shouldn't have allowed a range step then. */
2543 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2546 do_target_resume (resume_ptid
, step
, sig
);
2550 /* Resume the inferior. SIG is the signal to give the inferior
2551 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2552 rolls back state on error. */
2555 resume (gdb_signal sig
)
2561 catch (const gdb_exception
&ex
)
2563 /* If resuming is being aborted for any reason, delete any
2564 single-step breakpoint resume_1 may have created, to avoid
2565 confusing the following resumption, and to avoid leaving
2566 single-step breakpoints perturbing other threads, in case
2567 we're running in non-stop mode. */
2568 if (inferior_ptid
!= null_ptid
)
2569 delete_single_step_breakpoints (inferior_thread ());
2579 /* Counter that tracks number of user visible stops. This can be used
2580 to tell whether a command has proceeded the inferior past the
2581 current location. This allows e.g., inferior function calls in
2582 breakpoint commands to not interrupt the command list. When the
2583 call finishes successfully, the inferior is standing at the same
2584 breakpoint as if nothing happened (and so we don't call
2586 static ULONGEST current_stop_id
;
2593 return current_stop_id
;
2596 /* Called when we report a user visible stop. */
2604 /* Clear out all variables saying what to do when inferior is continued.
2605 First do this, then set the ones you want, then call `proceed'. */
2608 clear_proceed_status_thread (struct thread_info
*tp
)
2610 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2612 /* If we're starting a new sequence, then the previous finished
2613 single-step is no longer relevant. */
2614 if (tp
->suspend
.waitstatus_pending_p
)
2616 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2618 infrun_debug_printf ("pending event of %s was a finished step. "
2620 target_pid_to_str (tp
->ptid
).c_str ());
2622 tp
->suspend
.waitstatus_pending_p
= 0;
2623 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2628 ("thread %s has pending wait status %s (currently_stepping=%d).",
2629 target_pid_to_str (tp
->ptid
).c_str (),
2630 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2631 currently_stepping (tp
));
2635 /* If this signal should not be seen by program, give it zero.
2636 Used for debugging signals. */
2637 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2638 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2640 delete tp
->thread_fsm
;
2641 tp
->thread_fsm
= NULL
;
2643 tp
->control
.trap_expected
= 0;
2644 tp
->control
.step_range_start
= 0;
2645 tp
->control
.step_range_end
= 0;
2646 tp
->control
.may_range_step
= 0;
2647 tp
->control
.step_frame_id
= null_frame_id
;
2648 tp
->control
.step_stack_frame_id
= null_frame_id
;
2649 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2650 tp
->control
.step_start_function
= NULL
;
2651 tp
->stop_requested
= 0;
2653 tp
->control
.stop_step
= 0;
2655 tp
->control
.proceed_to_finish
= 0;
2657 tp
->control
.stepping_command
= 0;
2659 /* Discard any remaining commands or status from previous stop. */
2660 bpstat_clear (&tp
->control
.stop_bpstat
);
2664 clear_proceed_status (int step
)
2666 /* With scheduler-locking replay, stop replaying other threads if we're
2667 not replaying the user-visible resume ptid.
2669 This is a convenience feature to not require the user to explicitly
2670 stop replaying the other threads. We're assuming that the user's
2671 intent is to resume tracing the recorded process. */
2672 if (!non_stop
&& scheduler_mode
== schedlock_replay
2673 && target_record_is_replaying (minus_one_ptid
)
2674 && !target_record_will_replay (user_visible_resume_ptid (step
),
2675 execution_direction
))
2676 target_record_stop_replaying ();
2678 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2680 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2681 process_stratum_target
*resume_target
2682 = user_visible_resume_target (resume_ptid
);
2684 /* In all-stop mode, delete the per-thread status of all threads
2685 we're about to resume, implicitly and explicitly. */
2686 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2687 clear_proceed_status_thread (tp
);
2690 if (inferior_ptid
!= null_ptid
)
2692 struct inferior
*inferior
;
2696 /* If in non-stop mode, only delete the per-thread status of
2697 the current thread. */
2698 clear_proceed_status_thread (inferior_thread ());
2701 inferior
= current_inferior ();
2702 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2705 gdb::observers::about_to_proceed
.notify ();
2708 /* Returns true if TP is still stopped at a breakpoint that needs
2709 stepping-over in order to make progress. If the breakpoint is gone
2710 meanwhile, we can skip the whole step-over dance. */
2713 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2715 if (tp
->stepping_over_breakpoint
)
2717 struct regcache
*regcache
= get_thread_regcache (tp
);
2719 if (breakpoint_here_p (regcache
->aspace (),
2720 regcache_read_pc (regcache
))
2721 == ordinary_breakpoint_here
)
2724 tp
->stepping_over_breakpoint
= 0;
2730 /* Check whether thread TP still needs to start a step-over in order
2731 to make progress when resumed. Returns an bitwise or of enum
2732 step_over_what bits, indicating what needs to be stepped over. */
2734 static step_over_what
2735 thread_still_needs_step_over (struct thread_info
*tp
)
2737 step_over_what what
= 0;
2739 if (thread_still_needs_step_over_bp (tp
))
2740 what
|= STEP_OVER_BREAKPOINT
;
2742 if (tp
->stepping_over_watchpoint
2743 && !target_have_steppable_watchpoint ())
2744 what
|= STEP_OVER_WATCHPOINT
;
2749 /* Returns true if scheduler locking applies. STEP indicates whether
2750 we're about to do a step/next-like command to a thread. */
2753 schedlock_applies (struct thread_info
*tp
)
2755 return (scheduler_mode
== schedlock_on
2756 || (scheduler_mode
== schedlock_step
2757 && tp
->control
.stepping_command
)
2758 || (scheduler_mode
== schedlock_replay
2759 && target_record_will_replay (minus_one_ptid
,
2760 execution_direction
)));
2763 /* Calls target_commit_resume on all targets. */
2766 commit_resume_all_targets ()
2768 scoped_restore_current_thread restore_thread
;
2770 /* Map between process_target and a representative inferior. This
2771 is to avoid committing a resume in the same target more than
2772 once. Resumptions must be idempotent, so this is an
2774 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2776 for (inferior
*inf
: all_non_exited_inferiors ())
2777 if (inf
->has_execution ())
2778 conn_inf
[inf
->process_target ()] = inf
;
2780 for (const auto &ci
: conn_inf
)
2782 inferior
*inf
= ci
.second
;
2783 switch_to_inferior_no_thread (inf
);
2784 target_commit_resume ();
2788 /* Check that all the targets we're about to resume are in non-stop
2789 mode. Ideally, we'd only care whether all targets support
2790 target-async, but we're not there yet. E.g., stop_all_threads
2791 doesn't know how to handle all-stop targets. Also, the remote
2792 protocol in all-stop mode is synchronous, irrespective of
2793 target-async, which means that things like a breakpoint re-set
2794 triggered by one target would try to read memory from all targets
2798 check_multi_target_resumption (process_stratum_target
*resume_target
)
2800 if (!non_stop
&& resume_target
== nullptr)
2802 scoped_restore_current_thread restore_thread
;
2804 /* This is used to track whether we're resuming more than one
2806 process_stratum_target
*first_connection
= nullptr;
2808 /* The first inferior we see with a target that does not work in
2809 always-non-stop mode. */
2810 inferior
*first_not_non_stop
= nullptr;
2812 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2814 switch_to_inferior_no_thread (inf
);
2816 if (!target_has_execution ())
2819 process_stratum_target
*proc_target
2820 = current_inferior ()->process_target();
2822 if (!target_is_non_stop_p ())
2823 first_not_non_stop
= inf
;
2825 if (first_connection
== nullptr)
2826 first_connection
= proc_target
;
2827 else if (first_connection
!= proc_target
2828 && first_not_non_stop
!= nullptr)
2830 switch_to_inferior_no_thread (first_not_non_stop
);
2832 proc_target
= current_inferior ()->process_target();
2834 error (_("Connection %d (%s) does not support "
2835 "multi-target resumption."),
2836 proc_target
->connection_number
,
2837 make_target_connection_string (proc_target
).c_str ());
2843 /* Basic routine for continuing the program in various fashions.
2845 ADDR is the address to resume at, or -1 for resume where stopped.
2846 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2847 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2849 You should call clear_proceed_status before calling proceed. */
2852 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2854 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
2856 struct regcache
*regcache
;
2857 struct gdbarch
*gdbarch
;
2859 struct execution_control_state ecss
;
2860 struct execution_control_state
*ecs
= &ecss
;
2863 /* If we're stopped at a fork/vfork, follow the branch set by the
2864 "set follow-fork-mode" command; otherwise, we'll just proceed
2865 resuming the current thread. */
2866 if (!follow_fork ())
2868 /* The target for some reason decided not to resume. */
2870 if (target_can_async_p ())
2871 inferior_event_handler (INF_EXEC_COMPLETE
);
2875 /* We'll update this if & when we switch to a new thread. */
2876 previous_inferior_ptid
= inferior_ptid
;
2878 regcache
= get_current_regcache ();
2879 gdbarch
= regcache
->arch ();
2880 const address_space
*aspace
= regcache
->aspace ();
2882 pc
= regcache_read_pc_protected (regcache
);
2884 thread_info
*cur_thr
= inferior_thread ();
2886 /* Fill in with reasonable starting values. */
2887 init_thread_stepping_state (cur_thr
);
2889 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2892 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2893 process_stratum_target
*resume_target
2894 = user_visible_resume_target (resume_ptid
);
2896 check_multi_target_resumption (resume_target
);
2898 if (addr
== (CORE_ADDR
) -1)
2900 if (pc
== cur_thr
->suspend
.stop_pc
2901 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2902 && execution_direction
!= EXEC_REVERSE
)
2903 /* There is a breakpoint at the address we will resume at,
2904 step one instruction before inserting breakpoints so that
2905 we do not stop right away (and report a second hit at this
2908 Note, we don't do this in reverse, because we won't
2909 actually be executing the breakpoint insn anyway.
2910 We'll be (un-)executing the previous instruction. */
2911 cur_thr
->stepping_over_breakpoint
= 1;
2912 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2913 && gdbarch_single_step_through_delay (gdbarch
,
2914 get_current_frame ()))
2915 /* We stepped onto an instruction that needs to be stepped
2916 again before re-inserting the breakpoint, do so. */
2917 cur_thr
->stepping_over_breakpoint
= 1;
2921 regcache_write_pc (regcache
, addr
);
2924 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2925 cur_thr
->suspend
.stop_signal
= siggnal
;
2927 /* If an exception is thrown from this point on, make sure to
2928 propagate GDB's knowledge of the executing state to the
2929 frontend/user running state. */
2930 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2932 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2933 threads (e.g., we might need to set threads stepping over
2934 breakpoints first), from the user/frontend's point of view, all
2935 threads in RESUME_PTID are now running. Unless we're calling an
2936 inferior function, as in that case we pretend the inferior
2937 doesn't run at all. */
2938 if (!cur_thr
->control
.in_infcall
)
2939 set_running (resume_target
, resume_ptid
, true);
2941 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2942 gdb_signal_to_symbol_string (siggnal
));
2944 annotate_starting ();
2946 /* Make sure that output from GDB appears before output from the
2948 gdb_flush (gdb_stdout
);
2950 /* Since we've marked the inferior running, give it the terminal. A
2951 QUIT/Ctrl-C from here on is forwarded to the target (which can
2952 still detect attempts to unblock a stuck connection with repeated
2953 Ctrl-C from within target_pass_ctrlc). */
2954 target_terminal::inferior ();
2956 /* In a multi-threaded task we may select another thread and
2957 then continue or step.
2959 But if a thread that we're resuming had stopped at a breakpoint,
2960 it will immediately cause another breakpoint stop without any
2961 execution (i.e. it will report a breakpoint hit incorrectly). So
2962 we must step over it first.
2964 Look for threads other than the current (TP) that reported a
2965 breakpoint hit and haven't been resumed yet since. */
2967 /* If scheduler locking applies, we can avoid iterating over all
2969 if (!non_stop
&& !schedlock_applies (cur_thr
))
2971 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
2974 switch_to_thread_no_regs (tp
);
2976 /* Ignore the current thread here. It's handled
2981 if (!thread_still_needs_step_over (tp
))
2984 gdb_assert (!thread_is_in_step_over_chain (tp
));
2986 infrun_debug_printf ("need to step-over [%s] first",
2987 target_pid_to_str (tp
->ptid
).c_str ());
2989 global_thread_step_over_chain_enqueue (tp
);
2992 switch_to_thread (cur_thr
);
2995 /* Enqueue the current thread last, so that we move all other
2996 threads over their breakpoints first. */
2997 if (cur_thr
->stepping_over_breakpoint
)
2998 global_thread_step_over_chain_enqueue (cur_thr
);
3000 /* If the thread isn't started, we'll still need to set its prev_pc,
3001 so that switch_back_to_stepped_thread knows the thread hasn't
3002 advanced. Must do this before resuming any thread, as in
3003 all-stop/remote, once we resume we can't send any other packet
3004 until the target stops again. */
3005 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3008 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3010 started
= start_step_over ();
3012 if (step_over_info_valid_p ())
3014 /* Either this thread started a new in-line step over, or some
3015 other thread was already doing one. In either case, don't
3016 resume anything else until the step-over is finished. */
3018 else if (started
&& !target_is_non_stop_p ())
3020 /* A new displaced stepping sequence was started. In all-stop,
3021 we can't talk to the target anymore until it next stops. */
3023 else if (!non_stop
&& target_is_non_stop_p ())
3025 INFRUN_SCOPED_DEBUG_START_END
3026 ("resuming threads, all-stop-on-top-of-non-stop");
3028 /* In all-stop, but the target is always in non-stop mode.
3029 Start all other threads that are implicitly resumed too. */
3030 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3033 switch_to_thread_no_regs (tp
);
3035 if (!tp
->inf
->has_execution ())
3037 infrun_debug_printf ("[%s] target has no execution",
3038 target_pid_to_str (tp
->ptid
).c_str ());
3044 infrun_debug_printf ("[%s] resumed",
3045 target_pid_to_str (tp
->ptid
).c_str ());
3046 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3050 if (thread_is_in_step_over_chain (tp
))
3052 infrun_debug_printf ("[%s] needs step-over",
3053 target_pid_to_str (tp
->ptid
).c_str ());
3057 infrun_debug_printf ("resuming %s",
3058 target_pid_to_str (tp
->ptid
).c_str ());
3060 reset_ecs (ecs
, tp
);
3061 switch_to_thread (tp
);
3062 keep_going_pass_signal (ecs
);
3063 if (!ecs
->wait_some_more
)
3064 error (_("Command aborted."));
3067 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3069 /* The thread wasn't started, and isn't queued, run it now. */
3070 reset_ecs (ecs
, cur_thr
);
3071 switch_to_thread (cur_thr
);
3072 keep_going_pass_signal (ecs
);
3073 if (!ecs
->wait_some_more
)
3074 error (_("Command aborted."));
3078 commit_resume_all_targets ();
3080 finish_state
.release ();
3082 /* If we've switched threads above, switch back to the previously
3083 current thread. We don't want the user to see a different
3085 switch_to_thread (cur_thr
);
3087 /* Tell the event loop to wait for it to stop. If the target
3088 supports asynchronous execution, it'll do this from within
3090 if (!target_can_async_p ())
3091 mark_async_event_handler (infrun_async_inferior_event_token
);
3095 /* Start remote-debugging of a machine over a serial link. */
3098 start_remote (int from_tty
)
3100 inferior
*inf
= current_inferior ();
3101 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3103 /* Always go on waiting for the target, regardless of the mode. */
3104 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3105 indicate to wait_for_inferior that a target should timeout if
3106 nothing is returned (instead of just blocking). Because of this,
3107 targets expecting an immediate response need to, internally, set
3108 things up so that the target_wait() is forced to eventually
3110 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3111 differentiate to its caller what the state of the target is after
3112 the initial open has been performed. Here we're assuming that
3113 the target has stopped. It should be possible to eventually have
3114 target_open() return to the caller an indication that the target
3115 is currently running and GDB state should be set to the same as
3116 for an async run. */
3117 wait_for_inferior (inf
);
3119 /* Now that the inferior has stopped, do any bookkeeping like
3120 loading shared libraries. We want to do this before normal_stop,
3121 so that the displayed frame is up to date. */
3122 post_create_inferior (from_tty
);
3127 /* Initialize static vars when a new inferior begins. */
3130 init_wait_for_inferior (void)
3132 /* These are meaningless until the first time through wait_for_inferior. */
3134 breakpoint_init_inferior (inf_starting
);
3136 clear_proceed_status (0);
3138 nullify_last_target_wait_ptid ();
3140 previous_inferior_ptid
= inferior_ptid
;
3145 static void handle_inferior_event (struct execution_control_state
*ecs
);
3147 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3148 struct execution_control_state
*ecs
);
3149 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3150 struct execution_control_state
*ecs
);
3151 static void handle_signal_stop (struct execution_control_state
*ecs
);
3152 static void check_exception_resume (struct execution_control_state
*,
3153 struct frame_info
*);
3155 static void end_stepping_range (struct execution_control_state
*ecs
);
3156 static void stop_waiting (struct execution_control_state
*ecs
);
3157 static void keep_going (struct execution_control_state
*ecs
);
3158 static void process_event_stop_test (struct execution_control_state
*ecs
);
3159 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3161 /* This function is attached as a "thread_stop_requested" observer.
3162 Cleanup local state that assumed the PTID was to be resumed, and
3163 report the stop to the frontend. */
3166 infrun_thread_stop_requested (ptid_t ptid
)
3168 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3170 /* PTID was requested to stop. If the thread was already stopped,
3171 but the user/frontend doesn't know about that yet (e.g., the
3172 thread had been temporarily paused for some step-over), set up
3173 for reporting the stop now. */
3174 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3176 if (tp
->state
!= THREAD_RUNNING
)
3181 /* Remove matching threads from the step-over queue, so
3182 start_step_over doesn't try to resume them
3184 if (thread_is_in_step_over_chain (tp
))
3185 global_thread_step_over_chain_remove (tp
);
3187 /* If the thread is stopped, but the user/frontend doesn't
3188 know about that yet, queue a pending event, as if the
3189 thread had just stopped now. Unless the thread already had
3191 if (!tp
->suspend
.waitstatus_pending_p
)
3193 tp
->suspend
.waitstatus_pending_p
= 1;
3194 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3195 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3198 /* Clear the inline-frame state, since we're re-processing the
3200 clear_inline_frame_state (tp
);
3202 /* If this thread was paused because some other thread was
3203 doing an inline-step over, let that finish first. Once
3204 that happens, we'll restart all threads and consume pending
3205 stop events then. */
3206 if (step_over_info_valid_p ())
3209 /* Otherwise we can process the (new) pending event now. Set
3210 it so this pending event is considered by
3217 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3219 if (target_last_proc_target
== tp
->inf
->process_target ()
3220 && target_last_wait_ptid
== tp
->ptid
)
3221 nullify_last_target_wait_ptid ();
3224 /* Delete the step resume, single-step and longjmp/exception resume
3225 breakpoints of TP. */
3228 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3230 delete_step_resume_breakpoint (tp
);
3231 delete_exception_resume_breakpoint (tp
);
3232 delete_single_step_breakpoints (tp
);
3235 /* If the target still has execution, call FUNC for each thread that
3236 just stopped. In all-stop, that's all the non-exited threads; in
3237 non-stop, that's the current thread, only. */
3239 typedef void (*for_each_just_stopped_thread_callback_func
)
3240 (struct thread_info
*tp
);
3243 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3245 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3248 if (target_is_non_stop_p ())
3250 /* If in non-stop mode, only the current thread stopped. */
3251 func (inferior_thread ());
3255 /* In all-stop mode, all threads have stopped. */
3256 for (thread_info
*tp
: all_non_exited_threads ())
3261 /* Delete the step resume and longjmp/exception resume breakpoints of
3262 the threads that just stopped. */
3265 delete_just_stopped_threads_infrun_breakpoints (void)
3267 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3270 /* Delete the single-step breakpoints of the threads that just
3274 delete_just_stopped_threads_single_step_breakpoints (void)
3276 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3282 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3283 const struct target_waitstatus
*ws
)
3285 infrun_debug_printf ("target_wait (%d.%ld.%ld [%s], status) =",
3289 target_pid_to_str (waiton_ptid
).c_str ());
3290 infrun_debug_printf (" %d.%ld.%ld [%s],",
3294 target_pid_to_str (result_ptid
).c_str ());
3295 infrun_debug_printf (" %s", target_waitstatus_to_string (ws
).c_str ());
3298 /* Select a thread at random, out of those which are resumed and have
3301 static struct thread_info
*
3302 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3306 auto has_event
= [&] (thread_info
*tp
)
3308 return (tp
->ptid
.matches (waiton_ptid
)
3310 && tp
->suspend
.waitstatus_pending_p
);
3313 /* First see how many events we have. Count only resumed threads
3314 that have an event pending. */
3315 for (thread_info
*tp
: inf
->non_exited_threads ())
3319 if (num_events
== 0)
3322 /* Now randomly pick a thread out of those that have had events. */
3323 int random_selector
= (int) ((num_events
* (double) rand ())
3324 / (RAND_MAX
+ 1.0));
3327 infrun_debug_printf ("Found %d events, selecting #%d",
3328 num_events
, random_selector
);
3330 /* Select the Nth thread that has had an event. */
3331 for (thread_info
*tp
: inf
->non_exited_threads ())
3333 if (random_selector
-- == 0)
3336 gdb_assert_not_reached ("event thread not found");
3339 /* Wrapper for target_wait that first checks whether threads have
3340 pending statuses to report before actually asking the target for
3341 more events. INF is the inferior we're using to call target_wait
3345 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3346 target_waitstatus
*status
, target_wait_flags options
)
3349 struct thread_info
*tp
;
3351 /* We know that we are looking for an event in the target of inferior
3352 INF, but we don't know which thread the event might come from. As
3353 such we want to make sure that INFERIOR_PTID is reset so that none of
3354 the wait code relies on it - doing so is always a mistake. */
3355 switch_to_inferior_no_thread (inf
);
3357 /* First check if there is a resumed thread with a wait status
3359 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3361 tp
= random_pending_event_thread (inf
, ptid
);
3365 infrun_debug_printf ("Waiting for specific thread %s.",
3366 target_pid_to_str (ptid
).c_str ());
3368 /* We have a specific thread to check. */
3369 tp
= find_thread_ptid (inf
, ptid
);
3370 gdb_assert (tp
!= NULL
);
3371 if (!tp
->suspend
.waitstatus_pending_p
)
3376 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3377 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3379 struct regcache
*regcache
= get_thread_regcache (tp
);
3380 struct gdbarch
*gdbarch
= regcache
->arch ();
3384 pc
= regcache_read_pc (regcache
);
3386 if (pc
!= tp
->suspend
.stop_pc
)
3388 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3389 target_pid_to_str (tp
->ptid
).c_str (),
3390 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3391 paddress (gdbarch
, pc
));
3394 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3396 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3397 target_pid_to_str (tp
->ptid
).c_str (),
3398 paddress (gdbarch
, pc
));
3405 infrun_debug_printf ("pending event of %s cancelled.",
3406 target_pid_to_str (tp
->ptid
).c_str ());
3408 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3409 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3415 infrun_debug_printf ("Using pending wait status %s for %s.",
3416 target_waitstatus_to_string
3417 (&tp
->suspend
.waitstatus
).c_str (),
3418 target_pid_to_str (tp
->ptid
).c_str ());
3420 /* Now that we've selected our final event LWP, un-adjust its PC
3421 if it was a software breakpoint (and the target doesn't
3422 always adjust the PC itself). */
3423 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3424 && !target_supports_stopped_by_sw_breakpoint ())
3426 struct regcache
*regcache
;
3427 struct gdbarch
*gdbarch
;
3430 regcache
= get_thread_regcache (tp
);
3431 gdbarch
= regcache
->arch ();
3433 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3438 pc
= regcache_read_pc (regcache
);
3439 regcache_write_pc (regcache
, pc
+ decr_pc
);
3443 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3444 *status
= tp
->suspend
.waitstatus
;
3445 tp
->suspend
.waitstatus_pending_p
= 0;
3447 /* Wake up the event loop again, until all pending events are
3449 if (target_is_async_p ())
3450 mark_async_event_handler (infrun_async_inferior_event_token
);
3454 /* But if we don't find one, we'll have to wait. */
3456 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3458 if (!target_can_async_p ())
3459 options
&= ~TARGET_WNOHANG
;
3461 if (deprecated_target_wait_hook
)
3462 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3464 event_ptid
= target_wait (ptid
, status
, options
);
3469 /* Wrapper for target_wait that first checks whether threads have
3470 pending statuses to report before actually asking the target for
3471 more events. Polls for events from all inferiors/targets. */
3474 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3475 target_wait_flags options
)
3477 int num_inferiors
= 0;
3478 int random_selector
;
3480 /* For fairness, we pick the first inferior/target to poll at random
3481 out of all inferiors that may report events, and then continue
3482 polling the rest of the inferior list starting from that one in a
3483 circular fashion until the whole list is polled once. */
3485 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3487 return (inf
->process_target () != NULL
3488 && ptid_t (inf
->pid
).matches (wait_ptid
));
3491 /* First see how many matching inferiors we have. */
3492 for (inferior
*inf
: all_inferiors ())
3493 if (inferior_matches (inf
))
3496 if (num_inferiors
== 0)
3498 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3502 /* Now randomly pick an inferior out of those that matched. */
3503 random_selector
= (int)
3504 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3506 if (num_inferiors
> 1)
3507 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3508 num_inferiors
, random_selector
);
3510 /* Select the Nth inferior that matched. */
3512 inferior
*selected
= nullptr;
3514 for (inferior
*inf
: all_inferiors ())
3515 if (inferior_matches (inf
))
3516 if (random_selector
-- == 0)
3522 /* Now poll for events out of each of the matching inferior's
3523 targets, starting from the selected one. */
3525 auto do_wait
= [&] (inferior
*inf
)
3527 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3528 ecs
->target
= inf
->process_target ();
3529 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3532 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3533 here spuriously after the target is all stopped and we've already
3534 reported the stop to the user, polling for events. */
3535 scoped_restore_current_thread restore_thread
;
3537 int inf_num
= selected
->num
;
3538 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3539 if (inferior_matches (inf
))
3543 for (inferior
*inf
= inferior_list
;
3544 inf
!= NULL
&& inf
->num
< inf_num
;
3546 if (inferior_matches (inf
))
3550 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3554 /* Prepare and stabilize the inferior for detaching it. E.g.,
3555 detaching while a thread is displaced stepping is a recipe for
3556 crashing it, as nothing would readjust the PC out of the scratch
3560 prepare_for_detach (void)
3562 struct inferior
*inf
= current_inferior ();
3563 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3565 /* Is any thread of this process displaced stepping? If not,
3566 there's nothing else to do. */
3567 if (displaced_step_in_progress (inf
))
3570 infrun_debug_printf ("displaced-stepping in-process while detaching");
3572 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3574 while (displaced_step_in_progress (inf
))
3576 struct execution_control_state ecss
;
3577 struct execution_control_state
*ecs
;
3580 memset (ecs
, 0, sizeof (*ecs
));
3582 overlay_cache_invalid
= 1;
3583 /* Flush target cache before starting to handle each event.
3584 Target was running and cache could be stale. This is just a
3585 heuristic. Running threads may modify target memory, but we
3586 don't get any event. */
3587 target_dcache_invalidate ();
3589 do_target_wait (pid_ptid
, ecs
, 0);
3592 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3594 /* If an error happens while handling the event, propagate GDB's
3595 knowledge of the executing state to the frontend/user running
3597 scoped_finish_thread_state
finish_state (inf
->process_target (),
3600 /* Now figure out what to do with the result of the result. */
3601 handle_inferior_event (ecs
);
3603 /* No error, don't finish the state yet. */
3604 finish_state
.release ();
3606 /* Breakpoints and watchpoints are not installed on the target
3607 at this point, and signals are passed directly to the
3608 inferior, so this must mean the process is gone. */
3609 if (!ecs
->wait_some_more
)
3611 restore_detaching
.release ();
3612 error (_("Program exited while detaching"));
3616 restore_detaching
.release ();
3619 /* Wait for control to return from inferior to debugger.
3621 If inferior gets a signal, we may decide to start it up again
3622 instead of returning. That is why there is a loop in this function.
3623 When this function actually returns it means the inferior
3624 should be left stopped and GDB should read more commands. */
3627 wait_for_inferior (inferior
*inf
)
3629 infrun_debug_printf ("wait_for_inferior ()");
3631 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3633 /* If an error happens while handling the event, propagate GDB's
3634 knowledge of the executing state to the frontend/user running
3636 scoped_finish_thread_state finish_state
3637 (inf
->process_target (), minus_one_ptid
);
3641 struct execution_control_state ecss
;
3642 struct execution_control_state
*ecs
= &ecss
;
3644 memset (ecs
, 0, sizeof (*ecs
));
3646 overlay_cache_invalid
= 1;
3648 /* Flush target cache before starting to handle each event.
3649 Target was running and cache could be stale. This is just a
3650 heuristic. Running threads may modify target memory, but we
3651 don't get any event. */
3652 target_dcache_invalidate ();
3654 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3655 ecs
->target
= inf
->process_target ();
3658 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3660 /* Now figure out what to do with the result of the result. */
3661 handle_inferior_event (ecs
);
3663 if (!ecs
->wait_some_more
)
3667 /* No error, don't finish the state yet. */
3668 finish_state
.release ();
3671 /* Cleanup that reinstalls the readline callback handler, if the
3672 target is running in the background. If while handling the target
3673 event something triggered a secondary prompt, like e.g., a
3674 pagination prompt, we'll have removed the callback handler (see
3675 gdb_readline_wrapper_line). Need to do this as we go back to the
3676 event loop, ready to process further input. Note this has no
3677 effect if the handler hasn't actually been removed, because calling
3678 rl_callback_handler_install resets the line buffer, thus losing
3682 reinstall_readline_callback_handler_cleanup ()
3684 struct ui
*ui
= current_ui
;
3688 /* We're not going back to the top level event loop yet. Don't
3689 install the readline callback, as it'd prep the terminal,
3690 readline-style (raw, noecho) (e.g., --batch). We'll install
3691 it the next time the prompt is displayed, when we're ready
3696 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3697 gdb_rl_callback_handler_reinstall ();
3700 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3701 that's just the event thread. In all-stop, that's all threads. */
3704 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3706 if (ecs
->event_thread
!= NULL
3707 && ecs
->event_thread
->thread_fsm
!= NULL
)
3708 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3712 for (thread_info
*thr
: all_non_exited_threads ())
3714 if (thr
->thread_fsm
== NULL
)
3716 if (thr
== ecs
->event_thread
)
3719 switch_to_thread (thr
);
3720 thr
->thread_fsm
->clean_up (thr
);
3723 if (ecs
->event_thread
!= NULL
)
3724 switch_to_thread (ecs
->event_thread
);
3728 /* Helper for all_uis_check_sync_execution_done that works on the
3732 check_curr_ui_sync_execution_done (void)
3734 struct ui
*ui
= current_ui
;
3736 if (ui
->prompt_state
== PROMPT_NEEDED
3738 && !gdb_in_secondary_prompt_p (ui
))
3740 target_terminal::ours ();
3741 gdb::observers::sync_execution_done
.notify ();
3742 ui_register_input_event_handler (ui
);
3749 all_uis_check_sync_execution_done (void)
3751 SWITCH_THRU_ALL_UIS ()
3753 check_curr_ui_sync_execution_done ();
3760 all_uis_on_sync_execution_starting (void)
3762 SWITCH_THRU_ALL_UIS ()
3764 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3765 async_disable_stdin ();
3769 /* Asynchronous version of wait_for_inferior. It is called by the
3770 event loop whenever a change of state is detected on the file
3771 descriptor corresponding to the target. It can be called more than
3772 once to complete a single execution command. In such cases we need
3773 to keep the state in a global variable ECSS. If it is the last time
3774 that this function is called for a single execution command, then
3775 report to the user that the inferior has stopped, and do the
3776 necessary cleanups. */
3779 fetch_inferior_event ()
3781 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
3783 struct execution_control_state ecss
;
3784 struct execution_control_state
*ecs
= &ecss
;
3787 memset (ecs
, 0, sizeof (*ecs
));
3789 /* Events are always processed with the main UI as current UI. This
3790 way, warnings, debug output, etc. are always consistently sent to
3791 the main console. */
3792 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3794 /* Temporarily disable pagination. Otherwise, the user would be
3795 given an option to press 'q' to quit, which would cause an early
3796 exit and could leave GDB in a half-baked state. */
3797 scoped_restore save_pagination
3798 = make_scoped_restore (&pagination_enabled
, false);
3800 /* End up with readline processing input, if necessary. */
3802 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3804 /* We're handling a live event, so make sure we're doing live
3805 debugging. If we're looking at traceframes while the target is
3806 running, we're going to need to get back to that mode after
3807 handling the event. */
3808 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3811 maybe_restore_traceframe
.emplace ();
3812 set_current_traceframe (-1);
3815 /* The user/frontend should not notice a thread switch due to
3816 internal events. Make sure we revert to the user selected
3817 thread and frame after handling the event and running any
3818 breakpoint commands. */
3819 scoped_restore_current_thread restore_thread
;
3821 overlay_cache_invalid
= 1;
3822 /* Flush target cache before starting to handle each event. Target
3823 was running and cache could be stale. This is just a heuristic.
3824 Running threads may modify target memory, but we don't get any
3826 target_dcache_invalidate ();
3828 scoped_restore save_exec_dir
3829 = make_scoped_restore (&execution_direction
,
3830 target_execution_direction ());
3832 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3835 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3837 /* Switch to the target that generated the event, so we can do
3839 switch_to_target_no_thread (ecs
->target
);
3842 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3844 /* If an error happens while handling the event, propagate GDB's
3845 knowledge of the executing state to the frontend/user running
3847 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3848 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3850 /* Get executed before scoped_restore_current_thread above to apply
3851 still for the thread which has thrown the exception. */
3852 auto defer_bpstat_clear
3853 = make_scope_exit (bpstat_clear_actions
);
3854 auto defer_delete_threads
3855 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3857 /* Now figure out what to do with the result of the result. */
3858 handle_inferior_event (ecs
);
3860 if (!ecs
->wait_some_more
)
3862 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3863 bool should_stop
= true;
3864 struct thread_info
*thr
= ecs
->event_thread
;
3866 delete_just_stopped_threads_infrun_breakpoints ();
3870 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3872 if (thread_fsm
!= NULL
)
3873 should_stop
= thread_fsm
->should_stop (thr
);
3882 bool should_notify_stop
= true;
3885 clean_up_just_stopped_threads_fsms (ecs
);
3887 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3888 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3890 if (should_notify_stop
)
3892 /* We may not find an inferior if this was a process exit. */
3893 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3894 proceeded
= normal_stop ();
3899 inferior_event_handler (INF_EXEC_COMPLETE
);
3903 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3904 previously selected thread is gone. We have two
3905 choices - switch to no thread selected, or restore the
3906 previously selected thread (now exited). We chose the
3907 later, just because that's what GDB used to do. After
3908 this, "info threads" says "The current thread <Thread
3909 ID 2> has terminated." instead of "No thread
3913 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3914 restore_thread
.dont_restore ();
3918 defer_delete_threads
.release ();
3919 defer_bpstat_clear
.release ();
3921 /* No error, don't finish the thread states yet. */
3922 finish_state
.release ();
3924 /* This scope is used to ensure that readline callbacks are
3925 reinstalled here. */
3928 /* If a UI was in sync execution mode, and now isn't, restore its
3929 prompt (a synchronous execution command has finished, and we're
3930 ready for input). */
3931 all_uis_check_sync_execution_done ();
3934 && exec_done_display_p
3935 && (inferior_ptid
== null_ptid
3936 || inferior_thread ()->state
!= THREAD_RUNNING
))
3937 printf_unfiltered (_("completed.\n"));
3943 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
3944 struct symtab_and_line sal
)
3946 /* This can be removed once this function no longer implicitly relies on the
3947 inferior_ptid value. */
3948 gdb_assert (inferior_ptid
== tp
->ptid
);
3950 tp
->control
.step_frame_id
= get_frame_id (frame
);
3951 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3953 tp
->current_symtab
= sal
.symtab
;
3954 tp
->current_line
= sal
.line
;
3957 /* Clear context switchable stepping state. */
3960 init_thread_stepping_state (struct thread_info
*tss
)
3962 tss
->stepped_breakpoint
= 0;
3963 tss
->stepping_over_breakpoint
= 0;
3964 tss
->stepping_over_watchpoint
= 0;
3965 tss
->step_after_step_resume_breakpoint
= 0;
3971 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
3972 target_waitstatus status
)
3974 target_last_proc_target
= target
;
3975 target_last_wait_ptid
= ptid
;
3976 target_last_waitstatus
= status
;
3982 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
3983 target_waitstatus
*status
)
3985 if (target
!= nullptr)
3986 *target
= target_last_proc_target
;
3987 if (ptid
!= nullptr)
3988 *ptid
= target_last_wait_ptid
;
3989 if (status
!= nullptr)
3990 *status
= target_last_waitstatus
;
3996 nullify_last_target_wait_ptid (void)
3998 target_last_proc_target
= nullptr;
3999 target_last_wait_ptid
= minus_one_ptid
;
4000 target_last_waitstatus
= {};
4003 /* Switch thread contexts. */
4006 context_switch (execution_control_state
*ecs
)
4008 if (ecs
->ptid
!= inferior_ptid
4009 && (inferior_ptid
== null_ptid
4010 || ecs
->event_thread
!= inferior_thread ()))
4012 infrun_debug_printf ("Switching context from %s to %s",
4013 target_pid_to_str (inferior_ptid
).c_str (),
4014 target_pid_to_str (ecs
->ptid
).c_str ());
4017 switch_to_thread (ecs
->event_thread
);
4020 /* If the target can't tell whether we've hit breakpoints
4021 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4022 check whether that could have been caused by a breakpoint. If so,
4023 adjust the PC, per gdbarch_decr_pc_after_break. */
4026 adjust_pc_after_break (struct thread_info
*thread
,
4027 struct target_waitstatus
*ws
)
4029 struct regcache
*regcache
;
4030 struct gdbarch
*gdbarch
;
4031 CORE_ADDR breakpoint_pc
, decr_pc
;
4033 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4034 we aren't, just return.
4036 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4037 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4038 implemented by software breakpoints should be handled through the normal
4041 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4042 different signals (SIGILL or SIGEMT for instance), but it is less
4043 clear where the PC is pointing afterwards. It may not match
4044 gdbarch_decr_pc_after_break. I don't know any specific target that
4045 generates these signals at breakpoints (the code has been in GDB since at
4046 least 1992) so I can not guess how to handle them here.
4048 In earlier versions of GDB, a target with
4049 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4050 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4051 target with both of these set in GDB history, and it seems unlikely to be
4052 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4054 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4057 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4060 /* In reverse execution, when a breakpoint is hit, the instruction
4061 under it has already been de-executed. The reported PC always
4062 points at the breakpoint address, so adjusting it further would
4063 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4066 B1 0x08000000 : INSN1
4067 B2 0x08000001 : INSN2
4069 PC -> 0x08000003 : INSN4
4071 Say you're stopped at 0x08000003 as above. Reverse continuing
4072 from that point should hit B2 as below. Reading the PC when the
4073 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4074 been de-executed already.
4076 B1 0x08000000 : INSN1
4077 B2 PC -> 0x08000001 : INSN2
4081 We can't apply the same logic as for forward execution, because
4082 we would wrongly adjust the PC to 0x08000000, since there's a
4083 breakpoint at PC - 1. We'd then report a hit on B1, although
4084 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4086 if (execution_direction
== EXEC_REVERSE
)
4089 /* If the target can tell whether the thread hit a SW breakpoint,
4090 trust it. Targets that can tell also adjust the PC
4092 if (target_supports_stopped_by_sw_breakpoint ())
4095 /* Note that relying on whether a breakpoint is planted in memory to
4096 determine this can fail. E.g,. the breakpoint could have been
4097 removed since. Or the thread could have been told to step an
4098 instruction the size of a breakpoint instruction, and only
4099 _after_ was a breakpoint inserted at its address. */
4101 /* If this target does not decrement the PC after breakpoints, then
4102 we have nothing to do. */
4103 regcache
= get_thread_regcache (thread
);
4104 gdbarch
= regcache
->arch ();
4106 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4110 const address_space
*aspace
= regcache
->aspace ();
4112 /* Find the location where (if we've hit a breakpoint) the
4113 breakpoint would be. */
4114 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4116 /* If the target can't tell whether a software breakpoint triggered,
4117 fallback to figuring it out based on breakpoints we think were
4118 inserted in the target, and on whether the thread was stepped or
4121 /* Check whether there actually is a software breakpoint inserted at
4124 If in non-stop mode, a race condition is possible where we've
4125 removed a breakpoint, but stop events for that breakpoint were
4126 already queued and arrive later. To suppress those spurious
4127 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4128 and retire them after a number of stop events are reported. Note
4129 this is an heuristic and can thus get confused. The real fix is
4130 to get the "stopped by SW BP and needs adjustment" info out of
4131 the target/kernel (and thus never reach here; see above). */
4132 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4133 || (target_is_non_stop_p ()
4134 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4136 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4138 if (record_full_is_used ())
4139 restore_operation_disable
.emplace
4140 (record_full_gdb_operation_disable_set ());
4142 /* When using hardware single-step, a SIGTRAP is reported for both
4143 a completed single-step and a software breakpoint. Need to
4144 differentiate between the two, as the latter needs adjusting
4145 but the former does not.
4147 The SIGTRAP can be due to a completed hardware single-step only if
4148 - we didn't insert software single-step breakpoints
4149 - this thread is currently being stepped
4151 If any of these events did not occur, we must have stopped due
4152 to hitting a software breakpoint, and have to back up to the
4155 As a special case, we could have hardware single-stepped a
4156 software breakpoint. In this case (prev_pc == breakpoint_pc),
4157 we also need to back up to the breakpoint address. */
4159 if (thread_has_single_step_breakpoints_set (thread
)
4160 || !currently_stepping (thread
)
4161 || (thread
->stepped_breakpoint
4162 && thread
->prev_pc
== breakpoint_pc
))
4163 regcache_write_pc (regcache
, breakpoint_pc
);
4168 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4170 for (frame
= get_prev_frame (frame
);
4172 frame
= get_prev_frame (frame
))
4174 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4177 if (get_frame_type (frame
) != INLINE_FRAME
)
4184 /* Look for an inline frame that is marked for skip.
4185 If PREV_FRAME is TRUE start at the previous frame,
4186 otherwise start at the current frame. Stop at the
4187 first non-inline frame, or at the frame where the
4191 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4193 struct frame_info
*frame
= get_current_frame ();
4196 frame
= get_prev_frame (frame
);
4198 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4200 const char *fn
= NULL
;
4201 symtab_and_line sal
;
4204 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4206 if (get_frame_type (frame
) != INLINE_FRAME
)
4209 sal
= find_frame_sal (frame
);
4210 sym
= get_frame_function (frame
);
4213 fn
= sym
->print_name ();
4216 && function_name_is_marked_for_skip (fn
, sal
))
4223 /* If the event thread has the stop requested flag set, pretend it
4224 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4228 handle_stop_requested (struct execution_control_state
*ecs
)
4230 if (ecs
->event_thread
->stop_requested
)
4232 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4233 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4234 handle_signal_stop (ecs
);
4240 /* Auxiliary function that handles syscall entry/return events.
4241 It returns true if the inferior should keep going (and GDB
4242 should ignore the event), or false if the event deserves to be
4246 handle_syscall_event (struct execution_control_state
*ecs
)
4248 struct regcache
*regcache
;
4251 context_switch (ecs
);
4253 regcache
= get_thread_regcache (ecs
->event_thread
);
4254 syscall_number
= ecs
->ws
.value
.syscall_number
;
4255 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4257 if (catch_syscall_enabled () > 0
4258 && catching_syscall_number (syscall_number
) > 0)
4260 infrun_debug_printf ("syscall number=%d", syscall_number
);
4262 ecs
->event_thread
->control
.stop_bpstat
4263 = bpstat_stop_status (regcache
->aspace (),
4264 ecs
->event_thread
->suspend
.stop_pc
,
4265 ecs
->event_thread
, &ecs
->ws
);
4267 if (handle_stop_requested (ecs
))
4270 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4272 /* Catchpoint hit. */
4277 if (handle_stop_requested (ecs
))
4280 /* If no catchpoint triggered for this, then keep going. */
4286 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4289 fill_in_stop_func (struct gdbarch
*gdbarch
,
4290 struct execution_control_state
*ecs
)
4292 if (!ecs
->stop_func_filled_in
)
4295 const general_symbol_info
*gsi
;
4297 /* Don't care about return value; stop_func_start and stop_func_name
4298 will both be 0 if it doesn't work. */
4299 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4301 &ecs
->stop_func_start
,
4302 &ecs
->stop_func_end
,
4304 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4306 /* The call to find_pc_partial_function, above, will set
4307 stop_func_start and stop_func_end to the start and end
4308 of the range containing the stop pc. If this range
4309 contains the entry pc for the block (which is always the
4310 case for contiguous blocks), advance stop_func_start past
4311 the function's start offset and entrypoint. Note that
4312 stop_func_start is NOT advanced when in a range of a
4313 non-contiguous block that does not contain the entry pc. */
4314 if (block
!= nullptr
4315 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4316 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4318 ecs
->stop_func_start
4319 += gdbarch_deprecated_function_start_offset (gdbarch
);
4321 if (gdbarch_skip_entrypoint_p (gdbarch
))
4322 ecs
->stop_func_start
4323 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4326 ecs
->stop_func_filled_in
= 1;
4331 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4333 static enum stop_kind
4334 get_inferior_stop_soon (execution_control_state
*ecs
)
4336 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4338 gdb_assert (inf
!= NULL
);
4339 return inf
->control
.stop_soon
;
4342 /* Poll for one event out of the current target. Store the resulting
4343 waitstatus in WS, and return the event ptid. Does not block. */
4346 poll_one_curr_target (struct target_waitstatus
*ws
)
4350 overlay_cache_invalid
= 1;
4352 /* Flush target cache before starting to handle each event.
4353 Target was running and cache could be stale. This is just a
4354 heuristic. Running threads may modify target memory, but we
4355 don't get any event. */
4356 target_dcache_invalidate ();
4358 if (deprecated_target_wait_hook
)
4359 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4361 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4364 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4369 /* An event reported by wait_one. */
4371 struct wait_one_event
4373 /* The target the event came out of. */
4374 process_stratum_target
*target
;
4376 /* The PTID the event was for. */
4379 /* The waitstatus. */
4380 target_waitstatus ws
;
4383 /* Wait for one event out of any target. */
4385 static wait_one_event
4390 for (inferior
*inf
: all_inferiors ())
4392 process_stratum_target
*target
= inf
->process_target ();
4394 || !target
->is_async_p ()
4395 || !target
->threads_executing
)
4398 switch_to_inferior_no_thread (inf
);
4400 wait_one_event event
;
4401 event
.target
= target
;
4402 event
.ptid
= poll_one_curr_target (&event
.ws
);
4404 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4406 /* If nothing is resumed, remove the target from the
4410 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4414 /* Block waiting for some event. */
4421 for (inferior
*inf
: all_inferiors ())
4423 process_stratum_target
*target
= inf
->process_target ();
4425 || !target
->is_async_p ()
4426 || !target
->threads_executing
)
4429 int fd
= target
->async_wait_fd ();
4430 FD_SET (fd
, &readfds
);
4437 /* No waitable targets left. All must be stopped. */
4438 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4443 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4449 perror_with_name ("interruptible_select");
4454 /* Save the thread's event and stop reason to process it later. */
4457 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4459 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4460 target_waitstatus_to_string (ws
).c_str (),
4465 /* Record for later. */
4466 tp
->suspend
.waitstatus
= *ws
;
4467 tp
->suspend
.waitstatus_pending_p
= 1;
4469 struct regcache
*regcache
= get_thread_regcache (tp
);
4470 const address_space
*aspace
= regcache
->aspace ();
4472 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4473 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4475 CORE_ADDR pc
= regcache_read_pc (regcache
);
4477 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4479 scoped_restore_current_thread restore_thread
;
4480 switch_to_thread (tp
);
4482 if (target_stopped_by_watchpoint ())
4484 tp
->suspend
.stop_reason
4485 = TARGET_STOPPED_BY_WATCHPOINT
;
4487 else if (target_supports_stopped_by_sw_breakpoint ()
4488 && target_stopped_by_sw_breakpoint ())
4490 tp
->suspend
.stop_reason
4491 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4493 else if (target_supports_stopped_by_hw_breakpoint ()
4494 && target_stopped_by_hw_breakpoint ())
4496 tp
->suspend
.stop_reason
4497 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4499 else if (!target_supports_stopped_by_hw_breakpoint ()
4500 && hardware_breakpoint_inserted_here_p (aspace
,
4503 tp
->suspend
.stop_reason
4504 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4506 else if (!target_supports_stopped_by_sw_breakpoint ()
4507 && software_breakpoint_inserted_here_p (aspace
,
4510 tp
->suspend
.stop_reason
4511 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4513 else if (!thread_has_single_step_breakpoints_set (tp
)
4514 && currently_stepping (tp
))
4516 tp
->suspend
.stop_reason
4517 = TARGET_STOPPED_BY_SINGLE_STEP
;
4522 /* Mark the non-executing threads accordingly. In all-stop, all
4523 threads of all processes are stopped when we get any event
4524 reported. In non-stop mode, only the event thread stops. */
4527 mark_non_executing_threads (process_stratum_target
*target
,
4529 struct target_waitstatus ws
)
4533 if (!target_is_non_stop_p ())
4534 mark_ptid
= minus_one_ptid
;
4535 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4536 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4538 /* If we're handling a process exit in non-stop mode, even
4539 though threads haven't been deleted yet, one would think
4540 that there is nothing to do, as threads of the dead process
4541 will be soon deleted, and threads of any other process were
4542 left running. However, on some targets, threads survive a
4543 process exit event. E.g., for the "checkpoint" command,
4544 when the current checkpoint/fork exits, linux-fork.c
4545 automatically switches to another fork from within
4546 target_mourn_inferior, by associating the same
4547 inferior/thread to another fork. We haven't mourned yet at
4548 this point, but we must mark any threads left in the
4549 process as not-executing so that finish_thread_state marks
4550 them stopped (in the user's perspective) if/when we present
4551 the stop to the user. */
4552 mark_ptid
= ptid_t (event_ptid
.pid ());
4555 mark_ptid
= event_ptid
;
4557 set_executing (target
, mark_ptid
, false);
4559 /* Likewise the resumed flag. */
4560 set_resumed (target
, mark_ptid
, false);
4566 stop_all_threads (void)
4568 /* We may need multiple passes to discover all threads. */
4572 gdb_assert (exists_non_stop_target ());
4574 infrun_debug_printf ("starting");
4576 scoped_restore_current_thread restore_thread
;
4578 /* Enable thread events of all targets. */
4579 for (auto *target
: all_non_exited_process_targets ())
4581 switch_to_target_no_thread (target
);
4582 target_thread_events (true);
4587 /* Disable thread events of all targets. */
4588 for (auto *target
: all_non_exited_process_targets ())
4590 switch_to_target_no_thread (target
);
4591 target_thread_events (false);
4594 /* Use debug_prefixed_printf directly to get a meaningful function
4597 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4600 /* Request threads to stop, and then wait for the stops. Because
4601 threads we already know about can spawn more threads while we're
4602 trying to stop them, and we only learn about new threads when we
4603 update the thread list, do this in a loop, and keep iterating
4604 until two passes find no threads that need to be stopped. */
4605 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4607 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4610 int waits_needed
= 0;
4612 for (auto *target
: all_non_exited_process_targets ())
4614 switch_to_target_no_thread (target
);
4615 update_thread_list ();
4618 /* Go through all threads looking for threads that we need
4619 to tell the target to stop. */
4620 for (thread_info
*t
: all_non_exited_threads ())
4622 /* For a single-target setting with an all-stop target,
4623 we would not even arrive here. For a multi-target
4624 setting, until GDB is able to handle a mixture of
4625 all-stop and non-stop targets, simply skip all-stop
4626 targets' threads. This should be fine due to the
4627 protection of 'check_multi_target_resumption'. */
4629 switch_to_thread_no_regs (t
);
4630 if (!target_is_non_stop_p ())
4635 /* If already stopping, don't request a stop again.
4636 We just haven't seen the notification yet. */
4637 if (!t
->stop_requested
)
4639 infrun_debug_printf (" %s executing, need stop",
4640 target_pid_to_str (t
->ptid
).c_str ());
4641 target_stop (t
->ptid
);
4642 t
->stop_requested
= 1;
4646 infrun_debug_printf (" %s executing, already stopping",
4647 target_pid_to_str (t
->ptid
).c_str ());
4650 if (t
->stop_requested
)
4655 infrun_debug_printf (" %s not executing",
4656 target_pid_to_str (t
->ptid
).c_str ());
4658 /* The thread may be not executing, but still be
4659 resumed with a pending status to process. */
4664 if (waits_needed
== 0)
4667 /* If we find new threads on the second iteration, restart
4668 over. We want to see two iterations in a row with all
4673 for (int i
= 0; i
< waits_needed
; i
++)
4675 wait_one_event event
= wait_one ();
4678 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4679 target_pid_to_str (event
.ptid
).c_str ());
4681 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4683 /* All resumed threads exited. */
4686 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4687 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4688 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4690 /* One thread/process exited/signalled. */
4692 thread_info
*t
= nullptr;
4694 /* The target may have reported just a pid. If so, try
4695 the first non-exited thread. */
4696 if (event
.ptid
.is_pid ())
4698 int pid
= event
.ptid
.pid ();
4699 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4700 for (thread_info
*tp
: inf
->non_exited_threads ())
4706 /* If there is no available thread, the event would
4707 have to be appended to a per-inferior event list,
4708 which does not exist (and if it did, we'd have
4709 to adjust run control command to be able to
4710 resume such an inferior). We assert here instead
4711 of going into an infinite loop. */
4712 gdb_assert (t
!= nullptr);
4715 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4719 t
= find_thread_ptid (event
.target
, event
.ptid
);
4720 /* Check if this is the first time we see this thread.
4721 Don't bother adding if it individually exited. */
4723 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4724 t
= add_thread (event
.target
, event
.ptid
);
4729 /* Set the threads as non-executing to avoid
4730 another stop attempt on them. */
4731 switch_to_thread_no_regs (t
);
4732 mark_non_executing_threads (event
.target
, event
.ptid
,
4734 save_waitstatus (t
, &event
.ws
);
4735 t
->stop_requested
= false;
4740 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4742 t
= add_thread (event
.target
, event
.ptid
);
4744 t
->stop_requested
= 0;
4747 t
->control
.may_range_step
= 0;
4749 /* This may be the first time we see the inferior report
4751 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4752 if (inf
->needs_setup
)
4754 switch_to_thread_no_regs (t
);
4758 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4759 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4761 /* We caught the event that we intended to catch, so
4762 there's no event pending. */
4763 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4764 t
->suspend
.waitstatus_pending_p
= 0;
4766 if (displaced_step_finish (t
, GDB_SIGNAL_0
)
4767 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4769 /* Add it back to the step-over queue. */
4771 ("displaced-step of %s canceled: adding back to "
4772 "the step-over queue",
4773 target_pid_to_str (t
->ptid
).c_str ());
4775 t
->control
.trap_expected
= 0;
4776 global_thread_step_over_chain_enqueue (t
);
4781 enum gdb_signal sig
;
4782 struct regcache
*regcache
;
4785 ("target_wait %s, saving status for %d.%ld.%ld",
4786 target_waitstatus_to_string (&event
.ws
).c_str (),
4787 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4789 /* Record for later. */
4790 save_waitstatus (t
, &event
.ws
);
4792 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4793 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4795 if (displaced_step_finish (t
, sig
)
4796 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4798 /* Add it back to the step-over queue. */
4799 t
->control
.trap_expected
= 0;
4800 global_thread_step_over_chain_enqueue (t
);
4803 regcache
= get_thread_regcache (t
);
4804 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4806 infrun_debug_printf ("saved stop_pc=%s for %s "
4807 "(currently_stepping=%d)",
4808 paddress (target_gdbarch (),
4809 t
->suspend
.stop_pc
),
4810 target_pid_to_str (t
->ptid
).c_str (),
4811 currently_stepping (t
));
4819 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4822 handle_no_resumed (struct execution_control_state
*ecs
)
4824 if (target_can_async_p ())
4826 bool any_sync
= false;
4828 for (ui
*ui
: all_uis ())
4830 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4838 /* There were no unwaited-for children left in the target, but,
4839 we're not synchronously waiting for events either. Just
4842 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4843 prepare_to_wait (ecs
);
4848 /* Otherwise, if we were running a synchronous execution command, we
4849 may need to cancel it and give the user back the terminal.
4851 In non-stop mode, the target can't tell whether we've already
4852 consumed previous stop events, so it can end up sending us a
4853 no-resumed event like so:
4855 #0 - thread 1 is left stopped
4857 #1 - thread 2 is resumed and hits breakpoint
4858 -> TARGET_WAITKIND_STOPPED
4860 #2 - thread 3 is resumed and exits
4861 this is the last resumed thread, so
4862 -> TARGET_WAITKIND_NO_RESUMED
4864 #3 - gdb processes stop for thread 2 and decides to re-resume
4867 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4868 thread 2 is now resumed, so the event should be ignored.
4870 IOW, if the stop for thread 2 doesn't end a foreground command,
4871 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4872 event. But it could be that the event meant that thread 2 itself
4873 (or whatever other thread was the last resumed thread) exited.
4875 To address this we refresh the thread list and check whether we
4876 have resumed threads _now_. In the example above, this removes
4877 thread 3 from the thread list. If thread 2 was re-resumed, we
4878 ignore this event. If we find no thread resumed, then we cancel
4879 the synchronous command and show "no unwaited-for " to the
4882 inferior
*curr_inf
= current_inferior ();
4884 scoped_restore_current_thread restore_thread
;
4886 for (auto *target
: all_non_exited_process_targets ())
4888 switch_to_target_no_thread (target
);
4889 update_thread_list ();
4894 - the current target has no thread executing, and
4895 - the current inferior is native, and
4896 - the current inferior is the one which has the terminal, and
4899 then a Ctrl-C from this point on would remain stuck in the
4900 kernel, until a thread resumes and dequeues it. That would
4901 result in the GDB CLI not reacting to Ctrl-C, not able to
4902 interrupt the program. To address this, if the current inferior
4903 no longer has any thread executing, we give the terminal to some
4904 other inferior that has at least one thread executing. */
4905 bool swap_terminal
= true;
4907 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4908 whether to report it to the user. */
4909 bool ignore_event
= false;
4911 for (thread_info
*thread
: all_non_exited_threads ())
4913 if (swap_terminal
&& thread
->executing
)
4915 if (thread
->inf
!= curr_inf
)
4917 target_terminal::ours ();
4919 switch_to_thread (thread
);
4920 target_terminal::inferior ();
4922 swap_terminal
= false;
4926 && (thread
->executing
4927 || thread
->suspend
.waitstatus_pending_p
))
4929 /* Either there were no unwaited-for children left in the
4930 target at some point, but there are now, or some target
4931 other than the eventing one has unwaited-for children
4932 left. Just ignore. */
4933 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4934 "(ignoring: found resumed)");
4936 ignore_event
= true;
4939 if (ignore_event
&& !swap_terminal
)
4945 switch_to_inferior_no_thread (curr_inf
);
4946 prepare_to_wait (ecs
);
4950 /* Go ahead and report the event. */
4954 /* Given an execution control state that has been freshly filled in by
4955 an event from the inferior, figure out what it means and take
4958 The alternatives are:
4960 1) stop_waiting and return; to really stop and return to the
4963 2) keep_going and return; to wait for the next event (set
4964 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4968 handle_inferior_event (struct execution_control_state
*ecs
)
4970 /* Make sure that all temporary struct value objects that were
4971 created during the handling of the event get deleted at the
4973 scoped_value_mark free_values
;
4975 enum stop_kind stop_soon
;
4977 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
4979 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4981 /* We had an event in the inferior, but we are not interested in
4982 handling it at this level. The lower layers have already
4983 done what needs to be done, if anything.
4985 One of the possible circumstances for this is when the
4986 inferior produces output for the console. The inferior has
4987 not stopped, and we are ignoring the event. Another possible
4988 circumstance is any event which the lower level knows will be
4989 reported multiple times without an intervening resume. */
4990 prepare_to_wait (ecs
);
4994 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4996 prepare_to_wait (ecs
);
5000 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5001 && handle_no_resumed (ecs
))
5004 /* Cache the last target/ptid/waitstatus. */
5005 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5007 /* Always clear state belonging to the previous time we stopped. */
5008 stop_stack_dummy
= STOP_NONE
;
5010 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5012 /* No unwaited-for children left. IOW, all resumed children
5014 stop_print_frame
= false;
5019 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5020 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5022 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5023 /* If it's a new thread, add it to the thread database. */
5024 if (ecs
->event_thread
== NULL
)
5025 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5027 /* Disable range stepping. If the next step request could use a
5028 range, this will be end up re-enabled then. */
5029 ecs
->event_thread
->control
.may_range_step
= 0;
5032 /* Dependent on valid ECS->EVENT_THREAD. */
5033 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5035 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5036 reinit_frame_cache ();
5038 breakpoint_retire_moribund ();
5040 /* First, distinguish signals caused by the debugger from signals
5041 that have to do with the program's own actions. Note that
5042 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5043 on the operating system version. Here we detect when a SIGILL or
5044 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5045 something similar for SIGSEGV, since a SIGSEGV will be generated
5046 when we're trying to execute a breakpoint instruction on a
5047 non-executable stack. This happens for call dummy breakpoints
5048 for architectures like SPARC that place call dummies on the
5050 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5051 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5052 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5053 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5055 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5057 if (breakpoint_inserted_here_p (regcache
->aspace (),
5058 regcache_read_pc (regcache
)))
5060 infrun_debug_printf ("Treating signal as SIGTRAP");
5061 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5065 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5067 switch (ecs
->ws
.kind
)
5069 case TARGET_WAITKIND_LOADED
:
5070 context_switch (ecs
);
5071 /* Ignore gracefully during startup of the inferior, as it might
5072 be the shell which has just loaded some objects, otherwise
5073 add the symbols for the newly loaded objects. Also ignore at
5074 the beginning of an attach or remote session; we will query
5075 the full list of libraries once the connection is
5078 stop_soon
= get_inferior_stop_soon (ecs
);
5079 if (stop_soon
== NO_STOP_QUIETLY
)
5081 struct regcache
*regcache
;
5083 regcache
= get_thread_regcache (ecs
->event_thread
);
5085 handle_solib_event ();
5087 ecs
->event_thread
->control
.stop_bpstat
5088 = bpstat_stop_status (regcache
->aspace (),
5089 ecs
->event_thread
->suspend
.stop_pc
,
5090 ecs
->event_thread
, &ecs
->ws
);
5092 if (handle_stop_requested (ecs
))
5095 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5097 /* A catchpoint triggered. */
5098 process_event_stop_test (ecs
);
5102 /* If requested, stop when the dynamic linker notifies
5103 gdb of events. This allows the user to get control
5104 and place breakpoints in initializer routines for
5105 dynamically loaded objects (among other things). */
5106 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5107 if (stop_on_solib_events
)
5109 /* Make sure we print "Stopped due to solib-event" in
5111 stop_print_frame
= true;
5118 /* If we are skipping through a shell, or through shared library
5119 loading that we aren't interested in, resume the program. If
5120 we're running the program normally, also resume. */
5121 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5123 /* Loading of shared libraries might have changed breakpoint
5124 addresses. Make sure new breakpoints are inserted. */
5125 if (stop_soon
== NO_STOP_QUIETLY
)
5126 insert_breakpoints ();
5127 resume (GDB_SIGNAL_0
);
5128 prepare_to_wait (ecs
);
5132 /* But stop if we're attaching or setting up a remote
5134 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5135 || stop_soon
== STOP_QUIETLY_REMOTE
)
5137 infrun_debug_printf ("quietly stopped");
5142 internal_error (__FILE__
, __LINE__
,
5143 _("unhandled stop_soon: %d"), (int) stop_soon
);
5145 case TARGET_WAITKIND_SPURIOUS
:
5146 if (handle_stop_requested (ecs
))
5148 context_switch (ecs
);
5149 resume (GDB_SIGNAL_0
);
5150 prepare_to_wait (ecs
);
5153 case TARGET_WAITKIND_THREAD_CREATED
:
5154 if (handle_stop_requested (ecs
))
5156 context_switch (ecs
);
5157 if (!switch_back_to_stepped_thread (ecs
))
5161 case TARGET_WAITKIND_EXITED
:
5162 case TARGET_WAITKIND_SIGNALLED
:
5164 /* Depending on the system, ecs->ptid may point to a thread or
5165 to a process. On some targets, target_mourn_inferior may
5166 need to have access to the just-exited thread. That is the
5167 case of GNU/Linux's "checkpoint" support, for example.
5168 Call the switch_to_xxx routine as appropriate. */
5169 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5171 switch_to_thread (thr
);
5174 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5175 switch_to_inferior_no_thread (inf
);
5178 handle_vfork_child_exec_or_exit (0);
5179 target_terminal::ours (); /* Must do this before mourn anyway. */
5181 /* Clearing any previous state of convenience variables. */
5182 clear_exit_convenience_vars ();
5184 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5186 /* Record the exit code in the convenience variable $_exitcode, so
5187 that the user can inspect this again later. */
5188 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5189 (LONGEST
) ecs
->ws
.value
.integer
);
5191 /* Also record this in the inferior itself. */
5192 current_inferior ()->has_exit_code
= 1;
5193 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5195 /* Support the --return-child-result option. */
5196 return_child_result_value
= ecs
->ws
.value
.integer
;
5198 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5202 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5204 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5206 /* Set the value of the internal variable $_exitsignal,
5207 which holds the signal uncaught by the inferior. */
5208 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5209 gdbarch_gdb_signal_to_target (gdbarch
,
5210 ecs
->ws
.value
.sig
));
5214 /* We don't have access to the target's method used for
5215 converting between signal numbers (GDB's internal
5216 representation <-> target's representation).
5217 Therefore, we cannot do a good job at displaying this
5218 information to the user. It's better to just warn
5219 her about it (if infrun debugging is enabled), and
5221 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5225 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5228 gdb_flush (gdb_stdout
);
5229 target_mourn_inferior (inferior_ptid
);
5230 stop_print_frame
= false;
5234 case TARGET_WAITKIND_FORKED
:
5235 case TARGET_WAITKIND_VFORKED
:
5236 /* Check whether the inferior is displaced stepping. */
5238 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5239 struct gdbarch
*gdbarch
= regcache
->arch ();
5240 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5242 /* If this is a fork (child gets its own address space copy) and some
5243 displaced step buffers were in use at the time of the fork, restore
5244 the displaced step buffer bytes in the child process. */
5245 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5246 gdbarch_displaced_step_restore_all_in_ptid
5247 (gdbarch
, parent_inf
, ecs
->ws
.value
.related_pid
);
5249 /* If displaced stepping is supported, and thread ecs->ptid is
5250 displaced stepping. */
5251 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5253 struct regcache
*child_regcache
;
5254 CORE_ADDR parent_pc
;
5256 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5257 indicating that the displaced stepping of syscall instruction
5258 has been done. Perform cleanup for parent process here. Note
5259 that this operation also cleans up the child process for vfork,
5260 because their pages are shared. */
5261 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5262 /* Start a new step-over in another thread if there's one
5266 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5267 the child's PC is also within the scratchpad. Set the child's PC
5268 to the parent's PC value, which has already been fixed up.
5269 FIXME: we use the parent's aspace here, although we're touching
5270 the child, because the child hasn't been added to the inferior
5271 list yet at this point. */
5274 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5275 ecs
->ws
.value
.related_pid
,
5277 parent_inf
->aspace
);
5278 /* Read PC value of parent process. */
5279 parent_pc
= regcache_read_pc (regcache
);
5281 displaced_debug_printf ("write child pc from %s to %s",
5283 regcache_read_pc (child_regcache
)),
5284 paddress (gdbarch
, parent_pc
));
5286 regcache_write_pc (child_regcache
, parent_pc
);
5290 context_switch (ecs
);
5292 /* Immediately detach breakpoints from the child before there's
5293 any chance of letting the user delete breakpoints from the
5294 breakpoint lists. If we don't do this early, it's easy to
5295 leave left over traps in the child, vis: "break foo; catch
5296 fork; c; <fork>; del; c; <child calls foo>". We only follow
5297 the fork on the last `continue', and by that time the
5298 breakpoint at "foo" is long gone from the breakpoint table.
5299 If we vforked, then we don't need to unpatch here, since both
5300 parent and child are sharing the same memory pages; we'll
5301 need to unpatch at follow/detach time instead to be certain
5302 that new breakpoints added between catchpoint hit time and
5303 vfork follow are detached. */
5304 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5306 /* This won't actually modify the breakpoint list, but will
5307 physically remove the breakpoints from the child. */
5308 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5311 delete_just_stopped_threads_single_step_breakpoints ();
5313 /* In case the event is caught by a catchpoint, remember that
5314 the event is to be followed at the next resume of the thread,
5315 and not immediately. */
5316 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5318 ecs
->event_thread
->suspend
.stop_pc
5319 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5321 ecs
->event_thread
->control
.stop_bpstat
5322 = bpstat_stop_status (get_current_regcache ()->aspace (),
5323 ecs
->event_thread
->suspend
.stop_pc
,
5324 ecs
->event_thread
, &ecs
->ws
);
5326 if (handle_stop_requested (ecs
))
5329 /* If no catchpoint triggered for this, then keep going. Note
5330 that we're interested in knowing the bpstat actually causes a
5331 stop, not just if it may explain the signal. Software
5332 watchpoints, for example, always appear in the bpstat. */
5333 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5336 = (follow_fork_mode_string
== follow_fork_mode_child
);
5338 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5340 process_stratum_target
*targ
5341 = ecs
->event_thread
->inf
->process_target ();
5343 bool should_resume
= follow_fork ();
5345 /* Note that one of these may be an invalid pointer,
5346 depending on detach_fork. */
5347 thread_info
*parent
= ecs
->event_thread
;
5349 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5351 /* At this point, the parent is marked running, and the
5352 child is marked stopped. */
5354 /* If not resuming the parent, mark it stopped. */
5355 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5356 parent
->set_running (false);
5358 /* If resuming the child, mark it running. */
5359 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5360 child
->set_running (true);
5362 /* In non-stop mode, also resume the other branch. */
5363 if (!detach_fork
&& (non_stop
5364 || (sched_multi
&& target_is_non_stop_p ())))
5367 switch_to_thread (parent
);
5369 switch_to_thread (child
);
5371 ecs
->event_thread
= inferior_thread ();
5372 ecs
->ptid
= inferior_ptid
;
5377 switch_to_thread (child
);
5379 switch_to_thread (parent
);
5381 ecs
->event_thread
= inferior_thread ();
5382 ecs
->ptid
= inferior_ptid
;
5390 process_event_stop_test (ecs
);
5393 case TARGET_WAITKIND_VFORK_DONE
:
5394 /* Done with the shared memory region. Re-insert breakpoints in
5395 the parent, and keep going. */
5397 context_switch (ecs
);
5399 current_inferior ()->waiting_for_vfork_done
= 0;
5400 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5402 if (handle_stop_requested (ecs
))
5405 /* This also takes care of reinserting breakpoints in the
5406 previously locked inferior. */
5410 case TARGET_WAITKIND_EXECD
:
5412 /* Note we can't read registers yet (the stop_pc), because we
5413 don't yet know the inferior's post-exec architecture.
5414 'stop_pc' is explicitly read below instead. */
5415 switch_to_thread_no_regs (ecs
->event_thread
);
5417 /* Do whatever is necessary to the parent branch of the vfork. */
5418 handle_vfork_child_exec_or_exit (1);
5420 /* This causes the eventpoints and symbol table to be reset.
5421 Must do this now, before trying to determine whether to
5423 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5425 /* In follow_exec we may have deleted the original thread and
5426 created a new one. Make sure that the event thread is the
5427 execd thread for that case (this is a nop otherwise). */
5428 ecs
->event_thread
= inferior_thread ();
5430 ecs
->event_thread
->suspend
.stop_pc
5431 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5433 ecs
->event_thread
->control
.stop_bpstat
5434 = bpstat_stop_status (get_current_regcache ()->aspace (),
5435 ecs
->event_thread
->suspend
.stop_pc
,
5436 ecs
->event_thread
, &ecs
->ws
);
5438 /* Note that this may be referenced from inside
5439 bpstat_stop_status above, through inferior_has_execd. */
5440 xfree (ecs
->ws
.value
.execd_pathname
);
5441 ecs
->ws
.value
.execd_pathname
= NULL
;
5443 if (handle_stop_requested (ecs
))
5446 /* If no catchpoint triggered for this, then keep going. */
5447 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5449 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5453 process_event_stop_test (ecs
);
5456 /* Be careful not to try to gather much state about a thread
5457 that's in a syscall. It's frequently a losing proposition. */
5458 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5459 /* Getting the current syscall number. */
5460 if (handle_syscall_event (ecs
) == 0)
5461 process_event_stop_test (ecs
);
5464 /* Before examining the threads further, step this thread to
5465 get it entirely out of the syscall. (We get notice of the
5466 event when the thread is just on the verge of exiting a
5467 syscall. Stepping one instruction seems to get it back
5469 case TARGET_WAITKIND_SYSCALL_RETURN
:
5470 if (handle_syscall_event (ecs
) == 0)
5471 process_event_stop_test (ecs
);
5474 case TARGET_WAITKIND_STOPPED
:
5475 handle_signal_stop (ecs
);
5478 case TARGET_WAITKIND_NO_HISTORY
:
5479 /* Reverse execution: target ran out of history info. */
5481 /* Switch to the stopped thread. */
5482 context_switch (ecs
);
5483 infrun_debug_printf ("stopped");
5485 delete_just_stopped_threads_single_step_breakpoints ();
5486 ecs
->event_thread
->suspend
.stop_pc
5487 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5489 if (handle_stop_requested (ecs
))
5492 gdb::observers::no_history
.notify ();
5498 /* Restart threads back to what they were trying to do back when we
5499 paused them for an in-line step-over. The EVENT_THREAD thread is
5503 restart_threads (struct thread_info
*event_thread
)
5505 /* In case the instruction just stepped spawned a new thread. */
5506 update_thread_list ();
5508 for (thread_info
*tp
: all_non_exited_threads ())
5510 switch_to_thread_no_regs (tp
);
5512 if (tp
== event_thread
)
5514 infrun_debug_printf ("restart threads: [%s] is event thread",
5515 target_pid_to_str (tp
->ptid
).c_str ());
5519 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5521 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5522 target_pid_to_str (tp
->ptid
).c_str ());
5528 infrun_debug_printf ("restart threads: [%s] resumed",
5529 target_pid_to_str (tp
->ptid
).c_str ());
5530 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5534 if (thread_is_in_step_over_chain (tp
))
5536 infrun_debug_printf ("restart threads: [%s] needs step-over",
5537 target_pid_to_str (tp
->ptid
).c_str ());
5538 gdb_assert (!tp
->resumed
);
5543 if (tp
->suspend
.waitstatus_pending_p
)
5545 infrun_debug_printf ("restart threads: [%s] has pending status",
5546 target_pid_to_str (tp
->ptid
).c_str ());
5551 gdb_assert (!tp
->stop_requested
);
5553 /* If some thread needs to start a step-over at this point, it
5554 should still be in the step-over queue, and thus skipped
5556 if (thread_still_needs_step_over (tp
))
5558 internal_error (__FILE__
, __LINE__
,
5559 "thread [%s] needs a step-over, but not in "
5560 "step-over queue\n",
5561 target_pid_to_str (tp
->ptid
).c_str ());
5564 if (currently_stepping (tp
))
5566 infrun_debug_printf ("restart threads: [%s] was stepping",
5567 target_pid_to_str (tp
->ptid
).c_str ());
5568 keep_going_stepped_thread (tp
);
5572 struct execution_control_state ecss
;
5573 struct execution_control_state
*ecs
= &ecss
;
5575 infrun_debug_printf ("restart threads: [%s] continuing",
5576 target_pid_to_str (tp
->ptid
).c_str ());
5577 reset_ecs (ecs
, tp
);
5578 switch_to_thread (tp
);
5579 keep_going_pass_signal (ecs
);
5584 /* Callback for iterate_over_threads. Find a resumed thread that has
5585 a pending waitstatus. */
5588 resumed_thread_with_pending_status (struct thread_info
*tp
,
5592 && tp
->suspend
.waitstatus_pending_p
);
5595 /* Called when we get an event that may finish an in-line or
5596 out-of-line (displaced stepping) step-over started previously.
5597 Return true if the event is processed and we should go back to the
5598 event loop; false if the caller should continue processing the
5602 finish_step_over (struct execution_control_state
*ecs
)
5604 displaced_step_finish (ecs
->event_thread
,
5605 ecs
->event_thread
->suspend
.stop_signal
);
5607 bool had_step_over_info
= step_over_info_valid_p ();
5609 if (had_step_over_info
)
5611 /* If we're stepping over a breakpoint with all threads locked,
5612 then only the thread that was stepped should be reporting
5614 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5616 clear_step_over_info ();
5619 if (!target_is_non_stop_p ())
5622 /* Start a new step-over in another thread if there's one that
5626 /* If we were stepping over a breakpoint before, and haven't started
5627 a new in-line step-over sequence, then restart all other threads
5628 (except the event thread). We can't do this in all-stop, as then
5629 e.g., we wouldn't be able to issue any other remote packet until
5630 these other threads stop. */
5631 if (had_step_over_info
&& !step_over_info_valid_p ())
5633 struct thread_info
*pending
;
5635 /* If we only have threads with pending statuses, the restart
5636 below won't restart any thread and so nothing re-inserts the
5637 breakpoint we just stepped over. But we need it inserted
5638 when we later process the pending events, otherwise if
5639 another thread has a pending event for this breakpoint too,
5640 we'd discard its event (because the breakpoint that
5641 originally caused the event was no longer inserted). */
5642 context_switch (ecs
);
5643 insert_breakpoints ();
5645 restart_threads (ecs
->event_thread
);
5647 /* If we have events pending, go through handle_inferior_event
5648 again, picking up a pending event at random. This avoids
5649 thread starvation. */
5651 /* But not if we just stepped over a watchpoint in order to let
5652 the instruction execute so we can evaluate its expression.
5653 The set of watchpoints that triggered is recorded in the
5654 breakpoint objects themselves (see bp->watchpoint_triggered).
5655 If we processed another event first, that other event could
5656 clobber this info. */
5657 if (ecs
->event_thread
->stepping_over_watchpoint
)
5660 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5662 if (pending
!= NULL
)
5664 struct thread_info
*tp
= ecs
->event_thread
;
5665 struct regcache
*regcache
;
5667 infrun_debug_printf ("found resumed threads with "
5668 "pending events, saving status");
5670 gdb_assert (pending
!= tp
);
5672 /* Record the event thread's event for later. */
5673 save_waitstatus (tp
, &ecs
->ws
);
5674 /* This was cleared early, by handle_inferior_event. Set it
5675 so this pending event is considered by
5679 gdb_assert (!tp
->executing
);
5681 regcache
= get_thread_regcache (tp
);
5682 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5684 infrun_debug_printf ("saved stop_pc=%s for %s "
5685 "(currently_stepping=%d)",
5686 paddress (target_gdbarch (),
5687 tp
->suspend
.stop_pc
),
5688 target_pid_to_str (tp
->ptid
).c_str (),
5689 currently_stepping (tp
));
5691 /* This in-line step-over finished; clear this so we won't
5692 start a new one. This is what handle_signal_stop would
5693 do, if we returned false. */
5694 tp
->stepping_over_breakpoint
= 0;
5696 /* Wake up the event loop again. */
5697 mark_async_event_handler (infrun_async_inferior_event_token
);
5699 prepare_to_wait (ecs
);
5707 /* Come here when the program has stopped with a signal. */
5710 handle_signal_stop (struct execution_control_state
*ecs
)
5712 struct frame_info
*frame
;
5713 struct gdbarch
*gdbarch
;
5714 int stopped_by_watchpoint
;
5715 enum stop_kind stop_soon
;
5718 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5720 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5722 /* Do we need to clean up the state of a thread that has
5723 completed a displaced single-step? (Doing so usually affects
5724 the PC, so do it here, before we set stop_pc.) */
5725 if (finish_step_over (ecs
))
5728 /* If we either finished a single-step or hit a breakpoint, but
5729 the user wanted this thread to be stopped, pretend we got a
5730 SIG0 (generic unsignaled stop). */
5731 if (ecs
->event_thread
->stop_requested
5732 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5733 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5735 ecs
->event_thread
->suspend
.stop_pc
5736 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5740 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5741 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5743 switch_to_thread (ecs
->event_thread
);
5745 infrun_debug_printf ("stop_pc=%s",
5746 paddress (reg_gdbarch
,
5747 ecs
->event_thread
->suspend
.stop_pc
));
5748 if (target_stopped_by_watchpoint ())
5752 infrun_debug_printf ("stopped by watchpoint");
5754 if (target_stopped_data_address (current_top_target (), &addr
))
5755 infrun_debug_printf ("stopped data address=%s",
5756 paddress (reg_gdbarch
, addr
));
5758 infrun_debug_printf ("(no data address available)");
5762 /* This is originated from start_remote(), start_inferior() and
5763 shared libraries hook functions. */
5764 stop_soon
= get_inferior_stop_soon (ecs
);
5765 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5767 context_switch (ecs
);
5768 infrun_debug_printf ("quietly stopped");
5769 stop_print_frame
= true;
5774 /* This originates from attach_command(). We need to overwrite
5775 the stop_signal here, because some kernels don't ignore a
5776 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5777 See more comments in inferior.h. On the other hand, if we
5778 get a non-SIGSTOP, report it to the user - assume the backend
5779 will handle the SIGSTOP if it should show up later.
5781 Also consider that the attach is complete when we see a
5782 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5783 target extended-remote report it instead of a SIGSTOP
5784 (e.g. gdbserver). We already rely on SIGTRAP being our
5785 signal, so this is no exception.
5787 Also consider that the attach is complete when we see a
5788 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5789 the target to stop all threads of the inferior, in case the
5790 low level attach operation doesn't stop them implicitly. If
5791 they weren't stopped implicitly, then the stub will report a
5792 GDB_SIGNAL_0, meaning: stopped for no particular reason
5793 other than GDB's request. */
5794 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5795 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5796 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5797 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5799 stop_print_frame
= true;
5801 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5805 /* See if something interesting happened to the non-current thread. If
5806 so, then switch to that thread. */
5807 if (ecs
->ptid
!= inferior_ptid
)
5809 infrun_debug_printf ("context switch");
5811 context_switch (ecs
);
5813 if (deprecated_context_hook
)
5814 deprecated_context_hook (ecs
->event_thread
->global_num
);
5817 /* At this point, get hold of the now-current thread's frame. */
5818 frame
= get_current_frame ();
5819 gdbarch
= get_frame_arch (frame
);
5821 /* Pull the single step breakpoints out of the target. */
5822 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5824 struct regcache
*regcache
;
5827 regcache
= get_thread_regcache (ecs
->event_thread
);
5828 const address_space
*aspace
= regcache
->aspace ();
5830 pc
= regcache_read_pc (regcache
);
5832 /* However, before doing so, if this single-step breakpoint was
5833 actually for another thread, set this thread up for moving
5835 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5838 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5840 infrun_debug_printf ("[%s] hit another thread's single-step "
5842 target_pid_to_str (ecs
->ptid
).c_str ());
5843 ecs
->hit_singlestep_breakpoint
= 1;
5848 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5849 target_pid_to_str (ecs
->ptid
).c_str ());
5852 delete_just_stopped_threads_single_step_breakpoints ();
5854 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5855 && ecs
->event_thread
->control
.trap_expected
5856 && ecs
->event_thread
->stepping_over_watchpoint
)
5857 stopped_by_watchpoint
= 0;
5859 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5861 /* If necessary, step over this watchpoint. We'll be back to display
5863 if (stopped_by_watchpoint
5864 && (target_have_steppable_watchpoint ()
5865 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5867 /* At this point, we are stopped at an instruction which has
5868 attempted to write to a piece of memory under control of
5869 a watchpoint. The instruction hasn't actually executed
5870 yet. If we were to evaluate the watchpoint expression
5871 now, we would get the old value, and therefore no change
5872 would seem to have occurred.
5874 In order to make watchpoints work `right', we really need
5875 to complete the memory write, and then evaluate the
5876 watchpoint expression. We do this by single-stepping the
5879 It may not be necessary to disable the watchpoint to step over
5880 it. For example, the PA can (with some kernel cooperation)
5881 single step over a watchpoint without disabling the watchpoint.
5883 It is far more common to need to disable a watchpoint to step
5884 the inferior over it. If we have non-steppable watchpoints,
5885 we must disable the current watchpoint; it's simplest to
5886 disable all watchpoints.
5888 Any breakpoint at PC must also be stepped over -- if there's
5889 one, it will have already triggered before the watchpoint
5890 triggered, and we either already reported it to the user, or
5891 it didn't cause a stop and we called keep_going. In either
5892 case, if there was a breakpoint at PC, we must be trying to
5894 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5899 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5900 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5901 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5902 ecs
->event_thread
->control
.stop_step
= 0;
5903 stop_print_frame
= true;
5904 stopped_by_random_signal
= 0;
5905 bpstat stop_chain
= NULL
;
5907 /* Hide inlined functions starting here, unless we just performed stepi or
5908 nexti. After stepi and nexti, always show the innermost frame (not any
5909 inline function call sites). */
5910 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5912 const address_space
*aspace
5913 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5915 /* skip_inline_frames is expensive, so we avoid it if we can
5916 determine that the address is one where functions cannot have
5917 been inlined. This improves performance with inferiors that
5918 load a lot of shared libraries, because the solib event
5919 breakpoint is defined as the address of a function (i.e. not
5920 inline). Note that we have to check the previous PC as well
5921 as the current one to catch cases when we have just
5922 single-stepped off a breakpoint prior to reinstating it.
5923 Note that we're assuming that the code we single-step to is
5924 not inline, but that's not definitive: there's nothing
5925 preventing the event breakpoint function from containing
5926 inlined code, and the single-step ending up there. If the
5927 user had set a breakpoint on that inlined code, the missing
5928 skip_inline_frames call would break things. Fortunately
5929 that's an extremely unlikely scenario. */
5930 if (!pc_at_non_inline_function (aspace
,
5931 ecs
->event_thread
->suspend
.stop_pc
,
5933 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5934 && ecs
->event_thread
->control
.trap_expected
5935 && pc_at_non_inline_function (aspace
,
5936 ecs
->event_thread
->prev_pc
,
5939 stop_chain
= build_bpstat_chain (aspace
,
5940 ecs
->event_thread
->suspend
.stop_pc
,
5942 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5944 /* Re-fetch current thread's frame in case that invalidated
5946 frame
= get_current_frame ();
5947 gdbarch
= get_frame_arch (frame
);
5951 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5952 && ecs
->event_thread
->control
.trap_expected
5953 && gdbarch_single_step_through_delay_p (gdbarch
)
5954 && currently_stepping (ecs
->event_thread
))
5956 /* We're trying to step off a breakpoint. Turns out that we're
5957 also on an instruction that needs to be stepped multiple
5958 times before it's been fully executing. E.g., architectures
5959 with a delay slot. It needs to be stepped twice, once for
5960 the instruction and once for the delay slot. */
5961 int step_through_delay
5962 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5964 if (step_through_delay
)
5965 infrun_debug_printf ("step through delay");
5967 if (ecs
->event_thread
->control
.step_range_end
== 0
5968 && step_through_delay
)
5970 /* The user issued a continue when stopped at a breakpoint.
5971 Set up for another trap and get out of here. */
5972 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5976 else if (step_through_delay
)
5978 /* The user issued a step when stopped at a breakpoint.
5979 Maybe we should stop, maybe we should not - the delay
5980 slot *might* correspond to a line of source. In any
5981 case, don't decide that here, just set
5982 ecs->stepping_over_breakpoint, making sure we
5983 single-step again before breakpoints are re-inserted. */
5984 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5988 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5989 handles this event. */
5990 ecs
->event_thread
->control
.stop_bpstat
5991 = bpstat_stop_status (get_current_regcache ()->aspace (),
5992 ecs
->event_thread
->suspend
.stop_pc
,
5993 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
5995 /* Following in case break condition called a
5997 stop_print_frame
= true;
5999 /* This is where we handle "moribund" watchpoints. Unlike
6000 software breakpoints traps, hardware watchpoint traps are
6001 always distinguishable from random traps. If no high-level
6002 watchpoint is associated with the reported stop data address
6003 anymore, then the bpstat does not explain the signal ---
6004 simply make sure to ignore it if `stopped_by_watchpoint' is
6007 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6008 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6010 && stopped_by_watchpoint
)
6012 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6016 /* NOTE: cagney/2003-03-29: These checks for a random signal
6017 at one stage in the past included checks for an inferior
6018 function call's call dummy's return breakpoint. The original
6019 comment, that went with the test, read:
6021 ``End of a stack dummy. Some systems (e.g. Sony news) give
6022 another signal besides SIGTRAP, so check here as well as
6025 If someone ever tries to get call dummys on a
6026 non-executable stack to work (where the target would stop
6027 with something like a SIGSEGV), then those tests might need
6028 to be re-instated. Given, however, that the tests were only
6029 enabled when momentary breakpoints were not being used, I
6030 suspect that it won't be the case.
6032 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6033 be necessary for call dummies on a non-executable stack on
6036 /* See if the breakpoints module can explain the signal. */
6038 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6039 ecs
->event_thread
->suspend
.stop_signal
);
6041 /* Maybe this was a trap for a software breakpoint that has since
6043 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6045 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6046 ecs
->event_thread
->suspend
.stop_pc
))
6048 struct regcache
*regcache
;
6051 /* Re-adjust PC to what the program would see if GDB was not
6053 regcache
= get_thread_regcache (ecs
->event_thread
);
6054 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6057 gdb::optional
<scoped_restore_tmpl
<int>>
6058 restore_operation_disable
;
6060 if (record_full_is_used ())
6061 restore_operation_disable
.emplace
6062 (record_full_gdb_operation_disable_set ());
6064 regcache_write_pc (regcache
,
6065 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6070 /* A delayed software breakpoint event. Ignore the trap. */
6071 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6076 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6077 has since been removed. */
6078 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6080 /* A delayed hardware breakpoint event. Ignore the trap. */
6081 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6086 /* If not, perhaps stepping/nexting can. */
6088 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6089 && currently_stepping (ecs
->event_thread
));
6091 /* Perhaps the thread hit a single-step breakpoint of _another_
6092 thread. Single-step breakpoints are transparent to the
6093 breakpoints module. */
6095 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6097 /* No? Perhaps we got a moribund watchpoint. */
6099 random_signal
= !stopped_by_watchpoint
;
6101 /* Always stop if the user explicitly requested this thread to
6103 if (ecs
->event_thread
->stop_requested
)
6106 infrun_debug_printf ("user-requested stop");
6109 /* For the program's own signals, act according to
6110 the signal handling tables. */
6114 /* Signal not for debugging purposes. */
6115 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6116 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6118 infrun_debug_printf ("random signal (%s)",
6119 gdb_signal_to_symbol_string (stop_signal
));
6121 stopped_by_random_signal
= 1;
6123 /* Always stop on signals if we're either just gaining control
6124 of the program, or the user explicitly requested this thread
6125 to remain stopped. */
6126 if (stop_soon
!= NO_STOP_QUIETLY
6127 || ecs
->event_thread
->stop_requested
6129 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6135 /* Notify observers the signal has "handle print" set. Note we
6136 returned early above if stopping; normal_stop handles the
6137 printing in that case. */
6138 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6140 /* The signal table tells us to print about this signal. */
6141 target_terminal::ours_for_output ();
6142 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6143 target_terminal::inferior ();
6146 /* Clear the signal if it should not be passed. */
6147 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6148 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6150 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6151 && ecs
->event_thread
->control
.trap_expected
6152 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6154 /* We were just starting a new sequence, attempting to
6155 single-step off of a breakpoint and expecting a SIGTRAP.
6156 Instead this signal arrives. This signal will take us out
6157 of the stepping range so GDB needs to remember to, when
6158 the signal handler returns, resume stepping off that
6160 /* To simplify things, "continue" is forced to use the same
6161 code paths as single-step - set a breakpoint at the
6162 signal return address and then, once hit, step off that
6164 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6166 insert_hp_step_resume_breakpoint_at_frame (frame
);
6167 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6168 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6169 ecs
->event_thread
->control
.trap_expected
= 0;
6171 /* If we were nexting/stepping some other thread, switch to
6172 it, so that we don't continue it, losing control. */
6173 if (!switch_back_to_stepped_thread (ecs
))
6178 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6179 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6181 || ecs
->event_thread
->control
.step_range_end
== 1)
6182 && frame_id_eq (get_stack_frame_id (frame
),
6183 ecs
->event_thread
->control
.step_stack_frame_id
)
6184 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6186 /* The inferior is about to take a signal that will take it
6187 out of the single step range. Set a breakpoint at the
6188 current PC (which is presumably where the signal handler
6189 will eventually return) and then allow the inferior to
6192 Note that this is only needed for a signal delivered
6193 while in the single-step range. Nested signals aren't a
6194 problem as they eventually all return. */
6195 infrun_debug_printf ("signal may take us out of single-step range");
6197 clear_step_over_info ();
6198 insert_hp_step_resume_breakpoint_at_frame (frame
);
6199 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6200 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6201 ecs
->event_thread
->control
.trap_expected
= 0;
6206 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6207 when either there's a nested signal, or when there's a
6208 pending signal enabled just as the signal handler returns
6209 (leaving the inferior at the step-resume-breakpoint without
6210 actually executing it). Either way continue until the
6211 breakpoint is really hit. */
6213 if (!switch_back_to_stepped_thread (ecs
))
6215 infrun_debug_printf ("random signal, keep going");
6222 process_event_stop_test (ecs
);
6225 /* Come here when we've got some debug event / signal we can explain
6226 (IOW, not a random signal), and test whether it should cause a
6227 stop, or whether we should resume the inferior (transparently).
6228 E.g., could be a breakpoint whose condition evaluates false; we
6229 could be still stepping within the line; etc. */
6232 process_event_stop_test (struct execution_control_state
*ecs
)
6234 struct symtab_and_line stop_pc_sal
;
6235 struct frame_info
*frame
;
6236 struct gdbarch
*gdbarch
;
6237 CORE_ADDR jmp_buf_pc
;
6238 struct bpstat_what what
;
6240 /* Handle cases caused by hitting a breakpoint. */
6242 frame
= get_current_frame ();
6243 gdbarch
= get_frame_arch (frame
);
6245 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6247 if (what
.call_dummy
)
6249 stop_stack_dummy
= what
.call_dummy
;
6252 /* A few breakpoint types have callbacks associated (e.g.,
6253 bp_jit_event). Run them now. */
6254 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6256 /* If we hit an internal event that triggers symbol changes, the
6257 current frame will be invalidated within bpstat_what (e.g., if we
6258 hit an internal solib event). Re-fetch it. */
6259 frame
= get_current_frame ();
6260 gdbarch
= get_frame_arch (frame
);
6262 switch (what
.main_action
)
6264 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6265 /* If we hit the breakpoint at longjmp while stepping, we
6266 install a momentary breakpoint at the target of the
6269 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6271 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6273 if (what
.is_longjmp
)
6275 struct value
*arg_value
;
6277 /* If we set the longjmp breakpoint via a SystemTap probe,
6278 then use it to extract the arguments. The destination PC
6279 is the third argument to the probe. */
6280 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6283 jmp_buf_pc
= value_as_address (arg_value
);
6284 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6286 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6287 || !gdbarch_get_longjmp_target (gdbarch
,
6288 frame
, &jmp_buf_pc
))
6290 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6291 "(!gdbarch_get_longjmp_target)");
6296 /* Insert a breakpoint at resume address. */
6297 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6300 check_exception_resume (ecs
, frame
);
6304 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6306 struct frame_info
*init_frame
;
6308 /* There are several cases to consider.
6310 1. The initiating frame no longer exists. In this case we
6311 must stop, because the exception or longjmp has gone too
6314 2. The initiating frame exists, and is the same as the
6315 current frame. We stop, because the exception or longjmp
6318 3. The initiating frame exists and is different from the
6319 current frame. This means the exception or longjmp has
6320 been caught beneath the initiating frame, so keep going.
6322 4. longjmp breakpoint has been placed just to protect
6323 against stale dummy frames and user is not interested in
6324 stopping around longjmps. */
6326 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6328 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6330 delete_exception_resume_breakpoint (ecs
->event_thread
);
6332 if (what
.is_longjmp
)
6334 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6336 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6344 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6348 struct frame_id current_id
6349 = get_frame_id (get_current_frame ());
6350 if (frame_id_eq (current_id
,
6351 ecs
->event_thread
->initiating_frame
))
6353 /* Case 2. Fall through. */
6363 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6365 delete_step_resume_breakpoint (ecs
->event_thread
);
6367 end_stepping_range (ecs
);
6371 case BPSTAT_WHAT_SINGLE
:
6372 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6373 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6374 /* Still need to check other stuff, at least the case where we
6375 are stepping and step out of the right range. */
6378 case BPSTAT_WHAT_STEP_RESUME
:
6379 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6381 delete_step_resume_breakpoint (ecs
->event_thread
);
6382 if (ecs
->event_thread
->control
.proceed_to_finish
6383 && execution_direction
== EXEC_REVERSE
)
6385 struct thread_info
*tp
= ecs
->event_thread
;
6387 /* We are finishing a function in reverse, and just hit the
6388 step-resume breakpoint at the start address of the
6389 function, and we're almost there -- just need to back up
6390 by one more single-step, which should take us back to the
6392 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6396 fill_in_stop_func (gdbarch
, ecs
);
6397 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6398 && execution_direction
== EXEC_REVERSE
)
6400 /* We are stepping over a function call in reverse, and just
6401 hit the step-resume breakpoint at the start address of
6402 the function. Go back to single-stepping, which should
6403 take us back to the function call. */
6404 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6410 case BPSTAT_WHAT_STOP_NOISY
:
6411 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6412 stop_print_frame
= true;
6414 /* Assume the thread stopped for a breakpoint. We'll still check
6415 whether a/the breakpoint is there when the thread is next
6417 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6422 case BPSTAT_WHAT_STOP_SILENT
:
6423 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6424 stop_print_frame
= false;
6426 /* Assume the thread stopped for a breakpoint. We'll still check
6427 whether a/the breakpoint is there when the thread is next
6429 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6433 case BPSTAT_WHAT_HP_STEP_RESUME
:
6434 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6436 delete_step_resume_breakpoint (ecs
->event_thread
);
6437 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6439 /* Back when the step-resume breakpoint was inserted, we
6440 were trying to single-step off a breakpoint. Go back to
6442 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6443 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6449 case BPSTAT_WHAT_KEEP_CHECKING
:
6453 /* If we stepped a permanent breakpoint and we had a high priority
6454 step-resume breakpoint for the address we stepped, but we didn't
6455 hit it, then we must have stepped into the signal handler. The
6456 step-resume was only necessary to catch the case of _not_
6457 stepping into the handler, so delete it, and fall through to
6458 checking whether the step finished. */
6459 if (ecs
->event_thread
->stepped_breakpoint
)
6461 struct breakpoint
*sr_bp
6462 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6465 && sr_bp
->loc
->permanent
6466 && sr_bp
->type
== bp_hp_step_resume
6467 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6469 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6470 delete_step_resume_breakpoint (ecs
->event_thread
);
6471 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6475 /* We come here if we hit a breakpoint but should not stop for it.
6476 Possibly we also were stepping and should stop for that. So fall
6477 through and test for stepping. But, if not stepping, do not
6480 /* In all-stop mode, if we're currently stepping but have stopped in
6481 some other thread, we need to switch back to the stepped thread. */
6482 if (switch_back_to_stepped_thread (ecs
))
6485 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6487 infrun_debug_printf ("step-resume breakpoint is inserted");
6489 /* Having a step-resume breakpoint overrides anything
6490 else having to do with stepping commands until
6491 that breakpoint is reached. */
6496 if (ecs
->event_thread
->control
.step_range_end
== 0)
6498 infrun_debug_printf ("no stepping, continue");
6499 /* Likewise if we aren't even stepping. */
6504 /* Re-fetch current thread's frame in case the code above caused
6505 the frame cache to be re-initialized, making our FRAME variable
6506 a dangling pointer. */
6507 frame
= get_current_frame ();
6508 gdbarch
= get_frame_arch (frame
);
6509 fill_in_stop_func (gdbarch
, ecs
);
6511 /* If stepping through a line, keep going if still within it.
6513 Note that step_range_end is the address of the first instruction
6514 beyond the step range, and NOT the address of the last instruction
6517 Note also that during reverse execution, we may be stepping
6518 through a function epilogue and therefore must detect when
6519 the current-frame changes in the middle of a line. */
6521 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6523 && (execution_direction
!= EXEC_REVERSE
6524 || frame_id_eq (get_frame_id (frame
),
6525 ecs
->event_thread
->control
.step_frame_id
)))
6528 ("stepping inside range [%s-%s]",
6529 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6530 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6532 /* Tentatively re-enable range stepping; `resume' disables it if
6533 necessary (e.g., if we're stepping over a breakpoint or we
6534 have software watchpoints). */
6535 ecs
->event_thread
->control
.may_range_step
= 1;
6537 /* When stepping backward, stop at beginning of line range
6538 (unless it's the function entry point, in which case
6539 keep going back to the call point). */
6540 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6541 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6542 && stop_pc
!= ecs
->stop_func_start
6543 && execution_direction
== EXEC_REVERSE
)
6544 end_stepping_range (ecs
);
6551 /* We stepped out of the stepping range. */
6553 /* If we are stepping at the source level and entered the runtime
6554 loader dynamic symbol resolution code...
6556 EXEC_FORWARD: we keep on single stepping until we exit the run
6557 time loader code and reach the callee's address.
6559 EXEC_REVERSE: we've already executed the callee (backward), and
6560 the runtime loader code is handled just like any other
6561 undebuggable function call. Now we need only keep stepping
6562 backward through the trampoline code, and that's handled further
6563 down, so there is nothing for us to do here. */
6565 if (execution_direction
!= EXEC_REVERSE
6566 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6567 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6569 CORE_ADDR pc_after_resolver
=
6570 gdbarch_skip_solib_resolver (gdbarch
,
6571 ecs
->event_thread
->suspend
.stop_pc
);
6573 infrun_debug_printf ("stepped into dynsym resolve code");
6575 if (pc_after_resolver
)
6577 /* Set up a step-resume breakpoint at the address
6578 indicated by SKIP_SOLIB_RESOLVER. */
6579 symtab_and_line sr_sal
;
6580 sr_sal
.pc
= pc_after_resolver
;
6581 sr_sal
.pspace
= get_frame_program_space (frame
);
6583 insert_step_resume_breakpoint_at_sal (gdbarch
,
6584 sr_sal
, null_frame_id
);
6591 /* Step through an indirect branch thunk. */
6592 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6593 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6594 ecs
->event_thread
->suspend
.stop_pc
))
6596 infrun_debug_printf ("stepped into indirect branch thunk");
6601 if (ecs
->event_thread
->control
.step_range_end
!= 1
6602 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6603 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6604 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6606 infrun_debug_printf ("stepped into signal trampoline");
6607 /* The inferior, while doing a "step" or "next", has ended up in
6608 a signal trampoline (either by a signal being delivered or by
6609 the signal handler returning). Just single-step until the
6610 inferior leaves the trampoline (either by calling the handler
6616 /* If we're in the return path from a shared library trampoline,
6617 we want to proceed through the trampoline when stepping. */
6618 /* macro/2012-04-25: This needs to come before the subroutine
6619 call check below as on some targets return trampolines look
6620 like subroutine calls (MIPS16 return thunks). */
6621 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6622 ecs
->event_thread
->suspend
.stop_pc
,
6623 ecs
->stop_func_name
)
6624 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6626 /* Determine where this trampoline returns. */
6627 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6628 CORE_ADDR real_stop_pc
6629 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6631 infrun_debug_printf ("stepped into solib return tramp");
6633 /* Only proceed through if we know where it's going. */
6636 /* And put the step-breakpoint there and go until there. */
6637 symtab_and_line sr_sal
;
6638 sr_sal
.pc
= real_stop_pc
;
6639 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6640 sr_sal
.pspace
= get_frame_program_space (frame
);
6642 /* Do not specify what the fp should be when we stop since
6643 on some machines the prologue is where the new fp value
6645 insert_step_resume_breakpoint_at_sal (gdbarch
,
6646 sr_sal
, null_frame_id
);
6648 /* Restart without fiddling with the step ranges or
6655 /* Check for subroutine calls. The check for the current frame
6656 equalling the step ID is not necessary - the check of the
6657 previous frame's ID is sufficient - but it is a common case and
6658 cheaper than checking the previous frame's ID.
6660 NOTE: frame_id_eq will never report two invalid frame IDs as
6661 being equal, so to get into this block, both the current and
6662 previous frame must have valid frame IDs. */
6663 /* The outer_frame_id check is a heuristic to detect stepping
6664 through startup code. If we step over an instruction which
6665 sets the stack pointer from an invalid value to a valid value,
6666 we may detect that as a subroutine call from the mythical
6667 "outermost" function. This could be fixed by marking
6668 outermost frames as !stack_p,code_p,special_p. Then the
6669 initial outermost frame, before sp was valid, would
6670 have code_addr == &_start. See the comment in frame_id_eq
6672 if (!frame_id_eq (get_stack_frame_id (frame
),
6673 ecs
->event_thread
->control
.step_stack_frame_id
)
6674 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6675 ecs
->event_thread
->control
.step_stack_frame_id
)
6676 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6678 || (ecs
->event_thread
->control
.step_start_function
6679 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6681 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6682 CORE_ADDR real_stop_pc
;
6684 infrun_debug_printf ("stepped into subroutine");
6686 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6688 /* I presume that step_over_calls is only 0 when we're
6689 supposed to be stepping at the assembly language level
6690 ("stepi"). Just stop. */
6691 /* And this works the same backward as frontward. MVS */
6692 end_stepping_range (ecs
);
6696 /* Reverse stepping through solib trampolines. */
6698 if (execution_direction
== EXEC_REVERSE
6699 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6700 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6701 || (ecs
->stop_func_start
== 0
6702 && in_solib_dynsym_resolve_code (stop_pc
))))
6704 /* Any solib trampoline code can be handled in reverse
6705 by simply continuing to single-step. We have already
6706 executed the solib function (backwards), and a few
6707 steps will take us back through the trampoline to the
6713 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6715 /* We're doing a "next".
6717 Normal (forward) execution: set a breakpoint at the
6718 callee's return address (the address at which the caller
6721 Reverse (backward) execution. set the step-resume
6722 breakpoint at the start of the function that we just
6723 stepped into (backwards), and continue to there. When we
6724 get there, we'll need to single-step back to the caller. */
6726 if (execution_direction
== EXEC_REVERSE
)
6728 /* If we're already at the start of the function, we've either
6729 just stepped backward into a single instruction function,
6730 or stepped back out of a signal handler to the first instruction
6731 of the function. Just keep going, which will single-step back
6733 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6735 /* Normal function call return (static or dynamic). */
6736 symtab_and_line sr_sal
;
6737 sr_sal
.pc
= ecs
->stop_func_start
;
6738 sr_sal
.pspace
= get_frame_program_space (frame
);
6739 insert_step_resume_breakpoint_at_sal (gdbarch
,
6740 sr_sal
, null_frame_id
);
6744 insert_step_resume_breakpoint_at_caller (frame
);
6750 /* If we are in a function call trampoline (a stub between the
6751 calling routine and the real function), locate the real
6752 function. That's what tells us (a) whether we want to step
6753 into it at all, and (b) what prologue we want to run to the
6754 end of, if we do step into it. */
6755 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6756 if (real_stop_pc
== 0)
6757 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6758 if (real_stop_pc
!= 0)
6759 ecs
->stop_func_start
= real_stop_pc
;
6761 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6763 symtab_and_line sr_sal
;
6764 sr_sal
.pc
= ecs
->stop_func_start
;
6765 sr_sal
.pspace
= get_frame_program_space (frame
);
6767 insert_step_resume_breakpoint_at_sal (gdbarch
,
6768 sr_sal
, null_frame_id
);
6773 /* If we have line number information for the function we are
6774 thinking of stepping into and the function isn't on the skip
6777 If there are several symtabs at that PC (e.g. with include
6778 files), just want to know whether *any* of them have line
6779 numbers. find_pc_line handles this. */
6781 struct symtab_and_line tmp_sal
;
6783 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6784 if (tmp_sal
.line
!= 0
6785 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6787 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6789 if (execution_direction
== EXEC_REVERSE
)
6790 handle_step_into_function_backward (gdbarch
, ecs
);
6792 handle_step_into_function (gdbarch
, ecs
);
6797 /* If we have no line number and the step-stop-if-no-debug is
6798 set, we stop the step so that the user has a chance to switch
6799 in assembly mode. */
6800 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6801 && step_stop_if_no_debug
)
6803 end_stepping_range (ecs
);
6807 if (execution_direction
== EXEC_REVERSE
)
6809 /* If we're already at the start of the function, we've either just
6810 stepped backward into a single instruction function without line
6811 number info, or stepped back out of a signal handler to the first
6812 instruction of the function without line number info. Just keep
6813 going, which will single-step back to the caller. */
6814 if (ecs
->stop_func_start
!= stop_pc
)
6816 /* Set a breakpoint at callee's start address.
6817 From there we can step once and be back in the caller. */
6818 symtab_and_line sr_sal
;
6819 sr_sal
.pc
= ecs
->stop_func_start
;
6820 sr_sal
.pspace
= get_frame_program_space (frame
);
6821 insert_step_resume_breakpoint_at_sal (gdbarch
,
6822 sr_sal
, null_frame_id
);
6826 /* Set a breakpoint at callee's return address (the address
6827 at which the caller will resume). */
6828 insert_step_resume_breakpoint_at_caller (frame
);
6834 /* Reverse stepping through solib trampolines. */
6836 if (execution_direction
== EXEC_REVERSE
6837 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6839 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6841 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6842 || (ecs
->stop_func_start
== 0
6843 && in_solib_dynsym_resolve_code (stop_pc
)))
6845 /* Any solib trampoline code can be handled in reverse
6846 by simply continuing to single-step. We have already
6847 executed the solib function (backwards), and a few
6848 steps will take us back through the trampoline to the
6853 else if (in_solib_dynsym_resolve_code (stop_pc
))
6855 /* Stepped backward into the solib dynsym resolver.
6856 Set a breakpoint at its start and continue, then
6857 one more step will take us out. */
6858 symtab_and_line sr_sal
;
6859 sr_sal
.pc
= ecs
->stop_func_start
;
6860 sr_sal
.pspace
= get_frame_program_space (frame
);
6861 insert_step_resume_breakpoint_at_sal (gdbarch
,
6862 sr_sal
, null_frame_id
);
6868 /* This always returns the sal for the inner-most frame when we are in a
6869 stack of inlined frames, even if GDB actually believes that it is in a
6870 more outer frame. This is checked for below by calls to
6871 inline_skipped_frames. */
6872 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6874 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6875 the trampoline processing logic, however, there are some trampolines
6876 that have no names, so we should do trampoline handling first. */
6877 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6878 && ecs
->stop_func_name
== NULL
6879 && stop_pc_sal
.line
== 0)
6881 infrun_debug_printf ("stepped into undebuggable function");
6883 /* The inferior just stepped into, or returned to, an
6884 undebuggable function (where there is no debugging information
6885 and no line number corresponding to the address where the
6886 inferior stopped). Since we want to skip this kind of code,
6887 we keep going until the inferior returns from this
6888 function - unless the user has asked us not to (via
6889 set step-mode) or we no longer know how to get back
6890 to the call site. */
6891 if (step_stop_if_no_debug
6892 || !frame_id_p (frame_unwind_caller_id (frame
)))
6894 /* If we have no line number and the step-stop-if-no-debug
6895 is set, we stop the step so that the user has a chance to
6896 switch in assembly mode. */
6897 end_stepping_range (ecs
);
6902 /* Set a breakpoint at callee's return address (the address
6903 at which the caller will resume). */
6904 insert_step_resume_breakpoint_at_caller (frame
);
6910 if (ecs
->event_thread
->control
.step_range_end
== 1)
6912 /* It is stepi or nexti. We always want to stop stepping after
6914 infrun_debug_printf ("stepi/nexti");
6915 end_stepping_range (ecs
);
6919 if (stop_pc_sal
.line
== 0)
6921 /* We have no line number information. That means to stop
6922 stepping (does this always happen right after one instruction,
6923 when we do "s" in a function with no line numbers,
6924 or can this happen as a result of a return or longjmp?). */
6925 infrun_debug_printf ("line number info");
6926 end_stepping_range (ecs
);
6930 /* Look for "calls" to inlined functions, part one. If the inline
6931 frame machinery detected some skipped call sites, we have entered
6932 a new inline function. */
6934 if (frame_id_eq (get_frame_id (get_current_frame ()),
6935 ecs
->event_thread
->control
.step_frame_id
)
6936 && inline_skipped_frames (ecs
->event_thread
))
6938 infrun_debug_printf ("stepped into inlined function");
6940 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6942 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6944 /* For "step", we're going to stop. But if the call site
6945 for this inlined function is on the same source line as
6946 we were previously stepping, go down into the function
6947 first. Otherwise stop at the call site. */
6949 if (call_sal
.line
== ecs
->event_thread
->current_line
6950 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6952 step_into_inline_frame (ecs
->event_thread
);
6953 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6960 end_stepping_range (ecs
);
6965 /* For "next", we should stop at the call site if it is on a
6966 different source line. Otherwise continue through the
6967 inlined function. */
6968 if (call_sal
.line
== ecs
->event_thread
->current_line
6969 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6972 end_stepping_range (ecs
);
6977 /* Look for "calls" to inlined functions, part two. If we are still
6978 in the same real function we were stepping through, but we have
6979 to go further up to find the exact frame ID, we are stepping
6980 through a more inlined call beyond its call site. */
6982 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6983 && !frame_id_eq (get_frame_id (get_current_frame ()),
6984 ecs
->event_thread
->control
.step_frame_id
)
6985 && stepped_in_from (get_current_frame (),
6986 ecs
->event_thread
->control
.step_frame_id
))
6988 infrun_debug_printf ("stepping through inlined function");
6990 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
6991 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6994 end_stepping_range (ecs
);
6998 bool refresh_step_info
= true;
6999 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7000 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7001 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7003 if (stop_pc_sal
.is_stmt
)
7005 /* We are at the start of a different line. So stop. Note that
7006 we don't stop if we step into the middle of a different line.
7007 That is said to make things like for (;;) statements work
7009 infrun_debug_printf ("stepped to a different line");
7010 end_stepping_range (ecs
);
7013 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7014 ecs
->event_thread
->control
.step_frame_id
))
7016 /* We are at the start of a different line, however, this line is
7017 not marked as a statement, and we have not changed frame. We
7018 ignore this line table entry, and continue stepping forward,
7019 looking for a better place to stop. */
7020 refresh_step_info
= false;
7021 infrun_debug_printf ("stepped to a different line, but "
7022 "it's not the start of a statement");
7026 /* We aren't done stepping.
7028 Optimize by setting the stepping range to the line.
7029 (We might not be in the original line, but if we entered a
7030 new line in mid-statement, we continue stepping. This makes
7031 things like for(;;) statements work better.)
7033 If we entered a SAL that indicates a non-statement line table entry,
7034 then we update the stepping range, but we don't update the step info,
7035 which includes things like the line number we are stepping away from.
7036 This means we will stop when we find a line table entry that is marked
7037 as is-statement, even if it matches the non-statement one we just
7040 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7041 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7042 ecs
->event_thread
->control
.may_range_step
= 1;
7043 if (refresh_step_info
)
7044 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7046 infrun_debug_printf ("keep going");
7050 /* In all-stop mode, if we're currently stepping but have stopped in
7051 some other thread, we may need to switch back to the stepped
7052 thread. Returns true we set the inferior running, false if we left
7053 it stopped (and the event needs further processing). */
7056 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7058 if (!target_is_non_stop_p ())
7060 struct thread_info
*stepping_thread
;
7062 /* If any thread is blocked on some internal breakpoint, and we
7063 simply need to step over that breakpoint to get it going
7064 again, do that first. */
7066 /* However, if we see an event for the stepping thread, then we
7067 know all other threads have been moved past their breakpoints
7068 already. Let the caller check whether the step is finished,
7069 etc., before deciding to move it past a breakpoint. */
7070 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7073 /* Check if the current thread is blocked on an incomplete
7074 step-over, interrupted by a random signal. */
7075 if (ecs
->event_thread
->control
.trap_expected
7076 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7079 ("need to finish step-over of [%s]",
7080 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7085 /* Check if the current thread is blocked by a single-step
7086 breakpoint of another thread. */
7087 if (ecs
->hit_singlestep_breakpoint
)
7089 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7090 target_pid_to_str (ecs
->ptid
).c_str ());
7095 /* If this thread needs yet another step-over (e.g., stepping
7096 through a delay slot), do it first before moving on to
7098 if (thread_still_needs_step_over (ecs
->event_thread
))
7101 ("thread [%s] still needs step-over",
7102 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7107 /* If scheduler locking applies even if not stepping, there's no
7108 need to walk over threads. Above we've checked whether the
7109 current thread is stepping. If some other thread not the
7110 event thread is stepping, then it must be that scheduler
7111 locking is not in effect. */
7112 if (schedlock_applies (ecs
->event_thread
))
7115 /* Otherwise, we no longer expect a trap in the current thread.
7116 Clear the trap_expected flag before switching back -- this is
7117 what keep_going does as well, if we call it. */
7118 ecs
->event_thread
->control
.trap_expected
= 0;
7120 /* Likewise, clear the signal if it should not be passed. */
7121 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7122 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7124 /* Do all pending step-overs before actually proceeding with
7126 if (start_step_over ())
7128 prepare_to_wait (ecs
);
7132 /* Look for the stepping/nexting thread. */
7133 stepping_thread
= NULL
;
7135 for (thread_info
*tp
: all_non_exited_threads ())
7137 switch_to_thread_no_regs (tp
);
7139 /* Ignore threads of processes the caller is not
7142 && (tp
->inf
->process_target () != ecs
->target
7143 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7146 /* When stepping over a breakpoint, we lock all threads
7147 except the one that needs to move past the breakpoint.
7148 If a non-event thread has this set, the "incomplete
7149 step-over" check above should have caught it earlier. */
7150 if (tp
->control
.trap_expected
)
7152 internal_error (__FILE__
, __LINE__
,
7153 "[%s] has inconsistent state: "
7154 "trap_expected=%d\n",
7155 target_pid_to_str (tp
->ptid
).c_str (),
7156 tp
->control
.trap_expected
);
7159 /* Did we find the stepping thread? */
7160 if (tp
->control
.step_range_end
)
7162 /* Yep. There should only one though. */
7163 gdb_assert (stepping_thread
== NULL
);
7165 /* The event thread is handled at the top, before we
7167 gdb_assert (tp
!= ecs
->event_thread
);
7169 /* If some thread other than the event thread is
7170 stepping, then scheduler locking can't be in effect,
7171 otherwise we wouldn't have resumed the current event
7172 thread in the first place. */
7173 gdb_assert (!schedlock_applies (tp
));
7175 stepping_thread
= tp
;
7179 if (stepping_thread
!= NULL
)
7181 infrun_debug_printf ("switching back to stepped thread");
7183 if (keep_going_stepped_thread (stepping_thread
))
7185 prepare_to_wait (ecs
);
7190 switch_to_thread (ecs
->event_thread
);
7196 /* Set a previously stepped thread back to stepping. Returns true on
7197 success, false if the resume is not possible (e.g., the thread
7201 keep_going_stepped_thread (struct thread_info
*tp
)
7203 struct frame_info
*frame
;
7204 struct execution_control_state ecss
;
7205 struct execution_control_state
*ecs
= &ecss
;
7207 /* If the stepping thread exited, then don't try to switch back and
7208 resume it, which could fail in several different ways depending
7209 on the target. Instead, just keep going.
7211 We can find a stepping dead thread in the thread list in two
7214 - The target supports thread exit events, and when the target
7215 tries to delete the thread from the thread list, inferior_ptid
7216 pointed at the exiting thread. In such case, calling
7217 delete_thread does not really remove the thread from the list;
7218 instead, the thread is left listed, with 'exited' state.
7220 - The target's debug interface does not support thread exit
7221 events, and so we have no idea whatsoever if the previously
7222 stepping thread is still alive. For that reason, we need to
7223 synchronously query the target now. */
7225 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7227 infrun_debug_printf ("not resuming previously stepped thread, it has "
7234 infrun_debug_printf ("resuming previously stepped thread");
7236 reset_ecs (ecs
, tp
);
7237 switch_to_thread (tp
);
7239 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7240 frame
= get_current_frame ();
7242 /* If the PC of the thread we were trying to single-step has
7243 changed, then that thread has trapped or been signaled, but the
7244 event has not been reported to GDB yet. Re-poll the target
7245 looking for this particular thread's event (i.e. temporarily
7246 enable schedlock) by:
7248 - setting a break at the current PC
7249 - resuming that particular thread, only (by setting trap
7252 This prevents us continuously moving the single-step breakpoint
7253 forward, one instruction at a time, overstepping. */
7255 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7259 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7260 paddress (target_gdbarch (), tp
->prev_pc
),
7261 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7263 /* Clear the info of the previous step-over, as it's no longer
7264 valid (if the thread was trying to step over a breakpoint, it
7265 has already succeeded). It's what keep_going would do too,
7266 if we called it. Do this before trying to insert the sss
7267 breakpoint, otherwise if we were previously trying to step
7268 over this exact address in another thread, the breakpoint is
7270 clear_step_over_info ();
7271 tp
->control
.trap_expected
= 0;
7273 insert_single_step_breakpoint (get_frame_arch (frame
),
7274 get_frame_address_space (frame
),
7275 tp
->suspend
.stop_pc
);
7278 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7279 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7283 infrun_debug_printf ("expected thread still hasn't advanced");
7285 keep_going_pass_signal (ecs
);
7291 /* Is thread TP in the middle of (software or hardware)
7292 single-stepping? (Note the result of this function must never be
7293 passed directly as target_resume's STEP parameter.) */
7296 currently_stepping (struct thread_info
*tp
)
7298 return ((tp
->control
.step_range_end
7299 && tp
->control
.step_resume_breakpoint
== NULL
)
7300 || tp
->control
.trap_expected
7301 || tp
->stepped_breakpoint
7302 || bpstat_should_step ());
7305 /* Inferior has stepped into a subroutine call with source code that
7306 we should not step over. Do step to the first line of code in
7310 handle_step_into_function (struct gdbarch
*gdbarch
,
7311 struct execution_control_state
*ecs
)
7313 fill_in_stop_func (gdbarch
, ecs
);
7315 compunit_symtab
*cust
7316 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7317 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7318 ecs
->stop_func_start
7319 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7321 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7322 /* Use the step_resume_break to step until the end of the prologue,
7323 even if that involves jumps (as it seems to on the vax under
7325 /* If the prologue ends in the middle of a source line, continue to
7326 the end of that source line (if it is still within the function).
7327 Otherwise, just go to end of prologue. */
7328 if (stop_func_sal
.end
7329 && stop_func_sal
.pc
!= ecs
->stop_func_start
7330 && stop_func_sal
.end
< ecs
->stop_func_end
)
7331 ecs
->stop_func_start
= stop_func_sal
.end
;
7333 /* Architectures which require breakpoint adjustment might not be able
7334 to place a breakpoint at the computed address. If so, the test
7335 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7336 ecs->stop_func_start to an address at which a breakpoint may be
7337 legitimately placed.
7339 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7340 made, GDB will enter an infinite loop when stepping through
7341 optimized code consisting of VLIW instructions which contain
7342 subinstructions corresponding to different source lines. On
7343 FR-V, it's not permitted to place a breakpoint on any but the
7344 first subinstruction of a VLIW instruction. When a breakpoint is
7345 set, GDB will adjust the breakpoint address to the beginning of
7346 the VLIW instruction. Thus, we need to make the corresponding
7347 adjustment here when computing the stop address. */
7349 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7351 ecs
->stop_func_start
7352 = gdbarch_adjust_breakpoint_address (gdbarch
,
7353 ecs
->stop_func_start
);
7356 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7358 /* We are already there: stop now. */
7359 end_stepping_range (ecs
);
7364 /* Put the step-breakpoint there and go until there. */
7365 symtab_and_line sr_sal
;
7366 sr_sal
.pc
= ecs
->stop_func_start
;
7367 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7368 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7370 /* Do not specify what the fp should be when we stop since on
7371 some machines the prologue is where the new fp value is
7373 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7375 /* And make sure stepping stops right away then. */
7376 ecs
->event_thread
->control
.step_range_end
7377 = ecs
->event_thread
->control
.step_range_start
;
7382 /* Inferior has stepped backward into a subroutine call with source
7383 code that we should not step over. Do step to the beginning of the
7384 last line of code in it. */
7387 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7388 struct execution_control_state
*ecs
)
7390 struct compunit_symtab
*cust
;
7391 struct symtab_and_line stop_func_sal
;
7393 fill_in_stop_func (gdbarch
, ecs
);
7395 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7396 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7397 ecs
->stop_func_start
7398 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7400 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7402 /* OK, we're just going to keep stepping here. */
7403 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7405 /* We're there already. Just stop stepping now. */
7406 end_stepping_range (ecs
);
7410 /* Else just reset the step range and keep going.
7411 No step-resume breakpoint, they don't work for
7412 epilogues, which can have multiple entry paths. */
7413 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7414 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7420 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7421 This is used to both functions and to skip over code. */
7424 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7425 struct symtab_and_line sr_sal
,
7426 struct frame_id sr_id
,
7427 enum bptype sr_type
)
7429 /* There should never be more than one step-resume or longjmp-resume
7430 breakpoint per thread, so we should never be setting a new
7431 step_resume_breakpoint when one is already active. */
7432 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7433 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7435 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7436 paddress (gdbarch
, sr_sal
.pc
));
7438 inferior_thread ()->control
.step_resume_breakpoint
7439 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7443 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7444 struct symtab_and_line sr_sal
,
7445 struct frame_id sr_id
)
7447 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7452 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7453 This is used to skip a potential signal handler.
7455 This is called with the interrupted function's frame. The signal
7456 handler, when it returns, will resume the interrupted function at
7460 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7462 gdb_assert (return_frame
!= NULL
);
7464 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7466 symtab_and_line sr_sal
;
7467 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7468 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7469 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7471 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7472 get_stack_frame_id (return_frame
),
7476 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7477 is used to skip a function after stepping into it (for "next" or if
7478 the called function has no debugging information).
7480 The current function has almost always been reached by single
7481 stepping a call or return instruction. NEXT_FRAME belongs to the
7482 current function, and the breakpoint will be set at the caller's
7485 This is a separate function rather than reusing
7486 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7487 get_prev_frame, which may stop prematurely (see the implementation
7488 of frame_unwind_caller_id for an example). */
7491 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7493 /* We shouldn't have gotten here if we don't know where the call site
7495 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7497 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7499 symtab_and_line sr_sal
;
7500 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7501 frame_unwind_caller_pc (next_frame
));
7502 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7503 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7505 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7506 frame_unwind_caller_id (next_frame
));
7509 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7510 new breakpoint at the target of a jmp_buf. The handling of
7511 longjmp-resume uses the same mechanisms used for handling
7512 "step-resume" breakpoints. */
7515 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7517 /* There should never be more than one longjmp-resume breakpoint per
7518 thread, so we should never be setting a new
7519 longjmp_resume_breakpoint when one is already active. */
7520 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7522 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7523 paddress (gdbarch
, pc
));
7525 inferior_thread ()->control
.exception_resume_breakpoint
=
7526 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7529 /* Insert an exception resume breakpoint. TP is the thread throwing
7530 the exception. The block B is the block of the unwinder debug hook
7531 function. FRAME is the frame corresponding to the call to this
7532 function. SYM is the symbol of the function argument holding the
7533 target PC of the exception. */
7536 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7537 const struct block
*b
,
7538 struct frame_info
*frame
,
7543 struct block_symbol vsym
;
7544 struct value
*value
;
7546 struct breakpoint
*bp
;
7548 vsym
= lookup_symbol_search_name (sym
->search_name (),
7550 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7551 /* If the value was optimized out, revert to the old behavior. */
7552 if (! value_optimized_out (value
))
7554 handler
= value_as_address (value
);
7556 infrun_debug_printf ("exception resume at %lx",
7557 (unsigned long) handler
);
7559 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7561 bp_exception_resume
).release ();
7563 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7566 bp
->thread
= tp
->global_num
;
7567 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7570 catch (const gdb_exception_error
&e
)
7572 /* We want to ignore errors here. */
7576 /* A helper for check_exception_resume that sets an
7577 exception-breakpoint based on a SystemTap probe. */
7580 insert_exception_resume_from_probe (struct thread_info
*tp
,
7581 const struct bound_probe
*probe
,
7582 struct frame_info
*frame
)
7584 struct value
*arg_value
;
7586 struct breakpoint
*bp
;
7588 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7592 handler
= value_as_address (arg_value
);
7594 infrun_debug_printf ("exception resume at %s",
7595 paddress (probe
->objfile
->arch (), handler
));
7597 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7598 handler
, bp_exception_resume
).release ();
7599 bp
->thread
= tp
->global_num
;
7600 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7603 /* This is called when an exception has been intercepted. Check to
7604 see whether the exception's destination is of interest, and if so,
7605 set an exception resume breakpoint there. */
7608 check_exception_resume (struct execution_control_state
*ecs
,
7609 struct frame_info
*frame
)
7611 struct bound_probe probe
;
7612 struct symbol
*func
;
7614 /* First see if this exception unwinding breakpoint was set via a
7615 SystemTap probe point. If so, the probe has two arguments: the
7616 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7617 set a breakpoint there. */
7618 probe
= find_probe_by_pc (get_frame_pc (frame
));
7621 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7625 func
= get_frame_function (frame
);
7631 const struct block
*b
;
7632 struct block_iterator iter
;
7636 /* The exception breakpoint is a thread-specific breakpoint on
7637 the unwinder's debug hook, declared as:
7639 void _Unwind_DebugHook (void *cfa, void *handler);
7641 The CFA argument indicates the frame to which control is
7642 about to be transferred. HANDLER is the destination PC.
7644 We ignore the CFA and set a temporary breakpoint at HANDLER.
7645 This is not extremely efficient but it avoids issues in gdb
7646 with computing the DWARF CFA, and it also works even in weird
7647 cases such as throwing an exception from inside a signal
7650 b
= SYMBOL_BLOCK_VALUE (func
);
7651 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7653 if (!SYMBOL_IS_ARGUMENT (sym
))
7660 insert_exception_resume_breakpoint (ecs
->event_thread
,
7666 catch (const gdb_exception_error
&e
)
7672 stop_waiting (struct execution_control_state
*ecs
)
7674 infrun_debug_printf ("stop_waiting");
7676 /* Let callers know we don't want to wait for the inferior anymore. */
7677 ecs
->wait_some_more
= 0;
7679 /* If all-stop, but there exists a non-stop target, stop all
7680 threads now that we're presenting the stop to the user. */
7681 if (!non_stop
&& exists_non_stop_target ())
7682 stop_all_threads ();
7685 /* Like keep_going, but passes the signal to the inferior, even if the
7686 signal is set to nopass. */
7689 keep_going_pass_signal (struct execution_control_state
*ecs
)
7691 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7692 gdb_assert (!ecs
->event_thread
->resumed
);
7694 /* Save the pc before execution, to compare with pc after stop. */
7695 ecs
->event_thread
->prev_pc
7696 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7698 if (ecs
->event_thread
->control
.trap_expected
)
7700 struct thread_info
*tp
= ecs
->event_thread
;
7702 infrun_debug_printf ("%s has trap_expected set, "
7703 "resuming to collect trap",
7704 target_pid_to_str (tp
->ptid
).c_str ());
7706 /* We haven't yet gotten our trap, and either: intercepted a
7707 non-signal event (e.g., a fork); or took a signal which we
7708 are supposed to pass through to the inferior. Simply
7710 resume (ecs
->event_thread
->suspend
.stop_signal
);
7712 else if (step_over_info_valid_p ())
7714 /* Another thread is stepping over a breakpoint in-line. If
7715 this thread needs a step-over too, queue the request. In
7716 either case, this resume must be deferred for later. */
7717 struct thread_info
*tp
= ecs
->event_thread
;
7719 if (ecs
->hit_singlestep_breakpoint
7720 || thread_still_needs_step_over (tp
))
7722 infrun_debug_printf ("step-over already in progress: "
7723 "step-over for %s deferred",
7724 target_pid_to_str (tp
->ptid
).c_str ());
7725 global_thread_step_over_chain_enqueue (tp
);
7729 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7730 target_pid_to_str (tp
->ptid
).c_str ());
7735 struct regcache
*regcache
= get_current_regcache ();
7738 step_over_what step_what
;
7740 /* Either the trap was not expected, but we are continuing
7741 anyway (if we got a signal, the user asked it be passed to
7744 We got our expected trap, but decided we should resume from
7747 We're going to run this baby now!
7749 Note that insert_breakpoints won't try to re-insert
7750 already inserted breakpoints. Therefore, we don't
7751 care if breakpoints were already inserted, or not. */
7753 /* If we need to step over a breakpoint, and we're not using
7754 displaced stepping to do so, insert all breakpoints
7755 (watchpoints, etc.) but the one we're stepping over, step one
7756 instruction, and then re-insert the breakpoint when that step
7759 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7761 remove_bp
= (ecs
->hit_singlestep_breakpoint
7762 || (step_what
& STEP_OVER_BREAKPOINT
));
7763 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7765 /* We can't use displaced stepping if we need to step past a
7766 watchpoint. The instruction copied to the scratch pad would
7767 still trigger the watchpoint. */
7769 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7771 set_step_over_info (regcache
->aspace (),
7772 regcache_read_pc (regcache
), remove_wps
,
7773 ecs
->event_thread
->global_num
);
7775 else if (remove_wps
)
7776 set_step_over_info (NULL
, 0, remove_wps
, -1);
7778 /* If we now need to do an in-line step-over, we need to stop
7779 all other threads. Note this must be done before
7780 insert_breakpoints below, because that removes the breakpoint
7781 we're about to step over, otherwise other threads could miss
7783 if (step_over_info_valid_p () && target_is_non_stop_p ())
7784 stop_all_threads ();
7786 /* Stop stepping if inserting breakpoints fails. */
7789 insert_breakpoints ();
7791 catch (const gdb_exception_error
&e
)
7793 exception_print (gdb_stderr
, e
);
7795 clear_step_over_info ();
7799 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7801 resume (ecs
->event_thread
->suspend
.stop_signal
);
7804 prepare_to_wait (ecs
);
7807 /* Called when we should continue running the inferior, because the
7808 current event doesn't cause a user visible stop. This does the
7809 resuming part; waiting for the next event is done elsewhere. */
7812 keep_going (struct execution_control_state
*ecs
)
7814 if (ecs
->event_thread
->control
.trap_expected
7815 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7816 ecs
->event_thread
->control
.trap_expected
= 0;
7818 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7819 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7820 keep_going_pass_signal (ecs
);
7823 /* This function normally comes after a resume, before
7824 handle_inferior_event exits. It takes care of any last bits of
7825 housekeeping, and sets the all-important wait_some_more flag. */
7828 prepare_to_wait (struct execution_control_state
*ecs
)
7830 infrun_debug_printf ("prepare_to_wait");
7832 ecs
->wait_some_more
= 1;
7834 /* If the target can't async, emulate it by marking the infrun event
7835 handler such that as soon as we get back to the event-loop, we
7836 immediately end up in fetch_inferior_event again calling
7838 if (!target_can_async_p ())
7839 mark_infrun_async_event_handler ();
7842 /* We are done with the step range of a step/next/si/ni command.
7843 Called once for each n of a "step n" operation. */
7846 end_stepping_range (struct execution_control_state
*ecs
)
7848 ecs
->event_thread
->control
.stop_step
= 1;
7852 /* Several print_*_reason functions to print why the inferior has stopped.
7853 We always print something when the inferior exits, or receives a signal.
7854 The rest of the cases are dealt with later on in normal_stop and
7855 print_it_typical. Ideally there should be a call to one of these
7856 print_*_reason functions functions from handle_inferior_event each time
7857 stop_waiting is called.
7859 Note that we don't call these directly, instead we delegate that to
7860 the interpreters, through observers. Interpreters then call these
7861 with whatever uiout is right. */
7864 print_end_stepping_range_reason (struct ui_out
*uiout
)
7866 /* For CLI-like interpreters, print nothing. */
7868 if (uiout
->is_mi_like_p ())
7870 uiout
->field_string ("reason",
7871 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7876 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7878 annotate_signalled ();
7879 if (uiout
->is_mi_like_p ())
7881 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7882 uiout
->text ("\nProgram terminated with signal ");
7883 annotate_signal_name ();
7884 uiout
->field_string ("signal-name",
7885 gdb_signal_to_name (siggnal
));
7886 annotate_signal_name_end ();
7888 annotate_signal_string ();
7889 uiout
->field_string ("signal-meaning",
7890 gdb_signal_to_string (siggnal
));
7891 annotate_signal_string_end ();
7892 uiout
->text (".\n");
7893 uiout
->text ("The program no longer exists.\n");
7897 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7899 struct inferior
*inf
= current_inferior ();
7900 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7902 annotate_exited (exitstatus
);
7905 if (uiout
->is_mi_like_p ())
7906 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7907 std::string exit_code_str
7908 = string_printf ("0%o", (unsigned int) exitstatus
);
7909 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7910 plongest (inf
->num
), pidstr
.c_str (),
7911 string_field ("exit-code", exit_code_str
.c_str ()));
7915 if (uiout
->is_mi_like_p ())
7917 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7918 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7919 plongest (inf
->num
), pidstr
.c_str ());
7924 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7926 struct thread_info
*thr
= inferior_thread ();
7930 if (uiout
->is_mi_like_p ())
7932 else if (show_thread_that_caused_stop ())
7936 uiout
->text ("\nThread ");
7937 uiout
->field_string ("thread-id", print_thread_id (thr
));
7939 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7942 uiout
->text (" \"");
7943 uiout
->field_string ("name", name
);
7948 uiout
->text ("\nProgram");
7950 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7951 uiout
->text (" stopped");
7954 uiout
->text (" received signal ");
7955 annotate_signal_name ();
7956 if (uiout
->is_mi_like_p ())
7958 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7959 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7960 annotate_signal_name_end ();
7962 annotate_signal_string ();
7963 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7965 struct regcache
*regcache
= get_current_regcache ();
7966 struct gdbarch
*gdbarch
= regcache
->arch ();
7967 if (gdbarch_report_signal_info_p (gdbarch
))
7968 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
7970 annotate_signal_string_end ();
7972 uiout
->text (".\n");
7976 print_no_history_reason (struct ui_out
*uiout
)
7978 uiout
->text ("\nNo more reverse-execution history.\n");
7981 /* Print current location without a level number, if we have changed
7982 functions or hit a breakpoint. Print source line if we have one.
7983 bpstat_print contains the logic deciding in detail what to print,
7984 based on the event(s) that just occurred. */
7987 print_stop_location (struct target_waitstatus
*ws
)
7990 enum print_what source_flag
;
7991 int do_frame_printing
= 1;
7992 struct thread_info
*tp
= inferior_thread ();
7994 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
7998 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7999 should) carry around the function and does (or should) use
8000 that when doing a frame comparison. */
8001 if (tp
->control
.stop_step
8002 && frame_id_eq (tp
->control
.step_frame_id
,
8003 get_frame_id (get_current_frame ()))
8004 && (tp
->control
.step_start_function
8005 == find_pc_function (tp
->suspend
.stop_pc
)))
8007 /* Finished step, just print source line. */
8008 source_flag
= SRC_LINE
;
8012 /* Print location and source line. */
8013 source_flag
= SRC_AND_LOC
;
8016 case PRINT_SRC_AND_LOC
:
8017 /* Print location and source line. */
8018 source_flag
= SRC_AND_LOC
;
8020 case PRINT_SRC_ONLY
:
8021 source_flag
= SRC_LINE
;
8024 /* Something bogus. */
8025 source_flag
= SRC_LINE
;
8026 do_frame_printing
= 0;
8029 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8032 /* The behavior of this routine with respect to the source
8034 SRC_LINE: Print only source line
8035 LOCATION: Print only location
8036 SRC_AND_LOC: Print location and source line. */
8037 if (do_frame_printing
)
8038 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8044 print_stop_event (struct ui_out
*uiout
, bool displays
)
8046 struct target_waitstatus last
;
8047 struct thread_info
*tp
;
8049 get_last_target_status (nullptr, nullptr, &last
);
8052 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8054 print_stop_location (&last
);
8056 /* Display the auto-display expressions. */
8061 tp
= inferior_thread ();
8062 if (tp
->thread_fsm
!= NULL
8063 && tp
->thread_fsm
->finished_p ())
8065 struct return_value_info
*rv
;
8067 rv
= tp
->thread_fsm
->return_value ();
8069 print_return_value (uiout
, rv
);
8076 maybe_remove_breakpoints (void)
8078 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8080 if (remove_breakpoints ())
8082 target_terminal::ours_for_output ();
8083 printf_filtered (_("Cannot remove breakpoints because "
8084 "program is no longer writable.\nFurther "
8085 "execution is probably impossible.\n"));
8090 /* The execution context that just caused a normal stop. */
8096 DISABLE_COPY_AND_ASSIGN (stop_context
);
8098 bool changed () const;
8103 /* The event PTID. */
8107 /* If stopp for a thread event, this is the thread that caused the
8109 thread_info_ref thread
;
8111 /* The inferior that caused the stop. */
8115 /* Initializes a new stop context. If stopped for a thread event, this
8116 takes a strong reference to the thread. */
8118 stop_context::stop_context ()
8120 stop_id
= get_stop_id ();
8121 ptid
= inferior_ptid
;
8122 inf_num
= current_inferior ()->num
;
8124 if (inferior_ptid
!= null_ptid
)
8126 /* Take a strong reference so that the thread can't be deleted
8128 thread
= thread_info_ref::new_reference (inferior_thread ());
8132 /* Return true if the current context no longer matches the saved stop
8136 stop_context::changed () const
8138 if (ptid
!= inferior_ptid
)
8140 if (inf_num
!= current_inferior ()->num
)
8142 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8144 if (get_stop_id () != stop_id
)
8154 struct target_waitstatus last
;
8156 get_last_target_status (nullptr, nullptr, &last
);
8160 /* If an exception is thrown from this point on, make sure to
8161 propagate GDB's knowledge of the executing state to the
8162 frontend/user running state. A QUIT is an easy exception to see
8163 here, so do this before any filtered output. */
8165 ptid_t finish_ptid
= null_ptid
;
8168 finish_ptid
= minus_one_ptid
;
8169 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8170 || last
.kind
== TARGET_WAITKIND_EXITED
)
8172 /* On some targets, we may still have live threads in the
8173 inferior when we get a process exit event. E.g., for
8174 "checkpoint", when the current checkpoint/fork exits,
8175 linux-fork.c automatically switches to another fork from
8176 within target_mourn_inferior. */
8177 if (inferior_ptid
!= null_ptid
)
8178 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8180 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8181 finish_ptid
= inferior_ptid
;
8183 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8184 if (finish_ptid
!= null_ptid
)
8186 maybe_finish_thread_state
.emplace
8187 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8190 /* As we're presenting a stop, and potentially removing breakpoints,
8191 update the thread list so we can tell whether there are threads
8192 running on the target. With target remote, for example, we can
8193 only learn about new threads when we explicitly update the thread
8194 list. Do this before notifying the interpreters about signal
8195 stops, end of stepping ranges, etc., so that the "new thread"
8196 output is emitted before e.g., "Program received signal FOO",
8197 instead of after. */
8198 update_thread_list ();
8200 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8201 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8203 /* As with the notification of thread events, we want to delay
8204 notifying the user that we've switched thread context until
8205 the inferior actually stops.
8207 There's no point in saying anything if the inferior has exited.
8208 Note that SIGNALLED here means "exited with a signal", not
8209 "received a signal".
8211 Also skip saying anything in non-stop mode. In that mode, as we
8212 don't want GDB to switch threads behind the user's back, to avoid
8213 races where the user is typing a command to apply to thread x,
8214 but GDB switches to thread y before the user finishes entering
8215 the command, fetch_inferior_event installs a cleanup to restore
8216 the current thread back to the thread the user had selected right
8217 after this event is handled, so we're not really switching, only
8218 informing of a stop. */
8220 && previous_inferior_ptid
!= inferior_ptid
8221 && target_has_execution ()
8222 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8223 && last
.kind
!= TARGET_WAITKIND_EXITED
8224 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8226 SWITCH_THRU_ALL_UIS ()
8228 target_terminal::ours_for_output ();
8229 printf_filtered (_("[Switching to %s]\n"),
8230 target_pid_to_str (inferior_ptid
).c_str ());
8231 annotate_thread_changed ();
8233 previous_inferior_ptid
= inferior_ptid
;
8236 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8238 SWITCH_THRU_ALL_UIS ()
8239 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8241 target_terminal::ours_for_output ();
8242 printf_filtered (_("No unwaited-for children left.\n"));
8246 /* Note: this depends on the update_thread_list call above. */
8247 maybe_remove_breakpoints ();
8249 /* If an auto-display called a function and that got a signal,
8250 delete that auto-display to avoid an infinite recursion. */
8252 if (stopped_by_random_signal
)
8253 disable_current_display ();
8255 SWITCH_THRU_ALL_UIS ()
8257 async_enable_stdin ();
8260 /* Let the user/frontend see the threads as stopped. */
8261 maybe_finish_thread_state
.reset ();
8263 /* Select innermost stack frame - i.e., current frame is frame 0,
8264 and current location is based on that. Handle the case where the
8265 dummy call is returning after being stopped. E.g. the dummy call
8266 previously hit a breakpoint. (If the dummy call returns
8267 normally, we won't reach here.) Do this before the stop hook is
8268 run, so that it doesn't get to see the temporary dummy frame,
8269 which is not where we'll present the stop. */
8270 if (has_stack_frames ())
8272 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8274 /* Pop the empty frame that contains the stack dummy. This
8275 also restores inferior state prior to the call (struct
8276 infcall_suspend_state). */
8277 struct frame_info
*frame
= get_current_frame ();
8279 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8281 /* frame_pop calls reinit_frame_cache as the last thing it
8282 does which means there's now no selected frame. */
8285 select_frame (get_current_frame ());
8287 /* Set the current source location. */
8288 set_current_sal_from_frame (get_current_frame ());
8291 /* Look up the hook_stop and run it (CLI internally handles problem
8292 of stop_command's pre-hook not existing). */
8293 if (stop_command
!= NULL
)
8295 stop_context saved_context
;
8299 execute_cmd_pre_hook (stop_command
);
8301 catch (const gdb_exception
&ex
)
8303 exception_fprintf (gdb_stderr
, ex
,
8304 "Error while running hook_stop:\n");
8307 /* If the stop hook resumes the target, then there's no point in
8308 trying to notify about the previous stop; its context is
8309 gone. Likewise if the command switches thread or inferior --
8310 the observers would print a stop for the wrong
8312 if (saved_context
.changed ())
8316 /* Notify observers about the stop. This is where the interpreters
8317 print the stop event. */
8318 if (inferior_ptid
!= null_ptid
)
8319 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8322 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8324 annotate_stopped ();
8326 if (target_has_execution ())
8328 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8329 && last
.kind
!= TARGET_WAITKIND_EXITED
8330 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8331 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8332 Delete any breakpoint that is to be deleted at the next stop. */
8333 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8336 /* Try to get rid of automatically added inferiors that are no
8337 longer needed. Keeping those around slows down things linearly.
8338 Note that this never removes the current inferior. */
8345 signal_stop_state (int signo
)
8347 return signal_stop
[signo
];
8351 signal_print_state (int signo
)
8353 return signal_print
[signo
];
8357 signal_pass_state (int signo
)
8359 return signal_program
[signo
];
8363 signal_cache_update (int signo
)
8367 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8368 signal_cache_update (signo
);
8373 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8374 && signal_print
[signo
] == 0
8375 && signal_program
[signo
] == 1
8376 && signal_catch
[signo
] == 0);
8380 signal_stop_update (int signo
, int state
)
8382 int ret
= signal_stop
[signo
];
8384 signal_stop
[signo
] = state
;
8385 signal_cache_update (signo
);
8390 signal_print_update (int signo
, int state
)
8392 int ret
= signal_print
[signo
];
8394 signal_print
[signo
] = state
;
8395 signal_cache_update (signo
);
8400 signal_pass_update (int signo
, int state
)
8402 int ret
= signal_program
[signo
];
8404 signal_program
[signo
] = state
;
8405 signal_cache_update (signo
);
8409 /* Update the global 'signal_catch' from INFO and notify the
8413 signal_catch_update (const unsigned int *info
)
8417 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8418 signal_catch
[i
] = info
[i
] > 0;
8419 signal_cache_update (-1);
8420 target_pass_signals (signal_pass
);
8424 sig_print_header (void)
8426 printf_filtered (_("Signal Stop\tPrint\tPass "
8427 "to program\tDescription\n"));
8431 sig_print_info (enum gdb_signal oursig
)
8433 const char *name
= gdb_signal_to_name (oursig
);
8434 int name_padding
= 13 - strlen (name
);
8436 if (name_padding
<= 0)
8439 printf_filtered ("%s", name
);
8440 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8441 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8442 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8443 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8444 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8447 /* Specify how various signals in the inferior should be handled. */
8450 handle_command (const char *args
, int from_tty
)
8452 int digits
, wordlen
;
8453 int sigfirst
, siglast
;
8454 enum gdb_signal oursig
;
8459 error_no_arg (_("signal to handle"));
8462 /* Allocate and zero an array of flags for which signals to handle. */
8464 const size_t nsigs
= GDB_SIGNAL_LAST
;
8465 unsigned char sigs
[nsigs
] {};
8467 /* Break the command line up into args. */
8469 gdb_argv
built_argv (args
);
8471 /* Walk through the args, looking for signal oursigs, signal names, and
8472 actions. Signal numbers and signal names may be interspersed with
8473 actions, with the actions being performed for all signals cumulatively
8474 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8476 for (char *arg
: built_argv
)
8478 wordlen
= strlen (arg
);
8479 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8483 sigfirst
= siglast
= -1;
8485 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8487 /* Apply action to all signals except those used by the
8488 debugger. Silently skip those. */
8491 siglast
= nsigs
- 1;
8493 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8495 SET_SIGS (nsigs
, sigs
, signal_stop
);
8496 SET_SIGS (nsigs
, sigs
, signal_print
);
8498 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8500 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8502 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8504 SET_SIGS (nsigs
, sigs
, signal_print
);
8506 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8508 SET_SIGS (nsigs
, sigs
, signal_program
);
8510 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8512 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8514 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8516 SET_SIGS (nsigs
, sigs
, signal_program
);
8518 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8520 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8521 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8523 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8525 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8527 else if (digits
> 0)
8529 /* It is numeric. The numeric signal refers to our own
8530 internal signal numbering from target.h, not to host/target
8531 signal number. This is a feature; users really should be
8532 using symbolic names anyway, and the common ones like
8533 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8535 sigfirst
= siglast
= (int)
8536 gdb_signal_from_command (atoi (arg
));
8537 if (arg
[digits
] == '-')
8540 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8542 if (sigfirst
> siglast
)
8544 /* Bet he didn't figure we'd think of this case... */
8545 std::swap (sigfirst
, siglast
);
8550 oursig
= gdb_signal_from_name (arg
);
8551 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8553 sigfirst
= siglast
= (int) oursig
;
8557 /* Not a number and not a recognized flag word => complain. */
8558 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8562 /* If any signal numbers or symbol names were found, set flags for
8563 which signals to apply actions to. */
8565 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8567 switch ((enum gdb_signal
) signum
)
8569 case GDB_SIGNAL_TRAP
:
8570 case GDB_SIGNAL_INT
:
8571 if (!allsigs
&& !sigs
[signum
])
8573 if (query (_("%s is used by the debugger.\n\
8574 Are you sure you want to change it? "),
8575 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8580 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8584 case GDB_SIGNAL_DEFAULT
:
8585 case GDB_SIGNAL_UNKNOWN
:
8586 /* Make sure that "all" doesn't print these. */
8595 for (int signum
= 0; signum
< nsigs
; signum
++)
8598 signal_cache_update (-1);
8599 target_pass_signals (signal_pass
);
8600 target_program_signals (signal_program
);
8604 /* Show the results. */
8605 sig_print_header ();
8606 for (; signum
< nsigs
; signum
++)
8608 sig_print_info ((enum gdb_signal
) signum
);
8615 /* Complete the "handle" command. */
8618 handle_completer (struct cmd_list_element
*ignore
,
8619 completion_tracker
&tracker
,
8620 const char *text
, const char *word
)
8622 static const char * const keywords
[] =
8636 signal_completer (ignore
, tracker
, text
, word
);
8637 complete_on_enum (tracker
, keywords
, word
, word
);
8641 gdb_signal_from_command (int num
)
8643 if (num
>= 1 && num
<= 15)
8644 return (enum gdb_signal
) num
;
8645 error (_("Only signals 1-15 are valid as numeric signals.\n\
8646 Use \"info signals\" for a list of symbolic signals."));
8649 /* Print current contents of the tables set by the handle command.
8650 It is possible we should just be printing signals actually used
8651 by the current target (but for things to work right when switching
8652 targets, all signals should be in the signal tables). */
8655 info_signals_command (const char *signum_exp
, int from_tty
)
8657 enum gdb_signal oursig
;
8659 sig_print_header ();
8663 /* First see if this is a symbol name. */
8664 oursig
= gdb_signal_from_name (signum_exp
);
8665 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8667 /* No, try numeric. */
8669 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8671 sig_print_info (oursig
);
8675 printf_filtered ("\n");
8676 /* These ugly casts brought to you by the native VAX compiler. */
8677 for (oursig
= GDB_SIGNAL_FIRST
;
8678 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8679 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8683 if (oursig
!= GDB_SIGNAL_UNKNOWN
8684 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8685 sig_print_info (oursig
);
8688 printf_filtered (_("\nUse the \"handle\" command "
8689 "to change these tables.\n"));
8692 /* The $_siginfo convenience variable is a bit special. We don't know
8693 for sure the type of the value until we actually have a chance to
8694 fetch the data. The type can change depending on gdbarch, so it is
8695 also dependent on which thread you have selected.
8697 1. making $_siginfo be an internalvar that creates a new value on
8700 2. making the value of $_siginfo be an lval_computed value. */
8702 /* This function implements the lval_computed support for reading a
8706 siginfo_value_read (struct value
*v
)
8708 LONGEST transferred
;
8710 /* If we can access registers, so can we access $_siginfo. Likewise
8712 validate_registers_access ();
8715 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8717 value_contents_all_raw (v
),
8719 TYPE_LENGTH (value_type (v
)));
8721 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8722 error (_("Unable to read siginfo"));
8725 /* This function implements the lval_computed support for writing a
8729 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8731 LONGEST transferred
;
8733 /* If we can access registers, so can we access $_siginfo. Likewise
8735 validate_registers_access ();
8737 transferred
= target_write (current_top_target (),
8738 TARGET_OBJECT_SIGNAL_INFO
,
8740 value_contents_all_raw (fromval
),
8742 TYPE_LENGTH (value_type (fromval
)));
8744 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8745 error (_("Unable to write siginfo"));
8748 static const struct lval_funcs siginfo_value_funcs
=
8754 /* Return a new value with the correct type for the siginfo object of
8755 the current thread using architecture GDBARCH. Return a void value
8756 if there's no object available. */
8758 static struct value
*
8759 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8762 if (target_has_stack ()
8763 && inferior_ptid
!= null_ptid
8764 && gdbarch_get_siginfo_type_p (gdbarch
))
8766 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8768 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8771 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8775 /* infcall_suspend_state contains state about the program itself like its
8776 registers and any signal it received when it last stopped.
8777 This state must be restored regardless of how the inferior function call
8778 ends (either successfully, or after it hits a breakpoint or signal)
8779 if the program is to properly continue where it left off. */
8781 class infcall_suspend_state
8784 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8785 once the inferior function call has finished. */
8786 infcall_suspend_state (struct gdbarch
*gdbarch
,
8787 const struct thread_info
*tp
,
8788 struct regcache
*regcache
)
8789 : m_thread_suspend (tp
->suspend
),
8790 m_registers (new readonly_detached_regcache (*regcache
))
8792 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8794 if (gdbarch_get_siginfo_type_p (gdbarch
))
8796 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8797 size_t len
= TYPE_LENGTH (type
);
8799 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8801 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8802 siginfo_data
.get (), 0, len
) != len
)
8804 /* Errors ignored. */
8805 siginfo_data
.reset (nullptr);
8811 m_siginfo_gdbarch
= gdbarch
;
8812 m_siginfo_data
= std::move (siginfo_data
);
8816 /* Return a pointer to the stored register state. */
8818 readonly_detached_regcache
*registers () const
8820 return m_registers
.get ();
8823 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8825 void restore (struct gdbarch
*gdbarch
,
8826 struct thread_info
*tp
,
8827 struct regcache
*regcache
) const
8829 tp
->suspend
= m_thread_suspend
;
8831 if (m_siginfo_gdbarch
== gdbarch
)
8833 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8835 /* Errors ignored. */
8836 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8837 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8840 /* The inferior can be gone if the user types "print exit(0)"
8841 (and perhaps other times). */
8842 if (target_has_execution ())
8843 /* NB: The register write goes through to the target. */
8844 regcache
->restore (registers ());
8848 /* How the current thread stopped before the inferior function call was
8850 struct thread_suspend_state m_thread_suspend
;
8852 /* The registers before the inferior function call was executed. */
8853 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8855 /* Format of SIGINFO_DATA or NULL if it is not present. */
8856 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8858 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8859 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8860 content would be invalid. */
8861 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8864 infcall_suspend_state_up
8865 save_infcall_suspend_state ()
8867 struct thread_info
*tp
= inferior_thread ();
8868 struct regcache
*regcache
= get_current_regcache ();
8869 struct gdbarch
*gdbarch
= regcache
->arch ();
8871 infcall_suspend_state_up inf_state
8872 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8874 /* Having saved the current state, adjust the thread state, discarding
8875 any stop signal information. The stop signal is not useful when
8876 starting an inferior function call, and run_inferior_call will not use
8877 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8878 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8883 /* Restore inferior session state to INF_STATE. */
8886 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8888 struct thread_info
*tp
= inferior_thread ();
8889 struct regcache
*regcache
= get_current_regcache ();
8890 struct gdbarch
*gdbarch
= regcache
->arch ();
8892 inf_state
->restore (gdbarch
, tp
, regcache
);
8893 discard_infcall_suspend_state (inf_state
);
8897 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8902 readonly_detached_regcache
*
8903 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8905 return inf_state
->registers ();
8908 /* infcall_control_state contains state regarding gdb's control of the
8909 inferior itself like stepping control. It also contains session state like
8910 the user's currently selected frame. */
8912 struct infcall_control_state
8914 struct thread_control_state thread_control
;
8915 struct inferior_control_state inferior_control
;
8918 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8919 int stopped_by_random_signal
= 0;
8921 /* ID and level of the selected frame when the inferior function
8923 struct frame_id selected_frame_id
{};
8924 int selected_frame_level
= -1;
8927 /* Save all of the information associated with the inferior<==>gdb
8930 infcall_control_state_up
8931 save_infcall_control_state ()
8933 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8934 struct thread_info
*tp
= inferior_thread ();
8935 struct inferior
*inf
= current_inferior ();
8937 inf_status
->thread_control
= tp
->control
;
8938 inf_status
->inferior_control
= inf
->control
;
8940 tp
->control
.step_resume_breakpoint
= NULL
;
8941 tp
->control
.exception_resume_breakpoint
= NULL
;
8943 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8944 chain. If caller's caller is walking the chain, they'll be happier if we
8945 hand them back the original chain when restore_infcall_control_state is
8947 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8950 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8951 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8953 save_selected_frame (&inf_status
->selected_frame_id
,
8954 &inf_status
->selected_frame_level
);
8959 /* Restore inferior session state to INF_STATUS. */
8962 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8964 struct thread_info
*tp
= inferior_thread ();
8965 struct inferior
*inf
= current_inferior ();
8967 if (tp
->control
.step_resume_breakpoint
)
8968 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
8970 if (tp
->control
.exception_resume_breakpoint
)
8971 tp
->control
.exception_resume_breakpoint
->disposition
8972 = disp_del_at_next_stop
;
8974 /* Handle the bpstat_copy of the chain. */
8975 bpstat_clear (&tp
->control
.stop_bpstat
);
8977 tp
->control
= inf_status
->thread_control
;
8978 inf
->control
= inf_status
->inferior_control
;
8981 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
8982 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
8984 if (target_has_stack ())
8986 restore_selected_frame (inf_status
->selected_frame_id
,
8987 inf_status
->selected_frame_level
);
8994 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
8996 if (inf_status
->thread_control
.step_resume_breakpoint
)
8997 inf_status
->thread_control
.step_resume_breakpoint
->disposition
8998 = disp_del_at_next_stop
;
9000 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9001 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9002 = disp_del_at_next_stop
;
9004 /* See save_infcall_control_state for info on stop_bpstat. */
9005 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9013 clear_exit_convenience_vars (void)
9015 clear_internalvar (lookup_internalvar ("_exitsignal"));
9016 clear_internalvar (lookup_internalvar ("_exitcode"));
9020 /* User interface for reverse debugging:
9021 Set exec-direction / show exec-direction commands
9022 (returns error unless target implements to_set_exec_direction method). */
9024 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9025 static const char exec_forward
[] = "forward";
9026 static const char exec_reverse
[] = "reverse";
9027 static const char *exec_direction
= exec_forward
;
9028 static const char *const exec_direction_names
[] = {
9035 set_exec_direction_func (const char *args
, int from_tty
,
9036 struct cmd_list_element
*cmd
)
9038 if (target_can_execute_reverse ())
9040 if (!strcmp (exec_direction
, exec_forward
))
9041 execution_direction
= EXEC_FORWARD
;
9042 else if (!strcmp (exec_direction
, exec_reverse
))
9043 execution_direction
= EXEC_REVERSE
;
9047 exec_direction
= exec_forward
;
9048 error (_("Target does not support this operation."));
9053 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9054 struct cmd_list_element
*cmd
, const char *value
)
9056 switch (execution_direction
) {
9058 fprintf_filtered (out
, _("Forward.\n"));
9061 fprintf_filtered (out
, _("Reverse.\n"));
9064 internal_error (__FILE__
, __LINE__
,
9065 _("bogus execution_direction value: %d"),
9066 (int) execution_direction
);
9071 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9072 struct cmd_list_element
*c
, const char *value
)
9074 fprintf_filtered (file
, _("Resuming the execution of threads "
9075 "of all processes is %s.\n"), value
);
9078 /* Implementation of `siginfo' variable. */
9080 static const struct internalvar_funcs siginfo_funcs
=
9087 /* Callback for infrun's target events source. This is marked when a
9088 thread has a pending status to process. */
9091 infrun_async_inferior_event_handler (gdb_client_data data
)
9093 inferior_event_handler (INF_REG_EVENT
);
9100 /* Verify that when two threads with the same ptid exist (from two different
9101 targets) and one of them changes ptid, we only update inferior_ptid if
9102 it is appropriate. */
9105 infrun_thread_ptid_changed ()
9107 gdbarch
*arch
= current_inferior ()->gdbarch
;
9109 /* The thread which inferior_ptid represents changes ptid. */
9111 scoped_restore_current_pspace_and_thread restore
;
9113 scoped_mock_context
<test_target_ops
> target1 (arch
);
9114 scoped_mock_context
<test_target_ops
> target2 (arch
);
9115 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9117 ptid_t
old_ptid (111, 222);
9118 ptid_t
new_ptid (111, 333);
9120 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9121 target1
.mock_thread
.ptid
= old_ptid
;
9122 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9123 target2
.mock_thread
.ptid
= old_ptid
;
9125 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9126 set_current_inferior (&target1
.mock_inferior
);
9128 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9130 gdb_assert (inferior_ptid
== new_ptid
);
9133 /* A thread with the same ptid as inferior_ptid, but from another target,
9136 scoped_restore_current_pspace_and_thread restore
;
9138 scoped_mock_context
<test_target_ops
> target1 (arch
);
9139 scoped_mock_context
<test_target_ops
> target2 (arch
);
9140 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9142 ptid_t
old_ptid (111, 222);
9143 ptid_t
new_ptid (111, 333);
9145 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9146 target1
.mock_thread
.ptid
= old_ptid
;
9147 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9148 target2
.mock_thread
.ptid
= old_ptid
;
9150 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9151 set_current_inferior (&target2
.mock_inferior
);
9153 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9155 gdb_assert (inferior_ptid
== old_ptid
);
9159 } /* namespace selftests */
9161 #endif /* GDB_SELF_TEST */
9163 void _initialize_infrun ();
9165 _initialize_infrun ()
9167 struct cmd_list_element
*c
;
9169 /* Register extra event sources in the event loop. */
9170 infrun_async_inferior_event_token
9171 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9174 add_info ("signals", info_signals_command
, _("\
9175 What debugger does when program gets various signals.\n\
9176 Specify a signal as argument to print info on that signal only."));
9177 add_info_alias ("handle", "signals", 0);
9179 c
= add_com ("handle", class_run
, handle_command
, _("\
9180 Specify how to handle signals.\n\
9181 Usage: handle SIGNAL [ACTIONS]\n\
9182 Args are signals and actions to apply to those signals.\n\
9183 If no actions are specified, the current settings for the specified signals\n\
9184 will be displayed instead.\n\
9186 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9187 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9188 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9189 The special arg \"all\" is recognized to mean all signals except those\n\
9190 used by the debugger, typically SIGTRAP and SIGINT.\n\
9192 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9193 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9194 Stop means reenter debugger if this signal happens (implies print).\n\
9195 Print means print a message if this signal happens.\n\
9196 Pass means let program see this signal; otherwise program doesn't know.\n\
9197 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9198 Pass and Stop may be combined.\n\
9200 Multiple signals may be specified. Signal numbers and signal names\n\
9201 may be interspersed with actions, with the actions being performed for\n\
9202 all signals cumulatively specified."));
9203 set_cmd_completer (c
, handle_completer
);
9206 stop_command
= add_cmd ("stop", class_obscure
,
9207 not_just_help_class_command
, _("\
9208 There is no `stop' command, but you can set a hook on `stop'.\n\
9209 This allows you to set a list of commands to be run each time execution\n\
9210 of the program stops."), &cmdlist
);
9212 add_setshow_boolean_cmd
9213 ("infrun", class_maintenance
, &debug_infrun
,
9214 _("Set inferior debugging."),
9215 _("Show inferior debugging."),
9216 _("When non-zero, inferior specific debugging is enabled."),
9217 NULL
, show_debug_infrun
, &setdebuglist
, &showdebuglist
);
9219 add_setshow_boolean_cmd ("non-stop", no_class
,
9221 Set whether gdb controls the inferior in non-stop mode."), _("\
9222 Show whether gdb controls the inferior in non-stop mode."), _("\
9223 When debugging a multi-threaded program and this setting is\n\
9224 off (the default, also called all-stop mode), when one thread stops\n\
9225 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9226 all other threads in the program while you interact with the thread of\n\
9227 interest. When you continue or step a thread, you can allow the other\n\
9228 threads to run, or have them remain stopped, but while you inspect any\n\
9229 thread's state, all threads stop.\n\
9231 In non-stop mode, when one thread stops, other threads can continue\n\
9232 to run freely. You'll be able to step each thread independently,\n\
9233 leave it stopped or free to run as needed."),
9239 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9242 signal_print
[i
] = 1;
9243 signal_program
[i
] = 1;
9244 signal_catch
[i
] = 0;
9247 /* Signals caused by debugger's own actions should not be given to
9248 the program afterwards.
9250 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9251 explicitly specifies that it should be delivered to the target
9252 program. Typically, that would occur when a user is debugging a
9253 target monitor on a simulator: the target monitor sets a
9254 breakpoint; the simulator encounters this breakpoint and halts
9255 the simulation handing control to GDB; GDB, noting that the stop
9256 address doesn't map to any known breakpoint, returns control back
9257 to the simulator; the simulator then delivers the hardware
9258 equivalent of a GDB_SIGNAL_TRAP to the program being
9260 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9261 signal_program
[GDB_SIGNAL_INT
] = 0;
9263 /* Signals that are not errors should not normally enter the debugger. */
9264 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9265 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9266 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9267 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9268 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9269 signal_print
[GDB_SIGNAL_PROF
] = 0;
9270 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9271 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9272 signal_stop
[GDB_SIGNAL_IO
] = 0;
9273 signal_print
[GDB_SIGNAL_IO
] = 0;
9274 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9275 signal_print
[GDB_SIGNAL_POLL
] = 0;
9276 signal_stop
[GDB_SIGNAL_URG
] = 0;
9277 signal_print
[GDB_SIGNAL_URG
] = 0;
9278 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9279 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9280 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9281 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9283 /* These signals are used internally by user-level thread
9284 implementations. (See signal(5) on Solaris.) Like the above
9285 signals, a healthy program receives and handles them as part of
9286 its normal operation. */
9287 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9288 signal_print
[GDB_SIGNAL_LWP
] = 0;
9289 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9290 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9291 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9292 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9293 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9294 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9296 /* Update cached state. */
9297 signal_cache_update (-1);
9299 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9300 &stop_on_solib_events
, _("\
9301 Set stopping for shared library events."), _("\
9302 Show stopping for shared library events."), _("\
9303 If nonzero, gdb will give control to the user when the dynamic linker\n\
9304 notifies gdb of shared library events. The most common event of interest\n\
9305 to the user would be loading/unloading of a new library."),
9306 set_stop_on_solib_events
,
9307 show_stop_on_solib_events
,
9308 &setlist
, &showlist
);
9310 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9311 follow_fork_mode_kind_names
,
9312 &follow_fork_mode_string
, _("\
9313 Set debugger response to a program call of fork or vfork."), _("\
9314 Show debugger response to a program call of fork or vfork."), _("\
9315 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9316 parent - the original process is debugged after a fork\n\
9317 child - the new process is debugged after a fork\n\
9318 The unfollowed process will continue to run.\n\
9319 By default, the debugger will follow the parent process."),
9321 show_follow_fork_mode_string
,
9322 &setlist
, &showlist
);
9324 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9325 follow_exec_mode_names
,
9326 &follow_exec_mode_string
, _("\
9327 Set debugger response to a program call of exec."), _("\
9328 Show debugger response to a program call of exec."), _("\
9329 An exec call replaces the program image of a process.\n\
9331 follow-exec-mode can be:\n\
9333 new - the debugger creates a new inferior and rebinds the process\n\
9334 to this new inferior. The program the process was running before\n\
9335 the exec call can be restarted afterwards by restarting the original\n\
9338 same - the debugger keeps the process bound to the same inferior.\n\
9339 The new executable image replaces the previous executable loaded in\n\
9340 the inferior. Restarting the inferior after the exec call restarts\n\
9341 the executable the process was running after the exec call.\n\
9343 By default, the debugger will use the same inferior."),
9345 show_follow_exec_mode_string
,
9346 &setlist
, &showlist
);
9348 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9349 scheduler_enums
, &scheduler_mode
, _("\
9350 Set mode for locking scheduler during execution."), _("\
9351 Show mode for locking scheduler during execution."), _("\
9352 off == no locking (threads may preempt at any time)\n\
9353 on == full locking (no thread except the current thread may run)\n\
9354 This applies to both normal execution and replay mode.\n\
9355 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9356 In this mode, other threads may run during other commands.\n\
9357 This applies to both normal execution and replay mode.\n\
9358 replay == scheduler locked in replay mode and unlocked during normal execution."),
9359 set_schedlock_func
, /* traps on target vector */
9360 show_scheduler_mode
,
9361 &setlist
, &showlist
);
9363 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9364 Set mode for resuming threads of all processes."), _("\
9365 Show mode for resuming threads of all processes."), _("\
9366 When on, execution commands (such as 'continue' or 'next') resume all\n\
9367 threads of all processes. When off (which is the default), execution\n\
9368 commands only resume the threads of the current process. The set of\n\
9369 threads that are resumed is further refined by the scheduler-locking\n\
9370 mode (see help set scheduler-locking)."),
9372 show_schedule_multiple
,
9373 &setlist
, &showlist
);
9375 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9376 Set mode of the step operation."), _("\
9377 Show mode of the step operation."), _("\
9378 When set, doing a step over a function without debug line information\n\
9379 will stop at the first instruction of that function. Otherwise, the\n\
9380 function is skipped and the step command stops at a different source line."),
9382 show_step_stop_if_no_debug
,
9383 &setlist
, &showlist
);
9385 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9386 &can_use_displaced_stepping
, _("\
9387 Set debugger's willingness to use displaced stepping."), _("\
9388 Show debugger's willingness to use displaced stepping."), _("\
9389 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9390 supported by the target architecture. If off, gdb will not use displaced\n\
9391 stepping to step over breakpoints, even if such is supported by the target\n\
9392 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9393 if the target architecture supports it and non-stop mode is active, but will not\n\
9394 use it in all-stop mode (see help set non-stop)."),
9396 show_can_use_displaced_stepping
,
9397 &setlist
, &showlist
);
9399 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9400 &exec_direction
, _("Set direction of execution.\n\
9401 Options are 'forward' or 'reverse'."),
9402 _("Show direction of execution (forward/reverse)."),
9403 _("Tells gdb whether to execute forward or backward."),
9404 set_exec_direction_func
, show_exec_direction_func
,
9405 &setlist
, &showlist
);
9407 /* Set/show detach-on-fork: user-settable mode. */
9409 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9410 Set whether gdb will detach the child of a fork."), _("\
9411 Show whether gdb will detach the child of a fork."), _("\
9412 Tells gdb whether to detach the child of a fork."),
9413 NULL
, NULL
, &setlist
, &showlist
);
9415 /* Set/show disable address space randomization mode. */
9417 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9418 &disable_randomization
, _("\
9419 Set disabling of debuggee's virtual address space randomization."), _("\
9420 Show disabling of debuggee's virtual address space randomization."), _("\
9421 When this mode is on (which is the default), randomization of the virtual\n\
9422 address space is disabled. Standalone programs run with the randomization\n\
9423 enabled by default on some platforms."),
9424 &set_disable_randomization
,
9425 &show_disable_randomization
,
9426 &setlist
, &showlist
);
9428 /* ptid initializations */
9429 inferior_ptid
= null_ptid
;
9430 target_last_wait_ptid
= minus_one_ptid
;
9432 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9433 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9434 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9435 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9436 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
);
9438 /* Explicitly create without lookup, since that tries to create a
9439 value with a void typed value, and when we get here, gdbarch
9440 isn't initialized yet. At this point, we're quite sure there
9441 isn't another convenience variable of the same name. */
9442 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9444 add_setshow_boolean_cmd ("observer", no_class
,
9445 &observer_mode_1
, _("\
9446 Set whether gdb controls the inferior in observer mode."), _("\
9447 Show whether gdb controls the inferior in observer mode."), _("\
9448 In observer mode, GDB can get data from the inferior, but not\n\
9449 affect its execution. Registers and memory may not be changed,\n\
9450 breakpoints may not be set, and the program cannot be interrupted\n\
9458 selftests::register_test ("infrun_thread_ptid_changed",
9459 selftests::infrun_thread_ptid_changed
);